Photoelectric conversion device

Abstract

To provide a photoelectric conversion device for reducing influence of light from a light source other than a corresponding light source.SOLUTION: A photoelectric conversion device includes: a photon detection element for generating a light receiving pulse signal corresponding to incident light; a control section for controlling a light emitting pulse pattern of a light source, light emitting timing of the light source, and a gating period with the light emitting timing as reference; a gating section for outputting a light receiving pulse pattern of the incident light based on the light receiving pulse signal which has been input in the gating period; and a pattern detection section for comparing the light receiving pulse pattern with the light emitting pulse pattern, so as to output a signal corresponding to a comparison result. A length of the gating period is equal to or more than a duration of the light emitting pulse pattern.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a photoelectric conversion device. [Background technology]

[0002] Patent Document 1 discloses a distance measuring device that measures the distance to an object by emitting light from a light source and receiving light, including reflected light from the object, with a light receiving element. Patent Document 1 discloses a method of repeatedly performing measurements while changing a gating period during which photons are detected by the light receiving element. [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 the distance measuring method disclosed in Patent Document 1, in addition to the light emitted from the light source corresponding to the distance measuring device, light from other light sources may also be incident on the light receiving element.

[0005] An object of the present invention is to provide a photoelectric conversion device in which the influence of light from light sources other than the corresponding light source is reduced. [Means for solving the problem]

[0006] According to one disclosure of the present specification, there is provided a photoelectric conversion device comprising: a photon detection element that generates a received light pulse signal in response to incident light; a control unit that controls a light emission pulse pattern of a light source, the light emission timing of the light source, and a gating period based on the light emission timing; a gating unit that outputs a received light pulse pattern of the incident light based on the received light pulse signal input during the gating period; and a pattern detection unit that compares the received light pulse pattern with the light emission pulse pattern and outputs a signal in response to the comparison result, wherein the length of the gating period is equal to or longer than the length of the duration of the light emission pulse pattern. Effect of the Invention

[0007] According to the present invention, there is provided a photoelectric conversion device in which the influence of light from light sources other than the corresponding light source is reduced. [Brief description of the drawings]

[0008] [Figure 1] 1 is a hardware block diagram showing an example of a schematic configuration of a distance measuring device according to a first embodiment. [Diagram 2] 1 is a schematic diagram showing the overall configuration of a photoelectric conversion device according to a first embodiment. [Diagram 3] 1 is a schematic block diagram showing an example of the configuration of a sensor substrate according to a first embodiment. [Figure 4] 1 is a schematic block diagram showing an example of the configuration of a circuit board according to a first embodiment. [Diagram 5] 2 is a schematic block diagram showing an example of the configuration of one pixel of a photoelectric conversion unit and a pixel signal processing unit according to the first embodiment. FIG. [Figure 6] 3A to 3C are diagrams illustrating the operation of the avalanche photodiode according to the first embodiment. [Figure 7] 1 is a functional block diagram showing a schematic configuration example of a distance measuring device according to a first embodiment. [Figure 8] FIG. 2 is a pixel circuit diagram according to the first embodiment. [Figure 9] FIG. 2 is a timing chart showing the operation of the pixel circuit according to the first embodiment. [Figure 10] FIG. 11 is a pixel circuit diagram according to a second embodiment. [Figure 11] FIG. 11 is a timing chart showing the operation of a pixel circuit according to a comparative example of the second embodiment. [Figure 12] FIG. 11 is a timing chart showing the operation of the pixel circuit according to the second embodiment. [Figure 13] FIG. 11 is a pixel circuit diagram according to a third embodiment. [Figure 14] FIG. 13 is a schematic diagram of a device according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The same elements or corresponding elements in multiple drawings are denoted by the same reference numerals, and the description thereof may be omitted or simplified.

[0010] [First embodiment] 1 is a hardware block diagram showing a schematic configuration example of a distance measuring device 10 according to this embodiment. The distance measuring device 10 includes a photoelectric conversion device 100, a light source 300, and a signal processing circuit 500. Note that the configuration of the distance measuring device 10 shown in this embodiment is merely an example, and is not limited to the configuration shown in the figure.

[0011] The distance measuring device 10 is a device that measures the distance to the object X to be measured using a technology such as LiDAR (Light Detection And Ranging). The distance measuring device 10 measures the distance from the distance measuring device 10 to the object X based on the time difference between when the light emitted from the light source 300 is reflected by the object X and when it is received by the photoelectric conversion device 100. The distance measuring device 10 can also measure the distance to a plurality of points two-dimensionally by emitting laser light to a predetermined distance measuring range including the object X and receiving the reflected light by a pixel array. This allows the distance measuring device 10 to generate and output a distance image.

[0012] The light received by the photoelectric conversion device 100 includes ambient light such as sunlight in addition to the reflected light from the object X. Therefore, the distance measuring device 10 may perform distance measuring with reduced influence of ambient light by measuring the light incident in each of a plurality of periods (bin periods) and determining that the reflected light is incident in the period when the amount of light is at its peak.

[0013] The light source 300 is a device that emits light such as laser light to the outside of the distance measuring device 10. The light source 300 is, for example, a VCSEL (Vertical Cavity Surface Emitting Laser). The signal processing circuit 500 may include a processor that performs arithmetic processing of digital signals, a memory that stores digital signals, and the like. The signal processing circuit 500 may be, for example, an integrated circuit such as an FPGA (Field-Programmable Gate Array) or an ISP (Image Signal Processor). The signal processing circuit 500 may be integrated with a semiconductor device that constitutes the photoelectric conversion device 100, or may be an external arithmetic device separate from the semiconductor device.

[0014] The photoelectric conversion device 100 generates a pulse signal including a pulse based on the incident light. The photoelectric conversion device 100 includes, for example, an avalanche photodiode as a photoelectric conversion element. In this case, when one photon is incident on the avalanche photodiode and an electric charge is generated, one pulse is generated by avalanche multiplication. However, the photoelectric conversion device 100 may use, for example, a photoelectric conversion element using another photodiode.

[0015] In this embodiment, the photoelectric conversion device 100 includes a pixel array in which a plurality of photoelectric conversion elements (pixels) are arranged to form a plurality of rows and a plurality of columns. Here, a photoelectric conversion device that is a specific configuration example of the photoelectric conversion device 100 will be described with reference to Figs. 2 to 6. The configuration example of the photoelectric conversion device described below is one example. Photoelectric conversion devices applicable to the photoelectric conversion device 100 are not limited to this, and may be any device that can realize the function of Fig. 7 described later.

[0016] FIG. 2 is a schematic diagram showing the overall configuration of a photoelectric conversion device 100 according to this embodiment. The photoelectric conversion device 100 has a sensor substrate 11 (first substrate) and a circuit substrate 21 (second substrate) that are stacked on each other. The sensor substrate 11 and the circuit substrate 21 are electrically connected to each other. The sensor substrate 11 has a pixel region 12 in which a plurality of pixels 101 are arranged to form a plurality of rows and a plurality of columns. The circuit substrate 21 has a first circuit region 22 in which a plurality of pixel signal processing units 103 are arranged to form a plurality of rows and a plurality of columns, and a second circuit region 23 arranged on the periphery of the first circuit region 22. The second circuit region 23 may include a circuit for controlling the plurality of pixel signal processing units 103. The sensor substrate 11 has a light incident surface that receives incident light and a connection surface that faces the light incident surface. The sensor substrate 11 is connected to the circuit substrate 21 on the connection surface side. That is, the photoelectric conversion device 100 is a so-called back-illuminated type.

