WO2013099348A1 - 距離測定装置 - Google Patents
距離測定装置 Download PDFInfo
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- WO2013099348A1 WO2013099348A1 PCT/JP2012/071075 JP2012071075W WO2013099348A1 WO 2013099348 A1 WO2013099348 A1 WO 2013099348A1 JP 2012071075 W JP2012071075 W JP 2012071075W WO 2013099348 A1 WO2013099348 A1 WO 2013099348A1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/483—Details of pulse systems
- G01S7/486—Receivers
- G01S7/4861—Circuits for detection, sampling, integration or read-out
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
- G01S17/88—Lidar systems specially adapted for specific applications
- G01S17/89—Lidar systems specially adapted for specific applications for mapping or imaging
- G01S17/894—3D imaging with simultaneous measurement of time-of-flight at a 2D array of receiver pixels, e.g. time-of-flight cameras or flash lidar
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/483—Details of pulse systems
- G01S7/486—Receivers
- G01S7/4861—Circuits for detection, sampling, integration or read-out
- G01S7/4863—Detector arrays, e.g. charge-transfer gates
Definitions
- the embodiment of the present invention relates to a distance measuring device.
- a time-of-flight (TOF) method for measuring the distance from an object to the distance sensor by emitting pulsed light from a light source and receiving reflected light from the object by a distance sensor is known.
- Patent Documents 1 and 2 describe a distance measuring device based on the TOF method.
- the apparatus described in Patent Document 1 emits pulsed light from a light source, and a signal having a value corresponding to the amount of charge generated in a photodiode of a distance sensor in each of sub-periods having different lengths in one frame period. Is calculated from the distance sensor, and the distance is calculated based on the best signal among the plurality of acquired signals.
- the device described in Patent Document 2 has a configuration for extending the effective dynamic range of the distance sensor. Specifically, this device emits pulsed light from the light source, accumulates the charge generated by the photodiode of the distance sensor in the capacitor, resets the voltage when the voltage generated in the capacitor reaches the saturation voltage, and resets The distance is calculated based on the number of times and the final voltage generated in the capacitor.
- the light incident on the distance sensor includes background light in addition to the signal light generated when the pulsed light emitted from the light source is reflected by the object.
- the distance measuring devices described in Patent Documents 1 and 2 basically do not consider removal of noise components such as background light components included in the signal from the distance sensor.
- Patent Document 3 describes another distance measuring device based on the TOF method.
- the apparatus described in Patent Document 3 obtains a signal from a distance sensor by irradiating pulsed light from a light source in a first frame period, and signals from the distance sensor in a second frame period with the light source not emitting light.
- the frame period is a period from the reset of the charge in the accumulation region that accumulates the charge generated in the photosensitive region of the sensor to the next reset of the charge in the accumulation region.
- This apparatus removes a noise component in the signal by subtracting the signal in the second frame period from the signal in the first frame period. The apparatus calculates the distance based on the signal from which the noise component is removed in this way.
- the distance measuring device includes a light source unit, a sensor unit, and a processing unit.
- the light source unit emits modulated light.
- the sensor unit includes a photosensitive region that generates charges in response to incident light, a first storage region and a second storage region that store charges generated in the photosensitive region, and a photosensitive region and a first storage region.
- a first transfer electrode provided therebetween, a second transfer electrode provided between the photosensitive region and the second storage region, and a first transfer electrode provided between the first storage region and the reset potential.
- Reset switch, and a second reset switch provided between the second accumulation region and the reset potential.
- the processing unit calculates the distance by controlling the emission timing of the modulated light and the sensor unit.
- the processing unit controls the first reset switch and the second reset switch to connect the first storage region and the second storage region to the reset potential, and then the first storage region and the first storage region.
- A1 In one or more first charge transfer cycles within a period until the next storage region is connected to the reset potential, modulated light is emitted to the light source unit during one or more emission periods, and (a2) one The charge generated in the photosensitive region is accumulated in the first accumulation region by controlling the voltage applied to the first transfer electrode in one or more first transfer periods synchronized with the above emission period, and (a2) one or more The electric charge generated in the photosensitive region is accumulated in the second accumulation region by controlling the voltage applied to the second transfer electrode during one or more second transfer periods phase-inverted with respect to the first transfer period.
- the processing unit is one or more second charge transfer cycles within the frame period, and in the one or more second charge transfer cycles alternating with the one or more first charge transfer cycles, (b1) modulation into the light source unit Without emitting light, (b2) controlling the voltage applied to the first transfer electrode in the third transfer period to store the charge generated in the photosensitive region in the first storage region, and (b2) the third Charges generated in the photosensitive region are accumulated in the second accumulation region by controlling the voltage applied to the second transfer electrode during the fourth transfer period that is phase-inverted with the transfer period.
- the processing unit includes each of the one or more first charge transfer cycles and the next second charge transfer cycle.
- the processing unit is arranged between each of the one or more second charge transfer cycles and the next first charge transfer cycle. Another first read value corresponding to the amount of charge accumulated in the first accumulation region at the time point and another second read value corresponding to the amount of charge accumulated in the second accumulation region at the time point The value is acquired from the sensor unit.
- the processing unit is a value obtained by subtracting another first read value of the n-th and (n-1) -th second read cycles from a value twice the first read value of the n-th first read cycle. And a second read value different from the second read value of the nth first read cycle to the second read cycle of the nth and (n-1) th read cycles.
- a second value that is a value obtained by subtracting is calculated to obtain M first values and M second values.
- n indicates the order of the plurality of first read cycles and the plurality of second read cycles.
- the processing unit calculates the distance based on the M first values and the M second values.
- the modulated light is emitted to the light source unit in the first charge transfer cycle that distributes the charges to the first accumulation region and the second accumulation region by emitting the modulated light to the light source unit within one frame period.
- the second charge transfer cycle for distributing the charge to the first accumulation region and the second accumulation region is alternately performed.
- charges based on incident light including reflected light from the object with respect to the modulated light are accumulated in the accumulation region as increased charges
- noise such as background light is accumulated. Is accumulated as an increased charge.
- a value corresponding to the accumulated charge amount immediately after the second charge transfer cycle immediately before the first charge transfer cycle is determined from a value twice the read value corresponding to the accumulated charge amount immediately after the first charge transfer cycle.
- each first charge is obtained.
- Values corresponding to the increase in the charge amount in the transfer cycle are obtained. Since the distance measuring device calculates the distance based on the first value and the second value, the distance does not decrease the frame rate, and even if noise such as background light that fluctuates in a short period occurs, the distance is highly accurate. Can be calculated.
- the sensor unit of the distance measuring device does not require an additional storage region for acquiring charge based on noise other than the two storage regions for charge distribution, thus complicating the configuration of the sensor unit.
- the mounting area in the sensor unit can be used effectively.
- the time length for accumulating charges in the first accumulation region in the first charge transfer cycle, the time length for accumulating charges in the second accumulation region in the first charge transfer cycle, and the second charge may be substantially the same time length. .
- each of the plurality of first charge transfer cycles may include one first transfer period and one second transfer period. According to this embodiment, the time length of the first charge transfer cycle and the second charge transfer cycle corresponding to the first charge transfer cycle can be shortened. As a result, it is possible to calculate the distance with high accuracy even when noise that fluctuates in a shorter period occurs.
- a predetermined threshold value M first values based on one or more first read values and one or more other first read values obtained up to the last second read cycle
- M second values may be determined based on one or more second read values and one or more other second read values obtained up to the final second read cycle.
