Distance measuring device and apparatus

Abstract

To provide a technique advantageous for improving distance measuring accuracy.SOLUTION: A distance measuring device comprises: a plurality of pixels including a first pixel and a second pixel; a measuring circuit that measures time from light emission of a light source to light reception by the pixels; a signal line that connects the pixels and the measuring circuit; a first terminal for supplying a start signal to the measuring circuit; and a second terminal for supplying a test signal to the second pixel. Each of the plurality of pixels includes an output circuit connected to the corresponding signal line, the first pixel includes a first output circuit as an output circuit and a photoelectric conversion portion that outputs a signal to the first output circuit, and the second pixel includes a second output circuit connected to the second terminal as the output circuit. In a distance measurement period, the measuring circuit measures time from an input of the start signal via the first terminal to reception of a signal output from the first output circuit. In a test period, the measuring circuit measures time from an input of the test signal via the second terminal to reception of a signal output from the second output circuit in response to the test signal.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to distance measuring devices and instruments. [Background technology]

[0002] Patent Document 1 discloses a distance measuring device using a Time of Flight (ToF) method, which measures distance by measuring the time it takes from emitting light from a light source to detecting the light reflected by an object. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2017 / 0052065 Summary of the Invention [Problem to be solved by the invention]

[0004] In a distance measuring device, the delay time from when light is incident on a photoelectric conversion unit and converted into an electrical signal until when the converted electrical signal is detected may affect distance measuring accuracy.

[0005] An object of the present invention is to provide a technique that is advantageous for improving distance measurement accuracy. [Means for solving the problem]

[0006] In consideration of the above problem, a distance measuring device according to an embodiment of the present invention is a distance measuring device comprising a plurality of pixels including a first pixel and a second pixel, a measurement circuit for measuring a time from light emission by a light source to light reception by the plurality of pixels, one or more signal lines connecting the plurality of pixels to the measurement circuit, a first terminal for supplying a start signal to the measurement circuit, and a second terminal for supplying a test signal to the second pixel, wherein each of the plurality of pixels includes an output circuit connected to a corresponding signal line among the one or more signal lines, the first pixel includes a first output circuit as the output circuit and a photoelectric conversion unit that outputs a signal to the first output circuit, and the second pixel includes a second output circuit connected to the second terminal as the output circuit, and is characterized in that during a distance measurement period, the measurement circuit measures the time from input of the start signal via the first terminal to receiving a signal output from the first output circuit, and during a test period, the measurement circuit measures the time from input of the test signal via the second terminal to receiving a signal output from the second output circuit in response to the test signal. Effect of the Invention

[0007] According to the present invention, it is possible to provide a technique that is advantageous for improving distance measurement accuracy. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a diagram showing an example of the configuration of a distance measuring device according to the present embodiment. [Diagram 2] 2 is a diagram showing an example of the operation of the distance measuring device in FIG. 1; [Diagram 3] 2 is a diagram showing an example of the arrangement of a pixel in the distance measuring device of FIG. 1; [Figure 4] FIG. 4 is a diagram showing a modification of the pixel in FIG. [Diagram 5] FIG. 2 is a diagram for explaining an example of the configuration of the distance measuring device in FIG. 1; [Figure 6] FIG. 2 is a diagram for explaining an example of the configuration of the distance measuring device in FIG. 1; [Figure 7] FIG. 1 is a diagram showing an example of the configuration of a device incorporating a photoelectric conversion device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0010] A distance measuring device according to an embodiment of the present disclosure will be described with reference to FIGS. 1 to 6. FIG. 1 is a diagram showing an example of the configuration of a distance measuring device 100 according to this embodiment. The distance measuring device 100 includes a pixel region 110 in which a plurality of pixels are arranged, a measurement circuit 130 for measuring the time from light emission from a light source to light reception by the plurality of pixels, and one or more signal lines 160 for connecting the plurality of pixels to the measurement circuit 130. The distance measuring device 100 further includes a terminal START for supplying a start signal start to the measurement circuit 130, and a terminal TEST for supplying a test signal test to a pixel 112 among the pixels arranged in the pixel region 110, as will be described in detail later. The distance measuring device 100 also includes a digital processing circuit 140 and an output IF 150. The output of the output IF 150 is supplied to an external device 200 such as a personal computer. The external device 200 obtains information such as distance from the data obtained by the measurement circuit 130.

