Light projection devices and electronic equipment

Abstract

This application discloses a light projection device and an electronic device. The light projection device includes: a housing having an opening extending along a first direction; an optical element disposed in the opening, the optical element including a reflective area and a transmissive area; a light source disposed inside the housing and arranged opposite to the reflective area along the first direction; and a reflective element disposed inside the housing, at least a portion of the reflective element being arranged opposite to the transmissive area along the first direction. The reflective area is used to reflect light emitted by the light source to the reflective element, and the reflective element is used to reflect light emitted by the light source to the transmissive area. The light projection device and electronic device provided by this application can reduce the size of the light projection device along the focal length direction of the optical element while ensuring that the spatial projection field of view is within a suitable angular range and the speckle density in the speckle pattern is greater than a preset value, which is beneficial for miniaturization.

Description

Technical Field

[0001] This application relates to the field of electronic equipment technology, and in particular to a light projection device. Background Technology

[0002] 3D imaging technology, due to its advantages such as high precision, strong adaptability, and strong anti-counterfeiting capabilities, has been widely used in various fields such as mobile payment, smart locks, and security inspection. One of the most important modules in 3D imaging technology is the light projection device.

[0003] The optical projection device mainly consists of a laser, a collimating element, and diffractive optical elements. The laser beam emitted from the laser is projected outward through the collimating element and diffractive optical elements to form a structured light speckle pattern. Given a fixed field of view (FOV), the higher the density of the speckles, the larger the focal length of the corresponding collimating element. To ensure good imaging of the structured light speckle pattern, the density of the speckles in the pattern must be greater than a preset value. This limits the size of the optical projection device in the collimating element's focal length direction, making it difficult to miniaturize and hindering the development of miniaturized optical projection devices. Summary of the Invention

[0004] The light projection device and electronic device provided in this application can reduce the size of the light projection device along the focal length direction of the optical element while ensuring that the spatial projection field of view is within a suitable angular range and that the speckle density in the light speckle pattern is greater than a preset value, which is beneficial for miniaturization.

[0005] This application provides a light projection device, wherein the light projection device includes:

[0006] The housing has an opening extending through in a first direction;

[0007] An optical element is disposed in the opening, the optical element comprising a reflective region and a transmissive region;

[0008] A light source is disposed inside the housing and is positioned opposite to the reflective area along the first direction;

[0009] A reflective element is disposed inside the housing, and at least a portion of the reflective element is disposed opposite to the transmission area along the first direction;

[0010] The reflective area is used to reflect the light emitted by the light source to the reflective element, and the reflective element is used to reflect the light to the transmissive area.

[0011] In the light projection device described above, the reflecting area includes a first reflecting area and a second reflecting area, wherein the first reflecting area and the second reflecting area are respectively located on both sides of the transmitting area along the second direction;

[0012] The light source includes a first light source and a second light source. Along the first direction, the first light source corresponds to the first reflection area, and the second light source corresponds to the second reflection area.

[0013] The first direction is perpendicular to the second direction.

[0014] In the light projection device described above, the first light source is a random dot matrix light source disposed on the focal plane of the optical element; the second light source is a uniform dot matrix light source disposed on the defocus plane of the optical element.

[0015] In the light projection device described above, there is a first distance between the first light source and the optical element, a second distance between the second light source and the optical element, and a third distance between the reflective element and the optical element;

[0016] The sum of the first distance and the third distance is equal to the focal length of the optical element, and the sum of the second distance and the third distance is greater than or less than the focal length of the optical element.

[0017] In the light projection device described above, the housing includes a base plate, which is disposed opposite to the opening along the first direction, and the first light source, the second light source, and the reflective element are all disposed on the base plate;

[0018] A pad is provided between the second light source and the base plate; or a groove is provided on the base plate, and at least a portion of the second light source is embedded in the groove.

[0019] The reflective element is mounted on the base plate via a bracket.

[0020] In the light projection device described above, the light emitted by the first light source has a first illumination width at the first reflection area along the second direction, and the first illumination width is less than or equal to the size of the first reflection area along the second direction.

[0021] The light emitted by the second light source has a second illumination width at the second reflection area along the second direction, and the second illumination width is less than or equal to the size of the second reflection area along the second direction;

[0022] The light emitted by the first light source has a first emission width in the transmission region along the second direction, and the light emitted by the second light source has a second emission width in the transmission region along the second direction. The size of the transmission region along the second direction is greater than the first emission width and the second emission width.

