MOPOP - Chapter 15
Anticipation, obviousness and double-patenting
Table of contents
- 15.01 Anticipation – June 2016
- 15.01.01 Prior art when assessing anticipation
- 15.01.02 Assessing anticipation
- 15.01.03 Anticipation by prior sale or use
- 15.01.04 Implicit or inherent disclosure
- 15.01.05 Anticipation based on related teachings
- 15.02 Obviousness – June 2016
- 15.02.01 Prior art when assessing obviousness
- 15.02.02 Assessing obviousness
- 15.02.02a Person skilled in the art (Step 1(a))
- 15.02.02b Common general knowledge (Step 1(b))
- 15.02.02c Identifying the inventive concept (Step 2)
- 15.02.02d Identifying the differences between the inventive concept and the state of the art (Step 3)
- 15.02.02e Do the differences constitute an inventive step? (Step 4)
- 15.02.03 Obvious to try considerations
- 15.02.04 Aggregations
- 15.02.05 Obviousness and utility
- 15.02.06 Obviousness of anticipated claims
- 15.03 Claim date – June 2016
- 15.04 Grace period – September 2017
- 15.05 Establishing the publication date of prior art – January 2016
- 15.06 Double-patenting – September 2017
- 15.07 Selections – June 2016
- 15.08 Provisos – June 2016
Anticipation – June 2016
The requirement that an invention be novel finds its basis in the definition of invention in section 2 of the Patent Act – "any new [...] art, process, machine, manufacture or composition of matter or any new and useful improvement in any art, process, machine, manufacture or composition of matter". Footnote 1
In order for an invention to be novel, it must be established that individual disclosures in the prior art do not anticipate the claimed invention.
Whether a given disclosure is considered to be prior art is governed by section 28.2 of the Patent Act. Although any public disclosure of information may be considered in principle, for practical reasons the assessment is almost exclusively performed on the basis of written disclosures.
Anticipation is assessed on a claim-by-claim basis by asking whether the prior disclosure, when understood by the person skilled in the art in light of their common general knowledge, provides both a description of the claimed invention (disclosure) and sufficient instructions to enable the invention to be practised (enablement). Footnote 2
The comparison of the claimed invention to the prior disclosure is based on a comparison of the essential elements of the claim, properly construed, to the prior art. Footnote 3 Elements that are not required in order for the invention to solve the problem the inventors set out to address need not be disclosed in the anticipatory prior art. Furthermore, an invention is considered to have been previously described where the subject-matter previously disclosed would, if performed, infringe the later claim. Footnote 4
A prior disclosure is considered to be enabling for the purpose of anticipation if the person skilled in the art, where necessary through trial and error experimentation that is neither inventive nor an undue burden, can operate the disclosed invention successfully. Footnote 5
Prior art when assessing anticipation
Section 28.2 of the Patent Act defines what disclosures may be considered for the purpose of assessing anticipation. In summary, this section establishes: a grace period of one year prior to the filing date of an application during which disclosures originating from the applicant are excluded as prior art; third party disclosures anywhere in the world before the application claim date as prior art; and the conditions respecting first-to-file when a co-pending Canadian application filed by a person other than the applicant is prior art.
Pursuant to section 63 of the Patent Rules, an international application (i.e. one filed under the Patent Cooperation Treaty) is not considered to be a Canadian application for the purposes of first-to-file anticipation (paragraphs 28.2(1)(c) and (d) of the Patent Act) unless it has entered the national phase. Section 59 of the Patent Rules provides that once an international application enters the national phase to become a PCT national phase application, it is deemed to be an application filed in Canada.
In accordance with subsection 28.2(2) of the Patent Act, a Canadian application that is withdrawn before being opened to public inspection is considered, for the purposes of paragraphs 28.2(1)(c) and (d), never to have been filed. Consequently, such an application is not eligible as first-to-file prior art. Any Canadian application may be eligible as prior art under 28.2(1)(c) or (d) despite having been withdrawn after being opened to public inspection, even where it has been abandoned or refused.
Paragraph 28.2(1)(a) of the Patent Act provides that
The subject-matter defined by a claim in an application for a patent in Canada (the "pending application)" must not have been disclosed (a) more than one year before the filing date by the applicant, or by a person who obtained knowledge, directly or indirectly, from the applicant, in such a manner that the subject matter became available to the public in Canada or elsewhere[.]
This provision defines a public disclosure made by the applicant or by a person who obtained their knowledge directly or indirectly from the applicant more than one year before the filing date of the application as prior art for the assessment of anticipation, but excludes this disclosure as prior art if it was made in the one year grace period preceding the filing date. [See 15.04].
Third party anticipation
Paragraph 28.2(1)(b) of the Patent Act provides that
The subject-matter defined by a claim in an application for a patent in Canada (the "pending application") must not have been disclosed
(b) before the claim date by a person not mentioned in paragraph (a) in such a manner that the subject matter became available to the public in Canada or elsewhere[.]
This provision defines any public disclosure made by a third party (i.e. by a person other than the applicant or a person who obtained their knowledge directly or indirectly from the applicant) as prior art for the assessment of anticipation if it was made before the claim date [see 15.03].
First-to-file anticipation based on filing-date
Paragraph 28.2(1)(c) of the Patent Act provides that
The subject-matter defined by a claim in an application for a patent in Canada (the "pending application") must not have been disclosed
(c) in an application for a patent that is filed in Canada by a person other than the applicant, and has a filing date that is before the claim date[.]
This provision exists to give effect to first-to-file considerations, and allows a Canadian patent application that was not open to public inspection as of the subject application's claim date and which would consequently not be citable under paragraph 28.2(1)(b) of the Patent Act to nevertheless be considered for the purpose of anticipation. Note that the entire content of the earlier application is considered in assessing anticipation. The analysis is not limited by the matter claimed in the earlier application.
This provision defines a Canadian co-pending patent application, made by a third party, not open to public inspection as of the subject application's claim date and having a filing date earlier than the pending application claim date as prior art for the assessment of anticipation of the pending application. Paragraphs 28.2(1)(c) and (d) effectively establish Canada's first-to-file regime.
Where the applicability of a Canadian application as prior art under paragraph 28.2(1)(c) depends on the validity and extent of the priority claim of the application being examined, the examiner should obtain and verify the validity of the priority document.
First-to-file anticipation based on priority date
Paragraph 28.2(1)(d) of the Patent Act provides that
The subject-matter defined by a claim in an application for a patent in Canada (the "pending application") must not have been disclosed
(d) in an application (the "co pending application") for a patent that is filed in Canada by a person other than the applicant and has a filing date that is on or after the claim date if
(i) the co pending application is filed by
(A) a person who has, or whose agent, legal representative or predecessor in title has, previously regularly filed in or for Canada an application for a patent disclosing the subject matter defined by the claim, or
(B) a person who is entitled to protection under the terms of any treaty or convention relating to patents to which Canada is a party and who has, or whose agent, legal representative or predecessor in title has, previously regularly filed in or for any other country that by treaty, convention or law affords similar protection to citizens of Canada an application for a patent disclosing the subject matter defined by the claim,
(ii) the filing date of the previously regularly filed application is before the claim date of the pending application,
(iii) the filing date of the co pending application is within twelve months after the filing date of the previously regularly filed application, and
(iv) the applicant has, in respect of the co pending application, made a request for priority on the basis of the previously regularly filed application.
This provision expands the definition of prior art for the assessment of anticipation of a pending application to include Canadian co-pending applications not open to public inspection as of the subject application's claim date and having a claim date earlier than the pending application claim date.
The provision requires that the co-pending Canadian application have a validly claimed priority date that precedes the claim date of the application being examined. The content of the priority document of the co-pending application should be reviewed by the examiner to ensure that the subject-matter anticipated by the co-pending application is disclosed in its priority document. The assessment is based on the entirety of the information benefiting from the priority date, and is not further limited by the claims.
The test for anticipation, as set out by the Supreme Court in Apotex Inc. v. Sanofi-Synthelabo Canada Inc. 2008 SCC 61, requires that a single disclosure both disclose and enable the claimed invention. Footnote 6 The approach taken by the person skilled in the art in reading and applying the prior art differs slightly when assessing the two parts of the test.
