Transmitting modules, TOF devices and electronic equipment

Abstract

This application provides a transmitting module, a Time-of-Flight (TOF) device, and an electronic device. The transmitting module is applied to a TOF device and includes: a light source comprising M sub-light source groups, each sub-light source group including at least one sub-light source; and a light source driving module for sequentially driving each sub-light source group to continuously transmit N light pulse signals at preset intervals within each frame period, wherein the time when the second sub-light source group first transmits a light pulse signal within one frame period is located within the preset time interval between two adjacent light pulse signals transmitted by the first sub-light source group, and the times when the M sub-light source groups transmit N light pulse signals do not overlap, wherein the time when the first sub-light source group begins to transmit a light pulse signal within one frame period is earlier than the time when the second sub-light source group begins to transmit a light pulse signal.

Description

Technical Field

[0001] This application relates to the field of 3D technology, and more specifically, to a launch module, a time-of-flight (TOF) device, and electronic equipment. Background Technology

[0002] Time-of-flight (TOF) devices calculate the distance, or depth, of an object by measuring the time it takes for a light pulse to travel through space. Due to their advantages such as high accuracy and large measurement range, they are widely used in consumer electronics, autonomous driving, AR / VR and other fields.

[0003] The emitter of a Time-of-Flight (TOF) device is typically implemented using a vertical-cavity surface-emitting laser (VCSEL) array light source. Specifically, such as... Figure 1 As shown, the VCSEL dot matrix light source is divided into multiple sub-light source groups. Each sub-light source group repeatedly emits light pulse signals N times in a certain order. The receiver of the TOF device receives the light pulse signals returned from the external object in a certain order, thereby completing the sensing of one frame of image. The period Δt of the light pulse signal emitted by each sub-light source group is determined by the maximum ranging time of the TOF device and the dead time of the sensor at the receiver. Therefore, the frame period T of the TOF device has a lower limit:

[0004] T>M*N*Δt

[0005] Where M represents the number of sub-light source groups in the VCSEL dot matrix light source. When the light pulse signal period Δt is long, the VCSEL dot matrix light source is large, and the number of sub-light source groups is large, the frame rate of the TOF device will be severely limited, resulting in slow sensing speed, dynamic image response errors, and poor visual effects in the feedback image. Therefore, improving the projection efficiency of the transmitter in the TOF device, and thus increasing the frame rate of the TOF device, is an urgent problem to be solved. Summary of the Invention

[0006] This application provides a transmitter module, a Time-of-Flight (TOF) device, and an electronic device that can improve the projection efficiency of the transmitter in the TOF device, thereby increasing the frame rate of the TOF device.

[0007] Firstly, a transmitting module is provided, comprising:

[0008] The light source includes M sub-light source groups, each sub-light source group including at least one sub-light source, the sub-light source being used to emit light pulse signals, wherein M is a positive integer greater than 1;

[0009] The light source driving module is used to drive each sub-light source group to emit N light pulse signals continuously and at preset intervals in a preset order within each frame period, wherein N is a positive integer greater than 1. The N light pulse signals emitted sequentially by the M sub-light source groups within one frame period are used to project onto an external object to determine a one-frame depth image of the external object.

[0010] Specifically, within one frame period, the time when the second sub-light source group first emits a light pulse signal is located within the preset time interval between two adjacent light pulse signals emitted by the first sub-light source group, and the times when any two sub-light source groups emit light pulse signals do not overlap. Specifically, within one frame period, the time when the first sub-light source group first emits a light pulse signal is earlier than the time when the second sub-light source group first emits a light pulse signal.

[0011] In some alternative implementations, within a frame period, the first sub-light source group is the first of the M sub-light source groups to begin emitting light pulse signals.

[0012] In some optional implementations, the time when the other sub-light source groups (excluding the first sub-light source group) emit their first light pulse signal within one frame period is within the preset time interval between the first and second light pulse signals emitted by the first sub-light source group.

[0013] In some alternative implementations, the first sub-light source group and the second sub-light source group are two sub-light source groups with adjacent emission sequences.

[0014] In some alternative implementations, the time when the second sub-light source group first emits a light pulse signal within a frame period is within the preset time interval between the first and second light pulse signals emitted by the first sub-light source group.