- the processing unit (d1) another first read value of the nth second read cycle, another first read value of the nth second read cycle, and n ⁇ Sum of difference value with another first read value of the second read cycle of the first time, or another second value of the second read cycle of the nth time and the second value of the nth time
- the first read cycle and the second read cycle may be stopped, and (d2) one or more first read values obtained up to the n-th second read cycle, which is the final read cycle, and Determining M first values based on one or more other first readings, and a final second reading Cycle may be determined M second value based on the second read value and the further second read values of one or more one or more obtained by.
- the predetermined threshold value is set to a value equal to or larger than the read value corresponding to the saturated storage capacity of the storage region, thereby using the read value in a range not exceeding the read value corresponding to the saturated storage capacity, and the distance. Can be calculated. In addition, the dynamic range of the measurement distance can be improved. Furthermore, according to this embodiment, when the above-described sum exceeds a predetermined threshold, the acquisition of the read value from the sensor unit can be stopped, so that the calculation of the distance can be started early. .
- the processing unit (e1) sequentially integrates M first values to calculate M first integrated values, and sequentially integrates M second integrated values.
- M second integrated values are calculated
- the first estimated value is calculated using an approximate expression based on the M first integrated values
- the second estimated value is calculated as M It may be calculated using an approximate expression based on the second integrated value
- the distance may be calculated based on the first estimated value and the second estimated value.
- a distance measuring device that can calculate a distance with high accuracy even when noise that fluctuates in a short period occurs without reducing the frame rate. Can be done.
- FIG. 1 is a diagram schematically illustrating a distance measuring device according to an embodiment. It is a figure showing roughly an example of a sensor concerning one embodiment. It is a top view showing an example of one pixel unit in a sensor concerning one embodiment.
- FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3.
- FIG. 5 is a cross-sectional view taken along line VV in FIG. 3.
- FIG. 3 is a circuit diagram of one pixel unit of a sensor unit and a corresponding sample and hold circuit for the pixel unit according to an embodiment. It is a flowchart which shows the control and calculation of a process part which concern on one Embodiment. It is a timing chart of various signals used with a distance measuring device concerning one embodiment.
- FIG. 6 is a circuit diagram of one pixel unit of a sensor unit and a corresponding sample and hold circuit for the pixel unit according to another embodiment.
- FIG. 1 is a diagram schematically showing a distance measuring device according to an embodiment.
- a distance measuring device 10 shown in FIG. 1 is a device that obtains a distance between an object and the distance measuring device 10 by a time-of-flight (TOF) method.
- the distance measuring device 10 includes a light source unit 12, a sensor unit 14, and a processing unit 16.
- the light source unit 12 emits modulated light.
- the light source unit 12 may include a laser diode 12a and a driver circuit 12b.
- the driver circuit 12b supplies a modulation current synchronized with the drive pulse signal from the processing unit 16 to the laser diode 12a.
- the laser diode 12a emits modulated light according to the modulation current.
- the modulated light can include, for example, one or more pulsed lights.
- the sensor unit 14 may include a sensor 18, a digital-analog conversion unit (DAC) 20, and an analog-digital conversion unit (ADC) 22 in one embodiment.
- the DAC 20 converts the digital signal from the signal processing unit 16 a of the processing unit 16 into an analog signal and supplies the analog signal to the sensor 18.
- the ADC 22 converts the analog signal from the sensor 18 into a digital signal and supplies the digital signal to the processing unit 16.
- the processing unit 16 calculates the distance by controlling the emission timing of the modulated light of the light source unit 12 and the sensor unit 14.
- the processing unit 16 may include a signal processing unit 16a and a memory 16b.
- the signal processing unit 16a is an arithmetic circuit such as an FPGA (Field-Programmable Gate Array), and the memory 16b is an SRAM (Static Random Access Memory).
- FIG. 2 is a diagram schematically illustrating an example of a sensor according to an embodiment.
- the sensor 18 includes an imaging region IR, a sample and hold circuit group SHG, a switch group SWG, a horizontal shift register group HSG, signal lines H1 and H2, and output amplifiers OAP1 and OAP2.
- the sensor 18 may be configured as a line sensor that acquires a line of images.
- the imaging region IR includes a plurality of pixel units P (j) arranged in the horizontal direction.
- j is an integer of 1 to J
- J is an integer of 2 or more, and indicates the number of pixel units.
- FIG. 3 is a plan view showing an example of one pixel unit in the sensor according to the embodiment.
- 4 is a cross-sectional view taken along line IV-IV in FIG. 3
- FIG. 5 is a cross-sectional view taken along line VV in FIG.
- the pixel units P (1) to P (J) have the same structure shown in FIGS.
- the pixel unit P (j) includes a semiconductor substrate SB.
- the semiconductor substrate SB is, for example, a silicon substrate.
- the semiconductor substrate SB includes a first semiconductor region SR1 and a second semiconductor region SR2.
- the first semiconductor region SR1 is a p-type semiconductor region that provides one main surface SBF1 of the semiconductor substrate SB.
- the second semiconductor region SR2 is a p ⁇ type semiconductor region provided on the first semiconductor region SR1.
- the impurity concentration of the second semiconductor region SR2 is less than or equal to the impurity concentration of the first semiconductor region SR1.
- the semiconductor substrate SB can be formed by depositing a p-type semiconductor region on a p-type semiconductor substrate by an epitaxial growth method.
- An insulating film ISL is formed on the other main surface SBF2 of the semiconductor substrate SB.
- the insulating film ISL is made of, for example, SiO 2 .
- a photogate electrode PG is provided on the insulating film ISL.
- the photogate electrode PG is made of, for example, polysilicon. As shown in FIG. 3, in one embodiment, the photogate electrode PG may have a substantially rectangular planar shape.
- a region located below the photogate electrode PG functions as a photosensitive region that generates charges in response to incident light.
- a first transfer electrode TX1, a second transfer electrode TX2, and a third transfer electrode TX3 are provided on the insulating film ISL.
- These transfer electrodes TX1 to TX3 are made of, for example, polysilicon.
- the first transfer electrode TX1 and the second transfer electrode TX2 are arranged so that the photogate electrode PG exists between them.
- the two third transfer electrodes TX3 have a direction (hereinafter referred to as “Y direction”) that intersects a direction in which the first transfer electrode TX1 and the second transfer electrode TX2 are arranged (hereinafter referred to as “X direction”). ), The first transfer electrode TX1 is disposed between them. Further, the other two third transfer electrodes TX3 are arranged so that the second transfer electrode TX2 is interposed between them in the Y direction.
- a first accumulation region fd1 and a second accumulation region fd2 are formed in the second semiconductor region SR2.
- the first accumulation region fd1 and the second accumulation region fd2 accumulate charges transferred from the photosensitive region.
- the first accumulation region fd1 and the second accumulation region fd2 are arranged so that the photosensitive region is interposed between them.
- the first accumulation region fd1 and the second accumulation region fd2 are n + type semiconductor regions doped with n-type impurities at a high concentration.
- the insulating film ISL defines an opening above the first accumulation region fd1 and the second accumulation region fd2.
- An electrode 13 is provided in these openings.
- the electrode 13 is made of, for example, tungsten provided via a Ti / TiN film.
- the first transfer electrode TX1 exists between the electrode 13 on the first accumulation region fd1 and the photogate electrode PG, and the second transfer electrode TX2 corresponds to the second accumulation region. It is disposed between the electrode 13 on fd2 and the photogate electrode PG.
