Infrared 3D detection and emission end module and depth camera

Abstract

The application relates to an infrared 3D detection emitting end module and a depth camera, and relates to the fields of optics and electronics. The infrared 3D detection emitting end module comprises a light source group, a collimating mirror and a light beam shaper which are sequentially arranged along the light emitting direction of the light source group, wherein the collimating mirror is divided into at least two first optical areas, the light source group comprises at least two groups, each group of the light source group corresponds to a first optical area; the light source group is used for emitting a light beam towards the corresponding first optical area; the collimating mirror collimates and deflects the light beam through the first optical area to emit parallel light beams at a preset angle; and the light beam shaper is used for shaping the light beam emitted from the first optical area and projecting the shaped light beam onto a to-be-measured object. The infrared 3D detection emitting end module can improve the integration of the infrared 3D detection emitting end module, thereby reducing the overall volume of the infrared 3D detection emitting end module.

Description

Technical Field

[0001] The present invention relates to the field of optics and electronic technology, and in particular to an infrared 3D detection transmitter module and a depth camera. Background Art

[0002] 3D imaging technology is at the core of the next generation of human-computer interaction technology. In addition to its ability to image objects in 2D, it can also obtain depth information about them. This depth information enables functions such as 3D scanning, scene modeling, and gesture interaction. With the increasing demand for 3D imaging technology in mobile devices, depth cameras will be widely used in these devices.

[0003] Among them, the infrared 3D detection transmitter module is based on the core equipment in the structured light depth camera. It mainly emits multiple beams of planar light in different directions after the light beam emitted by the light source group is collimated, and then cooperates with the beam shaper to finally form a dot matrix projector to project tens of thousands of points onto the object to be measured. These points are identified to restore the three-dimensional information of the object to be measured. Generally, the size, energy consumption and performance of the structured light projection module determine the volume, power consumption and performance of the depth camera. However, the overall volume of the existing infrared 3D detection transmitter module is large, and the uniformity of the light intensity distribution in its large projection area is difficult to guarantee. Summary of the Invention

[0004] The purpose of the present invention is to provide an infrared 3D detection transmitter module and a depth camera, which can improve the integration of the infrared 3D detection transmitter module and thereby reduce the overall volume of the infrared 3D detection transmitter module.

[0005] The embodiment of the present invention is achieved as follows:

[0006] One aspect of the present invention provides an infrared 3D detection transmitter module, comprising a light source group, a collimator, and a beam shaper arranged sequentially along the light output direction of the light source group. The collimator is divided into at least two first optical regions, and the light source group comprises at least two groups, each corresponding to a first optical region. The light source group is configured to emit a light beam toward the corresponding first optical region. The collimator collimates and deflects the light beam through the first optical region to emit a parallel beam at a preset angle. The beam shaper is configured to shape the light beam emitted from the first optical region and project the shaped light beam onto an object to be measured. This infrared 3D detection transmitter module can improve the integration of the infrared 3D detection transmitter module, thereby reducing the overall size of the infrared 3D detection transmitter module.

[0007] Optionally, the beam shaper is a diffractive optical element.

[0008] Optionally, the light source group includes at least one point light source or at least one light source array.

[0009] Optionally, the light source group is a line light source or a surface light source.

[0010] Optionally, two adjacent first optical regions partially overlap to form an overlapping region, and the overlapping region can respectively collimate and deflect the light beams incident from the light source groups corresponding to the two adjacent first optical regions.

[0011] Optionally, the infrared 3D detection transmitting end module further includes at least two light modulators, and the light modulators correspond to the light source groups one by one.

[0012] Optionally, the beam shaper is divided into at least two second optical areas, and the second optical areas correspond to the first optical areas one-to-one.

[0013] Optionally, two or three first optical regions are provided on the collimating lens.

[0014] Optionally, each point position within each first optical region has the same deflection effect on the light beam.

[0015] One aspect of the present invention provides a depth camera including the aforementioned infrared 3D detection transmitter module. The depth camera can improve the integration of the infrared 3D detection transmitter module and thereby reduce the overall size of the infrared 3D detection transmitter module.

