Time-of-Flight TOF Sensor Modules and Electronic Devices

Abstract

To provide a Time-of-Flight (TOF) sensor module and an electronic device.SOLUTION: A light source is configured to emit m first beams at each of M time points and transmit the m first beams to a beam adjustment assembly. The beam adjustment assembly is configured to adjust the received m first beams to change them into S second beams, and then project the S second beams onto S areas on a detection surface, where M projection points that are in the same area on the detection surface and on which projection is performed at each of the M time points have different positions. A detection assembly is configured to receive S optical echo signals from the detection surface at each of the M time points, and convert the S optical echo signals to S electrical echo signals for storage at each time point. The optical echo signals are received at different times, thereby avoiding low image resolution caused by limitation due to the maximum number of detection elements that can be activated simultaneously.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present application relates to the field of sensing technology, and in particular to time-of-flight TOF sensor modules and electronic devices. [Background technology]

[0003] With the advancement of information technology, accurate and reliable information must be obtained first in information-based processing, and sensors are the main method and means for obtaining information. Currently, sensors are widely used in many fields, such as industrial production, space exploration, ocean exploration, environmental protection, resource exploration, medical diagnosis, and bioengineering. Three-dimensional (3D) sensors are a hot topic of research in the sensor field.

[0004] The technologies applicable to 3D sensors mainly include stereoscopic imaging, structured light, and time-of-flight (TOF) detection. TOF has advantages such as long detection distance and high resolution, making it an important technology used by 3D sensors. Traditional TOF detection is mainly classified into single-time full-projection TOF cameras and scanning device-based TOF scanners. Scanning device-based TOF scanners have relatively high spatial resolution, but impose relatively high requirements on the accuracy of the scanning angle and require complex scanning structures, making it difficult to miniaturize the TOF sensor module. Single-time full-projection TOF cameras have the advantages of high detection speed and a large field of view (FOV), but are limited by the detector element array, power consumption, and the maximum number of configurable memory in the sensor. The maximum size of the detector element array that can be activated simultaneously is 160 × 120, thereby limiting the resolution of the formed image. Summary of the Invention

[0005] The present application provides a TOF sensor module and an electronic device for solving the problem in the prior art of low image resolution due to the limitation imposed by the maximum number of detection elements that can be activated simultaneously.

[0006] According to a first aspect, the present application provides a TOF sensor module. The TOF sensor module includes a light source, a beam conditioning assembly, and a detection assembly. The light source is configured to emit m first beams at each of M time points and transmit the m first beams to the beam conditioning assembly. The beam conditioning assembly is configured to condition the received m first beams into S second beams and then project the S second beams onto S regions on a detection surface, the S regions being in one-to-one correspondence with the S second beams and located within the same region of the detection surface, and the M projection points onto which projection is performed at each of the M time points have different positions. The detection assembly is configured to receive S optical echo signals from the detection surface at each of M time points and convert the S optical echo signals into S electrical echo signals for storage at each time point, the S optical echo signals being in one-to-one correspondence with the S second beams, each optical echo signal being a signal obtained by reflecting the corresponding second beam by the detection surface, and both m and M being integers greater than or equal to 2, and S being an integer greater than m.

[0007] Based on the TOF sensor module, the light source separately emits m first beams at different times, each of which resides within the same region of the detection surface and is projected onto them at each of M time points. The M projection points have different positions. This is equivalent to performing M scans on each region of the detection surface. The detection assembly can simultaneously activate S detection elements at each time point to receive S optical echo signals, receiving a total of M×S optical echo signals at the M time points. In this way, image information can be determined based on the M×S optical echo signals, thereby helping to increase the resolution of the formed image. When S=160×120, the determined image resolution can be M×160×120. When M=4×4, the determined image resolution can be 640×480. In other words, based on the capability of a conventional sensor (which can simultaneously activate up to 160x120 detector elements), the TOF sensor module can form an image with a resolution of 640x480 or higher by reusing S detector elements at different times, which helps to avoid the problem that the resolution of the image formed by the TOF sensor module is relatively low due to the limitation imposed by the maximum number of detector elements that can be simultaneously activated.

[0008] In a possible implementation, the detection assembly may include K detection elements, where K is an integer greater than or equal to S, and the detection assembly is configured to power on S of the K detection elements at each of M time points. In other words, S of the K detection elements may be selected at each of M time points. By powering on S detection elements in the detection assembly at each of M time points, power consumption of the detection assembly can be reduced while addressing low image resolution caused by limitations imposed by the maximum number of detection elements that can be activated simultaneously.

[0009] Furthermore, optionally, the TOF sensor module further includes a processing circuit configured to acquire M×S electrical echo signals acquired at M time points from the detection assembly and determine image information based on the M×S electrical echo signals, which helps to avoid limitations imposed by a maximum number of detection elements that can be simultaneously activated in the detection assembly, thereby increasing the determined image resolution.

[0010] In the present application, S may be equal to m×n, and the beam adjusting assembly may be configured to adjust transmission directions of the received m first beams, split each of the adjusted m first beams into n second beams to obtain m×n second beams, and project the m×n second beams onto m×n regions on the detection surface, where the m×n regions are in one-to-one correspondence with the m×n second beams, and n is an integer greater than or equal to 2. The m×n second beams are projected onto the m×n regions on the detection surface, so that each region on the detection surface can be scanned and a super-resolution effect can be achieved.

[0011] In a possible implementation, the detection assembly may include m×n detector elements, with the m×n detector elements in one-to-one correspondence with the m×n regions. Each of the m×n detector elements is configured to receive an optical echo signal from the corresponding region at each of M time points and convert the optical echo signal from the corresponding region at each time point into an electrical echo signal for storage. In this way, when the detection assembly includes a relatively small number of detector elements, the image resolution of the TOF sensor module can be increased. In addition, the detection assembly includes a relatively small number of detector elements, thereby facilitating miniaturization of the TOF sensor module.

[0012] The present application provides, as examples, the following two possible TOF sensor modules:

[0013] Example 1

[0014] The light source includes M light source sections, each including m emitters. The m emitters in one of the M light source sections are configured to emit m first beams at each of M time points, and the light source sections used to emit the m first beams at each of the M time points change. In this way, the light source can emit m first beams at each of the M time points.

[0015] Further optionally, the beam adjusting assembly includes a collimation assembly and a beam splitting assembly. The collimation assembly is configured to adjust an included angle between any two adjacent first beams of the m first beams to a first angle and transmit the adjusted m first beams to the beam splitting assembly, where the first angle is determined based on a total field of view corresponding to the detection surface and a quantity m×n of second beams. The beam splitting assembly is configured to split each of the adjusted m first beams into n second beams.

[0016] In a possible implementation, if the total field of view corresponding to the detection surface is 64 x 48, and the quantity of the second beam is equal to 160 x 120, the first angle is equal to (64 / 160) x (48 / 120) = 0.4 x 0.4 degrees.

[0017] In a possible implementation, the M light source sections may be an M1×M2 array. In the horizontal direction of the M1×M2 array, the included angle between first beams emitted by two adjacent emitters in two adjacent light source sections is equal to or greater than an angle corresponding to a spacing between M1 projected points on the detection surface. In the vertical direction of the M1×M2 array, the included angle between first beams emitted by two adjacent emitters in two adjacent light source sections is equal to or greater than an angle corresponding to a spacing between M2 projected points on the detection surface. Both M1 and M2 are integers equal to or greater than 2.

[0018] In a possible implementation, the detection assembly may include m×n detector elements, each of which is powered on at each of M time points, and each of which is configured to receive optical echo signals from a corresponding region at each of the M time points and convert the optical echo signals from the corresponding region at each time point into electrical echo signals for storage.

[0019] Example 2

[0020] The light source includes P emitters, where P is an integer greater than m. At each time point, m emitters of the P emitters emit m first beams at preset intervals, and at each of the M time points, the m emitters used to emit the m first beams change. In this way, the light source can emit m first beams at each of the M time points.

[0021] In an optional implementation, the beam adjusting assembly includes a collimation assembly and a beam splitting assembly. The collimation assembly is configured to adjust an included angle between any two adjacent first beams of the m first beams to a second angle and transmit the adjusted m first beams to the beam splitting assembly, where the second angle is determined based on a total field of view corresponding to the detection surface and a number m of activated light sources. The beam splitting assembly is configured to split each of the adjusted m first beams into n second beams.

[0022] In a possible implementation, when the total field of view corresponding to the detection surface is 64 × 48, and the number m of activated emitters is equal to m × m, the second angle is equal to (64 / m) × (48 / m). Specifically, the second angle is (64 / m) degrees in the horizontal direction and (48 / m) degrees in the vertical direction.

