Laser projection module and depth camera
By making the wavelengths of the first light source and the second light source different in the laser projection module, and using the focus difference to achieve the defocusing effect, the optical path occlusion problem is solved, and the light source efficiency and detection distance are improved.
Patent Information
- Application Number
- CN202421575704.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-04
- Publication Date
- 2025-06-27
- Estimated Expiration
- 2034-07-04
AI Technical Summary
In depth cameras, in order to meet higher resolution and longer detection distances, the laser projection module needs to switch between floodlight illumination and speckle illumination, but the light path blocking is caused by the adjustment of the light source position, which affects the light source efficiency.
By making the wavelengths of the first light source and the second light source different, there is a focus difference between the second light source and the first light source, thereby making it easier to produce a defocus effect, so that the distance value between the first light source and the second light source can be smaller than a preset threshold value, avoiding light path occlusion.
The light source efficiency of the laser projection module is ensured, the optical path occlusion is avoided, and the higher resolution and a longer detection distance are ensured.
Smart Images
Figure CN223038174U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of optical technologies, and in particular, to a laser projection module and a depth camera. Background Art
[0002] Compared with traditional two-dimensional cameras, depth cameras can simultaneously capture the appearance of an object and its relative position and depth in space to obtain the three-dimensional spatial position information of the object. A laser projection module is a key component of a depth camera. The laser projection module includes a light source and an optical element. The laser projection module is used to project a specific laser pattern, such as a stripe, onto a target scene. These laser patterns will be deformed after irradiating the object surface. The image sensor of the depth camera captures these deformed patterns, and then processes and analyzes this information through a specific algorithm to calculate the depth information of the object. The depth camera can also project spots or uniform surface light, and then obtain the depth information of the object through time of flight.
[0003] In related technologies, in order to enable a depth camera to meet higher resolution and farther detection distances, usually two light sources share an optical element, and one light source in the laser projection module realizes speckle illumination, and the other light source realizes floodlight illumination, so that the laser projection module can realize switchable floodlight illumination and speckle illumination. However, since the prerequisite for a light source to realize floodlight illumination is to make this light source located at the defocus position of the optical element to achieve a defocus effect. Therefore, in order to match the two effects of the optical element to realize floodlight illumination and speckle projection, the distances between the two light sources and the optical element need to be different. That is to say, there needs to be a certain distance value between the two light sources. The inventor has found through research that if this distance value is too large, it may cause light path occlusion and affect the light source efficiency of the laser projection module. Summary of the Utility Model
[0004] The present application discloses a laser projection module and a depth camera, which can ensure the light source efficiency of the laser projection module.
[0005] To achieve the above object, the present application discloses a laser projection module, including:
[0006] A housing having an opening for laser projection;
[0007] An optical element disposed at the opening;
[0008] A first light source disposed in the housing and located on the bottom wall opposite to the opening, and the first light source emits a first laser beam towards the optical element;
[0009] A second light source, which is arranged inside the housing and located on the bottom wall opposite to the opening. The second light source emits a second laser beam towards the optical element. The first light source and the second light source are arranged at intervals. The wavelength difference value between the wavelength of the second laser beam and that of the first laser beam is greater than a first preset threshold, so that the distance value between the first light source and the second light source along the optical axis direction of the first light source is less than a second preset threshold.
[0010] Optionally, when the wavelength difference value between the wavelength of the second laser beam and that of the first laser beam is equal to a third preset threshold, along the optical axis direction of the first light source, the distance between the first light source and the optical element is equal to the distance between the second light source and the optical element.
[0011] Optionally, the wavelength of the first laser beam is greater than the wavelength of the second laser beam. Along the optical axis direction of the first light source, the distance between the first light source and the optical element is less than the distance between the second light source and the optical element.
[0012] Optionally, the equivalent focal length of the optical element is f, the distance between the first light source and the optical element is h1, the distance between the second light source and the optical element is h2, h1 = f and |h2 - h1| / h1 > 1 / 20.
[0013] Optionally, the difference between the wavelength of the first laser beam and the wavelength of the second laser beam is greater than 80 nm.
[0014] Optionally, both the first light source and the second light source are point light sources; or,
[0015] The first light source is a point light source and the second light source is a surface light source. Along the optical axis direction of the first light source, the distance between the first light source and the optical element is less than the distance between the second light source and the optical element.
