Micro LED projector

Abstract

To reduce the volume and the weight of a micro LED projector.SOLUTION: The micro LED projector has a micro LED panel and a collimator unit (14). The micro LED structure in a micro LED panel includes: a mesa structure; a micro lens (11) formed above the micro mesa structure; a p-type semiconductor layer (01); an n-type semiconductor layer (03); and a light-emitting layer (02) formed between the p-type semiconductor layer (01) and the n-type semiconductor layer (03). The center of the micro lens (11) is on the straight line which connects the center of the light-emitting layer (02) and the center of the collimator unit (14).SELECTED DRAWING: Figure 32

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This patent application claims the benefit of Patent Cooperation Treaty Application No. PCT / CN2021 / 143990, filed December 31, 2021, and Patent Cooperation Treaty Application No. PCT / CN2021 / 143988, filed December 31, 2021, each of which is incorporated by reference in its entirety.

[0002] The present disclosure relates generally to the technical field of light emitting diodes (LEDs), and more particularly to micro LED projectors. [Background technology]

[0003] Inorganic micropixel light-emitting diodes (hereafter referred to as "μ-LEDs" or "microLEDs") are gaining importance as they are used in a variety of applications, including self-emissive microdisplays, visible light communications, and optogenetics. μ-LEDs have demonstrated higher output performance than conventional LEDs due to better strain relaxation, improved light extraction efficiency, and uniform current spreading. μ-LEDs also have the following advantages over conventional LEDs: They exhibit improved thermal effects, operation at higher current densities, faster response times, a wider operating temperature range, higher resolution, color gamut, and contrast, and lower power consumption.

[0004] Inorganic μ-LEDs have traditionally been fabricated by etching III-V epitaxial layers to form multiple mesas. Most of the light emitted from the sidewalls of the mesas has a large emission angle perpendicular to the microdisplay. However, the emitted light with a large emission angle is blocked and lost in the augmented reality (AR) device and does not reach the human eye, resulting in low luminous efficiency. Therefore, it is necessary to reduce the luminous loss from the sidewalls of the mesas.

[0005] In addition, the chief ray angle of a conventional μ-LED cannot be changed and is always emitted vertically from the top of the mesa, which reduces the light emitted from the sidewall of the mesa, lowering the luminous efficiency and luminous intensity. Moreover, the chief ray angle of each μ-LED in a μ-LED array is the same as each other, which narrows the applications of the μ-LED array.

[0006] The above contents are only used to facilitate the understanding of the technical solutions of the present application, and are not admitted to be prior art. Summary of the Invention

[0007] To overcome the above drawbacks, the present disclosure provides a micro LED projector that controls the chief ray angle of the micro LED structure, reduces the loss of light emitted from the sidewall of the mesa, and reduces the volume and weight of the micro LED projector.

[0008] According to the present disclosure, a micro LED projector is provided, the micro LED projector comprising: A micro LED panel including a micro LED structure array, the micro LED structure including a mesa structure, a micro lens formed to be located above the micro mesa structure, a p-type semiconductor layer, an n-type semiconductor layer, and a light emitting layer formed between the p-type semiconductor layer and the n-type semiconductor layer; A collimator unit formed to collimate the light beam emitted from the micro LED structure to a preset target position; Equipped with A connected straight line connects the center of the collimator unit, the center of the microlens, and the center of the light-emitting layer.

[0009] In some embodiments, the center of the collimator unit is offset from a connected straight line, with the center of the microlens and the center of the light-emitting layer being on a first straight line, and the center of the collimator unit and the center of the light-emitting layer being on a second straight line.

[0010] In some embodiments, the second line is offset from the first line.

[0011] In some embodiments, the second line is deviated from the first line by an angle of 5° or less.

[0012] In some embodiments, the centers of the light-emitting layers are horizontally offset from a connecting straight line.

[0013] In some embodiments, the distance that the centers of the light emitting layers are horizontally offset from a connecting line is no more than 45% of the bottom width of the mesa structure.

[0014] In some embodiments, the offset distance of the centers of the light-emitting layers is 0.3 μm or less.

[0015] In some embodiments, the distance between the micro-LED panel and the surface of the collimator unit is less than or equal to the thickness of the collimator unit.

[0016] In some embodiments, the microlenses are hemispherical or spherical in shape.

[0017] In some embodiments, the micro LED structure further comprises a capping layer formed overlying the micro mesa structure and covering the micro lens.

[0018] In some embodiments, the capping layer material is selected from polymers, inorganic oxides, and inorganic nitrides.

[0019] In some embodiments, the inorganic oxide is silicon oxide and the inorganic nitride is silicon nitride.

[0020] In some embodiments, the central axis of the microlens is horizontally offset from the central axis of the mesa structure.

[0021] In some embodiments, the micro LED structure further comprises spacers at the bottom of the microlens and on top of the mesa structure.

[0022] In some embodiments, the spacer material is selected from polymers, inorganic oxides, and inorganic nitrides.

[0023] In some embodiments, the inorganic oxide is silicon oxide and the inorganic nitride is silicon nitride.

[0024] In some embodiments, the material of the capping layer is different from the material of the microlenses.

[0025] In some embodiments, the material of the microlens is selected from polymers, inorganic oxides, and inorganic nitrides.

[0026] In some embodiments, the inorganic oxide is silicon oxide and the inorganic nitride is silicon nitride.

[0027] In some embodiments, the diameter of the microlens is between 80% and 200% of the diameter of the mesa structure.

[0028] In some embodiments, the distance between the focal point of the microlens and the light emitting layer is less than or equal to twice the thickness of the mesa structure.

[0029] In some embodiments, the micro LED structure further comprises an anti-reflective coating formed on at least a portion of the surface of the microlens.

[0030] In some embodiments, an anti-reflective coating is formed at the surface location where light rays emerge from the microlenses.

[0031] In some embodiments, the chief ray is inclined with respect to the top surface of the micro-mesa structure and emerges from the microlens at an angle in the range of 0 to 45 degrees with respect to the vertical.

[0032] In some embodiments, the chief ray is perpendicular to the top surface of the micro-mesa structure and emanates from the top center of the microlens.

[0033] In some embodiments, an anti-reflective coating is formed on top of the microlenses.

[0034] In some embodiments, the anti-reflective coating is formed over the entire surface of the microlens.

[0035] In some embodiments, the thickness of the anti-reflective coating at the surface location where light rays leave the microlens is greater than the thickness of the anti-reflective coating at other locations on the microlens.

[0036] In some embodiments, the thickness of the antireflective coating on top of the microlens is greater than the thickness of the antireflective coating elsewhere in the microlens.

[0037] In some embodiments, the dielectric constant of the anti-reflective coating is between the dielectric constant of the microlens and that of air.

[0038] In order to achieve the above object, the present disclosure further provides a micro LED projector, the micro LED projector comprising: a first color micro LED panel, such as the micro LED panel described above, emitting light of a first color; a second color micro LED panel such as the micro LED panel described above, emitting light of a second color, wherein the first color is different from the second color; and an optical coupling element configured to face the direction of emission of the first color light beam of the first color micro LED panel and face the direction of emission of the second color light beam of the second color micro LED panel, and to combine the first color light beam and the second color light beam into a composite light beam; A collimator unit, such as the collimator described above, configured to collimate the light beam emitted from the micro LED structure to a pre-defined target position. Equipped with.

[0039] In some embodiments, the optical coupling element comprises a polarizing diffractive film on an inclined interface oriented in the direction of a first color light beam emission of a first color micro LED panel and oriented in the direction of a second color light beam emission of a second color micro LED panel.

[0040] In some embodiments, the micro LED projector further comprises a third color micro LED panel, such as the micro LED panel described above, emitting light of a third color, where the first color, the second color and the third color are different from each other.

[0041] In some embodiments, the optical coupling element comprises a polarizing and splitting film on another interface surface facing the third color light emission direction of the third color micro LED panel.

[0042] In some embodiments, the optical coupling element is an X-cube.

[0043] In some embodiments, the minimum distance between the micro-LED panel and the surface of the optical coupling element facing the micro-LED panel is less than or equal to two times the thickness of the micro-LED panel.

[0044] In some embodiments, collimated light is emitted from the emission surface of the optical coupling element and then enters the entrance surface of the collimator unit, and the distance between the emission surface of the optical coupling element and the entrance surface of the collimator unit is less than or equal to 200% of the thickness of the collimator unit.

[0045] In some embodiments, the diameter of the collimator unit is smaller than the side width of the X-cube.

[0046] Further, in accordance with the present disclosure, there is provided a micro LED projector, comprising: At least one color micro LED panel including a plurality of micro LEDs, wherein the chief ray angles of the micro LEDs in the micro LED panel are different; a collimator unit configured to collimate a light beam emitted from a micro LED panel to a predetermined target position, the micro LED panel having a light emitting area, the collimator having an incident surface, and the light emitted from the light emitting area of ​​the micro LED panel entering the incident surface of the collimator; Equipped with.

[0047] In some embodiments, the chief ray angles of the micro LEDs of at least one color micro LED panel are collimated to a point.

[0048] In some embodiments, the at least two color micro LED panels each emit light of one color, and the chief ray angles of the micro LEDs of each micro LED panel are collimated to a point.

[0049] In some embodiments, at least a first color micro LED panel emits light rays of a first color, a second color micro LED panel emits light rays of a second color, and a third color micro LED panel emits light rays of a third color, wherein the first color, second color, and third color are different from each other, and chief ray angles of the micro LEDs of the first color micro LED panel are collimated to a point, chief ray angles of the micro LEDs of the second color micro LED panel are collimated to a point, and chief ray angles of the micro LEDs of the third color micro LED panel are collimated to a point.

[0050] In some embodiments, the micro LED projector further comprises an optical combining element oriented in the direction of emission of each color light beam of the micro LED panel and configured to combine the color light beams into a combined beam, wherein the collimated light is emitted from an output surface of the optical combining element and incident on an input surface of the collimator unit.

[0051] In some embodiments, the area of ​​the emission surface is greater than the area of ​​the entrance surface.

[0052] In some embodiments, the diameter of the collimator unit is smaller than the side width of the optical coupling element.

[0053] In some embodiments, the optical coupling element has a plurality of light receiving surfaces respectively corresponding to each light emitting area of ​​the micro LED panel, and the minimum distance between the micro LED panel and the light receiving surface of the optical coupling element is less than or equal to 200% of the thickness of the micro LED panel.

[0054] In some embodiments, the lateral width of the light receiving surface of the optical coupling element is smaller than the lateral width of the light emitting area of ​​the first color micro LED panel.

[0055] In some embodiments, the distance between the emission surface of the optical coupling element and the entrance surface of the collimator unit is less than or equal to 200% of the thickness of the collimator unit.

[0056] In some embodiments, the distance between the emission surface of the optical coupling element and the entrance surface of the collimator unit is zero.

[0057] In some embodiments, the optical coupling element comprises a polarizing diffractive film on an inclined interface oriented in the direction of a first color light beam emission of a first color micro LED panel and oriented in the direction of a second color light beam emission of a second color micro LED panel.

[0058] In some embodiments, the micro LED projector further comprises a third color micro LED panel emitting light of a third color, wherein the first color, the second color, and the third color are different from each other.

[0059] In some embodiments, the optical coupling element comprises a polarizing and splitting film on another interface surface facing the third color light emission direction of the third color micro LED panel.

[0060] In some embodiments, the optical coupling element is an X-cube.

[0061] In some embodiments, the diameter of the collimator unit is equal to or less than the side width of the X-cube.

[0062] In some embodiments, the light emitting area of ​​the micro LED panel is larger than the entrance surface of the collimator unit.

[0063] In some embodiments, the width of the micro-LED panel is greater than the diameter of the entrance face of the collimator unit.