[0023] In a possible implementation, the detection assembly may power on each of the m×n detection elements at each of the M time points, each of the m×n detection elements configured to receive optical echo signals from a corresponding region at each of the M time points and convert the optical echo signals from the corresponding region at each time point into electrical echo signals for storage.

[0024] In a possible implementation, the M light source sections are integrally molded. In this way, it is possible to ensure that the M light source sections are on the same plane. In addition, the sizes of the M integrally molded light source sections are relatively small, thereby facilitating the miniaturization of the TOF sensor module.

[0025] According to a second aspect, the present application provides a TOF sensor module. The TOF sensor module includes a light source, a beam conditioning assembly, and a detection assembly. The light source is configured to emit m first beams at each of M time points and transmit the m first beams to the beam conditioning assembly, where m and M are both integers greater than or equal to 2. The beam conditioning assembly is configured to adjust the transmission directions of the received m first beams and then project the adjusted m first beams onto corresponding regions of a detection surface, where the projection points on the detection surface onto which the projection is performed at each of the M time points are located in separate regions. The detection assembly is configured to receive m optical echo signals from the corresponding regions of the detection surface at each of the M time points and convert the m optical echo signals into m electrical echo signals for storage at each time point, where the m optical echo signals correspond one-to-one to the m first beams and each optical echo signal is obtained by reflecting a corresponding second beam off the detection surface.

[0026] Based on the TOF sensor module, at each of M time points, after the m first beams emitted by the light source are adjusted by the beam adjusting assembly, the m first beams cover an area on the detection surface. The light source separately emits the m first beams at different times, and corresponding detection elements in the detection assembly are selected, thereby solving the problem that only a maximum of 160×120 detection elements can be activated simultaneously.

[0027] In a possible implementation, the light source includes M light source sections, each including m emitters, and the M light source sections are in one-to-one correspondence with the M regions. The m emitters in one of the M light source sections are configured to emit m first beams at each of M time points, and the light source section used to emit the m first beams at each of the M time points varies.

[0028] In a possible implementation, the detection assembly includes M detector regions, each of which corresponds one-to-one to the M light source sections, and each detector region includes multiple detector elements. Each detector region is configured to receive an optical echo signal obtained by reflecting, by a detection surface, a beam emitted by the light source section corresponding to the detector region. The detection assembly is configured to power on only each detector element in the detector region of the M detector regions that corresponds to the light source section used to emit the m first beams at each of the M time points. At each of the M time points, only one of the M detector regions is powered on, and the other detector regions are not powered on. In this manner, only some detector regions can be enabled to operate, thereby helping to reduce power consumption of the detection assembly.

[0029] In a possible implementation, the beam adjusting assembly is configured to adjust the transmission directions of the m first beams to uniformly project the m first beams onto corresponding areas. By uniformly projecting the m first beams onto corresponding areas of the detection surface, the corresponding areas of the detection surface can be uniformly scanned, thereby helping to improve the accuracy of the determined image information.

[0030] In a possible implementation, the M light source sections are integrally molded. In this way, it is possible to ensure that the M light source sections are on the same plane. In addition, the sizes of the M integrally molded light source sections are relatively small, thereby facilitating the miniaturization of the TOF sensor module.

[0031] In a possible implementation, a light pipe is disposed between the beam conditioning assembly and each of the M light source sections. The light pipe is configured to homogenize the received m first beams. This prevents the beam conditioning assembly from being close to the light source sections, thereby improving utilization of the beam conditioning assembly and helping to reduce the difficulty of assembling the TOF sensor module.

[0032] According to a third aspect, the present application provides an electronic device. The electronic device may include the TOF sensor module described in the first or second aspect and a fixing assembly. The fixing assembly is configured to fix the TOF sensor module. [Brief explanation of the drawings]

[0033] [Figure 1a] 1 is a schematic diagram of a beam splitting process of a DOE according to the present application. [Figure 1b] 1 is a schematic diagram of a detector structure according to the present application; [Figure 2] 1 is a schematic diagram of the working principle of a TOF sensor module according to the present application; [Figure 3] 1 is a schematic diagram of the structure of a TOF sensor module according to the present application. [Figure 4] 3A-3C are schematic diagrams of the positions of projected points in one region of the detection surface at four time points according to the present application; [Figure 5a] 1 is a schematic diagram of a light source structure according to the present application; [Figure 5b] 2 is a schematic diagram of another light source structure according to the present application; [Figure 5c] 1 is a schematic diagram of a composite structure of a light source array according to the present application; [Figure 6a] 1 is a schematic diagram of the optical path of a beam from a light source to a collimation assembly and then to a light splitting assembly in accordance with the present application. [Figure 6b] FIG. 2 is a schematic diagram of an optical path adjusted by a beam adjusting assembly according to the present application. [Figure 6c] 1 is a schematic diagram of an arrangement of projected points on a detection surface according to the present application; [Figure 6d] 1 is a schematic diagram of the structure of a detection assembly according to the present application. [Figure 6e] 1 is a schematic diagram of another detection assembly structure according to the present application. [Figure 7] 1 is a schematic diagram of another TOF sensor module structure according to the present application. [Figure 8] 1 is a schematic diagram of the relationship between a light source and a projected point on a detection surface according to the present application; [Figure 9] 10 is a schematic diagram of another relationship between a light source and a projection point according to the present application. [Figure 10] 4 is a schematic diagram of another relationship between a light source and a projected point on a detection surface according to the present application. FIG. [Figure 11a] 1 is a schematic diagram of yet another TOF sensor module structure according to the present application. [Figure 11b] FIG. 10 is a schematic diagram of the relationship between the spacing Δ4 between light source sections and the spacing D between regions of the detection surface according to the present application. [Figure 11c] 1 is a schematic diagram of the positional relationship between the DOE section and the light source section according to the present application. [Figure 11d] 10 is a schematic diagram of another positional relationship between a DOE section and a light source section according to the present application. [Figure 11e]1 is a schematic diagram of the relationship between light source sections and areas of a detection surface according to the present application. [Figure 12] 1 is a schematic diagram of the structure of an electronic device according to the present application; DETAILED DESCRIPTION OF THE INVENTION

[0034] To make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings.

[0035] In the following, some terms in this application will be explained to help those skilled in the art have a better understanding.

[0036] 1.Spatial resolution

[0037] Spatial resolution is the minimum distance between two adjacent objects that can be recognized in an image and is used to describe the ability to distinguish details of target objects in an image. Spatial resolution is one of the important indicators for evaluating sensor performance and is also an important basis for recognizing the shape and size of objects. Spatial resolution is usually expressed in terms of the size of an image element, image resolution, or field of view. An image element is a grid cell formed by discretizing ground information, and is the smallest area that can be distinguished in a scanned image. Image resolution is expressed by the line width that can be distinguished within a unit distance, or the number of equally spaced parallel lines. The field of view (IFOV) is the light acceptance angle or observation field of a single detector element (e.g., pixel) in a sensor, also known as the sensor's angular resolution, and is expressed in milliradians (mrad) or microradians (μrad). The field of view β is related to the wavelength λ and the numerical aperture D of the collector, i.e., β = λ / 2D. A smaller field of view indicates higher spatial resolution.

[0038] 2. Image resolution

[0039] Image resolution is the amount of information stored in an image, or the number of pixels in each inch of the image. The units of resolution are pixels per inch (PPI). It should be understood that the field of view of each pixel is equal to the total field of view corresponding to the detection surface divided by the total number of pixels in the sensor.

[0040] 3. Video Graphics Array (VGA)

[0041] VGA is a display resolution standard, and the supported resolution is 640 x 480.

[0042] 4. Diffractive Optical Element (DOE)

[0043] DOEs are also called binary optical devices. Beam splitting by DOEs is achieved by using the principle of diffraction. After a beam passes through a DOE, multiple diffraction orders can be generated. Each order corresponds to one beam. DOEs can perform one-dimensional beam splitting, two-dimensional beam splitting, etc., by using specific surface structure designs. Two-dimensional beam splitting means that a DOE can perform beam splitting separately in each of two directions (e.g., horizontal and vertical directions). For example, a DOE splits a 1x1 beam into 16x12 beams. This means that the DOE splits one beam into 16 beams in the horizontal direction and one beam into 12 beams in the vertical direction.

[0044] 1a is a schematic diagram of the beam splitting process of the DOE according to the present application. In FIG. 1a, an example is used in which the DOE splits one beam into four beams, and ±1 and ±2 indicate the diffraction orders. θ f indicates the full angle, and θ sdenotes the separation angle. It can be seen that some diffraction orders can be suppressed by designing the structure of the DOE. In Figure 1a, orders 0 and ±3 are suppressed.

