JP2021067534A - Distance measuring device - Google Patents

Abstract

To provide a distance measuring device that can measure a distance more quickly.SOLUTION: The distance measuring device according to the present disclosure includes: a light reception unit including a light reception element; a time measuring unit for measuring the time from when a light source emits light to when the light reception element receives the light and acquiring a measured value; a generation unit for generating a histogram of the measured value; an output unit for outputting data showing the distance to a measurement target object based on the histogram; and an output control unit for controlling data that the output unit is to output. The output control unit causes the output unit to output data showing a first distance of data showing distances with a first frequency and to output data showing a second distance with a second frequency.SELECTED DRAWING: Figure 15

Description

The present invention relates to a ranging device.

As one of the distance measuring methods for measuring the distance to the object to be measured using light, a distance measuring method called a direct ToF (Time of Flight) method is known. In the direct ToF method, the light emitted from the light source receives the reflected light reflected by the object to be measured by the sensor, and the distance to the target is measured based on the time from the emission of the light to the reception as the reflected light. To do.

Japanese Unexamined Patent Publication No. 2008-076390

In the direct ToF method of distance measurement, various internal information including the distance measurement result is output from the sensor. When it is desired to perform distance measurement at high speed by the direct ToF method and all of these internal information are sequentially output, the speed of distance measurement is limited by the output band rate-determining.

An object of the present disclosure is to provide a distance measuring device capable of measuring a distance at a higher speed.

The distance measuring device according to the present disclosure includes a light receiving unit including a light receiving element, a time measuring unit that measures the time from the light emitting timing when the light source emits light to the light receiving timing when the light receiving element receives light, and acquires a measured value. The output control unit includes a generation unit that generates a histogram of values, an output unit that outputs data indicating the distance to the object to be measured based on the histogram, and an output control unit that controls the data to be output to the output unit. Of the data indicating the distance, the data indicating the first distance is output to the output unit at the first frequency, and the data indicating the second distance is output to the output unit at the second frequency.

It is a figure which shows typically the distance measurement by the direct ToF method applicable to each embodiment. It is a figure which shows the histogram of an example based on the time when the light receiving part received light, which is applicable to each embodiment. It is a block diagram which shows the structure of an example of the electronic device which used the distance measuring device which concerns on each embodiment. It is a block diagram which shows the structural example of the distance measuring apparatus applicable to each embodiment in more detail. It is a figure which shows the basic structure example of the pixel circuit applicable to each embodiment. It is a schematic diagram which shows the example of the structure of the device applicable to the distance measuring device which concerns on each embodiment. It is a figure which shows the example of the scanning method of the pixel array part applicable to each embodiment. It is a figure which shows the example of the scanning method of the pixel array part applicable to each embodiment. It is a figure which shows the example of the relationship of a frame, a line and a distance measuring process applicable to each embodiment. It is a figure which shows more concretely the structural example of the pixel array part which concerns on each embodiment. It is a figure which shows the example of the detailed structure of the pixel array part which concerns on each embodiment. It is a figure which shows the example of the detailed structure of the pixel array part which concerns on each embodiment. It is a figure which shows the example of the configuration for reading a signal Vpls from each pixel circuit, which is applicable to each embodiment. It is a figure for demonstrating an example of output processing of distance measurement data and attribute data by an existing technique. It is a figure for demonstrating the example of switching the output of attribute data by communication with a host device by the existing technique. It is a block diagram which shows the structure of an example of the distance measuring apparatus which concerns on 1st Embodiment. It is a figure for demonstrating the output processing in the distance measuring apparatus which concerns on 1st Embodiment. It is a figure which shows the example of the histogram based on the time when each element (pixel circuit) received light. It is a figure which shows typically the example of the peak shape of a histogram. It is a figure which shows typically the example of the peak shape of a histogram. It is a figure which shows typically the example of the peak shape of a histogram. It is a figure for demonstrating the output processing in the distance measuring apparatus which concerns on the modification of 1st Embodiment. It is a figure for demonstrating the output processing of the distance measurement data which concerns on 2nd Embodiment. It is a figure which shows typically the example of the distance measurement processing by the whole pixel array part. It is a figure which shows the example of the thinning in the odd-numbered frame (odd) which concerns on 2nd Embodiment. It is a figure which shows the example of thinning in the even number frame (even) which concerns on 2nd Embodiment. It is a schematic diagram for demonstrating the output process which concerns on 3rd Embodiment. It is an example flowchart which shows the output process which concerns on 3rd Embodiment. It is a figure which shows the 1st Embodiment and the modification thereof, and the use example which uses the distance measuring apparatus which concerns on 2nd and 3rd Embodiment. It is a block diagram which shows the schematic structure example of the vehicle control system which is an example of the mobile body control system to which the technique which concerns on this disclosure can be applied. It is a figure which shows the example of the installation position of the imaging unit.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the following embodiments, the same parts are designated by the same reference numerals, so that duplicate description will be omitted.

