TOF depth measurement device and method

Abstract

The present invention discloses a TOF depth measurement device, including a transmitting module, which is used to project a dot matrix pattern to a target object; wherein the dot matrix pattern includes a real dot matrix formed by a real light spot and a virtual dot matrix formed by a virtual light spot; a collection module, which receives a reflected light signal reflected by the target object; the collection module includes an image sensor composed of a pixel array, wherein a part of the pixels in the pixel array are used to detect a first reflected light signal reflected by a real light spot, and another part of the pixels are used to detect a second reflected light signal directly reflected by a non-real light spot; a control and processor, which are respectively connected to the transmitting module and the collection module, filter the first reflected light signal according to the second reflected light signal to obtain a third reflected light signal, and calculate the phase difference based on the third reflected light signal to obtain a first depth map of the target object. The present invention solves the problem of multi-path interference of reflected light beams while achieving high-resolution depth images.

Description

Technical Field

[0001] The present invention relates to the field of three-dimensional imaging technology, and in particular to a TOF depth measurement device and method. Background Art

[0002] The depth measurement device of the Time of Flight (TOF) solution calculates the distance of the target object by calculating the time difference or phase difference from the light beam being emitted to the target area and reflected back by the target object to obtain the depth data information of the target object. The depth measurement device based on the TOF solution has begun to be used in the fields of three-dimensional measurement, gesture control, robot navigation, security and monitoring.

[0003] Traditional TOF depth measurement devices usually include a light source and a camera. The light source emits a flood beam to the target space to provide illumination, and the camera images the reflected flood beam. The depth measurement device calculates the distance of the object by calculating the time required for the beam to be reflected and received. However, when using traditional TOF depth measurement devices for distance sensing, on the one hand, the interference of ambient light will affect the measurement accuracy. For example, when the ambient light intensity is high or even reaches the flood light that can drown the light source, it will be difficult to distinguish the light beam of the light source, resulting in large measurement errors. On the other hand, traditional TOF depth measurement devices can only measure close objects, and the measurement of distant objects will produce huge errors.

[0004] In order to solve the problem of measuring distance, Chinese patent application No. 202010116700.2 discloses a TOF depth measurement device, in which the transmitting module emits a spot light beam. Since the spatial distribution of the spot light beam is relatively sparse and the energy of each spot is more concentrated, the measurement distance is farther, and the direct illumination intensity is higher than the intensity reflected by the multipath. Therefore, the light signal generated by the multipath can be distinguished, thereby improving the signal-to-noise ratio of the effective signal to reduce multipath interference. However, in this scheme, if the spot light beam is distributed more densely, the multipath interference cannot be eliminated; if the spot light beam is distributed more sparsely, the image resolution is not high.

[0005] The disclosure of the above background technology content is only used to assist in understanding the inventive concept and technical solution of the present invention. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above content has been disclosed on the filing date of this patent application, the above background technology should not be used to evaluate the novelty and creativity of the present application. Summary of the invention

[0006] An object of the present invention is to provide a TOF depth measurement device and method to solve at least one of the above-mentioned background technical problems.

[0007] To achieve the above object, the technical solution of the embodiment of the present invention is implemented as follows:

[0008] A TOF depth measurement device, comprising:

[0009] An emission module, used for projecting a dot matrix pattern onto a target object; wherein the dot matrix pattern includes a real dot matrix formed by a real light spot and a virtual dot matrix formed by a virtual light spot;

[0010] A collection module receives a reflected light signal reflected by a target object; the collection module comprises an image sensor composed of a pixel array, wherein a part of the pixels of the pixel array are used to detect a first reflected light signal reflected by the real light spot, and another part of the pixels are used to detect a second reflected light signal directly reflected by a non-real light spot;

[0011] The control and processor are respectively connected to the transmitting module and the collecting module, and filter the first reflected light signal according to the second reflected light signal to obtain a third reflected light signal, and calculate the phase difference based on the third reflected light signal to obtain a first depth map of the target object.

[0012] In some embodiments, the dot matrix pattern includes a plurality of the real light spots and a plurality of the virtual light spots; wherein the number of the real light spots is greater than the number of the virtual light spots.

