Projection module, imaging device, and electronic device

Abstract

The present application provides a projection module, an imaging device, and an electronic device. The projection module includes: a light source for projecting structured light; a collimating mirror disposed on the light-emitting side of the light source to collimate the structured light projected from the light source into parallel light; a diffractive optical element disposed on the light-emitting side of the collimating mirror; the diffractive optical element can be switched to a diffractive state and / or a diffusive state under the action of different voltages to diffract and / or scatter the parallel light projected from the collimating mirror. The imaging device includes an imaging module and a projection module; the electronic device includes an imaging device. By adopting the above technical solution, only one light source is provided to achieve the projection of structured light and pan-infrared light. In this way, the manufacturing cost of the projection module is saved, and at the same time, the volume of the projection module is reduced, which helps to realize the miniaturized design of the imaging device.

Description

Technical Field

[0001] This application belongs to the technical field of optical imaging. More specifically, it relates to a projection module, an imaging device, and an electronic device. Background Art

[0002] In the field of optical imaging, imaging devices for three-dimensional imaging mainly include a structured light projector, an infrared fill light, an infrared camera, and a color camera. During operation, the structured light projector projects structured light onto the target object, and the infrared camera receives the structured light to obtain an infrared image of the target object with structural features, and a depth map is obtained through algorithms; the infrared fill light projects pan-infrared light onto the target object, and the infrared camera receives the pan-infrared light to obtain a uniform infrared image of the target object; the color camera obtains a color image of the target object. Among them, the uniform infrared image and the color image can perform face detection, face framing, face feature comparison, face recognition, etc. in different scenarios. The depth map adds depth information of the target object and can effectively deal with planar attack means. In this way, in the field of face recognition, there are generally two light sources, namely a structured light projector and an infrared fill light, on the imaging device, resulting in a high manufacturing cost and a relatively large volume of the imaging device, which is not conducive to the miniaturization design of the imaging device. Summary of the Invention

[0003] One of the purposes of the embodiments of this application is to provide a projection module, aiming to solve the technical problems in the prior art that using two light sources leads to high cost and large volume of the imaging device.

[0004] To solve the above technical problems, the technical solution adopted in the embodiments of this application is:

[0005] A projection module is provided, including:

[0006] A light source for projecting structured light;

[0007] A collimating mirror is arranged on the light-emitting side of the light source to collimate the structured light projected from the light source into parallel light;

[0008] A diffractive optical element is arranged on the light-emitting side of the collimating mirror; the diffractive optical element can be switched to a diffractive state and / or a diffusive state under the action of different voltages to diffract and / or scatter the parallel light projected from the collimating mirror.

[0009] In one embodiment, the diffractive optical element includes a first microstructure arranged on the light-emitting side of the collimating mirror, and a plurality of first grooves are arranged at intervals on the side of the first microstructure facing away from the collimating mirror; the material of the first microstructure is polymer dispersed liquid crystal, and the first microstructure can be switched to a transparent state and / or a diffusive state under the action of different voltages.

[0010] In one embodiment, the diffractive optical element further includes a transparent first substrate and a transparent second substrate. The first substrate and the second substrate are sequentially arranged along the light-emitting direction of the light source, and the first microstructures are sandwiched between the first substrate and the second substrate.

[0011] In one embodiment, the diffractive optical element includes a third substrate, a fourth substrate, and a transparent second microstructure. The third substrate and the fourth substrate are sequentially arranged along the light-emitting direction of the light source. The third substrate is disposed on the light-emitting side of the collimating mirror, and the second microstructures are sandwiched between the third substrate and the fourth substrate; on the side of the second microstructure facing away from the third substrate, there are a plurality of second grooves distributed at intervals;

[0012] The material of the third substrate is polymer-dispersed liquid crystal, and the third substrate can be switched between a transparent state and / or a diffused state under the action of different voltages; alternatively, the material of the fourth substrate is polymer-dispersed liquid crystal, and the fourth substrate can be switched between a transparent state and / or a diffused state under the action of different voltages.

[0013] In one embodiment, the diffractive optical element includes a main body portion and a diffusing portion; the main body portion is disposed on the light-emitting side of the collimating mirror to diffract the structured light projected from the collimating mirror; the diffusing portion is made of polymer-dispersed liquid crystal and is disposed on the main body portion; the diffusing portion can be switched between a transparent state and / or a diffused state under the action of different voltages.

[0014] In one embodiment, the main body portion includes a transparent third microstructure. The third microstructure is disposed on the light-emitting side of the collimating mirror. On the side of the third microstructure facing away from the collimating mirror, there are a plurality of third grooves distributed at intervals, and the diffusing portion is disposed inside the third microstructure or on one side of the third microstructure along the light-emitting direction of the light source.

[0015] In one embodiment, the main body portion further includes a transparent fifth substrate and a transparent sixth substrate. The fifth substrate and the sixth substrate are sequentially arranged along the light-emitting direction of the light source, and the third microstructure is sandwiched between the fifth substrate and the sixth substrate; the diffusing portion is disposed inside the fifth substrate, inside the sixth substrate, on one side of the fifth substrate along the light-emitting direction of the light source, or on one side of the sixth substrate along the light-emitting direction of the light source.

[0016] In one embodiment, the diffractive optical element includes a diffractive region that can be switched between a diffractive state and a diffused state under the action of different voltages;

[0017] Alternatively, the diffractive optical element is divided into multiple diffractive regions, and each diffractive region can be switched to a diffractive state or a diffusive state under the action of different voltages.

[0018] This embodiment also provides an imaging device, including an imaging module and the projection module, where the imaging module is configured to receive the light projected by the projection module to image a target object.

[0019] This embodiment also provides an electronic device, including an electronic device body and the imaging device, where the imaging device is disposed on the electronic device body.

[0020] The beneficial effects of the projection module, imaging device, and electronic device provided in the embodiments of the present application are as follows: Compared with the prior art, in the present application, the diffractive optical element can be switched to a diffractive state and / or a diffusive state under the action of different voltages. When the diffractive optical element is switched to the diffractive state, the collimating mirror collimates the structured light projected from the light source into parallel light, and this parallel light undergoes a diffraction reaction in the diffractive optical element in the diffractive state and is projected externally, so that the projection module projects structured light; when the diffractive optical element is switched to the diffusive state, the collimating mirror collimates the structured light projected from the light source into parallel light, and this parallel light undergoes a diffusion reaction in the diffractive optical element in the diffusive state and scatters to form omnidirectional infrared light, so that the projection module projects omnidirectional infrared light. At this time, the projection module acts as an infrared fill light. Therefore, the projection module provided in this embodiment only sets one light source, that is, it realizes the projection work of structured light and omnidirectional infrared light. In this way, the manufacturing cost of the projection module is saved, and at the same time, the volume of the projection module is reduced, which helps the miniaturized design of the imaging device. Correspondingly, the imaging device and electronic device provided in this embodiment also have the advantages of the projection module. Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0022] Figure 1 It is a schematic diagram of the projection module provided in the embodiment of the present application in the first working mode state;

[0023] Figure 2 It is a schematic diagram of the projection module provided in the embodiment of the present application in the second working mode state;

[0024] Figure 3 It is a schematic diagram of the diffractive optical element of the projection module provided in the first embodiment of the present application Figure 1;

[0025] Figure 4 Schematic diagram of the diffractive optical element of the projection module provided in the first embodiment of the present application Figure 2 ;

[0026] Figure 5 Schematic diagram of the diffractive optical element of the projection module provided in the second embodiment of the present application Figure 1 ;

[0027] Figure 6 Schematic diagram of the diffractive optical element of the projection module provided in the second embodiment of the present application Figure 2 ;

[0028] Figure 7 Schematic diagram of the diffractive optical element of the projection module provided in the third embodiment of the present application Figure 1 ;

[0029] Figure 8 Schematic diagram of the diffractive optical element of the projection module provided in the third embodiment of the present application Figure 2 ;

[0030] Figure 9 Schematic diagram of the body part of the diffractive optical element provided in the fourth embodiment of the present application.