[0017] In this specification, "planar view" refers to a view from a direction perpendicular to the surface opposite to the light incident surface. Also, a cross section refers to a surface in a direction perpendicular to the surface opposite to the light incident surface of the sensor substrate 11. Note that the light incident surface may be rough when viewed microscopically, and in such a case, the planar view is defined based on the light incident surface when viewed macroscopically.

[0018] In the following description, the sensor substrate 11 and the circuit substrate 21 are described as being diced chips, but the sensor substrate 11 and the circuit substrate 21 are not limited to being chips. For example, the sensor substrate 11 and the circuit substrate 21 may be wafers. In addition, when the sensor substrate 11 and the circuit substrate 21 are diced chips, the photoelectric conversion device 100 may be manufactured by stacking them in a wafer state and then dicing them, or may be manufactured by stacking them after dicing.

[0019] 3 is a schematic block diagram showing an example of the arrangement of the sensor substrate 11. A plurality of pixels 101 arranged in a plurality of rows and a plurality of columns are arranged in the pixel region 12. Each of the plurality of pixels 101 has a photoelectric conversion unit 102 including an avalanche photodiode (hereinafter referred to as APD) as a photoelectric conversion element within the substrate.

[0020] The conductivity type of the charge pair generated in the APD and used as the signal charge is called the first conductivity type. The first conductivity type refers to a conductivity type in which the charge of the same polarity as the signal charge is the majority carrier. The conductivity type opposite to the first conductivity type, that is, the conductivity type in which the charge of the opposite polarity to the signal charge is the majority carrier, is called the second conductivity type. In the APD described below, the anode of the APD is at a fixed potential, and a signal is taken out from the cathode of the APD. Therefore, the semiconductor region of the first conductivity type is an N-type semiconductor region, and the semiconductor region of the second conductivity type is a P-type semiconductor region. The cathode of the APD may be at a fixed potential, and the signal may be taken out from the anode of the APD. In this case, the semiconductor region of the first conductivity type is a P-type semiconductor region, and the semiconductor region of the second conductivity type is an N-type semiconductor region. In the following, a case in which one node of the APD is at a fixed potential will be described, but the potentials of both nodes may be fluctuating.

[0021] 4 is a schematic block diagram showing an example of the configuration of the circuit board 21. The circuit board 21 has a first circuit area 22 in which a plurality of pixel signal processing units 103 are arranged in a plurality of rows and a plurality of columns.

[0022] Further, a vertical scanning circuit 110, a horizontal scanning circuit 111, a readout circuit 112, pixel output signal lines 113, an output circuit 114, and a control signal generating unit 115 are arranged on the circuit board 21. The multiple photoelectric conversion units 102 shown in Fig. 3 and the multiple pixel signal processing units 103 shown in Fig. 4 are electrically connected to each other via connection wiring provided for each pixel 101.

[0023] The control signal generating unit 115 is a control circuit that generates control signals for driving the vertical scanning circuit 110, the horizontal scanning circuit 111, and the readout circuit 112, and supplies these circuits with these signals. In this way, the control signal generating unit 115 controls the drive timing of each circuit.

[0024] The vertical scanning circuit 110 supplies a control signal to each of the pixel signal processing units 103 based on the control signal supplied from the control signal generation unit 115. The vertical scanning circuit 110 supplies a control signal to each pixel signal processing unit 103 for each row via a drive line provided for each row of the first circuit area 22. As will be described later, there may be multiple drive lines for each row. The vertical scanning circuit 110 may include logic circuits such as a shift register and an address decoder. In this way, the vertical scanning circuit 110 selects a row for outputting a signal from the pixel signal processing unit 103.

[0025] A signal output from the photoelectric conversion unit 102 of the pixel 101 is processed by a pixel signal processing unit 103. The pixel signal processing unit 103 acquires and holds a digital signal based on a pulse output from the APD included in the photoelectric conversion unit 102.

[0026] It is not necessary that one pixel signal processing unit 103 is provided for each pixel 101. For example, one pixel signal processing unit 103 may be shared by a plurality of pixels 101. In this case, the pixel signal processing unit 103 provides a signal processing function to each pixel 101 by sequentially processing the signals output from each photoelectric conversion unit 102.

[0027] The horizontal scanning circuit 111 supplies a control signal to the readout circuit 112 based on the control signal supplied from the control signal generation unit 115. The pixel signal processing unit 103 is connected to the readout circuit 112 via a pixel output signal line 113 provided for each column of the first circuit region 22. The pixel output signal line 113 of one column is shared by a plurality of pixel signal processing units 103 of the corresponding column. The pixel output signal line 113 includes a plurality of wirings, and has at least a function of outputting a digital signal from each pixel signal processing unit 103 to the readout circuit 112 and a function of supplying a control signal for selecting a column for outputting a signal to the pixel signal processing unit 103. The readout circuit 112 outputs a signal to a storage unit or a signal processing unit outside the photoelectric conversion device 100 via the output circuit 114 based on the control signal supplied from the control signal generation unit 115.

[0028] The photoelectric conversion units 102 in the pixel region 12 may be arranged one-dimensionally. Moreover, the function of the pixel signal processing unit 103 does not necessarily have to be provided for each pixel 101. For example, one pixel signal processing unit 103 may be shared by a plurality of pixels 101. In this case, the pixel signal processing unit 103 provides a signal processing function to each pixel 101 by sequentially processing signals output from each photoelectric conversion unit 102.

[0029] 3 and 4, a first circuit region 22 in which a plurality of pixel signal processing units 103 are arranged is arranged in a region overlapping the pixel region 12 in a plan view. A vertical scanning circuit 110, a horizontal scanning circuit 111, a readout circuit 112, an output circuit 114, and a control signal generating unit 115 are arranged so as to overlap between an end of the sensor substrate 11 and an end of the pixel region 12 in a plan view. In other words, the sensor substrate 11 has the pixel region 12 and a non-pixel region arranged around the pixel region 12. In the circuit substrate 21, a second circuit region 23 (described above in FIG. 2) in which the vertical scanning circuit 110, the horizontal scanning circuit 111, the readout circuit 112, the output circuit 114, and the control signal generating unit 115 are arranged is arranged in a region overlapping the non-pixel region in a plan view.

[0030] The arrangement of the pixel output signal lines 113, the readout circuits 112, and the output circuits 114 are not limited to those shown in Fig. 3. For example, the pixel output signal lines 113 may be arranged to extend in the row direction and shared by a plurality of pixel signal processing units 103 in the corresponding row. The readout circuits 112 may be arranged so that the pixel output signal lines 113 in each row are connected to each other.

