Distance image camera and control method

Abstract

This invention relates to a distance image capturing device and a control method for the distance image capturing device. The distance image capturing device includes: a light source unit that illuminates a light pulse into a measurement space where a subject exists; a light receiving unit having pixel circuits and pixel driving circuits, the pixel circuits having photoelectric conversion elements and charge storage units, the pixel driving circuits distributing and storing the charge in each of the charge storage units; and a distance image processing unit, wherein multiple pixel circuits are arranged in a two-dimensional matrix, each pixel circuit including: a transmission transistor that transmits the charge from the photoelectric conversion element to each of the charge storage units; and a reset transistor that discharges and initializes the charge stored in the charge storage units, wherein the distance image processing unit controls the reset transistor to perform different repetition numbers according to a predetermined control unit of the pixel circuits during repeated distribution of the charge.

Description

Technical Field

[0001] This invention relates to a distance image camera device and a control method.

[0002] This application claims priority to Japanese Patent Application No. 2025-054955, filed on March 28, 2025, the contents of which are incorporated herein by reference. Background Technology

[0003] Distance imaging devices that utilize the known speed of light and determine the distance between a measuring device and an object based on the time of flight of light in space (measurement space) have been realized (see, for example, Japanese Patent No. 4235729). In such imaging devices, for example, distance imaging elements comprising photoelectric conversion elements such as photodiodes are used for imaging. Furthermore, in TOF-type distance imaging devices, it is known to include photoelectric conversion elements that convert incident light into electrical charge, and distance imaging elements that distribute and store the charge converted by the photoelectric conversion elements in multiple charge storage units.

[0004] However, in conventional distance image cameras like those described above, if objects with different reflectivities are photographed when capturing distance images, the signal quantity will differ due to the reflectivity, even at the same distance.

[0005] Therefore, in conventional distance image cameras, for example, when recording under a single condition, there are situations where saturation or insufficient signal can occur due to reflectivity and distance, making it impossible to accurately measure the distance. To address this issue, conventional distance image cameras perform HDR (High Dynamic Range) conversion, synthesizing data corresponding to different recording conditions with varying reflectivity.

[0006] In conventional distance image camera devices, as a method of HDR conversion, HDR imaging during a frame can be performed by changing the number of times the distribution drive from the photodiode to the charge storage unit is changed according to column units or row units.

[0007] However, in conventional distance image imaging devices, for example, when different imaging conditions are implemented according to rows and columns, there is a problem of increased wiring within pixels and increased control complexity. Summary of the Invention

[0008] The present invention was made to solve the above-mentioned problems, and its purpose is to provide a distance image camera device and control method that can suppress the increase of control lines and achieve HDR through simple control.

[0009] To address the aforementioned problems, one aspect of the present invention relates to a distance image imaging device, comprising: a light source unit that irradiates a light pulse into a measurement space in which a subject exists; a light receiving unit having a pixel circuit and a pixel driving circuit, the pixel circuit having a photoelectric conversion element that generates a charge corresponding to the incident light, and a plurality of charge storage units for storing the charge, the pixel driving circuit distributing and storing the charge to the charge storage units in the pixel circuit at a predetermined timing synchronized with the irradiation of the light pulse; and a distance image processing unit that determines the measurement distance to the subject based on the amount of charge stored in each of the charge storage units. The pixel circuits are arranged in a two-dimensional matrix, and each pixel circuit includes: a transmission transistor corresponding to the plurality of charge storage sections, which transmits the charge from the photoelectric conversion element to each of the charge storage sections; and a reset transistor for discharging and initializing the charge stored in the charge storage sections. The distance image processing unit uses the transmission transistor to repeatedly distribute the charge, and during the repeated distribution of the charge, the reset transistor is controlled to repeat the process a different number of times according to a predetermined control unit of the pixel circuits arranged in the two-dimensional matrix.

[0010] Another aspect of the present invention relates to a control method for a distance image capturing device, the distance image capturing device comprising: a light source unit that irradiates a light pulse into a measurement space in which a subject exists; a light receiving unit having a pixel circuit and a pixel driving circuit, the pixel circuit having a photoelectric conversion element that generates a charge corresponding to the incident light and a plurality of charge storage units that store the charge, the pixel driving circuit distributing and storing the charge to the charge storage units in the pixel circuit at a predetermined timing synchronized with the irradiation of the light pulse; and a distance image processing unit that determines the measurement distance to the subject based on the amount of charge stored in the charge storage units. The pixel circuits are arranged in a two-dimensional matrix, and each pixel circuit includes: a transmission transistor corresponding to the plurality of charge storage portions, which transmits the charge from the photoelectric conversion element to each of the charge storage portions; and a reset transistor for discharging and initializing the charge stored in the charge storage portions. The control method includes: a control step in which the distance image processing unit repeatedly distributes the charge using the transmission transistor, and during the repeated distribution of the charge, the reset transistor is controlled in such a way that the number of repetitions is different according to a predetermined control unit of the pixel circuits arranged in the two-dimensional matrix.

[0011] Invention Effects According to the present invention, the increase of control lines can be suppressed and HDR can be achieved through simple control. Attached Figure Description

[0012] Figure 1 This is a block diagram illustrating an example of the distance image camera device according to this embodiment.

[0013] Figure 2 This is a block diagram illustrating an example of the distance image sensor in this embodiment.

[0014] Figure 3 This is a block diagram illustrating an example of the pixel circuit in this embodiment.

[0015] Figure 4 This diagram illustrates an example of the basic operation of the charge distribution processing of the distance image camera device in this embodiment.

[0016] Figure 5A This diagram illustrates an example of the HDR conversion operation of the distance image camera device in this embodiment.

[0017] Figure 5B This diagram illustrates an example of the HDR conversion operation of the distance image camera device in this embodiment.

[0018] Figure 5C This diagram illustrates an example of the HDR conversion operation of the distance image camera device in this embodiment.

[0019] Figure 6 This is a flowchart illustrating an example of the control processing for HDR conversion of the distance image camera device in this embodiment.

[0020] Figure 7A This is a diagram illustrating a first variation of the HDR conversion operation of the distance image camera device according to this embodiment.

[0021] Figure 7B This is a diagram illustrating a first variation of the HDR conversion operation of the distance image camera device according to this embodiment.

[0022] Figure 7C This is a diagram illustrating a first variation of the HDR conversion operation of the distance image camera device according to this embodiment.

[0023] Figure 8 This is a flowchart illustrating an example of the control processing for HDR conversion of the distance image camera device in the first variation of this embodiment.

[0024] Figure 9 This diagram illustrates an example of a distance image sensor used in HDR rendering within a conventional distance image camera device.

[0025] Figure 10A This is a diagram illustrating a second variation of the HDR conversion operation of the distance image camera device in this embodiment.

[0026] Figure 10B This is a diagram illustrating a second variation of the HDR conversion operation of the distance image camera device in this embodiment.