The first part of the test for anticipation asks whether a single prior teaching discloses the same invention that has been claimed in the application under consideration (or, where a claim encompasses several embodiments, of at least one operating embodiment of the claimed invention). In reading the prior disclosure to understand the matter it describes, the skilled person Footnote 7 is "taken to be trying to understand what the author of the description [in the prior patent] meant". Footnote 8 The prior disclosure is read in the same informed and purposive manner as the application itself, so as to fairly interpret its teachings, Footnote 9 as if being read by the person skilled in the art at the claim date of the claim under consideration. Footnote 10 The disclosure does not have to be an "exact description" of the claimed invention. The disclosure must be sufficient so that when read by a person skilled in the art willing to understand what is being said, it can be understood "without trial and error". Footnote 11 Even if the prior disclosure uses quite different terms to describe its subject-matter, "if carrying out the directions contained in the prior inventor's publication will inevitably result in something being made or done which [...] would constitute an infringement" of a claim being examined, the prior disclosure describes the same invention. Footnote 12
If the prior teaching does disclose the claimed invention, the next part of the test must be evaluated. That is, does the prior disclosure enable the disclosed invention to be operated without inventive effort or undue experimentation? [See Chapter 9 of this manual as it relates to disclosure]. At this stage, the person skilled in the art "is assumed to be willing to make trial and error experiments to get [the invention] to work". Footnote 13 Note that enablement does not mean that the earlier invention was actually put into practice, but simply that the earlier disclosure was sufficient to enable the person skilled in the art to build, operate or use the invention. If, on a fair and balanced reading of an earlier disclosure, it is unclear whether the disclosure is enabling of the claimed invention, the examiner must set forth the reasons for considering that the disclosure is, in fact, enabling. In contrast, where an applicant asserts that inventive effort or an undue burden would be required to operate an invention in view of an earlier disclosure, this should be supported by reasoned arguments and, as appropriate, by relevant facts.
While particular expressions of the test for anticipation have been provided by various Courts, a common thread is that the prior teaching has to anticipate "for [the] purpose of practical necessity", Footnote 14 implying that the test for anticipation is based on practical considerations rather than theoretical ones. Footnote 15 The test has been described as asking whether the prior art document gives "information which for the purpose of practical utility is equal to that given by the subject" application, Footnote 16 and similarly as asking whether the prior disclosure would allow the person skilled in the art to understand "and be able practically to apply the discovery without the necessity of making further experiments and gaining further information before the invention can be made useful". Footnote 17
In many circumstances, the concept of "reverse infringement" can be used to assess anticipation. Footnote 18 Based on the principle that "what amounts to infringement, if posterior, should, as a general rule, amount to anticipation, if anterior", Footnote 19 anticipation by reverse infringement asks "if the earlier disclosure were to be put into practice, would it infringe the later claims"? Footnote 20
While the jurisprudence describes the approach to anticipation using various expressions relevant to the facts of the cases then under consideration, ultimately it is important to bear in mind that the actual requirement to be satisfied is simply that provided in section 28.2 of the Patent Act. At its simplest, the assessment of anticipation can be reduced to this: the subject-matter of the claim being examined is analysed in order to identify the elements that are essential to the applicant's proposed solution to the problem being addressed by the application. The prior art is analysed to determine if it discloses and enables the use of the same elements (whether or not disclosed in the same terms) in a form suitable for the same purpose as the claimed matter. If so, the prior disclosure anticipates the later claimed subject-matter.
In performing this analysis, it may be necessary to determine whether claimed elements function in combination to produce a unitary or synergistic result. Where different elements or sets of elements in a claim operate independently of each other to produce distinct results, then the two do not form a proper combination, but rather define an aggregation. In such a case, the removal of one element would have no effect on how the remaining elements function. Where a claim is construed to define two or more collocated but distinct inventions, each invention should be individually assessed for anticipation. In such cases, a defect under section 28.2 of the Patent Act should not be raised unless all of the inventions are anticipated; if at least one invention is novel, the claimed subject-matter will not have been previously disclosed.
In assessing anticipation, it may also be determined that a claim encompasses many different operating embodiments. The claim will be anticipated if any one working embodiment is disclosed and enabled by the prior art. Footnote 21
An application is directed to improved methods of preparing rigid polyurethane foams with good insulating values. The application discloses that the inventors set out to improve the insulating values of rigid polyurethane foams by preparing them in the presence of a blowing agent comprising a perfluorocycloalkane and a straight-chain alkane in specific ratios. The application teaches that water may be used as a co-blowing agent.
Canadian application D1, filed by a third party before the claim date of the application but published later, discloses the use of a blowing agent falling within the ranges disclosed and claimed in the application in the preparation of rigid polyurethane foams. D1 is silent as to whether water should be used as a co-blowing agent. Because of its filing and publication dates, D1 is relevant for first-to-file anticipation under paragraph 28.2(1)(c) of the Patent Act but may not be considered when assessing obviousness.
A method for producing a rigid polyurethane foam, comprising the step of contacting a polyol and an isocyanate in the presence of a blowing agent, wherein the blowing agent comprises a perfluorocycloalkane and a straight-chain alkane in a ratio of x:y and wherein the blowing agent comprises 0.05 to 0.95 wt.% water as a co-blowing agent.
Person of ordinary skill in the art (POSITA)
The POSITA is a chemist knowledgeable in the field of rigid polyurethane foams, including their properties and how to prepare them.
Common General Knowledge (CGK)
It is common general knowledge that foams with good insulating properties can be prepared in the presence or absence of water as a co-blowing agent. Prior art documents D2 to D5 are representative of the CGK of the POSITA, all relate to rigid polyurethane foams prepared by related blowing agents, and further disclose that foams with good insulating properties can be prepared in the presence or absence of water as a co-blowing agent. Furthermore, these documents note that water is usually present in small quantities due to the hydrophilic nature of the polyol component used to prepare the foams.
It is clear from the description that the problem to be solved was how to improve methods of preparing rigid polyurethane foams having good insulation values.
The solution as detailed in the description is to prepare the rigid polyurethane foams in the presence of a blowing agent comprising a perfluorocycloalkane and a straight-chain alkane in specific ratios.
What are the essential elements?
In order to solve the problem of preparing rigid polyurethane foams having good insulating values, the following elements of the claim are considered essential:
- contacting a polyol and an isocyanate
- in the presence of a blowing agent comprising perfluorocycloalkane and a straight-chain alkane in specific ratios.
The following element is non-essential to achieving the proposed solution:
- the use of 0.05 to 0.95 wt. % water as a co-blowing agent.
Although the claimed method recites the use of water as a co-blowing agent, it is clear that the common general knowledge of the person skilled in the art includes the knowledge that rigid foams with good insulating properties can be prepared in the presence or absence of water as a co-blowing agent. This is consistent with the teachings of the application's description, which discloses that water "may" (not "must") be present, and which does not disclose any specific new results arising from the presence of water. The person skilled in the art would understand that the presence of water is not an essential element of claim 1.
Is the claim anticipated?
Yes, based on a comparison of the elements essential to solve the problem the inventors set out to address, the method of claim 1 is anticipated by the enabling disclosure of D1 under the first-to-file provisions of paragraph 28.2(1)(c) of the Patent Act.
Anticipation by prior sale or use
Although the majority of prior art consists of written disclosures, the sale or use of an invention can also be relevant prior art if it effectively provides an enabling disclosure of the application's claimed subject-matter prior to the claim date of the pending application. Footnote 22
To be considered to have disclosed the claimed invention, the prior sale or use must provide to the person skilled in the art information sufficient to comprehend the invention. Footnote 23 "The use of a product makes the invention part of the state of the art only so far as that use makes available the necessary information." Footnote 24 The information made available must be such that if the person skilled in the art were to write down that information, they would have drafted a clear and unambiguous description of the claimed invention. Footnote 25 Disclosure may be made if the public has the "opportunity to access the information that is the invention". Footnote 26
As was noted in Baker Petrolite Corp. v. Canwell Enviro Industries Ltd., in determining whether a publicly available product anticipates a claimed invention, the ability of the person skilled in the art to reverse engineer the product "in accordance with known analytical techniques" may be relevant. Footnote 27 What is required for this consideration is the ability to reverse engineer without inventive effort; it is not necessary to establish that the product was actually reverse engineered. Footnote 28
In considering whether anticipation by prior sale or use of an invention has occurred, the grace period provided for in paragraph 28.2(1)(a) of the Patent Act applies in respect of any making available of the invention by the applicant or by a person who obtained the relevant knowledge directly or indirectly from the applicant.
Implicit or inherent disclosure
An enabling disclosure is considered to disclose everything that would inevitably or necessarily occur or be done by a person practising the invention. Old and known subject-matter is not rendered novel simply by disclosing and claiming a feature which is inherently (i.e. necessarily present) or implicitly (i.e. suggested but not directly expressed) found in the prior art. Footnote 29 The concepts of inherent and implicit disclosure are related.