[0031] Fig. 5 is a schematic block diagram showing a configuration example of one pixel of the photoelectric conversion unit 102 and pixel signal processing unit 103 according to this embodiment. Fig. 5 shows a more specific configuration example including a connection relationship between the photoelectric conversion unit 102 arranged on the sensor substrate 11 and the pixel signal processing unit 103 arranged on the circuit substrate 21. Note that in Fig. 5, drive lines between the vertical scanning circuit 110 and the pixel signal processing unit 103 in Fig. 4 are shown as drive lines 127, 128, and 129.

[0032] The photoelectric conversion unit 102 has an APD 121. The pixel signal processing unit 103 has a quenching element 122, a waveform shaping unit 123, a signal acquisition circuit 125, a selection circuit 126, and a gating circuit 124.

[0033] The APD 121 generates charges according to the incident light by photoelectric conversion. A voltage VL (first voltage) is supplied to the anode of the APD 121. A cathode of the APD 121 is connected to a first terminal of the quench element 122 and an input terminal of the waveform shaping unit 123. A voltage VH (second voltage) higher than the voltage VL supplied to the anode is supplied to the cathode of the APD 121. As a result, a reverse bias voltage is supplied to the anode and cathode of the APD 121 such that the APD 121 performs avalanche multiplication. When charges are generated by the incident light in the APD 121 to which the reverse bias voltage is supplied, the charges undergo avalanche multiplication, generating an avalanche current.

[0034] There are two operation modes when a reverse bias voltage is supplied to the APD 121: Geiger mode and linear mode. The Geiger mode is a mode in which the APD 121 operates with a potential difference between the anode and cathode that is greater than the breakdown voltage, and the linear mode is a mode in which the APD 121 operates with a potential difference between the anode and cathode that is close to or less than the breakdown voltage.

[0035] An APD operated in Geiger mode is called a SPAD (Single Photon Avalanche Diode). In this case, for example, the voltage VL (first voltage) is −30 V, and the voltage VH (second voltage) is 1 V. The APD 121 may be operated in either linear mode or Geiger mode. In the case of a SPAD, the potential difference is larger than that of an APD in linear mode, and the effect of avalanche multiplication is more pronounced, so a SPAD is preferable.

[0036] The quench element 122 functions as a load circuit (quench circuit) during signal multiplication by avalanche multiplication. The quench element 122 suppresses the voltage supplied to the APD 121 to suppress avalanche multiplication (quench operation). The quench element 122 also returns the voltage supplied to the APD 121 to the voltage VH by passing a current corresponding to the voltage drop caused by the quench operation (recharge operation). The quench element 122 may be, for example, a resistive element. In this embodiment, the quench element 122 is a resistive element.

[0037] The waveform shaping unit 123 shapes the potential change of the cathode of the APD 121 obtained when a photon is detected, and outputs a pulse signal. For example, an inverter circuit is used as the waveform shaping unit 123. Although an example in which one inverter is used as the waveform shaping unit 123 is shown in Fig. 5, the waveform shaping unit 123 may be a circuit in which a plurality of inverters are connected in series, or may be another circuit having a waveform shaping effect.

[0038] The gating circuit 124 is a circuit that performs gating such that the pulse signal output from the waveform shaping unit 123 passes only for a predetermined period. During the period in which the pulse signal can pass through the gating circuit 124, a light receiving pulse signal based on the photons incident on the APD 121 is counted in the signal acquisition circuit 125 at the subsequent stage. Therefore, the gating circuit 124 controls the exposure period during which a signal is generated based on the incident light in the pixel 101. The period during which the pulse signal passes is controlled by a control signal supplied from the vertical scanning circuit 110 via the drive line 129. FIG. 5 shows an example in which one AND circuit is used as the gating circuit 124. A pulse signal and a control signal (gating signal) are input to two input terminals of the AND circuit. The AND circuit outputs the logical product of these signals to the signal acquisition circuit 125. Note that the gating circuit 124 may have a circuit configuration other than an AND circuit as long as it can realize gating. In addition, the waveform shaping unit 123 and the gating circuit 124 may be integrated by using a logic circuit such as a NAND circuit.

[0039] The signal acquiring circuit 125 has a counter that counts the pulse signals output from the waveform shaping unit 123 via the gating circuit 124 and holds a digital signal indicating the count value. When a control signal is supplied from the vertical scanning circuit 110 via the driving line 127, the signal acquiring circuit 125 resets the signal held by the counter.

[0040] A control signal is supplied to the selection circuit 126 from the vertical scanning circuit 110 shown in Fig. 4 via a drive line 128 shown in Fig. 5. In response to this control signal, the selection circuit 126 switches between electrical connection and non-connection between the signal acquisition circuit 125 and the pixel output signal line 113. The selection circuit 126 includes, for example, a buffer circuit for outputting a signal corresponding to a value held in the signal acquisition circuit 125.

[0041] 5, the selection circuit 126 switches between electrical connection and disconnection between the signal acquisition circuit 125 and the pixel output signal line 113, but the method of controlling the signal output to the pixel output signal line 113 is not limited to this. For example, a switch such as a transistor may be disposed at a node between the quench element 122 and the APD 121, between the photoelectric conversion unit 102 and the pixel signal processing unit 103, or the like, and the signal output to the pixel output signal line 113 may be controlled by switching between electrical connection and disconnection. Alternatively, the signal output to the pixel output signal line 113 may be controlled by changing the value of the voltage VH or voltage VL supplied to the photoelectric conversion unit 102 using a switch such as a transistor.

[0042] Figures 6(a), 6(b) and 6(c) are diagrams for explaining the operation of the APD 121 according to this embodiment. Figure 6(a) is a diagram showing the photon detection element 131 composed of the APD 121, the quench element 122 and the waveform shaping unit 123 in Figure 5. As shown in Figure 6(a), a connection node between the APD 121, the quench element 122 and the input terminals of the waveform shaping unit 123 is referred to as node A. Also, as shown in Figure 6(a), an output side of the waveform shaping unit 123 is referred to as node B.

[0043] FIG. 6(b) is a graph showing the time change of the potential of node A in FIG. 6(a). FIG. 6(c) is a graph showing the time change of the potential of node B in FIG. 6(a). In the period from time t0 to time t1, a voltage of VH-VL is applied to the APD 121 in FIG. 6(a). When a photon is incident on the APD 121 at time t1, avalanche multiplication occurs in the APD 121. As a result, an avalanche current flows through the quench element 122, and the potential of the node A drops. Thereafter, the amount of potential drop becomes larger, and the voltage applied to the APD 121 gradually decreases. Then, at time t2, the avalanche multiplication in the APD 121 stops. As a result, the voltage level of the node A does not drop below a certain value. Thereafter, during the period from time t2 to time t3, a current that compensates for the potential drop flows from the node at voltage VH through the quench element to node A, and at time t3 node A settles to its original potential.

[0044] In the above process, the potential of node B becomes high level during the period when the potential of node A is lower than a certain threshold. In this way, the waveform of the drop in the potential of node A caused by the incidence of a photon is shaped by waveform shaping section 123 and output as a pulse to node B.

[0045] Next, the overall configuration of the distance measuring device 10 will be described in more detail with reference to Fig. 7 and Fig. 8. Fig. 7 is a functional block diagram showing a schematic configuration example of the distance measuring device 10 according to this embodiment. Fig. 7 shows a more detailed configuration of the light source 300, the photoelectric conversion device 100, and the signal processing circuit 500 described in Fig. 1. Fig. 8 is a pixel circuit diagram according to this embodiment. Fig. 8 shows a more detailed circuit configuration for one pixel of the photoelectric conversion device 100.

