WO2021136105A1

WO2021136105A1 - Tof depth sensing module and image generation method

Info

Publication number: WO2021136105A1
Application number: PCT/CN2020/139598
Authority: WO
Inventors: 高少锐; 罗伟城; 吴巨帅; 邱孟; 郭帮辉; 宋小刚
Original assignee: 华为技术有限公司
Priority date: 2020-01-03
Filing date: 2020-12-25
Publication date: 2021-07-08
Also published as: CN113075641A

Abstract

A TOF depth sensing module (600) and an image generation method. The TOF depth sensing module (600) comprises: a laser light source (610), an optical element (620), a beam splitter (630), a receiving unit (640) and a control unit (650), the optical element (620) being provided in the direction that the laser light source (610) emits a beam. The laser light source (610) is used to generate a laser beam; the optical element (620) is used to control the direction of the laser beam, so as to obtain a first outgoing beam and a second outgoing beam; the beam splitter (630) is used to propagate, to different regions of the receiving unit (640), a third reflected beam obtained by reflecting the first outgoing beam by a target object and a fourth reflected beam obtained by reflecting the second outgoing beam by the target object. The heat loss of the TOF depth sensor module (600) is reduced.

Description

A TOF depth sensing module and image generation method

This application claims the priority of a Chinese patent application filed with the Chinese Patent Office on January 3, 2020, the application number is 202010006471.9, and the application name is "a TOF depth sensing module and image generation method", the entire content of which is incorporated by reference Incorporated in this application.

Technical field

This application relates to the field of TOF technology, and more specifically, to a TOF depth sensing module and an image generation method.

Background technique

Time of flight (TOF) technology is a commonly used depth or distance measurement technology. Its basic principle is that continuous light or pulsed light is emitted through the transmitter. When the continuous light or pulsed light illuminates the object to be measured, it will reflect , And then the receiving end receives the reflected light of the object to be measured. Next, by determining the flight time of the light from the transmitting end to the receiving end, the distance or depth of the object to be measured to the TOF system can be calculated.

Because the liquid crystal device has excellent polarization and phase adjustment capabilities, it is widely used in TOF depth sensing modules to achieve beam deflection. However, due to the birefringence characteristics of liquid crystal materials, existing TOF depth sensing modules using liquid crystal devices generally add a polarizer at the emitting end to realize the emission of polarized light. During the emergence of polarized light, due to the polarization selection effect of the polarizer, half of the energy is lost when the beam is emitted. This part of the energy lost will be absorbed or scattered by the polarizer and converted into heat, resulting in TOF depth sensing mode. The temperature rise of the group affects the stability of the TOF depth sensor module.

Summary of the invention

The present application provides a TOF depth sensing module and an image generation method to reduce the heat loss of the TOF depth sensing module and improve the signal-to-noise ratio of the TOF depth sensing module.

In the first aspect, a TOF depth sensor module is provided, the TOF depth sensor module includes a laser light source, an optical element, a beam splitter, a receiving unit, and a control unit, wherein the optical element is arranged on the laser light source to emit a beam Direction.

The functions of each module or unit in the TOF depth sensing module are as follows:

Laser light source is used to generate laser beam;

The optical element is used to control the direction of the laser beam to obtain the first outgoing beam and the second outgoing beam;

The beam splitter is used for transmitting the third reflected light beam obtained by reflecting the target object to the first outgoing light beam, and the fourth reflecting light beam obtained by reflecting the second outgoing light beam by the target object to different areas of the receiving unit.

Wherein, the exit direction of the first exit beam and the exit direction of the second exit beam are different, the first exit beam and the second exit beam are both single polarization beams, and the polarization direction of the first exit beam and the second exit beam are The polarization direction is orthogonal.

The polarization states of the first outgoing light beam and the second outgoing light beam may be left-handed circular polarization and right-handed circular polarization, respectively. Alternatively, the polarization of the first outgoing beam and the second outgoing beam may be linear polarization in the horizontal direction and linear polarization in the vertical direction, respectively.

Optionally, the above-mentioned control unit is used to control the birefringence parameter of the optical element to obtain the adjusted birefringence parameter, and the above-mentioned optical element is used to adjust the direction of the laser beam based on the adjusted birefringence parameter to obtain the first Outgoing beam and second outgoing beam.

Optionally, the above-mentioned first outgoing beam and second outgoing beam are obtained at the same time.

Wherein, the third reflected light beam is a light beam obtained by the target object reflecting the first outgoing light beam from the optical element, and the fourth reflected light beam is a light beam obtained by the target object reflecting the second outgoing light beam from the optical element.

The above-mentioned receiving unit may include a receiving lens and a sensor. The receiving lens can converge the reflected light beam to the sensor, so that the sensor can receive the reflected light beam, and then obtain the time when the reflected light beam is received by the receiving unit, and obtain the TOF corresponding to the outgoing beam. The TOF corresponding to the outgoing beam generates a depth map of the target object.

Specifically, the receiving lens may converge the third reflected light beam and the fourth reflected light beam to the sensor, and obtain the moment when the third reflected light beam and the fourth reflected light beam are received by the receiving unit through the sensor, so as to obtain the first emergent light beam and the second reflected light beam. The corresponding TOF is emitted, and finally the first depth map of the target object can be generated by the TOF corresponding to the first emitted light beam, and the second depth map of the target object can be generated according to the TOF corresponding to the second emitted light beam.

Wherein, the TOF corresponding to the first outgoing beam may specifically refer to the time difference information between the emitting moment of the first outgoing beam and the receiving moment of the third reflected beam; the TOF corresponding to the second outgoing beam may specifically refer to the second outgoing beam. Time difference information between the emission time of the light beam and the reception time of the fourth reflected light beam.

In the above process, the laser beam generated by the laser light source may contain multiple polarization states. For example, the laser beam includes left-handed circular polarization, right-handed circular polarization, and linear polarization. After processing by optical elements, a first outgoing beam with a left-handed circular polarization state and a second outgoing beam with a right-handed circular polarization state can be obtained. .

The above-mentioned different exit directions of the first exit beam and the second exit beam may specifically mean that the azimuth angle of the first exit beam is different from the azimuth angle of the second exit beam, but the inclination angles of the first exit beam and the second exit beam can be the same .

In the embodiments of this application, since there is no polarization filter device at the emitting end, the light beam emitted by the laser light source can reach the optical element with almost no loss (polarization filter device generally absorbs more light energy, which will cause a certain amount of heat loss) , Can reduce the heat loss of TOF depth sensor module.

The above-mentioned beam splitter is a passive selection device, which is generally not controlled by the control unit, and can respectively propagate light beams with different polarization states in the light beams with mixed polarization states to different areas of the receiving unit.

With reference to the first aspect, in some implementations of the first aspect, the above-mentioned optical element includes: a horizontal polarization control plate, a horizontal liquid crystal polarization grating, a vertical polarization control plate, and a vertical liquid crystal polarization grating.

Optionally, in the above-mentioned optical element, the distance between the lateral polarization control sheet, the lateral liquid crystal polarization grating, the longitudinal polarization control sheet, and the longitudinal liquid crystal polarization grating and the laser light source becomes larger in sequence.

Optionally, in the above-mentioned optical element, the distance between the longitudinal polarization control sheet, the longitudinal liquid crystal polarization grating, the lateral polarization control sheet, and the lateral liquid crystal polarization grating and the laser light source becomes larger in sequence.

With reference to the first aspect, in some implementations of the first aspect, the above-mentioned beam splitter is implemented based on any one of a liquid crystal polarization grating LCPG, a polarization beam splitting prism PBS, and a polarization filter.

With reference to the first aspect, in some implementations of the first aspect, the TOF depth sensing module further includes: a collimating lens, the collimating lens is arranged between the laser light source and the optical element, and the collimating lens is used for The laser beam is collimated to obtain a collimated beam; the above-mentioned optical element is used to control the direction of the collimated beam to obtain a first outgoing beam and a second outgoing beam.

The above collimation processing of the light beam by the collimating lens can obtain an approximately parallel light beam, which can increase the power density of the light beam, and thus can improve the effect of subsequent scanning with the light beam.

Optionally, the clear aperture of the collimating lens is less than or equal to 5 mm.

Due to the small size of the collimating lens, the TOF depth sensing module including the collimating lens is easier to integrate into the terminal device, which can reduce the space occupied in the terminal device to a certain extent.

With reference to the first aspect, in some implementations of the first aspect, the TOF depth sensing module further includes: a homogenization device, the homogenization device is arranged between the laser light source and the optical element, and the homogenization device is used for The angular spatial intensity distribution of the laser beam is adjusted to obtain a homogenized beam; the optical element is used to control the direction of the homogenized beam to obtain the first outgoing beam and the second outgoing beam.

With reference to the first aspect, in some implementations of the first aspect, the above-mentioned homogenizing device is a microlens diffuser or a diffractive optical diffuser.

With reference to the first aspect, in some implementations of the first aspect, the above-mentioned laser light source is a vertical cavity surface emitting laser (VCSEL).

Optionally, the above-mentioned laser light source is a Fabry-Perot laser (may be referred to as FP laser for short).

Compared with a single VCSEL, a single FP laser can achieve greater power, and at the same time the electro-optical conversion efficiency is higher than that of a VCSEL, which can improve the scanning effect of the TOF depth sensor module.

Optionally, the wavelength of the laser beam emitted by the above-mentioned laser light source is greater than 900 nm.

Since the intensity of light greater than 900nm in sunlight is relatively weak, when the wavelength of the laser beam is greater than 900nm, it helps to reduce interference caused by sunlight, thereby improving the scanning effect of the TOF depth sensor module.

Optionally, the wavelength of the laser beam emitted by the laser light source is 940 nm or 1550 nm.

Since the intensity of light near 940nm or 1550nm in sunlight is relatively weak, when the wavelength of the laser beam is 940nm or 1550nm, the interference caused by sunlight can be greatly reduced, and the scanning effect of the TOF depth sensor module can be improved.

With reference to the first aspect, in some implementations of the first aspect, the light-emitting area of the above-mentioned laser light source is less than or equal to 5×5 mm ² .

Due to the small size of the above-mentioned laser light source, the TOF depth sensing module containing the laser light source is relatively easy to be integrated into the terminal device, which can reduce the space occupied in the terminal device to a certain extent.

With reference to the first aspect, in some implementations of the first aspect, the average output optical power of the TOF depth sensing module is less than 800 mw.

When the average output optical power of the TOF depth sensor module is less than or equal to 800mw, the TOF depth sensor module has a smaller power consumption, which is convenient for installation in terminal equipment and other devices that are more sensitive to power consumption.

In a second aspect, an image generation method is provided. The image generation method is applied to a terminal device containing the TOF depth sensing module in the above first aspect. The image generation method includes: controlling a laser light source to generate a laser beam; controlling an optical element Control the direction of the laser beam to obtain the first outgoing beam and the second outgoing beam; control the beam splitter to reflect the third reflected beam from the target object to the first outgoing beam, and the target object to reflect the second outgoing beam The obtained fourth reflected light beam propagates to different areas of the receiving unit; the first depth map of the target object is generated according to the TOF corresponding to the first exit light beam; the second depth map of the target object is generated according to the TOF corresponding to the second exit light beam.

Among them, the exit direction of the first exit beam and the exit direction of the second exit beam are different, the first exit beam and the second exit beam are both beams with a single polarization state, the polarization direction of the first exit beam and the polarization direction of the second exit beam Orthogonal.

Optionally, the above method further includes: acquiring the TOF corresponding to the first outgoing beam and the TOF corresponding to the second outgoing beam.

Optionally, obtaining the TOF corresponding to the first outgoing beam and the TOF corresponding to the second outgoing beam includes: determining the TOF corresponding to the first outgoing beam according to the emitting time of the first outgoing beam and the receiving time of the third reflected beam; The emission time of the second outgoing light beam and the receiving time of the fourth reflected light beam determine the TOF corresponding to the second outgoing light beam.

Optionally, the above-mentioned image generation method further includes: splicing or combining the first depth map and the second depth map to obtain a depth map of the target object.

It should be understood that in the above image generation method, the third depth map, the fourth depth map, etc. can also be generated in a similar manner. Next, all the depth maps can be stitched or combined to obtain the final depth of the target object. Figure.

In the embodiments of this application, since there is no polarization filter device at the emitting end, the light beam emitted by the laser light source can reach the optical element with almost no loss (polarization filter device generally absorbs more light energy, which will cause a certain amount of heat loss) , Can reduce the heat loss of terminal equipment.

Optionally, the foregoing image generation method further includes: stitching the first depth map and the second depth map to obtain a depth map of the target object.

With reference to the second aspect, in some implementations of the second aspect, the above-mentioned terminal device further includes a collimating lens disposed between the laser light source and the optical element, and the above-mentioned image generation method further includes: using a collimating lens Performing collimation processing on the laser beam to obtain a collimated beam; the above-mentioned controlling optical element controls the direction of the laser beam to obtain the first outgoing beam and the second outgoing beam, including: controlling the optical element after the alignment treatment The direction of the light beam is controlled to obtain the first outgoing beam and the second outgoing beam.

In addition, the above collimation processing of the light beam by the collimating lens can obtain an approximately parallel light beam, which can increase the power density of the light beam, and thus can improve the effect of subsequent scanning with the light beam.

With reference to the second aspect, in some implementations of the second aspect, the above-mentioned terminal device further includes a homogenization device, the homogenization device is arranged between the laser light source and the optical element, and the above-mentioned image generation method further includes: using a homogenization device Adjust the energy distribution of the laser beam to obtain the homogenized beam; control the optical element to control the direction of the laser beam to obtain the first outgoing beam and the second outgoing beam, including: controlling the optical element to homogenize the beam The direction of the light beam is controlled to obtain the first outgoing light beam and the second outgoing light beam.

The homogenization process can make the optical power of the laser beam more uniform in the angular space, or distribute it according to a specific law, to prevent the local optical power from being too small, and to avoid blind spots in the final depth map of the target object.

In a third aspect, a terminal device is provided, and the terminal device includes the TOF depth sensing module in the above-mentioned first aspect.

The terminal device of the third aspect described above can execute the image generation method of the second aspect.

Description of the drawings

Figure 1 is a schematic diagram of the principle of lidar ranging;

2 is a schematic diagram of distance measurement using the TOF depth sensing module of the embodiment of the present application;

Fig. 3 is a schematic block diagram of a TOF depth sensing module according to an embodiment of the present application;

Figure 4 is a schematic diagram of a VCSEL;

Figure 5 is a schematic diagram of an array light source;

6 is a schematic diagram of using a beam splitter to split the light beam emitted by the array light source;

FIG. 7 is a schematic diagram of a projection area obtained by splitting the light beam emitted by the array light source by using a beam splitter;

FIG. 8 is a schematic diagram of a projection area obtained by splitting the light beam emitted by the array light source by using a beam splitter;

FIG. 9 is a schematic diagram of a projection area obtained by splitting the light beam emitted by the array light source using a beam splitter;

FIG. 10 is a schematic diagram of a projection area obtained by splitting the light beam emitted by the array light source using a beam splitter;

FIG. 11 is a schematic structural diagram of a TOF depth sensing module according to an embodiment of the present application;

FIG. 12 is a schematic diagram of beam splitting processing performed by a beam splitter;

FIG. 13 is a schematic structural diagram of a TOF depth sensing module according to an embodiment of the present application;

FIG. 14 is a schematic structural diagram of a TOF depth sensing module according to an embodiment of the present application;

FIG. 15 is a schematic diagram of the operation of the TOF depth sensing module according to the embodiment of the present application;

FIG. 16 is a schematic diagram of the light-emitting area of the array light source;

FIG. 17 is a schematic diagram of using a beam splitter to perform beam splitting processing on the light beam emitted by the array light source shown in FIG. 16;

FIG. 18 is a schematic flowchart of an image generation method according to an embodiment of the present application;

Figure 19 is a depth map of the target object at time t0-t3;

FIG. 20 is a schematic flowchart of an image generation method according to an embodiment of the present application;

FIG. 21 is a schematic flowchart of an image generation method according to an embodiment of the present application;

FIG. 22 is a schematic flowchart of obtaining the final depth map of the target object in the first working mode;

FIG. 23 is a schematic flow chart of obtaining the final depth map of the target object in the first working mode;

FIG. 24 is a schematic flowchart of obtaining the final depth map of the target object in the second working mode;

FIG. 25 is a schematic flowchart of obtaining the final depth map of the target object in the second working mode;

FIG. 26 is a schematic diagram of using the TOF depth sensing module of an embodiment of the present application to perform distance measurement;

FIG. 27 is a schematic block diagram of a TOF depth sensing module according to an embodiment of the present application;

Figure 28 is a schematic diagram of the spatial angle of the laser beam;

FIG. 29 is a schematic block diagram of a TOF depth sensing module according to an embodiment of the present application;

FIG. 30 is a schematic diagram of scanning a target object by the TOF depth sensing module according to an embodiment of the present application; FIG.

FIG. 31 is a schematic diagram of the scanning trajectory of the TOF depth sensor module according to an embodiment of the present application;

FIG. 32 is a schematic diagram of a scanning method of the TOF depth sensor module according to an embodiment of the present application;

FIG. 33 is a schematic block diagram of a TOF depth sensing module according to an embodiment of the present application;

FIG. 34 is a schematic block diagram of a TOF depth sensing module according to an embodiment of the present application;

35 is a schematic diagram of the structure of a liquid crystal polarization grating according to an embodiment of the present application;

FIG. 36 is a schematic structural diagram of a TOF depth sensing module according to an embodiment of the present application;

FIG. 37 is a schematic diagram of changing the physical characteristics of the liquid crystal polarization grating through periodic control signals;

Fig. 38 is a schematic diagram of a liquid crystal polarization grating controlling the direction of an input light beam;

Figure 39 is a schematic diagram of a voltage signal applied to a liquid crystal polarization grating;

FIG. 40 is a schematic diagram of the scanning trajectory of the TOF depth sensing module according to an embodiment of the present application;

Fig. 41 is a schematic diagram of the area to be scanned;

Fig. 42 is a schematic diagram of the area to be scanned;

FIG. 43 is a schematic structural diagram of a TOF depth sensing module according to an embodiment of the present application;

Fig. 44 is a schematic diagram of the electro-optic crystal controlling the direction of the light beam;

Figure 45 is a schematic diagram of a voltage signal applied to an electro-optic crystal;

FIG. 46 is a schematic diagram of the scanning trajectory of the TOF depth sensing module according to an embodiment of the application;

FIG. 47 is a schematic structural diagram of a TOF depth sensing module according to an embodiment of the present application;

Fig. 48 is a schematic diagram of the acousto-optic device controlling the direction of the light beam;

FIG. 49 is a schematic structural diagram of a TOF depth sensing module according to an embodiment of the present application;

Figure 50 is a schematic diagram of the OPA device controlling the direction of the light beam;

FIG. 51 is a schematic structural diagram of a TOF depth sensing module according to an embodiment of the present application;

FIG. 52 is a schematic flowchart of an image generation method according to an embodiment of the present application;

FIG. 53 is a schematic diagram of using the TOF depth sensing module of an embodiment of the present application to perform distance measurement;

FIG. 54 is a schematic structural diagram of a TOF depth sensing module according to an embodiment of the present application;

FIG. 55 is a schematic block diagram of a TOF depth sensing module according to an embodiment of the present application;

Fig. 56 is a schematic block diagram of a TOF depth sensing module according to an embodiment of the present application;

FIG. 57 is a schematic flowchart of an image generation method according to an embodiment of the present application;

FIG. 58 is a schematic block diagram of a TOF depth sensing module according to an embodiment of the present application;

FIG. 59 is a schematic block diagram of a TOF depth sensing module according to an embodiment of the present application;

FIG. 60 is a schematic block diagram of a TOF depth sensing module according to an embodiment of the present application;

Fig. 61 is a schematic structural diagram of a TOF depth sensing module according to an embodiment of the present application;

FIG. 62 is a schematic flowchart of an image generation method according to an embodiment of the present application;

FIG. 63 is a schematic structural diagram of a TOF depth sensing module according to an embodiment of the present application

FIG. 64 is a schematic structural diagram of a liquid crystal polarizing device according to an embodiment of the present application; FIG.

Figure 65 is a schematic diagram of the control sequence;

Fig. 66 is a timing chart of voltage drive signals;

FIG. 67 is a schematic diagram of the scanning area of the TOF depth sensor module at different times;

FIG. 68 is a schematic diagram of the depth map corresponding to the target object at time t0-t3;

Fig. 69 is a schematic diagram of the final depth map of the target object;

FIG. 70 is a schematic diagram of working with the TOF depth sensing module according to an embodiment of the present application;

FIG. 71 is a schematic structural diagram of a TOF depth sensing module according to an embodiment of the present application;

FIG. 72 is a schematic structural diagram of a TOF depth sensing module according to an embodiment of the present application;

FIG. 73 is a schematic structural diagram of a TOF depth sensing module according to an embodiment of the present application;

FIG. 74 is a schematic structural diagram of a TOF depth sensing module according to an embodiment of the present application;

FIG. 75 is a schematic structural diagram of a TOF depth sensing module according to an embodiment of the present application;

FIG. 76 is a schematic structural diagram of a TOF depth sensing module 500 according to an embodiment of the present application;

Fig. 77 is a schematic diagram of the morphology of a microlens diffuser;

FIG. 78 is a schematic flowchart of an image generation method according to an embodiment of the present application;

Fig. 79 is a schematic structural diagram of a TOF depth sensing module according to an embodiment of the present application;

FIG. 80 is a schematic diagram of a specific structure of a TOF depth sensing module according to an embodiment of the present application;

FIG. 81 is a schematic diagram of a specific structure of a TOF depth sensing module according to an embodiment of the present application;

FIG. 82 is a schematic diagram of a specific structure of a TOF depth sensing module according to an embodiment of the present application;

FIG. 83 is a schematic diagram of a specific structure of a TOF depth sensing module according to an embodiment of the present application;

FIG. 84 is a schematic structural diagram of a TOF depth sensing module 600 according to an embodiment of the present application;

FIG. 85 is a schematic structural diagram of a TOF depth sensing module 600 according to an embodiment of the present application;

FIG. 86 is a schematic structural diagram of a TOF depth sensing module 600 according to an embodiment of the present application;

Fig. 87 is a schematic diagram of a polarizing filter receiving a polarized light beam;

FIG. 88 is a schematic flowchart of an image generation method according to an embodiment of the present application;

FIG. 89 is a schematic diagram of a specific structure of a TOF depth sensing module according to an embodiment of the present application;

90 is a schematic diagram of a specific structure of a TOF depth sensing module according to an embodiment of the present application;

FIG. 91 is a schematic diagram of a specific structure of a TOF depth sensing module according to an embodiment of the present application;

FIG. 92 is a schematic diagram of a specific structure of a TOF depth sensing module according to an embodiment of the present application;

FIG. 93 is a schematic diagram of a specific structure of a TOF depth sensing module according to an embodiment of the present application;

FIG. 94 is a schematic diagram of the driving signal and the receiving signal of the TOF depth sensing module according to an embodiment of the present application;

95 is a schematic diagram of the angle and state of the light beam emitted by the TOF depth sensing module according to an embodiment of the present application;

FIG. 96 is a schematic structural diagram of a TOF depth sensing module according to an embodiment of the present application;

FIG. 97 is a schematic structural diagram of a TOF depth sensing module according to an embodiment of the present application;

FIG. 98 is a schematic structural diagram of a TOF depth sensing module according to an embodiment of the present application;

Fig. 99 is a schematic diagram of the principle of beam deflection performed by a flat-panel liquid crystal cell;

FIG. 100 is a schematic diagram of the principle of beam deflection performed by a flat panel liquid crystal cell;

FIG. 101 is a schematic flowchart of an image generation method according to an embodiment of the present application;

FIG. 102 is a schematic diagram of the FOV of the first light beam;

Fig. 103 is a schematic diagram of FOVs covered by M outgoing beams in different directions.

Detailed ways

The technical solution in this application will be described below in conjunction with the accompanying drawings.

Figure 1 is a schematic diagram of the principle of lidar ranging.

As shown in Figure 1, the transmitter of the lidar emits laser pulses (the pulse width can be in the order of nanoseconds to picoseconds), and at the same time the timer starts timing. When the laser pulses irradiate the target area, due to the surface of the target area The reflection of the laser will produce the reflected laser pulse. When the detector of the lidar receives the reflected laser pulse, the timer stops timing to obtain the TOF. Next, you can calculate the distance between the lidar and the target area based on TOF.

Specifically, the distance between the lidar and the target area can be determined according to formula (1).

L=c*T/2 (1)

Among them, in the above formula (1), L is the distance between the lidar and the target area, c is the speed of light, and T is the time of light propagation.

It should be understood that, in the TOF depth sensor module of the embodiment of the present application, the laser light source emits a light beam to be processed by other components in the TOF depth sensor module (for example, collimating lens, beam splitter, etc.) , So that the light beam is finally emitted from the emitting end. In this process, the light beam from a certain element in the TOF depth sensor module can also be called the light beam emitted by the element.

For example, a laser light source emits a light beam, which is then emitted after being collimated by a collimating lens. The light beam emitted by the collimating lens can actually be called the light beam from the collimating lens. The light beam emitted by the collimating lens here is not It does not mean the light beam emitted by the collimating lens itself, but the light beam emitted after processing the light beam propagated by the previous element.

In addition, in this application, the light beam emitted by the laser light source or the array light source may also be referred to as the light beam from the laser light source or the array light source.

