U.S. patent application number 11/360219 was filed with the patent office on 2006-06-29 for light emitting diode (led) picture element.
This patent application is currently assigned to Element Labs, Inc.. Invention is credited to Matthew Ward.
Application Number | 20060139917 11/360219 |
Document ID | / |
Family ID | 32330050 |
Filed Date | 2006-06-29 |
United States Patent
Application |
20060139917 |
Kind Code |
A1 |
Ward; Matthew |
June 29, 2006 |
Light emitting diode (LED) picture element
Abstract
A picture element lamp is disclosed that mixes light from LEDs
in a light guide. The light guide expands the perceived light
source and can redirect the light toward viewing locations.
Inventors: |
Ward; Matthew; (San
Francisco, CA) |
Correspondence
Address: |
FLIESLER MEYER, LLP
FOUR EMBARCADERO CENTER
SUITE 400
SAN FRANCISCO
CA
94111
US
|
Assignee: |
Element Labs, Inc.
Austin
TX
|
Family ID: |
32330050 |
Appl. No.: |
11/360219 |
Filed: |
February 23, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10608383 |
Jun 27, 2003 |
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11360219 |
Feb 23, 2006 |
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60460861 |
Apr 7, 2003 |
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60428052 |
Nov 21, 2002 |
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60428577 |
Nov 22, 2002 |
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Current U.S.
Class: |
362/231 |
Current CPC
Class: |
G09G 3/2003 20130101;
F21Y 2105/00 20130101; G02B 6/0048 20130101; G02B 6/0051 20130101;
G02B 6/0055 20130101; G02B 6/0068 20130101; F21Y 2115/10 20160801;
G09G 2300/026 20130101; G09G 3/30 20130101 |
Class at
Publication: |
362/231 |
International
Class: |
F21V 9/00 20060101
F21V009/00 |
Claims
1. A display system comprising: a group of lamps, each lamp
including different colored LEDs so that the lamps can glow with
different color light produced by mixing light of different colored
LEDs, each lamp including a light guide using substantially total
internal reflection to spread the light over a larger area; and a
control unit that drives the colors of the lamps in accordance with
a video signal.
2. The system of claim 1, wherein the lamps include a lamp
housing.
3. The system of claim 1, wherein the LEDs are positioned on a
circuit board.
4. The system of claim 1, wherein the group of lamps is a grid of
lamps.
5. The system of claim 4, wherein the pitch between lamps is 20 mm
or greater.
6. The system of claim 1, wherein the lamps includes a diffuser
plates.
7. The system of claim 6, wherein the diffuser plates increases the
contrast of the color.
8. The system of claim 1, wherein light from the LEDs goes into one
end of the light guide and comes out the front of the light
guide.
9. The system of claim 1, wherein the light guide includes a
collimator.
10. The system of claim 1, wherein the light guide includes facets
for reflecting light forward.
11. The system of claim 1, wherein the light guide is
rectangular.
12. The system of claim 1, wherein the light guide extends out from
a base.
13. The system of claim 1, wherein the light guide forms a
bulb.
14. The system of claim 13, wherein the bulb includes a center
cavity.
15. The system of claim 1, further comprising a frame to hold the
group of lamps.
16. The system of claim 15, further comprising an additional frame
containing another group of lamps.
17. The system of claim 1, further comprising a video processor
adapted to provide the video signal to the control unit.
18. The system of claim 1, wherein the control unit uses a subset
of the pixels in the video signal.
19. The system of claim 18, wherein the subset is determined by
address information.
20. A display system comprising: a group of lamps, at least some of
the lamps being greater than or equal to 20 mm in pixel size and
using at least one LED to produce light of different colors, the
lamps including a light guide using substantially total internal
reflection; and a control unit that sets the color of the lamps in
accordance with a video signal.