[0045] 5. Single-photon avalanche diode (SPAD)

[0046] A SPAD, also known as a single-photon detector, is a photoelectric detection avalanche diode capable of detecting a single photon. SPADs have relatively high sensitivity and are triggered upon the detection of a single photon. After being triggered, a SPAD typically requires approximately 10 ns to return to its initial state. Therefore, a SPAD can be configured to detect the presence of a photon, but not the quantity of photons. Typically, multiple SPADs exist within each detector in an image sensing system. For example, Figure 1b is a schematic diagram of a possible detector structure. The detector may include a 5x3 SPAD array. In other words, the 5x3 SPAD array may constitute a schematic diagram of the detector structure. In one possible case, all of the 5x3 SPADs may be selected. In another possible case, some of the 5x3 SPADs may be selected alternately. In Figure 1b, the active SPAD is the currently selected SPAD.

[0047] In this application, the TOF sensor module may be applied to electronic devices, for example, mobile phones, or in fields such as in-vehicle laser radar, autonomous driving, unmanned aerial vehicles, Internet of Vehicles, and security monitoring. The TOF sensor module transmits electromagnetic waves, receives the electromagnetic waves (i.e., optical echo signals) scattered by a target object, and compares and analyzes the received optical echo signals with the transmitted electromagnetic waves to extract information related to the target object, such as the distance from the target object, and in another example, forms an image of the target object, and in another example, obtains a three-dimensional point cloud density of the target object.

[0048] FIG. 2 is a schematic diagram of the operating principle of a TOF sensor module according to the present application. The TOF sensor module may include a laser and a detector. The laser is configured to emit a beam and transmit the beam to a detection region. The detection region may include a target object. The beam is transmitted to a detection surface (i.e., a surface where the target object receives light) of the detection region (i.e., the target object) and then reflected. The reflected signal is returned to the detector as an optical echo signal. Based on the received optical echo signal and the emitted beam, the detector can determine relevant information about the detection surface, such as its distance from the TOF sensor module, or, for another example, image information about the detection surface. Referring to FIG. 1b, the TOF sensor module is limited by the maximum number of detection elements that can be simultaneously activated in the detector. A detection element is an element configured to detect reflected optical echo signals. For example, when a detector element may include a SPAD and a time-to-digital converter (TDC), only a maximum of 160 x 120 detector elements can be activated simultaneously in the detector, thereby causing a problem that the resolution of the formed image is relatively low. Detector elements are also sometimes called pixels, photosensitive elements, light-sensing elements, or photodetector elements.

[0049] In view of the above-mentioned problems, the present application provides a TOF sensor module, wherein a detection assembly in the TOF sensor module can receive light echo signals from a detection surface at different times, and can determine image information based on the light echo signals received at different times to enhance the resolution of the formed image.

[0050] The TOF sensor module provided in the present application will be described in detail below with reference to FIGS. 3 to 11e.

[0051] FIG. 3 is a schematic diagram of the structure of a TOF sensor module according to the present application. The TOF sensor module may include a light source, a beam conditioning assembly, and a detection assembly. The light source is configured to emit m first beams at each of M time points and transmit the m first beams to the beam conditioning assembly, where m and M are both integers greater than or equal to 2. This can also be understood as the light source being configured to emit m first beams at an i-th time point, where i is an integer in the closed interval [1, M]. The beam conditioning assembly is configured to condition the received m first beams into S second beams and then project the S second beams onto S regions on the detection surface, where the S regions are in one-to-one correspondence with the S second beams. For the same region of the detection surface, one time point corresponds to one projection point, and the M projection points, which exist within the same region of the detection surface and are projected onto at each of the M time points, have different positions. The detection assembly is configured to receive S optical echo signals from the detection surface at each of the M time points and convert the S optical echo signals into S electrical echo signals for storage at each time point, where the S optical echo signals correspond one-to-one to the S second beams, and each optical echo signal is obtained by reflecting the corresponding second beam by the detection surface. It should be understood that the location of the detection assembly within the TOF sensor module may be any possible location capable of receiving the optical echo signals. FIG. 3 is merely an example. For another example, a semi-transparent, semi-reflective mirror may be used to transmit the first beam to the beam conditioning assembly and reflect the corresponding optical echo signals toward the detection assembly.

[0052] For example, M=4, and FIG. 4 is a schematic diagram of the positions of four projected points that exist within the same region of the detection surface and onto which a light source is projected at each of four time points. The positions of the four projected points within the region of the detection surface are different. Optionally, the four projected points may also cover the region. In this way, the effect of scanning the detection surface can be achieved without using a scanning element. It should be noted that the order of the projected points at the four time points in FIG. 4 is an example. This is not a limitation in the present application.

[0053] Based on the TOF sensor module, the light source is configured to separately emit m first beams at different times, which exist within the same region of the detection surface and are projected onto them at each of M time points. The M projection points have different positions. This is equivalent to performing M scans on each region of the detection surface. The detection assembly can simultaneously activate S detector elements at each time point to receive S optical echo signals, and can receive a total of M×S optical echo signals at the M time points. In this way, image information can be determined based on the M×S optical echo signals, thereby helping to increase the resolution of the formed image. When S=160×120, the determined image resolution can be M×160×120. When M=4×4, the determined image resolution can be 640×480. In other words, based on the capability of a conventional sensor (which can simultaneously activate a maximum of 160×120 detector elements), the TOF sensor module can form an image with a resolution of 640×480 or higher by reusing S detector elements at different times. This helps to avoid the problem of low resolution images formed by the TOF sensor module due to limitations imposed by the maximum number of detector elements that can be activated simultaneously.

[0054] It should be noted that the image information in this application is depth image information, for example, the distance between the detection surface and the TOF sensor module, as well as the orientation, height, velocity, attitude, and shape of the target on the detection surface.

[0055] In the following, the functional components and structures shown in FIG. 3 are described separately to provide a concrete implementation solution example.

[0056] 1.Light source

[0057] In this application, the emitter may be a laser, for example, a vertical cavity surface emitting laser (VCSEL) or an edge emitting laser (EEL). The pitch (see FIG. 5a) between VCSEL-based emitters is 30 μm, and the pitch between EEL-based emitters is 50 μm. The EEL-based emitters may implement independent addressing. Independent addressing means that any emitter in the light source may be independently selected (or said to be lit, activated, or powered on) and configured to emit a first beam.

[0058] Based on the emitter placement and lighting methods, the following provides two possible cases as examples.

[0059] Case 1: The light source includes M light source sections, each of which includes m emitters, and a scheme of lighting the emitters by using the light source sections is used.

[0060] The light source including M light source sections can be understood as the light source being divided into M sections.

[0061] Based on Case 1, an implementation of emitting m first beams by a light source at each of M time points may be as follows: m emitters in one of the M light source sections are configured to emit m first beams at each of M time points, and the light source section used to emit the m first beams at each of the M time points changes.

[0062] Based on Case 1, this can also be understood as m emitters in one light source section being activated at one time point, and the activated m emitters being configured to separately emit first beams to obtain m first beams. It should be noted that the M light source sections can be activated sequentially at M time points. Specifically, the first light source section is activated at a first time point, the second light source section is activated at a second time point, and so on. Alternatively, the M light source sections can be activated randomly. This is not a limitation in the present application.

[0063] In the present application, the M light source sections may be arranged in an M1×M2 array, where M1 and M2 are both integers greater than or equal to 2, and M1 and M2 may be equal or unequal. For example, the M light source sections may alternatively be arranged in a row having M columns or a column having M rows. This is not limited in the present application. FIG. 5a is a schematic diagram of the structure of a light source according to the present application. In FIG. 5a, for example, the light source may include 2×2 light source sections, and each light source section may include m emitters. The m emitters in the light source section may be arranged in an m1×m2 array, where m1 and m2 are both integers greater than or equal to 1. In FIG. 5a, for example, m1×m2=2×2. An emitter in one light source section is activated at each of M time points. For example, the 2x2 emitters in the light source section in the first row and first column are activated at a first time point, the 2x2 emitters in the light source section in the first row and second column are activated at a second time point, the 2x2 emitters in the light source section in the second row and first column are activated at a third time point, and the 2x2 emitters in the light source section in the second row and second column are activated at a fourth time point. Of course, the light source sections can alternatively be activated in a different order. This is not a limitation in the present application.

[0064] Case 2: The light source includes P emitters, and m emitters are selected from the P emitters at preset intervals.

[0065] As used herein, "every preset interval" can be every other emitter or every third emitter. In the case of an emitter array, the number of emitters in a row interval can be the same as or different from the number of emitters in a column interval.

[0066] Based on Case 2, an implementation of emitting m first beams by a light source at each of M time points may be as follows:

[0067] At preset intervals, m emitters selected from the P emitters are configured to emit m first beams at each of M time points, and the m emitters used to emit the m first beams at each of the M time points are different.

