CN216133199U - Laser projection device and depth camera - Google Patents

Abstract

The utility model discloses a laser projection device and a depth camera, wherein the laser projection device comprises a light source and a diffusion element, a floodlight beam with a preset field angle is formed by a light beam emitted by the light source through the diffusion element, and the floodlight beam is divided into a first area and a second area by configuring the light source or the diffusion element, wherein the light intensity of the first area is less than that of the second area. The utility model provides a laser projection device during operation light source emission beam forms floodlight beam after penetrating the diffusion component and jets out, makes the luminous intensity in floodlight beam different regions different through regulation and control to reduce the emergent power of laser projection device unilateral, can be suitable for the use scene that this side corresponds the high reflectivity target, reduce the production of the condition of overexposure, improve laser projection device's range of application.

Description

Laser projection device and depth camera

Technical Field

The utility model relates to the technical field of imaging equipment, in particular to a laser projection device and a depth camera.

Background

At present, with the development of scientific research in the optical field day by day and the continuous progress of digital imaging technology, a depth camera is widely researched as a three-dimensional imaging sensor and is applied to multiple fields such as home furnishing, exploration, semiconductors and intelligent terminals. The depth camera comprises a laser projection device, an image sensor and a processing circuit, wherein the laser projection device is used for projecting modulated laser signals towards a measured target, the image sensor is used for collecting laser reflection signals reflected by the target, and the processing circuit is used for calculating the time difference (phase difference) from the emission of the laser signals to the collection of the laser signals, acquiring the depth information of the target and completing the three-dimensional measurement of the target.

In the prior art, in a depth camera based on an indirect flight time technology, a laser projection device emits a uniform floodlight beam towards a target scene, and in the process of using some fixed scenes, the light emitted from a position close to a fixed side is easily blocked and reflected by the ground, a desktop or other working surfaces, so that reflected light signals received by an image sensor are too large, an overexposure phenomenon occurs, target three-dimensional information measured by the depth camera is inaccurate, and the measurement precision of the depth camera is reduced.

Therefore, how to design the laser projection device to adapt to different use scenarios still remains to be improved and developed to improve the application range.

SUMMERY OF THE UTILITY MODEL

In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a laser projection device and a depth camera, which are capable of solving the problem of overexposure phenomenon generated during the measurement process of the depth camera and ensuring the service performance of the depth camera.

The technical scheme of the utility model is as follows:

a laser projection device comprises a light source and a diffusion element, wherein a light beam emitted by the light source passes through the diffusion element to form a floodlight beam with a preset visual field angle, and the floodlight beam is divided into a first area and a second area by configuring the light source or the diffusion element, wherein the light intensity of the first area is less than that of the second area.

The laser projection device, wherein the light source is configured to include a first light source and a second light source, the first light source emitting a light beam that passes through the diffuser element to form a first region of the flood light beam, and the second light source emitting a light beam that passes through the diffuser element to form a second region of the flood light beam.

The laser projection device, wherein the light emitting aperture of the first light source is smaller than the light emitting aperture of the second light source.

The laser projection device is provided with a plurality of first light sources, and a plurality of second light sources; and the number of the first light sources is less than or equal to the number of the second light sources.

The laser projection device, wherein the light emitting aperture of the first light source is equal to the light emitting aperture of the second light source; and the number of the first light sources is less than that of the second light sources.

The laser projection device further comprises a driver, and the driver is used for controlling the first light source and the second light source to synchronously emit light.

The laser projection device, wherein the diffuser element is configured to include a first diffuser portion and a second diffuser portion, the energy compensation coefficient of the first diffuser portion is greater than the energy compensation coefficient of the second diffuser portion, the light beam emitted by the light source forms a second region of the flood light beam through the first diffuser portion, and the light beam emitted by the light source forms a first region of the flood light beam through the second diffuser portion.

The laser projection device, wherein the light source is configured as a vertical cavity surface emitting laser lattice.

The application also discloses a depth camera, wherein, include as above arbitrary laser projection device, still include image sensor and processing circuit, processing circuit control laser projection device sends optical signal and control image sensor gathers by the target reflection back the optical signal, calculates the phase difference of sending optical signal with the optical signal that reflects back is in order to calculate the distance of target.

The depth camera further comprises a substrate, and the laser projection device and the image sensor are arranged on the substrate in parallel.