Hereinafter, embodiments of the present disclosure will be described in the following order.
1. 1. Techniques applicable to each embodiment 1-1. Schematic explanation of distance measurement processing 1-2. Configuration example of distance measuring device 1-3. How to scan the pixel array section 1-4. Read control example for each element and pixel circuit 2. First Embodiment 2-1. Existing technology 2-2. Output processing according to the first embodiment 2-3. Example of information output from the ranging device 2-4. Modification example 3. Second embodiment 4. Third embodiment 5. Fourth Embodiment 5-1. A more specific example when the imaging device of the present disclosure is mounted on a vehicle.

[1. Technology applicable to each embodiment]
(1-1. Schematic explanation of distance measurement processing)
First, the techniques applicable to each embodiment of the present disclosure will be described. The present disclosure relates to a technique for performing distance measurement using light. In each embodiment, the ToF (Time Of Flight) method is directly applied as the distance measuring method. The direct ToF method is a method in which the light emitted from the light source receives the reflected light reflected by the object to be measured by the light receiving element, and the distance is measured based on the time difference between the light emission timing and the light receiving timing.

The distance measurement by the direct ToF method will be schematically described with reference to FIGS. 1 and 2. FIG. 1 is a diagram schematically showing distance measurement by the direct ToF method applicable to each embodiment. The distance measuring device 300 includes a light source unit 301 and a light receiving unit 302. The light source unit 301 is, for example, a laser diode, and is driven so as to emit laser light in a pulsed manner. The light emitted from the light source unit 301 is reflected by the object to be measured 303 and is received by the light receiving unit 302 as reflected light. The light receiving unit 302 includes a light receiving element that converts light into an electric signal by photoelectric conversion, and outputs a signal corresponding to the received light.

Here, the time when the light source unit 301 emits light (light emission timing) is time t ₀ , and the time when the light receiving unit 302 receives the reflected light reflected by the object to be measured 303 (light receiving timing). Let time t ₁ . If the constant c is the light velocity ^{(2.9979 × 10 8 [m /} sec]), the distance D between the distance measuring apparatus 300 and the object to be measured 303 is calculated by the following equation (1).
D = (c / 2) × (t ₁ −t ₀ )… (1)

The ranging device 300 repeats the above-mentioned processing a plurality of times. The light receiving unit 302 may include a plurality of light receiving elements, and the distance D may be calculated based on each light receiving timing when the reflected light is received by each light receiving element. The ranging device 300 _{classifies the time t m} (called the light receiving time t _{m ) from the light emitting timing time t 0} to the light receiving timing when the light is received by the light receiving unit 302 based on the class (bins). Generate a histogram.

The light received by the light receiving unit 302 during the light receiving time t _m is not limited to the reflected light emitted by the light source unit 301 and reflected by the object to be measured. For example, the ambient light around the ranging device 300 (light receiving unit 302) is also received by the light receiving unit 302.

FIG. 2 is a diagram showing an example histogram based on the time when the light receiving unit 302 receives light, which is applicable to each embodiment. In FIG. 2, the horizontal axis indicates the bin and the vertical axis indicates the frequency for each bin. The bins are obtained by classifying the light receiving time t _m for each predetermined unit time d. Specifically, bin # 0 is 0 ≦ t _m <d, bin # 1 is d ≦ t _m <2 × d, bin # 2 is 2 × d ≦ t _m <3 × d, ..., Bin # (N). -2) is (N-2) × d ≦ t _m <(N-1) × d. When the exposure time of the light receiving unit 302 is time t _ep , t _ep = N × d.

The distance measuring device 300 _{counts the number of times the light receiving time t m} is acquired based on the bin, obtains the frequency 310 for each bin, and generates a histogram. Here, the light receiving unit 302 also receives light other than the reflected light reflected from the light emitted from the light source unit 301. As an example of such light other than the target reflected light, there is the above-mentioned ambient light. The portion indicated by the range 311 in the histogram includes the ambient light component due to the ambient light. The ambient light is light that is randomly incident on the light receiving unit 302 and becomes noise with respect to the reflected light of interest.

On the other hand, the target reflected light is light received according to a specific distance, and appears as an active light component 312 in the histogram. The bin corresponding to the frequency of the peak in the active light component 312 becomes the bin corresponding to the distance D of the object to be measured 303. The distance measuring device 300 acquires the representative time of the bottle (for example, the time in the center of the bottle) as the time t ₁ described above, and calculates the distance D to the object to be measured 303 according to the formula (1) described above. be able to. In this way, by using a plurality of light receiving results, it is possible to perform appropriate distance measurement for random noise.

(1-2. Configuration example of distance measuring device)
FIG. 3 is a block diagram showing a configuration of an example of an electronic device using the distance measuring device according to each embodiment. In FIG. 3, the electronic device 6 includes a distance measuring device 1, a light source unit 2, a storage unit 3, a control unit 4, and an optical system 5.

The light source unit 2 corresponds to the light source unit 301 described above, and is a laser diode, and is driven so as to emit laser light in a pulsed manner, for example. A VCSEL (Vertical Cavity Surface Emitting LASER) that emits laser light can be applied to the light source unit 2 as a surface light source. Not limited to this, an array in which laser diodes are arranged on a line may be used as the light source unit 2, and a configuration in which the laser light emitted from the laser diode array is scanned in a direction perpendicular to the line may be applied. Furthermore, it is also possible to apply a configuration in which a laser diode as a single light source is used and the laser light emitted from the laser diode is scanned in the horizontal and vertical directions.