The TOF depth sensing module of the embodiment of the present application will be briefly introduced below with reference to FIG. 2.

FIG. 2 is a schematic diagram of distance measurement using the TOF depth sensing module of the embodiment of the present application.

As shown in Figure 2, the TOF depth sensing module can include a transmitting end (or a projection end), a receiving end, and a control unit. The transmitting end is used to generate the outgoing beam, and the receiving end is used to receive the reflected beam of the target object. (The reflected light beam is the light beam obtained by the target object reflecting the outgoing light beam), and the control unit can control the transmitting end and the receiving end to transmit and receive the light beam respectively.

In Figure 2, the transmitting end may generally include a laser light source, a beam splitter, a collimating lens and a projection lens (optional), the receiving end may generally include a receiving lens and a sensor, and the receiving lens and sensor may be collectively referred to as a receiving unit.

In FIG. 2, the TOF corresponding to the emitted light beam can be recorded by the timing device to calculate the distance from the TOF depth sensor module to the target area, and then the final depth map of the target object can be obtained. Wherein, the TOF corresponding to the outgoing beam may refer to the time difference information between the moment when the reflected beam is received by the receiving unit and the outgoing moment of the outgoing beam.

The laser light source in FIG. 2 may be an array light source.

The TOF depth sensor module of the embodiment of the application can be used for three-dimensions (3D) image acquisition, and the TOF depth sensor module of the embodiment of the application can be installed in a smart terminal (for example, a mobile phone, a tablet, a wearable device). Etc.), it is used to acquire depth images or 3D images, and can also provide gesture and body recognition for 3D games or somatosensory games.

The TOF depth sensing module of the embodiment of the present application will be described in detail below in conjunction with FIG. 3.

Fig. 3 is a schematic block diagram of a TOF depth sensing module according to an embodiment of the present application.

The TOF depth sensing module 100 shown in FIG. 3 includes an array light source 110, a collimating lens 120, a beam splitter 130, a receiving unit 140, and a control unit 150. The modules or units in the TOF depth sensing module 100 will be described in detail below.

Array light source 110:

The array light source 110 is used for generating (emitting) a laser beam.

Wherein, the aforementioned array light source 110 includes N light-emitting areas, each light-emitting area can independently generate a laser beam, and N is a positive integer greater than 1.

The above-mentioned control unit 150 is used to control the M light-emitting areas of the N light-emitting areas of the array light source 110 to emit light.

The collimating lens 120 is used for collimating the light beams emitted by the M light-emitting areas;

The beam splitter 130 is used to align the beam after the collimation processing of the collimating lens to perform beam splitting processing;

The receiving unit 140 is used to receive the reflected light beam of the target object.

Wherein, the above M is less than or equal to N, M is a positive integer, and N is a positive integer greater than 1; the above beam splitter is specifically used to divide each light beam received into multiple beams of light; the reflected light beam of the above target object It is the light beam obtained by the target object reflecting the light beam from the beam splitter. The light beams emitted by the above M light-emitting areas may also be referred to as light beams from the M light-emitting areas.

Since M is less than or equal to N, the control unit 150 can control part or all of the light-emitting areas in the array light source 110 to emit light.

The above-mentioned N light-emitting regions may be N independent light-emitting regions, that is, each of the above-mentioned N light-emitting regions can emit light independently or independently without being affected by other light-emitting regions. For each of the above-mentioned N light-emitting areas, each light-emitting area is generally composed of multiple light-emitting units. In the above-mentioned N light-emitting areas, different light-emitting areas are composed of different light-emitting units, that is, The same light-emitting unit belongs to only one light-emitting area. For each light-emitting area, when the light-emitting area is controlled to emit light, all the light-emitting units in the light-emitting area can emit light.

The total number of light-emitting areas of the array light source may be N. When M=N, the control unit can control all light-emitting areas of the array light source to emit light simultaneously or time-sharing.

Optionally, the above-mentioned control unit is used to control the M light-emitting areas of the N light-emitting areas of the array light source to emit light at the same time.

For example, the above-mentioned control unit may control the M light-emitting areas among the N light-emitting areas of the array light source to emit light at the time T0.

Optionally, the above-mentioned control unit is configured to control the M light-emitting areas of the N light-emitting areas of the array light source to respectively emit light at M different times.

For example, the above M=3, the above control unit can control the three light-emitting areas of the array light source to emit light at time T0, T1, and T2 respectively, that is, the first light-emitting area of the three light-emitting areas is at time T0 Light, the second light-emitting area emits light at time T1, and the third light-emitting area emits light at time T2.

Optionally, the above-mentioned control unit is configured to control the M light-emitting areas of the N light-emitting areas of the array light source to emit light at M0 different moments, where M0 is a positive integer greater than 1 and less than M.

For example, if M=3 and M0=2, the control unit can control one of the three light-emitting areas of the array light source to emit light at time T0, and control the other two light-emitting areas of the three light-emitting areas of the array light source to emit light at time T0. Lights up at T1.

In the embodiment of the present application, by controlling the time-sharing light emission of different light-emitting areas of the array light source and controlling the beam splitter to split the beam, the number of beams emitted by the TOF depth sensor module in a period of time can be increased, and the number of beams can be A higher spatial resolution and higher frame rate are achieved during the scanning of the target object.

Optionally, the light-emitting area of the aforementioned array light source 110 is less than or equal to 5×5 mm ² .

When the light-emitting area of the array light source 110 is less than or equal to 5×5 mm ² , the area of the array light source 110 is small, which can reduce the space occupied by the TOF depth sensor module 100 and facilitate the installation of the TOF depth sensor module 100 in a relatively space. Limited terminal equipment.

Optionally, the aforementioned array light source 110 may be a semiconductor laser light source.

The aforementioned array light source 110 may be a vertical cavity surface emitting laser (VCSEL).

Fig. 5 is a schematic diagram of a VCSEL. As shown in Fig. 5, the VCSEL includes a lot of light-emitting points (the black dot area in Fig. 5), and each light-emitting point can emit light under the control of the control unit.

Optionally, the above-mentioned laser light source may be a Fabry-Perot laser (may be referred to as FP laser for short).

Compared with a single VCSEL, a single FP laser can achieve greater power, and the electro-optical conversion efficiency is also higher than that of a VCSEL, which can improve the scanning effect.

Optionally, the wavelength of the laser beam emitted by the aforementioned array light source 110 is greater than 900 nm.

Since the intensity of light greater than 900nm in sunlight is relatively weak, when the wavelength of the laser beam is greater than 900nm, it helps to reduce interference caused by sunlight, and can improve the scanning effect of the TOF depth sensor module.

Optionally, the wavelength of the laser beam emitted by the aforementioned array light source 110 is 940 nm or 1550 nm.

Hereinafter, the case where the array light source 110 includes a plurality of independent light-emitting areas will be described in detail with reference to FIG. 5.

As shown in Figure 5, the array light source 110 is composed of mutually independent light-emitting

areas

111, 112, 113 and 114. There are several light-emitting units 1001 in each area, and several light-emitting units 1001 in each area are connected by a common electrode 1002. , The light-emitting units of different light-emitting areas are connected to different electrodes, so that the different areas are independent of each other.

For the array light source 110 shown in FIG. 5, the independent light-emitting

areas

111, 112, 113, and 114 can be separately controlled to emit light at different times through the control unit 150. For example, the control unit 150 may control the light-emitting

areas

111, 112, 113, and 114 to emit light at times t0, t1, t2, and t3, respectively.

Optionally, the light beam after collimation processing by the collimating lens 120 may be a quasi-parallel light with a divergence angle less than 1 degree.

The collimating lens 120 may be composed of one or more lenses. When the collimating lens 120 is composed of multiple lenses, the collimating lens 120 can effectively reduce the aberrations generated during the collimation process.

The collimating lens 120 may be composed of plastic material, or glass material, or both plastic material and glass material. When the collimating lens 120 is made of glass material, the collimating lens can reduce the influence of the back focal length of the temperature collimating lens 120 in the process of collimating the light beam.

Specifically, since the thermal expansion coefficient of the glass material is small, when the collimating lens 120 adopts the glass material, the influence of the back focal length of the temperature collimating lens 120 can be reduced.

Optionally, the clear aperture of the collimating lens 120 is less than or equal to 5 mm.

When the clear aperture of the collimating lens 120 is less than or equal to 5mm, the area of the collimating lens 120 is small, which can reduce the space occupied by the TOF depth sensor module 100, and facilitate the installation of the TOF depth sensor module 100 in a relatively space. Limited terminal equipment.

As shown in FIG. 3, the receiving unit 140 may include a receiving lens 141 and a sensor 142, and the receiving lens 141 is used to converge the reflected light beam to the sensor 142.

The aforementioned sensor 142 may also be referred to as a sensor array, and the sensor array may be a two-dimensional sensor array.

Optionally, the resolution of the above-mentioned sensor 142 is greater than or equal to P×Q, and the beam splitter splits the light beam emitted from a light-emitting area of the array light source 110 to obtain the number of beams P×Q, where P and Q All are positive integers.

The resolution of the upload sensor is greater than or equal to the number of beams obtained by the beam splitter 130 after splitting the beam from a light-emitting area of the array light source, so that the sensor 142 can receive the target object and reflect the beam from the beam splitter. The reflected light beam, in turn, enables the TOF depth sensor module to achieve normal reception of the reflected light beam.

Optionally, the aforementioned beam splitter 130 may be either a one-dimensional beam splitting device or a two-dimensional beam splitting device.

In actual application, one-dimensional beam splitting device or two-dimensional beam splitting device can be selected as required.

Specifically, in actual application, one-dimensional beam splitting device or two-dimensional beam splitting device can be selected according to the needs. When only the outgoing beam needs to be split in one dimension, one-dimensional beam splitting device can be used. When beam splitting in two dimensions, a two-dimensional beam splitting device is required.

When the aforementioned beam splitter 130 is a one-dimensional beam splitting device, the beam splitter 130 may specifically be a cylindrical lens array or a one-dimensional grating.

When the beam splitter 130 is a two-dimensional beam splitting device, the beam splitter 130 may specifically be a microlens array or a two-dimensional diffractive optical element (DOE).

The above-mentioned beam splitter 130 may be composed of a resin material or a glass material, or a combination of a resin material and a glass material.

When the components of the beam splitter 130 include glass materials, the effect of temperature on the performance of the beam splitter 130 can be effectively reduced, so that the beam splitter 130 maintains a relatively stable performance. Specifically, when the temperature changes, the thermal expansion coefficient of glass is lower than that of resin. Therefore, when the beam splitter 130 adopts a glass material, the performance of the beam splitter is relatively stable.

Optionally, the area of the beam incident end surface of the beam splitter 130 is smaller than 5×5 mm ² .

When the area of the beam incident end surface of the beam splitter 130 is less than 5×5mm ² , the area of the beam splitter 130 is smaller, which can reduce the space occupied by the TOF depth sensor module 100 and facilitate the integration of the TOF depth sensor module 100 is installed in terminal equipment with relatively limited space.

Optionally, the beam receiving surface of the aforementioned beam splitter 130 is parallel to the beam emitting surface of the array light source 110.

When the beam receiving surface of the beam splitter 130 is parallel to the beam emitting surface of the array light source 110, the beam splitter 130 can receive the light beam emitted by the array light source 110 more efficiently, and the receiving beam of the beam splitter 130 can be improved. effectiveness.

As shown in FIG. 3, the receiving unit 140 may include a receiving lens 141 and a sensor 142. The way in which the receiving unit receives the light beam will be introduced below in conjunction with specific examples.

For example, the above-mentioned array light source 110 includes 4 light-emitting areas, then the receiving lens 141 can be used to receive the target object to reflect the light beam generated by the beam splitter 130 at 4 different times (t4, t5, t6, and t7) The obtained reflected light beam 1, the reflected light beam 2, the reflected light beam 3, and the reflected light beam 4 are obtained, and the reflected light beam 1, the reflected light beam 2, the reflected light beam 3, and the reflected light beam 4 are propagated to the sensor 142.

Optionally, the above-mentioned receiving lens 141 may be composed of one or more lenses.

When the receiving lens 141 is composed of multiple lenses, the aberration generated when the receiving lens 141 receives the light beam can be effectively reduced.

In addition, the above-mentioned receiving lens 141 may be composed of a resin material or a glass material, or a combination of a resin material and a glass material.

When the receiving lens 141 includes a glass material, the influence of the temperature on the back focal length of the receiving lens 141 can be effectively reduced.

The above-mentioned sensor 142 can be used to receive the light beam propagated by the lens 141, and perform photoelectric conversion of the light beam propagated by the receiving lens 141, and convert the optical signal into an electrical signal, which is convenient for subsequent calculation of the beam from the transmitting end to the receiving end. The time difference between (this time difference can be called the flight time of the beam), and the distance between the target object and the TOF depth sensor module is calculated according to the time difference, and then the depth image of the target object is obtained.

The aforementioned sensor 142 may be a single-photon avalanche diode (SPAD).

Among them, SPAD is an avalanche photodiode that works in Geiger mode (bias voltage is higher than breakdown voltage). After receiving a single photon, there is a certain probability that an avalanche effect will occur, and a pulse current signal is instantly generated for detection. The time of arrival of the photon. Since the SPAD array used for the TOF depth sensing module described above requires a complicated quenching circuit, a timing circuit, and a storage and reading unit, the resolution of the existing SPAD array used for TOF depth sensing is limited.

In the case of a long distance between the target object and the TOF depth sensor module, the intensity of the reflected light from the target object transmitted by the receiving lens to the sensor is generally very weak, and the sensor needs to have very high detection sensitivity, while SPAD has single-photon detection Sensitivity and response time in the order of picoseconds, therefore, the use of SPAD as the sensor 142 in this application can improve the sensitivity of the TOF depth sensing module.

In addition to controlling the array light source 110, the aforementioned control unit 150 may also control the sensor 142.

The above-mentioned control unit 150 may maintain electrical connection with the array light source 110 and the sensor 142 to realize the control of the array light source 110 and the sensor 142.

Specifically, the control unit 150 can control the working mode of the sensor 142 so that at M different moments, the corresponding areas of the sensor can respectively receive the reflected light beams reflected by the target object on the light beams emitted by the corresponding light-emitting areas of the array light source 110.

Specifically, the part of the reflected beam of the target object located within the numerical aperture of the receiving lens will be received by the receiving lens and propagate to the sensor. Through the design of the receiving lens, each pixel of the sensor can receive the reflected beams from different areas of the target object. .

In this application, by dividing the light of the array light source and using the beam splitter for beam splitting, the number of beams emitted by the TOF depth sensor module at the same time can be increased, and the depth of the target object finally obtained can be increased. Image spatial resolution and high frame rate.

It should be understood that, as shown in FIG. 2, for the TOF depth sensing module of the embodiment of the present application, the projection end and the receiving end of the TOF depth sensing module may both be located on the same side of the target object.

Optionally, the output optical power of the TOF depth sensing module 100 is less than or equal to 800 mw.

Specifically, the maximum output optical power or average output power of the TOF depth sensing module 100 is less than or equal to 800 mW.

When the output optical power of the TOF depth sensing module 100 is less than or equal to 800 mw, the TOF depth sensing module 100 has a relatively small power consumption, which is convenient for installation in devices that are sensitive to power consumption such as terminal equipment.

Hereinafter, the process of obtaining the depth map of the target object by the TOF depth sensing module 100 of the embodiment of the present application will be described in detail with reference to FIGS. 6 to 10.

As shown in FIG. 6, the left figure is a schematic diagram of the light-emitting area of the array light source 110. The array light source 110 includes four light-emitting areas (also called light-emitting regions) A, B, C, and D. The four light-emitting areas are respectively at t0 , T1, t2 and t3 will light up at all times. The figure on the right is a schematic diagram of the surface of the target object projected by the light beam generated by the array light source 110 after being split by the beam splitter 130, where each point represents the projected spot, and the area enclosed by each black solid line is the sensor 142 The target area corresponding to a pixel in. In FIG. 6, the reproduction order of the corresponding beam splitter 130 is 4×4, that is to say, at each moment, the luminous spot generated by a region of the array light source will be copied after being copied by the beam splitter 130. It becomes 4×4 spots. Therefore, the beam splitter 130 can greatly increase the number of spots projected at the same time.

In FIG. 6, by respectively lighting the four light-emitting regions of the array light source 110 at times t0, t1, t2, and t3, depth maps of different positions of the target object can be obtained.

Specifically, schematic diagrams of the light beam emitted from the light-emitting area a of the array light source 110 at time t0 being projected onto the surface of the target object after the beam splitting process by the beam splitter 130 are respectively shown in FIG. 7.

Schematic diagrams of the light beam emitted from the light-emitting area b of the array light source 110 at time t1 being projected onto the surface of the target object after the beam splitting process by the beam splitter 130 are respectively shown in FIG. 8.

Schematic diagrams of the light beam emitted from the light-emitting area c of the array light source 110 at time t2 being projected onto the surface of the target object after the beam splitting process by the beam splitter 130 are respectively shown in FIG. 9.

Schematic diagrams of the light beam emitted from the light-emitting area d of the array light source 110 at time t3 being projected onto the surface of the target object after the beam splitting process by the beam splitter 130 are respectively shown in FIG. 10.

According to the beam projection conditions shown in Figure 7 to Figure 10, the depth maps corresponding to the target objects at t0, t1, t2, and t3 can be obtained, and then the depth maps corresponding to the target objects at t0, t1, t2, and t3 can be superimposed. Obtain a depth map of the target object with higher resolution.

In the TOF depth sensing module 100 shown in FIG. 3, the collimating lens 120 may be located between the array light source 110 and the beam fraction device 130, and the light beam emitted by the array light source 110 must first be collimated by the collimating lens 120. Then the beam splitter is used to align the processed light beam for processing.

Optionally, for the TOF depth sensor module 100 described above, the beam splitter 130 may also directly perform beam splitting processing on the light beam generated by the array light source 110, and then the collimating lens 120 may perform splitting processing on the beam splitting process. The beam is collimated.

A detailed description will be given below in conjunction with FIG. In the TOF depth sensing module 100 shown in FIG. 11, the specific functions of each module or unit are as follows:

The control unit 150 is configured to control the M light-emitting areas of the N light-emitting areas in the array light source 110 to emit light;

The beam splitter 130 is used to perform beam splitting processing on the light beams emitted by the M light-emitting regions;

The collimating lens 120 is used for collimating the light beam emitted by the beam splitter 130;

The receiving unit 140 is configured to receive the reflected light beam of the target object.

Wherein, the above-mentioned M is less than or equal to N, M is a positive integer, and N is a positive integer greater than 1. The beam splitter 130 is specifically used to divide each received light into multiple beams; the reflected light beam of the target object is The target object is aligned with the light beam emitted by the lens 120 to reflect the light beam. The light beams emitted by the above M light-emitting areas may also be referred to as light beams from the M light-emitting areas.

The main difference between the TOF depth sensor module shown in FIG. 11 and the TOF depth sensor module shown in FIG. 3 lies in the position of the collimating lens. In the TOF depth sensor module shown in FIG. The lens is located between the array light source and the beam splitter, and in the TOF depth sensor module shown in Figure 11, the beam splitter is located between the array light source and the collimating lens (equivalent to the collimating lens being located in the beam splitting The direction of the light beam emitted by the device).

The TOF depth sensor module 100 shown in FIG. 11 and the TOF depth sensor module 100 shown in FIG. 3 process the light beams emitted by the array light source 110 slightly differently. In the TOF depth sensor module 100 shown in FIG. 3, after the array light source 110 emits a light beam, the collimating lens 120 and the beam splitter 130 sequentially perform collimation processing and beam splitting processing. In the TOF depth sensor module 100 shown in FIG. 11, after the array light source 110 emits a light beam, the beam splitter 130 and the collimating lens 120 sequentially perform beam splitting and collimation processing.

The beam splitter 130 performs beam splitting processing on the light beam emitted by the array light source is introduced below in conjunction with the accompanying drawings.

As shown in FIG. 12, after the multiple light beams generated by the array light source 110 are split by the beam splitter 130, each light beam generated by the array light source 110 can be divided into multiple light beams. Many beams.

On the basis of the TOF depth sensing module shown in FIG. 11, the TOF depth sensing module 100 of the embodiment of the present application may further include an optical element whose refractive index is controllable. At the same time, the optical element can adjust the beam of a single polarization state to different directions, and can irradiate different beams to different directions without mechanical rotation and vibration, and can quickly locate the scanning area of interest.

FIG. 13 is a schematic structural diagram of a TOF depth sensing module according to an embodiment of the present application.

In the TOF depth sensing module 100 shown in FIG. 13, the specific functions of each module or unit are as follows:

The control unit 150 is configured to control the M light-emitting areas of the N light-emitting areas of the array light source 110 to emit light;

The control unit 150 is also used to control the birefringence parameter of the optical element 160 to change the propagation direction of the light beams emitted by the M light-emitting regions.

The beam splitter 130 is used to receive the light beam emitted by the optical element 160 and perform beam splitting processing on the light beam emitted by the optical element 160;

Optionally, the beam splitter 130 is specifically configured to divide each received light into multiple beams, and the beam splitter 130 may split the light beam emitted from one light-emitting area of the array light source 110 to obtain the light beam The number is P×Q.

Wherein, the reflected light beam of the target object is a light beam obtained by reflecting the light beam emitted by the beam splitter 130 by the target object. The light beams emitted by the above M light-emitting areas may also be referred to as light beams from the M light-emitting areas.

In FIG. 13, the optical element 160 is located between the array light source 110 and the beam splitter 130. In fact, the optical element 160 may also be located between the collimating lens 120 and the beam splitter 130, as described below with reference to FIG. 14.

FIG. 14 is a schematic structural diagram of a TOF depth sensing module according to an embodiment of the present application.

In the TOF depth sensing module 100 shown in FIG. 14, the specific functions of each module or unit are as follows:

The control unit 150 is also used to control the birefringence parameter of the optical element 160 to change the propagation direction of the light beam after the collimation lens 120 is collimated;

The working process of the TOF depth sensing module in the embodiment of the present application will be described in detail below with reference to FIG. 15.

FIG. 15 is a schematic diagram of the operation of the TOF depth sensing module according to the embodiment of the present application.

As shown in Figure 15, the TOF depth sensing module includes a projection end, a receiving end, and a control unit. The control unit is used to control the projection end to emit outgoing beams to scan the target area. The control unit also uses The receiving end is controlled to receive the reflected light beam reflected from the target scanning area.

Wherein, the projection end includes an array light source 110, a collimating lens 120, an optical element 160, a beam splitter 130, and a projection lens (optional). The receiving end includes a receiving lens 141 and a sensor 142. The control unit 150 is also used to control the timing synchronization of the array light source 110, the optical element 160, and the sensor 142.

The collimating lens 140 in the TOF depth sensing module shown in FIG. 15 may include 1-4 lenses, and the collimating lens 140 is used to convert the first light beam generated by the array light source 110 into approximately parallel light.

The working process of the TOF depth sensor module shown in Figure 15 is as follows:

(1) The light beam emitted by the array light source 110 is collimated by the collimating lens 120 to form a collimated light beam and reach the optical element 160;

(2) The optical element 160 realizes the orderly deflection of the light beam according to the timing control of the control unit, so that the angle of the deflected light beam after emission can be scanned in two dimensions;

(3) The deflected light beam emitted by the optical element 160 reaches the beam splitter 130;

(4) The beam splitter 130 replicates the deflected beams of each angle to obtain the output beams of multiple angles, thereby realizing the two-dimensional replication of the beams;

(5) In each scanning period, the receiving end can only image the target area illuminated by the spot;

(6) After the optical element completes all S×T scans, the two-dimensional array sensor in the receiving end will generate S×T images, and finally these images are stitched into a higher resolution image in the processor.

The array light source in the TOF depth sensor module of the embodiment of the application can have multiple light-emitting areas, and each light-emitting area can emit light independently. The array light source of the TOF depth sensor module of the embodiment of the application includes multiple light-emitting areas. In the case of the light-emitting area, the working process of the TOF depth sensor module is described in detail.

FIG. 16 is a schematic diagram of the light-emitting area of the array light source.

When the array light source 110 includes multiple light-emitting areas, the working process of the TOF depth sensing module of the embodiment of the present application is as follows:

(1) The light beams from the different light-emitting areas of the array light source 110 in time sharing form a collimated beam through the collimating lens 120, and reach the beam splitter 130. The beam splitter 130 is controlled by the timing signal of the control unit, and can realize the control of the light beam. Orderly deflection, so that the angle of the outgoing beam can be scanned in two dimensions;

(2) The beam after collimation by the collimator lens 120 reaches the beam splitter 130, which replicates the incident beam at each angle, and simultaneously generates multiple angles of outgoing beams, realizing two-dimensional beams copy;

(3) In each scanning period, the receiving end only images the target area illuminated by the spot;

(4) After the optical element completes all S×T scans, the two-dimensional array sensor in the receiving end will generate S×T images, and finally these images are stitched into a higher resolution image in the processor.

The scanning working principle of the TOF depth sensor module according to the embodiment of the present application will be described below in conjunction with FIG. 16 and FIG. 17.

As shown in Fig. 16, 111, 112, 113, 114 are independent light-emitting areas of the array light source, which can be lighted in time sharing, and 115, 116, 117, and 118 are light-emitting holes in different independent working areas of the array light source.

FIG. 17 is a schematic diagram of using a beam splitter to perform beam splitting processing on the light beam emitted by the array light source shown in FIG. 16.