[0013] In some embodiments, the control and processor calculates the depth values ​​of the pixels corresponding to the real light spot in the first depth map, and uses the depth values ​​to interpolate the pixels corresponding to the virtual light spot to obtain a second depth map, wherein the resolution of the second depth map is greater than the resolution of the first depth map.

[0014] In some embodiments, the real dot matrix and the virtual dot matrix are regularly arranged.

[0015] In some embodiments, the dot matrix pattern formed by the multiple real light spots around a single light spot of the virtual light spot is a hexagon, a quadrilateral or any other shape; the real dot matrix and the virtual dot matrix are arranged alternately.

[0016] Another technical solution of the embodiment of the present invention is:

[0017] A TOF depth measurement method comprises the following steps:

[0018] The transmitting module projects a dot matrix pattern toward the target object, wherein the dot matrix pattern includes a real dot matrix formed by a real light spot and a virtual dot matrix formed by a virtual light spot;

[0019] The acquisition module receives the reflected light signal reflected by the target object, wherein the acquisition module includes an image sensor composed of a pixel array, a part of the pixels of the pixel array detects the first reflected light signal reflected by the real light spot, and another part of the pixels detects the second reflected light signal directly reflected by the non-real light spot;

[0020] The control and processor filters the first reflected light signal according to the second reflected light signal to obtain a third reflected light signal, and calculates a phase difference based on the third reflected light signal to obtain a first depth map of the target object.

[0021] In some embodiments, the control and processor calculates the depth value of the pixel corresponding to the real light spot in the first depth map, and uses the depth value to interpolate the pixel corresponding to the virtual light spot to obtain a second depth map, and the resolution of the second depth map is greater than the resolution of the first depth map.

[0022] In some embodiments, the control and processor sets a detection threshold of depth value, searches for pixels below the detection threshold around pixels above the detection threshold, and interpolates the pixels below the detection threshold to obtain the second depth map.

[0023] In some embodiments, the dot matrix pattern includes a plurality of the real light spots and a plurality of the virtual light spots; wherein the number of the real light spots is greater than the number of the virtual light spots.

[0024] In some embodiments, the dot matrix pattern formed by the multiple real light spots around a single light spot of the virtual light spot is a hexagon, a quadrilateral or any other shape; the real dot matrix and the virtual dot matrix are arranged alternately.

[0025] The beneficial effects of the technical solution of the present invention are:

[0026] Compared with the prior art, the TOF depth measurement device of the present application can solve the problem of multi-path interference of reflected light beams while achieving high-resolution depth images. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0028] Figure 1 Schematic diagram of the structure of a TOF depth measurement device according to an embodiment of the present invention.

[0029] Figure 2 is a schematic illustration of multipath reflections of a transmitted light beam.

[0030] Figure 3a-3d Schematic diagram of a dot matrix pattern projected by an emission module of a TOF depth measurement device according to an embodiment of the present invention.

[0031] Figure 4 Schematic diagram of an image sensor pixel array of a TOF depth measurement device according to an embodiment of the present invention.

[0032] Figure 5 yes Figure 1 A graphical representation of the intensity of reflected light generated in an embodiment.

[0033] Figure 6 yes Figure 1 Illustration of the calculation for filtering out stray light signals in an embodiment.

[0034] Figure 7 FIG. 4 is a flow chart illustrating a TOF depth measurement method according to another embodiment of the present invention.

[0035] Figure 8 Is adopted Figure 1 Illustration of the electronics of an embodiment TOF depth measurement device. DETAILED DESCRIPTION

[0036] In order to make the technical problems, technical solutions and beneficial effects to be solved by the embodiments of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0037] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it can be directly on the other component or indirectly on the other component. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. In addition, connection can be used for fixing or for circuit connection.