[0046] The photoelectric conversion device 100 has a photon detection element 131, a control unit 132, a gating unit 133, and a signal acquisition circuit 125. The signal acquisition circuit 125 has a pattern detection unit 134 and a detection result storage unit 135. The photon detection element 131 has an APD 121, a quench element 122, and a waveform shaping unit 123. The gating unit 133 has a gating circuit 124. The pattern detection unit 134 has D flip-flops DFF1, DFF2, DFF3, and DFF4, and a pattern comparison unit 136. The detection result storage unit 135 has a counter 137. The signal processing circuit 500 has a distance calculation unit 501.

[0047] The control unit 132 drives and synchronizes the light source 300 and the photoelectric conversion device 100. Under the control of the control unit 132, the light source 300 emits light in a predetermined light emission pulse pattern in which light emission and non-light emission change at a certain period. As shown in FIG. 7, in this embodiment, the light emission pulse pattern is described as "1011". Here, "1" indicates a light emission period, and "0" indicates a non-light emission period. "1011" indicates that of four consecutive periods, the first, third, and fourth periods are light emission periods, and the second period is a non-light emission period. This light emission pulse pattern is a digital signal containing 4 bits of information.

[0048] The bit length of the light emission pulse pattern is not limited to 4 bits, and may be shorter or longer than 4 bits as long as it is 2 bits or more, and can be set appropriately depending on the semiconductor process used in the manufacture of the photoelectric conversion device 100. The longer the bit length of the light emission pulse pattern, the larger the circuit scale required for processing becomes, but more information can be included in the light emission pulse pattern. Also, the light emission pulse pattern is not limited to "1011" and can be set appropriately.

[0049] As described above, the light emission pulse pattern may include information according to the number of bits. An example of the information included in the light emission pulse pattern is identification information of the light source 300. Examples of the identification information of the light source 300 include a manufacturer ID of the light source 300, a model ID of the light source 300, and a serial number of the light source 300.

[0050] Another example of information included in the light emission pulse pattern is identification information of the photoelectric conversion device 100. Examples of the identification information of the photoelectric conversion device 100 include a manufacturer ID of the photoelectric conversion device 100, a model ID of the photoelectric conversion device 100, and a serial number of the photoelectric conversion device 100. In addition, when the distance measuring device 10 is configured as a device in which the photoelectric conversion device 100 and the light source 300 are integrated, the information included in the light emission pulse pattern may be identification information of the entire distance measuring device 10. By including such identification information in the light emission pulse pattern, the light emission pulse pattern can be set so as not to overlap with other devices.

[0051] Another example of information included in the light emission pulse pattern is the installation environment of the light source 300 or the photoelectric conversion device 100. Examples of the installation environment include the installation location of the light source 300, the installation location of the photoelectric conversion device 100, and the weather. By including such identification information in the light emission pulse pattern, additional information can be added to the light emission pulse pattern.

[0052] The light emission pulse pattern may also include information that combines a plurality of the above examples. For example, when the light emission pulse pattern is a digital signal of 24 bits or more, the most significant 6 bits may represent the manufacturer ID of the light source 300, the next 8 bits may represent the model ID of the light source 300, and the next 10 bits may represent the serial number of the light source 300. By combining a plurality of types of information, the light emission pulse pattern can be set so as to be less likely to overlap with other devices.

[0053] Moreover, it is not essential that the digital values ​​included in the light emission pulse pattern include information that is meaningful in itself, such as the above-mentioned identification information and installation environment. In other words, the digital values ​​included in the light emission pulse pattern may be determined randomly.

[0054] Light emitted from the light source 300 is reflected by the object X and received by the APD 121 of the photon detection element 131. The photon detection element 131 generates a light-receiving pulse signal according to the incident light and outputs it from node B to the gating unit 133. The light-receiving pulse signal is input to one input terminal of the gating circuit 124. The control unit 132 outputs a gating signal GATE indicating a gating period based on the light emission timing of the light source 300 to the gating unit 133. This gating signal GATE is input to the other input terminal of the gating circuit 124.

[0055] The control unit 132 outputs the gating signal GATE so as to sequentially shift the gating period for each period in which distance measurement is performed. The shift amount of the gating signal GATE can be appropriately set according to the distance measurement range, and can be set, for example, to about 10 nanoseconds to 1 microsecond. The gating circuit 124 is, for example, an AND circuit. The gating circuit 124 performs a gating operation to calculate the logical product of the light reception pulse signal and the gating signal GATE, and outputs the obtained signal to the pattern detection unit 134. When the light reception pulse signal is based on the light emitted from the light source 300, the signal output from the gating circuit 124 can include a light reception pulse pattern similar to the above-mentioned light emission pulse pattern.

[0056] The length of the gating period, i.e., the length of the on-period of the gating signal GATE, is set to be equal to or longer than the duration of the light emission pulse pattern. This allows the pattern detection unit 134 to acquire a received light pulse pattern that corresponds to the entire light emission pulse pattern. More typically, the length of the on-period of the gating signal GATE can be set to be approximately equal to the duration of the light emission pulse pattern. The length of the on-period of the gating signal GATE may be longer than the duration of the light emission pulse pattern, but a longer gating period reduces the number of shifts of the gating period performed within a given period, which may reduce the distance resolution or accuracy of ranging.

[0057] The output terminal of the gating circuit 124 is connected to the input terminal of the D flip-flop DFF1. The output terminal of the D flip-flop DFF1 is connected to the input terminal of the D flip-flop DFF2. The output terminal of the D flip-flop DFF2 is connected to the input terminal of the D flip-flop DFF3. The output terminal of the D flip-flop DFF3 is connected to the input terminal of the D flip-flop DFF4. The output terminals of the D flip-flops DFF1, DFF2, DFF3, and DFF4 are connected to the pattern comparing section 136. In this way, the D flip-flops DFF1, DFF2, DFF3, and DFF4 are cascade-connected to form a shift register.

[0058] A clock signal CLK is input to the control terminals of the D flip-flops DFF1, DFF2, DFF3, and DFF4. The operation timings of the D flip-flops DFF1, DFF2, DFF3, and DFF4 are controlled by the clock signal CLK. Each bit of the received light pulse pattern included in the received light pulse signal that has passed through the gating unit 133 is stored in the D flip-flops DFF1, DFF2, DFF3, and DFF4.

[0059] The pattern comparison section 136 compares each bit of the received light pulse pattern held in the D flip-flops DFF1, DFF2, DFF3, and DFF4 with a corresponding bit of the light emission pulse pattern set in advance in the photoelectric conversion device 100. In this way, the pattern comparison section 136 detects a pattern included in the received light pulse pattern. The pattern comparison section 136 outputs the pattern detection result to the counter 137 of the detection result storage section 135.

