Under-screen point cloud transmitting device, under-screen point cloud receiving device and under-screen point cloud device

Abstract

The utility model provides an under-screen point cloud transmitting device, an under-screen point cloud receiving device and an under-screen point cloud device, and relates to the technical field of optical super lenses. The under-screen point cloud transmitting device is arranged under a display screen, the display screen comprises pixel units arranged in an array, and the pixel units arranged in the array form an amplitude modulation grating; the under-screen point cloud transmitting device comprises a transmitting super lens; and the transmitting super lens is used for projecting a point cloud and providing a grating lobe suppression phase so as to suppress a grating lobe signal generated when the point cloud projected by the transmitting super lens penetrates through the display screen. According to the device, the grating lobe suppression effect can be realized on the premise of not changing the shape or position of the pixel unit in the display screen in the existing system, and unnecessary productivity waste is avoided.

Description

Technical Field

[0001] The present disclosure relates to the field of optical superlens technology. Specifically, the present disclosure relates to an under-screen point cloud transmitting device, an under-screen point cloud receiving device, and an under-screen point cloud device. Background Art

[0002] With the development of intelligent terminal devices, the demand for high-quality display screen imaging is increasing. The display screen is used to receive point clouds and reflect them back to the image sensor set under the screen for imaging. However, when the point cloud passes through the display screen, diffraction will occur, which will affect the imaging quality.

[0003] In the prior art, adjacent color pixels in a display screen are arranged in a staggered manner to break the periodicity of the arrangement of the color pixels, thereby reducing the diffraction effect of structured light passing through the display screen. Another method is to set the shape of the color pixels in the display screen to an irregular shape to break the regularity of the color pixels to reduce the diffraction effect.

[0004] However, the above solutions all suppress the diffraction effect by changing the shape or position of the color pixels in the display screen of the existing system. The display screen technology of the existing system is mature, so suppressing the diffraction display screen by changing the display screen will cause unnecessary waste of production capacity. Utility Model Content

[0005] In order to solve the problem of waste of production capacity caused by suppressing diffraction by modifying the existing system in the prior art, the first aspect of the present application provides an under-screen point cloud emission device, which is arranged under a display screen, and the display screen includes pixel units arranged in an array, and the pixel units arranged in the array constitute an amplitude modulated grating;

[0006] The under-screen point cloud emission device includes: an emission super lens;

[0007] The emitting metalens is used to project a point cloud and to provide a grating lobe suppression phase to suppress a grating lobe signal generated when the point cloud projected by the emitting metalens passes through a display screen.

[0008] Optionally, the grating lobe suppression phase satisfies:

[0009]

[0010] in, is the variable to be optimized; θ is the diffraction angle of the light beam passing through the emitting metalens; θ0 is the incident angle of the incident light beam received by the nth pixel unit from the light source array; θ i is the diffraction main lobe direction of the display screen.

[0011] Optionally, the grating lobe suppression phase also satisfies:

[0012] sin(θi )-sin(θ0)=0

[0013] Among them, θ i is the diffraction main lobe direction of the display screen; θ0 is the incident angle of the incident light beam received by the nth pixel unit from the light source array.

[0014] Optionally, the under-screen point cloud emitting device also includes a light source array for providing an incident light beam.

[0015] Optionally, the light source array comprises a vertical cavity surface emitting laser array.

[0016] A second aspect of the present application provides an under-screen point cloud receiving device, the device being arranged under a display screen, the display screen comprising pixel units arranged in an array, the pixel units arranged in the array constituting an amplitude modulated grating;

[0017] The under-screen point cloud receiving device includes: a receiving super lens;

[0018] The receiving super lens is used to receive the point cloud and to control the transmittance of the light beam received by the receiving super lens so as to filter out the grating lobe signal generated when the point cloud received by the receiving super lens passes through the display screen.

[0019] Optionally, the transmittance of the micro-nanostructure in the receiving superlens for incident light with an incident angle greater than θ1 is less than a transmittance threshold; wherein the incident angle θ1 satisfies:

[0020] θ1=arcsin(λ / d)

[0021] Where λ is the incident wavelength and d is the grating period of the display.

[0022] Optionally, the transmittance threshold is 10%.

[0023] Optionally, the under-screen point cloud receiving device also includes an image sensor for sensing the point cloud after the grating lobe signal is filtered out by the receiving super lens.

[0024] Optionally, the under-screen optical receiving device also includes a refractive lens.

[0025] Optionally, a refractive lens is disposed between the receiving metalens and the image sensor.

[0026] A third aspect of the present application provides an under-screen point cloud device, the device is arranged under a display screen, the display screen includes pixel units arranged in an array, and the pixel units arranged in the array constitute an amplitude modulated grating;

[0027] The under-screen point cloud device includes:

[0028] The under-screen point cloud transmitting device described in any one of the technical solutions provided in the first aspect of the present application, and / or the under-screen point cloud transmitting device described in any one of the technical solutions provided in the second aspect of the present application.