[0016] The beneficial effects of the present invention include:

[0017] The present application provides an infrared 3D detection transmitter module, which includes a light source group and a collimator and a beam shaper arranged in sequence along the light output direction of the light source group, wherein the collimator is divided into at least two first optical areas, the light source group includes at least two groups, each light source group corresponds to a first optical area; the light source group is used to emit a light beam toward the corresponding first optical area; the collimator collimates and deflects the light beam through the first optical area to emit a parallel light beam at a preset angle; the beam shaper is used to shape the light beam emitted from the first optical area and project the shaped light beam onto the object to be measured. In this way, when in use, the light beam emitted by each light source group will irradiate the first optical area corresponding to the collimator and the light source group, thereby being incident on the beam shaper through the collimation (or focusing) and deflection in a specific direction of the first optical area, and then being shaped by the beam shaper, and finally projecting the shaped light beam onto the object to be measured. By dividing the collimator into regions (i.e., into at least two first optical regions), the present application can achieve far-field diffraction without the need for a real focus. Compared with the prior art which requires the use of an ordinary collimator to achieve the imaging effect, thereby limiting the longitudinal length of the optical path (the prior art usually requires the distance from the light source to the collimator to be approximately equal to the focal length), the present application proposes the idea of ​​designing a new collimator based on far-field diffraction, which can break through this limitation and achieve the same optical effect with a longitudinal length shorter than the focal length. Therefore, the present application has further improved the optical path integration and can effectively reduce the volume of the infrared 3D detection transmitter module. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 One of the optical path diagrams of the infrared 3D detection transmitter module provided in an embodiment of the present invention;

[0020] Figure 2 One of the structural schematic diagrams of the light source group and the collimating lens provided in an embodiment of the present invention;

[0021] Figure 3 The second structural diagram of the light source group and the collimating lens provided in an embodiment of the present invention;

[0022] Figure 4 The third structural diagram of the light source group and the collimating lens provided in an embodiment of the present invention;

[0023] Figure 5 for Figure 4 Schematic diagram of the output light spot;

[0024] Figure 6 A light path diagram of far-field diffraction corresponding to the divergent collimator provided in an embodiment of the present invention;

[0025] Figure 7 A light path diagram of far-field diffraction corresponding to a collimating lens with arbitrary deflection provided by an embodiment of the present invention;

[0026] Figure 8 The optical path diagram of far-field diffraction of a common collimator provided by the prior art;

[0027] Figure 9 A schematic diagram of the optical path of a light source group and a collimating lens provided in an embodiment of the present invention;

[0028] Figure 10 A schematic diagram of the parallel optical path of the infrared 3D detection transmitter module provided in an embodiment of the present invention;

[0029] Figure 11 Schematic diagram of the output light spot of the parallel optical path of the infrared 3D detection transmitting end module provided by an embodiment of the present invention;

[0030] Figure 12 A schematic diagram of an overlapping area provided in an embodiment of the present invention;

[0031] Figure 13 The second optical path diagram of the infrared 3D detection transmitter module provided in an embodiment of the present invention;

[0032] Figure 14 The third optical path diagram of the infrared 3D detection transmitter module provided in an embodiment of the present invention.

[0033] Icon: 10-light source group; 20-collimator; 21-first optical area; 22-overlapping area; 30-beam shaper; 31-second optical area; L-distance between the light source group and the collimator; EFL-equivalent focal length. DETAILED DESCRIPTION

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0035] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0036] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0037] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" and the like indicate positions or locations based on the positions shown in the accompanying drawings, or the positions or locations in which the inventive product is typically placed when in use. These terms are intended solely to facilitate the description of the present invention and to simplify the description, and are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third," etc., are used solely to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0038] Furthermore, terms such as "horizontal" and "vertical" do not necessarily mean that a component must be absolutely horizontal or overhanging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0039] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0040] Please refer to Figure 1This embodiment provides an infrared 3D detection transmitter module, comprising a light source group 10, a collimator 20, and a beam shaper 30, arranged sequentially along the light emission direction of the light source group 10. The collimator 20 is divided into at least two first optical regions 21, and the light source group 10 comprises at least two groups, each corresponding to a first optical region 21. The light source group 10 is configured to emit a light beam toward the corresponding first optical region 21. The collimator 20 collimates and deflects the light beam through the first optical region 21, emitting a parallel beam at a predetermined angle. The beam shaper 30 is configured to shape the light beam emitted from the first optical region 21 and project the shaped light beam onto the object to be measured. This infrared 3D detection transmitter module can improve the integration level of the infrared 3D detection transmitter module, thereby reducing the overall size of the infrared 3D detection transmitter module.