[0011] The pixels arranged in the pixel region 110 include normal pixels 111 for use in distance measurement, pixels 112 for use in a test described later, and dummy pixels 113. The pixels 111 are arranged in an array in the center of the pixel region 110, for example, to form rows and columns. That is, the pixel region 110 has a plurality of pixels 111 arranged therein. The dummy pixels 113 may be arranged to surround the array in which the pixels 111 are arranged. The pixels 112 may be arranged adjacent to the outer edge of the plurality of pixels 111 arranged in an array, for example, as shown in FIG. 1. In this case, the plurality of pixels 112 may be arranged to form one column. In the configuration shown in FIG. 1, a plurality of pixels 112 are arranged. The plurality of pixels 112 arranged in the pixel region 110 may be connected to a common signal line 160, as shown in FIG. 1. However, this is not limited to this, and only one pixel 112 may be arranged in the pixel region 110.

[0012] The measurement circuit 130 includes an oscillator 131, a counter 132, and a time-to-digital converter (TDC) 133. The TDC 133 may be a set of so-called column TDCs arranged corresponding to each column in which a plurality of pixels 111 of the pixel region 110 are arranged. The counter 132 performs counting in response to an input from the oscillator 131. The TDC 133 acquires a count value using as a trigger a pulse input such as a start signal start or a stop signal stop output in response to the pixel 111 detecting light. In this embodiment, a configuration using the TDC 133 as the measurement circuit 130 is shown, but is not limited to this. For example, a gradually changing ramp signal may be used to detect the time from the value of the ramp signal to which the stop signal stop is input via the signal line 160.

[0013] The digital processing circuit 140 may include a memory 141 that stores the count value acquired by the measurement circuit 130. The digital processing circuit 140 may also output a reset signal reset that resets the counter 132 and the TDC 133 according to the distance measurement period that is repeatedly executed.

[0014] The output IF 150 transmits the count value stored in the memory 141 to the external device 200. The external device 200 acquires information such as distance from the count value obtained by the measurement circuit 130. The control circuit 120 controls the operation of each pixel arranged in the pixel region 110.

[0015] 2 is a diagram showing an example of the operation of the distance measuring device 100. A reset signal RESET is supplied from the digital processing circuit 140 to the counter 132, and the count value of the counter 132 is reset to "0", thereby starting one distance measuring period. Next, a start signal START is input to the terminal START, and the counter 132 starts counting. The start signal START is supplied from an external device to the distance measuring device 100, such as the external device 200. The start signal START is supplied not only to the distance measuring device 100 but also to a light source. For example, a light source using a laser or the like emits light in response to the start signal START.

[0016] There may be a delay of time τ from when the start signal start is supplied to the light source until light is emitted. The value of time τ may be acquired in advance. The count value after the time τ has elapsed since the start signal start is acquired by TDC133 (TDC133 for acquiring a count value corresponding to the start signal start) (start' in FIG. 2). In the first distance measurement period in FIG. 2, the count value of the timing of light emission of the light source corresponding to the start signal start is "2".

[0017] Next, a signal (light receiving signal: stop signal stop) outputted in response to the pixel 111 detecting light is inputted to the TDC 133. The TDC 133 (the TDC 133 for acquiring a count value corresponding to the stop signal stop among the TDCs 133) acquires the count value of the counter 132 at this time. The count value of the timing of light emission of the light source corresponding to the stop signal stop during the first distance measurement period in FIG. 2 is "6".

[0018] The count value obtained in the first distance measurement period is read by the digital processing circuit 140 and stored in the memory 141. Furthermore, the count value data is transmitted to the external device 200 via the output IF 150. In the external device 200, a calculation is performed, for example, of "6"-"2" from the count values ​​"2" and "6" obtained in the measurement circuit 130 to obtain a distance measurement value of "4". As shown in Fig. 2, the distance measurement period may be repeated, and distance measurement values ​​are sequentially obtained in the external device 200.