[0029] The technical solution in this application can produce the following beneficial effects:

[0030] The under-screen point cloud transmitting device provided in the present application can modulate the incident light beam from the light source by superimposing the modulation phase of the grating lobe suppression on the transmitting metalens, so that the point cloud modulated by the transmitting metalens does not produce a diffraction effect after reaching the display screen. The under-screen point cloud receiving device provided in the present application can filter out the grating lobes in the point cloud reflected back by the display screen by controlling the transmittance of the receiving metalens. In summary, the under-screen point cloud transmitting device, under-screen point cloud receiving device and under-screen point cloud device provided in the present disclosure can suppress the grating lobes without changing the display screen structure in the existing system, so as to achieve the purpose of suppressing the diffraction effect, thereby avoiding unnecessary waste of production capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification. The accompanying drawings illustrate embodiments of the present disclosure and together with the following description serve to explain the principles of the present disclosure.

[0032] Figure 1 A schematic diagram of the structure of an under-screen point cloud transmitting device provided in an embodiment of the present application is shown;

[0033] Figure 2 A schematic diagram of the structure of an under-screen point cloud receiving device provided in an embodiment of the present application is shown;

[0034] Figure 3 A schematic diagram showing an optional arrangement of an amplitude modulation grating formed by array-arranged pixel units in a display screen;

[0035] Figure 4 Another optional arrangement schematic diagram of an amplitude modulation grating formed by array-arranged pixel units in a display screen is shown;

[0036] Figure 5 A schematic diagram of the relative light intensity distribution of far-field diffraction of point cloud projection without display screen obstruction provided in Example 1 of the present application is shown;

[0037] Figure 6 A schematic diagram of relative light intensity distribution along the y=0 section line of point cloud projection without display screen obstruction provided in Example 1 of the present application is shown;

[0038] Figure 7 A schematic diagram of the relative light intensity distribution of far-field diffraction of point cloud projection under display screen obstruction provided in Example 1 of the present application is shown;

[0039] Figure 8 A schematic diagram of relative light intensity distribution along the y=0 section line of point cloud projection in the presence of display screen obstruction provided in Example 1 of the present application is shown;

[0040] Fig. 9 A schematic diagram of the relative light intensity distribution of far-field diffraction projected through a display screen point cloud after optimization of the emitting metalens provided in Example 1 of the present application is shown;

[0041] Fig.10 A schematic diagram of relative light intensity distribution along the y=0 section line projected by the diffraction point cloud of the display screen after optimization of the emitting metalens provided in Example 1 of the present application is shown;

[0042] Fig.11 A schematic diagram of the relative light intensity distribution of far-field diffraction received by a point cloud without the diffraction effect of a display screen provided in Example 1 of the present application is shown;

[0043] Fig.12 A schematic diagram of relative light intensity distribution along the y=0 section line received by a point cloud without the diffraction effect of a display screen provided in Example 1 of the present application is shown;

[0044] Fig.13 A modulation transfer function curve diagram of point cloud reception without display screen diffraction provided in Example 1 of the present application is shown;

[0045] Fig.14 A schematic diagram of the relative light intensity distribution of far-field diffraction received by a point cloud under the diffraction effect of a display screen provided in Example 1 of the present application is shown;

[0046] Fig.15 A schematic diagram of relative light intensity distribution along the y=0 section line received by a point cloud under the effect of display screen diffraction provided in Example 1 of the present application is shown;

[0047] Fig.16 A modulation transfer function curve diagram of point cloud reception under the effect of display screen diffraction provided in Example 1 of the present application is shown;

[0048] Fig.17 A schematic diagram of the relative light intensity distribution of far-field diffraction received by a point cloud optimized by a receiving metalens under the effect of display screen diffraction provided in Example 1 of the present application is shown;

[0049] Fig.18 A schematic diagram of relative light intensity distribution along the y=0 section line received by the point cloud optimized by the receiving metalens under the diffraction effect of the display screen provided in Example 1 of the present application is shown;

[0050] Fig.19A modulation transfer function curve of point cloud reception after optimization of the receiving superlens under the diffraction effect of the display screen provided in Example 1 of the present application is shown;

[0051] Fig. 20 A schematic diagram of the relative light intensity distribution of far-field diffraction of point cloud projection without display screen obstruction provided in Example 2 of the present application is shown;

[0052] Fig.21 A schematic diagram of relative light intensity distribution along the y=0 section line of point cloud projection without display screen obstruction provided in Example 2 of the present application is shown;

[0053] Fig. 22 A schematic diagram of the relative light intensity distribution of far-field diffraction of point cloud projection in the presence of display screen obstruction provided in Example 2 of the present application is shown;

[0054] Fig.23 A schematic diagram of relative light intensity distribution along the y=0 section line of point cloud projection in the presence of display screen obstruction provided in Example 2 of the present application is shown;

[0055] Fig.24 A schematic diagram of the relative light intensity distribution of far-field diffraction projected through the display screen point cloud after optimization of the emitting metalens provided in Example 2 of the present application is shown;

[0056] Fig.25 A schematic diagram of relative light intensity distribution along the y=0 section line projected by the diffraction point cloud of the display screen after optimization of the emitting metalens provided in Example 2 of the present application is shown;

