Receiver of laser radar and laser radar

Abstract

The invention provides a receiver of a laser radar and the laser radar. The receiver of the laser radar comprises an SPAD chip and a circuit chip. The SPAD chip comprises a pixel array. The pixel array extends in a first direction and a second direction. The pixel array comprises a plurality of pixels arranged along a first direction. The circuit chip comprises a plurality of integrating circuits and sampling circuits. The plurality of integration circuits are connected to the plurality of pixels and are configured to integrate electrical signals output by the plurality of pixels. The sampling circuit is connected with one of the plurality of integrating circuits and is configured to sample the integral of the integrating circuit and determine a pixel integral value. The plurality of integration circuits start integration based on an integration trigger signal. And if the pixel integral value exceeds the preset threshold value, the plurality of integral circuits stop integrating.

Description

Technical Field

[0001] This disclosure relates to the field of photoelectric detection technology, and more specifically, to a receiver and a lidar. Background Technology

[0002] In recent years, photoelectric detection sensors have been widely used. A single-photon avalanche photodiode (SPAD) is a photodetector operating in Geiger mode. SPADs can detect extremely weak light signals and have advantages such as small size, low power consumption, insensitivity to magnetic fields, and ease of integration. SPADs have wide applications in medical diagnostics, Time-of-Flight (TOF) imaging, and optical communication.

[0003] When SPADs are used for imaging, the dynamic power consumption of the circuit increases as the avalanche frequency surges under strong light. Compared to low-power imaging devices with complementary metal-oxide-semiconductor (CMOS) structures, SPADs exhibit higher dynamic power consumption when used for imaging.

[0004] The content of the background section is merely the technology known to the inventors of this disclosure and does not necessarily represent the prior art in this field. Summary of the Invention

[0005] In view of this, the present disclosure provides a receiver for a lidar and a lidar that can reduce the power consumption of a SPAD when used for imaging.

[0006] This disclosure provides a receiver for a lidar system, comprising:

[0007] A SPAD chip, comprising a pixel array extending along a first direction and a second direction, the pixel array including a plurality of pixels arranged along the first direction, and... Circuit chips, including: Multiple integrating circuits, connected to the multiple pixels, are configured to integrate the electrical signals output by the multiple pixels. A sampling circuit, connected to one of the plurality of integrating circuits, is configured to sample the integral of the integrating circuit to determine the pixel integral value. The multiple integration circuits start integration based on an integration trigger signal. If the pixel integration value exceeds a preset threshold, the multiple integration circuits stop integration.

[0008] Optionally, the preset threshold includes a first threshold and a second threshold. The sampling circuit performs integration sampling on the integrator based on the first sampling signal to determine the first pixel integration value. If the first pixel integration value exceeds the first threshold, the plurality of integrators stop integrating. The sampling circuit performs integration sampling on the integrator based on the second sampling signal to determine the second pixel integration value. If the second pixel integration value exceeds the second threshold, the plurality of integrators stop integrating. The second sampling signal is later than the first sampling signal.

[0009] Optionally, the preset threshold may further include a third threshold. The sampling circuit performs integration sampling on the integration circuit based on the third sampling signal to determine the third pixel integration value. If the third pixel integration value exceeds the third threshold, the plurality of integration circuits stop integrating. The third sampling signal is later than the second sampling signal.

[0010] Optionally, the receiver also includes: A time counter configured to output one or more of the first sampled signal, the second sampled signal, and the third sampled signal.

[0011] Optionally, the plurality of pixels includes a first pixel, a second pixel, and a third pixel. The first pixel includes a first filter and a first SPAD, the second pixel includes a second filter and a second SPAD, and the third pixel includes a third filter and a third SPAD. The passband wavelengths of the first filter, the second filter, and the third filter are different.

[0012] Optionally, the pixel array includes a plurality of first pixels, a plurality of second pixels, and a plurality of third pixels, wherein the plurality of first pixels extend along the second direction, the plurality of second pixels extend along the second direction, and the plurality of third pixels extend along the second direction.

[0013] Optionally, the circuit chip further includes a power supply circuit and a gating circuit. The gating circuit is configured to connect the power supply circuit and the plurality of pixels based on a power-on signal, so that the power supply circuit supplies power to the plurality of pixels. The gating circuit is also configured to disconnect the power supply circuit and the plurality of pixels based on a power-off signal.

[0014] Optionally, the receiver also includes: The comparison circuit is configured to output an integration stop signal when the pixel integration value exceeds the preset threshold, and the plurality of integration circuits stop integration based on the integration stop signal. The power-down signal is generated based on the integration termination signal.

[0015] Optionally, the circuit chip is configured to receive a control signal, generate the integration trigger signal and the power-on signal based on the rising edge of the control signal, and the circuit chip is further configured to generate the power-off signal based on the falling edge of the control signal when the pixel integration value does not exceed the preset threshold.

[0016] This disclosure provides a lidar, including: The transmitter is configured to emit a probe beam. The receiver described in any of the above possible embodiments is configured to receive the echo of the probe light reflected by the object, and The controller, connected to the receiver, is configured to generate an image based on the pixel integral value.

[0017] Optionally, the lidar further includes: A scanning mirror is configured to receive the echo and guide the echo to the receiver, and to deflect the probe light emitted by the transmitter, thereby achieving scanning of the third-directional field of view of the lidar.

[0018] The lidar receiver and lidar provided in this disclosure embodiment sample the integral of the integral circuit of one pixel among a plurality of pixels arranged along a first direction using a sampling circuit. When the integral value exceeds a preset threshold, the multiple integral circuits stop integrating. An integral value determined by the sampling circuit that is greater than the preset threshold reflects strong ambient light. In this case, the multiple integral circuits stop operating, reducing the receiver's power consumption under strong light. Furthermore, multiple pixels aligned along the first direction are connected to multiple integral circuits. This disclosure embodiment uses a single sampling circuit to sample one of the multiple integral circuits, reducing circuit complexity and cost.