[0016] Optionally, a first optical functional area and a second optical functional area are arranged on the optical element. The first optical functional area is used for imaging and focusing the first laser beam, and the second optical functional area is used for homogenizing the second laser beam.
[0017] Optionally, the wavelength of the first light source is greater than the wavelength of the second light source, and the equivalent focal length of the first optical functional area is greater than the equivalent focal length of the second optical functional area.
[0018] Optionally, along the optical axis direction of the first light source, the optical element has an upper surface and a lower surface. The first optical functional area is arranged on the lower surface, and the second optical functional area is arranged on the upper surface.
[0019] Optionally, an isolation member is further disposed in the housing, and the isolation member is located between the first light source and the second light source.
[0020] The present application also discloses a depth camera, including the above laser projection module.
[0021] Compared with the prior art, the beneficial effects of the present application are as follows:
[0022] Since the wavelength difference value between the second laser beam and the first laser beam is greater than the first preset threshold, when the second laser beam and the first laser beam pass through the same optical element, their respective light beam convergence situations will be different, resulting in different performances on the focal plane. That is to say, there is a focal point difference between the second light source and the first light source itself. When the first light source is located at the focal plane position of the optical element (i.e., the plane where the light converges or diverges after passing through the optical element), the first laser beam can be well converged or diverged to a specific point or area after passing through the optical element. However, due to the different wavelength of the second laser beam from the first laser beam, the refraction situation of the second laser beam when passing through the optical element is different from that of the first laser beam. Even if the distance value between the second light source and the first light source is less than the second preset threshold, this refractive index difference will cause the position where the second laser beam converges or diverges to deviate from the focal plane position of the optical element, thus presenting a defocus effect. That is to say, the wavelength difference leads to obvious differences in the focusing characteristics of the second laser beam and the first laser beam under the action of the optical element, and further causes the defocus effect of the second laser beam. Description of the Drawings
[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.
[0024] Figure 1 It is a schematic structural diagram of a laser projection module provided by an embodiment of the present application;
[0025] Figure 2 It is a schematic structural diagram of another laser projection module provided by an embodiment of the present application;
[0026] Figure 3 It is a schematic diagram of an optical element of a laser projection module provided by an embodiment of the present application;
[0027] Figure 4 It is a schematic diagram of a laser projection module with an isolation member provided by an embodiment of the present application.
[0028] Main Reference Numeral Descriptions
[0029] 1 - Laser projection module;
[0030] 100 - Housing; 110 Opening;
[0031] 200 - Optical element; 210 - First optical functional area; 220 - Second optical functional area;
[0032] 300 - First light source; 310 - First laser beam;
[0033] 400 - Second light source; 410 - Second laser beam;
[0034] 500 - Spacer. Detailed implementation manners
[0035] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.
[0036] In the present application, the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit that the indicated device, element or component must have a specific orientation, or be constructed and operated in a specific orientation.
[0037] Moreover, in addition to being able to represent the orientation or positional relationship, some of the above terms may also be used to represent other meanings. For example, the term "upper" may also be used to represent a certain attachment relationship or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in the present application can be understood according to the specific circumstances.
[0038] In addition, the terms "installed", "set", "provided with", "connected", "connected to" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral structure; it may be a mechanical connection or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, or there may be internal communication between two devices, elements or components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.
[0039] In addition, terms such as "first", "second", etc. are mainly used to distinguish different devices, components or parts (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance and quantity of the indicated devices, components or parts. Unless otherwise specified, the meaning of "a plurality of" is two or more.
[0040] As mentioned in the background art, in the related art, in order to make a depth camera meet higher resolution and farther detection distance, usually two light sources share one optical element, and one light source in the laser projection module realizes speckle illumination and the other light source realizes floodlight illumination. However, since the prerequisite for the light source to realize floodlight illumination is that the light source is located at the defocus position of the optical element, so as to make the light source achieve the defocus effect. Therefore, in order to match the two effects of floodlight illumination and speckle projection realized by the optical element, it is necessary to make the distances between the two light sources and the optical element different. That is to say, there needs to be a certain distance value between the two light sources. However, if this distance value is too large, it may cause light path occlusion and affect the light source efficiency of the laser projection module.
[0041] To solve the above technical problems, the present application provides a laser projection module. By making the wavelengths of the first light source and the second light source different, there is a focal point difference between the second light source and the first light source itself, so that the second light source is more likely to produce a defocus effect, thereby enabling the distance value between the first light source and the second light source to be small enough, or there is no distance value between the first light source and the second light source, avoiding the situation of light path occlusion between the first light source and the second light source caused by too large a distance value between the first light source and the second light source, and thus ensuring the light source efficiency of the laser projection module.