Compared with the prior art, the embodiment of the utility model has the following advantages:

the laser projection device disclosed in the application is used for the three-dimensional imaging process, and the during operation jets out the light beam to the surrounding environment, and the light source transmission beam forms floodlight beam behind the diffusion component and jets out, makes the luminous intensity in floodlight beam different regions different through regulation and control to reduce the emergent power of laser projection device unilateral, can be suitable for the use scene that this side corresponds the high reflectivity target, reduce the production of the condition of overexposure, improve laser projection device's range of application. Moreover, the laser projection device is applied to the depth camera, so that the probability of an overexposure phenomenon in the imaging process is reduced, the finally measured target three-dimensional information is more accurate, and the use performance of the depth camera is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic view of a laser projection apparatus according to the present invention;

FIG. 2 is a schematic cross-sectional view of a laser projection apparatus according to the present invention;

FIG. 3 is a schematic view of a light source according to the present invention;

FIG. 4 is a schematic view of another embodiment of a light source according to the present invention;

FIG. 5 is another schematic view of the light source of the present invention.

10, a laser projection device; 11. a light source; 111. a first light source; 112. a second light source; 12. a diffusion element; 121. a first diffusion portion; 122. a second diffusion portion; 20. an image sensor; 30. a substrate.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

At present, with the progress of social science and technology, the research and development work of electronic products is continuously developed, the market share of intelligent equipment is higher and higher, the intelligent equipment refers to any equipment, apparatus or machine with computing and processing capacity, and the intelligent equipment with complete functions must have sensitive and accurate sensing function, correct thinking and judging function and effective execution function; and the perception abilities given to the machine equipment by people include light induction, heat induction, force induction and the like.

For example, in an intelligent robot, an intelligent floor sweeping robot and an intelligent projector, a depth camera has a huge effect, a laser transmitting and receiving device is arranged in the depth camera, laser is transmitted to the surrounding environment, then detection is carried out by depending on a laser signal reflected back, and the time difference (phase difference) from transmission to reception of the laser signal is calculated, so that the three-dimensional information of the surrounding environment is calculated, and the applications of target detection, navigation obstacle avoidance, three-dimensional reconstruction and the like can be realized.

However, due to the limitation of the use position, the depth camera needs to be fixed on a supporting surface to work stably, when the depth camera emits light beams, light beam signals close to the supporting surface are easily reflected by the supporting surface, and therefore, the over-exposure phenomenon is easily caused when the light wave energy received by the sensor is too large; for example, when the sweeping robot is used, the depth camera is closer to the ground or the height of the table top, which is about 10 cm, and the receiving end in the field angle range of the ground or the table top side is easy to generate an overexposure phenomenon, so that the depth is not accurate enough. In addition, the current remedy is to reduce the light-emitting intensity of the depth camera, but the precision of the depth camera is deteriorated, and the imaging effect is not good.

It should be noted that, the present invention uses the scene of the depth camera on the ground as an example to describe the specific structure and the working principle of the present invention, but the application of the present invention is not limited to the imaging camera, and the present invention can be applied to the production and use processes of other similar optical devices; the method is not limited to the use scene used on the ground, and can be applied to other similar use scenes.

Referring to fig. 1 and 2, in an embodiment of the present invention, a laser projection device 10 is disclosed, wherein the laser projection device 10 includes a light source 11 and a diffusion member 12, a light beam emitted from the light source 11 passes through the diffusion member 12 to form a flood light beam with a predetermined field angle, and the flood light beam is divided into a first area and a second area by configuring the light source 11 or the diffusion member 12, wherein the light intensity of the first area is less than the light intensity of the second area. In a particular embodiment of the utility model, the controllable flood light beam has a lower intensity on the side close to the ground than on the side remote from the ground. In one embodiment, the light source 11 may be a Light Emitting Diode (LED), a Laser Diode (LD), an Edge Emitting Laser (EEL), a Vertical Cavity Surface Emitting Laser (VCSEL), or the like, or may be a one-dimensional or two-dimensional light source array composed of a plurality of light sources. Preferably, the light source array is a VCSEL array light source chip formed by generating a plurality of VCSEL light sources on a single semiconductor substrate, and the arrangement of the light sources in the light source array may be regular or irregular. The light beam emitted by the light source may be visible light, infrared light, ultraviolet light, or the like. The light source emits a light beam outward under the control of the driver.

The laser projection device disclosed in the application is used for the three-dimensional imaging process, and the during operation jets out the light beam to the surrounding environment, and light source 11 transmission beam forms floodlight beam after penetrating diffusion component 12 and jets out, makes the luminous intensity in floodlight beam different regions different through regulation and control to reduce the emergent power of laser projection device unilateral, can be suitable for the use scene that this side corresponds the high reflectivity target, reduce the production of the condition of overexposure, improve laser projection device's range of application. Moreover, the laser projection device is applied to the depth camera, so that the probability of an overexposure phenomenon in the imaging process is reduced, the finally measured target three-dimensional information is more accurate, and the use performance of the depth camera is improved.