[0019] In the embodiment shown in FIG. 2, the count value after the time τ has elapsed since the input of the start signal start is acquired as the count value of the timing of light emission of the light source according to the start signal start. However, this is not limited to this. There may be cases where the internal circuit delay of the start signals start to start' is different from the start signal start to the light emission timing (=τ). In this case, by grasping both the time of the start signals start to start' and τ in advance, a true distance measurement value can be obtained by calculation. Also, for example, the TDC 133 may acquire the count value of the counter 132 when the start signal start is supplied. For example, in the first distance measurement period, the count value of the counter 132 when the start signal start is supplied is "1". In that case, the external device 200 may obtain the distance measurement value by performing the calculation of stop value "6" - start value "1" + "1" - "τ".

[0020] Fig. 3(a) is a diagram showing a configuration example of a pixel 111, and Fig. 3(b) is a diagram showing a configuration example of a pixel 112. Each of the pixels 111 and 112 includes an output circuit 300 connected to a corresponding signal line 160. First, the pixel 111 will be described.

[0021] As shown in FIG. 3(a), the pixel 111 includes an output circuit 300 and a photoelectric conversion unit that outputs a signal to the output circuit 300. In this embodiment, a case where an avalanche photodiode (APD) 301 is used as the photoelectric conversion unit will be described. However, this is not limited to this, and a PN diode, a PIN diode, or the like may be used as the photoelectric conversion unit. The pixel 111 also includes a waveform shaping circuit 302, a quenching element 303, a monostable circuit 304, and an external light removal circuit 305. The external light removal circuit 305 is shared by a predetermined number of the pixels 111, 112 among the multiple pixels 111, 112.

[0022] As shown in Fig. 3(a), the APD 301 may be provided on the sensor substrate PDIC, and other components may be provided on the circuit substrate ROIC. In this case, the sensor substrate PDIC and the circuit substrate ROIC may be stacked. Furthermore, the circuit substrate ROIC may have a stacked structure in which multiple substrates are stacked.

[0023] The APD301 generates pairs of charges according to the incident light through photoelectric conversion. A potential VPDL is supplied to the anode of the APD301. A potential higher than the potential VPDL supplied to the anode is supplied to the cathode of the APD301. The higher potential is a maximum potential VDD in the case of FIG. 3(a). A reverse bias voltage is supplied to the anode and cathode such that the APD301 performs avalanche multiplication. By supplying such a reverse bias voltage, the charges generated by the incident light undergo avalanche multiplication, generating an avalanche current.

[0024] When a reverse bias voltage is supplied to the APD301, there are two modes: Geiger mode, in which the potential difference (voltage) between the anode and cathode is greater than the breakdown voltage, and linear mode, in which the potential difference between the anode and cathode is close to or less than the breakdown voltage. An APD that operates in Geiger mode is called a Single Photon Avalanche Diode (SPAD). For example, the potential VPDL is -30V, and the potential VDD is 1V. The APD301 may operate in either linear mode or Geiger mode.

[0025] The quench element 303 is connected between a power supply that supplies a potential VDD and the APD 301. The quench element 303 functions as a load circuit (quench circuit) during signal multiplication by avalanche multiplication, and has a function of suppressing avalanche multiplication by suppressing the voltage supplied to the APD 301 (quench operation). The quench element 303 also has a function of returning the voltage supplied to the APD 301 to the voltage (VDD-VPDL) by flowing a current equivalent to the voltage drop caused by the quench operation (recharge operation).

[0026] The waveform shaping circuit 302 shapes the potential change of the cathode of the APD 301 obtained when a photon is detected, and outputs a pulse signal. For example, an inverter circuit is used as the waveform shaping circuit 302. In the configuration shown in Fig. 4, an example is shown in which one inverter is used as the waveform shaping circuit 302. However, the present invention is not limited to this, and a circuit in which a plurality of inverters are connected in series may be used as the waveform shaping circuit 302.