- a voltage VTX1 that reduces the potential of the semiconductor region below the first transfer electrode TX1 is applied to the first transfer electrode TX1.
- the voltage VTX1 is given from the DAC 20 based on the digital signal from the signal processing unit 16a.
- a voltage VTX2 that reduces the potential of the semiconductor region below the second transfer electrode TX2 is applied to the second transfer electrode TX2.
- the voltage VTX2 is given from the DAC 20 based on the digital signal from the signal processing unit 16a.
- an n + type semiconductor region SR3 is formed in the second semiconductor region SR2.
- four semiconductor regions SR3 are provided.
- the pair of semiconductor regions SR3 and the other pair of semiconductor regions SR3 are provided such that the photosensitive region is interposed therebetween.
- the insulating film ISL defines openings, and electrodes 13 are provided in these openings.
- the electrode 13 is made of, for example, tungsten provided via a Ti / TiN film.
- a corresponding third transfer electrode TX3 is interposed between the electrode 13 on one semiconductor region SR3 and the photogate electrode PG.
- Charge is transferred from the photosensitive region to the semiconductor region SR3 by applying the voltage VTX3 to the third transfer electrode TX3 to reduce the potential of the semiconductor region below the third transfer electrode TX3.
- the voltage VTX3 is given from the DAC 20 based on the digital signal from the signal processing unit 16a.
- the electrode 13 in the semiconductor region SR3 is also connected to a predetermined potential Vdd (see FIG. 6). This potential Vdd is set by the DAC 20 based on the digital signal from the signal processing unit 16a.
- FIG. 6 is a circuit diagram of one pixel unit of the sensor unit and a corresponding sample and hold circuit for the pixel unit according to an embodiment.
- the sample and hold circuit group SHG of the sensor 18 includes J first sample and hold circuits SH1 and J second sample and hold circuits SH2.
- Each first sample hold circuit SH1 and each second sample hold circuit SH2 are connected to a corresponding pixel unit P (j) (a corresponding pixel unit among the pixel units P (1) to P (J)).
- the sample and hold circuit group SHG includes J sample and hold circuit pairs SHP (1) to SHP (J) each including one first sample and hold circuit SH1 and one second sample and hold circuit.
- J sample-and-hold circuit pairs SHP (1) to SHP (J) are associated with pixel units P (1) to P (J), respectively.
- the pixel unit P (j) further includes a first reset switch RS1, a second reset switch RS2, and charge-voltage conversion circuits A1 and A2.
- the first reset switch RS1 is provided between the reset potential Vr and the electrode 13 on the first accumulation region fd1.
- the second reset switch RS2 is provided between the reset potential Vr and the electrode 13 on the second accumulation region fd2.
- the reset potential Vr is set by the DAC 20 based on the digital signal from the signal processing unit 16a.
- the reset pulse signal Sres is given to the first reset switch RS1 and the second reset switch RS2 from the signal processing unit 16a.
- the reset pulse signal Sres is supplied to the first reset switch RS1 and the second reset switch RS2
- the first accumulation region fd1 and the second accumulation region fd2 are connected to the reset potential Vr.
- the charge in the first accumulation region fd1 and the charge in the second accumulation region fd2 are reset.
- the period from the timing when the charges in the first accumulation region fd1 and the second accumulation region fd2 are reset to the next reset timing is a frame period Tf (see FIG. 8).
- the input of the circuit A1 is connected to the electrode 13 on the first storage region fd1, and the output of the circuit A1 is connected to the switch SW10 of the sample hold circuit SH1.
- the circuit A1 converts the charge amount in the first accumulation region fd1 into a voltage, and provides the voltage to the sample hold circuit SH1.
- the input of the circuit A2 is connected to the electrode 13 on the second accumulation region fd2, and the output of the circuit A2 is connected to the switch SW12 of the sample hold circuit SH2.
- the circuit A2 converts the amount of charge in the second accumulation region fd2 into a voltage, and provides the voltage to the sample hold circuit SH2.
- the sample hold circuit SH1 includes a switch SW10 and a capacitor CP10.
- the sample hold circuit SH2 includes a switch SW12 and a capacitor CP12.
- the sampling pulse signal Ssamp is given to the switch SW10 and the switch SW12 from the signal processing unit 16a.
- the sampling pulse signal Ssamp is applied to the switches SW10 and SW12, the output of the circuit A1 and the capacitor CP10 are connected, and the output of the circuit A2 and the capacitor CP12 are connected.
- the output voltage of the circuit A1 is held across the capacitor CP10, and the output voltage of the circuit A2 is held across the capacitor CP12.
- the switch group SWG of the sensor 18 includes J switches SW1 and J switches SW2. Each switch SW1 and each switch SW2 are connected to the capacitor CP10 of the sample hold circuit SH1 and the capacitor CP12 of the sample hold circuit SH2 for the corresponding pixel unit among the pixel units P (1) to P (J), respectively. Yes. That is, the switch group SWG includes J switch pairs SWP (1) to SWP (J) each including one switch SW1 and one switch SW2. The J switch pairs SWP (1) to SWP (J) are associated with the sample and hold circuit pairs SHP (1) to SHP (J), respectively.
- a read pulse signal Sread is applied to the switches SW1 and SW2.
- the read pulse signal Sread is supplied from the horizontal shift register group HSG.
- the horizontal shift register group HSG has J horizontal shift registers.
- the horizontal shift register can include, for example, a flip-flop. These horizontal shift registers are arranged in the arrangement direction of the pixel units P (1) to P (J).
- the horizontal shift register provided at one end in the horizontal shift register group HSG is given a start signal from the signal processing unit 16a. Further, a clock signal is given from the signal processing unit 16a to all the horizontal shift registers.
- the J horizontal shift registers sequentially apply the read pulse signal Sread to the switch pairs SWP (1) to SWP (J). In this way, when the read pulse signal Sread is applied, the sample hold circuit SH1 and the sample hold circuit SH2 of the sample hold circuit pair SHP (1) to SHP (J) are sequentially connected to the signal line H1 and the signal line H2. .
- the capacitor CP10 of the sample hold circuit SH1 and the capacitor CP12 of the sample hold circuit SH2 are connected to the signal line H1 and the signal line H2, respectively.
- the voltage held in the sample hold circuit SH1 is input to the output amplifier OAP1 via the signal line H1.
- the voltage held in the sample hold circuit SH2 is input to the output amplifier OAP2 via the signal line H2.
- Each of the output amplifier OAP1 and the output amplifier OAP2 amplifies the input voltage and outputs the amplified voltage to the ADC 22.
- the ADC 22 converts the input voltage signal into a digital value having a value corresponding to the magnitude of the voltage signal.
- the digital value output by the ADC 22 is stored in the memory 16b of the processing unit 16.
- a digital value based on the voltage signal from the output amplifier OAP1 is stored in the memory 16b as a first read value to be described later.
- the first read value becomes smaller as the amount of accumulated charge in the first accumulation region fd1 is larger.
- a digital value based on the voltage signal from the output amplifier OAP2 is stored in the memory 16b as a second read value to be described later.
- the second read value becomes smaller as the amount of accumulated charge in the second accumulation region fd2 increases.
- FIG. 7 is a flowchart showing control and calculation of the processing unit 16 according to an embodiment.
- FIG. 8 is a timing chart of various signals used in the distance measuring apparatus according to the embodiment.
- the processing unit 16 performs control and calculation described below with reference to FIGS. 7 and 8 for each pixel unit.
