1. A three-dimensional imaging module, comprising:

the projection module comprises a light source and a diffusion sheet; the light source is used for emitting structured light with a polarization direction; the diffusion sheet is arranged on the light-emitting side of the light source and can be switched into a transparent state and/or a scattering state for scattering the structured light into uniform infrared light;

the receiving module comprises an infrared chip and a first polaroid; the infrared chips and the light source are distributed at intervals; the first polaroid is arranged on the light incident side of the infrared chip, and the polarization direction of the first polaroid is consistent with the polarization direction of the structured light emitted by the light source.

2. The three-dimensional imaging module of claim 1, wherein the light source comprises a vertical cavity surface emitting laser and a second polarizer; the vertical cavity surface emitting lasers and the infrared chip are distributed at intervals; the second polaroid is arranged between the vertical cavity surface emitting laser and the diffusion sheet, and the polarization directions of the second polaroid and the first polaroid are consistent.

3. The three-dimensional imaging module of claim 1, wherein the light source is a horizontal cavity surface emitting laser.

4. The three-dimensional imaging module of claim 1, wherein the diffuser has a plurality of diffusing regions, each of the diffusing regions being switchable between a transparent state and a scattering state.

5. The three-dimensional imaging module according to claim 4, wherein the plurality of diffusion regions are distributed in a matrix; alternatively, the plurality of diffusion regions are sequentially arranged circumferentially.

6. The three-dimensional imaging module according to any one of claims 1 to 5, wherein the diffuser comprises two conductive films and a diffuser disposed between the two conductive films, the conductive films are transparent and disposed on the light-emitting side of the light source; the conductive film is used for being externally connected with voltage so that the diffuser can be switched under the action of different voltages.

7. The three-dimensional imaging module of claim 6, wherein the diffuser is suspended particles or polymer dispersed liquid crystal.

8. The three-dimensional imaging module of claim 6, wherein the diffuser further comprises two transparent substrates, and wherein the conductive films are disposed between the two transparent substrates.

9. The three-dimensional imaging module according to any one of claims 1-5, wherein the projection module further comprises a diffractive optical element and a collimating lens, the collimating lens is disposed between the light source and the diffuser, and the diffractive optical element is disposed on the light exit side of the diffuser or between the collimating lens and the diffuser; or, the projection module further comprises a diffractive optical element, the diffractive optical element is arranged between the light source and the diffusion sheet, and the diffractive optical element can collimate the structured light.

10. The three-dimensional imaging module according to any of claims 1-5, wherein the receiving module further comprises an imaging lens and a filter both disposed between the infrared chip and the first polarizer; the imaging lens is arranged between the optical filter and the infrared chip, or the imaging lens is arranged between the optical filter and the first polaroid.

Background

The three-dimensional imaging module is mainly used for acquiring three-dimensional imaging information of an imaging target, so that the three-dimensional imaging module is widely applied to industrial measurement and face recognition work, and the living standard of people is greatly improved.

Currently, the three-dimensional imaging modules on the market generally have the following defects:

1. three-dimensional imaging modules typically include a structured light projector, an infrared illuminator, an infrared receiving module, and a color camera. The infrared receiving module is used for receiving the structured light projected by the structured light projector to obtain an infrared image with structural characteristics, and the infrared image with the structural characteristics can obtain a depth image after passing through an algorithm; the infrared receiving module is also used for receiving the uniform infrared light projected by the infrared illuminator so as to obtain a uniform infrared image; a color camera acquires a color image; therefore, the three-dimensional imaging module can respectively obtain an infrared image with structural characteristics, a uniform infrared image and a color image in work, and is applied to face recognition work in the field of face recognition. However, in order to make the three-dimensional imaging module be applicable to the face recognition field, the three-dimensional imaging module needs to be provided with two light sources, namely a structured light projector and an infrared irradiator, so that the manufacturing cost is high, and the volume of the three-dimensional imaging module is relatively large, which is not beneficial to the miniaturization design of the three-dimensional imaging module.

2. The limit of luminous power of limited to structured light projector and infrared light projector, the luminous intensity homogeneous phase of the structured light that the structured light projector launched and the even infrared light that the infrared light projector launched is relatively more weak, and, infrared receiving module receives the interference of ambient light easily when the formation of image, especially under the stronger condition of ambient light, make infrared receiving module be difficult to follow the target object that the structured light and/or even infrared light throwed in the ambient light, the formation of image effect of three-dimensional formation of image module has been influenced, thereby influence the precision of depth map.

Disclosure of Invention

One of the purposes of the embodiment of the application is as follows: the utility model provides a three-dimensional imaging module, aims at solving prior art, adopts two light sources to lead to three-dimensional imaging module with high costs, bulky, and infrared receiving module is difficult to discern the technical problem of target object under the stronger condition of ambient light.

In order to solve the technical problem, the embodiment of the application adopts the following technical scheme:

provided is a three-dimensional imaging module, including:

the projection module comprises a light source and a diffusion sheet; the light source is used for emitting structured light with a polarization direction; the diffusion sheet is arranged on the light-emitting side of the light source and can be switched into a transparent state and/or a scattering state for scattering the structured light into uniform infrared light;

the receiving module comprises an infrared chip and a first polaroid; the infrared chips and the light source are distributed at intervals; the first polaroid is arranged on the light incident side of the infrared chip, and the polarization direction of the first polaroid is consistent with the polarization direction of the structured light emitted by the light source.