[0027] Monostable circuit 304 is a circuit with a waveform shaping effect that is provided because there is a possibility that waveform shaping circuit 302 may not be sufficient for subsequent circuits. For example, a differentiation circuit that cuts out the signal output from waveform shaping circuit 302 into a single pulse may be used as monostable circuit 304.

[0028] The external light removal circuit 305 is a circuit for determining that a signal output from a plurality of pixels 111 is not noise but a signal that detects light. In the example shown in FIG. 3(a), the external light removal circuit 305 is shared by four pixels 111. For example, when a signal input from two or more pixels 111 among the signals of "1 (light detection)" or "0 (no output)" input from the four pixels 111 to the external light removal circuit 305 is input with "1", the external light removal circuit 305 outputs "1" to the subsequent and gate. As a result, a signal is output to the measurement circuit 130 via the signal line 160. Here, a case is shown in which a signal is determined to be noise when "1" is input from only one pixel 111 out of the four pixels 111. However, the number of pixels 111 sharing one external light removal circuit 305 and the number of inputs of "1" for the external light removal circuit 305 to determine that the signal is light detected may be appropriately determined.

[0029] During the distance measurement period, the measurement circuit 130 measures the time from input of a start signal start via the terminal START to reception of a signal output from the output circuit 300 disposed downstream of the APD 301 of the pixel 111. In this case, if a signal delay occurs in the output circuit 300, this may affect the distance measurement accuracy. Therefore, in this embodiment, in order to measure the delay time occurring downstream of the APD 301 of the pixel 111, the pixel 112 shown in FIG. 3B is disposed in the pixel area 110. In this embodiment, as described above, the TDC acquires the counter value of the counter 132 at each timing, thereby measuring the time (delay time).

[0030] As shown in FIG. 3B, the pixel 112 basically has the same configuration as the pixel 111 in order to measure the delay time generated in the pixel 111. Therefore, the pixel 112 also has an output circuit 300. The output circuit 300 arranged in the pixel 111 and the output circuit arranged in the pixel 112 may have the same configuration. In addition, as described above, the pixel 112 and the pixel 111 may be arranged so as to be adjacent to each other. If the configuration of the pixel 112 is significantly different from the configuration of the pixel 111, for example, the environmental conditions during the process may change between the pixel 111 close to the pixel 112 and the pixel 111 distant from the pixel 112. In that case, it is considered that the characteristics of the pixel 111 close to the pixel 112 during the process may change from the pixel 111 distant from the pixel 112. In other words, the pixel 112 may reduce the accuracy of acquiring the delay time generated in the pixel 111 arranged at a position distant from the pixel 112. Therefore, the pixel 112 may include a photoelectric conversion unit similar to the pixel 111. When the photoelectric conversion unit arranged in the pixel 111 is an APD 301, the photoelectric conversion unit arranged in the pixel 112 may be the APD 301 similar to the pixel 111, as shown in FIG.

[0031] On the other hand, the APD 301 arranged in the pixel 112 is not connected to the output circuit 300. Instead, the output circuit 300 arranged in the pixel 112 is connected to a terminal TEST for supplying a test signal test. Thereby, during the test period, the measurement circuit 130 measures the time from the input of the test signal test via the terminal TEST to the reception of a signal output from the output circuit 300 arranged in the pixel 112 in response to the test signal test. The test signal test may be, for example, a known analog signal that imitates a signal output from the APD 301 via the waveform shaping circuit 302.

[0032] For example, after a predetermined time has elapsed since the start signal start is input via the terminal START, the test signal test is input via the terminal TEST. Also, for example, simultaneously with the input of the start signal start via the terminal START, the test signal test is input via the terminal TEST. The TDC 133 for acquiring a count value corresponding to the start signal start among the TDCs 133 acquires a count value of the counter 132 corresponding to the start signal start. The TDC 133 for acquiring a count value corresponding to the stop signal stop among the TDCs 133 acquires a count value of the counter 132 at the time when a signal corresponding to the test signal test (stop signal stop) is input to the TDC 133. The acquired count value is transmitted to the external device 200 via the memory 141 and the output IF 150, and a delay time occurring in the output circuit 300 can be obtained.