- the signal processing unit 16a of the processing unit 16 first applies the reset pulse signal Sres to the first reset switch RS1 and the second RS2, and thereby the first accumulation region fd1 and the second accumulation region. fd2 is connected to the reset potential Vr. As a result, the charge accumulated in the first accumulation region fd1 and the charge accumulated in the second accumulation region fd2 are reset, and the frame period Tf is started (step S11). This frame period then continues until the reset pulse signal Sres is applied to the first reset switch RS1 and the second RS2.
- the processing unit 16 obtains the first value Q1dc (0) and the second value Q2dc (0) from the sensor unit 14, and the first value Q1dc (0) and the second value Q2dc (0). ) Is stored in the memory 16b as an initial value (step S12).
- the signal processing unit 16a gives the sampling pulse signal Ssamp to the switches SW10 and SW12 before the start of the first first charge transfer cycle Cy1.
- the voltage corresponding to the amount of charge accumulated in the first accumulation region fd1 at the time before the first first charge transfer cycle Cy1 is held in the sample hold circuit SH1, and the second accumulation at that time.
- a voltage corresponding to the amount of charge accumulated in the region fd2 is held in the sample hold circuit SH2.
- the signal processing unit 16a supplies a start signal and a clock signal to the horizontal shift register group HSG so that the read pulse signal Sread is supplied from the horizontal shift register to the switches SW1 and SW2.
- the first value Q1dc (0) and the second value Q2dc (0) are acquired.
- the first value Q1dc (0) and the second value Q2dc (0) are accumulated in the first accumulation region fd1 between the output timing of the reset pulse signal Sres and the output timing of the first sampling pulse signal Ssamp.
- the signal processing unit 16a sets n to 1 (step S13), the first to Nth first and second charge transfer cycles, and the first to Nth first and second read cycles. Try to explain below.
- “N” indicates the order of the maximum cycle set in advance.
- the signal processing unit 16a gives the drive pulse signal SL to the light source unit 12 to emit modulated light from the light source unit 12 (step S14).
- the time length of the emission period of the modulated light from the light source unit 12 is T0.
- the signal processing unit 16a may supply a plurality of pulse signals to the light source unit 12 within the period T0 as the drive pulse signal SL, and cause the light source unit 12 to emit a plurality of pulse lights.
- the signal processing unit 16a sends a digital signal to the sensor unit 14 so that the High level voltage signal VTX1 is applied to the first transfer electrode TX1 within the first transfer period T1 of the nth first charge transfer cycle Cy1. give. In addition, the signal processing unit 16a outputs a digital signal to the sensor unit so that the High level voltage signal VTX2 is applied to the second transfer electrode TX2 within the second transfer period T2 of the nth first charge transfer cycle Cy1. 14
- the first transfer period T1 is synchronized with the drive pulse signal SL. That is, the rising timing of the drive pulse signal SL and the rising timing of the voltage signal VTX1 are substantially synchronized, and the duration T0 of the drive pulse signal SL and the first transfer period T1 have substantially the same time length.
- the second transfer period T2 is phase-inverted with the first transfer period T1. That is, the phase of the second transfer period T2 is 180 degrees behind the phase of the first transfer period T1. More specifically, the falling timing of the voltage signal VTX1 and the rising timing of the voltage signal VTX2 are substantially synchronized, and the first transfer period T1 and the second transfer period T2 have approximately the same time length.
- the first charge transfer cycle Cy1 includes one first transfer period T1 and one second transfer period T2.
- the signal processing unit 16a applies a low level voltage signal to the third transfer electrode TX3.
- a digital signal is given to the sensor unit 14 so that VTX3 is given.
- the third transfer electrode TX3 is supplied with a high-level voltage signal VTX3 during a period other than the first transfer period T1 and the second transfer period T2 in the first charge transfer cycle Cy1.
- the charge corresponding to the incident light to the photosensitive region is not transferred to the semiconductor region SR3, but the first charge In a period other than the first transfer period T1 and the second transfer period T2 of the transfer cycle Cy1, the charge generated in the photosensitive region is transferred to the semiconductor region SR3 and removed.
- the signal processing unit 16a corresponds to the first read value Q1ac (n) corresponding to the amount of charge accumulated in the first accumulation region fd1 and the amount of charge accumulated in the second accumulation region fd2.
- the second read value Q2ac (n) is acquired from the sensor unit 14, and the first read value Q1ac (n) and the second read value Q2ac (n) are stored in the memory 16b (step S15).
- the signal processing unit 16a sends the sampling pulse signal Ssamp to the switch SW10 and the sampling pulse signal Ssamp at a time point between the end point of the nth first charge transfer cycle and the start point of the nth second charge transfer cycle. Applied to the switch SW12. As a result, the voltage corresponding to the amount of charge accumulated in the first accumulation region fd1 at the time between the end of the first charge transfer cycle and the start of the next second charge transfer cycle is sampled and held. A voltage corresponding to the amount of charge held in the circuit SH1 and stored in the second storage region fd2 at that time is held in the sample hold circuit SH2.
- the signal processing unit 16a supplies a start signal and a clock signal to the horizontal shift register group HSG so that the read pulse signal Sread is supplied from the horizontal shift register to the switches SW1 and SW2 in the n-th first read cycle. Accordingly, the processing unit 16 acquires the first read value Q1ac (n) and the second read value Q2ac (n) from the sensor unit 14.
- the first read value Q1ac (n) is stored in the first storage region fd1 at the time between the end of the nth first charge transfer cycle and the start of the nth second charge transfer cycle.
- the second read value Q2ac (n) is a value corresponding to the amount of charge accumulated in the second accumulation region fd2 at that time.
- the signal processing unit 16a stops the emission of the modulated light from the light source unit 12 in the n-th second charge transfer cycle Cy2 (step S16). That is, in the second charge transfer cycle Cy2, the signal processing unit 16a does not supply a drive pulse signal to the light source unit 12.
- the signal processing unit 16a sends a digital signal to the sensor unit 14 so that the high-level voltage signal VTX1 is applied to the first transfer electrode TX1 within the third transfer period T3 of the n-th second charge transfer cycle Cy2. give. In addition, the signal processing unit 16a outputs a digital signal to the sensor unit so that the High-level voltage signal VTX2 is applied to the second transfer electrode TX2 within the fourth transfer period T4 of the n-th second charge transfer cycle Cy2. 14
- the relationship between the phase of the third transfer period T3 and the phase of the fourth transfer period T4 is the same as the relationship between the phase of the first transfer period T1 and the phase of the second transfer period T2.
- the first transfer period T1, the second transfer period T2, the third transfer period T3, and the fourth transfer period T4 have substantially the same time length.
- the signal processing unit 16a applies the low level voltage signal VTX3 to the third transfer electrode TX3. Is given to the sensor unit 14. Further, the signal processing unit 16a applies the low-level voltage signal VTX3 to the third transfer electrode TX3 during a period other than the third transfer period T1 and the fourth transfer period T4 in the second charge transfer cycle Cy2. The digital signal is supplied to the sensor unit 14 so that the digital signal is transmitted.
- the signal processing unit 16a corresponds to the first read value Q1dc (n) corresponding to the charge amount accumulated in the first accumulation region fd1 and the charge amount accumulated in the second accumulation region fd2.
- the second read value Q2dc (n) is acquired from the sensor unit 14, and the first read value Q1dc (n) and the second read value Q2dc (n) are stored in the memory 16b (step S17).