As shown in Figure 17, 120 is a copy level generated by the beam splitter (the black solid line box in the upper left corner of Figure 17), and 121 is the target area corresponding to a pixel of the two-dimensional array sensor (121 includes 122, 123, 124 and 125), 122 is the spot generated by the light-emitting hole 115 through the beam splitter for beam scanning, 123 is the spot generated by the light-emitting hole 116 using optical elements for beam scanning, and 124 is the light-emitting hole 117 using optical elements for beam scanning The generated spot 125 is the spot generated by the light-emitting hole 118 using the optical element to scan the beam.

The specific scanning process of the TOF depth sensing module with the array light source shown in FIG. 16 is as follows:

Only 115 lights up, and the optical elements scan beams separately to achieve 122 spot spots;

115 is extinguished, 116 is lit, and the optical elements perform beam scanning respectively to realize the spot of 123;

Turn off 116, turn on 117, and the optical elements perform beam scanning respectively to achieve 124 spots;

Turn off 117, turn on 118, and the optical elements will scan the beams to achieve 125 spots;

Through the above four steps, the spot scanning of the target area corresponding to one pixel of the two-dimensional array sensor can be completed.

The optical element 160 in Figures 13 to 15 above can be any of liquid crystal polarization gratings, electro-optic devices, acousto-optic devices, optical phased array devices, etc., related to liquid crystal polarization gratings, electro-optic devices, acousto-optic devices, For detailed introduction of optical phased array devices and other devices, please refer to the related descriptions in the first to fourth cases below.

The TOF depth sensing module of the embodiment of the present application is described in detail above with reference to the accompanying drawings, and the image generation method of the embodiment of the present application is introduced below with reference to the accompanying drawings.

FIG. 18 is a schematic flowchart of an image generation method according to an embodiment of the present application. The method shown in FIG. 18 may be executed by a terminal device including the TOF depth sensing module of the embodiment of the present application. Specifically, the method shown in FIG. 18 may be executed by a terminal device including the TOF depth sensing module shown in FIG. 3. The method shown in FIG. 18 includes steps 2001 to 2006, and these steps are respectively described in detail below.

In 2001, the control unit is used to control the M light-emitting areas of the N light-emitting areas of the array light source to emit light at M different times.

Among them, M is less than or equal to N, M is a positive integer, and N is a positive integer greater than 1.

In the above step 2001, the light emission of the array light source can be controlled by the control unit.

Specifically, the control unit may respectively send control signals to the M light-emitting areas of the array light source at M times, so as to control the M light-emitting areas to emit light individually at M different times.

For example, as shown in FIG. 6, the array light source 110 includes four independent light-emitting areas A, B, C, and D. Then, the control unit can send four independent light-emitting areas A, B, C, and D at t0, t1, t2, and t3, respectively. B, C, and D send out control signals to make the four independent light-emitting areas A, B, C, and D emit light at t0, t1, t2, and t3, respectively.

In 2002, the collimating lens was used to collimate the light beams generated by the M light-emitting areas at M different moments to obtain the collimated light beams.

Still taking Fig. 6 as an example, when the four independent light-emitting areas A, B, C, and D of the array light source emit light beams at t0, t1, t2, and t3, respectively, the collimating lens can control the light-emitting areas A, B , C and D emit light beams at t0, t1, t2, and t3, respectively, for collimation processing to obtain the collimated light beams.

2003. Use beam splitter to align the beam after beam splitting.

The beam splitter can specifically divide each received light into multiple beams, and the number of beams obtained by the beam splitter from one light-emitting area of the array light source can be P×Q.

As shown in Figure 6, the light-emitting areas A, B, C, and D of the array light source emit light beams at t0, t1, t2, and t3, respectively. Then, the light-emitting areas A, B, C, and D are at t0, t1, t2, and The beam emitted at t3 is processed by the collimating lens and then incident into the beam splitter for processing. The beam splitter performs beam splitting on the light-emitting areas A, B, C, and D. The results can be shown on the right side of Figure 6 .

Optionally, the beam splitting processing in the above step 2003 specifically includes: performing one-dimensional or two-dimensional beam splitting processing on the beams generated after the alignment processing of the beam splitter.

2004. Use the receiving unit to receive the reflected beam of the target object.

The reflected light beam of the target object mentioned above is the light beam obtained by the target object reflecting the light beam from the beam splitter.

Optionally, the receiving unit in step 2004 includes a receiving lens and a sensor. In step 2004, using the receiving unit to receive the reflected light beam of the target object includes: using the receiving lens to converge the reflected light beam of the target object to the sensor. The sensor here may also be referred to as a sensor array, and the sensor array may be a two-dimensional sensor array.

Optionally, the resolution of the aforementioned sensor is greater than or equal to P×Q, and the number of beams obtained by the beam splitter from one light-emitting area of the array light source is P×Q.

Wherein, the above P and Q are both positive integers. The resolution of the uploaded sensor is greater than or equal to the number of beams after the beam splitter splits the beam from a light-emitting area of the array light source, so that the sensor can receive the reflected beam obtained by the target object reflecting the beam from the beam splitter , So that the TOF depth sensor module can realize the normal reception of the reflected beam.

2005. Generate M depth maps according to the TOF corresponding to the light beams emitted by the M light-emitting areas of the array light source at M different times.

The TOF corresponding to the light beams emitted by the M light-emitting areas of the array light source at M different times may specifically refer to the difference between the emission time of the light beams emitted by the M light-emitting areas of the array light source and the corresponding reflected light beams at M different times. Receive the time difference information between the moments.

For example, the array light source includes three light-emitting areas A, B, and C. The light-emitting area A emits a light beam at T0, the light-emitting area B emits a light beam at T1, and the light-emitting area C emits a light beam at T2. Then, the TOF corresponding to the light beam emitted by the light-emitting area A at time T0 may specifically refer to that the light beam emitted by the light-emitting area A at time T0 undergoes the collimation processing of the collimating lens and the beam splitting processing of the beam splitter, and reaches the target object. After the reflection of the target object, the time difference information between the time when it finally reaches the receiving unit (or is received by the receiving unit) and the time T0. The TOF corresponding to the light beam emitted by the light-emitting area B at time T1 and the TOF corresponding to the light beam emitted by the light-emitting area C at time T2 have similar meanings. Optionally, the foregoing M depth maps are respectively depth maps corresponding to M region sets of the target object, and there is a non-overlapping region between any two region sets in the M region sets.

Optionally, generating M depth maps of the target object in the foregoing step 2005 specifically includes:

2005a. Determine the distance between the M areas of the target object and the TOF depth sensor module according to the TOF corresponding to the light beams emitted by the M light-emitting areas at M different times;

2005b. According to the distance between the M regions of the target object and the TOF depth sensing module, generate a depth map of the M regions of the target object.

2006. Obtain the final depth map of the target object according to the M depth maps.

Specifically, in step 2006, M depth maps may be line-spliced to obtain a depth map of the target object.

For example, through the above steps 2001 to 2005, the depth map of the target object at time t0-t3 is obtained. The depth maps at these four time points are shown in Figure 19, and the depth maps at time t0-t3 shown in Figure 19 are spliced. , The final depth map of the target object can be as shown in Figure 69.

When the structure of the TOF depth sensor module is different, the process of the corresponding image generation method is also different. The image generation method of the embodiment of the present application will be introduced below with reference to FIG. 20.

FIG. 20 is a schematic flowchart of an image generation method according to an embodiment of the present application. The method shown in FIG. 20 may be executed by a terminal device including the TOF depth sensing module of the embodiment of the present application. Specifically, the method shown in FIG. 20 may be executed by a terminal device including the TOF depth sensing module shown in FIG. 11. The method shown in FIG. 20 includes steps 3001 to 3006, and these steps are respectively described in detail below.

3001. Utilize a control unit to control the M light-emitting areas of the N light-emitting areas of the array light source to emit light at M different times.

Wherein, the aforementioned N light-emitting regions do not overlap each other, M is less than or equal to N, M is a positive integer, and N is a positive integer greater than 1.

The above-mentioned use of the control unit to control the M light-emitting areas of the N light-emitting areas of the array light source to emit light at M different times may specifically refer to the use of the control unit to control the M light-emitting areas to emit light at M different times in sequence.

For example, as shown in FIG. 16, the array light source includes four light-emitting

areas

111, 112, 113, and 114. Then, the control unit can control 111, 112, and 113 to emit light at time T0, time T1, and time T2, respectively. Alternatively, the control unit may also control 111, 112, 113, and 114 to emit light at time T0, time T1, time T2, and time T3, respectively.

3002, using a beam splitter to perform beam splitting processing on the light beams respectively generated by the M light-emitting regions at M different moments.

The above-mentioned beam splitter is specifically used to divide each received light into multiple light beams.

The above-mentioned use of a beam splitter to split the beams generated by the M light-emitting regions at M different moments may specifically refer to the use of a beam splitter to separately perform beam splitters on the light beams generated by the M light-emitting regions at M different moments. Splitting processing.

For example, as shown in Figure 16, the array light source includes four light-emitting

areas

111, 112, 113, and 114. The control unit can control 111, 112, and 113 to emit light at T0, T1, and T2, respectively. Then, the beam splits The device can split the beam emitted by 111 at time T0, split the beam emitted by 112 at time T1, and split the beam emitted by 112 at time T2 (it should be understood that the beam from The time required for the luminous area to reach the beam splitter).

Optionally, the beam splitting processing in step 3002 specifically includes: using a beam splitter to perform one-dimensional or two-dimensional splitting processing on the light beams generated by the M light-emitting regions at M different moments.

3003. Use a collimating lens to collimate the beam from the beam splitter.

For example, still taking Figure 16 as an example, the beam splitter splits the beams emitted by 111, 112, and 113 at T0, T1, and T2. Then, the collimating lens can split the beam at T0. The beam splitter is collimated by the 111 beam splitter, the beam splitter 112 is collimated at time T1, and the beam split by the beam splitter 113 is collimated at time T2. The beam is collimated.

3004. Use the receiving unit to receive the reflected light beam of the target object.

Wherein, the reflected light beam of the target object is a light beam obtained by the target object reflecting the light beam from the collimating lens.

Optionally, the receiving unit in the above step 3004 includes a receiving lens and a sensor. In the above step 3004, using the receiving unit to receive the reflected light beam of the target object includes: using the receiving lens to converge the reflected light beam of the target object to the sensor. The sensor here may also be referred to as a sensor array, and the sensor array may be a two-dimensional sensor array.

3005. Generate M depth maps according to TOFs corresponding to light beams emitted at M different moments by the M light-emitting areas of the array light source.

For example, the array light source includes three light-emitting areas A, B, and C. The light-emitting area A emits a light beam at T0, the light-emitting area B emits a light beam at T1, and the light-emitting area C emits a light beam at T2. Then, the TOF corresponding to the light beam emitted by the light-emitting area A at time T0 may specifically refer to that the light beam emitted by the light-emitting area A at time T0 undergoes the collimation processing of the collimating lens and the beam splitting processing of the beam splitter, and reaches the target object. After the reflection of the target object, the time difference information between the time when it finally reaches the receiving unit (or is received by the receiving unit) and the time T0. The TOF corresponding to the light beam emitted by the light-emitting area B at time T1 and the TOF corresponding to the light beam emitted by the light-emitting area C at time T2 have similar meanings.

The foregoing M depth maps are respectively depth maps corresponding to M region sets of the target object, and there is a non-overlapping region between any two region sets in the M region sets.

Optionally, the foregoing step 3005 generates M depth maps, which specifically includes:

3005a. Determine the distance between the M areas of the target object and the TOF depth sensor module according to the TOFs corresponding to the light beams emitted by the M light-emitting areas at M different times;

3005b. According to the distance between the M regions of the target object and the TOF depth sensing module, generate a depth map of the M regions of the target object.

3006. Obtain a final depth map of the target object according to the M depth maps.

Optionally, obtaining the final depth map of the target object in the foregoing step 3006 includes: performing row stitching on M depth maps to obtain the depth map of the target object.

For example, the depth map obtained through the process of steps 3001 to 3005 above can be as shown in Figure 68, which shows the depth map corresponding to time t0-t3, and the depth map corresponding to time t0-t3 can be spliced as Figure 69 shows the final depth map of the target object.

In the embodiment of the present application, by controlling the time-sharing light emission of different light-emitting areas of the array light source and controlling the beam splitter to split the beam, the number of beams emitted by the TOF depth sensor module in a period of time can be increased, and more A depth map, so that the final depth map obtained by splicing multiple depth maps has a higher spatial resolution and a higher frame rate.

The method shown in FIG. 20 is similar to the method in FIG. 18 in the main processing process. The main difference is that the method shown in FIG. 20 first uses a beam splitter to split the light beam emitted by the array light source, and then uses collimation. The lens collimates the beam after beam splitting. In the method shown in FIG. 18, a collimating lens is first used to collimate the light beam emitted by the array light source, and then the beam splitter is used to collimate the light beam after the beam splitting process.

When the image generation method of the embodiment of the present application is executed by a terminal device, the terminal device may be in different working modes, the light emitting mode of the array light source in the different working modes, and the subsequent method of generating the final depth map of the target object are different. The following describes in detail how to obtain the final depth map of the target object in different working modes in conjunction with the accompanying drawings.

FIG. 21 is a schematic flowchart of an image generation method according to an embodiment of the present application.

The method shown in FIG. 21 includes steps 4001 to 4003, and these steps are respectively described in detail below.

4001. Determine the working mode of the terminal device.

The above-mentioned terminal device includes a first working mode and a second working mode. In the first working mode, the control unit can control the L light-emitting areas of the N light-emitting areas of the array light source to emit light at the same time. In the second working mode, The control unit can control the M light-emitting areas among the N light-emitting areas of the array light source to emit light at M different times.

It should be understood that when it is determined in step 4001 that the terminal device is working in the first working mode, step 4002 is executed, and when it is determined in step 4001 that the terminal device is working in the second working mode, step 4003 is executed.

The specific process of determining the working mode of the terminal device in step 4001 will be described in detail below.

Optionally, determining the working mode of the terminal device in the foregoing step 4001 includes: determining the working mode of the terminal device according to the user's working mode selection information.

Wherein, the user's work mode selection information is used to select one of the first work mode and the second work mode as the work mode of the terminal device.

Specifically, when the above-mentioned image generation method is executed by a terminal device, the terminal device may obtain the user's work mode selection information from the user. For example, the user can input the user's work mode selection information through the operation interface of the terminal device.

The foregoing determination of the working mode of the terminal device according to the user's working mode selection information enables the user to flexibly select and determine the working mode of the terminal device.

Optionally, determining the working mode of the terminal device in the foregoing step 4001 includes: determining the working mode of the terminal device according to the distance between the terminal device and the target object.

Specifically, in the case that the distance between the terminal device and the target object is less than or equal to the preset distance, it can be determined that the terminal device is working in the first working mode; and the distance between the terminal device and the target object is greater than the preset distance In the case of, it can be determined that the terminal device is working in the second working mode.

When the distance between the terminal device and the target object is small, the array light source has sufficient luminous power to simultaneously emit multiple light beams that reach the target object. Therefore, when the distance between the terminal device and the target object is small, by adopting the first working mode, multiple light-emitting areas of the array light source can emit light at the same time, which is convenient for obtaining the depth information of more areas of the target object later. If the resolution of the depth map is constant, increase the frame rate of the depth map of the target object.

When the distance between the terminal device and the target object is large, since the total power of the array light source is limited, the second working mode can be used to obtain the depth map of the target object. Specifically, by controlling the array light source to emit light beams in a time-sharing manner, the light beams from the array light source in a time-sharing manner can also reach the target object. This allows the terminal device to obtain the depth information of different regions of the target object in time sharing when the target object is far away, thereby obtaining the depth map of the target object.

Optionally, determining the working mode of the terminal device in the above step 4001 includes: determining the working mode of the terminal device according to the scene in which the target object is located.

Specifically, when the terminal device is in an indoor scene, it can be determined that the terminal device is working in the first working mode; when the terminal device is in an outdoor scene, it can be determined that the terminal device is working in the second working mode.

When the terminal device is in an indoor scene, because the distance between the terminal device and the target object is relatively short, the external noise is relatively weak, and the array light source has sufficient luminous power to emit multiple light beams that reach the target object at the same time. Therefore, when the distance between the terminal device and the target object is small, by adopting the first working mode, multiple light-emitting areas of the array light source can emit light at the same time, which is convenient for obtaining the depth information of more areas of the target object later. If the resolution of the depth map is constant, increase the frame rate of the depth map of the target object.

When the terminal device is in an outdoor scene, since the distance between the terminal device and the target object is relatively long, the external noise is relatively large, and the total power of the array light source is limited, the second working mode can be used to obtain the depth map of the target object . Specifically, by controlling the array light source to emit light beams in a time-sharing manner, the light beams from the array light source in a time-sharing manner can also reach the target object. This allows the terminal device to obtain the depth information of different regions of the target object in time sharing when the target object is far away, thereby obtaining the depth map of the target object.

According to the above-mentioned distance between the terminal device and the target object or the scene in which the target object is located, the working mode of the terminal device can be flexibly determined, so that the terminal device can work in a suitable working mode.

4002. Acquire a final depth map of the target object in the first working mode.

4003. Acquire a final depth map of the target object in the second working mode.

In the embodiment of the application, the image generation method has different working modes. Therefore, the first working mode or the second working mode can be selected according to different situations to generate the depth map of the target object, which can improve the flexibility of generating the depth map of the target object. High-resolution depth maps of the target object can be obtained in both working modes.

The process of obtaining the final depth map of the target object in the first working mode will be described in detail below in conjunction with FIG. 22.

Fig. 22 is a schematic flow chart of obtaining the final depth map of the target object in the first working mode. The process shown in FIG. 22 includes steps 4002A to 4002E, and these steps are respectively described in detail below.

4002A. Control the L light-emitting areas of the N light-emitting areas of the array light source to emit light at the same time.

Among them, L is less than or equal to N, L is a positive integer, and N is a positive integer greater than 1.

In step 4002A, the control unit can be used to control the L light-emitting areas of the N light-emitting areas of the array light source to emit light at the same time. Specifically, the control unit may send control signals to L light-emitting areas among the N light-emitting areas of the array light source at time T, so as to control the L light-emitting areas to emit light at time T at the same time.

For example, the array light source includes four independent light-emitting areas A, B, C, and D. Then, the control unit can send control signals to the four independent light-emitting areas A, B, C, and D at time T, so that the four independent light-emitting areas A, B, C, and D The light-emitting areas A, B, C, and D emit light at time T at the same time.

4002B. Use a collimating lens to collimate the light beams emitted from the L light-emitting areas.

Assuming that the array light source includes four independent light-emitting areas A, B, C, and D, then the collimating lens can collimate the light beams emitted from the light-emitting areas A, B, C, and D of the array light source at time T to obtain collimation The processed beam.

In step 4002B, the beam is collimated by the collimating lens to obtain a nearly parallel beam, which can increase the power density of the beam, and further improve the effect of subsequent scanning with the beam.

4002C. Use the beam splitter to align the beam generated by the collimation lens to perform beam splitting processing.

4002D. Use the receiving unit to receive the reflected beam of the target object.

4002E. Obtain the final depth map of the target object according to the TOF corresponding to the light beams emitted by the L light-emitting regions.

The TOF corresponding to the light beams emitted by the L light-emitting areas may specifically refer to the time difference information between the receiving time of the reflected light beams corresponding to the light beams respectively emitted by the L light-emitting areas of the array light source at time T and time T.

Optionally, the receiving unit includes a receiving lens and a sensor, and using the receiving unit to receive the reflected light beam of the target object in step 4002D includes: using the receiving lens to converge the reflected light beam of the target object to the sensor.

The above-mentioned sensor may also be referred to as a sensor array, and the sensor array may be a two-dimensional sensor array.

Optionally, the resolution of the aforementioned sensor is greater than P×Q, and the number of beams obtained by the beam splitter from one light-emitting area of the array light source is P×Q.

Wherein, the above P and Q are both positive integers. Since the resolution of the upload sensor is greater than the number of beams after the beam splitter splits the beam from a light-emitting area of the array light source, the sensor can receive the reflected beam obtained by the target object reflecting the beam from the beam splitter, This enables the TOF depth sensor module to achieve normal reception of the reflected light beam.

Optionally, generating the final depth map of the target object in the foregoing step 4002E specifically includes:

(1) Generate depth maps of L regions of the target object according to the TOF corresponding to the light beams emitted by the L light-emitting regions;

(2) Synthesize the depth map of the target object according to the depth maps of the L regions of the target object.

The above method shown in FIG. 22 can be executed by the TOF depth sensing module shown in FIG. 3 or a terminal device including the TOF depth sensing module shown in FIG. 3.

When the relative positional relationship between the collimating lens and the beam splitter in the TOF depth sensing module is different, the process of obtaining the final depth map of the target object in the first working mode is also different. The process of obtaining the final depth map of the target object in the first working mode will be described below in conjunction with FIG. 23.

Fig. 23 is a schematic flow chart of obtaining the final depth map of the target object in the first working mode. The process shown in FIG. 23 includes steps 4002a to 4002e, and these steps are respectively described in detail below.

4002b. Use a beam splitter to split the beams of the L light-emitting areas.

4002c. Use a collimating lens to collimate the beam from the beam splitter to obtain a collimated beam.

The above-mentioned reflected light beam of the target object is a light beam obtained by reflecting the light beam after the target object is aligned and processed.

4002e. Obtain a final depth map of the target object according to the TOF corresponding to the light beams emitted by the L light-emitting regions.

The process shown in FIG. 23 and the process shown in FIG. 22 are both how to obtain the final depth map of the target object in the first working mode. The main difference is that in FIG. 23, the beam splitter is used to send out the array light source. After beam splitting, the collimating lens is used to collimate the beam after splitting; and in Figure 22, the collimating lens is used to collimate the beam emitted by the array light source, and then it can be used The beam splitter aligns the processed beam to perform beam splitting processing.

The process of obtaining the final depth map of the target object in the second working mode will be described in detail below with reference to FIG. 24.

Fig. 24 is a schematic flow chart of obtaining the final depth map of the target object in the second working mode. The process shown in FIG. 24 includes steps 4003A to 4003E, and these steps are respectively described in detail below.

4003A. Control the M light-emitting areas of the N light-emitting areas of the array light source to emit light at M different times.

Wherein, the above M is less than or equal to N, and both M and N are positive integers.

In step 4003A, the light emission of the array light source can be controlled by the control unit. Specifically, the control unit may respectively send control signals to the M light-emitting areas of the array light source at M times, so as to control the M light-emitting areas to emit light individually at M different times.

For example, the array light source includes four independent light-emitting areas A, B, C, and D. Then, the control unit can send control signals to the four independent light-emitting areas A, B, and C at t0, t1, and t2, respectively, so that this Three independent light-emitting areas A, B, and C emit light at t0, t1, and t2, respectively.

4003B. Use a collimating lens to collimate the light beams generated by the M light-emitting areas at M different times to obtain the collimated light beams.

In the above step 4003B, the collimating lens is used to collimate the light beams generated by the M light-emitting areas at M different moments. Specifically, it may refer to the collimating lens that is used to collimate the light beams generated by the M light-emitting areas at M different moments. The beam is collimated.

Assuming that the array light source includes four independent light-emitting areas A, B, C, and D, the three independent light-emitting areas A, B, and C of the array light source emit light at t0, t1, and t2 under the control of the control unit, Then, the collimating lens can collimate the light beams emitted from the light-emitting areas A, B, and C at t0, t1, and t2, respectively.

By collimating the light beam through the collimating lens, an approximately parallel light beam can be obtained, the power density of the light beam can be increased, and the subsequent scanning effect of the light beam can be improved.

4003C. Use a beam splitter to align the processed beams for beam splitting.

4003D, using the receiving unit to receive the reflected beam of the target object.

The above-mentioned beam splitter is specifically used to divide each received light into multiple light beams. The reflected light beam of the target object mentioned above is the light beam obtained by the target object reflecting the light beam from the beam splitter.

4003E. Generate M depth maps according to the TOFs corresponding to the light beams emitted by the M light-emitting areas at M different moments.

4003F. Obtain the final depth map of the target object according to the M depth maps.

Optionally, the foregoing M depth maps are respectively depth maps corresponding to M region sets of the target object, and there is a non-overlapping region between any two region sets in the M region sets.

Optionally, the receiving unit includes a receiving lens and a sensor. In step 4003D, using the receiving unit to receive the reflected light beam of the target object includes: using the receiving lens to converge the reflected light beam of the target object to the sensor.

Optionally, the resolution of the sensor is greater than or equal to P×Q, and the number of beams obtained by the beam splitter from one light-emitting area of the array light source is P×Q.

Optionally, generating M depth maps in the foregoing step 4003E specifically includes:

(1) Determine the distance between the M areas of the target object and the TOF depth sensor module according to the TOF corresponding to the light beams emitted by the M light-emitting areas at M different times;

(2) According to the distance between the M regions of the target object and the TOF depth sensing module, generate the depth map of the M regions of the target object;

(3) Synthesize the depth map of the target object according to the depth maps of the M regions of the target object.

The above method shown in FIG. 24 can be executed by the TOF depth sensing module shown in FIG. 3 or a terminal device including the TOF depth sensing module shown in FIG. 3.