[0015] In some alternative implementations, the frame periods do not overlap, or adjacent frame periods partially overlap.

[0016] In some alternative implementations, the interval between the start of light pulse signals of two adjacent sub-light source groups is greater than or equal to the maximum TOF that the TOF device can measure.

[0017] In some optional implementations, the transmitting module further includes:

[0018] A modulation element is used to modulate the light pulse signal emitted by each sub-light source to form a modulation pulse signal, and to project the modulation pulse signal onto an external object.

[0019] In some alternative implementations, the modulation element includes a diffractive optical element, the modulation pulse signal is a light spot array, and the diffractive optical element is used to diffract the light pulse signal emitted by each sub-light source group to form the light spot array.

[0020] Secondly, a TOF device is provided, including...

[0021] The transmitting module as described in any one of the above, and

[0022] A receiving module includes a pixel array, the pixel array including multiple pixel unit groups, each pixel unit group including at least one pixel unit, each pixel unit group corresponding to one of the multiple sub-light source groups of the transmitting module, each pixel unit group being used to receive the light pulse signal returned from the external object after the light pulse signal illuminates the external object when the corresponding sub-light source group emits a light pulse signal.

[0023] In some optional implementations, the receiving module further includes:

[0024] Multiple readout circuit groups, each corresponding to a pixel unit group, wherein each readout circuit group is used to determine the time of flight of the optical pulse signal received by the corresponding pixel unit group and convert the time of flight of the optical pulse signal into a digital signal.

[0025] Thirdly, an electronic device is provided, comprising:

[0026] The TOF device as described in any one of the above statements. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the driving method of the light source in related technologies.

[0028] Figure 2 This is a schematic diagram of a face recognition device according to an embodiment of this application.

[0029] Figure 3 These are examples of several grouping methods for sub-light source groups.

[0030] Figures 4-7 This is an example of a driving method for a light source according to an embodiment of this application.

[0031] Figure 8 This is a schematic diagram of an electronic device according to an embodiment of this application. Detailed Implementation

[0032] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0033] It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, the described features and structures can be combined in any suitable manner in one or more embodiments.

[0034] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0035] In the following description, numerous specific details are provided to provide a full understanding of the embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced even without one or more of the specific details described, or by employing other structures, components, etc. In other instances, well-known structures or operations are not shown or described in detail to avoid obscuring the focus of this application.

[0036] Please see Figure 2 , Figure 2 A schematic structural diagram of a TOF device 10 according to an embodiment of this application is shown. Optionally, the TOF device 10 can be installed on an electronic device. The electronic device includes, but is not limited to, smartphones, tablets, computers, laptops, desktop computers, smart wearable devices, smart door locks, in-vehicle electronic devices, medical devices, aviation devices, and other devices or apparatuses that require 3D information sensing capabilities.

[0037] Optionally, the TOF device 10 may be, for example, a Direct Time of Flight (D-TOF) device. The D-TOF device performs depth information sensing based on the direct time-of-flight detection principle. The D-TOF device obtains the depth information of the external object 20 by directly calculating the time difference between the light pulse signal emitted by the transmitting module 11 and the light pulse signal received by the receiving module 12. Alternatively, the TOF device 10 may also be, for example, an Indirect Time of Flight (I-TOF) device. The I-TOF device performs depth information sensing based on the indirect time-of-flight detection principle. The I-TOF device obtains the depth information of the external object 20 by calculating the phase difference between the light pulse signal emitted by the transmitting module 11 and the light pulse signal received by the receiving module 12.

[0038] In the embodiments described below, the TOF device 10 is described as a D-TOF device, but the present application is not limited thereto.

[0039] Specifically, such as Figure 2 As shown, the TOF device 10 includes a transmitting module 11 and a receiving module 12. The transmitting module 11 is used to transmit an optical signal 201 to the space of the external object 20. At least a portion of the transmitted optical signal 201 returns from the external object 20 to form an optical signal 202. The returned optical signal 202 carries depth information (or depth-of-field information) of the external object 20. At least a portion of the optical signal 202 is received by the receiving module 12.

[0040] Optionally, the TOF device 10 may further include a processing module 13, used to determine the depth information of the external object 20 based on the time difference or phase difference between the optical signal 201 and the optical signal 202, thereby enabling the TOF device 10 to perform depth imaging of the external object.