[0033] By obtaining the delay time generated by the output circuit 300, it becomes possible to obtain a distance measurement value from the difference between the obtained count values, taking into consideration the delay time generated by the output circuit 300, as shown in Fig. 2. For example, the external device 200 may obtain a distance measurement value by further subtracting a count value corresponding to the delay time generated by the output circuit 300 from the difference between the count value corresponding to the start signal start and the count value corresponding to the stop signal stop. This makes it possible to improve the distance measurement accuracy for the count value obtained by the distance measuring device 100.

[0034] When the above-mentioned external light removal circuit 305 is provided, for example, the external light removal circuit 305 may be set to always output "1" to the subsequent AND gate during the test period. Also, for example, when the pixel region 110 has a configuration in which multiple pixels 112 are connected to the external light removal circuit 305, the test signal test may be supplied simultaneously to multiple pixels 112 connected to the same external light removal circuit 305.

[0035] 1, the pixel 112 outputs a signal to a TDC 133 (column TDC) that receives a signal from the pixel 111 adjacent to the pixel 112, via a signal line 160 connected to the pixel 111 adjacent to the pixel 112. However, this is not limited to this, and a TDC 133 (column TDC) corresponding to the column in which the pixel 112 is arranged may be arranged.

[0036] The pixel 112 arranged to measure the delay time of the output circuit 300 during the test period is not limited to the configuration shown in FIG. 3(b). For example, as shown in FIG. 4(a), the APD 301 arranged in the pixel 112 may be connected to the output circuit 300. In the configuration of FIG. 4(a), the waveform shaping circuit 302 is configured to operate as a tri-state buffer. When the control signal CONT output from the control circuit 120 is at a low level, the output of the waveform shaping circuit 302 is controlled to a high impedance. On the other hand, when the control signal CONT is at a high level, the waveform shaping circuit 302 outputs a signal corresponding to the output of the APD 301. During the test period, the control signal CONT is set to a low level. Also, for example, as shown in FIG. 4(b), the pixel 112 may be configured to be switchable between the connection between the terminal TEST and the output circuit 300 and the connection between the APD 301, which is a photoelectric conversion unit arranged in the pixel 112, and the output circuit 300. By having the pixel 112 have the configuration shown in Figs. 4(a) and 4(b), the pixel 112 can output a signal for performing distance measurement during the distance measurement period, similar to the pixel 111. For example, some of the pixels 111 arranged in the pixel region 110 may be replaced with the pixels 112 shown in Figs. 4(a) and 4(b). This makes it possible to obtain the tendency of the delay time of the output circuit 300 in the plane of the pixel region 110. Furthermore, all of the pixels 111 arranged in the pixel region 110 may be replaced with the pixels 112 shown in Figs. 4(a) and 4(b). This makes it possible to obtain the delay time of the output circuit 300 of the pixel 112 at any position arranged in the pixel region 110.

[0037] For example, as shown in Fig. 1, when the pixels 112 for measuring the delay time generated in the output circuit 300 are arranged to form one column, the circuit size may become large if the output circuit 300 is arranged for each pixel 112. For example, in the configuration shown in Fig. 3(b), the pixels 112 adjacent to each other in the column direction share elements 306 to 308 arranged in a stage subsequent to the element 309 connected to the terminal SEL to which a signal for selecting the pixel 112 capable of outputting a signal is input. As a result, for example, even in a configuration in which a part of the pixel 111 is replaced with the pixel 112 as in the example shown in Fig. 1, the size of the circuit arranged in the distance measuring device 100 can be suppressed.

[0038] Furthermore, as shown in FIG. 5, an element 306 connected to the signal line 160 of the output circuit 300 arranged in the pixel 112 may be shared by more pixels 112. The element 306 is an element connected to a terminal SEL ROW to which a row selection signal is input to select a pixel 112 that outputs a signal to the signal line 160 among the pixels 112 arranged in the column direction. The element 306 may be an element in the final stage between the pixel 112 and the signal line 160. For example, the pixels 112 arranged in one column and arranged across 256 rows may share the element 306 every 16 pixels. This makes it possible to suppress an increase in the circuit size caused by arranging the pixels 112.