[0038] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0039] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0040] Reference Figure 1 As shown, as an embodiment of the present invention, a TOF depth measurement device is provided. Figure 1 The TOF depth measurement device 10 is a schematic diagram of the structure of an embodiment of the present invention. The TOF depth measurement device 10 includes a transmitting module 11, a collection module 12, and a control and processor 13 connected to the transmitting module 11 and the collection module 12 respectively. Among them, the transmitting module 11 is used to project a dot matrix pattern to the target object 20, and the dot matrix pattern includes a real dot matrix formed by a real light spot and a virtual dot matrix formed by an area without light spot illumination; the collection module 12 receives a reflected light signal reflected back by the target object 20; the collection module 12 includes an image sensor 121 composed of a pixel array, wherein a part of the pixels of the pixel array are used to detect a first reflected light signal reflected back by the real light spot from the target object 20, and another part of the pixels are used to detect a second reflected light signal directly reflected back by a non-real light spot; the control and processor 13 filters the first reflected light signal according to the second reflected light signal to obtain a third light signal, and calculates the phase difference based on the third reflected light signal to obtain a first depth map of the target object 20.

[0041] The emission module 11 includes a light source and a light source driver (not shown in the figure), etc. The light source may be a light source such as a light emitting diode (LED), an edge emitting laser (EEL), a vertical cavity surface emitting laser (VCSEL), etc., or a light source array composed of multiple light sources. The light beam emitted by the light source may be visible light, infrared light, ultraviolet light, etc., which is not particularly limited in the embodiment of the present invention.

[0042] In one embodiment, the emission module 11 further includes a diffractive optical element (DOE) for replicating the dot pattern emitted by the light source. It is understandable that, assuming that the dot pattern emitted by the light source is a periodically arranged pattern, adjacent dot patterns are adjacent to each other after being replicated by the diffractive optical element DOE, that is, the final pattern does not have obvious gaps or overlaps.

[0043] The acquisition module 12 includes a TOF image sensor 121, a lens unit, and may also include a filter (not shown in the figure); wherein the lens unit receives and images at least part of the light beam reflected back by the target object 20 on at least part of the TOF image sensor; the filter is a narrow-band filter that matches the wavelength of the light source to suppress background light noise in the remaining bands. The TOF image sensor can be an image sensor composed of a charge coupled device (CCD), a complementary metal oxide semiconductor (CMOS), an avalanche diode (AD), a single photon avalanche diode (SPAD), etc. The size of the sensor array represents the resolution of the depth camera, such as 320x240, etc. Generally, a readout circuit (not shown in the figure) composed of one or more devices such as a signal amplifier, a time-to-digital converter (TDC), and an analog-to-digital converter (ADC) is also connected to the image sensor 121.

[0044] In some embodiments, the TOF image sensor includes at least one pixel, each pixel includes two or more taps for storing and reading or discharging charge signals generated by incident photons under the control of corresponding electrodes. For example, the TOF image sensor includes two taps, and the taps are switched in sequence in a certain order within a single frame period (or a single exposure time) to collect corresponding photons, so as to receive light signals and convert them into electrical signals.

[0045] The control and processor 13 can be an independent dedicated circuit, such as a dedicated SOC chip, FPGA chip, ASIC chip, etc. composed of a CPU, memory, bus, etc., or it can include a general processing circuit. For example, when the TOF depth measurement device is integrated into a smart terminal such as a mobile phone, a television, a computer, etc., the processing circuit in the smart terminal can serve as at least a part of the control and processor 13.

[0046] The control and processor 13 is used to provide an emission instruction signal required for the light source to emit laser light, and the light source emits a light beam to the target object 20 under the control of the emission instruction signal.

[0047] In some embodiments, the control and processor 13 also provides a demodulation signal (collection signal) of each tap in each pixel of the TOF image sensor, and the tap collects the electrical signal generated by the reflected light beam reflected back from the target object 20 under the control of the demodulation signal. It can be understood that the electrical signal is related to the intensity of the reflected light beam, and the control and processor 13 processes the electrical signal and calculates the phase difference to obtain the distance of the target object 20.

[0048] Reference Figure 2, the "multi-path" situation is explained below. Usually, in order to cover all pixel areas, the TOF depth measurement device generally uses a floodlight as a light source. However, the floodlight beam is dense, and the light flux received by the pixel is usually not only generated by direct reflection from the target object, but also includes stray light reflected multiple times. Specifically, the emission module 11 emits a light beam 201, which is scattered after irradiating the target object 50 and can be reflected back to the acquisition module 12 through multiple paths.