[0031] Among them, each reference numeral in the figure:

[0032] 10 - Light source; 20 - Collimating mirror; 30 - Diffractive optical element; 31 - First microstructure; 311 - First polymer matrix; 3111 - First groove; 3112 - First convex part; 312 - First liquid crystal microdroplet; 32 - First substrate; 33 - Second substrate; 34 - Second microstructure; 341 - Second groove; 342 - Second convex part; 35 - Third substrate; 351 - Second polymer matrix; 352 - Second liquid crystal microdroplet; 36 - Fourth substrate; 361 - Third polymer matrix; 362 - Third liquid crystal microdroplet; 37 - Body part; 371 - Third microstructure; 3711 - Third groove; 3712 - Third convex part; 372 - Fifth substrate; 373 - Sixth substrate; 40 - Conductive film; 41 - First conductive film; 42 - Second conductive film; X - First direction. Detailed implementation manners

[0033] The embodiments of the present application will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where 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 intended to explain the present application, and should not be construed as limiting the present application.

[0034] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present application.

[0035] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically and clearly defined, and two or more includes two.

[0036] In the present application, unless otherwise clearly specified and limited, the terms "mounted", "connected", "connected to", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0037] The following is a detailed description in conjunction with specific drawings and embodiments:

[0038] Embodiment 1

[0039] Please refer to Figure 1 and Figure 2, the projection module provided by the embodiment of the present application includes a light source 10, a collimating mirror 20, and a diffractive optical element 30. The light source 10, the collimating mirror 20, and the diffractive optical element 30 are sequentially and spaced apart along a first direction X. Among them, the first direction X is the light-emitting direction of the light source 10, that is, the light-emitting direction of the collimating mirror 20 and the light-emitting direction of the diffractive optical element 30. It can be understood that the collimating mirror 20 is disposed on the light-emitting side of the light source 10, and the diffractive optical element 30 is disposed on the light-emitting side of the collimating mirror 20. It should be noted that the light source 10 is used to project structured light. Among them, the light source 10 can be set as a vertical cavity surface emitting laser (VCSEL), or can be set as a horizontal cavity surface emitting laser (HCSEL). The collimating mirror 20 is used to collimate the structured light projected by the light source 10 to collimate the structured light projected by the light source 10 into parallel light. During operation, the structured light projected by the light source 10 first passes through the collimating mirror 20, forms parallel light under the collimation of the collimating mirror 20, then projects onto the diffractive optical element 30, and finally projects from the diffractive optical element 30 onto an external target object.

[0040] The diffractive optical element 30 can be switched to a diffractive state and / or a diffusive state under the action of different voltages. It can be understood that under the action of different voltages, there are three cases of state switching of the diffractive optical element 30: the first case is that the diffractive optical element 30 is switched to a diffractive state to perform a diffractive action on the parallel light; the second case is that the diffractive optical element 30 is switched to a diffusive state to perform a scattering action on the parallel light; the third case is that a part of the diffractive optical element 30 is switched to a diffractive state and the other part is switched to a diffusive state, then the diffractive optical element 30 is simultaneously switched to a diffractive state and a diffusive state to perform a diffractive action on a part of the parallel light in a region and perform a diffusive action on another part of the parallel light.

[0041] It should be noted that a conductive film 40 is provided on the diffractive optical element 30. The conductive film 40 includes a first conductive film 41 and a second conductive film 42. The first conductive film 41 and the second conductive film 42 are sequentially distributed on the diffractive optical element 30 along the first direction X. Electrodes are provided on both the first conductive film 41 and the second conductive film 42. An external voltage device controls the voltages of the first conductive film 41 and the second conductive film 42 through the electrodes, so that the diffractive optical element 30 is under different voltages, and thus switches states under the action of different voltages, specifically switching to a diffractive state and / or a diffusive state. Among them, the conductive film 40 can be formed by using indium tin oxide, carbon nanotube conductive coating, silver nanowire, etc. The material of the conductive film 40 is not uniquely limited here.

[0042] Optionally, in this embodiment, when the conductive film 40 is energized and the voltages of the first conductive film 41 and the second conductive film 42 are at a preset value, the diffractive optical element 30 is switched to a diffractive state; when the conductive film 40 is not energized, the diffractive optical element 30 is switched to a diffusive state.

[0043] It should also be noted that, as Figure 1 shown, Figure 1 FIG. shows a schematic diagram of the projection module in working mode 1. At this time, the diffractive optical element 30 is in a diffractive state. The light source 10 projects structured light and projects it onto the collimating mirror 20; the collimating mirror 20 collimates the structured light projected by the light source 10 and collimates the structured light into parallel light, and then projects the parallel light onto the diffractive optical element 30 in the diffractive state; the diffractive optical element 30 diffracts the parallel light projected from the collimating mirror 20, specifically, performs diffractive beam expansion and replication on the parallel light, and finally projects the structured light after the beam expansion and replication onto an external target object. In this way, the projection module projects the structured light after collimation and diffraction onto the target object, which helps the external imaging module to identify the target object based on the structured light for imaging the target object, so as to obtain an infrared image with structural features, which helps to obtain a depth map subsequently.

[0044] It should also be noted that, as Figure 2 shown, Figure 2 FIG. shows a schematic diagram of the projection module in working mode 2. At this time, the diffractive optical element 30 is in a diffusive state. The structured light projected by the light source 10 is first projected onto the collimating mirror 20 to be collimated into parallel light under the collimation of the collimating mirror 20, and then projected onto the diffractive optical element 30 in the diffusive state with the parallel light. The diffractive optical element 30 performs a diffusive effect on the parallel light, causing the parallel light to scatter and form omnidirectional infrared light, and finally projects it onto an external target object. In this way, the projection module projects omnidirectional infrared light onto the target object at this time, which helps the external imaging module to identify the target object based on the omnidirectional infrared light for imaging the target object, so as to obtain a uniform infrared image; it can be understood that the projection module at this time can be regarded as an infrared fill light, which plays an infrared fill light role to enable the imaging module to obtain a uniform infrared image.