- the signal processing unit 16a transmits the sampling pulse signal Ssamp to the switch SW10 and the switch SW12 between the end of the nth second charge transfer cycle and the start of the (n + 1) th first charge transfer cycle. To give. As a result, a voltage corresponding to the amount of charge stored in the first storage region fd1 at the time between the end of the second charge transfer cycle and the start of the next first charge transfer cycle is supplied to the sample hold circuit SH1. The voltage corresponding to the charge amount stored in the second storage region fd2 at that time is held in the sample hold circuit SH2.
- the signal processing unit 16a supplies a start signal and a clock signal to the horizontal shift register group HSG so that the read pulse signal Sread is supplied from the horizontal shift register to the switches SW1 and SW2 in the n-th second read cycle.
- the processing unit 16 acquires the first read value Q1dc (n) and the second read value Q2dc (n) from the sensor unit 14.
- the first read value Q1dc (n) is stored in the first storage region fd1 at the time between the end of the nth second charge transfer cycle and the start of the (n + 1) th first charge transfer cycle.
- the second read value Q2dc (n) is a value corresponding to the amount of charge accumulated in the second accumulation region fd2 at that time.
- the signal processing unit 16a calculates the first value Q1 (n) and the second value Q2 (n) (step S18). Specifically, the first value Q1 (n) is obtained by multiplying the first read value Q1ac (n) by the first read value Q1dc (n ⁇ 1) and the first read value Q1dc (n). ) Is subtracted. The second value Q2 (n) is obtained by subtracting the second read value Q2dc (n-1) and the second read value Q2dc (n) from a value twice the second read value Q2ac (n). It is obtained as a value.
- the signal processing unit 16a calculates a difference value k1 (n) and a difference value k2 (n) (step S19).
- the difference value k1 (n) includes the first read value Q1dc (n) of the nth second read cycle and the first read value Q1dc (n-1) of the (n-1) th second read cycle. It is obtained by calculating
- the difference value k2 (n) is calculated by using the second read value Q2dc (n) of the nth second read cycle and the second read value Q2dc (n ⁇ 1) of the (n ⁇ 1) th second read cycle. ) To obtain the difference.
- Q1 (0) can be substituted for the first read value Q1dc (0)
- Q2 (0) can be substituted for the second read value Q2dc (0).
- the signal processing unit 16a obtains a first predicted value Q1dc (n + 1) and a second predicted value Q2dc (n + 1) (step S20).
- the first predicted value Q1dc (n + 1) is obtained by calculating the sum of the first read value Q1dc (n) and the difference value k1 (n).
- the second predicted value Q2dc (n + 1) is obtained by calculating the sum of the first read value Q2dc (n) and the difference value k2 (n).
- the first predicted value Q1dc (n + 1) is a predicted value of the first read value of the (n + 1) th second read cycle.
- the second predicted value Q1dc (n + 1) is a predicted value of the second read value of the (n + 1) th second read cycle.
- the signal processing unit 16a compares the first predicted value Q1dc (n + 1) and the second predicted value Q2dc (n + 1) with a predetermined threshold value Qth (step S21).
- the threshold value Qth is equal to or greater than the first read value corresponding to the saturated storage capacity of the first storage region fd1 and the second read value corresponding to the saturated storage capacity of the second storage region fd2. It is set to be the above numerical value. If the first predicted value Q1dc (n + 1) is greater than or equal to the threshold value Qth and the second predicted value Q2dc (n + 1) is greater than or equal to the threshold value Qth, the determination result in step S21 is “No”, and signal processing The process of unit 16a proceeds to step S22.
- step S22 it is tested whether n is N or more. If n is smaller than N in step S22, the signal processing unit 16a increments the value of n by 1 (step S23) and repeats the processing from step S14. On the other hand, if n is greater than or equal to N in step S22, the processing of the signal processing unit 16a proceeds to step S24.
- step S21 If the first predicted value Q1dc (n + 1) or the second predicted value Q2dc (n + 1) exceeds the threshold value Qth as a result of the comparison in step S21, that is, the processing by the signal processing unit 16a. Advances to step S24. Therefore, when the first predicted value Q1dc (n + 1) or the second predicted value Q2dc (n + 1) exceeds the threshold value Qth, the processing unit 16 performs the first read cycle after the (n + 1) th time and the (n + 1) th time after the first read cycle. The acquisition and storage of the read values of the two read cycles are stopped.
- the threshold value Qth is equal to the larger read value of the first read value corresponding to the saturated storage capacity of the first storage region fd1 and the second read value corresponding to the saturated storage capacity of the second storage region fd2.
- the processing unit 16 can acquire the first read value in a range not exceeding the read value corresponding to the saturated storage capacity of the first storage region fd1, and the second storage region fd2
- the second read value in a range not exceeding the read value corresponding to the saturated storage capacity can be acquired.
- the dynamic range of the measurement distance can be improved.
- the distance measurement accuracy can be improved.
- the calculation after step S24 of the signal processing unit 16a can be started early.
- the threshold value Qth is greater of the first read value corresponding to the saturated storage capacity of the first storage region fd1 and the second read value corresponding to the saturated storage capacity of the second storage region fd2. It may be set to a value larger than the other read value. According to this embodiment, the sensor unit 14 can be used in a range in which the linearity of the relationship between the accumulated charge amount and the incident light amount of each of the first accumulation region fd1 and the second accumulation region fd2 is excellent. Therefore, the distance measurement accuracy can be further improved.
- the signal processing unit 16a obtains a first estimated value Q1est and a second estimated value Q2est (step S24).
- the first estimated value Q1est is calculated based on the M first values Q1 (1,..., M). Specifically, as shown in the equation (1), the first value Q1dc (0) is added to a value obtained by accumulating the M first values Q1 (1,..., M). Estimated value Q1est is calculated.
- the second estimated value Q2est is calculated based on the M second values Q2 (1,..., M). Specifically, as shown in the equation (2), by adding a value Q2dc (0) to a value obtained by accumulating M second values Q2 (1,..., M), Estimated value Q2est is calculated.
- the signal processing unit 16a calculates a distance (step S25). Specifically, the signal processing unit 16a calculates the distance L by the calculation of the following formula (3).
- c is the speed of light
- ⁇ is the first read value and the second read value when the same amount of incident light is incident on the photosensitive region in the first transfer period T1 and the second transfer period T2. Ratio.
- the signal processing unit 16a outputs a one-line distance image having a gray value corresponding to the distance calculated for each pixel. In one embodiment, the signal processing unit 16a may repeat the control and calculation described with reference to FIGS. 7 and 8 so as to update the distance image for each frame period.
- Q1ac (n), Q1dc (n), Q2ac (n), and Q2dc (n) are represented by the following formula (4).
- q1ac corresponds to the increase in the amount of charge based on the reflected light from the object with respect to the modulated light, that is, the amount of charge based on the signal light, among the increase in the amount of charge in the first accumulation region in the nth first charge transfer cycle.
- the value to be q2ac is a value corresponding to an increase in the charge amount based on the signal light among the increase in the charge amount in the second accumulation region in the nth first charge transfer cycle.
- q1ad is a value corresponding to an increase in the amount of charge based on factors other than the signal light among the increase in the amount of charge in the first accumulation region in the nth first charge transfer cycle.
- q2ad is a value corresponding to an increase in the amount of charge based on factors other than the signal light among the increase in the amount of charge in the second accumulation region in the nth first charge transfer cycle.
- q1dd is a value corresponding to the increase in the amount of charge in the first accumulation region in the nth second charge transfer cycle.
- Q2dd is a component corresponding to an increase in the amount of charge in the second accumulation region in the n-th second charge transfer cycle.