[0060] For example, the pattern comparison unit 136 outputs "1" to the counter 137 when each bit of the received light pulse pattern matches the corresponding bit of the emitted light pulse pattern, and outputs "0" to the counter 137 when any of them do not match. The counter 137 has a function of holding the detection result output from the pattern detection unit 134. "1" is a signal indicating that light emitted from the light source 300 has been received, and "0" is a signal indicating that light emitted from the light source 300 has not been received. The signal holding function of the counter 137 may be included in the pattern detection unit 134 or the pattern comparison unit 136.

[0061] The distance calculation unit 501 calculates distance information based on the shift amount of the on-period of the gating signal GATE relative to the light emission start time of the light source 300 and the detection result stored in the detection result storage unit. When the value stored in the detection result storage unit 135 is "1", the distance calculation unit 501 calculates the distance using the formula "speed of light x shift amount ÷ 2". For example, when the shift amount of the gating signal GATE relative to the light emission start time is 1 microsecond and the value stored in the detection result storage unit 135 is "1", the distance calculation unit 501 calculates the distance to be about 150 m based on the above formula. When the value stored in the detection result storage unit 135 is "0", the distance calculation unit 501 does not calculate the distance. In this way, in this embodiment, the effect of light from a light source other than the light source 300 (light from another distance measurement device, ambient light, etc.) can be reduced by using the comparison result between the light reception pulse pattern and the light emission pulse pattern for distance measurement.

[0062] In the above example, it is assumed that the measurement by the gating signal GATE of one shift amount is performed once, but the measurement by the gating signal GATE of one shift amount may be performed multiple times. In that case, the counter 137 of the detection result storage unit 135 is configured to be able to hold a count value of multiple bits. This allows the detection result storage unit 135 to hold the results of multiple measurements. In that case, the distance calculation unit 501 may generate a frequency distribution by multiple count values ​​corresponding to multiple shift amounts, and calculate the distance by detecting the peak of the frequency distribution. When a part of the received light pulse pattern is missing, when the detection of the incident light fails, etc., a measurement error may occur. By performing the measurement by the gating signal GATE of one shift amount multiple times, the effect of this measurement error is reduced, and the distance measurement accuracy may be improved.

[0063] Next, the operation of the distance measuring device 10 will be described in more detail with reference to Figs. 8 and 9. Fig. 9 is a timing diagram showing the operation of the pixel circuit according to this embodiment. Fig. 9 shows the clock signal CLK, the gating signal GATE, and the potentials of nodes A, B, Y, Q1, Q2, Q3, and Q4. Furthermore, "light source" in Fig. 9 shows the light emission pulse pattern of the light source 300. Note that in the illustration of Fig. 9, the influence of the delay time, threshold voltage, etc. of the waveform shaping unit 123 is not taken into consideration for the sake of simplicity of explanation.

[0064] 8, node A is a connection node of the APD 121, the quench element 122, and the input terminal of the waveform shaping unit 123. Node B is a node of the output terminal of the waveform shaping unit 123. Node Y is a node of the output terminal of the gating circuit 124. Nodes Q1, Q2, Q3, and Q4 are nodes of the output terminals of D flip-flops DFF1, DFF2, DFF3, and DFF4, respectively.

[0065] 9, the clock signal CLK is a signal common to the photoelectric conversion device 100 and the light source 300, and functions as a synchronization signal for the photoelectric conversion device 100 and the light source 300. However, the photoelectric conversion device 100 and the light source 300 may operate according to individual clock signals, and the photoelectric conversion device 100 and the light source 300 may be synchronized by a synchronization signal separate from these clock signals.

[0066] At time t10, the light source 300 starts emitting light in response to the rising edge of the clock signal CLK. Then, at time t11, the light source 300 stops emitting light in response to the rising edge of the clock signal CLK. The period from time t10 to time t11 corresponds to the first bit of the light emission pulse pattern.

[0067] In the period from time t11 to time t12, the light source 300 does not emit light. The period from time t11 to time t12 corresponds to the second bit of the light emission pulse pattern.

[0068] At time t12, the light source 300 starts emitting light in response to the rising edge of the clock signal CLK. At time t13, the light source 300 maintains the emitting state at the rising edge of the clock signal CLK. Then, at time t14, the light source 300 stops emitting light in response to the rising edge of the clock signal CLK. The period from time t12 to time t13 corresponds to the third bit of the light emission pulse pattern. The period from time t13 to time t14 corresponds to the fourth bit of the light emission pulse pattern.

[0069] As described above, in the period from time t10 to time t14, the light source 300 emits light with the light emission pulse pattern of “1011” under the control of the control unit 132. Thereafter, the emitted light is reflected by the object X. The reflected light is incident on the APD 121.

[0070] From time t15 to time t16, light corresponding to the first bit of the light emission pulse pattern is incident on the APD 121. The difference between time t15 and time t10 corresponds to the flight time of light. When light is incident on the APD 121 at time t15, avalanche multiplication occurs in the APD 121, and the potential of the node A drops. Thereafter, the amount of potential drop becomes larger, the voltage applied to the APD 121 gradually decreases, and the avalanche multiplication in the APD 121 stops. As a result, the voltage level of the node A does not drop below a certain value. Thereafter, a current that compensates for the voltage drop flows from the node of voltage VH through the quench element 122 to the node A, and the node A settles to the original potential by time t16.

[0071] From time t16 to time t17 is a period during which light corresponding to the second bit of the light emission pulse pattern is incident on the APD 121. Since the light source 300 is not emitting light from time t11 to time t12, no light is incident on the APD 121 and the potential of the node A does not change.

[0072] From time t17 to time t18 is a period during which light corresponding to the third bit of the light emission pulse pattern is incident on the APD 121, and from time t18 to time t19 is a period during which light corresponding to the fourth bit of the light emission pulse pattern is incident on the APD 121. During these periods, similar to the period from time t15 to time t16, the potential of node A fluctuates due to the incident light.

[0073] Due to these operations, the potential of the node B is at a high level during the period from time t15 to time t16 and the period from time t17 to time t19, and the potential of the node B is at a low level during the period from time t16 to time t17. Here, it is assumed that the gating signal GATE input to the gating circuit 124 is at a high level during the period from time t15 to time t19. The gating circuit 124 outputs the logical product of the potential of the node B and the high level potential of the gating signal GATE to the node Y. The potential of the node Y is at a high level during the period from time t15 to time t16 and the period from time t17 to time t19, and the potential of the node Y is at a low level during the period from time t16 to time t17. Therefore, the light receiving pulse pattern input to the pattern detection unit 134 during the period from time t15 to time t19 is "1011".

[0074] The D flip-flops DFF1, DFF2, DFF3, and DFF4 constitute a shift register, and each D flip-flop transmits an input signal to the subsequent stage at the timing when the clock signal CLK rises. A high-level pulse based on the light incident at time t15 is delayed by the D flip-flop DFF1 and transmitted to the node Q1 at time t16 in response to the rising edge of the clock signal CLK. Similarly, this pulse is transmitted to the node Q2 at time t17, to the node Q3 at time t18, and to the node Q4 at time t19. In this way, the light receiving pulse pattern of "1011" input to the pattern detection unit 134 is transmitted to the subsequent D flip-flops in sequence at each rise of the clock signal CLK. At time t19, the signals of the nodes Q1, Q2, Q3, and Q4 indicate "1", "0", "1", and "1", respectively.

