Light-emitting chip, display backplane and projection device

Abstract

The application relates to the technical field of projection equipment, in particular to a light-emitting chip, a display backboard and a projection equipment, wherein the projection equipment comprises a projection lens and a display backboard composed of light-emitting chips; the light-emitting chip comprises a first electrode, a second electrode and a third electrode, and a first semiconductor layer, a first light-emitting layer, a second semiconductor layer, a second light-emitting layer and a third semiconductor layer which are sequentially stacked; a first end of the first electrode is arranged on a first surface of the first semiconductor layer, a first end of the second electrode is arranged on a first surface of the second semiconductor layer, and a first end of the third electrode is arranged on a first surface of the third semiconductor layer; the first light-emitting layer and the second light-emitting layer are respectively used for emitting light of different wave bands. The application has the beneficial effect that two projection lenses adopt one display backboard, and the projection of multiple images in different directions is realized through one display backboard, so that the application scene of the projection equipment is enriched.

Description

Technical Field

[0001] The present invention relates to the technical field of projection equipment, and in particular to a light-emitting chip, a display back panel and a projection equipment. Background Art

[0002] Micro Light Emitting Diode (Micro LED) is a new generation of display technology that has higher brightness, better luminous efficiency, and lower power consumption than the existing organic light-emitting diode (OLED) technology. Since Micro LED has various characteristics that are superior to the existing OLED technology, as the technology continues to advance, its application prospects as a new display device are very broad.

[0003] In today's world, projection technology is a common display technology used in existing display devices. There are two mainstream projection systems. One uses a liquid crystal panel or digital light processing projection system that emits light through a backlight source. This projection system transmits light to a liquid crystal modulator screen to project an image. However, the backlight source makes the entire projection system bulky and inconvenient for users. The other method uses a Micro LED display as the image source for the projection system. Because Micro LEDs can emit light themselves, eliminating the need for an additional backlight source, they can effectively reduce the overall size of the projection system. However, due to the single light output direction of Micro LED displays, they can only project an image in one direction. Their functionality is relatively limited and cannot meet the complex display requirements of today's projection display devices. Summary of the Invention

[0004] The object of the present invention is to provide a light-emitting chip, a display back panel and a projection device to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides a light-emitting chip, comprising:

[0006] A first electrode, a second electrode, and a third electrode, and a first semiconductor layer, a first light-emitting layer, a second semiconductor layer, a second light-emitting layer, and a third semiconductor layer stacked in sequence;

[0007] A surface of the first semiconductor layer in contact with the first light-emitting layer is a first surface, a surface of the first light-emitting layer facing away from the first semiconductor layer is a second surface, a surface of the second semiconductor layer facing away from the first light-emitting layer is a third surface, a surface of the second light-emitting layer facing away from the second semiconductor layer is a fourth surface, and a surface of the third semiconductor layer facing away from the second light-emitting layer is a fifth surface;

[0008] The first surface is larger than the third surface, and the third surface is larger than the fifth surface;

[0009] The first electrode is disposed on the first surface of the first semiconductor layer, the second electrode is disposed on the third surface of the second semiconductor layer, and the third electrode is disposed on the fifth surface of the third semiconductor layer;

[0010] The light emitted by the first light-emitting layer and the light emitted by the second light-emitting layer are the same color light in different wavelength bands.

[0011] Optionally, the first semiconductor layer is a first N-type semiconductor layer, the second semiconductor layer is a P-type semiconductor layer, and the third semiconductor layer is a second N-type semiconductor layer.

[0012] Optionally, the first semiconductor layer and the third semiconductor layer are N-type doped direct bandgap layers; and the P-type semiconductor layer is a P-type doped direct bandgap layer.

[0013] Optionally, the first light-emitting layer is a quantum well layer of a first wavelength band, the second light-emitting layer is a quantum well layer of a second wavelength band, the first wavelength band is not equal to the second wavelength band, and the first wavelength band and the second wavelength band belong to the same light color.

