Reducing the occurrence of defective pixels in a light-emitting array

Abstract

The light-emitting device of the present invention includes an array of a plurality of light-emitting pixels, and one or more transmissive optical elements located at the light-emitting surface of the light-emitting pixel array. One or more of the light-emitting pixels are defective. Each optical element is located at the position of the corresponding defective light-emitting pixel, extends above the defective pixel, and at least partially laterally extends above one or more adjacent pixels. Each optical element laterally transmits at least a portion of the light emitted by the adjacent pixels to propagate away from the array from the position of the defective pixel, thereby reducing the appearance of the defective pixel.

Description

[0001] Priority Claim

[0002] This application claims priority to (i) U.S. Provisional Application No. 63 / 121,465, filed Dec. 4, 2020, in the name of Lopez et al. and entitled “Method for reducing dead pixel appearance in LED matrix modules” and (ii) U.S. Non-Provisional Application No. 17 / 539,941, filed Dec. 1, 2021, in the name of Lopez et al. and entitled “Reduction of defective pixel appearance in light-emitting arrays”; each of the aforementioned applications is incorporated herein by reference in its entirety. Field of the Invention

[0003] The present invention generally relates to light-emitting diodes and phosphor-converted light-emitting diodes. Background Art

[0004] Semiconductor light-emitting diodes and laser diodes (collectively referred to herein as “LEDs”) are one of the most efficient light sources currently available. The emission spectrum of an LED typically exhibits a single narrow peak at a wavelength determined by the structure of the device and the composition of the semiconductor materials of which it is composed. By appropriately selecting the device structure and material system, an LED can be designed to operate at ultraviolet, visible, or infrared wavelengths.

[0005] An LED can be combined with one or more wavelength-converting materials (generally referred to herein as “phosphors”) that absorb the light emitted by the LED and emit light at a longer wavelength in response. For such a phosphor-converted LED (“pcLED”), the fraction of the light emitted by the LED that is absorbed by the phosphor depends on the amount of phosphor material in the optical path of the light emitted by the LED, e.g., on the concentration of the phosphor material in a phosphor layer disposed on or around the LED and the thickness of the layer.

[0006] A phosphor-converted LED can be designed such that all of the light emitted by the LED is absorbed by one or more phosphors, in which case the emission from the pcLED comes entirely from the phosphors. In such a case, for example, the phosphors can be selected to emit light in a narrow spectral region that is not directly and efficiently generated by the LED.

[0007] Alternatively, a pcLED can be designed such that only a portion of the light emitted by the LED is absorbed by the phosphor, in which case the emission from the pcLED is a mixture of the light emitted by the LED and the light emitted by the phosphor. By appropriately selecting the LED, the phosphor, and the phosphor composition, such a pcLED can be designed to emit white light having, for example, a desired color temperature and desired color rendering properties.

[0008] Multiple LEDs or pcLEDs can be formed together on a single substrate to form an array. Such an array can be used to form an active lighting display, such as those employed in, for example, smartphones and smartwatches, computers or video displays, augmented or virtual reality displays, or signage; or to form an adaptive lighting source, such as those employed in, for example, motor vehicle headlights, streetlights, camera flash sources, or flashlights (i.e., torches). An array having one or several or many individual devices per millimeter (e.g., a device pitch or spacing of about one millimeter, a few hundred micrometers, or less than 100 micrometers, and a separation between adjacent devices of less than 100 micrometers or only a few tens of micrometers or less) is generally referred to as a miniLED array or a microLED array (alternatively, a μLED array). Such a miniLED array or microLED array can also, in many instances, include a phosphor converter as described above; such an array can be referred to as a pc-miniLED array or a pc-microLED array. SUMMARY OF THE INVENTION

[0009] The light-emitting device of the present invention includes an array of a plurality of light-emitting pixels, and one or more transmissive optical elements located at a light-emitting surface of the light-emitting pixel array. One or more of the light-emitting pixels are defective. Each optical element is located at the position of a corresponding defective light-emitting pixel, extends above the defective pixel, and laterally extends at least partially above one or more adjacent pixels. Each optical element laterally transmits at least a portion of the light emitted by the adjacent pixels to propagate away from the array from the position of the defective pixel. Thus, the appearance of the defective pixel is reduced.

[0010] The objectives and advantages related to LEDs, pcLEDs, miniLED arrays, pc-miniLED arrays, microLED arrays, and pc-microLED arrays may become apparent when referring to the examples illustrated in the accompanying drawings and described in the following written description or the appended claims.

[0011] The present Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. The present Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to assist in determining the scope of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 FIG. 1 shows a schematic cross-sectional view of an exemplary pcLED.

[0013] Figure 2A and Figure 2B FIGS. 2A and 2B respectively show a schematic cross-sectional view and a top view of an exemplary array of pcLEDs.

[0014] Figure 3A FIG. 3 shows a schematic cross-sectional view of an exemplary array of pcLEDs arranged relative to a waveguide and a projection lens. Figure 3B FIG. 4 shows an arrangement similar to the arrangement of Figure 3A but without a waveguide.

[0015] Figure 4A FIG. 5 shows a schematic top view of an exemplary array of miniLEDs or microLEDs and an enlarged portion of a 3×3 LED of the array. Figure 4B FIG. 6 shows a perspective view of several LEDs of an exemplary array of pc-miniLEDs or pc-microLEDs monolithically formed on a substrate. Figure 4C FIG. 7 is a schematic side cross-sectional view of an example of a close-packed array of multicolor phosphor-converted LEDs on a monolithic die and substrate.

[0016] Figure 5A FIG. 8 is a schematic top view of a portion of an exemplary LED display, where each display pixel is a red, green, or blue phosphor-converted LED pixel. Figure 5B FIG. 9 is a schematic top view of a portion of an exemplary LED display, where each display pixel includes a plurality of phosphor-converted LED pixels (red, green, and blue) integrated onto a single die, and the single die is bonded to a control circuit backplane.