[0075] The pattern comparison unit 136 compares the signals of the nodes Q1, Q2, Q3, and Q4 at this time with the pre-stored light emission pulse pattern "1011" and outputs a signal according to the comparison result. This allows the pattern comparison unit 136 to determine whether the incident light is light emitted from the light source 300. In this example, the light reception pulse pattern "1011" matches the light emission pulse pattern "1011" of the light source 300. Therefore, the pattern comparison unit 136 outputs "1" (first signal) to the counter 137 as a signal indicating that the light emitted from the light source 300 has been received. The counter 137 counts up based on this signal.

[0076] 9 shows an example in which the received light pulse pattern and the emitted light pulse pattern match, but this is not always the case. For example, if the light received by the photon detection element 131 is emitted from a light source other than the light source 300, the received light pulse pattern does not match the emitted light pulse pattern. In this case, the pattern comparison unit 136 outputs "0" (second signal) to the counter 137 as a signal indicating that the light emitted from the light source 300 is not received. In this case, the counter 137 does not count up.

[0077] Examples of light sources other than the light source 300 include light sources of other distance measuring devices and light sources of ambient light such as sunlight. These light sources do not have a unique light emission pulse pattern or have a light emission pulse pattern different from that of the light source 300. If the incident light is emitted from these light sources, the received light pulse pattern and the light emission pulse pattern do not match in the pattern detection process in the pattern comparison unit 136. Therefore, the pattern comparison unit 136 can identify whether the received light is emitted from the light source 300 of the distance measuring device 10 or from another light source.

[0078] The distance measuring device 10 of this embodiment has a function of comparing the light receiving pulse pattern of the light received by the photon detecting element 131 with the light emitting pulse pattern of the light source 300, and outputting a signal according to the comparison result. This allows the distance measuring device 10 to distinguish whether the light received by the photon detecting element 131 is emitted from the light source 300 of the distance measuring device 10 or from another light source, and reduce the influence of light emitted from the other light source on the distance measuring accuracy. Therefore, according to this embodiment, a photoelectric conversion device in which the influence of light from light sources other than the corresponding light source is reduced is provided.

[0079] [Second embodiment] In this embodiment, an example will be described in which the quench element 122 described in the first embodiment is a transistor and a recharge operation can be performed by a clock signal CLK. Descriptions of elements common to the first embodiment may be omitted or simplified as appropriate.

[0080] Fig. 10 is a pixel circuit diagram according to this embodiment. The difference between this embodiment and the pixel circuit diagram of the first embodiment shown in Fig. 8 is that the quench element 122 is a PMOS transistor 122a controlled by a clock signal CLK. The drain of the PMOS transistor 122a is connected to the cathode of the APD 121 and the input terminal of the waveform shaping unit 123. The voltage VH is supplied to the source of the PMOS transistor 122a. The clock signal CLK is input to the gate of the PMOS transistor 122a. That is, in this embodiment, a common clock signal CLK is input to the gate of the PMOS transistor 122a and the control terminals of the D flip-flops DFF1, DFF2, DFF3, and DFF4.

[0081] The PMOS transistor 122a is turned on when the potential of the clock signal CLK is at a low level, and is turned off when the potential of the clock signal CLK is at a high level. The PMOS transistor 122a functions as a recharge circuit that periodically resets the output potential of the APD 121 based on the clock signal CLK. The clock signal CLK is common to the PMOS transistor 122a and the shift register. Therefore, the timing at which the PMOS transistor 122a performs the reset operation is synchronized with the timing at which the pattern detection unit 134 acquires one bit of the light reception pulse pattern.

[0082] Next, the operation and effect of the pixel circuit according to this embodiment will be described with reference to Figs. 11 and 12. Fig. 11 is a timing diagram showing the operation of a pixel circuit according to a comparative example of the second embodiment. Fig. 12 is a timing diagram showing the operation of a pixel circuit according to the second embodiment. Figs. 11 and 12 show the clock signal CLK and the potentials of nodes A and B extracted from the timing diagram shown in Fig. 9 around time t15 to time t19 when light is received. Figs. 11 and 12 also show the threshold value TH at which the level of the output signal of the waveform shaping section 123 switches.

[0083] Fig. 11 is a timing diagram assuming a case where the period of the light emission pulse or the period of the clock signal CLK is shorter than the settling time of the potential of node A in the circuit configuration of the first embodiment. Problems that may arise in the configuration of the first embodiment will be explained using Fig. 11. Note that the light emission pulse pattern is "1011" as in the first embodiment.

[0084] At time t15, when a photon P1 is incident on the APD 121, avalanche multiplication occurs in the APD 121, causing a drop in the potential of the node A. At time t31, the potential of the node A becomes lower than the threshold TH, and the potential of the node B changes from the low level to the high level.

[0085] At time t16, since no light is incident, no potential fluctuation at node A occurs due to avalanche multiplication, but the potential fluctuation at time t15 has not yet settled, and the potential at node A is lower than the threshold TH. Therefore, the potential at node B is maintained at a high level. At time t32, the potential at node A becomes higher than the threshold TH, and the potential at node B changes from a high level to a low level.

[0086] When a photon P2 is incident on the APD 121 at time t17, avalanche multiplication occurs in the APD 121, and the potential of node A drops. At time t33, the potential of node A falls below the threshold TH, and the potential of node B changes from low to high. Thereafter, when a photon P3 is incident on the APD 121 at time t18, avalanche multiplication occurs in the APD 121, and the potential of node A drops again. At this time, the state in which the potential of node A is lower than the threshold TH continues, so the potential of node B is maintained at a high level. At time t34, the potential of node A rises above the threshold TH, and the potential of node B changes from high to low.

[0087] As described above, since the settling time of the potential of node A is longer than the period of the light emission pulse or the period of the clock signal CLK, the potential of node B is at a high level during the period from time t16 to time t32, even though no light is incident. This may result in the received light pulse pattern being erroneously detected as "1111".

[0088] FIG. 12 is a timing diagram assuming a case where the circuit configuration of the second embodiment is applied in the situation of FIG.

[0089] At time t15, when the clock signal CLK goes high, the PMOS transistor 122a is turned off. When a photon P1 is incident on the APD 121 at time t15, avalanche multiplication occurs in the APD 121, and the potential of the node A drops. At time t31, the potential of the node A falls below the threshold TH, and the potential of the node B goes from low to high.

[0090] At time t41, when the clock signal CLK goes to low level, the PMOS transistor 122a is turned on. This resets the potential of the node A to its original potential. This reset causes the potential of the node A to become higher than the threshold TH, and the potential of the node B goes from high level to low level.

[0091] At time t16, no light is incident, so no potential fluctuation occurs at node A due to avalanche multiplication. Unlike the example in Fig. 11, the potential at node A is higher than the threshold TH because the potential is reset at time t41. Therefore, the potential at node B is maintained at a low level.

[0092] At time t17, when the clock signal CLK goes high, the PMOS transistor 122a is turned off. When a photon P2 is incident on the APD 121 at time t17, avalanche multiplication occurs in the APD 121, and the potential of the node A drops. At time t33, the potential of the node A falls below the threshold TH, and the potential of the node B goes from low to high.