[0014] Based on the same concept, the present invention also provides a display backplane, which includes:

[0015] a substrate;

[0016] a driving array disposed on the substrate;

[0017] The light-emitting chip as described above is arranged on the driving array;

[0018] A refractive layer provided on the light-emitting side of the light-emitting chip;

[0019] A waveguide is provided on the light emitting path of the light emitting chip, the waveguide comprising a first side surface and a second side surface, the first side surface is close to the light emitting chip, the first side surface is arranged opposite to the second side surface, and the second side surface is away from the light emitting chip;

[0020] a plurality of first gratings disposed on a first side surface of the waveguide, each of the first gratings being disposed on a light-emitting path of a corresponding light-emitting chip, and configured to guide a light beam of a first wavelength band emitted by the light-emitting chip into a first direction;

[0021] A plurality of second gratings are arranged on the second side surface of the waveguide, each of the second gratings is arranged on the light output path of the corresponding light emitting chip, and the second gratings are used to guide the second wavelength band light emitted by the light emitting chip into a second direction.

[0022] Optionally, the refractive layer covers the light-emitting chip in an arc shape, and is used to collimate the light beam initially set by the light-emitting chip.

[0023] Optionally, the refractive index of the refractive layer is greater than or equal to 1.6 and less than or equal to 1.7.

[0024] Optionally, a light shielding layer is provided on the first side surface of the waveguide, and the light shielding layer corresponds to the gaps between adjacent first gratings and the gaps between adjacent light-emitting chips.

[0025] Optionally, a transparent layer is provided between the refractive layer and the waveguide, so as to ensure that the distances between the light-emitting chips in each group facing each other and the waveguide are the same.

[0026] Based on the same concept, the present invention also provides a projection device, which includes a projection lens, a frame and a display back panel as described above, and the two projection lenses are installed at an angle through the frame in the first direction and the second direction of the light-emitting side of the display back panel, for bidirectional projection to form a first projection image and a second projection image.

[0027] In the projection device of the present invention, two projection lenses are installed in front of a display backplane, and the display backplane is composed of multiple light-emitting chips. By adjusting the angle of the output light by the display backplane, a projection device can present multiple images in different directions or project two parts of an image. While maintaining the compact size of the device itself, it effectively meets the complex display requirements of today's projection display devices, making the device suitable for a variety of application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a structural principle diagram of a light-emitting chip of the present invention.

[0029] Figure 2 This is a structural principle diagram of a display backplane of the present invention.

[0030] Figure 3 This is a partial structural principle diagram of a display backplane of the present invention.

[0031] Figure 4 The figure is a top view of a display backplane according to the present invention.

[0032] Figure 5 This is a structural principle diagram of a projection device of the present invention.

[0033] In the accompanying drawings: 1-light-emitting chip, 101-first N-type semiconductor layer, 102-first light-emitting layer, 103-P-type semiconductor layer, 104-second light-emitting layer, 105-second N-type semiconductor layer, 106-first electrode, 107-second electrode, 108-third electrode, 2-display backplane, 201-substrate, 202-refractive layer, 203-transparent layer, 204-waveguide, 205-first grating, 206-second grating, 207-light-shielding layer, 3-pixel structure, 4-display, 5-projection lens.

[0034] R represents red light, B represents blue light, and G represents green light; B1+B2 represents a mixture of blue light from the first and second bands; B1 represents blue light from the first band; B2 represents blue light from the second band; G1 represents green light from the first band; G2 represents green light from the second band; R1+B1+G1 represents light from the first band; R2+B2+G2 represents light from the second band. DETAILED DESCRIPTION

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0036] See also Figure 1 In an embodiment of the present invention, a light-emitting chip 1 includes: a first electrode 106, a second electrode 107, and a third electrode 108, and a first semiconductor layer, a first light-emitting layer 102, a second semiconductor layer, a second light-emitting layer 104, and a third semiconductor layer stacked in sequence; a first end of the first electrode 106 is arranged on a first surface of the first semiconductor layer, a first end of the second electrode 107 is arranged on a first surface of the second semiconductor layer, and a first end of the third electrode 108 is arranged on a first surface of the third semiconductor layer; the first light-emitting layer 102 and the second light-emitting layer 104 are respectively used to emit light in different wavelength bands.