[0041] Among them, each light source group 10 corresponds to a first optical area 21. At the same time, it should be noted that, in this embodiment, the light source group 10 may include at least one point light source or at least one light source array. It should be noted that the infrared 3D detection transmitting end module provided in this application is usually applied to the infrared band, which requires that the light beam emitted by the light source group 10 corresponds to the infrared band. For example, when the light source group 10 includes a point light source, there should be a first optical area 21 corresponding to a point light source, such as Figure 2 When the light source group 10 includes two point light sources, there should be a first optical region 21 corresponding to the two point light sources, such as Figure 3 When the light source group 10 includes a light source array, there should be a first optical region 21 corresponding to a light source array, such as Figure 4 As shown, correspondingly, through Figure 4 The structure of the infrared 3D detection transmitter module shown in FIG. Figure 5 The spot diagram shown.

[0042] Of course, when multiple point light sources correspond to one first optical region 21, the light source group 10 should also include multiple light sources. For example, the light source group 10 may include three point light sources, four point light sources, or five point light sources.

[0043] Furthermore, the light source group 10 can also be a linear light source or a surface light source. As above, when the light source group 10 is a linear light source or a surface light source, it can also include one or more.

[0044] The collimator 20 is provided in the light emitting direction of the light source group 10, and is used to collimate and deflect the light beam emitted by the light source group 10. Specifically, in this embodiment, the collimator 20 is divided into at least two first optical regions 21, such as Figure 1 As shown ( Figure 1The collimator lens 20 is shown as being divided into three first optical regions 21 ).

[0045] It should be noted that the present application does not limit the number of regions into which the collimator 20 is divided, and those skilled in the art may determine the number according to the circumstances, for example, dividing the collimator 20 into two first optical regions 21 , three first optical regions 21 , or four first optical regions 21 .

[0046] The plurality of first optical regions 21 on the collimating lens 20 are respectively used to collimate and deflect the light beams generated by the corresponding light source groups 10 , so as to emit parallel light beams at a preset angle.

[0047] The beam shaper 30 is used to shape the light beam emitted from the first optical region 21 and project the shaped light beam onto the object to be detected. For example, when performing facial recognition, the shaped light beam is projected onto the face. Optionally, the beam shaper 30 can be a diffractive optical element or a refractive optical element to achieve various optical functions.

[0048] It should be noted that the new collimator 20 provided in this application (i.e., the collimator 20 divided into at least two first optical regions 21) has a spatial collimation effect, but does not necessarily have a true focus. Because the working distance of the infrared 3D detection transmitter module is much larger than its own structural dimensions, it belongs to the far-field diffraction of light. Therefore, the design and evaluation of the collimator 20 of this application should be judged by the spot distribution of the far-field diffraction.

[0049] like Figures 6 to 8 As shown, Figure 6 is the optical path diagram of the far-field diffraction corresponding to the divergent collimator 20, Figure 7 is the optical path diagram of the far-field diffraction corresponding to the arbitrarily deflected collimator 20, Figure 8 This is the optical path diagram of the far-field diffraction of an ordinary collimator. It can be seen that Figure 6 and Figure 7 The two new collimating lenses 20 and Figure 8 The far-field diffraction formed by the ordinary collimator shown is basically the same, and it is a feasible solution for applications such as structured light that use far-field diffraction. In other words, the infrared 3D detection transmitter module provided by this application does not need to rely on the "focal length", as long as the required pattern can appear in the far-field diffraction. The collimator 20 provided by this application is divided into the first optical area 21, which can even be divergent and randomly arranged, such as Figure 6 and Figure 7 As shown, these can all obtain far-field diffraction that meets the same conditions.

[0050] At the same time, the present application can achieve the effect of compressing the volume of the entire infrared 3D detection transmitting end module by dividing the collimator 20 into reasonable areas (i.e., the division of the first optical area 21). Figure 9 As shown, after the light beams emitted by each light source group 10 are collimated and deflected by their respective first optical regions 21, the light beams all propagate toward the central optical axis. The convergence point of the light beams from different first optical regions 21 is the equivalent focus (not the true focus). In this case, the distance between the collimator 20 and the equivalent focus is the equivalent focal length EFL. In contrast, a conventional collimator will converge the uncollimated light beams at the focus of the central optical axis, which has a true focus. In this way, the present application can avoid the problem of the larger size of the entire infrared 3D detection transmitting end module caused by having a true focus in the prior art by having a collimator 20 with at least two first optical regions 21.

