Light detection device and distance measuring system

Abstract

[Problem] To provide a light detection device and a distance measurement system with which it is possible to improve distance measurement accuracy at a long distance without increasing the number of pixels. [Solution] This light detection device is provided with: a first counter group comprising two or more first counters; a first pixel circuit or a first pixel circuit group connected to the first counter group; a first pixel connected to the first pixel circuit, or a first pixel group connected to the first pixel circuit group; a second counter group including two or more second counters; a second pixel circuit or a second pixel circuit group connected to the second counter group; a second pixel connected to the second pixel circuit, or a second pixel group connected to the second pixel circuit group; and a switching circuit for switching between counting the number of transitions of the output signal of the first pixel circuit or the first pixel circuit group using the first counter group and not using the second counter group, or counting using the first counter group and the second counter group.

Description

Technical Field

[0001] The present disclosure relates to a light detection device and a distance measurement system. Background Art

[0002] There has been proposed a technology for measuring the distance to an object over short to long distances using a single photon avalanche diode (SPAD) capable of detecting weak light (for example, see Patent Documents 1 and 2).

[0003] In order to receive reflected light from an object over a short to long range, it is necessary to receive reflected light from the object over a long period of time. Patent Document 1 discloses a configuration in which a photon counter that measures the number of times a SPAD detects light (photons) is provided for each pixel, and a merging process that enables a plurality of photon counters provided for a plurality of pixels to operate in a time-division manner to count photons over a long period of time.

[0004] Reference List

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2022-73105

[0007] Patent Document 2: Japanese Patent Application Publication No. 2021-92437 Summary of the Invention

[0008] Problems to be solved by the present invention

[0009] In the case of Patent Document 1, in order to expand the measurable range, it is necessary to increase the number of pixels subjected to binning processing, which leads to a decrease in effective resolution.

[0010] Furthermore, if the number of pixels in the pixel array unit is increased while performing binning processing, the size of the pixel array unit increases, making miniaturization difficult. Furthermore, the larger the number of pixels in the pixel array unit, the more pixel circuits are required, resulting in higher power consumption.

[0011] It is possible to consider arranging the photon counters on a chip (substrate) different from the pixel array unit and increasing the number of photon counters per pixel without performing merging processing, but in this case, the circuit scale of the photon counter becomes large, making it impossible to reduce the chip size.

[0012] On the other hand, in the case of Patent Document 2, a histogram generator is provided for each macropixel consisting of multiple pixels. Although Patent Document 2 does not disclose a counter, the histogram generator essentially has a function similar to that of a counter. In order to perform long-distance ranging using the configuration disclosed in Patent Document 2, it is sufficient to increase the number of histogram generators provided for each macropixel. However, in this case, the circuit scale of the histogram generator becomes large, making it impossible to reduce the size of the chip on which the histogram generator is implemented, similar to Patent Document 1.

[0013] As described above, both Patent Document 1 and Patent Document 2 have a common problem: an increase in the number of photon counters or histogram generators used for long-distance ranging or the like leads to an increase in circuit scale, making it impossible to reduce the chip size.

[0014] Therefore, an object of the present disclosure is to provide a light detection device and a ranging system that allow the accuracy of long-distance ranging to be improved without increasing the number of pixels.

[0015] Solution to the problem

[0016] In order to solve the above problems, according to the present disclosure, a light detection device is provided, comprising:

[0017] a first counter group, comprising at least two first counters;

[0018] a first pixel circuit or a first pixel circuit group connected to the first counter group;

[0019] a first pixel connected to a first pixel circuit or a first pixel group connected to a first pixel circuit group;

[0020] a second counter group, comprising at least two second counters;

[0021] a second pixel circuit or a second pixel circuit group connected to the second counter group;

[0022] a second pixel connected to a second pixel circuit or a second pixel group connected to a second pixel circuit group; and

[0023] The switching circuit switches between counting the number of transitions of the output signal of the first pixel circuit or the first pixel circuit group using the first counter group without using the second counter group and counting the number of transitions using both the first counter group and the second counter group.

[0024] The first pixel or the first pixel group may include an active pixel or an active pixel group for receiving reflected light from the object, and

[0025] The second pixel or the second pixel group may include a passive pixel or a passive pixel group that is not used to receive the reflected light.

[0026] The present invention may further include a mode selection unit that selects a first mode or a second mode. In the first mode, the first counter group is used without using the second counter group to count the number of transitions of the output signal of the first pixel circuit or the first pixel circuit group. In the second mode, both the first counter group and the second counter group are used to count the number of transitions.

[0027] The switching circuit may perform switching according to the selection made by the mode selection unit.

[0028] The count values ​​of the first counter group and the second counter group can be used to measure the distance to the object.

[0029] In the case where the second mode is selected, the measurable range can be longer than in the case where the first mode is selected, and

[0030] Regardless of whether the first mode or the second mode is selected, the range resolution and the resolution may be the same.

[0031] The measurable range in the case where the second mode is selected may be equal to an integral multiple of at least two times the measurable range in the case where the first mode is selected.

[0032] Each of the first mode and the second mode may further include an exclusively selectable third mode and a fourth mode,

[0033] In a third mode, one of the first counter groups may be used to count the number of transitions of the output signal of the first pixel circuit or the first pixel circuit group, and

[0034] In the fourth mode, a plurality of first counter groups may be used to count the number of transitions of the output signal of the first pixel circuit or the first pixel circuit group.

[0035] The fourth mode may further include an exclusively selectable fifth mode, a sixth mode, and a seventh mode,

[0036] The sixth mode may have a longer measurable range than the fifth mode, a lower distance resolution than the fifth mode, and the same resolution as the fifth mode, and

[0037] The seventh mode may be longer in a measurable range than the fifth mode, and has the same distance resolution and resolution as the fifth mode.

[0038] The device may further include: a first substrate including a pixel array unit, wherein a plurality of first pixels or a first pixel group and a plurality of second pixels or a second pixel group are arranged in the pixel array unit; and

[0039] A second substrate is provided, wherein a plurality of first pixel circuits or first pixel circuit groups, a plurality of first counter groups, a plurality of second pixel circuits or second pixel circuit groups, a plurality of second counter groups and a plurality of switching circuits are arranged, and the second substrate is stacked on the first substrate.

[0040] A plurality of first pixels or a plurality of first pixel groups may be arranged in a predetermined pixel area in the pixel array unit, and

[0041] A plurality of second pixels or a plurality of second pixel groups may be arranged in a pixel area other than a predetermined pixel area in the pixel array unit.

[0042] It may also include an output unit that generates output data including first bit string data and second bit string data, the first bit string data including information about the mode selected by the mode selection unit, and the second bit string data including the count value of the first counter group when the first mode is selected or the count values ​​of both the first and second counter groups when the second mode is selected.

[0043] When the second mode is selected, the first bit string data may include information on the number of second counter groups connected to the first counter group.

[0044] The first bit string data may include information for identifying whether to perform a merge process of performing counting using at least two of the first counter group or to perform counting using one of the first counter group.

[0045] The first bit string data may include information for identifying whether to count the number of transformations within a specific pixel region of interest or to count the number of transformations within a predetermined partial pixel region.

[0046] The second bit string data may include a plurality of bit string data, in which count values ​​of the first counter group and the second counter group corresponding to each pixel of all the first pixels are arranged in pixel order when the second mode is selected.

[0047] It may also include: a first pixel array unit in which a plurality of first pixels or a first pixel group and a plurality of second pixels or a second pixel group are arranged and arranged;

[0048] a second pixel array unit in which a plurality of third pixels each capturing subject light is arranged; and

[0049] The control unit controls the light receiving range of the second pixel array unit according to the focal length of the subject light incident on the second pixel array unit.

[0050] In the case of controlling the focal length of the second pixel array unit toward the telephoto end side, the control unit may further reduce the size of the pixel area of ​​the plurality of first pixels or the plurality of first pixel groups in the first pixel array unit.

[0051] The optical system driving unit may further be included to drive a focus-adjustable optical system that adjusts the focal length of the subject light incident on the second pixel array unit, wherein

[0052] The control unit may control the optical system driving unit based on a measurement result of a distance from the object to the reflected light received from the object through the plurality of first pixels or the plurality of first pixel groups in the first pixel array unit.

[0053] According to the present disclosure, a ranging system is provided, comprising:

[0054] a light-emitting device for illuminating an object with light;

[0055] a light receiving unit that receives light emitted by the light emitting device and reflected by the subject;

[0056] a distance measuring unit that measures a distance to an object based on the light emitted by the light emitting device and the reflected light received by the light receiving unit; and

[0057] A control unit controls the light emitting device, the light receiving unit and the distance measuring unit, wherein:

[0058] The light receiving unit includes:

[0059] A pixel array unit comprising a plurality of first pixels or a first pixel group and a plurality of second pixels or a second pixel group;

[0060] a plurality of first pixel circuits connected to the plurality of first pixels; or a plurality of first pixel circuit groups connected to the plurality of first pixel groups;

[0061] a first counter group, provided for each of the plurality of first pixel circuits or the plurality of first pixel circuit groups, the first counter group including a plurality of first counters;

[0062] a plurality of second pixel circuits connected to the plurality of second pixels, or a plurality of second pixel circuit groups connected to the plurality of second pixel groups;

[0063] a second counter group provided for each of the plurality of second pixel circuits or the plurality of second pixel circuit groups, the second counter group including a plurality of second counters; and

[0064] A switching circuit switches between counting the number of transitions of each output signal of a plurality of first pixel circuits or a plurality of first pixel circuit groups using a corresponding first counter group without using a corresponding second counter group, and counting the number of transitions using both the corresponding first counter group and the corresponding second counter group.

[0065] The light emitting device may include a plurality of light emitting units capable of individually controlling whether to emit light based on control of a control unit, and

[0066] The control unit may control the size of the light emitting areas emitting light in the plurality of light emitting units in conjunction with the size of the pixel areas of the plurality of first pixels or the plurality of first pixel groups in the pixel array unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 : is a block diagram showing a schematic configuration of a distance measuring system 2 including a light detection device according to the first embodiment.

[0068] Figure 2 yes Figure 1 Detailed block diagram of the light detection device shown.

[0069] Figure 3 This is a circuit diagram of the pixels of the pixel array unit and the AFE unit of the ranging processing unit.

[0070] Figure 4 is the cathode of the SPAD and Figure 3 The voltage waveform diagram of the pixel signal output by the pixel circuit shown.

[0071] Figure 5A It shows Figure 2 A circuit diagram of an embodiment of the internal configuration of a generation unit is shown.

[0072] Figure 5B is a diagram illustrating an embodiment of a histogram generated by a generation unit.

[0073] Figure 6A is a diagram illustrating a pixel group subjected to binning processing.

[0074] Figure 6B : is a circuit diagram showing a distribution circuit and a counter group that perform a merging process.

[0075] Figure 7 is a schematic perspective view of a semiconductor chip used as a light detecting device.

[0076] Figure 8 is a circuit diagram of main components of the photodetection device according to the first embodiment.

[0077] Figure 9 is a diagram showing a schematic configuration of a distance measuring system in the case where all light emitting elements emit light simultaneously.

[0078] Figure 10 is a diagram showing a schematic configuration of a distance measuring system in a case where some light emitting elements emit light simultaneously.

[0079] Figure 111 is a diagram illustrating an example in which the host control unit controls the light detection device and the light emitting apparatus according to the first embodiment.

[0080] Figure 12 is a diagram illustrating an embodiment of pixel locations of active pixels and passive pixels on a pixel array.

[0081] Figure 13 FIG. 1 is a diagram illustrating an embodiment in which pixel regions outside the ROI region are set as inactive pixels.

[0082] Figure 14 is a diagram showing a correspondence relationship between active pixels and passive pixels in the case where a plurality of light spot areas are set.

[0083] Figure 15 is a diagram illustrating an example of count values ​​of a second counter group connected to a first counter group.

[0084] Figure 16 is a diagram illustrating an example of count values ​​of a first counter group for active pixels and a second counter group for passive pixels in a case where the second counter group is not used as part of the first counter group.