[0037] Specifically, the first semiconductor layer is a first N-type semiconductor layer 101, specifically a first N-type doped direct bandgap layer; the third semiconductor layer is a second N-type semiconductor layer 105, specifically a second N-type doped direct bandgap layer; the second semiconductor layer is a P-type semiconductor layer 103, specifically a P-type doped direct bandgap layer, that is, a P-type doped GaN (gallium nitride) layer; the first N-type semiconductor layer 101 and the second N-type semiconductor layer 105 are N-type doped GaN (gallium nitride) layers; the P-type semiconductor layer 103 is a P-type doped GaN (gallium nitride) layer; the first light-emitting layer 102 and the second light-emitting layer 104 are quantum well layers; after the first electrode 106 and the second electrode 107 are energized, the electrons generated in the first N-type semiconductor layer 101 in the first light-emitting layer 102 collide and recombine with the holes generated in the P-type semiconductor layer 103 to generate photons.

[0038] The first ends of the first electrode 106, the second electrode 107, and the third electrode 108 are respectively disposed on the first surfaces of the first semiconductor layer, the second semiconductor layer, and the third semiconductor layer. The first surface of the first semiconductor layer contacts the first surface of the first light-emitting layer, the second surface of the first light-emitting layer 102 contacts the second surface of the second semiconductor layer, the first surface of the second semiconductor layer contacts the first surface of the second light-emitting layer 104, and the second surface of the second light-emitting layer 104 contacts the second surface of the third semiconductor layer. A first gap is provided between the first electrode 106 and the first and second semiconductor layers, respectively, and a second gap is provided between the second electrode 107 and the second and third semiconductor layers. The first and second gaps increase the heat dissipation efficiency of the first and second light-emitting layers 102 and 104, maintaining stable operation.

[0039] In addition, the first electrode, the second electrode, and the third electrode are conductive materials such as metals, and may include aluminum (Al), platinum (Pt), palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), molybdenum, titanium (Ti), tungsten (W) or copper (Cu); after the first electrode 106 and the second electrode 107 are energized, electrons generated in the first N-type semiconductor layer 101 in the first light-emitting layer 102 collide and recombine with holes generated in the P-type semiconductor layer 103 to generate photons; after the third electrode 108 and the second electrode 107 are energized, electrons generated in the second N-type semiconductor layer 105 in the second light-emitting layer 104 collide and recombine with holes generated in the P-type semiconductor layer 103 to generate photons.

[0040] The first light-emitting layer 102 and the second light-emitting layer 104 can be quantum dots, quantum wells, multiple quantum wells, or any combination of quantum dots, quantum wells, and multiple quantum wells.

[0041] See also Figure 1 In the embodiment of the present invention, the light emitted from the first light-emitting layer 102 and the light emitted from the second light-emitting layer 104 are the same color light.

[0042] Specifically, the first light-emitting layer 102 is a quantum well layer, which produces blue light in the first band (450-460nm), and the second light-emitting layer 104 is a quantum well layer, which produces blue light in the second band (470-480nm); the first light-emitting layer 102 is a quantum well layer, which produces green light in the first band (495-505nm), and the second light-emitting layer 104 is a quantum well layer, which produces green light in the second band (515-525nm); the first light-emitting layer 102 is a quantum well layer, which produces red light in the first band (620-630nm), and the second light-emitting layer 104 is a quantum well layer, which produces red light in the second band (640-650nm).

[0043] Optionally, the light emitted by the first light-emitting layer 102 and the light emitted by the second light-emitting layer 104 may be lights of different colors, thereby meeting the needs of more application scenarios.

[0044] In order to solve the problem of a single light emission direction of light emitted by a light emitting chip, an embodiment of the present invention provides a display back panel 2 .

[0045] See also Figure 2 In an embodiment of the present invention, a display backplane 2 includes: a substrate 201; a driving array disposed on the substrate 201; a light-emitting chip 1 as described above disposed on the driving array; a refractive layer 202 disposed on the light-emitting side of the light-emitting chip 1; a waveguide 204 disposed on the light-emitting path of the light-emitting chip 1, the waveguide 204 including a first side surface and a second side surface, the first side surface being close to the light-emitting chip 1, the first side surface being disposed opposite to the second side surface, and the second side surface being away from the light-emitting chip 1; a plurality of first gratings 205 disposed on the first side surface of the waveguide 204; and a plurality of second gratings 206 disposed on the second side surface of the waveguide 204.