Description
PRIORITY CLAIM
[0001] This application is a continuation of U.S. patent
application Ser. No. 10/608,383, entitled "Light Emitting Diode
(LED) Picture Element", filed Jun. 27, 2003; which claims priority
to U.S. Provisional Patent Application No. 60/428,052, entitled
"Method for Creating 360 Degree Viewable Pixels for LED Based Large
Screen Video Displays," filed Nov. 21, 2002; U.S. Provisional
Patent Application No. 60/428,577, entitled "Thin Self Contained
LED Picture Element for Use in Large Format Low Resolution
Displays," filed Nov. 22, 2002 and U.S. Provisional Application No.
60/460,861, entitled "Light Emitting Diode (LED) Picture Element,"
filed Apr. 7, 2003.
FIELD OF INVENTION
[0002] The present invention relates to lamps, especially lamps
which contain light emitting diodes.
BACKGROUND
[0003] Existing video displays which use light emitting diodes
(LEDs) are currently highly restricted by viewing distance. The
pixels are composed of clusters of red, green and blue LEDs which
must be viewed from a significant distance if proper color
homogenization is to take place. The use of clusters of LEDs also
guarantees that there will be a color shift when the screen is
viewed from off center. As a viewer moves away from the center axis
and off to one side of the video display the LEDs on that side
start to eclipse the LEDs on the opposite side of the screen.
Depending on the configuration and number of LEDs this can be a
significant problem.
[0004] Other problems with the existing video displays are that the
screens are anywhere from 8 to 12 inches deep with additional depth
required for service. They cannot be easily reconfigured for curved
walls or other design driven modifications. They are not designed
to accept shelving or signage or relate in any way to any other
object in an environment.
[0005] Video displays manufactured using clusters of red, green and
blue light emitting diodes (LEDs) as pixels can be divided into two
categories, Modular Enclosure and Open Frame. Modular Enclosure
screens are fabricated in housings or frames which contain the
processing, power distribution and cable assemblies required to
drive the LED clusters which are either grouped on large printed
circuit boards (PCBs) or encapsulated in a single housing. The
fronts of these screens are covered with louvers to block sunlight
which diminishes the video screens apparent contrast. Open Frame
screens are designed to allow some transparency through the use of
a slat system or a net system. In a slat system the LED clusters
are on long PCBs. In the net system the LED clusters are mounted to
a section of netting. None of these screen configurations allows
for a pixel to be viewed from 360 degrees.
BRIEF SUMMARY
[0006] One embodiment of the present invention comprises of a
system consisting of a group of lamps. The lamps including
different colored LEDs. The lamps produce light by mixing light of
the different colored LEDs. The lamps include a light guide to
spread the light over a larger area. The system also includes a
control unit adapted to use a video signal to control colors of the
lamps.
[0007] In one embodiment, the lamps are rectangular. The
rectangular lamps can contain light guides which can receive the
light from the LEDs from the top and redirect the light toward
viewing positions. The light guide can spread the apparent source
of the light. In other embodiments, the lamps contain light guides
that protrude outside of the base which contains the LEDs. The
light from the LEDs goes into the light guide and is reflected
outward.
[0008] One embodiment of the present invention is a lamp including
a LEDs of different colors and a light guide which spreads the
light of the LEDs in a larger area. The lamp can glow with
different colored lights produced by mixing different colored
LEDs.
[0009] One embodiment of the present invention is a system
including a group of lamps, the lamps including LEDs, the lamps
including a light guide to spread the light over a larger area; and
a control unit adapted to adjust the intensity of the LEDs in
accordance with a video signal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a diagram that illustrates a lighting display
using the picture element lamps of one embodiment of the present
invention.
[0011] FIG. 2A is a functional diagram illustrating frames
containing control units, frame power units and a group of
lamps.
[0012] FIG. 2B is a diagram illustrating a system of one embodiment
of the present invention.
[0013] FIG. 3 is a diagram of a cross section of a picture element
lamp of one embodiment of the present invention.
[0014] FIG. 4 is a cross section of a light of one embodiment of
the present invention.
[0015] FIGS. 5A and 5B are diagrams illustrating a light guide of
one embodiment of the present invention
[0016] FIGS. 6A and 6B are diagrams that illustrate the snapping of
a lamp into a frame of one embodiment of the present of the present
invention.