[0019] It should be understood that the above general description and the following detailed description are merely exemplary and explanatory, and are not intended to limit the technical solutions of this disclosure.

[0020] To make the above-mentioned objects, features and advantages of this disclosure more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments will be briefly described below. These drawings are incorporated in and constitute a part of this specification. They illustrate embodiments conforming to this disclosure and, together with the specification, serve to explain the technical solutions of this disclosure. It should be understood that the following drawings only show some embodiments of this disclosure and should not be considered as limiting the scope. Those skilled in the art can obtain other related drawings based on these drawings without creative effort.

[0022] Figure 1 A schematic diagram of a lidar consistent with some embodiments of this disclosure is shown.

[0023] Figure 2 A schematic diagram of an exemplary receiver consistent with some embodiments of this disclosure is shown.

[0024] Figure 3 A schematic diagram of an exemplary pixel array consistent with some embodiments of this disclosure is shown.

[0025] Figure 4a A schematic diagram of an exemplary pixel array consistent with other embodiments of this disclosure is shown.

[0026] Figure 4b A schematic diagram of an exemplary pixel array consistent with some other embodiments of the present disclosure is shown.

[0027] Figure 5 A schematic diagram of an exemplary lidar consistent with other embodiments of this disclosure is shown.

[0028] Figure 6 A schematic block diagram of an exemplary circuit chip consistent with some embodiments of this disclosure is shown.

[0029] Figure 7 A schematic block diagram of an exemplary circuit chip consistent with other embodiments of this disclosure is shown.

[0030] Figure 8 A schematic block diagram of an exemplary circuit chip consistent with some other embodiments of this disclosure is shown.

[0031] Figure 9a A schematic diagram of an exemplary first signal relationship consistent with some embodiments of this disclosure is shown.

[0032] Figure 9b A schematic diagram of an exemplary second signal relationship consistent with some embodiments of this disclosure is shown.

[0033] Figure 9cA schematic diagram of an exemplary third signal relationship consistent with some embodiments of this disclosure is shown.

[0034] Figure 9d A schematic diagram of an exemplary fourth signal relationship consistent with some embodiments of this disclosure is shown. Detailed Implementation

[0035] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the specific implementation methods of this disclosure will be described below with reference to the accompanying drawings. The accompanying drawings described below are merely some embodiments of this disclosure. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without creative effort. Adjustments and improvements made without departing from the concept of this disclosure are all within the protection scope of this disclosure.

[0036] To keep the drawings simple, each figure only schematically shows the parts related to the corresponding embodiment, and they do not represent the actual structure of the product. In addition, for the sake of simplicity and ease of understanding, some figures only schematically show parts of components with the same structure or function, and there may actually be more or fewer components with the same structure or function.

[0037] Unless otherwise defined, the technical or scientific terms used in the claims and description shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar words used in this patent application description and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. The terms “an” or “a” and similar words do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising” or “including” and similar words mean that the element or object preceding “comprising” or “including” encompasses the element or object listed following “comprising” or “including” and its equivalents, and do not exclude other elements or objects. The terms “connected,” “coupled,” or “linked” and similar words are not limited to physical or mechanical connections, nor are they limited to direct or indirect connections.

[0038] Unless otherwise specified, all embodiments mentioned herein can be combined to form new technical solutions. Furthermore, unless otherwise specified, all technical features and preferred features mentioned herein can be combined to form new technical solutions.

[0039] In this disclosure, the terms "or" and "and / or" describe the relationship between related objects and indicate a non-exclusive inclusion. For example, "A and / or B" and "A or B" can include: the presence of only "A", the presence of only "B", and the presence of both "A" and "B", where "A" and "B" can be singular or plural. As another example, "A, B, and / or C" and "A, B, or C" can include: the presence of only "A", the presence of only "B", the presence of only "C", the presence of both "A" and "B", the presence of both "A" and "C", the presence of both "B" and "C", and the presence of both "A", "B", and "C", where "A", "B", and "C" can be singular or plural. Furthermore, the symbol " / " in this disclosure indicates an "or" relationship between the related objects before and after the symbol. In this disclosure, the term "at least one A or B" has the same meaning as "A or B" described above. The term "at least one A, B, or C" has the same meaning as "A, B, or C" above. "One or more" of multiple objects refers to any one or any combination of multiple objects, such as "one or more of A, B, and C" including: "A alone", "B alone", "C alone", "A and B", "A and C", "B and C", or "A, B, and C".

[0040] Laser detection is a remote sensing technology. LiDAR (LiDAR System) uses lasers to measure distances and create three-dimensional (3D) images of objects and landscapes. During object detection, the LiDAR emits a laser beam. This laser beam is reflected off the object's surface. The reflected light (also called the echo) is received by the LiDAR and converted into an electrical signal. The LiDAR processes this electrical signal to determine information about the object, such as its distance, position, or velocity. LiDAR can also create real-time 3D models of the environment. This model can be represented as a point cloud. A point cloud is a collection of three-dimensional data points representing the surfaces of objects, structures, and environments within a specific area. Each data point in the point cloud can be defined using its coordinates in a coordinate system. These coordinates represent the data point's position in three-dimensional space. Using point clouds, vehicles can accurately identify the positions of objects on the road, such as cars, pedestrians, and / or cyclists.

[0041] In some embodiments, LiDAR can generate point clouds, which simplifies and simplifies the processing of driver assistance algorithms. LiDAR can provide high-resolution 3D vision for vehicles, such as intelligent vehicles. Working in conjunction with cameras or other types of radar, LiDAR can enhance a vehicle's perception capabilities to handle more complex road conditions, such as dark environments or unknown objects on highways. LiDAR can further provide high-performance automotive-grade LiDAR solutions, ensuring safer and smarter driver assistance, such as L2+ driver assistance. Once configured, LiDAR can be widely used in passenger cars and commercial vehicles equipped with advanced driver assistance systems (ADAS) and / or autonomous driving (automated transportation). LiDAR can also be applied to any suitable end device, such as drones or robots. For example, LiDAR can support robotic applications such as delivery robots and logistics robots.