[0017] Figure 6A FIG. 10 shows a schematic top view of an exemplary electronic board on which a pcLED array can be mounted, and Figure 6B similarly shows an exemplary pcLED array mounted on an electronic board of Figure 6A FIG. 11.

[0018] Figure 7 FIG. 12 is a schematic top view of an exemplary inventive light-emitting array having defective pixels and transmissive optical elements. For clarity, any wavelength conversion layer (if present) is omitted.

[0019] Figure 8A and Figure 8B FIG. 13 is a schematic side cross-sectional view of an exemplary inventive light-emitting array having defective pixels and transmissive optical elements.

[0020] Figure 9A and Figure 9B is a schematic side cross-sectional view of an exemplary inventive light-emitting array having defective pixels and transmissive optical elements.

[0021] Figure 10 are graphs of simulated near-field emission rate versus lateral position for several exemplary light-emitting arrays.

[0022] Figure 11 illustrates an exemplary method of fabricating the inventive light-emitting array.

[0023] The depicted examples are shown schematically only; all features may not be shown in complete detail or to scale; for clarity, some features or structures may be exaggerated or reduced relative to other features or structures, or may be omitted entirely; the drawings should not be considered to be to scale unless explicitly indicated as such. For example, the vertical dimensions or layer thicknesses of the individual LEDs may be exaggerated relative to their lateral extent or relative to the substrate or phosphor thickness. The examples shown should not be construed as limiting the scope of the present disclosure or the appended claims. Detailed Description

[0024] The following detailed description should be read with reference to the drawings, in which like reference numerals refer to like elements throughout the different figures. The drawings, which are not necessarily to scale, depict selected examples and are not intended to limit the scope of the subject matter of the invention. The detailed description illustrates, by way of example, and not by way of limitation, the principles of the subject matter of the invention. For purposes of simplicity and clarity, the detailed descriptions of well-known devices, circuits, and methods may be omitted so as not to obscure the description of the subject matter of the invention with unnecessary detail.

[0025] Figure 1 Illustrated is an example of an individual pcLED 100 that includes a semiconductor diode structure 102 (collectively referred to herein as “LED” or “semiconductor LED”) disposed on a substrate 104, and a wavelength-converting structure (e.g., phosphor layer) 106 disposed on the semiconductor LED. The semiconductor diode structure 102 generally includes an active region disposed between an n-type layer and a p-type layer. Application of a suitable forward bias across the diode structure 102 causes light emission from the active region. The wavelength of the emitted light is determined by the composition and structure of the active region.

[0026] The LED can be, for example, a Group III nitride LED that emits blue, violet, or ultraviolet light. LEDs formed from any other suitable material system and emitting light of any other suitable wavelength can also be used. Other suitable material systems can include, for example, Group III phosphide materials, Group III arsenide materials, other binary, ternary, or quaternary alloys of gallium, aluminum, indium, nitrogen, phosphorus, or arsenic, or II-VI materials.

[0027] Depending on the desired optical output from the pcLED, any suitable phosphor material can be used for or incorporated into the wavelength conversion structure 106.

[0028] Figures 2A - 2B A cross-sectional view and a top view of an array 200 of pcLEDs 100 disposed on a substrate 204 are shown, each pcLED 100 including a phosphor pixel 106. Such an array can include any suitable number of pcLEDs arranged in any suitable manner. In the illustrated example, the array is depicted as being formed monolithically on a shared substrate, but alternatively, the pcLED array can be formed of discrete individual pcLEDs (e.g., singulated devices assembled onto an array substrate). Individual phosphor pixels 106 are shown in the illustrated example, but alternatively, an adjacent layer of phosphor material can be disposed across multiple LEDs 102. In some instances, the array 200 can include a light barrier (e.g., reflective, scattering, and / or absorptive) between adjacent LEDs 102, phosphor pixels 106, or both. The substrate 204 can optionally include electrical traces or interconnects, or CMOS or other circuitry for driving the LEDs, and can be formed of any suitable material.

[0029] Optionally, each pcLED 100 can include a lens or other optical element, or be arranged in combination with a lens or other optical element, which is positioned adjacent to or disposed on the phosphor layer. Such an optical element (not shown in the figures) can be referred to as a "primary optical element". Additionally, as Figures 3A - 3B shown, the pcLED array 200 (e.g., mounted on an electronic board) can be arranged in combination with a secondary optical element (such as a waveguide, a lens, or both) for use in an intended application. In Figure 3A shown, light emitted by each pcLED 100 of the array 200 is collected by a corresponding waveguide 192 and directed to a projection lens 294. For example, the projection lens 294 can be a Fresnel lens. For example, this arrangement can be suitable for use in vehicle headlights or other adaptive lighting sources. As needed or desired, each pixel can include any suitable type or arrangement of other primary or secondary optical elements. In Figure 3B shown, light emitted by the pcLEDs of the array 200 is directly collected by the projection lens 294 without using an intervening waveguide. This arrangement can be particularly suitable when the pcLEDs can be spaced sufficiently close to each other, and can also be used in vehicle headlights as well as camera flash applications or other lighting sources. For example, miniLED or microLED display applications can use the same Figures 3A - 3BAn optical arrangement similar to the one depicted. Generally, depending on the desired application, any suitable arrangement of optical elements (primary, secondary, or both) can be used in combination with the pcLEDs described herein.