[0041] Optionally, the processing unit 13 can be a processing module of the TOF device 10, or a processing module of an electronic device including the TOF device 10, such as the main control module of the electronic device. This application embodiment does not limit the scope of the application.

[0042] Optionally, the depth information of the external object 20 in the embodiments of this application can be used for fields such as 3D modeling, face recognition, autonomous driving, simultaneous localization and mapping (SLAM), etc., and this application does not limit it.

[0043] The transmitting module 11 includes a light source 110 and a modulation element 112. The light source 110 is used to emit light pulse signals, and the modulation element 112 is used to modulate the light pulse signals emitted by the light source 110 to form modulated pulse signals. Figure 2 The light signal 201 is generated and projected onto the external object 20. Optionally, the light signal 201 is, for example, a speckle pattern.

[0044] In some embodiments, the receiving module 12 includes an image sensor, the image sensor including a pixel array 120, the pixel array 120 being used to receive light signals 202 returned from the external object 20 to determine depth information of the external object 20.

[0045] Optionally, the receiving module 12 further includes a second lens unit 121, which is used to receive the light signal 202 returned from the external object 20, and to collimate or converge the light signal 202 before transmitting it to the pixel array 120.

[0046] In this embodiment, the light source 110 includes M sub-light source groups, each sub-light source group including at least one sub-light source, where M is a positive integer greater than 1. The M sub-light source groups are used to emit light pulse signals in a phased manner, that is, when one sub-light source group emits a light pulse signal, the other sub-light source groups do not emit light pulse signals.

[0047] It should be understood that the embodiments of this application do not specifically limit the specific position of the sub-light sources in each sub-light source group in the light source 110. For example, each sub-light source group may include one or more rows of sub-light sources, one or more columns of sub-light sources in the light source 110, or the sub-light sources in each sub-light source group may be discretely distributed in the light source 110, etc.

[0048] Figure 3 Here is an example of M sub-light source groups, where light source 110 is a 4x4 sub-light source array and the sub-light sources are divided into 4 groups, each of which is distinguished by a different symbol in the diagram.

[0049] In this embodiment of the application, the pixel array 120 includes a plurality of pixel unit groups, each pixel unit group including at least one pixel unit, each pixel unit group corresponding to one of the M sub-light source groups, and each pixel unit group is used to receive the light pulse signal 202 returned from the external object 20 after the light pulse signal illuminates the external object 20 when the corresponding sub-light source group emits a light pulse signal, so as to obtain a depth image of the external object 20.

[0050] Figure 1The driving method of sub-light source groups in related technologies is illustrated. Each sub-light source group repeatedly emits light pulse signals N times in a certain order. The corresponding pixel unit group in the receiving module receives the light pulse signals returned from the external object 20 in a certain order, thereby completing the sensing of one frame of image. The period Δt of the light pulse signal emitted by each sub-light source group is determined by the maximum ranging time of the TOF device and the dead time of the sensor at the receiving end. Therefore, the frame period T of the TOF device has a lower limit:

[0051] T>M*N*Δt

[0052] When the period Δt of the light pulse signal is long and the number of sub-light source groups is large, the projection efficiency of the light source is very low, which severely limits the frame rate (the reciprocal of the frame period) of the TOF device. This may lead to a series of problems such as slow sensing speed, dynamic image response errors, and poor visual effect of feedback image.

[0053] In view of this, the embodiments of this application provide a driving method for a light source, which can improve the projection efficiency of the light source and thus shorten the time required to obtain an image frame.

[0054] In this embodiment of the application, the transmitting module 11 further includes:

[0055] The light source driving module 111 is used to drive each of the M sub-light source groups to emit light pulse signals continuously and at preset intervals N times in a preset order within each frame period, wherein N is a positive integer greater than 1.

[0056] It should be understood that the embodiments of this application do not specifically limit the order in which the M sub-light source groups emit optical pulse signals. As an example, if the M sub-light source groups are divided by rows, the emission order of the M sub-light source groups can be from top to bottom in the rows; or, if the M sub-light source groups are divided by columns, the emission order of the M sub-light source groups can be from left to right in the columns. Alternatively, the emission order of the M sub-light source groups can be adjusted as needed, and this application is not limited to these methods.