Inherent features of a disclosed invention include properties and characteristics of the elements of the invention, such as the ductility of a metal used in a part in a machine, the mechanism of action of a drug taken to treat a disease, or the thermoplastic properties of a polymer.
Implicit features include those things that a person skilled in the art would, in view of their common general knowledge, necessarily understand to be part of what one would do in order to operate the disclosed invention. If a chemical process calls for ‘distillation at reduced pressure' without further elaboration, the use of some means for reducing the pressure to below atmospheric is implicit. If a watch band is to be assembled using parts that interact to give the band greater flexibility, the use of attachment means to hold the parts together would be understood by the person skilled in the art and could be considered implicit in the disclosure even if no specific directions to attach the parts together were given. Footnote 30
The mere discovery of the properties of a previously disclosed invention does not make that invention newly patentable, but where the discovery leads to a new practical application of the previous invention that new practical application may be patentable. Footnote 31
Consider that a prior art document discloses a chemical compound X and how to make it, and establishes that compound X is useful in treating disease Y. Where subsequent research uncovers the mechanism of action of the compound, a claim to the use of compound X to treat disease Y via the newly discovered mechanism is not novel. Compound X inherently treated disease Y via the mechanism, and the discovery has not led to a new use for the known compound. Footnote 32 However, if the discovery of the mechanism allows one to conclude that compound X would also be useful in treating disease Z, the use of compound X to treat disease Z may be patentable.
Where features implicit or inherent in a previously disclosed invention are being considered when assessing anticipation, it is important to recognise that such features do not create a new invention if a person using the previously disclosed invention would already have achieved the benefits arising from the presence of the implicit or inherent features. This follows from the "well-known principle in Patent law that a man need not state the effect or the advantage of his invention, if he describes his invention so as to produce it". Footnote 33 The earlier invention is sufficiently disclosed even if all its advantages were not taught, and the earlier inventor "is entitled to its benefit even if he does not fully appreciate or realize the advantages that flow from it or cannot give the scientific reasons for them". Footnote 34 Performing the earlier invention would provide the benefits arising from the implicit or inherent features; under the principle of anticipation by reverse infringement [15.01.02], the earlier disclosure would be anticipatory.
Where a conclusion of anticipation requires the presence of an inherent or implicit feature, it is necessary for the examiner to clearly explain the basis for concluding that the feature is implicit or inherent to the matter of the prior disclosure. Where such a conclusion is supported by secondary references, the date of publication of these references is not important.
In the field of respiratory diseases, the use of a powdered drug C is well known.
An applicant files an application A, which describes a powder inhaler capable of aerosolizing and delivering powdered medicament to a recipient. Their specification describes and illustrates the inhaler as having means for varying airflow volume and resistance and notes that adjustments thereto may be made for delivering unspecified powdered medicaments. No indication is made as to the specific airflow properties of the inhaler but feature Z is illustrated.
More than 12 months after the publication of application A, the applicant files application B, which describes a delivery-efficacy testing regimen for the inhaler claimed in application A. Application B does not describe any inventive medicament, but does refer to drug C. No modifications to the inhaler are disclosed in application B.
Claims of application B:
- A dry powder inhaler for delivering a powdered drug, comprising feature Z and having a delivery efficiency of at least W wherein the inhaler has a flow resistance of X at a flow rate of Y.
- The dry powder inhaler according to claim 1 wherein the powdered drug is C.
Analysis: Application B discloses that the dry powder inhaler described in application A was used for the applicant's trials, and does not describe any modifications made to the inhaler. It must be concluded that whenever the dry powder inhaler of application A is used, it will have the delivery efficiency, flow resistance and flow rate defined in the claim. These are merely inherent properties of a dry powder inhaler as described in application A. Inclusion of these properties in the claim of application B does not direct claim 1 to a different dry powder inhaler than the one disclosed in application A. Claim 1 is therefore anticipated.
Claim 2 defines the dry powder inhaler of claim 1 wherein the drug that will be delivered is the well-known drug C. Since no adaptation of the inhaler is, in view of application B, required for it to deliver drug C, the claim remains directed, simply, to the inhaler disclosed in application A and is anticipated. Defining that the inhaler is capable of delivering drug C merely specifies one of its inherent abilities.
Anticipation based on related teachings
Anticipation assesses whether a single prior disclosure both revealed the invention in a claim being examined and enabled a person skilled in the art to operate it.
In some limited situations, a single prior disclosure can comprise teachings in more than a single document. This may occur where a primary source of information makes explicit reference to specific teachings in a secondary source, thereby making clear to the skilled reader that the teachings of the secondary source are to be relied on in order to understand or complete the disclosure of the invention in the primary source.
In order to consider multiple sources of information to comprise a single disclosure, there must be an unambiguous relationship between the two sources. References in one source that merely mention the other are not sufficient to establish such a relationship. Rather, the first source must direct the reader to use the teachings of the second source for the purposes of understanding and operating the invention.
Obviousness – June 2016
The requirement that an invention be inventive was, prior to October 1, 1996, recognised judicially as inherent to the definition of invention Footnote 35 but is now more formally reflected in the Patent Act. Footnote 36 Ingenuity is tested by determining whether the claimed invention is obvious (i.e. uninventive) when considered by a person skilled in the art in light of their common general knowledge and the state of the art as a whole. Footnote 37 In contrast to the approach for assessing anticipation [see 15.01.02], the evaluation of obviousness allows for a consideration of the combined teachings of multiple prior art documents that the person skilled in the art would discover in a "reasonable and diligent search". Footnote 38
The use of the term "obvious" in section 28.3 of the Patent Act has not changed the inherent requirement that an invention be the result of ingenuity. Footnote 39 The courts have noted that "obviousness is an attack on a patent based on its lack of inventiveness" Footnote 40 and "[t]he courts have chosen to define ‘lack of inventiveness' rather than ‘inventiveness' and have called it ‘obviousness' ". Footnote 41
Obviousness is assessed on a claim-by-claim basis by asking whether the claimed invention is obvious (or uninventive) when considered by the person skilled in the art in light of their common general knowledge and the state of the art as a whole. As with the assessment of anticipation, the assessment of obviousness is based on the elements which would be recognised by a person skilled in the art as providing the solution to a given problem. There is nothing inventive in adding elements to a claim that are irrelevant to the invention's successful operation.
To be considered obvious, the teachings present in the prior art must be sufficient so that, if combined, they would lead to the claimed invention (or to a working embodiment within the claim). Furthermore, it must be obvious (i.e. uninventive) to combine the necessary teachings so as to arrive at the claimed invention.
Prior art when assessing obviousness
Section 28.3 of the Patent Act defines what disclosures may be considered for the purpose of assessing obviousness. Although any public disclosure of information may be considered in principle, for practical reasons the assessment is almost exclusively performed on the basis of written disclosures. In summary, this section provides for a one-year grace period with respect to disclosures by the applicant before the filing date and allows any third party disclosure anywhere in the world made prior to the claim date to be considered.
Obviousness and prior disclosures by the applicant
Paragraph 28.3(a) of the Patent Act provides that
The subject matter defined by a claim in an application for a patent in Canada must be subject matter that would not have been obvious on the claim date to a person skilled in the art or science to which it pertains, having regard to
(a) information disclosed more than one year before the filing date by the applicant, or by a person who obtained knowledge, directly or indirectly, from the applicant in such a manner that the information became available to the public in Canada or elsewhere.
This provision defines public disclosures by the applicant, or by a person who obtained their knowledge directly or indirectly from the applicant, made more than one year before the filing date of the application as prior art for the assessment of obviousness, but excludes these disclosures as prior art if made in the one year grace period preceding the filing date. For further information on grace period see 15.04.
Obviousness and third party disclosures
Paragraph 28.3(b) of the Patent Act provides that
The subject matter defined by a claim in an application for a patent in Canada must be subject matter that would not have been obvious on the claim date to a person skilled in the art or science to which it pertains, having regard to
(b) information disclosed before the claim date by a person not mentioned in paragraph (a) in such a manner that the information became available to the public in Canada or elsewhere.
This provision defines any public disclosure made by a third party (i.e. by a person other than the applicant or a person who obtained their knowledge directly or indirectly from the applicant) as prior art for the assessment of obviousness if it was made before the claim date [see 15.03].
Obviousness is assessed from the viewpoint of the person skilled in the art, in light of their common general knowledge and the state of the art as it was on the claim date. For a claimed invention to satisfy the requirement of section 28.3 of the Patent Act there must be present that "characteristic or quality" (i.e. that "scintilla of invention necessary to support the patent" Footnote 42) which serves to elevate the matter of the claims from mere workshop improvement to real invention. Footnote 43
Although various tests have been expressed for assessing obviousness, the inquiry is not well served by attempting to rigidly apply any one test in all circumstances. Footnote 44 It is important to address the question in an informed way and the Supreme Court has endorsed a four-step analysis for this purpose, wherein the first three steps frame the inquiry and the fourth step is to ask the pertinent question.