[0085] Figure 17 is based on Figure 8 A circuit diagram of main components of a modified example of a light detection device.

[0086] Figure 18 is a diagram summarizing the characteristics of the light detecting device according to the first embodiment.

[0087] Figure 19A is a diagram showing a histogram generated in the second comparative example.

[0088] Figure 19B is a diagram showing a histogram generated in the third comparative example.

[0089] Figure 19C is a diagram showing a histogram generated in the fourth comparative example.

[0090] Figure 20 is a diagram showing the configuration of main parts of a distance measuring system including a light detection device according to a second embodiment.

[0091] Figure 21 2 is a diagram showing main components of a ranging system including an AF lens driver.

[0092] Figure 22 It shows Figure 21 Flowchart of the processing operation of the ranging system shown.

[0093] Figure 23Ais a diagram showing a structure of output data in a case where all pixels are active pixels and binning processing is not performed.

[0094] Figure 23B is a diagram showing a structure of output data in a case where some pixels are active pixels.

[0095] Figure 23C : is a diagram showing the structure of output data in the case where the merge process is performed.

[0096] Figure 23D : is a diagram showing a structure of output data in the case where a first counter group and a second counter group are connected under a condition including both active pixels and passive pixels.

[0097] Figure 24 is a block diagram of main components of a photodetection device 1 according to a fourth embodiment.

[0098] Figure 25 is a block diagram showing an embodiment of a schematic configuration of a vehicle control system.

[0099] Figure 26 It is an explanatory diagram showing an embodiment of the installation positions of the vehicle exterior information detection portion and the imaging unit. DETAILED DESCRIPTION

[0100] Hereinafter, embodiments of a light detection device and a ranging system will be described with reference to the accompanying drawings. Hereinafter, the main components of the light detection device and the ranging system will be described, but the light detection device and the ranging system may have components and functions not shown or described. The following description is not intended to exclude components and functions not shown or described.

[0101] (First embodiment)

[0102] Figure 1 1 is a block diagram showing a schematic configuration of a distance measuring system 2 including the light detection device 1 according to the first embodiment. Figure 1 The distance measuring system 2 shown includes a light detection device 1 , an application unit 3 , a light emitting device 4 and a host control unit 5 .

[0103] Light-emitting device 4 emits light pulse signals at regular intervals. Light-emitting device 4 can scan the propagation direction of the light pulse signals in one or two dimensions at predetermined intervals. Furthermore, light-emitting device 4 includes multiple light-emitting elements, and each light-emitting element can independently change the timing of emitting light pulse signals. This allows light-emitting device 4 to freely change the size and position of the light-emitting area where at least two light-emitting elements emit light simultaneously.

[0104] When the object 6 is illuminated with the light pulse signal emitted from the light emitting device 4, the light detecting device 1 receives the reflected light signal from the object 6. The light detecting device 1 includes a light receiving unit 11 and a distance measurement processing unit 12. The light receiving unit 11 repeatedly receives the light pulse signal emitted from the light emitting device 4 at regular intervals. The distance measurement processing unit 12 generates a histogram representing the light reception frequency at each light reception timing of the reflected light signal and measures the distance to the object 6 based on the peak position of the histogram.

[0105] The application unit 3 can perform arbitrary processing using the distance data on the object 6 output from the light detection device 1. For example, the application unit 3 can generate a distance image based on the distance data.

[0106] The host control unit 5 controls the light emitting device 4, the light detecting device 1, and the application unit 3. The host control unit 5 may be, for example, a central processing unit (CPU), a personal computer (PC), a server, etc. In addition, the host control unit 5 may be implemented on the same semiconductor chip as the light detecting device 1.

[0107] Figure 2 yes Figure 1 Detailed block diagram of the light detection device 1 in FIG. Figure 2 As shown, the light detection device 1 includes a light receiving unit 11, a distance measurement processing unit 12, a control unit 13, a distance measurement control unit 14, a light emission timing control unit 15, a clock generation unit 16, a pixel control unit 17, and an interface (I / F) unit 18.

[0108] The light receiving unit 11 includes a pixel array unit 19. The pixel array unit 19 includes a plurality of pixels 20 arranged in a first direction X and a second direction Y. Each pixel 20 includes at least one light receiving element. For example, the light receiving element is a photodiode or a SPAD. Hereinafter, an embodiment in which the SPAD 21 is used as the light receiving element will be mainly described.

[0109] The pixel control unit 17 can individually control each pixel 20 of the pixel array unit 19 to determine whether to enable the pixel 20 to receive the reflected light signal from the object 6. This enables only pixel areas of arbitrary size and position in the pixel array unit 19 to receive the reflected light signal.

[0110] The distance measurement processing unit 12 includes an analog front end unit (hereinafter referred to as an AFE unit) 22 , a generating unit 23 , and a distance measurement unit 24 .

[0111] The AFE unit 22 has a plurality of pixel circuits 25 provided in a one-to-one correspondence with the pixels 20 of the pixel array unit 19. When the corresponding SPAD 21 receives the reflected light signal, each pixel circuit 25 outputs a pixel signal having a predetermined pulse width.

[0112] The generation unit 23 generates a histogram based on the output timing and output frequency of the pixel signals output from each pixel circuit 25. The histogram has a number of bins corresponding to the number of pixels that received the reflected light signal. More specifically, the generation unit 23 includes a counter group that includes multiple counters for each pixel 20. The multiple counters count the number of times the corresponding pixel 20 receives the reflected light signal for each timing at which the corresponding pixel 20 receives the reflected light signal. The count value of each counter corresponds to one bin of the histogram. The generation unit 23 generates a histogram having multiple bins based on the count values ​​of the multiple counters.

[0113] The distance measuring unit 24 measures the distance to the object 6 based on the peak position of the histogram generated by the generating unit 23. The distance measuring unit 24 can measure the distance by averaging the values ​​(frequencies) of a plurality of bins near the peak position of the histogram.

[0114] The control unit 13 controls each unit of the light detection device 1. The distance measurement control unit 14 controls the AFE unit 22, the generation unit 23, and the distance measurement unit 24 of the distance measurement processing unit 12 according to instructions from the control unit 13. The pixel control unit 17 controls each pixel 20 of the pixel array unit 19 according to instructions from the control unit 13 to determine whether to cause the pixel 20 to receive reflected light. The light emission timing control unit 15 controls the timing of the emission of the light pulse signal by each light emitting element of the light emitting device 4 according to instructions from the control unit 13. At least some of the control unit 13, the distance measurement control unit 14, the pixel control unit 17, and the light emission timing control unit 15 may be integrated to form an integrated control unit.

[0115] The clock generation unit 16 generates a clock signal for synchronizing each unit of the light detection device 1. The I / F unit 18 outputs information on the distance to the object 6 measured by the distance measurement processing unit 12.

[0116] Figure 3 is a circuit diagram of the pixel 20 of the pixel array unit 19 and the AFE unit 22 of the ranging processing unit 12. The pixel circuit 25 of the AFE unit 22 includes a PMOS transistor Q1 and an inverter 26. The PMOS transistor Q1 has a source connected to the reference voltage node Vs, and has a drain connected to the cathode of the SPAD 21 and the input node of the inverter 26. The control signal Vc from the pixel control unit 17 is input to the gate of the PMOS transistor Q1. With this configuration, the PMOS transistor Q1 serves as a current source 9. The pixel control unit 17 can disconnect the PMOS transistor Q1 according to the control signal Vc. This makes it possible to forcibly stop the light receiving operation of the pixel 20. The SPAD 21 has an anode connected to, for example, a negative potential node (-Vbd). The pixel signal is output from the output node of the inverter 26.

[0117] Figure 4 is a voltage waveform diagram of the cathode of the SPAD 21, and the pixel signal output Figure 3 The pixel circuit 25 shown in FIG. Figure 4 , the voltage waveform of the cathode of SPAD 21 is represented as W1, and the voltage waveform of the pixel signal is represented as W2. The cathode of SPAD 21 maintains the same voltage Vs as the reference voltage node Vs until SPAD 21 detects a photon and the pixel signal is at a low level. Detecting photons by SPAD 21 is called excitation. When SPAD 21 is ignited at time t0, the cathode voltage of SPAD 21 decreases rapidly to become lower than the threshold voltage Vth of inverter 26. Therefore, the pixel signal output from inverter 26 is converted from a low level to a high level. Thereafter, the cathode voltage of SPAD 21 gradually increases, and the pixel signal output from inverter 26 transitions from a high level to a low level at time t1 when the cathode voltage exceeds the threshold voltage Vth of inverter 26.

[0118] As described above, when the SPAD 21 is activated, the pixel circuit 25 outputs a pixel signal having a predetermined pulse width. Therefore, the pixel circuit 25 converts the firing of the SPAD 21 into a digital pixel signal and outputs the pixel signal.

[0119] Figure 5A Yes Figure 2 A circuit diagram of an embodiment of the internal structure of the generating unit 23 is shown, Figure 5B : is a diagram showing an embodiment of a histogram generated by the generation unit 23. Figure 5A As shown, the generating unit 23 has a distribution circuit 27 and a histogram generating unit 29 having a counter group 28. The distribution circuit 27 includes a plurality of switches 30. The counter group 28 in the histogram generating unit 29 includes a plurality of counters 31, the number of which is equal to the number of switches 30.

[0120] Each of the plurality of switches 30 is associated with one of the counters 31 in the counter group 28. The count value of each of the plurality of counters 31 constituting the counter group 28 corresponds to Figure 5B Frequency values ​​for one bin of the histogram shown.

[0121] Each of the multiple switches 30 switches whether to cause the corresponding counter 31 to count the number of transitions of the pixel signal output from the corresponding pixel circuit 25. The multiple switches 30 perform switching operations based on instructions from the distance measurement control unit 14. The distance measurement control unit 14 controls the switching timing of the multiple switches 30 according to the time elapsed for the self-luminous device 4 to emit the light pulse signal. In this article, causing the counter 31 connected to the switch 30 to perform a counting operation is referred to as "turning on the switch 30." The multiple switches 30 are turned on at different timings. As a result, the multiple counters 31 respectively measure the light reception frequency of the reflected light signal as a count value each time the light receiving unit 11 receives the reflected light signal.

[0122] In this embodiment, a plurality of counter groups 28, each comprising at least two pixels 20 (e.g., four pixels), can be used to perform binning processing to count the reflected light signals received by the pixel group. Binning allows for counting reflected light signals from a greater distance, thereby increasing the measurable range.

[0123] Figure 6A is a diagram showing a pixel group 30g to be subjected to binning processing, Figure 6B 2 is a circuit diagram showing a distribution circuit 27 and a counter group 28 suitable for the merging process.

[0124] Figure 6A An example is shown in which the binning process is performed using the pixel group 30 g of 2×2 pixels 20 as a unit, but the number of pixels belonging to the pixel group 30 g serving as the unit of the binning process is freely determined.

[0125] Figure 6B The distribution circuit 27 shown includes a plurality of switches 30 and an OR circuit 32. The OR circuit 32 performs a logical OR operation on a plurality of pixel signals output from all pixel circuits 25 belonging to the pixel group 30g as a unit for merging processing. The pixel circuit 25 connected to each pixel 20 that has received the reflected light signal outputs a pixel signal including a high-level pulse signal. According to this structure, when at least one pixel 20 belonging to the pixel group 30g as a unit for merging processing receives the reflected light signal, at least one output pixel signal becomes a high-level pulse signal, and the output signal of the OR circuit 32 becomes a high level. The plurality of switches 30 perform switching operations according to instructions from the ranging control unit 14. When the output signal of the OR circuit 32 becomes a high level, the count value of the corresponding counter 31 increases via any one of the switches 30. Although in Figure 6B Although not shown in the figure, a plurality of counter groups 28 are provided for the pixel group 30g used as a unit for merging processing, so that these counter groups 28 can be used to measure count values ​​corresponding to reflected light signals from an object located at a certain distance, thereby improving the ranging accuracy of the object located at a certain distance.