[0045] In the embodiments of the present application, the diffractive optical element 30 can be switched to a diffractive state and / or a diffusive state under the action of different voltages. When the diffractive optical element 30 is switched to the diffractive state, the collimating mirror 20 collimates the structured light projected from the light source 10 into parallel light, and this parallel light undergoes a diffraction reaction in the diffractive optical element 30 in the diffractive state and is projected externally, so that the projection module projects structured light; when the diffractive optical element 30 is switched to the diffusive state, the collimating mirror 20 collimates the structured light projected from the light source 10 into parallel light, and this parallel light undergoes a diffusion reaction in the diffractive optical element 30 in the diffusive state and scatters to form infrared floodlight, so that the projection module projects infrared floodlight. At this time, the projection module acts as an infrared fill light. Therefore, the projection module provided in this embodiment only sets one light source 10, that is, the projection work of structured light and infrared floodlight is realized. In this way, the manufacturing cost of the projection module is saved, and at the same time, the volume of the projection module is reduced, which is helpful for the miniaturized design of the imaging device.

[0046] In one embodiment, please refer to Figures 1 to 4 , the diffractive optical element 30 includes a first microstructure 31, the first microstructure 31 is arranged on the light-emitting side of the collimating mirror 20, and a plurality of first grooves 3111 distributed at intervals are arranged on the side of the first microstructure 31 facing away from the collimating mirror 20; the material of the first microstructure 31 is set as polymer dispersed liquid crystal, that is, the first microstructure 31 is made of the material of polymer dispersed liquid crystal.

[0047] Under the action of different voltages, the first microstructure 31 can be switched to a transparent state so that the first microstructure 31 is in the diffractive state; and / or, the first microstructure 31 is switched to the diffusive state. It can be understood that the first microstructure 31 is switched to the transparent state, or the first microstructure 31 is switched to the diffusive state, or a part of the first microstructure 31 is switched to the transparent state and the other part is switched to the diffusive state.

[0048] It should be noted that the first conductive film 41 and the second conductive film 42 are respectively arranged on the opposite sides of the first microstructure 31 along the first direction X. Both the first conductive film 41 and the second conductive film 42 are externally connected to a voltage device through electrodes. The external voltage device controls the voltage between the first conductive film 41 and the second conductive film 42 through the electrodes, so that the first microstructure 31 can be under different voltages. Then, the first microstructure 31 can be switched between a transparent state and / or a diffused state under the action of different voltages. Among them, when the first conductive film 41 and the second conductive film 42 are energized and the voltage is at a preset value, the state of the first microstructure 31 corresponding to the first conductive film 41 and the second conductive film 42 is switched to the transparent state. Based on the fact that there are a plurality of first grooves 3111 spaced apart from each other on the side of the first microstructure 31 facing away from the collimating mirror 20, the first microstructure 31 has a diffraction effect, that is, at this time the first microstructure 31 is in a diffraction state. When the first conductive film 41 and the second conductive film 42 are not energized, the first microstructure 31 corresponding to the first conductive film 41 and the second conductive film 42 is switched to the diffused state.

[0049] In a specific embodiment, the first microstructure 31 includes a first polymer matrix 311 and a plurality of first liquid crystal microdroplets 312. The plurality of first liquid crystal microdroplets 312 are dispersedly arranged on the first polymer matrix 311. When the first conductive film 41 and the second conductive film 42 are not energized, the optical axes of the first liquid crystal microdroplets 312 are in a free orientation, so the refractive index of the first liquid crystal microdroplets 312 is different from that of the first polymer matrix 311. At this time, the first microstructure 31 corresponding to the first conductive film 41 and the second conductive film 42 is in the diffused state. When the parallel light projected from the collimating mirror 20 passes through the first microstructure 31 in the diffused state, the parallel light is scattered on the first microstructure 31 to form infrared light, which is projected onto an external target object. When the first conductive film 41 and the second conductive film 42 are energized, the first liquid crystal microdroplets 312 change their optical axis orientations under the action of the voltage. When the voltage of the first conductive film 41 and the second conductive film 42 is at a preset value, the refractive index of the first liquid crystal microdroplets 312 changes and becomes the same as the refractive index of the first polymer matrix 311. Then, the first microstructure 31 corresponding to the first conductive film 41 and the second conductive film 42 is in the transparent state. Based on the design of the first grooves 3111, the first microstructure 31 is in the diffraction state at this time. When the parallel light projected from the collimating mirror 20 passes through the first microstructure 31 in the diffraction state, the parallel light is expanded and replicated on the first microstructure 31, and finally projected onto an external target object.

[0050] By adopting the above technical solution, the first microstructure 31 is made of a polymer-dispersed liquid crystal material, so that the first microstructure 31 can be switched to a diffractive state and / or a diffusive state respectively through its own structure. It can be understood that the first microstructure 31 integrates a diffractive function and a diffusive function, so that the projection module selectively projects structured light and / or pan-infrared light, without the need to additionally provide an optical element for scattering the structured light into pan-infrared light. In this way, the use of optical elements in the projection module is reduced, the manufacturing cost of the projection module is saved, and at the same time, the volume of the projection module is reduced, which helps to further realize the miniaturized design of the imaging device.

[0051] It should also be noted that a plurality of first grooves 3111 are provided on the side of the first microstructure 31 facing away from the collimating mirror 20, that is, a plurality of first grooves 3111 are provided on the light-emitting side of the first microstructure 31, and the plurality of first grooves 3111 are spaced apart on the light-emitting side of the first microstructure 31; correspondingly, a plurality of spaced-apart first protrusions 3112 are provided on the light-emitting side of the first microstructure 31, and the first protrusions 3112 and the first grooves 3111 are adjacently arranged, so that the light-emitting side of the first microstructure 31 has an uneven design. In this way, when the first microstructure 31 is in a transparent state, the distribution of the first protrusions 3112 and the first grooves 3111 on the light-emitting side of the first microstructure 31 makes the optical paths of different incident lights emitted from the light-emitting side of the first microstructure 31 different, and the phase of the incident light is modulated by changing the optical path difference of the incident light, so as to obtain the replicated and expanded structured light. Among them, the distribution mode of the first grooves 3111 and the first protrusions 3112 needs to be designed according to the required diffractive performance of the first microstructure 31, and can be regularly distributed or irregularly distributed, which is not uniquely limited here.

[0052] In a specific embodiment, the first conductive film 41 and the second conductive film 42 are sequentially distributed along the first direction X. Then, the first conductive film 41 is disposed on the side of the first microstructure 31 close to the collimating mirror 20 along the first direction X, and the second conductive film 42 is disposed on the side of the first microstructure 31 facing away from the collimating mirror 20 along the first direction X, that is, the second conductive film 42 is disposed on the first grooves 3111 and / or the first protrusions 3112 of the first microstructure 31. Optionally, the first conductive film 41 and the second conductive film 42 are respectively electroplated on opposite sides of the first microstructure 31 along the first direction X.

[0053] In one embodiment, please refer to Figure 3 and Figure 4, the diffractive optical element 30 further includes a first substrate 32 and a second substrate 33, both the first substrate 32 and the second substrate 33 are structures in a transparent state. The collimating mirror 20, the first substrate 32, and the second substrate 33 are sequentially distributed along the first direction X. The first microstructure 31 is sandwiched between the first substrate 32 and the second substrate 33, and the first substrate 32 is disposed on the light-emitting side of the collimating mirror 20; it can be understood that both the first convex portion 3112 and the first groove 3111 of the first microstructure 31 are disposed on the side of the first microstructure 31 close to the second substrate 33. It should be noted that the parallel light projected from the collimating mirror 20 sequentially passes through the first substrate 32, the first microstructure 31, and the second substrate 33, and then is projected onto an external target object; it should also be noted that the settings of the first substrate 32 and the second substrate 33 help to achieve the encapsulation and protection of the first microstructure 31 and ensure the performance of the first microstructure 31.