The beneficial effect of the three-dimensional imaging module that this application embodiment provided lies in: compared with the prior art, in this application, on the one hand, the diffusion piece is located the light-emitting side of light source, and can switch into transparent state and/or scattering state, then the structured light of light source transmission is under the effect of diffusion piece, can throw to the target object with the form of structured light and/or the form of even infrared light at last, thereby make receiving module group receiving structure light and/or even infrared light, in order to obtain the infrared picture and/or the even infrared picture of band structure characteristic, thus, the module of throwing has only set up a light source, can realize the throwing of structured light and even infrared light, thus, the cost of manufacture of the module of throwing has been saved, the volume of the module of throwing has also been reduced simultaneously, help the miniaturized design of three-dimensional imaging module. On the other hand, the light source is used for emitting the structured light with the polarization direction, so that the structured light and/or the uniform infrared light projected by the projection module are both in the polarization direction; the income light side of infrared chip is located to first polaroid, and the polarization direction of first polaroid and the polarization direction of the structure light of light source transmission are unanimous, that is, the polarization direction of first polaroid is unanimous with the polarization direction of the structure light and/or the even infrared light that the module throws out, therefore, make first polaroid filter most ambient light, the influence of ambient light to infrared chip has been reduced, guarantee that infrared chip can accurately discern the target object, thereby obtain the accuracy, the infrared picture and/or the even infrared picture of complete band structure characteristic, thereby improve three-dimensional imaging module's formation of image effect and degree of accuracy.

In one embodiment, the light source includes a vertical cavity surface emitting laser and a second polarizer; the vertical cavity surface emitting lasers and the infrared chip are distributed at intervals; the second polaroid is arranged between the vertical cavity surface emitting laser and the diffusion sheet, and the polarization directions of the second polaroid and the first polaroid are consistent.

By adopting the technical scheme, the first polaroid and the second polaroid are arranged, so that the interference of ambient light on the infrared chip can be greatly reduced by the projection module only by adopting a common vertical cavity surface emitting laser, the infrared chip can accurately and completely identify a target object, and the imaging effect and accuracy of the three-dimensional imaging module are improved.

In one embodiment, the light source is a horizontal cavity surface emitting laser.

By adopting the technical scheme, the interference of the ambient light to the infrared chip is greatly reduced, so that the infrared chip can more accurately and completely identify the target object, the cost and the volume of the projection module are saved, and the improvement of the diffraction uniformity and the efficiency of the diffraction optical element is facilitated after the diffraction optical element is subsequently designed.

In one embodiment, the diffusion sheet has a plurality of diffusion regions, each of which is switchable to a transparent state or a scattering state.

By adopting the technical scheme, the diffusion sheet is provided with the plurality of diffusion areas, and the diffusion sheet is matched with the light source, so that the infrared light projected from the diffusion sheet at the same time comprises the areas of the structured light and the uniform infrared light, the states of the same target object under different illumination can be obtained, namely the infrared image and the uniform infrared image of the same target object with the structural characteristics are obtained, the types of the infrared images acquired by the algorithm are increased, and the safety and the attack resistance of face recognition are improved.

In one embodiment, a plurality of the diffusion regions are distributed in a matrix; alternatively, the plurality of diffusion regions are sequentially arranged circumferentially.

Through adopting above-mentioned technical scheme for a plurality of diffusion regions of diffusion piece can be the matrix distribution or establish to the periphery ring in proper order according to the demand of reality, and the homoenergetic makes infrared picture that the infrared chip acquireed have the infrared picture of taking the structure characteristic simultaneously and even infrared picture, so, help diffusing the flexibility that sets up of piece, also guaranteed the degree of accuracy of the imaging operation of three-dimensional imaging module simultaneously.

In one embodiment, the diffusion sheet comprises two conductive films and a diffuser arranged between the two conductive films, wherein the conductive films are transparent and are arranged on the light emitting side of the light source; the conductive film is used for being externally connected with voltage so that the diffuser can be switched under the action of different voltages.

By adopting the technical scheme, the state of the diffuser is switched under the action of voltage, so that the state switching of the whole diffusion sheet is realized, the operation of switching the state of the diffusion sheet is very simple, and the cost is lower.

In one embodiment, the diffuser is a suspended particle or polymer dispersed liquid crystal.

By adopting the technical scheme, the light transmittance of the suspended particles or the polymer dispersed liquid crystal can be adjusted under the action of voltage, and the integral state switching of the diffuser and the conductive film is realized. And suspension particles or polymer dispersed liquid crystal are common and easy to obtain, which is beneficial to simplifying the manufacturing process of the diffusion sheet.

In one embodiment, the diffusion sheet further comprises two transparent substrates, and the two conductive films are arranged between the two transparent substrates.

By adopting the technical scheme, the two conductive films and the diffuser are arranged between the two transparent substrates, so that the conductive films and the diffuser are favorably packaged and protected, and the state switching operation of the diffuser is ensured.

In one embodiment, the projection module further comprises a diffractive optical element and a collimating lens, the collimating lens is arranged between the light source and the diffusion sheet, and the diffractive optical element is arranged on the light-emitting side of the diffusion sheet or between the collimating lens and the diffusion sheet; or, the projection module further comprises a diffractive optical element, the diffractive optical element is arranged between the light source and the diffusion sheet, and the diffractive optical element can collimate the structured light.