[0126] The light detecting device 1 according to the present embodiment can be configured using stacked semiconductor chips. Figure 7 is a schematic perspective view of a semiconductor chip 40 equipped with the capabilities of the light detection device 1 . Figure 7 The semiconductor chip 40 shown in FIG. 4 includes a stack of a first substrate 44 and a second substrate 45. The first substrate 44 is provided on the side of the surface on which the reflected light signal is incident. The second substrate 45 is stacked on the side of the first substrate 44 opposite to the incident surface.

[0127] A pixel array unit 19 is provided on the first substrate 44. In a more specific embodiment, the pixel array unit 19 is arranged on almost the entire surface of the first substrate 44 on which the reflected light signal is incident. In the pixel array unit 19, a plurality of pixels 20 are arranged. An AFE unit 22 having a plurality of pixel circuits 25, a generating unit 23, and a ranging unit 24 are configured on the second substrate 45. It should be noted that at least a portion of the generating unit 23 and the ranging unit 24 may be arranged on the first substrate 44. Alternatively, at least a portion of the generating unit 23 and the ranging unit 24 may be arranged on a third substrate (not shown) stacked on the second substrate 45. The third substrate may not be stacked on the first substrate 44 and the second substrate 45, but may be provided on a semiconductor chip different from the semiconductor chip 40 including the first substrate 44 and the second substrate 45.

[0128] Various signal transmissions between the first substrate 44 and the second substrate 45 are performed via vias, Cu-Cu bonding, bumps, wiring patterns, and the like.

[0129] and Figure 6A similar, Figure 7 An example in which the binning process can be performed with 2×2 pixels is shown, but the number of pixels used as a unit of the binning process is freely determined.

[0130] The pixels 20 of the pixel array unit 19 included in the light receiving unit 11 can correspond one-to-one to the multiple light emitting elements included in the light emitting device 4. In this case, the greater the number of light emitting elements that emit light simultaneously among the multiple light emitting elements, the greater the number of pixels in the pixel array unit 19 of the light receiving unit 11 that receive the reflected light signal. In the case where the light emitting device 4 includes surface light emitting elements such as vertical cavity surface emitting lasers (VCSELs), the greater the number of light emitting elements that emit light simultaneously in the light emitting device 4, the lower the luminous intensity of each light emitting element, and the lower the S / N ratio when the light receiving element receives the reflected light signal. When the luminous intensity of each light emitting element decreases, the light pulse signal does not travel a longer distance, thereby reducing the distance accuracy of the object 6 located at a certain distance.

[0131] Therefore, in order to improve the accuracy of distance measurement of distant objects 6, it is desirable to cause only some of the multiple light-emitting elements included in the light-emitting device 4 to emit light simultaneously to ensure that the light emission intensity of each light-emitting element does not become too low. The fewer the number of light-emitting elements that emit light simultaneously in the light-emitting device 4, the fewer the number of pixels 20 that receive reflected light signals in the light-receiving unit 11. Therefore, it is desirable that the control unit 13 controls the number of pixels 20 that receive reflected light signals in the light-receiving unit 11 based on the number of light-emitting elements that simultaneously emit light signals in the light-receiving device 4 to prevent the light-receiving unit 11 from consuming unnecessary power.

[0132] Here, the pixel 20 that receives the reflected light signal is referred to as an active pixel (first pixel) 20a, and the pixel 20 that does not receive the reflected light signal is referred to as a passive pixel (second pixel) 20n. The active pixel 20a is arranged in a predetermined pixel area within the pixel array unit 19, and the passive pixel 20n is arranged in a pixel area other than the predetermined pixel area within the pixel array unit 19. According to an instruction from the control unit 13, the pixel control unit 17 turns on the PMOS transistor Q1 connected to the cathode of the SPAD 21 of the active pixel 20a to activate the current source 9, and turns off the PMOS transistor Q1 connected to the cathode of the SPAD 21 of the passive pixel 20n to stop the current source 9. This configuration prevents the reference voltage Vs from being supplied to the cathode of the SPAD 21 of the passive pixel 20n, so that light reception of the passive pixel 20n can be forcibly stopped, and the power consumption of the light receiving unit 11 can be reduced.

[0133] As described above, since the passive pixel 20n does not receive the reflected light signal, the counter group 28 disposed downstream of the SPAD 21 is not used. Therefore, in the first embodiment, the counter group 28 of the passive pixel 20n can be used as part of the counter group 28 of the active pixel 20a. In this case, the second counter group 28n is used while being connected to the counter group 28.

[0134] It should be noted that in this article, as will be described later Figure 8 As shown, the counter group 28 provided for the active pixel 20a is referred to as a first counter group 28a, each counter 31 constituting the first counter group 28a is referred to as a first counter 31a, the counter group 28 provided for the passive pixel 20n is referred to as a second counter group 28n, and each counter 31 constituting the second counter group 28n is referred to as a second counter 31n.

[0135] Figure 8 is a circuit diagram of main components of the photodetection device 1 according to the first embodiment. Figure 8 A configuration capable of executing the merge process is shown. Figure 8The structure of the pixel circuit 25 and the like connected to four active pixels 20 a and eight passive pixels 20 n as a unit for binning processing is shown.

[0136] like Figure 8 As shown, the light detection device 1 of the first embodiment includes a pixel circuit 25 connected to the active pixel 20a (hereinafter referred to as the active pixel circuit 25a), a first distribution circuit 27a connected to the active pixel circuit 25a, a first counter group 28a connected to the first distribution circuit 27a, a pixel circuit 25 connected to the passive pixel 20n (hereinafter referred to as the passive pixel circuit 25n), a second distribution circuit 27n connected to the passive pixel circuit 25n, a second counter group 28n connected to the second distribution circuit 27n, and a counter switching circuit 33, which switches whether to connect the second counter group 28n to the first counter group 28a.

[0137] The counter switching circuit 33 switches between connecting the end of the second distribution circuit 27n connected to the passive pixel 20n to the second counter group 28n and connecting one end of the second distribution circuit 27n to the end of the first distribution circuit 27a connected to the active pixel 20a. That is, the counter switching circuit 33 switches between counting the number of transitions of the pixel signal output from the active pixel circuit 25a using the first counter group without using the second counter group 28n and counting the number of transitions using both the first counter group 28a and the second counter group 28n.

[0138] The first distribution circuit 27 a , the second distribution circuit 27 n , and the counter switching circuit 33 each include a plurality of switches 30 . The distance measurement control unit 14 controls the switching of each switch 30 .

[0139] The second distribution circuit 27n includes a plurality of switches 30 connected to the second counter group 28n and switches 30 that switch between connecting the other ends of the plurality of switches 30 to the OR circuit 32 and connecting the other ends of the plurality of switches 30 to the counter switching circuit 33. The counter switching circuit 33 includes the switches 30 connected between one end of the first distribution circuit 27a and one end of the second distribution circuit 27n.

[0140] In the case of performing long-distance ranging, the ranging control unit 14 performs switching control on the counter switching circuit 33 to connect the second counter group 28n connected to the inactive pixel 20n to the first counter group 28a. Therefore, each of the second counters 31n constituting the second counter group 28n is used to generate data for some bins of the histogram generated based on the result of receiving light through the active pixel 20a.

[0141] The ranging control unit 14 functions as a mode selection unit that selects either a first mode in which the number of transitions of the pixel signal output from the active pixel circuit 25 a is counted using the first counter group 28 a without using the second counter group 28 n, or a second mode in which the number of transitions is counted using both the first counter group 28 a and the second counter group 28 n.

[0142] The count values ​​of the first counter group 28a and the second counter group 28n are used to measure the distance to the object 6. When the second mode is selected, the measurable range is longer than when the first mode is selected. As a specific example, the measurable range when the second mode is selected is equal to an integer multiple of at least twice the measurable range when the first mode is selected. Regardless of whether the first or second mode is selected, the distance resolution and resolution are the same.

[0143] Both the first mode and the second mode may have an exclusively selectable third mode and fourth mode. In the third mode, a single first counter group 28a is used to count the number of transitions of the signal output from the first pixel circuit 25. The third mode is a mode in which all pixels 20 of the pixel array unit 19 are active pixels 20a and no binning process is performed. In the fourth mode, multiple first counter groups 28a are used to count the number of transitions of the signal output from the first pixel circuit 25. The fourth mode is a mode in which all pixels 20 of the pixel array unit 19 are active pixels 20a and binning process is performed.

[0144] The fourth mode can have an exclusively selectable fifth mode, a sixth mode, and a seventh mode. The sixth mode has a longer measurable range than the fifth mode, a lower distance resolution than the fifth mode, and the same resolution as the fifth mode. The seventh mode has a longer measurable range than the fifth mode, and the same distance resolution and resolution as the fifth mode.

[0145] As described above, by connecting the second counter group 28n provided for the passive pixel 20n to the first counter group 28a, the number of bins of the histogram can be increased, thereby improving the accuracy of long-distance ranging.

[0146] Figure 9 and Figure 10 is a diagram showing a schematic configuration of a distance measuring system 2 including a light detecting device 1 and a light emitting device 4 according to the first embodiment. Figure 9 A state is shown in which all the light emitting elements 41 of the light emitting device 4 emit light simultaneously and all the pixels 20 of the light receiving unit 11 receive reflected light signals. Figure 101 and 2 show a state in which some of the plurality of light emitting elements 41 included in the light emitting device 4 emit light simultaneously and some of the plurality of pixels 20 included in the light receiving unit 11 receive reflected light signals. Figure 10 In FIG, the pixel 20 that receives the reflected light signal serves as the active pixel 20 a , and the pixel 20 that does not receive the reflected light signal serves as the passive pixel 20 n .

[0147] like Figure 9 and Figure 10 As shown, the light-emitting device 4 includes a VCSEL 42, in which a plurality of light-emitting elements 41 are arranged in a planar direction to achieve surface emission, and a laser diode driver (LDD) 43, which drives the VCSEL 42. The light-detecting device 1 includes a first substrate 44 and a second substrate 45 stacked on the first substrate 44. The first substrate 44 includes a pixel array unit 19 in which a plurality of pixels 20 are arranged in a planar direction. Each pixel 20 includes at least one SPAD 21. Figure 9 and Figure 10 An example is shown in which the area of ​​the second substrate 45 is larger than that of the first substrate 44 , but the size ratio between the first substrate 44 and the second substrate 45 is freely determined.

[0148] The light detecting device 1 transmits a signal in a low voltage differential signal (LVDS) format including distance measurement information about the object 6 and a serial peripheral interface (SPI) signal for serially transmitting various control signals to the LDD 43. The LDD 43 controls the light emitting area of ​​the VCSEL 42 based on the SPI signal. The SPI signal is an example of a serial communication method, and control signals of different communication methods can be transmitted from the light detecting device 1 to the LDD 43.

[0149] exist Figure 8 , an example has been described in which the second counter group 28n provided for the passive pixel 20n is used to expand the bins of the histogram of the active pixel 20a. However, the second counter group 28n can be used to expand the bit width of the first counter group 28a provided for the active pixel 20a. In this case, the bit width of each of the first counters 31a constituting the first counter group 28a can be expanded, making it possible to repeatedly perform distance measurement over a longer period of time, thereby improving the accuracy of the distance measurement of the object 6.

[0150] It should be noted that Figure 9 and Figure 10In the embodiment described above, the size of the light-emitting area of ​​the light-emitting device 4 and the size of the pixel area of ​​the active pixel 20a of the pixel array unit 19 are correlated, but they are not necessarily correlated. The technical features of the light-detecting device 1 according to the present embodiment are that the second counter group 28n provided for the passive pixel 20n is connected to the first counter group 28a provided for the active pixel 20a, and the size of the light-emitting area of ​​the light-emitting device 4 and the size of the pixel area of ​​the active pixel 20a of the pixel array unit 19 are not necessarily correlated.

[0151] Figure 11 1 is a diagram illustrating an example of controlling the light detecting device 1 and the light emitting device 4 by the host control unit 5 according to the first embodiment. The host control unit 5 controls the control unit 13 of the light detecting device 1 and the LDD 43 of the light emitting device 4 using, for example, an inter-integrated circuit (I2C) signal. Note that the I2C signal is an example, and the host control unit 5 can send control signals using different communication methods to the control unit 13 and the LDD 43.