[0039] Next, a configuration example between the terminal TEST for inputting the test signal test and the pixel 112 will be described with reference to FIG. 6. When multiple pixels 112 are arranged, if the time it takes for the test signal test to reach the output circuit 300 of the pixel 112 from the input of the terminal TEST differs between the pixels 112, the accuracy of acquiring the delay time of the output circuit 300 may be reduced. Therefore, the distance measuring device 100 may have a configuration capable of inputting the test signal TEST from the terminal TEST to each of the multiple pixels 112 approximately simultaneously. For example, as shown in FIG. 6, the circuit configuration between the terminal TEST and the multiple pixels 112 may be a tree structure. By making it possible to input the test signal test to each pixel 112 approximately simultaneously, it becomes possible to check changes in the characteristics of the output circuits 300 arranged in the column direction. This may make it possible to further improve the distance measuring accuracy.

[0040] As described above, in the pixel 112 arranged in the distance measuring device 100, it is possible to measure the delay time from the detection of light in the photoelectric conversion unit to the reception of a signal by the measuring circuit 130. This makes it possible to improve the distance measurement accuracy. The arrangement of the pixels 112 may be arranged to form a row on the outer edge of the pixels 111 arranged in an array as shown in FIG. 1. However, the arrangement is not limited to this, and the pixels 112 may be arranged in an appropriate place in the pixel region 110. For example, only one pixel 112 may be arranged in the pixel region 110. By arranging one pixel 112, it is possible to measure the delay time of the output circuit 300, etc., and the distance measurement accuracy can be improved compared to the case where the pixel 112 is not arranged. In addition, the pixels 112 as shown in FIGS. 4(a) and 4(b) may occupy most of the pixels arranged in the pixel region 110. For example, the pixels 111 and the pixels 112 may be arranged in equal numbers. In addition, for example, there may be more pixels 112 than pixels 111. Furthermore, for example, among the pixels arranged in the pixel region 110, the pixels other than the dummy pixels 113 may be the pixels 112. The arrangement of the pixels 111 and 112, and further the dummy pixels 113 may be determined appropriately.

[0041] An application example of the distance measuring device 100 according to the above-mentioned embodiment will be described below. FIG. 7 is a schematic diagram of an equipment EQP equipped with the distance measuring device 100. The distance measuring device 100 may be, for example, a semiconductor chip having a stacked structure in which a pixel region 110 is provided. As shown in FIG. 7, the distance measuring device 100 is accommodated in a semiconductor package PKG. The package PKG may include a base to which the distance measuring device 100 is fixed, a cover such as glass facing the distance measuring device 100, and a conductive connection member such as a bonding wire or bump that connects a terminal provided on the base to a terminal provided on the distance measuring device 100. The equipment EQP may further include at least one of a control device CTRL, a processing device PRCS, a display device DSPL, and a memory device MMRY.

[0042] The optical system OPT forms an image on the pixel region 110 and may be, for example, a lens, a shutter, or a mirror. The control device CTRL controls the operation of the distance measuring device 100 and may be, for example, a semiconductor device such as an ASIC. The processing device PRCS processes a signal output from the distance measuring device 100 and may be, for example, a semiconductor device such as a CPU or an ASIC. The display device DSPL may be an EL display device or a liquid crystal display device that displays data obtained by the distance measuring device 100. The memory device MMRY may be a magnetic device or a semiconductor device that stores data obtained by the distance measuring device 100. The memory device MMRY may be a volatile memory such as an SRAM or a DRAM, or a non-volatile memory such as a flash memory or a hard disk drive. The mechanical device MCHN may have a moving part or a propulsion part such as a motor or an engine. The mechanical device MCHN may also drive parts of the optical system OPT for, for example, zooming, focusing, and shutter operation. In the device EQP, the data output from the distance measuring device 100 is displayed on the display device DSPL, or transmitted to the outside by a communication device (not shown) included in the device EQP. For this reason, the device EQP may include a memory device MMRY and a processing device PRCS.