[0064] Many other advantages and features of the present disclosure will become further understood from the following detailed description and the accompanying drawings. [Brief description of the drawings]

[0065] [Figure 1] FIG. 1 is a structural diagram of a micro LED structure according to a first embodiment of the present disclosure. [Diagram 2] FIG. 2 is a structural diagram of a micro LED structure with minimized reflection structure according to a first embodiment of the present disclosure. [Diagram 3] FIG. 2 is a structural diagram of a micro LED structure with minimized reflection structure according to a first embodiment of the present disclosure. [Figure 4] FIG. 1 is a top view of a micro LED structure according to a first embodiment of the present disclosure. [Diagram 5] FIG. 2 is a top view of another micro LED structure according to a first embodiment of the present disclosure. [Figure 6] FIG. 1 is a structural diagram of a micro LED structure according to a first embodiment of the present disclosure. [Figure 7] FIG. 1 is a structural diagram of a micro LED structure according to a first embodiment of the present disclosure. [Figure 8] FIG. 1 is a structural diagram of a micro LED structure according to a first embodiment of the present disclosure. [Figure 9] FIG. 1 is a structural diagram of a micro LED projector according to a first embodiment of the present disclosure. [Figure 10] FIG. 1 is a structural diagram of a micro LED projector according to a first embodiment of the present disclosure. [Figure 11] FIG. 1 is a structural diagram of a micro LED package according to a first embodiment of the present disclosure. [Figure 12] FIG. 1 is a structural diagram of a micro LED package according to a first embodiment of the present disclosure. [Figure 13] FIG. 1 is a structural diagram of a micro LED package according to a first embodiment of the present disclosure. [Figure 14] FIG. 1 is a structural diagram of a micro LED package according to a first embodiment of the present disclosure. [Figure 15] FIG. 1 is a structural diagram of a micro LED projector according to a first embodiment of the present disclosure. [Figure 16] FIG. 1 is a structural diagram of a micro LED projector according to a first embodiment of the present disclosure. [Figure 17] FIG. 1 is a structural diagram of a micro LED projector according to a first embodiment of the present disclosure. [Figure 18] FIG. 1 is a structural diagram of a micro LED projector according to a first embodiment of the present disclosure. [Figure 19] FIG. 1 is a structural diagram of a micro LED panel according to a first embodiment of the present disclosure. [Figure 20] FIG. 2 is a structural diagram of a micro LED structure according to a second embodiment of the present disclosure. [Figure 21] FIG. 2 is a structural diagram of a micro LED structure according to a second embodiment of the present disclosure. [Figure 22] FIG. 2 is a structural diagram of a micro LED structure according to a second embodiment of the present disclosure. [Figure 23] FIG. 2 is a structural diagram of a micro LED structure according to a second embodiment of the present disclosure. [Figure 24] FIG. 2 is a structural diagram of a micro LED structure according to a second embodiment of the present disclosure. [Diagram 25] FIG. 2 is a structural diagram of a micro LED structure according to a second embodiment of the present disclosure. [Figure 26] FIG. 2 is a structural diagram of a micro LED structure according to a second embodiment of the present disclosure. [Figure 27] FIG. 13 is a structural diagram of a micro LED structure according to a third embodiment of the present disclosure. [Figure 28] FIG. 13 is a structural diagram of a micro LED structure according to a third embodiment of the present disclosure. [Figure 29] FIG. 13 is a structural diagram of a micro LED structure according to a third embodiment of the present disclosure. [Diagram 30] FIG. 13 is a structural diagram of a micro LED structure according to a third embodiment of the present disclosure. [Diagram 31] FIG. 11 is a structural diagram of a micro LED structure according to a fourth embodiment of the present disclosure. [Diagram 32] FIG. 13 is a structural diagram of a micro-optical engine according to a fifth embodiment of the present disclosure. [Diagram 33] FIG. 13 is a structural diagram of a micro-optical engine according to a fifth embodiment of the present disclosure. [Diagram 34] FIG. 13 is a structural diagram of a micro-optical engine according to a fifth embodiment of the present disclosure. [Diagram 35] FIG. 13 is a structural diagram of a micro LED projector according to a fifth embodiment of the present disclosure. [Diagram 36] FIG. 13 is a structural diagram of a micro LED projector according to a fifth embodiment of the present disclosure. [Figure 37] FIG. 13 is a structural diagram of a micro LED projector according to a fifth embodiment of the present disclosure. [Figure 38] FIG. 13 is a block diagram of a micro LED display device according to a sixth embodiment of the present disclosure. [Figure 39] FIG. 13 is a block diagram of a micro LED display device according to a sixth embodiment of the present disclosure. [Diagram 40] FIG. 13 is a block diagram of a micro LED display device according to a sixth embodiment of the present disclosure. [Diagram 41] FIG. 13 is a structural diagram of a micro LED glass according to a sixth embodiment of the present disclosure. [Diagram 42] FIG. 13 is a structural diagram of a micro LED display device according to a sixth embodiment of the present disclosure. [Diagram 43] FIG. 13 is a structural diagram of a micro LED display device according to a sixth embodiment of the present disclosure. [Diagram 44] FIG. 13 is a structural diagram of four quadrant regions in the micro LED glasses according to the sixth embodiment of the present disclosure. [Diagram 45] FIG. 13 is a structural diagram showing the distribution of monolithic micro LED projectors in micro LED glasses according to the sixth embodiment of the present disclosure. [Figure 46] FIG. 13 is a structural diagram showing the distribution of monolithic micro LED projectors in micro LED glasses according to the sixth embodiment of the present disclosure. [Figure 47] FIG. 13 is a structural diagram showing the distribution of monolithic micro LED projectors in micro LED glasses according to the sixth embodiment of the present disclosure. [Figure 48] FIG. 13 is a structural diagram showing the distribution of monolithic micro LED projectors in micro LED glasses according to the sixth embodiment of the present disclosure. [Figure 49] FIG. 13 is a structural diagram showing the distribution of monolithic micro LED projectors in micro LED glasses according to the sixth embodiment of the present disclosure. [Figure 50] FIG. 13 is a structural diagram showing the distribution of a monolithic micro LED projector in a pair of micro LED glasses according to a sixth embodiment of the present disclosure. [Figure 51] FIG. 13 is a structural diagram showing the distribution of a monolithic micro LED projector in a pair of micro LED glasses according to a sixth embodiment of the present disclosure. [Figure 52]FIG. 13 is a structural diagram showing the distribution of a monolithic micro LED projector in a pair of micro LED glasses according to a sixth embodiment of the present disclosure. [Figure 53] FIG. 13 is a structural diagram showing a one-dimensional distribution of a monolithic micro LED projector according to a sixth embodiment of the present disclosure. [Figure 54] FIG. 13 is a structural diagram showing an array of a monolithic micro LED projector according to a sixth embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0066] In order to facilitate a further understanding of the invention, reference will now be made in detail to the presently preferred embodiments of the invention. The specific embodiments described and the accompanying drawings are merely illustrative of specific ways to make and use the invention and are not intended to limit the scope of the invention or the appended claims.

[0067] EMBODIMENT 1 Referring to FIG. 1, a micro LED structure according to an embodiment includes a mesa structure and a reflector structure 00. The mesa structure may be a micro LED structure including at least one light emitting unit, a first type semiconductor layer 01, a second type semiconductor layer 03, and a light emitting layer 02. The micro LED structure may further include a top contact 06 and a bottom contact 05. The light emitting layer 02 is formed on top of the first type semiconductor layer 01, and the second type semiconductor layer 03 is formed on top of the light emitting layer 02. The first type semiconductor layer 01 and the second type semiconductor layer 03 are of different conductivity types. For example, in some embodiments, the first type semiconductor layer 01 is P type while the second type semiconductor layer 03 is N type, or the first type semiconductor layer 01 is N type while the second type semiconductor layer 03 is P type. Preferably, the material of the first-type semiconductor layer 01 is p-GaAs, p-AlGaInP, p-GaN, etc., and the material of the second-type semiconductor layer 03 is n-GaAs, n-AlGaInP, n-GaN, etc. The light-emitting layer 02 is formed by a quantum well layer. In some embodiments, the material of the quantum well layer is AlGaInP / GaInP, GaN / InGaN, GaAs, GaN, etc. Preferably, the thickness of the first-type semiconductor layer 01 is smaller than the thickness of the second-type semiconductor layer 03, and the thickness of the light-emitting layer 02 is smaller than the thickness of the first-type semiconductor layer 01. Preferably, the thickness of the first-type semiconductor layer 01 is in the range of 50 nm to 2 μm, and the thickness of the second-type semiconductor layer 03 is in the range of 100 nm to 2 μm. Preferably, the thickness of the quantum well layer is 30 nm or less, or the quantum well layer includes at most 6 pairs of quantum wells.

[0068] The reflecting structure 00 is formed to reflect light emitted from the sidewall of the mesa structure toward the outside. The reflecting structure 00 may be formed around the mesa structure.

[0069] With reference to FIG. 1, when the central axis of the reflecting structure L1 is aligned with the central axis of the mesa structure, the chief ray of the micro LED structure is aligned with the central axis of the mesa structure. With reference to FIG. 2 and FIG. 3, when the central axis L1 of the reflecting structure is not aligned with the central axis of the mesa structure, the chief ray of the micro LED structure is shifted from the central axis of the mesa structure by an angle. To change the chief ray angle of the micro LED structure, the central axis of the reflecting structure is shifted from the central axis of the mesa structure. In some embodiments consistent with FIG. 1 and FIG. 2, to shift the central axis of the reflecting structure, the gap width D1 of the reflecting structure can be increased or decreased with one position of the reflecting structure as a fixed point. In some embodiments consistent with FIG. 1 and FIG. 3, the entire reflecting structure is shifted from left to right, but the gap width D1 of the reflecting structure is not changed. More specifically, D1 represents the bottom width of the hollow opening inside the reflecting structure. In some embodiments consistent with FIG. 4, the hollow opening is a cylinder, and D1 is the diameter of the cylinder (as shown by the dotted line in FIG. 4). In some embodiments consistent with Figure 5, the hollow opening is rectangular and D1 is the width or length of the rectangle (as shown by the dotted line in Figure 5). The chief ray angle is the angle of the chief ray with respect to the central axis of the reflective structure.

[0070] Preferably, the chief ray angle of the micro LED structure reflected by the reflective structure is in the range of 0 to 45°. The distance between the central axis L1 of the reflective structure 00 and the central axis of the mesa structure is greater than 50% of the bottom width of the mesa structure, and preferably is less than or equal to 100% of the bottom width of the mesa structure. Furthermore, a protective isolation layer 10 may be formed on the sidewall surface of the mesa structure, so that the bottom edge of the reflective structure 00 may contact the protective isolation layer 10 without any gap between the bottom edge of the mesa structure and the bottom edge of the reflective structure 00.

[0071] In some embodiments, the sidewalls of the reflecting structure 00 are inclined with respect to the vertical. Preferably, the inclination angle of the sidewalls of the reflecting structure 00 facing the mesa structure is in the range of 0 to 60° with respect to the vertical level. The top of the reflecting structure 00 may be higher, lower or equal to the top of the mesa structure. Preferably, the height of the reflecting structure 00 is 10% to 200% of the height of the mesa structure. The bottom thickness D2 of the reflecting structure 00 is 10% to 90% of the length of the space between the bottom edge of the mesa structure and the bottom edge of the reflecting structure 00. In some embodiments, D2 represents the maximum thickness of the reflecting structure 00 from the edge of the hollow opening to the exit edge of the reflecting structure 00. In some embodiments consistent with Figures 1 to 3 and 6, D2 is the bottom thickness of the reflecting structure 00 from the bottom edge of the hollow opening to the bottom outer edge of the reflecting structure 00. 7, D2 is the top thickness of the reflective structure 00 from the top edge of the hollow opening to the top outer edge of the reflective structure 00. In some embodiments, the hollow opening is formed by the inner sidewall of the reflective structure 00.

[0072] In some embodiments, the sidewalls of the mesa structure are inclined relative to the horizontal level. Preferably, the inclination direction of the sidewalls of the mesa structure is in a direction intersecting the inclination direction of the sidewalls of the reflecting structure 00 facing the mesa structure. In some embodiments consistent with FIG. 6, a part of the sidewalls of the mesa structure is parallel to the inner sidewall of the right half of the reflecting structure 00 facing the mesa structure, but the sidewalls of the mesa structure are not parallel to the inner sidewall of the other left half of the reflecting structure 00, so that the central axis of the reflecting structure 00 is shifted from right to left. If the sidewalls of the mesa structure are parallel to the inner sidewall of the left half of the reflecting structure facing the mesa structure, but the sidewalls of the mesa structure are not parallel to the inner sidewall of the right half of the reflecting structure 00, the central axis L1 of the reflecting structure 00 is shifted from left to right, as shown in FIG. 6. In some embodiments consistent with FIG. 7, the entire sidewall of the reflecting structure 00 may be parallel to the sidewall of the mesa structure, and the central axis L1 of the reflecting structure 00 is aligned with the central axis of the mesa structure.

[0073] Preferably, the reflective structure 00 is formed of a highly reflective metal or polymer, or a distributed Bragg reflector or highly reflective polymer. Preferably, the highly reflective metal is selected from one or more of Ag, Au, Al, etc. Preferably, the highly reflective polymer is polytetrafluoroethylene, etc.

[0074] In some further embodiments consistent with FIG. 8, a top conductive layer 09 is formed on the top of the mesa structure and on the top surface of the reflective structure 00, so that the second type conductor layer 03 can be electrically connected to the reflective structure 00 by the top conductive layer 09. A top contact 06 is formed between the top conductive layer 09 and the top of the mesa structure. A bottom contact 05 and a bottom conductive structure 04 are sequentially formed on the bottom of the mesa structure. An IC backside 07 is formed on the bottom of the mesa structure and is electrically connected to the bottom conductive structure 04 via a contact pad 071. It is noted that in this specification, the top conductive layer 09 is transparent. Here, an isolation layer 10 is formed on the sidewalls of the mesa structure, and the top conductive layer 09 is formed on the isolation layer 10, the top of the mesa structure, the top contact 06, and the exposed top surface of the IC backside 07. It is noted that in another embodiment, the isolation layer 10 can be formed on the top of the mesa structure, so that the isolation layer 10 is formed on the sidewalls and the top of the isolation layer, and not directly on the top of the mesa structure. In one embodiment, the top conductive layer 09 is formed on the sidewalls and the top of the reflective structure 00. In another embodiment, the top conductive layer 09 can be first formed on the mesa structure and the top of the IC backside 07, and then the reflective structure 00 can also be formed on the top conductive layer 09 around the mesa structure. Since the isolation layer 10 is further formed on the top of the IC backside 07, the top conductive layer 09 can be formed on the isolation layer 10 on the top surface of the IC backside 07, but not directly on the top surface of the IC backside. It is noted that the top conductive layer 09 can be transparent. The material of the top conductive layer 09 can be ITO, FTO, etc.

[0075] In some embodiments, a microlens 11 is formed on the mesa structure. Herein, a spacer 081 is formed at the bottom of the microlens 11 and on the top conductive layer 09. Note that in another embodiment, the microlens 11 can be formed directly on the top conductive layer 09. A dielectric layer 08 is formed between the mesa structure and the reflective structure 00. The material of the spacer 081 can be the same as the material of the dielectric layer 08.