[0027] Explanation of reference numerals in the attached figures 1…distance image camera device 2…Light Source Section 3…Light-receiving section 4… Distance Image Processing Unit 21…Light source device 22…diffuser plate 31…lens 32… Distance Image Sensor 41…Timing Control Department 42…Distance Calculation Unit 43… Measurement and Control Department 320…Light-receiving area Pixel circuits 321, 321-1, 321-2, 321-3, 321-4… 322…Pixel driving circuit 323…Vertical Scan Circuit 324… Horizontal Scan Circuit 325…pixel signal processing circuit 326…Control Circuit C1, C2, C3, C4… Charge storage capacitors CS, CS1, CS2, CS3, CS4… Charge accumulation section FD, FD1, FD2, FD3, FD4… Floating diffuser section G, G1, G2, G3, G4… Transmission transistors GD…charge discharge transistor OB…subject PD… Photoelectric conversion element PO…light pulse RL…reflected light RT1, RT2, RT3, RT4… Reset transistors SF, SF1, SF2, SF3, SF4... source follower transistors SL, SL1, SL2, SL3, SL4… select transistors Detailed Implementation

[0028] Hereinafter, a distance image camera device according to one embodiment of the present invention will be described with reference to the accompanying drawings.

[0029] Figure 1 This is a block diagram illustrating an example of the distance image camera device 1 according to this embodiment.

[0030] like Figure 1 As shown, the distance image capturing device 1 includes a light source unit 2, a light receiving unit 3, and a distance image processing unit 4. Furthermore, in Figure 1 The image also shows the object, namely the subject OB, whose distance is measured using the distance image camera device 1.

[0031] The light source unit 2, under the control of the distance image processing unit 4, illuminates light pulses PO into the space of the photographic object where the subject OB, whose distance is measured in the distance image imaging device 1, exists. The light source unit 2 is, for example, a surface-emitting semiconductor laser module such as a vertically oriented surface-emitting laser (VCSEL). In addition, the light source unit 2 includes a light source device 21 and a diffuser plate 22.

[0032] The light source device 21 is a laser light source that emits a near-infrared wavelength (e.g., a wavelength range of 850 nm to 940 nm) that forms a light pulse PO that irradiates the subject OB. The light source device 21 is, for example, a semiconductor laser light-emitting element. The light source device 21 emits pulsed laser light according to the control from the measurement and control unit 43.

[0033] The diffuser plate 22 is an optical component that diffuses the near-infrared laser emitted by the light source device 21 into a surface wide enough to irradiate the subject OB. The pulsed laser light diffused by the diffuser plate 22 is emitted as a light pulse PO and irradiates the subject OB.

[0034] The light-receiving unit 3 receives the reflected light RL from the light pulse PO reflected by the subject OB, whose distance is measured in the distance image imaging device 1, and outputs a pixel signal corresponding to the received reflected light RL. The light-receiving unit 3 includes a lens 31 and a distance image sensor 32.

[0035] Lens 31 is an optical lens that guides the incident reflected light RL to the distance image sensor 32. Lens 31 directs the incident reflected light RL toward the distance image sensor 32, so that the pixel circuit 321 in the light-receiving area of ​​the distance image sensor 32 receives light (incident light).

[0036] The distance image sensor 32 is an imaging element used in the distance image imaging device 1. The distance image sensor 32 has multiple pixel circuits 321 and pixel driving circuits 322 that control each pixel circuit 321 in a two-dimensional light-receiving area.

[0037] The pixel circuit 321 includes a photoelectric conversion element (e.g., the photoelectric conversion element PD described later), a plurality of charge storage units corresponding to the photoelectric conversion element (e.g., charge storage units CS (CS1 to CS4 described later) described later), and constituent elements for distributing charge to each charge storage unit.

[0038] The pixel driving circuit 322 turns on each charge accumulation section CS (CS1 to CS4) and the transmission transistor G (described later) respectively at a predetermined accumulation timing synchronized with the irradiation of the light pulse PO, thereby distributing and accumulating charge to them.

[0039] For further details regarding the distance image sensor 32, which includes pixel circuit 321 and pixel driving circuit 322, please refer to [link / reference]. Figure 2 To be described later.

[0040] The distance image sensor 32, under control from the measurement and control unit 43, distributes the charge generated by the photoelectric conversion element to each charge storage unit. Furthermore, the distance image sensor 32 outputs a pixel signal corresponding to the amount of charge distributed to the charge storage units. In the distance image sensor 32, multiple pixel circuits are configured in a two-dimensional matrix, and each pixel circuit outputs a corresponding one-frame pixel signal.

[0041] Here, refer to Figure 2 The detailed configuration of the distance image sensor 32 will be explained.

[0042] Figure 2 This is a block diagram illustrating an example of the distance image sensor 32 in this embodiment.

[0043] like Figure 2 As shown, the distance image sensor 32 includes, for example, a light-receiving area 320 configured with multiple pixel circuits 321, and a pixel driving circuit 322. Furthermore, the pixel driving circuit 322 includes a vertical scanning circuit 323 with allocation operation, a horizontal scanning circuit 324, a pixel signal processing circuit 325, and a control circuit 326.

[0044] The light-receiving area 320 is the area where multiple pixel circuits 321 are configured. Figure 2 The image shows an example of a two-dimensional matrix arranged in 8 rows and 8 columns.

[0045] Multiple pixel circuits 321 are arranged in a two-dimensional matrix, accumulating a charge equivalent to the amount of light received. For a detailed description of the pixel circuit 321, please refer to [link to relevant documentation]. Figure 3 To be described later.

[0046] The control circuit 326 provides unified control of the distance image sensor 32. For example, the control circuit 326 controls the operation of the components of the distance image sensor 32 according to instructions from the measurement control unit 43 of the distance image processing unit 4. Alternatively, the control of the components of the distance image sensor 32 can be directly performed by the measurement control unit 43, in which case the control circuit 326 can be omitted.

[0047] The vertical scanning circuit 323 controls the pixel circuits 321 arranged in the light-receiving area 320 row by row according to the control from the control circuit 326. The vertical scanning circuit 323 causes the pixel signal processing circuit 325 to output a voltage signal corresponding to the amount of charge stored in the charge storage section CS of the pixel circuit 321. In this case, the vertical scanning circuit 323 distributes and stores the charge converted by the photoelectric conversion element to the charge storage section CS of the pixel circuit 321.

[0048] The pixel signal processing circuit 325 performs predetermined signal processing (e.g., noise suppression processing, A / D conversion processing, etc.) on the voltage signals output from the pixel circuits 321 of each column, according to the control from the control circuit 326.

[0049] The horizontal scanning circuit 324 is a circuit that, under the control of the control circuit 326, sequentially outputs the signals from the pixel signal processing circuit 325 in a time sequence. Thus, pixel signals equivalent to the charge of accumulating one frame are sequentially output to the distance image processing unit 4. In the following description, it is assumed that the pixel signal processing circuit 325 performs A / D conversion processing, and that the pixel signals are digital signals.

[0050] Next, refer to Figure 3 The configuration of the pixel circuit 321 arranged within the light-receiving area 320 of the distance image sensor 32 will be described.

[0051] Figure 3 This is a block diagram illustrating an example of the pixel circuit 321 in this embodiment.

[0052] also, Figure 3 The pixel circuit 321 shown is a configuration example having four pixel signal readout units RU (RU1 to RU4).