[0042] Please see Figure 1 , Figure 1 A schematic diagram of an exemplary lidar consistent with some embodiments of this disclosure is shown. For example... Figure 1 As shown in the figure, the lidar 100 provided in this embodiment of the present disclosure includes a transmitter 10, a receiver 20 and a controller 30.

[0043] In this embodiment of the disclosure, transmitter 10 can emit a probe light L to detect object 200. Receiver 20 can receive the echo L' reflected by object 200 from the probe light L and convert the received echo L' into an electrical signal. Controller 30 is connected to receiver 20 and can process the electrical signal output by receiver 20. In some embodiments, controller 30 can generate an image based on pixel integration values ​​output by receiver 20.

[0044] In some embodiments, the transmitter 10 may include a driving circuit and a laser. The laser can emit laser light under the drive of the driving circuit. Optionally, the wavelength of the laser emitted by the laser can be any one of 905nm, 940nm, or 1550nm. The laser can also emit laser light of other wavelengths. The driving circuit may include a driver integrated circuit, such as an analog chip, a digital chip, or a digital-analog hybrid chip.

[0045] For example, the laser may include a semiconductor laser, such as a vertical-cavity surface-emitting laser (VCSEL), an edge-emitting laser (EEL), or other semiconductor lasers capable of generating laser light. In some embodiments, the laser may also include a fiber laser or a solid-state laser.

[0046] In some embodiments, the transmitter 10 may include a plurality of lasers. Optionally, the plurality of lasers may be arranged in an emission array. For example, the plurality of lasers may be arranged in a one-dimensional array. Another example is that the plurality of lasers may be arranged in a two-dimensional array. The plurality of lasers may be aligned. Alternatively, the plurality of lasers may be staggered. In some embodiments, the transmitter 10 may include a laser chip integrating multiple lasers, or multiple discrete lasers.

[0047] For example, controller 30 may include, but is not limited to, hardware circuits implemented with application-specific integrated circuits (ASICs), programmable logic devices (PLDs), microcontroller units (MCUs), microprocessor units (MPUs), digital signal processors (DSPs), or central processing units (CPUs). For instance, hardware circuits implemented with PLDs may include field-programmable gate arrays (FPGAs).

[0048] See Figure 2 As shown, Figure 2 A schematic diagram of an exemplary receiver consistent with some embodiments of this disclosure is shown. For example... Figure 2 As shown, receiver 20 includes a single photon avalanche diode (SPAD) chip 21 and a circuit chip 22.

[0049] See Figure 3 As shown, Figure 3 A schematic diagram of an exemplary pixel array consistent with some embodiments of this disclosure is shown. Figure 3As shown, the SPAD chip 21 includes a pixel array. The pixel array extends along a first direction a and a second direction b. The pixel array includes a plurality of pixels X arranged along the first direction a. For example, the first direction a is perpendicular to the second direction b. In some embodiments, the pixel array includes a plurality of SPADs. The plurality of SPADs are arranged in a two-dimensional array.

[0050] For example, a pixel X comprises a single SPAD. A two-dimensional arrangement of SPADs constitutes a pixel array. Alternatively, a pixel X may comprise a plurality of SPADs. The electrical signals of a plurality of SPADs can be combined to form pixel data. A plurality of SPADs can be arranged in one-dimensional or two-dimensional arrays.

[0051] In some embodiments, see Figure 4a As shown, Figure 4a A schematic diagram of a pixel array consistent with other embodiments of this disclosure is shown. For example... Figure 4a As shown, along the first direction a, a plurality of pixels X include a first pixel X1, a second pixel X2, and a third pixel X3. The first pixel X1, the second pixel X2, and the third pixel X3 are aligned along the second direction b. The first pixel X1 includes a first filter (not shown) and a first SPAD. The second pixel X2 includes a second filter and a second SPAD. The third pixel X3 includes a third filter and a third SPAD. The first filter, the second filter, and the third filter have different passband wavelengths.

[0052] For example, the first filter has a transmittance of not less than a transmittance threshold for light with wavelengths of 620–750 nm. The second filter has a transmittance of not less than a transmittance threshold for light with wavelengths of 495–570 nm. The third filter has a transmittance of not less than a transmittance threshold for light with wavelengths of 450–495 nm. The transmittance threshold can be any value within the range of 90%–99%. For example, the transmittance threshold can be 90%, 91%, 92%, 95%, 96%, or 98%. The transmittance of the first, second, and third filters for light in the corresponding wavelength ranges can be the same or different.

[0053] For example, the first filter allows red light to pass through. The first pixel X1 is a red light (R) pixel. The second filter allows green light to pass through. The second pixel X2 is a green light (G) pixel. The third filter allows blue light to pass through. The third pixel X3 is a blue light (B) pixel.

[0054] The pixel array along the first direction a includes multiple monochromatic light pixels (e.g., R pixels, G pixels, and B pixels). The data from these three monochromatic light pixels can be combined to generate color image data. Along the second direction b, the resolution of the image data is consistent with the number of pixels, eliminating the need for interpolation to increase the data volume or resolution.

[0055] It should be noted that this disclosure does not limit the order of the first filter, second filter, and third filter. For example, along the first direction a, the filters can be R pixels, G pixels, and B pixels. Alternatively, along the first direction a, the filters can also be in the order of G pixels, B pixels, and R pixels, or in the order of B pixels, G pixels, and R pixels. Multiple pixels X in the first direction a can also include other types of pixels, such as yellow light pixels or white light pixels.

[0056] Figure 4a The receiver shown includes a column of R pixels, a column of G pixels, and a column of B pixels arranged along direction b, which is merely an example. In some embodiments, a group of pixels arranged along direction a includes R pixels, G pixels, and B pixels. The pixel arrangement of different groups along direction b can be different. For example, the first group along direction a may be in the order of R pixels, G pixels, and B pixels. The second group along direction a may be in the order of G pixels, B pixels, and R pixels. The third group along direction a may be in the order of B pixels, R pixels, and G pixels.