[0023] The light projection device described above, wherein the optical element includes a substrate layer, a plurality of nanopillars, and an encapsulation component;

[0024] The nanopillars extend along the first direction and are arranged at intervals along the second and third directions. One end of each nanopillar is connected to the surface of the substrate layer facing the interior of the housing. The encapsulation component fills the gaps between adjacent nanopillars and covers the other end of each nanopillar.

[0025] The first direction, the second direction, and the third direction are perpendicular to each other.

[0026] In the light projection device described above, the arrangement of each nanopillar opposite to the first reflective region along the first direction is the same as the arrangement of each nanopillar opposite to the second reflective region along the first direction; the arrangement of each nanopillar opposite to the transmission region along the first direction is different from the arrangement of each nanopillar opposite to the second reflective region or the second reflective region along the first direction.

[0027] In the light projection device described above, the arrangement of each nanopillar opposite to the first reflective region along the first direction, the arrangement of each nanopillar opposite to the second reflective region along the first direction, and the arrangement of each nanopillar opposite to the transmissive region along the first direction are all different.

[0028] In the light projection device described above, the second light source has a plurality of second light-emitting holes, the second light-emitting holes are arranged at intervals along the second direction and / or the third direction, and the dimension between the second light-emitting hole and the adjacent second light-emitting hole along the second direction is greater than or equal to the dimension between the second light-emitting hole and the adjacent second light-emitting hole along the third direction;

[0029] The radius of the diffuse spot generated after projection of each of the second light-emitting holes is greater than or equal to half the dimension of the second light-emitting hole and the adjacent second light-emitting hole along the second direction.

[0030] This application also provides an electronic device, wherein the electronic device includes a light receiving device and a light projection device as described above, the light receiving device being used to receive light emitted by the light projection device.

[0031] The light projection device and electronic device provided in this application, by setting an optical element with a reflective area and a transmission area at the opening of the housing, and setting a reflective element inside the housing, so that the light source and the reflective area are set opposite to each other, the light emitted by the light source can be reflected twice through the reflective area and the reflective element before reaching the transmission area and exiting to the outside of the housing, which is equivalent to folding the light path. This can ensure that the light path transmission path meets the focal length requirements of the optical element, thereby ensuring that the spatial projection field of view is within a suitable angle range and that the speckle density in the light speckle pattern is greater than a preset value, while reducing the size of the light projection device along the focal length direction of the optical element, which is conducive to the miniaturization of the light projection device and electronic device. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 A schematic diagram illustrating the structural principle of the light projection device provided in this application;

[0034] Figure 2 A schematic diagram of a structured light speckle pattern formed by the projection of a first light source into the light projection device provided in this application;

[0035] Figure 3 A schematic diagram of a structured light speckle pattern formed by the projection of a second light source into the light projection device provided in this application;

[0036] Figure 4 A schematic diagram showing the structural dimensions of the light projection device provided in this application;

[0037] Figure 5 Another structural dimension diagram of the light projection device provided in this application;

[0038] Figure 6 A schematic diagram of the structure of the optical elements of the light projection device provided in this application;

[0039] Figure 7 A schematic diagram of the structural units comprising the transmission region of the optical element of the light projection device provided in this application;

[0040] Figure 8 A schematic diagram of the arrangement of nanopillars of the optical elements of the light projection device provided in this application;

[0041] Figure 9 A layout diagram of the second light-emitting aperture of the second light source for the light projection device provided in this application;

[0042] Figure 10A schematic diagram of the distribution of the diffuse spot formed by the projection of the second light-emitting aperture of the second light source of the light projection device provided in this application;

[0043] Figure 11 A schematic diagram of the structure of the electronic device provided in this application.

[0044] Explanation of icon numbers:

[0045] 1. Housing; 11. Opening; 12. Base plate; 121. Groove; 13. Pad; 14. Support; 2. Optical element; S. Reflective area; 21. First reflective area; 22. Second reflective area; 23. Transmission area; 24. Base layer; 25. Nanopillar; 26. Encapsulation component; 3. Light source; 31. First light source; 311. First light-emitting aperture; 32. Second light source; 321. Second light-emitting aperture; 4. Reflective element; 5. Electronic device; 51. Light receiving device;

[0046] X, first direction; Y, second direction; Z, third direction. Detailed Implementation

[0047] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0048] Currently, the mainstream 3D imaging technologies include: 3D structured light imaging, time-of-flight imaging, and binocular stereo imaging. Among them, 3D structured light technology is widely used in various fields such as mobile payment, smart communication devices, smart door locks, robots, and security inspection due to its advantages such as high precision, strong adaptability, and strong anti-counterfeiting. One of its most critical modules is the 3D structured light projection device.