[0152] The I2C signal transmitted from the host control unit 5 to the control unit 13 includes pixel position information on the active pixel 20a of the pixel array unit 19. The control unit 13 stores the pixel position information of the active pixel 20a sent from the host control unit 5 in the register 46 or the like.

[0153] The control unit 13 has a pixel setting unit 47 and an allocation setting unit 48. The pixel setting unit 47 transmits a signal indicating whether each pixel 20 of the pixel array unit 19 is an active pixel 20a or a passive pixel 20n to the distance measurement control unit 14 based on the pixel position information about the active pixel 20a transmitted from the host control unit 5.

[0154] The distribution setting unit 48 transmits switching control signals of the first distribution circuit 27 a , the second distribution circuit 27 n , and the plurality of switches 30 included in the counter switching circuit 33 to each switch 30 based on the pixel position of the active pixel 20 a transmitted from the host control unit 5 .

[0155] The ranging control unit 14 turns on the PMOS transistor Q1 connected to the cathode of the SPAD 21 of each active pixel 20 a of the pixel array unit 19 based on the signal transmitted from the pixel setting unit 47 of the control unit 13, and turns off the PMOS transistor Q1 connected to the cathode of the SPAD 21 of each passive pixel 20 n.

[0156] The distance measurement control unit 14 supplies power supply voltage to the AFE unit 22 of the active pixel circuit 25 a connected to each active pixel 20 a and stops supplying power supply voltage to the AFE unit 22 of the passive pixel circuit 25 n connected to each passive pixel 20 n .

[0157] The first distribution circuit 27 a , the second distribution circuit 27 n , and the counter switching circuit 33 perform switching control based on a signal sent from the distribution setting unit 48 to determine whether to connect the second counter group 28 n to the first counter group 28 a .

[0158] The I2C signal transmitted from the host control unit 5 to the LDD 43 of the light-emitting device 4 includes light-emitting area information about the light-emitting device 4. The LDD 43 stores the light-emitting area information transmitted from the host control unit 5 in the register 49. The LDD 43 includes an output circuit 50 that generates a drive signal indicating whether to drive each light-emitting element 41 of the VCSEL 42 based on the light-emitting area information. The VCSEL 42 controls whether to cause each light-emitting element 41 to emit light based on the drive signal output from the output circuit 50.

[0159] Figure 12 2 is a diagram illustrating an example of pixel positions of active pixels 20 a and passive pixels 20 n on a pixel array. Figure 12 The embodiment shown is one in which the pixel region of the active pixel 20a is arranged at the center of the pixel array unit 19 and the pixel regions of the passive pixels 20n are arranged around the pixel region of the active pixel 20a. By switching and controlling each switch 30 of the second distribution circuit 27n connected to the passive pixel circuit 25n of the passive pixel 20n, the second counter group 28n provided for the passive pixel 20n can be connected to the first counter group 28a provided for the active pixel 20a. Figure 12 The wiring 53 connecting the first distribution circuit 27 a connected to the first counter group 28 a and the second distribution circuit 27 n connected to the second counter group 28 n is schematically shown.

[0160] Note that the first distribution circuit 27 a , the second distribution circuit 27 n , the counter switching circuit 33 , the first counter group 28 a , and the second counter group 28 n are arranged on a second substrate 44 stacked on the first substrate 45 on which the pixel array unit 19 is arranged. Figure 12 A state where the first substrate 44 and the second substrate 45 stacked together are viewed from above is shown.

[0161] According to this embodiment, the number of first counters 31a constituting the first counter group 28a can be effectively increased while maintaining the resolution of the active pixels 20a. Therefore, the number of bins of the histogram can be increased to improve the distance accuracy of the object 6 located at a distance.

[0162] As described above, the second counter group 28n can be used not only to increase the number of histogram bins but also to extend the bit width of each first counter 31a of the first counter group 28a. In this case, the number of repetitions of the distance measurement of the object 6 can be further increased, thereby improving the accuracy of the distance measurement.

[0163] Figure 12 An embodiment in which the pixel region of the active pixel 20 a is arranged in the center of the pixel array unit 19 is shown, but the arrangement of the active pixels 20 a in the pixel array unit 19 and the size of the pixel region of the active pixel 20 a are freely determined.

[0164] In addition, when an object 6 is detected at any pixel position of the pixel array unit 19, a region of interest (ROI) area can be set at the position where the object 6 exists in the pixel array unit 19 based on the detection result, and each pixel 20 in the ROI area can be set as an active pixel 20a.

[0165] Figure 13 is a diagram illustrating an example in which each pixel 20 in the ROI region 54 functions as an active pixel 20 a and the pixel region other than the ROI region 54 includes inactive pixels 20 n . Figure 13 An example is shown where each active pixel 20a in the ROI area 54 is associated with any one of the passive pixels 20n. Figure 13 An embodiment is shown in which each active pixel 20a is associated with a passive pixel 20n located in a first direction X (horizontal direction) outside an ROI region 54. The active pixel 20a and the passive pixel 20n associated with each other are connected by a wiring 55. Each wiring 55 for association extends in the first direction X, and can reduce variations in signal propagation delay by preventing variations in the length of each wiring 55.

[0166] Note that each active pixel 20 a can be associated with a passive pixel 20 n located in a second direction (vertical direction) Y outside the ROI region 54. The size of the ROI region 54 can be further expanded by associating the passive pixels 20 n at pixel positions outside the ROI region 54 with the pixel positions of the active pixels 20 a in the ROI region 54.

[0167] Furthermore, more than two passive pixels 20n may be associated with one active pixel 20a. Figure 13 An embodiment is shown in which the wiring 55 extending in the second direction Y associates two passive pixels 20 n with one active pixel 20 a .

[0168] When the size of the ROI region 54 is limited, the pixel region of the passive pixel 20n outside the ROI region 54 can be ensured so that the length of the wiring 55 for associating the active pixel 20a and the passive pixel 20n can be as short as possible.

[0169] Figure 14 1 is a diagram showing a correspondence relationship between active pixels 20a and passive pixels 20n in a case where a plurality of light point regions 56 are provided in the pixel array unit 19. Figure 14 In the embodiment, each pixel 20 in each light spot area 56 functions as an active pixel 20 a , and each pixel 20 outside each light spot area 56 functions as an inactive pixel 20 n .

[0170] exist Figure 14 In the embodiment, each active pixel 20a in each light spot area 56 is associated with a passive pixel 20n located adjacent to the active pixel 20a outside the light spot area 56. Thus, the wiring 55 connecting the active pixel 20a and the corresponding passive pixel 20n can be shortened. The pixel position and size of each light spot area 56 can be freely controlled based on the pixel position information from the host control unit 5.

[0171] Figure 14 The plurality of active pixels 20a included in each light spot area 56 described in may be used as a unit for the merging process. Each of the plurality of active pixels 20a serving as a unit for the merging process may be associated with an active pixel 20n.

[0172] Which portion of the pixel array unit 19 is set as the light spot area 56 can be freely determined, and the wiring 55 for associating the plurality of pixels 20 can be set in advance so that the light spot area 56 can be set at any pixel position.

[0173] In addition, also in Figure 14 In the embodiment, a wiring 55 for associating two or more passive pixels 20n with one active pixel 20a may be provided.

[0174] It is possible to freely switch whether all pixels 20 of the pixel array unit 19 receive the reflected light signal or only Figure 13 The ROI area 54 shown receives the reflected light signal or only uses Figure 14 Light spot region 56 is shown receiving the reflected light signal.

[0175] Figure 151 is a diagram showing an embodiment of the count values ​​of the first counter group 28a and the count values ​​of the second counter group 28n connected to the first counter group 28a for the pixel region (ROI region 54 or light spot region 56) of the active pixels 20a provided in a portion of the pixel array unit 19. As shown in the figure, the count value of the second counter group, which was initially assumed to be zero, becomes a non-zero value. The second counter group 28n having a non-zero count value is used, for example, as information about the corresponding bin of the histogram.

[0176] Figure 16 is a diagram illustrating an example of count values ​​of the first counter group 28a of the active pixel 20a and the second counter group 28n of the passive pixel 20n in the case where the second counter group 28n is not used as part of the first counter group 28a. Figure 16 In this case, the count values ​​of the second counter group 28n are all zero, and the number of bins of the histogram cannot be expanded accordingly.

[0177] Figure 17 yes Figure 8 A circuit diagram of the main components of the light detection device 1 of a modified example. Figure 17 In, with Figure 8 The same components as in FIG are denoted by the same reference numerals, and the main differences will be described below.

[0178] exist Figure 17 In the embodiment of the present invention, some switches 30 in the second distribution circuit 27n are replaced with OR circuits 60. The OR circuit 60 performs a logical OR operation on the output signal of the OR circuit 32n, which performs a logical OR operation on the multiple pixel signals output from the multiple passive pixel circuits 25n, and the output signal of the OR circuit 60, which performs a logical OR operation on the multiple pixel signals output from the multiple active pixel circuits 25a after the merging process. The multiple pixel signals output from the multiple passive pixel circuits 25n are always at a low level, and the output signal of the OR circuit 32 will not become a high level. On the other hand, when any one of the multiple active pixel circuits 25a receives a reflected light signal, the OR circuit 32a becomes a high level. Therefore, when the OR circuit 60 is used instead of the switch 30, when the output of the OR circuit 32a becomes a high level, the output of the OR circuit 60 can be set to a high level, thereby obtaining the same effect as turning on the switch 30.

[0179] Figure 18 is a diagram summarizing the characteristics of the light detecting device 1 according to the first embodiment. Figure 18, the characteristics of the light detection device 1 according to the first embodiment are compared with the characteristics of the first and fifth comparative examples. The first comparative example is an embodiment in which all pixels 20 of the pixel array unit 19 are used as active pixels 20a and no merging process is performed. The second comparative example is an embodiment in which merging process is performed using 2×2 pixels (hereinafter, merging pixels) of the pixel array unit 19 as units. The third comparative example is an embodiment in which merging process is performed using 2×2 merging pixels of the pixel array unit 19 as units, and the bin width of the histogram generated based on the count value of the first counter group 28a for the merging pixels is doubled. The fourth comparative example is an embodiment in which merging process is performed using 2×2 merging pixels of the pixel array unit 19 as units, and the two first counter groups 28a are operated in a time-division manner. The fifth comparative example is an embodiment in which merging process is performed using 2×4 merging pixels of the pixel array unit 19 as units. Figure 18 The illustrated light detection device 1 according to the present embodiment is an example in which the binning process is performed in units of 2×2 binning pixels of the pixel array unit 19 , and one second counter group 28 n is connected to the first counter group 28 a .

[0180] In the second comparative example, since the binning process is performed using 2×2 binning pixels as a unit, the resolution is reduced to 1 / 2 compared to the first comparative example, but the number of first counter groups 28a is increased fourfold, thereby improving the distance resolution fourfold compared to the first comparative example. Figure 13 In FIG, the distance resolution is expressed as L / 4, which means that the resolution of a short distance interval can be obtained. The second comparative example obtains the same frame rate as the first comparative example.

[0181] In the third comparative example, due to the difference between the Figure 19A Compared to the histogram shown in Figure 19B As shown, the bin width of the histogram is widened, so the measurable range is doubled compared to the second comparative example, but the distance resolution is halved. In addition, the third comparative example achieves the same resolution and frame rate as those of the second comparative example.

[0182] In the fourth comparative example, Figure 19C As shown, since the two first counter groups 28a are operated in a time-division manner to generate two histograms (a first histogram and a second histogram), the measurable range is doubled compared to the first and second comparative examples. On the other hand, the frame rate is halved compared to the first to third comparative examples. Furthermore, the fourth comparative example achieves the same distance resolution as the second comparative example.

[0183] In the fifth comparative example, the number of pixels subjected to the binning process is doubled compared to the second to fourth comparative examples, resulting in a fourfold increase in resolution compared to the first comparative example. Furthermore, because the binning number is doubled in the fifth comparative example, the number of first counter groups 28a is also doubled. Therefore, the measurable range in the fifth comparative example is doubled compared to the second comparative example, while the distance resolution is approximately the same. The fifth comparative example achieves a frame rate that is approximately the same as that of the first to third comparative examples.