Through adopting above-mentioned technical scheme for the structure light that throws the module and throws again to outside target object after all through collimation and diffraction, also guarantee the diffraction and the collimation of throwing the module promptly, make structure light and/or even infrared light can throw to outside target object more accurately on.

In one embodiment, the receiving module further comprises an imaging lens and an optical filter which are both arranged between the infrared chip and the first polarizer; the imaging lens is arranged between the optical filter and the infrared chip, or the imaging lens is arranged between the optical filter and the first polaroid.

By adopting the technical scheme, the structured light and/or the uniform infrared light reflected from the target object are/is required to be collimated and focused by the imaging lens, so that the structured light and/or the uniform infrared light can be received by the infrared chip to the maximum extent; moreover, the optical filter can also filter out ambient light, so that the interference of the ambient light to the infrared chip is prevented, and the identification accuracy and the imaging effect of the infrared chip to a target object are ensured.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

Fig. 1 is a schematic view of a three-dimensional imaging module according to an embodiment of the present disclosure;

FIG. 2 is a schematic view of a projection module of the three-dimensional imaging module of FIG. 1;

FIG. 3 is a schematic diagram of a receiving module of the three-dimensional imaging module of FIG. 1;

FIG. 4 is a schematic view of a light source of the projection module of FIG. 2;

FIG. 5 is a schematic view of a conductive film of one embodiment of the projection module of FIG. 2;

FIG. 6 is an imaging result of the receiving module of FIG. 3;

FIG. 7 is a schematic view of a conductive film of another embodiment of the projection module of FIG. 2;

FIG. 8 is a schematic view of a diffuser plate of the projection module of FIG. 2.

Wherein, in the figures, the respective reference numerals:

10-a main board; 20-a projection module; 21-a light source; 211-vertical cavity surface emitting laser; 212-a second polarizer; 22-a diffusion sheet; 221-a conductive film; 221 a-conductive region; 222-a diffuser; 223-an electrode; 224-a transparent substrate; 225-fixing glue; 23-a diffractive optical element; 24-a collimating lens; 30-a receiving module; 31-an infrared chip; 32-a first polarizer; 33-an imaging lens; 34-an optical filter; 35-a second circuit board; 40-color camera.

Detailed Description

Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present application and should not be construed as limiting the present application.

In the description of the present application, it is to be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, as used herein, refer to an orientation or positional relationship indicated in the drawings, which is for convenience and simplicity of description, and does not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and thus, is not to be considered as limiting.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise, wherein two or more includes two.

In this application, unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can include, for example, fixed connections, removable connections, or integral parts; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

The following detailed description is made with reference to the accompanying drawings and examples:

example one

Referring to fig. 1 to 3, the three-dimensional imaging module according to the embodiment of the present disclosure includes a projection module 20 and a receiving module 30 that are disposed at an interval. In this embodiment, the three-dimensional imaging module further includes a main board 10, and the projection module 20 and the receiving module 30 are disposed on the main board 10 at intervals; of course, in other embodiments, the three-dimensional imaging module may not be provided with the main board 10, and both the projection module 20 and the receiving module 30 are directly electrically connected to an external control device.

The projection module 20 includes a light source 21 and a diffusion sheet 22. The light source 21 is arranged on the mainboard 10 and electrically connected to the mainboard 10; wherein the light source 21 is configured to emit structured light with a polarization direction. Diffusion sheet 22 is provided on the light exit side of light source 21, and at least a part of diffusion sheet 22 can be switched to a transparent state or a scattering state, so that diffusion sheet 22 can be switched to a transparent state and/or a scattering state as a whole. The receiving module 30 includes an infrared chip 31 and a first polarizer 32, the infrared chip 31 is disposed on the motherboard 10 and electrically connected to the motherboard 10, and the infrared chip 31 and the light source 21 are distributed at intervals; the first polarizer 32 is disposed on the light incident side of the infrared chip 31. It will be appreciated that, in operation, structured light with a polarization direction emitted from the light source 21 first passes through the diffuser 22 to be projected from the diffuser 22 to an external target object, and then is reflected at the target object to be received by the infrared chip 31 after passing through the first polarizer 32, so that the infrared chip 31 performs an imaging operation.

Here, diffusion sheet 22 can be switched between a transparent state and/or a scattering state, and it is understood that diffusion sheet 22 can be switched between a transparent state, a scattering state, or both a transparent state and a scattering state. When the diffusion sheet 22 is switched to the transparent state, the structured light emitted by the light source 21 is still projected to an external target object in the form of structured light under the action of the diffusion sheet 22 in the transparent state, the structured light is reflected on the target object and passes through the first polarizer 32 to be received by the infrared chip 31, and at this time, the infrared chip 31 obtains an infrared image of a band structure characteristic of the target object based on the structured light, and the infrared image of the band structure characteristic can obtain a depth map after calculation; when the diffusion sheet 22 is switched to the scattering state, the structured light emitted by the light source 21 is scattered under the action of the diffusion sheet 22 in the scattering state and is projected to an external target object in the form of uniform infrared light, then the light source 21 and the diffusion sheet 22 in the scattering state cooperate to replace an infrared illuminator in the prior art to realize the projection of uniform infrared light, the uniform infrared light is reflected on the target object and passes through the first polarizing sheet 32 to be received by the infrared chip 31, and at this time, the infrared chip 31 acquires a uniform infrared image of the target object based on the uniform infrared light; when the diffusion sheet 22 is switched to the transparent state and the scattering state at the same time, it can be understood that a part of the diffusion sheet 22 is in the transparent state and another part of the diffusion sheet 22 is in the scattering state, so that under the action of the diffusion sheet 22, a part of the structured light emitted by the light source 21 is still projected to the target object in the form of structured light, and another part of the structured light is scattered to form uniform infrared light and projected to the target object in the form of uniform infrared light, wherein both the structured light and the uniform infrared light are received by the infrared chip 31 through the first polarizing sheet 32, so that the infrared chip 31 can simultaneously acquire an infrared image and a uniform infrared image of the band structure characteristics. Therefore, in this embodiment, the diffusion sheet 22 functions to enable the infrared chip 31 to obtain an infrared image and/or a uniform infrared image with structural features, thereby ensuring that the three-dimensional imaging module is applied to face recognition operations.