[0057] Fig.26 A schematic diagram of the relative light intensity distribution of far-field diffraction of point cloud reception without display screen diffraction provided in Example 2 of the present application is shown;

[0058] Fig. 27 A schematic diagram of relative light intensity distribution along the y=0 section line received by a point cloud without the diffraction effect of a display screen provided in Example 2 of the present application is shown;

[0059] Fig.28 A modulation transfer function curve diagram of point cloud reception without display screen diffraction provided in Example 2 of the present application is shown;

[0060] Fig.29 A schematic diagram of the relative light intensity distribution of far-field diffraction received by a point cloud under the effect of display screen diffraction provided in Example 2 of the present application is shown;

[0061] Fig.30 A schematic diagram of relative light intensity distribution along the y=0 section line received by a point cloud under the diffraction effect of a display screen provided in Example 2 of the present application is shown;

[0062] Fig.31A modulation transfer function curve diagram of point cloud reception under the effect of display screen diffraction provided in Example 2 of the present application is shown;

[0063] Fig.32 A schematic diagram of the relative light intensity distribution of the far-field diffraction received by the point cloud after optimization of the receiving metalens under the diffraction effect of the display screen provided in Example 2 of the present application is shown;

[0064] Fig.33 A schematic diagram of relative light intensity distribution along the y=0 section line received by the point cloud after optimization of the receiving superlens under the diffraction effect of the display screen provided in Example 2 of the present application is shown;

[0065] Fig.34 A modulation transfer function curve of the point cloud received after optimization of the receiving superlens in the presence of display screen diffraction provided in Example 2 of the present application is shown.

[0066] The reference numerals in the figure represent respectively:

[0067] 1: display screen; 11: pixel unit; 12: glass cover layer; 13: control circuit layer; 14: light emitting structure layer; 141: transparent cathode; 142: transparent filling material; 143: light emitting material layer;

[0068] 2: base;

[0069] 21: emitting superlens; 211: first micro-nanostructure;

[0070] 22: receiving super lens; 221: second micro-nano structure;

[0071] 3: Light source array:

[0072] 4: Image sensor;

[0073] 5: Refractive lens.

[0074] 61: light-transmitting area; 62: non-light-transmitting area; DETAILED DESCRIPTION

[0075] The present disclosure will now be described more fully below with reference to the accompanying drawings, in which various embodiments are shown. However, the present disclosure can be implemented in many different ways and should not be construed as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure will be exhaustive and complete, and will fully convey the scope of the present disclosure to those skilled in the art. The same reference numerals throughout the text represent the same components. Furthermore, in the accompanying drawings, the thickness, ratios, and sizes of the components are exaggerated for clarity.

[0076] The terms used herein are only used for the purpose of describing specific embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, "one", "the", "at least one" as used herein do not represent a limitation on quantity, but are intended to include both the singular and the plural. For example, unless the context clearly indicates otherwise, "a component" has the same meaning as "at least one component". "At least one" should not be interpreted as being limited to the number "one". "Or" means "and / or". The term "and / or" includes any and all combinations of one or more of the associated listed items.

[0077] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meanings as those generally understood by those skilled in the art. Terms defined in commonly used dictionaries should be interpreted as having the same meanings as in the relevant technical context, and unless clearly defined in the specification, these terms are not interpreted as having formal meanings in an idealized or overly formal sense.

[0078] The meaning of “include” or “comprising” specifies properties, quantities, steps, operations, components or a combination thereof, but does not exclude other properties, quantities, steps, operations, components or a combination thereof.

[0079] Embodiments are described herein with reference to cross-sectional views as idealized embodiments. Thus, variations in shape relative to the illustrated diagram are anticipated as a result of, for example, manufacturing techniques and / or tolerances. Therefore, the embodiments described herein should not be interpreted as being limited to the specific shapes of the regions as shown herein, but should include deviations in shape due to, for example, manufacturing. For example, a region shown or described as flat may typically have rough and / or nonlinear features. Moreover, the sharp angles shown may be rounded. Therefore, the regions shown in the figures are schematic in nature, and their shapes are not intended to illustrate the precise shape of the regions and are not intended to limit the scope of the claims.

[0080] Hereinafter, exemplary embodiments according to the present application will be described with reference to the accompanying drawings.

[0081] In a first aspect, an embodiment of the present application provides an under-screen point cloud transmitting device, such as Figure 1 As shown, the device is arranged below the display screen 1, that is, arranged on a side close to the pixel unit 11. The device includes an emitting super lens 21 for projecting a point cloud and for providing a grating lobe suppression signal to suppress the grating lobe signal generated by the point cloud projected by the emitting super lens 21 when passing through the display screen 1.

[0082] In the embodiments of the present application, Figure 1As shown, the display screen 1 includes pixel units 11 arranged in an array, a glass cover layer 12, a control circuit layer 13 and a light-emitting structure layer 14. A point cloud emission device under the screen is provided on one side of the pixel unit 11, and a light-emitting structure layer 14 is provided on the other side. The control circuit layer 13 and the glass cover layer 12 are sequentially provided on the side of the light-emitting structure 14 away from the pixel unit 11. The light-emitting structure layer 14 also includes a transparent cathode 141, a transparent filling material 142 and a light-emitting material layer 143.