[0076] In some embodiments, the chief ray angle of the micro LED structure can be changed by changing the position of the reflecting structure 00. The mesa structure can emit one or more colors. As described above, the mesa structure includes one light emitting unit. In some embodiments, the mesa structure includes multiple light emitting units, and the light emitting units emit light of different colors. In some embodiments, the mesa structure includes two light emitting units, and each of the light emitting units emits a different color. In some embodiments, the mesa structure includes three light emitting units, and each of the light emitting units emits a different color, which can be referenced in US Patent Applications US62 / 863559 and US16 / 567007.

[0077] In some further embodiments, the above-mentioned micro LED structure may be applied to a micro LED projector field. In some embodiments consistent with Fig. 9, a micro LED projector comprises a first micro LED panel 201, a second micro LED panel 202, and an optical coupling element 301. Consistent with Fig. 9, the dotted lines represent the boundaries for displaying an image or the human eye, and the arrows represent the light rays emitted from the micro LED panels.

[0078] The first micro LED panel 201 emits light of a first color, where the first micro LED panel 201 includes a first micro LED array, where the first micro LED structure is selected from the aforementioned micro LED structures having a light emitting layer of the first color. The second micro LED panel 202 emits light of a second color, where the second micro LED panel 202 includes a second micro LED array, where the second micro LED structure is selected from the aforementioned micro LED structures having a light emitting layer of the second color. The optical coupling element 301 is formed to receive light rays emitted from the first micro LED panel 201 and light rays emitted from the direction of the second micro LED panel 202. In some further embodiments, the optical coupling element 301 comprises a polarizing and splitting film facing the first color light rays emitted from the first micro LED panel 201 and the second color light rays emitted from the second micro LED panel 202. In some embodiments consistent with FIG. 9, the optical coupling element 301 is made by two lenses with a dichroic film at the slanted interface, and the slanted line represents the dichroic film. The dichroic film transmits only the light beam emitted from the second micro LED panel 202 and reflects the light beam emitted from the first micro LED panel 201. In some embodiments, the second micro LED panel 202 emits two different colors of light, such as a second color light and a third color light, and the first micro LED panel 201 emits only a single first color light, where the first color, the second color, and the third color are different from each other. Herein, the chief ray angle of the first micro LED panel 201 is 0°, and the light beams emitted from the first micro LED panel 201 are parallel to each other. Also, the chief ray angle of the second micro LED panel 202 is 0°, and the light beams emitted from the second micro LED panel 202 are parallel to each other. The chief ray angle of the micro LEDs of the first micro LED panel and the chief ray angle of the micro LEDs of the second micro LED panel are symmetrical with respect to the inclined interface.Here, the chief ray angle of the micro LEDs of the first micro LED panel 201 and the chief ray angle of the micro LEDs of the second micro LED panel 202 are symmetrical with respect to the inclined boundary surface.

[0079] In some embodiments consistent with FIG. 10, the first micro LED panel 201 emits light of a first color, where the first micro LED panel 201 includes a first micro LED array, where the first micro LED structure is selected from the aforementioned micro LED structures having a light emitting layer of the first color. The second micro LED panel 202 emits light of a second color, where the second micro LED panel 202 includes a second micro LED array, where the second micro LED structure is selected from the aforementioned micro LED structures having a light emitting layer of the second color. A third micro LED panel 203 is further included in this embodiment. The third micro LED panel 203 emits light of a third color, where the third micro LED panel 203 includes a third micro LED array, where the third micro LED structure is selected from the aforementioned micro LED structures having a third light emitting layer. Where the first color, the second color, and the third color are different from each other. The optical coupling element 301 comprises a first polarizing and dispersing element film facing the first color light beam emitted from the first micro LED panel 201 and the second color light beam emitted from the second micro LED panel 202. The optical coupling element 301 further comprises a second polarizing and dispersing element film facing the third color light beam emission direction of the third micro LED panel 203 and the second color light beam emission direction of the second micro LED panel 202. Preferably, the optical coupling element 301 is an X-cube. The X-cube includes dichroic films arranged in an "X" shape. The structure of the X-cube can be understood by those skilled in the art, so it will not be further described here. It is noted that the first color, the second color, and the third color can be selected from red, blue, green, orange, yellow, etc. Here, the micro LED panels are assembled on different surfaces of the X-cube, and the micro LED panels face the dichroic films. Furthermore, two adjacent micro LED panels 201 and 202 or 202 and 203 are in a mirror image relationship, with the dichroic film between the two adjacent micro LED panels 201 and 202 or 202 and 203 acting as a mirror. It should be noted that in some embodiments, the optical coupling element 301 may also be an "X" optical coupling panel instead of an X-cube.The support frame may include an optical coupling element 301 that exposes the surface of the X-cube so that light emitted from the micro LEDs may enter the X-cube.

[0080] In some further embodiments, the X-cube 301 can be fixed in the support frame by adhesive or mechanical connection method without adhesive. For example, the micro LED panel can be glued on the support frame by adhesive or adhesive, or the micro LED panel can be mechanically connected with the optical coupling element 301 so that the micro LED panel is clamped with the support frame. It should be noted that the micro LED panel can be directly formed on the surface of the X-cube. A cooling element may be formed on the back of the micro LED panel to dissipate heat of the micro LED panel to the outside. In another embodiment, a cooling element can be formed on the support frame connected with the micro LED panel to dissipate heat of the support frame and the micro LED panel to the outside.

[0081] Herein, a micro LED package structure for a micro LED panel is disclosed. The micro LED package structure includes a main circuit board including a printed circuit for controlling the micro LED panel, a circuit branch individually connected to the main circuit board, and a micro LED panel individually configured on an end surface of the circuit branch. Furthermore, the width of the circuit branch is equal to or less than the width of the X-cube on which the circuit branch is assembled. Preferably, the circuit branch is flexible and can be folded and assembled with an optical coupling element. It is noted that a micro LED panel is individually configured on each of the circuit branches and electrically connected to each of the circuit branches.

[0082] 11, each of the micro LED panels 201, 202, and 203 may be packaged before being assembled with the optical coupling element 301. In some embodiments, at least three micro LED panels are packaged together on a printed circuit board, such as a flexible printed circuit (FPC) board. The micro LED panels 201, 202, 203 are individually configured on each of the circuit branches and electrically connected to each of the circuit branches. Furthermore, the micro LED panels 201, 202, 203 are configured on an end surface of each of the circuit branches. In some embodiments, the bottom edge of the micro LED panel 201, 202, 203 of one of the circuit branches is not lower than the side edge of the other circuit branch.

[0083] Further disclosed herein is a micro LED light module including the aforementioned micro LED package structure for a micro LED panel, where the micro LED package structure is assembled with a micro optical coupling element 301. The micro LED panel is assembled facing the optical coupling element 301. Preferably, the width of the circuit branch is equal to or less than the width of the X-cube (optical coupling element 301). In some embodiments, the tops of the micro LED panels 201, 202, 203 are at the same horizontal level. Furthermore, the circuit branches 1102, 1103, 1104 are flexible to be assembled with the optical coupling element 301, and the circuit branches 1102, 1103, 1104 are folded to face the optical coupling element 301. In another embodiment, the circuit branches 1102, 1103, 1104 are not flexible to be assembled with the optical coupling element 301.

[0084] In some embodiments consistent with FIG. 11, the FPC board comprises a main circuit board 1101 and a number of circuit branches 1102, 1103, 1104 from the main circuit board 1101. The circuit branches 1102, 1103, 1104 are formed to be flexible and foldable for assembly with the optical coupling element 301, so that the circuit branches 1102, 1103, 1104 are folded to face the optical coupling element 301. The circuit of the main board 1101 is the same as the circuit of the branches 1102, 1103, 1104. In some embodiments, three micro LED panels 201, 202, 203 are formed on the end faces of the branches (first branch 1102, second branch 1103, third branch 1104) and electrically connected with the circuit of the branches. Preferably, the first branch 1102 and the third branch 1104 are symmetrical with respect to the central axis of the second branch 1103. The three micro LED panels 201, 202, 203 can be formed with the optical coupling element 301 (as shown in FIG. 10) by folding or bending the branches in any direction to form an assembled structure consistent with FIG. 10. In some embodiments consistent with FIG. 10 and FIG. 11, the distance WD between the bottom edge of the micro LED panel 201 in the first branch 1102 and the bottom edge of the micro LED panel 203 in the third branch 1104 is equal to or close to the width of the optical coupling element 301. Thus, the top edges of the three micro LED panels 201, 202, and 203 are at the same horizontal level (as shown in FIG. 10) when formed with the optical coupling element 301. In some embodiments, the first branch 1102 and the third branch 1104 can be folded and stacked together to form the FPC substrate shown in Figure 12. In some embodiments consistent with Figures 10 and 12, the width WD1 of branch 1103 is equal to or close to the width of X-cube 301. The width of X-cube 301 can be less than the width of branch 1103. For example, the width of X-cube 301 can be at least the width of the active light emitting or optical area.The active light-emitting area 1106 is the light-emitting area of ​​the micro LED panel 201, and the light area is the light-transmitting area on the X-cube 301 surface formed by the light rays emitted from the micro LED panel 201. Preferably, in some embodiments consistent with FIG. 13, the FPC includes a main substrate 1101 and three branches 1102, 1103, 1104. The main substrate 1101 includes a bottom substrate 110101 and a top substrate 110102. The width of the top substrate 110102 is greater than the width of the bottom substrate 110101. The circuit of the bottom substrate 110101 is divided into three sub-circuits. The three sub-circuits are separately connected with the micro LED panels 201, 202, 203 and separately formed in the three branches 1102, 1103, 1104. To form the FPC board as shown in FIG. 12, the first branch 1102 can be folded along dotted lines Z1 and Z2 separately, and the third branch 1104 can be folded along dotted lines Z3 and Z4. In some embodiments consistent with FIG. 12, the first branch 1102 can be folded along dotted line Z5, the second branch 1103 can be folded along dotted line Z6, and the third branch 1104 can be folded along dotted line Z7 to form an assembled structure in which three micro LED panels 201, 202, 203 are arranged around the X-cube 301 as shown in FIG. 10. It is noted that the FPC board of the embodiment consistent with FIG. 12 can be formed not only by folding the branches, but also by directly printing circuits on the main board and the branches without folding the branches. It is noted that the shape of the micro LED panel can be rectangular, square, etc. The profile of the micro LED array area in the micro LED panel can be rectangular, square, etc. Here, the width of the first circuit branch 1102, the width of the second circuit branch 1103, and the width of the third circuit branch 1104 are the same. Note that in some embodiments, the circuit branches 1102, 1103, 1104 are not flexible due to being assembled with the optical coupling element 301.

[0085] In some embodiments, the end of the FPC board for supporting the micro LED panel comprises a support base on the opposite side to the micro LED panel. The other end of the FPC board comprises a connector and a memory. In some embodiments consistent with FIG. 14, the printed circuit board 1420 is long and flexible like an FPC. The long printed circuit board 1420 has a first end and a second end. The micro display panel 1410 is formed on the surface of the first end of the printed circuit board 1420 and is electrically connected to the printed circuit board 1420. The support base 1430 is formed on the other surface of the first end of the printed circuit board 1420 opposite the micro display panel 1410. The flash memory 1440 is formed on the surface of the second end of the circuit board 1420. Optionally, the flash memory 1440 and the micro display panel 1410 are formed on the same side of the circuit board 1420. Note that the flash memory module 1430 is formed in the flash memory 1440 and is electrically connected to the printed circuit board 1420. The connector 1450 is formed on the other surface of the second end of the printed circuit board 1420 opposite to the flash memory 1440, and is electrically connected to the printed circuit board 1420 and the flash memory 1440. Furthermore, the connector 1450 and the support base 1430 are formed on the same surface of the printed circuit board 1420. In some further embodiments, a central processing unit is formed between the connector 1450 and the printed circuit board 1420. The central processing unit is used to process image data acquired from outside. Here, a cooling element can be formed on the back of the support base to transfer heat of the micro LED panel.

[0086] In some embodiments consistent with Figures 9 and 10, the minimum distance between the micro LED panel 201, 202 or 203 and the surface of the X-cube 301 facing the micro LED panel 201, 202 or 203 is not more than twice the thickness of the micro LED panel 201, 202 or 203, preferably the minimum distance between the micro LED panel 201, 202 or 203 and the surface of the X-cube 301 facing the micro LED panel 201, 202 or 203 is not more than 2 mm, preferably not more than 1 mm. The dimensions of the X-cube 301 are determined by the active light emitting areas of the micro LED panels 201, 202 and 203 and the light area of ​​the X-cube 301 surface formed by the light rays emitted from the micro LED panel 201, 202 or 203. The X-cube 301 is a cube structure with six faces having the same area. The active light emitting areas of the micro LED panels 201, 202, 203 are identical. Each surface area of ​​the X-cube 301 can be smaller than the active light emitting area. That is, the width of the active light emitting area can be the same as or larger than the width of the surface of the X-cube 301, and the height of the active light emitting area can be the same as or larger than the height of the surface of the X-cube 301. In some embodiments, each surface area of ​​the X-cube 301 is at least as large as the light area. That is, the width of the light area can be equal to or smaller than the width of the surface of the X-cube 301, and the height of the light area can be equal to or smaller than the height of the surface of the X-cube 301. For example, in some embodiments, the light area on the surface of the X-cube 301 is a circle with a diameter of 3 mm, and the surface facing the micro LED panel 201, such that the surface area of ​​the X-cube 301 facing the micro LED panel 201 is 3 mm by 3 mm. Furthermore, the light area is equal to or smaller than the active light emitting area. When the chief ray angle of the micro LED panel 201, 202 or 203 is 0°, i.e., all the chief ray angles of the micro LED structures in the micro LED panel 201, 202 or 203 are 0°, the surface area of ​​the X-cube 301 is at least as large as the active light-emitting area, and preferably not larger than 200% of the active light-emitting area, as shown in FIG. 9 and FIG. 10.It should be noted that if the chief light rays of the micro LED structures of the micro LED panels 201, 202 or 203 are collimated to a single point, the light area will be smaller than the active light emitting area, and if the chief light rays of the micro LED structures of the micro LED panels 201, 202 or 203 are diverged to the surroundings instead of being collimated to a single point, the light area of ​​the X-cube 301 will be larger than the active light emitting area.

