Note: Descriptions are shown in the official language in which they were submitted.
SELECTABLE CONTROL FOR HIGH INTENSITY LED ILLUMINATION SYSTEM
TO MAINTAIN CONSTANT COLOR TEMPERATURE
[0001]
BACKGROUND
[0002] Entertainment facilities such as stadiums, arenas and concert halls
seek ways
to offer unique experiences with lighting and special effects. However, the
current methods
of providing such effects through lighting have been limited because of the
manual
operation required to change colors, intensities and positions associated with
overhead light
fixtures. In addition, the ability to rapidly change lighting effects is
limited due to the
significant amount of time that it takes to start and illuminate high
intensity discharge
fixtures, such as high intensity discharge lamps. Further, because of the
amount of light
required to be emitted by many stadium lights, the lights may require a
significant amount of
energy and may generate a substantial amount of heat.
[0003] In addition, some facilities desire the maintenance of certain
characteristics of
light, such as intensity or color temperature. In certain facilities such as
stadiums and sports
arenas, the events that occur in the arena have very specific lighting
specifications. For
example, a hockey league may require relatively cool light of a color
temperature of
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approximately 5500K, while a concert may desire a slightly warmer light of a
color
temperature of approximately 4000K. It is very expensive for facilities to
maintain a variety
of light fixtures to meet all of these specifications.
[0004] This document describes new illumination devices and control systems
that
are directed to solving the issues described above, and/or other problems.
SUMMARY
[0005] In an embodiment, a lighting system includes a group of light emitting
diode
(LED) illumination devices, each of which includes a first group of LEDs of a
first color
temperature and a second group of LEDs of a second color temperature. The
system also
includes illumination device drivers, wherein each illumination device driver
is configured
to control a corresponding LED illumination device. One or more sensors are
configured to
measure a characteristic of light received from the illumination devices in an
area of an
environment that is illuminated by the devices. A wireless transmitter may be
electrically
connected to the sensor and configured to transmit measurements detected by
the sensor. A
controller may include a processor and programming instructions on a computer-
readable
medium (i.e., as software or firmware) that are configured to cause the
processor to detect
when a value of the measured light characteristic received by a sensor
deviates from a
desired value. In response to detecting that the value of the measured light
characteristic
deviates from the desired value, the controller will generate commands to
cause the device
drivers for each of the LED illumination devices to control the first group of
LEDs and the
second group of LEDs in its corresponding illumination device so that the
desired color
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temperature of light will be received at the location of the sensor while
maintaining a
substantially constant illuminance level at the location.
[0006] The commands that cause the device drivers to control the first group
of
LEDs and the second group of LEDs in each illumination device so that the
desired color
temperature of light will be received at the location may include instructions
to increase the
drive current delivered to the first group of LEDs and decrease the drive
current delivered to
the second group of LEDs in each illumination device. The commands that cause
the device
drivers to control the first group of LEDs and the second group of LEDs so
that the
illuminance level remains substantially constant may include commands to: (i)
automatically
reduce the brightness of one of the groups of LEDs by decreasing a width of
voltage pulses
applied to that group of LEDs or increasing spacing between voltage pulses
applied to that
group of LEDs; and (ii) automatically increase the brightness of the other
group of LEDs by
increasing a width of voltage pulses applied to that group of LEDs or
decreasing spacing
between voltage pulses applied to that group of LEDs.
[0007] If the sensors include a light intensity sensor, then when a value of
measured
light intensity exceeds a threshold, the device drivers may reduce the
brightness of a group
of the LEDs by decreasing a width of voltage pulses applied to the group of
LEDs or
increasing spacing between voltage pulses applie9 to the group of LEDs to
maintain an
illuminance level at the location within the threshold. When the value of
measured light
intensity is below the threshold, the device drivers may automatically
increase the brightness
of a group of the LEDs by increasing a width of voltage pulses applied to the
group of LEDs
or by decreasing spacing between voltage pulses applied to the group of LEDs
to maintain
the illuminance level at the location within the threshold.
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[0008] If the sensor(s) include a color temperature sensor, then when a value
of color
temperature detected by the sensor has moved above or below a threshold, the
system may
control drive currents delivered to the first group of LEDs and the second
group of LEDs so
that the light detected by the sensor at the location will exhibit a color
temperature that is
within the threshold. To maintain the substantially constant illuminance level
at the
location, the system may reduce the brightness of one of the groups of LEDs by
decreasing a
width of voltage pulses applied to that group of LEDs or increasing spacing
between voltage
pulses applied to that group of LEDs, and it may increase the brightness of
the other group
of LEDs by increasing a width of voltage pulses applied to that group of LEDs
or decreasing
spacing between voltage pulses applied to that group of LEDs.
[0009] If the sensor(s) include a Du, sensor, then when the value of Duv
detected by
the sensor has moved above or below a threshold, the system may control drive
currents
delivered to the first group of LEDs and the second group of LEDs so that the
light emitted
by all of the LEDs will exhibit a Duv that is within the threshold. To
maintain the
substantially constant illuminance level at the location, the system may again
reduce the
brightness of one of the group of LEDs by decreasing a width of voltage pulses
applied to
that groups of LEDs or increasing spacing between voltage pulses applied to
that group of
LEDs, and it may increase the brightness of the other group of LEDs by
increasing a width
of voltage pulses applied to that group of LEDs or decreasing spacing between
voltage
pulses applied to that group of LEDs.
[0010] In another embodiment, a lighting system includes a group of light
emitting
diode (LED) illumination devices. Optionally, each illumination device may
include a first
group of LEDs of a first color temperature, a second group of LEDs of a second
color
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temperature, and device driver. The system also includes a user interface
comprising one or
more user input structures, and a controller comprising a processor and a non-
transitory
memory containing programming. The programming is configured to cause the
processor to
receive a selection of a scene from the user interface. The scene corresponds
to a
requirement to direct light of a specified color temperature and illuminance
level to a
location. The programming causes the processor to identify a set of the
illumination devices
that correspond to the scene, and to generate commands to cause the device
drivers for each
of the identified illumination devices to control its corresponding
illumination device so that
the specified color temperature and illuminance level of light will be
received at the
location. The controller will transmit the commands to the device drivers for
the
illumination devices that correspond to the scene.
[0011] Optionally, when generating the commands, the system may identify a
drive
current for each group of LEDs, and it may include the identified drive
current for each
group in the group's command so that the device emits light at the
substantially constant
illuminance level. For example, the device drivers may control the identified
illumination
devices so that the specified color temperature of light will be received at
the location by
increasing the drive current delivered to the first group of LEDs and
decreasing the drive
current delivered to the second group of LEDs in each illumination device that
corresponds
to the scene. To control the identified illumination devices so that the
specified illuminance
level of light is received at the location, the device drivers may
automatically reduce the
brightness of one of the groups of LEDs by decreasing a width of voltage
pulses applied to
that group of LEDs or increasing spacing between voltage pulses applied to one
group of
LEDs, and increasing the brightness of the other group of LEDs by increasing a
width of
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voltage pulses applied to that group of LEDs or decreasing spacing between
voltage pulses
applied to that other group of LEDs.
[0012] Optionally, to identify the group of LED illumination devices that
correspond
to the selected scene, the system may access a data storage facility
comprising sets of scene
data, retrieve a set of scene data that corresponds to the selected scene, and
extract an
identification of the group of LED devices that correspond to the selected
scene from the
retrieved set of scene data.
[0013] The system also may include a color termperature sensor positioned in
the
lighting environment, and programming that is configured to cause the
controller to perform
a calibration event for a zone in which the sensor is located. To perform the
calibration
event, the controller may receive color temperature data from the sensor and
compare the
received color temperature data to a desired color temperature. The controller
may then
command one or more device drivers for one or more illumination devices
associated with
the sensor's zone to increase a drive current to a first group of the LEDs in
each illumination
device associated with the zone and decrease a drive current to a second group
of the LEDs
in each illumination device associated with the zone until the sensor detects
the desired color
temperature in the zone. When the sensor detects the desired color
temperature, the system
may store the drive currents that are then in effect to a data set for the
scene.