[0184] The light detection device 1 according to this embodiment has a measurable range that is substantially the same as that of the third to fifth embodiments, and a resolution that is substantially the same as that of the second to fourth embodiments. Furthermore, the light detection device 1 according to this embodiment has a distance resolution that is substantially the same as that of the second, fourth, and fifth embodiments. Furthermore, the light detection device 1 according to this embodiment has a frame rate that is substantially the same as that of the first to third and fifth embodiments.

[0185] As described above, in the first embodiment, since the second counter group 28n provided for the passive pixel 20n can be connected to the first counter group 28a provided for the active pixel 20a, the number of bins of the histogram for the active pixel 20a can be expanded, thereby improving the accuracy of distance measurement of the distant object 6. Alternatively, the second counter group 28n can be used to expand the bit width of each first counter 31a constituting the first counter group 28a, thereby improving the accuracy of distance measurement.

[0186] In the first embodiment, when the reflected light signal is received only in the light spot area 56 or the ROI area 54, the second counter group 20n provided for the passive pixel 28n can be effectively used. Therefore, the distance to the distant object 6 can be accurately measured without increasing the number of pixels of the pixel array unit 19.

[0187] (Second embodiment)

[0188] The light detection device 1 according to the second embodiment includes not only the light receiving unit 11 for distance measurement but also an imaging unit that captures object light.

[0189] Figure 20 2 is a diagram showing the configuration of main parts of a distance measuring system 2 including a light detection device 1 according to a second embodiment. Figure 20 The distance measuring system 2 in the embodiment includes a light detecting device 1, a light emitting device 4 and a host control unit 5. Figure 20 In, with Figure 9 The same components as in FIG are denoted by the same reference numerals, and the main differences will be described below.

[0190] Similar to Figure 7 , Figure 20 The light detecting device 1 shown includes a first substrate 44 on which the light receiving unit 11 is arranged and a second substrate 45 stacked on the first substrate 44. Figure 2 Similarly, the distance measurement processing unit 12 , the distance measurement control unit 14 , the light emission timing control unit 15 , the clock generation unit 16 , and the I / F unit 18 are arranged on the second substrate 45 .

[0191] in addition, Figure 20 The illustrated light detection device 1 includes an imaging unit 61 that captures light from a subject. The imaging unit 61 is also referred to as an image sensor. The imaging unit 61 is a semiconductor chip distinct from the stacked semiconductor chip 40 comprising the first substrate 44 and the second substrate 45. Alternatively, the imaging unit 61 may be disposed in a vacant area of ​​the first substrate 44.

[0192] The imaging unit 61 captures the image through a telephoto optical system ( Figure 20 The optical system may be a zoom lens with an adjustable focal length. Alternatively, a first imaging unit that captures the subject light transmitted through the telephoto optical system or a second imaging unit that captures the subject light transmitted through the wide-angle optical system may be freely selected.

[0193] Similar to Figure 9 , the light emitting device 4 includes a VCSEL 42 and an LDD 43. The host control unit 5 controls the imaging unit 61, the light receiving unit 11, and the LDD 43 using, for example, an I2C signal. Figure 20 The illustrated imaging unit 61 captures subject light transmitted through the telephoto optical system.

[0194] Figure 20 The imaging unit 61, light receiving unit 11, and light emitting device 4 shown operate in conjunction with each other under the control of the host control unit 5. When the imaging unit 61 captures subject light transmitted through the telephoto optical system, the light emitting device 4 narrows the light emitting area when measuring the distance to the object 6 located at a certain distance. The light receiving unit 11 receives the reflected light signal from the object 6 using the light spot area 56 having a pixel area of ​​a size corresponding to the light emitting area.

[0195] On the other hand, when the imaging unit 61 captures subject light for a wide-angle focal length, the light emitting device 4 widens the light emitting area, and the light receiving unit 11 receives a reflected light signal from the object 6 using a pixel area having a size corresponding to the light emitting area.

[0196] Figure 211 is a diagram showing the main components of the distance measuring system 2, which includes an AF lens driver (optical system driving unit) 62 that variably controls the focal length of the adjustable focus optical system (AF lens) of the imaging unit 61. The imaging unit 61 transmits an SPI signal to the light receiving unit 11, for example. The SPI signal includes information about the focal length of the AF lens. The light receiving unit 11 sends the SPI signal not only to the LDD 43 but also to the AF lens driver 62. In addition, Figure 20 Similarly, the host control unit 5 sends, for example, an I 2 C signal to the imaging unit 61 , the light receiving unit 11 , and the LDD 43 .

[0197] In the case where the imaging unit 61 captures an image of the object 6 located at a certain distance, the imaging unit 61 transmits information to this effect using an SPI signal. The SPI signal output from the imaging unit 61 is provided to the AF lens driver 62 via the light receiving unit 11. The AF lens driver 62 adjusts the focal length of the AF lens (not shown). In addition, the VCSEL 42 adjusts the light emitting area according to the focal length of the AF lens. In addition, the light receiving unit 11 controls the pixel area of ​​the active pixel 20a of the pixel array unit 19 according to the focal length of the AF lens. The control unit 13 controls the AF lens driver 62 based on the result of the distance measurement of the object of the reflected light from the object, and the reflected light is received by the light receiving unit 11.

[0198] Figure 22 It shows Figure 21 Flowchart of the processing operation of the ranging system 2 shown in FIG. First, it is determined whether to start the telephoto auto focus (AF) operation (step S1). The processing stays at step S1 until the telephoto AF operation starts. Optionally, the processing may be terminated without starting the telephoto AF operation. Figure 22 in the processing.

[0199] When starting the telephoto AF operation (Yes in step S1), the host device activates the telephoto imaging unit 61 (step S2). Next, the host device sets information about the telephoto focal length to the imaging unit 61 (step S3). The imaging unit 61 starts the telephoto focus adjustment operation (AF operation) (step S4).

[0200] The imaging unit 61 transmits the telephoto AF operation information to the light receiving unit 11 using the SPI signal (step S5). The light receiving unit 11 transmits the telephoto AF operation information to the LDD 43 using the SPI signal (step S6).

[0201] The light receiving unit 11 sets the pixel area of ​​the active pixel 20a based on the telephoto AF operation information (step S7). The LDD 43 sets the light emitting area of ​​the VCSEL 42 based on the telephoto AF operation information and starts emitting light (step S8).

[0202] The light receiving unit 11 receives the reflected light signal using the pixel area of ​​the active pixel 20a set in step S7, and starts the distance measurement process (step S9). The distance to the object 6 is measured based on the result of the reflected light signal received by the light receiving unit 11. Specifically, the distance to the object 6 is measured based on the peak position of the histogram, and the AF lens driver 62 is controlled based on the measured distance to the object 6 (step S10). The AF lens driver 62 adjusts the focal length of the AF lens according to the measured distance to the object 6 (step S11).

[0203] As described above, in the second embodiment, a telephoto imaging unit 61 is provided that captures subject light, and when the imaging unit 61 captures an image of an object located at a certain distance, the light-emitting area of ​​the light-emitting device 4 and the pixel area of ​​the active pixels 20a of the light-receiving unit 11 are controlled in conjunction with the focal length of the subject light incident on the imaging unit 61. With this configuration, when the imaging unit 61 captures an image of an object located at a certain distance, the light-emitting area of ​​the light-emitting device 4 is narrowed, the pixel area of ​​the active pixels 20a of the light-receiving unit 11 is narrowed, and the second counter group 28n of the passive pixels 20n is connected to the first counter group 28a. This allows for improved accuracy in distance measurement of the object 6 located at a certain distance.

[0204] (Third embodiment)

[0205] The third embodiment has a distinctive feature of the format of output data output from the generation unit 23 in the distance measurement processing unit 12 of the light detection device 1 according to the first embodiment or the second embodiment.

[0206] In the light detection device 1 according to the first or second embodiment, the second counter group 28n provided for the passive pixel 20n may be connected to the first counter group 28a. However, it is not possible to determine, based solely on the count values ​​of the first counter group 28a and the second counter group 28n, whether the count values ​​indicate the connection of the first counter group 28a and the second counter group 28n or whether the count values ​​indicate the independent reception results of the reflected light signal.

[0207] Therefore, the light detecting device 1 according to the third embodiment is characterized by adding various types of information to the output data output by the generating unit 23 in order to determine what the count values ​​of the first counter group 28 a and the second counter group 28 n represent.

[0208] The light detecting device 1 according to the third embodiment has a structure similar to Figure 2 The generation unit 23 of the distance measurement processing unit 12 outputs, for example, Figure 23A 、 Figure 23B 、 Figure 23C and Figure 23D Output data in any of the data formats shown. Figure 23A is a diagram showing a structure of output data when all the pixels 20 of the pixel array unit 19 function as active pixels 20 a and binning processing is not performed. Figure 23B 20 is a diagram showing a structure of output data in a case where some pixels of the pixel array unit 19 serve as active pixels 20 a . Figure 23C : is a diagram showing the structure of output data in the case where the merge process is performed. Figure 23D 1 is a diagram showing a structure of output data in the case where the first counter group 28 a and the second counter group 28 n are connected under the condition that both the active pixel 20 a and the passive pixel 20 n are included in the pixel array unit 19 .

[0209] exist 23A to 23D In any of the figures, for each frame, the output data includes embedded data (first bit string data) and a plurality of payload data (second bit string data). The embedded data includes information indicating characteristics of the payload data, and includes, for example, counter connection count information indicating the number of second counter groups 28n connected to the first counter group 28a, counter connection mode information for identifying whether the active pixel 20a is in the ROI area 54 or in the light spot area 56, and merging information indicating whether to perform merging processing. The embedded data may include information other than Figure 23A Information other than the three shown.

[0210] All pixels 20 of the pixel array unit 19 are active pixels 20a, and the output data without the merging process is as follows: Figure 23A As shown, the payload data of all pixels 20 are included in the order in which the pixels 20 are arranged.

[0211] like Figure 23C As shown, output data in the case where the pixel array unit 19 performs binning processing includes payload data including count values ​​of a plurality of pixels 20 (hereinafter referred to as binning pixels) serving as units of binning processing to combine the arrangement order of pixels.

[0212] like Figure 23D As shown, the output data in the case where the active pixel 20a and the passive pixel 20n coexist in the pixel array unit 19 includes payload data and payload data, the payload data including the count value of each first counter 31a constituting the first counter group 28a, and the payload data including the count value of each second counter 31n constituting the second counter group 28n connected to the first counter group 28a.

[0213] The generation unit 23 in the distance measurement processing unit 12 outputs the 23A to 23D The output data in the data format shown enables the ranging unit 24 to identify whether merging processing has been performed, whether the light spot area 56 or the ROI area 54 has been set in the pixel array unit 19, how many second counter groups 28n are connected to the first counter group 28a, etc., and accurately measure the distance to the object 6.

[0214] In the above-mentioned first to third embodiments, examples are mainly described in which the pixel array unit 19 including the distribution circuit 27 and the counter group 28 and the ranging processing unit 12 are arranged on separate substrates, but there is no limitation on where the pixel array unit 19 and the ranging processing unit 12 are arranged, and for example, the pixel array unit 19 and the ranging processing unit 12 may be arranged on the same substrate.

[0215] In addition, you can use Figure 5A The configuration shown is one in which the counter group 28 is integrated into the histogram generation unit 29 to eliminate the need for a separate counter group 28, but even in this case, a plurality of histogram generation units 29 can be connected as needed by connecting the distribution circuit 27 to the plurality of histogram generation units 29.

[0216] (Fourth embodiment)

[0217] In the first to third embodiments described above, an example in which the counter group 28 is provided for each pixel has been described, but the counter group 28 may be provided for each group of a plurality of pixels. In this case, the counter group 28 may be integrated into the histogram generating unit 29.

[0218] Figure 24 is a block diagram of main components of a photodetection device 1 according to a fourth embodiment. Figure 24 The light detection device 1 shown generates a histogram using a macro pixel 20m including a plurality of active pixels 20a or using a plurality of active pixels 20a in a macro pixel 20m as a unit. The pixel array unit 19 includes at least one macro pixel 20m and a plurality of passive pixels other than the macro pixel 20m.