[0054] To facilitate the transmission of light through the first substrate 32 and the second substrate 33, both the first substrate 32 and the second substrate 33 are made of a material with high light transmittance, and optionally, the first substrate 32 and the second substrate 33 are made of alkaline earth borosilicate glass.

[0055] It should be noted that the first conductive film 41 and the second conductive film 42 are respectively disposed on opposite sides of the first microstructure 31 along the first direction X. Then, the first conductive film 41 is disposed between the first microstructure 31 and the first substrate 32, and the second conductive film 42 is disposed between the first microstructure 31 and the second substrate 33. In this way, the first microstructure 31, the first conductive film 41, and the second conductive film 42 are sandwiched between the first substrate 32 and the second substrate 33; wherein, the second conductive film 42 is disposed between the first convex portion 3112 and the second substrate 33, and / or the second conductive film 42 is disposed between the first groove 3111 and the second substrate 33.

[0056] In one embodiment, please refer to Figures 1 to 4 , the diffractive optical element 30 includes a diffractive region that can be switched to a diffractive state or a diffusive state under the action of different voltages; or, the diffractive optical element 30 is divided into multiple diffractive regions, the distribution plane of the multiple diffractive regions is perpendicular to the first direction X, and each diffractive region can be switched to a diffractive state or a diffusive state under the action of different voltages.

[0057] It should be noted that the diffractive optical element 30 includes a diffractive region. It can be understood that the entire diffractive optical element 30 is a diffractive region, and the entire diffractive optical element 30 is switched to a diffractive state or a diffusive state under the action of different voltages; optionally, the first microstructure 31 of the diffractive optical element 30 is used to switch states, then the first microstructure 31 includes a diffractive region, and the entire first microstructure 31 is a diffractive region. As Figure 3 shown,Figure 3 The schematic diagram shows that the first microstructure 31 has only one diffraction region; the first conductive film 41 and the second conductive film 42 are respectively arranged on opposite sides of the first microstructure 31 along the first direction X and are correspondingly arranged. Both the first conductive film 41 and the second conductive film 42 are set to be one. Then, the first groove 3111 provided in the first microstructure 31 and the second conductive film 42 provided on the first convex portion 3112 are continuously arranged to form a second conductive film 42. In this way, by adjusting the voltage between the first conductive film 41 and the second conductive film 42 through an external voltage device, the entire first microstructure 31 can be in different voltage states. Then, the first microstructure 31 can be switched to a diffraction state or a diffusion state at different voltages, so that the imaging device can obtain an infrared image with structural features or a uniform infrared image.

[0058] It should also be noted that the diffractive optical element 30 is divided into multiple diffraction regions. It can be understood that the diffractive optical element 30 is composed of multiple diffraction regions, and the distribution direction of the multiple diffraction regions is perpendicular to the first direction X. Then, each diffraction region can be switched to a diffraction state or a diffusion state under the action of different voltages. Optionally, the first microstructure 31 is used to switch states. Then, the first microstructure 31 is divided into multiple diffraction regions, that is, the first microstructure 31 is composed of multiple diffraction regions, and the distribution direction of the multiple diffraction regions is perpendicular to the first direction X, and each diffraction region of the first microstructure 31 can be switched to a diffraction state or a diffusion state under the action of different voltages. As Figure 4 shown, Figure 4 The schematic diagram shows that the first microstructure 31 is divided into multiple diffraction regions; the first conductive film 41 and the second conductive film 42 are respectively arranged on opposite sides of the first microstructure 31 along the first direction X. Both the first conductive film 41 and the second conductive film 42 are set to be multiple, and the multiple first conductive films 41 and the multiple second conductive films 42 are arranged in one-to-one correspondence along the first direction X. Then, there are multiple discontinuous first conductive films 41 provided on one side of the first microstructure 31, and multiple discontinuous second conductive films 42 provided on the other side of the first microstructure 31; moreover, both the first conductive film 41 and the second conductive film 42 are provided on opposite sides of each diffraction region along the first direction X, and one first conductive film 4 in and one second conductive film 42 are correspondingly arranged to adjust the voltage of the corresponding diffraction region under the control of an external voltage device. In this way, each diffraction region can be switched to a diffraction state or a diffusion state at different voltages. Among them, both the first conductive film 41 and the second conductive film 42 are provided on opposite sides of each diffraction region along the first direction X, and both the first conductive films 41 and the second conductive films 42 can be controlled by an external voltage device. Then, the external voltage device can control the voltage of each diffraction region separately through the first conductive film 41 and the second conductive film 42, so as to realize the adjustment of the state switching of each diffraction region separately.

[0059] It can be understood that according to the actual imaging requirements, if only the infrared image with structural features needs to be obtained, the voltage device adjusts the voltage between the plurality of first conductive films 41 and the second conductive films 42 to control the voltage of all diffraction regions of the first microstructure 31, so that all diffraction regions are switched to the diffraction state. Then, the parallel light passing through all diffraction regions, after undergoing diffraction replication and beam expansion reactions, is still projected onto the external target object in the form of structured light. In this way, when the imaging module images, it can obtain the infrared image with structural features of the target object based on this structured light; correspondingly, if only a uniform infrared image needs to be obtained, the voltage device can also adjust the voltage between the plurality of first conductive films 41 and the second conductive films 42 to control the voltage of all diffraction regions, so that all diffraction regions are switched to the diffusion state. Then, the parallel light passing through all diffraction regions, after undergoing scattering, is projected onto the external target object in the form of pan-infrared light. In this way, when the imaging module images, it can obtain the uniform infrared image of the target object based on this pan-infrared light.

[0060] It can also be understood that the voltage of the multiple diffraction regions of the first microstructure 31 can be individually controlled by an external voltage device through the first conductive films 41 and the second conductive films 42, so that each diffraction region can be switched to the diffraction state or the diffusion state under the action of different voltages. Then, the external voltage device can control the voltage between some of the first conductive films 41 and the second conductive films 42, so that a part of the diffraction regions of the first microstructure 31 are switched to the diffraction state, and another part of the diffraction regions of the first microstructure 31 are switched to the diffusion state. In this way, a part of the diffraction regions of the first microstructure 31 are in the diffraction state, and another part of the diffraction regions are in the diffusion state; when the parallel light projected from the collimator 20 passes through the diffractive optical element 30 and is projected onto the external target object, a part of the parallel light passes through the diffraction regions in the diffraction state and is projected onto the target object in the form of structured light, and another part of the parallel light passes through the diffraction regions in the diffusion state and undergoes a scattering effect, so as to be projected onto the external target object in the form of pan-infrared light. Therefore, the diffractive optical element 30 and a light source 10 cooperate, so that the projection module can project independent structured light and pan-infrared light at the same time. Then, when the external imaging module performs imaging work, the infrared image of the target object obtained by it has both the part of the infrared image with structural features and the part of the uniform infrared image. In this way, the imaging module can obtain two types of infrared images at one time based on the state of the target object under the illumination of structured light and pan-infrared light at the same time, increasing the types of infrared images collected by the algorithm and improving the security and anti-attack ability of recognition.