[0087] In some embodiments consistent with FIG. 15-17, when the chief ray angle of at least some micro LED structures in the micro LED panel 201, 202 or 203 is greater than 0°, the surface area of ​​the X-cube 301 is at least as large as the light area, preferably less than or equal to 200% of the active light emitting area. In some embodiments consistent with FIG. 15, the dotted square representing the minimized X-cube has a surface area equal to the light area, herein the chief ray angle at the center of the micro LED panel 201, 202 or 203 is 0°. The chief ray angle of the micro LED structures of the micro LED panel 201, 202 or 203 increases from the center of the micro LED panel 201, 202 or 203 to the edge of the micro LED panel 201, 202 or 203. Thus, the light is collimated at one point in the X-cube 301 and transmits from the X-cube 301 to display an inverted image on the interface (dotted line). In some embodiments consistent with FIG. 16, the central chief ray angle of the micro LED panel 201, 202 or 203 is 0°. The chief ray angle of the micro LED structures in the micro LED panel 201, 202 or 203 is less than that of FIG. 15, and thus the light rays are collimated at a point off the X-cube 301. The light rays also transmit from the X-cube 301 to display a minimized image on the interface (dotted line). In some embodiments consistent with FIG. 17, the chief ray angle of the center of the micro LED array in the micro LED panel 201, 202 or 203 is greater than 0°, and thus the center of the image on the interface (dotted line) is not aligned with the center of the X-cube 301, and now the image is shifted downward from the central axis of the X-cube 301, as shown in FIG. 17. Furthermore, because the chief ray angles of the micro LED structures in the micro LED panels 201, 202 or 203 are varied, the dimensions of the X-cube 301 can be reduced compared to the X-cube 301 of the embodiment consistent with FIGS. 9 and 10 where the chief ray angle of the entire micro LED panel is 0°.

[0088] In some further embodiments, the three micro LED panels 201, 202, and 203 are vertically arranged around the periphery of the X-cube 301. In some embodiments, again consistent with FIG. 15, an imaginary rectangle (large dotted rectangle in FIG. 15) is formed by the top sides of the two micro LED panels 201 and 203 facing each other. The diagonal length of the top side of the X-cube 301 is less than or equal to 200% of the diagonal length of the imaginary rectangle and at least as long as the diagonal length of the minimized square (small dotted square in FIG. 15), preferably at least as long as the vertices of the active light emitting areas.

[0089] In some embodiments consistent with FIG. 18, where the omission points represent multiple micro LED structures, multiple micro LED structures are arranged in an array to form a micro LED array, which is used as the light emitting area of ​​the micro LED panel. In the micro LED panel, referring to some embodiments consistent with FIG. 19, a cross-sectional view of a micro LED array is shown. Here, the number of micro LED structures is not the actual number, the hemisphere represents the micro LED structure with the micro lens, the dotted lines represent the boundary surface, and the arrows represent the chief ray from the micro LED structure. The chief ray angles of the micro LED structures are different. In some embodiments, the chief ray angles of the micro LED structures increase from any point above the micro LED array to the edge of the micro LED array (such as from the center of the micro LED array to the edge of the micro LED array). Thus, the chief ray of the micro LED structures in the micro LED array can be automatically collimated at a point above the micro LED array (such as a point at the central axis of the micro LED array) as shown in FIG. 19. This micro LED array panel is also shown in FIG. 15-FIG. 17. Preferably, the chief ray angle of the micro LED structure is increased by a certain amount (such as 1°). The certain amount depends on the row number and column number of the micro LED array and the dimensions of the micro LED array. The chief ray angle can be changed by shifting the aforementioned reflective structure along a horizontal level. Alternatively, in another embodiment, the chief ray angle can be changed by shifting the micro lens along a horizontal level, which can be seen in US Patent Application No. 17 / 486,113.

[0090] Note that the central axis of the micro LED array is the axis perpendicular to the micro LED array panel and crossing the center of symmetry. The horizontal level is parallel to the surface of the micro LED array panel, such as the top surface of the micro mesa structure. The chief ray angle is the angle between the chief ray and the vertical direction.

[0091] In some further embodiments, a micro LED array panel may include a plurality of the aforementioned micro LED structures formed in an array. The micro LED array panel is a micro self-emitting panel, in which at least one micro LED forms one pixel.

[0092] 8, the micro LED structures of the micro LED panels 201, 202, and 203 may be organic or inorganic LEDs. The light emitting area of ​​the micro LED array panels 201, 202, and 203 may be very small, e.g., 3 mm * 5 mm. In some embodiments, the light-emitting area is the area of ​​the micro LED array in the micro LED panel. The micro LED array panel includes a micro LED array forming a pixel array of 1600×1200, 680×480, 1920×1080, etc. The diameter of the micro LED structure is in the range of about 200 nm to 2 μm. An IC backside 07 is formed on the backside of the micro LED array and is electrically connected to the micro LED array. The IC backside 07 receives signals such as image data from the outside through a signal line and controls the corresponding micro LED to emit or not emit light. The IC backside 07 generally employs an 8-bit digital-to-analog converter (DAC). The 8-bit DAC has 256 levels of representation, each level corresponding to one gray level. That is, the 8-bit DAC can provide 256 different gray levels. Since any of the 256 gray levels can be applied to the micro LED, a gray level in the range of 0 to 255 can be displayed by one pixel. Optionally, the brightness value of the micro LED can be controlled by the voltage amplitude or current amplitude of the signal acquired by the backside of the IC, while the gray level can be indicated by the time interval (e.g., pulse width) of the signal, which can be understood by those skilled in the art.

[0093] EMBODIMENT 2 20, the micro LED structure includes a mesa structure and a micro lens 11. Furthermore, the above-mentioned reflective structure 00 can be formed around the mesa structure. For details of the mesa structure and the reflective structure 00, please refer to the description of the first embodiment. Furthermore, an anti-reflection film 12 is formed on at least a part of the surface of the micro lens 11.

[0094] In some embodiments consistent with FIG. 20, the anti-reflection coating 12 is formed on the emission portion of the surface of the microlens 11 where the light beam is emitted. Here, the chief ray of the micro LED structure is perpendicular to the top surface of the mesa structure and is emitted from the top center of the microlens 11. The anti-reflection coating 12 is formed on the top of the microlens 11. In some embodiments consistent with FIG. 21, the chief ray is inclined to the top surface of the mesa structure and is emitted from the microlens 11 at an angle in the range of 0 to 45 degrees with respect to the vertical direction. The anti-reflection coating 12 is formed on a portion of the surface of the microlens 11 as shown in FIG. 21.

[0095] 22 and 23, an anti-reflective coating 12 may be formed on the entire surface of the microlens 11. A dielectric layer 08 is formed around the mesa structure, and a spacer 081 is formed on the dielectric layer 08, on top of the mesa structure, and on top of the reflective structure 00. Additionally, an anti-reflective coating 12 is further formed on top of the spacer 081.

[0096] 23, the thickness of the antireflection film 12 formed on the light-emitting portion is greater than the thickness of the antireflection film 12 formed at other positions on the microlens 11. Furthermore, when the chief ray is perpendicular to the top surface of the mesa structure, the thickness of the antireflection film 12 on the top of the microlens 11 is greater than the thickness of the antireflection film 12 at other positions on the microlens 11.

[0097] Due to various chief ray angles of light emission caused by shifting the reflecting structure or microlens, optical loss of light rays occurs in the microlens 11 and on the surface of the microlens 11, which cannot be avoided. Therefore, the anti-reflection film 12 can improve the transmittance of the light rays emitted from the microlens 11, thereby improving the light emission efficiency of the micro LED structure. Preferably, the thickness of the anti-reflection film 12 is in the range of 1 nm to 10 μm. And the dielectric constant of the anti-reflection film 12 is between the dielectric constant of the microlens and the dielectric constant of air. The material of the anti-reflection film 12 is a polymer, an inorganic oxide, or an inorganic nitride. The inorganic oxide can be silicon oxide, Al2O3, TiO2. Furthermore, the inorganic nitride can be silicon nitride or aluminum nitride (Si3N4, Al3N4, etc.). The anti-reflection film 12 is transparent and has high transmission efficiency. The shape of the anti-reflection film 12 can be conformal to the shape of the microlens 11. That is, the radius of curvature of the anti-reflective coating 12 is the same as the radius of the microlens 11. For example, the shape of the anti-reflective coating 12 can be an arc shape, a hemisphere shape, etc. It is noted that in another embodiment, the shape of the anti-reflective coating 12 can be a sphere having a different radius compared to the microlens 11. It is noted that the anti-reflective coating 12 can also be used as a protective layer to protect the surface of the microlens 11 from damage.

[0098] In some embodiments, the chief ray angle of the micro LED structure can be changed by shifting the reflector structure 00 as described above, or by shifting the micro lens 11 along the top surface of the mesa structure. For example, the central axis of the micro lens 11 is shifted from the central axis of the mesa structure to change the chief ray angle of the micro LED structure.

[0099] For details of the mesa structure, the reflective structure, and the IC back surface 07, please refer to the description of the first embodiment.

[0100] Furthermore, a spacer 081 is formed at the bottom of the microlens 11 and between the mesa structure and the microlens 11. The thickness of the spacer 081 can be adjusted according to actual requirements. Preferably, the thickness of the spacer 081 can be smaller than the radius of curvature of the microlens 11 in the embodiment. It should be noted that in another embodiment, the thickness of the spacer 081 is equal to or larger than the radius of the microlens 11. The distance between the focal point of the microlens 11 and the light emitting layer 02 is determined by the thickness of the spacer 081 and the radius of the microlens 11. Preferably, the thickness of the spacer 081 is less than 50% of the radius of the microlens 11. Also, the thickness of the spacer is within the range of 10% to 200% of the height of the microlens.

[0101] The micro LED structure in the second embodiment can also be applied to the micro LED projector described in the first embodiment.

[0102] It should also be noted that in other embodiments, the chief ray angle can be changed by shifting the microlenses 11 along the horizontal level, as shown in the embodiments consistent with Figures 24 and 25. Thus, in these embodiments, no reflecting structure is required. Also, in the embodiments consistent with Figure 26, the chief ray angle can be changed by shifting the microlenses along the horizontal level and simultaneously shifting the reflecting structure 00. Thus, in these embodiments, both the reflecting structure 00 and the microlenses 11 are required.

[0103] EMBODIMENT 3 27, the micro LED structure comprises a mesa structure and a micro lens 11. The micro LED structure further comprises the aforementioned reflective structure 00, a spacer 081, an isolation layer 10 and a dielectric layer 08. For details of the mesa structure, the micro lens 11, the spacer 081, the isolation layer 10, the dielectric layer 08 and the reflective structure 00, please refer to embodiments 1 and 2.

[0104] In some embodiments consistent with FIG. 27, the shape of the micro-mesa structure is as follows: the top surface area of ​​the micro-mesa structure is smaller than the bottom surface area of ​​the micro-mesa structure, like a trapezoid. Furthermore, the distance between the focal point of the micro-lens 11 and the top of the micro-mesa structure is not more than 70% of the height of the micro-mesa structure, as shown in FIG. 27 (the black dot represents the focal position, which will be explained below). Preferably, the radius of curvature of the micro-lens 11 is in the range of 100 nm to 10 μm, and the diameter of the micro-lens 11 is larger than the top width of the micro-mesa structure. It is noted that when the chief ray angle of the micro-LED structure is larger than 0°, the diameter of the micro-lens 11 can be smaller than the top width of the micro-mesa structure.

[0105] When a spacer 081 is formed between the microlens 11 and the mesa structure, the focal position of the microlens 11 is determined by the thickness of the spacer 081, the height of the microlens 11, and the radius of curvature of the microlens 11. In some embodiments consistent with FIG. 28, the black dots represent focal positions, the thickness of the spacer 081 is greater than 100%-300% of the radius of curvature, and the focal position is above the top surface of the micromesa structure. In some embodiments consistent with FIG. 29, the black dots represent focal positions, the thickness of the spacer 081 is about 100%-300% of the radius of curvature, and the focal position is on the top surface of the micromesa structure. In some embodiments consistent with FIG. 27, the thickness of the spacer 081 is less than 100%-300% of the radius of curvature, and the focal position is below the top of the micromesa structure.

[0106] Furthermore, in some embodiments, the position of the focal point is determined by the radius of curvature of the microlens when no spacer is formed between the mesa structure and the microlens 11. In some embodiments consistent with FIG. 30, the black dot represents the focal point position, the radius of curvature of the microlens 11 is 50%-100% of the height of the mesa structure, and the distance between the focal point position of the microlens 11 and the top of the micromesa structure is 70% or less of the height of the micromesa structure.