[0030] Although Figure 2A and Figure 2B show a 3×3 array of nine pcLEDs, such arrays can include, for example, LEDs on the order of 10 1 、10 2 、10 3 、10 4 or more, as schematically shown, for example, in Figure 4A Each LED 100 (i.e., pixel) can have a width w1 (e.g., side length) in the plane of the array 200 that is, for example, less than or equal to 1 millimeter (mm), less than or equal to 500 micrometers, less than or equal to 100 micrometers, or less than or equal to 50 micrometers. The LEDs 100 in the array 200 can be separated from each other by a street, lane, or trench 230 having a width w2 in the plane of the array 200 that is, for example, several hundred micrometers, less than or equal to 100 micrometers, less than or equal to 50 micrometers, less than or equal to 20 micrometers, less than or equal to 10 micrometers, or less than or equal to 5 micrometers. The pixel pitch or spacing D1 is the sum of w1 and w2. Although the illustrated examples show rectangular pixels arranged in a symmetric matrix, these pixels and arrays can have any suitable shape or arrangement, whether symmetric or asymmetric. Multiple separate LED arrays can be combined in any applicable format and in any suitable arrangement to form a larger combined array or display.

[0031] LEDs with a dimension w1 (e.g., side length) in the array plane that is less than or equal to about 0.10 millimeters are generally referred to as microLEDs, and an array of such microLEDs can be referred to as a microLED array. LEDs with a dimension w1 (e.g., side length) between approximately 0.10 millimeters and approximately 1.0 millimeters are generally referred to as miniLEDs, and an array of such miniLEDs can be referred to as a miniLED array.

[0032] An array of LEDs, miniLEDs, or microLEDs, or portions of such arrays, can be formed as a segmented monolithic structure in which individual LED pixels are electrically isolated from each other by trenches and / or insulating materials. Figure 4BA perspective view showing an example of such a segmented monolithic LED array 200 is presented. The pixels in the array (i.e., the individual semiconductor LED devices 102) are separated by trenches 230, which are filled to form n-type contacts 234. The monolithic structure is grown or disposed on a substrate 204. Each pixel includes a p-type contact 236, a p-GaN semiconductor layer 102b, an active region 102a, and an n-GaN semiconductor layer 102c; the layers 102a / 102b / 102c together form the semiconductor LED 102. The wavelength-converting material 106 can be deposited on the semiconductor layer 102c (or other applicable intermediate layer). A passivation layer 232 can be formed within the trenches 230 to separate at least a portion of the n-type contacts 234 from one or more layers of the semiconductor. The n-type contacts 234, other materials within the trenches 230, or materials different from those within the trenches 230 can extend into the converter material 106 to form a complete or partial optical isolation barrier 220 between the pixels.

[0033] Figure 4C A schematic cross-sectional view of a closely packed array 200 of monolithic die and multicolor phosphor-converted LEDs 100 on a substrate 204 is shown. This side view shows a GaN LED 102 attached to the substrate 204 via metal interconnects 239 (e.g., gold-gold interconnects or solder attached to copper microcolumns) and metal interconnects 238. The phosphor pixels 106 are located on or above the corresponding GaN LED pixels 102. The semiconductor LED pixels 102 or the phosphor pixels 106 (usually both) can be coated on their sides with mirrors or diffusive scattering layers to form an optical isolation barrier 220. In this example, each phosphor pixel 106 is one of three different colors, e.g., a red phosphor pixel 106R, a green phosphor pixel 106G, and a blue phosphor pixel 106B (still generally or collectively referred to as phosphor pixels 106). Such an arrangement can enable the use of the LED array 200 as a color display.

[0034] Each LED (pixel) in the LED array can be individually addressable, addressable as part of a group or subset of pixels in the array, or may not be addressable. Thus, a light-emitting pixel array is useful for any application that requires or benefits from fine-grained intensity, spatial, and temporal control of light distribution. These applications can include, but are not limited to, precise special patterning of the emitted light from pixel blocks or individual pixels, including in some instances forming an image as a display device. Depending on the application, the emitted light can be spectrally distinct, time-adaptive, and / or environment-responsive. The light-emitting pixel array can provide a pre-programmed light distribution in various intensity, spatial, or temporal patterns. The emitted light can be at least partially based on received sensor data and can be used for optical wireless communication. The associated electronics and optics can be distinct at the pixel, pixel-block, or device level.

[0035] Figure 5A and Figure 5B FIG. 200 is an example of an LED array 200 employed in a display application, where the LED display includes a large number of display pixels. In some examples (e.g., as in Figure 5A ), each display pixel includes a single semiconductor LED pixel 102 and a phosphor pixel 106R, 106G, or 106B of a corresponding single color (red, green, or blue). Each display pixel provides only one of the three colors. In some examples (e.g., as in Figure 5B ), each display pixel includes a plurality of semiconductor LED pixels 102 and a plurality of corresponding phosphor pixels 106 of multiple colors. In the example shown, each display pixel includes a 3×3 array of semiconductor pixels 102; three of those LED pixels have red phosphor pixels 106R, three have green phosphor pixels 106G, and three have blue phosphor pixels 106B. Thus, each display pixel can produce any desired color combination. In the example shown, the spatial arrangement of the phosphor pixels 106 of different colors is different between display pixels; in some examples (not shown), each display pixel can have the same arrangement of phosphor pixels 106 of different colors.

[0036] As Figure 6A and 6BAs shown in FIG. 0, the pcLED array 200 can be mounted on an electronic board 300, which includes a power supply and control module 302, a sensor module 304, and an LED attachment area 306. The power supply and control module 302 can receive power and control signals from an external source and signals from the sensor module 304, and the power supply and control module 302 controls the operation of the LEDs based on these signals. The sensor module 304 can receive signals from any suitable sensor (e.g., from a temperature or light sensor). Alternatively, the pcLED array 200 can be mounted on a separate board (not shown) from the power supply and control module and the sensor module.

[0037] One of the challenges of using large arrays of small LED pixels is to ensure that almost all pixels are operating properly and are lit to a desired or required emission rate level. During fabrication, a small group of abnormal pixels can be identified that are not sufficiently lit (or not lit at all) and appear as dark or dim spots. Defective pixels are also often referred to as bad pixels. Depending on the local distribution of such defective pixels on the light-emitting array, even a fraction of defective pixels less than one percent of the array can, in some instances, prevent its use in many applications. Thus, it is desirable to develop techniques or structures that reduce such fabrication yield loss of the light-emitting array by reducing the occurrence of defective pixels as dark or dim spots.