[0057] In this embodiment of the application, within one frame period, each sub-light source group emits N light pulse signals. These N light pulse signals are emitted continuously and periodically (the period is the preset time). The period of the light pulse signal can be called the light pulse period, i.e., Δt.

[0058] It should be noted that, in the embodiments of this application, the optical pulse signal refers to the high-level portion, the duration of the high level is the width of the optical pulse signal, the interval Δt between optical pulse signals refers to the low-level portion between the high levels of two optical pulse signals, and the period Δt of the optical pulse signal includes the duration of both the high and low levels.

[0059] As mentioned earlier, in related technologies, each sub-light source group needs to wait for the flight time of the light pulse signal illuminating the external object and reflecting back, as well as the quiet time after the receiving module receives the light pulse signal, before emitting the next pulse signal. The delay is relatively long, which causes the light pulse period to be a multiple of the width of the light pulse signal, affecting the projection efficiency of the light source.

[0060] Since the light pulse signal emitted by each sub-light source group is received by the corresponding pixel unit group in the specific optical routing receiving module, the transmitter and receiver are in one-to-one correspondence, and the mutual interference is low.

[0061] Based on this, the present application provides a driving method in which the light source driving module 111 can drive the M sub-light source groups to alternately emit light pulse signals. That is, after a sub-light source group emits a light pulse signal, it does not need to wait for the aforementioned Δt before emitting the next light pulse signal, thereby increasing the emission density of the light pulse signal per unit time, reducing the total emission time of the light source 110, and improving the projection efficiency of the light source 110.

[0062] Furthermore, in some embodiments, the emission times of optical pulse signals from any two sub-light source groups among the M sub-light source groups do not overlap. In other words, the optical pulse signals emitted by any two sub-light source groups do not overlap in time.

[0063] In some embodiments of this application, the time when the second sub-light source group first emits a light pulse signal within a frame period is located within the preset time interval between two adjacent light pulse signals emitted by the first sub-light source group, wherein the time when the first sub-light source group first emits a light pulse signal within a frame period is earlier than the time when the second sub-light source group first emits a light pulse signal.

[0064] That is, the sub-light source group that emits light pulse signals later can emit light pulse signals within the interval between two adjacent light pulse signals emitted by the sub-light source group that emits light pulse signals earlier.

[0065] It should be understood that the emission order of the sub-light source groups referred to in the embodiments of this application is based on the time of the first emission of the light pulse signal by the sub-light source group within a frame period.

[0066] In some embodiments, the first sub-light source group is the first of the M sub-light source groups to begin emitting optical pulse signals within a frame period. That is, the emission sequence of the first sub-light source group is 1. The second sub-light source group is any sub-light source group that begins emitting optical pulse signals after the first sub-light source group. For example, the emission sequence of the second sub-light source group can be 2, 3, or M, etc.

[0067] As a specific example, within a frame period, the time when the other sub-light source groups (excluding the first sub-light source group) emit their first light pulse signals is within the preset time interval between the first and second light pulse signals emitted by the first sub-light source group.

[0068] In other words, each sub-light source group that emits a light pulse signal can begin emitting its light pulse signal within the interval between the first and second light pulse signals emitted by the first sub-light source group. This driving method is equivalent to all sub-light source groups sequentially emitting light pulse signals within the first light pulse cycle, which helps to shorten the total emission time of the light source and improve its projection efficiency.

[0069] like Figure 4 As shown, the M sub-light source groups include sub-light source group 1, sub-light source group 2, sub-light source group 3, and sub-light source group 4. The light source driving module 111 can drive the four sub-light source groups to emit light pulse signals sequentially according to the order of the light source group numbers from smallest to largest. For example, after sub-light source group 1 emits the first pulse signal, it sequentially drives sub-light source group 2, sub-light source group 3, and sub-light source group 4 to start emitting light pulse signals.

[0070] In other embodiments, the first sub-light source group and the second sub-light source group are two sub-light source groups with adjacent emission sequences. In this case, within one frame period, the power driving module 111 can drive the second sub-light source group to start emitting light pulse signals within the preset time interval between the first and second light pulse signals emitted by the first sub-light source group.