[0068] In a possible implementation, "every other preset interval" may mean activating one emitter every other emitter. Figure 5b is a schematic diagram of another light source structure according to the present application. In Figure 5b, for example, the light source includes 8x2 emitters, and the preset intervals are every other emitter in both the row and column directions. The first, third, fifth, and seventh emitters in the first row are activated at a first time point. The second, fourth, sixth, and eighth emitters in the first row are activated at a second time point. The first, third, fifth, and seventh emitters in the second row are activated at a third time point. The second, fourth, sixth, and eighth emitters in the second row are activated at a fourth time point.

[0069] 2.Beam Adjustment Assembly

[0070] In the present application, S may be equal to m×n. Further, optionally, the beam adjusting assembly may be configured to adjust transmission directions of the received m first beams, split each of the adjusted m first beams into n second beams to obtain m×n second beams, and project the m×n second beams onto m×n regions on the detection plane, where the m×n regions are in one-to-one correspondence with the m×n second beams, and n is an integer greater than or equal to 2.

[0071] In an optional implementation, the beam adjusting assembly adjusts the included angle between any two adjacent first beams among the m first beams to a first angle and splits each of the m first beams into n second beams. The m emitters in one light source section are activated at each of M time points and are present in the same region of the detection surface, and projection is performed on them at each of the M time points. The M projected points have different positions; in other words, the positions of the projected points in multiple regions of the detection surface can be switched. Switching the positions of the projected points achieves the effect of scanning the detection surface (see FIG. 4 ). In other words, the beam adjusting assembly can control the positional arrangement of the projected points on the detection surface by adjusting the m first beams.

[0072] Based on the light source described in Case 1, in a possible implementation, the beam adjusting assembly may include a collimation assembly and a beam splitting assembly. The collimation assembly is configured to adjust the included angle between any two adjacent first beams among the m first beams coming from the light source to a first angle and transmit the adjusted m first beams to the beam splitting assembly. The beam splitting assembly is configured to split each of the adjusted m first beams into n second beams to obtain m×n second beams. The first angle is determined based on the total field of view corresponding to the detection surface and the number of second beams, m×n. In other words, the magnitude of the first angle is related to the total field of view and the number of beams obtained through splitting by the beam splitting assembly. For example, using one dimension as an example, if the total field of view corresponding to the detection surface is 64 degrees, when m×n=160, the first angle is equal to 64 / 160=0.4 degrees. For another example, using two dimensions as an example, if the total field of view corresponding to the detection surface is 64 × 48 degrees, when m × n = 160 × 120, the first angle is equal to (64 / 160) × (48 / 120) = 0.4 × 0.4 degrees, and m × n = 160 × 120 indicates that there are 160 second beams in the horizontal direction and 120 second beams in the vertical direction. Of course, the collimation assembly can alternatively adjust the included angle between two adjacent first beams in different directions to be different angles. This is not limited in the present application. It should be understood that the total field of view corresponding to the detection surface is usually approximately equal to the total field of view corresponding to the detector. Total field of view corresponding to the detector = field of view of each detection element in the detector × total number of detection elements in the detector.

[0073] Furthermore, optionally, the collimation assembly may collimate the diverging first beams emitted by each emitter into parallel beams. Additionally, because the emitters are positioned differently in the vertical direction, the parallel beams are collected at different angles of incidence on the plane where the beam splitter assembly is located. Using the light source shown in FIG. 5a as an example, FIG. 6a is a schematic diagram of an example beam path from the light source to the collimation assembly and then to the beam splitter assembly. The first beam emitted by the light source has a specific maximum angle. In FIG. 6a, three straight lines represent one first beam. The first beam from the light source is collimated by the collimation assembly into parallel beams, and the collimated first beam is transmitted to the beam splitter assembly.

[0074] FIG. 6b is a schematic diagram of the optical path adjusted by the beam adjusting assembly. For illustrative purposes, an example is used in which two first beams are received from a light source at a time and the beam splitting assembly splits each first beam into two second beams. The collimation assembly is configured to adjust the included angle between two adjacent first beams from the light source to a first angle α. Since the collimation assembly performs the same change on the transmission direction of each first beam, the beam splitting assembly also performs the same change on the transmission direction of each second beam. Therefore, after the first beam is split by the beam splitting assembly, the included angle between two adjacent second beams obtained is also α. The included angle between two adjacent second beams is also sometimes referred to as the separation angle. By adjusting the included angle between any two adjacent first beams among the m first beams from the light source to the first angle, m×n second beams are uniformly projected at the same position within the m×n region on the detection surface. 6b, at a time point, the 2×2 second beams are uniformly projected onto the upper left corners of all 2×2 regions of the detection surface, and at a time point after that, the 2×2 second beams can be uniformly projected onto positions adjacent to the upper left corners of all 2×2 regions of the detection surface.

[0075] Based on the light source described in Case 2, in a possible implementation, the beam adjusting assembly may include a collimation assembly and a beam splitting assembly. The collimation assembly is configured to adjust the included angle between any two adjacent first beams among the m first beams to a second angle and transmit the adjusted m first beams to the beam splitting assembly, where the second angle is determined based on the total field of view corresponding to the detection surface and the number m of activated light sources. For example, if the total field of view corresponding to the detection surface is 64 × 48 degrees, and m = 16 × 12, the second angle is equal to (64 / 16) × (48 / 12) = 4 × 4 degrees. The beam splitting assembly is configured to split each of the adjusted m first beams into n second beams. To form an image with a resolution of 320 x 240, when the total field of view corresponding to the detection surface is 64 x 48 degrees, it can be seen that the angle between beams corresponding to two adjacent projection points on the detection surface is 64 / 320 = 0.2 degrees. The zeroth-order diffracted light of the m first beams is uniformly projected onto a 320 x 240 area. Specifically, the spacing between the projection points of the zeroth-order diffracted light of any two adjacent first beams among the m first beams is 19 projection points, and the included angle between any two adjacent first beams = second angle = [(64 / 320) x (320 / 16)] x [(64 / 320) x (240 / 12)] = [0.2 x 20] x [0.2 x 20] = 4 x 4 degrees. It should be understood that the spacing of 19 projected points means that the spacing between two projected points on the detection plane of the zeroth-order diffracted light of two adjacent first beams is 19 projected points. In other words, the pitch between the centers of the projected points corresponding to the two beams of zeroth-order diffracted light is 20 projected points (see FIG. 10).

[0076] In a possible implementation, the collimation assembly may be a collimator, a collimation mirror, a microlens, or a combination of microlenses. Optionally, the focal length of the collimator, the collimation mirror, the microlens, or the combination of microlenses may be adjusted to adjust the included angle between two adjacent first beams coming from the light source. The beam splitting assembly may be a DOE, a polarizing beam splitter (PBS), or a diffraction grating.

[0077] In this application, the focal length f of a collimator, a collimation mirror, a microlens, or a combination of microlenses can be adjusted or selected to adjust the included angle between any two adjacent first beams among the m first beams coming from the light source to be a first angle. To facilitate the explanation of the solution, a collimator will be used as an example below. The included angle between two adjacent first beams is related to the focal length f of the collimator and the pitch of the emitters in the light source. Specifically, this is as follows: f = pitch / tan(α), where α is the included angle between two adjacent first beams. For example, if the pitch size between EEL-based emitters is 30 μm and the included angle between any two adjacent first beams among the m first beams is as follows: α = 0.4 degrees, then f = pitch / tan(α). α ) = 30 / tan(0.4) = 4.3 mm. This can also be understood as meaning that by adjusting / selecting the focal length of the collimator to 4.3 mm, the included angle between any two adjacent first beams among the m first beams coming from the light source can be adjusted to 0.4 degrees.

[0078] In a possible implementation, when the beam splitting assembly is a DOE, the second beam is a diffracted beam of the first beam. The projected point of the zeroth-order diffracted beam of the first beam on the detection surface is the direct projected point of the first beam. The projected points of the ±1st-order diffracted beams, ±2nd-order diffracted beams, ±3rd-order diffracted beams, etc. on the detection surface are equivalent to the projected points obtained by separately copying the projected point of the zeroth-order diffracted beam to the corresponding regions. Referring to Figure 6c, the +1st-order diffracted beam in region B is equivalent to the diffracted beam obtained by copying the zeroth-order diffracted beam in region A to region B.

[0079] 3. Detection Assembly

[0080] FIG. 6e is a schematic diagram of another detection assembly structure according to the present application. The detection assembly may include a SPAD array and a TDC array. Optionally, the detection assembly may further include a memory and a control circuit. For example, the TDC array is a 5×5 TDC array, and the SPAD array is also a 5×5 array. The 5×5 SPAD array corresponds to the 5×5 TDC array. It is assumed that the TDC starts timing when it detects the first pulse signal. The TDC stops timing when one of the at least one SPAD corresponding to the TDC acquires an optical echo signal reflected from the detection surface. In this case, the time of flight detected by the TDC can be acquired. Each TDC / SPAD corresponds to a storage unit in the memory. The control circuit stores the time of flight detected by the SPAD / TDC in the memory.