[0061] Embodiment 2

[0062] Please refer to Figure 1 、 Figure 2 、Figure 5 and Figure 6 The projection module of this embodiment is generally the same as that of the first embodiment, except for the specific structure of the diffractive optical element 30; the diffractive optical element 30 includes a third substrate 35, a fourth substrate 36, and a second microstructure 34. The collimating mirror 20, the third substrate 35, and the fourth substrate 36 are sequentially distributed along the first direction X. The third substrate 35 is disposed on the light-emitting side of the collimating mirror 20, and the second microstructure 34 is sandwiched between the third substrate 35 and the fourth substrate 36. Among them, the settings of the third substrate 35 and the fourth substrate 36 achieve the protection of the second microstructure 34; during operation, the parallel light projected from the collimating mirror 20 sequentially passes through the third substrate 35, the second microstructure 34, and the fourth substrate 36, and then is projected onto an external target object.

[0063] It should be noted that the structure of the second microstructure 34 is the same as that of the first microstructure 31 in the first embodiment, but the material of the second microstructure 34 is different from that of the first microstructure 31. The second microstructure 34 is not a structure made of polymer-dispersed liquid crystal, but a structure in a transparent state. Optionally, the second microstructure 34 is made of quartz or glass with a high transmittance. A plurality of second grooves 341 are provided on the side of the second microstructure 34 facing away from the third substrate 35, that is, a plurality of second grooves 341 are provided on the light-emitting side of the second microstructure 34, and the plurality of second grooves 341 are spaced apart; correspondingly, a plurality of second protrusions 342 are provided on the light-emitting side of the second microstructure 34 at intervals, and the second protrusions 342 and the second grooves 341 are adjacent to each other, and the light-emitting side of the second microstructure 34 has an uneven design. In this way, the distribution of the second grooves 341 and the second protrusions 342 on the light-emitting side of the second microstructure 34 makes the optical paths of different incident lights exiting from the light-emitting side of the second microstructure 34 different, and the phase of the incident light is modulated by changing the optical path difference of the incident light, so as to obtain the replicated and expanded outgoing light. In this way, the second microstructure 34 realizes the diffraction effect. Among them, the distribution manner of the second grooves 341 and the second protrusions 342 needs to be designed according to the required diffraction performance of the second microstructure 34, and can be regularly distributed or irregularly distributed, which is not uniquely limited here. Among them, both the second grooves 341 and the second protrusions 342 are provided on the side of the second microstructure 34 facing away from the third substrate 35.

[0064] It should also be noted that the structure of the third substrate 35 is the same as that of the first substrate 32 in the first embodiment, but the material of the third substrate 35 is different from that of the first substrate 32. The third substrate 35 is made of a polymer-dispersed liquid crystal material. Under the action of different voltages, the third substrate 35 can be switched to a transparent state, so that the diffractive optical element 30 is in a diffractive state; and / or, the third substrate 35 can be switched to a diffusive state, so that the diffractive optical element 30 is in a diffusive state. It can be understood that when the third substrate 35 is switched to a transparent state, the diffractive optical element 30 is in a diffractive state; or, when the third substrate 35 is switched to a diffusive state, the diffractive optical element 30 is in a diffusive state; or, a part of the third substrate 35 is switched to a transparent state and another part is switched to a diffusive state, so that a part of the diffractive optical element 30 is switched to a diffractive state and another part is switched to a diffusive state.

[0065] Among them, the structure of the fourth substrate 36 is the same as that of the second substrate 33 in the first embodiment, both of which are in a transparent state, and the material of the fourth substrate 36 is the same as that of the second substrate 33.

[0066] It should also be noted that the first conductive film 41 and the second conductive film 42 are respectively disposed on opposite sides of the third substrate 35 along the first direction X. Optionally, the first conductive film 41 and the second conductive film 42 are electroplated on opposite sides of the third substrate 35 along the first direction X. In this way, the first conductive film 41 is disposed on the side of the third substrate 35 along the first direction X close to the collimating mirror 20, and the second conductive film 42 is disposed between the third substrate 35 and the second microstructure 34.

[0067] It should also be noted that the third substrate 35 includes a second polymer matrix 351 and a plurality of second liquid crystal microdroplets 352, and the plurality of second liquid crystal microdroplets 352 are dispersedly arranged on the second polymer matrix 351. When the first conductive film 41 and the second conductive film 42 on the third substrate 35 are energized and the voltage is at a preset value, the refractive index of the second polymer matrix 351 is the same as that of the second liquid crystal microdroplets 352, so that the third substrate 35 corresponding to the first conductive film 41 and the second conductive film 42 is in a transparent state. The parallel light projected from the collimating mirror 20 passes through the third substrate 35 in the transparent state, and then undergoes the diffraction beam expansion and replication of the second microstructure 34, and finally passes through the transparent fourth substrate 36 to be projected onto an external target object in the form of structured light; at this time, the diffractive optical element 30 corresponding to the first conductive film 41 and the second conductive film 42 is in a diffractive state. When the first conductive film 41 and the second conductive film 42 on the third substrate 35 are not energized, the refractive index of the second polymer matrix 351 is different from that of the second liquid crystal microdroplets 352, so that the third substrate 35 corresponding to the first conductive film 41 and the second conductive film 42 is in a diffusive state. The parallel light projected from the collimating mirror 20 first passes through the third substrate 35 in the diffusive state and is scattered to form pan-infrared light under the diffusion of the third substrate 35, and then passes through the transparent second microstructure 34 and the fourth substrate 36 in sequence, and finally is projected onto an external target object; at this time, the diffractive optical element 30 corresponding to the first conductive film 41 and the second conductive film 42 is in a diffusive state; wherein, after the parallel light is scattered by the third substrate 35 to form pan-infrared light, the second microstructure 34 no longer diffracts the light emitted from the third substrate 35, that is, it does not perform a diffractive effect on the pan-infrared light.

[0068] By adopting the above technical solution, the third substrate 35 is made of a polymer-dispersed liquid crystal material, so that the third substrate 35 can be switched to a transparent state or a diffusive state respectively through its own structure, so as to correspondingly switch the diffractive optical element 30 to a diffractive state or a diffusive state, thereby enabling the projection module to selectively project structured light or pan-infrared light, without additionally setting an optical element for scattering structured light into pan-infrared light. In this way, the use of optical elements of the projection module is reduced, the manufacturing cost of the projection module is saved, and at the same time, the volume of the projection module is reduced, which helps to further realize the miniaturized design of the imaging device.

[0069] In one embodiment, the third substrate 35 includes a diffractive region or includes a plurality of diffractive regions.

[0070] Optionally, as Figure 5As shown, the third substrate 35 includes one of the above-mentioned diffraction regions. On both sides of the third substrate 35 along the first direction X, a first conductive film 41 and a second conductive film 42 are provided. Both the first conductive film 41 and the second conductive film 42 are set to one. By adjusting the voltage between the first conductive film 41 and the second conductive film 42 through an external voltage device, the entire third substrate 35 can be in different voltage states. Then, the third substrate 35 can be switched to a diffraction state or a diffusion state at different voltages, so that the imaging device can obtain an infrared image with structural features or a uniform infrared image.