[0053] like Figure 3As shown, the pixel circuit 321 includes a photoelectric conversion element PD, a charge discharge transistor GD, and four pixel signal readout units RU (RU1 to RU4) that output voltage signals from corresponding output terminals O (O1 to O4). Each pixel signal readout unit RU includes a transmission transistor G, a floating diffuser FD, a charge storage capacitor C, a reset transistor RT, a source follower transistor SF, and a selection transistor SL. The floating diffuser FD and the charge storage capacitor C constitute the charge storage unit CS.

[0054] exist Figure 3 In the pixel circuit 321 shown, the pixel signal readout unit RU1, which outputs a voltage signal from the output terminal O1, includes a transmission transistor G1, a floating diffuser FD1, a charge storage capacitor C1, a reset transistor RT1, a source follower transistor SF1, and a selection transistor SL1. In the pixel signal readout unit RU1, the floating diffuser FD1 and the charge storage capacitor C1 constitute the charge storage unit CS1. Pixel signal readout units RU2 to RU4 have the same configuration.

[0055] A photoelectric conversion element (PD) is an embedded photodiode that performs photoelectric conversion on incident light, generates a charge corresponding to the incident light, and stores the generated charge. In this embodiment, the incident light enters from the space of the object being measured.

[0056] In pixel circuit 321, the charge generated by photoelectric conversion element PD through photoelectric conversion of incident light is distributed to four charge storage units CS (CS1 to CS4), and each voltage signal corresponding to the amount of charge distributed is output to pixel signal processing circuit 325.

[0057] Furthermore, the configuration of the pixel circuit 321 disposed on the distance image sensor 32 is not limited to Figure 3 The pixel circuit 321 shown, which has four pixel signal readout units RU (RU1 to RU4), can also be configured with two or more pixel signal readout units RU. Furthermore, the pixel circuit 321 can have three or more pixel signal readout units RU.

[0058] Furthermore, in the driving of the pixel circuit 321, when the light pulse PO is irradiated at the illumination time To, the reflected light RL is delayed by a delay time Td before being received by the distance image sensor 32. Under the control of the measurement and control unit 43, the pixel driving circuit 322 distributes the charge generated in the photoelectric conversion element PD synchronously with the irradiation of the light pulse PO according to the frame period by supplying the accumulation driving signals TX1 to TX4 to the transmission transistors G (G1, G2, G3, G4) according to their respective timings, and accumulates them sequentially in the charge accumulation units CS1, CS2, CS3, CS4.

[0059] In addition, the pixel driving circuit 322 controls the reset transistor RT and the selection transistor SL respectively through the driving signals RST and SEL, converts the charge stored in the charge storage section CS into an electrical signal through the source follower transistor SF, and outputs the generated electrical signal to the distance calculation section 42 through the output terminal O.

[0060] The transfer transistor G is a transfer transistor that corresponds to multiple charge storage sections CS respectively, and transfers charge from the photoelectric conversion element PD to each charge storage section CS.

[0061] In addition, the reset transistor RT initializes the device by discharging the charge accumulated in the charge storage section CS (floating diffusion section FD and charge storage capacitor C).

[0062] In addition, under the control of the measurement and control unit 43, the pixel driving circuit 322 turns on the charge discharge transistor GD through the driving signal RSTD, so that the charge generated in the photoelectric conversion element PD flows to the power supply VDD and discharges (eliminates the charge).

[0063] return Figure 1 The distance image processing unit 4 controls the distance image capturing device 1 to calculate the distance to the subject OB. Based on the amount of charge accumulated in each of the charge accumulators CS, the distance image processing unit 4 measures the distance to the subject OB existing in the measurement space as the measurement distance. Using the transmission transistor G, the distance image processing unit 4 repeatedly distributes charge within one frame, and based on the amount of charge accumulated in each of the charge accumulators CS according to a set number of distributions (cumulative counts), measures the distance to the subject OB existing in the measurement space as the measurement distance.

[0064] In addition, in order to handle the imaging of multiple subjects OB with different reflectivities or distances, the distance image processing unit 4 performs HDR control processing within 1 frame to realize different allocation times (cumulative times) to the charge accumulation unit CS.

[0065] In the HDR control process, the distance image processing unit 4 controls the reset transistor RT in a manner that results in different repetition numbers, for example, during the repeated period of charge distribution, according to a predetermined control unit of the pixel circuits 321 arranged in a two-dimensional matrix.

[0066] Here, the control unit is, for example, a two-dimensional matrix of row or column units. In HDR-enhanced control processing, for example, the reset transistor RT is controlled in a manner that the number of repetitions varies according to the row units (odd rows and even rows) or the column units (odd columns and even columns).

[0067] Furthermore, details regarding the processing performed by the distance image processing unit 4 to control the reset transistor RT in a manner that results in different repetition counts will be described later.

[0068] In the case of HDR control processing, the distance image processing unit 4 performs prediction and formal measurement. The distance image processing unit 4 performs prediction by a driving method that calculates the distance and reflectivity of the subject OB as a condition of the subject OB. Next, based on the condition of the subject OB existing in the measurement space, the distance image processing unit 4 performs formal measurement by controlling the reset transistor RT in a manner that the number of repetitions varies according to the control units of the pixel circuit 321 (e.g., odd rows and even rows). Then, through the formal measurement, the distance image processing unit 4 calculates the measurement distance to the subject OB using HDR.

[0069] In addition, the distance image processing unit 4 includes a timing control unit 41, a distance calculation unit 42, and a measurement control unit 43.

[0070] The timing control unit 41, under the control of the measurement control unit 43, controls the timing of various control signals required for measurement. These control signals include, for example, signals controlling the illumination of the light pulse PO, signals distributing and accumulating reflected light RL in multiple charge accumulation units CS, and signals controlling the number of accumulations per frame. The number of accumulations refers to the number of times the process of distributing and accumulating charge in the charge accumulation units CS is repeated; it is a predetermined number of distributions within the frame period. The product of this number of accumulations and the time width (accumulation time width) during each distribution and charge accumulation process constitutes the exposure time.

[0071] Here, refer to Figure 4 The basic operation of the charge distribution processing of the distance image camera device 1 is explained.

[0072] Figure 4 This diagram illustrates an example of the basic operation of the charge distribution processing of the distance image capturing device 1 in this embodiment. Here, the timing of one basic operation, for example, representing one accumulation cycle, is shown.

[0073] exist Figure 4 In the waveforms, waveform W1 represents the state L1 of illumination by the light pulse PO, and waveform W2 represents the state L2 of reception of the reflected light RL. Additionally, waveforms W3 to W7 represent the states of the charge discharge transistor GD and the transfer transistors G1 to G4. In waveforms W3 to W7, the H (High) state represents the ON state, and the L (Low) state represents the OFF state (non-conducting state).

[0074] like Figure 4As shown, in one basic operation of the accumulation cycle, firstly, at time T1, the timing control unit 41 causes the light source unit 2 to output a light pulse PO (refer to waveform W1), and drives the pixel driving circuit 322 to turn off the charge discharge transistor GD (refer to waveform W3).