[0049] The light projection device mainly includes a laser, a collimating element, and a diffractive optical element 2. The light beam emitted by the laser is projected outward through the collimating element and the diffractive optical element 2 to form a structured light speckle pattern. To ensure a good imaging effect of the structured light speckle pattern, the density of speckles in the pattern must be greater than a preset value, and the spatial projection field of view (FOV) of the light projection device must be within a suitable angular range. With a fixed spatial projection field of view, the greater the density of speckles, the larger the focal length of the corresponding collimating element. For example, when the spatial projection field of view is 85°, the focal length of the collimating element is generally greater than 3mm, which limits the size of the light projection device in the collimating element's focal length direction, hindering the miniaturization of the light projection device. Taking a left-right folding electronic device 5 as an example, thinness is a crucial dimension. For instance, some folding electronic devices 5 have a body thickness of only 4.6mm when unfolded. Considering the screen, battery cover, and other structural components, the height of the light projection device must be less than 2.6mm, and the focal length of the collimating element must be less than 2mm, making existing light projection devices unable to meet the design requirements.

[0050] In view of the problems existing in the above-mentioned related technologies, this application provides a light projection device that can reduce the size of the light projection device along the focal length direction of the optical element 2 while ensuring that the spatial projection field of view is within a suitable angular range and the speckle density in the light speckle pattern is greater than a preset value, which is conducive to the miniaturization of light projection devices and electronic devices.

[0051] It should be noted that the terms indicating direction, such as first direction X, second direction Y, and third direction Z, are only used to more clearly illustrate the structure of this application in conjunction with the accompanying drawings, and this application is not limited thereto. The first direction X, second direction Y, and third direction Z are all perpendicular to each other.

[0052] like Figure 1 As shown, this application provides a light projection device, which includes a housing 1, an optical element 2, a light source 3, and a reflective element 4.

[0053] The housing 1 has an opening 11 extending along a first direction X; the optical element 2 is disposed at the opening 11. Optionally, a support member is provided on the inner surface of the housing 1 near the opening 11, and the optical element 2 is fixed on the support member to maintain the position of the optical element 2.

[0054] The optical element 2 includes a reflective region S and a transmission region 23. The reflective region S can reflect light, and the transmission region 23 allows light to pass through and propagate. The light source 3 is located inside the housing 1 and is arranged opposite to the reflective region S along the first direction X. The reflective element 4 is located inside the housing 1 and is spaced apart from the light source 3. At least a portion of the reflective element 4 is arranged opposite to the transmission region 23 along the first direction X.

[0055] The reflective zone S is used to reflect the light emitted by the light source 3 to the reflective element 4, and the reflective element 4 is used to further reflect the light to the transmission zone 23.

[0056] Transmission zone 23 integrates collimation and beam splitting functions to achieve collimation and beam splitting of light.

[0057] Optical element 2 is a superlens that can achieve abnormal angle reflection. When light is perpendicularly incident on the reflection area S, a certain reflection angle can be generated so that the reflected light can be transmitted to the reflection element 4, and then reflected by the reflection element 4 to the transmission area 23 and emitted to the outside of the housing 1.

[0058] The light projection device provided in this application provides an optical element 2 with a reflection area S and a transmission area 23 at the opening 11 of the housing 1, and a reflective element is provided inside the housing 1. The light source 3 is positioned opposite to the reflection area S. The light emitted by the light source 3 can be reflected twice by the reflection area S and the reflective element before reaching the transmission area 23 and exiting to the outside of the housing 1. This is equivalent to folding the light path, which can ensure that the light path transmission path meets the focal length requirements of the optical element 2. Thus, while ensuring that the spatial projection field of view is within a suitable angle range and the speckle density in the light speckle pattern is greater than the preset value, the size of the light projection device along the focal length direction of the optical element 2 is reduced, which is beneficial to the miniaturization of light projection devices and electronic devices.