[0043] The equipment EQP incorporating the distance measuring device 100 can be applied to surveillance cameras, and on-board cameras mounted on transport equipment such as automobiles, railroad cars, ships, aircraft, and industrial robots. In addition, the equipment EQP incorporating the distance measuring device 100 can be applied not only to transport equipment but also to a wide range of equipment that uses object recognition, such as an intelligent transport system (ITS).

[0044] The disclosure of this specification includes the following ranging devices and instruments:

[0045] (Item 1) A distance measuring device comprising: a plurality of pixels including a first pixel and a second pixel; a measurement circuit for measuring a time from light emission from a light source to light reception by the plurality of pixels; one or more signal lines connecting the plurality of pixels and the measurement circuit; a first terminal for supplying a start signal to the measurement circuit; and a second terminal for supplying a test signal to the second pixel, each of the plurality of pixels includes an output circuit connected to a corresponding one of the one or more signal lines; the first pixel includes a first output circuit as the output circuit and a photoelectric conversion unit that outputs a signal to the first output circuit; the second pixel includes a second output circuit connected to the second terminal as the output circuit; during a distance measurement period, the measurement circuit measures a time from input of the start signal via the first terminal to receiving a signal output from the first output circuit; A distance measuring device characterized in that, during a test period, the measurement circuit measures the time from the input of the test signal via the second terminal to the reception of a signal output from the second output circuit in response to the test signal.

[0046] (Item 2) 2. The distance measuring device according to item 1, wherein the plurality of pixels includes a plurality of second pixels including the second pixel.

[0047] (Item 3) 3. The distance measuring device according to item 2, wherein the plurality of second pixels are connected to a common signal line among the one or more signal lines.

[0048] (Item 4) the second output circuit includes an element connected to a corresponding one of the one or more signal lines; the plurality of second pixels include a third pixel and a fourth pixel, The distance measuring device according to item 2 or 3, characterized in that the second output circuit arranged in the third pixel and the second output circuit arranged in the fourth pixel share one of the elements.

[0049] (Item 5) 5. The distance measuring device according to any one of items 2 to 4, characterized in that the test signal can be input simultaneously from the second terminal to each of the plurality of second pixels.

[0050] (Item 6) 6. The distance measuring device according to any one of items 2 to 5, wherein a circuit configuration between the second terminal and the plurality of second pixels is a tree structure.

[0051] (Item 7) the plurality of pixels includes a plurality of first pixels including the first pixel, The plurality of first pixels are arranged in an array to form rows and columns in a pixel region; 7. The distance measuring device according to any one of items 2 to 6, wherein the second pixels are arranged adjacent to the outer edges of the first pixels arranged in an array.

[0052] (Item 8) 8. The distance measuring device according to item 7, wherein the plurality of second pixels are arranged to form a single column.

[0053] (Item 9) 9. The distance measuring device according to any one of items 1 to 8, wherein the second pixel further includes a photoelectric conversion unit.

[0054] (Item 10) 10. The distance measuring device according to item 9, wherein the photoelectric conversion unit arranged in the second pixel is not connected to the second output circuit.

[0055] (Item 11) 10. The distance measuring device according to item 9, wherein the photoelectric conversion unit arranged in the second pixel is connected to the second output circuit.

[0056] (Item 12) The distance measuring device described in item 9, characterized in that the connection between the second terminal and the second output circuit, and the connection between the photoelectric conversion unit arranged in the second pixel and the second output circuit are configured to be switchable.

[0057] (Item 13) 13. The distance measuring device according to any one of items 9 to 12, wherein the photoelectric conversion unit arranged in the second pixel is an avalanche photodiode.

[0058] (Item 14) 14. The distance measuring device according to any one of claims 1 to 13, wherein the output circuit includes a monostable circuit.

[0059] (Item 15) the output circuit includes an external light removal circuit; 15. The distance measuring device according to any one of items 1 to 14, wherein the external light removal circuit is shared by a predetermined number of the plurality of pixels.