[0075] Next, the timing control unit 41 sequentially turns on the transmission transistors G1 to G4, distributing and accumulating the charge generated by the photoelectric conversion element PD to the charge accumulation units CS1 to CS4 (refer to waveforms W4 to W7). Furthermore, after turning off the transmission transistor G4, the timing control unit 41 turns on the charge discharge transistor GD (refer to waveform W3).

[0076] Next, at time T2, the timing control unit 41 causes the next light source unit 2 to output a light pulse PO (refer to waveform W1), and drives the pixel driving circuit 322 to turn off the charge discharge transistor GD (refer to waveform W3).

[0077] In addition, Figure 4 In this process, the period CYC1 from time T1 to time T2 is the period of one basic operation of the accumulation cycle. By repeating this period CYC1, charge is accumulated in charge accumulation sections CS1 to CS4.

[0078] In addition, the timing control unit 41 performs, for example, control of the reset transistor RT for the aforementioned HDRization.

[0079] The distance calculation unit 42 outputs distance information calculated from the pixel signal output from the distance image sensor 32, which is then used to calculate the distance to the subject OB. The distance calculation unit 42 calculates the delay time from the illumination light pulse PO to the reception of the reflected light RL based on the amount of charge stored in the multiple charge storage units CS. The distance calculation unit 42 calculates the distance to the subject OB based on the calculated delay time.

[0080] The distance calculation unit 42 calculates the delay time Td using the following formula (1), which is based on the fact that the amount of charge equivalent to the reflected light RL component is distributed and stored in the two charge storage units CS at a ratio corresponding to the delay time Td from the incident light RL to the distance image capturing device 1. The distance calculation unit 42 calculates the round-trip distance to the subject OB by multiplying the delay time Td obtained using formula (1) by the speed of light. Then, the distance calculation unit 42 calculates the distance to the subject OB by setting the round-trip distance calculated above to 1 / 2. Furthermore, in formula (1), it is based on the premise that the amount of charge equivalent to the external light component (interference light component) is stored in the charge storage unit CS1, and the amount of charge equivalent to the reflected light RL component is distributed and stored in the charge storage units CS2 and CS3.

[0081] Td=To×(Q3-Q1) / (Q2+Q3-2×Q1)…(1) Where To is the duration of the irradiation pulse PO.

[0082] The amount of charge stored in the charge storage section CS1 of Q1.

[0083] The amount of charge stored in the Q2 charge storage section CS2.

[0084] The amount of charge stored in the Q3 charge storage section CS3.

[0085] Furthermore, the example shown in Equation (1) is an example where the charge of the reflected light RL is distributed and accumulated in charge accumulation sections CS2 and CS3, with a charge equivalent to that of the reflected light RL component. Therefore, although the accumulation is slightly different in charge accumulation sections CS1 and CS2, or charge accumulation sections CS3 and CS4, the basic method for calculating the delay time Td based on the ratio of the charge accumulated in the two charge accumulation sections CS is the same.

[0086] Measurement control unit 43 controls timing control unit 41. For example, measurement control unit 43 sets the number of times a frame is accumulated and the accumulation time width, and controls timing control unit 41 to capture images according to the set content.

[0087] The measurement control unit 43 controls the timing control unit 41 to execute the aforementioned prediction. The distance calculation unit 42 calculates the distance to the subject OB and the reflectivity of the subject OB. The measurement control unit 43 uses the distance to the subject OB and the reflectivity as the condition of the subject OB. Based on the condition of the subject OB, it determines the number of repetitions (accumulation times) of the control unit (e.g., odd-numbered row units and even-numbered row units) of the pixel circuit 321.

[0088] The measurement control unit 43 controls the timing control unit 41 to perform formal measurements, for example, by setting different repetition numbers according to odd-numbered row units and even-numbered row units.

[0089] Additionally, the measurement control unit 43 calculates the distance to the subject OB based on the formal measurement using the distance calculation unit 42. Depending on the condition of the subject OB, the measurement control unit 43 selects, for example, either the distance of the pixel circuits 321 in odd-numbered rows or the distance of the pixel circuits 321 in even-numbered rows, and performs HDR processing to generate a distance image.

[0090] Next, with reference to the accompanying drawings, the operation of the distance image camera device 1 of this embodiment will be described.

[0091] Figures 5A to 5CThis diagram illustrates an example of the HDR conversion operation of the distance image capturing device 1 in this embodiment. Here, an example of capturing images with different number of repetitions (cumulative counts) in odd and even rows of the pixel circuit 321 within one frame will be described.

[0092] Figure 5A This represents an example of the light-receiving area 320 of the distance image sensor 32.

[0093] exist Figure 5A In the diagram, group SG1 represents the group of pixel circuits 321 in odd-numbered rows (first pixel circuit group), and group SG2 represents the group of pixel circuits 321 in even-numbered rows (second pixel circuit group).

[0094] in addition, Figure 5B This indicates the drive signal when the distance image camera device 1 of this embodiment is HDR-ified.

[0095] exist Figure 5B In the diagram, pixel circuits 321-1 and 321-3 are groups of pixel circuits 321 in odd-numbered rows, and pixel circuits 321-2 and 321-4 are groups of pixel circuits 321 in even-numbered rows.

[0096] like Figure 5B As shown, for group SG1 of pixel circuits 321 in odd-numbered rows, there are signal lines (control lines) connected to the drive signal RSTx-1 of the reset transistor RT and the drive signal SELx-1 of the selection transistor SL. Furthermore, for group SG2 of pixel circuits 321 in even-numbered rows, there are signal lines (control lines) connected to the drive signal RSTx-2 of the reset transistor RT and the drive signal SELx-2 of the selection transistor SL.

[0097] In addition, drive signal RSTx represents drive signals RST1 to RST4, and drive signal SELx represents drive signals SEL1 to SEL4.

[0098] In addition, the drive signals TX1 to TX4 of the transmission transistors G1 to G4, and the drive signal RSTD of the charge discharge transistor GD are common in groups SG1 and SG2.

[0099] in addition, Figure 5C It indicates that it was used Figure 5A as well as Figure 5B The distance image sensor 32 shown is an example of the HDR control processing of the distance image camera device of this embodiment.

[0100] exist Figure 5C In the "repeated processing", the distance image processing unit 4 repeatedly performs the above-mentioned process. Figure 4The basic operation of CYC1 during the period shown is as follows. In addition, during "repeated stop", the transmission transistors G1 to G4 are turned off by the drive signals TX1 to TX4, and the charge discharge transistor GD is turned on by the drive signal RSTD.

[0101] In addition, Figure 5C In the diagram, waveform W11 represents the number of repetitions of group SG1 in odd-numbered rows, and waveform W12 represents the number of repetitions of group SG2 in even-numbered rows.

[0102] like Figure 5C As shown, the distance image processing unit 4 first performs "repeated processing", and then temporarily sets it to "repeated stop" at time T11. That is, the distance image processing unit 4 turns off the transmission transistors G1 to G4 and turns on the charge discharge transistor GD.

[0103] Furthermore, the period TR1, from the start of “repeated processing” to time T11, corresponds to the first period.