[0219] Figure 24 The illustrated light detection device 1 includes an active pixel circuit group 25ag, a first time-determined value (TDC) 65a, a first histogram generation unit 29a, and a first distribution circuit 27a for each active pixel group 20ag. Each active pixel group 20ag includes at least two active pixels 20a belonging to a macropixel 20m. The first TDC 65a converts the pixel signals output from the active pixel circuit group 25ag into temporal digital signals. The first histogram generation unit 29a generates a histogram based on the temporal digital signals. The first distribution circuit 27a is disposed between the first TDC 65a and the first histogram generation unit 29a.

[0220] also, Figure 24 The light detection device shown includes, for each passive pixel group 20ng including at least two passive pixels 20n, a passive pixel circuit group 25ng, a second TDC 65n, a second histogram generation unit 29n, and a second distribution circuit 27n.

[0221] The first histogram generating unit 29 a and the second histogram generating unit 29 n each have a function of counting a temporal digital signal.

[0222] The first distribution circuit 27a and the second distribution circuit 27n are composed of Figure 2 The distance measurement control unit 14 shown performs switching control. For example, in the case of performing long distance measurement, the distance measurement control unit 14 may connect the second histogram generation unit 29n corresponding to the passive pixel group 20ng to the first histogram generation unit 29a.

[0223] As described above, in the fourth embodiment, a first histogram generation unit 29a is provided for each set of the plurality of active pixels 20a, and a second histogram generation unit 29n is provided for each set of the plurality of passive pixels 20n. In the fourth embodiment, the second histogram generation unit 29n can be connected to the first histogram generation unit 29a as needed, and similarly to the first to third embodiments, more counters (histogram generation units) can be used to perform distance measurement for long-distance distance measurement without increasing the total number of counters.

[0224] (Application Example)

[0225] The technology according to the present disclosure can be applied to various products. For example, the technology according to the present disclosure can also be implemented as a device installed on any type of mobile body (such as an automobile, electric vehicle, hybrid electric vehicle, motorcycle, bicycle, personal mobility, aircraft, drone, ship, robot, construction machine or agricultural machine (tractor)).

[0226] Figure 25 7010 is a block diagram showing an embodiment of a schematic configuration of a vehicle control system 7000 as an example of a mobile body control system to which the technology according to the present disclosure can be applied. The vehicle control system 7000 includes a plurality of electronic control units connected to each other via a communication network 7010. Figure 25In the illustrated embodiment, a vehicle control system 7000 includes a driving system control unit 7100, a body system control unit 7200, a battery control unit 7300, an external vehicle information detection unit 7400, an internal vehicle information detection unit 7500, and an integrated control unit 7600. For example, a communication network 7010 connecting the plurality of control units to each other may be an in-vehicle communication network conforming to any standard, such as a controller area network (CAN), a local interconnect network (LIN), a local area network (LAN), FlexRay (registered trademark), or the like.

[0227] Each control unit includes a microcomputer that performs calculations according to various programs; a storage unit that stores the programs executed by the microcomputer and parameters used for various operations; and a drive circuit that drives various controlled devices. Each control unit also includes a network interface (I / F) for communicating with other control units via the communication network 7010; and a communication I / F for communicating with devices and sensors inside and outside the vehicle via wired or wireless communication. Figure 25 The functional components of the illustrated integrated control unit 7600 include a microcomputer 7610, a general-purpose communication I / F 7620, a dedicated communication I / F 7630, a positioning unit 7640, a beacon receiving unit 7650, an in-vehicle device I / F 7660, a sound / image output unit 7670, an in-vehicle network I / F 7680, and a storage unit 7690. Other control units similarly include a microcomputer, a communication I / F, a storage unit, and the like.

[0228] The driving system control unit 7100 controls the operation of devices related to the vehicle's drive system according to various programs. For example, the driving system control unit 7100 functions as a control device for a driving force generating device (such as an internal combustion engine, a drive motor, etc.) for generating driving force for the vehicle, a driving force transmission mechanism for transmitting driving force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, a braking device for generating braking force for the vehicle, and the like. The driving system control unit 7100 may also function as a control device for an anti-lock braking system (ABS), an electronic stability control (ESC), and the like.

[0229] Driving system control unit 7100 is connected to vehicle state detection unit 7110. Vehicle state detection unit 7110 includes, for example, at least one of a gyroscopic sensor for detecting the angular velocity of the vehicle's axial rotational motion, an acceleration sensor for detecting vehicle acceleration, and sensors for detecting the amount of accelerator pedal operation, amount of brake pedal operation, steering wheel angle, engine speed, wheel speed, and the like. Driving system control unit 7100 performs computational processing using signals input from vehicle state detection unit 7110 to control the internal combustion engine, drive motor, electric power steering, brake system, and the like.

[0230] The body system control unit 7200 controls the operation of various devices installed on the vehicle body according to various programs. For example, the body system control unit 7200 functions as a control device for a keyless entry system, a smart key system, power windows, and various lights such as the headlights, backup lights, brake lights, turn signals, and fog lights. In this case, radio waves transmitted from a mobile device can be input to the body system control unit 7200 as a substitute for signals from buttons or various switches. The body system control unit 7200 receives these input radio waves or signals and controls the vehicle's door locks, power windows, lights, and other functions.

[0231] The battery control unit 7300 controls the secondary battery 7310, which serves as a power source for driving the motor, according to various programs. For example, information regarding battery temperature, battery output voltage, the amount of charge remaining in the battery, and the like is supplied to the battery control unit 7300 from the battery device including the secondary battery 7310. The battery control unit 7300 performs arithmetic operations using these signals and controls the temperature of the secondary battery 7310 or controls a cooling device provided to the battery device or the like.

[0232] The vehicle exterior information detection unit 7400 detects information outside the vehicle including the vehicle control system 7000. For example, the vehicle exterior information detection unit 7400 is connected to at least one of the imaging unit 7410 and the vehicle exterior information detection unit 7420. The imaging unit 7410 includes at least one of a time-of-flight (ToF) camera, a stereo camera, a monocular camera, an infrared camera, and other cameras. For example, the vehicle exterior information detection unit 7420 includes at least one of an environmental sensor for detecting current atmospheric conditions or weather conditions and a peripheral information detection sensor for detecting other vehicles, obstacles, pedestrians, and the like outside the vehicle including the vehicle control system 7000.

[0233] For example, the environmental sensor may be at least one of a raindrop sensor for detecting rain, a fog sensor for detecting fog, a sunlight sensor for detecting sunlight levels, and a snow sensor for detecting snowfall. The peripheral information detection sensor may be at least one of an ultrasonic sensor, a radar device, and a LIDAR device (a light detection and ranging device, or a laser imaging detection and ranging device). Each of the imaging unit 7410 and the vehicle exterior information detection unit 7420 may be configured as an independent sensor or device, or may be configured as a device in which multiple sensors or devices are integrated.

[0234] Here, Figure 26The following illustrates an example of the installation locations of the imaging unit 7410 and the vehicle exterior information detection unit 7420. Imaging units 7910, 7912, 7914, 7916, and 7918 are installed, for example, at least one of the front nose, side mirrors, rear bumper, and rear doors of the vehicle 7900, and the upper portion of the windshield within the vehicle. Imaging unit 7910, located within the vehicle's front nose, and imaging unit 7918, located within the vehicle's upper portion of the windshield, primarily capture images of the front of the vehicle 7900. Imaging units 7912 and 7914, located within the side mirrors, primarily capture images of the sides of the vehicle 7900. Imaging unit 7916, located within the rear bumper or rear door, primarily captures images of the rear of the vehicle 7900. Imaging unit 7918, located within the vehicle's upper portion of the windshield, primarily detects vehicles ahead, pedestrians, obstacles, signals, traffic signs, lanes, and the like.

[0235] Notice, Figure 26 Examples of imaging ranges for each of imaging units 7910, 7912, 7914, and 7916 are shown. Imaging range a represents the imaging range of imaging unit 7910, which is positioned at the front nose. Imaging ranges b and c represent the imaging ranges of imaging units 7912 and 7914, respectively, that are provided to the side mirrors. Imaging range d represents the imaging range of imaging unit 7916, which is positioned at the rear bumper or rear door. For example, by superimposing image data captured by imaging units 7910, 7912, 7914, and 7916, a bird's-eye view image of vehicle 7900 viewed from above can be obtained.

[0236] The exterior information detection units 7920, 7922, 7924, 7926, 7928, and 7930 located at the front, rear, sides, corners, and above the windshield of vehicle 7900 can also be, for example, ultrasonic sensors or radar devices. The exterior information detection units 7920, 7926, and 7930 located at the front nose, rear bumper, rear door, and above the windshield inside the vehicle 7900 can also be, for example, LIDAR devices. These exterior information detection units 7920 and 7930 are primarily used to detect preceding vehicles, pedestrians, obstacles, and the like.

[0237] return Figure 25, will be described further. The outside vehicle information detection unit 7400 causes the imaging unit 7410 to capture images outside the vehicle and receive captured image data. In addition, the outside vehicle information detection unit 7400 receives detection information from the outside vehicle information detection unit 7420 connected to the outside vehicle information detection unit 7400. In the case where the outside vehicle information detection unit 7420 is an ultrasonic sensor, a radar device, or a LIDAR device, the outside vehicle information detection unit 7400 transmits ultrasonic waves, electromagnetic waves, etc., and receives information on the received reflected waves. Based on the received information, the outside vehicle information detection unit 7400 can perform processing to detect objects such as humans, vehicles, obstacles, signs, and text on the road surface, or detect the distance to the object. In addition, the outside vehicle information detection unit 7400 can also perform environmental recognition processing to identify rainfall, fog, road conditions, etc. based on the received information. The outside vehicle information detection unit 7400 can calculate the distance to objects outside the vehicle based on the received information.

[0238] In addition, the vehicle exterior information detection unit 7400 can perform image recognition processing based on the received image data to identify humans, vehicles, obstacles, signs, text on the road, etc., or detect the distance thereto. The vehicle exterior information detection unit 7400 can perform processing such as distortion correction and alignment on the received image data, and combine image data imaged by multiple different imaging units 7410 to generate a bird's-eye view image or a panoramic image. The vehicle exterior information detection unit 7400 can use the image data captured by the imaging unit 7410, which includes different imaging units, to perform viewpoint conversion processing.

[0239] The in-vehicle information detection unit 7500 detects information about the interior of the vehicle. For example, the in-vehicle information detection unit 7500 is connected to a driver state detection unit 7510 that detects the state of the driver. The driver state detection unit 7510 may include a camera that images the driver, a biosensor that detects the driver's biological information, a microphone that collects sounds inside the vehicle, and the like. The biosensor is, for example, provided in a seat surface, a steering wheel, and the like, and detects the biological information of a passenger sitting on the seat or the driver holding the steering wheel. Based on the detection information input from the driver state detection unit 7510, the in-vehicle information detection unit 7500 can calculate the driver's fatigue or the driver's concentration, or can determine whether the driver is dozing off. The in-vehicle information detection unit 7500 may subject the audio signal obtained by collecting the sounds to processing such as noise cancellation processing.

[0240] The integrated control unit 7600 controls general operations within the vehicle control system 7000 according to various programs. The integrated control unit 7600 is connected to an input unit 7800. The input unit 7800 is implemented by a device capable of inputting operations by the occupant, such as a touch panel, buttons, microphone, switch, or lever. The integrated control unit 7600 may be supplied with data obtained through voice recognition of speech input via the microphone. The input unit 7800 may, for example, be a remote control device using infrared or other radio waves, or an externally connected device that supports the operation of the vehicle control system 7000, such as a mobile phone or personal digital assistant (PDA). The input unit 7800 may, for example, be a camera. In this case, the occupant can input information through gestures. Alternatively, data obtained by detecting the movement of a wearable device worn by the occupant can be input. Furthermore, the input unit 7800 may include, for example, an input control circuit that generates an input signal based on information input by the occupant using the input unit 7800 and outputs the generated input signal to the integrated control unit 7600. The occupants and the like input various data or instruct processing operations to the vehicle control system 7000 by operating the input unit 7800 .