The distance measuring device 1 includes a plurality of light receiving elements corresponding to the light receiving unit 302 described above. The plurality of light receiving elements are arranged in a two-dimensional lattice shape (matrix shape), for example, to form a light receiving surface. The optical system 5 guides light incident from the outside to a light receiving surface included in the distance measuring device 1.

The control unit 4 controls the overall operation of the electronic device 6. For example, the control unit 4 supplies the distance measuring device 1 with a light emitting trigger that is a trigger for causing the light source unit 2 to emit light. The distance measuring device 1 causes the light source unit 2 to emit light at a timing based on this light emission trigger, and stores a _{time t 0 indicating the light emission timing.} Further, the control unit 4 sets a pattern for distance measurement for the distance measuring device 1 in response to an instruction from the outside, for example.

_{The ranging device 1 counts the number of times that time information (light receiving time t m} ) indicating the timing at which light is received on the light receiving surface is acquired within a predetermined time range, obtains the frequency for each bin, and obtains the above-mentioned histogram. Generate. The distance measuring device 1 further calculates the distance D to the object to be measured based on the generated histogram. The information indicating the calculated distance D is stored in the storage unit 3.

FIG. 4 is a block diagram showing in more detail an example of the basic configuration of the distance measuring device 1 applicable to each embodiment. In FIG. 4, the distance measuring device 1 includes a pixel array unit 100, a distance measuring processing unit 101, a pixel control unit 102, an overall control unit 103, a clock generation unit 104, a light emission timing control unit 105, and an interface ( I / F) 106 and. The pixel array unit 100, the distance measuring processing unit 101, the pixel control unit 102, the overall control unit 103, the clock generation unit 104, the light emission timing control unit 105, and the interface 106 are arranged on, for example, one semiconductor chip.

In FIG. 4, the overall control unit 103 controls the overall operation of the ranging device 1 according to, for example, a program incorporated in advance. Further, the overall control unit 103 can also execute control according to an external control signal supplied from the outside. The clock generation unit 104 generates one or more clock signals used in the distance measuring device 1 based on the reference clock signal supplied from the outside. The light emission timing control unit 105 generates a light emission control signal indicating the light emission timing according to the light emission trigger signal supplied from the outside. The light emission control signal is supplied to the light source unit 2 and also to the distance measuring processing unit 101.

The pixel array unit 100 includes a plurality of pixel circuits 10, 10, ... The operation of each pixel circuit 10 is controlled by the pixel control unit 102 according to the instruction of the overall control unit 103. For example, the pixel control unit 102 controls reading of pixel signals from each pixel circuit 10 for each block including p (p × q) pixel circuits 10 in the row direction and q in the column direction. be able to. Further, the pixel control unit 102 can scan each pixel circuit 10 in the row direction and further scan in the column direction in units of the block to read a pixel signal from each pixel circuit 10. Not limited to this, the pixel control unit 102 can also control each pixel circuit 10 independently.

Further, the pixel control unit 102 can set a predetermined area of the pixel array unit 100 as a target area, and the pixel circuit 10 included in the target area can be a target pixel circuit 10 for reading a pixel signal. Furthermore, the pixel control unit 102 can collectively scan a plurality of rows (plurality of lines), further scan the plurality of rows (plural lines) in the column direction, and read a pixel signal from each pixel circuit 10.

The pixel signal read from each pixel circuit 10 is supplied to the distance measuring processing unit 101. The distance measuring processing unit 101 includes a conversion unit 110, a generation unit 111, and a signal processing unit 112.

The pixel signal read from each pixel circuit 10 and output from the pixel array unit 100 is supplied to the conversion unit 110. Here, the pixel signal is asynchronously read from each pixel circuit 10 included in the target area and supplied to the conversion unit 110. That is, the pixel signal is read out from the light receiving element and output according to the timing when the light is received in each pixel circuit 10 included in the target area.

The conversion unit 110 converts the pixel signal supplied from the pixel array unit 100 into digital information. That is, the pixel signal supplied from the pixel array unit 100 is output corresponding to the timing at which light is received by the light receiving element included in the pixel circuit 10 to which the pixel signal corresponds. The conversion unit 110 converts the supplied pixel signal into time information indicating the timing.

The generation unit 111 generates a histogram based on the time information in which the pixel signal is converted by the conversion unit 110. Here, the generation unit 111 counts the time information based on the unit time d set by the setting unit 113, and generates a histogram.

The signal processing unit 112 performs predetermined arithmetic processing based on the histogram data generated by the generation unit 111, and calculates, for example, distance information. The signal processing unit 112 creates an approximate curve of the histogram based on the data of the histogram generated by the generation unit 111, for example. The signal processing unit 112 can detect the peak of the curve to which this histogram is approximated and obtain the distance D based on the detected peak.

When the signal processing unit 112 approximates the curve of the histogram, the signal processing unit 112 can apply a filter process to the curve to which the histogram is approximated. For example, the signal processing unit 112 can suppress a noise component by performing a low-pass filter process on a curve whose histogram is approximated.

Although details will be described later, the signal processing unit 112 can acquire information such as peak intensity, peak start and end positions, etc. based on the approximate curve of this histogram. Each piece of information including distance information acquired from the approximate curve of the histogram in the signal processing unit 112 is referred to as distance measurement information (distance measurement data).