[0104] Next, at time T12, the distance image processing unit 4 turns on the reset transistor RT for the odd-numbered rows group GR1, and initializes the charge accumulation section CS of the odd-numbered rows. For example, the distance image processing unit 4 sets the drive signal RSTx-1 to state H, thus turning on the reset transistor RT for the odd-numbered rows. Here, the charge accumulation amount of the charge accumulation section CS of the odd-numbered rows group SG1 is initialized, as shown in waveform W11, and the repetition count is also initialized.

[0105] Next, at time T13, the distance image processing unit 4 turns off the reset transistor RT for the odd-numbered row group GR1, and at time T14, it restarts the "repeated processing" for the odd-numbered row group GR1 and the even-numbered row group GR2.

[0106] Here, the period TRR is the reset period for group GR1 in odd-numbered rows, and the period TRstp is the "repeated stop" period for group GP2 in even-numbered rows.

[0107] Next, at time T15, the distance image processing unit 4 ends the "repetition processing". As a result, the number of repetitions for the odd-numbered row group GR1 is N1, and the number of repetitions for the even-numbered row group GP2 is N2 (N2>N1). The odd-numbered row group GR1 and the even-numbered row group GP2 can achieve different numbers of repetitions.

[0108] Furthermore, the period TR2 from time T14 to time T15 corresponds to the second period.

[0109] Additionally, during the period TRrd from time T15 to time T16, the distance image processing unit 4 performs readout processing of the charge stored in the charge storage unit CS of each pixel circuit 321. Furthermore, the period from the start of the initial "repeated processing" to time T16 corresponds to the recording period of one frame.

[0110] like Figure 5C As shown, after repeatedly distributing charge during the first period (period TR1), the distance image processing unit 4 performs the following control: for the odd-numbered rows group GR1 (first pixel circuit group), charge initialization is performed via the reset transistor RT; for the even-numbered rows group GP2 (second pixel circuit group), charge initialization is not performed via the reset transistor RT. The distance image processing unit 4 then performs the control to repeatedly distribute charge during a second period (period TR2) different from the first period (period TR1).

[0111] As a result, within one frame, the number of repetitions for group GR1 in odd-numbered rows is N1, and the number of repetitions for group GP2 in even-numbered rows is N2. N1 corresponds to the number of repetitions in period TR2, and N2 corresponds to the number of repetitions in (period TR1 + period TR2).

[0112] Furthermore, the distance image processing unit 4 uses the pixel circuit 321 of the odd-numbered rows of group GR1 for a number of times N1 when the reflectivity of the subject OB is high (e.g., reflectivity 80%), and uses the pixel circuit 321 of the even-numbered rows of group GR2 for a number of times N2 when the reflectivity of the subject OB is low (e.g., reflectivity 20%), to generate an HDR-enhanced distance image.

[0113] Next, refer to Figure 6 The control processing for HDR conversion of the distance image camera device 1 in this embodiment will be explained.

[0114] Figure 6 This is a flowchart illustrating an example of the HDR control processing of the distance image camera device 1 in this embodiment.

[0115] like Figure 6 As shown, the distance image processing unit 4 of the distance image imaging device 1 first performs prediction (step S101). The distance image processing unit 4 performs prediction by using a driving method that knows the distance and relative reflectivity of each of the multiple subjects OB existing in the measurement space.

[0116] Next, the distance image processing unit 4 uses the pixel signal obtained by prediction to calculate the distance and reflectivity of the subject OB (step S102).

[0117] Next, the distance image processing unit 4 determines the number of repetitions for each control unit (e.g., odd-numbered rows and even-numbered rows respectively) based on the distance to the subject OB and the reflectivity (step S103). The distance image processing unit 4 sets the number of repetitions to be less when the distance is close or the reflectivity is high, and sets the number of repetitions to be more when the distance is far or the reflectivity is low.

[0118] Next, the distance image processing unit 4 controls the drive signal RSTx of each control unit (e.g., odd rows and even rows) to a predetermined number of repetitions, and performs a formal measurement (step S104). Specifically, the distance image processing unit 4 performs the control shown in FIG5 above and performs the formal measurement.

[0119] Next, the distance image processing unit 4 uses the pixel signals obtained through formal measurement to calculate the distance to the subject OB and generates a distance image (step S105). The distance image processing unit 4 generates an HDR-based distance image. The distance image imaging device 1 outputs the distance image generated by the distance image processing unit 4. After processing in step S105, the distance image processing unit 4 ends the processing.

[0120] As described above, the distance image capturing device 1 of this embodiment includes a light source unit 2, a light receiving unit 3, and a distance image processing unit 4. The light source unit 2 irradiates a light pulse PO into the measurement space where the subject OB exists. The light receiving unit 3 includes a pixel circuit 321 and a pixel driving circuit 322. The pixel circuit 321 includes a photoelectric conversion element PD that generates a charge corresponding to the incident light, and a plurality of charge storage units CS that store the charge. The pixel driving circuit 322 distributes and stores charge to the charge storage units CS in the pixel circuit 321 at a predetermined timing synchronized with the irradiation of the light pulse PO. The distance image processing unit 4 determines the measurement distance to the subject OB based on the amount of charge stored in each charge storage unit CS. The pixel circuit 321 has a plurality of pixels arranged in a two-dimensional matrix. Each pixel circuit 321 includes: a transmission transistor G, which corresponds to each of the plurality of charge storage units CS and transmits charge from the photoelectric conversion element PD to each charge storage unit CS; and a reset transistor RT, which discharges the charge stored in the charge storage units CS to initialize the device. The distance image processing unit 4 uses the transmission transistor G to repeatedly distribute charge. During the repeated distribution of charge, the reset transistor RT is controlled in a manner that the number of repetitions is different according to the predetermined control units of the pixel circuits 321 arranged in a two-dimensional matrix.

[0121] Therefore, the distance image camera 1 of this embodiment can achieve different repetition counts according to the control unit by controlling the reset transistor RT. Thus, the distance image camera 1 of this embodiment can suppress the increase of control lines (signal lines of drive signals) and achieve HDR through simple control such as controlling the reset transistor RT.

[0122] Furthermore, in this embodiment, the pixel circuit 321 of the control unit includes a first pixel circuit group (group GR1 of odd-numbered rows of pixel circuits 321) and a second pixel circuit group (group GR2 of even-numbered rows of pixel circuits 321). After the distance image processing unit 4 repeatedly performs charge distribution during the first period (e.g., period TR1), it controls the first pixel circuit group to initialize its charge using a reset transistor RT, and the second pixel circuit group to not initialize its charge using a reset transistor RT. Furthermore, it controls the repeated charge distribution during a second period (e.g., period TR2) that is different from the first period.

[0123] Therefore, the distance image camera 1 of this embodiment can achieve two stages of repetition within one frame, for example, in odd-numbered rows and even-numbered rows, by controlling whether or not to initialize the charge through the reset transistor RT.

[0124] Furthermore, in this embodiment, the control unit is a two-dimensional matrix of row or column units. Therefore, the distance image camera 1 of this embodiment can achieve different repetition counts according to row or column units, thus enabling HDR processing according to row or column units.