[0042] The technical solution of the present application will be further described below in conjunction with specific embodiments and drawings.
[0043] See Figure 1, this application provides a laser projection module 1, and the laser projection module 1 includes: a housing 100, an optical element 200, a first light source 300, and a second light source 400. The housing 100 has an opening 110 for laser projection; the optical element 200 is disposed at the opening 110; the first light source 300 is disposed inside the housing 100 and on the bottom wall opposite to the opening 110, and the first light source 300 emits a first laser beam 310 towards the optical element 200; the second light source 400 is disposed inside the housing 100 and on the bottom wall opposite to the opening 110, and the second light source 400 emits a second laser beam 410 towards the optical element 200. The first light source 300 and the second light source 400 are spaced apart, and the wavelength difference value between the wavelength of the second laser beam 410 and that of the first laser beam 310 is greater than a first preset threshold, so that the distance value between the first light source 300 and the second light source 400 along the optical axis direction of the first light source 300 is less than a second preset threshold.
[0044] Wherein, the optical axis direction of the first light source 300 is Figure 1 the direction indicated by the arrow X1 in
[0045] Wherein, the optical element 200 is used to adjust and control the first laser beam 310 and the second laser beam 410, so that the first laser beam 310 and the second laser beam 410 form a projection image that meets the requirements. For example, the first laser beam 310 and the second laser beam 410 are focused or collimated, so that the first laser beam 310 and the second laser beam 410 can be projected more concentratedly and more parallelly, improving the brightness and clarity of the projection, and realizing operations such as magnification, reduction, and deformation of the image to meet different projection requirements. It can also filter the first laser beam 310 and the second laser beam 410 to remove unnecessary wavelengths or colors to achieve specific projection effects, and divide the first laser beam 310 and the second laser beam 410 into different wavelengths or colors to achieve effects such as multi-color projection or color projection.
[0046] Since the wavelength difference value between the second laser beam 410 and the first laser beam 310 is greater than the first preset threshold, when the second laser beam 410 and the first laser beam 310 pass through the same optical element 200, their respective light ray convergence situations will be different, resulting in different performances on the focal plane. That is to say, there is a focal point difference between the second light source 400 and the first light source 300 itself. When the first light source 300 is located at the focal plane position of the optical element 200 (i.e., the plane where the light rays converge or diverge after passing through the optical element 200), the first laser beam 310 can be well converged or diverged to a specific point or area after passing through the optical element 200. However, due to the different wavelength of the second laser beam 410 from that of the first laser beam 310, the refraction situation of the second laser beam 410 when passing through the optical element 200 is different from that of the first laser beam 310. When the distance value between the second light source 400 and the first light source 300 is less than the second preset threshold, this refractive index difference will also cause the position where the second laser beam 410 converges or diverges to deviate from the focal plane position of the optical element 200, thus presenting a defocus effect. That is to say, the wavelength difference causes obvious differences in the focusing characteristics of the second laser beam 410 and the first laser beam 310 under the action of the optical element 200, and further causes a defocus effect on the second laser beam 410.
[0047] For example, even if the distances between the second light source 400, the first light source 300 and the optical element 200 are the same, when the first light source 300 is located at the focal plane position of the optical element 200, the second light source 400 is already in a defocus position. That is to say, the second light source 400 itself can already achieve a defocus effect. That is, even if the distances between the second light source 400, the first light source 300 and the optical element 200 are the same, the second light source 400 can also achieve floodlighting. Compared with the related technology where the distance between the first light source 300 and the second light source 400 and the optical element 200 is adjusted to make one of the light sources achieve a defocus effect, in this embodiment, by making the wavelength difference value between the first light source 300 and the second light source 400 greater than the first preset threshold, there is a focal point difference between the second light source 400 and the first light source 300 itself, so that it is easier for the second light source 400 to produce a defocus effect, thereby making the distance value between the first light source 300 and the second light source 400 less than the second preset threshold, or there is no distance value between the first light source 300 and the second light source 400, avoiding the situation of light path occlusion between the first light source 300 and the second light source 400 caused by too large a distance value between the first light source 300 and the second light source 400, and thus ensuring the light source efficiency of the laser projection module 1.