Specifically, as an implementation manner of the present embodiment, it is disclosed that the light source 11 is configured as a Vertical-Cavity Surface-Emitting Laser (VCSEL) lattice. The VCSEL is developed on the basis of gallium arsenide semiconductor materials, is different from other light sources, has the advantages of high directivity, small volume, circular output light spots, single longitudinal mode output, small threshold current, low price, low power consumption, easiness in integration into a large-area array and the like, and has the characteristics of narrow light-emitting angle, high optical purity, high optical response speed, accuracy in rear-end sensing and the like, wherein the optical response speed of the VCSEL is 10 times that of a light-emitting diode; moreover, the die bonding and wire bonding process is consistent with that of the light emitting diode chip, special design is not needed, and the use is convenient. In the embodiment, the VCSEL lattice is used for emitting more concentrated light waves, then the image sensor is used for accurately and quickly sensing the light waves reflected back by the target and outputting electric signals, so that the depth information of the surrounding environment is obtained according to the electric signals, and the three-dimensional image is accurately constructed.

It should be noted that the light source 11 in this embodiment may also be composed of an array of light emitting elements such as an infrared emitter, an ultraviolet emitter, etc., and the imaging effect can be achieved as long as a corresponding signal receiving device is disposed on the electronic device.

Referring to fig. 3, as another implementation manner of the embodiment, it is disclosed that the light source 11 is configured to include a first light source 111 and a second light source 112, a light beam emitted by the first light source 111 passes through the diffusion member 12 to form a first area of a flood light beam, and a light beam emitted by the second light source 112 passes through the diffusion member 12 to form a second area of the flood light beam. When the light source 11 works, the first light source 111 and the second light source 112 emit light beams synchronously, and the light intensity of the first light source 111 and the light intensity of the second light source 112 can be controlled simply and conveniently by controlling the first light source 111 and the second light source 112 respectively, so that the floodlight beams are divided into areas with different light intensities easily. In an embodiment of the present invention, the first light source 111 is disposed on the side close to the ground, and the second light source 112 is disposed on the side away from the ground, so as to ensure that the light intensity of the emitted floodlight beam close to the ground is less than that of the floodlight beam away from the ground, thereby reducing the emergent power of the near side of the depth camera, reducing the occurrence of overexposure, and improving the usability of the depth camera.

Specifically, in this embodiment, the first light source 111 and the second light source 112 adopt the same structure, for example, both adopt VCSELs, which is beneficial to saving raw material types, facilitating manufacturing, reducing cost, and making it easier to control the light emitting states of the two light sources differently during use.

As shown in fig. 3, as another implementation manner of the present embodiment, it is disclosed that the light emitting aperture of the first light source 111 is smaller than the light emitting aperture of the second light source 112. The light emitting aperture of the first light source 111 is small, and the emitting power is small, for example, the ratio of the light emitting aperture of the second light source 112 to the light emitting aperture of the first light source 111 is 3:1, when the current with the same voltage is passed, the emitting power of the second light source 112 is about 3 times of the emitting power of the first light source 111, and in the working process of the depth camera, the first light source 111 is close to the ground, the light wave emitted to the ground is less, and the light signal reflected from the ground is correspondingly less, so that the overexposure phenomenon is reduced, the high-precision clear reflected light signal is obtained, and the accurate depth result is obtained.

As shown in fig. 4, as another implementation manner of the present embodiment, it is disclosed that a plurality of first light sources 111 are provided, and a plurality of second light sources 112 are also provided; and, the number of the first light sources 111 is less than or equal to the number of the second light sources 112. The number of the second light sources 112 may meet the requirement of high-precision imaging of the depth camera, the number of the first light sources 111 is reduced by a part on the basis, for example, the first light sources 111 and the second light sources 112 are both VCSELs, the plurality of first light sources 111 are arranged in a rectangular array to form a first light source array, the plurality of second light sources 112 are also arranged in a rectangular array to form a second light source array, however, each row of the second light sources 112 is provided with 3 light emitting points, each row of the first light sources 111 is provided with 2 light emitting points, after passing through currents of the same voltage, the light output power of the second light source array is about 1.5 times that of the first light source array, the light output intensities of the first light sources and the second light sources may be the same or different, and preferably, the light intensities of the first light sources and the second light sources are the same. In this case, the first light source 111 is close to the ground, and the smaller the light output power is, the less the overexposure phenomenon will occur, so that the imaging result obtained by the depth camera is clear, accurate and effective. In addition, as shown in fig. 5, when the light emitting aperture of the first light source 111 is smaller than the light emitting aperture of the second light source 112, and a smaller number of the first light sources 111 are provided, the light emitting intensity of all the first light sources 111 as a whole can be further reduced, and a better effect of preventing the overexposure phenomenon can be obtained.

