WO2009026378A2

WO2009026378A2 - Integrated optical pixel apparatus

Info

Publication number: WO2009026378A2
Application number: PCT/US2008/073735
Authority: WO
Inventors: Matthew E. Ward
Original assignee: Element Labs, Inc.
Priority date: 2007-08-21
Filing date: 2008-08-20
Publication date: 2009-02-26
Also published as: TWI464716B; TW200917183A; WO2009026378A3

Abstract

An integrated optical pixel apparatus includes a pixel including a carrier, a first substrate disposed in the carrier, and a plurality of light emitting elements disposed on a front surface of the first substrate, where the carrier includes a sealing material disposed therein and surrounding at least a portion of the first substrate.

Description

INTEGRATED OPTICAL PICTURE ELEMENT Cross-reference to Related Applications

[0001] This application, pursuant to 35 U. S. C. § 119(e), claims priority to U.S.

Patent Application Serial No. 60/957,050 filed on August 21, 2007 and entitled "Integrated Optical Picture Element" in the name of Matthew Ward, which is hereby incorporated by reference in its entirety.

BACKGROUND

Field of the Disclosure

[0002] Embodiments disclosed herein generally relate to individual pixels that are used to form video displays. More specifically, embodiments disclosed herein relate to an integrated optical pixel apparatus used within a video display.

Background Art

[0003] Display units for entertainment, architectural, and advertising purposes have commonly been constructed of numbers of light emitting elements, such as LEDs or incandescent lamps mounted onto flat panels. These light emitting elements may be selectively turned on and off to create patterns, graphics and video displays for both informational and aesthetic purposes. It is well known to construct these displays of tiles or large panels, each containing several light emitting elements, which may be assembled in position for an entertainment show or event, or as an architectural or advertising display. Examples of such systems are disclosed in U.S. Patent Nos. 6,813,853, 6,704,989 and 6,314,669.

[0004] Increasingly, display units are being used on the exteriors of buildings for entertainment, architectural, or advertising purposes in a manner that does not fully integrate them into the style and physical envelope of the building. For example, Times Square in New York City and the Las Vegas Strip are two areas littered with such display units either contained within the curtain wall of glass buildings or grafted onto the outside of buildings with little regard for the buildings' architecture. This is exemplified by the multiple billboard-style displays located in these areas. [0005] Large outdoor video displays used in advertising, sports, and other public video applications are typically assembled using a combination of plastic housing and structural components housing a circuit board containing light emitting diodes, power distribution, and driver electronics. Such assemblies are well known and are available as single pixels as described for example by Yoksza et al in U.S. Patent No. 5,410,328 (Figure IA), multiple pixel strips as disclosed for example by Masanobu Miura in U.S. Patent No. 5,268,828 (Figure IB), and multi-pixel modules as described for example by Matsumura et al in U.S. Patent No. 5,785,415 (Figure 1C). Modifications and refinements of these basic designs are well known and may include the substitution of surface mount emitters and components for through-hole emitters.

[0006] In Figure IA, a view of a prior art single pixel system as described by

Yoksza et al in US Patent 5,410,328 is shown. Light emitting diodes (LEDs) 22 connect through an electrical jack 42 to a separate driver board. In Figure IB, a view of a prior art multiple pixel strip system as described by Masanobu Miura in US Patent 5,268,828 is shown. LEDs 103a connect to a wired substrate 2 which, in turn, connects to a separate remote driver board. Further, in Figure 1C, a view of a prior art pixel module as described by Matsumura et al in US Patent 5,785,415 is shown. In Figure 1C, multiple LEDs are assembled on a base plate fitted with seals and waterproof packing. The LED drivers are then separate and, thus, may not be protected by these seals.

[0007] The basic components in the modules noted above undergo a high degree of processing, assembly, and re-packaging prior to their inclusion in the finished LED display. For example, the LED dies may be assembled into packages, the driver chips may then be packaged, and the circuit board on which the LED packages are mounted must contain secondary components to adjust driver voltages and handle the data signals. Accordingly, there exists a need for a light emitting apparatus that improves upon these prior art support systems for continued development and success within the various light emitting industries.