[0107] It should be noted that as the radius of curvature of the microlens 11 increases, the focal position moves downward if the height of the microlens 11 is kept at a preset value; furthermore, if the diameter of the microlens 11 not including the spacer 081 is larger than the bottom width of the mesa structure and the height of the microlens 11 is smaller than the radius of the microlens 11, the focal position of the microlens 11 can reach out of the bottom of the mesa structure. Furthermore, if the diameter of the microlens 11 is 100%-200% of the top width of the mesa structure or equal to the bottom width of the mesa structure, the distance between the focal point of the microlens 11 and the top of the micromesa structure is not more than 70% of the height of the micromesa structure. Preferably, the radius of curvature of the microlens is in the range of 100 nm-10 μm.

[0108] Furthermore, the surface roughness of the mesa structure is another factor that affects the focal position. The mesa structure scatters light on the surface of the microlens 11 and the surface of the mesa structure, so the actual focal position of the microlens 11 cannot reach too deep into the mesa structure. Preferably, the distance between the focal point of the microlens 11 and the top of the micromesa structure is not more than 70% of the height of the micromesa structure. In some embodiments, the distance between the focal point and the top surface of the mesa structure is 30% of the height of the micromesa structure. Preferably, the surface roughness of the micromesa structure is 1 nm to 100 nm.

[0109] Preferably, the surface roughness of the microlens 11 is in the range of 1 nm to 100 nm. The material of the microlens 11 is selected from polymers, inorganic oxides, and inorganic nitrides. The inorganic material can be silicon oxide or silicon nitride. It is noted that the material of the microlens 11 can be different from the material of the spacer 081, or in some embodiments, the material of the microlens 11 can be the same as the material of the spacer 081.

[0110] At least, different focal positions of the microlenses and different chief ray angles of the microLED structures determine different luminous intensities and efficiencies.

[0111] The micro LED structure in the third embodiment can also be applied to the micro LED projector described in the first embodiment.

[0112] For details of the micro LED structure, please refer to the descriptions of embodiments 1 and 2.

[0113] EMBODIMENT 4 31, the mesa structure is different from that of embodiment 3. The mesa structure in embodiment 4 is an inverted trapezoid, in which the top surface area of ​​the micro-mesa structure is larger than the bottom surface area of ​​the micro-mesa structure.

[0114] Furthermore, as mentioned above, the surface roughness of the microlens 11 and the surface roughness of the mesa structure are further influencing factors of the focal position. Due to the surface roughness of the microlens 11 and the mesa structure, the light is scattered on the surface of the microlens 11 and the surface of the mesa structure, so that the actual focal position of the microlens 11 cannot reach too deep in the mesa structure. Preferably, the surface roughness of the microlens is in the range of 1 nm to 1000 nm. Therefore, the distance between the focal position of the microlens 11 and the top of the micromesa structure is less than 100% of the height of the micromesa structure, which is the same as in the third embodiment. In the inverted trapezoidal micro LED structure, the radius of curvature of the microlens 11 can be larger than that of the trapezoidal micro LED structure in the third embodiment, so that the focal position can be located deeper in the mesa structure compared to the focal position in the third embodiment. When the diameter of the microlens 11 is 80% to 120% of the top width of the inverted trapezoidal mesa structure or equal to the bottom width of the mesa structure, the distance between the focal point of the microlens 11 and the top of the inverted trapezoidal micromesa structure is 100% or less of the height of the inverted trapezoidal micromesa structure. Preferably, the radius of curvature of the microlens 11 is in the range of 100 nm to 10 μm.

[0115] The micro LED structure in the third embodiment can also be applied to the micro LED projector described in the first embodiment.

[0116] For other details of the micro LED structure, please refer to the descriptions of embodiments 1 to 3.

[0117] EMBODIMENT 5 In this embodiment 5, a micro LED projector is provided. In some embodiments consistent with FIG. 32, the micro LED projector includes a micro LED panel and a collimator unit 14. The micro LED panel includes a micro LED structure array including a plurality of the aforementioned micro LED structures. It should be noted that in the embodiment consistent with FIG. 32, only one micro LED structure is illustrated for the description of the embodiment 5, but this is not limiting to the scope of the present disclosure. The collimator unit 14 is formed in the light emission direction to collimate the light beam emitted from the micro LED structure to a pre-set target position, such as a display screen, a wall, or a human eye (not shown in FIG. 32).

[0118] Here, in some embodiments consistent with Figs. 32-34, in each mesa structure, the center of the microlens 11 and the center of the light emitting layer 02 are positioned on a first straight line. Note that in some embodiments, the center of the collimator unit 14 is formed to be offset from the first straight line. The center of the collimator unit 14 and the center of the light emitting layer 02 are positioned on a second straight line. The second straight line can be aligned with the first straight line or offset by a certain deflection angle. Preferably, the deflection angle is 5° or less.

[0119] In some embodiments, the connecting line connects the center of the collimator unit 14, the center of the microlens 11, and the center of the light emitting layer 02. Furthermore, the center of the light emitting layer 02 may be horizontally offset from the connecting line. Preferably, the horizontally offset distance of the center of the light emitting layer 02 from the connecting line is 45% or less of the bottom width of the mesa structure. In some embodiments, the bottom width of the mesa structure is 1 μm, and the offset distance of the center of the light emitting layer 02 is 0.3 μm or less.

[0120] The shape of the microlens 11 can be a hemisphere, a sphere, or other irregular shape. The center of the microlens 11 can be the center of a hemisphere or a sphere, or the geometric center of an irregular shape, such as a combination of a hemisphere and a parabola, or a combination of at least two hemispheres with different diameters, or a combination of at least two circular arc lines with different radii of curvature.

[0121] In some embodiments, the micro LED structure further comprises a capping layer 13 covering the micro lenses 11 and above the micro mesa structure. The material of the capping layer 13 is a polymer, an inorganic oxide, or an inorganic nitride (such as silicon oxide or silicon nitride). Furthermore, the capping layer 13 is also deposited between adjacent micro lenses 11.

[0122] Here, the distance between the focal point of the microlens 11 and the light emitting layer 02 is 200% or less of the thickness of the mesa structure.

[0123] For other details of the micro LED structure, please refer to the descriptions of the first to fourth embodiments.

[0124] It should be noted that other elements may be formed between the micro LED structure and the collimator 14, such as optical coupling elements, which will be shown and described below.

[0125] Further, in some embodiments consistent with FIG. 35, the collimator unit 14 as shown in FIG. 32-34 is a collimator group. Here, the micro LED projector includes a micro LED panel 15 and a collimator group 1400. The collimator group 1400 includes a plurality of lenses for displaying an optical image. Preferably, the number of lenses is 6 or less, and the focal length of the collimator group 1400 is less than 2.5. Furthermore, the micro LED panel is formed so as not to contact the collimator unit 14 (collimator group 1400). The distance between the micro LED panel and the surface of the collimator unit 14 (collimator group 1400) is equal to or less than the thickness of the collimator unit 14 (collimator group 1400). Preferably, the distance between the micro LED panel and the surface of the collimator unit 14 (collimator group 1400) is equal to or less than 2 mm. The micro LED panel 15 has a light emitting region, and the collimator unit 14 has an input surface. The light emitted from the light emitting region is incident on the input surface of the collimator unit 14. Here, the light emitting area is larger than the incident surface of the collimator unit 14. Moreover, the width of the micro LED panel 15 is larger than the diameter of the incident surface of the collimator unit 14, so that the volume and weight of the micro LED projector are reduced. It is noted that the LED structure comprises two or more micro LED panels. Furthermore, it is noted that the aforementioned light area of ​​the collimator unit 14 is equal to or smaller than the incident surface of the collimator unit 14.

[0126] Here, the chief ray angles of the micro LEDs of the micro LED panel 15 are not the same. It should be noted that in some embodiments, the chief ray angles of some micro LEDs are the same as each other, and the chief ray angles of some micro LEDs are different from each other. Preferably, the chief ray angles of the micro LEDs of the micro LED panel 15 are collimated to a point.

[0127] Further, the at least two kinds of color micro LED panels each emit a light beam of one color, and the chief ray angle of the micro LEDs of each micro LED panel is collimated to one point. Further, the micro LED projector further comprises an optical coupling element oriented in the light beam emission direction of each color of the micro LED panel, and configured to combine the light beams of the colors into a combined beam. The collimated light is emitted from the output surface of the optical coupling element and enters the input surface of the collimator unit, where the area of ​​the output surface is larger than the area of ​​the input surface. Further, the diameter of the collimator unit is smaller than the side width of the optical coupling element. Further, the distance between the output surface of the optical coupling element and the input surface of the collimator unit is not more than 200% of the thickness of the collimator unit. In some embodiments, the distance between the output surface of the optical coupling element and the input surface of the collimator unit is zero.

[0128] Furthermore, the optical coupling element has a plurality of light receiving surfaces respectively corresponding to the light emitting areas of the micro LED panel. Preferably, the minimum distance between the micro LED panel and the light receiving surface of the optical coupling element is less than or equal to 200% of the thickness of the micro LED panel. Furthermore, the side width of the light receiving surface of the optical coupling element is smaller than the side width of the light emitting area of ​​the micro LED panel of the first color.

[0129] Here, the micro LED structure in the fifth embodiment can also be applied to a micro LED projector. In some embodiments consistent with Fig. 36, the micro LED projector of the fifth embodiment includes a first color micro LED panel 201, a second color micro LED panel 202, an optical coupling element 301, and a collimator group 1400 in order, where the first color is different from the second color. Note that the collimator unit 14 includes the collimator group 1400 or an optical lens.

[0130] The optical combining element 301 faces the first color light emitting direction of the first micro LED panel 201 and faces the second color light emitting direction of the second micro LED panel 202, and combines the first color light ray and the second color light ray into a combined light beam. The collimator group 1400 then collimates the combined light beam to a preset target position, not shown in Fig. 36. The preset target position can be a display screen, a wall, or a human eye.

[0131] The first micro LED panel 201 emits light of a first color. The first micro LED panel 201 comprises a first color micro LED structure array, the first color micro LED structure array comprises a plurality of first color micro LED structures. The first color micro LED structures are selected from the aforementioned micro LED structures having a first color light emitting layer. The second micro LED panel 202 emits light of a second color. The second micro LED panel 202 comprises a second color micro LED structure array, the second color micro LED structure array comprises a plurality of second color micro LED structures. The second color micro LED structures are selected from the aforementioned micro LED structures having a second color light emitting layer. The optical coupling element 301 is formed to receive light rays emitted from the first micro LED panel 201 and light rays emitted from the direction of the second micro LED panel 202. Further, the optical coupling element 301 comprises a polarizing and splitting film facing the first color light beam emitted from the first micro LED panel 201 and the second color light beam emitted from the second micro LED panel 202. The collimator group 1400 receives the light beam from the optical coupling element 301 and collimates the light beam to a preset target position. It is noted that in another embodiment, the first micro LED panel 201 may emit two color light beams and the second micro LED panel 202 may emit one color light beam. In some embodiments, the optical coupling element 301 is formed to receive the light beam emitted from the first micro LED panel 201 and the light beam emitted from the direction of the second micro LED panel 202. Further, the optical coupling element 301 configures a polarizing and splitting film facing the light beam emitted from the first micro LED panel 201 and the light beam emitted from the second micro LED panel 202. Preferably, the optical coupling element 301 is an X-cube. The structure of an X-cube will be understood by those skilled in the art.

[0132] Furthermore, the collimated light is emitted from the emission surface of the optical coupling element 301 and enters the entrance surface of the collimator unit 14 (collimator group 1400). The distance between the emission surface of the optical coupling element 301 (X-cube) and the entrance surface of the collimator unit 14 (collimator group 1400) is equal to or greater than zero. Preferably, the distance between the emission surface of the optical coupling element 301 and the entrance surface of the collimator unit 14 is equal to or less than 200% of the thickness of the collimator unit.

[0133] Furthermore, the chief ray angle of the micro LEDs of the first color micro LED panel 201 is collimated to one point, the chief ray angle of the micro LEDs of the second color micro LED panel 202 is collimated to one point, and the area of ​​the emission surface is larger than the area of ​​the entrance surface. Furthermore, the diameter of the collimator unit 14 (collimator group 1400) can be equal to or smaller than the side width of the X-cube. Furthermore, the light emitted from the first light-emitting region of the first color micro LED panel is incident on the first light-receiving surface of the optical coupling element 301. The side width of the first light-receiving surface of the optical coupling element 301 is smaller than the side width of the first light-emitting region of the first color micro LED panel 201. The light emitted from the second light-emitting region of the second color micro LED panel 202 is incident on the second light-receiving surface of the optical coupling element 301. The side width of the second light-receiving surface of the optical coupling element 301 is smaller than the side width of the second light-emitting region of the second color micro LED panel 202.

[0134] In another embodiment, the diameter of the collimator unit 14 (collimator group 1400) is larger than the side width of the X-cube. Preferably, the diameter of the collimator unit 14 (collimator group 1400) is 200% or less of the side width of the X-cube 301.

[0135] Further, in some embodiments consistent with Figure 37, the micro LED projector comprises, in sequence, a first color micro LED panel 201, a second color micro LED panel 202, a third color micro LED panel 203, an optical coupling element 301, and a collimator group 1400. The first micro LED panel 201 emits light rays of a first color, the second micro LED panel 202 emits light rays of a second color, and the third micro LED panel 203 emits light rays of a third color.