[0017] FIG. 7 is a cross section of a lamp containing a light guide
that extends from the base.
[0018] FIGS. 8A and 8B are diagrams that illustrate the lamp of
FIG. 7.
[0019] FIG. 9 is a diagram of a flag-based embodiment.
DETAILED DESCRIPTION
[0020] FIG. 1 illustrates an example of a picture element (pixel)
lamp display within a retail environment. The picture element lamps
can display information from a video signal. In this example, the
picture element lamps mix light from clusters of red, green and
blue LEDs. The picture element lamps preferably include a light
guide to mix the light from the LEDs. The light guide spreads the
perceived origin of the light over a wider area as well as
redirects the light to viewer locations.
[0021] FIG. 2A illustrates an example in which frames 202 and 204
are used. Frames can include a control unit, such as control units
206 and 208. The control units can be, for example, a video driver.
The control units receive a video signal over the video data bus
210 from a video processor 212. Any type of video signal can be
used. The control unit can select a sub-set of the pixels of the
video data to drive the LEDs in the lamp groups 214 and 216. The
sub-set of pixels can be determined by addresses which are provided
across the control bus 220 or in another manner. In one example,
the lamp group 212 is an 8.times.8 grid of lamps. An 8.times.8
sub-set of pixels within the video signal can be selected to
determine color information for the lamps. Data for more than one
pixel in the video can be used to produce a single color to be
displayed on a picture element lamp within the lamp groups 214 and
216. The control unit can be used to adjust the intensity of the
LEDs in accordance with a video signal. A monochrome embodiment can
use LEDs of the same color to produce a single color, or
"black-and-white", display.
[0022] In one embodiment, the color information from the video
signal is converted to driving voltages for the LEDs. The LEDs are
preferably calibrated so that the same driving voltage produces
similar color intensities for the different colored LEDs.
[0023] FIG. 2B is a diagram of one embodiment of the present
invention. In this example, a personal computer 250 with local
monitor 252 controls a signal processor 254. The signal processor
can provide a video signal to multiple panels 256. Each panel is
constructed of multiple lamps 258.
[0024] FIG. 3 illustrates a frame 300 containing a group of lamps
302. In the example of FIG. 3, the lamps form an 8.times.8 grid.
The lamp grid can be regular or unregular, with or without missing
pixels.
[0025] Picture element lamps use a light guide to mix colors and
spread the light so that the apparent source of light is a
relatively wide region such as, the front facing surface of the
lamps 302. This makes it comfortable to view the lamp from a few
feet away. The low resolution picture element lamps are thus very
useful for designers and architects to incorporate into video
displays in retail environments.
[0026] In one embodiment, the pitch, the distance from the center
of one pixel to the center of the next pixel, is no less than 20
millimeters. In a preferred embodiment, the pitch is 40 mm or
greater.
[0027] In one embodiment, the pixel size of the lamp is about 20 mm
or greater in width. Since the picture element lamps are relatively
large, the disadvantages of prior art systems is avoided. Such
pixels element lamps are significantly larger than what is normally
use in video displays. Video displays focus on making the pixels as
small as possible and the use of larger pixels is
counter-intuitive.
[0028] The use of the pixel wall element also addresses a number of
criteria, in addition to viewing distance, which influence
decisions regarding the use of low resolution video displays. Depth
is a critical issue in any design process given the cost of floor
space in any building. The wall mounted, picture element can be
made relatively thin. The low resolution video display can be
adapted to work with a wide variety of design specifications while
maintaining a low price point. The low resolution video display can
be easily integrated with other interior requirements such as
shelving and signage.
[0029] In one embodiment, each pixel is packaged as a
self-contained lamp for ease of maintenance. A housing conceals the
LEDs.