[0081] In the present application, the detection assembly may include K detection elements, and at each of M time points, S detection elements of the K detection elements may be powered on (see FIG. 1b), where K is an integer greater than or equal to S.

[0082] In a possible implementation, the detection assembly may include m×n detector elements, which typically include a SPAD and a TDC. Referring to FIG. 6d, a SPAD is used herein simply to illustrate a detector element, and the m×n detector elements are in one-to-one correspondence with the m×n regions. In other words, one detector element corresponds to one region of the detection surface. Each of the m×n detector elements is configured to receive an optical echo signal from the corresponding region at each of M time points and convert the optical echo signal from the corresponding region at each time point into an electrical echo signal for storage. Using one detector element as an example, the detector element may receive one optical echo signal from the corresponding region at a first time point, one optical echo signal from the corresponding region at a second time point, and so on, so that a total of M optical echo signals are acquired at M time points. In other words, one detector element corresponds to M regions. light The echo signals may be stored. It should be noted that if the detector assembly includes m×n detector elements, at each of M time points, when an emitter in one light source section is selected, all of the m×n detector elements may be powered on, or if the number of detector elements included in the detector assembly is greater than m×n, at each of M time points, when an emitter in one light source section is selected, only m×n of the detector elements may be powered on. For example, if the detector assembly includes 320×240 detector elements, only 160×120 of the detector elements may be powered on at each time point. In this way, All Detector element The electricity Powered on There is no need Therefore, power consumption can be reduced.

[0083] In this application, the detection assembly includes a detector, which may include an array of detection elements, for example, a SPAD array, a PIN-type photodiode array (also called a PIN junction diode), or an avalanche photodiode (APD) array.

[0084] In the present application, the TOF sensor module may further include a processing circuit, and the processing circuit is configured to acquire M×S electrical echo signals acquired at M time points from the detection assembly and determine image information based on the M×S electrical echo signals. electricity Based on the echo signals, image information is determined, thereby helping to increase the resolution of the formed image.

[0085] Further, optionally, the processing circuit may be integrated within the detection assembly or may be a processor within an electronic device or laser radar in which the TOF sensor module is disposed, for example, a central processing unit (CPU) within a mobile phone. If the processing circuit is integrated within the detection assembly, the detection assembly may transmit the stored electrical echo signals to the processing circuit, and the processing circuit may determine image information based on the received electrical echo signals. If the processing circuit is a processor within an electronic device or laser radar in which the TOF sensor module is disposed, the detection assembly may transmit the stored electrical echo signals to the processor, and the processor may determine image information based on the received electrical echo signals.

[0086] In the present application, the TOF sensor module may further include a light receiving assembly configured to receive the light echo signal from the detection surface and transmit the light echo signal to the detection assembly. In a possible implementation, the light receiving assembly may be a lens group.

[0087] Further, optionally, the TOF sensor module may further include an optical filter, which may be positioned in front of the light receiving assembly or between the light receiving assembly and the detection assembly to reduce the effect of ambient light on the detection assembly.

[0088] Based on the above, the following provides two specific examples of the TOF sensor module with reference to specific hardware structures to help further understand the structure of the TOF sensor module.

[0089] In the following two examples, to facilitate explanation of the solution, for example, the beam conditioning assembly includes a collimator and a DOE, the total field of view corresponding to the detection surface is 64 x 48 degrees, and the detection assembly can simultaneously activate up to 160 x 120 detection elements.

[0090] Example 1

[0091] To implement VGA for the formed image, when a maximum of 160 × 120 detector elements can be activated simultaneously in the detector assembly (i.e., the image resolution is 640 × 480), in a possible case, the light source includes 4 × 4 = 16 light source sections, each of which includes 10 × 10 emitters. The 10 × 10 first beams emitted by the 10 × 10 emitters in each light source section pass through a collimator and are then projected onto the DOE. The number of effective beams obtained through division by the DOE is 16 × 12 (16 and 12 are the numbers of effective beams obtained through division by the DOE in the horizontal and vertical directions, respectively). The number of second beams coming from one light source section is as follows: m × n = (16 × 10) × (12 × 10) = 160 × 120. Specifically, when m emitters of a single light source patch are activated, 160 x 120 second beams may be generated, which are projected onto 160 x 120 areas on the detection plane. For 4 x 4 light source patches, (4 x 160) x (4 x 120) = 640 x 480 second beams may be generated. the result, The resolution of the generated image can be 640 x 480. do.

[0092] It should be noted that any one or more of the number of light source sections in the light source, the number of emitters included in the light source sections, and the number of effective beams obtained through division by the DOE can be further changed so that the resolution of the image formed by the TOF sensor module can meet VGA. It should be understood that a resolution of 640 x 480 or higher can be achieved by increasing the number of light source sections in the light source, and / or the number of emitters in the light source sections, and / or the number of effective beams obtained through division by the DOE.

[0093] FIG. 7 is a schematic diagram of another TOF sensor module structure according to the present application. The TOF sensor module may include a light source, a beam conditioning assembly, and a detection assembly. The beam conditioning assembly includes a collimator and a DOE. The light source includes 4×4=16 light source sections. Each light source section includes 10×10 emitters. The 10×10 emitters in one of the 4×4 light source sections emit 10×10 first beams at each time point, and the light source section used to emit the 10×10 first beams at each of the 16 time points changes. This can also be understood as the 10×10 emitters in the first light source section each emit 10×10 first beams at a first time point, the 10×10 emitters in the second light source section each emit 10×10 first beams at a second time point, and so on.

[0094] The collimator is configured to adjust the transmission direction of the received 10×10 first beams to adjust the included angle between any two adjacent first beams of the 10×10 first beams in each direction to a first angle. The first angle is determined based on the total field of view and the number m×n of second beams. Specifically, the first angle = (64 / 160) × (48 / 120) = 0.4 × 0.4. Specifically, the included angle between any two adjacent first beams of the 10×10 first beams adjusted by the collimator in each of the horizontal and vertical directions is 0.4 degrees. Since the included angle between two adjacent first beams after adjustment is 0.4 degrees, 10 emitters with different heights in one light source section can cover a field of view of 10 × 0.4 = 4 degrees, and four light source sections can cover a field of view of 4 × 4 = 16 degrees.

[0095] To adjust the included angle between two adjacent first beams to be a first angle, the focal length of the collimator is as follows: f=pitch / tan(α)=pitch / tan(0.4). When the emitter is an EEL-based emitter, f=30 / tan(0.4)=4.3 mm.

[0096] The collimator then transmits the adjusted 10x10 first beams to the DOE. The DOE is configured to split each of the adjusted 10x10 first beams into 16x12 second beams to obtain 160x120 second beams, and project the 160x120 second beams at the same positions within the 160x120 region on the detection surface. A total of 4x4 light source segments are activated at 16 time points, allowing four scans to be performed within each of the 160x120 regions on the detection surface. Specifically, each light source segment is projected onto 160x120 projection points on the detection surface, and the 4x4 light source segments are projected onto (160x4)x(120x4) projection points on the detection surface. When the total field of view corresponding to the detection surface is 64 × 48 degrees, to form a VGA image, the angle between the beams corresponding to two adjacent projection points on the detection surface is 64 / 640 = 0.1 degrees. In other words, the included angle between two adjacent second beams corresponding to two adjacent projection points on the detection surface is 0.1 degrees. Referring to Figure 4, the projection point corresponding to the first time point and the projection point corresponding to the second time point are two adjacent projection points, the pitch between the centers of the two adjacent projection points is one projection point, the included angle between the two second beams corresponding to the two adjacent projection points is 0.1 degrees, the included angle between the two second beams corresponding to the interval of one projection point is 0.2 degrees, and the included angle between the two second beams corresponding to the interval of two projection points is 0.3 degrees.

[0097] Referring to FIG. 4 , one light source section is activated at one time point. For example, four light source sections are activated at four time points. To achieve the effect of scanning the detection surface, each of the 160×120 second beams from the first light source section is projected onto the upper left corner of each of the 160×120 regions on the detection surface (i.e., the projection point corresponding to the first time point), and each of the 160×120 second beams from the second light source section is projected onto a position adjacent to the upper left corner of each of the 160×120 regions on the detection surface (the projection point corresponding to the second time point), and so on. In other words, the projection points on the detection surface of two adjacent second beams from two adjacent light source sections are adjacent and do not overlap.