When the relative positional relationship between the collimating lens and the beam splitter in the TOF depth sensing module is different, the process of obtaining the final depth map of the target object in the second working mode is also different. The process of obtaining the final depth map of the target object in the second working mode will be described below in conjunction with FIG. 25.

Fig. 25 is a schematic flow chart of obtaining the final depth map of the target object in the second working mode. The process shown in FIG. 25 includes steps 4003a to 4003f, which are described in detail below.

Among them, M is less than or equal to N, and both M and N are positive integers.

4003b. Use a beam splitter to split the light beams generated by the M light-emitting areas at M different moments.

For example, the array light source includes four independent light-emitting areas A, B, C, and D. Under the control of the control unit, the light-emitting area A emits light at time T0, the light-emitting area B emits light at time T1, and the light-emitting area C emits light at time T2. Then, the beam splitter can split the light beam from the light-emitting area A at time T0, split the light beam from the light-emitting area B at time T1, and split the light beam from the light-emitting area C at time T2. deal with.

4003c. Use a collimating lens to collimate the beam from the beam splitter.

4003d. Use the receiving unit to receive the reflected beam of the target object.

The above-mentioned reflected light beam of the target object is a light beam obtained by the target object reflecting the light beam from the collimating lens.

Optionally, the receiving unit includes a receiving lens and a sensor, and using the receiving unit to receive the reflected light beam of the target object in step 4003d includes: using the receiving lens to converge the reflected light beam of the target object to the sensor.

The process shown in Fig. 25 and the process shown in Fig. 24 are both how to obtain the final depth map of the target object in the second working mode. The main difference is that in Fig. 25, the beam splitter is used to send out the array light source. After beam splitting, the collimating lens is used to collimate the beam after splitting; and in Figure 24, the collimating lens is used to collimate the beam emitted by the array light source, and then it can be used The beam splitter aligns the processed beam to perform beam splitting processing.

A TOF depth sensing module and an image generation method according to an embodiment of the present application are described in detail above with reference to FIGS. 1 to 25. In the following, another TOF depth sensing module and image generation method according to an embodiment of the present application will be described in detail with reference to FIGS. 26 to 52.

Traditional TOF depth sensing modules generally use mechanical rotating or vibrating parts to drive optical structures (for example, mirrors, lenses, prisms, etc.) or the emitting light source itself rotates or vibrates to change the propagation direction of the laser beam to achieve alignment. Scanning of different areas of the target object. However, the TOF depth sensing module has a relatively large size and is not suitable for installation in some devices with limited space (for example, mobile terminals). In addition, this type of TOF depth sensor module generally uses a continuous scanning method to scan, and the generated scan trajectory is generally continuous, which has poor flexibility when scanning the target object and cannot quickly locate the area of interest. (region of interest, ROI). For this reason, the embodiments of the present application provide a method that can irradiate different beams to different directions without mechanical rotation and vibration, and can quickly locate the scanning area of interest. A detailed description is given below in conjunction with the drawings.

The TOF depth sensing module of the embodiment of the present application will be briefly introduced below with reference to FIG. 26.

FIG. 26 is a schematic diagram of distance measurement using the TOF depth sensor module of an embodiment of the present application.

As shown in Figure 26, the TOF depth sensing module can include a transmitting end (or a projection end), a receiving end, and a control unit. The transmitting end is used to emit the outgoing beam, and the receiving end is used to receive the reflected beam of the target object. (The reflected light beam is the light beam obtained by the target object reflecting the outgoing light beam), the control unit can control the transmitting end and the receiving end to transmit and receive the light beams respectively.

In Figure 26, the transmitting end can generally include a laser light source, a collimating lens (optional), a polarization filter, optical elements, and a projection lens (optional). The receiving end can generally include a receiving lens and a sensor, and the receiving lens and sensor can be Collectively referred to as the receiving unit.

In FIG. 26, the timing device can be used to record the TOF corresponding to the emitted light beam to calculate the distance from the TOF depth sensor module to the target area, thereby obtaining the final depth map of the target object. Wherein, the TOF corresponding to the outgoing beam may refer to the time difference information between the moment when the reflected beam is received by the receiving unit and the outgoing moment of the outgoing beam.

The TOF depth sensor module of the embodiment of the application can be used for 3D image acquisition, and the TOF depth sensor module of the embodiment of the application can be set in a smart terminal (for example, a mobile phone, a tablet, a wearable device, etc.). For the acquisition of depth images or 3D images, gesture and body recognition can also be provided for 3D games or somatosensory games.

The TOF depth sensing module of the embodiment of the present application will be described in detail below in conjunction with FIG. 27.

FIG. 27 is a schematic block diagram of a TOF depth sensing module according to an embodiment of the present application.

The TOF depth sensing module 200 shown in FIG. 27 includes a laser light source 210, a polarization filter device 220, an optical element 230, a receiving unit 240, and a control unit 250. Among them, the polarization filter device 220 is located between the laser light source 210 and the optical element 230, and these modules or units in the TOF depth sensing module 200 will be described in detail below.

Laser light source 210:

The laser light source 210 is used to generate a laser beam. Specifically, the laser light source 210 can generate light of multiple polarization states.

Optionally, the laser beam emitted by the laser light source 210 is a single beam of quasi-parallel light, and the divergence angle of the laser beam emitted by the laser light source 210 is less than 1°.

Optionally, the above-mentioned laser light source may be a semiconductor laser light source.

The above-mentioned laser light source may be a vertical cavity surface emitting laser (VCSEL).

Optionally, the wavelength of the laser beam emitted by the above-mentioned laser light source 210 is greater than 900 nm.

Optionally, the wavelength of the laser beam emitted by the laser light source 210 is 940 nm or 1550 nm.

Polarization filter 220:

The polarization filter device 220 is used to filter the laser beam to obtain a beam with a single polarization state.

The light beam with a single polarization state filtered by the polarization filter device 220 is one of multiple polarization states of the light beam generated by the laser light source 210.

For example, the laser beam generated by the laser light source 210 includes linearly polarized light, left-handed circularly polarized light, and right-handed circularly polarized light in different directions. Then, the polarization filter device 220 can change the polarization state of the laser beam into left-handed circularly polarized light and right-handed circularly polarized light. The rotating deflection light is filtered out, and a beam of linearly polarized light with a polarization state in a specific direction is obtained.

Optical element 230:

The optical element 230 is used to adjust the direction of the beam of a single polarization state.

Among them, the refractive index parameter of the optical element 230 is controllable. When the refractive index of the optical element 230 is different, the optical element 230 can adjust the beam of a single polarization state to different directions.

The propagation direction of the laser beam will be described below in conjunction with the drawings. The propagation direction of the laser beam can be defined by a spatial angle. As shown in Figure 28, the spatial angle of the laser beam includes the angle θ between the laser beam and the z-axis direction of the rectangular coordinate system of the exit surface and the angle between its projection on the XY plane and the X-axis direction.

When scanning with a laser beam, the spatial angle of the laser beam θ or

Will change.

Control unit 250:

The control unit 250 is used to control the refractive index parameter of the optical element 230 to change the propagation direction of the light beam with a single polarization state.

The aforementioned control unit 250 can generate a control signal. The control signal can be a voltage signal or a radio frequency drive signal. The refractive index parameter of the optical element 230 can be changed by the control signal, so that the single polarization state received by the optical element 20 can be changed. The exit direction of the beam.

Receiving unit 240:

The receiving unit 240 is used to receive the reflected light beam of the target object.

Wherein, the reflected light beam of the target object is a light beam obtained by the target object reflecting a light beam of a single polarization state.

Specifically, a beam of a single polarization state will irradiate the surface of the target object after passing through the optical element 230, and the reflection of the surface of the target object will generate a reflected beam, which can be received by the receiving unit 240.

The receiving unit 240 may specifically include a receiving lens 241 and a sensor 242, and the receiving lens 241 is used to receive the reflected light beam and converge the reflected light beam to the sensor 242.

In the embodiments of the present application, because the birefringence of the optical element can adjust the beam to different directions at the same time, the propagation direction of the beam can be adjusted by controlling the birefringence parameter of the optical element, thereby realizing the non-mechanical The rotation mode adjusts the beam propagation direction, which can realize the discrete scanning of the beam, and can more flexibly measure the depth or distance of the surrounding environment and the target object.

That is to say, in the embodiment of the present application, by controlling the refractive index parameter of the optical element 230, the spatial angle of the beam of a single polarization state can be changed, so that the optical element 230 can deflect the propagation direction of the beam of a single polarization state. Furthermore, the output beam whose scanning direction and scanning angle meet the requirements can be output, and discrete scanning can be realized, the flexibility during scanning is high, and the ROI can be quickly located.

Optionally, the aforementioned control unit 250 is further configured to generate a depth map of the target object according to the TOF corresponding to the laser beam.

The TOF corresponding to the laser beam may specifically refer to the time difference information between the moment when the reflected beam corresponding to the laser beam is received by the receiving unit and the moment when the laser light source emits the laser beam. The reflected beam corresponding to the laser beam may specifically refer to the beam generated after the laser beam reaches the target object after being processed by the polarization filter device and the optical element, and is reflected after the target object.

FIG. 29 is a schematic block diagram of a TOF depth sensing module according to an embodiment of the present application.

As shown in FIG. 29, the TOF depth sensing module 200 further includes a collimating lens 260, which is located between the laser light source 210 and the polarization filter device 220, and the collimating lens 260 is used to perform a laser beam on the laser beam. Collimation processing; the polarization filter device 220 is used to filter the light beam after collimation processing on the collimating lens to obtain a single polarization state light beam.

Optionally, the light-emitting area of the above-mentioned laser light source 210 is less than or equal to 5×5 mm ² .

Due to the small size of the above-mentioned laser light source and collimating lens, the TOF depth sensor module containing the above-mentioned devices (laser light source, collimating lens) is relatively easy to be integrated into the terminal equipment, which can reduce the terminal equipment to a certain extent. The space occupied in the device.

Optionally, the average output optical power of the TOF depth sensing module 200 is less than 800 mw.

FIG. 30 is a schematic diagram of scanning a target object by the TOF depth sensing module according to an embodiment of the present application.

As shown in Figure 30, the optical element 230 can emit outgoing beam 1 at time T0. At a time T1, if you need to change the scanning direction and scanning angle, you can directly control the optical element to emit outgoing beam 2 at time T1. At a time T2, if the scanning direction and the scanning angle need to be changed, a control signal can be sent to control the optical element to emit the outgoing beam 3 at time T2. The TOF depth sensor module 200 can directly output the emitted light beams in different directions at different times, so as to realize the scanning of the target object.

The following describes in detail the effect of the TOF depth sensing module 200 in implementing discrete scanning with reference to FIG. 31.

FIG. 31 is a schematic diagram of the scanning trajectory of the TOF depth sensor module according to an embodiment of the present application.

As shown in Figure 31, the TOF depth sensor module can start scanning from scanning point A. When it is necessary to switch from scanning point A to scanning point B for scanning, the optical element 230 can be directly controlled by the control unit 250 to make the output The beam directly irradiates the scanning point B without having to gradually move from the scanning point A to the scanning point B (it is not necessary to move from A to B along the dashed line between AB in the figure). Similarly, when it is necessary to switch from scanning point B to scanning point C for scanning, the optical element 230 can also be controlled by the control unit 250, so that the outgoing beam directly irradiates scanning point C without gradually moving from scanning point B to Scan point C (it is not necessary to move from B to C along the dotted line between BC in the figure).

Therefore, the TOF depth sensor module 200 can realize discrete scanning, the scanning flexibility is high, and the area to be scanned can be quickly located.

Since the TOF depth sensor module 200 can realize discrete scanning, the TOF depth sensor module 200 can use a variety of scanning trajectories to scan a certain area when scanning. The selection of scanning methods is more flexible and it is also convenient for TOF depth. The timing control design of the sensing module 200.

The scanning method of the TOF depth sensor module 200 will be described below by taking a 3×3 two-dimensional dot matrix in conjunction with FIG. 32 as an example.

FIG. 32 is a schematic diagram of a scanning method of the TOF depth sensor module according to an embodiment of the present application.

As shown in FIG. 32, the TOF depth sensor module 200 can start scanning at the upper left corner of the two-dimensional dot matrix and scan until the end at the lower right corner of the two-dimensional dot matrix. Such scanning methods include scanning methods A to Scanning method F. In addition to scanning the seedlings from the upper left corner of the two-dimensional dot matrix, you can also scan from the center point of the two-dimensional dot matrix until all the points of the two-dimensional dot matrix are scanned, thereby completing all the scanning of the two-dimensional dot matrix. , Such scanning methods include scanning mode G to scanning mode J.

In addition, it is also possible to start scanning from any point in the two-dimensional array until the scanning of all points in the two-dimensional array is completed. As shown in the scanning mode K in FIG. 32, scanning can be started from the points in the first row and second column of the two-dimensional array until the center point in the two-dimensional array is scanned, thereby completing all scanning of the two-dimensional array dot matrix.

Optionally, the above-mentioned optical element 230 is any one of a liquid crystal polarization grating, an optical phased array, an electro-optical device, and an acousto-optical device.

The specific structure of the optical element 230 will be described in detail below with reference to the drawings.

The first case: the optical element 230 is a liquid crystal polarization grating (LCPG). In the first case, the birefringence of the optical element 230 is controllable. When the birefringence of the optical element is different, the optical element can adjust the beam of a single polarization state to different directions.

The liquid crystal polarization grating is a new type of grating device based on the principle of geometric phase. It acts on circularly polarized light and has electro-optical tunability and polarization tunability.

The liquid crystal polarization grating is a grating formed by using the periodic arrangement of liquid crystal molecules. The general manufacturing method is to control the director of the liquid crystal molecules (the direction of the long axis of the liquid crystal molecules) in one direction to gradually change linearly and periodically. of. By controlling the polarization state of the incident light, the circularly deflected light can be diffracted to the +1 order or -1 order, and the beam can be deflected by switching between the diffraction order and the zero order.

FIG. 33 is a schematic block diagram of a TOF depth sensing module according to an embodiment of the present application.

As shown in FIG. 33, the optical element 230 is a liquid crystal polarization grating, and the control unit 250 can control the laser light source to emit a laser beam to the liquid crystal polarization grating, and control the liquid crystal polarization grating to deflect the direction of the laser beam through a control signal to obtain the outgoing beam.

Optionally, the above-mentioned liquid crystal polarization grating includes horizontal LCPG components and vertical LCPG components.

FIG. 34 is a schematic block diagram of a TOF depth sensing module according to an embodiment of the present application.

As shown in Figure 34, the liquid crystal polarization grating is composed of horizontal LCPG components and vertical LCPG components. The horizontal LCPG components can achieve discrete random scanning in the horizontal direction, and the vertical LCPG components can achieve vertical scanning. Discrete random scan of direction. When the horizontal LCPG component and the vertical LCPG component are combined together, two-dimensional discrete random scanning in the horizontal and vertical directions can be realized.

It should be understood that FIG. 34 only shows the case where the horizontal LCPG is in front and the vertical LCPG is behind (the distance between the horizontal LCPG and the laser light source is smaller than the distance between the vertical LCPG and the laser light source). In fact, in this application, in the liquid crystal polarization grating, the vertical LCPG can also be in the front and the horizontal LCPG in the back (the distance between the vertical LCPG and the laser light source is smaller than the horizontal LCPG and the laser The distance from the light source).

In this application, when the liquid crystal polarization grating includes horizontal LCPG components and vertical LCPG components, two-dimensional discrete random scanning in the horizontal and vertical directions can be realized.

Optionally, in the first case, the liquid crystal polarization grating may further include a horizontal polarization control plate and a vertical polarization control plate.

When the polarization control plate is included in the liquid crystal polarization grating, the polarization state of the light beam can be controlled.

FIG. 35 is a schematic diagram of the structure of a liquid crystal polarization grating according to an embodiment of the present application.

As shown in FIG. 35, the liquid crystal polarization grating includes not only a horizontal LCPG and a vertical LCPG, but also a horizontal polarization control plate and a vertical polarization control plate. In FIG. 35, the horizontal LCPG is located between the horizontal polarization control plate and the vertical polarization control plate, and the vertical polarization control plate is located between the horizontal LCPG and the vertical LCPG.

FIG. 36 is a schematic structural diagram of a TOF depth sensing module according to an embodiment of the present application.

As shown in Figure 36, the structure of the liquid crystal polarization grating in the TOF depth sensor module is shown in Figure 35. The distances between the horizontal polarization control film, the horizontal LCPG, the vertical polarization control film, and the vertical LCPG and the laser light source are sequentially changed. Big.

Optionally, the various components in the liquid crystal polarization grating shown in FIG. 35 may have the following combinations.

Combination method 1:124;

Combination method 2: 342;

Combination mode 3: 3412.

Among them, in the above-mentioned

combination

1, 1 can indicate the closely-adhered horizontal polarization control plate and the vertical polarization control plate. At this time, the two closely-adjacent polarization control plates are equivalent to one polarization control plate. Therefore, in the

combination method

1, 1 is used to represent the horizontal polarization control sheet and the vertical polarization control sheet that are bonded together. Similarly, in the above-mentioned

combination mode

2, 3 can indicate the close-fitting horizontal polarization control film and the vertical polarization control film. At this time, the two close-fitting polarization control films are equivalent to one polarization control film. Therefore, the combination mode 2 3 is used to represent the horizontal polarization control plate and the vertical polarization control plate that are bonded together.

When the optical element 230 of combination mode 1 or combination mode 2 is placed in the TOF depth sensor module, the horizontal polarization control plate or the vertical polarization control plate are both located on the side close to the laser light source, while the horizontal LCPG and the vertical LCPG are both located far away One side of the laser light source.

When the optical element 230 of the combination mode 3 is placed in the TOF depth sensor module, the distance between the longitudinal polarization control plate, the longitudinal LCPG, the lateral polarization control plate, and the lateral LCPG and the laser light source becomes larger in sequence.

It should be understood that the above three combinations of liquid crystal polarization gratings and the combination in FIG. 35 are only examples. In fact, the various components of the optical element in the present application may also have different combinations. It is only necessary to ensure that the distance between the lateral polarization control plate and the laser light source is smaller than the distance between the lateral LCPG and the laser light source, and the distance between the lateral polarization control plate and the laser light source is smaller than the distance between the lateral LCPG and the laser light source.

As shown in Figure 37, the physical characteristics of the liquid crystal polarization grating can be changed periodically by inputting a periodic control signal (in Figure 37, the period of the control signal is Λ) to the liquid crystal polarization grating, specifically, the internal liquid crystal of the liquid crystal polarization grating can be made The arrangement of the molecules changes (liquid crystal molecules are generally rod-shaped, and the orientation of the liquid crystal molecules will change due to the influence of the control signal), thereby realizing the deflection of the direction of the laser beam.

When the liquid crystal polarization grating and the polarizer are combined at the same time, the control of the different directions of the light beam can be realized.

As shown in Figure 38, the incident light is controlled by the left-handed and right-handed circular polarizers and the voltage of the LCPG to achieve beam control in three different directions. The deflection angle of the outgoing light can be determined according to the following diffraction grating equation.

In the above diffraction grating equation, θ _m is the direction angle of the m-order emitted light, λ is the wavelength of the laser light, Λ is the period of the LCPG, and θ is the incident angle of the incident light. It can be seen from the above diffraction grating equation that the deflection angle θ _m depends on the size of the LCPG grating period, the wavelength and the size of the incident angle, where m only takes 0 and ±1. Among them, when m is set to 0, it means that the direction is not deflected and the direction is unchanged. When m is set to 1, it means that it is deflection to the left or counterclockwise relative to the incident direction, and m is −1 means that it is deflected to the right or clockwise relative to the incident direction (m The meaning of +1 and m is -1 can also be reversed).

The single-chip LCPG can achieve 3 angles of deflection, and then obtain 3 angles of outgoing beams. Therefore, by cascading the LCPG in multiple layers, more angles of outgoing beams can be obtained. Therefore, the combination of the N-layer polarization control plate (the polarization control plate is used to control the polarization of the incident light and realize the conversion of left-handed light and right-handed light) and the N-layer LCPG can theoretically achieve 3 ^N deflection angles.

For example, as shown in Figure 35, the optical element of the TOF depth sensor module is composed of

devices

1, 2, 3, and 4, where

devices

1, 2, 3, and 4 represent the horizontal polarization control plate, the horizontal LCPG, and the vertical polarization control, respectively. The plate and longitudinal LCPG can control the direction and angle of beam deflection by controlling the voltage of each group of polarization control plates and LCPG.

Taking the realization of 3x3 point scanning as an example, the voltage signals shown in Figure 39 are applied to the

devices

1, 2, 3, and 4 shown in Figure 36 (the 1, 2, 3, and 4 in Figure 39 respectively indicate that they are applied to the

devices

1, 2, 3, and 4). The voltage signals on the

devices

1, 2, 3, and 4 shown in FIG. 36), the laser beam emitted by the laser light source can be controlled to realize the scanning track shown in FIG. 40.

Specifically, assuming that the incident light is left-handed circularly polarized light, the lateral LCPG is deflected to the left under the incident of the left-handed light, and the longitudinal LCPG is deflected downward under the incident of the left-handed light. The deflection direction of the beam at each time will be described in detail below.

When the two ends of the horizontal polarization control plate are high-voltage signals, the polarization state of the light beam passing through the horizontal polarization control plate does not change. When the two ends of the horizontal polarization control plate are low-voltage signals, the polarization state of the light beam passing through the horizontal polarization control plate will change. change. Similarly, when the two ends of the longitudinal polarization control plate are high-voltage signals, the polarization state of the beam passing through the longitudinal polarization control plate does not change. When the two ends of the longitudinal polarization control plate are low-voltage signals, the polarization state of the beam passing through the longitudinal polarization control plate is The polarization state will change.

At time 0, the incident light of device 1 is left-handed circularly polarized light. Because device 1 applies a low voltage, the right-handed circularly polarized light is emitted after device 1; the incident light of device 2 is right-handed circularly polarized light. Device 2 is applied with a high voltage, after passing device 2, the output is still right-handed circularly polarized light; the incident light of device 3 is right-handed circularly polarized light, because device 3 is applied with a low voltage, after passing through device 3, the output is left-handed circularly polarized light. Circularly polarized light; the incident light of device 4 is left-handed circularly polarized light. Since device 4 applies high voltage, the emitted light is still left-handed circularly polarized light after passing through device 4; therefore, at time 0, after passing through device 1 to device 4, it enters The direction of the light does not change, and the polarization state does not change. As shown in Fig. 40, the scanning point corresponding to time 0 is at the position shown in the center t0 of Fig. 40.

At time t0, the incident light of device 1 is left-handed circularly polarized light. Because device 1 applies high voltage, the emitted light is still left-handed circularly polarized light after passing through device 1; the incident light of device 2 is left-handed circularly polarized light. 2. Low voltage is applied. After passing through device 2, right-handed circularly polarized light deflected to the left will be emitted; the incident light of device 3 is right-handed circularly polarized light deflected to the left. After device 3, the left-handed circularly polarized light deflected to the left is emitted; the incident light of device 4 is left-handed circularly polarized light deflected to the left. Since the high voltage applied to the device 4, the emitted light is still deflected to the left after passing through the device 4 Left-handed circularly polarized light; that is, relative to time 0, the light beam emitted from the device 4 at time t0 is deflected to the left, and the corresponding scanning point in FIG. 40 is the position shown by t0.

At time t1, the incident light of device 1 is left-handed circularly polarized light. Because device 1 applies high voltage, the emitted light is still left-handed circularly polarized light after passing through device 1; the incident light of device 2 is left-handed circularly polarized light. 2. Low voltage is applied. After passing through device 2, right-handed circularly polarized light that is deflected to the left is emitted; the incident light of device 3 is right-handed circularly polarized light that is deflected to the left. Device 3 emits right-handed circularly polarized light deflected to the left; the incident light of device 4 is right-handed circularly polarized light deflected to the left. Since device 4 applies a low voltage, it emits leftwardly deflected after passing through device 4 And the left-handed circularly polarized light deflected upward; that is, relative to time 0, the light beam emitted from the device 4 at time t1 is deflected leftward and upward, and the corresponding scanning point in FIG. 40 is the position shown by t1.

At time t2, the incident light of device 1 is left-handed circularly polarized light. Since device 1 applies a low voltage, the right-handed circularly polarized light is emitted after device 1; the incident light of device 2 is right-handed circularly polarized light. Device 2 is applied with high voltage. After device 2 is passed through, the right-handed circularly polarized light is emitted; the incident light of device 3 is right-handed circularly polarized light. Since device 3 is applied with high voltage, the light emitted after passing through device 3 It is still right-handed circularly polarized light; the incident light of device 4 is right-handed circularly polarized light. Because device 4 applies a low voltage, the left-handed circularly polarized light that is deflected upward after passing through device 4 is emitted; that is, relative to 0 At time t2, the light beam emitted by the device 4 is deflected upward, and the corresponding scanning point in FIG. 40 is the position shown by t2.

At t3, the incident light of device 1 is left-handed circularly polarized light. Since device 1 is applied with a low voltage, the right-handed circularly polarized light is emitted after passing through device 1; the incident light of device 2 is right-handed circularly polarized light. Device 2 is applied with a low voltage. After passing through device 2, right-handed circularly polarized light is emitted; the incident light of device 3 is right-handed circularly polarized light. Since device 3 is applied with low voltage, After passing through device 3, the left-handed circularly polarized light deflected to the right is emitted; the incident light of device 4 is left-handed circularly polarized light deflected to the right. Since the low voltage is applied to the device 4, after passing through the device 4, the emitted light is deflected to the right and The left-handed circularly polarized light deflected upward; that is, relative to time 0, the beam emitted from the device 4 at time t3 is deflected to the right and upward, and the corresponding scanning point in FIG. 40 is the position shown in t3.