SUMMARY OF THE DISCLOSURE

[0008] In one aspect, embodiments disclosed herein relate to an integrated optical pixel apparatus. The apparatus includes a pixel that has a carrier, a first substrate disposed in the carrier, and a plurality of light emitting elements disposed on a front surface of the first substrate. The carrier then includes a sealing material disposed therein and surrounding at least a portion of the first substrate.

[0009] Further, in another aspect, embodiments disclosed herein relate to a method for creating an integrated optical pixel apparatus. The method includes disposing a plurality of light emitting elements on a front surface of a first substrate, disposing a driver on a second substrate, connecting the back surface of a first substrate with the second substrate, disposing the first and second substrates into a carrier, and injecting a sealing material into at least a portion of the remaining space within the carrier.

[0010] Furthermore, in yet another aspect, embodiments disclosed herein relate to a method for displaying an image. The method includes providing a pixel having a carrier, a first substrate disposed in the carrier, and a plurality of light emitting elements disposed on a front surface of the first substrate. The carrier then includes a sealing material disposed therein and surrounding at least a portion of the first substrate. The method then further includes sending a signal to pixel, in which the pixel is configured to emit light based on the signal.

[0011] Other aspects and advantages of the present disclosure will be apparent from the following description and the appended claims.

BRIEF DESCRIPTION OF DRAWINGS

[0012] Figures IA-C show multiple views of prior art systems having LEDs disposed therein.

[0013] Figure 2 shows a perspective view of a pixel in accordance with embodiments disclosed herein.

[0014] Figure 3 shows a cross-sectional view of a pixel in accordance with embodiments disclosed herein.

[0015] Figure 4 shows a front view of a pixel in accordance with embodiments disclosed herein.

[0016] Figure 5 shows a rear view of a pixel in accordance with embodiments disclosed herein. [0017] Figure 6 shows a side view of a pixel in accordance with embodiments disclosed herein.

[0018] Figure 7 shows a cross-sectional view of a pixel in accordance with embodiments disclosed herein.

[0019] Figure 8 shows a front view of a micro-shader in accordance with embodiments disclosed herein.

[0020] Figure 9 shows a detailed perspective view of a pixel in accordance with embodiments disclosed herein.

[0021] Figure 10 shows a perspective view of a plurality pixels in accordance with embodiments disclosed herein.

DETAILED DESCRIPTION

[0022] Specific embodiments of the present disclosure will now be described in detail with reference to the accompanying figures. Like elements in the various figures may be denoted by like reference numerals for consistency. Further, in the following detailed description of embodiments of the present disclosure, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to one of ordinary skill in the art that the embodiments disclosed herein may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description.

[0023] In one aspect, embodiments disclosed herein generally relate to an integrated optical pixel apparatus. Lhe apparatus includes a pixel having a carrier, a first substrate disposed in the carrier, and a plurality of light emitting elements disposed on a front surface of the first substrate. Lhe carrier then includes a sealing material disposed therein and surrounding at least a portion of the first substrate. Further, the pixel may include a second substrate, in which the second substrate may be attached to a back surface of the first substrate. A driver, one or more electrical contacts, and/or a thermal shield may then be disposed upon the second substrate to provide support for the pixel. As such, the pixel may be configured to receive a data and/or a power signal, and then emit light based upon the data and/or the power signal. [0024] Referring to Figure 2, a perspective view of a pixel in accordance with embodiments of the present disclosure is shown. In this embodiment, the pixel includes multiple light emitting elements 201 attached, such as bonded, to a substrate 202. These light emitting elements 201 and substrate 202 may be enclosed in a carrier 203, in which the carrier 203 may be used to house and/or provide protection for the light emitting elements 201 and the substrate 202. A sealing material, such as a silicone gel, may then be injected into the carrier 203. For example, a through hole 204 may be formed within a side of the carrier 203, in which the sealing material may be disposed within the carrier 203 using the through hole 204.