[0059] like Figure 1 As shown, the light projection device provided in this application includes a reflection area S comprising a first reflection area 21 and a second reflection area 22, which are respectively located on both sides of the transmission area 23 along the second direction Y. Correspondingly, the light source 3 includes a first light source 31 and a second light source 32. Along the first direction X, the first light source 31 corresponds to the first reflection area 21, and the second light source 32 corresponds to the second reflection area 22. This arrangement allows the light emitted by the first light source 31 to reach the transmission area 23 through reflection by the first reflection area 21 and the reflection element 4, and the light emitted by the second light source 32 to reach the transmission area 23 through the second reflection area 22 and the reflection element 4.

[0060] Optionally, the first light source 31 and the second light source 32 may be different light sources 3 or the same light source 3, in order to obtain different usage methods.

[0061] like Figure 2 As shown, the light projection device provided in this application includes a first light source 31, which is a random dot matrix light source 3. Multiple first light-emitting holes 311 are randomly arranged in the projection along the first direction X. The random dot matrix light source 3 is located on the focal plane of the optical element 2. After the random dot matrix light source 3 is copied and projected into space, it forms a dense dot matrix distribution for generating 3D images.

[0062] like Figure 2 and Figure 3 As shown, the light projection device provided in this application includes a second light source 32, which is a uniform dot matrix light source 3. Multiple second light-emitting holes 321 are randomly arranged in the projection along the first direction X. The uniform dot matrix light source 3 is located on the defocus plane of the optical element 2. After the uniform dot matrix light source 3 is copied and projected into space, it forms a uniform dot matrix distribution for generating a 2D image.

[0063] like Figure 4 and Figure 5 As shown, in the light projection device provided in this application, there is a first distance between the first light source 31 and the optical element 2, a second distance between the second light source 32 and the optical element 2, and a third distance between the reflective element 4 and the optical element 2;

[0064] The sum of the first distance and the third distance is equal to the focal length of optical element 2, and the sum of the second distance and the third distance is greater than or less than the focal length of optical element 2. This achieves the arrangement of random dot matrix light source 3 on the focal plane and uniform dot matrix light source 3 on the defocus plane, while simultaneously increasing the focal length while reducing the overall size of the light projection device along the first direction X.

[0065] like Figure 4 and Figure 5 As shown, the light projection device provided in this application includes a housing 1 comprising a base plate 12, which is disposed opposite to the opening 11 along a first direction X. A first light source 31, a second light source 32, and a reflective element 4 are all disposed on the base plate 12. The base plate 12 is a circuit board, on which the first light source 31 and the second light source 32 are disposed and powered.

[0066] Optionally, during setup, the distance between the base plate 12 and the optical element 2 can be adjusted so that when the first light source 31 is directly mounted on the base plate 12, the first light source 31 is located on the focal plane of the optical element 2.

[0067] A pad 13 is provided between the second light source 32 and the base plate 12; or a groove 121 is provided on the base plate 12, and at least a portion of the second light source 32 is embedded in the groove 121. This causes the position of the second light source 32 to deviate from the focal plane and be located on the defocus plane. Correspondingly, the reflection path of the light emitted by the second light source 32 is greater than or less than the reflection path of the light source 3 emitted by the first light source 31. In this way, 2D imaging and 3D imaging are achieved through the cooperation of the first light source 31 and the second light source 32.

[0068] The pad 13 can be a ceramic pad 13. After defocusing, the points projected into space become larger, and the speckles overlap, ultimately achieving area array projection.

[0069] The reflective element 4 is mounted on the base plate 12 via the bracket 14. The bracket 14 provides a mounting base for the reflective element 4. At the same time, by adjusting the size of the bracket 14 along the first direction X, the distance between the reflective element 4 and the optical element 2 can be adjusted to achieve the effect of fine adjustment of the focal length.

[0070] Specifically, such as Figure 4 and Figure 5 As shown, the light projection device provided in this application has a first illumination width at the first reflection area 21 along the second direction Y, where the first illumination width is less than or equal to the size of the first reflection area 21 along the second direction Y; so that all the light emitted by the first light source 31 is reflected by the first reflection area 21 and reaches the transmission area 23, thereby reducing light loss and improving light utilization.

[0071] The light emitted by the second light source 32 has a second illumination width along the second direction Y at the second reflection area 22. The second illumination width is less than or equal to the size of the second reflection area 22 along the second direction Y, so that all the light emitted by the second light source 32 is reflected by the second reflection area 22 and reaches the transmission area 23, thereby reducing light loss and improving light utilization.