At t4, the incident light of device 1 is left-handed circularly polarized light. Since device 1 applies a low voltage, it emits right-handed circularly polarized light after passing through device 1; the incident light of device 2 is right-handed circularly polarized light. Device 2 is applied with a low voltage. After device 2, the left-handed circularly polarized light that is deflected to the right is emitted; the incident light of device 3 is left-handed circularly polarized light that is deflected to the right. Because device 3 is applied with a low voltage, it passes through the device. After 3, the right-handed circularly polarized light deflected to the right is emitted; the incident light of device 4 is the right-handed circularly polarized light deflected to the right. Since the high voltage applied to the device 4, the emitted light is still deflected to the right after passing through the device 4 That is to say, relative to time 0, the light beam emitted from the device 4 at time t0 is deflected to the right, and the corresponding scanning point in FIG. 40 is the position shown by t4.

At time t5, the incident light of device 1 is left-handed circularly polarized light. Since device 1 applies a low voltage, the right-handed circularly polarized light is emitted after passing through device 1; the incident light of device 2 is right-handed circularly polarized light. Device 2 is applied with a low voltage. After passing through device 2, right-handed circularly polarized light is emitted; the incident light of device 3 is right-handed circularly polarized light. Since device 3 is applied with high voltage, After passing through the device 3, the right-handed circularly polarized light that is deflected to the right is emitted; the incident light of the device 4 is the right-handed circularly polarized light that is deflected to the right. Left-handed circularly polarized light deflected to the right and deflected downward; that is to say, relative to time 0, the beam emitted by device 4 at time t5 is deflected to the right and downward, and the corresponding scanning point in Figure 40 is at t5. Show the location.

At t6, the incident light of device 1 is left-handed circularly polarized light. Because device 1 applies a low voltage, the right-handed circularly polarized light is emitted after device 1; the incident light of device 2 is right-handed circularly polarized light. Device 2 is applied with a high voltage. After device 2 is emitted, right-handed circularly polarized light is emitted; the incident light of device 3 is right-handed circularly polarized light. Since device 3 is applied with a low voltage, the light emitted after passing through device 3 It is left-handed circularly polarized light; the incident light of device 4 is left-handed circularly polarized light. Since device 4 applies a low voltage, the right-handed circularly polarized light deflected downward after passing through device 4 is emitted; that is, relative to time 0 , The beam emitted by the device 4 at time t6 is deflected downward, and the corresponding scanning point in FIG. 40 is the position shown in t6.

At t7, the incident light of device 1 is left-handed circularly polarized light. Because device 1 applies high voltage, the emitted light is still left-handed circularly polarized light after passing through device 1; the incident light of device 2 is left-handed circularly polarized light. 2. Low voltage is applied. After passing through device 2, right-handed circularly polarized light deflected to the left is emitted; the incident light of device 3 is right-handed circularly polarized light deflected to the left. After device 3, the left-handed circularly polarized light deflected to the left is emitted; the incident light of device 4 is left-handed circularly polarized light deflected to the left. Since the low voltage applied to the device 4, after passing through the device 4, the emitted light is deflected to the left and to the left. The downwardly deflected right-handed circularly polarized light; that is to say, relative to time 0, the light beam emitted from the device 4 at time t7 is deflected to the left and upward, and the corresponding scanning point in FIG. 40 is the position shown in t7.

It should be understood that this is only an illustration of the possible scan trajectories of the TOF depth sensor module in conjunction with FIG. 39 and FIG. 40. Any discrete random scan can be realized by changing the voltage controlling each group of polarization control plates and the LCPG.

For example, by changing the voltages for controlling each group of polarization control plates and LCPG, various scanning trajectories shown in FIG. 32 can be realized.

When using traditional lidar to scan a target object, it is often necessary to first perform a coarse scan of the target area (Coarse scan), and then perform a higher resolution fine scan (Fine scan) after the region of interest (ROI) is found. . Since the TOF depth sensor module of the embodiment of the present application can realize discrete scanning, it can directly locate the region of interest for fine scanning, which can greatly save the time required for fine scanning.

For example, as shown in Fig. 41, the total number of points in the area to be scanned (the entire rectangular area including the contour of the human body) is M, and the ROI (the image area located in the contour image of the human body in Fig. 41) occupies 1 of the total area of the area to be scanned. /N.

When scanning the area to be scanned as shown in FIG. 41, it is assumed that the point scanning rate of the conventional lidar and the lidar of the embodiment of the present application are both K points/second, and the ROI area needs to be scanned finely. For scanning, the resolution for fine scanning needs to be increased to four times the original (that is, 4K dots/sec). Then, the time required to complete the fine scanning of the ROI using the TOF depth sensing module of the embodiment of the application is t ₁ , and the time required to complete the fine scanning of the ROI using the traditional lidar is t ₂ , because the implementation of this application The TOF depth sensor module of the example can realize discrete scanning, so it can directly locate the ROI and perform a fine scan on the ROI, and the scanning time required is short. However, the traditional lidar performs linear scanning, and it is difficult to accurately locate the ROI. Therefore, the traditional lidar needs to perform a fine scan on the entire area to be scanned, which greatly increases the scanning time. As shown in Figure 42, the TOF depth sensing module of the embodiment of the present application can directly locate the ROI and perform fine scanning of the ROI (as shown in Figure 42, the density of the scanning points in the ROI is significantly greater than that of the scanning points outside the ROI. density).

In addition, the above t ₁ and t ₂ can be calculated using the following two formulas (2) and (3), respectively.

From the above formula (2) and formula (3), it can be seen that the time required to perform fine scanning of the ROI using the TOF depth sensing module of the embodiment of the present application is only 1% of the time required for the traditional lidar to perform fine scanning. /N, which greatly shortens the time required for fine scanning of ROI.

Since the TOF depth sensor module of the embodiment of the present application can realize discrete scanning, the TOF depth sensor module of the embodiment of the present application can implement ROI regions (cars, people, buildings, and random patches) of any shape. Fine scanning, especially some asymmetric areas and discrete ROI blocks. In addition, the TOF depth sensing module of the embodiment of the present application can also achieve uniform or non-uniform distribution of the dot density in the scanning area.

The second case: the optical element 230 is an electro-optical device.

In the second case, when the optical element 230 is an electro-optical device, the control signal may be a voltage signal, and the voltage signal may be used to change the refractive index of the electro-optical device, so that the position of the electro-optical device relative to the laser light source is unchanged. The laser beam is deflected in different directions to obtain the outgoing beam whose scanning direction matches the control signal.

Optionally, as shown in FIG. 43, the above-mentioned electro-optic device may include a lateral electro-optic crystal (horizontal deflection electro-optic crystal) and a longitudinal electro-optic crystal (vertical deflection electro-optic crystal). Among them, the horizontal electro-optic crystal can realize the deflection of the laser beam in the horizontal direction, and the longitudinal electro-optic crystal can realize the deflection of the laser beam in the vertical direction.

Optionally, the electro-optic crystal may specifically be a potassium tantalate niobate (KTN) crystal, a deuterated potassium dihydrogen phosphate (DKDP) crystal, and a lithium niobate (LN) crystal. Any kind.

The working principle of the electro-optic crystal will be briefly introduced below in conjunction with the drawings.

As shown in Figure 44, when a voltage signal is applied to the electro-optic crystal, due to the second-order photoelectric effect of the electro-optic crystal, a refractive index difference will occur in the electro-optic crystal (that is, the refractive index of different regions in the electro-optic crystal will be different) , So that the incident beam is deflected, as shown in Figure 44, the outgoing beam has a certain deflection relative to the direction of the incident beam.

The deflection angle of the outgoing beam with respect to the incident beam can be calculated according to the following formula (4).

In the above formula (4), θ _max represents the maximum deflection angle of the outgoing beam relative to the incident beam, n is the refractive index of the electro-optic crystal, g _11y is the second-order electro-optic coefficient, and E _max is the maximum electric field that can be applied to the electro-optic crystal strength,

Is the second-order electro-optic coefficient gradient in the y direction.

It can be seen from the above formula (4) that by adjusting the intensity of the applied electric field (that is, adjusting the voltage applied to the electro-optic crystal), the deflection angle of the beam can be controlled, so as to realize the scanning of the target area. In addition, in order to achieve a larger deflection angle, multiple electro-optic crystals can be cascaded.

As shown in Figure 43, the optical element includes a horizontal deflection electro-optic crystal and a vertical deflection electro-optic crystal. These two electro-optic crystals are responsible for the horizontal and vertical beam deflection respectively. After the control voltage signal shown in Figure 45 is applied, , Can realize 3x3 scanning as shown in Figure 46. Specifically, in FIG. 45, 1 and 2 respectively represent the control voltage signals applied to the horizontal deflection electro-optic crystal and the vertical deflection electro-optic crystal.

The third case: the optical element 230 is an acousto-optic device.

As shown in FIG. 47, the optical element 230 is an acousto-optic device. The acousto-optic device may include a transducer. When the optical element 230 is an acousto-optic device, the control signal may specifically be a radio frequency control signal. The radio frequency control signal can be used to control the transducer to generate sound waves of different frequencies to change the acousto-optic device. The refractive index of the device further enables the acousto-optic device to deflect the laser beam in different directions under the condition that the position of the acousto-optic device is unchanged relative to the laser light source, so as to obtain the outgoing beam whose scanning direction matches the control signal.

As shown in Figure 48, the acousto-optic devices include sound absorbers, quartz and piezoelectric transducers. After the acousto-optic device receives the electrical signal, the piezoelectric transducer can generate an acoustic wave signal under the action of the electrical signal. The acoustic wave signal will change the refractive index distribution of the quartz when transmitted in the acousto-optic device, thereby forming a grating, making the quartz It can produce a certain angle of deflection to the incident light beam, and when the input control signals are different at different times, the acousto-optic device can produce outgoing light beams in different directions at different times. As shown in Fig. 48, the deflection direction of the outgoing beam of quartz at different moments (T0, T1, T2, T3, and T4) can be different.

When the electrical signal incident on the acousto-optic device is a periodic signal, the quartz in the acousto-optic device periodically changes due to the refractive index distribution, so a periodic grating is formed. The use of the periodic grating can realize the detection of the incident beam. The cyclical deflection.

In addition, the intensity of the emitted light of the acousto-optic device is directly related to the power of the radio frequency control signal input to the acousto-optic device, and the angle of diffraction of the incident beam is also directly related to the frequency of the radio frequency control signal. By changing the frequency of the radio frequency control signal, the angle of the outgoing beam can also be adjusted accordingly. Specifically, the deflection angle of the outgoing beam relative to the incident beam can be determined according to the following formula (5).

In the above formula (5), θ is the deflection angle of the outgoing beam relative to the incident beam, λ is the wavelength of the incident beam, f _s is the frequency of the radio frequency control signal, and v _s is the speed of the sound wave. Therefore, the light deflector can scan the laser beam in a larger angle range, and at the same time can accurately control the exit angle of the laser beam.

The fourth case: the optical element 230 is an optical phased array (OPA) device.

The case where the optical element 230 is an OPA device 49 and 50 is described in detail below with reference to the accompanying drawings.

As shown in FIG. 49, the optical element 230 is an OPA device, and the incident light beam can be deflected by the OPA device, so as to obtain the outgoing light beam whose scanning direction matches the control signal.

OPA devices are generally composed of one-dimensional or two-dimensional phase shifter arrays. When there is no phase difference between the phase shifters, the light reaches the isophase surface at the same time, and the light travels forward without interference. Therefore, beam deflection does not occur.

After each phase shifter is added with a phase difference (taking the uniform phase difference provided by each optical signal as an example, the phase difference between the second waveguide and the first waveguide is Δ, the third waveguide and the first waveguide The phase difference is 2Δ, and so on). At this time, the isophase plane is no longer perpendicular to the waveguide direction, but has a certain deflection. The beams satisfying the isophase relationship will be coherent and constructive, and the beams that do not meet the isophase condition Will cancel each other out, so the direction of the beam is always perpendicular to the isophase plane.

As shown in Fig. 50, assuming that the distances between adjacent waveguides are both d, the optical path difference of the light beam output from the adjacent waveguides to the isophase plane is ΔR=d·sinθ. Among them, θ represents the deflection angle of the beam. Since this optical path difference is caused by the phase difference of the array element, ΔR=Δ·λ/2π, so the deflection of the beam can be achieved by introducing the phase difference in the array element, which is OPA's principle of deflecting light beams.

Therefore, the deflection angle θ=arcsin(Δ·λ/(2π*d)), by controlling the phase difference of adjacent phase shifters, such as π/12, π/6, the beam deflection angle is arcsin(λ/(24d )) and arcsin(λ/(12d)). In this way, by controlling the phase of the phase shifter array, deflection in any two-dimensional direction can be achieved. The phase shifter can be made of liquid crystal materials, and different voltages are applied to make the liquid crystal produce different phase differences.

Optionally, as shown in FIG. 51, the TOF depth sensing module 200 further includes:

A collimating lens 260, the collimating lens 260 is located between the laser light source 210 and the polarization filter device 220, the collimating lens 260 is used for collimating the laser beam; the polarization filter device 220 is used for collimating the lens 260 The processed beam is filtered to obtain a beam with a single polarization state.

In addition, the collimating lens 260 may also be located between the polarization filter 220 and the optical element 230. In this case, the polarization filter 220 first polarizes the light beam generated by the laser light source to obtain a single polarization beam, and then Next, the collimating lens 260 collimates the beam of a single polarization state.

Optionally, the aforementioned collimating lens 260 may also be located on the right side of the optical element 230 (the distance between the collimating lens 260 and the laser light source 210 is greater than the distance between the optical element 230 and the laser light source 210), in this case, After the optical element 230 adjusts the direction of the light beam with a single polarization state, the collimating lens 260 then collimates the light beam with a single polarization state after the direction adjustment.

The TOF depth sensing module 200 of the embodiment of the present application is described in detail above with reference to FIGS. 26 to 51, and the image generation method of the embodiment of the present application is described below with reference to FIG. 52.

FIG. 52 is a schematic flowchart of an image generation method according to an embodiment of the present application.

The method shown in FIG. 52 may be executed by the TOF depth sensing module of the embodiment of the present application or a terminal device including the TOF depth sensing module of the embodiment of the present application. Specifically, the method shown in FIG. 52 may be executed by the TOF depth sensing module 200 shown in FIG. 27 or a terminal device including the TOF depth sensing module 200 shown in FIG. 27. The method shown in FIG. 52 includes steps 4001 to 4005, and these steps are respectively described in detail below.

5001. Control a laser light source to generate a laser beam.

Among them, the above-mentioned laser light source can generate light with multiple polarization states.

For example, the above-mentioned laser light source can generate light of multiple polarization states such as linear polarization, left-handed circular polarization, and right-handed circular polarization.

5002. Use a polarization filter device to filter the laser beam to obtain a beam with a single polarization state.

The single polarization state may be any one of linear polarization, left-handed circular polarization, and right-handed circular polarization.

For example, in step 5001, the laser beam generated by the laser light source includes linearly polarized light, left-handed circularly polarized light, and right-handed circularly polarized light. Then, in step 5002, the polarization state of the laser beam can be changed to left-handed circularly polarized light. Right-handed circularly polarized light, left-handed circularly polarized light and right-handed circularly polarized light are screened out, and only linearly polarized light in a specific direction is retained. Optionally, a quarter wave plate may be included in the polarization filter device to make the filtered line The polarized light is converted into left-handed circularly polarized light (or right-handed circularly polarized light).

5003. Control the optical element to have different birefringence parameters at M different moments, so as to obtain M outgoing beams in different directions.

The birefringence parameter of the above-mentioned optical element is controllable. When the birefringence of the optical element is different, the optical element can adjust the beam of a single polarization state to different directions. The above M is a positive integer greater than 1. The above-mentioned M reflected light beams are light beams obtained by reflecting M outgoing light beams in different directions by the target object.

At this time, the above-mentioned optical element may be a liquid crystal polarization grating. For the specific situation of the liquid crystal polarization grating, please refer to the description of the first case above.

Optionally, the above-mentioned optical element having different birefringence parameters at M times may specifically include the following two situations:

Case 1: The birefringence parameters of the optical element at any two of the M times are different;

Case 2: There are at least two moments in the M moments of the optical element, and the birefringence parameters of the optical element at the at least two moments are different.

In case 1, assuming M=5, then the optical element corresponds to 5 different birefringence parameters at 5 moments.

In case 2, assuming that M=5, the optical element only needs to have two times out of five times corresponding to different birefringence parameters.

5004. Use the receiving unit to receive M reflected light beams.

5005. Generate a depth map of the target object according to the TOF corresponding to the outgoing beams in M different directions.

The TOF corresponding to the M outgoing light beams in different directions may specifically refer to the time difference information between the time when the reflected light beams corresponding to the M outgoing light beams in different directions are received by the receiving unit and the outgoing time of the M outgoing light beams in different directions. .

Assuming that the above-mentioned M outgoing beams in different directions include outgoing beam 1, then the reflected light beam corresponding to outgoing beam 1 can be a light beam that indicates that the outgoing beam 1 reaches the target object and is reflected after passing through the target object.

Optionally, generating a depth map of the target object in the foregoing step 5005 specifically includes:

5005a. Determine the distance between the M regions of the target object and the TOF depth sensing module according to the TOF corresponding to the M outgoing beams in different directions.

5005b. Generate a depth map of the M regions of the target object according to the distance between the M regions of the target object and the TOF depth sensing module; synthesize the depth map of the target object according to the depth maps of the M regions of the target object.

In the method shown in Figure 52, the beam can also be collimated,

Optionally, before the foregoing step 5002, the method shown in FIG. 52 further includes:

5006. Collimate the laser beam to obtain the collimated beam.

After the laser beam is collimated, obtaining a beam of a single polarization state in the above step 5002 specifically includes: using a polarization filter device to align the beam after the treatment to obtain a single polarization state of light.

Before the polarization filter device is used to filter the laser beam to obtain a single polarization beam, by collimating the laser beam, an approximately parallel beam can be obtained, which can increase the power density of the beam, and further improve the subsequent scanning using the beam. effect.

The beam after the collimation process may be a quasi-parallel beam with a divergence angle of less than 1 degree.

It should be understood that, in the method shown in FIG. 52, collimation processing can also be performed on the beam of a single polarization state. Specifically, the method shown in FIG. 52 further includes:

5007. Perform collimation processing on a beam of a single polarization state to obtain a collimated beam.

The foregoing step 5007 may be located between step 5002 and step 5003, and the foregoing step 5007 may also be located between step 5003 and step 5004.

When the above step 5007 is between step 5002 and step 5003, the polarization filter device filters the laser beam generated by the laser light source to obtain a single polarization beam. Next, the single polarization beam is collimated through a collimating lens Straightening process obtains the collimated beam, and then the optical element controls the propagation direction of the beam with a single polarization state.

When the above step 5007 is between step 5003 and step 5004, after the optical element changes the propagation direction of the single polarization beam, the collimating lens then collimates the single polarization beam to obtain the post-collimation process Beam.

It should be understood that in the method shown in FIG. 52, step 5006 and step 5007 are optional steps, and any one of step 5006 or 5007 can be selected to be executed.

A TOF depth sensing module and an image generation method according to an embodiment of the present application are described in detail above with reference to FIGS. 26 to 52. In the following, another TOF depth sensing module and image generation method according to an embodiment of the present application will be described in detail with reference to FIGS. 53 to 69.

Traditional TOF depth sensing modules often use pulsed TOF technology for scanning, but pulsed TOF technology requires the sensitivity of the photodetector to be high enough to achieve single-photon detection capability. Commonly used photodetectors often use single-photon avalanche Diode (SPAD), due to the complex interface and processing circuit of SPAD, the resolution of commonly used SPAD sensors is low, which is insufficient to meet the high spatial resolution requirements of depth sensing. To this end, the embodiments of the present application provide a TOF depth sensing module and an image generation method, which improve the spatial resolution of depth sensing through block illumination and time-division multiplexing. The following describes this type of TOF depth sensing module and image generation method in detail with reference to the accompanying drawings.

The TOF depth sensing module of the embodiment of the present application will be briefly introduced below with reference to FIG. 53.

FIG. 53 is a schematic diagram of distance measurement using the TOF depth sensor module of an embodiment of the present application.

As shown in Figure 53, the TOF depth sensing module can include a transmitting end (or a projection end), a receiving end, and a control unit. The transmitting end is used to emit the outgoing beam, and the receiving end is used to receive the reflected beam of the target object. (The reflected light beam is the light beam obtained by the target object reflecting the outgoing light beam), the control unit can control the transmitting end and the receiving end to transmit and receive the light beams respectively.

In Figure 53, the transmitting end may generally include a laser light source, a polarization filter, a collimating lens (optional), a first optical element and a projection lens (optional), and the receiving end may generally include a receiving lens, a second optical element and sensor. In FIG. 53, the timing device can be used to record the TOF corresponding to the emitted light beam to calculate the distance from the TOF depth sensor module to the target area, and then obtain the final depth map of the target object. Wherein, the TOF corresponding to the outgoing beam may refer to the time difference information between the moment when the reflected beam is received by the receiving unit and the outgoing moment of the outgoing beam.

As shown in Figure 53, the FOV of the laser beam can be adjusted by the beam shaping device and the first optical element, and different scanning beams can be emitted from t0-t17, and the FOV of the beam emitted at t0-t17 can be spliced. The target FOV can be reached, and the resolution of the TOF depth sensor module can be improved.

The TOF depth sensing module of the embodiment of the present application will be described in detail below with reference to FIG. 54.

FIG. 54 is a schematic block diagram of a TOF depth sensing module according to an embodiment of the present application.

The TOF depth sensing module 300 shown in FIG. 54 includes a laser light source 310, a polarization filter device 320, a beam shaping device 330, a first optical element 340, a second optical element 350, a receiving unit 360, and a control unit 370. As shown in FIG. 54, the transmitting end of the TOF depth sensing module 300 includes a laser light source 310, a polarization filter device 320, a beam shaping device 330 and a first optical element 340, and the receiving end of the TOF depth sensing module 300 includes a second The optical element 350 and the receiving unit 360. The first optical element 340 and the second optical element 350 are respectively elements located at the transmitting end and the receiving end of the TOF depth sensor module 300, wherein the first optical element is mainly the direction of the light beam at the transmitting end The control is performed to obtain the outgoing light beam, and the second optical element mainly controls the direction of the reflected light beam so that the reflected light beam is deflected to the receiving unit.

The modules or units in the TOF depth sensing module 300 will be introduced in detail below.

Laser light source 310:

The laser light source 310 is used to generate a laser beam. Specifically, the laser light source 310 can generate light of multiple polarization states.

Optionally, the laser beam emitted by the above-mentioned laser light source 310 is a single quasi-parallel light, and the divergence angle of the laser beam emitted by the laser light source 310 is less than 1°.

Optionally, the above-mentioned laser light source 310 is a semiconductor laser light source.

Optionally, the above-mentioned laser light source 310 is a Fabry-Perot laser (may be referred to as FP laser for short).

Optionally, the wavelength of the laser beam emitted by the laser light source 310 is greater than 900 nm.

Optionally, the wavelength of the laser beam emitted by the laser light source 310 is 940 nm or 1550 nm.

The light-emitting area of the above-mentioned laser light source 310 is less than or equal to 5×5 mm ² .

Due to the small size of the above-mentioned laser light source, the TOF depth sensing module 300 containing the laser light source is relatively easy to be integrated into the terminal device, which can reduce the space occupied in the terminal device to a certain extent.

Optionally, the average output optical power of the TOF depth sensing module is less than 800 mw.

Polarization filter 320:

The polarization filter device 320 is used to filter the laser beam to obtain a beam with a single polarization state.

The light beam with a single polarization state filtered by the polarization filter device 320 is one of multiple polarization states of the light beam generated by the laser light source 310.

For example, the laser beam generated by the laser light source 310 includes linearly polarized light, left-handed circularly polarized light, and right-handed circularly polarized light. Then, the polarization filter device 320 can change the polarization state of the laser beam to left-handed circularly polarized light and right-handed circularly polarized light. Left-handed circularly polarized light and right-handed circularly polarized light are filtered out, and only linearly polarized light in a specific direction is retained. Optionally, a quarter wave plate may be included in the polarization filter device to convert the filtered linearly polarized light into left-handed Circularly polarized light (or right-handed circularly polarized light).

Beam shaping device 330:

The beam shaping device 330 is used to adjust the laser beam to obtain the first beam.

Wherein, the range of the FOV of the first beam includes [5°×5°, 20°×20°].

It should be understood that the FOV in the horizontal direction of the FOV of the first light beam may be between 5° and 20° (including 5° and 20°), and the FOV in the vertical direction of the FOV of the first light beam may be between 5° and 20°. Between (including 5° and 20°).

Control unit 370:

The control unit 370 is configured to control the first optical element to respectively control the directions of the first light beams at M different moments, so as to obtain M outgoing light beams in different directions.

Wherein, the range of the total FOV covered by the outgoing beams of the M different directions includes [50°×50°, 80°×80°].

The above-mentioned control unit 370 is further configured to control the second optical element to deflect the M reflected light beams obtained by reflecting the target object on the M outgoing light beams in different directions to the receiving unit.