[0098] In the present application, the pitch Δ1 (see FIG. 5a or FIG. 8) between two adjacent emitters of two adjacent light source sections can be set so that the projection points of two adjacent second beams from the two adjacent light source sections on the detection surface are adjacent and do not overlap. FIG. 8 is a schematic diagram of the relationship between the light source and the projection points on the detection surface according to the present application. To facilitate the explanation of the solution, an example in FIG. 8 is used for explanation, in which the light source includes four light source sections, each including three emitters. The included angle between the first beams emitted by two adjacent emitters of two adjacent light source sections of the light source is equal to or greater than the angle corresponding to the interval between the four projection points on the detection surface. Each region of the detection surface includes four projection points. The interval between the direct projection points of two adjacent emitters belonging to the same light source section is three projection points (the included angle between two corresponding second beams is 0.4 degrees). The interval between the direct projection points of the first beams emitted by two adjacent emitters belonging to two adjacent light source sections is four projection points (the included angle between two corresponding second beams is 0.5 degrees, and the pitch between the centers of the projection points of the two second beams is as follows: Δ2 = 5 projection points). In FIG. 8, the same filled area indicates the projection points of the second beams coming from the same light source section. The ±4th order projection points on the detection surface in FIG. 8 can be understood as follows: in each of the three regions other than the region where the zeroth order diffracted light is located, the zeroth order diffracted light is copied once, thereby performing four scans, i.e., achieving the super-resolution effect.

[0099] It should be noted that the ±1st-order diffracted light beams from the (i+1)th light source section are positioned to the left or right of the zeroth-order diffracted light beams from the i-th light source section. For example, the −1st-order diffracted light beams from the second light source section are positioned to the left of the zeroth-order diffracted light beams from the first light source section. For another example, the −1st-order diffracted light beams from the third light source section are positioned to the right of the zeroth-order diffracted light beams from the second light source section. To form a schematic diagram of the arrangement of projected points in FIG. 8, the ±2nd-order diffracted light beams from the (i+1)th light source section are positioned to the left or right of the ±1st-order diffracted light beams from the i-th light source section, and so on, so that the projected points on the detection plane can be closely connected. In addition, more orders of beam splitting may be required for the first beam coming from the edge light source section of the light source. Referring to FIG. 8, the leftmost projected point is the zeroth-order diffracted light beam of the first beam coming from the first light source section. In the third row, the −1st, −2nd, and −3rd diffracted orders from the first light source section are to the left of the 0th diffracted order and are not projected onto the detection plane. In other words, the +1st, +2nd, and +3rd diffracted orders of the first beam from the first light source section are effective beams. Therefore, it can be determined that the DOE splits each first beam into m×n second beams, and the m×n second beams are effective beams. During actual beam splitting, the DOE may obtain more than m×n beams through splitting. For example, if the DOE splits each first beam into 16×12 second beams, this means that the number of effective second beams into which the DOE splits each first beam is 16×12. It should be understood that if the wasted diffraction orders are not taken into account, the beam splitting orders of the DOE are ±8 orders × (±6) orders, or if the wasted diffraction orders are taken into account, the beam splitting orders of the DOE are typically ±12 orders × (±10) orders.

[0100] The detection assembly may include 160 x 120 detector elements, with one detector element corresponding to one region. In FIG. 7 , for example, two regions correspond to two SPADs. When 10 x 10 emitters of one light source section are activated, all 160 x 120 detector elements included in the detection assembly may be selected, and each detector element may be configured to receive optical echo signals from the corresponding region and convert the optical echo signals from the corresponding region into electrical echo signals for storage at each time point. At 4 x 4 time points, each detector element may receive 4 x 4 optical echo signals from the corresponding region to obtain an image with a resolution of (4 x 160) x (4 x 120) = 640 x 480.

[0101] Based on Example 1, non-scanning three-dimensional detection with VGA resolution or higher resolution can be implemented based on the capabilities of conventional detectors. By activating the light source sections of the light source through switching, the second beam can be projected onto different areas of the detection surface, thereby implementing resolution superposition and achieving TOF with VGA resolution or a million-level resolution.

[0102] Example 2

[0103] When a maximum of 160 × 120 detector elements can be activated simultaneously in the detector assembly to form an image with a resolution of 320 × 240, in a possible case, the light source includes 32 × 24 emitters, and the preset interval is one emitter activated every other emitter (see FIG. 5b). In Example 2, 16 × 12 emitters can be activated at each time, and the number of effective beams obtained through division by the DOE is on the order of 10 × 10. Specifically, the DOE can divide a 1 × 1 first beam into 10 × 10 second beams. The number of second beams projected onto the detector plane at one time is as follows: m × n = (16 × 10) × (12 × 10) = 160 × 120. Specifically, 16x12 emitters are activated at each of two time points so that the formed image has a resolution of 320x240. It should be noted that one or more of the preset interval between the emitters activated each time, the number of emitters activated each time, and the number of effective beams obtained through division by the DOE can be designed to achieve a resolution of 320x240. This is not limited in the present application. It should be understood that by changing the preset interval between the emitters activated each time, and / or the number of emitters activated each time, and / or the number of effective beams obtained through division by the DOE, the resolution of the formed image can reach 640x480 or more.

[0104] FIG. 9 is a schematic diagram of the structure of yet another TOF sensor module according to the present application. The TOF sensor module may include a light source, a beam conditioning assembly, and a detection assembly. The beam conditioning assembly may include a collimator and a DOE. The light source includes 32×24 emitters. At each of two time points, 16×12 emitters of the 32×24 emitters emit 16×12 first beams at preset intervals (one emitter apart), and the 16×12 emitters used to emit the 16×12 first beams at each of two time points change. This can also be understood as activating one emitter at intervals of one emitter (see the description of Case 2), activating 16×12 emitters of the 32×24 emitters, and emitting 16×12 first beams from the activated 16×12 emitters.

[0105] The collimator is configured to adjust the transmission direction of the received 16×12 first beams to adjust the included angle between any two adjacent first beams of the 16×12 first beams in each direction to a second angle. The second angle is determined based on the total field of view corresponding to the detection surface and the number m of activated emitters. Specifically, the second angle = (64 / 16) × (48 / 12) = 4 × 4. Specifically, the included angle between any two adjacent first beams of the 16×12 first beams in each of the two directions obtained after adjustment by the collimator is 4 degrees. The collimator transmits the adjusted first beams to the DOE, and in this case, it can be understood that the included angle between two adjacent second beams belonging to the same time point in each of the horizontal and vertical directions is 4 degrees. The angle corresponding to two adjacent projection points is (64 / 320) x (48 / 240) = 0.2 x 0.2. Therefore, the distance between the directly projected points of the first beams coming from two adjacent emitters at the same time is 19 projection points (in other words, the pitch between the directly projected points of the two first beams is 20 projection points). See Figure 10.

[0106] In Example 2, to achieve uniform placement of the projected points on the detection plane, the focal length of the collimator can be adjusted to achieve a spacing Δ3 between the direct projection points of the first beams of two adjacent emitters (e.g., two adjacent emitters 1 in FIG. 10 ) among the m activated emitters. The included angle between the two first beams at a spacing of 19 projected points is as follows: α = (64 / 320) × 20 = 4 degrees. Therefore, the focal length of the collimator can be selected or adjusted as follows: f = pitch / tan(α) = pitch / tan(4).

[0107] Further, the collimator transmits the adjusted 16x12 first beams to the DOE. The DOE is configured to split each of the adjusted 16x12 first beams into 10x10 second beams to obtain 160x120 second beams, and project the 160x120 second beams onto the same positions of the 160x120 regions on the detection surface, for example, onto the upper left corners of each region on the detection surface in FIG. 9. For a detailed description, please refer to FIG. 4. The details will not be described again in this specification.

[0108] The detection assembly may include 160 x 120 detector elements, each of which may receive two light echo signals from a corresponding region of the detection surface to obtain an image with a resolution of (2 x 160) x (2 x 120) = 320 x 240.

[0109] Based on Example 2, at each of M time points, m emitters are activated at preset intervals (e.g., equal intervals), and the resolution of the formed image can reach 320x240 or more without any special design for emitter placement.

[0110] 11a is a schematic diagram of yet another TOF sensor module structure according to the present application. The TOF sensor module may include a light source, a beam conditioning assembly, and a detection assembly. The light source is configured to emit m first beams at each of M time points and transmit the m first beams to the beam conditioning assembly, where m and M are both integers greater than or equal to 2.

[0111] In a possible implementation, m emitters in one of M light source sections emit m first beams at each time point, and the light source section used to emit the m first beams at each of the M time points changes. In Fig. 11a, for example, the light source includes M light source sections, and each light source section includes m emitters. For example, Fig. 11a shows the i-th light source section and the (i+1)-th light source section. The m emitters included in the i-th light source section emit m first beams. For details, please refer to the description of Case 1 of the light source in Fig. 3, and the details will not be described again in this specification.