The four steps in the analysis were set out by the Court in Apotex Inc. v. Sanofi-Synthelabo Canada Inc. as: Footnote 45
- (1) (a) Identify the notional "person skilled in the art";
(b) Identify the relevant common general knowledge of that person;
- (2) Identify the inventive concept of the claim in question or if that cannot readily be done, construe it;
- (3) Identify what, if any, difference exists between the matter cited as forming part of the "state of the art" and the inventive concept of the claim or the claim as construed;
- (4) Viewed without any knowledge of the alleged invention as claimed, do those differences constitute steps which would have been obvious to the person skilled in the art or do they require any degree of invention?
The Supreme Court's admonition against attempting to apply any one test in all circumstances refers specifically to the question asked at step 4.
The Sanofi four-step analysis will typically be done intuitively and automatically by an examiner. Where there appears to be a disagreement between the examiner and applicant(s) as to whether or not a claim is obvious, the Sanofi four-step analysis should be set out in a report. This analysis must be set out in a pre-final or Final Action report.
To inform the first step of the Sanofi four-step analysis, guidelines for the identification of the person skilled in the art and of the common general knowledge follow. It should be kept in mind that the person skilled in the art and the common general knowledge of said person are considered in many aspects of examination and the following discussion is useful in this regard.
Person skilled in the art (Step 1(a))
The person skilled in the art is a fictitious construct that represents an average worker competent in the field or fields relevant to the invention. Footnote 46 The person skilled in the art can represent an individual, or a team of individuals whose conjoint knowledge is relevant to the invention in suit. Footnote 47
The person skilled in the art is considered to be competent; a logical but unimaginative worker in the field, Footnote 48 who is neither a dull-witted incompetent nor a creative, intuitive expert. Footnote 49 In a highly technical field, the person skilled in the art may be presumed to have expert-level knowledge and skills. Footnote 50 The skilled person need not be a manufacturer or designer, but must understand the problem to be overcome, have knowledge of means to address the problem and the likely effect of using the means. Footnote 51 Furthermore, the person skilled in the art is reasonably diligent in keeping up with advances in the field or fields of relevance to the invention, Footnote 52 and has the advantage of being multilingual and thereby being able to comprehend prior art in any language. Footnote 53 Note that the person skilled in the art may have knowledge from outside the field of the invention, although it should not be presumed that they would. Footnote 54 In this context, the nature of the problem being addressed by the alleged invention may be helpful in defining the skilled person.
The person skilled in the art is presumed to read prior disclosures in the same manner as the specification of the application itself. That is, with a mind willing to understand Footnote 55 and desirous of success. Footnote 56 In understanding the significance of the prior art, they may apply teachings from one source to another setting or even combine teachings. Footnote 57
During examination, the person skilled in the art is relevant in many contexts. It is important to recognise that there is only a single description of the person skilled in the art for a given alleged invention. Nevertheless, the common general knowledge of the person skilled in the art will depend on the date at which an understanding of the application is required. Footnote 58 Note that in some circumstances, this can require the person skilled in the art to rely on knowledge which, while generally accepted at the relevant date, was later shown to be wrong. Footnote 59
Depending on the specifics of a given case, it may be necessary to explicitly identify the person skilled in the art. It should be stressed that this is not necessary where the nature of the person skilled in the art does not appear to be under debate or where it is unlikely to impact on any conclusions as to patentability.
Where the specific nature of the person skilled in the art is relevant for resolving an issue during examination, the examiner will determine who this person is by reference to the field or fields relevant to the invention and will consider comments by the applicant in the determination. The person skilled in the art may be ascertained from the language of the specification of the application. Footnote 60 Attributes such as proclivity for engaging in research or experimentation may help form the profile of the skilled person.
Although the characterisation of the person skilled in the art should be done carefully, Footnote 61 it should also be done with a certain degree of generalisation. Footnote 62 During examination, an examiner must attempt to interpret the application and the prior art using the appropriate knowledge that the person skilled in the art would have possessed at the claim date. Specific details such as the skilled person's exact educational background or length of work experience are typically unnecessary and have the potential to be misleading or overly restrictive; precise definitions of the skilled person should therefore be avoided.
Common general knowledge (Step 1(b))
"Common general knowledge means knowledge generally known by persons skilled in the relevant art at the relevant time." Footnote 63 The common general knowledge in a field has been described as the knowledge that emerges as common themes from the "forest of art", and which becomes commonly known to the ordinary person skilled in the art. Footnote 64 This knowledge undergoes continuous evolution and growth. Footnote 65
The common general knowledge distinguishes the body of information that is widely recognised from that which is simply publicly available. Individual disclosures may become common general knowledge, but only when they are generally known and regarded as a good basis for further action. Footnote 66 At the same time, some information that forms part of the common general knowledge may not have been written down at all.
Where the common general knowledge in a field becomes relevant for the purposes of examination, examiners may refer to information they believe to have been common general knowledge as of the claim date. Unless it becomes evident through the applicant's comments that the nature of the common general knowledge is not common ground and is reasonably in dispute, an examiner need not identify documents establishing the common general knowledge.
Where it is appropriate or necessary to establish the common general knowledge in a field (for example where the examiner and applicant disagree as to the common general knowledge), this can be done by citing established reference works (such as textbooks, review articles, handbooks, etc.) or by demonstrating commonality of certain knowledge in a number of disclosures in the field. The common general knowledge at a certain date can be confirmed by subsequent publications, Footnote 67 or by showing that the knowledge had been accepted in the field over a period of time. Statements in the application’s description that describe certain information or knowledge as commonly known may be relied upon, without verification, as establishing aspects of the common general knowledge; an applicant will be bound to such comments. Footnote 68
Identifying the inventive concept (Step 2)
The inventive concept of a claim is not necessarily the same as the essential elements gleaned following a purposive construction analysis. Construing the inventive concept for the purpose of the obviousness analysis is a separate exercise from claim construction, meaning that the construction of the claims is not determinative of the inventive concept. Footnote 69
Purposive construction is used to determine the essential elements of a claim i.e., those elements that provide the solution to the problem that the inventor set out to solve. In contrast, the inventive concept comprises the feature or features of the claim that appear to be inventive over the common general knowledge and/or which the applicant appears to consider inventive. It should be remembered that the identification of the inventive concept should be based on a reading of the specification as a whole from the perspective of the person skilled in the art, in light of their CGK. The inventive concept may be determined to be a combination of the same essential elements identified during the purposive construction analysis and will generally include at least some of the essential elements, but it might not include all the essential elements of the claim as construed.
Purposive construction is outlined in Chapter 13 of this manual.
Identifying the differences between the inventive concept and the state of the art (Step 3)
At step 3 of the obviousness analysis, the inventive concept of the claim in step 2 is compared to the state of the art to determine whether, or to what extent, an equivalent or similar solution to the problem being addressed by the applicant was known at the claim date. The state of the art refers to the information available to the person skilled in the art in accordance with section 28.3 of the Patent Act, and generally will be identified by reference to specific prior art documents that would have been discovered in a "reasonable and diligent search".
Should there be no difference between the inventive concept of the claim and the state of the art, the claim is most likely defective for being anticipated or obvious. For example, a claim may be anticipated where there is no difference between the inventive concept of a claim and only one prior art disclosure that is cited as state of the art, provided that the prior art disclosure is enabling. In cases where the prior art disclosure is not enabling, the claim may not be anticipated but may still be obvious. A claim may also be obvious where more than one state of the art document is required to arrive at the inventive concept.
Where differences exist between the inventive concept of the claim and the state of the art, it must be determined whether these differences would have been obvious to the person skilled in the art as of the claim date.
Do the differences constitute an inventive step? (Step 4)
Once any differences between the state of the art and the inventive concept of the claim or the claim as construed have been identified, it must be determined whether the subject matter of the claim is obvious or is the result of inventive ingenuity. This must be done without presupposing that the specific problem addressed by the inventors was recognised in the prior art, so as to avoid adopting an improper "hindsight" perspective. Where the existence or nature of a problem was unobvious, the act of identifying the problem may inform the inventive concept.
As noted above, various tests have been articulated in the jurisprudence in order to answer this question, and the Supreme Court has cautioned that no single expression of this test is likely to apply to all circumstances. Although the test question may be framed taking into account the nature of the specific case in question, one must never lose sight that its purpose is to evaluate the statutory requirement of section 28.3 of the Patent Act and care should be taken to ensure the question is not phrased in such a way that a different standard is applied.