[0083] According to the above embodiment, the pixel units 11 are arranged in an array and form an amplitude modulated grating, such as Figure 3 and Figure 4 As shown, the area that can pass through the point cloud is the light-transmitting area 61, and the area that cannot pass through the point cloud is the non-light-transmitting area 62. Optionally, the array-arranged pixel units 11 can form a square or regular hexagonal amplitude modulation grating.

[0084] In the embodiment of the present application, the process of projecting the point cloud is located under the array-arranged pixel units 11, so the projection of the point cloud is subject to the amplitude control of the array-arranged pixel units 11. When the projected point cloud passes through the array-arranged pixel units 11, the generated diffracted light is superimposed on the point cloud, so that the point cloud generates grating lobes during the projection process.

[0085] Therefore, the present application eliminates the grating lobes generated during the projection of the point cloud by setting an under-screen point cloud emitting device under the display screen 1, thereby achieving the purpose of suppressing the grating lobes without changing the shape or position of the pixel unit 11 in the display screen 1 in the existing system, thereby avoiding unnecessary waste of production capacity.

[0086] In a preferred embodiment, Figure 1 As shown, the point cloud emitting device under the screen includes an emitting superlens 21 and a light source array 3. Among them, the light source array 3 can be optionally a vertical cavity surface emitting laser array (VCSEL light source array, Vertical Cavity Surface Emitting Laser), and the light source array 3 is preferably used to provide an incident light beam with a wavelength of 940nm.

[0087] According to the above embodiment, the emitting superlens 21 is used to receive the incident light beam from the light source array 3, and emits the point cloud after superimposing the point cloud generation phase optimized by the GS algorithm (Gerchberg-Saxton Algorithm) and the grating lobe suppression phase on the incident light beam. The point cloud has a grating lobe suppression phase so that the grating lobes generated by the point cloud when passing through the display screen 1 are offset, thereby achieving the purpose of suppressing the grating lobe during the point cloud projection process. Among them, the emitting superlens 21 includes a substrate 2 and a first micro-nano structure 211 arranged on the surface of the substrate 2. The present application can superimpose and modulate the phase of the first micro-nano structure 211 so that the emitting superlens 21 has both the point cloud generation phase and the grating lobe suppression phase, so that the incident light beam from the light source array 3 generates a point cloud with a grating lobe suppression phase after passing through the first superlens 21, and the point cloud can be coherently destructed in the grating lobe direction when passing through the display screen 1, thereby achieving the purpose of suppressing the grating lobe.

[0088] Specifically, the light beam passing through the emitting super lens 21 has a diffraction angle θ. At this time, the relationship between the total electric field E(θ) and the diffraction angle θ satisfies:

[0089]

[0090] d=a+b(2)

[0091] Wherein, θ0 is the incident angle of the incident light beam received by the mth pixel unit 11 from the light source array 3. For example, when m=1, θ0 is the incident angle of the incident light beam received by the first pixel unit 11 from the light source array 3. a is the side length of the light-transmitting area, b is the side length of the non-light-transmitting area, d is the grating constant, λ is the wavelength of the incident light beam from the light source array 3, M is the number of pixel units 11, and Δφ m The phase modulation term A needs to be added to transmit the superlens 21. n is the amplitude of the near-field emitted light of the m-th pixel unit 11.

[0092] Furthermore, the phase difference between adjacent pixel units 11 satisfies:

[0093]

[0094] Where d is the grating constant, λ is the beam wavelength of the point cloud, and Δφ m The phase modulation term that needs to be added to the transmitting superlens 21, θ is the diffraction angle of the point cloud, θ0 is the incident angle of the incident light beam received by the mth pixel unit 11 from the light source array 3, for example, when m=1, θ0 is the incident angle of the incident light beam received by the first pixel unit 11 from the light source array 3.

[0095] According to the above embodiment, the grating lobe suppression phase needs to satisfy:

[0096]

[0097] Wherein, θ is the diffraction angle of the light beam passing through the transmitting super lens 21 for projecting the point cloud, θ0 is the incident angle of the incident light beam received by the m-th pixel unit 11 from the light source array 3, and θ i is the diffraction main lobe direction of display screen 1, is the variable that needs to be optimized.

[0098] Specifically, in order to make the phase modulation term added to the emitting superlens 21 satisfy the grating lobe suppression phase of the light beam passing through the emitting superlens 21, that is, in order to make the main lobe position satisfy the coherent constructive condition, the grating lobe suppression phase also needs to satisfy:

[0099] sin(θ i )-sin(θ0)=0(5)

[0100] Among them, θ i is the diffraction main lobe direction of the display screen 1; θ0 is the incident angle of the incident light beam received by the mth pixel unit 11 from the light source array 3. When θ=θ i When , formula (5) satisfies the condition, so that Δφ in formula (3) m =0, to satisfy the condition of coherent constructive phase in the main lobe direction.