[0049] exist Figure 2 In the example, it is assumed that the target object 50 is a corner of a wall, and the emission light beam 201 irradiates the target object 50. The collection module 12 detects at least a portion of the first reflected light 202 that is directly reflected by the light beam 201 from the target object 20; if the emission light beam 201 scatters toward other areas of the target object 50 after irradiating the target object 50, the collection module 12 will detect the second reflected light 203 that has a longer flight path than the first reflected light 202. Similarly, the emission light beam 201 may be scattered more than once, and finally the collection module 12 may detect the third reflected light 204 that has a longer flight path than the second reflected light 203, or even reflected light from other paths, which will result in a "multi-path" situation. Since the flight time of the direct reflected light and the indirect reflected light is different, the interference of the multi-path will cause the depth value obtained by the corresponding pixel to deviate.

[0050] Reference Figure 3a-3d As shown, in some embodiments of the present invention, the dot pattern projected by the emission module is as follows Figure 3a-3d The dot pattern 30 includes a real dot matrix formed by real light spots and a virtual dot matrix formed by the area without light spots. For the convenience of explanation, the area without light spots is represented by virtual light spots in the following, that is, the real light spots form a real dot matrix, and the virtual light spots form a virtual dot matrix. It can be understood that the virtual light spots mentioned in this embodiment are an abstract expression for the purpose of more simply and clearly explaining the arrangement rules of the real light spots, and cannot be simply understood literally as virtual light spots.

[0051] like Figure 3a and Figure 3b As shown, the dot pattern 30 can be a hexagon, as shown by the dotted line in the figure; of course, it can also be a quadrilateral, as shown by the dotted line in the figure. Figure 3d shown. Figure 3a In the dot matrix pattern 30, a virtual light spot 302 is arranged between every two real light spots 301 in an even-numbered row, and a virtual dot matrix pattern composed of a plurality of virtual light spots 302 is arranged crosswise; Figure 3b In the dot matrix pattern 30 shown, a virtual light spot 302 is also set between every two real light spots 301 in the even-numbered rows, and the dot matrix pattern composed of multiple virtual light spots 302 is arranged in a plurality of squares; Figure 3cThe dot pattern 30 shown has a virtual light spot 302 arranged between two real light spots 301 and two real light spots 301 in even-numbered rows, and as shown by the dotted line in the figure, the dot pattern composed of a plurality of virtual light spots 302 is arranged in a plurality of rectangles; Figure 3d The dot pattern 30 shown is a quadrilateral, wherein a virtual light spot 302 is arranged between every two real light spots 301 in even-numbered rows, and the dot pattern composed of multiple virtual light spots 302 is arranged in multiple squares. It can be understood that the positions of the virtual light spots and the real light spots shown in the figure are only for the convenience of illustrating that the dot pattern composed of the virtual light spots and the real light spots has diversity, and is not limited thereto. The virtual light spots can also be in odd-numbered rows or even-numbered rows and other positions, and the light spots are not necessarily circular, but can also be elliptical or square or other shapes.

[0052] Figure 3a-3d It is shown that the dot pattern formed by multiple real light spots 301 around a single virtual light spot 302 can be a hexagon, a quadrilateral or any other shape, the real dot pattern and the virtual dot pattern are arranged alternately, and the number of real light spots 301 is greater than the number of virtual light spots 302, so that the dot pattern can be projected by the emission module 11 to reduce the multipath effect while improving the image resolution. It can be understood that the real dot pattern and the virtual dot pattern can be arranged regularly or irregularly. Preferably, a regular arrangement is adopted to make the depth value distribution more regular.

[0053] Next, the launch module is used to project the target object. Figure 3d Taking the dot matrix pattern shown as an example, the image sensor 121 detects the first reflected light signal reflected by the real light spot 301 through the target object 20 and detects the second reflected light signal directly reflected by the non-real light spot 302, and the control and processor filters the first reflected light signal based on the second reflected light signal. It can be understood that the second reflected light signal is a stray light signal, and the first reflected light signal includes the light signal directly reflected by the real light spot and the stray light signal. The stray light signal in the first reflected light signal is filtered out based on the second reflected light signal, so as to obtain the light signal directly reflected by the real light spot (i.e., the third reflected light signal mentioned above) to improve the signal-to-noise ratio of the image.