[0112] Furthermore, optionally, the M light source sections included in the light source are integrally molded. In this way, it is possible to ensure that the M light source sections are on the same plane. The light source provided with reference to FIG. 5a includes four light source sections, specifically, 4×4 emitters are grouped into 2×2 light source sections, and the 4×4 emitters are integrally molded. Compared with a bonded light source array, the M integrally molded light source sections do not require additional assembly to control surface flatness. FIG. 5c is a schematic diagram of a combination of a 2×2 light source array. In the light source array shown in FIG. 5c, the 2×2 light source arrays need to be assembled, and it is necessary to ensure that the 2×2 light source arrays are on the same plane. Therefore, assembly is relatively difficult.

[0113] 5a and 5c, the spacing Δ4 between the light source sections in FIG. 5a can be controlled to be approximately 40 μm, and the spacing Δ5 between the light source arrays in FIG. 5c needs to be at least 100 μm because assembly is required. In other words, the light source sections in the present application facilitate miniaturization of the TOF sensor module. Furthermore, the size of the M light source sections is relatively small so that the driving unit of the light source can be integrated below or next to the light source. This facilitates miniaturization of the TOF sensor module.

[0114] The beam conditioning assembly is configured to adjust the transmission directions of the received m first beams and then project the adjusted m first beams onto corresponding regions of the detection surface. The projection points on the detection surface onto which projection is performed at each of the M time points are arranged in separate regions. This can also be understood as all second beams from one light source section being projected onto corresponding regions of the detection surface. In Figure 11a, the m first beams from the i-th light source section are adjusted by the beam conditioning assembly and then projected onto the i-th region.

[0115] In a possible implementation, the beam adjusting assembly is configured to adjust the transmission directions of the m first beams to uniformly project the m first beams onto corresponding regions. In the following, four implementations for uniformly projecting the m first beams onto the i-th region are provided as examples.

[0116] Implementation 1: The beam conditioning assembly includes a collimator.

[0117] The collimator is configured to adjust the included angle between any two adjacent first beams among the m first beams to a third angle. The third angle is determined based on a field of view corresponding to the i-th region and the number m of first beams. The field of view corresponding to the i-th region = total field of view of the detection surface / M. The third angle = total field of view of the detection surface / M / m.

[0118] Implementation 2: The beam conditioning assembly includes a beam tuner (DOE tuner), also called a beam scaler.

[0119] The beam scaler is configured to expand each of the m first beams coming from the ith light source section of the light source to expand the m first beams into one uniform beam, and project the uniform beam onto the ith region.

[0120] Implementation 3: The beam conditioning assembly includes a collimator and a DOE.

[0121] The collimator is configured to adjust the included angle between any two adjacent first beams among the m first beams coming from the i-th light source section of the light source to be a third angle. The DOE is configured to split each adjusted first beam into n second beams. The third angle is determined based on a field of view corresponding to the i-th region and the number of second beams, m×n. The field of view corresponding to the i-th region = total field of view of the detection surface / M. The third angle = total field of view of the detection surface / M / (m×n).

[0122] This can also be understood as the collimator being configured to transmit m first beams coming from the i-th light source section of the light source to the DOE or diffuser at a specific maximum angle or in parallel at a specific angle. The DOE or diffuser appropriately diffuses or shapes the received first beams and transmits the first beams to the i-th region of the detection surface. The beams transmitted to the i-th region can be circular or square in shape, or in a dense grid pattern. This is not limited in the present application.

[0123] Implementation 4: The beam conditioning assembly includes a collimator and a beam tuner.

[0124] The collimator is configured to transmit the m first beams from the ith light source section of the light source in parallel at a third angle to the beam tuner, which diffuses the collimated light and transmits the collimated and diffused light to the ith region of the detection surface.

[0125] It should be noted that the collimator may be closer to the light source and further from the detection surface than the DOE, or the collimator may be further from the light source and closer to the detection surface than the DOE.

[0126] The detection assembly is configured to receive m optical echo signals from corresponding regions of the detection surface at each of M time points; specifically, the detection assembly receives m optical echo signals from the first region at a first time point, receives m optical echo signals from the second region at a second time point, and similarly receives m optical echo signals from the M region at an Mth time point; at each time point, the detection assembly converts the m optical echo signals into electrical echo signals for storage; the m optical echo signals are in one-to-one correspondence with the m first beams; and the optical echo signals are signals obtained by reflecting the corresponding first beams by the detection surface.

[0127] In a possible implementation, the detection assembly may include M detector element regions, and the M detector element regions of the detection assembly are in one-to-one correspondence with the M light source sections. Each detector element region includes a plurality of detector elements, and each detector element region is configured to receive an optical echo signal obtained by reflecting, by a detection surface, a beam emitted by a light source section corresponding to the detector element region. The detection assembly is configured to power on only each detector element in the detector element region among the M detector element regions that corresponds to the light source section used to emit the m first beams at each of the M time points. In other words, when the ith light source section of the light source emits m first beams, Detection Assembly A corresponding ith detector element area is selected. The ith detector element area of the detector assembly is configured to receive optical echo signals coming from the corresponding area of the detector surface. In this way, the m first beams emitted by the m emitters of the ith light source section are adjusted by the beam adjusting assembly, and then uniformly cover the ith area of the detector surface. In addition, Detection AssemblyA corresponding ith detection element area is selected, and the ith detection element area can receive m light echo signals from the ith area of the detection surface, thereby helping to avoid the problem in the prior art of low image resolution because only a maximum of 160×120 detection elements can be activated simultaneously.

[0128] Based on the TOF sensor module, at each of M time points, after the m first beams emitted by the light source are adjusted by the beam adjusting assembly, the m first beams cover an area of the detection surface. The light source separately emits the m first beams at different times, and corresponding detection elements in the detection assembly are selected, thereby solving the problem that only a maximum of 160×120 detection elements can be activated simultaneously.

[0129] It should be noted that the spacing Δ4 between the light source sections can be effectively controlled by using M integrally molded light source sections. The relatively small spacing Δ4 between the light source sections facilitates continuous connection between the projected points on the detection surface. The beneficial effects will be described in detail below with reference to specific examples.

[0130] FIG. 11b is a schematic diagram of the relationship between the spacing Δ4 between light source sections and the spacing D between regions on the detection surface according to the present application. The spacing D between two adjacent regions on the detection surface is determined by the spacing Δ4 between the light source regions. When the spacing Δ4 between the light source regions is relatively small, complete coverage of the detection surface can be achieved as much as possible by designing the DOE / diffuser to diverge at a small angle or through appropriate defocusing of the collimation mirror (i.e., the light source is not positioned on the focal plane of the collimation mirror). Designing a DOE to diverge at a small angle is relatively easy. For example, an iterative design method can be used. When the maximum angle of the DOE's emitted light is relatively small, scalar diffraction theory is satisfied, and it is relatively easy to obtain diffracted light with relatively high efficiency and uniformity through iteration. Alternatively, when the spacing Δ4 between the light source regions is relatively small, complete coverage of the detection surface can be achieved through appropriate defocusing of the collimation mirror. Appropriate defocusing of the collimation mirror helps to control the uniformity of the projection points that lie on the detection surface and onto which the projection is performed, and can ensure complete coverage of the detection surface.

[0131] It should be noted that when the spacing Δ4 between the light source sections is relatively large and the maximum angle of the emitted light of the DOE / diffuser needs to be designed to be relatively large, the global search / vector design method needs to be used in this specification, which requires a relatively large amount of calculation and makes it difficult to control the diffraction efficiency and uniformity.

[0132] In a possible implementation, the beam adjusting assembly may include a beam adjusting section. For example, the beam adjusting assembly may be divided into M beam adjusting sections, and the M light source sections are in one-to-one correspondence with the M beam adjusting sections. To facilitate the description of the solution, an example in which the beam adjusting sections are DOE / diffusers will be used below for explanation. In other words, the light source sections are in one-to-one correspondence with the DOE / diffuser sections, that is, one light source section corresponds to one DOE / diffuser section.

[0133] In a possible implementation, the DOE / diffuser can be located on the side of the light source closer to the detection surface, or the light source and DOE / diffuser can be bonded to form a wafer-level integrated device. Fig. 11c is a schematic diagram of the positional relationship between the DOE section and the light source section according to the present application. In Fig. 11c, the i-th light source section is used as an example. The i-th section emits m first beams, which are deflected and homogenized by the DOE and then transmitted to the i-th region of the detection surface.

[0134] FIG. 11d is a schematic diagram of another positional relationship between the DOE sections and the light source sections according to the present application. One light pipe can be fixed for each light source section. In FIG. 11d, the i-th light source section is used as an example. The i-th light source section emits m first beams. The m first beams are homogenized by the corresponding i-th light pipe and then transmitted to the corresponding i-th DOE section. The m first beams are deflected and further homogenized by the corresponding i-th DOE section and then transmitted to the i-th region of the detection surface. This prevents the DOE sections from being close to the light source sections, thereby helping to improve DOE utilization and reduce the difficulty of assembling the TOF sensor module.