[0030] FIG. 4 illustrates a cross section of a picture element lamp
of one embodiment of the present invention. The LEDs can be mounted
on a printed circuit board (PCB) in a strip 402 at the base of the
pixel. A cable assembly can connect from PCB 402 to a control unit
(driver board) which converts incoming video information into
voltage for the LEDs. Light from the LEDs is directed into a light
guide 404. The light guide can be constructed of a plastic, glass
or other material. In one embodiment, the light guide 404 has a
collimator 406 to collimate light from the LEDs. The light guide
404 can also use facets 408 to reflect the light forward toward
viewing positions. The facets 408 preferably use total internal
reflection. In one embodiment, the light guide uses diffusion, such
as a Fresnel grating, on the front facing surface 410. The back
and/or sides of the housing can be treated with or composed of a
reflective material. Light from the lamp is directed forward toward
an optional cover 412. The cover 412 can be a diffusion plate
and/or tinted to improve the contrast of the color.
[0031] FIGS. 5A and 5B illustrates a side and top view of a light
guide of one embodiment of the present invention. In one
embodiment, the lamps fit into a frame. The frame can be a plastic
frame that is lightweight and easy to manufacture. This plastic
frame can also house a power supply and a control unit (video
driver board). In one embodiment, the back of the housing features
a cleat system which allows the housing to be directly attached to
a wall. As shown in FIG. 3, the frame can be curved or have a
custom shape enhancing the utility of the pixel lamps. The frame
can also have penetrations to allow shelving or other items to be
bolted through the low resolution LED display and into a structural
system.
[0032] FIGS. 6A and 6B illustrates the connection of the pixel lamp
housing 602 to a portion of the frame 604 of the current
embodiment. In this example, the lamp 602 includes a cover 604 and
housing 606. The housing 606, includes an extension 606a, which
engages a portion of the frame 604 to allow the housing to click
into the frame.
[0033] Surface Mounted LEDs can be used. Surface Mounted LEDs are
relatively expensive but allow for a more compact lamp. A separate
mixing light guide may be used, with or without a reflector, in
order to achieve a more complete homogenization of color. The LEDs
may be mounted perpendicular to the light guide. Organic LEDs
(OLEDs) may be used to create the pixel lamps. Though-hole LEDs can
also be used. The housing may be used as a floor by using the bolt
holes to mount a plexiglass front surface which would be supported
by structural elements under the housing. The lamps may be removed
from the housing and used separately with the same power
distribution and video driver. The pixel size is not fixed.
Different sized pixel lamps may be used in one system. The driver
board may have an adjustment for cable length due to resistive
losses in the cables. Different types of materials may be used as
light guides. A screen can be fabricated without the tinted plastic
front face if contrast is not a priority. Slugs or plastic covers
with no electronics can be mixed in with functioning pixels in a
grid. Textured front faces or other coverings may be attached or
hung in front of the pixels. A coating may be used on the front
face to improve contrast. LED clusters at both ends can be used to
maximize light output and color mixing a pixel lamp. The pixel
lamps can be housed in a transparent plastic or glass sheet. The
pixel lamps can be used to edge light shelving or to backlight
signage.
[0034] The materials for the lamp can be IP 66 or IP 68 approved
materials to allow for the external use of the lamps. In one
embodiment, the LEDs are grouped on the PCB in clusters of red,
green and blue LEDs. The LEDs can preferably be calibrated so that
a conventional video driver for LEDs to produce light that can be
mixed within the light guide with the lamps of the present
invention.
[0035] The picture element lamps can use a video signal to provide
dynamic lighting effects within a store or other location. The
video signal can be a prestored signal from a storage medium, such
as a DVD or computer memory. Alternately, the video signal can be
from a camera or computer generated.
[0036] Another embodiment of the present invention uses a light
guide that extends from a base. FIG. 7 illustrates a cross
sectional view of a light guide 702 including a cavity 704. In this
example, light guide 702 is bulbed. Light from the LEDs on PCB 706
is sent into the light guide 702. The light guide can include a
collimator adjacent to the PCB 706. The light guide 702 can include
facets within the cavity. The lamp 700 of FIG. 7 can be arranged
into groups. FIGS. 8A and 8B illustrates one example of a light
guide for the picture element lamp of FIG. 7. Other possible shapes
include globes, cubes, stars, etc.