[0025] The carrier 203 may be formed from or include a variety of materials. As shown, the carrier 203 is formed substantially of a transparent material, such as a clear material. This clear material may include a hard silicone or optically similar material. However, in addition to this transparent material, the carrier 203 may include materials having various other properties to have many desired effects. In other embodiments, the carrier may include a diffusive material, so as to diffuse the light when being transmitted through the carrier, a colored material, so as to effect the light color when being transmitted through the carrier, a refractive material, so as to effect the angle of the light when being transmitted through the carrier, and a reflective material, so as to reflect some or all of the light with the carrier. These materials for the carrier may be used in combination when constructing the housing.

[0026] In accordance with one or more embodiments disclosed herein, one or more properties of the sealing material disposed within the carrier may be substantially similar to the properties of the carrier. For example, in one embodiment, the index of refraction of the sealing material may be substantially similar to the index of refraction of the carrier. Further, in another embodiment, the color of the sealing material may be substantially similar to the color of the carrier. As such, this may enable light that is transmitted through the sealing material to look substantially the same to an observer as light that is transmitted through the carrier.

[0027] However, those having ordinary skill in the art will appreciate that the present disclosure is not so limited, and in other embodiments, one or more properties of the sealing material disposed within the carrier may be substantially different from the properties of the carrier. For example, in one embodiment, the color of the sealing material may be substantially different from the color of the carrier. As such, when light is transmitted through both the sealing material and the carrier, the properties of the light may be affected differently by each of these components of the pixel to create light having new properties. Alternatively though, any translucent or transparent sealing material known in the art may used to fill the carrier, or at least a portion of the carrier.

[0028] Referring now to Figure 3, a cross-sectional view of a pixel in accordance with embodiments of the present disclosure is shown. In this embodiment, the pixel includes light emitting elements 301 that may be attached, such as die bonded, to a first substrate 302. Further, the pixel may include a second substrate 310, in which the second substrate may include a driver circuit (discussed more below) and may be attached to the rear surface of the first substrate 302. Advantageously, this arrangement may enable the driver circuit to be thermally isolated from the light emitting elements 301, in which the first substrate 302 and the second substrate 310 may absorb or dissipate a substantial amount of the heat from the light emitting elements 301. As such, the heat formed by the light emitting elements 301, when in use, may not substantially affect the driver circuit, such as by affecting the function (e.g., speed) or the mechanical properties (e.g., strength) of the driver circuit. The first substrate 302 and second substrate 310 may then be assembled into a carrier 320. As similar to above, a sealing material may then be disposed within the carrier 320, such as filling substantially all, or at least a portion of the carrier 320 with the sealing material.

[0029] As discussed, the light emitting pixel of the present disclosure includes one or more light emitting elements. The light emitting element may then include a light emitting diode, an organic light emitting diode, a polymer light emitting diode, or any other light emitting element know in the art. Generally though, the light emitting pixel will include multiple light emitting elements. Assuming then that more than one light emitting element is used within a light emitting pixel, the light emitting elements may then be the same or different colors, or the same or different sizes, or the same or different types. For example, as shown in Figure 2, the light emitting packages include nine light emitting elements. By having nine light emitting elements, the colors of the light emitting elements may be varied. As such, the light emitting package may include one or more red, green, blue, orange, cyan, and white light emitting elements.

[0030] Referring now to Figure 4, a front view of a pixel in accordance with embodiments of the present disclosure is shown. In this embodiment, the pixel includes multiple light emitting elements 401a-j, and further includes a through hole 404 formed therein. As discussed above, the light emitting elements 401a-j may include any combination of desired colors and/or intensity of colors. For example, in this embodiment, light emitting elements 401c and 40 Ie are red, light emitting elements 401b and 40 If are blue, light emitting elements 401a and 40 Ig are green, light emitting elements 40 Id and 40 Ij are cyan, and light emitting element 41Oh is orange.

[0031] Further, those having ordinary skill in the art will appreciate that the light emitting elements may be arranged in a variety of physical arrangements. For example, in the present embodiment, light emitting elements 401a-j are arranged in a square grid array. However, in other embodiments, the light emitting elements may be arranged in a circular pattern, a rectangular pattern, or any other pattern or arrangement known in the art.