[0038] Accordingly, the light-emitting device of the present invention includes an array 400 of a plurality of light-emitting pixels 402, and one or more transmissive optical elements 450 located on the light-emitting surface of the light-emitting pixel array 400 (such as Figure 7 , Figure 8A , Figure 8B , Figure 9A and Figure 9B(In the figure). A 4×4 segment of the array 400 is shown; the array 400 may include any suitable number or arrangement of light-emitting pixels 402, and in some examples may include any suitable type of light barrier 420 between adjacent pixels 402. One or more of the light-emitting pixels 402 may be defective and are hereinafter referred to as and labeled in the drawings as (one or more) defective pixels 402D. Each optical element 450 is located at and extends above the position of a corresponding defective light-emitting pixel 402D, and laterally extends at least partially above one or more pixels 402 of the array 400 adjacent to the corresponding defective pixel 402D. These adjacent pixels are hereinafter referred to as and labeled in the drawings as adjacent pixels 402A. Note that any reference herein to "pixel 402" includes all pixels of the array 400, which includes defective pixels 402D and adjacent pixels 402A. Each optical element 450 laterally transmits some of the light emitted by the adjacent light-emitting pixels 402A to propagate away from the array 400 from the position of the defective pixel 402D, and thus appears to have been emitted by the defective pixel 402D. Thereby, the appearance of the defective pixel 402D is reduced because some of the light emitted by its neighbors 402A appears to be emitted from its position. In some examples, the optical element 450 may be transparent; in some examples, the optical element 450 acts as a diffusive scatterer and may include scattering particles (e.g., titanium oxide or other suitable materials) for this purpose. The optical element 450 causes a greater amount of lateral transmission of light than would otherwise occur in the absence of the optical element 450. The scattering particles (if present) may serve to reduce the emission rate or color variation across the region of the defective pixel 402D.

[0039] A method of manufacturing the device of the present invention (e.g., as Figure 11 (In the figure)) may begin by identifying one or more defective pixels 402D of the array 400, e.g., using imaging or electrical testing. In some examples, the pixels 402 may be activated sequentially, one at a time, in groups, or according to any suitable scheme, and the positions of the detected defective pixels 402D are recorded. By attaching pre-formed optical elements 450 or by forming the optical elements 450 in situ (described further below), the corresponding transmissive optical elements 450 may be positioned at the location of each defective pixel 402D. Each optical element 450 extends above the corresponding defective light-emitting pixel 402D and laterally extends at least partially above the corresponding adjacent pixels 402A.

[0040] After positioning one or more optical elements 450, in some examples, the method may further include testing each defective pixel 402D against a predetermined light compensation level. In some examples, the testing may require that each defective pixel 402D exhibits an emission rate greater than 30%, 50%, 66%, or 75% of the emission rate of an adjacent pixel 402A when the adjacent pixel 402A is activated.

[0041] In some examples, each light-emitting pixel 402 includes a corresponding semiconductor light-emitting diode (LED) and may be arranged in any suitable manner (including any of the arrangements described above). In some examples, the light-emitting pixel 402 may include one or more doped or undoped Group III-V, Group II-VI, or Group IV semiconductor materials or alloys or mixtures thereof; in some examples, each light-emitting pixel 402 may include one or more p-n junctions, one or more quantum wells, one or more multiple quantum wells, or one or more quantum dots. In some examples, the light emitted by the light-emitting pixel 402 may have a vacuum wavelength greater than 0.20 μm, greater than 0.4 μm, greater than 0.8 μm, less than 10 μm, less than 2.5 μm, or less than 1.0 μm. In some examples, each light-emitting pixel 402 of the array 400 may be operable independently of at least one other light-emitting pixel 402 of the array 400; in some examples, all light-emitting pixels 402 may be operable independently of each other. In some examples, the pitch (i.e., spacing) of the light-emitting pixels 402 of the array 400 may be less than about 1.0 mm, less than about 0.50 mm, less than about 0.33 mm, less than about 0.20 mm, less than about 0.10 mm, less than about 0.08 mm, less than about 0.05 mm, less than about 0.033 mm, or less than about 0.020 mm. In some examples, the light-emitting pixels 402 of the array 400 may be separated by non-emitting pixel boundaries having a non-zero width less than 0.10 mm, less than 0.050 mm, less than 0.033 mm, less than 0.020 mm, less than 0.010 mm, or less than 0.005 mm. In some examples, these boundaries may include light barriers 420 of any suitable type or arrangement (e.g., reflective, scattering, or absorptive).

[0042] In some examples, the output of the light-emitting device 400 is the light directly emitted by the light-emitting pixels 402 (e.g., semiconductor LEDs). In such examples, each optical element 450 may be located directly on the corresponding light-emitting surface of the LED of a corresponding defective pixel 402D and one or more corresponding adjacent light-emitting pixels 402A.

[0043] In some examples, the light-emitting device 400 may include any suitable type of wavelength conversion layer 406, including those described above. Some or all of the light emitted by the light-emitting pixels 402 is absorbed by the wavelength conversion layer 406, which in turn emits light of one or more longer wavelengths. In some examples (including Figure 8A , Figure 8B , Figure 9A and Figure 9B shown in), the wavelength conversion layer 406 may form an adjacent layer extending over a plurality of light-emitting pixels 402 of the array 400 (including over any defective pixel 402D and its adjacent pixels 402A). In some other examples, the wavelength conversion layer 406 may include a plurality of discrete wavelength conversion pixel elements, each wavelength conversion pixel element being located on or above a corresponding one of the light-emitting pixels 402 of the array 400 (including over any defective pixel 402D and its adjacent pixels 402A).