[0241] The storage unit 7690 may include a read-only memory (ROM) that stores various programs executed by the microcomputer and a random access memory (RAM) that stores various parameters, operation results, sensor values, etc. In addition, the storage unit 7690 may be implemented by a magnetic storage device such as a hard disk drive (HDD), a semiconductor storage device, an optical storage device, a magneto-optical storage device, or the like.

[0242] The general communication I / F 7620 is a widely used communication I / F that mediates communications with various devices present in the external environment 7750. The general communication I / F 7620 can implement cellular communication protocols such as Global System for Mobile Communications (GSM (registered trademark)), Worldwide Interoperability for Microwave Access (WiMAX (registered trademark)), Long Term Evolution (LTE (registered trademark)), LTE-Advanced (LTE-A), or other wireless communication protocols such as wireless LAN (also known as Wireless Fidelity (Wi-Fi (registered trademark)) and Bluetooth (registered trademark). For example, the general communication I / F 7620 can connect to devices (e.g., application servers or control servers) present on an external network (e.g., the Internet, a cloud network, or a company-specific network) via a base station or access point. Furthermore, for example, the general communication I / F 7620 can connect to terminals present near the vehicle (e.g., the driver's terminal, a pedestrian or a store, or a machine-type communication (MTC) terminal) using peer-to-peer (P2P) technology.

[0243] The dedicated communication I / F 7630 is a communication I / F that supports the development of communication protocols for use in vehicles. The dedicated communication I / F 7630 can implement standard protocols such as Wireless Access in Vehicular Environments (WAVE) (which is a combination of Institute of Electrical and Electronics Engineers (IEEE) 802.11p as a lower layer and IEEE 1609 as a higher layer), Dedicated Short Range Communication (DSRC), or cellular communication protocols. The dedicated communication I / F 7630 generally implements V2X communication, which is a concept that includes one or more of the following: vehicle-to-vehicle communication, road-to-vehicle communication, vehicle-to-home communication, and pedestrian-to-vehicle communication.

[0244] The positioning unit 7640 performs positioning by, for example, receiving a global navigation satellite system (GNSS) signal (e.g., a GPS signal from a global positioning system (GPS) satellite) from a GNSS satellite, and generates position information including the latitude, longitude, and altitude of the vehicle. Incidentally, the positioning unit 7640 may identify the current position by exchanging signals with a wireless access point, or may obtain position information from a terminal such as a mobile phone, a personal handyphone system (PHS), or a smartphone having a positioning function.

[0245] For example, the beacon receiving unit 7650 receives radio waves or electromagnetic waves transmitted from a radio station installed on a road or the like, and thereby obtains information on the current position, congestion, closed roads, necessary time, etc. Incidentally, the function of the beacon receiving unit 7650 may be included in the above-mentioned dedicated communication I / F 7630.

[0246] The in-vehicle device I / F 7660 is a communication interface that mediates the connection between the microcomputer 7610 and the various in-vehicle devices 7760 present in the vehicle. The in-vehicle device I / F 7660 can establish a wireless connection using a wireless communication protocol such as wireless LAN, Bluetooth (registered trademark), near field communication (NFC), or wireless universal serial bus (WUSB). In addition, the in-vehicle device I / F 7660 can establish a wired connection via a universal serial bus (USB), a high-definition multimedia interface (HDMI (registered trademark)), a mobile high-definition link (MHL), etc. via a connection terminal (and a cable, if necessary) not shown in the figure. The in-vehicle device 7760 may, for example, include at least one of a mobile device and a wearable device owned by the occupant and an information device carried or attached to the vehicle. The in-vehicle device 7760 may also include a navigation device that searches for a route to any destination. The in-vehicle device I / F 7660 exchanges control signals or data signals with these in-vehicle devices 7760.

[0247] The in-vehicle network I / F 7680 is an interface that mediates communication between the microcomputer 7610 and the communication network 7010. The in-vehicle network I / F 7680 transmits and receives signals and the like according to a predetermined protocol supported by the communication network 7010.

[0248] The microcomputer 7610 of the integrated control unit 7600 controls the vehicle control system 7000 according to various programs based on information obtained via at least one of the general communication I / F 7620, the dedicated communication I / F 7630, the positioning unit 7640, the beacon receiving unit 7650, the in-vehicle device I / F 7660, and the in-vehicle network I / F 7680. For example, the microcomputer 7610 can calculate control target values ​​for the driving force generation device, the steering mechanism, or the braking device based on the information obtained about the interior and exterior of the vehicle, and output control commands to the driving system control unit 7100. For example, the microcomputer 7610 can perform cooperative control to implement functions of an advanced driver assistance system (ADAS), including collision avoidance or shock absorption for the vehicle, follow-up driving based on a following distance, maintaining vehicle speed for driving, warning of vehicle collision, warning of vehicle deviation from a lane, and the like. In addition, the microcomputer 7610 can perform cooperative control intended for autonomous driving by controlling the driving force generating device, steering mechanism, braking device, etc. based on the information obtained about the vehicle's surrounding environment, which enables the vehicle to travel automatically without depending on the driver's operation, etc.

[0249] Based on information obtained via at least one of the general communication I / F 7620, the dedicated communication I / F 7630, the positioning unit 7640, the beacon receiving unit 7650, the in-vehicle device I / F 7660, and the in-vehicle network I / F 7680, the microcomputer 7610 can generate three-dimensional distance information between the vehicle and objects such as surrounding structures and people, and generate local map information including information about the surroundings of the vehicle's current location. Furthermore, based on the obtained information, the microcomputer 7610 can predict dangers such as a vehicle collision, the approach of pedestrians, or entering a closed road, and generate a warning signal. The warning signal can, for example, generate a warning sound or illuminate a warning light.

[0250] The sound / image output unit 7670 transmits an output signal of at least one of sound and image to an output device, which can visually or auditorily notify the occupants of the vehicle or the outside of the vehicle of information. Figure 25In an embodiment of the present invention, an audio speaker 7710, a display unit 7720, and an instrument panel 7730 are illustrated as output devices. For example, the display unit 7720 may include at least one of an onboard display and a head-up display. The display unit 7720 may have an augmented reality (AR) display function. The output device may be different from these devices and may be another device such as headphones, a wearable device such as a glasses-type display worn by a passenger, a projector, a lamp, etc. In the case where the output device is a display device, the display device visually displays the results obtained by various processes performed by the microcomputer 7610 or information received from another control unit in various forms such as text, images, tables, graphics, etc. In addition, in the case where the output device is an audio output device, the audio output device converts an audio signal consisting of reproduced audio data or sound data, etc. into an analog signal and outputs the analog signal audibly.

[0251] Note that in Figure 25 In the illustrated embodiment, at least two control units connected to each other via the communication network 7010 can be integrated into a single control unit. Alternatively, each individual control unit can include multiple control units. In addition, the vehicle control system 7000 may include another control unit not shown in the figure. In addition, part or all of the functions performed by one of the control units described above can be assigned to another control unit. That is, as long as information is sent and received via the communication network 7010, predetermined arithmetic processing can be performed by any control unit. Similarly, a sensor or device connected to one of the control units can be connected to another control unit, and multiple control units can send and receive detection information to each other via the communication network 7010.

[0252] In the above vehicle control system 7000, see Figure 2 The light detection device 1 of this embodiment described above can be applied to Figure 25 The vehicle exterior information detection unit 7400 of the application example shown.

[0253] It should be noted that the present technology can have the following configurations.

[0254] (1) A light detection device comprising:

[0255] a first counter group, comprising at least two first counters;

[0256] a first pixel circuit or a first pixel circuit group connected to the first counter group;

[0257] a first pixel connected to a first pixel circuit or a first pixel group connected to a first pixel circuit group;

[0258] a second counter group, comprising at least two second counters;

[0259] a second pixel circuit or a second pixel circuit group connected to the second counter group;

[0260] a second pixel connected to a second pixel circuit or a second pixel group connected to a second pixel circuit group; and

[0261] The switching circuit switches between counting the number of transitions of the output signal of the first pixel circuit or the first pixel circuit group using the first counter group without using the second counter group and counting the number of transitions using both the first counter group and the second counter group.

[0262] (2) The light detection device according to (1), wherein

[0263] The first pixel or the first pixel group includes an active pixel or an active pixel group for receiving reflected light from the object, and

[0264] The second pixel or the second pixel group includes a passive pixel or a passive pixel group that is not used to receive reflected light.

[0265] (3) The light detection device according to (1) or (2), further comprising:

[0266] a mode selection unit, the mode selection unit selecting a first mode or a second mode, in which the first mode counts the number of transitions of the output signal of the first pixel circuit or the first pixel circuit group using the first counter group without using the second counter group, and in which the second mode counts the number of transitions using both the first counter group and the second counter group, wherein

[0267] The switching circuit performs switching according to the selection made by the mode selection unit.

[0268] (4) The light detection device according to (3), wherein

[0269] The count values ​​of the first counter group and the second counter group are used to measure the distance to the object.

[0270] In the case where the second mode is selected, the measurable range is longer than in the case where the first mode is selected, and

[0271] Regardless of whether the first or second mode is selected, the distance resolution and resolution are the same.

[0272] (5) The light detection device according to (4), wherein

[0273] The measurable range in the case where the second mode is selected is equal to an integral multiple of at least two times the measurable range in the case where the first mode is selected.

[0274] (6) The light detection device according to any one of (3) to (5), wherein

[0275] Each of the first mode and the second mode further includes an exclusively selectable third mode and a fourth mode,

[0276] In a third mode, one of the first counter groups is used to count the number of transitions of the output signal of the first pixel circuit or the first pixel circuit group, and

[0277] In the fourth mode, a plurality of first counter groups are used to count the number of transitions of the output signal of the first pixel circuit or the first pixel circuit group.

[0278] (7) The light detection device according to (6), wherein

[0279] The fourth mode also includes the exclusively selectable fifth mode, sixth mode, and seventh mode,

[0280] The sixth mode is longer than the fifth mode in measurable range, lower than the fifth mode in distance resolution, and the same as the fifth mode in resolution, and

[0281] The seventh mode is longer than the fifth mode in a measurable range and is identical to the fifth mode in distance resolution and resolution.

[0282] (8) The light detection device according to any one of (1) to (7), further comprising:

[0283] a first substrate including a pixel array unit in which a plurality of first pixels or a first pixel group and a plurality of second pixels or a second pixel group are arranged; and

[0284] A second substrate is provided, wherein a plurality of first pixel circuits or first pixel circuit groups, a plurality of first counter groups, a plurality of second pixel circuits or second pixel circuit groups, a plurality of second counter groups and a plurality of switching circuits are arranged, and the second substrate is stacked on the first substrate.

[0285] (9) The light detection device according to (8), wherein

[0286] A plurality of first pixels or a plurality of first pixel groups are arranged in a predetermined pixel area in the pixel array unit, and

[0287] A plurality of second pixels or a plurality of second pixel groups are arranged in a pixel area other than a predetermined pixel area in the pixel array unit.

[0288] (10) The light detection device according to any one of (3) to (7), further comprising:

[0289] an output unit that generates output data including first bit string data and second bit string data, the first bit string data including information about the mode selected by the mode selection unit, the second bit string data including a count value of the first counter group when the first mode is selected or count values ​​of both the first counter group and the second counter group when the second mode is selected; and an output unit that generates a signal.

[0290] (11) The light detection device according to (10), wherein

[0291] When the second mode is selected, the first bit string data includes information on the number of second counter groups connected to the first counter group.

[0292] (12) The light detection device according to (10) or (11), wherein

[0293] The first bit string data includes information for identifying whether to perform a merging process in which counting is performed using at least two of the first counter group or to perform counting using one of the first counter group.

[0294] (13) The light detection device according to any one of (10) to (12), wherein

[0295] The first bit string data contains information for identifying whether the number of transitions in a specific pixel region of interest is to be counted or the number of transitions in a predetermined partial pixel region is to be counted.