In the embodiment of the present application, the FOV of the beam is adjusted by the beam shaping device, so that the first beam has a larger FOV, and at the same time, the scanning is performed in a way of over-time multiplexing (the first optical element emits in different directions at different times The outgoing beam) can improve the spatial resolution of the final depth map of the target object.

FIG. 55 is a schematic block diagram of a TOF depth sensing module according to an embodiment of the present application.

As shown in FIG. 55, the TOF depth sensing module further includes: a collimating lens 380, the collimating lens 380 is located between the laser light source 310 and the polarization filter device 320, the collimating lens 380 is used to collimate the laser beam Straightening processing; the polarization filter device 320 is used to align the collimated light beam with the collimated lens 380 to filter, to obtain a single polarization state light beam.

FIG. 56 is a schematic block diagram of a TOF depth sensing module according to an embodiment of the present application. In FIG. 56, the aforementioned collimating lens 380 may also be located between the polarization filter device 320 and the beam shaping device 330. The collimating lens 380 is used for collimating the beam of a single polarization state; the beam shaping device 330 is used for adjusting the FOV after the collimating lens 380 is collimated to obtain the first beam.

It should be understood that the aforementioned collimating lens may also be located between the optical shaping device 330 and the first optical element 340. In this case, the collimating lens performs collimation processing on the beam after the beam shaping device 330 has been shaped. The processed light beam is processed by the first optical element.

In addition, the collimating lens 380 can be located at any possible position in the TOF depth sensing module 300, and collimate the light beam in any possible process.

Optionally, the horizontal distance between the first optical element and the second optical element is less than or equal to 1 cm.

Optionally, the above-mentioned first optical element and/or the second optical element is a rotating mirror device.

Among them, the rotating mirror device realizes the control of the emission direction of the emitted light beam by rotating.

The above-mentioned rotating mirror device may specifically be a microelectromechanical system galvanometer or a polygonal rotating mirror.

The first optical element may be any one of a liquid crystal polarization grating, an electro-optical device, an acousto-optic device, an optical phase control array device, etc. The second optical element may also be a liquid crystal polarization grating, an electro-optical device, an acousto-optical device, Any of the optical phased array devices and other devices. For the specific content of liquid crystal polarization gratings, electro-optical devices, acousto-optic devices, optical phased array devices and other devices, please refer to the descriptions in the first to fourth cases above.

Combination method 1:124;

Combination method 2: 342;

Combination mode 3: 3412.

In the above-mentioned

combination mode

1, 1 may indicate the closely-adhered horizontal polarization control sheet and vertical polarization control sheet, and in the above-mentioned

combination mode

2, 3 may indicate the close-adjacent horizontal polarization control sheet and vertical polarization control sheet.

Wherein, when the first optical element 340 or the second optical element 350 of the combination mode 1 or the combination mode 2 is placed on the TOF depth sensing module, the horizontal polarization control sheet or the vertical polarization control sheet are both located on the side close to the laser light source , And the horizontal LCPG and the vertical LCPG are located on the side away from the laser light source.

When the first optical element 340 or the second optical element 350 of the combination mode 3 is placed in the TOF depth sensor module, the distance between the longitudinal polarization control plate, the longitudinal LCPG, the lateral polarization control plate, and the lateral LCPG and the laser light source becomes larger in sequence .

It should be understood that the above three combinations of liquid crystal polarization gratings and the combination in FIG. 35 are only examples. In fact, the various components in the optical element in the present application may also have different combinations. It is only necessary to ensure that the distance between the lateral polarization control plate and the laser light source is smaller than the distance between the lateral LCPG and the laser light source, and the distance between the lateral polarization control plate and the laser light source is smaller than the distance between the lateral LCPG and the laser light source.

Optionally, the above-mentioned second optical element includes: a horizontal polarization control plate, a horizontal liquid crystal polarization grating, a vertical polarization control plate, and a vertical liquid crystal polarization grating. The distance between the sensor and the sensor becomes larger.

Optionally, the above-mentioned beam shaping device is composed of a diffuser lens and a rectangular aperture.

The TOF depth sensing module of the embodiment of the present application is described above with reference to FIGS. 53 to 56. The image generation method of the embodiment of the present application is described in detail below with reference to FIG. 57.

FIG. 57 is a schematic flowchart of an image generation method according to an embodiment of the present application.

The method shown in FIG. 57 can be executed by the TOF depth sensing module or the terminal device including the TOF depth sensing module of the embodiment of the present application. Specifically, the method shown in FIG. 57 can be executed by the TOF depth sensing module shown in FIG. 54 The depth sensor module or a terminal device including the TOF depth sensor module shown in FIG. 54 is implemented. The method shown in FIG. 57 includes steps 5001 to 5006, and these steps are respectively described in detail below.

5001. Control a laser light source to generate a laser beam;

5002. Filter the laser beam by using a polarization filter device to obtain a beam with a single polarization state.

The aforementioned single polarization state is one of the multiple polarization states.

For example, the foregoing multiple polarization states may include linear polarization, left-handed circular polarization, and right-handed circular polarization, and the foregoing single polarization state may be any one of linear polarization, left-handed circular polarization, and right-handed circular polarization.

5003. Use a beam shaping device to adjust the laser beam to obtain a first beam.

Optionally, the above step 5003 specifically includes: using a beam shaping device to adjust the angular spatial intensity distribution of the beam of a single polarization state to obtain the first beam.

Wherein, the range of the FOV of the first light beam includes [5°×5°, 20°×20°];

5004. Control the first optical element to respectively control the directions of the first light beams from the beam shaping device at M different moments to obtain M outgoing light beams in different directions.

Wherein, the range of the total FOV covered by the above-mentioned M outgoing beams in different directions includes [50°×50°, 80°×80°].

5005. Control the second optical element to deflect the M reflected light beams obtained by reflecting the target object on the M outgoing light beams in different directions to the receiving unit.

5006. Generate a depth map of the target object according to the TOFs corresponding to the M outgoing beams in different directions.

Optionally, the above step 5006 specifically includes: generating a depth map of the M regions of the target object according to the distance between the M regions of the target object and the TOF depth sensing module; according to the depth map of the M regions of the target object Synthesize the depth map of the target object.

Optionally, the above step 5004 specifically includes: the control unit generates a first voltage signal, the first voltage signal is used to control the first optical element to control the direction of the first light beam at M different moments to obtain M different directions The above step 5005 includes: the control unit generates a second voltage signal, and the second voltage signal is used to control the second optical element to deflect the M reflected light beams obtained by reflecting the target object on the M outgoing beams in different directions to the receiving unit.

Wherein, the first voltage signal and the second voltage signal have the same voltage value at the same time.

In the TOF depth sensor module 300 shown in FIG. 54 above, the transmitting end and the receiving end use different optical elements to control the beam emission and reception. Optionally, the TOF depth sensor in the embodiment of the present application In the module, the transmitting end and the receiving end can also use the same optical element to control the beam emission and reception.

The following describes in detail the situation where the transmitting end and the receiving end share the same optical element to realize the reflection and reception of the light beam with reference to FIG. 58.

FIG. 58 is a schematic block diagram of a TOF depth sensing module according to an embodiment of the present application.

The TOF depth sensing module 400 shown in FIG. 58 includes a laser light source 410, a polarization filter device 420, a beam shaping device 430, an optical element 440, a receiving unit 450, and a control unit 460. As shown in FIG. 58, the transmitting end of the TOF depth sensing module 400 includes a laser light source 410, a polarization filter device 420, a beam shaping device 430, and an optical element 440. The receiving end of the TOF depth sensing module 400 includes an optical element 440 and The receiving unit 450, the transmitting end and the receiving end of the TOF depth sensing module 400 share an optical element 440. The optical element 440 can not only control the light beam at the transmitting end to obtain the outgoing light beam, but also control the reflected light beam so that the reflected light beam is deflected to the receiving unit 450.

The modules or units in the TOF depth sensing module 400 will be introduced in detail below.

Laser light source 410:

The laser light source 410 is used to generate a laser beam;

Optionally, the laser beam emitted by the laser light source 410 is a single beam of quasi-parallel light, and the divergence angle of the laser beam emitted by the laser light source 410 is less than 1°.

Optionally, the above-mentioned laser light source 410 is a semiconductor laser light source.

The above-mentioned laser light source 410 may be a vertical cavity surface emitting laser (VCSEL).

Optionally, the above-mentioned laser light source 410 may also be a Fabry-Perot laser (may be referred to as FP laser for short).

Optionally, the wavelength of the laser beam emitted by the laser light source 410 is greater than 900 nm.

Optionally, the wavelength of the laser beam emitted by the laser light source 410 is 940 nm or 1550 nm.

The light-emitting area of the above-mentioned laser light source 410 is less than or equal to 5×5 mm ² .

Due to the small size of the above-mentioned laser light source, the TOF depth sensing module 400 including the laser light source is relatively easy to be integrated into the terminal device, which can reduce the space occupied in the terminal device to a certain extent.

Optionally, the average output optical power of the TOF depth sensing module 400 is less than 800 mw.

The polarization filter device 420 is used to filter the laser beam to obtain a beam of a single polarization state;

The beam shaping device 430 is used to adjust the FOV of the beam of a single polarization state to obtain the first beam;

The control unit 460 is configured to control the optical element 440 to respectively control the direction of the first light beam at M different times to obtain M outgoing light beams in different directions;

The control unit 460 is further configured to control the optical element 440 to deflect the M reflected light beams obtained by reflecting the target object on the M outgoing light beams in different directions to the receiving unit 450 respectively.

Wherein, the aforementioned single polarization state is one of multiple polarization states;

The FOV of the first beam includes [5°×5°, 20°×20°]; the range of the total FOV covered by the M outgoing beams in different directions includes [50°×50°, 80°×80° ].

In the embodiment of this application, the FOV of the light beam is adjusted by the beam shaping device, so that the first light beam has a larger FOV, and at the same time, the scanning is performed in a way of over-time multiplexing (optical elements emit different directions at different times. Beam), which can improve the spatial resolution of the final depth map of the target object.

Optionally, the above-mentioned control unit 460 is further configured to: generate a depth map of the target object according to the TOFs respectively corresponding to the M outgoing beams in different directions.

The TOF corresponding to the M exit beams in different directions may specifically refer to the time difference information between the moment when the reflected light beams corresponding to the M exit beams in different directions are received by the receiving unit and the exit times of the M exit beams in different directions. .

Optionally, the above definitions on the laser light source 310, the polarization filter device 320, and the beam shaping device 330 in the TOF depth sensing module 300 are also applicable to the laser light source 410 and the polarization filter device in the TOF depth sensing module 400. 420 and beam shaping device 430.

Optionally, the above-mentioned optical element is a rotating mirror device.

Wherein, the above-mentioned rotating mirror device realizes the control of the emission direction of the emitted light beam through rotation.

Optionally, the above-mentioned rotating mirror device is a microelectromechanical system galvanometer or a multi-faceted rotating mirror.

The case where the optical element is a rotating mirror device will be described below with reference to the accompanying drawings.

FIG. 59 is a schematic block diagram of a TOF depth sensing module according to an embodiment of the present application.

As shown in FIG. 59, the TOF depth sensing module further includes a collimating lens 470, which is located between the laser light source 410 and the polarization filter device 420, and the collimating lens 470 is used to collimate the laser beam. Straightening processing; the polarization filter device 420 is used to align the collimated light beam with the collimated lens 470 to filter, to obtain a light beam with a single polarization state.

FIG. 60 is a schematic block diagram of a TOF depth sensing module according to an embodiment of the present application. In FIG. 60, the aforementioned collimating lens 470 may also be located between the polarization filter device 420 and the beam shaping device 430. The collimating lens 470 is used for collimating the beam of a single polarization state; the beam shaping device 430 is used for adjusting the FOV after the collimating lens 470 is collimated to obtain the first beam.

It should be understood that the aforementioned collimating lens may also be located between the optical shaping device 430 and the optical element 440. In this case, the collimating lens performs collimation processing on the beam after the beam shaping device 430 has been shaped. The light beam is processed by the optical element 440.

In addition, the collimating lens 470 can be located at any possible position in the TOF depth sensing module 400, and collimate the light beam in any possible process.

As shown in Figure 61, the TOF depth sensing module includes a laser light source, a homogenizing device, a beam splitter, a microelectromechanical systems (MEMS) galvanometer, a receiving lens, and a sensor. The MEMS in the picture includes electrostatic galvanometer, electromagnetic galvanometer and polygon mirror. Since the rotating mirror devices all work in a reflective mode, the optical path in the TOF depth sensing module is a reflective optical path, and the transmission and reception are coaxial optical paths, and the polarizing device and lens can be shared through the beam splitter. In FIG. 61, the polarizing device is specifically a MEMS galvanometer.

Optionally, the above-mentioned optical element 440 is a liquid crystal polarizing element.

Optionally, the above-mentioned optical element 440 includes: a horizontal polarization control plate, a horizontal liquid crystal polarization grating, a vertical polarization control plate, and a vertical liquid crystal polarization grating.

Optionally, in the above-mentioned optical element 440, the distance between the horizontal polarization control film, the horizontal liquid crystal polarization grating, the vertical polarization control film, and the vertical liquid crystal polarization grating and the laser light source becomes larger in sequence, or the vertical polarization control film and the vertical liquid crystal polarization grating , The distance between the horizontal polarization control plate and the horizontal liquid crystal polarization grating and the laser light source becomes larger in turn.

Optionally, the above-mentioned beam shaping device 430 is composed of a diffuser lens and a rectangular aperture.

The above-mentioned optical element may be any one of a liquid crystal polarization grating, an electro-optical device, an acousto-optical device, an optical phased array device and the like. For the specific content of liquid crystal polarization gratings, electro-optical devices, acousto-optic devices, optical phased array devices and other devices, please refer to the descriptions in the first to fourth cases above.

FIG. 62 is a schematic flowchart of an image generation method according to an embodiment of the present application.

The method shown in FIG. 62 may be executed by the TOF depth sensing module or a terminal device including the TOF depth sensing module of the embodiment of the present application. Specifically, the method shown in FIG. 62 may be executed by the TOF depth sensing module shown in FIG. 58 The depth sensor module or a terminal device including the TOF depth sensor module shown in FIG. 58 is implemented. The method shown in FIG. 62 includes steps 6001 to 6006, and these steps are respectively described in detail below.

6001. Control the laser light source to generate a laser beam.

6002 Use a polarization filter device to filter the laser beam to obtain a beam with a single polarization state.

6003. Use a beam shaping device to adjust the beam of a single polarization state to obtain the first beam.

The range of the FOV of the first light beam includes [5°×5°, 20°×20°].

6004. The control optical element respectively controls the directions of the first light beam from the beam shaping device at M different moments to obtain M outgoing light beams in different directions.

The range of the total FOV covered by the above-mentioned M outgoing beams in different directions includes [50°×50°, 80°×80°].

6005. The control optical element respectively deflects the M reflected light beams obtained by reflecting the target object on the M outgoing light beams in different directions to the receiving unit.

6006. Generate a depth map of the target object according to the TOFs corresponding to the emitted light beams in different directions.

In the embodiment of this application, the FOV of the light beam is adjusted by the beam shaping device, so that the first light beam has a larger FOV, while scanning is performed in a way of over-time multiplexing (optical elements emit different directions at different times Beam), which can improve the spatial resolution of the final depth map of the target object.

Optionally, the above step 6006 specifically includes: determining the distance between the M regions of the target object and the TOF depth sensing module according to the TOFs corresponding to the M outgoing beams in different directions; according to the M regions of the target object and the TOF depth sensing module; The distance between the TOF depth sensing modules generates a depth map of the M regions of the target object; the depth map of the target object is synthesized according to the depth maps of the M regions of the target object.

Optionally, the above step 6003 specifically includes: using a beam shaping device to adjust the angular spatial intensity distribution of the beam of a single polarization state to obtain the first beam.

The specific working process of the TOF depth sensing module 400 according to the embodiment of the present application will be described in detail below with reference to FIG. 63.

FIG. 63 is a schematic structural diagram of a TOF depth sensing module according to an embodiment of the present application.

The specific implementation and functions of the various components of the TOF depth sensing module shown in Figure 63 are as follows:

(1) The laser light source is a VCSEL array.

The VCSEL light source is capable of emitting a beam array with good directivity.

(2) The polarizer is a polarizing filter device, and the polarizer can be located in front (below) or behind (above) the homogenizing device.

(3) The homogenizing device may be a diffractive optical element (DOE) or an optical diffuser (may be called a Diffuser).

The beam array is processed into a substantially uniform beam block after being processed by a homogenizing device.

(3) The optical element is a multilayer LCPG (Liquid Crystal Polarization Grating).

It should be understood that in the above-mentioned FIG. 63, only the case where the polarizer is located under the light homogenizing device is shown. In fact, the polarizer may also be located above the light homogenizing device.

For the specific principle of controlling the direction of the light beam by the liquid crystal polarization grating, please refer to the related content described in FIG. 37 and FIG. 38.

In Figure 63, through the cooperation of the multilayer liquid crystal polarization grating and the quarter wave plate, the emitted light is reflected by the target, and when it returns to the polarizer, it happens to pass through an extra optical length of 1/2. This design It happens that the deflecting direction of the polarizer to the return light is opposite to that of the emitted light. Under the quasi-coaxial approximation, the obliquely emitted light returns to the original path after reflection, deflects back to the direction parallel to the emitted light, and reaches the receiving lens. The receiving end uses a beam deflection device to selectively illuminate the target by the emitted light into blocks and image the entire receiver (SPAD array). When the target is illuminated in blocks, each block is received by the entire receiver, and the complete image can be obtained by stitching the images at each time. In this way, the time division multiplexing of the receiver is realized to achieve the purpose of multiplying the resolution.

(4) The receiving lens is completed by an ordinary lens, and the received light is imaged on the receiver.

(5) The receiver is a SPAD array.

SPAD can detect single photons, and the time of single photon pulses it detects can be accurately recorded. Every time the VCSEL emits light, the SPAD is activated. The VCSEL emits light beams periodically, while the SPAD array can count the time when each pixel receives the reflected light in each cycle. Through statistics on the time distribution of the reflected signal, the reflected signal pulse can be fitted to calculate the delay time.

The key device of this embodiment is a beam deflection device shared by the projection end and the receiving end, that is, a liquid crystal polarizing device. In this embodiment, the beam deflection device includes a multilayer LCPG, which is also called an electrically controlled liquid crystal polarizing device.

Fig. 64 is a schematic structural diagram of a liquid crystal polarizing device according to an embodiment of the present application.

An optional specific structure of a liquid crystal polarizer is shown in Figure 64. In Figure 64, 1 represents a horizontal single-angle LCPG, 2 represents a horizontal double-angle LCPG, 3 represents a longitudinal single-angle LCPG, 4 represents a longitudinal double-angle LCPG, and 5 It is a polarization control plate. Among them, there are 5 polarization control plates, which are located on the left side of the 4 LCPGs shown in Fig. 64, and the numbers are 5.1, 5.2, 5.3, and 5.4, respectively.

The control unit can be used to control the liquid crystal polarizing device shown in FIG. 64, and the control sequence can be as shown in FIG. 65 (scanning starts at time t0 and continues to time t15). The timing diagram of the drive signal generated by the control unit is shown in Figure 66.

Figure 66 shows the voltage drive signals of the device polarization control plates 5.1, 5.2, 5.3 and 5.4 from time t0 to time t15. The voltage drive signal includes two signals of low level and high level, in which the low level is represented by 0 , The high level is represented by 1. Then, the voltage driving signals of the polarization control plates 5.1, 5.2, 5.3, and 5.4 from time t0 to time t15 are specifically shown in Table 1.

Table 1

时序Timing	电压Voltage
t0t0	01110111
t1t1	10111011
t2t2	00010001
t3t3	11011101
t4t4	01000100
t5t5	10001000
t6t6	00100010
t7t7	11101110
t8t8	01100110
t9t9	10101010
t10t10	00000000
t11t11	11001100
t12t12	01010101
t13 t13	10011001
t14t14	00110011
t15t15	11111111

For example, in Table 1, in the time interval t0, the voltage drive signal of the polarization control plate 5.1 is a low-level signal, and the voltage drive signals of the polarization control plate 5.2 to 5.4 are high-level signals. Therefore, the voltage corresponding to time t0 The signal is 0111.

As shown in Figure 64, the electrically controlled liquid crystal polarizer is composed of an LCPG and a polarization control plate. The voltage drive signal for 4*4 scanning is shown in Figure 66, where 5.1, 5.2, 5.3, and 5.4 respectively represent the voltage drive signals applied to the four polarization control plates. The entire FOV is divided into 4*4 blocks, from t0 to t15 is the time interval to illuminate each block respectively. Among them, when the voltage driving signal shown in FIG. 66 is applied, the state of the light beam passing through each device when passing through the liquid crystal deflection device is shown in Table 2.

Table 2

The meanings shown in Table 2 are explained below. In the items in Table 2, the values in parentheses are voltage signals, L means left-handed, R means right-handed, and values such as 1 and 3 represent the angle of beam deflection, where , The deflection angle indicated by 3 is greater than the deflection angle indicated by 1.

For example, for R 1-1, R means right-handed, the first 1 means left (if the first is -1, it means right), and the second -1 means top (if the second is 1, it means below).

For another example, for L 3-3, L means left-handed, the first 3 means the rightmost (if the first is -3, it means the leftmost), and the second -3 means the uppermost (the second is 3 means the bottom).

When the voltage driving signal shown in FIG. 66 is applied to the liquid crystal polarizer, the scanning area of the TOF depth sensor module at different times is shown in FIG. 67.

The following describes the depth map obtained in the embodiment of the present application with reference to the accompanying drawings. As shown in FIG. 68, it is assumed that the depth map corresponding to the target object from time t0 to time t3 can be obtained through time-sharing scanning, where the depth map from time t0 to time t3 can be obtained. The resolution of the depth map is 160×120. By stitching the corresponding depth maps from time t0 to time t3, the final depth map of the target object as shown in Figure 69 can be obtained. The final depth map of the target object has a resolution of 320 ×240. It can be seen from FIG. 68 and FIG. 69 that by stitching the depth maps obtained at different times, the resolution of the finally obtained depth map can be improved.

A TOF depth sensing module and an image generation method according to an embodiment of the present application are described in detail above with reference to FIGS. 53 to 69. Hereinafter, another TOF depth sensing module and image generation method according to an embodiment of the present application will be described in detail with reference to FIGS. 70 to 78.

In the TOF depth sensor module, liquid crystal devices can be used to adjust the direction of the light beam, and in the TOF depth sensor module, a polarizer is generally added at the transmitting end to realize the emission of polarized light. However, in the process of polarized light emission, due to the polarization selection effect of the polarizer, half of the energy will be lost when the beam is emitted. This part of the energy lost will be absorbed or scattered by the polarizer and converted into heat, resulting in TOF depth sensing The temperature rise of the module affects the stability of the TOF depth sensor module. Therefore, how to reduce the heat loss of the TOF depth sensing module is a problem that needs to be solved.

Specifically, in the TOF depth sensing module of the embodiment of the present application, the heat loss of the TOF depth sensing module can be reduced by transferring the polarizer from the transmitting end to the receiving end. The TOF depth sensing module of the embodiment of the present application will be described in detail below with reference to the accompanying drawings.

The TOF depth sensing module of the embodiment of the present application will be briefly introduced below with reference to FIG. 70.

FIG. 70 is a schematic diagram of the TOF depth sensing module working with the embodiment of the present application. As shown in Figure 70, the TOF depth sensor module can include a transmitting end (or a projection end), a receiving end, and a control unit. The transmitting end is used to emit the outgoing beam, and the receiving end is used to receive the reflection of the target object. For the light beam (the reflected light beam is the light beam obtained by the target object reflecting the outgoing light beam), the control unit can control the transmitting end and the receiving end to transmit and receive the light beam respectively.

In Figure 70, the transmitting end may generally include a laser light source, a collimating lens (optional), a homogenizing device, an optical element, and a projection lens (optional); the receiving end generally includes: a beam selection device and a receiving unit, where the receiving The unit may specifically include a receiving lens and a sensor.

The TOF depth sensor module shown in Figure 70 will project two or more different states of projection light (state A, state B) at the same time. After the two different states of projection light reach the receiving end after reflection, the beam The selection device selects to let the reflected light of a certain state enter the sensor according to the instruction time-sharing, and perform deep imaging of the light of a specific state, and then the beam deflection device can scan in different directions to achieve the coverage of the target FOV.

The TOF depth sensor module shown in FIG. 70 can be used for 3D image acquisition. The TOF depth sensor module of the embodiment of the present application can be set in a smart terminal (for example, a mobile phone, a tablet, a wearable device, etc.), and For the acquisition of depth images or 3D images, gesture and body recognition can also be provided for 3D games or somatosensory games.

The TOF depth sensing module of the embodiment of the present application will be described in detail below with reference to FIG. 71.

The TOF depth sensing module 500 shown in FIG. 71 includes a laser light source 510, an optical element 520, a beam selection device 530, a receiving unit 540, and a control unit 550.

The modules or units in the TOF depth sensing module 500 will be introduced in detail below.

Laser light source 510:

The laser light source 510 is used to generate a laser beam.

Optionally, the wavelength of the laser beam emitted by the above-mentioned laser light source 510 is greater than 900 nm.

Optionally, the wavelength of the laser beam emitted by the laser light source 510 is 940 nm or 1550 nm.