[0032] Referring now to Figure 5, a rear view of a pixel in accordance with embodiments of the present disclosure is shown. In this embodiment, the pixel is shown as enclosed within a surface mount package. This surface mount package may enable the pixel to be disposed within a system of other pixels (discussed more below). As shown, the pixel may include electrical pad connections 540 and a driver circuit 510 disposed on a surface thereof. In this embodiment, the electrical connections 540 and driver circuit 510 are mounted on a back/bottom surface of the pixel so as to not be apparent to the ordinary observer. By having the electrical connections 540, data and/or power signals may be transmitted to the light emitting elements. As such, the light emitting pixel may then be electrically connected to a power unit and/or a processor. The power unit and the processor may send power signals and/or data signals back and forth with the light emitting pixel, in particular with the light emitting elements. Based on the power signal, the light emitting elements may be selectively powered on and off or emit light with varying intensities, and based on the data signal, the light emitting elements may selectively emit light of different colors. Furthermore, with multiple light emitting elements, the lighting emitting pixel, in accordance with embodiments disclosed herein, may be configured to display an image based upon the power and data signals.

[0033] The driver circuit 510, then, may process drive voltages and currents for individual light emitting elements may be provided within the light emitting pixel by the driver circuit 510. For example, multiple light emitting element color sub-pixels may be controlled with only six connections. The six connections 540 shown in this embodiment may control a pixel with any number of sub-pixels. For example, the pixel may comprise three sub-pixels, red, green, and blue. Alternatively, the driver circuit 510 may also be configured to control a pixel with red, green, blue, cyan, orange, and white sub-pixels. Further, the driver circuit 510 may have a dedicated thermal pad 541 for removing heat from the driver circuit and/or controlling heat for the light emitting pixel altogether.

[0034] Referring now to Figures 6 and 7, multiple views of a pixel in accordance with embodiments of the present disclosure is shown. As shown in Figure 6, the pixel 601 may have a series of micro-shaders 650 attached to a front surface thereof. For example, the micro-shaders may be embedded or bonded to the pixel 601 through the sealing material disposed within the pixel 601. The sealing material may be disposed within the pixel 601 such that the sealing material forms a bond between the pixel 601 and the micro-shaders 650. Those having ordinary skill in the art though will appreciate that the micro-shaders 650 may be attached to the pixel 601 using for example, a mechanical fastener, adhesive, magnetic fastener, or any other means known in the art, without departing from the scope of the present disclosure. Advantageously then, the micro-shaders may provide shade for the light emitting elements in pixel from sunlight and ambient light. This may improve the viewing contrast and apparent brightness of a display that includes pixel.

[0035] Further, in Figure 7, a pixel 701 is shown having micro-shaders also attached to a front surface thereof. In this embodiment, the pixel 701 also includes a connector 760 attached to a back surface thereof, opposite of the micro-shaders, in which the connector 760 may accommodate mounting and/or attaching the pixel 701 to other pixels to form a light emitting system. The connector 760 may be formed within the carrier 702 of the pixel 701, as shown, or the connector 760 may alternatively be formed separately and attached to the pixel 701. Further, as shown, though the connector 760 is shown as formed as part of the back surface of the pixel 701, the connector 760 may be formed upon and/or attached to any surface of the pixel 701.

[0036] Referring now to Figure 8, a front view of a micro-shader 870 in accordance with embodiments of the present disclosure is shown. In this embodiment, the micro-shader 870 may include a plurality of thin angular structures that may be used to minimize the effect of ambient light. Further, the front and back surfaces of the micro-shader 870, or at least a portion thereof, may include an anti-reflective coating, such as, for example an anti-reflective coating. Such an anti-reflective coating was described by Petrucci-Samija et al in the paper titled Optilon™ Anti- Reflective Optical Coatings for Front Surface of Flat Panel Displays that was presented to the 2007 Society for Information Display Conference.