[0037] The light guides can be used to create large video displays
in which each picture element can be viewed from 360 degrees
vertical orientation and 160 degrees horizontal orientation. The
pixel lamps can be placed anywhere with no fixed distance between
the lamp and the required video processing.
[0038] Existing screens have a fixed relationship in pitch which is
a measurement of the distance from a pixel center to the next pixel
center. A 10 mm screen fabricated using the Modular Enclosure
method will always be a 10 mm screen. The design of the bulbed
pixel lamp allows a designer to change pitch in a graduated manner
within one screen while the screen is being installed.
[0039] The LED cluster may be Surface Mounted Device (SMD). In one
embodiment, a basic cluster is composed of at least one red, green
and blue LED mounted to a PCB. A cable assembly from the LED
cluster to a driver board 6. The cable assembly may or may not be
IP 68 rated for outdoor use. A light guide assembly can include a
visible element such as a bulb and may also include a neck and/or a
collimating lens (not pictured). The parts in this assembly can be
selected based on the LEDs being used. Light guides can be composed
of optical grade PMMA/Acrylic and other material. A layer of
light-scattering diffusion on the outside of the bulb which can be
applied as a coating or as a surface treatment. This may also
include a UV coating and an anti-reflective coating.
[0040] A control unit, such as a driver board, can send line
voltages down the cable assembly to the LED cluster. Light from the
LED cluster is channeled into the light guide assembly. If it is
required by the type of LED used, the light guide will initially be
used to mix the colors of the individual red, green and blue LEDs.
The light will next pass into the visible part of the light guide,
such as the bulb, where it is reflected until it strikes the
outside of the bulb can be treated to allow the light in the guide
to escape. This makes the light guide glow.
[0041] Any number of such pixel lamps may be used in a system. To
maximize light output and color mixing a tube could be used with
LED clusters at both ends. The light guides can be irregular shapes
and heights to create a video topography. Surface Mounted LEDs may
require no mixing light guide and a significantly smaller bulb
portion. A high intensity white (or other color) LED can shine down
from the middle to light space below while the video pixel makes
the lamp glow. This in essence becomes a pixel within a pixel.
[0042] A coating may be used to improve contrast. Alternate
materials may be used for the light guide such as polycarbonate.
Any number of LED's may be used as well as different combinations
of colors. Applications for a bulb based pixel lamps include a
video ceiling, a video dividing wall, a video curtain for a
performance in the round and a window decoration in an atrium. The
screen can also be used in conjunction with a number of hard and
soft translucent coverings.
[0043] One embodiment of the present invention uses a group of
relatively large pixel lamps. In one embodiment, at least some of
the lamps being greater than or equal to 20 mm in pixel size. At
least one LED can be used to produce light of different colors. A
control unit is adapted to set the color of the lamps in accordance
with a video signal.
[0044] The lamps can be constructed using a light guide as
described above. The light guide can spread the light over a wider
area. Light from different colored LEDs is mixed in the light
guide.
[0045] Alternately, an embodiment without a light guide can be
used. Large-sized LEDs can be used. In one embodiment, groups of
LEDs or clusters of LEDs driven with the same signal can be used.
The LED(s), LED groups or LED clusters can be positioned on the
outside of the lamp. In this way a pixel size of greater than 20 mm
can be created.
[0046] Organic LEDS (OLEDs) and polymer LEDs (PLEDs) can be used.
OLEDs and PLEDs are especially useful for the embodiment without a
light guide.
[0047] In addition to retail environments, the embodiments of the
present invention are useful for many other applications including
concert touring, TV production, other architectural environments,
clubs, theme parks, corporate events, etc. In one embodiment users
can use the lamps to form scenic elements.
[0048] There are many uses for the lamps in furniture for use as
table tops, Chinese/Japanese folding screens, counter tops,
headboard for beds, and shelving. The lamps can be a substitute for
traditional ceramic/mosaic tiles for example in showers, etc.