[0071] Optionally, as Figure 6 shown, the third substrate 35 is divided into multiple above-mentioned diffraction regions. The first conductive film 41 and the second conductive film 42 are respectively arranged on opposite sides of the third substrate 35 along the first direction X. Both the first conductive film 41 and the second conductive film 42 are set to multiple. The multiple first conductive films 41 and the multiple second conductive films 42 are arranged in one-to-one correspondence. And on opposite sides of each diffraction region along the first direction X, there are both a first conductive film 41 and a second conductive film 42. In this way, by separately controlling the voltage between the first conductive film 41 and the second conductive film 42 on opposite sides of each diffraction region through an external voltage device, the diffraction region can be switched to a diffraction state or a diffusion state. In this way, the external voltage device can separately control the voltage between the first conductive film 41 and the second conductive film 42 on multiple diffraction regions, so that all the diffraction regions on the entire third substrate 35 are switched to a transparent state. In this way, the parallel light projected from the collimating mirror 20 undergoes diffraction replication and beam expansion reactions after passing through the third substrate 35, the second microstructure 34, and the fourth substrate 36 in sequence, and is projected onto an external target object. Then, the imaging module can obtain an infrared image with structural features based on this structured light. Or, all the diffraction regions on the third substrate 35 are switched to a diffusion state. The parallel light projected from the collimating mirror 20 undergoes a scattering reaction after passing through the third substrate 35, the second microstructure 34, and the fourth substrate 36 in sequence, and is projected onto an external target object in the form of uniform infrared light. Then, the imaging module can obtain a uniform infrared image based on this uniform infrared light. Or, some of the diffraction regions on the third substrate 35 are switched to a transparent state, and some other diffraction regions are switched to a diffusion state, so that some parts of the diffractive optical element 30 are switched to a diffraction state, and some other parts are switched to a diffusion state.

[0072] The remaining parts of this embodiment are the same as those of Embodiment 1. For the features not explained in this embodiment, the explanations of Embodiment 1 are adopted and will not be elaborated here.

[0073] Embodiment 3

[0074] Please refer to Figure 7 and Figure 8, this embodiment is basically the same as the second embodiment, with the only difference being that: the material of the third substrate 35 is different from that of the third substrate 35 in the second embodiment. The third substrate 35 in this embodiment is a structure in a transparent state, and optionally, the third substrate 35 is made of quartz or glass with a high transmittance; the material of the fourth substrate 36 is different from that of the second substrate 33, and the material of the fourth substrate 36 is polymer dispersed liquid crystal.

[0075] It can be understood that the first conductive film 41 and the second conductive film 42 are respectively disposed on opposite sides of the fourth substrate 36 along the first direction X. The external voltage device controls the voltages of the first conductive film 41 and the second conductive film 42, so that the fourth substrate 36 switches between a transparent state and / or a diffused state under the action of different voltages. Among them, the first conductive film 41 is disposed between the fourth substrate 36 and the second microstructure 34, and the second conductive film 42 is disposed on the side of the fourth substrate 36 away from the second microstructure 34. Optionally, the first conductive film 41 and the second conductive film 42 are electroplated on opposite sides of the fourth substrate 36 along the first direction X by electroplating. It can be understood that when the fourth substrate 36 switches to the lens state, the diffractive optical element 30 is in the diffractive state; or, when the fourth substrate 36 switches to the diffused state, the diffractive optical element 30 is in the diffused state; or, a part of the fourth substrate 36 switches to the transparent state and another part switches to the diffused state, so that a part of the diffractive optical element 30 switches to the diffractive state and another part switches to the diffused state.

[0076] It should be noted that the fourth substrate 36 includes a third polymer matrix 361 and a plurality of third liquid crystal droplets 362, and the plurality of third liquid crystal droplets 362 are dispersedly arranged on the third polymer matrix 361. When the first conductive film 41 and the second conductive film 42 are energized and the voltage is at a preset value, the refractive index of the third polymer matrix 361 is the same as that of the third liquid crystal droplets 362, so that the fourth substrate 36 corresponding to the first conductive film 41 and the second conductive film 42 is in a transparent state. The parallel light projected from the collimating mirror 20 passes through the transparent third substrate 35, and then undergoes the diffraction beam expansion and replication effects of the second microstructure 34, and finally passes through the transparent fourth substrate 36 and is projected onto an external target object in the form of structured light; at this time, the diffractive optical element 30 is in the diffractive state. When the first conductive film 41 and the second conductive film 42 are not energized, the refractive index of the third polymer matrix 361 is different from that of the third liquid crystal droplets 362, so the fourth substrate 36 corresponding to the first conductive film 41 and the second conductive film 42 is in a diffused state. The parallel light projected from the collimating mirror 20 first passes through the transparent third substrate 35, then passes through the second microstructure 34, and finally passes through the diffused fourth substrate 36, and is scattered to form pan-infrared light under the diffusion effect of the fourth substrate 36, and is finally projected onto an external target object; at this time, the diffractive optical element 30 is in the diffused state.

[0077] By adopting the above technical solution, the fourth substrate 36 is made of a polymer-dispersed liquid crystal material. Then, the fourth substrate 36 can be switched to a transparent state or a diffused state respectively through its own structure, so that the diffractive optical element 30 is switched to a diffractive state or a diffused state accordingly. There is no need to additionally provide an optical element for scattering structured light into pan-infrared light. In this way, the use of optical elements in the projection module is reduced, the manufacturing cost of the projection module is saved, and at the same time, the volume of the projection module is reduced, which helps to further realize the miniaturized design of the imaging device.

[0078] It should also be noted that in this embodiment, the fourth substrate 36 includes one diffractive region or multiple diffractive regions.

[0079] Optionally, as Figure 7 shown, if the fourth substrate 36 includes one of the above diffractive regions, then both the first conductive film 41 and the second conductive film 42 on the opposite sides of the fourth substrate 36 along the first direction X are provided as one. The external voltage device adjusts the voltage between the first conductive film 41 and the second conductive film 42, so that the fourth substrate 36 is switched to a transparent state or a diffused state under the action of different voltages, thereby enabling the imaging device to obtain an infrared image with structural features or a uniform infrared image.

[0080] Optionally, as Figure 8 shown, if the fourth substrate 36 includes multiple of the above diffractive regions, both the first conductive film 41 and the second conductive film 42 on the opposite sides of the fourth substrate 36 along the first direction X are provided as multiple. The multiple first conductive films 41 and the multiple second conductive films 42 are arranged in one-to-one correspondence, and both the first conductive film 41 and the second conductive film 42 are provided on the opposite sides of each diffractive region along the first direction X. In this way, the external voltage device can switch the diffractive region to a diffractive state or a diffused state by separately controlling the voltage between the first conductive film 41 and the second conductive film 42 on the opposite sides of each diffractive region. It can be understood that when an infrared image with structural features needs to be obtained, the external voltage device controls the voltages of all diffractive regions on the fourth substrate 36, so that all diffractive regions of the fourth substrate 36 are in a transparent state; when a uniform infrared image needs to be obtained, the external voltage device controls the voltages of all diffractive regions on the fourth substrate 36, so that all diffractive regions of the fourth substrate 36 are in a diffused state; the external voltage device can also control some diffractive regions to be switched to a transparent state and another part of the diffractive regions to be switched to a diffused state, so as to obtain an infrared image that has both an infrared image with structural features and a uniform infrared image, increasing the types of infrared images.