[0101] Furthermore, by substituting formula (4) into formula (3), we can obtain:

[0102]

[0103] Where d is the grating constant, λ is the beam wavelength of the point cloud, and Δφ m is the phase modulation term that needs to be added, θ is the diffraction angle of the point cloud, and θ i is the diffraction main lobe direction of the display screen 1, θ0 is the incident angle of the incident light beam received by the mth pixel unit 11 from the light source array 3, for example, when m=1, θ0 is the incident angle of the incident light beam received by the first pixel unit 11 from the light source array 3.

[0104] Specifically, due to Δφ in formula (3) m = 0, so that Δφ in formula (6) = 0, at this time the coherent phase condition is met in the main lobe direction. Then, the optimization method such as genetic algorithm and particle swarm algorithm is used to optimize The coherent cancellation condition can be satisfied in the grating lobe direction, thereby achieving the effect of suppressing the grating lobe. It is possible to make Δφ 0 in the main lobe direction and π in the grating lobe direction, thereby achieving the condition of coherent constructive phase in the main lobe direction and the condition of coherent destructive phase in the grating lobe direction, so as to achieve the effect of suppressing the grating lobe.

[0105] In summary, when the point cloud transmitting device under the screen is used to project the point cloud, the grating lobe suppression phase Δφ for eliminating the grating lobe can be superimposed on the original point cloud phase of the transmitting super lens 21. m , thereby achieving the purpose of suppressing the grating lobes attached to the point cloud when it passes through the display screen 1.

[0106] A second aspect of the present application provides an under-screen point cloud receiving device, such as Figure 2 As shown, it is arranged below the display screen 1, that is, arranged on a side close to the pixel unit 11. The device includes a receiving super lens 22, which is used to receive the point cloud and control the transmittance of the received light beam to filter out the grating lobe signal generated by the point cloud received by the receiving super lens 22 when passing through the display screen 1.

[0107] In the embodiment of the present application, the process of receiving the point cloud is located below the array-arranged pixel units 11, so the point cloud reflected by the object will be subject to the amplitude regulation of the array-arranged pixel units 11 when passing through the display screen 1. When the point cloud reflected by the object passes through the array-arranged pixel units 11, the generated diffracted light will be superimposed on the point cloud, so that the point cloud will generate grating lobes during the projection process.

[0108] Therefore, the present application eliminates the grating lobes generated during the point cloud reception process by setting an under-screen point cloud receiving device under the display screen 1, thereby achieving the purpose of suppressing the grating lobes without changing the shape or position of the pixel unit 11 in the display screen in the existing system, thereby avoiding unnecessary waste of production capacity.

[0109] In a preferred embodiment, the under-screen point cloud receiving device includes a receiving super lens 22 and an image sensor 4, and the image sensor 4 is used to sense the point cloud after the grating lobe signal is filtered out by the second super lens 21. Optionally, the under-screen point cloud receiving device may also include a refractive lens 5, which is arranged between the receiving super lens 22 and the image sensor 4. In the embodiment of the present application, by setting the refractive lens 5, aberrations such as field curvature can be corrected, thereby achieving high-quality imaging effects.

[0110] According to the above embodiment, the receiving super lens 22 is used to receive the point cloud reflected by the target object and passing through the display screen 1. The point cloud is accompanied by grating lobes after passing through the amplitude modulated grating. The receiving super lens 22 includes a substrate 2 and a second micro-nano structure 221 arranged on the surface of the substrate 2. Since the grating lobes are all caused by high-order diffraction, the incident angle of the grating lobes when passing through the receiving super lens 22 is greater than the diffraction angle of the first-order diffraction. The diffraction angle of the first-order diffraction is the smallest diffraction angle among the diffraction angles of each high-order diffraction. Therefore, the present application can design the second micro-nano structure 221, preferably, by designing the cross-sectional shape of the second micro-nano structure 221, so as to reduce the transmittance of the second micro-nano structure 221 when the incident angle of the point cloud is greater than the first-order diffraction angle, so that the point cloud with an incident angle greater than the first-order diffraction angle cannot pass through the receiving super lens 22, thereby achieving the purpose of filtering out the grating lobes generated by high-order diffraction.

[0111] Specifically, according to the grating equation:

[0112] dsin(θ)=m D *λ(7)

[0113] Where d is the grating constant, θ is the diffraction angle, and m D is the diffraction order, and λ is the incident wavelength.

[0114] When the diffraction order m D =1, that is, the first-order diffraction has the smallest diffraction angle among all higher-order diffraction. At this time, the incident angle β1 corresponding to the point cloud satisfies:

[0115] β11=arcsin(λ / d)(8)

[0116] Where d is the grating constant and λ is the incident wavelength.

[0117] Optionally, the transmittance of the second micro-nanostructure 221 for point clouds with an incident angle greater than β1 is less than a transmittance threshold. In a preferred embodiment, the transmittance threshold is 10%, that is, for point clouds with an incident angle greater than β1, the transmittance of the second micro-nanostructure 221 is less than 10%.