[0014] In addition or alternatively, the system may include a light intensity
sensor in
the environment. If so, the when performing the calibration event the system
may receive
light intensity data from the sensor and compare the received light intensity
data to a desired
intensity level. The system may then command one or more device drivers for
one or more
illumination devices associated with the sensor's zone to use pulse width
modulation to alter
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brightness of light produced by LEDs in each illumination device associated
with the zone
until the sensor detects the desired intensity level in the zone. When the
sensor detects the
desired intensity level, the system may store PWM settings that are then in
effect to a data
set for the scene.
[0015] Optionally, the sensor or sensors may be attached to a robotic
transport
device. The device may rotate the sensors to collect light characteristic data
from multiple
angles with respect to a surface, such as a playing surface, stage or the
ground.
[0016] In another embodiment, a light fixture includes a light emitting diode
(LED)
structure, a housing with one or more sensors, and control circuitry that is
configured to
receive data from the sensor and automatically alter characteristics of light
emitted by the
LEDs in the fixture in response to the received data. Optionally, the light
fixture may
include an opening that receives and secures the LED structure, a body portion
that provides
a heat sink for the LED structure, and/or a power supply that is secured to an
area of the
body portion that is distal from the LED structure. The sensor (which may be a
single
sensor or multiple sensors) will be configured to sense a characteristic of
light in a vicinity
of the LED structure. Optionally, the sensor may be housed in a sensor
compartment, and
the light fixture may include a reflecting structure that is positioned to
reflect light emitted
by the LEDs toward the sensor. The control card may contain control circuitry
that is
configured to receive data from the sensor and automatically alter a
characteristic of light
emitted by one or more of the LEDs in response to the received data.
[0017] For example, if the sensor includes a light intensity sensor, the
control
circuitry may be programmed so that when the control circuitry receives data
from the light
intensity sensor indicating that light intensity is above a threshold, the
control circuitry will
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automatically reduce the brightness of a group of the LEDs by decreasing a
width of voltage
pulses applied to the group of LEDs or increasing spacing between voltage
pulses applied to
the group of LEDs to maintain the ambient light level within the desired
range. When the
control circuitry receives data from the light sensor indicating that the
light intensity is
below a threshold, the control circuitry may automatically increase the
brightness of a group
of the LEDs by increasing a width of voltage pulses applied to the group of
LEDs or
decreasing spacing between voltage pulses applied to the group of LEDs to
maintain the
ambient light level within the desired range.
[00181 If the sensor includes a color temperature sensor, and if the LEDs of
the light
fixture include a first group of LEDs that exhibit a first color temperature
and a second
group of LEDs that exhibit a second color temperature, then the control
circuitry may be
programmed so that when the control circuitry receives data from the sensor
indicating that
detected color temperature has moved above or below a threshold, the control
circuitry will
generate commands to control drive currents delivered to the first group of
LEDs and the
second group of LEDs so that the light emitted by the light fixture will
exhibit a color
temperature that is within the threshold. The commands also may include
commands to
control the first group of LEDs and the second group of LEDs so that the
illuminance level
of the light detected by the sensor will not substantially change when the
drive currents
change in response to the commands. The commands to control the first group of
LEDs and
the second group of LEDs so that the illuminance level of the light detected
by the sensor
will not substantially change when the drive currents change may include
commands to: (i)
automatically reduce the brightness of one of the group of LEDs by decreasing
a width of
voltage pulses applied to that group of LEDs or increasing spacing between
voltage pulses
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applied to that group of LEDs; and (ii) automatically increase the brightness
of the other
group of LEDs by increasing a width of voltage pulses applied to that group of
LEDs or
decreasing spacing between voltage pulses applied to that group of LEDs.
[0019] As another example, if the sensor includes a Du, sensor, and if the
plurality of
LEDs include a first group of LEDs that exhibit a first color temperature and
a second group
of LEDs that exhibit a second color temperature, then the control circuitry
may be
programmed so that when the control circuitry receives data from the sensor
indicating that
detected Du, has moved above or below a threshold, the control circuitry will
generate
commands to control drive currents delivered to the first group of LEDs and
the second
group of LEDs so that the light emitted by the light fixture will exhibit a
Du, that is within
the threshold. The commands also may include commands to control the first
group of
LEDs and the second group of LEDs so that the illuminance level of the light
detected by
the sensor will not substantially change when the drive currents change in
response to the
commands. The commands to control the first group of LEDs and the second group
of
LEDs so that the illuminance level of the light detected by the sensor will
not substantially
change when the drive currents change may include commands to: (i)
automatically reduce
the brightness of one of the group of LEDs by decreasing a width of voltage
pulses applied
to that group of LEDs or increasing spacing between voltage pulses applied to
that group of
LEDs; and (2) automatically increase the brightness of the other group of LEDs
by
increasing a width of voltage pulses applied to that group of LEDs or
decreasing spacing
between voltage pulses applied to that group of LEDs.
[0020] Optionally, the light fixture also may include an ambient air
temperature
sensor. If so, then the control circuitry may be programmed so that when the
control
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circuitry receives data from the ambient air temperature sensor indicating
that ambient air
temperature is above a threshold, the control circuitry will automatically
alter a
characteristic of light emitted by one or more of the LEDs in response to the
received
ambient air temperature.
[0021] In some embodiments, the opening of the light fixture may be circular.
The
LED structure may be positioned and shaped to form a ring structure in the
opening around
a central area, and the sensor may be contained in a sensor compartment
positioned in a
central area of the opening.
[0022] Optionally, the light fixture also may include a power sensor that is
configured to measure voltage across a group of the LEDs; and the control
circuitry may be
programmed so that, when it receives data from the power sensor indicating
that the voltage
across the group of LEDs has changed by at least a threshold amount, it causes
current
delivered to the group of LEDs to change to maintain light emitted by the
remaining LEDs
in the group at a desired illuminance level.
BRIEF DESCRIPTION OF 111E DRAWINGS
100231 FIG. 1 illustrates an example of a lighting system and control devices
for
such a system.
[0024] FIG. 2 illustrates a front view of an example of one embodiment of an
illumination device that may be used with the system disclosed in this
document.
[0025] FIG. 3A illustrates a perspective view from a first side of the device
of FIG.
2, while FIG 3B illustrates a perspective view of the device from a second
side.
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[0026] FIG. 4 illustrates a perspective view of the device of FIG. 1 with the
power
supply detached from the unit.
[0027] FIG. 5 illustrates a top view of the device of FIG. 1, and shows an
embodiment of the housing's fins that provide a heat sink effect.
[0028] FIGs. 6A and 68 illustrate an example of a heat sink body portion.
[0029] FIG. 7 illustrates an embodiment of a clamshell-type housing for a body
portion of the device of FIG. 1.
[0030] FIG. 8 illustrates how a body portion of the device of FIG. 1 may
receive a
portion of a light emitting diode (LED) array structure.
[0031] FIG. 9 illustrates an embodiment of the device with an expanded view of
an
LED module.
[0032] FIGs. 10A and 10B illustrate a lens cover for an LED module.
[0033] FIG. 11 illustrates an example of an LED array on a substrate, with a
control
card.
[0034] FIGs. 12A and 12B illustrate data that may be used for color tuning of
an
LED lighting device.
[0035] FIG. 13 illustrates an example of a user interface device.
[0036] FIG. 14 illustrates example components that may receive signals and
selectively control LED groups.
[0037] FIG. 15 illustrates example components of an electronic device that may
implement a user interface.
[0038] FIG. 16 illustrates an example of an environment in which lighting
devices
and sensors may be used in the context of various embodiments.
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DETAILED DESCRIPTION
[00391 As used in this document, the singular forms "a," "an," and "the"
include
plural references unless the context clearly dictates otherwise. Unless
defined otherwise, all
technical and scientific terms used herein have the same meanings as commonly
understood
by one of ordinary skill in the art. As used in this document, the term
"comprising" means
"including, but not limited to."