[0044] In some examples, the optical element 450 is located between the light-emitting pixel array 402 and the wavelength conversion layer 406 (e.g., as in Figure 8A and Figure 8B ). In some of those examples (e.g., as in Figure 8A ), there may be a distinct boundary between each optical element 450 and an adjacent portion of the wavelength conversion layer 406. In some other examples of those examples (where the wavelength conversion layer 406 is porous), each light-emitting element 450 may include a portion injected into the pores of the wavelength conversion layer 406 (e.g., as in Figure 8B ). For example, the porous wavelength conversion layer 406 may be formed as an aggregate of, for example, precipitated phosphor particles, self-assembled phosphor particles, or layer-bonded phosphor particles (e.g., using chemical vapor deposition or atomic layer deposition). In examples including the injected portion of the optical element 450, a portion of the optical element 450 may remain outside the porous wavelength conversion layer 406 (as in the example of Figure 8B ); in other examples, the optical element may be completely surrounded within the pores of the porous wavelength conversion layer 406. In examples where there is an optical element 450 between the array 400 and the wavelength conversion layer 406, the optical element 450 may be positioned on the array 400 before the layer 406 is attached to or formed on the array 400.

[0045] In some examples, the wavelength conversion layer 406 is located between the light-emitting pixel array 400 and the optical element 450 (e.g., as in Figure 9A and Figure 9B ). In some of those examples (e.g., as in Figure 9AIn (the examples), there may be a distinct boundary between each optical element 450 and an adjacent portion of the wavelength conversion layer 406. In some other examples among those examples (where the wavelength conversion layer is porous), each light-emitting element 450 may include a portion (e.g., as shown in Figure 9B In the examples including the injected portion of the optical element 450, a portion of the optical element 450 may remain outside the porous wavelength conversion layer 406 (as shown in Figure 9B In the examples); in other examples, the optical element may be completely surrounded within the pores of the porous wavelength conversion layer 406. In examples having the wavelength conversion layer 406 between the array 400 and the optical element 450, the optical element 450 may be positioned on the layer 406 after the layer 406 is attached to the array 400 or formed on the array 400.

[0046] In examples where all or a portion of the optical element 450 is outside the wavelength conversion layer 406, the transparent or translucent material of the optical element 450 allows some light entering from the adjacent pixel 402A to propagate laterally toward the defective pixel 402D. Multiple internal reflections or refractions, or multiple scattering events ultimately cause some light emitted by the adjacent pixel 402A to leave the optical element 450 and propagate away from the array 400 from the location of the defective pixel 402D, seemingly having been emitted by it. In some examples, by injecting all or a portion of the optical element 450 into the pores of the porous wavelength conversion layer 406, the presence of the optical element 450 within the pores (instead of, for example, air) reduces the refractive index contrast between the pores and the wavelength conversion material of the layer 406. This reduced refractive index contrast reduces the optical scattering that may have occurred within the layer 406, thereby allowing more light emitted by the adjacent pixel 402A to reach the location of the defective pixel 402D. Some of this light leaves the wavelength conversion layer 406 from the location of the defective pixel 402D and propagates away from the array 400, seemingly having been emitted by the defective pixel 402D.

[0047] In some examples, the optical element 450 may be pre-formed, positioned at the location of the defective pixel 402D, and attached to the array 400 or the layer 406 in any suitable manner (e.g., pick-and-place positioning, attachment using an adhesive, etc.). Such a process may result in an arrangement similar to that of the examples of Figure 8A or Figure 9A In the examples.

[0048] In some other examples, the optical element 450 can be formed at the location of the defective pixel 402D on the array 400 or the layer 406. In some examples, one or more drops of a liquid or semi-liquid precursor can be deposited at the location of each defective pixel 402D. Examples of suitable precursors can include one or more polymer precursors (e.g., monomers, initiators, crosslinkers, etc.) or spin-on glass precursors (e.g., a suspension of silica particles with boron, phosphorus, or other additives). In some examples, the precursor can include suspended light-scattering particles (e.g., titanium oxide) of any suitable composition. Curing the deposited precursor droplets forms the optical element 450, which includes one or more solid polymer materials (e.g., one or more silicone resins) or one or more solid spin-on glass materials. If light-scattering particles are present in the precursor, the optical element 450 will include the light-scattering particles.

[0049] In some examples, the optical element 450 can have a circular raised shape, such as: a dome, hemisphere, spherical cap, or spherical segment (with a circular edge in some instances), a hemisphere, spherical dome, or spherical segment (with a circular edge in some instances), a semi-ellipsoid, ellipsoidal dome, or ellipsoidal segment (with a circular edge in some instances), a droplet, or a meniscus, etc. In some examples, such a shape can be easily produced from the deposition and curing of a liquid or semi-liquid precursor.

[0050] In some examples, the liquid or semi-liquid precursor can be deposited at the location of the defective pixel 402D on the porous wavelength conversion layer 406. Depending on the wettability of the precursor with respect to the porous layer 406, in some examples, the precursor can be injected into the pores of the layer 406. Upon curing, some or all of the resulting optical element 450 can be injected into the pores of the layer 406, thereby producing an arrangement such as Figure 8B or Figure 9B the arrangement of.

[0051] Figure 10 A graph showing the simulated relative emissivity as a function of the lateral position across a light-emitting pixel array with a 40-μm spacing is shown. Curve 499 corresponds to all fully functional pixels 402; curve 498 corresponds to fully defective pixels 402D without any optical element 450 (no emission); curve 497 corresponds to fully defective pixels 402D in an example using the spin-on glass material arrangement as in Figure 8A ; curve 496 corresponds to as in Figure 9BThe completely defective pixel 402D in an example of the arrangement of injected silicone droplets used in

[0052] In addition to the foregoing, the following example embodiments fall within the scope of the present disclosure or the appended claims.