The distance measurement data including the distance information obtained by the signal processing unit 112 is supplied to the interface 106. The interface 106 functions as an output unit that outputs the distance information supplied from the signal processing unit 112 to the outside as output data. .. As the interface 106, for example, MIPI (Mobile Industry Processor Interface) can be applied.

In the above description, the distance measurement data including the distance information obtained by the signal processing unit 112 is output to the outside via the interface 106, but this is not limited to this example. That is, the histogram data, which is the histogram data generated by the generation unit 111, may be output from the interface 106 to the outside. In this case, the distance measurement condition information set by the setting unit 113 may omit the information indicating the filter coefficient. The histogram data output from the interface 106 is supplied to, for example, an external information processing device, and is appropriately processed.

FIG. 5 is a diagram showing a basic configuration example of the pixel circuit 10 applicable to each embodiment. In FIG. 5, the pixel circuit 10 includes a light receiving element 1000, transistors 1100, 1102 and 1103, an inverter 1104, a switch unit 1101, and an AND circuit 1110.

The light receiving element 1000 converts the incident light into an electric signal by photoelectric conversion and outputs the signal. In each embodiment, the light receiving element 1000 converts the incident photon (photon) into an electric signal by photoelectric conversion, and outputs a pulse corresponding to the incident of the photon. In each embodiment, a single photon avalanche diode is used as the light receiving element 1000. Hereinafter, a single photon avalanche diode will be referred to as a SPAD (Single Photon Avalanche Diode). SPAD has a characteristic that when a large negative voltage that causes avalanche multiplication is applied to the cathode, electrons generated in response to the incident of one photon cause avalanche multiplication and a large current flows. By utilizing this characteristic of SPAD, the incident of one photon can be detected with high sensitivity.

In FIG. 5, in the light receiving element 1000 which is a SPAD, the cathode is connected to the coupling portion 1120 and the anode is connected to the voltage source of the voltage (−Vbd). The voltage (−Vbd) is a large negative voltage for generating an avalanche multiplication for SPAD. The coupling unit 1120 is connected to one end of the switch unit 1101 whose on (closed) and off (open) are controlled according to the signal EN_PR. The other end of the switch unit 1101 is connected to the drain of the transistor 1100, which is a P-channel MOSFET (Metal Oxide Semiconductor Field Effect Transistor). The source of the transistor 1100 is connected to the power supply voltage Vdd. Further, a coupling portion 1121 to which a reference voltage Vref is supplied is connected to the gate of the transistor 1100.

The transistor 1100 is a current source that outputs a current corresponding to the power supply voltage Vdd and the reference voltage Vref from the drain. With such a configuration, a reverse bias is applied to the light receiving element 1000. When a photon is incident on the light receiving element 1000 with the switch unit 1101 turned on, the avalanche multiplication is started, and a current flows from the cathode of the light receiving element 1000 toward the anode.

A signal extracted from the connection point between the drain of the transistor 1100 (one end of the switch unit 1101) and the cathode of the light receiving element 1000 is input to the inverter 1104. The inverter 1104 performs, for example, a threshold value determination on the input signal, inverts the signal each time the signal exceeds the threshold value in the positive direction or the negative direction, and outputs the signal as a pulsed signal Vpls.

The signal Vpls output from the inverter 1104 is input to the first input terminal of the AND circuit 1110. The signal EN_F is input to the second input end of the AND circuit 1110. The AND circuit 1110 outputs the signal Vpls from the pixel circuit 10 via the terminal 1122 when both the signal Vpls and the signal EN_F are in the high state.

In FIG. 5, the coupling portion 1120 is further connected to the drains of the transistors 1102 and 1103, which are N-channel MOSFETs, respectively. The sources of transistors 1102 and 1103 are connected, for example, to a ground potential. The signal XEN_SPAD_V is input to the gate of the transistor 1102. Further, the signal XEN_SPAD_H is input to the gate of the transistor 1103. When at least one of the transistors 1102 and 1103 is in the off state, the cathode of the light receiving element 1000 is forcibly set to the ground potential, and the signal Vpls is fixed in the low state.

The signals XEN_SPAD_V and XEN_SPAD_H are used as two-dimensional grid-like vertical and horizontal control signals in which each pixel circuit 10 is arranged in the pixel array unit 100, respectively. As a result, the on / off state of each pixel circuit 10 included in the pixel array unit 100 can be controlled for each pixel circuit 10. The on state of the pixel circuit 10 is a state in which the signal Vpls can be output, and the off state of the pixel circuit 10 is a state in which the signal Vpls cannot be output.

For example, in the pixel array unit 100, the signal XEN_SPAD_H is set to the state in which the transistor 1103 is turned on for the continuous q columns of the two-dimensional lattice, and the signal XEN_SPAD_V is set to the state in which the transistor 1102 is turned on for the continuous p rows. To do. As a result, the output of each light receiving element 1000 can be enabled in a block shape of p rows × q columns. Further, since the signal Vpls are output from the pixel circuit 10 by the AND circuit 1110 by the logical product of the signal EN_F, the output of each light receiving element 1000 enabled by the signals XEN_SPAD_V and XEN_SPAD_H, for example, is more detailed. Enable / disable can be controlled.