In answering the question at step 4, the factors to be considered include:
- (i) the climate in the relevant field at the time the alleged invention was made, including not only knowledge and information available but also attitudes, trends, prejudices and expectations that would define the person skilled in the art;
- (ii) any motivation in existence at the time of the alleged invention to solve a recognised problem in the field of the invention; and
- (iii) the time and effort involved in the invention Footnote 70
It should also be remembered that "the inventive ingenuity necessary to support a valid patent may be found in the underlying idea, or in the practical application of that idea, or in both. It may happen that the idea or conception is a meritorious one, but that once suggested, its application is very simple. Again, it may be that the idea is an obvious one, but that ingenuity is required to put it into practise. Or, again, the idea itself may have merit and the method of carrying it into practise also requires inventive ingenuity". Footnote 71
Where the problem to be solved was already recognised in the art, it may be appropriate to inquire only into whether inventive ingenuity was required to conceive of the claimed solution and put it into practice. Where, however, the problem or its underlying cause was not previously recognised or understood, there may be an invention even where the proposed solution to the newly identified problem would have been immediately apparent to the person skilled in the art. Inventive ingenuity, however, does not exist if the alleged problem never existed and was simply an artificial obstacle or "straw man" developed to imply inventiveness in the proposed "solution". Footnote 72
The assessment of obviousness is approached by considering the prior art as a whole, and the teachings of several documents may be combined in order to show why the claimed subject-matter is not the result of inventive ingenuity. When combining teachings from several documents, the relationship of the documents to each other, and to the person skilled in the art, must be considered. An explanation as to why it was obvious to combine the teachings may be necessary in situations where it is not self-evidently so. This may be given, for example, by establishing why a motivation to combine the teachings in the cited documents exists, whether based on the teachings of the documents themselves, on the common general knowledge or trends in the field of the invention.
Where a document from outside the field of the invention is relied upon in the analysis, the need to explain why it would be obvious to apply the teachings to the field of the invention is greater.
Example of Sanofi four-step analysis:
An application discloses a method of cleaning lead from the interior of a steam still using a high pressure stream of water. Suitable operating parameter ranges are disclosed, encompassing those that were actually used by the inventors to successfully clean a still.
The use of high-pressure water to clean surfaces has many applications, and is used in many environments. A search of the prior art reveals documents D1-D3. D1 teaches a method of removing carbon deposits from the interior of a smoke stack by sweeping a high pressure stream of cleaning fluid over the encrusted surface. D2 teaches a wet abrasion process for removing calcium deposits from tiles, and includes illustrations of distributed and focussed spray patterns and of workers sweeping a sprayer at a surface from a distance. D3 teaches a pressure washer for cleaning barnacles off the hull of a vessel, and discloses interchangeable nozzles attachable to a wand where each nozzle produces a specific spray pattern. Each of the documents discloses operating parameters suitable for its specific environment.
A method of removing lead residue from the interior of a steam still, wherein a stream of fluid from a nozzle is directed to a surface of the steam still at a velocity of between 300 and 1200 ft/s, with the nozzle held from 1-12 inches from the surface at an angle of between 15 and 45 degrees.
Analysis: The problem addressed in the application is cleaning deposits off a hard surface.
In order to determine whether the claimed subject-matter is inventive, the claim is assessed via the four step method [see 15.02.02].
- (1) (a) Identify the notional "person skilled in the art":
The person skilled in this art is taken to be a technician familiar with high-pressure washing and general removal, i.e., cleaning, of deposits from surfaces.
(b) Identify the relevant common general knowledge of that person:
The common general knowledge includes an understanding of typical operating parameters for pressure-washers, suitable cleaning agents and common applications for such washers.
(2) Identify the inventive concept of the claim in question:
In this case the inventive concept includes all of claim 1: a method of removing lead residue from the interior of a steam still, wherein a stream of fluid from a nozzle is directed to a surface of the steam still at a velocity of between 300 and 1200 ft/s, with the nozzle held from 1-12 inches from the surface at an angle of between 15 and 45 degrees.
(3) Identify what, if any, difference exists between the matter cited as forming part of the "state of the art" and the inventive concept of the claim or the claim as construed:
The inventive concept of the claim differs from the state of the art (D1 to D3) in specifying that the surface to be cleaned is the interior of a steam still and in establishing certain specific operating parameters.
(4) Viewed without any knowledge of the alleged invention as claimed, do those differences constitute steps which would have been obvious to the person skilled in the art or do they require any degree of invention?
The person skilled in the art, presented with a steam still surface requiring cleaning would arrive at the operating parameters defined in the claim without inventive ingenuity or undue burden. The use of a pressure-washer in a steam still is directly analogous to its use in the environments disclosed in D1 to D3, and uninventive in view of those disclosures. No unexpected result arises from operating the washer within the parameters defined in the claim. The subject-matter of the claim is therefore obvious.
Obvious to try considerations
Determining whether a claimed invention is obvious at step 4 of the obviousness inquiry may involve asking whether the claimed subject matter is obvious because the route to the invention would have been obvious to try. This approach may be especially pertinent in "areas of endeavour where advances are often won by experimentation" Footnote 73 but there are no restrictions on its applicability to specific technologies. Footnote 74
When considering an obvious to try analysis, the following non-exhaustive list of factors is relevant:
- Is it more or less self evident that what is being tried ought to work? Are there a finite number of identified predictable solutions known to the person skilled in the art?
- What is the extent, nature and amount of effort required to achieve the invention? Are routine trials carried out or is the experimentation prolonged and arduous, such that the trials would not be considered routine?
- Is there a motive provided in the prior art to find the solution the patent addresses? Footnote 75
When assessing obviousness during examination, these factors may be recast as questions to be considered by the examiner:
Would the person skilled in the art have been aware, in view of the prior art and the common general knowledge on the claim date, that a limited number of predictable and identifiable solutions exist to the same or a similar problem such that they would believe that one of those solutions more or less self evidently ought to work to solve the problem being addressed?
For the purpose of the obvious to try analysis, it is not necessary that a particular choice from the available solutions be immediately obvious as providing the claimed subject-matter, nor is it necessary that a particular option be best suited to providing the solution. If none of the limited number of predictable and identifiable solutions is related to the solution covered by the claimed subject-matter, the examiner may conclude that the skilled person would not have deemed the subject-matter obvious to try.
Could the person skilled in the art be expected to arrive specifically at the solution claimed, starting from the limited number of solutions conceptually identified in factor 1, without inventive step or undue burden? That is, would the solution be arrived at by routine and predictable methods, and without requiring prolonged and arduous effort?
The more difficult it is to arrive at the claimed subject-matter from the limited number of likely solutions, the less likely it is that a conclusion of obvious to try is appropriate. Where the person skilled in the art would need to exercise inventive ingenuity in order to solve problems for the purpose of testing the various solutions, for example, it cannot be considered obvious for the person skilled in the art to have tried that route.
In cases where the obvious to try test may be appropriate, the examiner will objectively determine if the exercise of inventive ingenuity or undue effort were necessary to arrive at the claimed solution. The examiner will take into account the nature of the person skilled in the art and the knowledge and the climate in the relevant field or fields at the claim date. The subjective experience of the inventors will not be considered relevant unless it can be established that it reflects what would have been expected of the hypothetical person skilled in the art.
Does the person skilled in the art, in view of the prior art, have a motive to find the solution the problem addressed by the application?
The existence of motivation, in the broadest sense, to solve problems in the field of the invention through scientific inquiry will generally not be sufficient to sustain a conclusion that the claimed invention is obvious to try. It will usually be necessary to show that there was a more specific motivation to work along similar lines as those pursued by the inventor. The person skilled in the art must have been motivated to conduct experiments in the area of the invention, aimed at solving the same or a similar problem to that addressed by the inventor by identifying a solution such as that defined in the claim under consideration.
The attitudes, prejudices and expectations of the person skilled in the art and their awareness of the trends in their field are relevant factors to consider in assessing subject-matter as obvious to try, and are assessed in light of the state of the prior art.
It should be remembered that obvious to try considerations are used to determine whether the subject matter of a claim is the result of inventive ingenuity and, by consequence, is unobvious. Factors 1 to 3 might be thought of as asking whether it was obvious to search for a solution to the problem addressed by the inventors (the motivation factor) and whether the route to the claimed subject matter was also obvious. If there was no invention in either conceiving of the solution or reducing it to a practical form, the claimed subject matter is not the result of an inventive step and is therefore obvious.