[0125] Furthermore, in this embodiment, the distance image processing unit 4 performs prediction using a driving method that calculates the distance and reflectivity of the subject OB as a condition of the subject OB. Based on the condition of the subject OB existing in the measurement space, the distance image processing unit 4 performs formal measurement by controlling the reset transistor RT to perform different repetitions according to the control unit of the pixel circuit 321. Through formal measurement, the distance image processing unit 4 calculates the measurement distance to the subject OB using HDR.

[0126] Therefore, the distance image camera device 1 of this embodiment can use prediction to more appropriately set different number of repetitions, thus enabling HDR with better measurement accuracy.

[0127] Furthermore, the control method of this embodiment is the control method of the distance image camera device 1 described above, which includes a control step. In the control step, the distance image processing unit 4 repeatedly distributes charge using the transmission transistor G. During the repeated distribution of charge, the reset transistor RT is controlled to repeat a different number of times according to a predetermined control unit of the pixel circuits 321 arranged in a two-dimensional matrix.

[0128] Therefore, the control method of this embodiment achieves the same effect as the distance image camera device 1 described above, suppressing the increase of control lines (signal lines of drive signals) and realizing HDR through simple control such as the control of the reset transistor RT.

[0129] Next, refer to Figures 7A to 7C as well as Figure 8 A first variation of the distance image camera device 1 of this embodiment will be described. In this first variation, a variation will be described in which the control of the reset transistor RT is combined with the control of the charge discharge transistor GD and the transmission transistor G to achieve, for example, four different repetition rates in a 2-row × 2-column configuration.

[0130] Figures 7A to 7C This is a diagram illustrating a first variation of the HDR conversion operation of the distance image camera device 1 in this embodiment.

[0131] Figure 7A This is an example of the light-receiving area 320 of the distance image sensor 32, which represents a first variant example where the number of repetitions is controlled by 2 rows × 2 columns.

[0132] exist Figure 7A The diagram shows four groups of pixel circuits 321 (GR1, GR2, GR3, GR4): odd row odd column, odd row even column, even row odd column, and even row even column.

[0133] in addition, Figure 7B This represents the drive signal for HDR conversion of the distance image camera device 1 in the first variant example.

[0134] exist Figure 7B In this diagram, pixel circuit 321-1 represents group SG1 with odd rows and odd columns, and pixel circuit 321-2 represents group SG2 with even rows and odd columns. Additionally, pixel circuit 321-3 represents group SG3 with odd rows and even columns, and pixel circuit 321-4 represents group SG4 with even rows and even columns.

[0135] In addition, such as Figure 7BAs shown, drive signals TX1-1 to TX4-1 and drive signal RSTD-1 are drive signals used for odd-numbered sequences, while drive signals TX1-2 to TX4-2 and drive signal RSTD-2 are drive signals used for even-numbered sequences.

[0136] in addition, Figure 7C It indicates that it was used Figure 7A as well as Figure 7B The distance image sensor 32 shown is an example of the HDR control processing of the distance image camera device of this embodiment.

[0137] In addition, Figure 7C In the diagram, waveform W21 represents the number of repetitions of group SG1 in odd-numbered rows and odd-numbered columns, and waveform W22 represents the number of repetitions of group SG2 in even-numbered rows and odd-numbered columns. Additionally, waveform W23 represents the number of repetitions of group SG3 in odd-numbered rows and even-numbered columns, and waveform W24 represents the number of repetitions of group SG4 in even-numbered rows and even-numbered columns.

[0138] like Figure 7C As shown, the distance image processing unit 4 first performs "repeated processing" on the odd-numbered columns and "repeated stopping" on the even-numbered columns.

[0139] At time T21, the distance image processing unit 4 performs "repeated processing" on the even number sequence.

[0140] Next, at time T22, the distance image processing unit 4 is temporarily set to "repeated stop". That is, the distance image processing unit 4 turns off the transmission transistors G1 to G4 and turns on the charge discharge transistor GD.

[0141] Furthermore, period TRstp1 represents the "repeated stop" period from the start of processing up to time T21. Additionally, period TR11 is the "repeated processing" period from the start of processing up to time T22, and period TR12 is the "repeated processing" period from time T21 up to time T22, both corresponding to the first period.

[0142] Next, at time T23, the distance image processing unit 4 turns on the reset transistor RT for the odd-numbered rows (GR1, GR3) and initializes the charge accumulation section CS of the odd-numbered rows. For example, the distance image processing unit 4 sets the drive signal RSTx-1 to state H, turning on the reset transistor RT for the odd-numbered rows. Here, the charge accumulation amount of the charge accumulation section CS of the odd-numbered rows (GR1, GR3) is initialized, as shown in waveforms W21 and W23, and the repetition count is also initialized.

[0143] Next, at time T24, the distance image processing unit 4 turns off the reset transistor RT for the odd-numbered rows (GR1, GR3), and at time T25, it restarts the "repeated processing" for the odd-numbered rows (GR1, GR3) and the even-numbered rows (GR2, GR4).

[0144] Here, the period TRR is the reset period for the odd-numbered rows (GR1, GR3), and the period TRstp2 is the "repeated stop" period for the even-numbered rows (GR2, GR4).

[0145] Next, at time T26, the even-numbered groups (GR3, GR4) of the distance from the image processing unit 4 are set to "repeated stop" again.

[0146] Next, at time T27, the "repeated processing" of the four pairs of odd-numbered columns (GR1, GR2) of the image processing unit ends.

[0147] The result of this control is that the number of repetitions for group GR1 (odd rows, odd columns) is N21, and the number of repetitions for group GR2 (even rows, odd columns) is N22. Additionally, the number of repetitions for group GR3 (odd rows, even columns) is N23, and the number of repetitions for group GR4 (even rows, even columns) is N24.

[0148] Thus, in the first variation, four different repetition counts can be achieved.

[0149] Furthermore, period TR21 is the period from time T25 to time T27, and period TR22 is the period from time T25 to time T26, both corresponding to the second period. In addition, period TRstp3 represents the period of "repeated stops" from time T26 to time T27.

[0150] Additionally, during the period TRrd from time T27 to time T28, the image processing unit 4 performs readout processing of the charge stored in the charge storage unit CS of each pixel circuit 321. Furthermore, the period from the start of the initial "repeated processing" to time T28 corresponds to the recording period of one frame.

[0151] like Figure 7C As shown, during the repetition period, the distance image processing unit 4 controls the charge discharge transistor GD and the reset transistor RT in combination with different repetition numbers, corresponding to the combination of control of the charge discharge transistor GD and control of the reset transistor RT. That is, the distance image processing unit 4 controls the combination of control that turns the charge discharge transistor GD on and turns off the transmission transistor G to turn on and control that turns on the reset transistor RT to turn on, with different repetition numbers.

[0152] As a result, within one frame, the number of repetitions for group GR1 (odd rows, odd columns) is N21, and the number of repetitions for group GP2 (even rows, odd columns) is N22. N21 corresponds to the number of repetitions in period TR21, and N22 corresponds to the number of repetitions in (period TR11 + period TR21).