[0060] (Item 16) 16. The distance measuring device according to any one of items 1 to 15, wherein the photoelectric conversion unit arranged in the first pixel is an avalanche photodiode.

[0061] (Item 17) 17. The distance measuring device according to any one of items 1 to 16, wherein the first output circuit and the second output circuit have the same configuration.

[0062] (Item 18) A distance measuring device according to any one of items 1 to 17, a processing device for processing a signal output from the distance measuring device; An apparatus comprising:

[0063] The invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0064] 100: distance measuring device, 111, 112: pixels, 130: measuring circuit, 160: signal line, 300: output circuit, START, TEST: terminals

Claims

1. A distance measuring device comprising: a plurality of pixels including a first pixel and a second pixel; a measurement circuit for measuring a time from light emission from a light source to light reception by the plurality of pixels; one or more signal lines connecting the plurality of pixels to the measurement circuit; a first terminal for supplying a start signal to the measurement circuit; and a second terminal for supplying a test signal to the second pixel, each of the plurality of pixels includes an output circuit connected to a corresponding one of the one or more signal lines; the first pixel includes a first output circuit as the output circuit and a photoelectric conversion unit that outputs a signal to the first output circuit; the second pixel includes a second output circuit connected to the second terminal as the output circuit; during a distance measurement period, the measurement circuit measures a time from input of the start signal via the first terminal to receiving a signal output from the first output circuit; A distance measuring device characterized in that, during a test period, the measurement circuit measures the time from the input of the test signal via the second terminal to the reception of a signal output from the second output circuit in response to the test signal.

2. The distance measuring device according to claim 1 , wherein the plurality of pixels includes a plurality of second pixels including the second pixel.

3. The distance measuring device according to claim 2 , wherein the second pixels are connected to a common signal line among the one or more signal lines.

4. the second output circuit includes an element connected to a corresponding one of the one or more signal lines; the plurality of second pixels include a third pixel and a fourth pixel, 3. The distance measuring device according to claim 2, wherein the second output circuit arranged in the third pixel and the second output circuit arranged in the fourth pixel share one of the elements.

5. 3. The distance measuring device according to claim 2, further comprising a configuration capable of simultaneously inputting the test signal from the second terminal to each of the plurality of second pixels.

6. 3. The distance measuring device according to claim 2, wherein a circuit configuration between the second terminal and the plurality of second pixels is a tree structure.

7. the plurality of pixels includes a plurality of first pixels including the first pixel, The plurality of first pixels are arranged in an array to form rows and columns in a pixel region; 3. The distance measuring device according to claim 2, wherein the second pixels are arranged adjacent to outer edges of the first pixels arranged in an array.

8. 8. The distance measuring device according to claim 7, wherein the plurality of second pixels are arranged to form one column.

9. The distance measuring device according to claim 1 , wherein the second pixel further includes a photoelectric conversion portion.

10. The distance measuring device according to claim 9 , wherein the photoelectric conversion portion disposed in the second pixel is not connected to the second output circuit.

11. The distance measuring device according to claim 9 , wherein the photoelectric conversion portion arranged in the second pixel is connected to the second output circuit.

12. The distance measuring device according to claim 9, characterized in that the second pixel is configured so that the connection between the second terminal and the second output circuit, and the connection between the photoelectric conversion unit arranged in the second pixel and the second output circuit are switchable.

13. The distance measuring device according to claim 9 , wherein the photoelectric conversion portion disposed in the second pixel is an avalanche photodiode.

14. 2. A distance measuring device according to claim 1, wherein the output circuit includes a monostable circuit.

15. the output circuit includes an external light removal circuit; 2. The distance measuring device according to claim 1, wherein the external light removal circuit is shared by a predetermined number of the plurality of pixels.

16. 2. The distance measuring device according to claim 1, wherein the photoelectric conversion portion disposed in the first pixel is an avalanche photodiode.

17. 2. The distance measuring device according to claim 1, wherein the first output circuit and the second output circuit have the same configuration.

18. A distance measuring device according to any one of claims 1 to 17, a processing device for processing a signal output from the distance measuring device; An apparatus comprising:

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