[0053] Example 1. A light-emitting device, comprising: (a) an array of a plurality of light-emitting pixels, one or more of the light-emitting pixels being defective; and (b) one or more transmissive optical elements located at the light-emitting surface of the light-emitting pixel array, (c) each optical element being located at the position of a corresponding one of the one or more defective light-emitting pixels and extending above the corresponding defective light-emitting pixel and at least partially laterally above one or more light-emitting pixels of the array adjacent to the corresponding defective pixel, (d) each optical element being arranged to laterally transmit at least a portion of the light emitted by one or more corresponding adjacent light-emitting pixels to propagate away from the array from the position of the corresponding defective pixel.

[0054] Example 2. The device according to Example 1, wherein each light-emitting pixel includes a corresponding light-emitting diode (LED).

[0055] Example 3. The device according to any one of Examples 2 or 3, wherein each optical element is directly located on the corresponding light-emitting surface of the corresponding defective pixel and one or more corresponding adjacent light-emitting pixels.

[0056] Example 4. The device according to any one of Examples 1 to 3, further comprising a wavelength conversion layer located at the light-emitting surface of the light-emitting pixel array, wherein one or more optical elements are located between the light-emitting pixel array and the wavelength conversion layer.

[0057] Example 5. The device according to any one of Examples 1 or 2, further comprising a wavelength conversion layer located at the light-emitting surface of the light-emitting pixel array, between the one or more optical elements and the light-emitting pixel array.

[0058] Example 6. The device according to any one of Examples 4 or 5, wherein the wavelength conversion layer is porous and each light-emitting element includes a portion injected into the pores of the wavelength conversion layer.

[0059] Example 7. The device according to any one of Examples 4 or 5, wherein each optical element forms a distinct boundary with an adjacent portion of the wavelength conversion layer.

[0060] Example 8. The device according to any one of Examples 4 to 7, wherein the wavelength conversion layer is formed over the plurality of light-emitting pixels of the array and includes an adjacent layer extending over each defective pixel and the corresponding adjacent pixel.

[0061] Example 9. The device according to any one of Examples 4 to 7, wherein the wavelength conversion layer includes a plurality of discrete wavelength conversion pixel elements, each wavelength conversion pixel element being located on or above a corresponding one of the light-emitting pixels of the array and including over each defective pixel and the corresponding adjacent pixel.

[0062] Example 10. The device according to any one of Examples 1 to 9, wherein one or more of the optical elements have a circular convex shape.

[0063] Example 11. The device according to any one of Examples 1 to 10, wherein one or more of the optical elements include one or more spin-on glass materials.

[0064] Example 12. The device according to any one of Examples 1 to 11, wherein one or more of the optical elements include one or more polymers or one or more silicone resins.

[0065] Example 13. The device according to any one of Examples 1 to 12, wherein one or more of the optical elements include light-scattering particles.

[0066] Example 14. The device according to any one of Examples 1 to 13, wherein each light-emitting pixel of the array is operable independently of at least one other light-emitting pixel of the array.

[0067] Example 15. The device according to any one of Examples 1 to 14, wherein the spacing between the light-emitting pixels of the array is less than about 1.0 mm, less than about 0.50 mm, less than about 0.33 mm, less than about 0.20 mm, less than about 0.10 mm, less than about 0.08 mm, less than about 0.05 mm, less than about 0.033 mm or less than about 0.020 mm.

[0068] Example 16. The device according to any one of Examples 1 to 15, wherein the light-emitting pixels of the array are separated by non-light-emitting pixel boundaries having a non-zero width of less than 0.10 mm, less than 0.050 mm, less than 0.033 mm, less than 0.020 mm, less than 0.010 mm or less than 0.005 mm.

[0069] Example 17. The device according to any one of Examples 1 to 16, wherein the light-emitting pixels include one or more doped or undoped group III-V, II-VI or IV semiconductor materials or alloys or mixtures thereof.

[0070] Example 18. The device according to any one of Examples 1 to 17, wherein each light-emitting pixel comprises one or more p-n junctions, one or more quantum wells, one or more multiple quantum wells, or one or more quantum dots.

[0071] Example 19. The device according to any one of Examples 1 to 18, wherein the light emitted by the light-emitting pixel has a vacuum wavelength greater than 0.20 μm, greater than 0.4 μm, greater than 0.8 μm, less than 10 μm, less than 2.5 μm, or less than 1.0 μm.

[0072] Example 20. A method for manufacturing the device according to any one of Examples 1 to 19, the method comprising: (A) identifying one or more defective pixels of the array; and (B) positioning a corresponding transmissive optical element at the location of each of the one or more defective light-emitting pixels, each optical element extending over the corresponding defective light-emitting pixel and laterally at least partially over one or more light-emitting pixels of the array adjacent to the corresponding defective pixel.

[0073] Example 21. A method for manufacturing the device according to Example 4 or any one of Examples 6 to 19, the method comprising: (A) identifying one or more defective pixels of the array; (B) positioning a corresponding transmissive optical element at the location of each of the one or more defective light-emitting pixels, each optical element extending over the corresponding defective light-emitting pixel and laterally at least partially over one or more light-emitting pixels of the array adjacent to the corresponding defective pixel; and (C) forming a wavelength conversion layer after positioning the corresponding optical element, wherein one or more optical elements are positioned between the light-emitting pixel array and the wavelength conversion layer.

[0074] Example 22. A method for manufacturing the device according to any one of Examples 5 to 19, the method comprising: (A) identifying one or more defective pixels of the array; and (B) positioning a corresponding transmissive optical element at the location of each of the one or more defective light-emitting pixels on the wavelength conversion layer, the wavelength conversion layer being between the one or more optical elements and the light-emitting pixel array, each optical element extending over the corresponding defective light-emitting pixel and laterally at least partially over one or more light-emitting pixels of the array adjacent to the corresponding defective pixel.