[0153] Additionally, within one frame, the number of repetitions for group GR3 (odd rows, even columns) is N23, and the number of repetitions for group GP4 (even rows, even columns) is N24. N23 corresponds to the number of repetitions in period TR23, and N24 corresponds to the number of repetitions in (period TR12 + period TR22).

[0154] Next, refer to Figure 8 The control processing for HDR conversion of the distance image camera device 1 in the first modified example will be explained.

[0155] Figure 8 This is a flowchart illustrating an example of the HDR control processing of the distance image camera device 1 in the first modified example.

[0156] exist Figure 8 In this process, the steps S201 and S202 are the same as described above. Figure 6 The processes in steps S101 and S102 shown are the same, so their descriptions are omitted here.

[0157] In step S203, the distance image processing unit 4 determines the number of repetitions for each control unit (e.g., odd-numbered rows and even-numbered rows respectively) based on the distance to the subject OB and the reflectivity. As shown in Figure 7 above, the distance image processing unit 4 determines four different numbers of repetitions.

[0158] Next, the distance image processing unit 4 controls the drive signals RSTx-1, RSTx-2, TX1-1 to TX4-1, TX1-2 to TX4-2, RSTD-1, and RSTD-2 to perform a formal measurement, repeating the determined number of times. Specifically, the distance image processing unit 4 performs the control shown in FIG7 above to execute the formal measurement.

[0159] Next, the distance image processing unit 4 uses the pixel signal obtained through formal measurement to calculate the distance to the subject OB and generates a distance image (step S205). The distance image processing unit 4 generates an HDR-based distance image. The distance image imaging device 1 outputs the distance image generated by the distance image processing unit 4. After processing in step S205, the distance image processing unit 4 ends the processing.

[0160] As explained above, in the first variation, each pixel circuit 321 further includes a charge discharge transistor GD that discharges charge from the photoelectric conversion element PD. During the repetition period, the distance image processing unit 4 controls the charge discharge transistor GD and the reset transistor RT in combination with different repetition numbers, corresponding to the combination of control of the charge discharge transistor GD and control of the reset transistor RT. That is, the distance image processing unit 4 controls the combination of control that turns the charge discharge transistor GD on and turns off the transmission transistor G and control that turns on the reset transistor RT, with different repetition numbers.

[0161] Therefore, the distance image camera device 1 of this embodiment can achieve, for example, four different repetitions of 2 rows × 2 columns within one frame by combining the control of turning on the charge discharge transistor GD and turning off the transmission transistor G with the control of turning on the reset transistor RT.

[0162] also, Figure 9 This figure is shown for comparison, illustrating an example of a distance image sensor in the case of HDR rendering in a prior art distance image camera device.

[0163] like Figure 9 As shown, in existing distance image imaging devices, to achieve four different repetition counts in a 2x2 array, the signal lines of the two systems—drive signals TX1-1 to TX4-1 and drive signal RSTD-1, and drive signals TX1-2 to TX4-2 and drive signal RSTD-2—must pass through one column of pixel circuit 321. Therefore, in existing distance image imaging devices, the size of the distance image sensor increases, and control becomes more complex.

[0164] In contrast, in the distance image camera device 1 of the first variation of this embodiment, as shown in FIG7, a column of pixel circuits 321 can be controlled by a single system signal line, which can suppress the increase of control lines and the increase of the size of the distance image sensor 32, and achieve HDR through simple control.

[0165] Next, referring to FIG10, a second variation of the distance image camera device 1 of this embodiment will be described. In the second variation, a variation in which the timing of the control of the reset transistor RT is set to multiple times, for example, three or more different repetition times such as three rows of three repetition times, will be described.

[0166] Figure 10A as well as Figure 10B This is a diagram illustrating a second variation of the HDR conversion operation of the distance image camera device 1 in this embodiment.

[0167] Figure 10A This is an example of a second variant of a distance image sensor 32, where the light-receiving area 320 is controlled by row units to control the number of repetitions of three different types.

[0168] exist Figure 10A In this diagram, group SG1 represents the group in the (3n+1)th row, group SG2 represents the group in the (3n+2)th row, and group SG3 represents the group in the (3n+3)th row. Here, n is 0 or a positive integer.

[0169] in addition, Figure 10B It indicates that it was used Figure 10A The distance image sensor 32 shown is an example of the HDR control processing of the distance image camera device of this embodiment.

[0170] In addition, Figure 10B In the diagram, waveform W31 represents the number of repetitions of group SG1 in row (3n+1), waveform W32 represents the number of repetitions of group SG2 in row (3n+2), and waveform W33 represents the number of repetitions of group SG3 in row (3n+3).

[0171] like Figure 10B As shown, the distance image processing unit 4 first performs "repeated processing," and at time T31, the distance image processing unit 4 is temporarily set to "repeated stop." That is, the distance image processing unit 4 turns the transmission transistors G1 to G4 into the off state and turns the charge discharge transistor GD into the on state.

[0172] Next, at time T32, the distance image processing unit 4 turns on the reset transistor RT for group GR1 in row (3n+1) and initializes the charge storage unit CS in row (3n+1).

[0173] Next, at time T33, the distance image processing unit 4 turns off the reset transistor RT for group GR1 in row (3n+1). At time T34, the "repeated processing" restarts for group GR1 in row (3n+1), group GR2 in row (3n+2), and group GR3 in row (3n+3).

[0174] Here, TRR1 is the reset period for group GR1 in line (3n+1), and TRstp1 is the "repeated stop" period for group GR2 in line (3n+2) and group GR3 in line (3n+3).

[0175] Next, at time T35, the distance image processing unit 4 is temporarily set to "repeated stop". That is, the distance image processing unit 4 turns off the transmission transistors G1 to G4 and turns on the charge discharge transistor GD.

[0176] Next, at time T36, the distance image processing unit 4 turns on the reset transistor RT for group GR2 in row (3n+2) and initializes the charge storage unit CS in row (3n+2).

[0177] Next, at time T37, the distance image processing unit 4 turns off the reset transistor RT for group GR2 in row (3n+2). At time T38, the "repeated processing" restarts for group GR1 in row (3n+1), group GR2 in row (3n+2), and group GR3 in row (3n+3).

[0178] Here, TRR2 is the reset period for group GR2 in row (3n+2), and TRstp2 is the "repeated stop" period for group GR1 in row (3n+1) and group GR3 in row (3n+3).

[0179] Next, at time T39, the distance image processing unit 4 ends the "repeated processing". As a result, the number of repetitions for group GR1 in row (3n+1) is N31, the number of repetitions for group GR2 in row (3n+2) is N32, and the number of repetitions for group GR3 in row (3n+3) is N33, thus achieving three different numbers of repetitions.

[0180] Additionally, during the period TRrd from time T39 to time T40, the distance image processing unit 4 performs readout processing of the charge stored in the charge storage unit CS of each pixel circuit 321. Furthermore, the period from the start of the initial "repeated processing" to time T40 corresponds to the recording period of one frame.

[0181] As explained above, in the second variation of this embodiment, the distance image processing unit 4 controls the timing of turning the reset transistor RT to the ON state according to the control unit change during the repetition period, so that the repetition number can be different according to the control unit.