[0072] The light emitted by the first light source 31 has a first emission width in the transmission region 23 along the second direction Y, and the light emitted by the second light source 32 has a second emission width in the transmission region 23 along the second direction Y. The size of the transmission region 23 along the second direction Y is greater than the first emission width and the second emission width.

[0073] Both the first light source 31 and the second light source 32 have a divergence angle θ; optionally, the divergence angle of the first light source 31 and the divergence angle of the second light source 32 can be the same or different, and can be adjusted according to design requirements.

[0074] Optionally, in the light projection device provided in this application, the divergence angle is greater than or equal to 15° and less than or equal to 25°.

[0075] The dimension of the first reflective area 21 along the second direction Y is a. The dimension of the first reflective area 21 along the second direction Y can be determined according to the first distance and the divergence angle of the first light source 31. Specifically, the first distance is f1, and the dimension of the first reflective area 21 along the second direction Y must satisfy a=2*f1*tan(θ / 2)±0.2mm.

[0076] The dimension of the second reflection area 22 along the second direction Y is b. The dimension of the second reflection area 22 along the second direction Y can be determined according to the second distance and the divergence angle of the second light source 32. Specifically, the second distance is f2, and the dimension of the second reflection area 22 along the second direction Y must satisfy b=2*f2*tan(θ / 2)±0.2mm;

[0077] The dimension of the transmission region 23 along the second direction Y is c. The dimension of the transmission region 23 along the second direction Y can be determined according to the first distance, the third distance and the divergence angle. Specifically, the third distance is f3. The dimension of the transmission region 23 along the second direction Y must satisfy c = 2*(f1+f3)*tan(θ / 2) ± 0.2mm.

[0078] When the dimensions of the first reflective area 21 along the second direction Y, the second reflective area 22 along the second direction Y, and the transmission area 23 along the second direction Y satisfy the requirements of the above formula, the focal length of the optical element 2 and the projection effect when the light projection device is used can be effectively guaranteed, while the overall size of the light projection device along the first direction X can be reduced.

[0079] Taking the size of the light projection device along the first direction X as 2.7mm as an example, after subtracting the size of the base plate 12 and the optical element 2, the allowable distance between the optical element 2 and the base plate 12 is 2mm; when distributed as follows: when the nanopillars 25 of the optical element 2 face the base plate 12, f1 = 2mm, f3 = 1mm, and the focal length = f1 + f2 = 3mm; when the nanopillars 25 of the optical element 2 face away from the base plate 12, the measured focal length is 3.5mm, which effectively extends the focal length of the optical element 2. By extending the focal length, the density distribution of speckle patterns in the speckle pattern can be effectively improved.

[0080] like Figure 6 As shown, the light projection device provided in this application includes an optical element 2 that is a superlens. The optical element 2 includes a substrate layer 24, a plurality of nanopillars 25, and an encapsulation component 26. The substrate layer 24 is made of quartz glass. The nanopillars 25 extend along a first direction X and are arranged at intervals along a second direction Y and a third direction Z. One end of each nanopillar is connected to the surface of the substrate layer 24 facing the interior of the housing 1. The nanopillars 25 are made of silicon. The encapsulation component 26 fills the gaps between adjacent nanopillars 25 and covers the other end of each nanopillar 25. The encapsulation component 26 is used to protect the nanopillars 25.

[0081] Optionally, when the divergence angle of the first light source 31 is the same as the divergence angle of the second light source 32, the arrangement of each nanopillar 25 opposite to the first reflection region 21 along the first direction X is the same as the arrangement of each nanopillar 25 opposite to the second reflection region 22 along the first direction X; however, the arrangement of each nanopillar 25 opposite to the transmission region 23 along the first direction X is different from the arrangement of each nanopillar 25 opposite to the second reflection region 22 or the second reflection region 22 along the first direction X.

[0082] Optionally, when the divergence angle of the first light source 31 is different from that of the second light source 32, the arrangement of each nanopillar 25 opposite to the first reflection area 21 along the first direction X, the arrangement of each nanopillar 25 opposite to the second reflection area 22 along the first direction X, and the arrangement of each nanopillar 25 opposite to the transmission area 23 along the first direction X are all different.