[0049] The lamps can be used as floor panels and ceiling tiles. The
lamps can cover the outside of a building or be used to produce
doors. The lamps can also be used in traffic lights and other info
display signs. The use of the lamps of the present invention may
require fewer LED's and be more compact than current traffic lights
systems. The light guide can be curved or an irregular shape
(octagon, mosaic tile, etc). The light guide can be an entire
object: such as a chair, table top, body panel on a car.
[0050] The frames used can be constructed of a flexible material,
such as rubber. This can allow the frames to be connected to a
curved wall for example. The frames can be hinged.
[0051] The lamps can be light from the edge to allow the lamps to
be placed with little or no gap between the tiles. The tiles can
have beveled edges allowing the LEDs to shine in at an angle from
behind. Mirrors, prisms, or other optical devices can be used to
reflect the light. This may make the system slightly deeper, but it
can eliminate/minimize the frame around each pixel.
[0052] In one embodiment, the light guide is mostly transparent
when the LEDs are turned off and suitable for use as a window. When
turned on, the light guide glows with color.
[0053] In one embodiment, a large diffuser which covers multiple
lamps is positioned in front of the lamps to make a seamless image.
The diffuser can be positioned some distance from the lamps.
[0054] In one embodiment, the circuit board and a light guide are
placed in a metal frame and no assembly holds the two together
before placing them in the frame. The frame and the light guides
can be a single piece of molded acrylic or polycarbonate. The
circuit boards containing the LEDs can be slotted in place in this
block.
[0055] In one embodiment, the light guide can include active and
non-active areas. The non-active area will not glow as
significantly as the active area. An active area of the light guide
ca be a distance from the LED source in a larger sheet of acrylic
instead of starting right by the LED sources.
[0056] A light guide can have variable density of reflecting
material. One use of a variable density of reflecting material is
to help maintain an even light output as light intensity falls off
from the source. A gradient pattern can keep the apparent intensity
constant.
[0057] In one embodiment, a wall can be made of vertical rods where
the light guides radiate from the rods in a fixed or variable
manner. The rods themselves can also move. FIG. 9 illustrates one
example of such an embodiment.
[0058] In one embodiment, a lamp is a laminated piece of
plastic/glass where the LEDs and the light guides are contained in
a sandwich. All of the elements can be transparent.
[0059] Silk screening can be used to create different shapes and
patterns on the lamps. Reflective materials behind the light guide
can be used to show different images when the light is off.
[0060] The lamps can be a single or dual color version. A single
color version can effectively produces a black-and-white display.
Information for a single or dual color version can be derived from
a video signal.
[0061] The lamps can be wirelessly connected to control elements
using a wireless connection such as WiFi, Bluetooth, etc.
[0062] The lamps can be linked to a trigger, such as a doorbell.
The lamps can use music to set the light functionality. For
example, an audio signal can be used to produce a video signal that
drives the lamps. The lamps can be linked to a clock to shine
different colors at different times in the day. The lamps can have
a touch sensitive surface that activates the lights. Interactive
feedback can be used to trigger the lights from sensors to detect,
weight, sound, heat/motion, and/or ambient light levels.
[0063] In one embodiment a video output on the last lamp in a
sequence is used to help verify remotely that the system is
working.
[0064] In one embodiment, a laminated panel is used where the LEDs
and the light guides are contained within a sandwich of transparent
panels. The transparent panels could be acrylic, polycarbonate of
glass or any other optically appropriate material.
[0065] In one embodiment, dichromic or other red, green and blue
filters are used with white LED light sources to create a source of
illumination for the light guide.
[0066] The foregoing description of preferred embodiments of the
present invention has been provided for the purposes of
illustration and description, it is not intended to be exhaustive
or to limit the invention to the precise forms disclosed. Many
modifications and variations will be apparent to one of ordinary
skill in the relevant arts. The embodiments were chosen and
described in order to best explain the principles of the invention
and its practical application, thereby enabling others skilled in
the art to understand the invention for various embodiments and
with various modifications that are suited to the particular use
contemplated. It is intended that the scope of the invention be
defined by the claims and their equivalence.
* * * * *