[0075] Example 23. The method according to Example 22, further comprising forming or attaching a wavelength conversion layer at the light-emitting surface of the light-emitting pixel array before positioning the corresponding optical element.

[0076] Example 24. The method according to any one of Examples 20 to 23, further comprising testing each defective pixel of the array against a predetermined light compensation level after positioning the corresponding optical element.

[0077] Example 25. According to the method described in Example 24, each defective pixel passes the test only when the emissivity exhibited when the corresponding adjacent pixel is activated is greater than 30%, greater than 50%, greater than 66%, or greater than 75% of the emissivity of the corresponding adjacent pixel.

[0078] Example 26. According to the method described in any one of Examples 20 to 25, the optical element is formed by depositing one or more drops of a liquid or semi-liquid precursor at the location of each defective pixel and curing the precursor to form the corresponding optical element.

[0079] Example 27. According to the method described in Example 26, the liquid precursor comprises one or more spin-on glass precursors or one or more polymer precursors.

[0080] Example 28. According to the method described in any one of Examples 26 or 27, the liquid precursor comprises suspended light-scattering particles.

[0081] Example 29. According to the method described in any one of Examples 26 to 28, the wavelength conversion layer is porous and the precursor is injected into the pores of the wavelength conversion layer before curing.

[0082] Example 30. According to the method described in any one of Examples 20 to 25, the optical element is pre-formed and attached at the location of each defective pixel.

[0083] This disclosure is illustrative and not restrictive. Given this disclosure, further modifications will be apparent to those skilled in the art and are intended to fall within the scope of this disclosure or the appended claims. It is intended that equivalents or modifications of the disclosed example embodiments and methods should fall within the scope of this disclosure or the appended claims.

[0084] In the foregoing detailed description, for purposes of streamlining the disclosure, various features from several example embodiments may be combined. This method of disclosure should not be construed to reflect an intention that any claimed embodiment requires more features than are expressly recited in the corresponding claim. Rather, as reflected in the appended claims, the inventive subject matter may lie in less than all of the features of a single disclosed example embodiment. Accordingly, the present disclosure should be construed to implicitly disclose any embodiment having any suitable subset of one or more features shown, described, or claimed in this application, any suitable subset including those subsets that may not be expressly disclosed herein. A "suitable" subset of features includes only features that are neither incompatible nor mutually exclusive with any other feature of that subset. Accordingly, the appended claims are hereby incorporated in their entirety into the detailed description, where each claim itself is a separately disclosed embodiment. Further, each of the appended dependent claims should be construed as merely for the purpose of disclosure by incorporating the claim into the detailed description as if written in multiple dependent form and subordinate to all of the foregoing claims with which it is not inconsistent. It should also be noted that the cumulative scope of the appended claims may, but need not, cover the entire subject matter disclosed in this application.

[0085] The following explanations shall apply for the purposes of this disclosure and the appended claims. Unless otherwise expressly stated, the words "comprising", "including", "having", and variations thereof shall be understood wherever they appear as open-ended terms, meaning as if the phrase "at least" were appended after each instance thereof. The article "a" shall be construed as "one or more", unless "only one", "single", or other similar limitation is expressly stated or implied in a particular context; similarly, the article "the" shall be construed as "one or more of...", unless "only one of...", "single one of...", or other similar limitation is expressly stated or implied in a particular context. The conjunction "or" shall be construed as inclusive, unless: (i) it is otherwise expressly stated, e.g., by using "or...or...", "only one of...", or similar language; or (ii) two or more of the listed alternatives are understood or disclosed (implicitly or explicitly) to be incompatible or mutually exclusive in a particular context. In the latter case, "or" shall be understood to cover only those combinations involving non-mutually exclusive alternatives. In one example, each of "dog or cat", "one or more of dog or cat", and "one or more dogs or cats" shall be construed as one or more dogs without any cats, or one or more cats without any dogs, or one or more of each. In another example, each of "dog, cat, or mouse", "one or more of dog, cat, or mouse", and "one or more dogs, cats, or mice" shall be construed as (i) one or more dogs without any cats or mice, (ii) one or more cats without any dogs or mice, (iii) one or more mice without any dogs or cats, (iv) one or more dogs and one or more cats without any mice, (v) one or more dogs and one or more mice without any cats, (vi) one or more cats and one or more mice without any dogs, or (vii) one or more dogs, one or more cats, and one or more mice. In another example, each of "two or more of dog, cat, or mouse" or "two or more dogs, cats, or mice" shall be construed as (i) one or more dogs and one or more cats without any mice, (ii) one or more dogs and one or more mice without any cats, (iii) one or more cats and one or more mice without any dogs, or (iv) one or more dogs, one or more cats, and one or more mice; "three or more", "four or more", etc. shall be construed similarly.

[0086] For the purposes of this disclosure or the appended claims, when listing numerical values (with or without terms such as "about equal to", "substantially equal to", "greater than about", "less than about", etc.), the standard conventions related to measurement precision and significant figures should be applied, unless a different interpretation is clearly set forth. For zero amounts described by phrases such as "substantially prevent", "substantially absent", "substantially eliminate", "about equal to zero", "negligible", etc., each such phrase should mean the following: the amount in question has been reduced or diminished to such an extent that, in the context of the intended operation or use of the disclosed or claimed device or method, for practical purposes, the overall behavior or performance of the device or method is no different from what would have occurred if the zero amount had actually been completely removed, precisely equal to zero, or otherwise precisely a zero amount.