It can be understood that, in the present embodiment, the three-dimensional imaging module further includes a color camera 40 electrically connected to the main board 10, and the color camera 40 is disposed on the main board 10 and spaced apart from the light source 21 and the infrared chip 31. The color camera 40 is used to acquire a color image of the target object.

In the present embodiment, the polarization direction of the first polarizer 32 is consistent with the polarization direction of the structured light emitted by the light source 21, and it is not interpreted that the polarization direction of the first polarizer 32 is exactly the same as the polarization direction of the structured light emitted by the light source 21, and it can be understood that the polarization direction of the first polarizer 32 is substantially the same as or substantially the same as the polarization direction of the structured light emitted by the light source 21. It should be noted here that, during the image forming operation, the light source 21 emits structured light with a polarization direction, and the structured light is projected to the target object in the same polarization direction under the action of the diffusion sheet 22, that is, the polarization directions of the structured light and/or the uniform infrared light projected to the outside from the diffusion sheet 22 are the same as the polarization direction of the structured light emitted from the light source 21; then, under the action of reflection of the structured light and/or the uniform infrared light passing through the target object, since the polarization direction of the structured light and/or the uniform infrared light is consistent with the direction of the first polarizer 32, the structured light and/or the uniform infrared light can be received by the infrared chip 31 through the first polarizer 32, and the ambient light in the external environment, which is inconsistent with the polarization direction of the first polarizer 32, cannot pass through the first polarizer 32 and cannot be received by the infrared chip 31.

In the embodiment of the present application, on the one hand, the diffusion sheet 22 is disposed on the light exit side of the light source 21, and can be switched to the transparent state and/or the scattering state, then the structured light emitted by the light source 21 is under the effect of the diffusion sheet 22, and finally can be projected to the target object in the form of the structured light and/or the uniform infrared light, so that the receiving module 30 receives the structured light and/or the uniform infrared light, and further obtains the infrared image and/or the uniform infrared image with structural characteristics, thus, the projecting module 20 is only provided with one light source 21, and the projection of the structured light and the uniform infrared light can be realized, thus, the manufacturing cost of the projecting module 20 is saved, the volume of the projecting module 20 is also reduced, and the miniaturization design of the three-dimensional imaging module. On the other hand, the light source 21 is configured to emit structured light with a polarization direction, so that the structured light and/or the uniform infrared light projected by the projection module 20 all have the polarization direction; the first polarizer 32 is disposed on the light incident side of the infrared chip 31, and the polarization direction of the first polarizer 32 is consistent with the polarization direction of the structured light emitted by the light source 21, that is, the polarization direction of the first polarizer 32 is consistent with the polarization direction of the structured light and/or the uniform infrared light projected by the projection module 20, so that most of the ambient light is filtered by the first polarizer 32, the influence of the ambient light on the infrared chip 31 is reduced, it is ensured that the infrared chip 31 can accurately identify the target object from the ambient light, the infrared image and/or the uniform infrared image with accurate and complete band structure characteristics are obtained, and the imaging effect and accuracy of the three-dimensional imaging module are improved.

In one embodiment, referring to fig. 1, 2 and 4, the light source 21 includes a vertical cavity surface emitting laser 211 and a second polarizer 212. The vertical cavity surface emitting laser 211 is disposed on the main board 10 and electrically connected to the main board 10; it can be understood that the vcsel 211 can be directly attached to the motherboard 10 and electrically connected to the motherboard 10, and of course, the vcsel 211 can also be attached to a first circuit board, and the first circuit board is fixed to the motherboard 10 through a connector, so that the vcsel 211 is electrically connected to the motherboard 10 through the first circuit board. The vertical cavity surface emitting laser 211 is used for emitting structured light and is spaced apart from the infrared chip 31. The second polarizer 212 is disposed between the light-emitting side of the vcsel 211 and the light-entering side of the diffuser 22, and it can be understood that the structured light emitted from the vcsel 211 passes through the second polarizer 212 and is polarized under the polarization effect of the second polarizer 212 to become a structured light with a fixed polarization direction, and then passes through the diffuser 22 and is projected to an external target object. Here, the polarization direction of the second polarizer 212 is the same as the polarization direction of the first polarizer 32.