[0081] The remaining part of this embodiment is the same as that of Embodiment 2. For the features not explained in this embodiment, the explanations of Embodiment 2 are adopted and will not be elaborated here.

[0082] Example 4

[0083] Please refer to Figure 1 、 Figure 2 and Figure 9 together. The differences between this example and Example 1, Example 2, and Example 3 lie in the specific structure of the diffractive optical element 30.

[0084] The diffractive optical element 30 in this example includes a body portion 37 and a diffusion portion (not shown in the figure). The body portion 37 is disposed on the light-emitting side of the collimating mirror 20, and the body portion 37 is the structure of the diffractive optical element 30 for diffracting light; the body portion 37 is in a transparent state. The diffusion portion is a polymer-dispersed liquid crystal, and the diffusion portion is disposed on the body portion 37; under the action of different voltages, the diffusion portion can be switched between a transparent state and / or a diffused state.

[0085] It should be noted that the body portion 37 is used for diffraction. The diffusion portion is used to switch between a transparent state and / or a diffused state under the action of different voltages; it can be understood that the first conductive film 41 and the second conductive film 42 of the conductive film 40 are respectively disposed on opposite sides of the diffusion portion along the first direction X, and an external pressurizing device controls the voltages of the first conductive film 41 and the second conductive film 42, so that the diffusion portion is switched between a transparent state and / or a diffused state under the action of different voltages. Among them, when the diffusion portion is switched to the transparent state, the diffractive optical element 30 is in a diffractive state; or, when the diffusion portion is switched to the diffused state, the diffractive optical element 30 is in a diffused state; or, a part of the diffusion portion is switched to the transparent state, and another part is switched to the diffused state, so that a part of the diffractive optical element 30 is switched to the diffractive state, and another part is switched to the diffused state. When the first conductive film 41 and the second conductive film 42 are energized and the voltage is at a preset value, the diffusion portion corresponding to the first conductive film 41 and the second conductive film 42 is switched to the transparent state, and then the parallel light projected from the collimating mirror 20 passes through the diffusion portion and the body portion 37 in the transparent state, is diffracted and expanded, replicated, and then projected onto an external target object in the form of structured light; at this time, the diffractive optical element 30 is in a diffractive state. When the first conductive film 41 and the second conductive film 42 are not energized, the diffusion portion corresponding to the first conductive film 41 and the second conductive film 42 is switched to the diffused state, and then the parallel light projected from the collimating mirror 20 is scattered to form infrared light when passing through the diffusion portion in the diffused state, and finally projected onto an external target object; at this time, the diffractive optical element 30 is in a diffused state.

[0086] Wherein, the diffusion part is a polymer dispersed liquid crystal, and the diffusion part includes a polymer matrix and a plurality of liquid crystal droplets dispersedly arranged on the polymer matrix; under the action of different voltages, by adjusting the refractive index of the liquid crystal droplets in the diffusion part, the diffusion part is switched to a transparent state and / or a diffusion state.

[0087] By adopting the above technical solution, the diffractive optical element 30 can be switched to a diffusion state or a diffractive state, so that only one light source 10 is provided in the projection module, and the projection of structured light and pan-infrared light can be realized. In this way, the manufacturing cost of the projection module is saved, and at the same time, the volume of the projection module is reduced, which helps the miniaturized design of the imaging device.

[0088] In one embodiment, please refer to Figure 9 , the body part 37 includes a third microstructure 371, and the third microstructure 371 is arranged on the light-emitting side of the collimating mirror 20.

[0089] A plurality of third grooves 3711 are provided on the side of the third microstructure 371 facing away from the collimating mirror 20, that is, a plurality of third grooves 3711 are provided on the light-emitting side of the third microstructure 371, and the plurality of third grooves 3711 are spaced apart; correspondingly, a plurality of third convex portions 3712 are provided on the light-emitting side of the third microstructure 371, and the third convex portions 3712 and the third grooves 3711 are adjacent to each other, so that the light-emitting side of the third microstructure 371 is designed to be uneven; in this way, by changing the optical path difference of the incident light, the phase of the incident light is modulated, and the diffractive beam expansion and replication of the incident light are realized, so the third microstructure 371 is used for diffractive action. Among them, the structure of the third microstructure 371 is the same as that of the first microstructure 31 and the second microstructure 34 in the above embodiments, the difference is that: the third microstructure 371 is a structure in a transparent state and is used for diffractive action.

[0090] The diffusion part is arranged inside the third microstructure 371; or, the diffusion part is arranged on one side of the third microstructure 371 along the first direction X. Since the diffusion part can be switched to a transparent state or a diffusion state, in this way, the parallel light emitted from the collimating mirror 20 can pass through the diffusion part in the transparent state or the diffusion part in the diffusion state.

[0091] By adopting the above technical solution, the diffusion part is integrated inside the third microstructure 371 or disposed on one side of the third microstructure 371, and the diffusion part can be switched between a transparent state and / or a diffused state under the action of different voltages, so that the diffractive optical element 30 can be switched between a diffractive state and / or a diffused state when the diffusion part switches states; moreover, the diffusion part is integrated inside the third microstructure 371, which improves the integration degree of the third microstructure 371 and the diffusion part and helps to further reduce the volume of the projection module; the diffusion part is disposed on one side of the third microstructure 371, which helps to simplify the bonding process of the third microstructure 371 and the diffusion part.

[0092] In one embodiment, please refer to Figure 9 , the body part 37 further includes a fifth substrate 372 and a sixth substrate 373. The collimating mirror 20, the fifth substrate 372, and the sixth substrate 373 are sequentially distributed along the first direction X. The fifth substrate 372 is disposed on the light-emitting side of the collimating mirror 20, and the third microstructure 371 is clamped between the fifth substrate 372 and the sixth substrate 373. During operation, the parallel light projected from the collimating mirror 20 sequentially passes through the fifth substrate 372, the third microstructure 371, and the sixth substrate 373, and then is projected onto an external target object. Among them, the fifth substrate 372 has the same structure as the first substrate 32 and the third substrate 35 in the above embodiment, and the sixth substrate 373 has the same structure as the second substrate 33 and the fourth substrate 36 in the above embodiment. The only difference is that both the fifth substrate 372 and the sixth substrate 373 are structures in a transparent state, that is, the entire body part 37 of the diffractive optical element 30 is a structure in a transparent state, and the overall material of the body part 37 is not polymer dispersed liquid crystal.

[0093] It should be noted that the arrangement of the fifth substrate 372 and the sixth substrate 373 realizes the protection of the third microstructure 371.

[0094] It should also be noted that the diffusion part is disposed inside the fifth substrate 372, or the diffusion part is disposed inside the sixth substrate 373, or the diffusion part is disposed on one side of the fifth substrate 372 along the first direction X, or the diffusion part is disposed on one side of the sixth substrate 373 along the first direction X. By adopting the above technical solution, the diffusion part can be disposed inside the fifth substrate 372, on one side of the fifth substrate 372, inside the sixth substrate 373, or on one side of the sixth substrate 373, which improves the flexibility of the arrangement of the diffusion part and helps to realize the switching of the diffractive optical element 30 between the diffractive state and the diffused state.