[0087] For the purposes of this disclosure and the appended claims, any labeling of elements, steps, limitations, or other parts of an embodiment, example, or claim (e.g., first, second, third, etc., (a), (b), (c), etc., or (i), (ii), (iii), etc.) is for clarity purposes only and should not be construed as implying any kind of ordering or priority of the parts so labeled. If any such ordering or priority is intended, it will be explicitly enumerated in the embodiment, example, or claim, or in some instances, based on the specific content of the embodiment, example, or claim, it will be implicit or inherent. In the appended claims, if it is desired to invoke the provisions of 35 U.S.C. § 112(f) in a device claim, then the word "means" will appear in that device claim. If it is desired to invoke those provisions in a method claim, then the phrase "step for..." will appear in that method claim. Conversely, if the word "means" or "step for..." does not appear in a claim, then the provisions of 35 U.S.C. § 112(f) are not intended to be invoked for that claim.

[0088] If any one or more of the incorporated disclosures conflict in part or in whole with this disclosure or are different in scope from this disclosure, then, for the extent of the conflict, the broader disclosure, or the broader term definition, this disclosure shall control. If such incorporated disclosures conflict in part or in whole with each other, then, for the extent of the conflict, the later-disclosed disclosure shall control.

[0089] An abstract is provided as needed to assist those searching for specific subject matter within the patent literature. However, the abstract is not intended to imply that any particular claim necessarily covers any of the elements, features, or limitations recited therein. The scope of the subject matter covered by each claim should be determined solely by the recitation of that claim.

Claims

1. A light-emitting device, comprising: an array of LEDs, one or more of which are defective; and a set of one or more transmissive optical elements located at a light-emitting surface of the LED array, each transmissive optical element in the set being located at the position of a corresponding one of the one or more defective LEDs, extending above the corresponding defective LED, and extending laterally at least partially above one or more LEDs in the array adjacent to the corresponding defective LED, each transmissive optical element in the set being arranged to laterally transmit at least a portion of the light emitted by one or more corresponding adjacent LEDs to propagate away from the array from the position of the corresponding defective LED, each transmissive optical element in the set being formed by curing a precursor liquid droplet deposited at the position of a corresponding one of the one or more defective LEDs.

2. The light-emitting device according to claim 1, further comprising a wavelength conversion layer located at the light-emitting surface of the LED array, wherein the one or more transmissive optical elements are located between the LED array and the wavelength conversion layer.

3. The light-emitting device according to claim 1, further comprising a wavelength conversion layer located at the light-emitting surface of the LED array, between the one or more transmissive optical elements and the LED array.

4. The light-emitting device according to claim 1, further comprising a wavelength conversion layer located at the light-emitting surface of the LED array, the wavelength conversion layer being porous, and each transmissive optical element comprising a portion injected into the pores of the wavelength conversion layer.

5. The light-emitting device according to claim 1, wherein each LED in the array is operable independently of at least one other LED in the array.

6. The light-emitting device according to claim 1, wherein the spacing between the LEDs in the array is less than 0.10 mm.

7. The light-emitting device according to claim 1, wherein one or more of the transmissive optical elements have a circular convex shape.

8. The light-emitting device according to claim 1, wherein one or more of the transmissive optical elements comprise one or more spin-on glass materials, one or more polymers, or one or more silicone resins.

9. The light-emitting device according to claim 1, wherein one or more of the transmissive optical elements comprise light-scattering particles.

10. An illumination system, comprising: a light-emitting module, comprising an array of LEDs, one or more of which are defective, a set of one or more transmissive optical elements located at a light-emitting surface of the LED array, each transmissive optical element in the set being located at the position of a corresponding one of the one or more defective LEDs, extending above the corresponding defective LED, and extending laterally at least partially above one or more LEDs in the array adjacent to the corresponding defective LED, and a power supply and control module configured and connected to control the operation of the LEDs in the array, Each transmissive optical element in the set is arranged to laterally transmit at least a portion of the light emitted by one or more corresponding adjacent LEDs, to propagate away from the array from the location of the corresponding defective LED. Each transmissive optical element in the set is formed by curing a droplet of precursor fluid deposited at the location of a corresponding one of the one or more defective LEDs. And A set of one or more secondary optical elements arranged to collect light emitted by the array of LEDs.

11. The lighting system according to claim 10, wherein the LED array includes 10 4 or more LEDs.

12. The lighting system according to claim 10, wherein the spacing of the LEDs in the array is less than 0.10 mm.

13. The lighting system according to claim 10, further comprising a sensor module configured and connected to transmit a signal to the power supply and control module, the power supply and control module being configured and connected to control the operation of the LEDs in the array based on the signal received from the sensor module.

14. The lighting system according to claim 10, wherein the light emitting module and the set of one or more secondary optical elements are configured and arranged as a motor vehicle headlamp.

15. A method of manufacturing a light emitting device, the method comprising: Identifying one or more defective LEDs in an LED array; And Positioning a corresponding transmissive optical element at the location of each of the one or more identified defective LEDs, each transmissive optical element extending over the corresponding defective LED and laterally at least partially over one or more LEDs of the array adjacent to the corresponding defective LED, each transmissive optical element being arranged to laterally transmit at least a portion of the light emitted by one or more corresponding adjacent LEDs, to propagate away from the array from the location of the corresponding defective LED, the transmissive optical element being formed by depositing one or more droplets of a liquid or semi-liquid precursor at the location of each defective LED and curing the precursor to form the corresponding transmissive optical element.

16. The method according to claim 15, further comprising forming or attaching a wavelength conversion layer at the light emitting surface of the LED array, (i) wherein one or more transmissive optical elements are between the LED array and the wavelength conversion layer, (ii) wherein the wavelength conversion layer is between the LED array and the one or more transmissive optical elements, or (iii) wherein the one or more transmissive optical elements include corresponding portions injected into holes in the wavelength conversion layer.

17. The method according to claim 15, further comprising, after positioning the corresponding transmissive optical elements, testing each defective LED in the array against a predetermined light compensation level, each defective LED passing the test only if the emission rate exhibited when the corresponding adjacent LED is activated is greater than 30% of the emission rate of the corresponding adjacent LED.

18. The method according to claim 15, wherein the transmissive optical elements are pre-formed and attached at the location of each defective LED.

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