[0093] At time t42, when the clock signal CLK goes to low level, the PMOS transistor 122a is turned on. This resets the potential of the node A to its original potential. This reset causes the potential of the node A to become higher than the threshold TH, and the potential of the node B goes from high level to low level.

[0094] At time t18, when the clock signal CLK goes high, the PMOS transistor 122a is turned off. At time t17, when a photon P2 is incident on the APD 121, avalanche multiplication occurs in the APD 121, and the potential of the node A drops. At time t43, the potential of the node A falls below the threshold TH, and the potential of the node B goes from low to high.

[0095] At time t44, when the clock signal CLK goes to low level, the PMOS transistor 122a is turned on. This resets the potential of the node A to its original potential. This reset causes the potential of the node A to become higher than the threshold TH, and the potential of the node B goes from high level to low level.

[0096] As described above, the potential of node A is reset by turning on the PMOS transistor 122a. As a result, even if the settling time is longer than the period of the light emission pulse or the period of the clock signal CLK, the potential of node B becomes low level during the period from time t16 to time t17 when no light is incident. Therefore, by resetting the potential using the PMOS transistor 122a, the possibility of erroneous detection due to the settling time as shown in FIG. 11 is reduced.

[0097] According to the present embodiment, a photoelectric conversion device in which the influence of light from a light source other than the corresponding light source is reduced is provided, as in the first embodiment. Furthermore, according to the present embodiment, a photoelectric conversion device in which the possibility of erroneous detection due to the settling time is reduced is provided.

[0098] [Third embodiment] In this embodiment, a configuration example of a pixel circuit that can detect incident light by integrating output signals from multiple photon detection elements will be described. Descriptions of elements common to the first embodiment may be omitted or simplified as appropriate.

[0099] FIG. 13 is a pixel circuit diagram according to this embodiment. In the photoelectric conversion device 100 of this embodiment, a plurality of photon detection elements 131a and 131b are connected in parallel to the gating section 133. That is, the output terminal of the waveform shaping section 123 of the photon detection element 131a is connected to one input terminal of the gating circuit 124, and the output terminal of the waveform shaping section 123 of the photon detection element 131b is connected to the other input terminal of the gating circuit 124. The gating circuit 124 performs a gating operation to calculate the logical product of the light receiving pulse signal from the photon detection element 131a, the light receiving pulse signal from the photon detection element 131b, and the gating signal GATE, and outputs the obtained signal to the pattern detection section 134. This makes it possible to invalidate the light when it is incident on only one of the photon detection elements 131a and 131b. This reduces the possibility of erroneous detection due to the influence of external light, etc.

[0100] According to this embodiment, a photoelectric conversion device is provided in which the influence of light from light sources other than the corresponding light source is further reduced.

[0101] In this embodiment, the two photon detecting elements 131a and 131b are connected in parallel to the gating section 133, but the number of photon detecting elements connected to the gating section 133 may be three or more.

[0102] [Fourth embodiment] 14(a) and 14(b) are block diagrams of devices related to the vehicle-mounted distance measuring device in this embodiment. The device 80 has a distance measuring unit 803, which is an example of the distance measuring device in the above-mentioned embodiment, and a signal processing device (processing device) that processes a signal from the distance measuring unit 803. The device 80 has a distance measuring unit 803 that measures the distance to an object, and a collision determination unit 804 that determines whether or not there is a possibility of collision based on the measured distance. Here, the distance measuring unit 803 is an example of a distance information acquisition unit that acquires distance information to the object. That is, the distance information is information related to the distance to the object, etc. The collision determination unit 804 may determine the possibility of collision using the distance information.

[0103] The device 80 is connected to a vehicle information acquisition device 810, and can acquire vehicle information such as vehicle speed, yaw rate, and steering angle. In addition, the device 80 is connected to a control ECU 820, which is a control device that outputs a control signal to generate a braking force for the vehicle based on the judgment result of the collision judgment unit 804. In addition, the device 80 is also connected to an alarm device 830 that issues an alarm to the driver based on the judgment result of the collision judgment unit 804. For example, when the judgment result of the collision judgment unit 804 indicates that there is a high possibility of a collision, the control ECU 820 performs vehicle control to avoid a collision and reduce damage by applying the brakes, releasing the accelerator, suppressing engine output, etc. The alarm device 830 warns the user by sounding an alarm such as a sound, displaying alarm information on the screen of a car navigation system, etc., and applying vibrations to a seat belt or steering wheel. These devices of the device 80 function as a mobile object control unit that controls the operation of controlling the vehicle as described above.

[0104] In this embodiment, the device 80 measures distances around the vehicle, for example, in front or behind. Fig. 14(b) shows the device when measuring distances in front of the vehicle (distance measurement range 850). A vehicle information acquisition device 810 as a distance measurement control means sends an instruction to the device 80 or distance measurement unit 803 to perform a distance measurement operation. With this configuration, the accuracy of distance measurement can be further improved.

[0105] Although the above describes an example of control to prevent collision with other vehicles, the present invention can also be applied to control of automatic driving by following other vehicles, control of automatic driving to prevent deviation from lanes, etc. Furthermore, the device is not limited to vehicles such as automobiles, but can be applied to moving bodies (moving devices) such as ships, aircraft, artificial satellites, industrial robots, and consumer robots. In addition, the present invention can be applied to devices that use object recognition or biometric recognition, such as intelligent transport systems (ITS) and surveillance systems, in addition to moving bodies.

[0106] [Modified embodiment] The present invention is not limited to the above-described embodiments and can be modified in various ways. For example, an example in which a part of the configuration of any of the embodiments is added to another embodiment, or an example in which a part of the configuration of any of the embodiments is replaced with a part of the configuration of another embodiment, is also an embodiment of the present invention.

[0107] The disclosure of this specification includes the complement of the concepts described in this specification. In other words, if the specification states, for example, that "A is B" (A=B), the specification is deemed to disclose or suggest that "A is not B" even if the statement that "A is not B" (A≠B) is omitted. This is because when it states that "A is B," it is assumed that the case that "A is not B" is taken into consideration.