It should be noted here that a Vertical-Cavity Surface-Emitting Laser 211 (VCSEL, also known as Vertical-Cavity Surface-Emitting Laser) is a commonly used light emitter, as shown in fig. 4, the Vertical-Cavity Surface-Emitting Laser 211 is mainly used for Emitting point-like structured light, the light Emitting power is relatively low, the infrared chip 31 of the receiving module 30 is easily affected by ambient light in an outdoor or a scene with strong ambient light, and an image formed by the point-like structured light on a target object is difficult to be recognized from the ambient light. Since the polarization direction of the second polarizer 212 is identical to the polarization direction of the first polarizer 32, the point-like structured light emitted from the vertical cavity surface emitting laser 211 is polarized by the polarization of the second polarizing plate 212 to form structured light having the same polarization direction as that of the first polarizing plate 32, and thus, the structured light polarized by the second polarizer 212, when reflected by the first polarizer 32 via the diffusion sheet 22 and the object, can pass through the first polarizer 32 smoothly to be received by the infrared chip 31, thus, ambient light in the external environment that is not in accordance with the polarization direction of the first polarizer 32 cannot pass through the first polarizer 32, and thus cannot be received by the infrared chip 31, and thus, the arrangement of the first polarizer 32 and the second polarizer 212 reduces the interference of the ambient light to the infrared chip 31, thereby reducing the influence of the ambient light on the imaging operation of the infrared chip 31.

It should be noted here that, as shown in fig. 4, the structured light emitted by the vcsel 211 can be decomposed into two components with perpendicular polarization directions, the circles in the schematic diagram represent the components perpendicular to the light beam propagation plane, the short lines in the schematic diagram represent the components parallel to the light beam propagation plane, and the arrows on the second polarizer 212 represent that the polarization direction of the second polarizer 212 is parallel to the light beam propagation plane, so that all the components parallel to the light beam propagation plane of the structured light emitted by the vcsel 211 can be transmitted through the second polarizer 212 to be projected to the target object. Accordingly, as shown in FIG. 3, the arrows on the first polarizer 32 indicate that the polarization direction of the first polarizer 32 is parallel to the beam propagation plane, so that the components of the structured and/or homogeneous infrared light reflected from the target object that are parallel to the beam propagation plane can all be transmitted through the first polarizer 32.

In this embodiment, by adopting the above technical scheme, the first polarizer 32 and the second polarizer 212 are arranged, so that the projection module 20 can greatly reduce the interference of the ambient light to the infrared chip 31 only by using the commonly used vertical cavity surface emitting laser 211, so that the infrared chip 31 can accurately and completely identify the target object from the ambient light, and the imaging effect and accuracy of the three-dimensional imaging module are improved.

In an embodiment, referring to fig. 2, 5 and 6, the diffusion sheet 22 has a plurality of independent diffusion regions, and each diffusion region can switch between a transparent state and a scattering state. It can be understood that the diffusion sheet 22 has a plurality of electrodes 223, each diffusion region has an electrode 223 thereon, and the electrode 223 is used for externally connecting a voltage, so that an external device can control the voltage of each diffusion region through the electrode 223 corresponding to the diffusion region, thereby switching the diffusion region to a transparent state or a scattering state; that is, the electrodes 223 between the plurality of diffusion regions are independent of each other, and the external device can control the voltages of the different diffusion regions through the different electrodes 223, so that the plurality of diffusion regions can be individually controlled to be switched to the transparent state or the scattering state.

In this embodiment, among the plurality of diffusion regions of the diffusion sheet 22, a part of the diffusion regions is switched to a transparent state under the voltage control of the external device, and another part of the diffusion regions is switched to a scattering state under the voltage control of the external device; the structured light emitted from the light source 21 passes through the diffusion sheet 22 and is projected to an external target object, wherein a part of the structured light passes through the diffusion region in the transparent state and is still projected from the diffusion region to the target object in the form of structured light, and another part of the structured light passes through the diffusion region in the scattering state and is scattered, thereby being projected from the diffusion region to the outside in the form of uniform infrared light. Therefore, the arrangement of one light source 21 enables the projection module 20 to project mutually independent structured light and uniform infrared light at the same time by changing the structure of the diffusion sheet 22, so that the structured light and the uniform infrared light are received by the infrared chip 31 after being reflected by the target object through the first polarizer 32, the infrared chip 31 obtains an infrared image based on the structured light and the uniform infrared light, and the distribution of the infrared image just corresponds to the structure of the diffusion sheet 22; it is understood that the infrared image acquired by the infrared chip 31 at this time has a plurality of imaging regions independent of each other, wherein one of the imaging regions is an infrared image of the band structure feature, and the other imaging region is a uniform infrared image, as shown in fig. 6, the imaging region denoted by reference numeral M is an infrared image of the band structure feature, and the imaging region denoted by reference numeral N is a uniform infrared image.

Therefore, by adopting the above technical solution, the diffusion sheet 22 is provided with a plurality of diffusion areas, so that the diffusion sheet 22 and one light source 21 are matched, and an infrared image and a uniform infrared image with a band structure characteristic in one infrared image acquired by the infrared chip 31 can be realized; specifically, in practical applications, the structured light emitted by one light source 21 is projected onto the target object after being acted by the diffusion sheet 22, that is, the target object is simultaneously illuminated by the structured light and the uniform infrared light, and the infrared chip 31 acquires the state of the target object simultaneously illuminated by the structured light and the uniform infrared light at one time to acquire two types of infrared images at one time, so that the infrared chip 31 can acquire the infrared image and the uniform infrared image of the band structure feature at the same time without performing two receiving operations, that is, the infrared image and the uniform infrared image of the band structure feature are acquired in sequence without switching the state of the diffusion sheet 22 or switching the light source 21. Thus, the infrared light projected from the diffusion sheet 22 at the same time includes both the structured light region and the uniform infrared light region, so that the states of the same target object under different illumination can be obtained, that is, the infrared image and the uniform infrared image of the same target object with the band structure characteristics are obtained, the types of infrared images acquired by the algorithm are increased, and the safety and the attack resistance of identification are improved.