- the first value Q1 (n) and the second value Q2 (n) are represented by the following formulas (5) and (6). Therefore, the first value Q1 (n) represents an increase in the charge amount based on the signal light among the increase in the charge amount in the first accumulation region in the nth first charge transfer cycle.
- the second value Q2 (n) represents the increase in the amount of charge based on the signal light among the increase in the amount of charge in the second accumulation region in the nth first charge transfer cycle.
- the first estimated value Q1est is calculated based on the first value Q1
- the second estimated value Q2est is the second value. Is calculated based on the value Q2. Therefore, the distance L calculated by the calculation of Expression (3) is based on the first value Q1 and the second value Q2, and is obtained based on the value from which noise is removed. Therefore, the distance measuring apparatus 10 can calculate the distance with high accuracy even when noise such as background light that fluctuates in a short period occurs without reducing the frame rate.
- the number of times of the first transfer period and the number of times of the second transfer period included in the first read cycle are each one. Therefore, the time length of each cycle can be shortened. Therefore, according to this embodiment, it is possible to calculate the distance with high accuracy even if noise that fluctuates in a shorter period occurs.
- the signal processing unit 16a may calculate the first estimated value Q1est and the second estimated value Q2est as described below. That is, the signal processing unit 16a sequentially accumulates the first values Q1 (1,..., M) as shown in the equation (7), and M first accumulated values Q1int (1,. .., M), and the second values Q1 (1,..., M) are sequentially integrated to obtain M second integrated values Q2int (1,..., M).
- the signal processing unit 16a calculates the approximate expression based on the M first integrated values Q1int (1,..., M) and the M second integrated values Q2int (1,..., M). A correction value for the first integrated value Q1int and a correction value for the second integrated value Q2int are calculated using the approximate expression based on the above. Then, the signal processing unit 16a calculates the first estimated value Q1est by obtaining the sum of the correction value of the first integrated value Q1int and the value Q1dc (0). Similarly, the signal processing unit 16a calculates the second estimated value Q2est by obtaining the sum of the correction value of the second integrated value Q2int and the value Q2 (0).
- the correction value of the first integrated value Q1int is a correction value of all the integrated values of the M first values Q1 (1,..., M), and the second integrated value.
- the correction value of Q2int may be a correction value of all integrated values of the M second values Q2 (1,..., M).
- the approximate expression can be created based on the method of least squares. In addition, other known approximate expression creation methods may be used.
- the first estimated value Q1est is based on the correction value of the first integrated value Q1int calculated using the approximate expression
- the second estimated value Q2est is calculated using the approximate expression. 2 based on the correction value of the integrated value Q2int. Therefore, even if a part of the M first values Q1 (1,..., M) and the M second values Q2 (1,.
- the influence of the read value including the fluctuation can be reduced. Therefore, the distance measurement accuracy can be further improved.
- FIG. 9 is a flowchart illustrating control and calculation of a processing unit according to another embodiment.
- the processing unit 16 of the distance measuring device 10 may perform control and calculation shown in FIG.
- the processing unit 16 of the distance measuring device 10 does not perform steps S18 to S21 in FIG. 7 in the control and calculation shown in the flowchart in FIG. That is, the processes in steps S14 to S17 are performed up to N predetermined first and second read cycles.
- the signal processing unit 16a of the processing unit 16 specifies the Mth first and second read cycles that are the best among the N first and second read cycles that have been executed (step S26).
- the best M-th read cycle includes a first read value Q1dc and a second read value Q2dc that do not exceed a predetermined threshold among N read cycles, that is, are equal to or greater than a predetermined threshold. It can be determined as the maximum read cycle acquired.
- the predetermined threshold is a value equal to or larger than the larger read value of the read value corresponding to the saturation charge amount of the first accumulation region fd1 and the read value corresponding to the saturation charge amount of the second accumulation region fd2. Can be set.
- the first estimated value Q1est and the second estimated value Q2est are calculated (step S27).
- the first estimated value Q1est is the integrated value and value of the first value Q1 (1,... M) described above in step S18 and step S24, as shown in equation (8). It is obtained by addition with Q1dc (0).
- the second estimated value Q2est is obtained by adding the integrated value of the second values Q2 (1,... M) and the value Q2dc (0).
- the first estimated value Q1est finds M first values Q1 (1,... M), and the first value Q1 (1, .., M) in order to obtain M first integrated values Q1int (1,..., M), and M first integrated values Q1int (1,..., M). ) Is used to calculate the correction value of the first integrated value Q1int, and the sum of the correction value and Q1dc (0) is obtained.
- the second estimated value Q2est is obtained as M second values Q2 (1,... M), and the second value Q2 (1,.
- the signal processing unit 16a calculates the distance L according to Expression (3) using the first estimated value Q1est and the second estimated value Q2est obtained in step S27.
- the distance L may be calculated by specifying the best cycle M after N predetermined first and second read cycles.
- FIG. 10 is a timing chart of various signals used in the distance measuring device according to another embodiment.
- a plurality of emission periods of modulated light from the light source unit 12 are provided in each first charge transfer cycle Cy1. That is, the drive pulse signal is supplied to the light source unit 12 in a plurality of emission periods in each first charge transfer cycle Cy1.
- each first charge transfer cycle Cy1 is provided with three first transfer periods T1 and three second transfer periods T2.
- the time length of the third transfer period T3 of each second charge transfer cycle Cy2 is set to three times the time length of the first transfer period T1, and the second charge transfer cycle Cy2
- the time length of the fourth transfer period T4 is set to three times the time length of the second transfer period T2.
- the time length for accumulating charges in the first accumulation region fd1 in each first charge transfer cycle Cy1 the time length for accumulating charges in the second accumulation region fd2 in each first charge transfer cycle Cy1
- the time length for accumulating charges in the first accumulation region fd1 in the second charge transfer cycle Cy2 and the time length for accumulating charges in the second accumulation region fd2 in each second charge transfer cycle Cy2 are substantially Same time length.
- a plurality of modulated light emission periods, a plurality of first transfer periods T1, and a plurality of second transfer periods T2 are provided in each first charge transfer cycle Cy1. Also good.
- FIG. 11 is a diagram illustrating an example of a sensor according to still another embodiment.
- FIG. 12 is a circuit diagram of one pixel unit of a sensor unit and a corresponding sample and hold circuit for the pixel unit according to still another embodiment.
- the distance measuring device 10 may have a sensor 18A shown in FIG.
- the sensor 18A has an imaging region IR having I ⁇ J pixel units P (i, j).
- i is an integer of 1 to I
- j is an integer of 1 to J
- I and J are integers of 2 or more.
- I ⁇ J pixel units P (i, j) are arranged in I rows and J columns.
- two vertical signal lines V1 (j) and V2 (j) for each column of the pixel unit are provided.
- the switch SW20 is connected to the output of the circuit A1 of the pixel unit P (i, j) of the sensor 18A, and the switch SW20 corresponds via the corresponding vertical signal line V1 (j). Is connected to the switch SW10 of the sample hold circuit SH1.
- the switch SW22 is connected to the output of the circuit A2 of the pixel unit P (i, j), and the switch SW22 is connected to the switch SW12 of the corresponding sample and hold circuit SH2 via the corresponding vertical signal line V2 (j). It is connected to the.
- the sensor 18A further includes a vertical shift register group VSG.
- the vertical shift register group VSG includes a plurality of vertical shift registers arranged in the vertical direction. Each vertical shift register includes, for example, a flip-flop.