[0057] In some embodiments, the pixel array along the first direction a includes a plurality of first pixels X1, a plurality of second pixels X2, and a plurality of third pixels X3. The number of first pixels X1, second pixels X2, and third pixels X3 along the first direction a can be the same or different. For example, along the first direction a, the pixel array includes two R pixels, two G pixels, and two B pixels. Data of pixels of the same color can be superimposed, which is equivalent to increasing the exposure time and improving image quality. The two R pixels, two G pixels, and two B pixels can be arranged in RGBRGB order, RRGGBB order, or other arrangement orders.

[0058] In some embodiments, the pixel array includes a plurality of first pixels X1, a plurality of second pixels X2, and a plurality of third pixels X3. The plurality of first pixels X1 extend along the second direction b. The plurality of second pixels X2 extend along the second direction b. The plurality of third pixels X3 extend along the second direction b.

[0059] For example, along the second direction b, multiple first pixels X1 can be arranged alternately or aligned. Similarly, along the second direction b, multiple second pixels X2 can be arranged alternately or aligned. And again, along the second direction b, multiple third pixels X3 can be arranged alternately or aligned. Alternate arrangement means that at least one pixel among the multiple pixels is not on the same straight line.

[0060] In some embodiments, see Figure 4b As shown, Figure 4bA schematic diagram of a pixel array consistent with some embodiments of the present disclosure is shown. Along a first direction a, the plurality of pixels further includes a plurality of ranging pixels Y. For example, a ranging pixel Y includes a SPAD. As another example, a ranging pixel Y includes a plurality of SPADs. The electrical signals of the plurality of SPADs can be combined to form a ranging pixel data. The plurality of SPADs can be arranged in one dimension or two dimensions. Imaging can be achieved through the first pixel X1, the second pixel X2, and the third pixel X3, and ranging can be achieved through the ranging pixels. The pixel array for imaging and the pixel array for ranging are integrated into a SPAD chip.

[0061] For example, SPADs for imaging and SPADs for ranging are fabricated on the same substrate. A uniformly arranged array of SPADs can be formed on the substrate. Some SPADs are formed as imaging pixels. Some SPADs are formed as ranging pixels. A filter can be integrated onto the SPADs of the ranging pixel. The passband wavelength range of this filter includes the wavelength of the probe light of the lidar. The filter can also be encapsulated on the ranging pixel. The number of SPADs included in the imaging pixel and the ranging pixel can be the same or different. For example, the number of SPADs included in the ranging pixel is greater than the number of SPADs included in the imaging pixel. The electrical signals of the SPADs in the ranging pixel are superimposed to form the ranging pixel data, which can improve the signal-to-noise ratio of lidar detection. An imaging pixel includes fewer SPADs; without changing the overall size of the imaging pixel array, the number of imaging pixels can be increased, thereby improving image resolution.

[0062] See Figure 5 As shown, Figure 5 A schematic diagram of an exemplary lidar consistent with other embodiments of this disclosure is shown. For example... Figure 5 As shown, in some embodiments, the lidar 100 further includes a scanning mirror 40. In some embodiments, the scanning mirror 40 can change the transmission direction of the probe light or echo in at least one direction. The at least one direction may include either or both of a horizontal and a vertical direction.

[0063] For example, the scanning mirror 40 can receive the echo L' and guide the echo L' to the receiver 20. The scanning mirror 40 can also deflect the probe light emitted by the transmitter 10 to scan the field of view of the lidar 100 in a third direction. Optionally, the receiver 20 is vertically mounted inside the lidar 100. The second direction b corresponds to the vertical direction of the lidar. The third direction can be the same as the first direction a. Optionally, the third direction can be different from the first direction a. For example, there can be an angle between the third direction and the first direction a, such as any value from 0 to 5°, 45°, 60°, 75°, or 90°, etc.

[0064] For example, the scanning mirror 40 may include a rotating reflector, a reciprocating pendulum mirror, or a galvanometer (e.g., a MEMS mirror, a Galvo mirror, etc.). For example, the scanning mirror 40 may include one or more reflective surfaces. Multiple reflective surfaces may have an included angle.

[0065] As the scanning mirror 40 scans in a third direction, the ranging pixels can determine depth information at multiple angles in that third direction. Image pixels can determine image information at multiple angles in that third direction. In some embodiments, the lidar may include multiple detection cycles. One detection cycle may correspond to a sampling angle of the lidar. In some embodiments, the lidar may include a first detection cycle and a second detection cycle. The first detection cycle corresponds to a first sampling angle. The second detection cycle corresponds to a second sampling angle. The first sampling angle is different from the second sampling angle. Exemplarily, the sampling angle includes a sampling angle in a third direction.

[0066] In some embodiments, the ranging pixel can determine first depth information in a first detection cycle. The image pixel can determine first image information in the first detection cycle. The ranging pixel and the imaging pixel have different positions in a third direction. The first depth information and the first image information have different field-of-view angles in the same detection cycle in a third direction. The ranging pixel can determine second depth information in a second detection cycle. The image pixel can determine second image information in a second detection cycle. The second depth information and the second image information have different field-of-view angles in a third direction. The first detection cycle and the second detection cycle do not overlap. In some embodiments, the first depth information and the second image information can correspond to the same field-of-view angle in a third direction. The lidar can determine image and depth fusion information for the corresponding third-direction field-of-view angle based on the first depth information and the second image information.

[0067] For example, the first depth information determined in the first detection cycle and the second image information determined in the second detection cycle correspond to the same field of view in a third direction. The difference between the angles in the third direction corresponding to the first and second detection cycles is related to the angular resolution of the lidar in the third direction. The time difference between the first and second detection cycles is related to the angular resolution of the lidar in the third direction, the field of view range, and the frame rate of the lidar.