[0136] The first micro LED panel 201 emits light of a first color. The first micro LED panel 201 comprises a first color micro LED structure array, the first color micro LED structure array comprises a plurality of first color micro LED structures. The first color micro LED structures are selected from the aforementioned micro LED structures having a first color light emitting layer. The second micro LED panel 202 emits light of a second color. The second micro LED panel 202 comprises a second color micro LED structure array, the second color micro LED structure array comprises a plurality of second color micro LED structures. The second color micro LED structures are selected from the aforementioned micro LED structures having a second color light emitting layer. The third micro LED panel 203 comprises a third micro LED structure array, the third micro LED structure array comprises a plurality of third color micro LED structures. And the third color micro LED structures are selected from micro LED structures having a third color light emitting layer, the first color, the second color and the third color being different from each other. The optical coupling element 301 comprises a first polarizing and splitting film facing the first color light beam emitted from the first micro LED panel 201 and the second color light beam emitted from the second micro LED panel 202. Furthermore, the optical coupling element 301 comprises a second polarizing and splitting film facing the second color light beam emission direction of the second micro LED panel 202 and facing the third color light beam emission direction of the third micro LED panel 203. Preferably, the optical coupling element 301 is an X-cube. The structure of the X-cube can be understood by those skilled in the art.

[0137] Furthermore, the collimated light is emitted from the emission surface of the optical coupling element 301 and enters the entrance surface of the collimator unit 14 (collimator group 1400). The distance between the emission surface of the optical coupling element 301 (X-cube) and the entrance surface of the collimator unit 14 (collimator group 1400) is equal to or greater than zero. Preferably, the distance between the emission surface of the optical coupling element 301 and the entrance surface of the collimator unit 14 is equal to or less than 200% of the thickness of the collimator unit 14.

[0138] Furthermore, the chief ray angles of the micro LEDs of the first color micro LED panel 201 are collimated to one point, the chief ray angles of the micro LEDs of the second color micro LED panel 202 are collimated to one point, and the chief ray angles of the micro LEDs of the third color micro LED panel 203 are collimated to one point. The area of ​​the emission surface of the optical coupling element 301 is larger than the area of ​​the entrance surface of the collimator unit 14. Furthermore, the diameter of the collimator unit 14 (collimator group 1400) can be equal to or smaller than the side width of the optical coupling element, for example, the side width of the X-cube. Furthermore, the light emitted from the first light-emitting region of the first color micro LED panel 201 is incident on the first light-receiving surface of the optical coupling element 301. The side width of the first light-receiving surface of the optical coupling element 301 is smaller than the side width of the first light-emitting region of the first color micro LED panel 201. The light emitted from the second light-emitting region of the second color micro LED panel 202 is incident on the second light-receiving surface of the optical coupling element 301. The side width of the second light-receiving surface of the optical coupling element 301 is smaller than the side width of the second light-emitting region of the second color micro LED panel 202. And the light emitted from the third light-emitting region of the third color micro LED panel 203 is incident on the third light-receiving surface of the optical coupling element 301. The side width of the third light-receiving surface of the optical coupling element 301 is smaller than the side width of the third light-emitting region of the third color micro LED panel 203.

[0139] In some embodiments, the diameter of the collimator unit 14 (collimator group 1400) is larger than the side width of the X-cube. Preferably, the diameter of the collimator unit 14 (collimator group 1400) is 200% or less of the side width of the X-cube 301.

[0140] It should be noted that in some embodiments, the micro LED devices disclosed herein include one, two, three, four or more micro LED panels.

[0141] A plurality of micro LED structures are arranged in an array to form a micro LED array, which is used as the light-emitting area of ​​the micro LED panel. In the micro LED panel, the chief ray angles of the micro LED structures are different. For example, the chief ray angle of the micro LED structure increases from any point above the micro LED array to the edge of the micro LED array (such as from the center of the micro LED array to the edge of the micro LED array). Thus, the chief ray of the micro LED structure in the micro LED array can be automatically collimated at a point above the micro LED array (such as a point at the central axis of the micro LED array), as shown in FIG. 19. This micro LED array panel is also shown in FIG. 15-FIG. 17. Preferably, the chief ray angle of the micro LED structure is increased by a certain amount (such as 1° or other angle). The certain amount depends on the row number and column number of the micro LED array and the dimension of the micro LED array. The chief ray angle can be changed by shifting the aforementioned reflective structure along the horizontal level. Alternatively, in another embodiment, the chief ray angle can be changed by shifting the microlenses along the horizontal level, see US patent application Ser. No. 17 / 486,113.

[0142] For details of the structure of the micro LED, please refer to the descriptions of the first to fourth embodiments.

[0143] In some embodiments consistent with FIG. 35, the dimensions of the collimator group 1400 will be smaller because the dimensions of the micro LED panel 15 are very small and the chief ray angle is adjustable. In some embodiments, the diameter of the lens of the collimator group 1400 will be reduced and the thickness of the lens will be reduced, so the volume of the collimator group 1400 will be further reduced. Similarly, referring to the embodiments consistent with FIG. 36 and FIG. 37, the dimensions of the micro LED panels 201, 202, and 203 will be very small and the chief ray angle is adjustable, so the dimensions of the optical coupling element 301 and the dimensions of the collimator group 1400 will be smaller. In some embodiments, the width of the X-cube will be reduced and the volume of the X-cube will be further reduced. In some embodiments, the diameter of the lens of the collimator group 1400 will be reduced and the thickness of the lens will be reduced, so the volume of the collimator group 1400 will be further reduced. In some more specific embodiments, the micro LED panel 201, 202, or 203 is 3mm or less, the width of the X-cube is 3mm or less, the diameter of the lens of the collimator group 1400 is 3mm or less, and the length of the collimator group 1400 is 3mm or less, making the optical engine or micro LED projector even smaller, facilitating a lighter and more miniaturized device. As the chief ray angles of the micro LED structures in the micro LED panels 201, 202, 203 are different and collimated to a single point (as described above), the dimensions of the X-cube and the dimensions of the collimator group 1400 will become smaller and smaller.

[0144] In some embodiments, the central axis of the micro LED array is an axis perpendicular to the micro LED array panel and passing through the center of symmetry of the micro LED array. The horizontal level is parallel to the surface of the micro LED array panel.

[0145] In some further embodiments, a micro LED array panel may comprise a plurality of the aforementioned micro LEDs formed in an array. The micro LED array panel is a micro self-emitting panel. The micro LEDs in the panel may be organic or inorganic LEDs. The light emitting area of ​​the micro LED array panel may be less than 3 mm. *It is very small, measuring only 5mm. The light-emitting area is the area of ​​the micro LED array. The micro LED array panel includes a micro LED array that forms a pixel array of 1600x1200, 680x480, 1920x1080, etc. The diameter of the micro LED is in the range of 200nm to 2μm. An IC backside is formed on the backside of the micro LED array and is electrically connected to the micro LED array. The IC backside receives signals such as image data from the outside through a signal line, and controls the corresponding micro LED to emit light. The IC backside generally employs an 8-bit digital-to-analog converter (DAC). An 8-bit DAC has 256 levels of display, and each level corresponds to one gray level. That is, an 8-bit DAC can provide 256 different gray levels. Since any of the 256 gray levels can be applied to the micro LED, a gray level in the range of 0 to 255 can be displayed by one pixel. Optionally, the brightness value of the micro LED can be controlled by the voltage amplitude or current amplitude of the signal received by the IC backside. Alternatively, the grey level can be indicated by the time interval (eg pulse width) of the signal.

[0146] For details of the micro LED projector and the micro LED panel, please refer to the descriptions of the first to fourth embodiments.

[0147] EMBODIMENT 6 In some embodiments consistent with Fig. 38, a micro LED display device is provided, comprising at least one monolithic micro LED projector 1601 and a light guide 1602. The monolithic micro LED projector 1601 is configured to generate monochrome images of one or different colors separately. The light guide 1602 is configured to receive the monochrome images from the monolithic micro LED projectors, respectively. The light guide 1602 is further configured to transmit the monochrome images and superimpose the monochrome images to combine them into an objective image.

[0148] In some embodiments, the monolithic micro LED projector includes a monolithic micro LED panel and a collimator group, and the light from the monolithic micro LED panel is formed to transmit through the collimator group and is corrected there. For this monolithic micro LED projector, please refer to the above-mentioned micro LED projector shown in Figures 32 to 35. Here, the micro LED array of the monolithic micro LED panel applies micro LEDs to display pixels. In the micro LED panel, the chief ray angles of the micro LEDs are different. Here, the micro LEDs include a micro mesa structure and a micro lens, and for at least some of the micro LEDs, the central axis of the micro lens is shifted from the central axis of the micro mesa structure. Note that the chief ray angle of the micro LED structure can be realized by the reflection structure 00 described in embodiment 1, and further refer to U.S. Patent Application No. 17 / 486,113. Furthermore, the micro LED structure can be the micro LED structure in the above-mentioned embodiments 1 to 5. For details of the structure of the micro LED, please refer to the description of embodiments 1 to 5. In some embodiments, the micro LED projector has dimensions of 5mm x 5mm x 5mm or less, the micro LED panel has dimensions of 5mm x 5mm or less, and the micro LED display device has a thickness of 3mm or less.

[0149] Here, the chief ray angle of the micro LEDs in the micro LED panel increases from any point above the micro LED array to the edge of the micro LED array. Preferably, in some embodiments, the chief ray angle of the micro LEDs in the micro LED panel increases from the center of the micro LED array to the edge of the micro LED array. For further details on the chief ray angle and its relationship to the micro LED array, please refer to the description of embodiments 1 to 5.

[0150] Since the chief ray angle of the micro LED is formed to be collimated in a certain direction, the light area on the collimator group is smaller than the light area from a conventional micro LED projector having a micro LED with the same chief ray angle of 90°. This reduces the volume of the micro LED projector and the volume of the light guide, making it easy to combine the micro LED projector with the light guide. Furthermore, the micro LED display device can reduce the weight and volume of a headset, a head-up device, a VR device, an AR device, or other micro display device.

[0151] Further, in some embodiments consistent with Figure 39, the monolithic micro LED projector comprises a first monolithic micro LED projector unit 16011, a second monolithic micro LED projector unit 16012, and a third monolithic micro LED projector unit 16013. The first monolithic micro LED projector unit 16011 generates a first monochrome image in a first color, the second monolithic micro LED projector unit 16012 generates a second monochrome image in a second color, and the third monolithic micro LED projector unit 16013 generates a third monochrome image in a third color. Further, the first monolithic micro LED projector unit 16011 comprises at least one first sub-monolithic micro LED projector 160111, the second monolithic micro LED projector unit 16012 comprises at least one second sub-monolithic micro LED projector 160121, and the third monolithic micro LED projector unit 16013 comprises at least one third sub-monolithic micro LED projector 160131. Preferably, in some embodiments consistent with FIG. 40, the first monolithic micro LED projector unit 16011 comprises one first sub-monolithic micro LED projector 160111, the second monolithic micro LED projector unit 16012 comprises one second sub-monolithic micro LED projector 160121, and the third monolithic micro LED projector unit 16013 comprises two third sub-monolithic micro LED projectors 160131. Note that the first color, the second color, and the third color are different. In some embodiments, the first color is blue, the second color is green, and the third color is red. In some embodiments consistent with FIG. 41, the micro LED display device is a glass 1701. The glass 1701 includes one blue micro LED projector B, one green micro LED projector G, and two red micro LED projectors R.

[0152] In some embodiments consistent with Figure 42, the light guide includes at least two light gratings 16021 aligned with the monolithic micro LED projector units 16011, 16012, 16013, respectively, each providing a different color monochrome image. In some embodiments consistent with Figure 43, the light guide 1602 includes at least two light gratings 16021 aligned with the monolithic micro LED projectors 160111, 160121, and 160131, respectively, each providing a monochrome image.

[0153] In some embodiments consistent with Figures 38 and 39, the micro LED display device comprises an optical coupling unit 1603. The optical coupling unit 1603 is configured to receive a monochrome image and couple the monochrome image to an objective image by superimposing the monochrome image. The optical coupling unit 1603 can be a conventional optical coupling unit as small as possible and can be fitted into the light guide 1602. This can be understood by those skilled in the art.

[0154] It should be noted that in the embodiments consistent with Figures 34-37, a space is formed between the monolithic micro LED projector 1601 and the optical waveguide 1602. The spacing between the surface of the collimator unit 14 and the optical waveguide 1602 is equal to or less than the thickness of the collimator unit 14. Preferably, the spacing between the surface of the collimator unit 14 and the optical waveguide 1602 is equal to or less than 3 mm.

[0155] Furthermore, the optical waveguide 1602 has an input region. The chief ray emitted from the collimator unit 14 is formed to be parallel to the normal direction of the input region. The angular deviation between the chief ray emitted from the collimator unit 14 and the normal direction of the input region is 5° or less.

[0156] This micro LED display device can be applied to micro LED glasses. The micro LED glasses include the above-mentioned monolithic micro LED projector 1601 and light guide 1602, which will not be described again in this specification. The relationship between the monolithic micro LED projector 1601 and glasses will be further described later.

[0157] In some embodiments consistent with FIG. 44, the glass 1701 is formed into four quadrants (four regions formed by two dotted lines) based on the center of the glass 1701 (black dot) and the right-angled cross lines (two right-angled cross lines). The glass includes four quadrant regions I, II, III, and IV, which are divided by the aforementioned four quadrants based on the center of the glass. It should be noted that the center of the glass 1701 is the geometric center of the glass 1701. In some embodiments, the center of the glass 1701 is a position facing the human eye. The four quadrant regions I, II, III, and IV are provided as a first quadrant region I, a second quadrant region II, a third quadrant region III, and a fourth quadrant region IV, respectively.