[0296] (14) The light detection device according to any one of (10) to (13), wherein

[0297] The second bit string data includes a plurality of bit string data in which count values ​​of the first counter group and the second counter group corresponding to each of all the first pixels are arranged in pixel order when the second mode is selected.

[0298] (15) The light detection device according to any one of (1) to (14), further comprising:

[0299] a first pixel array unit in which a plurality of first pixels or a first pixel group and a plurality of second pixels or a second pixel group are arranged;

[0300] a second pixel array unit in which a plurality of third pixels each capturing subject light is arranged; and

[0301] The control unit controls the light receiving range of the second pixel array unit according to the focal length of the subject light incident on the second pixel array unit.

[0302] (16) The light detection device according to (15), wherein

[0303] In the case of controlling the focal length of the second pixel array unit toward the telephoto side, the control unit further reduces the size of the pixel area of ​​the plurality of first pixels or the plurality of first pixel groups in the first pixel array unit.

[0304] (17) The light detection device according to (15) or (16), further comprising:

[0305] an optical system driving unit that drives a focus-adjustable optical system that adjusts the focal length of the subject light incident on the second pixel array unit, wherein

[0306] The control unit controls the optical system driving unit based on a measurement result of the distance to the object based on reflected light from the object received by the plurality of first pixels or the plurality of first pixel groups in the first pixel array unit.

[0307] (18) A distance measurement system comprising:

[0308] a light-emitting device for illuminating an object with light;

[0309] a light receiving unit that receives light emitted by the light emitting device and reflected by the subject;

[0310] a distance measuring unit that measures a distance to an object based on the light emitted by the light emitting device and the reflected light received by the light receiving unit; and

[0311] A control unit controls the light emitting device, the light receiving unit and the distance measuring unit, wherein:

[0312] The light receiving unit includes:

[0313] A pixel array unit comprising a plurality of first pixels or a first pixel group and a plurality of second pixels or a second pixel group;

[0314] a plurality of first pixel circuits connected to the plurality of first pixels; or a plurality of first pixel circuit groups connected to the plurality of first pixel groups;

[0315] a first counter group, provided for each of the plurality of first pixel circuits or the plurality of first pixel circuit groups, the first counter group including a plurality of first counters;

[0316] a plurality of second pixel circuits connected to the plurality of second pixels, or a plurality of second pixel circuit groups connected to the plurality of second pixel groups;

[0317] a second counter group provided for each of the plurality of second pixel circuits or the plurality of second pixel circuit groups, the second counter group including a plurality of second counters; and

[0318] A switching circuit switches between counting the number of transitions of each output signal of a plurality of first pixel circuits or a plurality of first pixel circuit groups using a corresponding first counter group without using a corresponding second counter group, and counting the number of transitions using both the corresponding first counter group and the corresponding second counter group.

[0319] (19) The ranging system according to (18), wherein

[0320] The light emitting device includes a plurality of light emitting units capable of individually controlling whether to emit light based on control of a control unit, and

[0321] The control unit controls the size of the light emitting areas of the plurality of light emitting units in combination with the size of the pixel areas of the plurality of first pixels or the plurality of first pixel groups in the pixel array unit.

[0322] The various aspects of the present disclosure are not limited to the above-described embodiments, but include various modifications that can be conceived by those skilled in the art, and the effects of the present disclosure are not limited to the above-described effects. That is, various additions, modifications, and partial deletions may be made without departing from the concept and spirit of the present disclosure as defined in the claims and their equivalents.

[0323] Reference Symbol List

[0324] 1. Light detection device

[0325] 2 Ranging System

[0326] 3 Application Unit

[0327] 4 Light-emitting device

[0328] 5 Host control unit

[0329] 6 Objects

[0330] 9 Current Source

[0331] 11 Light receiving unit

[0332] 12 Distance measurement processing unit

[0333] 13 Control Unit

[0334] 14 Distance measurement control unit

[0335] 15. Luminous timing control unit

[0336] 16 clock generation units

[0337] 17 Pixel Control Unit

[0338] 18I / F unit

[0339] 19 pixel array unit

[0340] 20 pixels

[0341] 20a Active Pixel

[0342] 20n passive pixels

[0343] 22AFE unit

[0344] 23 Generation Unit

[0345] 24 Distance measuring device

[0346] 25 First pixel circuit

[0347] 25 pixel circuit

[0348] 25a Active pixel circuit

[0349] 25n passive pixel circuit

[0350] 26 Inverter

[0351] 27 Distribution Circuit

[0352] 27a First distribution circuit 27a

[0353] 27n Second distribution circuit

[0354] 28 counter groups

[0355] 28a First counter group

[0356] 28n Second counter group

[0357] 29 Histogram generation unit

[0358] 30 switches

[0359] 30g pixel group

[0360] 31 counter

[0361] 31a First counter

[0362] 31n Second Counter

[0363] 32OR circuit

[0364] 32a OR circuit

[0365] 32n OR circuit

[0366] 33 Counter switching circuit

[0367] 40 semiconductor chips

[0368] 41 Light-emitting element

[0369] 44 first substrate

[0370] 45 second substrate

[0371] 46 registers

[0372] 47 pixel setting unit

[0373] 48 Allocation Setting Unit

[0374] 49 registers

[0375] 50 Output circuit

[0376] 53 Wiring

[0377] 54ROI area

[0378] 55 Wiring

[0379] 56 light spot area

[0380] 60OR circuit

[0381] 61 imaging units

[0382] 62AF lens driver

Claims

1. A light detection device, comprising: a first counter group, comprising at least two first counters; a first pixel circuit or a first pixel circuit group connected to the first counter group; a first pixel connected to the first pixel circuit; or a first pixel group connected to the first pixel circuit group; a second counter group, comprising at least two second counters; a second pixel circuit or a second pixel circuit group connected to the second counter group; a second pixel connected to the second pixel circuit; or a second pixel group connected to the second pixel circuit group; as well as A switching circuit switches between counting the number of transitions of the output signal of the first pixel circuit or the first pixel circuit group without using the second counter group but using the first counter group and counting the number of transitions using both the first counter group and the second counter group.

2. The light detection device according to claim 1, wherein The first pixel or the first pixel group comprises an active pixel or an active pixel group for receiving reflected light from an object; and The second pixel or the second pixel group includes a passive pixel or a passive pixel group not used for receiving the reflected light.

3. The light detection device according to claim 1 , further comprising: a mode selection unit configured to select a first mode or a second mode, wherein in the first mode, the number of transitions of the output signal of the first pixel circuit or the first pixel circuit group is counted without using the second counter group but using the first counter group; and in the second mode, the number of transitions is counted using both the first counter group and the second counter group, wherein: The switching circuit performs switching according to the selection made by the mode selection unit.

4. The light detection device according to claim 3, wherein The count values ​​of the first counter group and the second counter group are used to measure the distance to the object; When the second mode is selected, the measurable range is longer than when the first mode is selected; and Regardless of whether the first mode or the second mode is selected, the distance resolution and the resolution are the same.

5. The light detection device according to claim 4, wherein The measurable range in a case where the second mode is selected is equal to an integer multiple of at least two times the measurable range in a case where the first mode is selected. The light detection device according to claim 3 , wherein: Each of the first mode and the second mode further includes an exclusively selectable third mode and a fourth mode; In the third mode, one of the first counter groups is used to count the number of transitions of the output signal of the first pixel circuit or the first pixel circuit group; and In the fourth mode, the plurality of first counter groups are used to count the number of transitions of the output signal of the first pixel circuit or the first pixel circuit group.

7. The light detection device according to claim 6, wherein The fourth mode also includes an exclusively selectable fifth mode, a sixth mode, and a seventh mode; In the sixth mode, the measurable range is longer than that of the fifth mode, the distance resolution is lower than that of the fifth mode, and the resolution is the same as that of the fifth mode; and In the seventh mode, the measurable range is longer than that of the fifth mode, and the distance resolution and the resolution are the same as those of the fifth mode.

8. The light detection device according to claim 1, further comprising: A first substrate includes a pixel array unit, in which a plurality of the first pixels or the first pixel group and a plurality of the second pixels or the second pixel group are arranged; as well as A second substrate, in which a plurality of the first pixel circuits or the first pixel circuit groups, a plurality of the first counter groups, a plurality of the second pixel circuits or the second pixel circuit groups, a plurality of the second counter groups, and a plurality of the switching circuits are arranged, and the second substrate is stacked on the first substrate.

9. The light detection device according to claim 8, wherein A plurality of the first pixels or a plurality of the first pixel groups are arranged in a predetermined pixel area in the pixel array unit; and A plurality of the second pixels or a plurality of the second pixel groups are arranged in a pixel area other than the predetermined pixel area in the pixel array unit.

10. The light detection device according to claim 3, further comprising: an output unit that generates output data including first bit string data including information about a mode selected by the mode selection unit and second bit string data including a count value of the first counter group when the first mode is selected or including count values ​​of both the first counter group and the second counter group when the second mode is selected. The light detection device according to claim 10 , wherein: When the second mode is selected, the first bit string data includes information on the number of the second counter groups connected to the first counter group.

12. The light detection device according to claim 10, wherein The first bit string data includes information for identifying whether to perform a merge process of counting using at least two of the first counter groups or whether to perform counting using one of the first counter groups.

13. The light detection device according to claim 10, wherein The first bit string data includes information for identifying whether the number of transformations is counted within a specific pixel region of interest or whether the number of transformations is counted within a predetermined partial pixel region.

14. The light detection device according to claim 10, wherein The second bit string data includes a plurality of bit string data in which count values ​​of the first counter group and the second counter group corresponding to each of all the first pixels are arranged in pixel order when the second mode is selected.

15. The light detection device according to claim 1, further comprising: a first pixel array unit, in which a plurality of the first pixels or the first pixel group and a plurality of the second pixels or the second pixel group are arranged; a second pixel array unit in which a plurality of third pixels each capturing subject light is arranged; as well as A control unit controls a light receiving range of the second pixel array unit according to a focal length of the subject light incident on the second pixel array unit.

16. The light detection device according to claim 15, wherein In a case where the focal length of the second pixel array unit is controlled toward the telephoto side, the control unit further reduces the size of the pixel area of ​​the plurality of first pixels or the plurality of first pixel groups in the first pixel array unit.

17. The light detection device according to claim 15, further comprising: an optical system driving unit that drives a focus-adjustable optical system that adjusts a focal length of the subject light incident on the second pixel array unit, wherein The control unit controls the optical system driving unit based on a measurement result of a distance to the object, the measurement result being based on reflected light from the object received by the plurality of first pixels or the plurality of first pixel groups in the first pixel array unit.

18. A ranging system comprising: a light-emitting device that illuminates an object with light; a light receiving unit for receiving reflected light generated by the light emitted by the light emitting device and reflected by the object; a distance measuring unit that measures a distance to the object based on the light emitted by the light emitting device and the reflected light received by the light receiving unit; as well as A control unit controls the light emitting device, the light receiving unit and the distance measuring unit, wherein: The light receiving unit includes: A pixel array unit comprising a plurality of first pixels or a first pixel group and a plurality of second pixels or a second pixel group; a plurality of first pixel circuits connected to the plurality of first pixels; or a plurality of first pixel circuit groups connected to the plurality of first pixel groups; a first counter group, provided for each of the plurality of first pixel circuits or the plurality of first pixel circuit groups, the first counter group including a plurality of first counters; a plurality of second pixel circuits connected to the plurality of second pixels; or a plurality of second pixel circuit groups connected to the plurality of second pixel groups; a second counter group provided for each of the plurality of second pixel circuits or the plurality of second pixel circuit groups, the second counter group including a plurality of second counters; and A switching circuit switches between counting the number of transitions of each of the output signals of the plurality of first pixel circuits or the plurality of first pixel circuit groups without using the corresponding second counter group but using the corresponding first counter group and counting the number of transitions using both the corresponding first counter group and the corresponding second counter group.

19. The ranging system according to claim 18, wherein: The light emitting device includes a plurality of light emitting units each of which can be controlled to emit light based on control of the control unit; and The control unit controls the size of the light-emitting areas of the plurality of light-emitting units in combination with the size of the pixel areas of the plurality of first pixels or the plurality of first pixel groups in the pixel array unit.

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