[00401 When used in this document, the terms "upper" and "lower," as well as
"vertical" and "horizontal," are not intended to have absolute orientations
but are instead
intended to describe relative positions of various components with respect to
each other. For
example, a first component may be an "upper" component and a second component
may be
a "lower" component when a light fixture is oriented in a first direction. The
relative
orientations of the components may be reversed, or the components may be on
the same
plane, if the orientation of a light fixture that contains the components is
changed. The
claims are intended to include all orientations of a device containing such
components.
100411 FIG. 1 illustrates a lighting system in which any number of lighting
devices
10a, 10b, 10c are positioned at various locations in an environment, such as a
wall, ceiling,
mast, tower or other supporting structure in a stadium, arena, concert hall,
outdoor
amphitheater or other entertainment facility or other location. Each
illumination device may
include a number of light emitting diodes (LEDs), and in various embodiments a
number of
LEDs sufficient to provide a high intensity LED device. Each illumination
device may
include or be connected to a device controller 210(a), 210(b), 210(c) that
includes wiring
and circuitry to supply power and/or control signals to one or more lights. A
device
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controller may be an external device, or an integral device that includes
various components
of an illumination device's control card. Each device controller 210(a),
210(b), 210(c) may
include a receiver that receives wireless signals from one or more
transmitters. The
transmitters may be included in, for example, one or more user interface
devices 202.
[0042] Each interface device 202 may include selectable user inputs,
programming,
a processor or circuitry, and a transmitter for transmitting command signals
to the various
illumination devices. For example, the user inputs may include inputs to turn
certain lights
in a certain zone of an environment on or off, in which case the interface
device will
generate and send signals with encoded data that instruct the zone's lights to
turn on and off.
The user inputs also may include brightness level adjustments for one or more
zones and/or
lights, or scenes that are designed to set various lighting devices at various
brightness levels.
Each user input command will cause the user interface device to send a signal
that includes
data indicating which illumination devices should be operated by the signal.
When a control
device detects a signal that is intended for its illumination device, it will
cause its
illumination device to execute the command that corresponds to the control
signal.
[0043] In addition, any number of external light sensors 205a ¨ 205n may be
positioned at a location or multiple locations in an environment, such as a
stadium playing
field, a stage in a concert hall, or a court/floor/ice rink in an area, to
detect the intensity of
light. The external light sensors may include transmitters that send status
information and/or
commands to any or all of the illumination device controllers and/or the
interface device.
For example, a particular illumination device controller 210c may be
programmed to detect
signals from a particular sensor 205a that is positioned in an area at which
the controller's
corresponding light fixture 10c directs light. The sensor may sense light
intensity, color
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temperature and/or color rendering index (CRI) in its vicinity and transmit
intensity data to
the device controller 210c. The device controller 210c may be programmed to
increase the
LED device's 10c brightness if the local intensity data is less than a
threshold, or it may
decrease the LED device's 10c brightness if the local intensity data is
greater than a
threshold. As described above, the controller may do this by increasing or
decreasing the
frequency of "on" signals that cycle the LEDs on and off by PWM.
Alternatively, the
sensor 205a itself may include programming and electronics that cause it to
send a
command to the controller 210c, such as an increase brightness command if
local intensity is
less than a threshold level or a decrease brightness command if local
intensity is greater than
a threshold level.
[0044] It is intended that the portions of this disclosure describing LED
modules and
control systems and methods may include various types of devices. For example,
the LED
modules, control systems and control methods may include those disclosed in
International
Patent Application No. PCT/US2012/069442, filed September 13, 2012 by Nolan et
al., the
disclosure of which is incorporated herein by reference in its entirety. FIG.
2 illustrates a
front view of an example of one embodiment of an illumination device that may
be used
with this system. FIGs. 3A and 3B illustrate perspective views from opposite
sides of the
device of FIG. 2. The illumination device 10 includes a housing 25 that
encases various
components of a light fixture. The housing 25 includes an opening in which a
set of light
emitting diode (LED) array modules 11 ¨ 14 are secured to form a multi-array
LED
structure 18. The LED array modules 11 ¨ 14 are positioned to emit light away
from the
fixture. The opening also provides a sensor compartment 15, which may be
enclosed, open
or partially open, and via which one or more sensors may detect information
about the
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environment exterior to the device. The sensors may include sensors that
detect light,
ambient temperature, color temperature or other properties of the ambient area
in front of the
LED array modules 11 ¨ 14. Optionally, the sensor compartment 15 may be fully
enclosed
in a housing to protect the sensors from rain and dust, or at least some of
the compartment
may include an opening to ambient air. Optionally, some or all of the sensors
may be
positioned in the LED modules instead of or in addition to the sensor
compartment.
[0045] Optionally, the fixture may include one or more reflectors 19, such as
mirrors or other reflective substrates, positioned and angled to reflect some
of the light
emitted by the LED modules tward the sensor compartment 15. The reflectors 19
are
reflective structures that may be attached to the housing 25, the shroud 29
(described
below), any of the LED modules 11-14, or any other suitable component of the
fixtures. In
this way, the sensor(s) may be positioned at or near the same plane as the
LEDs, rather than
substantially above the plane.
[0046] The opening of the housing 25 may be circular as shown, with the sensor
compartment 15 for the sensors positioned at the center of the circle and the
LED array
modules 11 - 14 positioned around the central open section to form a ring-
shaped overall
LED structure, although other shapes and configurations are possible. The LED
arrays 11-
14 may include four arrays, each of which is positioned in a quadrant of the
circle as shown.
Alternatively, any other number of LED array modules, such as one, two, three,
five or more
LED array modules, may be positioned within the opening in any configuration.
[0047] The device's housing 25 includes a body portion 27 and an optional
shroud
portion 29. The body portion 27 serves as a heat sink that dissipates heat
that is generated
by the LED arrays. The body / heat sink 27 may be formed of aluminum and/or
other metal,
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plastic or other material, and it may include any number of fins 22a... 22n on
the exterior
to increase its surface area that will contact a surrounding cooling medium
(typically, air).
Thus, the body portion 27 may have a bowl shape (i.e., semi-hemishpherical) as
shown, the
LED array structure 18 may fit within the opening of the bowl, and heat from
the LED array
modules 11 ¨ 14 may be drawn away from the array and dissipated via the fins
22a. . .22n
on the exterior of the bowl. In addition, the housing may include a shroud 29
that extends
from the body 27 and beyond the LED array module. The shroud may be semi-
circular in
shape when the multi-array LED structure is circular, and it may be angled or
shaped to
shield an upper portion of the light assembly from rain while directing,
focusing and/or
reflecting light so that the light is concentrated in a desired direction
(e.g., downward).
100481 The body 27 may be formed as a single piece, or it may be formed of two
pieces that fit together as in a clamshell-type structure as shown. In a
clamshell design, a
portion of the interior wall of the clamshell near its opening may include a
groove, ridge, or
other supporting structure that is configured to receive and secure the LED
structure in the
opening when the clamshell is closed. In addition, the fins 22a. . .22n may be
curved or
arced as shown, with the base of each fin's curve/arc positioned proximate the
opening/LED
modules, and the apex of each fin's curve/arc positioned distal from the
opening/LED
modules to further help draw heat away from the LED modules.
[0049] Typically, any openings of the housing 25 will be sealed with a
weatherproofing material such as rubber or silicone. In addition, the housing
may include a
shroud 29 that extends from the body 27 and beyond the LED modules. The shroud
may be
semi-circular in shape when the multi-module LED structure is circular, and it
may be
angled or shaped to shield an upper portion of the light assembly from rain
while directing,
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focusing and/or reflecting light so that the light is concentrated in a
desired direction (e.g.,
downward). In this way, the housing 25 may provide a dust-resistant and water-
resistant
housing that protects electronic components of the illumination device. This
may be
sufficient to meet the standards required to provide a National Electrical
Manufacturers
Association (NEMA) type 1 or type 2 enclosure. For outdoor installations, the
housing may
sealed to provide a NEMA type 3 enclosure.