[0118] To sum up, the second aspect of the embodiment of the present application provides an under-screen point cloud receiving device, which can perform a two-dimensional topological design on the second micro-nano structure 221 on the transmitting superlens 22, so that the receiving superlens 22 cannot pass through the point cloud with an incident angle greater than the first-order diffraction angle, thereby achieving the purpose of filtering out the grating lobe signal generated by high-order diffraction.

[0119] The third aspect of the present application provides an under-screen point cloud device, which is arranged below the display screen 1, that is, arranged on a side close to the pixel unit 11. The device includes: an under-screen point cloud transmitting device as described in any one of the technical solutions provided in the first aspect of the embodiment of the present application, and / or an under-screen point cloud receiving device as described in any one of the technical solutions provided in the second aspect of the embodiment of the present application.

[0120] The following are specific embodiments provided in this application:

[0121] Example 1

[0122] Since the size of a single Mini-LED (Mini Light-Emitting Diode) chip used in mobile phone displays is 50 to 200 μm, and the size of a single Micro-LED (Micro Light Emitting Diode) chip can currently reach 4 to 20 μm, the grating constant d is generally on the order of 10 μm. The main wavelength of the VCSEL light source array is in the near-infrared, including 850nm, 940nm and 1150nm wavelengths. In addition, the current mobile phone display screen generally has an aperture ratio of About 30%.

[0123] Based on the above parameters, Example 1 of the present application selects a mobile phone display screen and a 940nm VCSEL point light source as the embodiment of the present application. The field of view (FOV) in the x-axis and y-axis directions is 60°, the grating constant is d=10μm, and the aperture ratio of the mobile phone display screen is k=30% (i.e. b=5.48μm, where b is the side length of the non-light-transmitting area in the embodiment of the present application).

[0124] Figures 5 to 10 is the simulation result of the above-mentioned embodiment 1. Among them, Figure 5 and Figure 6 They are respectively a schematic diagram of the relative light intensity distribution of the far-field diffraction of the point cloud projection without the obstruction of the display screen 1 and a schematic diagram of the relative light intensity distribution along the y=0 section line; Figures 7 and 8 They are respectively a schematic diagram of the relative light intensity distribution of the far-field diffraction of the point cloud projection under the display screen 1 and a schematic diagram of the relative light intensity distribution along the y=0 section line; Figures 9 and 10The diagrams are respectively the far-field diffraction relative light intensity distribution diagram of the diffraction point cloud projected through the display screen 1 after optimization by the emitting super lens 21 and the relative light intensity distribution diagram along the y=0 section line. As can be seen from the figure, the projection diffraction efficiency of the point cloud projected without the obstruction of the display screen 1 is close to 80%. The diffraction efficiency of the point cloud projected after diffraction by the display screen 1 is only 55.01%. After optimization by the emitting super lens 21, the diffraction efficiency of the point cloud projected after diffraction by the display screen 1 is 75.54%. Among them, the diffraction efficiency is defined as the projected point cloud 1 / e 2 The ratio of the total energy in to the incident energy. In summary, compared with the point cloud that has not been optimized by the emitting superlens 21, the diffraction efficiency of the point cloud projected after diffraction by the display screen 1 after the emitting superlens 21 is optimized is increased by 20.53%, and is not much different from the diffraction efficiency of the point cloud without the display screen 1 blocking the projection, which proves that the under-screen point cloud emitting device provided in this embodiment has an excellent grating lobe suppression effect.

[0125] In addition, during the point cloud projection process, the uniformity of the light intensity at each point is also an important performance indicator, which is represented by the light intensity contrast of each point in this embodiment. The light intensity contrast satisfies:

[0126]

[0127] Among them, I max is the maximum light intensity projected by the point cloud, I min is the minimum light intensity projected by each point cloud. According to the above formula (9), the lower the light intensity contrast, the better the uniformity of the light intensity.

[0128] According to the above embodiment, simulation results show that the light intensity contrast of the projected point cloud without being blocked by the display screen 1 is 3.57%, while the light intensity contrast of the point cloud projected after diffraction by the display screen 1 is 11.452%. At the same time, considering the optimized diffraction effect of the display screen 1, the light intensity contrast of the emitting metalens 21 after diffraction by the display screen 1 is 8.31%, which is 3.14% lower than the light intensity contrast and has good uniformity.

[0129] Based on the parameters of the above embodiments, Figures 11 to 19 is the simulation result of point cloud reception. Figures 11 to 13 The far-field diffraction relative light intensity distribution of the point cloud received without the diffraction effect of the display screen 1, the relative light intensity distribution schematic diagram along the y=0 section line, and the modulation transfer function curve diagram; Figures 14 to 16 It is a schematic diagram of the relative light intensity distribution of the far-field diffraction received by the point cloud under the diffraction effect of the display screen 1, a schematic diagram of the relative light intensity distribution along the y=0 section line, and a modulation transfer function curve diagram; Figures 17 to 19It is a schematic diagram of the relative light intensity distribution of the far-field diffraction received by the point cloud after optimization of the receiving super lens 22 under the diffraction effect of the display screen 1, a schematic diagram of the relative light intensity distribution along the y=0 section, and a modulation transfer function curve.