Where the questions in factors 1 and 3 can be answered in the affirmative, and the conclusion when considering factor 2 is that the subject-matter of the claim would be arrived at by routine trials that were not prolonged and arduous, it can be concluded that the subject matter of the claim is obvious since it would have been obvious to try to identify the claimed matter from among a finite number of likely solutions one of which more or less self evidently ought to work.
Little guidance exists as to which areas of endeavour are those in which advances are often won by experimentation, although it has been commented that in such areas "there may be numerous interrelated variables with which to experiment". Footnote 76 Where there are a finite number of identified, predictable solutions known to the person skilled in the art and a motivation provided in the prior art to find the solution the application addresses, these factors can be indicative that one is in an area of endeavour where advances are often won by experimentation. The "threshold" question of whether obvious to try is applicable is considered to be inherently addressed when the factors of the test itself are considered.
As stated in section 15.01.02, elements that cooperate to produce a unitary result must be considered in combination when novelty is being assessed. It is not necessary for any of the individual elements of a claim to be new provided the elements are combined to produce a unitary result that is different from the sum of the results of the elements. Footnote 77 Such combinations are patentable whereas "a mere aggregation of elements is not". Footnote 78 The subject-matter of a claim is considered to be a mere aggregation if each of the elements performs its own individual function and if any one element is removed the remaining elements would continue to perform their own individual function. Footnote 79
When an invention is merely a juxtaposition of parts or known devices, and each part or device merely functions as would be expected if it were used on its own, the assembly is not a true combination but is a mere aggregation. An aggregation of old parts cannot form the basis of a patentable invention.
An aggregation should be identified as a defect under section 28.3 of the Patent Act as being obvious. Separate prior art documents may be cited to show that each individual part is known in the prior art.
Obviousness and utility
In many cases, the ingenuity of an invention is related to its utility. This is particularly the case where some unexpected result is achieved through the subject-matter of the claim. This can arise, for example, where a known product or process is modified in some way that makes it novel and leads to the unexpected result. The unexpected result could be, for example, that the product or process becomes useful for some new purpose or provides some additional advantage when used for its intended purpose. Alternatively, the unexpected result could be that despite simplifying the known product or process (for example, by omitting parts or steps) the utility of the original product or process is retained.
Where the invention lies in discovering that a known thing has properties that make it useful for some new purpose, that mere discovery does not confer patentability on the known thing. The new use may be patented, however, if it is novel and unobvious.
Minor variations in existing inventions, such as the changing of size, shape, proportion or quality, Footnote 80 where the result is merely the doing of "the same thing in the same way, by substantially the same means, with better results, is not such an invention as will sustain a patent". Footnote 81 The substitution of a superior material for an inferior material, where the advantages of the substitution were expected, has similarly been found to be obvious. Footnote 82
Even where the use is different, there must be something unexpected or inventive in play to support a patent. "A patent for the mere new use of a known contrivance, without any additional ingenuity in overcoming fresh difficulties is bad and cannot be supported. If the new use involves no ingenuity, but is in manner and purpose analogous to the old use, although not quite the same, there is no invention". Footnote 83
Where a combination of parts is being considered, "[a]ll the elements being old, and the functions to be performed being identical, [it can] be patentable only if it performed the old function in some better or cheaper way than did the earlier machines - there must be a new mode of operation resulting from the combination [...]; it is not invention to combine old devices in a new machine or manufacture without producing some new mode of operation...". Footnote 84 Absent a new unitary result arising from their combination, an assemblage of known parts is merely an uninventive aggregation [see 15.02.04].
The assessment of utility and obviousness may also be somewhat interdependent where the utility of the invention must be based on a sound prediction, particularly where the information necessary to permit a person skilled in the art to soundly predict that a known thing would be useful for some given purpose forms part of the state of the art. Although in certain situations it may be that an invention either lacks sound prediction or is obvious, it must be remembered that the assessment of sound prediction and the assessment of obviousness are distinct tests. Footnote 85 The former is based on the applicant's own description and drawings, scientifically accepted laws or principles and the common general knowledge of the skilled person, while the latter is based on the state of the art.
Obviousness of anticipated claims
Where the subject-matter of a claim is considered to be anticipated by a prior art disclosure, it will often also be considered to be obvious. The existence of an anticipatory disclosure will typically lead to the conclusion at step 3 of the Sanofi obviousness analysis that there is no difference between the inventive concept of the claim and the state of the art [see 15.02.02].
Where the applicant's amendments or arguments in response to the examiner's requisition overcome the lack of novelty defect, the claim may nevertheless remain defective for obviousness.
In the interests of keeping examination efficient, examiners having identified that a claim is defective in view of the prior art need not provide separate analyses for anticipation and obviousness defects where a single analysis is applicable to both assessments. It remains permissible for both defects to be identified in a later report, particularly where the applicant's amendments or arguments have assisted in more clearly identifying any points of disagreement in respect of the applicability of the cited prior art.
When responding to an examiner's report identifying a lack of novelty, an applicant may be well served to provide comments explaining why the claimed subject-matter should be considered unobvious even if obviousness was not explicitly identified as a defect in the examiner's report. While no single test is appropriate in all cases where obviousness is a consideration, the Sanofi four-step analysis outlined in 15.02.02 will generally be used by the examiner. An applicant should consider this approach when formulating an argument.
Where an examiner considers that an impasse is developing in respect of the applicability of the prior art, and that the application is approaching rejection in a Final Action, separate analyses for anticipation and obviousness should be provided. This must be done at least one report before the Final Action. More information on the requirements for issuing a Final Action may be found in Chapter 21 of this manual.
Claim date – June 2016
In accordance with section 28.1 of the Patent Act, a claim's claim date is the earliest validly claimed priority date for that claim or, where there is no valid priority date, is the application's filing date.
A valid priority date is one based on an earlier regularly filed application that discloses the claimed invention and on which a claim for priority was made within the allowed time. The earlier regularly filed application may conveniently be referred to as a "priority document", and may be an earlier application filed by an eligible person in Canada or an earlier application filed by an eligible person in an eligible country. Chapter 7 of this manual details priority claims in greater detail.
In principle, each claim in an application may have a different claim date from all other claims, although in practice it is typical for an application to claim priority from one or two priority documents.
Where a public disclosure would be relevant prior art for the assessment of anticipation or obviousness if a claim’s claim date is the application’s filing date, but not relevant if the claim’s claim date is a specific priority date, it will be necessary for the examiner to verify the content of the relevant priority document. The priority is valid only to the extent that the priority document discloses the same subject-matter as is claimed in the application. Where the scope of the teachings in the priority document and the application are different, the claim in the application may not benefit from the earlier claim date. Where, for example, the priority document teaches a specific embodiment and the application claims generalised subject-matter covering the specific embodiment, a claim to the generalised subject-matter may not benefit from the priority date if further support for the generalised subject-matter is not found in the priority document, whereas a claim limited in scope to the specific embodiment disclosed in the priority document would.
Grace period – September 2017
The Patent Act provides for a one-year grace period before the filing date, during which information that became publicly available due to a disclosure by the applicant, or by a person who obtained knowledge, directly or indirectly, from the applicant, is not considered during the assessment of whether the claimed invention is novel and inventive.
As defined in section 2 of the Patent Act, the term applicant “includes an inventor and the legal representatives of an applicant or inventor”. The term legal representative itself “includes heirs, executors, administrators of the estate, liquidators of the succession, guardians, curators, tutors, transferees and all other persons claiming through applicants for patents and patentees of inventions or through holders of certificates of supplementary protection”.
In considering whether the grace period applies to a given disclosure of information, the prior disclosure is only protected by the grace period if the person making the disclosure was, or must be deemed to have been, the applicant or a person who obtained knowledge, directly or indirectly, from the applicant at the time the earlier disclosure was made (i.e. at the date of making available to the public, such as the date of publication or of laying open for public inspection). Footnote 86
The grace period covers any prior disclosure, whether an oral disclosure such as a presentation at a conference or a written disclosure such as an article in a trade journal. Since the majority of disclosures of information relevant to patent examination are publically available documents, the applicability of the grace period is typically assessed by considering whether the application being examined and the prior publication share authors (e.g. whether the inventors were the authors of a prior publication) or, where the prior disclosure is a patent document, had the same applicant. It must be remembered that, in respect of domestic patent documents, the grace period applies when considering anticipation or obviousness, but not when assessing double-patenting.
In cases where the applicability of the grace period is in dispute, the applicant may provide such evidence as they consider appropriate to support a relationship between the author of the prior disclosure and the applicant.