[00501 While the LED array is positioned at one side of the body 27, the
opposing
side of the body may include a power supply 30. The power supply 30 may
include a
battery, solar panel, or circuitry to receive power from an external and/or
other internal
source. As shown, the external housing of the power supply 30 also may include
fins to help
dissipate heat from the power supply. Power wiring may be positioned within
the body 27
to direct power from the power supply 30 to the LED array modules 11-14. The
power
supply 30 may extend from the rear of the housing as shown, or it may be
placed into the
housing so that it is flush or substantially flush with the rear of the
housing 25, or it may be
configured to extend to some point between being flush with the housing 25 and
the
extended position of the configuration shown in FIGs. 3A and 3B.
[00511 The housing may be attached to a support structure 40, such as a base
or
mounting yoke, optionally by one or more connectors 41. As shown, the
connectors 41 may
include axles about which the housing and/or support structure may be rotated
to enable the
light assembly to be positioned to direct light at a desired angle.
[00521 FIG. 3B helps to illustrate components of the lighting device that can,
in
some embodiments, have self-cooling effects through its use of a sensor
opening 15 in the
front of the bowl (which is otherwise covered by the LED structure). When the
LED array
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operates, heat generated by the LEDs will rise and dissipate through the heat
sink, creating a
negative pressure that may draw cool ambient air into the housing via an
opening near the
sensor compartment 15. This chimney effect helps keep the LED array structure
unit cool
during operation. FIG. 3B also illustrates that the shroud 29 may have a
variable width so
that an upper portion positioned at the top of LED structure 18 is wider than
a lower portion
positioned at the bottom of the LED structure. This helps to reduce the amount
of light
wasted to the atmosphere by reflecting and redirecting stray light downward to
the intended
illumination surface..
[0053] As shown in FIG. 4, the power supply 30 may be detachable from the
lighting device's housing 25 so that it can be replaced and/or removed for
maintenance
without the need to remove the entire device from an installed location, or so
that it can be
remotely mounted to reduce weight. In addition, the power supply may include a
power
supply housing made of a set of fins 32a . . . 32n that are positioned
lengthwise along an
axis that extends away from the LED array when the power supply is installed
in the device.
The fins of the power supply housing thus provide an additional heat sink that
draws heat
away from the power supply during operation. The power supply housing and/or a
portion
of the lighting unit housing 25 may include one or more antennae, transceivers
or other
communication devices 34 that can receive control signals from an external
source. For
example, the illumination device may include a wireless receiver and an
antenna that is
configured to receive control signals via a wireless communication protocol.
Optionally, a
portion of the lighting unit housing 25 or shroud 29 may be equipped with an
attached laser
pointer that can be used to identify a distal point in an environment to which
the lighting
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device directs its light. The laser pointer can thus help with installation
and alignment of the
device to a desired focal point.
[0054] As shown in FIG. 4, the power supply 30 may be detachable from the
lighting device's housing 25 so that it can be replaced and/or removed for
maintenance
without the need to remove the entire device from an installed location, or so
that it can be
remotely mounted to reduce weight. In addition, the power supply may include a
power
supply housing made of a set of fins 32a ... 32n that are positioned
lengthwise along an
axis that extends away from the LED array when the power supply is installed
in the device.
The fins of the power supply housing thus provide an additional heat sink that
draws heat
away from the power supply during operation. The power supply housing and/or a
portion
of the lighting unit housing 25 may include one or more antennae, transceivers
or other
communication devices 34 that can receive control signals from an external
source. For
example, the illumination device may include a wireless receiver and an
antenna that is
configured to receive control signals via a wireless communication protocol.
Optionally, a
portion of the lighting unit housing 25 or shroud 29 may be equipped with an
attached laser
pointer that can be used to identify a distal point in an environment to which
the lighting
device directs its light. The laser pointer can thus help with installation
and alignment of the
device to a desired focal point.
[0055] FIG. 5 illustrates a top view of the device 10 and shows one embodiment
of
how the heat sink may help to keep the LED structure cool. In some embodiments
the
housing may be substantially or fully enclosed to provide a dome that receives
the LED
structure. In other embodiments, such as that shown in FIG. 5, the body
portion 27 of the
housing may be open so that the fins 22a ... 22n are positioned to extend away
from the
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shroud 29 at an angle that is substantially perpendicular to the axis of the
widest dimension
(i.e., supporting panels) of the LED structure and shroud's opening.
[0056] The fins 22a ... 22n may be positioned substantially vertically (i.e.,
lengthwise from a top portion of the LED array structure and shroud 29 to a
bottom portion
of the same). Optionally, one or more lateral supports 23a ... 23n may be
interconnected
with the fins to provide support to the housing. The lateral supports 23a ...
23n may be
positioned substantially parallel to the axis of the widest dimension of the
LED structure as
shown, or they may be curved to extend away from the LED structure, or they
may be
formed of any suitable shape and placed in any position. Each support may
connect two or
more of the fins. In this embodiment shown in FIG. 5, the fins and optional
supports 23a..
. 23n form the body portion 27 as a grate, and hot air may rise through the
spaces that exist
between the fins and supports of the grate. In addition, precipitation may
freely fall through
the openings of the grate. In addition, any small debris (such dust or bird
droppings) that is
caught in the grate may be washed away when precipitation next occurs.
[00571 FIG. 4 also shows that a thermal insulating structure 37 may be
positioned in
the body and may receive the power supply so that the power supply is secured
to the body
but thermally separated from the body. The thermal insulating structure 37 may
be a
structure that provides a barrier or wall, a plate, a ring that separates the
fins of the body
from those of the power supply, or any other suitable configuration. The
thermal insulating
structure may be made of any suitable insulating material, such as a ceramic
material. FIG.
also shows that the insulating structure 37 may have a central opening so that
the power
supply 30 may be received into the body 27 via a receptacle 35. The receptacle
35 may have
inner dimensions that are at least as large as those of the power supply's
housing. The
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receptacle and/or any portions of the body 27 may removably secure the power
supply 30 in
place by friction and/or by or more connectors such as clips, hooks, bolts or
other
connecting structures. For example, as shown in FIG. 6A, the body 27 may have
a number
of anchors 52a . . . 52n that receive and secure one or more connectors of the
power supply.
Returning to FIG. 5, the power supply 30 may include one or more plugs, wires
or other
connectors so that the supply can deliver power to the LED structure. Note
that the power
supply 30 is optional and need not be part of the lighting device. The
lighting device can be
connected to an external power source by one or more wires, plugs, busses or
other
conductors.
10058] The illustration of FIG. 6A also illustrates a cross section A-A. FIG.
6B
shows a side view of this cross section in a top half 27a of the body, with
the uppermost
portion of the body portion illustrated to the right in FIG. 6B, and the lower
section of the
body portion illustrated to the left in FIG. 6B. As illustrated in FIG. 6B,
the fins of the
cross-section sweep away from the LED structure 18, and form a cavity 29
within the body
to provide a heat sink. The rightmost portion 27a may be connected to a lower
body portion
as illustrated in FIG. 7. The fins and connecting structures of the body
portion 27 are made
of a durable yet lightweight material, such as aluminum, an aluminum alloy
such as A380 or
ADC12, or other materials.
[00591 FIG. 7 illustrates that the housing 27 may be formed of two or more
molded
sections 27a, 27b that fit together as a clamshell-type structure. Each
section 27a, 27b may
include one or more pins, receptacles, clips, or other receiving structures
that help align
and/or secure the sections together when positioned in place and connected to
the shroud
and/or power supply receptacle (shown in other Figures). The two sections 27a,
27b form a
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cavity 29 within the body when connected. FIG. 8 illustrates that each housing
section 27a
may form part of the opening in which the LED structure resides. Each LED
module of the
LED structure may include one or more conducting substrates 38 that serve to
hold the
LEDs in place and provide the primary cooling path to the LEDs. The substrates
may be
made of any support material (such as fiberglass or aluminum) with conductive
elements
(such as traces, bars or wires) placed thereon or therein to direct power to
the LEDs. FIG. 8
also illustrates an embodiment in which two LED modules form the LED
structure, and each
LED module is configured in a half-circle configuration. Thus, with a circular
opening, the
LED modules may be semi-circular in shape so that two, three, four or more of
them
together form a circle that fits within the opening.