Of course, in this embodiment, if only the infrared image with the structural features needs to be obtained according to actual specific requirements, the external device can control the voltages of all diffusion areas of the diffusion sheet 22 to switch all diffusion areas of the diffusion sheet 22 to the transparent state, so that the structured light is projected to the outside in the form of structured light after passing through all diffusion areas, and is finally received by the infrared chip 31; accordingly, if only a uniform infrared pattern needs to be acquired, the external apparatus can control the voltages of all the diffusion areas of the diffusion sheet 22 to switch all the diffusion areas of the diffusion sheet 22 to the scattering state, so that the structured light is projected to the outside in the form of uniform infrared light after passing through all the diffusion areas, and is finally received by the infrared chip 31.

In one embodiment, referring to fig. 5 and fig. 6, the plurality of diffusion regions are distributed in a matrix, it can be understood that each diffusion region is substantially in a block shape, and the plurality of block-shaped diffusion regions are independent from each other and distributed in a matrix; thus, when a part of the diffusion region is switched to a transparent state and another part of the diffusion region is switched to a scattering state, after the structured light emitted by the light source 21 passes through the diffusion region in the transparent state, a part of the structured light passes through the diffusion region in the scattering state to form uniform infrared light, the structured light and the uniform infrared light are projected to the outside and received by the infrared chip 31, so that the infrared chip 31 obtains an infrared image having a part of the infrared image of the band structure characteristic and a part of the uniform infrared image, both the infrared image of the band structure characteristic and the uniform infrared image are substantially block-shaped, and the infrared image of the band structure characteristic and the uniform infrared image are also distributed in a matrix corresponding to the structure of the diffusion sheet 22, thereby facilitating the analysis and calculation of the infrared image and the uniform infrared image of the subsequent structure characteristic, thereby realizing the face recognition function.

Referring to fig. 7, in the present embodiment, a plurality of diffusion regions may be further disposed to be sequentially arranged circumferentially; it will be appreciated that a first diffusion zone is located in the middle of diffuser 22, a second diffusion zone is located around the periphery of the first diffusion zone, a third diffusion zone is located around the periphery of the second diffusion zone so as to simultaneously surround the periphery of the first diffusion zone, a fourth diffusion zone is located around the periphery … … of the third diffusion zone, and so on, so as to achieve sequential surrounding of the plurality of diffusion zones to the periphery.

Therefore, by adopting the above technical scheme, a plurality of diffusion areas of the diffusion sheet 22 can be in matrix distribution or sequentially arranged towards the outer periphery according to actual requirements, and all the diffusion areas can make the infrared image acquired by the infrared chip 31 have the infrared image with the band structure characteristic and the uniform infrared image at the same time, and the infrared image with the band structure characteristic and the uniform infrared image can be clearly displayed, so that the arrangement flexibility of the diffusion sheet 22 is facilitated, and the accuracy of the imaging effect of the three-dimensional imaging module is also ensured.

In one embodiment, referring to fig. 8, the diffusion sheet 22 includes two conductive films 221 and a diffuser 222 disposed between the two conductive films 221, and the conductive films 221 are transparent and disposed on the light emitting side of the light source 21. The conductive film 221 is used for externally connecting a voltage, so that the diffuser 222 is switched to a transparent state, a scattering state, and a transparent state and a scattering state under the action of different voltages; it is understood that the electrode 223 is provided on the conductive film 221, and an external device controls the voltage of the conductive film 221 through the electrode 223, thereby switching the state of the entire diffusion sheet 22; it can also be understood that the diffuser 222 changes the property of the diffuser 222 to block the structured light under the action of the voltage to change the amount of the structured light directly transmitted through the conductive film 221, thereby changing the state of the whole formed by the diffuser 222 and the conductive film 221. Here, in this embodiment, after the external device controls the voltage of the conductive film 221, the diffuser 222 is switched to the transparent state by the voltage, that is, the transparent state of the entire diffusion sheet 22 is realized; diffuser 222 can also be switched to a scattering state, i.e., a transparent state that achieves the entire diffuser 22; the diffuser 222 can also be switched to a transparent state and a scattering state at the same time, that is, a part of the diffuser 222 is in a transparent state and a part of the diffuser is in a scattering state, so that the structured light transmitted through the conductive film 221 is partially projected to the outside in the form of structured light, and the other part is projected to the outside in the form of uniform infrared light.

By adopting the above technical scheme, the diffuser 222 is switched under the action of voltage, so that the state switching of the whole diffusion sheet 22 is realized, the operation of switching the state of the diffusion sheet 22 is very simple, and the cost is low.

In this embodiment, the conductive film 221 may be formed by nano indium tin oxide, carbon nanotube conductive film, nano silver wire, etc., and the material of the conductive film 221 is not limited herein.