[0071] In other words, the position of the next light pulse signal emitted by the sub-light source group can be located within the interval between the first and second light pulse signals emitted by the previous light pulse signal emitted by the sub-light source group.

[0072] It should be understood that the above emission order of the sub-light source groups and the insertion position of each sub-light source group between the light pulse signals emitted by other sub-light source groups are merely examples. The embodiments of this application adjust the emission order of the sub-light source groups and the insertion position of each sub-light source group between the light pulse signals emitted by other sub-light source groups according to actual needs, so as to further reduce the mutual interference between sub-light source groups, reduce the local emission power of the light source and the problem of local overheating of components in the light source due to insufficient heat dissipation. This application is not limited to this.

[0073] Figure 5 This illustrates another driving method for the sub-light source group. For example... Figure 5 As shown, the light source driving module 111 can drive the four sub-light source groups 1, 3, 2, and 4 to emit light pulse signals sequentially. Specifically, the time when sub-light source group 3 begins emitting light pulses can be within the interval between the first and second light pulse signals emitted by sub-light source group 1; the time when sub-light source group 2 begins emitting light pulses can be within the interval between the second and third light pulse signals emitted by sub-light source group 1; and the time when sub-light source group 4 begins emitting light pulses can be within the interval between the second and third light pulse signals emitted by sub-light source group 2.

[0074] Optionally, in some embodiments of this application, the frame periods do not overlap in time.

[0075] That is, there is no interleaving between the light pulse signals used to form depth images of different frames.

[0076] This driving method can avoid interference between images from different frames.

[0077] As one implementation, after each of the M sub-light source groups has emitted the N light pulse signals, the light source driving module 111 sequentially drives the M sub-light source groups to start emitting N light pulse signals to form another frame of image.

[0078] For example, such as Figure 5 As shown, after sub-light source group 1, sub-light source group 2, sub-light source group 3 and sub-light source group 4 have all emitted N light pulse signals, N light pulse signals for forming the next frame image are emitted in sequence.

[0079] Alternatively, in some other embodiments of this application, adjacent frame periods partially overlap.

[0080] This means that there is interleaving between the light pulse signals used to form depth images of different frames.

[0081] Optionally, in the embodiments of this application, any two optical pulse signals do not overlap in time, regardless of whether the two optical pulse signals are used to form a depth image frame.

[0082] In one implementation, if there are sub-light source groups that have completed the transmission of N light pulse signals within a frame period, and there are also sub-light source groups that have not completed the transmission of N light pulse signals, then the light source driving module 111 can drive the sub-light source groups that have completed the transmission of N light pulse signals to start transmitting N light pulse signals to form the next frame image.

[0083] For example, such as Figure 6 As shown, after sub-light source group 1 and sub-light source group 3 have emitted N light pulses, sub-light source group 2 and sub-light source group 4 have not yet completed the emission of N light pulse signals. In this case, the light source driving module 111 can drive sub-light source group 1 and sub-light source group 3 to start emitting N light pulse signals in sequence to form the next frame image.

[0084] This driving method can further increase the emission density of the light pulse signal per unit time, thereby improving the projection efficiency of the light source and reducing the time to acquire a single frame image.

[0085] It should be understood that when the second sub-light source group emits a light pulse signal during the interval between two consecutive light pulse signals emitted by the first sub-light source group, the second sub-light source group can start emitting the light pulse signal at any position within that interval, and this application does not limit this.

[0086] like Figure 7 As shown, the second sub-light source group begins emitting light pulse signals during the interval between the first sub-light source group emitting the first light pulse signal and emitting the second light pulse signal. The position at which the second sub-light source group begins emitting light pulse signals has an offset relative to the position at which the first sub-light source group first emits light pulse signals. In some specific implementations, this offset is greater than or equal to the width of the light pulse signal and less than the light pulse period Δt minus the width of the light pulse signal. For example, if the light pulse period is 50 ns and the high-level duration is 800 ps, ​​the offset is greater than or equal to 800 ps and less than or equal to 49.2 ns.

[0087] In some embodiments, the light source driving module 111 can control the interval between the light pulse signals emitted by two adjacent sub-light source groups to be greater than or equal to the maximum TOF that the TOF device 10 can measure, i.e., the offset is greater than the maximum TOF, so as to avoid the problem of excessive instantaneous power on the receiving surface caused by the simultaneous reception of light pulse signals emitted by different sub-light source groups after being emitted back from the external object 20 by the pixel array 120.