It should be noted that the VCSELs in this embodiment may be arranged in a rectangular array, or may be arranged in a circular array or a polygonal array, and all of them may form a flood light beam through the diffusion member 12. Preferably, the first light sources 111 and the second light sources 112 are arranged in the same manner, so that the light output amount at each height in the direction perpendicular to the ground is relatively uniform, the incident angle and the reflection angle of the emitted light on the reflection surface are relatively uniform, and the reflected light wave signals are more accurate, so that a more accurate imaging result is obtained.

Specifically, as another implementation manner of the present embodiment, it is disclosed that the light emitting aperture of the first light source 111 is equal to the light emitting aperture of the second light source 112; moreover, a plurality of first light sources 111 are provided, a plurality of second light sources 112 are also provided, and the number of first light sources 111 is smaller than the number of second light sources 112. When the apertures of the first light source 111 and the second light source 112 are equal, the VCSELs of the same model can be used, the types of parts can be reduced when the depth camera is manufactured, the cost is saved, the installation mode is simpler, the manufacturing process is simplified, and the light emitting state of the floodlight beam can be regulated and controlled by controlling the number of the first light source 111 and the second light source 112 which emit light only through circuit control; in the actual manufacturing process, the number of the second light sources 112 is set to meet the requirement of normal imaging, and on this basis, the number of the first light sources 111 is set to be smaller than that of the second light sources 112, so that all the first light sources 111 form an area with weak light intensity in the flood light beam integrally, the area is close to the ground, the reflection of the ground can be reduced, and the overexposure phenomenon is reduced.

Specifically, as another implementation manner of the present embodiment, it is disclosed that the lighting device further includes a driver (not shown in the drawings), and the driver is configured to control the first light source 111 and the second light source 112 to emit light synchronously. Two light sources are driven to work simultaneously through one driver, and the operation is simpler and more convenient.

As shown in fig. 2, as another implementation manner of the present embodiment, it is disclosed that the diffusing member 12 is configured to include a first diffusing part 121 and a second diffusing part 122, an energy compensation coefficient of the first diffusing part 121 is greater than an energy compensation coefficient of the second diffusing part 122, a light beam emitted by the light source 11 forms a second area of a flood light beam through the first diffusing part 121, and a light beam emitted by the light source 11 forms a first area of the flood light beam through the second diffusing part 122. In one embodiment of the present application, the first diffuser portion 121 is disposed on the side away from the ground, and the second diffuser portion 122 is disposed on the side close to the ground. The diffusion elements 12 are also arranged to be unevenly distributed, such as the ratio of the energy compensation coefficient of the first diffusion 121 to the energy compensation coefficient of the second diffusion 122 is about 3:1, the high energy compensation coefficient of the first diffusion part 121 enables the laser signal emitted from the second light source 112 to maintain sufficient intensity, to be emitted to a long distance, and to have sufficient energy to be reflected back to be detected, thereby ensuring an accurate depth measurement result; the energy compensation coefficient of the second diffusion portion 122 is set to be lower, so that the light output power of the first light source 111 is reduced, and the overexposure phenomenon generated on the side close to the ground can be prevented.

Specifically, the first diffusion part 121 and the second diffusion part 122 of the diffusion element 12 in the present embodiment, and the first light source 111 and the second light source 112 of the light source 11 may be designed at the same time, and the first light source 111 and the second diffusion part 122 are disposed in order along the optical axis direction, and the second light source 112 corresponds to the first diffusion part 121, and is configured as an effective over-exposure prevention laser projection device. Of course, only the first diffusion part 121 and the second diffusion part 122 may be provided, the light source 11 may use a conventional light emitting element, and the conventional diffusion element 12 may also be used, so that the light intensity of different areas of the flood light beam is regulated by only providing the first light source 111 and the second light source 112, thereby achieving the purpose of avoiding overexposure.