Establishing the publication date of prior art – January 2016
In order for a prior disclosure to be considered prior art, the date at which it became available to the public must generally be known. Where the exact date on which a disclosure was made to the public is not known, the disclosure cannot be cited unless a reliable basis exists for concluding that the information was available to the public before the relevant date (i.e. claim date).
For patent documents (issued patents and applications), this information is usually known. In other cases, it may be less clear. It will usually be possible to determine the publication date of articles published by reputable journals, magazines and similar publications. In many cases, the actual date of publication will be indicated (either of the article in particular or of the issue of the publication in which it is found). In certain cases, only the month and year of publication will be identified. In such cases, it cannot be presumed that the document became available to the public before the last day of the month. Where only a year of publication is available, it cannot be presumed that the publication date was earlier than December 31 of that year.
There may be methods for establishing earlier actual publication dates, including (in the case of documents available on the internet) establishing dates of first publication via third party archiving services.
Verifying the validity of priority documents
In order to verify the validity of a priority document the examiner should first attempt to acquire the document from a reliable source, e.g. WIPO's PATENTSCOPE database or the International Bureau. Where the priority document is not retrievable by the examiner or where the content of a non-certified copy of the priority document has been relied upon and some question exists as to its accuracy, the applicant may be requisitioned in accordance with section 89 of the Patent Rules to provide a certified copy of the priority document.
Section 89 of the Patent Rules provides that
[w]here a previously regularly filed application on the basis of which a request for priority is based is taken into account by an examiner pursuant to sections 28.1 to 28.4 of the Act, the examiner may requisition the applicant to file a certified copy of the previously regularly filed application and a certification from the patent office in which the application was filed indicating the actual date of its filing.
Double-patenting – September 2017
Double-patenting refers to the judicially recognised proscription against an applicant being granted more than one patent for a single invention. Footnote 87 The principles governing the doctrine of double-patenting have evolved in the jurisprudence, which now recognises two branches: "same invention" and "obviousness" double-patenting. Footnote 88
Underlying this doctrine is the recognition by the Courts that "a second patent [can] not be justified unless the claims [exhibit] "novelty or ingenuity" over the first patent". Footnote 89 In essence, once a patent is granted for an invention, "further invention" is required to support another patent. Footnote 90
The assessment of double-patenting, in practical terms, can be understood as a specialised evaluation of anticipation and obviousness wherein the "prior art" consists solely of one other patent by the same applicant (the "existing patent"). The assessment differs from the statutory assessment of anticipation and obviousness in two important ways:
- i) the "prior art" under consideration is not citable under paragraph 28.2(1)(a) or 28.3(a) of the Patent Act; and
- ii) only the claims of the "prior art" patent by the same applicant are considered in the assessment.
The assessment involves a comparison of the claims rather than the disclosure, as the claims define the monopoly. However, claim comparison is not done on a literal construction of the claims; claims are to be given a purposive construction based on a reading of the specification through the eyes of the skilled person, taking into account their common general knowledge. If the claims of the existing patent, when understood by the person skilled in the art in light of the common general knowledge on the claim date and the teachings of the specification as a whole, anticipate or render obvious the claims of the application being examined, the claims are not patentably distinct from each other. Granting both sets of claims would therefore result in double-patenting. Where it can be concluded that the claims in an application are "not patentably distinct" from the claims in the existing patent, the test under either the "same invention" or "obviousness" branch of the doctrine of double-patenting would have been met.
As mentioned above, double-patenting only arises when considering patents belonging to the same inventor or applicant as the application being examined.
The meaning of “same applicant” for the purpose of double-patenting is based on the definition of applicant from section 2 of the Patent Act, and therefore includes an inventor and the legal representatives of an applicant or inventor. The term legal representative itself includes heirs, executors, administrators of the estate, liquidators of the succession, guardians, curators, tutors, transferees and all other persons claiming through applicants for patents and patentees of inventions or through holders of certificates of supplementary protection.
In many cases the named inventor(s) and the applicant may be the same, but this is not a requirement. Applicants may have many individuals working on different aspects of related projects and may consequently list different inventors on an application. Regardless of the persons listed as inventors, double-patenting restrictions apply to an applicant as though the same inventors were listed.
The Office takes the position that the doctrine of double-patenting applies if the application being examined belonged to the “same applicant” at any time.
Overlap is a term of convenience describing the situation in which an operating embodiment in a claim of an application being examined is identical to an operating embodiment in a claim in an existing patent. The embodiment in the existing patent, being the same as that in the application being examined, therefore acts as a bar against the latter; granting that embodiment in two patents would result in double-patenting.
An operating embodiment can be either the entirety of the claimed subject-matter, or one of several alternatives within a claim. In the latter case, it is possible that the overlap between the claims involves only a small fraction of the scope of the claim in one or both documents. Nevertheless, having the embodiment in question be granted in two patents would result in double-patenting.
Overlap may occur in situations where the claims in the application and the existing patent otherwise appear to be directed to distinct inventions. Where overlap is identified between claims in an application and an existing patent, the claim being examined is not patentably distinct from the claim in the existing patent insofar as the overlapping subject-matter is concerned. The claim being examined is consequently defective due to double-patenting. Removing the overlap, such as by deleting the duplicated subject-matter from the application would remove the double-patenting defect.
An applicant files two applications consecutively (or concurrently as the case may be). One application claiming feature A issues to patent before the other application. The remaining application claims feature B. Each document has a dependent claim that defines A+B. Granting the application would result in double-patenting for the embodiment A+B, but if the dependent claim directed to that embodiment is removed from the application, and presuming B is not obvious in view of A, the double-patenting defect would be removed.
Double-patenting is often described as barring a second patent in view of an ‘earlier patent', and the "sin of double patenting" Footnote 91 is often described in terms of the problem of evergreening Footnote 92 a monopoly by extending the rights in time through the filing of subsequent applications differing only in uninventive details.
It has been noted, however, that a further patent can provide additional rights to the patentee beyond an extension of the term of the monopoly, and that the overriding principle is the need for a further patent to exhibit novelty and ingenuity in order to be justified. Footnote 93 The Office takes the position that having more than one patent to a single invention is not permitted by the doctrine of double-patenting, whether or not the further patent extends the term of the monopoly right granted in the existing patent. The Office takes the position that an "earlier patent" is simply a patent that has already issued and which claims an invention that is not patentably distinct from that in the claims of the application being examined.
This position considers a further patent to be an inappropriate extension of rights both in the sense that the rights in the existing patent would not be exclusive to the existing patent (as provided by section 42 of the Patent Act) and that those rights would not be limited to the term of the existing patent (as provided by section 44 of the Patent Act).
It is not necessary for the existing patent to have issued from an application having an earlier filing or claim date than the application being examined. There are many reasons for which a later filed application could be issued to patent before an earlier filed application, including many factors controlled by the applicant (the request for examination date, a request for advanced examination, the time taken to respond to reports, etc.).
The Office takes the position that an extension of rights can occur whether or not the rights conferred by an existing patent are still available to the patentee. The expiry of the existing patent does not alter that the issuance of the existing patent bars the grant of a further patent defining an invention not patentably distinct from that in the existing patent. In such cases, the grant of a further patent would restore rights that had expired or been surrendered, thus extending the patent rights.
Where two applications belonging to the same applicant define inventions that are not patentably distinct from one another, the examiner will inform the applicant that a potential double-patenting issue exists. Preferably, this is done in reports on both applications (where a report is warranted; see below), in order to ensure the applicant is fully aware of the potential problem. This potential defect is not identified in a requisition under section 30 of the Patent Rules, since it is not an actual defect until one of the applications issues to patent. Rather, the applicant is advised of the potential defect. Where an application is otherwise in condition for allowance, it will not be held back solely because of a potential double-patenting issue (i.e., a theoretical future defect does not delay allowance of an application). This applies to applications that are in a condition for allowance when first examined; applicants should consequently exercise care when filing applications with closely-related claims, to ensure that all the claims to a given invention are included in a single application. Once a first application issues, the subsequent application(s) will contain an identifiable defect.
Double-patenting is identified between an application and an issued patent regardless of whether the potential defect was identified between the applications while co-pending. This is so whether the double-patenting existed at the time the existing patent's application was allowed, or was subsequently introduced to the application being examined by way of amendment. It is up to the applicant to ensure that all the claims to a given invention are included in a single application. Where a patent issues, but claims to certain aspects of the defined invention were omitted during the application stage (whether accidentally or by design), double-patenting will prevent the granting of those claims in a subsequent patent unless they represent "further invention" over the claims in the existing patent.