[0048] Exemplarily, the first preset threshold is greater than or equal to 10 nm, and the second preset threshold is between 50 μm and 300 μm. When the first preset threshold is equal to 10 nm, the distance value between the first light source 300 and the second light source 400 can be reduced by 2 μm to 10 μm based on the second preset threshold.
[0049] Of course, the above is only an illustration of the setting positions of the first light source 300 and the second light source 400, rather than a limitation on the setting positions of the first light source 300 and the second light source 400. The distances between the first light source 300, the second light source 400 and the optical element 200 can be the same or different, which should be known to those skilled in the art.
[0050] In a possible embodiment, referring to Figure 1 , when the wavelength difference value between the second laser beam 410 and the first laser beam 310 is equal to the third preset threshold, along the optical axis direction of the first light source 300, the distance between the first light source 300 and the optical element 200 is equal to the distance between the second light source 400 and the optical element 200.
[0051] Among them, the optical axis direction of the first light source 300 is Figure 1 the direction indicated by the arrow X1 in
[0052] It should be noted that the wavelength difference value between the second laser beam 410 and the first laser beam 310 being equal to the third preset threshold can be exactly equal or approximately equal.
[0053] Exemplarily, if the wavelength of the first laser beam 310 is equal to the wavelength of the second laser beam 410 and the distance value between the first light source 300 and the second light source 400 is 80 μm, the third preset threshold is 80 nm. Therefore, when the wavelength difference value between the second laser beam 410 and the first laser beam 310 is 80 nm, the distance between the first light source 300 and the optical element 200 is equal to the distance between the second light source 400 and the optical element 200. Similarly, if the wavelength of the first laser beam 310 is equal to the wavelength of the second laser beam 410 and the distance value between the first light source 300 and the second light source 400 is 100 μm, the third preset threshold is 100 nm. Therefore, when the wavelength difference value between the second laser beam 410 and the first laser beam 310 is equal to 100 nm, the distance between the first light source 300 and the optical element 200 is equal to the distance between the second light source 400 and the optical element 200. That is to say, the value of the third preset threshold depends on the distance value between the first light source 300 and the second light source 400 when the wavelength of the first laser beam 310 in the laser projection module 1 is equal to the wavelength of the second laser beam 410.
[0054] Thus, if it is necessary for the first light source 300 and the second light source 400 to achieve speckle illumination and floodlight illumination respectively. For example, to make the first light source 300 achieve speckle illumination and the second light source 400 achieve floodlight illumination, it is only necessary to place the first light source 300 at the focal plane position of the optical element 200, and make the distance between the second light source 400 and the optical element 200 equal to the distance between the first light source 300 and the optical element 200. Since the wavelengths of the second light source 400 and the first light source 300 are equal to the third preset threshold, the second light source 400 is in the defocus position and can achieve the defocus effect. Moreover, the optical path occlusion between the first light source 300 and the second light source 400 is avoided, thus ensuring the light source efficiency of the laser projection module 1.
[0055] In a possible embodiment, referring to Figure 2 , the wavelength of the first laser beam 310 is greater than the wavelength of the second laser beam 410. Along the optical axis direction of the first light source 300, the distance between the first light source 300 and the optical element 200 is less than the distance between the second light source 400 and the optical element 200.
[0056] Wherein, the optical axis direction of the first light source 300 is Figure 2 the direction indicated by the arrow X2 in
[0057] Exemplarily, let the wavelength of the first laser beam 310 be 940 nm as the light source for speckle illumination, and the wavelength of the second laser beam 410 be 850 nm as the light source for floodlight illumination. Since speckle illumination is usually used for long-distance detection applications, the distance between the first light source 300 and the optical element 200 is made less than the distance between the second light source 400 and the optical element 200. That is to say, the first light source 300 is closer to the optical element 200, so that the optical element 200 has a larger angular aperture for the first light source 300, thereby enabling the optical element 200 to fully receive the first laser beam 310, reducing the waste of light energy where part of the first laser beam 310 cannot reach the aperture of the optical element 200, improving the light source efficiency, and further making the first light source 300 more suitable for long-distance detection applications. In addition, making the wavelength of the first laser beam 310 be 940 nm is more friendly to eye safety on the basis of meeting the high-power requirements for long-distance detection corresponding to speckle illumination. For floodlight illumination corresponding to short-distance detection, the optical power can be lower. Therefore, making the wavelength of the second laser beam 410 be 850 nm can meet the requirements of eye safety on the basis of meeting floodlight illumination.