[0046] Specifically, the first grating is used to adjust the emission angle of the first wavelength band of the light emitted by the light-emitting chip 1; the second grating 206 is used to adjust the emission angle of the second wavelength band of the light emitted by the light-emitting chip 1. A light-shielding layer 207 is provided on the first side surface of the waveguide 204. The light-shielding layer corresponds to the gaps between adjacent first gratings and the gaps between adjacent light-emitting chips. The light-shielding layer 207 does not interfere with the first grating and is suitable for various application scenarios by adjusting the angle of the emitted light. The refractive layer 202 covers the light-emitting chip 1 in an arc shape, increasing the light-emitting refractive surface of the light-emitting chip, thereby increasing the light-emitting utilization rate of the light-emitting chip. The light-shielding layer corresponds to the gaps between adjacent first gratings and the gaps between adjacent light-emitting chips to prevent light leakage.

[0047] In the embodiment of the present invention, the refractive index of the refractive layer 202 is greater than or equal to 1.6 and less than or equal to 1.7.

[0048] Specifically, such as Figure 3 Taking the blue light display backplane as an example, a spherical resin is coated on the blue light emitting chip to form a refractive layer 202. The spherical resin can be made of materials with a refractive index of 1.6 to 1.7, such as methyltrimethoxysilane (MTMS), vinyltrimethoxysilane (VTMS), and polymethyl methacrylate (PMMA).

[0049] A transparent layer 203 is provided between the refractive layer and the waveguide to ensure uniform spacing between each group of opposing light-emitting chips and the waveguide, ensuring the flatness of the display backplane. This ensures that the distances between the light emitted from each light-emitting chip and the first and second gratings are equal, ensuring the same conditions for adjusting the output angle of the first and second gratings, and improving the visual continuity of the output light. Transparent layer 203 is made of a transparent material with a refractive index below 1.5, and is made of glass or a transparent polymer material. By providing an arc-shaped refractive layer 202 on the light-emitting path of the blue light-emitting chip, the light emitted by the light-emitting chip 1 is focused into light in one direction. Then, a first grating 205 and a second grating 206 are provided on the two side surfaces of the waveguide 204. The first grating 205 and the second grating 206 are used to adjust the emission angle of the second wavelength band of the light emitted by the light-emitting chip 1. This allows the light emitted by the blue light-emitting chip to be controlled and can be adjusted as needed to achieve the effect of emitting light in different directions. Similarly, the green light display backplane and the red light display backplane are as described above, and the specific details will not be described in detail.

[0050] like Figure 4 As shown, a pixel structure 3 is composed of a blue light emitting chip, a green light emitting chip, and a red light emitting chip. An array of several pixel structures constitutes a display 4. The blue light emitting chip, the green light emitting chip, and the red light emitting chip can be adjusted as needed to achieve the effect of emitting light in different directions.

[0051] See also Figure 5 In another embodiment of the present invention, a projection device includes a projection lens, a frame and a display back panel as described above, wherein the two projection lenses are installed at an angle on the light-emitting side of the display back panel through the frame, and are used for bidirectional projection to form a first projection image and a second projection image.

[0052] Specifically, the display backplane 2 includes: a substrate 201; a driver array disposed on the substrate 201; a light-emitting chip 1 as described above disposed on the driver array; a refractive layer 202 disposed on the light-emitting side of the light-emitting chip 1; a waveguide 204 disposed in the light-emitting path of the light-emitting chip 1, the waveguide 204 including a first side surface proximal to the light-emitting chip 1 and disposed opposite the second side surface, and the second side surface distal from the light-emitting chip 1; a plurality of first gratings 205 disposed on the first side surface of the waveguide 204; and a plurality of second gratings 206 disposed on the second side surface of the waveguide 204. The pixel structure 3, formed by splicing together several display backplanes 2, is encapsulated by a frame to form a display 4. Two projection lenses 5 are mounted in front of each display 4. Multiple images in different directions or two portions of a single image are projected through the display 4, achieving the effect of a single display 4 projecting in different directions, thus enriching application scenarios.