- a start signal is given to the vertical shift register provided at one end in the arrangement direction from the signal processing unit 16a. Further, a clock signal is given from the signal processing unit 16a to all the vertical shift registers.
- the vertical shift register group VSG sequentially applies row selection signals to the switches SW20 and SW22 of the plurality of pixel units P (i, j) in the row order.
- the outputs of the circuits A1 and A2 of the plurality of pixel units (i, j) in each column are sequentially connected to the corresponding vertical signal lines V1 (j) and V2 (j), so that the plurality of pixel units P (
- the output voltages i, j) are sequentially held in the row order in the corresponding sample and hold circuits SH1 and SH2.
- the output voltages of the plurality of pixel units (j, i) in each row are held in the corresponding sample hold circuits SH1 and SH2
- the voltage held in the sample hold circuits SH1 and SH2 is changed to the horizontal shift register group HSG.
- the signal processing part 16a can form a two-dimensional distance image by performing the calculation demonstrated in FIG. 7 or FIG. 9 about each pixel unit.
- corresponding sample hold circuits SH1 and SH2 are provided for each column of pixel units.
- corresponding sample hold circuits SH1 and SH2 are provided for each pixel unit.
- the number of pixel units in the imaging region IR may be one.
- the order of a plurality of steps in the flowcharts described with reference to FIGS. 7 and 9 can be arbitrarily changed within a range that does not contradict the purpose of the embodiments.
- SYMBOLS 10 Distance measuring device, 12 ... Light source part, 12a ... Laser diode, 12b ... Driver circuit, 14 ... Sensor part, 16 ... Processing part, 16a ... Signal processing part, 16b ... Memory, 18 ... Sensor, 20 ... DAC (digital) -Analog conversion unit), 22 ... ADC (analog-digital conversion unit), fd1 ... first storage region, fd2 ... second storage region, TX1 ... first transfer electrode, TX2 ... second transfer electrode, A1 ... charge-voltage conversion circuit (first conversion unit), A2 ... charge-voltage conversion circuit (second conversion unit), SH1 ... first sample hold circuit, SH2 ... second sample hold circuit.
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Abstract
Description
Claims (7)
- 飛行時間法により対象物に対する距離を求める距離測定装置であって、
変調光を放出する光源部と、
入射光に応じて電荷を発生する光感応領域、前記光感応領域で発生した電荷を蓄積する第1の蓄積領域及び第2の蓄積領域、前記光感応領域と前記第1の蓄積領域との間に設けられた第1の転送電極、前記光感応領域と前記第2の蓄積領域との間に設けられた第2の転送電極、前記第1の蓄積領域とリセット電位との間に設けられた第1のリセットスイッチ、並びに、前記第2の蓄積領域とリセット電位との間に設けられた第2のリセットスイッチを有するセンサ部と、
前記変調光の放出タイミング及び前記センサ部を制御して、距離を算出する処理部と、
を備え、
前記処理部は、
前記第1のリセットスイッチ及び前記第2のリセットスイッチを制御して前記第1の蓄積領域及び前記第2の蓄積領域を前記リセット電位に接続してから該第1の蓄積領域及び該第2の蓄積領域を次に前記リセット電位に接続するまでのフレーム期間内の複数の第1の電荷転送サイクルにおいて、一以上の放出期間に前記光源部に前記変調光を放出させ、前記一以上の放出期間に同期した一以上の第1の転送期間に前記第1の転送電極に与える電圧を制御して前記光感応領域で発生した電荷を前記第1の蓄積領域に蓄積させ、前記一以上の第1の転送期間と位相反転した一以上の第2の転送期間に前記第2の転送電極に与える電圧を制御して前記光感応領域で発生した電荷を前記第2の蓄積領域に蓄積させ、
前記フレーム期間内の複数の第2の電荷転送サイクルであり前記複数の第1の電荷転送サイクルと交互の該一以上の第2の電荷転送サイクルにおいて、前記光源部に前記変調光を放出させず、第3の転送期間に前記第1の転送電極に与える電圧を制御して前記光感応領域で発生した電荷を前記第1の蓄積領域に蓄積させ、前記第3の転送期間と位相反転した第4の転送期間に前記第2の転送電極に与える電圧を制御して前記光感応領域で発生した電荷を前記第2の蓄積領域に蓄積させ、
前記複数の第1の電荷転送サイクルのそれぞれに対応する複数の第1の読出しサイクルにおいて、該複数の第1の電荷転送サイクルのそれぞれと次の前記第2の電荷転送サイクルの間の時点に前記第1の蓄積領域に蓄積されている電荷量に応じた第1の読出し値及び該時点に前記第2の蓄積領域に蓄積されている電荷量に応じた第2の読出し値を、前記センサ部から取得し、
前記複数の第2の電荷転送サイクルのそれぞれに対応する複数の第2の読出しサイクルにおいて、該複数の第2の電荷転送サイクルのそれぞれと次の前記第1の電荷転送サイクルの間の時点に前記第1の蓄積領域に蓄積されている電荷量に応じた別の第1の読出し値及び該時点に前記第2の蓄積領域に蓄積されている電荷量に応じた別の第2の読出し値を、前記センサ部から取得し、
n回目の前記第1の読出しサイクルの前記第1の読出し値の2倍の値からn回目及びn-1回目の前記第2の読出しサイクルの前記別の第1の読出し値を差し引いた値である第1の値、及び、n回目の前記第1の読出しサイクルの前記第2の読出し値の2倍の値からn回目及びn-1回目の前記第2の読出しサイクルの前記別の第2の読出し値を差し引いた値である第2の値を算出して、M個の第1の値及びM個の第2の値を求め、ここで、nは前記複数の第1の読出しサイクル及び前記複数の第2の読出しサイクルの順番を示し、
前記M個の第1の値及び前記M個の第2の値に基づいて、距離を算出する、
距離測定装置。 - 前記第1の電荷転送サイクルにおいて前記第1の蓄積領域に電荷を蓄積させる時間長、前記第1の電荷転送サイクルにおいて前記第2の蓄積領域に電荷を蓄積させる時間長、前記第2の電荷転送サイクルにおいて前記第1の蓄積領域に電荷を蓄積させる時間長、及び、前記第2の電荷転送サイクルにおいて前記第2の蓄積領域に電荷を蓄積させる時間長は、実質的に同じ時間長である、請求項1に記載の距離測定装置。
- 前記複数の第1の電荷転送サイクルの各々は、一回の前記第1の転送期間、及び、一回の前記第2の転送期間を含む、請求項1又は2に記載の距離測定装置。
- 前記処理部は、
前記複数の第2の読出しサイクルのうち、前記別の第1の読出し値及び前記別の第2の読出し値が所定の閾値を超えない最終の第2の読出しサイクルを特定し、
該最終の第2の読出しサイクルまでに得られた一以上の前記第1の読出し値及び一以上の前記別の第1の読出し値に基づいて前記M個の第1の値を求め、該最終の第2の読出しサイクルまでに得られた一以上の前記第2の読出し値及び一以上の前記別の第2の読出し値に基づいて前記M個の第2の値を求める、
請求項1~3の何れか一項に記載の距離測定装置。 - 前記処理部は、n回目の前記第2の読出しサイクルの前記別の第1の読出し値と、n回目の前記第2の読出しサイクルの前記別の第1の読出し値とn-1回目の前記第2の読出しサイクルの前記別の第1の読出し値との間の差分値との和、又は、n回目の前記第2の読出しサイクルの前記別の第2の値と、n回目の前記第2の読出しサイクルの前記別の第2の値とn-1回目の前記第2の読出しサイクルの前記別の第2の値との間の差分値との和が、所定の閾値を超える場合に、n+1回目以降の前記第1の読出しサイクル及び前記第2の読出しサイクルを停止し、
最終の読出しサイクルであるn回目の前記第2の読出しサイクルまでに得られた一以上の前記第1の読出し値及び一以上の前記別の第1の読出し値に基づいて前記M個の第1の値を求め、該最終の読出しサイクルまでに得られた一以上の前記第2の読出し値及び一以上の前記別の第2の読出し値に基づいて前記M個の第2の値を求める、
請求項1~3の何れか一項に記載の距離測定装置。 - 前記処理部は、前記M個の第1の値の積算値及び前記M個の第2の値の積算値に基づいて、前記距離を算出する、請求項1~5の何れか一項に記載の距離測定装置。
- 前記処理部は、