[0058] Of course, the above is only an example of the wavelengths of the first laser beam 310 and the second laser beam 410, rather than a limitation on the wavelengths of the first laser beam 310 and the second laser beam 410. The wavelength of the first laser beam 310 can also be any wavelength such as 1310 nm, etc., and the wavelength of the second laser beam 410 can also be any wavelength such as 905 nm, etc. As long as the distance between the first light source 300 and the optical element 200 is less than the distance between the second light source 400 and the optical element 200, and the wavelength of the first light source 300 is greater than the wavelength of the second light source 400, those skilled in the art should be aware of this.
[0059] In a possible embodiment, the equivalent focal length of the optical element 200 is f, the distance between the first light source 300 and the optical element 200 is h1, the distance between the second light source 400 and the optical element 200 is h2, and h1 = f and |h2 - h1| / h1 > 1 / 20.
[0060] It should be noted that the above |h2 - h1| / h1 > 1 / 20 should be understood as the ratio of the distance value between the first light source 300 and the second light source 400 to the distance between the first light source 300 and the optical element 200 is greater than 1 / 20.
[0061] If the first light source 300 is used as the light source for speckle illumination and the second light source 400 is used as the light source for floodlight illumination, then it is necessary to make the first light source 300 located at the focal plane position of the optical element 200, that is, the distance h1 between the first light source 300 and the optical element 200 is h1 = f, while the second light source 400 needs to deviate from the focal plane position of the optical element 200 to achieve a defocus effect, that is, the distance h2 between the second light source 400 and the optical element 200 is not equal to f. If |h2 - h1| / h1 < 1 / 20, it may cause the distance value between the second light source 400 and the first light source 300 to be too small, resulting in a poor defocus effect of the second light source 400. In this embodiment, |h2 - h1| / h1 > 1 / 20 is used to make the distance value between the second light source 400 and the first light source 300 sufficient, so that the second light source 400 can more easily achieve a defocus effect.
[0062] In a preferred embodiment, the actual tolerance of the setting position of the first light source 300 needs to satisfy |h1 - f| / f < 5%, and the actual tolerance of the setting position of the second light source 400 needs to satisfy |h2 - f| / f > 5%.
[0063] In a possible embodiment, the difference between the wavelength of the first laser beam 310 and the wavelength of the second laser beam 410 is greater than 80 nm.
[0064] It should be noted that the greater the difference between the wavelength of the first laser beam 310 and the wavelength of the second laser beam 410, when the first light source 300 as the light source for speckle illumination is located at the focal plane position of the optical element 200, the second light source 400 only needs to be at a shorter distance from the first light source 300 to more easily achieve the defocus effect.
[0065] If the difference between the wavelength of the first laser beam 310 and the wavelength of the second laser beam 410 is less than or equal to 80 nm, it will result in too small a wavelength difference between the first laser beam 310 and the second laser beam 410. The distance between the second light source 400 and the optical element 200 needs to be much greater than the distance between the first light source 300 and the optical element 200. That is to say, the distance value between the second light source 400 and the first light source 300 needs to be large enough to enable the second light source 400 to achieve the defocus effect. Therefore, in this embodiment, the difference between the wavelength of the first laser beam 310 and the wavelength of the second laser beam 410 is made greater than 80 nm, so that the wavelength difference between the first laser beam 310 and the second laser beam 410 is relatively large. Thus, when the distance value between the second light source 400 and the first light source 300 is small, the second light source 400 can also achieve the defocus effect, or when there is no distance value between the second light source 400 and the first light source 300, the second light source 400 can also achieve the defocus effect.
[0066] In a possible embodiment, both the first light source 300 and the second light source 400 are point light sources.
[0067] By making both the first light source 300 and the second light source 400 point light sources, the first light source and the second light source can provide more accurate light spot positioning, which helps to improve the accuracy of depth measurement. Moreover, the point light source can form a clearer and more distinct light spot pattern, facilitating subsequent image processing and analysis. In addition, the light source does not require complex optical elements to shape and diffuse the light source, can be more conveniently calibrated and adjusted, can reduce the performance requirements for optical elements, and thus reduce the production cost of the laser projection module.