[0053] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0054] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A display backplane, characterized in that: include: a substrate; a driving array disposed on the substrate; A light-emitting chip is arranged on the driving array; a refractive layer disposed on the light-emitting side of the light-emitting chip and used to collimate the light emitted by the light-emitting chip; A waveguide is provided on the light emitting path of the light emitting chip, the waveguide comprising a first side surface and a second side surface, the first side surface is close to the light emitting chip, the first side surface is arranged opposite to the second side surface, and the second side surface is away from the light emitting chip; a plurality of first gratings disposed on a first side surface of the waveguide, each of the first gratings being disposed on a light-emitting path of a corresponding light-emitting chip, and configured to guide a light beam of a first wavelength band emitted by the light-emitting chip into a first direction; a plurality of second gratings disposed on a second side surface of the waveguide, each second grating being disposed on a light-emitting path of a corresponding light-emitting chip, and configured to direct a second wavelength band light beam emitted by the light-emitting chip into a second direction; The light-emitting chip includes: A first electrode, a second electrode, and a third electrode, and a first semiconductor layer, a first light-emitting layer, a second semiconductor layer, a second light-emitting layer, and a third semiconductor layer stacked in sequence; A surface of the first semiconductor layer in contact with the first light-emitting layer is a first surface, a surface of the first light-emitting layer facing away from the first semiconductor layer is a second surface, a surface of the second semiconductor layer facing away from the first light-emitting layer is a third surface, a surface of the second light-emitting layer facing away from the second semiconductor layer is a fourth surface, and a surface of the third semiconductor layer facing away from the second light-emitting layer is a fifth surface; The first surface is larger than the third surface, and the third surface is larger than the fifth surface; The first electrode is disposed on the first surface of the first semiconductor layer, the second electrode is disposed on the third surface of the second semiconductor layer, and the third electrode is disposed on the fifth surface of the third semiconductor layer; The light emitted by the first light-emitting layer and the light emitted by the second light-emitting layer are the same color light in different wavelength bands; A light shielding layer is provided on the first side surface of the waveguide, and the light shielding layer corresponds to the gaps between adjacent first gratings and the gaps between adjacent light emitting chips.

2. The display backplane according to claim 1, characterized in that: The refractive layer is arc-shaped and covers the light emitting chip, and is used for collimating the light beam initially emitted by the light emitting chip.

3. The display backplane according to claim 2, wherein: The refractive index of the refractive layer is greater than or equal to 1.6 and less than or equal to 1.

7.

4. A display backplane according to any one of claims 1 to 3, characterized in that: A transparent layer is provided between the refractive layer and the waveguide, so as to ensure that the distances between the light emitting chips and the waveguide in each group relative to each other are the same.

5. The display backplane according to any one of claims 1 to 3, characterized in that: The light emitting chip includes at least one of a red light emitting chip, a green light emitting chip and a blue light emitting chip.

6. The display backplane according to any one of claims 1 to 3, characterized in that: The first semiconductor layer is a first N-type semiconductor layer, the second semiconductor layer is a P-type semiconductor layer, and the third semiconductor layer is a second N-type semiconductor layer.

7. The display backplane according to claim 6, characterized in that: The first semiconductor layer and the third semiconductor layer are N-type doped direct bandgap layers; the P-type semiconductor layer is a P-type doped direct bandgap layer.

8. A display backplane according to claim 1, 2, 3 or 7, characterized in that: The first light-emitting layer is a quantum well layer of a first wavelength band, the second light-emitting layer is a quantum well layer of a second wavelength band, the first wavelength band is not equal to the second wavelength band, and the first wavelength band and the second wavelength band belong to the same light color.

9. A projection device, characterized in that: It includes a projection lens, a frame and a display backplane as described in any one of claims 1 to 8, wherein the two projection lenses are installed at an angle through the frame in the first direction and the second direction on the light-emitting side of the display backplane, and are used for bidirectional projection to form a first projection image and a second projection image.

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