[00601 FIG. 9 illustrates an embodiment of the device, with an expanded view
of one
of the LED array modules 12 of the LED structure 18. As shown, the module 12
includes a
conductive substrate 38 on which a number of LEDs 39 are positioned. The LEDs
39 may
be arranged in one or more rows, matrices, or other arrangements with
corresponding
components supported in place and/or spaced apart by supports. For example,
the LEDs
may form matrices of n x n LEDs, such as 4x4 or 8x8 matrices. Alternatively,
as shown in
FIG. 9, the LEDs in each module 12 may be positioned in curved rows so that
when all
modules are positioned within the opening, the LED structure 18 comprises
concentric rings
of LEDs. The substrate 38 may include a portion that is a printed circuit
board. Driver
circuitry on the circuit board may deliver current to the LEDs, and the LED
array modules
may include multi-wire connectors with prongs and/or receptacles for
connecting to external
conductors and/or signal wires, or other LED array modules. A lens cover 41
may be
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positioned over the substrate 38 to protect the substrate 38 and LEDs 39 from
the ambient
elements, as well as to focus and/or direct light emitted by the LEDs 39.
[00611 FIGs. 10A and 10B illustrate an underside of an embodiment of a lens
cover
41. As shown, the lens cover 41 includes a set of lenses 45a. . . 45n, each of
which is
positioned to fit over an LED that has been placed on the substrate. The LEDs,
and thus the
lenses, may form an array. Optionally, more than one LED may share a lens. The
spacing
of LEDs (and thus the lenses) with respect to each other may vary based on the
size of the
LEDs. As shown in FIG. 1013, each lens 45a. . . 45n may be dome-shaped, with
the apex of
each dome being flat or concave to receive light from the corresponding LED,
and the larger
part of each dome being positioned on the outer side the cover to direct the
light. The
standoff and slope of each dome may vary depending on the desired beam angle
that is to be
achieved by the lighting device. For example, a lighting system may be
provided with
domes of at least six different shapes to correspond to various beam limiting
(collimating)
standards. Alternatively, the LEDs may be domeless and/or equipped with other
lens
structures.
[0062] FIGs. 10A and 10B illustrate an optional area of the lens cover 41 on
which
no lenses appear. This may be the case of a portion of the lens cover 41
covers an area of
the substrate that contains no LEDs, or in areas where no lenses are desired
to be positioned
over the LEDs. For example, the substrate may include a printed circuit board
that provides
control functions. If so, then the lens cover 41 will not need to include
lenses in that area,
and it may instead simply be a solid cover over those portions of the
substrate.
Alternatively, one or more LEDs may be equipped with no domes over the LEDs so
that the
beam is not limited, or one or more LEDs may be equipped with a channel 47
that serves as
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CA 02875013 2014-12-17
a collimator to focus the beam of light from its associated LED. In addition,
LEDs are
normally manufactured with a primary lens. In some embodiments, the dome
lenses 45a...
45n may be added as secondary lens structures over the LEDs' primary lenses.
In other
embodiments, LEDs with no primary lens may be used, in which case the dome
lenses 45a.
.. 45n may serve as the only lens for one or more of the LEDs. When dome
lenses 45a...
45n are used, they may be spaced apart from each other, adjacent to each other
as shown in
FIGs. 10A and 10B, configured so that their bases slightly overlap, or in any
combination of
such positioning options. In situations where the bases overlap, a small
amount of overlap
may be selected to help reduce glare from the LED assembly during operation.
The amount
of overlap may be any suitable amount, such as approximately 2% of the base
area of each
dome, approximately 3% of the base area of each dome. approximately 5% of the
base area
of each dome, approximate 7% of the base area of each dome, approximately 10%
of the
base area of each dome, any range between the percentages listed above, or
other
percentages.
[0063] FIG. 11 illustrates an example of a portion of an LED array module 134.
The
LED array module includes any number of LEDs 164. The LEDs may be arranged in
rows,
matrices, or other arrangements with corresponding components supported in
place and/or
spaced apart to form modules of any number of LEDs. The LEDs may be arranged
and
mounted on a circuit board 160. Driver circuitry on the circuit board 160 may
deliver
current to the LEDs, and the LED array modules may include multi-wire
connectors with
prongs and/or receptacles for connecting to external conductors and/or signal
wires, or other
LED array modules.
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[0064] One or more circuit control cards 55 may be positioned under, adjacent
to
or otherwise near the LED array modules to provide power to the LEDs. The LEDs
to
which power is supplied may be selectively controlled by control circuitry
such as that
described below in this document. The control card may include a supporting
substrate
made of a material such as fiberglass, and a non-transitory computable-
readable memory for
storing programming instructions and/or monitored data and/or operational
history data, one
or more processors, a field programmable gate array (FPGA), application
specific integrated
circuit (ASIC) or other integrated circuit structures, and a received for
receiving control
signals from an external transmitter. The LED array assembly 134 and control
card 55 may
be placed within an opening of one end of the housing body.
[0065] The circuitry of the control card 55 and or the LED array module 134
may
operate to maintain a constant current draw across the LEDs and automatically
adjust the
intensity of the emitted light in response to feedback collected by the
sensors. For example,
each LED array module 134 may be arranged so that groups of LEDs are
electrically
connected in series. Each group may be served by a programmable system on a
chip (SoC)
174 which serves to receive a command from telemetry and send duty cycle
information to
multiple strings of LEDs.
[0066] Under ordinary operation, the system may include one or more power
supplies, each of which applies a default direct current (DC) voltage (e.g.,
36 volts or 48
volts) to an LED group, and each LED in any given group may have a constant
voltage drop
across it. Each string of LEDs may comprise a set of LEDs connected in series,
so that the
string maintains the circuit if one bulb should fail. The system may include
sensors that
monitor current and/or voltage drop across each series, or across individual
LEDs in a series.
CA 02875013 2014-12-17
If the values monitored by these sensors change, it may indicate that one or
more LEDs in a
string has failed. For example, if string includes five bulbs connected in
parallel, each of
which is rated at 2 amps (A) each, an applied current of 10A will be divided
equally across
each bulb. If one bulb fails, the hardware may maintain the circuit, and the
voltage drop
across the string may occur, thus changing the intensity of light output by
the device
[90671 To protect against this, if any of the sensors detects that the voltage
across a
string has dropped by more than a threshold amount (indicating that a bulb has
failed), the
control card may generate a command to adjust the drive current across that
string to
compensate for the lost bulb. The control card may do this by any suitable
means, such as
by adjusting a variable resistor that is connected in the power delivery
circuit, or by causing
a variable transformer to reduce the voltage, or by implementing a command on
a
programmable system on a chip. The system may also selectively control the
remaining
LEDs using pulse width modulation, as will be described in more detail below.
These
methods can help to maintain the overall light output by the group of LEDs at
a constant
intensity, and the detected light at a desired illuminance level, even if one
or more LEDs in a
series may fail.
[00681 Alternatively, the sensors may include light intensity sensors, CRI
sensors,
CCT sensors, Du, sensors, and/or ambient air temperature sensors. The control
card may be
programmed to receive data from the sensors and selectably control the LEDs to
maintain a
desired light output when it determines that measured light intensity. CRI,
CCT, Duv, or
ambient air temperature exceeds or falls below a threshold. The threshold may
be a value,
or it may be a range of values with an upper and lower value. Optionally, the
threshold may
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be a time-sensitive threshold, such as a threshold amount of change within a
certain period
of time or a sustained measurement above or below a threshold over a certain
period of time.
100691 In an option where the control card controls the LEDs by pulse width
modulation (PWM), an oscillating output from the processor repeatedly turns
the LEDs on
and off by applying a pulsed voltage. Each pulse is of a constant voltage
level, and the
control circuitry varies the width of each pulse and/or the space between each
pulse. When
a pulse is active, the LEDs may be turned on, and when the pulses are inactive
the LEDs
may be turned off. If the duty cycle of the "on" state is 50%, then the LEDs
may be on
during 50% of the overall cycle of the control pulses. The pulses are
delivered rapidly so
that the human eye does not detect a strobing effect ¨ at least 24 pulses per
second. The
control card may dim the lights by reducing the duty cycle ¨ and effectively
extending the
time period between each "on" pulse ¨ so that the LEDs are off more than they
are on.