[0068] In another possible embodiment, the first light source 300 is a point light source, the second light source 400 is a surface light source, and along the optical axis direction of the first light source 300, the distance between the first light source 300 and the optical element 200 is less than the distance between the second light source 400 and the optical element 200.
[0069] By making the first light source 300 a point light source and the second light source 400 a surface light source, the first light source 300 is used for speckle illumination and the second light source 400 is used for floodlight illumination. Moreover, the distance between the first light source 300 and the optical element 200 is less than the distance between the second light source 400 and the optical element 200, so that the point light source is closer to the optical element 200, enabling the point light source to form a clearer and more distinct spot pattern, facilitating subsequent image processing and analysis, and thus enabling the laser projection module 1 to produce better speckle illumination and floodlight illumination effects.
[0070] In a possible embodiment, referring to Figure 3 , a first optical functional area 210 and a second optical functional area 220 are provided on the optical element 200. The first optical functional area 210 is used for imaging and focusing the first laser beam 310, and the second optical functional area 220 is used for homogenizing the second laser beam 410.
[0071] Among them, the first optical functional area 210 being used for imaging and focusing the first laser beam 310 should be understood as that the first optical functional area 210 can not only converge the first laser beam 310 to a specific position to form a clear spot (i.e., the focusing function), but also enable the converged first laser beam 310 to exhibit certain imaging characteristics, such as forming a specific pattern or shape. The second optical functional area 220 being used for homogenizing the second laser beam 410 should be understood as that the second optical functional area 220 can make the second laser beam 410 form a relatively uniform light field within its coverage range, achieving the effect of large-area uniform illumination.
[0072] By setting the first optical functional region 210 and the second optical functional region 220 on the optical element 200, if it is necessary for the first light source 300 to achieve speckle illumination, the first optical functional region 210 can be used to converge the first laser beam 310 to a specific position to form a clear light spot and form a specific pattern or shape, so that the first light source 300 can better achieve speckle illumination to better achieve long-distance detection. If it is necessary for the second light source 400 to achieve floodlight illumination, the second optical functional region 220 can be used to homogenize the second laser beam 410, so that the second laser beam 410 forms a relatively uniform light field within its coverage range, achieving the effect of large-area uniform illumination, so that the second light source 400 can better achieve floodlight illumination to better achieve short-distance detection. Through such a partition design, the optical element 200 can simultaneously achieve two different functions of imaging focusing and homogenization, meeting different application requirements, making the applicability of the optical element 200 wider. Moreover, by using specially designed functional regions to process the first laser beam 310 and the second laser beam 410, the first laser beam 310 and the second laser beam 410 can be better optimized. For example, the first laser beam 310 can obtain high-quality imaging and focusing, while the second laser beam 410 can achieve good homogenization effects.
[0073] In addition, compared with using different optical elements 200 in the related art to achieve two different functions of imaging focusing and homogenization, in this embodiment, the first optical functional region 210 and the second optical functional region 220 are provided on the same optical element 200. The first optical functional region 210 is used to perform imaging and focusing processing on the first laser beam 310, and the second optical functional region 220 is used to perform homogenization processing on the second laser beam 410. This integrated partition design can more effectively utilize space and material resources.
[0074] In a possible embodiment, the wavelength of the first laser beam 310 is greater than the wavelength of the second laser beam 410, and the equivalent focal length of the first optical functional region 210 is greater than the equivalent focal length of the second optical functional region 220.
[0075] Thus, the first optical functional region 210 corresponds to the first laser beam 310 with a relatively longer wavelength, and the second optical functional region 220 corresponds to the second laser beam with a relatively shorter wavelength. When the first light source 300 is located at the focal plane position of the first optical functional region 210, even if the distance between the second light source 400 and the optical element 200 is equal to the distance between the first light source 300 and the optical element 200, the second light source 400 is in the defocus position of the second optical functional region 220, making it easier for the second light source 400 to produce a defocus effect to further reduce the distance value between the first light source 300 and the second light source 400.
[0076] In a possible embodiment, along the optical axis direction of the first light source 300, the optical element 200 has an upper surface and a lower surface. The first optical functional area 210 is disposed on the lower surface, and the second optical functional area 220 is disposed on the upper surface.