[0037] Alternatively, the micro-shader 870 may be include very small features, such as those described by Kim et al in the paper Thin Film Coatings that Reflect Virtually No Light. An anti-reflective coating, similar to that as described by Kim et al, may be applied under a harder top protective coating and may assist in optimizing the performance of the light extraction of the total internal reflection (TIR) color mixing section from the pixel. Further, each of the anti-reflective coatings, as described by Petrucci-Samija and Kim, may be used in combination, such as by applying the Petrucci-Samija anti-reflective coating on the front surface of the micro-shader 870, and applying the Kim anti-reflective coating on the back surface of the micro-shader 870. Advantageously, the micro-shader 870 may also be used to reflect infrared light by using larger features than those disclosed within Petrucci- Samija and Kim, thereby also serving as a heat shield.

[0038] Referring now to Figure 9, a detailed view of a pixel having a light guide in accordance with embodiments of the present disclosure is shown. In this embodiment, the pixel may include a carrier 902, in which a light guide 970 may be attached to or formed with the carrier 902. This light guide 970 may then guide and transmit light to a photo receptor disposed adjacent or attached to the pixel. For example, the photo receptor may be mounted on a driver circuit or, alternatively, may be mounted on a substrate. The light guide 970 and photo receptor may then sample light from near the center of the pixel to measure properties of the light emitted by the pixel. For example, the light guide 970 and photo receptor may measure the color, brightness, and/or white balance of the light being emitted by the pixel.

[0039] Alternatively, the light guide 970 and photo receptor may also be used to receive coded light signal data from a remote controller. The photo receptor may be any suitable receptor known in the art, such as a photo diode, a photo transistor, a charge-coupled device ("CCD"), or another photosensitive integrated circuit or assembly. As such, the remote controller may send coded light signal data to the pixel, in which the light guide and photo receptor would be configured to receive the data. Although a single light guide and photo receptor are illustrated in Figure 9, further embodiments may include multiple light guides and/or multiple photo receptors. Further, because of the color mixing of the light emitting from the light emitting elements within the pixel, the photo receptor and the light guide 970 may be used to measure features or characteristics of each pixel, such as the homogenized chrominance and luminance of each pixel.

[0040] Referring now to Figure 10, a detailed view of a multiple pixels lOOla-c in accordance with embodiments of the present disclosure is shown. In this embodiment, each of the pixels 1001a-c includes an overmolded shader attached to a front surface thereof. Further, each of the pixels 1001a-c may be include an over- molded front cover 1002a attached thereto. Advantageously, a top 1003 a of the front cover 1002a may then provide structural support and protection for the multiple pixels 1001a-c, in addition to providing shade for the pixels 1001a-c to improve apparent brightness and display contrast. Similarly, pixels lOOld-f may also be fitted with a cover 1002b and shader 1003b.

[0041] Embodiments of the integrated optical pixel apparatus disclosed herein may provide for one or more of the following advantages. First, the integrated optical pixel apparatus disclosed herein may allow for light emitting elements or other light emitting devices to be integrated with driver circuitry in a carrier, thereby resulting in a highly integrated pixel package. Next, the integrated optical pixel apparatus disclosed herein may further allow for thermal management systems and luminance and chromaticity feedback systems to be integrated in the same highly integrated pixel package. Further, the integrated optical pixel apparatus disclosed herein may allow for an integrated pixel package to be protected from environmental effects by, for example, a sealing material or shader. Finally, the integrated optical pixel apparatus disclosed herein may allow for a highly integrated pixel package that is compatible with both surface mount and non-surface mount systems. While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments may be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.

Claims

CLAIMSWhat is claimed is:

1. An integrated optical pixel apparatus, comprising: a pixel comprising: a carrier; a first substrate disposed in the carrier; and a plurality of light emitting elements disposed on a front surface of the first substrate, wherein the carrier comprises a sealing material disposed therein and surrounding at least a portion of the first substrate.