[0068] See Figure 6 As shown, Figure 6 A schematic block diagram of an exemplary circuit chip consistent with some embodiments of this disclosure is shown. For example... Figure 6As shown, the circuit chip 22 includes multiple integrating circuits 221 and a sampling circuit 222. The multiple integrating circuits 221 are connected to multiple pixels X arranged along a first direction a. For example, one pixel X can be connected to one integrating circuit 221. The integrating circuit 221 can integrate the electrical signal output by the connected pixel X. The sampling circuit 222 is connected to one of the multiple integrating circuits 221. The sampling circuit 222 can sample the integration of the integrating circuit 221 to determine the pixel integration value. The multiple integrating circuits 221 start integrating based on an integration trigger signal. If the pixel integration value exceeds a preset threshold, the multiple integrating circuits 221 stop integrating.

[0069] The receiver 20 provided in this embodiment uses a sampling circuit 222 to sample the integral of an integration circuit 221 of one of a plurality of pixels arranged along a first direction a. If the integral value exceeds a preset threshold, the plurality of integration circuits 221 stop integrating. An integral value determined by the sampling circuit that is greater than the preset threshold reflects strong ambient light. In this case, the plurality of integration circuits 221 stop operating, reducing the dynamic power consumption of the receiver 20 under strong light. This embodiment uses a single sampling circuit 222 to sample one of the plurality of integration circuits 221, reducing circuit complexity and cost.

[0070] In some embodiments, the circuit chip 22 can also receive a control signal and generate an integration trigger signal and a power-on signal based on the rising edge of the control signal. The circuit chip 22 can also generate a power-off signal based on the falling edge of the control signal when the pixel integration value does not exceed the preset threshold. Multiple pixels X can be powered off based on the power-off signal.

[0071] For example, circuit chip 22 can sample the rising edge of an external control signal and generate a power-on signal after sampling the rising edge. The power-on signal is used to control the power-on of pixel X in the pixel array. For example, a power-on signal can control the power-on of all pixels in the pixel array. Or, a power-on signal can control the power-on of some pixels in the pixel array. The external control signal and the corresponding power-on signal can cause the pixels X in the pixel array to be powered on in a preset timing sequence. Circuit chip 22 can also generate an integration trigger signal after a configurable delay. Multiple integration circuits 221 can start integration based on this integration trigger signal.

[0072] For example, circuit chip 22 can also sample the falling edge of the external control signal and generate a power-down signal after sampling the falling edge. The power-down signal can be used to control all pixels X in the pixel array that are currently powered on to power off. Circuit chip 22 can control the power-on and power-off of the pixel array by sampling the rising and falling edges of the external control signal. SPADs are highly sensitive. Even extremely weak light can cause the SPAD to generate current, increasing power consumption. By controlling the pixels to power on at the beginning of the integration period and power off at the end of the integration period through the power-on and power-down signals, circuit chip 22 can suppress the SPAD's response to light outside the integration period and reduce the chip's power consumption.

[0073] It should be noted that one sampling circuit 222 corresponds to a group of pixels along the first direction a. Multiple groups of pixels along the second direction b can correspond to multiple sampling circuits 222. In some embodiments, the number of sampling circuits 222 may be less than the number of pixel groups arranged along the second direction b. For example, multiple groups of pixels X operate in a preset time sequence. The number of sampling circuits 222 can be the same as the number of pixel groups operating simultaneously. Pixel groups operating in different time sequences can share a sampling circuit 222. Within the integration period of a group of pixels, that group of pixels is selected to work with the sampling circuit 222. The number and connection method of the integration circuits 221 can be similar to those of the sampling circuits 222.

[0074] In some embodiments, the pixels sampled by different sampling circuits 222 have the same color filter. For example, each sampling circuit can sample the integral of the first pixel (e.g., red) in each group of pixels along the first direction a. Alternatively, each sampling circuit can sample the integral of the second pixel (e.g., green) in each group of pixels along the first direction a. Furthermore, each sampling circuit can sample the integral of the third pixel (e.g., blue) in each group of pixels along the first direction a. In this way, the pixels connected to each group of sampling circuits have the same color, avoiding deviations caused by different color filters due to different transmittance.

[0075] In some embodiments, the preset threshold may include a first threshold and a second threshold. The sampling circuit 222 determines a first pixel integral value by sampling the integration of the integrator circuit 221 based on a first sampling signal. If the first pixel integral value exceeds the first threshold, the multiple integrator circuits 221 stop integrating. At this time, the pixel's integration time and integration start time are consistent with the time interval between the first sampling signal and the second sampling signal. If the first pixel integral value does not exceed the first threshold, the sampling circuit 222 further determines a second pixel integral value by sampling the integration of the integrator circuit 221 based on a second sampling signal. If the second pixel integral value exceeds the second threshold, the multiple integrator circuits 221 stop integrating. At this time, the pixel's integration time and integration start time are consistent with the time interval between the second sampling signal and the second sampling signal. The second sampling signal is later than the first sampling signal. The second threshold may be greater than the first threshold. The second threshold may also be equal to the first threshold.

[0076] In this embodiment, by setting two sampling signals, the dynamic range of the receiving chip's imaging can be improved. For example, if the ambient light intensity is strong, the first pixel integration value may exceed a first threshold during the first sampling. Multiple integration circuits 221 can be controlled to stop integration. If the ambient light intensity is insufficient for the first pixel integration value to exceed the first threshold, a second sampling can be performed to obtain a second pixel integration value. If the second pixel integration value exceeds a second threshold, multiple integration circuits 221 can be controlled to stop integration. If the second pixel integration value still does not exceed the second threshold, multiple integration circuits 221 continue integration until the integration period ends. This avoids the high power consumption caused by prolonged integration of the SPAD under strong light and also allows for response to ambient light of varying intensities, improving imaging quality.

[0077] Here, the first threshold and the second threshold can be set according to actual needs. For example, the first threshold and the second threshold can be any value in the range of 100 to 300.

[0078] In some embodiments, the preset threshold may further include a third threshold. If the second pixel integral value does not exceed the second threshold, the sampling circuit 222 may further sample the integral of the integrator 221 based on the third sampling signal to determine the third pixel integral value. If the third pixel integral value exceeds the third threshold, the multiple integrator circuits stop integrating. At this time, the pixel integration time and the time interval between the integration start time and the third sampling signal are consistent. The third sampling signal is later than the second sampling signal. The third threshold may be greater than the second threshold. The third threshold may also be equal to the second threshold.