Further, for example, by supplying the signal EN_PR that turns off the switch unit 1101 to the pixel circuit 10 including the light receiving element 1000 whose output is invalidated, the supply of the power supply voltage Vdd to the light receiving element 1000 is stopped. The pixel circuit 10 can be turned off. This makes it possible to reduce the power consumption of the pixel array unit 100.

These signals XEN_SPAD_V, XEN_SPAD_H, EN_PR and EN_F are generated by the overall control unit 103 based on, for example, parameters stored in a register or the like of the overall control unit 103. The parameters may be stored in the register in advance, or may be stored in the register according to an external input. Each signal XEN_SPAD_V, XEN_SPAD_H, EN_PR and EN_F generated by the overall control unit 103 is supplied to the pixel array unit 100 by the pixel control unit 102.

The control by the signals EN_PR, XEN_SPAD_V and XEN_SPAD_H using the switch unit 1101 and the transistors 1102 and 1103 described above is controlled by the analog voltage. On the other hand, the control by the signal EN_F using the AND circuit 1110 is the control by the logic voltage. Therefore, the control by the signal EN_F can be performed at a lower voltage than the control by the signals EN_PR, XEN_SPAD_V and XEN_SPAD_H, and is easy to handle.

FIG. 6 is a schematic diagram showing an example of a device configuration applicable to the distance measuring device 1 according to each embodiment. In FIG. 6, the distance measuring device 1 is configured by stacking a light receiving chip 20 made of a semiconductor chip and a logic chip 21, respectively. In FIG. 6, for the sake of explanation, the light receiving chip 20 and the logic chip 21 are shown in a separated state.

In the light receiving chip 20, the light receiving elements 1000 included in each of the plurality of pixel circuits 10 are arranged in a matrix in the region of the pixel array unit 100. Further, in the pixel circuit 10, the transistors 1100, 1102 and 1103, the switch unit 1101, the inverter 1104, and the AND circuit 1110 are formed on the logic chip 21. The cathode of the light receiving element 1000 is connected between the light receiving chip 20 and the logic chip 21 via, for example, a coupling portion 1120 by a CCC (Copper-Copper Connection) or the like.

The logic chip 21 is provided with a logic array unit 200 including a signal processing unit that processes a signal acquired by the light receiving element 1000. With respect to the logic chip 21, the signal processing circuit unit 201 that processes the signal acquired by the light receiving element 1000 in close proximity to the logic array unit 200, and the element control that controls the operation as the distance measuring device 1. Section 203 and may be provided.

For example, the signal processing circuit unit 201 can include the distance measuring processing unit 101 described above. Further, the element control unit 203 can include the pixel control unit 102, the overall control unit 103, the clock generation unit 104, the light emission timing control unit 105, and the interface 106 described above.

The configuration on the light receiving chip 20 and the logic chip 21 is not limited to this example. Further, the element control unit 203 can be arranged for the purpose of other driving or control, for example, in the vicinity of the light receiving element 1000, in addition to the control of the logic array unit 200. In addition to the arrangement shown in FIG. 6, the element control unit 203 can be provided in an arbitrary region of the light receiving chip 20 and the logic chip 21 so as to have an arbitrary function.

(1-3. Pixel array section scanning method)
Next, an example of a scanning method of the pixel array unit 100 applicable to each embodiment will be schematically described. 7A and 7B are diagrams showing an example of a scanning method of the pixel array unit 100 applicable to each embodiment.

For example, in FIG. 7A, the pixel array unit 100 has a size in which Y rows of X (for example, 600) pixel circuits 10 are arranged. That is, the pixel array unit 100 has a total of (X) X columns (X) and Y rows (Y) in the row direction (horizontal direction in FIG. 7A) and the column direction (vertical direction in FIG. 7A), respectively. × Y) pixel circuits 10 are arranged in a matrix arrangement.

Here, in the present disclosure, as shown in FIG. 7A, the block 11 including p × q pixel circuits 10 is treated as one pixel in the pixel array unit 100. That is, in the pixel array unit 100, distance measurement is performed for each block 11 which is a block including p × q pixel circuits 10. The block 11 is an addition unit for adding the number of _{light receiving times t m when generating a histogram.} More specifically, for each block 11, distance measurement processing such as exposure, photon detection, histogram generation, and peak detection is executed in each pixel circuit 10 included in the block 11. The block 11 can be treated as one pixel because the detection results of the plurality of pixel circuits 10 are collected and output as one. In FIG. 7A and FIG. 7B described later, the block 11 is shown as including 5 × 4 pixel circuits 10 for the sake of explanation.

In the following, the block 11 will be referred to as an element 11 in consideration of the fact that the block 11 is treated as a pixel.

As shown in FIG. 7A, when distance measurement processing is executed simultaneously in each element 11 on the entire surface of the pixel array unit 100, there are restrictions in terms of power consumption, data communication band, circuit scale, and the like. Therefore, the pixel array unit 100 is divided into a plurality of regions, and the distance measuring process is sequentially performed on the divided regions.

FIG. 7B is a diagram schematically showing the execution of the distance measuring process in which the pixel array unit 100 is divided into a plurality of regions. As shown in FIG. 7B, the pixel array unit 100 is vertically divided into regions according to the height of the element 11, and distance measurement processing is executed for each divided region.