[0088] It should be understood that the maximum TOF of the TOF device 10 can be determined according to the application scenario, ranging range, etc., and this application does not limit it.

[0089] Assuming the time offset between the last sub-light source group emitting a light pulse signal and the first sub-light source group emitting a light pulse signal in the M sub-light source groups is X light pulse periods, then the lower limit of the frame period of the light source driving method according to the embodiments of this application is (N+X)*Δt. Therefore, with Figure 1 Compared to the driving method of the light source shown, the driving method of the light source in this embodiment of the application greatly reduces the total emission time of the light source and improves the projection efficiency of the light source.

[0090] It should be understood that the embodiments of this application do not specifically limit the wavelength range and implementation method of the light pulse signal emitted by the light source 110. For example, it can be infrared light, ultraviolet light, visible light, etc. The light source 110 can be, for example, a light-emitting diode (LED), VCSEL, Fabry Perot (FP), laser (LD), distributed feedback (DFB) laser, and electro-absorption modulated laser (EML), etc., and the embodiments of this application do not limit it in this way.

[0091] In some embodiments, the light source may include a single light source or multiple light sources, such as a regular or irregular array of light sources. Taking the light source 110 as a VCSEL-type light source as an example, the light source 110 may include a semiconductor substrate and a VCSEL array chip composed of multiple VCSEL light sources arranged on the semiconductor substrate.

[0092] This application does not limit the implementation of the plurality of sub-light source groups in the light source. Taking the light source 110 as a VCSEL type light source as an example, the light source 110 may include a single VCSEL light source, the VCSEL light source may include multiple light-emitting points, the multiple light-emitting points form the plurality of sub-light source groups, and each sub-light source group includes at least one light-emitting point. Alternatively, the light source 110 includes multiple VCSEL light sources, each VCSEL light source includes one light-emitting point, the multiple VCSEL light sources form the plurality of sub-light source groups, and each sub-light source group includes at least one VCSEL light source.

[0093] In some embodiments, the modulation element 112 can be a diffractive optical element (DOE), which can diffract the incident light pulse signal to form a speckle pattern. In one embodiment, the DOE can split the incident light pulse signal to form multiple light pulse signals, such as tens of thousands, thousands, hundreds, tens, or several light pulse signals, and emit these multiple light pulse signals to the external object 20, with each light pulse signal forming a light spot on the surface of the external object 20. In another embodiment, the DOE can diffract the incident light pulse signal to form a light spot array, i.e., regularly arranged spots. In other embodiments, the DOE can also diffract the incident light pulse signal to form other patterns, such as a speckle pattern, or a light spot array with a certain degree of randomness.

[0094] By replicating the light pulse signal emitted by the light source 110 through the DOE, the light pulse signal emitted to the external object 20 is composed of multiple replicated light pulse signals, which is beneficial to expanding the field of view and the number of light pulse signals of the TOF device 10 and improving the imaging effect.

[0095] In some embodiments, the modulation element 112 may also include a microlens array, which is composed of a plurality of microlens units arranged in a specific order. In one embodiment, the plurality of microlens units are used to receive light pulse signals from the light source 110 and generate an array of light pulse signals corresponding to the arrangement of the microlens units, which are then emitted outwards. In another embodiment, the light source 110 also includes a plurality of sub-light sources corresponding to the arrangement in the microlens array. Each microlens unit receives the light pulse signal from its corresponding sub-light source and collimates or focuses it before emitting an array of light pulse signals outwards. The array of light pulse signals can be randomly arranged or regularly arranged.

[0096] Optionally, in some embodiments, the transmitting module 11 further includes a first lens unit 113, disposed between the light source 110 and the modulation element 112, for collimating or converging the light pulse signal emitted by the sub-light source group and transmitting it to the modulation element 112. Further, the modulation element 112 modulates the light pulse signal into a modulated pulse signal, i.e., the light signal 201, and projects the light signal 201 onto the external object 20. Further, the light signal 202 returned from the external object 20 is received by the pixel array in the receiving module 12.