[0079] For example, the third threshold can be any value within the range of 100 to 300. By setting a third sampling signal, the precision of the receiving chip's judgment on integration time can be further improved. Power consumption can be reduced under different ambient light intensities without affecting image quality.

[0080] In some embodiments, the first threshold, the second threshold, and the third threshold may be equal. The first threshold, the second threshold, and the third threshold may be set based on actual needs, for example, to ensure that the power consumption and image quality of the receiver are within acceptable limits.

[0081] In some embodiments, the time interval between the first sampling signal and the start of the integration period is a first duration. The time interval between the second sampling signal and the start of the integration period is a second duration. The time interval between the third sampling signal and the start of the integration period is a third duration. For example, the first duration may be less than the second duration. Or, the first duration may be equal to the second duration. The second duration may be less than the third duration. Or, the second duration may be equal to the third duration. Or, the first duration may be greater than the second duration. For example, the second duration is N times the first duration. N > 1. The third duration is M times the second duration. M > 1. Exemplarily, M ≥ 2. N ≥ 2. For another example, the second duration is an integer multiple of the first duration. The third duration is an integer multiple of the second duration. For example, the second duration is twice the first duration. The third duration is twice the second duration. For yet another example, the first duration is equal to the second duration. The third duration is twice the first duration. If the ambient light is strong, the integration circuit can easily reach the preset threshold in a short time. The weaker the ambient light, the less likely the integration circuit is to reach the preset threshold. Setting the third duration to be greater than the second duration, and the second duration to be greater than or equal to the first duration, allows the integral value sampling to adapt to the characteristics of ambient light. This can reduce power consumption while saving sampling times, which is beneficial for reducing the power consumption and complexity of the circuit chip.

[0082] In some embodiments, the time interval between the start and end of the integration period is a fourth duration. For example, the fourth duration is greater than the third duration. The third duration is greater than the second duration. The second duration may be greater than or equal to the first duration. For example, the fourth duration is P times the third duration. P > 1. The third duration is M times the second duration. M > 1. The second duration is N times the first duration. N > 1. For example, P ≥ 2. M ≥ 2. N ≥ 2.

[0083] The sampling circuit samples the integral of the integrator at different sampling times, enabling timely determination of ambient light intensity. Integration stops when the integral generated by the ambient light intensity exceeds a preset threshold. The more sampling times and corresponding sample signals, the more precise the determination of ambient light intensity; however, this also increases the complexity of the configured circuitry and control signals. This embodiment sets three sampling times and three sample signals, which can reduce power consumption while improving image accuracy, and is beneficial for controlling circuit complexity and chip area.

[0084] It should be noted that, based on the embodiments disclosed herein, the number of sampling signals, sampling times, and corresponding preset thresholds can be flexibly set. For example, the sampling circuit can also determine the fourth pixel integral by sampling the integral of the integrator circuit based on the fourth sampling signal. The integrator circuit can stop integrating in response to the fourth pixel integral value exceeding the fourth threshold. The fourth sampling signal is later than the third sampling signal.

[0085] See Figure 7 As shown, Figure 7A schematic block diagram of an exemplary circuit chip consistent with other embodiments of this disclosure is shown. In some embodiments, such as Figure 7 As shown, circuit chip 22 also includes a time counter 223. The time counter 223 is connected to the sampling circuit 222. The time counter 223 can output one or more of the aforementioned first sampling signal, second sampling signal, and third sampling signal.

[0086] For example, the time counter 223 can output different sampling signals at different time thresholds. For instance, the time counter 223 can start timing based on an integration trigger signal, generate and output a first sampling signal when the integration time reaches a first integration time, generate and output a second sampling signal when the integration time reaches a second integration time, and generate and output a third sampling signal when the integration time reaches a third integration time.

[0087] See Figure 8 As shown, Figure 8 A schematic block diagram of an exemplary circuit chip consistent with further embodiments of this disclosure is shown. In some embodiments, such as Figure 8 As shown, circuit chip 22 also includes a comparator circuit 224. Comparator circuit 224 is connected to sampling circuit 222. Comparator circuit 224 can output an integration termination signal when the pixel integration value exceeds a preset threshold. Multiple integration circuits 221 stop integration based on this integration termination signal. A power-down signal can be generated based on the integration termination signal.

[0088] For example, after sampling circuit 222 samples the pixel integration value, it can transmit the pixel integration value to comparison circuit 224. Comparison circuit 224 can compare the pixel integration value with a preset threshold, and output an integration termination signal when the pixel integration value exceeds the preset threshold. This integration termination signal can generate a power-down signal. Thus, when the pixel integration value exceeds the preset threshold, multiple integration circuits 221 stop integrating. The row of pixels corresponding to the sampling circuit 222 will also be powered down, which can further reduce power consumption.

[0089] In some embodiments, circuit chip 22 further includes a power supply circuit 225 and a gating circuit 226. The gating circuit can connect the power supply circuit 225 and the plurality of pixels X based on a power-on signal, so that the power supply circuit 225 supplies power to the plurality of pixels X. The gating circuit 226 can also disconnect the power supply circuit 225 and the plurality of pixels X based on a power-off signal.

[0090] For example, gating circuit 226 may include a gating switch. The gating switch may include a metal-oxide-semiconductor field-effect transistor (MOSFET). The gating switch may also include other components, such as a bipolar junction transistor (BJT) or an insulated gate bipolar transistor (IGBT).

[0091] See Figures 9a-9d As shown, the rising edge of the power-on signal represents the power-on signal, and the falling edge represents the power-off signal. The rising edge of the integration trigger / stop signal represents the integration trigger signal. The falling edge of the integration trigger / stop signal represents the integration stop signal. T represents one clock cycle. It should be noted that the delay of one clock cycle or 1-2 clock cycles is merely an example; in other embodiments, it can be more or less, depending on actual needs.