[0158] Furthermore, the monolithic micro LED projector can be fabricated inside the glass, on the edge of the glass, or on the outside of the glass.

[0159] A monolithic micro LED projector is formed in at least one of quadrant regions I, II, III or IV. In some embodiments, a monolithic micro LED projector is formed in at least one of the first quadrant region I, the second quadrant region II, the third quadrant region III, or the fourth quadrant region IV. In some embodiments, the monolithic micro LED projectors are not formed in the same quadrant region. In some embodiments, each of the monolithic micro LED projectors is separately formed in a different quadrant region.

[0160] Preferably, in some embodiments consistent with Figure 45, points P1, P2, P3, P4 are centers of four quadrant regions I, II, III, IV, respectively. Each of the four quadrants is divided into four sub-quadrant(s) and provided as sub-quadrant(s) in each of the four quadrants. Preferably, in some embodiments consistent with Figures 46-49, a monolithic micro LED projector is formed to be located in or on the edge of at least one quadrant region I, II, III or IV.

[0161] In some embodiments consistent with Figures 46 and 47, the monolithic micro LED projectors are formed at the four corners of the glass. In some embodiments, the monolithic micro LED projectors are formed in different quadrant regions. In some embodiments consistent with Figure 46, a red micro LED projector R is positioned in the second quadrant region II and the third quadrant region III, a green micro LED projector G is positioned in the first quadrant region I, and a blue micro LED projector B is positioned in the fourth quadrant region IV.

[0162] In some embodiments, some of the monolithic micro LED projectors are formed in the same quadrant region and some of the monolithic micro LED projectors are formed in different quadrant regions from each other. In some embodiments consistent with FIG. 47, the red micro LED projector R is positioned in the second quadrant region II, the green micro LED projector G is positioned in the first quadrant region I, and the blue micro LED projector B is positioned in the fourth quadrant region IV.

[0163] Additionally, the monolithic micro LEDs can be positioned within the same quadrant region, such as the glass shown in Figure 41. Additionally, in some embodiments consistent with Figure 48, the monolithic micro LED projectors are formed to be positioned at either the top edge, bottom edge, left edge, or right edge of the glass.

[0164] In some embodiments, the monolithic micro LED projector is formed to be positioned on the outside of the glass. In some embodiments consistent with FIG. 49, an edge protrusion 18 extends outward from the edge of the glass 1701. The monolithic micro LED projectors R, G, and B are formed to be positioned on the edge protrusion 18 with the light emitting surface of the monolithic micro LED projectors R, G, and B facing the entrance area of ​​the light guide 1602. In addition, the edge protrusion 18 can connect the glass to a glass stem or any other element. Furthermore, the edge protrusion 18 is connected to at least one edge of the four quadrants. Preferably, the edge protrusion 18 corresponds to at least one edge of a sub-quadrant (e.g., the edge of the sub-quadrant in the upper right corner).

[0165] In some embodiments consistent with FIG. 45, the monolithic micro LED projector is formed to be positioned near the center P1, P2, P3, or P4. It is noted that the monolithic micro LED projector can be formed at the center P1, P2, P3, or P4, or at a position offset from the center P1, P2, P3, or P4. Furthermore, in each of the quadrant regions I, II, III, and IV, the deviation distance between the monolithic micro LED projector and the center P1, P2, P3, or P4 is 50% to 150% or less of the distance between the center P1, P2, P3, or P4 and the center of the glass (a point at the center of the glass 1701). It is noted that in some embodiments, the deviation distance between the monolithic micro LED projector and the center P1, P2, P3, or P4 is within a range of 0.1 mm to 3 mm. It is noted that the center of one quadrant region I, II, III, or IV is the geometric center of the quadrant, respectively. Furthermore, it is noted that the above-mentioned positions of the monolithic micro LED projector are equivalent to the following positions of the monolithic micro LED projector: The area of ​​one quadrant region I, II, III or IV is divided into four sub-regions based on the center of the glass; The monolithic micro LED projector is positioned near or at a shared corner (location of points P1, P2, P3, P4) of the four sub-regions; The deviation of the monolithic micro LED projector from the shared corner is no more than 5% of the side length of the sub-region.

[0166] Here, in some embodiments, the glasses can be monocular glasses. Furthermore, in some embodiments, the glasses can be applied in pairs. The monolithic micro LED projectors are positioned in a pair of glasses, and the monolithic micro LED projectors are positioned in separate glasses, where the left glass includes the same number and color of monolithic micro LED projectors as the right glass. In some embodiments, the number of monolithic micro LED projectors in the left glass is different from the number in the right glass. The colors of the monolithic micro LED projectors in the left glass and the right glass are different. Furthermore, the position of the monolithic micro LED projector in the left glass is the same as the position of the monolithic micro LED projector in the right glass. Preferably, the position of the monolithic micro LED projector in the left glass is in a mirror relationship with the position of the monolithic micro LED projector in the right glass. In some embodiments, the position of the monolithic micro LED projector in the left glass is different from the position of the monolithic micro LED projector in the right glass. The position of the monolithic micro LED projector in the left glass is symmetric or asymmetric with respect to the position of the monolithic micro LED projector in the right glass with respect to the central axis between the left glass and the right glass. In some embodiments consistent with FIG. 50, the distribution of the green micro LED projector G, the blue micro LED projector B, and the red micro LED projector R in the left glass 17011 is symmetric with respect to the distribution in the right glass 17012. In some embodiments consistent with FIG. 51, the green micro LED projector G, the blue micro LED projector B, and the red micro LED projector R are all formed in the same quadrant of the left glass and are symmetric with respect to the respective projectors in the right glass. Note that the distribution of the monolithic micro LED projectors in the left glass may not be symmetric with the distribution of the monolithic micro LED projectors in the right glass. In some embodiments, the monolithic micro LED projectors may be formed only in the right glass or the left glass.In some embodiments consistent with Fig. 52, a central connector is formed between the left glass and the right glass, and a monolithic micro LED projector can also be formed in the central connector. Preferably, in some embodiments, the monolithic micro LED projector is formed in the central connector near either the left glass or the right glass. In some embodiments, a green micro LED projector is formed in the central connector closer to the right glass.

[0167] In some embodiments, either the number or color of the monolithic micro LED projectors in the left glass differs from those in the right glass, such that the left glass displays an image of a first color and the right glass displays an image of a second color. Further, in some embodiments, the number of monolithic micro LED projectors in the left glass differs from the number of monolithic micro LED projectors in the right glass, such that the left glass displays an image of the same color as the right glass. Further, the position of the monolithic micro LED projectors in the left glass differs from the position of the monolithic micro LED projectors in the right glass, such that the left glass displays an image of the same color as the right glass.

[0168] Furthermore, the monolithic micro LED projector is formed in a one-dimensional array. For example, referring to FIG. 53, a red micro LED projector R, a green micro LED projector G, and a blue micro LED projector B are arranged in a line. In an embodiment, referring to FIG. 54, the monolithic micro LED projector is formed in an M×N array, where M is a positive integer equal to or greater than 1, and N is a positive integer equal to or greater than 1. In another embodiment, the monolithic micro LED projector can be formed in any geometric shape. For example, the monolithic micro LED projector can be formed in a circular, triangular, trapezoidal, or other shape.

[0169] Additionally, the light guide includes an image output area, in some embodiments, facing at least one eye of a person when the person wears the glasses.

[0170] It should be noted that the micro-LED glasses can be AR glasses, VR glasses, or other types of glasses.

[0171] It should be noted that the number of monolithic micro LED projector units is not limited to three as above, but may be four, five, or more. Furthermore, the number of channels of the light lattice is the same as the number of monolithic micro LED projector units or the same as the number of monolithic micro LED projectors.

[0172] It is further noted that the micro LED panel includes a micro LED array and an IC backplane formed on the backplane of the micro LED array, where the IC backplane controls turning on or off each LED in the micro LED array. In some embodiments, the micro LED array is bonded to the IC backplane by a metal bonding process. Each micro LED panel is individually controlled by a corresponding IC backplane. In some embodiments, in a first color micro LED panel, an IC backplane is formed to control the micro LED array in the first color micro LED panel, and is further formed to not control the micro LED array in the second color micro LED panel.

[0173] It should be noted that in some embodiments, the micro LED projector is located within the glass, the edge protrusion, or the central connection, while in other embodiments, the micro LED projector can be located anywhere within the glass, the edge protrusion, or the central connection such that the chief ray emitted from the collimator unit 14 can enter the entrance area of ​​the light guide.

[0174] The above description is merely an embodiment of the present disclosure, and the present disclosure is not limited thereto. Any modifications, equivalent replacements, and improvements made without departing from the concept and principle of the present disclosure shall be included within the protection scope of the present disclosure.

[0175] This embodiment may be further described using the following clauses. 1. A micro light emitting diode (LED) projector, comprising: A micro LED panel including a micro LED structure array, the micro LED structure including a mesa structure, a micro lens formed to be located above the micro mesa structure, a p-type semiconductor layer, an n-type semiconductor layer, and a light emitting layer formed between the p-type semiconductor layer and the n-type semiconductor layer; A collimator unit formed to collimate the light beam emitted from the micro LED structure to a preset target position; Equipped with A connected straight line connects the center of the collimator unit, the center of the microlens, and the center of the light-emitting layer of a micro LED projector.

[0176] 2. A micro LED projector as described in clause 1, wherein the center of the collimator unit is offset from a connected straight line, the center of the microlens and the center of the light-emitting layer are on a first straight line, and the center of the collimator unit and the center of the light-emitting layer are on a second straight line.

[0177] 3. The micro LED projector of claim 2, wherein the second straight line is offset from the first straight line.

[0178] 4. The micro LED projector of claim 3, wherein the deflection angle of the second straight line offset from the first straight line is 5° or less.

[0179] 5. A micro LED projector as described in clause 1, wherein the center of the light emitting layer is horizontally offset from the connecting straight line.

[0180] 6. The micro LED projector of clause 5, wherein the distance the center of the light emitting layer is horizontally offset from the connecting straight line is no more than 45% of the bottom width of the mesa structure.

[0181] 7. The micro LED projector according to clause 6, wherein the offset distance of the centers of the light emitting layers is 0.3 μm or less.

[0182] 8. The micro LED projector of clause 1, wherein the distance between the micro LED panel and the surface of the collimator unit is less than or equal to the thickness of the collimator unit.

[0183] 9. The micro LED projector of claim 1, wherein the micro lenses are hemispherical or spherical in shape.

[0184] 10. A micro LED projector as described in clause 1, wherein the micro LED structure further comprises a capping layer formed over the micro mesa structure and covering the micro lens.

[0185] 11. The micro LED projector according to claim 10, wherein the material of the microlens is selected from polymers, inorganic oxides, and inorganic nitrides.

[0186] 12. A micro LED projector as claimed in claim 11, wherein the inorganic oxide is silicon oxide and the inorganic nitride is silicon nitride.

[0187] 13. The micro LED projector of claim 1, wherein the central axis of the microlens is shifted horizontally from the central axis of the mesa structure.

[0188] 14. The micro LED projector of claim 1, wherein the micro LED structure further comprises a spacer at the bottom of the micro lens and on top of the mesa structure.

[0189] 15. The micro LED projector of claim 14, wherein the spacer material is selected from polymers, inorganic oxides, and inorganic nitrides.

[0190] 16. A micro LED projector as claimed in claim 15, wherein the inorganic oxide is silicon oxide and the inorganic nitride is silicon nitride.

[0191] 17. A micro LED projector as described in clause 10, wherein the material of the capping layer is different from the material of the microlens.

[0192] 18. A micro LED projector as described in clause 1, wherein the material of the microlens is selected from polymers, inorganic oxides, and inorganic nitrides.

[0193] 19. A micro LED projector as described in clause 18, wherein the inorganic oxide is silicon oxide and the inorganic nitride is silicon nitride.

[0194] 20. The micro LED projector of claim 1, wherein the diameter of the micro lens is 80% to 200% of the diameter of the mesa structure.

[0195] 21. A micro LED projector as described in clause 1, wherein the distance between the focal point of the microlens and the light emitting layer is less than or equal to twice the thickness of the mesa structure.

[0196] 22. The micro LED projector of clause 1, wherein the micro LED structure further comprises an anti-reflection coating formed on at least a portion of the surface of the micro lens.

[0197] 23. A micro LED projector as described in clause 22, wherein an anti-reflection film is formed at a surface location where light rays are emitted from the microlens.

[0198] 24. A micro LED projector as described in clause 23, wherein the chief ray is inclined with respect to the top surface of the micro mesa structure and is emitted from the micro lens at an angle in the range of 0 to 45° with respect to the vertical direction.

[0199] 25. A micro LED projector as described in clause 24, wherein the chief ray is perpendicular to the top surface of the micro mesa structure and is emitted from the top center of the micro lens.

[0200] 26. The micro LED projector of claim 22, wherein an anti-reflection coating is formed on top of the micro lens.

[0201] 27. A micro LED projector as described in clause 22, wherein an anti-reflection film is formed on the entire surface of the micro lens.

[0202] 28. A micro LED projector as described in clause 27, wherein the thickness of the anti-reflection coating at the surface location where the light beam is emitted from the microlens is greater than the thickness of the anti-reflection coating at other locations on the microlens.