In an embodiment, referring to fig. 5, 7 and 8, the diffusion sheet 22 has a plurality of diffusion areas; it can be understood that the conductive film 221 has a plurality of conductive regions 221a, each conductive region 221a has an electrode 223 thereon, and each conductive region 221a has a diffusion 222 distributed thereon, and one conductive region 221a and the diffusion 222 thereon constitute one diffusion region. It should be noted here that each conductive region 221a is externally connected with a voltage through the electrode 223, and an external device can control the voltage of the conductive region 221a through the electrode 223 corresponding to each conductive region 221a, so as to switch the state of the diffuser 222 on the conductive region 221a, that is, switch the state of the whole formed by the conductive film 221 and the diffuser 222, so that a part of the whole formed by the conductive film 221 and the diffuser 222 is in a transparent state, and another part is in a scattering state, so that the infrared chip 31 can simultaneously obtain an infrared image having both a band structure characteristic and a uniform infrared image.

Correspondingly, the conductive regions 221a of the conductive film 221 are distributed in a matrix, so that the diffusion regions are distributed in a matrix; alternatively, the plurality of conductive regions 221a of the conductive film 221 are sequentially provided around the outer circumference, so that the plurality of diffusion regions are sequentially provided around the outer circumference.

In one embodiment, referring to fig. 8, the diffuser 222 is a suspended particle or polymer dispersed liquid crystal. By adopting the technical scheme, the suspended particles can be rearranged under the action of voltage so as to adjust the transmission performance of the suspended particles to the structural light; or, the polymer dispersed liquid crystal adjusts the refractive index of the liquid crystal microdroplets of the polymer dispersed liquid crystal under the action of voltage; in this way, the adjustment of the light transmission performance of the diffuser 222 is achieved to switch the state of the suspended particles or the polymer dispersed liquid crystal, and the adjustment of the transmission performance of the structured light of the whole formed by the diffuser 222 and the conductive film 221 is achieved, and thus, the state switching of the whole formed by the diffuser 222 and the conductive film 221 is achieved. Moreover, the suspended particles or polymer dispersed liquid crystals are common and easy to obtain, which helps to simplify the manufacturing process of the diffusion sheet 22.

In one embodiment, referring to fig. 8, the diffusion sheet 22 further includes two transparent substrates 224, the transparent substrates 224 are glass substrates, two conductive films 221 are disposed between the two transparent substrates 224, and the diffuser 222 is disposed between the two conductive films 221. By adopting the above technical solution, the diffuser 222 is arranged between the two conductive films 221, so that the two conductive films 221 sandwich the diffuser 222, thereby realizing encapsulation and protection of the diffuser 222, facilitating prevention of leakage of the diffuser 222, and ensuring state switching operation of the diffuser 22; the transparent substrate 224 is transparent and is conducive to transmission of structured light and/or uniform infrared light, and the two conductive films 221 and the diffuser 222 are both disposed between the two transparent substrates 224, which is conducive to encapsulation and protection of the conductive films 221 and the diffuser 222, thereby ensuring the state switching operation of the diffusion sheet 22.

It should be noted here that the structured light emitted from the light source 21 passes through one transparent substrate 224 and one conductive film 221 in sequence, forms structured light and/or uniform infrared light after passing through the diffuser 222, and finally passes through the other conductive film 221 and the other transparent substrate 224 in sequence to be projected to an external target object. Of course, in the present embodiment, the transparent substrate 224 may also be provided with three, four, or more than five, and the specific distribution may be set according to actual requirements.

In a specific embodiment, a fixing adhesive 225 is disposed between the transparent substrate 224 and the conductive film 221, and the fixing adhesive 225 is used for fixing the transparent substrate 224 and the conductive film 221.

In one embodiment, referring to fig. 2, the projection module 20 further includes a diffractive optical element 23 and a collimating lens 24, and the collimating lens 24 is disposed between the light-emitting side of the light source 21 and the light-entering side of the diffusion sheet 22, it can be understood that when the light source 21 includes the vertical cavity surface emitting laser 211 and the second polarizer 212, the collimating lens 24 is disposed between the light-emitting side of the second polarizer 212 and the light-entering side of the diffusion sheet 22. The diffractive optical element 23 is disposed between the light-emitting side of the collimating lens 24 and the light-entering side of the diffusion sheet 22, and it can be understood that the light source 21, the collimating lens 24, the diffractive optical element 23 and the diffusion sheet 22 are sequentially distributed along the light-emitting side of the light source 21, and the structured light emitted from the light source 21 is firstly collimated by the collimating lens 24, then diffracted by the diffractive optical element 23, and finally projected to the outside by the diffusion function of the diffusion sheet 22. Of course, in other embodiments, the diffractive optical element 23 may also be disposed on the light exit side of the diffuser 22.

In another embodiment, the projection module 20 further comprises a diffractive optical element 23 for diffracting the structured light, the diffractive optical element 23 being disposed between the light exit side of the light source 21 and the light entrance side of the diffuser 22, it being understood that when the light source 21 comprises the VCSEL 211 and the second polarizer 212, the diffractive optical element 23 is disposed between the light exit side of the second polarizer 212 and the light entrance side of the diffuser 22. In this embodiment, the diffractive optical element 23 can also collimate the structured light. In this embodiment, the diffractive optical element 23 integrates two functions of diffraction and collimation, so that the structured light emitted from the light source 21 can be diffracted and collimated after passing through the diffractive optical element 23, and thus, the use of the optical element is reduced, and the design cost and the volume of the projection module 20 are reduced.

Through adopting above-mentioned technical scheme for the structure light that throws module 20 and/or even infrared light that throws all through collimation and diffraction effect after throw to outside target object on, also guarantee to throw the diffraction effect and the collimation of module 20 promptly, make structure light and/or even infrared light can throw to outside target object more accurately on.