[0092] In some embodiments, such as Figures 9a-9d As shown, the circuit chip generates a power-on signal after sampling the rising edge of the control signal and delaying it by 1~2T. The power-on signal powers on all pixels X in the pixel array. After a configurable delay, the circuit chip generates an integration trigger signal. The integration trigger signal enables multiple integration circuits 221 to start integrating. When the integration time reaches the integration time threshold, the sampling circuit 222 samples based on the sampling signal to determine the pixel integration value.

[0093] Figure 9b A schematic diagram illustrating an exemplary second signal relationship consistent with some embodiments of this disclosure is shown. For example, such as... Figure 9b As shown, when the integration time reaches the first integration time, the sampling circuit 222 performs the first sampling based on the first sampling signal to determine the first pixel integration value. The first pixel integration value exceeds the first threshold. The circuit chip generates an integration termination signal. The circuit chip also generates a power-down signal based on the integration termination signal (e.g., a power-down signal is generated one clock cycle after the integration termination signal). A group of pixels X (e.g., a row of pixels) in the pixel array corresponding to the sampling circuit along the first direction a is powered down. In this case, the integration time of this group of pixels X is consistent with the time interval between the integration trigger signal and the integration termination signal. For example, the integration time of this group of pixels X can be represented by the first integration time.

[0094] Figure 9c A schematic diagram illustrating an exemplary third signal relationship consistent with some embodiments of this disclosure is shown. For example, such as... Figure 9cAs shown, when the integration time reaches the first integration time, the sampling circuit 222 performs a first sampling based on the first sampling signal to determine the first pixel integration value. The first pixel integration value does not exceed the first threshold. When the integration time reaches the second integration time, the sampling circuit 222 performs a second sampling based on the second sampling signal to determine the second pixel integration value. The sampled second pixel integration value exceeds the second threshold. The circuit chip generates an integration termination signal and generates a power-down signal based on the integration termination signal. For example, the circuit chip generates the power-down signal one clock cycle after the integration termination signal. A group of pixels X corresponding to the sampling circuit along the first direction a is powered down. In this case, the integration time of this group of pixels X is consistent with the time interval between the integration trigger signal and the integration termination signal. For example, the integration time of this group of pixels X can be represented by the second integration time.

[0095] Figure 9d A schematic diagram illustrating an exemplary fourth signal relationship consistent with some embodiments of this disclosure is shown. For example, such as... Figure 9d As shown, when the integration time reaches the first integration time, the sampling circuit 222 performs a first sampling based on the first sampling signal to determine the first pixel integration value. The sampled first pixel integration value does not exceed the first threshold. When the integration time reaches the second integration time, the sampling circuit 222 performs a second sampling based on the second sampling signal to determine the second pixel integration value. The sampled second pixel integration value does not exceed the second threshold. When the integration time reaches the third integration time, the sampling circuit 222 performs a third sampling based on the third sampling signal to determine the third pixel integration value. The sampled third pixel integration value exceeds the third threshold. The circuit chip generates an integration termination signal and generates a power-down signal based on the integration termination signal. For example, the circuit chip generates a power-down signal one clock cycle after the integration termination signal. A group of pixels X corresponding to the sampling circuit along the first direction a is powered down. In this case, the integration time of this group of pixels X is consistent with the time interval between the integration trigger signal and the integration termination signal. For example, the integration time of this group of pixels X can be represented by the third integration time.

[0096] Example, reference Figure 9a The integral values ​​of the first, second, and third pixels all do not exceed their corresponding integration thresholds. The circuit chip generates an integration termination signal after sampling the falling edge of the external control signal, and then generates a power-down signal based on the integration termination signal. All pixels X in the pixel array are powered down. In this case, the integration time of this group of pixels X is consistent with the integration period. For example, the integration time of this group of pixels X can be represented by the duration or end time of the integration period.

[0097] In some embodiments, circuit chip 22 may further include an output circuit (not shown). The output circuit can generate output data based on pixel integral values ​​and corresponding integration times. This output data is used to generate an image.

[0098] For example, the output data includes the integral value and integration time. Multiple integrator circuits 221 share the integration time. The integral values ​​of pixels of different colors, combined with the color corresponding to the pixel, can be used to determine the color image.

[0099] For example, the integration time can be output in binary code. For instance, a specific integration time can be represented using 2 bits of binary data. For example, 00 can indicate that the integration time is determined by the high-level duration of the control signal. 01 indicates that the integration time is determined based on the duration of the first sampled signal. 10 indicates that the integration time is determined based on the duration of the second sampled signal. 11 indicates that the integration time is determined based on the duration of the third sampled signal.

[0100] In some embodiments, for pixels that prematurely end integration (e.g., pixels that stop integrating because their first pixel integration value exceeds a first threshold), the total integration value for the entire integration cycle can be determined based on the actual integration time. For example, the target pixel integration value corresponding to the high level can be determined based on the ratio between the sampling time and the high level of the control signal and the current pixel integration value. For instance, if the second sampling time is half the high level time of the control signal, and the sampled pixel integration value is 'a', then the pixel integration value corresponding to the high level duration of the control signal is 2a. 2a can be used as the pixel integration value within the integration cycle. Downstream circuitry can generate the corresponding image based on the pixel integration value 2a. In this way, more accurate pixel integration can be determined while reducing SPAD imaging power consumption, thus improving image quality.

[0101] Optionally, the transmitter 10 may include transmitting optics. Transmitting optics include one or more optical components such as lenses or lens groups, mirrors, filters, beam splitters, apertures, and homogenizers. The receiver 20 may include receiving optics. Receiving optics include one or more optical components such as lenses or lens groups, mirrors, filters, beam splitters, apertures, and homogenizers. The transmitting and receiving optics may be independently configured, or they may be fully or partially multiplexed (the multiplexed portion may be referred to as "transmitting and receiving optics"). For example, the transmitting and receiving optics may include at least one of a common lens, a common lens group, a common mirror, a common aperture, and a common beam splitter. The laser emitted by the laser and the echo reflected by the object may pass through at least one of the common lens, common lens group, common mirror, common aperture, and common beam splitter.