Alternatively, the control card may increase the brightness of the LEDs by
increasing the
duty cycle.
[0070] The control card may receive data from the sensors and apply that data
to a
rule set to determine whether to increase, decrease, or maintain the intensity
of the LEDs.
For example, if an ambient air temperature sensor detects that the temperature
in the vicinity
of the LED array module exceeds a threshold, the control card may cause the
LEDs to dim
by reducing the voltage output of each transformer and/or reducing the duty
cycle of the
LEDs in the module. If a light sensor detects that an ambient light level is
above a desired
range, the control circuitry may automatically reduce the brightness of a
group of the LEDs
by decreasing a width of voltage pulses applied to the group of LEDs or
increasing spacing
between voltage pulses applied to the group of LEDs to maintain the ambient
light level
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within the desired range. If the light sensor detects that the ambient light
level is above (or
below) a desired threshold, the control circuitry may automatically reduce (or
increase)
increase the brightness a group of the LEDs by reducing (or increasing) a
width of voltage
pulses applied to the group of LEDs, or by increasing (or decreasing) spacing
between
voltage pulses applied to the group of LEDs to maintain the ambient light
level within a
desired range.
[00711 Optionally. any LED module may include several LED strings or groups of
different colors. For example, a module may include a red (R) LED series, a
green (G) LED
series, a blue (B) LED series, and a white (W) LED series. If so, the color of
light emitted
by the unit may be selectably controlled by the control card in response to
external
commands as described below.
[0072] In addition or alternatively, some, all, or portions of the LED arrays
may
include white LEDs of different temperatures so that they can be selectively
driven at
different levels to produce variable temperature white light from the same
fixture. In
addition, any LED module may include various strings or groups, all of which
emit white
light, but which collectively exhibit a variety of color temperatures. For
example, various
LED lamps may have LEDs ranging from about 2700K to about 6500K, from about
4000K
to about 6500K, some in a range around 5000K, or other ranges and
combinations. The
different types of LEDs may be relatively evenly distributed throughout the
device's LED
structure so that the device exhibits a uniform appearance when it emits
light. In these
situations, the control card may automatically alter the drive currents
delivered to particular
sets of LEDs in order to maintain a desired CCT output by the device. .
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CA 02875013 2014-12-17
[0073] In an embodiment where the light characteristic sensor is integral with
or
attached to the light fixture, an illumination device may have a first set of
LEDs having a
CCT of (for example) 4000K and second set of LEDs having a CCT of (for
example)
6500K. The light fixture control card may include programming to maintain the
light
emitted by the device at a threshold level or threshold range. When the sensor
detects that
the emitted light exceeds or falls below the threshold, the control card may
implement a
process that applies an algorithm, reference a lookup table, or use other
suitable methods to
determine what drive currents to apply to each of the groups of LEDs to
achieve the desired
CCT. For example, if the desired output is a CCT of 5000K, the system may
drive the first
set (4000K) of LEDs at a current of 1250 ma and the second set (6500K) of LEDs
at a drive
current of about 900 ma. The same process or a similar process may be applied
when the
sensor measures Duv. The algorithms and lookup table amounts may be set so
that the
system does not substantially change the illuminance level measured by light
intensity
sensors in the sensor compartment when the drive current changes are
implemented.
[0074] To control the color or color temperature of light directed to a
particular
area of an environment, the system's interface device (202 in FIG. 1) may
include or be in
communication with a processor and computer-readable memory containing
programming
instructions that enable a user to selectably control the light emitted by the
various
illumination devices. For example, the environment may be divided into a
number of zones,
and each illumination device may be assigned to one or more of the zones. When
the
system receives a command to direct light of a specified color or color
temperature to a
particular zone, it may identify the illumination devices that should be
activated and send a
signal containing instructions to the controllers (210a ... 210n in FIG. 1)
for the
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illumination devices associated with that zone. Each controller may then send
a signal to the
control card (55 in FIG. 11) of its associated illumination device to
selectively activate a
group of the devices LED's that will cause the device to emit light of the
desired color or
color temperature.
[0075] The interface device, controllers, and/or control cards may, when
generating
their output, identify what drive currents to apply to various groups of LEDs
to achieve the
desired color or color temperature. The selection of color temperatures for
LEDs may vary
based on the groups of LEDs that are available in the device. For example, an
illumination
device may have a first group of 100 LEDs having a color temperature of 4000K
and second
group of 100 LEDs having a color temperature of 6500K. If the system receives
a command
to emit light at a specified color temperature, it may use an algorithm,
reference a lookup
table, or use other suitable methods to determine what drive currents to apply
to each group
of LEDs to achieve the desired temperature. As a simple example, as
illustrated in FIG.
12A, the system may have a table or algorithm that identifies drive currents
to apply to the
4000K LEDs (represented by line 603) and the 6500K LEDs (represented by line
601) to a
achieve a desired color temperature. Each line may relate to a particular LED
drive circuit,
as will be described in more detail below in the discussion of FIG. 13.
Different drivers may
exhibit different characteristics, and the slope and other characteristics of
the lines shown in
FIG. 12A may vary based on the driver chip that is used. The system may
perform
diagnostics on a chip to learn this information during an initialization
process, or this
information may be entered as a data file or manually and then stored for use
during
operation of the lighting system.
CA 02875013 2014-12-17
[0076] In the example of FIG. 12A, if the desired output is a color
temperature of
5000K, the system may drive the 4000K LEDs at a current of 1250 ma and the
6500K LEDs
at a drive current of about 900 ma. FIG. 12B illustrates what luminous flux
may result from
achieving various color temperatures. Thus, desired luminous flux could be as
an input, and
the system may then determine the color temperature that would yield the
luminous flux,
and then look up or calculate the required drive currents to achieve the
desired luminous
flux. FIG. 12B also illustrates plateau parameters at which a light may
operate and maintain
a substantially constant luminance level. Operating the light in accordance
with the
parameters in the plateau area may yield a substantially constant luminance
level.
100771 In some embodiments, the system may be operated to maintain a constant
light output from one or more groups of LEDs so that the light level as
measured using any
suitable unit of measure, such as lumens output by the light or footcandles
measured by one
or more sensors positioned at various locations in the lighting environment
(e.g., playing
field, stage, etc.). Each of these units may be referred to in this document
as "luminance" or
"intensity" of light, or "illuminance" in the context of an area. All such
terms may be used
interchangeably in this document, such that a one of these values will be
equivalent to
another one of these values. Maintenance of substantially constant illuminance
may enable
the system to maintain substantially constant light levels in all areas of the
environment,
even while the colors of the light are changing.
[0078] In some embodiments, the system also may include a data storage
facility
comprising sets of scene data. When a user interface receives a selection of a
scene, the
system may access the data storage facility and retrieve a set of scene data
that corresponds
to the selected scene. It may then extract an identification of the group of
LED devices that
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correspond to the selected scene from the retrieved scene data. The system
also may
identify a color selection for each multi-color devices in the group having
LEDs by, for each
such LED device, identifying a first group of LEDs of a first color
temperature and a second
group of LEDs of a second color temperature. Then, for each of the LED devices
that
correspond to the group, the system identify a first drive current for the
first group of LEDs
and a second drive current for the second group of LEDs. The combination of
first and
second drive currents will cause the system to operate at a substantially
constant luminance
level and a desired overall color temperature.
[0079] In some embodiments, the system may include a user interface via which
a
user may define or select a scene. FIG. 13 illustrates an example of such a
device 700, in
which a set of activators 703 such as buttons, knobs, switches, touch-screen
display
elements or other user selectable interface elements supported by a housing
701 and which
are configured to enable a user to select a scene or define a scene. When a
user selects any
of the interface elements to request that a set of lights provide a defined
scene, circuitry or
programming may cause the device to transmit, optionally via a wireless
transmitter 709, a
command to the device drivers to adjust their settings to implement the scene.