Hereinafter, each region in which the pixel array unit 100 is vertically divided according to the height of the element 11 is referred to as a line. Further, the area including all the lines in the pixel array unit 100 is called a frame. In other words, the frame is an area in the pixel array unit 100 that includes all the pixel circuits 10 that are effective for distance measurement. The period for scanning all the elements 11 included in the frame is called the frame period, and the period for scanning all the elements 11 included in the line is called the line period.

In FIG. 7B, when the distance measuring process on the lower end line of the pixel array unit 100 is completed (first time), the distance measuring process is executed for each element 11 on the line immediately above it (second time). Hereinafter, in the same manner, the pixel array unit 100 is scanned in the horizontal direction in units of 11 elements to perform distance measurement processing, and the scan in units of lines is sequentially executed for lines adjacent in the vertical direction. Distance measurement is performed in units of distance measurement for one line. When the distance measurement process for one frame is completed, the distance measurement process for the next frame period is executed in the same manner.

FIG. 8 is a diagram showing an example of the relationship between the frame period, the line period, and the distance measuring process, which can be applied to each embodiment. In FIG. 8, the progress of time is shown to the right, and the frame period, line period, and distance measurement data are shown from the top. Further, in the line period, the high state indicates the period during which the scan of each element 11 is executed. In the example of FIG. 8, each line period has a length of, for example, several tens [μsec], and distance measurement processing is executed at this number of several tens [μsec], distance measurement data X is output, and a plurality of distance measurement data X are output within one frame period. Line processing is executed. One frame period has a length of, for example, several [msec]. That is, it is necessary that all the results of the distance measuring process by each element 11 included in one line are output from the distance measuring device 1 (interface 106) within a period of several tens of [μsec].

(1-4. Example of read control for each element and pixel circuit)
Next, an example of read control for 400 elements and 10 pixel circuits, which can be applied to each embodiment, will be described. FIG. 9 is a diagram showing more specifically a configuration example of the pixel array unit 100 according to each embodiment. The pixel control unit 102 described with reference to FIG. 4 is shown separately as a horizontal control unit 102a and a vertical control unit 102b in FIG.

In FIG. 9, the pixel array unit 100 includes a total of (xxy) pixel circuits 10 in x columns in the horizontal direction and y rows in the vertical direction. Further, in FIG. 9 and the examples of FIGS. 10 and 11 described later, the element 11 is shown as including three pixel circuits 10 in the horizontal direction and three in the vertical direction, for a total of nine pixel circuits 10.

For example, the signal EN_SPAD_H corresponding to the above-mentioned signal XEN_SPAD_H for controlling each pixel circuit 10 in the row direction (horizontal direction), that is, in a column unit is a 3-bit signal ([2: 0]) in which the element 11 is a unit. Is output from the overall control unit 103 and supplied to the horizontal control unit 102a. That is, the signals EN_SPAD_H [0], EN_SPAD_H [1], and EN_SPAD_H [2] for the three pixel circuits 10 arranged continuously in the horizontal direction are merged and transmitted by this one 3-bit signal.

In the example of FIG. 9, the signals EN_SPAD_H # 0 [2: 0], EN_SPAD_H # 1 [2: 0], ..., EN_SPAD_H # (x / 3) [2: 0], in order from the leftmost element 11 of the pixel array unit 100. ] Is generated by the overall control unit 103 and supplied to the horizontal control unit 102a. The horizontal control unit 102a has a 3-bit value ([0],] of each signal EN_SPAD_H # 0 [2: 0], EN_SPAD_H # 1 [2: 0], ..., EN_SPAD_H # (x / 3) [2: 0]. Each column of the corresponding element 11 is controlled according to (shown as [1] and [2]).

Similarly, for example, the signal EN_SPAD_V corresponding to the above-mentioned signal XEN_SPAD_V for controlling each pixel circuit 10 in the column direction (vertical direction), that is, in row units is a 3-bit signal having element 11 as a unit and is an overall control unit. It is output from 103 and supplied to the vertical control unit 102b. That is, the signals EN_SPAD_V [0], EN_SPAD_V [1], and EN_SPAD_V [2] for the three pixel circuits 10 arranged continuously in the vertical direction are merged and transmitted by this one 3-bit signal.

In the example of FIG. 9, the signals EN_SPAD_V # 0 [2: 0], EN_SPAD_V # 1 [2: 0], ..., EN_SPAD_V # (y / 3) [2: 0], in order from the element 11 at the lower end of the pixel array unit 100. ] Is generated by the overall control unit 103 and supplied to the vertical control unit 102b. The vertical control unit 102b corresponds to each signal according to the three-bit values of EN_SPAD_V # 0 [2: 0], EN_SPAD_V # 1 [2: 0], ..., EN_SPAD_V # (y / 3) [2: 0]. Control each row of element 11.

Although not shown, the signal EN_PR is output from the overall control unit 103 as a 3-bit signal with the element 11 as a unit and supplied to the vertical control unit 102b, for example, like the signal EN_SPAD_V described above. The vertical control unit 102b controls each line of the corresponding element according to the 3-bit value of each signal EN_PR.