[0077] By disposing the first optical functional area 210 on the lower surface of the optical element 200 and the second optical functional area 220 on the upper surface of the optical element 200, the distance between the first light source 300 and the first optical functional area 210 is made closer, so that the angle subtended by the first optical functional area 210 with respect to the first light source 300 is larger, enabling the first optical functional area 210 to fully receive the first laser beam 310, reducing the waste of light energy where part of the first laser beam 310 cannot reach the aperture of the first optical functional area 210, improving the light source efficiency, and further making the first light source 300 more suitable for long-distance detection applications. Also, the distance between the second light source 400 and the second optical functional area 220 is made farther, so that the second light source 400 can more easily produce a defocus effect, not only enabling a better floodlighting effect of the second light source 400, but also further reducing the distance value between the first light source 300 and the second light source 400.
[0078] In a possible embodiment, referring to Figure 4 , a separator 500 is further disposed in the housing 100, and the separator 500 is located between the first light source 300 and the second light source 400.
[0079] Wherein, the separator 500 is a dark or light-tight member.
[0080] By disposing the separator 500 in the housing 100 and making the separator 500 located between the first light source 300 and the second light source 400, it is possible to prevent the first laser beam 310 and the second laser beam 410 from interfering or crosstalking with each other, ensuring the independence and accuracy of their respective functions, and also helping to maintain the purity of the first laser beam 310 and the second laser beam 410, avoiding problems such as a decrease in imaging quality and a deterioration in homogenization effect due to mutual influence, and enabling more precise control and adjustment of the two light sources, and better optimizing the working states of the first light source 300 and the second light source 400 according to needs.
[0081] This application also provides a depth camera, and the depth camera includes the above laser projection module 1.
[0082] Wherein, the laser projection module 1 in the embodiment of this application can have the same structure as the laser projection module 1 in the above embodiment and can bring the same or similar beneficial effects. For details, reference can be made to the description in the above embodiment, and the embodiment of this application will not be elaborated herein.
[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the laser projection module and the depth camera of the present application, rather than limiting them; although the laser projection module and the depth camera of the present application have been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.
Claims
1. A laser projection module, characterized in that: include: a housing having an opening for laser projection; an optical element, wherein the optical element is disposed at the opening; a first light source, which is disposed in the housing and located on a bottom wall opposite to the opening, and emits a first laser beam toward the optical element; A second light source, the second light source is arranged in the shell and is located on the bottom wall opposite to the opening, the second light source emits a second laser beam toward the optical element, the first light source and the second light source are arranged at an interval, and the wavelength difference between the wavelength of the second laser beam and the wavelength of the first laser beam is greater than a first preset threshold value, so that the distance value between the first light source and the second light source along the optical axis direction of the first light source is less than a second preset threshold value.
2. The laser projection module according to claim 1, characterized in that: When the wavelength difference between the second laser beam and the first laser beam is equal to a third preset threshold, along the optical axis of the first light source, the distance between the first light source and the optical element is equal to the distance between the second light source and the optical element.
3. The laser projection module according to claim 1, characterized in that: The wavelength of the first laser beam is greater than that of the second laser beam, and along the optical axis direction of the first light source, the distance between the first light source and the optical element is less than the distance between the second light source and the optical element.
4. The laser projection module according to claim 3, characterized in that: The equivalent focal length of the optical element is f, the distance between the first light source and the optical element is h1, the distance between the second light source and the optical element is h2, h1=f and |h2-h1| / h1>1 / 20.
5. The laser projection module according to claim 1, characterized in that: The difference between the wavelength of the first laser beam and the wavelength of the second laser beam is greater than 80 nm.
6. The laser projection module according to claim 1, characterized in that: The first light source and the second light source are both point light sources; or, The first light source is a point light source, the second light source is a surface light source, and along the optical axis direction of the first light source, the distance between the first light source and the optical element is smaller than the distance between the second light source and the optical element.
7. The laser projection module according to claim 6, characterized in that: The optical element is provided with a first optical functional area and a second optical functional area. The first optical functional area is used for imaging and focusing the first laser beam, and the second optical functional area is used for homogenizing the second laser beam.
8. The laser projection module according to claim 7, characterized in that: The wavelength of the first light source is greater than the wavelength of the second light source, and the equivalent focal length of the first optical functional area is greater than the equivalent focal length of the second optical functional area.
9. The laser projection module according to claim 7, characterized in that: Along the optical axis direction of the first light source, the optical element has an upper surface and a lower surface, the first optical functional area is arranged on the lower surface, and the second optical functional area is arranged on the upper surface.
10. A depth camera, characterized in that: The depth camera comprises the laser projection module described in any one of claims 1-9.