The scene
may include desired color temperatures, intensities, or other light
characteristics at various
sections of an environment such as an arena, concert hall, stadium, theater,
convention
center room, stage, or other area that is to be lit. As noted above, the user
interface is an
electronic device and/or a software module running on an electronic device
that includes
inputs by which a user may enter commands that the system will use to
selectably control
lights. The user interface 700 may have multiple pre-programmed inputs that
call for pre-
defined scenes. When the desired scene is selected, the user interface may
acquire the
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I.
lookup table or algorithm itself, such as by retrieving it from a local memory
or a networked
or cloud-based data storage facility. Alternatively, the user interface 700
may send a unique
identifier for the scene to one or more lighting devices with which it is in
communication,
and each device could then use that identifier to could acquire the lookup
table or algorithm
and establish the settings for each lighting device that match the identified
scene.
[0080] For example, referring to FIG. 14, the system may include a receiver
811
that receives commands and monitored data signals from an external wired or
wireless
communication device. The receiver may pass the commands to a master control
unit 812,
such as a processor that implements software or firmware, a computing device,
or a
programmable system-on-a chip that stores information that can be used to
selectively
activate various drivers 801-804 that each control current to one or more sets
of LEDs.
Each driver 801-804 may control a separate illumination device, or a group of
LEDs within
a particular illumination device. The devices may receive power via a
converter 821 which
is protected from voltage or current variances by an input protection device
822 such as a
surge protector. The receiver also may include input protection 801 such as a
firewall or
device that protects the receiver against receiving and/or passing to the
master control unit
unauthorized signals.
[0081] The selection of which LED drivers to activate, and at what level, may
be
determined in real time by the system based on the input of a desired color
temperature,
intensity or other characteristic of light in a particular zone. For example,
the receiver 802
may receive a desired temperature and pass it to the master controller 803,
which will also
receive monitored data from the zone (such as light intensity or color
temperature) and
generate commands to select, or increase or decrease current to, a particular
group of LEDs
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for an illumination device that is directed to that zone if the monitored data
indicates that the
light intensity or color temperature in the zone is below or above the desired
temperature by
at least a threshold amount. Alternatively, the various commands and drive
currents may be
stored in a computer-readable memory in association with various scenes, and
the system
may issue commands corresponding to a scene when a user selects a particular
scene.
[0082] For example, consider the implementation discussed above of an
illumination device having a two strings of LEDs. one with a 4000K color
temperature
(CCT) and one with a 6500K CCT. The master controller may be programmed to use
a
formula to select the group of LEDs to drive to achieve the desired
temperature. The system
may use a set of equations to balance the total light output such as:
drive current for 4000K LEDs = -3242.21n(Desired CCT) -26892; and
drive current for 6500K LEDs = -33121n(Desired CCT) +29674;
whereby the system sets the drive currents applied to the LED groups in each
affected lighting device so that (4000K drive current) + (6500K drive current)
is always less
than or equal to a maximum total drive current of 2300 mA.
[0083] When the system receives a command to change the color temperature
output
by the light, the system may automatically adjust the light intensity directed
to the
environment by increasing or decreasing the drive current for some or all of
the LEDs that
are used to operate at the new color temperature. For example, the system may
use the two
equations to balance the total light output of the fixture or group of
fixtures, so that as one
string of LEDs is driven with higher current, an adjacent string (or another
selected string) is
driven with less current. Selection of other color temperature LEDs may
require a different
set of equations. The equations may be implemented in software, firmware,
programmed
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CA 02875013 2014-12-17
=
onto a chip, or applied in a custom control interface which then sends the
commands to the
master controller via the receiver. A user may fine tune the color temperature
by using a
user interface (such as a control device) to increase or decrease a desired
CCT. The system
may then increase the drive current in one group of LEDs having a first color
temperature,
while simultaneously decreasing the drive current in a second group of LEDs
having a
different color temperature, to achieve the desired CCT output and light
intensity.
[0084] As noted above, various sensors, such as light intensity, color
rendering index
(CRI) sensors, Duv sensors, and/or color temperature sensors, may be located
on the playing
surface, stage, or other lighting environment. The sensors may be arranged in
any suitable
arrangement, such as a grid. The sensors may be either permanently installed,
or portable to
be installed temporarily for calibration events. Once sensors are in place, an
optional
calibration event may begin. In the calibration event, all data will be
acquired in a zone
through one data acquisition event. Both light intensity and color temperature
in the lighting
environment, as well as other parameters such as CRI or Du, may be acquired at
this time.
Zone size will be dependent on the number and placement of sensors.
100851 The sensors may be in electronic communication with a master
controller.
Once data is acquired by the sensors, to continue the calibration they may
send the
infoimation to the controller (such as the master controller, or another
processing device),
which will perform a calculation that uses the received intensity or color
temperature
information and a reference level as variables and determines whether or how
much to
change (increase or decrease) the drive current to apply to each luminaire (or
individual sets
of LEDs within a luminaire) that is positioned to direct light to that zone.
An example
equation used in this scenario follows:
CA 02875013 2014-12-17
=
=
(Target Intensity-Acquired Intensity)
[0086] ADrive Current = 1.33 x
(Acquired Intensity)
[0087] In this equation, the target intensity is a user- or system-specified
intensity
that is to be maintained in the zone, and the acquired intensity is a sum,
average, mean or
other composite function of the intensity levels acquired by the sensors in
the zone. Other
equations may be used in various embodiments. The calibration process may be
done
during initial facility setup, when initiated later by a user or by a facility
change, or in some
embodiments automatically at periodic intervals
[0088] The system may then automatically implement the change, and repeat the
measuring and adjustment process until the desired color temperature and light
intensity are
achieved. The system may do this for a group of desired color temperatures and
light
intensities, and it may store this information in a data storage facility as a
data set, such as a
lookup table. Then, when the system receives a command to cause light of a
desired
intensity or color temperature to appear in a zone it may retrieve that data
and use it to select
the appropriate illumination devices and LED groups to drive, and at what
level.
[0089] For example, when a user enters a command in the user interface to
change
the applied scene, or to change the color temperature of light emitted in a
zone or by a
specific device, the system may select the LEDs to be driven, and drive
currents to be
applied to each LED group, by looking up the data stored in the calibration
process. The
same process may occur if a sensor detects that a light characteristic at a
particular location
has deviated from a threshold level or range. If the selected or threshold
color temperature
for a group of LEDs does not have associated drive currents stored in the
memory, the
system may calculate appropriate drive currents using algorithms such as those
described
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CA 02875013 2014-12-17
above. It may also update the data in the memory to include the newly-
calculated drive
currents.
[0090] In an option where the control card controls the LEDs by pulse width
modulation (PWM), an oscillating output from the processor repeatedly turns
the LEDs on
and off based by applying a pulsed voltage. Each pulse is of a constant
voltage level, and
the control circuitry varies the width of each pulse and/or the space between
each pulse.
When a pulse is active, the LEDs may be turned on, and when the pulses are
inactive the
LEDs may be turned off. If the duty cycle of the "on" state is 50%, then the
LEDs may be
on during 50% of the overall cycle of the control pulses. The pulses are
delivered rapidly so
that the human eye does not detect a strobing effect ¨ at least 24 pulses per
second. The
control card may dim the lights by reducing the duty cycle ¨ and effectively
extending the
time period between each "on" pulse ¨ so that the LEDs are off more than they
are on.
Alternatively, the control card may increase the brightness of the LEDs by
increasing the
duty cycle. The system may selectively change the PWM applied to a lighting
device when
it changes other characteristics (such as CCT) in order to maintain
substantially constant
illuminance in an area while changing the CCT or other characteristics.