[0051] In addition, it should be noted that, for example, Figure 1 As shown, when the collimating lens 20 is divided into three first optical regions 21 , correspondingly, the deflection direction of the light beam by each first optical region 21 may be the same or different.

[0052] For example, when the three first optical regions 21 are required to deflect the light beams in different directions, the structures of the three first optical regions 21 can be individually designed to achieve deflection in different directions. Since the different deflection directions of the light beams by the first optical regions 21 result in different structures of the corresponding first optical regions 21, the design of the structure of each first optical region 21 should be determined based on actual conditions. In actual applications, those skilled in the art can design the structure of the corresponding first optical region 21 based on the deflection direction of each first optical region 21. Therefore, this application does not impose any restrictions on the structure of the first optical regions 21.

[0053] Of course, in this embodiment, the deflection effect of each point position in each of the first optical regions 21 on the light beam may also be the same.

[0054] Please refer to Figure 10 and Figure 11 As shown, Figure 10 As shown in the figure, two groups of light source groups 10 correspond to two first optical regions 21 respectively, and the deflection angles of the two first optical regions 21 of the collimator 20 are the same (specifically, the deflection angles are both 0°, i.e., no deflection). In this way, two parallel light paths can be obtained. Among them, the far-field diffraction intensity distribution of the two parallel light paths should be the same. Since the two light paths are independent of each other, their far-field diffraction can be directly superimposed according to the light intensity (such as Figure 11As shown in Figure 1, a diffraction order matrix is ​​created, where the intensity of each diffraction order is the sum of the corresponding diffraction orders from the two optical paths. This creates a complementary mechanism, allowing errors in one optical path to be compensated by the others. Only when all optical paths exhibit the same error will the final light effect be significantly improved.

[0055] On this basis, the beam shaper 30 can also be divided into regions accordingly, that is, the beam shaper 30 is divided into at least two second optical regions 31, and the second optical regions 31 correspond to the first optical regions 21 one by one, such as Figure 14 The structures of each second optical region 31 can be the same or different.

[0056] When the structures of each second optical region 31 are different, the effects of machining errors or random errors in each second optical region 31 are generally different. This makes it difficult for the infrared 3D detection transmitter module provided by this application to have the same optical errors. In this case, the complementary effect brought about by the parallel optical path structure can greatly improve the uniformity and stability of the optical system.

[0057] In summary, the present application provides an infrared 3D detection transmitting end module, which includes a light source group 10 and a collimator 20 and a beam shaper 30 arranged in sequence along the light output direction of the light source group 10, wherein the collimator 20 is divided into at least two first optical areas 21, and the light source group 10 includes at least two groups, each light source group 10 corresponds to a first optical area 21; the light source group 10 is used to emit a light beam toward the corresponding first optical area 21; the collimator 20 collimates and deflects the light beam through the first optical area 21 to emit a parallel light beam at a preset angle; the beam shaper 30 is used to shape the light beam emitted from the first optical area 21, and project the shaped light beam onto the object to be measured. Thus, when in use, the light beam emitted by each light source group 10 will illuminate the first optical region 21 of the collimator 20 corresponding to the light source group 10, and then enter the beam shaper 30 through the collimation (or convergence) and deflection in a specific direction of the first optical region 21. Then, the light beam is shaped by the beam shaper 30, and finally the shaped light beam is projected onto the object to be measured. The present application divides the collimator 20 into regions (i.e., into at least two first optical regions 21), so that far-field diffraction can be achieved without a real focus. Compared with the prior art that requires the use of ordinary collimators to achieve the imaging effect, thereby limiting the longitudinal length of the optical path (the prior art usually requires the distance L between the light source group and the collimator to be approximately equal to the focal length), the present application proposes a design of a new collimator 20 based on far-field diffraction, which can break through this limitation and achieve the same optical effect with a longitudinal length less than the focal length. Therefore, the present application has further improved the integration of the optical path and can effectively reduce the volume of the infrared 3D detection transmitter module.