Optionally, the light-emitting area of the aforementioned laser light source 510 is less than or equal to 5×5 mm ² .

Optical element 520:

The optical element 520 is arranged in the exit direction of the laser beam. The optical element 520 is used to control the direction of the laser beam to obtain a first exit beam and a second exit beam. The exit direction of the first exit beam and the second exit beam are The exit directions of the light beams are different, and the polarization direction of the first exit light beam and the polarization direction of the second exit light beam are orthogonal.

Optionally, as shown in FIG. 35, the above-mentioned optical element 520 may include: a horizontal polarization control film, a horizontal liquid crystal polarization grating, a vertical polarization control film, and a vertical liquid crystal polarization grating, wherein the horizontal polarization control film, the horizontal liquid crystal polarization grating, and the vertical polarization control film The distance between the plate and the longitudinal liquid crystal polarization grating and the laser light source becomes larger in turn.

Alternatively, in the above-mentioned optical element 520, the distance between the longitudinal polarization control sheet, the longitudinal liquid crystal polarization grating, the lateral polarization control sheet, and the lateral liquid crystal polarization grating and the laser light source becomes larger in sequence.

Receiving unit 540:

The receiving unit 540 may include a receiving lens 541 and a sensor 542.

The control unit 550 and the beam selection device 530:

The control unit 550 is used to control the operation of the beam selection device 530 through a control signal. Specifically, the control unit 550 may generate a control signal for controlling the beam selection device 530 to separate the third reflected beam and the The fourth reflected light beam propagates to the sensor, where the third reflected light beam is the light beam obtained by the target object reflecting the first outgoing light beam, and the fourth reflected light beam is the light beam obtained by the target object reflecting the second outgoing light beam.

The above-mentioned beam selection device 530 can respectively propagate beams of different polarization states to the receiving unit at different times under the control of the control unit 550. The time-sharing mode adopted by the beam selection device 530 here propagates the received reflected beam to the receiving unit 540. Compared with the beam splitter 630 in the TOF depth sensor module 600 below, it can more fully Using the receiving resolution of the receiving unit 540, the resolution of the finally obtained depth map is also relatively high.

Optionally, the control signal generated by the aforementioned control unit 550 is used to control the beam selection device 530 to respectively propagate the third reflected beam and the fourth reflected beam to the sensor in different time intervals.

That is, under the control of the control signal generated by the control unit 550, the above-mentioned beam selection device can respectively propagate the third reflected light beam and the fourth reflected light beam to the receiving unit at different times.

Optionally, as an embodiment, the above-mentioned beam selection device 530 is composed of a quarter wave plate + a half wave plate + a polarizer.

As shown in FIG. 72, the TOF depth sensing module 500 may further include:

The collimating lens 560 is arranged in the exit direction of the laser beam, and the collimating lens is arranged between the laser light source and the optical element. The collimating lens 560 is used to collimate the laser beam to obtain collimation The processed light beam; the optical element 520 is used to align the direction of the processed light beam to control the first outgoing beam and the second outgoing beam.

As shown in FIG. 73, the TOF depth sensing module 500 may further include:

The homogenization device 570 is arranged in the exit direction of the laser beam, and the collimating lens is arranged between the laser light source 510 and the optical element 520. The homogenization device 570 is used to adjust the energy distribution of the laser beam to obtain The homogenized light beam; the optical element is used to control the direction of the homogenized light beam to obtain the first outgoing light beam and the second outgoing light beam.

Optionally, the above-mentioned homogenizing device is a microlens diffuser or a diffractive optical diffuser (DOE diffuser).

It should be understood that the TOF depth sensing module 500 may include a collimating lens 560 and a light homogenizing device 570 at the same time. The collimating lens 560 and the light homogenizing device 570 are both located between the laser light source 510 and the optical element 520. For the collimating lens 560 As for the homogenization device 570, the distance between the collimating lens 560 and the laser light source may be closer, or the distance between the homogenization device 570 and the laser light source may be closer.

As shown in FIG. 74, the distance between the collimating lens 560 and the laser light source 510 is smaller than the distance between the homogenizing device 570 and the laser light source 510.

In the TOF depth sensor module 500 shown in FIG. 74, the laser beam emitted by the laser light source 510 is first collimated by the collimating lens 560, and then homogenized by the homogenizing device 570, and then propagated to the optical element 520 To process.

In the embodiments of the present application, homogenization processing can make the optical power of the laser beam more uniform in the angular space, or distribute it according to a specific law, to prevent local optical power from being too small, and to avoid blind spots in the final depth map of the target object.

As shown in FIG. 75, the distance between the collimating lens 560 and the laser light source 510 is greater than the distance between the homogenizing device 570 and the laser light source 510.

In the TOF depth sensor module 500 shown in FIG. 74, the laser beam emitted by the laser light source 510 is first homogenized by the homogenizing device 570, and then collimated by the collimating lens 560 before being transmitted to the optics. Processing in element 520.

The specific structure of the TOF depth sensing module 500 will be described in detail below in conjunction with FIG. 76.

FIG. 76 is a schematic diagram of a specific structure of a TOF depth sensing module 500 according to an embodiment of the present application.

As shown in FIG. 76, the TOF depth sensing module 500 includes a projection end, a control unit, and a receiving end. Among them, the projection end includes a laser light source, a homogenizing device, and a beam deflection device; the receiving end includes a beam deflection device, a beam (dynamic) selection device, a receiving lens, and a two-dimensional sensor; the control unit is used to control the projection end and the receiving end to complete the beam Scan. In addition, the beam deflection device in FIG. 76 corresponds to the optical element in FIG. 71, and the beam (dynamic) selection device in FIG. 76 corresponds to the beam selection device in FIG. 71.

The specific devices used by each module or unit will be described in detail below.

The laser light source may be a vertical cavity surface emitting laser (VCSEL) array light source;

The homogenizing device can be a diffractive optical diffuser;

The beam deflection device can be a multilayer LCPG and a quarter wave plate;

The electronically controlled LCPG includes an electronically controlled horizontal LCPG component and an electrically controlled vertical LCPG component.

Among them, the use of multi-layer cascaded electronically controlled LCPG can realize two-dimensional block scanning in the horizontal and vertical directions. The quarter wave plate is used to convert the circularly polarized light from the LCPG into linearly polarized light to achieve the quasi-coaxial effect of the transmitting end and the receiving end.

The wavelength of the aforementioned VCSEL array light source may be greater than 900 nm. Specifically, the wavelength of the aforementioned VCSEL array light source may be 940 nm or 1550 nm.

Among them, the intensity of the solar spectrum in the 940nm band is relatively weak, which helps reduce noise caused by sunlight in outdoor scenes. In addition, the laser light emitted by the aforementioned VCSEL array light source may be continuous light or pulsed light. The VCSEL array light source can also be divided into several blocks to realize time-sharing control, so that different areas can be lit in time-sharing.

The function of the diffractive optical diffuser is to shape the light beam emitted by the VCSEL array light source into a uniform square or rectangular light source with a certain FOV (for example, a 5°x5° FOV).

The role of the multilayer LCPG and the quarter wave plate is to realize the scanning of the beam.

The receiving end and the transmitting end share a multi-layer LCPG and a quarter wave plate. The beam selection device at the receiving end is composed of a quarter wave plate + an electronically controlled half wave plate + a polarizer. The receiving lens at the receiving end can be a single lens or multiple lenses. The combination of lenses. The sensor at the receiving end is a single-photon avalanche diode (SPAD) array. Because SPAD has the sensitivity of single-photon detection, it can increase the detection range of the Lidar system.

For the above-mentioned TOF depth sensing module 500, the polarization selection device at the transmitting end is moved to the receiving end. As shown in Figure 76, the laser light emitted by the ordinary VCSEL array light source has no fixed polarization state, and can be decomposed into a linearly polarized laser parallel to the paper surface and a linearly polarized laser perpendicular to the paper surface, and the linearly polarized laser will be divided into Two lasers with different polarization states (left-handed circular polarization and right-handed circular polarization) have different emission angles, and the corresponding polarization states of the two lasers are converted into linear polarization parallel to the paper after passing through the quarter wave plate. And the linear polarization perpendicular to the paper surface. The retroreflected beams generated by the two lasers with different polarization states irradiating the object in the target area will be received by the 1/4 wave plate and LCPG shared with the transmitting end and become with the same divergence angle but different deflection states-left-handed circular polarization Light and right-handed circularly polarized light-laser light. The beam selection device at the receiving end is composed of a quarter-wave plate + an electronically controlled half-wave plate + a polarizer. After the received light passes through the quarter-wave plate, the polarization state is converted into linear polarized light parallel to the paper surface and a line perpendicular to the paper surface. Polarized light, in this way, through the time-sharing control of the electronically controlled half-wave plate, the polarization state of the linearly polarized light can be rotated by 90 degrees or the polarization state of the half-wave plate will not be changed, and the linear polarization parallel to the paper surface and perpendicular to the paper can be achieved. The linearly polarized light of the surface is transmitted through time sharing, and at the same time, the light of another polarization state is absorbed or scattered by the polarizer.

Compared with the existing TOF depth sensing module in which the polarization selection device is located at the transmitting end, since the polarization selection device of the present application is located at the receiving end, the energy absorbed or scattered by the polarizer is significantly reduced. Assuming that the detection distance is R meters, the target The reflectivity of the object is ρ, and the entrance pupil diameter of the receiving system is D. Under the same receiving FOV, the incident energy P _t of the polarization selection device of the TOF depth sensing module 500 in the embodiment of the present application is:

Wherein, P is the transmitted energy emitted end, at a distance of 1m, energy can be reduced by about ¹⁰⁴ times.

In addition, it is assumed that the TOF depth sensor module 500 of the embodiment of this application and the conventional TOF depth sensor module patent use the same power non-polarized light source, because in the TOF depth sensor module 500 of the embodiment of this application, the outdoor The light is non-polarized, and half of the light entering the receiving detector will be absorbed or scattered, while the outdoor light in the TOF depth sensing module in the traditional solution will all enter the detector. Therefore, the implementation of this application The signal-to-noise ratio of the example will be doubled in the same situation.

Based on the TOF depth sensor module 500 shown in FIG. 76, the diffractive optical diffuser (DOE diffuser) behind the VCSEL array light source can also be changed to a microlens diffuser (Diffuser). Since the microlens diffuser is based on geometric optics to achieve uniform light, its transmission efficiency can reach more than 80%, while the transmission efficiency of the traditional diffractive optical diffuser (DOE diffuser) is only about 70%. The morphology of the microlens diffuser is shown in Figure 77. It is composed of a series of randomly distributed microlenses. The position and morphology of each microlens are designed through simulation optimization, so that the reshaped beam is as uniform as possible and the transmission efficiency is Higher.

FIG. 78 is a schematic flowchart of an image generation method according to an embodiment of the present application.

The method shown in FIG. 78 may be executed by the TOF depth sensing module or the terminal device including the TOF depth sensing module of the embodiment of the present application. Specifically, the method shown in FIG. 78 may be executed by the TOF depth sensing module shown in FIG. 71 The depth sensor module or a terminal device including the TOF depth sensor module shown in Figure 71 is implemented. The method shown in FIG. 78 includes steps 7001 to 7006, and these steps are respectively described in detail below.

7001. Control the laser light source to generate a laser beam;

7002. The control optical element controls the direction of the laser beam to obtain a first outgoing beam and a second outgoing beam.

7003. Control the beam selection device to propagate the third reflected beam obtained by reflecting the target object on the first outgoing beam and the fourth reflected beam obtained by reflecting the target object on the second outgoing beam to different areas of the receiving unit.

7004. Generate a first depth map of the target object according to the TOF corresponding to the first outgoing beam.

7005. Generate a second depth map of the target object according to the TOF corresponding to the second outgoing beam.

Wherein, the exit direction of the first exit beam is different from the exit direction of the second exit beam, and the polarization direction of the first exit beam is orthogonal to the polarization direction of the second exit beam.

Optionally, the method shown in FIG. 78 further includes: stitching the first depth map and the second depth map to obtain a depth map of the target object.

It should be understood that in the method shown in FIG. 78, the third depth map, the fourth depth map, etc. can also be generated in a similar manner. Next, all the depth maps can be spliced or combined to obtain the target object. The final depth map.

Optionally, the aforementioned terminal device further includes a collimating lens, which is arranged between the laser light source and the optical element, and the method shown in FIG. 78 further includes:

7006. Use a collimating lens to collimate the laser beam to obtain a collimated beam;

The above step 7002 specifically includes: controlling the direction of the light beam after the optical element is aligned to obtain the first outgoing light beam and the second outgoing light beam.

Optionally, the above-mentioned terminal device further includes a light homogenizing device, the light homogenizing device is arranged between the laser light source and the optical element, and the method shown in FIG. 78 further includes:

7007. Use a homogenizing device to adjust the energy distribution of the laser beam to obtain a homogenized beam;

The above step 7002 specifically includes: controlling the optical element to control the direction of the light beam after homogenization treatment to obtain the first outgoing light beam and the second outgoing light beam.

Based on the above steps 7001 to 7005, the method shown in FIG. 78 may further include step 7006 or step 7007.

Alternatively, on the basis of the above steps 7001 to 7005, the method shown in FIG. 78 may further include step 7006 and step 7007. In this case, after step 7001 is executed, step 7006 may be executed first, then step 7007, and then step 7002 may be executed, or step 7007 may be executed first, then step 7006, and then step 7002 may be executed. That is to say, after the laser light source in step 7001 generates the laser beam, the laser beam can be collimated and homogenized (the energy distribution of the laser beam is adjusted by the homogenizer), and then the optics can be controlled. The component controls the direction of the laser beam. Alternatively, after the laser light source in step 7001 generates the laser beam, the laser beam can be homogenized (the energy distribution of the laser beam is adjusted by the homogenization device) and collimated, and then the optical element can be controlled to The direction of the laser beam is controlled.

A TOF depth sensing module and an image generation method according to an embodiment of the present application are described in detail above with reference to FIGS. 70 to 78. In the following, another TOF depth sensing module and image generation method according to an embodiment of the present application will be described in detail with reference to FIGS. 79 to 88.

Because the liquid crystal device has excellent polarization and phase adjustment capabilities, it is widely used in TOF depth sensing modules to achieve beam deflection. However, due to the birefringence characteristics of liquid crystal materials, existing TOF depth sensing modules using liquid crystal devices generally add a polarizer at the emitting end to realize the emission of polarized light. During the emergence of polarized light, due to the polarization selection effect of the polarizer, half of the energy is lost when the beam is emitted. This part of the energy lost will be absorbed or scattered by the polarizer and converted into heat, resulting in TOF depth sensing mode. The temperature rise of the group affects the stability of the TOF depth sensor module. Therefore, how to reduce the heat loss of the TOF depth sensor module and improve the signal-to-noise ratio of the TOF depth sensor module is a problem that needs to be solved.

This application provides a new TOF depth sensor module, which reduces the heat loss of the system by transferring the polarizer from the transmitting end to the receiving end, and at the same time improves the signal-to-noise ratio of the system relative to the background stray light.

The TOF depth sensing module of the embodiment of the present application will be briefly introduced below with reference to FIG. 79.

The TOF depth sensing module 600 shown in FIG. 79 includes a laser light source 610, an optical element 620, a beam splitter 630, a receiving unit 640, and a control unit 650.

The modules or units in the TOF depth sensing module 600 will be introduced in detail below.

Laser light source 610:

The laser light source 610 is used to generate a laser beam.

Optionally, the above-mentioned laser light source 610 is a vertical cavity surface emitting laser (VCSEL).

Optionally, the above-mentioned laser light source 610 is a Fabry-Perot laser (may be referred to as FP laser for short).

Optionally, the wavelength of the laser beam emitted by the laser light source 610 is greater than 900 nm.

Optionally, the wavelength of the laser beam emitted by the laser light source 610 is 940 nm or 1550 nm.

Optionally, the light-emitting area of the above-mentioned laser light source 610 is less than or equal to 5×5 mm ² .

Optical element 620:

The optical element 620 is arranged in the exit direction of the laser beam. The optical element 420 is used to control the direction of the laser beam to obtain a first exit beam and a second exit beam. The exit direction of the first exit beam and the second exit beam are The exit directions of the light beams are different, and the polarization direction of the first exit light beam and the polarization direction of the second exit light beam are orthogonal.

Optionally, as shown in FIG. 35, the above-mentioned optical element 620 may include: a horizontal polarization control plate, a horizontal liquid crystal polarization grating, a vertical polarization control plate, and a vertical liquid crystal polarization grating, wherein the horizontal polarization control plate and the horizontal liquid crystal polarization grating The distance between the polarization grating, the longitudinal polarization control sheet, and the longitudinal liquid crystal polarization grating and the laser light source becomes larger in sequence.

Alternatively, in the above-mentioned optical element 620, the distance between the longitudinal polarization control sheet, the longitudinal liquid crystal polarization grating, the lateral polarization control sheet, and the lateral liquid crystal polarization grating and the laser light source becomes larger in sequence.

Receiving unit 640:

The receiving unit 640 may include a receiving lens 641 and a sensor 642.

Beam splitter 630:

The beam splitter 630 is used to transmit the third reflected light beam obtained by the target object reflecting the first outgoing light beam and the fourth reflected light beam obtained by the target object reflecting the second outgoing light beam to different areas of the sensor.

Optionally, the above-mentioned beam splitter is implemented based on any one of a liquid crystal polarization grating LCPG, a polarization beam splitting prism PBS, and a polarization filter.

In this application, by transferring the polarizer from the transmitting end to the receiving end, the heat loss of the system can be reduced. In addition, by installing a beam splitter at the receiving end, the signal-to-noise ratio of the TOF depth sensor module can be improved.

As shown in FIG. 80, the TOF depth sensing module 600 may further include: a collimating lens 660, the collimating lens 660 is arranged in the exit direction of the laser beam, and the collimating lens 660 is arranged in the laser light source 610 and the optical element 620 In between, the collimating lens 660 is used to collimate the laser beam to obtain the collimated beam; when the collimating lens 660 is disposed between the laser light source 610 and the optical element 620, the optical element 620 is used to collimate the laser beam. The direction of the beam after the collimation process is controlled to obtain the first outgoing beam and the second outgoing beam.

As shown in FIG. 81, the TOF depth sensing module 600 may further include:

The homogenization device 670, the homogenization device 670 is arranged in the exit direction of the laser beam, and the homogenization device 670 is arranged between the laser light source and the optical element, and the homogenization device 670 is used to adjust the energy distribution of the laser beam to obtain uniformity. The light beam; when the homogenization device 670 is arranged between the laser light source 610 and the optical element 620, the optical element 620 is used to control the direction of the homogenized beam to obtain the first and second exit beams .

Optionally, the above-mentioned light homogenizing device may be a microlens diffuser sheet or a diffractive optical diffuser sheet.

It should be understood that the TOF depth sensing module 600 may include a collimating lens 660 and a light homogenizing device 670 at the same time. The collimating lens 660 and the light homogenizing device 670 may both be located between the laser light source 610 and the optical element 620. For the collimating lens For the 660 and the homogenization device 670, either the collimating lens 660 and the laser light source may be closer, or the homogenization device 670 and the laser light source may be closer.

As shown in FIG. 82, the distance between the collimating lens 660 and the laser light source 610 is smaller than the distance between the homogenizing device 670 and the laser light source 610.

In the TOF depth sensor module 600 shown in FIG. 82, the laser beam emitted by the laser light source 610 is first collimated by the collimating lens 660, and then homogenized by the homogenizing device 670, and then propagated to the optical element 620 To process.

As shown in FIG. 83, the distance between the collimating lens 660 and the laser light source 610 is greater than the distance between the homogenizing device 670 and the laser light source 610.

In the TOF depth sensor module 600 shown in FIG. 83, the laser beam emitted by the laser light source 610 is first homogenized by the homogenizing device 670, and then collimated by the collimating lens 660 before being transmitted to the optics. Process in element 620.

The specific structure of the TOF depth sensing module 600 will be described in detail below in conjunction with the accompanying drawings.

FIG. 84 is a schematic structural diagram of a TOF depth sensing module 600 according to an embodiment of the present application.

As shown in Figure 84, the TOF depth sensor module 600 includes a projection end and a receiving end. The laser light source at the projection end is a VCSEL light source, the homogenizing device is a diffractive optical diffuser (DOE Diffuser), and the beam element is a multilayer LCPG and A quarter-wave plate, where each layer of LCPG includes: an LCPG component that is electrically controlled in the horizontal direction and an LCPG component that is electrically controlled in the vertical direction. The use of multi-layer cascaded LCPG can realize two-dimensional block scanning in the horizontal and vertical directions.

The wavelength of the aforementioned VCSEL array light source may be greater than 900 nm. Specifically, the wavelength of the aforementioned VCSEL array light source may be 940 nm or 1650 nm.

When the wavelength of the VCSEL array light source can be 940nm or 1650nm, the solar spectrum intensity is relatively weak, which is beneficial to reduce the noise caused by sunlight in outdoor scenes.

The laser light emitted by the above-mentioned VCSEL array light source may be continuous light or pulsed light. The VCSEL array light source can also be divided into several blocks to realize time-sharing control, so that different areas can be lit in time-sharing.

The function of the diffractive optical diffuser is to shape the light beam emitted by the VCSEL array light source into a uniform square or rectangular light source with a certain FOV (for example, a 5°×5° FOV).

The receiving end and the transmitting end share a multilayer LCPG and 1/4 wave plate. The receiving lens at the receiving end can be a single lens or a combination of multiple lenses. The sensor at the receiving end is a single-photon avalanche diode (SPAD) array. Since the SPAD has a single-photon detection sensitivity, the detection distance of the TOF depth sensor module 600 can be increased. The receiving end contains a beam splitter, which is implemented by a single-layer LCPG. At the same time, the projection end will use two polarization states of light to project into different FOV ranges, and then pass through the receiving end multi-layer LCPG and then converge into the same light, and then pass through the beam splitter according to the different deflection states. Two beams of different directions are projected to different positions of the SPAD array.

FIG. 85 is a schematic structural diagram of a TOF depth sensing module 600 according to an embodiment of the present application.

The difference between the TOF depth sensor module 600 shown in FIG. 85 and the TOF depth sensor module 600 shown in FIG. 84 is that in FIG. 84, the beam splitter is implemented by a single-layer LCPG, while in FIG. 85, The beam splitter is realized by a polarization beam splitter, which is usually formed by glueing the edges and corners of the coating. Since the polarization beam splitter is an off-the-shelf product, the use of the polarization beam splitter as the beam splitter has certain cost advantages.

As shown in Figure 85, the two orthogonal polarization states of the reflected beam will be separated on the polarization beam splitter. One passes through the SPAD array sensor, and the other is reflected and then reflected by the other mirror to enter the SPAD. Array sensor.

FIG. 86 is a schematic structural diagram of a TOF depth sensing module according to an embodiment of the present application.

The difference from the TOF depth sensor module 600 shown in FIG. 84 is that in FIG. 86, the beam splitter is implemented by a polarizing filter. For example, in Figure 86, a quarter wave plate can be used.

The polarization filter is similar to the pixel image processing, and the polarization states that can be transmitted on adjacent pixels are different and correspond to each SPAD pixel. In this way, the SPAD sensor can receive two polarization state information at the same time.

Fig. 87 is a schematic diagram of a polarized light beam received by a polarizing filter.

As shown in FIG. 87, different regions of the polarization filter can transmit H polarization or V polarization, where H polarization represents polarization in the horizontal direction, and V polarization represents polarization in the vertical direction. In Figure 87, the different areas on the polarization filter only allow the beams of the corresponding polarization state to reach the corresponding position of the sensor. For example, H polarization allows only vertically and horizontally polarized light beams to reach the corresponding position of the sensor, and V polarization allows only vertically polarized light beams to reach the corresponding position of the sensor.

When the beam splitter adopts a polarizing filter, since the polarizing filter is relatively thin and small in size, it is easy to integrate into a smaller terminal device.

FIG. 88 is a schematic flowchart of an image generation method according to an embodiment of the present application.

The method shown in FIG. 88 may be executed by the TOF depth sensing module or the terminal device including the TOF depth sensing module of the embodiment of the present application. Specifically, the method shown in FIG. 88 may be executed by the TOF depth sensing module shown in FIG. 79 The depth sensor module or the terminal device including the TOF depth sensor module shown in FIG. 79 is implemented. The method shown in FIG. 88 includes steps 8001 to 8006, and these steps are respectively described in detail below.

8001. Control the laser light source to generate a laser beam.

8002. The control optical element controls the direction of the laser beam to obtain a first outgoing beam and a second outgoing beam.

8003. Control the beam splitter to propagate the third reflected light beam obtained by reflecting the target object on the first outgoing light beam and the fourth reflected light beam obtained by reflecting the target object on the second outgoing light beam to different areas of the receiving unit.

8004. Generate a first depth map of the target object according to the TOF corresponding to the first outgoing beam.

8005. Generate a second depth map of the target object according to the TOF corresponding to the second outgoing beam.

The process of the method shown in FIG. 88 is the same as the basic process of the method shown in FIG. 78. The main difference is that in step 7003 of the method shown in FIG. 78, the third reflected light beam and the fourth reflected light beam are reflected by a beam selection device. The beam propagates to different areas of the receiving unit. In step 8003 of the method shown in FIG. 88, the third reflected light beam and the fourth reflected light beam are propagated to different areas of the receiving unit through the beam splitter.

Optionally, the method shown in FIG. 88 further includes: stitching the first depth map and the second depth map to obtain a depth map of the target object.