[0097] It should be understood that the pixel unit in the embodiments of this application may refer to a combination of pixels used to determine a depth information of an external object 20. Optionally, a pixel unit may include one or more pixels, such as an array of pixels composed of multiple pixels, such as adjacent 2*2 pixels.

[0098] Optionally, in the embodiments of this application, the pixel can be a charge-coupled device (CCD), a complementary metal-oxide-semiconductor (CMOS), an avalanche diode (AD), a single-photon avalanche diode (SPAD), or other similar devices. A SPAD can respond to an incident single photon to achieve single-photon detection. Due to its advantages such as high sensitivity and fast response speed, it can achieve long-distance, high-precision measurement. The following description uses a pixel unit implemented using a SPAD as an example, but this application is not limited to this.

[0099] For example, a pixel unit may include a single-photon avalanche photodiode (SPAD), or, for example, the pixel unit may be an array of pixels composed of multiple SPADs.

[0100] In this embodiment, since the light pulse signals emitted by the sub-light source groups are alternated, different pixel unit groups may simultaneously receive light pulse signals at the receiving end. To reduce the impact of modifying the driving method at the transmitting end on the output at the receiving end, the TOF device 10 may further include:

[0101] Multiple readout circuit groups 122, each readout circuit group 122 corresponding to one of the multiple pixel unit groups in the pixel array, each readout circuit group is used to detect the time of flight of the light pulse signal received by the corresponding pixel unit group and convert the time of flight into a digital signal.

[0102] That is, the readout circuits of the pixel units corresponding to different sub-light source groups are independent. In this way, even if light pulse signals arrive at different pixel units at the same time, the readout circuits corresponding to the different pixel units can perform readout operations independently, avoiding the problem that different pixel units cannot be read separately when they receive light signals at the same time when sharing a readout circuit.

[0103] Optionally, each readout circuit group includes one or more readout circuits, each readout circuit corresponding to a pixel unit, and each readout circuit is used to determine the time of flight of the optical pulse signal received by the corresponding pixel unit and convert the time of flight of the optical pulse signal into a digital signal.

[0104] In this embodiment of the application, the digital signal output by each readout circuit is used to determine a depth information of the external object 20, and the digital signals output by all readout circuits are used to determine a frame depth image of the external object 20.

[0105] In some embodiments, each readout circuit includes a time-to-digital converter circuit for determining the time of flight of the light pulse signal received by the corresponding pixel unit and converting the time of flight into a digital signal.

[0106] As an example, the time-to-digital conversion circuit can be implemented using a Time Digital Converter (TDC), or it can be implemented using other equivalent circuits capable of converting time information into digital signals. The following description uses the implementation of the time-to-digital conversion circuit using a TDC as an example, but the embodiments of this application are not limited thereto.

[0107] Specifically, in a D-TOF device implemented using SPAD, a single photon incident on the SPAD will cause an avalanche. The SPAD outputs an avalanche signal to the Time-Controlled Array (TDC), which then detects the time interval between the photon's emission from the transmitting module 11 and the avalanche, i.e., the time of flight. Further, the TDC can convert this time of flight into a digital signal. In this embodiment, the TDC can detect the time of flight of light pulse signals emitted multiple times by the sub-light source group and received by the SPAD, and output a digital signal corresponding to each time of flight. For example, if N is 100,000, and each sub-light source emits 100,000 light pulse signals, if a pixel unit receives 1,000 light pulse signals, the TDC can determine the time of flight of these 1,000 light pulse signals and convert them into corresponding digital signals. Further, the TDC outputs the obtained digital signal to the subsequent processing module 13, which further processes the digital signal to determine the depth information of the external object 20.

[0108] For example, the processing module 13 may include a histogram module, used to perform histogram statistics on the digital signal corresponding to the flight time of the light pulse signal output by the TDC to draw a histogram reflecting the waveform of the light pulse signal. Based on this histogram, the flight time of the light pulse signal can be accurately obtained. Furthermore, the depth information of the external object 20 can be calculated based on the flight time.

[0109] Optionally, the readout circuit may further include circuits such as signal amplifiers, but this application is not limited thereto. Optionally, some or all of the readout circuit may also be integrated into the image sensor.