10 and 11 are diagrams showing an example of the detailed configuration of the pixel array unit 100 according to each embodiment. More specifically, FIGS. 10 and 11 show control by the signal EN_F.

As shown in FIG. 10, the signal EN_F is a signal supplied for each control target 130 including a plurality of adjacent rows of the pixel array unit 100. Here, the controlled object 130 is shown as including three columns according to the size of the element 11. Further, as the signal EN_F, the same signal is supplied to each line included in the control target 130 for each line having a predetermined cycle. That is, in this example in which the control target 130 includes three columns, the same signal EN_F is supplied to the three pixel circuits 10 in the same row. In FIG. 10, as an example, the signal EN_F is a 42-bit (shown as [41: 0]) signal, and the same signal is supplied every 42 lines (7 lines × 6). In the example of FIG. 10, signals EN_F # 0 [41: 0], EN_F # 1 [41: 0], ..., EN_F # (x / 3) [41: 0] is output from the overall control unit 103 and supplied to the horizontal control unit 102a.

The horizontal control unit 102a controls each bit of each signal EN_F # 0 [41: 0], EN_F # 1 [41: 0], ..., EN_F # (x / 3) [41: 0], respectively. Supply to each line of 130. As shown in FIG. 11, the horizontal control unit 102a transmits the signal EN_F # 0 [0] to the control target 130 at the left end of the pixel array unit 100, for example, in the first line and the 42nd line (m + 1) line ( m is an integer of 1 or more), ..., 42nd (n + 1) th row, ..., And is supplied every 42 rows. Similarly, the horizontal control unit 102a supplies the signal EN_F # 0 [2] to the second line, the 42nd line (m + 2) line, ..., Every 42 lines. In FIG. 11, the uppermost row of the control target 130 is the first half of the 42 row unit, and the signal EN_F # 0 [20] is supplied.

That is, by the 42-bit signal EN_F [41: 0], the set of three pixel circuits 10 arranged continuously in the horizontal direction is the signal EN_F [0] for the 42 sets arranged continuously in the vertical direction. , EN_F [1], ..., EN_F [41] are merged and transmitted.

In this way, the pixel array unit 100 can be controlled differently for each of a plurality of columns by the signal EN_F. Further, the pixel array unit 100 is supplied with the same signal EN_F for each of a plurality of rows (for each line) in the plurality of columns. Therefore, for each pixel circuit 10 included in the pixel array unit 100, it is possible to control the plurality of columns as the minimum unit in the width direction and the plurality of rows (lines) as the period.

FIG. 12 is a diagram showing an example of a configuration for reading a signal Vpls from each pixel circuit 10 applicable to each embodiment. In FIG. 12, as shown by arrows in the figure, the horizontal direction of the figure is the column direction.

In each embodiment, the read wiring for reading the signal Vpls is shared for each of a predetermined number of pixel circuits 10 in the column direction. In the example of FIG. 12, the read wiring is shared for each of the v pixel circuits 10. For example, consider groups 12 _u , 12 _{u + 1} , 12 _{u + 2} , ... Group 12 _u includes pixel circuits 10 ₁₁ to 10 _1v , group 12 _{u + 1} includes pixel circuits 10 ₂₁ to 10 _2v , and group 12 _{u + 2} includes 10 ₃₁ to 10 _3v , and so on.

In each group 12 _u , 12 _{u + 1} , 12 _{u + 2} , ..., The read wiring of the pixel circuit 10 whose position in the group corresponds is shared. In the example of FIG. 12, as the head side of the position to the right of the figure, the first pixel circuit 10 ₁₁ of the group 12 _u, Group 12 u _{+ 1} of the first pixel circuit 10 _21, Group 12 u _{+ 2} of The read wiring of the first pixel circuit 10 ₃₁ , ... Is shared. In the example of FIG. 12, a plurality of read wirings are connected by sequentially connecting the read wirings of the _{pixel circuits 10 11} , 10 ₂₁ , 10 _{31 , ... Via the OR circuits 41 11} , 41 ₂₁ , 41 _{31, ....} Is being shared.

For example, for group 12 _u , OR circuits 41 ₁₁ , 41 ₁₂ , ..., 41 _1v are provided for each of the pixel circuits 10 ₁₁ to 10 _1v included in group 12 _u, and at the first input terminal of each. , Pixel circuit 10 ₁₁ to 10 _1v read wiring is connected. The group 12 Similarly, with respect to _{u + 1,} respectively provided OR circuit 41 ₂₁ to 41 _2v to the pixel circuits 10 ₂₁ to 10 _2v in the group 12 _{u + 1.} Similarly, for the group 12 _{u + 2} , OR circuits 41 _{31 to} 41 _3v are provided for the pixel circuits 10 ₃₁ to 10 _3v included in the group 12 _{u + 2, respectively.}

The outputs of the OR circuits 41 _{11 to} 41 _1v are input to, for example, the distance measuring processing unit 101.