[0130] According to the above embodiment, it can be seen from the simulation results that although the diffraction effect of the display screen 1 will not increase the peak half-maximum full width (FWHM) of the large focused light spot, it will cause the side lobes of the focused light spot to become stronger, thereby reducing the focusing efficiency and MTF (Modulation Transfer Function) value of the point cloud reception. The focusing efficiency is defined as the focusing light spot 1 / e 2 The ratio of the total energy in to the total energy in the receiving surface. As can be seen from the figure, the focusing efficiency without the diffraction of the display screen 1 is 71.16%, while the focusing efficiency after the diffraction of the display screen 1 is reduced to 53.91%, which is 17.25% lower than the focusing efficiency without the diffraction of the display screen 1. The focusing efficiency after optimization by the receiving superlens 22 can reach 67.20%, which is 13.69% higher than the focusing efficiency after the diffraction of the superimposed display screen 1, which is significantly improved. At the same time, the MTF value (100 line pairs / mm) of the diffraction of the superimposed display screen 1 is reduced from 0.78 without the diffraction of the display screen 1 to 0.60, while the MTF value after optimization by the receiving superlens 22 can be increased to 0.76, which is only 0.02 lower than the MTF value without the diffraction of the display screen 1, thereby proving that the receiving superlens 22 in the under-screen point cloud receiving device provided in this embodiment can filter the grating lobe signal well.

[0131] Example 2

[0132] In Example 2 of the present application, the same mobile phone display screen and 1550nm VCSEL point light source as in Example 1 are selected as the embodiment of the present application, wherein the field of view (FOV) in the x-axis and y-axis directions are both 60°, the grating constant is d=10μm, and the aperture ratio of the mobile phone display screen is k=30% (i.e. b=5.48μm).

[0133] Figure 20 to Figure 25 is the simulation result of the above-mentioned embodiment 2. Among them, Fig. 20 and Fig.21 They are respectively a schematic diagram of the relative light intensity distribution of the far-field diffraction of the point cloud projection without the obstruction of the display screen 1 and a schematic diagram of the relative light intensity distribution along the y=0 section line; Figure 22 to Figure 23 They are respectively a schematic diagram of the relative light intensity distribution of the far-field diffraction of the point cloud projection under the display screen 1 and a schematic diagram of the relative light intensity distribution along the y=0 section line; Figure 24 to Figure 25The diagrams are respectively the far-field diffraction relative light intensity distribution diagram of the diffraction point cloud projected through the display screen 1 after optimization by the emitting super lens 21 and the relative light intensity distribution diagram along the y=0 section line. As can be seen from the figure, the projection diffraction efficiency of the point cloud projected without the obstruction of the display screen 1 is close to 80%. The diffraction efficiency of the point cloud projected after diffraction by the display screen 1 is only 56.73%. After optimization by the emitting super lens 21, the diffraction efficiency of the point cloud projected after diffraction by the display screen 1 is 67.95%. Among them, the diffraction efficiency is defined as the projected point cloud 1 / e 2 The ratio of the total energy in to the incident energy. In summary, compared with the point cloud that has not been optimized by the emitting superlens 21, the diffraction efficiency of the point cloud projected after diffraction by the display screen 1 after the emitting superlens 21 is optimized is increased by 11.22%, and is not much different from the diffraction efficiency of the point cloud without the display screen 1 blocking the projection, which proves that the under-screen point cloud emitting device provided in this embodiment has an excellent grating lobe suppression effect.

[0134] According to the above embodiment, the simulation results of point cloud uniformity show that the light intensity contrast of the projected point cloud without being blocked by the display screen 1 is 4.24%, while the light intensity contrast of the point cloud projected after diffraction by the display screen 1 is 11.76%. At the same time, considering the optimized diffraction effect of the display screen 1, the light intensity contrast of the emitting metalens 21 after diffraction by the display screen 1 is 9.28%, which is a decrease of 2.48% in comparison.

[0135] Based on the parameters of the above embodiments, Figure 26 to Figure 34 is the simulation result of point cloud reception. Figure 26 to Figure 28 It is a schematic diagram of the relative light intensity distribution of the far-field diffraction received by the point cloud without the diffraction effect of the display screen 1, a schematic diagram of the relative light intensity distribution along the y=0 section line, and a modulation transfer function curve diagram; Figure 29 to Figure 31 It is a schematic diagram of the relative light intensity distribution of the far-field diffraction received by the point cloud under the diffraction effect of the display screen 1, a schematic diagram of the relative light intensity distribution along the y=0 section line, and a modulation transfer function curve diagram; Figure 32 to Figure 34 It is a schematic diagram of the relative light intensity distribution of the far-field diffraction received by the point cloud after optimization of the receiving super lens 22 under the diffraction effect of the display screen 1, a schematic diagram of the relative light intensity distribution along the y=0 section, and a modulation transfer function curve.