In one embodiment, referring to fig. 3, the receiving module 30 further includes an imaging lens 33 and a filter 34, and both the imaging lens 33 and the filter 34 are disposed between the infrared chip 31 and the first polarizer 32. The imaging lens 33 is disposed between the light entrance side of the filter 34 and the light exit side of the first polarizer 32. It will be appreciated that the structured light and/or the uniform infrared light reflected from the target object is first polarized by the first polarizer 32, then passes through the imaging lens 33 to achieve focusing, and finally is filtered by the filter 34 to be received by the infrared chip 31. It should be noted here that, after the structured light and/or the uniform infrared light reflected by the target object is reflected by the target object, the structured light and/or the uniform infrared light and the ambient light are incident on the first polarizer 32 at the same time, and the first polarizer 32 will filter the light perpendicular to the polarization direction thereof, that is, most of the ambient light, so that the structured light and/or the uniform infrared light and a small portion of the ambient light are focused by the imaging lens 33 and then filtered by the optical filter 34, and finally the structured light and/or the uniform infrared light is received by the infrared chip 31, that is, the optical filter 34 filters the ambient light, so that the interference of the ambient light to the infrared chip 31 is avoided, and the recognition accuracy and the imaging effect of the infrared chip 31 to the target object are ensured. By adopting the technical scheme, the structural light and/or the uniform infrared light reflected from the target object need to be focused by the imaging lens 33, so that the structural light and/or the uniform infrared light can be received by the infrared chip 31 to the maximum extent; in addition, the optical filter 34 can also filter out ambient light, so as to prevent the ambient light from interfering with the infrared chip 31, thereby ensuring the recognition accuracy and the imaging effect of the infrared chip 31 on the target object. In addition, it should be further noted that the first polarizer 32 can filter out ambient light with a polarization direction different from that of the first polarizer 32, and the optical filter 34 can also filter out other ambient light, and the first polarizer 32 and the optical filter 34 can allow all the structured light and/or the uniform infrared light to pass through, so that interference of the ambient light on the infrared chip 31 is greatly avoided.

Of course, in other embodiments, the imaging lens 33 may also be disposed between the light-emitting side of the filter 34 and the light-entering side of the infrared chip 31,

in a specific embodiment, the receiving module 30 further includes a second circuit board 35, the infrared chip 31 is disposed on the second circuit board 35, and the second circuit board 35 is disposed on the motherboard 10 and electrically connected to the motherboard 10, so that the infrared chip 31 is electrically connected to the motherboard 10 through the second circuit board 35; of course, in other embodiments, the infrared chip 31 can also be directly attached to the motherboard 10 and electrically connected to the motherboard 10.

Example two

The present embodiment is substantially the same as the first embodiment, and the differences are only that: the light source 21 is a horizontal cavity surface emitting laser. The horizontal cavity surface emitting laser is fixed on the mainboard 10 through the first circuit board and is electrically connected with the mainboard 10; or, the horizontal cavity surface emitting laser is directly attached to the main board 10 and electrically connected to the main board 10. It should be noted here that the Horizontal Cavity Surface Emitting Laser (HCSEL) as the light source 21 has several advantages: first, the horizontal cavity surface emitting laser is mainly used for emitting linear structured light, the structured light emitted by the horizontal cavity surface emitting laser has a polarization direction, and the polarization direction of the emitted structured light is consistent with the polarization direction of the first polarizer 32, so that the structured light emitted by the horizontal cavity surface emitting laser can pass through the first polarizer 32 to be received by the infrared chip 31 after the diffusion sheet 22 acts, and then the horizontal cavity surface emitting laser and the first polarizer 32 are matched to filter most of ambient light, thereby greatly reducing the interference of the ambient light to the infrared chip 31, and further enabling the infrared chip 31 to more accurately and completely identify the target object. Second, the light emitting power of the horizontal cavity surface emitting laser is high, and the entire surface of the horizontal cavity surface emitting laser as the light source 21 can emit light with relatively high light emitting density, so that the infrared chip 31 can better identify the target object. Third, the polarization of the structured light emitted by the horizontal cavity surface emitting laser is relatively good, which contributes to higher diffraction uniformity and diffraction efficiency of the diffractive optical element 23 when the diffractive optical element 23 is designed to match the polarization characteristics of the horizontal cavity surface emitting laser. Fourthly, the divergence angle of the horizontal cavity surface emitting laser is relatively small, that is, the structured light emitted from the horizontal cavity surface emitting laser has a certain collimation effect, so that the design difficulty of the collimating mirror is reduced, and thus, the collimation function of the collimating mirror can be directly integrated onto the diffractive optical element 23, so that the diffractive optical element 23 has a collimation function, thereby further saving the design cost of the projection module 20, reducing the volume of the projection module 20, and contributing to the miniaturization design of the three-dimensional imaging module.

The rest of this embodiment is the same as the first embodiment, and the unexplained features in this embodiment are explained by the first embodiment, which is not described herein again.

EXAMPLE III

The present embodiment is substantially the same as the first embodiment, and the differences are only that: the diffusion sheet 22 may be provided with only one diffusion region and accordingly the conductive film 221 has only one conductive region 221a, so that an external device can switch the diffusion sheet 22 to a transparent state or a scattering state by controlling the voltage of the conductive film 221 to move the diffusion object 222 on the conductive film 221.

The rest of this embodiment is the same as the first embodiment, and the unexplained features in this embodiment are explained by the first embodiment, which is not described herein again.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.