It should be understood that in the method shown in FIG. 88, the third depth map, the fourth depth map, etc. can also be generated in a similar manner. Next, all the depth maps can be spliced or combined to obtain the target object. The final depth map.

Optionally, the foregoing terminal device further includes a collimating lens, which is disposed between the laser light source and the optical element, and the method shown in FIG. 88 further includes:

8006. Use a collimating lens to collimate the laser beam to obtain a collimated beam;

The above step 8002 specifically includes: controlling the direction of the beam after the optical element is aligned to obtain the first outgoing beam and the second outgoing beam.

Optionally, the above-mentioned terminal equipment further includes a light homogenizing device, the light homogenizing device is arranged between the laser light source and the optical element, and the method shown in FIG. 88 further includes:

8007. Use homogenizing devices to adjust the energy distribution of the laser beam to obtain a homogenized beam;

The above step 8002 specifically includes: controlling the optical element to control the direction of the laser beam to obtain the first outgoing beam and the second outgoing beam, including: controlling the optical element to control the direction of the homogenized beam to obtain the first Outgoing beam and second outgoing beam.

Based on the above steps 8001 to 8005, the method shown in FIG. 88 may further include step 8006 or step 8007.

Alternatively, on the basis of the above steps 8001 to 8005, the method shown in FIG. 88 may further include step 8006 and step 8007. In this case, after performing step 8001, step 8006 may be performed first, then step 8007, and then step 8002 may be performed, or step 8007 may be performed first, then step 8006, and then step 8002 may be performed. That is to say, after the laser light source in step 8001 generates the laser beam, the laser beam can be collimated and homogenized (the energy distribution of the laser beam is adjusted by the homogenizing device), and then the optics can be controlled. The component controls the direction of the laser beam. Alternatively, after the laser light source in step 8001 generates the laser beam, the laser beam can be homogenized (the energy distribution of the laser beam is adjusted by the homogenization device) and collimated, and then the optical elements can be controlled to The direction of the laser beam is controlled.

A TOF depth sensing module and an image generation method according to an embodiment of the present application are described in detail above with reference to FIGS. 79 to 88. In the following, another TOF depth sensing module and image generation method according to an embodiment of the present application will be described in detail with reference to FIGS. 89 to 101.

Due to the excellent polarization and phase adjustment capabilities of liquid crystal devices, liquid crystal devices are often used in TOF depth sensing modules to control the beam. However, due to the limitations of the liquid crystal material itself, its response time has a certain limit, usually on the order of milliseconds. The scanning frequency of TOF depth sensing modules using liquid crystal devices is relatively low (usually less than 1khz).

This application provides a new TOF depth sensor module, which realizes an increase in the scanning frequency of the system by controlling the timing of the driving signal of the electronically controlled liquid crystal at the transmitting end and the receiving end to be staggered for a certain period of time (for example, half a cycle).

The TOF depth sensing module of the embodiment of the present application will be briefly introduced below with reference to FIG. 89.

The TOF depth sensing module 700 shown in FIG. 89 includes a laser light source 710, an optical element 720, a beam selection device 730, a receiving unit 740, and a control unit 750.

Laser light source 710:

The laser light source 710 is used to generate a laser beam.

Optionally, the above-mentioned laser light source 710 is a vertical cavity surface emitting laser (VCSEL).

Optionally, the above-mentioned laser light source 710 is a Fabry-Perot laser (may be referred to as FP laser for short).

Optionally, the wavelength of the laser beam emitted by the laser light source 710 is greater than 900 nm.

Optionally, the wavelength of the laser beam emitted by the laser light source 710 is 940 nm or 1550 nm.

Optionally, the light-emitting area of the aforementioned laser light source 710 is less than or equal to 5×5 mm ² .

Optionally, the average output optical power of the TOF depth sensing module 700 is less than 800 mw.

Optical element 720:

The optical element 720 is arranged in the direction in which the laser light source emits the light beam, and the optical element 720 is used to deflect the laser light beam under the control of the control unit 750 to obtain the outgoing light beam.

Beam selection device 730:

The beam selection device 730 is used to select a beam with at least two polarization states from the beams in each period in the reflected beam of the target object under the control of the control unit 750 to obtain the received beam, and transmit the received beam to the receiving unit 740.

Wherein, the above-mentioned outgoing light beam is a light beam that changes periodically, and the size of the change period of the outgoing light beam is the first time interval. In the outgoing light beam, the inclination angles of the light beams in adjacent periods are different, and there are at least two types of light beams in the same period. The polarization state, the inclination angle of the light beam in the same period is the same and the azimuth angle is different.

In the embodiment of the present application, the direction and polarization state of the beam emitted by the laser light source are adjusted by optical elements and beam selection devices, so that the inclination angles of the emitted beams of adjacent periods are different, and the beams in the same period have at least two polarization states , Thereby increasing the scanning frequency of the TOF depth sensor module.

In this application, the control unit controls the timing of the control signal at the transmitting end and the receiving end to be staggered for a certain period of time, which can increase the scanning frequency of the TOF depth sensing module.

Optionally, as shown in FIG. 35, the above-mentioned optical element 720 includes: a horizontal polarization control plate, a horizontal liquid crystal polarization grating, a vertical polarization control plate, and a vertical liquid crystal polarization grating. Wherein, the distance between the lateral polarization control sheet, the lateral liquid crystal polarization grating, the longitudinal polarization control sheet, and the longitudinal liquid crystal polarization grating and the laser light source becomes larger in sequence.

Alternatively, in the above-mentioned optical element 720, the distance between the longitudinal polarization control sheet, the longitudinal liquid crystal polarization grating, the lateral polarization control sheet, and the lateral liquid crystal polarization grating and the laser light source becomes larger in this order.

Optionally, the above-mentioned beam selection device is composed of a quarter wave plate + an electronically controlled half wave plate + a polarizer.

As shown in FIG. 90, the TOF depth sensing module may further include: a collimating lens 760, which is arranged between the laser light source 710 and the optical element 720, and the collimating lens 760 is used to collimate the laser beam Processing; the above-mentioned optical element 720 is used to deflect the beam after the collimation processing of the collimating lens under the control of the control unit 750 to obtain the outgoing beam.

When the TOF depth sensor module includes a collimating lens, the collimating lens can be used to collimate the beam of light emitted by the laser light source first, and an approximately parallel beam can be obtained, which can increase the power density of the beam, thereby increasing the subsequent use of beams The effect of scanning.

As shown in FIG. 91, the TOF depth sensing module 700 further includes a light homogenizing device 770, which is arranged between the laser light source 710 and the optical element 720, and the light homogenizing device 770 is used to adjust the angle of the laser beam. The spatial intensity distribution is adjusted; the optical element 720 is used to control the direction of the light beam after the homogenization device 720 is homogenized under the control of the control unit 750 to obtain the outgoing light beam.

Optionally, the aforementioned light homogenizing device 770 is a microlens diffusion sheet or a diffractive optical diffusion sheet.

It should be understood that the TOF depth sensing module 700 may include a collimating lens 760 and a light homogenizing device 770 at the same time. The collimating lens 760 and the light homogenizing device 770 may both be located between the laser light source 710 and the optical element 720. For the collimating lens For the 760 and the homogenization device 770, the distance between the collimating lens 760 and the laser light source may be closer, or the distance between the homogenization device 770 and the laser light source may be closer.

FIG. 92 is a schematic diagram of a specific structure of a TOF depth sensing module according to an embodiment of the present application.

As shown in FIG. 92, the distance between the collimating lens 760 and the laser light source 710 is smaller than the distance between the homogenizing device 770 and the laser light source 710.

In the TOF depth sensor module 700 shown in FIG. 92, the laser beam emitted by the laser light source 710 is first collimated by the collimator lens 760, and then is homogenized by the homogenizing device 770 and then propagated to the optical element 720. To process.

FIG. 93 is a schematic diagram of a specific structure of a TOF depth sensing module according to an embodiment of the present application.

As shown in FIG. 93, the distance between the collimating lens 760 and the laser light source 710 is greater than the distance between the homogenizing device 770 and the laser light source 710.

In the TOF depth sensor module 700 shown in FIG. 93, the laser beam emitted by the laser light source 710 is first homogenized by the homogenizing device 770, and then collimated by the collimating lens 760 before being transmitted to the optics. Processing in element 720.

The working process of the TOF depth sensing module 700 will be described below in conjunction with FIG. 94 and FIG. 95.

As shown in Fig. 94, assuming that the highest frequencies of the electronic control devices at the transmitting end and the receiving end of the TOF depth sensing module 700 are both 1/T, then the control unit is used to stagger the control timing of the transmitting end and the receiving end by half a cycle (0.5T ), then every 0.5T time, the receiving end sensor can receive light beams in different spatial positions.

As shown in Figure 95, in the time of 0～0.5T, the receiving end sensor receives the light beam of angle 1 state A; in the time of 0.5T～T, the receiving end sensor receives the light beam of angle 1 state B; in the time of T～1.5 In the time of T, the receiving end sensor receives the beam of angle 2 state A; in the time of 1.5T ~ 2T, the receiving end sensor receives the beam of angle 2 state B, so the scanning frequency of the system is increased from 1/T to 2/T , Doubled.

The specific structure of the TOF depth sensing module 700 will be described in detail below with reference to the accompanying drawings.

FIG. 96 is a schematic structural diagram of a TOF depth sensing module 700 according to an embodiment of the present application.

As shown in FIG. 96, the TOF depth sensing module 700 includes a projection end, a receiving end and a control unit. The projection end includes: a light source, a homogenizing device, and an optical element; the receiving end includes: an optical element, a beam selection device, a receiving lens, and a two-dimensional sensor; the control unit is used to control the projection end and the receiving end to complete the beam scanning.

Among them, the laser light source at the projection end is a VCSEL light source, the homogenizing device is a diffractive optical diffuser (DOE Diffuser), and the beam element is a multilayer LCPG and a quarter-wave plate. Each layer of LCPG includes: an electronically controlled horizontal direction LCPG component And electronically controlled vertical LCPG components. The use of multi-layer cascaded LCPG can realize two-dimensional block scanning in the horizontal and vertical directions.

This application can dynamically select light of different angles and different states to enter the sensor through the time-sharing control of the transmitting end and the receiving end. As shown in Figure 96, the laser light emitted by the ordinary VCSEL array light source has no fixed polarization state, and can be decomposed into a linearly polarized laser parallel to the paper surface and a linearly polarized laser perpendicular to the paper surface, and the linearly polarized laser will be divided into Two lasers with different polarization states (left-handed circular polarization and right-handed circular polarization) have different emission angles, and the corresponding polarization states of the two lasers are converted into linear polarization parallel to the paper after passing through the quarter wave plate. And the linear polarization perpendicular to the paper surface. The retroreflected beams generated by the two lasers with different polarization states irradiating the object in the target area will be received by the 1/4 wave plate and LCPG shared with the transmitting end and become with the same divergence angle but different deflection states-left-handed circular polarization Light and right-handed circularly polarized light-laser light. The beam selection device at the receiving end is composed of a quarter-wave plate + an electronically controlled half-wave plate + a polarizer. After the received light passes through the quarter-wave plate, the polarization state is converted into linear polarized light parallel to the paper surface and a line perpendicular to the paper surface. Polarized light, in this way, through the time-sharing control of the electronically controlled half-wave plate, the polarization state of the linearly polarized light can be rotated by 90 degrees or the polarization state of the half-wave plate will not be changed, and the linear polarization parallel to the paper surface and perpendicular to the paper can be achieved. The linearly polarized light of the surface is transmitted through time sharing, and at the same time, the light of another polarization state is absorbed or scattered by the polarizer.

In Figure 96, the time-sharing control signals of the transmitter and receiver can be as shown in Figure 94. By staggering the control timing of the electronically controlled LCPG of the transmitter and the electronically controlled half-wave plate of the receiver by half a cycle (0.5T), it can be realized The scanning frequency of the system is doubled.

FIG. 97 is a schematic structural diagram of a TOF depth sensor module 700 according to an embodiment of the present application.

As shown in Fig. 97, based on the TOF depth sensor module shown in Fig. 96, the diffractive optical diffuser (DOE Diffuser) behind the VCSEL array light source is changed to a micro lens diffuser (Diffuser). Since the microlens diffuser is based on geometric optics to achieve uniform light, its transmission efficiency can reach more than 80%, while the transmission efficiency of the traditional diffractive optical diffuser (DOE diffuser) is only about 70%. The morphology of the microlens diffuser is shown in Figure 77. It is composed of a series of randomly distributed microlenses. The position and morphology of each microlens are designed through simulation optimization, so that the reshaped beam is as uniform as possible and the transmission efficiency is Higher.

The TOF depth sensor module shown in Fig. 97 has the same driving principle as the TOF depth sensor module shown in Fig. 96, except that the diffractive optical diffuser (DOE Diffuser) in the TOF depth sensor module shown in Fig. 96 ) Is replaced with an optical diffuser to improve the transmission efficiency of the emitting end, and the rest will not be repeated.

For the TOF depth sensor module shown in Figure 97, the time-sharing control signals of the transmitter and receiver can be as shown in Figure 94 by staggering the control timing of the electronically controlled LCPG on the transmitter and the electronically controlled half-wave plate on the receiver. Half a period (0.5T), the system scanning frequency can be doubled.

FIG. 98 is a schematic structural diagram of a TOF depth sensing module 700 according to an embodiment of the present application.

On the basis of the TOF depth sensing module shown in FIG. 96 or FIG. 97, the optical element can be changed from a multilayer LCPG plus a quarter wave plate to a multilayer flat panel liquid crystal cell, as shown in FIG. 98. Multi-layer flat-panel liquid crystal cells are used to achieve beam deflection at multiple angles and in horizontal and vertical directions. The beam selection device at the receiving end is composed of an electrically controlled half-wave plate and a polarizer.

The principle of beam deflection of the flat panel liquid crystal cell is shown in Figure 99 and Figure 100, using a wedge-shaped polymer (Polymer) interface to achieve beam deflection. The refractive index of the wedge-shaped polymer material should be _{equal to the ordinary refractive index n 0 of the} liquid crystal, so as shown in Figure 99, when the optical axis of the liquid crystal molecules are aligned parallel to the x direction, the incident light parallel to the paper will produce a certain amount of light. The deflection of the angle, the size of the deflection angle can be controlled by controlling the voltage applied to it, and the incident light perpendicular to the paper surface will travel along a straight line. In this way, by stacking multiple layers of flat liquid crystal cells with different orientations (the optical axis is parallel to the x direction or the y direction), the deflected incident light can be projected to different angles at the same time.

By the same principle, by controlling the driving voltage of the flat-panel liquid crystal cell at the transmitting end and the driving voltage of the electronically controlled half-wave plate at the receiving end, the control timing of the two is staggered by half a cycle (0.5T), and the LCD scanning frequency can be improved.

FIG. 101 is a schematic flowchart of an image generation method according to an embodiment of the present application.

The method shown in FIG. 101 may be executed by a TOF depth sensing module or a terminal device including the TOF depth sensing module of the embodiment of the present application. Specifically, the method shown in FIG. 101 may be executed by the TOF depth sensing module shown in FIG. 89 The depth sensor module or a terminal device including the TOF depth sensor module shown in FIG. 89 is implemented. The method shown in FIG. 101 includes steps 9001 to 9004, and these steps are respectively described in detail below.

9001. Control the laser light source to generate a laser beam.

9002. Control the optical element to deflect the laser beam to obtain the outgoing beam.

9003. Control the beam selection device to select beams with at least two polarization states from the beams in each period of the reflected beams of the target object to obtain the received beam, and transmit the received beam to the receiving unit.

9004. Generate a depth map of the target object according to the TOF corresponding to the outgoing beam.

The TOF corresponding to the outgoing light beam may specifically be information indicating the time difference between the time when the reflected light beam corresponding to the outgoing light beam is received by the receiving unit and the outgoing time of the outgoing light source. Wherein, the reflected light beam corresponding to the outgoing light beam may specifically indicate that the outgoing light beam reaches the target object after being processed by the optical element and the beam selection device, and is generated after being reflected by the target object.

In the embodiments of the present application, the direction and polarization state of the beam emitted by the laser light source are adjusted by optical elements and beam selection devices, so that the inclination angles of the emitted beams of adjacent periods are different, and the beams in the same period have at least two polarization states , Thereby increasing the scanning frequency of the TOF depth sensor module.

Optionally, the foregoing terminal device further includes a collimating lens, which is disposed between the laser light source and the optical element. In this case, the method shown in FIG. 101 further includes:

9005. Use a collimating lens to collimate the laser beam to obtain a collimated beam;

Deflection of the laser beam in the above step 9002 to obtain the emergent beam specifically includes: controlling the direction of the beam after the optical element is aligned to obtain the emergent beam.

Optionally, the foregoing terminal equipment further includes a light homogenizing device, which is arranged between the laser light source and the optical element. In this case, the method shown in FIG. 101 further includes:

9006. Use a homogenizing device to adjust the energy distribution of the laser beam to obtain a homogenized beam;

Deflection of the laser beam in step 9002 to obtain the outgoing beam specifically includes: controlling the optical element to control the direction of the homogenized light beam to obtain the outgoing beam.

The FOV of the beam obtained by the beam shaping device in the TOF depth sensing module 300 will be introduced below in conjunction with FIG. 102 and FIG. 103.

The beam shaping device 330 in the TOF depth sensing module 300 adjusts the laser beam to obtain the first beam, and the FOV of the first beam includes [5°×5°, 20°×20°].

Fig. 102 is a schematic diagram of the FOV of the first light beam.

As shown in Figure 102, the first beam emerges from point O. The FOV of the first beam in the vertical direction is angle A, the FOV in the horizontal direction is angle B, and the rectangle E is the first beam projected on the target object. Area (the first light beam projected on the target object can be a rectangular area, of course, it can also have other shapes). Among them, the value range of angle A is between 5° and 20° (which can include 5° and 20°). Similarly, the value range of angle B is also between 5° and 20° (which can include 5° and 20°). °).

In the above TOF depth sensing module 300, the control unit 370 may be used to control the first optical element to control the direction of the first light beam at M different moments, so as to obtain M outgoing light beams in different directions. , The range of the total FOV covered by the M outgoing beams in different directions includes [50°×50°, 80°×80°].

Specifically, as shown in Fig. 103, M outgoing beams in different directions are emitted from point O, and the area covered on the target object is a rectangle F, where the angle C is the FOV of the M outgoing beams in different directions in the vertical direction. The superimposed value of, the angle D is the superimposed value of the horizontal FOV of the outgoing beams of M different directions. The value range of angle C is between 50° and 80° (which can include 50° and 80°), and the value range of angle D is also between 50° and 80° (which can include 50° and 80°) .

The above explanation of the first light beam generated by the TOF depth sensor module 300 and the FOV of the outgoing light beams in M different directions in conjunction with FIGS. 102 and 103 is also applicable to the first light beam generated by the TOF depth sensor module 400, and M outgoing beams in different directions will not be repeated here.

A person of ordinary skill in the art may realize that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether these functions are executed by hardware or software depends on the specific application and design constraint conditions of the technical solution. Professionals and technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered beyond the scope of this application.

Those skilled in the art can clearly understand that, for the convenience and conciseness of description, the specific working process of the system, device and unit described above can refer to the corresponding process in the foregoing method embodiment, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed system, device, and method can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division, and there may be other divisions in actual implementation, for example, multiple units or components may be combined It can be integrated into another system, or some features can be ignored or not implemented. In addition, the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, devices or units, and may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the objectives of the solutions of the embodiments.

In addition, the functional units in the various embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units may be integrated into one unit.

If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on this understanding, the technical solution of the present application essentially or the part that contributes to the existing technology or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including Several instructions are used to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage media include: U disk, mobile hard disk, read-only memory (read-only memory, ROM), random access memory (random access memory, RAM), magnetic disks or optical disks and other media that can store program codes. .

The above are only specific implementations of this application, but the protection scope of this application is not limited to this. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in this application. Should be covered within the scope of protection of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

A TOF depth sensor module, characterized in that, the TOF depth sensor module includes a laser light source, an optical element, a beam splitter, a receiving unit and a control unit, wherein the optical element is arranged on the laser light source to emit The direction of the beam;

The laser light source is used to generate a laser beam;

The control unit is used to control the birefringence parameter of the optical element to obtain the adjusted birefringence parameter;

The optical element is used to adjust the direction of the laser beam based on the adjusted birefringence parameters to obtain a first outgoing beam and a second outgoing beam, wherein, when the birefringence of the optical element is different The optical element can adjust the laser beam to different directions, wherein the exit direction of the first exit beam is different from the exit direction of the second exit beam, and the first exit beam and the second exit beam are different from each other. The two outgoing beams are both beams with a single polarization state, and the polarization direction of the first outgoing beam is orthogonal to the polarization direction of the second outgoing beam;

The beam splitter is used to transmit the third reflected light beam obtained by reflecting the target object to the first outgoing light beam, and the fourth reflecting light beam obtained by reflecting the target object to the second outgoing light beam to propagate the receiving unit different regions.
The TOF depth sensor module of claim 1, wherein the optical element comprises: a horizontal polarization control film, a horizontal liquid crystal polarization grating, a vertical polarization control film, and a vertical liquid crystal polarization grating.
The TOF depth sensor module according to claim 2, wherein the horizontal polarization control film, the horizontal liquid crystal polarization grating, the vertical polarization control film, and the vertical liquid crystal polarization grating and the laser light source The distance between the vertical polarization control plate, the vertical liquid crystal polarization grating, the horizontal polarization control plate, and the horizontal liquid crystal polarization grating and the laser light source are sequentially increased.
The TOF depth sensing module according to any one of claims 1-3, wherein the beam splitter is based on any one of a liquid crystal polarization grating LCPG, a polarization beam splitting prism PBS, and a polarization filter. Kind of realization.
The TOF depth sensing module according to any one of claims 1 to 4, wherein the TOF depth sensing module further comprises:

A collimating lens, the collimating lens is arranged between the laser light source and the optical element, and the collimating lens is used for collimating the laser beam to obtain a collimated beam;

The optical element is used to control the direction of the beam after the collimation process to obtain the first outgoing beam and the second outgoing beam.
The TOF depth sensor module of claim 5, wherein the clear aperture of the collimating lens is less than or equal to 5 mm.
The TOF depth sensing module according to any one of claims 1 to 4, wherein the TOF depth sensing module further comprises:

The homogenization device is arranged between the laser light source and the optical element, and the homogenization device is used to adjust the angular spatial intensity distribution of the laser beam to obtain a homogenized beam ；

The optical element is used to control the direction of the light beam after homogenization to obtain the first outgoing light beam and the second outgoing light beam.
The TOF depth sensor module of claim 7, wherein the light homogenizing device is a microlens diffuser or a diffractive optical diffuser.
8. The TOF depth sensing module of any one of claims 1-8, wherein the laser light source is a Fabry-Perot FP laser.
8. The TOF depth sensing module of any one of claims 1-8, wherein the laser light source is a vertical cavity surface emitting laser.
The TOF depth sensing module according to any one of claims 1-10, wherein the light-emitting area of the laser light source is less than or equal to 5×5 mm 2 .
The TOF depth sensing module according to any one of claims 1-11, wherein the average output optical power of the TOF depth sensing module is less than 800 mw.
An image generation method, the image generation method is applied to a terminal device containing a TOF depth sensing module, the TOF depth sensing module including a laser light source, an optical element, a sensor, a beam selection device, a receiving unit, and a control unit , Wherein the optical element is arranged in the direction of the light beam emitted by the laser light source, characterized in that the image generation method includes:

Controlling the laser light source to generate a laser beam;

Controlling the optical element to control the direction of the laser beam to obtain a first outgoing beam and a second outgoing beam, wherein the outgoing direction of the first outgoing beam and the outgoing direction of the second outgoing beam are different, The first outgoing beam and the second outgoing beam are both beams of a single polarization state, and the polarization direction of the first outgoing beam is orthogonal to the polarization direction of the second outgoing beam;

The beam splitter is controlled to propagate to the receiving unit the third reflected light beam obtained by reflecting the target object on the first outgoing light beam, and the fourth reflected light beam obtained by reflecting the target object on the second outgoing light beam Different areas of

Acquiring the TOF corresponding to the first outgoing beam and the TOF corresponding to the second outgoing beam;

Generating a first depth map of the target object according to the TOF corresponding to the first outgoing beam;

According to the TOF corresponding to the second outgoing beam, a second depth map of the target object is generated.
The image generation method according to claim 13, wherein the terminal device further comprises a collimating lens, the collimating lens is arranged between the laser light source and the optical element, and the image generation method further include:

Collimating the laser beam by using the collimating lens to obtain a collimated beam;

Controlling the optical element to control the direction of the laser beam to obtain a first outgoing beam and a second outgoing beam includes:

The optical element is controlled to control the direction of the beam after the collimation process to obtain the first outgoing beam and the second outgoing beam.
The image generation method according to claim 13 or 14, wherein the terminal device further comprises a light homogenization device, the light homogenization device is arranged between the laser light source and the optical element, and the image generation Methods also include:

Adjusting the energy distribution of the laser beam by using the homogenization device to obtain a beam after homogenization treatment;

The controlling the optical element to control the direction of the laser beam to obtain a first outgoing beam and a second outgoing beam includes:

The optical element is controlled to control the direction of the light beam after the homogenization process to obtain the first outgoing light beam and the second outgoing light beam.