As shown in fig. 1, as another embodiment of the present invention, a depth camera is disclosed, wherein the depth camera includes the laser projection device 10 as described above, and further includes an image sensor 20 and a processing circuit (not shown), the processing circuit controls the laser projection device 10 to emit a light signal and controls the image sensor 20 to collect the light signal reflected back by a target, a phase difference between the emitted light signal and the reflected light signal is calculated to calculate a depth of the target, and a host computer can restore a three-dimensional image of a scene based on depth information of the target.

Specifically, as another implementation manner of the embodiment, it is disclosed that the depth camera further includes a substrate 30, and the light source 11 and the image sensor 20 are arranged in parallel on the substrate 30. The light beam is transmitted along a straight line, so that the light beam emitted by the light source 11 is reflected by a target and enters the image sensor, the image sensor 20 and the light source 11 are arranged on the substrate 30 in parallel, the light beam can be emitted from the same side of the substrate 30, the reflected light signal can be received, the accurate light signal can be obtained, and the accurate and complete depth measurement result can be formed.

Specifically, as another implementation manner of the present embodiment, it is disclosed that the light source 11 and the image sensor 20 are located on the same horizontal plane. The light source 11 emits a flood light beam in the direction of the optical axis parallel to the ground, and when there is an obstacle on the light path, the reflected light beam is still on the same horizontal plane without displacement in the vertical direction, so the image sensor 20 is also arranged on the horizontal plane to better receive the reflected light signal.

In summary, the present application discloses a laser projection device 10, wherein the laser projection device 10 includes a light source 11 and a diffusion member 12, a light beam emitted from the light source passes through the diffusion member to form a floodlight beam with a predetermined field angle, and the floodlight beam is divided into a first area and a second area by configuring the light source 11 or the diffusion member 12 to regulate and control the floodlight beam, wherein the light intensity of the first area is less than the light intensity of the second area. The laser projection device disclosed in the application is used for the three-dimensional imaging process, and the during operation jets out the light beam to the surrounding environment, and light source 11 sends the light beam and forms floodlight beam after penetrating diffusion component 12 and jets out, makes the luminous intensity in floodlight beam different regions different through regulation and control to reduce the emergent power of laser projection device 10 unilateral, can be suitable for the use scene that this side corresponds the high reflectivity target, reduce the production of the condition of overexposure, improve laser projection device 10's range of application. Moreover, the laser projection device 10 is applied to the depth camera, so that the probability of an overexposure phenomenon in the imaging process is reduced, the finally measured target three-dimensional information is more accurate, and the use performance of the depth camera is improved.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict.

It will be understood that the utility model is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the utility model is limited only by the appended claims.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the utility model, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims (10)

1. A laser projection device is characterized by comprising a light source and a diffusion element, wherein a light beam emitted by the light source passes through the diffusion element to form a floodlight beam with a preset visual field angle, and the floodlight beam is divided into a first area and a second area by configuring the light source or the diffusion element so as to regulate and control the floodlight beam, wherein the light intensity of the first area is less than that of the second area.

2. The laser projection device of claim 1, wherein the light source is configured to include a first light source that emits a light beam that passes through the diffuser element to form a first region of the flood light beam and a second light source that emits a light beam that passes through the diffuser element to form a second region of the flood light beam.

3. The laser projection device of claim 2, wherein the first light source has a smaller light emitting aperture than the second light source.

4. A laser projection device as claimed in claim 3, wherein the first light source is provided in plurality and the second light source is provided in plurality; and the number of the first light sources is less than or equal to the number of the second light sources.

5. The laser projection device of claim 2, wherein the first light source has a light emitting aperture equal to the light emitting aperture of the second light source; and the number of the first light sources is less than that of the second light sources.

6. The laser projection device of claim 2, further comprising a driver for controlling the first light source and the second light source to emit light synchronously.

7. The laser projection device of claim 1, wherein the diffuser element is configured to include a first diffuser portion and a second diffuser portion, the first diffuser portion having an energy compensation factor greater than the energy compensation factor of the second diffuser portion, the light source emitting a light beam that passes through the first diffuser portion to form a second region of the flood light beam, the light source emitting a light beam that passes through the second diffuser portion to form a first region of the flood light beam.

8. The laser projection device of any of claims 1 to 7, wherein the light source is configured as a vertical cavity surface emitting laser array.

9. A depth camera comprising the laser projection device of any one of claims 1-8, further comprising an image sensor and processing circuitry, the processing circuitry controlling the laser projection device to emit a light signal and controlling the image sensor to collect the light signal reflected back by a target, and calculating a phase difference between the emitted light signal and the reflected light signal to calculate a distance to the target.

10. The depth camera of claim 9, further comprising a substrate on which the laser projection device and the image sensor are juxtaposed.

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