[0054] like Figure 3d As shown, the transmitting module 11 projects a dot pattern 30 toward the target object 20, and the dot pattern 30 includes a plurality of real light spots 301 (indicated by solid lines in the figure) and a plurality of virtual light spots 302 (indicated by dotted lines in the figure); a part of the pixels of the pixel array of the image sensor 121 collects the first reflected light signals reflected back by the plurality of real light spots 301 from the target object 20, and another part of the pixels collects the second reflected light signals directly reflected back by the non-target object 20, as shown in FIG. Figure 4As shown. For the convenience of explanation, it is assumed that each real light spot 301 and each virtual light spot 302 occupy approximately 2x2=4 pixels. In fact, the real light spot 301 and the virtual light spot 302 can be of other sizes. It can be understood that if the real light spots are distributed more densely, the pixels occupied by the virtual light spots are smaller, so the calculated depth map resolution is higher. It should be noted that the pixels occupied by the virtual light spots refer to the dot matrix pattern that is denser than the real light spots, and do not refer to the comparison of the pixels occupied by the virtual light spots with the pixels occupied by the real light spots, that is, it is a comparison in general, not a comparison of a single light spot.

[0055] Specifically, the photons received by the pixels corresponding to the real light spot 301 include the light signal directly reflected by the real light spot 301 and the stray light signal caused by multipath or background light; the photons received by the pixels corresponding to the virtual light spot 302 only include the stray light signal. Since the energy of the light signal directly reflected by the real light spot is greater than the energy of the stray light, the light signal intensity of the pixels occupied by the real light spot 301 is significantly higher than the light signal intensity of the pixels occupied by the virtual light spot 302. Therefore, the control and processor 13 can filter out the stray light signal received by the pixels occupied by the real light spot 301 based on the stray light signal intensity of the pixels occupied by the virtual light spot 302.

[0056] like Figure 5 As shown, for example, a detection threshold can be set to find the pixels occupied by the virtual light spot 302, wherein the acquisition module 12 detects the peak intensity 503 at each real light spot 301 and the stray light signal intensity 501 of the pixels occupied by the virtual light spot 302. The control and processor 13 can find the pixels occupied by the virtual light spot by setting the detection threshold 502. It can be understood that the peak intensity 503 (i.e., the aforementioned first reflected light signal) is the sum of the light signal intensity directly reflected by the real light spot and the stray light signal intensity 501, and the stray light signal intensity 501 is the aforementioned second reflected light signal. Therefore, based on the stray light signal intensity 501, the stray light signal contained in the peak intensity 503 is filtered out, thereby obtaining the light signal directly reflected by the real light spot.

[0057] like Figure 6 As shown, assuming that the first light signal reflected back by the real light spot occupies pixel 601, and the stray light signal occupies pixel 602, the first light signal occupied by the pixel 601 is filtered out according to the average value of the stray light signal pixels to obtain the pixel value 603 of the light signal directly reflected by the real light spot, which can improve the signal-to-noise ratio of the image.

[0058] In one embodiment, the control and processor 13 can calculate the phase difference based on the light signal directly reflected by the real light spot to obtain the first depth map, calculate the depth value of the pixel corresponding to the real light spot in the first depth map, and interpolate the pixel corresponding to the virtual light spot using the depth value of the real light spot to obtain a second depth map with higher resolution. It is understandable that the control and processor 13 can be based on the following method: Figure 5 The method shown sets a detection threshold of the depth value, and pixels above the detection threshold are valid pixels, that is, pixels corresponding to the real light spot, and then pixels below the detection threshold are searched around the pixel to interpolate the pixels below the detection threshold.

[0059] Reference Figure 7 As shown, another embodiment of the present invention further provides a TOF depth measurement method, Figure 7 The TOF depth measurement method of this embodiment is shown in the flowchart. The method includes the following steps:

[0060] S701, the transmitting module projects a dot matrix pattern to the target object, wherein the dot matrix pattern includes a real dot matrix formed by a real light spot and a virtual dot matrix formed by an area without light spot illumination;

[0061] Specifically, the transmitting module projects a dot pattern toward the target object, in which the number of real dots is greater than the number of virtual dots; wherein the real dot pattern and the virtual dot pattern are regularly arranged, and the real dot pattern and the virtual dot pattern are cross-arranged, and the dot pattern formed by multiple real light spots around a single light spot of the virtual dot pattern can be a quadrilateral or a hexagon.