[0083] Optionally, the reflective element 4 can be a superlens or a conventional mirror. If the reflective element 4 is a superlens, the arrangement of the nanopillars 25 of the reflective element 4 in the projection of the first direction X is different from the arrangement of the nanopillars 25 of the first reflective region 21 and the nanopillars 25 of the second reflective region 22.

[0084] Optionally, each nanopillar 25 has the same dimension along the first direction X, which can simplify the manufacturing process and effectively reduce production difficulty.

[0085] Superlenses are subwavelength structural units composed of many periodically arranged dielectric or plasmon polariton materials (such as... Figure 7 The subwavelength structural unit (as shown) is composed of several subwavelength structural units. Each subwavelength structural unit has a different size (diameter d, and / or height h, and / or period p). By artificially designing the dimensions of these subwavelength structural units, the optical response of the incident light, including its amplitude, phase, and polarization, can be manipulated, thus acting as a light-focusing agent. All subwavelength structural units are located on a substrate material. Common substrates used are glass substrates, polymer plastics, sapphire, and other materials with high light transmittance and durability. Optionally, the subwavelength structural units can be exposed to air or covered by a layer of other material (such as photoresist, optical adhesive, polymer, etc.) to improve the overall stability of the planar lens structure. The cross-section of the subwavelength structural unit can be a centrally symmetric shape, such as a square, ring, or circle, to achieve polarization insensitivity. In some specific applications, it can also be designed as an asymmetrical shape, such as a rectangle or V-shape, to achieve polarization insensitivity. For subwavelength structural units made of dielectric materials, the aforementioned dimensions d, h, and p are often about half of the operating wavelength.

[0086] Based on the operating wavelength λ, the modulation of the phase and transmittance of the incident light by a single nanopillar 25 under different heights, center distances, and widths is calculated using finite-difference time-domain or strict coupled-wave analysis methods. The width range of the optical antenna that satisfies the conditions of transmittance close to 1 and incident light phase modulation range of [0, 2π] is selected.

[0087] like Figure 8As shown, each subwavelength structural unit comprises five nanopillars 25 with dimensions of 100 nm, 134 nm, 144 nm, 154 nm, and 200 nm, respectively, px = 300 nm, and py = 1500 nm, which can produce anomalous reflections when incident perpendicularly.

[0088] For the projection region, the nanopillars 25 need to perform two functions: collimation and beam splitting (diffraction). The collimation phase and diffraction phase are designed separately, and then their phases are superimposed. For collimation, since the focal length is above 3mm, a spherical phase can be used. For the diffraction phase, under normal incidence, the grating period changes with the number of nanometers within the period, thus changing the number of diffraction orders. Therefore, when there are many structured light points, a larger period should be selected, i.e., more nanopillars 25 within a single period. For example, the widths of the silicon nanopillars 25 are 243 nm, 293 nm, 227 nm, 215 nm, 456 nm, 283 nm, 456 nm, 214.4 nm, 227 nm, 293 nm, and 243 nm, respectively, and the diffraction efficiency can reach 90.12%.

[0089] like Figure 9 and Figure 10 As shown, the light projection device provided in this application includes a second light source 32 having a plurality of second light-emitting holes 321. The second light-emitting holes 321 are spaced apart along a second direction Y and / or a third direction Z. The dimension between two adjacent second light-emitting holes 321 along the second direction Y is greater than or equal to the dimension between two adjacent second light-emitting holes 321 along the third direction Z. The radius of the diffuse spot generated after projection from each second light-emitting hole 321 is greater than or equal to half the dimension between two adjacent second light-emitting holes 321 along the second direction Y. This satisfies the defocusing requirement, thereby ensuring the area array projection effect of the uniform dot matrix light source 3.

[0090] like Figure 11 As shown, this application also provides an electronic device 5, wherein the electronic device 5 includes a light receiving device 51 and a light projection device as described above, the light receiving device 51 and the light projection device are arranged at a distance, and the light receiving device 51 is used to receive the light emitted by the light projection device.

[0091] The electronic device 5 provided in this application has an optical element 2 with a reflective area S and a transmission area 23 at the opening 11 of the housing 1, and a reflective element is set inside the housing 1, so that the light source 3 is set opposite to the reflective area S. The light emitted by the light source 3 can be reflected twice through the reflective area S and the reflective element and then reach the transmission area 23 and be emitted to the outside of the housing 1. This is equivalent to folding the light path, which can ensure that the light path transmission path meets the focal length requirements of the optical element 2. Thus, while ensuring that the spatial projection field of view is within a suitable angle range and the speckle density in the light speckle pattern is greater than the preset value, the size of the light projection device along the focal length direction of the optical element 2 is reduced, which is conducive to the miniaturization of the light projection device and electronic device.