[0058] Also, in this embodiment, optionally, as Figure 12 As shown, two adjacent first optical regions 21 partially overlap to form an overlapping region 22 , and the overlapping region 22 can collimate and deflect the light beams incident from the light source groups 10 corresponding to the two adjacent first optical regions 21 .

[0059] It should be noted that those skilled in the art can design the structure of the overlapping region 22 based on the optical properties required by the two adjacent first optical regions 21. The present application does not limit its specific structure, as long as the overlapping region 22 can simultaneously have the optical properties of the two adjacent first optical regions 21. In other words, when the light beam of each light source group 10 is incident on the corresponding first optical region 21, its deflection direction and collimation effect should not change (that is, it should be the same as when it is incident on the non-overlapping first optical region 21).

[0060] By partially overlapping two adjacent first optical regions 21, the present application can provide the infrared 3D detection transmitter module of the present application with a certain tolerance. It does not necessarily require a clear boundary. It only requires that when the infrared 3D detection transmitter module is working, more than 50% of the light intensity of each light source group 10 is distributed within the corresponding first optical region 21, that is, it is considered that the area of ​​the collimator 20 is divided from the design perspective. In this way, the division method of the first optical region 21 on the collimator 20 can be effectively simplified.

[0061] In traditional infrared 3D detection transmitter modules, the light sources essentially belong to the same optical path, so it is difficult to achieve zoned lighting. In this application, the split collimator 20 is divided into at least two first optical areas 21, and an independent light source group 10 is set corresponding to each first optical area 21, which can divide the optical path into multiple independent sub-optical paths, so the effect of zoned lighting can be easily achieved.

[0062] For details, please refer to Figure 13 In order to facilitate the realization of zoned lighting, in this embodiment, the infrared 3D detection transmitting end module further includes at least two light modulators (not shown), and the light modulators correspond to the light source groups 10 one by one.

[0063] The light modulator is used to adjust the optical parameters of the light source groups 10 (eg, adjust the color, intensity, etc. of each light source group 10 ) so that each light source group 10 can emit a light beam in a specific manner as needed.

[0064] The present invention also provides a depth camera including the above-mentioned infrared 3D detection transmitter module. The depth camera can improve the integration of the infrared 3D detection transmitter module and thereby reduce the overall volume of the infrared 3D detection transmitter module.

[0065] Since the specific structure and beneficial effects of the above-mentioned infrared 3D detection transmitting end module have been described in detail above, they will not be repeated here.

[0066] The foregoing description is merely an optional embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

[0067] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. An infrared 3D detection transmitter module, characterized in that: It includes a light source group and a collimator and a beam shaper sequentially arranged along the light output direction of the light source group, wherein the collimator is divided into at least two first optical areas, the light source group includes at least two groups, and each group of the light source groups corresponds to one of the first optical areas; The light source group is used to emit a light beam toward the corresponding first optical area; the collimator collimates and deflects the light beam through the first optical area to emit a parallel light beam at a preset angle; the beam shaper is used to shape the light beam emitted from the first optical area and project the shaped light beam onto the object to be measured; Two adjacent first optical regions partially overlap to form an overlapping region, and the overlapping region can respectively collimate and deflect the light beams incident from the light source groups corresponding to the two adjacent first optical regions.

2. The infrared 3D detection transmitter module according to claim 1, characterized in that: The beam shaper is a diffractive optical element.

3. The infrared 3D detection transmitter module according to claim 1, characterized in that: The light source group includes at least one point light source or at least one light source array.

4. The infrared 3D detection transmitter module according to claim 1, characterized in that: The light source group is a linear light source or a surface light source.

5. The infrared 3D detection transmitter module according to claim 1, characterized in that: The infrared 3D detection transmitting end module further includes at least two light modulators, and the light modulators correspond one-to-one to the light source groups.

6. The infrared 3D detection transmitter module according to claim 1, characterized in that: The beam shaper is divided into at least two second optical areas, and the second optical areas correspond to the first optical areas one by one.

7. The infrared 3D detection transmitter module according to claim 1, characterized in that: The collimating mirror is provided with two or three first optical areas.

8. The infrared 3D detection transmitter module according to claim 1, characterized in that: Each point position within each of the first optical regions has the same deflection effect on the light beam.

9. A depth camera, characterized in that The infrared 3D detection transmitting end module comprises the infrared 3D detection transmitting end module according to any one of claims 1 to 8.

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