[0091] The control card may receive data from the various sensors in the
environment and apply that data to a rule set to determine whether to
increase, decrease, or
maintain the intensity of the LEDs. For example, if a sensor detects that the
illuminance of
light in the vicinity of the sensor exceeds a threshold, the control card may
receive this
information and in response cause the LEDs to dim by reducing the voltage
output of each
transformer and/or reducing the duty cycle of the LEDs in the module. When
used in this
document, the term "threshold" may refer to a value, or it may refer to a
range of values
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CA 02875013 2014-12-17
with an upper and lower value. Each such option is intended to be included
within the scope
of the term.
100921 For example, an illumination device may have a first set of LEDs having
a
CCT of 4000K and second set of LEDs having a CCT of 6500K. The light fixture
control
card may include programming to maintain the light emitted by the device at a
threshold
level or threshold range. When the sensor detects that the emitted light
exceeds or falls
below the threshold, the control card may implement a process that applies an
algorithm,
references a lookup table, or use other suitable methods to determine what
drive currents to
apply to each of the groups of LEDs to achieve the desired CCT. For example,
if the desired
output is a CCT of 5000K, the system may drive the 4000K LEDs at a current of
1250 ma
and the 6500K LEDs at a drive current of about 900 ma. The same process or a
similar
process may be applied when the sensor measures Diiv. The algorithms and
lookup table
amounts may be set so that the system does substantially change the
illuminance level
measured by light intensity sensors in the sensor department when the drive
current changes
are implemented.
[0093] Alternatively, the system may maintain the output of each illumination
device even as the lighting source degrades over time due to dust collecting
on the lenses,
yellowing of the lenses caused by exposure to ultraviolet (UV) light, movement
of the light,
or other factors. To do this, as illustrated in FIG. 1, various sensors 205a
... 205n may
monitor properties of the light emitted. When the system determines that the
intensity of
light in an area has been reduced to a threshold, or by at least a threshold
amount over a time
period, it may alert the interface device 202 and/or controllers 210a ...
210n, which in
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CA 02875013 2014-12-17
response may generate commands that cause the control cards of the relevant
illumination
device to increase the current delivered to LEDs, this increasing their
output..
100941 FIG. 15 depicts an example of internal hardware that may be used
to
contain or implement the various processes and systems as discussed above that
relate to a
user interface and/or controller. An electrical bus 900 serves as an
information highway
interconnecting the other illustrated components of the hardware. A computing
device will
include one or more processors. CPU 905 is a central processing unit of the
system,
performing calculations and logic operations required to execute a program.
CPU 905,
alone or in conjunction with one or more of the other elements disclosed in
FIG. 15, is a
processing device, computing device or processor as such terms are used within
this
disclosure. As used in this document, the tennis "processor" and "processing
device" may
include a single processor or a group of processors that collectively perform
various steps of
a process. Read only memory (ROM) 910 and random access memory (RAM) 915
constitute examples of memory devices. As used in this document, the terms
"computer-
readable medium," "memory" or "memory device" are used interchangeably and may
include a single memory device, a group of memory devices, or a sector or
other subdivision
of such a device.
100951 A controller 920 interfaces with one or more optional memory devices
925
that service as data storage facilities to the system bus 900. These memory
devices 925 may
include, for example, an external DVD drive or CD ROM drive, a hard drive,
flash memory,
a USB drive, a distributed storage medium such as a cloud-based architecture,
or another
type of device that serves as a data storage facility. As indicated
previously, these various
drives and controllers are optional devices. Additionally, the memory devices
925 may be
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CA 02875013 2014-12-17
configured to include individual files for storing any software modules or
instructions,
auxiliary data, incident data, common files for storing groups of contingency
tables and/or
regression models, or one or more databases for storing the information as
discussed above.
[0096] Program instructions, software or interactive modules for performing
any of
the functional steps associated with the processes as described above may be
stored in the
ROM 910 and/or the RAM 915. Optionally, the program instructions may be stored
on a
tangible computer readable medium such as a compact disk, a digital disk,
flash memory, a
memory card, a USB drive, an optical disc storage medium, a distributed
storage medium
such as a cloud-based architecture, and/or other recording medium.
[0097] A display interface 930 may permit information from the bus 900 to be
displayed on the display 935 in audio, visual, graphic or alphanumeric format.
Communication with external devices may occur using various communication
ports 940. A
communication port 940 may be attached to a communications network, such as
the Internet,
a local area network or a cellular telephone data network.
[0098] The hardware may also include an interface 945 which allows for receipt
of
data from input devices such as a keyboard 950 or other input device 955 such
as a remote
control, a pointing device, a video input device and/or an audio input device.
[0099] FIG. 16 illustrates an example of a lit environment 1000, in this case
a
football field that is to be an illuminated surface 1001 in a stadium, in
which a set of LED
lighting devices 1051-1058 are positioned at various locations and which
direct light to the
illuminated surface 1001. The sensors (represented by dark circles on the
illuminated
surface 1001) may measure characteristics of the light and send the
information to a
controller. Thus, the illumination devices are positioned at various locations
of an
CA 02875013 2014-12-17
= =
entertainment facility, and the sensors are located proximate to a playing
surface or stage of
the facility.
1001001 Each sensor may be assigned to a zone ¨ i.e., an area of the
illuminated
surface -and may thus gather characteristics of light directed to the zone,
such as color
temperature, Du, and intensity. When a system controller receives a command to
implement
a scene at a particular zone, the controller will access a data set and
receive parameters that
correspond to the scene, such as one or more areas affected by the scene,
color temperatures
and light intensities associated with each area for the scene, and an
identification of the
lighting devices that direct light to areas of the scene. For example, the
controller may
access a data storage facility with various scene data, retrieve a set of
scene data that
corresponds to the selected scene, and extract from the scene data an
identification of the
lighting devices that correspond to the scene. The controller may then cause
the affected
light fixtures to automatically alter their color temperature and/or light
intensity output so
that the desired color temperatures and light intensities are directed to each
area of the
illuminated surface that is part of the scene. Optionally, if a sensor for an
area detects that
the color temperature or intensity (illuminance level) has deviated from the
values assigned
to that area for the scene, then when the controller receives this information
it may generate
a command that causes one or more of the lighting devices to alter their color
temperature or
brightness of output light in order to achieve the assigned values in the
affected area.
[00101] The sensors such as those shown in FIG. 10 may be installed on a
surface
and used to collect light measurement data and transmit the data to the
controller to make
real-time adjustments during an event. Alternatively, or in addition the
sensors may be used
for calibration of the system or collection of data to define a scene. For
example, a sensor
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CA 02875013 2014-12-17
may be positioned in a location, and various lighting devices may be directed
to the location
while the sensor collects color temperature, intensity, CRI, or other
light characteristic
data. The data may be collected by manually placing the sensor at each target
location, or
the sensor may be placed on or in a robotic transport device, such as a
manually operated
vehicle or drone. Optionally, the vehicle or drone may be programmed with
location and
route data so that it automatically moves throughout the facility to collect
data. When the
sensor reaches each location, it may be positioned at various angles with
respect to the plane
of the ground to collect measure characteristics of light received at various
angles. For
example, the sensor may be positioned so that it receives light from a
horizontal direction, a
vertical direction, and/or any angle in between. The positioning may occur
manually, or the
robotic transport device may include one or more motors, axles or other
components that can
rotate the sensor and automatically collect light from various angles.
[00102] If the sensed data does not match the desired data for a location,
then the
lights may be adjusted using drive current variation or PWM techniques such as
those
described above until the desired characteristics are detected. When the
desired
characteristics are detected, the system may save a record of the lighting
system parameters
(e.g., drive currents and PWM settings for each light fixture associated with
the scene) to the
set of scene data. In this way, later, when a user of the user interface
selects a scene, all of
the data for all lighting devices associated from the scene may be retrieved
from the data set,
and commands to cause each affected lighting device to operate according to
the scene's
parameters may be sent to the lighting devices.
[00103] The features and functions disclosed above, as well as alternatives,
may be
combined into many other different systems or applications. Various presently
unforeseen
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CA 02875013 2014-12-17
or unanticipated alternatives, modifications, variations or improvements may
be made by
those skilled in the art, each of which is also intended to be encompassed by
the disclosed
embodiments.
43