[0095] In one embodiment, the diffusion part has one of the above diffraction regions. The first conductive film 41 and the second conductive film 42 on the opposite sides of the main body part 37 in the first direction X are both provided with one. The external voltage device adjusts the voltage between the first conductive film 41 and the second conductive film 42, so that the diffusion part is switched to a transparent state and / or a diffusion state under the action of different voltages, thereby enabling the imaging device to obtain an infrared image with structural features or a uniform infrared image.

[0096] Optionally, the diffusion part is divided into a plurality of the above diffraction regions. The first conductive film 41 and the second conductive film 42 are respectively arranged on the opposite sides of the diffusion part in the first direction X, and both the opposite sides of each diffraction region in the first direction X are provided with the first conductive film 41 and the second conductive film 42. In this way, the external voltage device controls the voltage between the first conductive film 41 and the second conductive film 42 on the opposite sides of each diffraction region separately, so that each diffraction region is switched to a diffraction state or a diffusion state.

[0097] The remaining parts of this embodiment are the same as those of the first embodiment. For the features not explained in this embodiment, the explanations of the first embodiment are adopted and will not be elaborated here.

[0098] Embodiment Five

[0099] Please refer to Figure 1 and Figure 2 , this embodiment provides an imaging device, which includes an imaging module and a projection module. The projection module is used to project structured light and / or pan-infrared light onto an external target object. The imaging module receives the structured light and / or pan-infrared light projected by the projection module onto the target object to identify the target object through the structured light and / or pan-infrared light projected by the projection module, so as to image the target object. It should be noted that the infrared image of the target object obtained by the imaging module based on the structured light and / or pan-infrared light projected by the projection module is an infrared image with structural features, or a uniform infrared image, or a region with an infrared image with structural features and also a region with a uniform infrared image.

[0100] Among them, the imaging module includes an infrared camera and a color camera. The infrared camera can obtain an infrared image with structural features based on the structured light and can obtain a uniform infrared image based on the pan-infrared light, and the color camera is used to obtain a color image. Therefore, the imaging device provided in this embodiment has the functions of obtaining the depth map, uniform infrared image and color image of the target object, and can be applied to the face-swiping field to effectively cope with planar attack means.

[0101] By adopting the above technical solution, the projection module only sets one light source 10, which realizes the projection of structured light and general infrared light. In this way, the manufacturing cost of the projection module is saved, and at the same time, the volume of the projection module is reduced, which helps the miniaturization design of the imaging device.

[0102] The rest of this embodiment is the same as that of the first, second, third or fourth embodiment. For the features not explained in this embodiment, the explanations of the first, second, third or fourth embodiment are adopted and will not be elaborated here.

[0103] Embodiment Six

[0104] Please refer to Figure 1 and Figure 2 , this embodiment provides an electronic device, including an electronic device body and an imaging device, and the imaging device is arranged on the electronic device body.

[0105] By adopting the above technical solution, the projection module only sets one light source 10, which realizes the projection of structured light and general infrared light. In this way, the manufacturing cost of the projection module is saved, and at the same time, the volume of the projection module is reduced, which helps the miniaturization design of the imaging device, and thus helps the miniaturization design of the electronic device.

[0106] It should be noted that through the concept of the above embodiments, the electronic device provided in this embodiment has the functions of obtaining the depth map, uniform infrared map and color map of the target object, and can be applied to the face recognition field to effectively cope with planar attack means; among them, the electronic device body provided in this embodiment can be, but is not limited to, terminals such as mobile phones, tablets or laptop computers.

[0107] The rest of this embodiment is the same as that of the first, second, third, fourth or fifth embodiment. For the features not explained in this embodiment, the explanations of the first, second, third, fourth or fifth embodiment are adopted and will not be elaborated here.

[0108] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A projection module, characterized in that, Comprising: A light source for projecting structured light; A collimating mirror disposed on the light-emitting side of the light source to collimate the structured light projected from the light source into parallel light; A diffractive optical element disposed on the light-emitting side of the collimating mirror; The diffractive optical element is divided into a plurality of diffractive regions, and each diffractive region can be individually switched to a diffractive state or a diffusive state under the action of different voltages to diffract or scatter the parallel light projected from the collimating mirror, so that the projection module can project independent structured light and infrared light simultaneously.

2. The projection module according to claim 1, wherein The diffractive optical element includes a first microstructure disposed on the light-emitting side of the collimating mirror, and a plurality of first grooves are provided at intervals on the side of the first microstructure facing away from the collimating mirror; the material of the first microstructure is polymer dispersed liquid crystal, and the first microstructure can be switched to a transparent state and / or a diffusive state under the action of different voltages.

3. The projection module according to claim 2, wherein The diffractive optical element further includes a transparent first substrate and a transparent second substrate, and the first substrate and the second substrate are sequentially distributed along the light-emitting direction of the light source, and the first microstructure is sandwiched between the first substrate and the second substrate.

4. The projection module according to claim 1, wherein The diffractive optical element includes a third substrate, a fourth substrate, and a transparent second microstructure. The third substrate and the fourth substrate are sequentially distributed along the light-emitting direction of the light source. The third substrate is disposed on the light-emitting side of the collimating mirror, and the second microstructure is sandwiched between the third substrate and the fourth substrate; a plurality of second grooves are provided at intervals on the side of the second microstructure facing away from the third substrate; The material of the third substrate is polymer dispersed liquid crystal, and the third substrate can be switched to a transparent state and / or a diffusive state under the action of different voltages; Alternatively, the material of the fourth substrate is polymer dispersed liquid crystal, and the fourth substrate can be switched to a transparent state and / or a diffusive state under the action of different voltages.

5. The projection module according to claim 1, characterized in that, The diffractive optical element includes a main body portion and a diffusive portion; the main body portion is disposed on the light-emitting side of the collimating mirror to diffract the structured light projected from the collimating mirror; the diffusive portion is polymer dispersed liquid crystal and is disposed on the main body portion; the diffusive portion can be switched to a transparent state and / or a diffusive state under the action of different voltages.

6. The projection module according to claim 5, wherein, The main body portion includes a transparent third microstructure disposed on the light-emitting side of the collimating mirror, and a plurality of third grooves are provided at intervals on the side of the third microstructure facing away from the collimating mirror, and the diffusive portion is disposed inside the third microstructure or on one side of the third microstructure along the light-emitting direction of the light source.

7. The projection module according to claim 6, wherein, The main body portion further includes a transparent fifth substrate and a transparent sixth substrate, and the fifth substrate and the sixth substrate are sequentially distributed along the light-emitting direction of the light source, and the third microstructure is sandwiched between the fifth substrate and the sixth substrate; the diffusive portion is disposed inside the fifth substrate, inside the sixth substrate, on one side of the fifth substrate along the light-emitting direction of the light source, or on one side of the sixth substrate along the light-emitting direction of the light source.

8. An imaging device, comprising an imaging module, characterized in that, It further includes a projection module as described in any one of claims 1-7, and the imaging module is configured to receive the light projected by the projection module to image a target object.

9. An electronic device, comprising an electronic device body, characterized in that, It further includes an imaging device as described in claim 8, and the imaging device is disposed on the electronic device body.

Images