[0135] It should be noted that the DOE is configured to shape the received beam and deflect the emission angle. Different light source sections correspond to different emission angles. Referring to FIG. 11b, the polarization directions of the emitted light of different light source sections are different.

[0136] Compensation for the spacing Δ4 between the light source sections needs to be further considered in the DOE design. As shown in FIG. 11e, three edge light source sections (1, 2, 3) are used as an example. The DOE is configured to homogenize and deflect the beam coming from each light source section so that the beam is transmitted to the corresponding area of the detection surface. Because there is a gap between the light source sections but no gap between the areas of the detection surface (i.e., the beam needs to completely cover the detection surface), the beam coming from the light source section needs to be expanded outward to the area indicated by the dashed box so that the light source sections have a one-to-one correspondence with the areas of the detection surface. For example, light source section 1 in the dashed box corresponds to area 1 of the detection surface, light source section 2 in the dashed box corresponds to area 2 of the detection surface, light source section 3 in the dashed box corresponds to area 3 of the detection surface, and so on.

[0137] Based on the structure and function principle of the TOF sensor module described above, the present application further provides an electronic device. The electronic device may include a TOF sensor module and a fixing structure, and the fixing structure is configured to fix the TOF sensor module. Of course, the electronic device may further include other components, such as a processor, a memory, a wireless communication device, a sensor, a touch screen, and a display.

[0138] In this application, an electronic device may be a mobile phone, a tablet computer, or a wearable device (e.g., a smart watch), etc. Exemplary embodiments of an electronic device include, but are not limited to, a device using IOS®, Android®, Microsoft®, or another operating system.

[0139] 12 is a schematic diagram of the structure of an electronic device according to an embodiment of the present application. The electronic device 100 may include a processor 111, a TOF sensor module 112, a display 113, and a fixed assembly 114. It should be understood that the hardware structure shown in FIG. 12 is merely an example. A terminal device to which the present application is applicable may include more or fewer components than the electronic device 100 shown in FIG. 12, may combine two or more components, or may have a different component configuration. The various components shown in the figure may be implemented using hardware, software, or a combination of hardware and software, including one or more signal processing and / or application-specific integrated circuits.

[0140] The processor 111 may include one or more processing units. For example, the processor 111 may include an application processor (AP), a graphics processing unit (GPU), an image signal processor (ISP), a controller, a digital signal processor (DSP), etc. The different processing units may be separate components or may be integrated into one or more processors.

[0141] Please refer to the above description for the TOF sensor module 112. Details will not be described again here.

[0142] Display 113 may be configured to display images, etc. Display 113 may include a display panel. The display panel may be a liquid crystal display (LCD), an organic light-emitting diode (OLED), an active-matrix organic light-emitting diode (AMOLED), a flexible light-emitting diode (FLED), a mini-LED, a micro-LED, a micro-OLED, or a quantum dot light-emitting diode (QLED), etc. In some embodiments, electronic device 100 may include one or H displays 113, where H is a positive integer greater than or equal to two.

[0143] The fixing assembly 114 is configured to fix the TOF sensor module to the electronic device. For example, the fixing assembly may be a bracket, and the TOF sensor module may be fixed to the electronic device by using the bracket, or the fixing assembly may be a mechanical part formed by another component in the electronic device (e.g., a middle frame in a mobile phone), or the fixing assembly may be various adhesives or connectors (e.g., solder and screws).

[0144] In the embodiments of the present application, if there is no special explanation or logical conflict, and the terms and / or descriptions in different embodiments are not contradictory and can be cross-referenced, the technical features in different embodiments may be combined to form a new embodiment based on internal logical relationships.

[0145] In this application, the term "and / or" describes an association relationship between associated objects and may indicate that three relationships may exist. For example, A and / or B may indicate the following cases: when only A exists, when both A and B exist, and when only B exists, where A and B may be singular or plural. "At least one of the following items (pieces)" or similar expressions means any combination of these items, including a single item (piece), or any combination of multiple items (pieces). For example, at least one of a, b, and c (pieces) may represent a, b, c, "a and b," "a and c," "b and c," or "a, b, and c," where a, b, and c may be singular or plural. In the text description of this application, the symbol " / " usually indicates an "or" relationship between associated objects. It should be understood that in this application, "uniform" does not mean absolute uniformity and may allow for certain engineering errors.

[0146] It should be understood that the various numbers used in the embodiments of the present application are merely used to facilitate description and are not used to limit the scope of the embodiments of the present application. The sequence numbers of the above-described processes do not indicate the order of execution. The order of execution of the processes should be determined based on the functions and internal logic of the processes. Terms such as "first" and "second" are intended to distinguish between similar objects and do not necessarily describe a specific order or sequence. Furthermore, the terms "comprise," "have," and any other variations thereof are intended to cover non-exclusive inclusions, for example, including a series of steps or units. A method, system, product, or device is not necessarily limited to its explicitly enumerated steps or units and may include other steps or units not explicitly enumerated or inherent to such a process, method, product, or device.

[0147] While the present application has been described with reference to particular features and embodiments thereof, it is apparent that various modifications and combinations may be made thereto without departing from the spirit and scope of the present application. Correspondingly, this specification and the accompanying drawings are merely exemplary illustrations of the solutions defined by the appended claims, and any or all modifications, variations, combinations, or equivalents that fall within the scope of the present application are to be considered.

[0148] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. The present application intends to cover these modifications and variations to the embodiments of the present application, provided that they fall within the scope of protection defined by the following claims in the present application and their equivalent technologies.

Claims

1. 1. A time-of-flight (TOF) sensor module comprising a light source, a beam conditioning assembly, and a detection assembly, the light source includes M light source sections, each light source section including m emitters, the m emitters in one of the M light source sections are configured to emit m first beams at each of M time points and transmit the m first beams to the beam adjusting assembly, m and M are both integers greater than 1, and the light source sections used to emit the m first beams at different time points are different; the beam conditioning assembly is configured to condition the m received first beams into S second beams, and then project the S second beams onto S regions of a detection surface, the S regions having a one-to-one correspondence with the S second beams, and M projection points located within the same region of the detection surface and projected at each of the M time points have different positions, where S is an integer greater than m; the detection assembly is configured to receive S optical echo signals from the detection surface at each of the M time points and convert the S optical echo signals at each time point into S electrical echo signals for storage, the S optical echo signals being in one-to-one correspondence with the S second beams, and each optical echo signal being a signal obtained by reflecting a corresponding second beam by the detection surface; the beam conditioning assembly includes a collimation assembly and a beam splitting assembly; a beam splitting assembly configured to split each of the m adjusted first beams into n second beams; a beam adjusting assembly configured to adjust an included angle between any two adjacent first beams among the m first beams to a first angle; and transmit the adjusted m first beams to the beam splitting assembly; the first angle being determined based on a total field of view corresponding to the detection surface and a number m×n of second beams; and the beam splitting assembly configured to split each of the m adjusted first beams into n second beams.

2. 2. The TOF sensor module of claim 1, wherein S is equal to m×n, and wherein the beam adjusting assembly, when adjusting the m received first beams into the S second beams, is configured to adjust transmission directions of the m received first beams and split each of the adjusted m first beams into n second beams to obtain m×n second beams, and project the m×n second beams onto m×n regions on the detection surface, wherein the m×n regions are in one-to-one correspondence with the m×n second beams, and n is an integer greater than 1.

3. the detection assembly includes m×n detection elements, the m×n detection elements being in one-to-one correspondence with the m×n regions; 3. The TOF sensor module of claim 2, wherein when the detection assembly is configured to receive the S optical echo signals from the detection surface at each of the M time points and convert the S optical echo signals into the S electrical echo signals for storage at each time point, each of the m×n detection elements is configured to receive an optical echo signal from a corresponding region at each of the M time points and convert the optical echo signal from the corresponding region into an electrical echo signal for storage at each time point.

4. The TOF sensor module according to claim 1 , wherein the M light source sections are integrally formed.

5. the sensing assembly includes K sensing elements, where K is an integer greater than or equal to S; The TOF sensor module of claim 1 , wherein the detection assembly is configured to power on the S detection elements of the K detection elements at each of the M time points.

6. the TOF sensor module further includes a processing circuit; 2. The TOF sensor module of claim 1, wherein the processing circuitry is configured to acquire M×S electrical echo signals acquired at the M time points from the detection assembly and determine image information based on the M×S electrical echo signals.

7. The TOF sensor module of claim 1 , wherein the detection assembly includes a single photon avalanche diode (SPAD) and a time-to-digital converter (TDC).

8. 8. An electronic device comprising the TOF sensor module of claim 1 and a fixing assembly configured to fix the TOF sensor module.

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