[0108] The disclosure of this specification includes the following configurations. (Configuration 1) a photon detection element that generates a light receiving pulse signal in response to incident light; a control unit that controls a light emission pulse pattern of a light source, a light emission timing of the light source, and a gating period based on the light emission timing; a gating unit that outputs a light receiving pulse pattern of the incident light based on the light receiving pulse signal input during the gating period; a pattern detection unit that compares the received light pulse pattern with the emitted light pulse pattern and outputs a signal according to the comparison result; having The length of the gating period is equal to or greater than the duration of the light emission pulse pattern. A photoelectric conversion device comprising: (Configuration 2) The pattern detection unit outputs a first signal indicating that light has been received when it is determined that the received light pulse pattern and the emitted light pulse pattern match. 2. The photoelectric conversion device according to configuration 1. (Configuration 3) The pattern detection unit outputs a second signal indicating that light is not being received when it is determined that the received light pulse pattern and the emitted light pulse pattern do not match. 3. The photoelectric conversion device according to configuration 2. (Configuration 4) The first signal is further comprised of a counter. 4. The photoelectric conversion device according to claim 2 or 3. (Configuration 5) The distance from the photoelectric conversion device to the target object is calculated based on the count value held in the counter. 5. The photoelectric conversion device according to configuration 4. (Configuration 6) The pattern detection unit includes a shift register that stores a digital signal included in the received light pulse pattern. 6. The photoelectric conversion device according to any one of configurations 1 to 5. (Configuration 7) The pattern detection unit compares each bit of the digital signal stored in the shift register with a corresponding bit of the light emission pulse pattern. 7. The photoelectric conversion device according to configuration 6. (Configuration 8) The pattern detection unit determines that the received light pulse pattern and the light emission pulse pattern match when each bit of the digital signal stored in the shift register matches a corresponding bit of the light emission pulse pattern. 8. The photoelectric conversion device according to configuration 7. (Configuration 9) The pattern detection unit determines that the received light pulse pattern and the light emission pulse pattern do not match when each bit of the digital signal stored in the shift register does not match at least one corresponding bit of the light emission pulse pattern. 9. The photoelectric conversion device according to configuration 8. (Configuration 10) The photon detection element includes an avalanche photodiode and a recharge circuit that resets the output potential of the avalanche photodiode. 10. The photoelectric conversion device according to any one of configurations 1 to 9. (Configuration 11) The recharge circuit periodically performs the reset. 11. The photoelectric conversion device according to configuration 10. (Configuration 12) The timing at which the recharge circuit performs the reset is synchronized with the timing at which the pattern detection unit acquires one bit of the received light pulse pattern. 12. The photoelectric conversion device according to claim 11, (Configuration 13) A plurality of the photon detection elements are provided, The gating section receives the light receiving pulse signal from each of the plurality of photon detecting elements. 13. The photoelectric conversion device according to any one of configurations 1 to 12. (Configuration 14) The light emission pulse pattern includes a digital signal of 2 or more bits. 14. The photoelectric conversion device according to any one of configurations 1 to 13. (Configuration 15) The light emission pulse pattern includes identification information of the light source or the photoelectric conversion device. 15. The photoelectric conversion device according to any one of configurations 1 to 14. (Configuration 16) The light emission pulse pattern includes information indicating an installation environment of the light source or the photoelectric conversion device. 16. The photoelectric conversion device according to any one of configurations 1 to 15. (Configuration 17) The light pulse pattern includes randomly determined digital values. 17. The photoelectric conversion device according to any one of configurations 1 to 16, (Configuration 18) The gating section includes a logic circuit that outputs a logical product of the light receiving pulse signal and a gating signal indicating the gating period. 18. The photoelectric conversion device according to any one of configurations 1 to 17. (Configuration 19) The photoelectric conversion device according to any one of configurations 1 to 18, a signal processing unit that processes a signal output from the photoelectric conversion device; A distance measuring device comprising: (Configuration 20) A mobile object, The photoelectric conversion device according to any one of configurations 1 to 18, a distance information acquisition unit that acquires distance information to an object from a signal output from the photoelectric conversion device; a moving object control unit that controls the moving object based on the distance information; A moving object comprising:

[0109] The present invention can also be realized by a process in which a program for implementing one or more of the functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) for implementing one or more of the functions.

[0110] It should be noted that the above-mentioned embodiments are merely examples of the implementation of the present invention, and the technical scope of the present invention should not be interpreted as being limited by these embodiments. In other words, the present invention can be implemented in various forms without departing from its technical concept or main features. [Explanation of symbols]

[0111] 100 Photoelectric conversion device 131 Photon detector 132 Control section 133 Gating section 134 Pattern detection unit 300 light source

Claims

1. a photon detection element that generates a light receiving pulse signal in response to incident light; a control unit that controls a light emission pulse pattern of a light source, a light emission timing of the light source, and a gating period based on the light emission timing; a gating unit that outputs a light receiving pulse pattern of the incident light based on the light receiving pulse signal input during the gating period; a pattern detection unit that compares the received light pulse pattern with the emitted light pulse pattern and outputs a signal according to the comparison result; having The length of the gating period is equal to or greater than the duration of the light emission pulse pattern. A photoelectric conversion device comprising:

2. The pattern detection unit outputs a first signal indicating that light has been received when it is determined that the received light pulse pattern and the emitted light pulse pattern match.

2. The photoelectric conversion device according to claim 1.

3. The pattern detection unit outputs a second signal indicating that light is not being received when it is determined that the received light pulse pattern and the emitted light pulse pattern do not match.

3. The photoelectric conversion device according to claim 2.

4. The first signal is further comprised of a counter.

3. The photoelectric conversion device according to claim 2.

5. The distance from the photoelectric conversion device to the target object is calculated based on the count value held in the counter.

5. The photoelectric conversion device according to claim 4.

6. The pattern detection unit includes a shift register that stores a digital signal included in the received light pulse pattern.

2. The photoelectric conversion device according to claim 1.

7. The pattern detection unit compares each bit of the digital signal stored in the shift register with a corresponding bit of the light emission pulse pattern.

7. The photoelectric conversion device according to claim 6.

8. The pattern detection unit determines that the received light pulse pattern and the light emission pulse pattern match when each bit of the digital signal stored in the shift register matches a corresponding bit of the light emission pulse pattern.

8. The photoelectric conversion device according to claim 7.

9. The pattern detection unit determines that the received light pulse pattern and the light emission pulse pattern do not match when each bit of the digital signal stored in the shift register does not match at least one corresponding bit of the light emission pulse pattern.

9. The photoelectric conversion device according to claim 8.

10. The photon detection element includes an avalanche photodiode and a recharge circuit that resets the output potential of the avalanche photodiode.

2. The photoelectric conversion device according to claim 1.

11. The recharge circuit periodically performs the reset. The photoelectric conversion device according to claim 10 .

12. The timing at which the recharge circuit performs the reset is synchronized with the timing at which the pattern detection unit acquires one bit of the light reception pulse pattern. The photoelectric conversion device according to claim 11 .

13. A plurality of the photon detection elements are provided, The gating section receives the light receiving pulse signal from each of the plurality of photon detecting elements.

2. The photoelectric conversion device according to claim 1.

14. The light emission pulse pattern includes a digital signal of 2 or more bits.

2. The photoelectric conversion device according to claim 1.

15. The light emission pulse pattern includes identification information of the light source or the photoelectric conversion device.

2. The photoelectric conversion device according to claim 1.

16. The light emission pulse pattern includes information indicating an installation environment of the light source or the photoelectric conversion device.

2. The photoelectric conversion device according to claim 1.

17. The light pulse pattern includes randomly determined digital values.

2. The photoelectric conversion device according to claim 1.

18. The gating section includes a logic circuit that outputs a logical product of the light receiving pulse signal and a gating signal indicating the gating period.

2. The photoelectric conversion device according to claim 1.

19. The photoelectric conversion device according to any one of claims 1 to 18, a signal processing unit that processes a signal output from the photoelectric conversion device; A distance measuring device comprising:

20. A mobile object, The photoelectric conversion device according to any one of claims 1 to 18, a distance information acquisition unit that acquires distance information to an object from a signal output from the photoelectric conversion device; a moving object control unit that controls the moving object based on the distance information; A moving object comprising:

Images