[0062] S702, the acquisition module receives the reflected light signal reflected by the target object, wherein the acquisition module includes an image sensor composed of a pixel array, a part of the pixels of the pixel array detects the first reflected light signal reflected by the real light spot, and another part of the pixels detects the second reflected light signal directly reflected by the non-real light spot;

[0063] In some embodiments, a portion of pixels in the pixel array detects at least a portion of reflected light signals including the real light spot directly reflected back by the target object, while another portion of pixels detects a light beam reflected by background light or scattered by the real light spot.

[0064] S703: The control and processor filters the first reflected light signal according to the second reflected light signal to obtain a third reflected light signal, and calculates a phase difference based on the third reflected light signal to obtain a first depth map of the target object.

[0065] Specifically, the control and processor can calculate the phase difference based on the light signal directly reflected by the real light spot to obtain the first depth map, calculate the depth value on the pixel corresponding to the real light spot in the first depth map, and interpolate the pixel corresponding to the virtual light spot based on the depth value of the real light spot to obtain a second depth map with higher resolution. It can be understood that the control and processor 13 can set a threshold value of the depth value, and the pixels above the threshold are valid pixels, that is, the pixels corresponding to the real light spot, and then search for pixels below the threshold around the pixel to interpolate the pixels below the threshold.

[0066] As another embodiment of the present invention, an electronic device is also provided, which may be a desktop, desktop-mounted device, a portable device, a wearable device or a vehicle-mounted device, a robot, etc. Specifically, the device may be a laptop computer or an electronic device to allow gesture recognition or biometrics. In other examples, the device may be a head-mounted device for identifying objects or dangers in the user's surroundings to ensure safety. For example, a virtual reality system that obstructs the user's vision of the environment may detect objects or dangers in the surroundings to provide the user with warnings about nearby objects or obstacles. In other examples, it may be a mixed reality system that mixes virtual information and images with the user's surroundings, and may detect objects or people in the user's environment to integrate virtual information with the physical environment and objects. In other examples, it may also be a device used in fields such as unmanned driving. Reference Figure 8 As shown, taking a mobile phone as an example, the electronic device 800 includes a shell 81, a screen 82, and the TOF depth measurement device described in the above embodiment; wherein the transmitting module 11 and the collecting module 12 of the TOF depth measurement device are arranged on the same surface of the electronic device 800, and are used to transmit a floodlight beam to the target object and receive the floodlight beam reflected back by the target object and form an electrical signal.

[0067] An embodiment of the present application also provides a storage medium for storing a computer program, which at least performs the method described above when executed.

[0068] The storage medium may be implemented by any type of volatile or non-volatile storage device, or a combination thereof. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a magnetic random access memory (FRAM), a flash memory, a magnetic surface memory, an optical disc, or a compact disc read-only memory (CD-ROM); the magnetic surface memory may be a disk memory or a tape memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory (SRAM), synchronous static random access memory (SSRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), direct memory bus random access memory (DRRAM). The storage media described in the embodiments of the present invention are intended to include, but are not limited to, these and any other suitable types of memory.

[0069] It is to be understood that the above content is a further detailed description of the present invention in conjunction with specific / preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, without departing from the concept of the present invention, it can also make several substitutions or modifications to these described embodiments, and these substitutions or modifications should be deemed to belong to the protection scope of the present invention. In the description of this specification, the description of reference terms "an embodiment", "some embodiments", "preferred embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention.

[0070] In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples without contradicting each other. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions and modifications can be made herein without departing from the scope defined by the appended claims.