[0102] Optionally, the circuit chip 22 may also include a signal processing circuit (not shown). This signal processing circuit can perform filtering, amplification, waveform acquisition, accumulation, or calibration on the sampled data.

[0103] In some embodiments, the signal processing circuit may include analog front-end circuitry for gating pixel readouts and / or amplifying analog signals. In some embodiments, the signal processing circuit may include a filtering circuit. The filtering circuit can smooth and reduce noise in the sampled data. In some embodiments, the signal processing circuit may include a time-to-digital converter (TDC). The TDC can convert time information into a digital signal. In some embodiments, the signal processing circuit may include an accumulation circuit. The accumulation circuit can perform summation operations on the sampled data. For example, it can accumulate the sampled data output after multiple SPAD triggers. Or, for example, it can accumulate the sampled data output after multiple SPAD triggers. In some embodiments, the signal processing circuit may include a calibration circuit. For example, the calibration circuit can calibrate the sampled data based on ambient light, temperature, etc. For example, the calibration circuit can calibrate based on the sampled data of neighboring SPADs.

[0104] It is understood that the structures illustrated in the embodiments of this disclosure do not constitute a specific limitation on the testing apparatus for lenses in lidar. In other embodiments of this disclosure, the testing apparatus for lenses in lidar may include more or fewer components than illustrated, or combine some components, or split some components, or have different component arrangements. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0105] Furthermore, the aforementioned circuits may include corresponding circuits or chips, etc. In this embodiment, the specific circuits are not limited, as long as each circuit can achieve its corresponding function. In addition, the circuits can be integrated on the same circuit board and disposed in the same housing, or they can be integrated on different circuit boards and disposed in different housings. The specific combination can be made according to the actual situation, and no specific limitation is made here.

[0106] The embodiments described above are some, but not all, of the embodiments disclosed herein. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without inventive effort are within the scope of protection of this disclosure.

[0107] Furthermore, the technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0108] Finally, it should be noted that the above-described embodiments are merely specific implementations of this disclosure, used to illustrate the technical solutions of this disclosure, and not to limit it. The protection scope of this disclosure is not limited thereto. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the scope of the technology disclosed in this disclosure; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this disclosure. All should be covered within the protection scope of this disclosure. Therefore, the protection scope of this disclosure should be determined by the protection scope of the claims.

Claims

1. A receiver for a lidar system, characterized in that, include: A SPAD chip, comprising a pixel array extending along a first direction and a second direction, the pixel array including a plurality of pixels arranged along the first direction, and... Circuit chips, including: Multiple integrating circuits, connected to the multiple pixels, are configured to integrate the electrical signals output by the multiple pixels. A sampling circuit, connected to one of the plurality of integrating circuits, is configured to sample the integral of the integrating circuit to determine the pixel integral value. The multiple integration circuits start integration based on an integration trigger signal. If the pixel integration value exceeds a preset threshold, the multiple integration circuits stop integration.

2. The receiver according to claim 1, characterized in that, The preset threshold includes a first threshold and a second threshold. The sampling circuit performs integration sampling on the integrator based on the first sampling signal to determine the first pixel integration value. If the first pixel integration value exceeds the first threshold, the plurality of integrators stop integrating. The sampling circuit performs integration sampling on the integrator based on the second sampling signal to determine the second pixel integration value. If the second pixel integration value exceeds the second threshold, the plurality of integrators stop integrating. The second sampling signal is later than the first sampling signal.

3. The receiver according to claim 2, characterized in that, The preset threshold also includes a third threshold. The sampling circuit performs integration sampling on the integration circuit based on the third sampling signal to determine the third pixel integration value. If the third pixel integration value exceeds the third threshold, the plurality of integration circuits stop integrating. The third sampling signal is later than the second sampling signal.

4. The receiver according to claim 3, characterized in that, Also includes: A time counter configured to output one or more of the first sampled signal, the second sampled signal, and the third sampled signal.

5. The receiver according to claim 1, characterized in that, The plurality of pixels includes a first pixel, a second pixel, and a third pixel. The first pixel includes a first filter and a first SPAD, the second pixel includes a second filter and a second SPAD, and the third pixel includes a third filter and a third SPAD. The passband wavelengths of the first filter, the second filter, and the third filter are different.

6. The receiver according to claim 5, characterized in that, The pixel array includes a plurality of first pixels, a plurality of second pixels, and a plurality of third pixels, wherein the plurality of first pixels extend along the second direction, the plurality of second pixels extend along the second direction, and the plurality of third pixels extend along the second direction.

7. The receiver according to claim 1, characterized in that, The circuit chip also includes a power supply circuit and a gating circuit. The gating circuit is configured to connect the power supply circuit and the plurality of pixels based on a power-on signal, so that the power supply circuit supplies power to the plurality of pixels. The gating circuit is also configured to disconnect the power supply circuit and the plurality of pixels based on a power-off signal.

8. The receiver according to claim 7, characterized in that, Also includes: The comparison circuit is configured to output an integration stop signal when the pixel integration value exceeds the preset threshold, and the plurality of integration circuits stop integration based on the integration stop signal. The power-down signal is generated based on the integration termination signal.

9. The receiver according to claim 7, characterized in that, The circuit chip is configured to receive a control signal, generate the integration trigger signal and the power-on signal based on the rising edge of the control signal, and the circuit chip is further configured to generate the power-off signal based on the falling edge of the control signal when the pixel integration value does not exceed the preset threshold.

10. A lidar, characterized in that, include: The transmitter is configured to emit a probe beam. The receiver according to any one of claims 1-9, the receiver being configured to receive the echo of the probe light reflected by the object, and The controller, connected to the receiver, is configured to generate an image based on the pixel integral value.

11. The lidar according to claim 10, characterized in that, The lidar also includes: A scanning mirror is configured to receive the echo and guide the echo to the receiver, and to deflect the probe light emitted by the transmitter, thereby achieving scanning of the third-directional field of view of the lidar.

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