[0110] like Figure 8As shown in the illustration, this application also provides an electronic device 600, which includes a Time-of-Flight (TOF) device 610. The TOF device 610 can be the TOF device 10 described in the previous embodiments. For specific implementation details, please refer to the relevant descriptions in the foregoing embodiments, which will not be repeated here. The electronic device 600 includes, but is not limited to, devices or apparatuses that require TOF functionality, such as smartphones, tablets, computers, laptops, desktop computers, smart wearable devices, smart door locks, in-vehicle electronic devices, medical devices, and aviation devices.

[0111] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A launch module, comprising: The emission module is applied to a TOF device, and the emission module comprises: a light source comprising M sub-light source groups, each of the sub-light source groups comprising at least one sub-light source, the sub-light source being configured to emit a light pulse signal, wherein M is a positive integer greater than 1; a light source driving module configured to drive each of the sub-light source groups to emit N light pulse signals in a preset order in each frame period, the N being a positive integer greater than 1, and the N light pulse signals emitted by the M sub-light source groups in a frame period being configured to be projected to an external object to determine a frame depth image of the external object; wherein a time at which a second sub-light source group emits a light pulse signal for the first time in a frame period is located in the preset time interval between two adjacent light pulse signals emitted by a first sub-light source group, and a time at which any two of the M sub-light source groups emit a light pulse signal does not overlap, wherein a time at which the first sub-light source group emits a light pulse signal for the first time in a frame period is earlier than a time at which the second sub-light source group emits a light pulse signal for the first time in the frame period; a light source driving mode frame period of the light source driving module is (N+X)*Δt, wherein an offset between a time at which a last sub-light source group of the M sub-light source groups starts to emit a light pulse signal and a time at which a first sub-light source group starts to emit a light pulse signal is X light pulse periods; an interval between times at which two adjacent sub-light source groups start to emit a light pulse signal is greater than or equal to a maximum TOF that can be measured by the TOF device.

2. The launch module of claim 1, wherein, In a frame period, the first sub-light source group is a first sub-light source group that starts to emit a light pulse signal among the M sub-light source groups.

3. The launch module of claim 2, wherein, In a frame period, a time at which each of the M sub-light source groups other than the first sub-light source group emits a light pulse signal for the first time is located in the preset time interval between a time at which the first sub-light source group emits a light pulse signal for the first time and a time at which the first sub-light source group emits a light pulse signal for the second time.

4. The launch module of claim 1, wherein, The first sub-light source group and the second sub-light source group are two adjacent sub-light source groups in an emission order.

5. The launch module of claim 4, wherein, In a frame period, a time at which the second sub-light source group emits a light pulse signal for the first time is located in the preset time interval between a time at which the first sub-light source group emits a light pulse signal for the first time and a time at which the first sub-light source group emits a light pulse signal for the second time.

6. The launch module of any one of claims 1-5, wherein, The frame periods do not overlap with each other, or adjacent frame periods partially overlap.

7. The launch module of any one of claims 1-5, wherein, The emission module further comprises: a modulation element configured to modulate the light pulse signal emitted by each of the sub-light sources to form a modulation pulse signal, and project the modulation pulse signal to an external object.

8. The launch module of claim 7, wherein, The modulation element comprises a diffractive optical element, and the modulation pulse signal is a spot array, and the diffractive optical element is configured to diffract the light pulse signal emitted by each of the sub-light source groups to form the spot array.

9. A TOF device, characterized by The emission module comprises: the emission module according to any one of claims 1 to 8, and the emission module according to any one of claims 1 to 8. The receiving module comprises a pixel array, the pixel array comprises a plurality of pixel cell groups, each pixel cell group comprises at least one pixel cell, each pixel cell group in the plurality of pixel cell groups corresponds to one sub-light source group in the plurality of sub-light source groups of the emitting module, and each pixel cell group is used to receive the light pulse signal returned from an external object after the external object is irradiated by the light pulse signal emitted by the corresponding sub-light source group.

10. The TOF device of claim 9, wherein, The receiving module further comprises: a plurality of readout circuit groups, each readout circuit group corresponds to one pixel cell group, and each readout circuit group is used to determine the time of flight of the light pulse signal received by the corresponding pixel cell group and convert the time of flight of the light pulse signal into a digital signal.

11. An electronic device, comprising: Comprise: The TOF device of claim 9 or 10.

Images