Division at the direction of the Office
The Supreme Court has noted that if "patents are granted on divisional applications directed by the Patent Office, none of them should be deemed invalid, or open to attack, by reason only of the grant of the original patent". Footnote 94
Where an examiner has identified a lack of unity of invention in a report on an application, and the applicant files a divisional application in response to that report, the claims in the divisional application are exempt from examination for double-patenting if they are identical to claims identified by the examiner in the parent application as lacking unity and they differ from those retained in the parent application.
Chapter 14 of this manual details the procedures for identifying a lack of unity among the claims of an application. Subsequent to any divisional applications that result from an examiner's identification of multiple inventions in a parent application, a double-patenting defect will not be identified where the claims in the divisional application correspond to claims identified in the report as belonging to a different invention than that defined in the claims retained in the parent. This is typically the case where the applicant has adhered to the claim groupings identified by the examiner.
Where, however, the claims in the divisional do not correspond to the groupings identified in the report on the parent application, whether at filing or as the result of subsequent amendment, they will be examined for double-patenting. This is typically the case where the applicant either determines that groupings different from those identified by the examiner are appropriate, or where subsequent to division the applicant amends the claims (in either the parent or the divisional application) so as to change the claimed invention.
Selections – June 2016
A selection, as the term is used in patent law, rests on the idea that if a disclosure has provided a general description of an invention (e.g. a genus), it may be that certain things falling within the scope of the general teachings can nevertheless be considered to be different inventions (e.g. a species of the genus). These further inventions must be based on the disclosure of substantial advantages not disclosed by the inventors of the broad invention.
The three conditions that must be satisfied for a patentable selection are that:
- (i) the selection be based on some substantial advantage;
- (ii) the whole of the selection must possess the advantage; and
- (iii) the advantage must be in respect of a quality of a special character peculiar to the whole selection. Footnote 95
It is important to note that the advantage (which can include avoiding a substantial disadvantage) must be in comparison to the overall group from which the selection has been made, and be made on the basis of sufficient representative testing and not simply be a comparison to a few isolated members of the overall group. Footnote 96
It should be remembered that in assessing whether an alleged selection is patentable, the patentability of a claim must also be assessed against the usual requirements (novelty, utility, ingenuity, sufficiency of disclosure, etc.) Footnote 97
A newly discovered, substantial advantage is necessary to provide the utility and inventive step to the selection for patentability to be acknowledged. Footnote 98 Although there is no special or higher disclosure burden for a selection in comparison with any other type of invention, the advantage must be properly disclosed for there to be an invention Footnote 99 and, if unclear, the new utility arising from the advantage must also be disclosed. If there is no way to assess the purported "advantage", there is no way for the person skilled in the art to appreciate that an invention has been "correctly and fully" described. An inventor "has in truth disclosed no invention whatever if he merely says that the selected group possesses the advantages. Apart altogether from the question of what is called sufficiency, he must disclose an invention; he fails to do this in the case of a selection for special characteristics, if he does not adequately define them." Footnote 100
A purported selection whose utility has not been established, by demonstration or sound prediction [see Chapter 12 of this manual], is necessarily not an invention. Establishing that there is, in fact, an advantage requires that some point of reference be disclosed. Mere statements that a certain embodiment of an identified group is "preferred" or possesses an otherwise unspecified advantage, benefit or improved property are not sufficient to adequately disclose the substantial advantage necessary to establish inventive selection. Footnote 101
The ingenuity of the alleged selection involves a consideration of whether "a particular member or group within [the earlier disclosed] class [has] the same or different properties, and, if different, how different?". Footnote 102 Its novelty rests on the fact that the selected aspects of the prior disclosure had not previously been made: per Maughan J. in I.G. Farbenindustrie, "[i]t must be remembered, of course, that the selected compounds have not been made before, or the patent would fail for want of novelty". Footnote 103
If an operating embodiment within the selection claim has already been made, the advantages of the invention have already been made available and the claimed invention is anticipated. If something within the selection claim was merely listed in the prior document, however, without disclosing the advantage upon which the selection is based, the requirement for prior disclosure is not met and there is no anticipation.
Where a purported selection is not anticipated, it may nevertheless be found to be obvious. The assessment of the obviousness of a selection may in some cases be directly assessed by a consideration of whether the alleged advantage is truly unexpected, but may also arise (particularly in the chemical arts) in the context of an obvious to try analysis Footnote 104 [see 15.02.03].
An application discloses that it is known to raise sunken ships by pumping a plurality of buoyant bodies through a tube into the ship, and that in the past this had been done by pumping hollow spheres into the ship. The application discloses the use, in particular, of tetrahedral bodies, whose greater packing density increases the effectiveness of the method.
A search of the prior art reveals the use of buoyant bodies to raise sunken ships, but does not indicate the particulars of the shape of said bodies. One piece of prior art appears to illustrate spherical bodies for this purpose.
A method for raising a sunken ship, the method comprising the steps of: 1) establishing a conduit between a surface pump and the sunken ship, 2) pumping a plurality of generally tetrahedral shaped buoyant bodies into the ship via the conduit.
Analysis: The prior art teaches the use of buoyant bodies in general, but it appears that only spherical shapes were specifically used. The application teaches that tetrahedral bodies have a substantially higher packing factor than spherical bodies and achieve better packing efficiencies than those of rectilinear or curvilinear bodies. The result of using tetrahedral bodies enables greater packing into a sunken ship and thus higher maximum buoyancy as well as substantially greater retention of the buoyant bodies in the ship (i.e., loss prevention). Given the disclosure of an advantage specific to the use of tetrahedral bodies, it appears their use could be approached as a potential selection from among the generic means "buoyant bodies". Since no prior disclosure of the use of tetrahedra exists, novelty can be acknowledged. The obviousness of claim 1 would have to be evaluated to determine whether the selection of tetrahedra in particular from "buoyant bodies" in general leads to an unexpected benefit such that an inventive step could be acknowledged.
Provisos – June 2016
Where an applicant is aware of relevant prior art at the time of filing, or becomes aware of relevant prior art during prosecution, they may choose to amend their claim in order to exclude certain embodiments disclosed in the prior art.
One method for excluding known subject-matter is by a proviso; a statement that provides that the claim does not include some specified matter. The term proviso is used herein to refer to any such exclusionary limitation, regardless of the precise language used to express it (e.g. an attachment means, provided said attachment means is not a rubber-based adhesive; a straight chain alkyl group other than an ethyl or propyl group; a non-field effect transistor).
A proviso based on a prior art disclosure may be introduced to an application in order to establish novelty. To comply with subsection 38.2(2) of the Patent Act the proviso should not introduce new matter (e.g. by broadening the claim outside what was reasonably inferable from the original specification).
A proviso may be used to establish novelty, or inventive step over the prior art. When introduced as an amendment, a proviso that excludes a feature that was not necessarily present in the original claim should be very carefully considered, since the newly-identified feature is presumably not required for the proper operation of the claimed subject-matter.
In general, a proviso will therefore render a claim patentable where the broad claim would have been considered novel and inventive if it were not for an isolated earlier disclosure of something within the claim. A broad product claim might, for example, be anticipated by a specific product suitable for the same purpose as that taught by the applicant, but which was disclosed in the earlier document for a different use. Excluding the specific product might render the remaining subject-matter of the claim novel. Depending on the relationship between the two uses, the proviso might be sufficient to also render the amended claim unobvious.
Where a claim is amended to include a number of provisos to establish novelty and inventiveness, a greater level of scrutiny is necessary to ensure that the remaining subject-matter is still a single invention, and that the nature of the invention described in the original application has not been obscured or changed (e.g. by defining the invention solely in terms of what it is not, rather than what it is).
An application describes the therapeutic effectiveness of a class of compounds which have, in common, structural element A. Prior art application D1 discloses compound X as a useful drug in the therapy of disease Y, X comprises structural element A. Subsequent to the publication of D1, the applicant found that A is an element essential to the effective treatment of disease Y in the class of compounds.
- A compound having <structural element A> for use in treating disease Y.
- A compound having <structural element A> for use in treating disease Y, provided said compound is not compound X.
Analysis: Claim 1 is anticipated by D1 because compound X has established utility as an effective treatment for Y and comprises structural element A.
Claim 2 is not anticipated by D1 as the proviso removes the applicability of D1 by tying the effective treatment to previously unknown importance of element A in said treatment.
Having been deemed novel in view of the proviso, the inventive concept of claim 2 would require additional analysis to determine inventiveness in view of the common general knowledge at the claim date.
Information regarding unity and provisos can be found in subsection 14.08.07 of this manual.
Endnotes for Chapter 15
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