前記M個の第1の値を順に積算してM個の第1の積算値を算出し、前記M個の第2の値の積算値を順に積算してM個の第2の積算値を算出し、
第1の推定値を前記M個の第1の積算値に基づく近似式を用いて算出し、第2の推定値を前記M個の第2の積算値に基づく近似式を用いて算出し、
前記第1の推定値及び前記第2の推定値に基づいて、前記距離を算出する、
請求項1~5の何れか一項に記載の距離測定装置。
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Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20180106902A1 (en) * | 2015-04-28 | 2018-04-19 | Hamamatsu Photonics K.K. | Distance measurement device |
Families Citing this family (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5781918B2 (ja) * | 2011-12-28 | 2015-09-24 | 浜松ホトニクス株式会社 | 距離測定装置 |
US9528760B2 (en) * | 2012-03-12 | 2016-12-27 | Mitsubishi Rayon Co., Ltd. | Method for producing porous membrane and drying device of porous membrane |
CN107533136B (zh) * | 2015-06-24 | 2020-08-25 | 株式会社村田制作所 | 距离传感器 |
WO2017022219A1 (ja) * | 2015-08-04 | 2017-02-09 | パナソニックIpマネジメント株式会社 | 固体撮像装置の駆動方法 |
KR20170060353A (ko) | 2015-11-24 | 2017-06-01 | 삼성전자주식회사 | 전자 장치, 거리 측정 센서 및 그 제어 방법 |
JP6659447B2 (ja) | 2016-05-02 | 2020-03-04 | 浜松ホトニクス株式会社 | 距離センサ |
EP3757616A4 (en) * | 2018-08-31 | 2021-05-05 | Shenzhen Goodix Technology Co., Ltd. | TIME-OF-FLIGHT-BASED DISTANCE MEASUREMENT PROCESS AND DISTANCE MEASUREMENT SYSTEM |
US11175390B2 (en) * | 2018-12-24 | 2021-11-16 | Beijing Voyager Technology Co., Ltd. | Real-time estimation of DC bias and noise power of light detection and ranging (LiDAR) |
JP7175872B2 (ja) * | 2019-11-14 | 2022-11-21 | 株式会社日立エルジーデータストレージ | 測距装置 |
US11947050B2 (en) * | 2021-07-07 | 2024-04-02 | Beijing Voyager Technology Co., Ltd. | Temperature control through thermal recycle |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2004294420A (ja) * | 2003-02-03 | 2004-10-21 | Shoji Kawahito | 距離画像センサ |
JP2005235893A (ja) * | 2004-02-18 | 2005-09-02 | National Univ Corp Shizuoka Univ | 光飛行時間型距離センサ |
JP2006523074A (ja) | 2003-04-11 | 2006-10-05 | カネスタ インコーポレイテッド | センサのダイナミックレンジを差分拡大する方法及びシステム |
US7379100B2 (en) | 2004-02-12 | 2008-05-27 | Canesta, Inc. | Method and system to increase dynamic range of time-of-flight (TOF) and/or imaging sensors |
JP2009041943A (ja) * | 2007-08-06 | 2009-02-26 | Denso Corp | 計測装置 |
Family Cites Families (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS57179772A (en) * | 1981-04-30 | 1982-11-05 | Toshiba Corp | Measuring device of radiant ray |
US5848305A (en) * | 1996-01-31 | 1998-12-08 | Canon Kabushiki Kaisha | Circulating shift register and distance measuring device |
US8119965B2 (en) * | 2006-01-25 | 2012-02-21 | Kyocera Corporation | Image sensor having two light receiving elements and camera module having the image sensor |
JP2008122223A (ja) | 2006-11-13 | 2008-05-29 | Suzuki Motor Corp | 距離計測装置 |
JP5105549B2 (ja) | 2006-11-30 | 2012-12-26 | 国立大学法人静岡大学 | 半導体測距素子及び固体撮像装置 |
JP5171158B2 (ja) | 2007-08-22 | 2013-03-27 | 浜松ホトニクス株式会社 | 固体撮像装置及び距離画像測定装置 |
US8035806B2 (en) * | 2008-05-13 | 2011-10-11 | Samsung Electronics Co., Ltd. | Distance measuring sensor including double transfer gate and three dimensional color image sensor including the distance measuring sensor |
DE102009037596B4 (de) * | 2009-08-14 | 2014-07-24 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Pixelstruktur, System und Verfahren zur optischen Abstandsmessung sowie Steuerschaltung für die Pixelstruktur |
JP5274424B2 (ja) * | 2009-10-07 | 2013-08-28 | 本田技研工業株式会社 | 光電変換素子、受光装置、受光システム及び測距装置 |
JP5558999B2 (ja) * | 2009-11-24 | 2014-07-23 | 浜松ホトニクス株式会社 | 距離センサ及び距離画像センサ |
JP5302244B2 (ja) * | 2010-02-26 | 2013-10-02 | 浜松ホトニクス株式会社 | 距離画像センサ |
JP5781918B2 (ja) * | 2011-12-28 | 2015-09-24 | 浜松ホトニクス株式会社 | 距離測定装置 |
-
2011
- 2011-12-28 JP JP2011288343A patent/JP5876289B2/ja active Active
-
2012
- 2012-08-21 WO PCT/JP2012/071075 patent/WO2013099348A1/ja active Application Filing
- 2012-08-21 US US14/357,817 patent/US9151831B2/en active Active
- 2012-08-21 EP EP12863980.4A patent/EP2799906B1/en active Active
- 2012-08-21 KR KR1020147003426A patent/KR101883529B1/ko active IP Right Grant
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2004294420A (ja) * | 2003-02-03 | 2004-10-21 | Shoji Kawahito | 距離画像センサ |
JP2006523074A (ja) | 2003-04-11 | 2006-10-05 | カネスタ インコーポレイテッド | センサのダイナミックレンジを差分拡大する方法及びシステム |
US7379100B2 (en) | 2004-02-12 | 2008-05-27 | Canesta, Inc. | Method and system to increase dynamic range of time-of-flight (TOF) and/or imaging sensors |
JP2005235893A (ja) * | 2004-02-18 | 2005-09-02 | National Univ Corp Shizuoka Univ | 光飛行時間型距離センサ |
JP2009041943A (ja) * | 2007-08-06 | 2009-02-26 | Denso Corp | 計測装置 |
Non-Patent Citations (1)
Title |
---|
See also references of EP2799906A4 |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20180106902A1 (en) * | 2015-04-28 | 2018-04-19 | Hamamatsu Photonics K.K. | Distance measurement device |
US10871568B2 (en) * | 2015-04-28 | 2020-12-22 | Hamamatsu Photonics K.K. | Distance measurement device |
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