2. The integrated optical pixel apparatus of claim 1, wherein the pixel further comprises: a second substrate containing a driver circuit electrically connected to the plurality of light emitting elements, wherein the second substrate is disposed in the carrier, and wherein the second substrate is attached to the rear of the first substrate.

3. The integrated optical pixel apparatus of claim 2, wherein the second substrate and the driver circuit are thermally isolated from the plurality of light emitting elements.

4. The integrated optical pixel apparatus of claim 1, further comprising a plurality of electrical pads disposed on a rear surface of the pixel and electrically connected to at least one of the light emitting elements.

5. The integrated optical pixel apparatus of claim 1, wherein the carrier comprises silicone.

6. The integrated optical pixel apparatus of claim 4, further comprising a thermal pad disposed on the rear surface of the pixel to remove heat from the driver circuit.

7. The integrated optical pixel apparatus of claim 1, wherein the plurality of light emitting elements comprise a plurality of colors.

8. The integrated optical pixel apparatus of claim 1, wherein each of the plurality of light emitting elements comprises a light emitting diode.

9. The integrated optical pixel apparatus of claim 1, wherein the sealing material comprises at least one of a transparent sealing material and a translucent sealing material.

10. The integrated optical pixel apparatus of claim 1, wherein the sealing material comprises a silicone gel.

11. The integrated optical pixel apparatus of claim 1 , wherein the sealing material comprises an index of refraction substantially the same as an index of refraction of the carrier.

12. The integrated optical pixel apparatus of claim 1, wherein the light emitting apparatus further comprises: a micro-shader layer disposed on a front surface of the pixel and comprising a plurality of shaders embedded in a front face of the carrier.

13. The integrated optical pixel apparatus of claim 12, further comprising an anti-reflective coating disposed on at least one of a front surface and a back surface of the micro- shader layer.

14. The integrated optical pixel apparatus of claim 1, wherein the carrier further comprises a light guide and a photo receptor, wherein the light guide is configured to transmit light from a front surface of the carrier to the photo receptor.

15. The integrated optical pixel apparatus of claim 14, wherein the photo receptor comprises at least one of a photo diode, a photo transistor, and a charge-coupling device.

16. The integrated optical pixel apparatus of claim 1, further comprising: a plurality of pixels; and an over-molded shader comprising: an over-molded silicone cover, wherein at least one pixel is fitted to the over- molded silicone cover, and wherein a front of the over-molded silicone cover is configured to provide shade for the at least one pixel fitted thereto.

17. A method for creating an integrated optical pixel apparatus, the method comprising: disposing a plurality of light emitting elements on a front surface of a first substrate; disposing a driver on a second substrate; connecting the back surface of a first substrate with the second substrate; disposing the first and second substrates into a carrier; and injecting a sealing material into at least a portion of the remaining space within the carrier.

18. The method for creating an integrated optical pixel apparatus according to claim 17, further comprising: embedding micro-shaders into the front surface of the silicone carrier.

19. The method for creating an integrated optical pixel apparatus according to claim 18, further comprising: disposing an anti-reflective coating on at least one of a front surface and a back surface of the micro-shaders.

20. The method for creating an integrated optical pixel apparatus according to claim 17, further comprising: disposing a surface mount package on the back surface of the silicone carrier.

21. The method for creating an integrated optical pixel apparatus according to claim 17, further comprising: disposing a photo sensor within the carrier; and disposing a light guide between a front surface of the carrier and the photo sensor.

22. The method for creating an integrated optical pixel apparatus according to claim 17, further comprising: connecting at least one pixel to an over-molded silicone cover.

23. The method for creating an integrated optical pixel apparatus according to claim 17, wherein the carrier comprises silicone.

24. A method for displaying an image, comprising: providing a pixel comprising: a carrier; a first substrate disposed in the carrier; and a plurality of light emitting elements disposed on a front surface of the first substrate, wherein the carrier comprises a sealing material disposed therein and surrounding at least a portion of the first substrate; and sending a signal to pixel, wherein the pixel is configured to emit light based on the signal.

25. The method for displaying an image according to claim 24, wherein the signal comprises at least one of a power signal and a data signal.