[0092] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0093] In the description of this application, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "middle", "rear", "left", "right", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0094] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0095] The above description is merely a specific implementation of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A light projection device, characterized in that, The light projection device includes: The housing has an opening extending through in a first direction; An optical element is disposed in the opening, the optical element comprising a reflective region and a transmissive region; A light source is disposed inside the housing and is positioned opposite to the reflective area along the first direction; A reflective element is disposed inside the housing, and at least a portion of the reflective element is disposed opposite to the transmission area along the first direction; The reflective area is used to reflect the light emitted by the light source to the reflective element, and the reflective element is used to reflect the light to the transmission area. The reflective area includes a first reflective area and a second reflective area, which are respectively located on both sides of the transmission area along the second direction. The light source includes a first light source and a second light source. Along the first direction, the first light source corresponds to the first reflection area, and the second light source corresponds to the second reflection area. The first direction is perpendicular to the second direction, the first light source is a random dot matrix light source, and the random dot matrix light source is disposed on the focal plane of the optical element; the second light source is a uniform dot matrix light source, and the uniform dot matrix light source is disposed on the defocus plane of the optical element.

2. The light projection device according to claim 1, characterized in that, The first light source and the optical element have a first distance, the second light source and the optical element have a second distance, and the reflective element and the optical element have a third distance; The sum of the first distance and the third distance is equal to the focal length of the optical element, and the sum of the second distance and the third distance is greater than or less than the focal length of the optical element.

3. The light projection device according to claim 2, characterized in that, The housing includes a base plate, which is disposed opposite to the opening along the first direction. The first light source, the second light source, and the reflective element are all disposed on the base plate. A pad is provided between the second light source and the base plate; or a groove is provided on the base plate, and at least a portion of the second light source is embedded in the groove. The reflective element is mounted on the base plate via a bracket.

4. The light projection device according to claim 2, characterized in that, The light emitted by the first light source has a first illumination width at the first reflection area along the second direction, and the first illumination width is less than or equal to the size of the first reflection area along the second direction; The light emitted by the second light source has a second illumination width at the second reflection area along the second direction, and the second illumination width is less than or equal to the size of the second reflection area along the second direction; The light emitted by the first light source has a first emission width in the transmission region along the second direction, and the light emitted by the second light source has a second emission width in the transmission region along the second direction. The size of the transmission region along the second direction is greater than the first emission width and the second emission width.

5. The light projection device according to claim 1, characterized in that, The optical element includes a substrate layer, multiple nanopillars, and encapsulation components; The nanopillars extend along the first direction and are arranged at intervals along the second and third directions. One end of each nanopillar is connected to the surface of the substrate layer facing the interior of the housing. The encapsulation component fills the gaps between adjacent nanopillars and covers the other end of each nanopillar. The first direction, the second direction, and the third direction are perpendicular to each other.

6. The light projection device according to claim 5, characterized in that, The arrangement of the nanopillars opposite to the first reflective region along the first direction is the same as the arrangement of the nanopillars opposite to the second reflective region along the first direction; the arrangement of the nanopillars opposite to the transmissive region along the first direction is different from the arrangement of the nanopillars opposite to the second reflective region or the second reflective region along the first direction.

7. The light projection device according to claim 5, characterized in that, The arrangement of the nanopillars opposite to the first reflective region along the first direction, the arrangement of the nanopillars opposite to the second reflective region along the first direction, and the arrangement of the nanopillars opposite to the transmissive region along the first direction are all different.

8. The light projection device according to claim 1, characterized in that, The second light source has a plurality of second light-emitting holes, which are spaced apart along the second direction and / or the third direction. The dimension between a second light-emitting hole and an adjacent second light-emitting hole along the second direction is greater than or equal to the dimension between a second light-emitting hole and an adjacent second light-emitting hole along the third direction. The radius of the diffuse spot generated after projection of each of the second light-emitting holes is greater than or equal to half the dimension of the second light-emitting hole and the adjacent second light-emitting hole along the second direction.

9. An electronic device, characterized in that, The electronic device includes a light receiving device and a light projection device as described in any one of claims 1 to 8, wherein the light receiving device is used to receive light emitted by the light projection device.

Images