[0136] According to the above embodiment, it can be seen from the simulation results that although the diffraction effect of the display screen 1 does not increase the peak half-maximum full width (FWHM) of the large focused light spot, it will cause the side lobes of the focused light spot to become stronger, thereby reducing the focusing efficiency and MTF (Modulation Transfer Function) value of the point cloud reception. The focusing efficiency is defined as the focused light spot 1 / e 2The ratio of the total energy in to the total energy in the receiving surface. As can be seen from the figure, the focusing efficiency without the diffraction of the display screen 1 is 71.48%, while the focusing efficiency after the diffraction of the display screen 1 is reduced to 57.58%, which is 13.9% lower than the focusing efficiency without the diffraction of the display screen 1. The focusing efficiency after optimization by the receiving superlens 22 can reach 67.09%, which is 9.41% higher than the focusing efficiency after the diffraction of the superimposed display screen 1, which is significantly improved. At the same time, the MTF value (100 line pairs / mm) of the diffraction of the superimposed display screen 1 is reduced from 0.65 without the diffraction of the display screen 1 to 0.55, while the MTF value after optimization by the receiving superlens 22 can be increased to 0.63, which is only 0.02 lower than the MTF value without the diffraction of the display screen 1, thereby proving that the receiving superlens 22 in the under-screen point cloud receiving device provided in this embodiment can filter the grating lobe signal well.

[0137] The above is only a specific implementation of the embodiment of the present application, but the protection scope of the embodiment of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or replacements within the technical scope disclosed in the embodiment of the present application, which should be included in the protection scope of the embodiment of the present application. Therefore, the protection scope of the embodiment of the present application shall be based on the protection scope of the claims.

Claims

1. A point cloud transmitting device under a screen, characterized in that: The under-screen point cloud emission device is arranged under the display screen (1), the display screen (1) comprises pixel units (11) arranged in an array, and the pixel units (11) arranged in an array constitute an amplitude modulated grating; The under-screen point cloud emission device comprises: an emission super lens (21); The emitting metal lens (21) is used to project a point cloud and to provide a grating lobe suppression phase to suppress a grating lobe signal generated when the point cloud projected by the emitting metal lens (21) passes through the display screen (1).

2. The under-screen point cloud transmitting device according to claim 1, characterized in that: The grating lobe suppression phase satisfies: in, is a variable to be optimized; θ is the diffraction angle of the light beam passing through the emitting metalens (21); θ0 is the incident angle of the incident light beam received by the nth pixel unit (11) from the light source array (3); θ i is the diffraction main lobe direction of the display screen (1).

3. The under-screen point cloud transmitting device according to claim 2, characterized in that: The grating lobe suppression phase also satisfies: sin(θ i )-sin(θ0)=0 Among them, θ i is the diffraction main lobe direction of the display screen (1); θ0 is the incident angle of the incident light beam received by the nth pixel unit (11) from the light source array (3).

4. The under-screen point cloud transmitting device according to claim 1, characterized in that: The under-screen point cloud emitting device also includes a light source array (3) for providing an incident light beam.

5. The under-screen point cloud transmitting device according to claim 4, characterized in that: The light source array (3) comprises a vertical cavity surface emitting laser array.

6. A point cloud receiving device under a screen, characterized in that: The under-screen point cloud receiving device is arranged under a display screen (1), the display screen (1) comprises pixel units (11) arranged in an array, and the pixel units (11) arranged in an array constitute an amplitude modulated grating; The under-screen point cloud receiving device comprises: a receiving super lens (22); The receiving super lens (22) is used to receive a point cloud and to control the transmittance of a light beam received by the receiving super lens (22) so as to filter out a grating lobe signal generated when the point cloud received by the receiving super lens (22) passes through the display screen (1).

7. The under-screen point cloud receiving device according to claim 6, characterized in that: The transmittance of the micro-nanostructure (201) in the receiving superlens (22) for incident light with an incident angle greater than θ1 is less than a transmittance threshold; wherein the incident angle θ1 satisfies: θ1=arcsin(λ / d) Wherein, the λ is the incident wavelength; and the d is the grating period of the display screen (1).

8. The under-screen point cloud receiving device according to claim 7, characterized in that: The transmittance threshold is 10%.

9. The under-screen point cloud receiving device according to claim 6, characterized in that: The under-screen point cloud receiving device also includes an image sensor (4) for sensing the point cloud after the grating lobe signal is filtered out by the receiving super lens (22).

10. The under-screen point cloud receiving device according to claim 9, characterized in that: The under-screen point cloud receiving device also includes a refractive lens (5).

11. The under-screen point cloud receiving device according to claim 10, characterized in that: The refractive lens (5) is arranged between the receiving superlens (22) and the image sensor (4).

12. An under-screen point cloud device, characterized in that: The under-screen point cloud device is arranged under a display screen (1), the display screen (1) comprises pixel units (11) arranged in an array, and the pixel units (11) arranged in an array constitute an amplitude modulated grating; The under-screen point cloud device comprises: The under-screen point cloud transmitting device according to any one of claims 1 to 5, and / or An under-screen point cloud receiving device as described in any one of claims 6 to 11.

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