[0203] 29. The micro LED projector of clause 27, wherein the thickness of the anti-reflective coating on top of the microlens is greater than the thickness of the anti-reflective coating at other positions on the microlens.

[0204] 30. A micro LED projector as described in clause 22, wherein the dielectric constant of the anti-reflection coating is between the dielectric constant of the microlens and that of air.

[0205] 31. A micro LED projector, a first color micro LED panel according to the micro LED panel of clause 1, emitting light of a first color; a second color micro LED panel according to the micro LED panel of clause 1 emitting light of a second color, the first color being different from the second color; an optical coupling element configured to face the direction of emission of the first color light beam of the first color micro LED panel and face the direction of emission of the second color light beam of the second color micro LED panel, and to combine the first color light beam and the second color light beam into a composite light beam; a collimator unit according to clause 1, configured to collimate the light beam emitted from the micro LED structure to a pre-defined target position; A micro LED projector equipped with

[0206] 32. A micro LED projector as described in clause 31, wherein the optical coupling element is provided with a polarizing and splitting film oriented in the direction of emission of a first color light beam of a first color micro LED panel and / or in the direction of emission of a second color light beam of a second color micro LED panel.

[0207] 33. The micro LED projector of clause 31, further comprising a third color micro LED panel of the micro LED projector of clause 1, emitting light of a third color, the first color, the second color and the third color being different from each other.

[0208] 34. A micro LED projector as described in clause 33, wherein the optical coupling element comprises a polarizing and splitting film oriented in the third color light emission direction of the third color micro LED panel.

[0209] 35. The micro LED projector of clause 33, wherein the optical coupling element is an X-cube.

[0210] 36. A micro LED projector as described in clause 31, wherein the minimum distance between the micro LED panel and the surface of the optical coupling element facing the micro LED panel is less than or equal to twice the thickness of the micro LED panel.

[0211] 37. A micro LED projector as described in clause 31, wherein collimated light is emitted from the emission surface of the optical coupling element and then enters the entrance surface of the collimator unit, and the distance between the emission surface of the optical coupling element and the entrance surface of the collimator unit is less than or equal to 200% of the thickness of the collimator unit.

[0212] 38. The micro LED projector according to clause 31, wherein the diameter of the collimator unit is smaller than the side width of the X-cube.

[0213] 39. A micro LED projector, At least one color micro LED panel including a plurality of micro LEDs, wherein the chief ray angles of the micro LEDs in the micro LED panel are different; a collimator unit configured to collimate a light beam emitted from a micro LED panel to a predetermined target position, the micro LED panel having a light emitting area, the collimator having an incident surface, and the light emitted from the light emitting area of ​​the micro LED panel entering the incident surface of the collimator; A micro LED projector equipped with

[0214] 40. A micro LED projector as described in clause 39, wherein the chief ray angles of the micro LEDs in at least one color micro LED panel are collimated to a single point.

[0215] 41. The micro LED projector of clause 40, comprising at least two different color micro LED panels, each of which emits light beams of one color, and the chief ray angles of the micro LEDs of each micro LED panel are collimated to a single point.

[0216] 42. The micro LED projector of clause 41, wherein at least a micro LED panel of a first color emits light rays of a first color, a micro LED panel of a second color emits light rays of a second color, and a micro LED panel of a third color emits light rays of a third color, the first color, the second color, and the third color are different from each other, and a chief ray angle of the micro LEDs of the micro LED panel of the first color is collimated to a point, a chief ray angle of the micro LEDs of the micro LED panel of the second color is collimated to a point, and a chief ray angle of the micro LEDs of the micro LED panel of the third color is collimated to a point.

[0217] 43. The micro LED projector further comprises an optical combining element configured to face the light beams of each color emitted from the micro LED panel and combine the light beams of that color into a combined beam; 42. The micro LED projector of claim 41, wherein collimated light is emitted from an output surface of the optical coupling element and enters an input surface of the collimator unit.

[0218] 44. A micro LED projector as described in clause 43, wherein the area of ​​the emission surface is greater than the area of ​​the entrance surface.

[0219] 45. A micro LED projector as described in clause 43, wherein the diameter of the collimator unit is smaller than the side width of the optical coupling element.

[0220] 46. ​​A micro LED projector as described in clause 43, wherein the optical coupling element has a plurality of light receiving surfaces each corresponding to each light emitting area of ​​the micro LED panel, and the minimum distance between the micro LED panel and the light receiving surface of the optical coupling element is less than or equal to 200% of the thickness of the micro LED panel.

[0221] 47. A micro LED projector as described in clause 46, wherein the side width of the light receiving surface of the optical coupling element is smaller than the side width of the light emitting area of ​​the micro LED panel of the first color.

[0222] 48. A micro LED projector as described in clause 43, wherein the distance between the emission surface of the optical coupling element and the entrance surface of the collimator unit is less than or equal to 200% of the thickness of the collimator unit.

[0223] 49. The micro LED projector according to claim 48, wherein the distance between the emission surface of the optical coupling element and the entrance surface of the collimator unit is zero.

[0224] 50. A micro LED projector as described in clause 43, wherein the optical coupling element comprises a polarizing and splitting film oriented in the direction of emission of a first color light beam of a first color micro LED panel and / or in the direction of emission of a second color light beam of a second color micro LED panel.

[0225] 51. The micro LED projector of clause 50, further comprising a third color micro LED panel emitting light of a third color, the first color, the second color, and the third color being different from each other.

[0226] 52. A micro LED projector as described in clause 51, wherein the optical coupling element comprises a polarizing and splitting film oriented in the third color light emission direction of the third color micro LED panel.

[0227] 53. The micro LED projector of clause 43, wherein the optical coupling element is an X-cube.

[0228] 54. A micro LED projector as described in clause 53, wherein the diameter of the collimator unit is equal to or less than the side width of the X-cube.

[0229] 55. A micro LED projector as described in clause 39, wherein the light emitting area of ​​the micro LED panel is larger than the entrance surface of the collimator unit.

[0230] 56. A micro LED projector as described in clause 55, wherein the width of the micro LED panel is greater than the diameter of the entrance surface of the collimator unit.

[0231] As used herein, unless otherwise stated, the term "or" encompasses all possible combinations unless impracticable. For example, if it is stated that a micro LED panel may include A or B, the micro LED panel may include A, or B, or A and B, unless otherwise stated or impracticable. As a second example, if it is stated that a micro LED panel may include A, B, or C, the micro LED panel may include A, or B, or C, or A and B, or A and C, or B and C, or A, B, and C, unless otherwise stated or impracticable.

[0232] In the foregoing specification, the embodiments have been described with reference to numerous specific details that may vary from implementation to implementation. Certain adaptations and modifications may be made to the described embodiments. Other embodiments will be apparent to those skilled in the art from consideration of the detailed description and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope and spirit of the invention being indicated by the following claims. Additionally, the order of steps depicted in the figures is for illustrative purposes only and is not intended to be limited to the particular order of steps. Thus, one skilled in the art will appreciate that steps may be performed in different orders while performing the same method.

Claims

1. 1. A micro light emitting diode (LED) projector, comprising: A micro LED panel including an array of micro LED structures, the micro LED structures including a mesa structure, a micro lens formed to be located above the micro mesa structure, a p-type semiconductor layer, an n-type semiconductor layer, and a light emitting layer formed between the p-type semiconductor layer and the n-type semiconductor layer; a collimator unit configured to collimate the light beam emitted from the micro LED structure to a preset target position; Equipped with A micro LED projector, wherein a connected straight line connects the center of the collimator unit, the center of the microlens, and the center of the light emitting layer.

2. 2. The micro LED projector of claim 1, wherein the center of the collimator unit is offset from the connected straight line, the center of the microlens and the center of the light emitting layer are on a first straight line, and the center of the collimator unit and the center of the light emitting layer are on a second straight line.

3. 3. The micro LED projector of claim 2, wherein the second straight line is offset from the first straight line.

4. 4. The micro LED projector of claim 3, wherein the second straight line is offset from the first straight line by an angle of 5° or less.

5. 2. The micro LED projector of claim 1, wherein the center of the light emitting layer is horizontally offset from the connecting line.

6. 6. The micro LED projector of claim 5, wherein the offset distance of the center of the light emitting layer horizontally offset from the connecting line is less than or equal to 45% of the bottom width of the mesa structure.

7. 7. The micro LED projector of claim 6, wherein the offset distance of the centers of the light emitting layers is 0.3 μm or less.

8. 2. The micro LED projector of claim 1, wherein a distance between the micro LED panel and a surface of the collimator unit is equal to or less than a thickness of the collimator unit.

9. The micro LED projector of claim 1 , wherein the microlenses are hemispherical or spherical in shape.

10. 2. The micro LED projector of claim 1, wherein the micro LED structure further comprises a capping layer formed over the micro mesa structure and covering the micro lens.

11. 11. The micro LED projector of claim 10, wherein the material of the capping layer is selected from polymers, inorganic oxides, and inorganic nitrides.

12. 12. The micro LED projector of claim 11, wherein the inorganic oxide is silicon oxide and the inorganic nitride is silicon nitride.

13. 2. The micro LED projector of claim 1, wherein a central axis of the microlens is horizontally shifted from a central axis of the mesa structure.

14. 10. The micro LED projector of claim 1, wherein the micro LED structure further comprises a spacer at the bottom of the micro lens and on top of the mesa structure.

15. 15. The micro LED projector of claim 14, wherein the spacer material is selected from polymers, inorganic oxides, and inorganic nitrides.

16. 16. The micro LED projector of claim 15, wherein the inorganic oxide is silicon oxide and the inorganic nitride is silicon nitride.

17. 11. The micro LED projector of claim 10, wherein the material of the capping layer is different from the material of the microlenses.

18. 2. The micro LED projector of claim 1, wherein the material of the microlens is selected from polymers, inorganic oxides, and inorganic nitrides.

19. 20. The micro LED projector of claim 18, wherein the inorganic oxide is silicon oxide and the inorganic nitride is silicon nitride.

20. 2. The micro LED projector of claim 1, wherein the diameter of the micro lens is between 80% and 200% of the diameter of the mesa structure.

21. 2. The micro LED projector of claim 1, wherein the distance between the focal point of the microlens and the light emitting layer is less than or equal to twice the thickness of the mesa structure.

22. 10. The micro LED projector of claim 1, wherein the micro LED structure further comprises an anti-reflective coating formed on at least a portion of a surface of the micro lens.

23. 23. The micro LED projector of claim 22, wherein the anti-reflective coating is formed at the surface location where the light beam is emitted from the microlens.

24. 24. The micro LED projector of claim 23, wherein a chief ray is inclined with respect to a top surface of the micro-mesa structure and is emitted from the micro lens at an angle in the range of 0 to 45 degrees with respect to the vertical.

25. 25. The micro LED projector of claim 24, wherein the chief ray is perpendicular to the top surface of the micro-mesa structure and emanates from the top center of the microlens.

26. 23. The micro LED projector of claim 22, wherein the anti-reflective coating is formed on top of the microlens.

27. 23. The micro LED projector of claim 22, wherein the anti-reflection film is formed on the entire surface of the micro lens.

28. 28. The micro LED projector of claim 27, wherein the thickness of the anti-reflective coating at the surface location where the light rays are emitted from the microlens is greater than the thickness of the anti-reflective coating at other locations on the microlens.

29. 28. The micro LED projector of claim 27, wherein the thickness of the anti-reflective coating on top of the microlens is greater than the thickness of the anti-reflective coating elsewhere on the microlens.

30. 23. The micro LED projector of claim 22, wherein the dielectric constant of the anti-reflection coating is between the dielectric constant of the microlens and that of air.

31. A micro LED projector, A first color micro LED panel according to claim 1 , emitting light of a first color; A second color micro LED panel according to claim 1 , emitting light of a second color, said first color being different from said second color; and an optical coupling element oriented in the direction of emission of the first color light beams of the first color micro LED panel and in the direction of emission of the second color light beams of the second color micro LED panel, configured to combine the first color light beams and the second color light beams into a combined light beam; a collimator unit according to claim 1 , which is configured to collimate the light beam emitted from the micro LED structure to a preset target position; A micro LED projector comprising:

32. 32. The micro LED projector of claim 31 , wherein the optical coupling element comprises a polarizing and splitting film oriented in the direction of emission of the first color light beam of the first color micro LED panel and oriented in the direction of emission of the second color light beam of the second color micro LED panel.

33. 32. The micro LED projector of claim 31 further comprising a third color micro LED panel according to claim 1 , the micro LED projector emitting light of a third color, the first color, the second color, and the third color being different from each other.

34. 34. The micro LED projector of claim 33, wherein the optical coupling element comprises a polarizing dispersing film oriented in the direction of emission of the third color light beam of the third color micro LED panel.

35. 34. The micro LED projector of claim 33, wherein the optical coupling element is an X-cube.

36. 32. The micro LED projector of claim 31 , wherein a minimum distance between the micro LED panel and the surface of the optical coupling element facing the micro LED panel is less than or equal to twice a thickness of the micro LED panel.

37. 32. The micro LED projector of claim 31 , wherein the collimated light is emitted from an emission surface of the optical coupling element and then enters an entrance surface of the collimator unit, and the distance between the emission surface of the optical coupling element and the entrance surface of the collimator unit is less than or equal to 200% of a thickness of the collimator unit.

38. 32. The micro LED projector of claim 31 , wherein the diameter of the collimator unit is smaller than the side width of the X-cube.

Images