[0071] Furthermore, the scope of the present invention is not intended to be limited to the particular embodiments of the processes, machines, manufactures, compositions of matter, means, methods, and steps described in the specification. One of ordinary skill in the art will readily appreciate that the above disclosures, processes, machines, manufactures, compositions of matter, means, methods, or steps, currently existing or to be developed, may be utilized to perform substantially the same functions as the corresponding embodiments described herein or to obtain substantially the same results as the embodiments described herein. Therefore, the appended claims are intended to include within their scope such processes, machines, manufactures, compositions of matter, means, methods, or steps.

Claims

1. A TOF depth measurement device, characterized in that: include: An emission module, used for projecting a dot matrix pattern onto a target object; wherein the dot matrix pattern includes a real dot matrix formed by a real light spot and a virtual dot matrix formed by a virtual light spot; A collection module receives a reflected light signal reflected by a target object; the collection module comprises an image sensor composed of a pixel array, wherein a part of the pixels of the pixel array are used to detect a first reflected light signal reflected by the real light spot, and another part of the pixels are used to detect a second reflected light signal directly reflected by a non-real light spot; the photons received by the pixels corresponding to the real light spot include the light signal directly reflected by the real light spot and the stray light signal caused by multipath; the photons received by the pixels not corresponding to the real light spot only include the stray light signal; The control and processor are respectively connected to the transmitting module and the collecting module, filter the first reflected light signal according to the second reflected light signal to obtain a third reflected light signal, and calculate the phase difference based on the third reflected light signal to obtain a first depth map of the target object.

2. The TOF depth measurement device according to claim 1, characterized in that: The dot matrix pattern includes a plurality of the real light spots and a plurality of the virtual light spots; wherein the number of the real light spots is greater than the number of the virtual light spots.

3. The TOF depth measurement device according to claim 1, characterized in that: The control and processor calculates the depth value of the pixel corresponding to the real light spot in the first depth map, and interpolates the pixel corresponding to the virtual light spot using the depth value to obtain a second depth map, wherein the resolution of the second depth map is greater than the resolution of the first depth map.

4. The TOF depth measurement device according to claim 1, characterized in that: The real dot matrix and the virtual dot matrix are arranged regularly.

5. The TOF depth measurement device according to claim 1, characterized in that: The dot matrix pattern formed by the multiple real light spots around a single light spot of the virtual light spot is a hexagon, a quadrilateral or any other shape; the real dot matrix and the virtual dot matrix are arranged alternately.

6. A TOF depth measurement method, characterized in that: The steps include: The transmitting module projects a dot matrix pattern toward the target object, wherein the dot matrix pattern includes a real dot matrix formed by a real light spot and a virtual dot matrix formed by a virtual light spot; The acquisition module receives the reflected light signal reflected by the target object, wherein the acquisition module includes an image sensor composed of a pixel array, a part of the pixels in the pixel array detects the first reflected light signal reflected by the real light spot, and another part of the pixels detects the second reflected light signal directly reflected by the non-real light spot; the photons received by the pixels corresponding to the real light spot include the light signal directly reflected by the real light spot and the stray light signal caused by multipath; the photons received by the pixels not corresponding to the real light spot only include the stray light signal; The control and processor filters the first reflected light signal according to the second reflected light signal to obtain a third reflected light signal, and calculates a phase difference based on the third reflected light signal to obtain a first depth map of the target object.

7. The TOF depth measurement method according to claim 6, wherein: The control and processor calculates the depth value of the pixel corresponding to the real light spot in the first depth map, and interpolates the pixel corresponding to the virtual light spot using the depth value to obtain a second depth map, wherein the resolution of the second depth map is greater than the resolution of the first depth map.

8. The TOF depth measurement method according to claim 7, wherein: The control and processor sets a detection threshold of the depth value, searches for pixels below the detection threshold around pixels above the detection threshold, and interpolates the pixels below the detection threshold to obtain the second depth map.

9. The TOF depth measurement method according to claim 6, wherein: The dot matrix pattern includes a plurality of the real light spots and a plurality of the virtual light spots; wherein the number of the real light spots is greater than the number of the virtual light spots.

10. The TOF depth measurement method according to claim 6, characterized in that: The dot matrix pattern formed by the multiple real light spots around a single light spot of the virtual light spot is a hexagon, a quadrilateral or any other shape; the real dot matrix and the virtual dot matrix are arranged alternately.

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