[0182] Therefore, in the second variation of this embodiment, the distance image camera 1 can achieve more than three different repetitions within one frame by changing the timing of turning the reset transistor RT into the ON state, for example, as shown in FIG10.

[0183] Furthermore, the present invention is not limited to the embodiments described above, and modifications can be made without departing from the spirit of the present invention.

[0184] For example, in the above embodiment, an example of pixel circuit 321 having 4 charge storage units CS (CS1, CS2, CS3, CS4) is described, but it is not limited to this, and may also have 3 or more N charge storage units CS.

[0185] Furthermore, in the above embodiment, an example was described in which the control of the reset transistor RT was combined with the control of the charge discharge transistor GD and the transmission transistor G to achieve four different repetition counts of 2 rows × 2 columns within one frame, but this is not a limitation. The distance image processing unit 4 may also combine the control of the reset transistor RT with the control of the charge discharge transistor GD and the transmission transistor G to control the repetition counts in a manner that results in N rows × M columns (N × M) different repetition counts.

[0186] Furthermore, each component of the aforementioned distance image camera device 1 has an internal computer system. Moreover, programs for implementing the functions of each component of the aforementioned distance image camera device 1 can be recorded on a computer-readable recording medium, allowing the computer system to read and execute the program recorded on the recording medium, thereby performing the processing within each component of the aforementioned distance image camera device 1. Here, "allowing the computer system to read and execute the program recorded on the recording medium" includes installing programs on the computer system. The term "computer system" here includes hardware such as an operating system and peripheral devices.

[0187] Additionally, "computer system" can also include multiple computer devices connected via a network of communication lines, including the Internet, WAN, LAN, and dedicated lines. Furthermore, "computer-readable recording media" refers to removable media such as floppy disks, optical disks, ROMs, and CD-ROMs, as well as storage devices such as hard disks built into a computer system. Thus, the recording medium storing programs can also be a non-transitory recording medium such as a CD-ROM.

[0188] Furthermore, the recording medium also includes internal or external recording media accessible from a distribution server for distributing the program. Alternatively, the program may be divided into multiple parts, downloaded at different time intervals, and distributed to different distribution servers for each part of the assembly comprised of the image capturing device 1. Moreover, the "computer-readable recording medium" also includes a medium that retains the program for a certain period of time, such as volatile memory (RAM) within a computer system that acts as a server or client when the program is sent via a network. Additionally, the program described above may be a program used to implement the aforementioned functions. Furthermore, it may be a so-called differential file (differential program) capable of implementing the aforementioned functions through combination with a program already recorded in the computer system.

[0189] Alternatively, some or all of the above functions can be implemented as integrated circuits such as LSI (Large Scale Integration). Each of these functions can be processorized individually, or some or all can be integrated and processorized. Furthermore, the method of integrated circuit implementation is not limited to LSI; it can also be implemented using dedicated circuits or general-purpose processors. Additionally, when advancements in semiconductor technology have led to the development of integrated circuit technologies that replace LSI, integrated circuits based on these technologies can also be used.

[0190] It should be understood that these are illustrative of the invention and should not be considered limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the scope of the invention. Therefore, the invention should not be considered limited by the foregoing description but by the claims.

Claims

1. A distance image camera device, comprising: The light source irradiates a light pulse into the measurement space where the subject exists; The light-receiving section includes a pixel circuit and a pixel driving circuit. The pixel circuit has a photoelectric conversion element that generates a charge corresponding to the incident light, and a plurality of charge storage sections for storing the charge. The pixel driving circuit distributes and stores the charge in the charge storage sections of the pixel circuit at a predetermined timing synchronized with the irradiation of the light pulse. The distance image processing unit determines the measurement distance to the subject based on the amount of charge stored in the charge storage units. The pixel circuits are arranged in a two-dimensional matrix. Each pixel circuit has: A transmission transistor, corresponding to each of the plurality of charge storage sections, transmits charge from the photoelectric conversion element to each of the charge storage sections; and The reset transistor discharges and initializes the charge stored in the charge storage section. The distance image processing unit is, Using the transmission transistor, the charge is repeatedly distributed, and during the repeated distribution of the charge, the reset transistor is controlled in a manner that the number of repetitions is different according to a predetermined control unit of the pixel circuit arranged in the two-dimensional matrix.

2. The distance image camera device according to claim 1, wherein, The pixel circuit of the control unit includes a first pixel circuit group and a second pixel circuit group. The distance image processing unit is, After repeatedly distributing the charge during the first period, control is performed to initialize the charge of the first pixel circuit group through the reset transistor, and to initialize the charge of the second pixel circuit group without using the reset transistor, and then control is performed to repeatedly distribute the charge during a second period different from the first period.

3. The distance image camera device according to claim 2, wherein, The control unit is the row or column unit of the two-dimensional matrix.

4. The distance image camera device according to claim 1, wherein, Each pixel circuit also includes a charge discharge transistor for discharging the charge from the photoelectric conversion element. During the repetition period, the distance image processing unit controls the combination of the charge discharge transistor and the reset transistor in a manner that results in different repetition numbers, corresponding to the combination of control of the charge discharge transistor and control of the reset transistor.

5. The distance image camera device according to claim 4, wherein, The distance image processing unit is, The control that turns the charge discharge transistor on and turns the transfer transistor off, and the control that turns the reset transistor on, are combined in a manner that results in different repetition counts.

6. The distance image camera device according to claim 1, wherein, The distance image processing unit controls the timing of turning on the reset transistor according to the control unit during the repetition period, so that the number of repetitions varies according to the control unit.

7. The distance image capturing device according to any one of claims 1 to 6, wherein, The distance image processing unit is, Prediction is performed using a driving method that calculates the distance and reflectivity of the subject as the basis for determining the subject's condition. Based on the condition of the subject existing in the measurement space, a formal measurement is performed by controlling the reset transistor in a manner that the number of repetitions varies according to the control unit of the pixel circuit. The formal measurement was used to calculate the measurement distance to the subject using HDR (High Dynamic Range).

8. The distance image camera device according to claim 7, wherein, The plurality of charge storage units are three or more charge storage units.

9. A control method for a distance image camera device, the distance image camera device comprising: The light source irradiates a light pulse into the measurement space where the subject exists; The light-receiving part has a pixel circuit and a pixel driving circuit. The pixel circuit has a photoelectric conversion element that generates a charge corresponding to the incident light and a plurality of charge storage units that store the charge. The pixel driving circuit distributes and stores the charge in the charge storage units of the pixel circuit at a predetermined timing synchronized with the irradiation of the light pulse. as well as The distance image processing unit determines the measurement distance to the subject based on the amount of charge stored in the charge storage units. The pixel circuits are arranged in a two-dimensional matrix. Each pixel circuit has: A transmission transistor, corresponding to a plurality of charge storage portions, transmits the charge from the photoelectric conversion element to each of the charge storage portions; as well as The reset transistor discharges and initializes the charge stored in the charge storage section. The control method includes: The control step involves the distance image processing unit repeatedly distributing the charge using the transmission transistor. During the repeated distribution of the charge, the reset transistor is controlled in a manner that the number of repetitions varies according to a predetermined control unit of the pixel circuits arranged in the two-dimensional matrix.

Images