Taking the pixel circuits 10 ₁₁ , 10 ₂₁ and 10 ₃₁ as an example, in the OR circuit 41 ₁₁ , the read wiring of the pixel circuit 10 ₁₁ is connected to the first input terminal, and the OR circuit 41 ₂₁ is connected to the second input terminal. The output is connected. In the OR circuit 41 ₂₁ , the read wiring of the pixel circuit 10 ₂₁ is connected to the first input terminal, and the output of the _{OR circuit 41 31 is connected to the second input terminal.} The same applies to the OR circuit 41 _{31 and later.}

With respect to the configuration shown in FIG. 12, for example, the vertical control unit 102b simultaneously reads out from each pixel circuit 10 whose position corresponds to each _{group 12 u} , 12 _{u + 1} , 12 _{u + 2, ... By the signal EN_SPAD_V.} Is controlled so as not to be performed. In other words, the vertical control unit 102b controls only one of the plurality of pixel circuits 10 arranged in the row every (v-1) so that it can be read out. In the example of FIG. 12, the vertical control unit 102b controls, for example, _{not to read from the pixel circuit 10 11} and the pixel circuit 10 ₂₁ and the pixel circuit 10 ₃₁ at the same time. Not limited to this, the control of simultaneous reading in the column direction can also be performed by the horizontal control unit 102a using the signal EN_F.

On the other hand, in the configuration shown in FIG. 12, the vertical control unit 102b can specify simultaneous reading from v pixel circuits 10 arranged continuously in a row. At this time, the vertical control unit 102b can specify the pixel circuit 10 that reads out at the same time _{across the groups 12 u} , 12n + 1, 12 _{u + 2, ....} That is, in the configuration shown in FIG. 12, v continuous pixel circuits 10 in the column direction can be simultaneously read out. For example, the third pixel circuit 10 ₁₃ from the beginning in the group 12 _u, from the beginning in the group 12 u _{+ 1} to the second pixel circuit 10 _22, v pixel circuits arranged in succession It is possible to specify simultaneous reading for 10.

Further, when the vertical control unit 102b specifies simultaneous reading from v pixel circuits 10 arranged continuously in a row, the vertical control unit 102b controls so as not to read from other pixel circuits 10 in the row. Therefore, for example, the output of the _{OR circuit 41 11} is the signal Vpls read from the pixel circuit 10 of any one of _{the pixel circuits 10 11} , 10 ₂₁ , 10 _{31, ....}

In this way, by connecting the read wiring of each pixel circuit 10 and performing read control for each pixel circuit 10, it is possible to reduce the number of read wires in a column unit.

[2. First Embodiment]
Next, the first embodiment of the present disclosure will be described. The first embodiment of the present disclosure makes it possible to suppress the output band rate-determining when outputting distance measurement data and other information (referred to as attribute data). More specifically, in the first embodiment, the frequency of output is different between the distance measurement data and the other information (attribute data). More specifically, when the distance measurement data is output at the first frequency, the attribute data is output at a second frequency lower than the first frequency.

(2-1. Existing technology)
First, in order to facilitate understanding, the output of distance measurement data and attribute data by the existing technology will be schematically described. Here, for each line, distance measurement data X by all the elements 11 included in the line is output from the distance measurement device 1 for each line, and four types of attribute data, attribute data p, q, r, and s, are measured. It is assumed that it is output from the distance device 1. Specific examples of attribute data will be described later.

FIG. 13 is a diagram for explaining an example of output processing by the existing technique. FIG. 13 is a diagram corresponding to FIG. 8 described above, and since the meaning of each part is the same as that of FIG. 8, the description thereof is omitted here. As shown in FIG. 13, in the existing technique, the plurality of attribute data p, q, r and s are output in synchronization with the distance measurement data X, respectively. In this method, five systems of data are output for each line, for example, the output band of the interface 106 is compressed. Therefore, even when the distance measuring process is executed at high speed, the processing speed as a whole becomes the output band rate-determining.

Further, the attribute data p, q, r and s may be output once for each of a plurality of distance measurements. According to the existing technology, in this case, each information output from the interface 106 is switched by communication with an external host device. FIG. 14 is a diagram for explaining an example in which the output of attribute data is switched by communication with the host device according to the existing technology. FIG. 14 is a diagram corresponding to FIG. 8 described above, and since the meaning of each part is the same as that of FIG. 8, the description thereof is omitted here. Further, in FIG. 14, the system of the ranging data X is omitted.

In the case of the example of FIG. 14, since it takes a predetermined time for the communication process with the host device, for example, the setting for switching between the output of the attribute data p and the output of the attribute data q has a sufficient time, for example. It needs to be executed between frames 351. Since it takes a long time for the output of the attribute data p to switch to the output of the next attribute data q, it may be difficult to output the information at an appropriate timing.

(2-2. Output processing according to the first embodiment)
Next, the output processing of the distance measurement data and the attribute data according to the first embodiment will be described. In the first embodiment, the output of a plurality of different attribute data is switched for each distance measurement, that is, in synchronization with the output timing of the distance measurement data.

FIG. 15 is a block diagram showing a configuration of an example of the distance measuring device according to the first embodiment. In FIG. 15, in the distance measuring device 1a according to the first embodiment, a setting unit 113, a set value storage unit 114, and an output control unit 140 are added to the distance measuring device 1 shown in FIG. 4 described above. There is.

Further, in FIG. 15, a temperature measuring unit 150 and an illuminance measuring unit 151 are shown as means for acquiring some of the attribute data. The temperature measuring unit 150 measures the temperature of the pixel array unit 100 and outputs temperature information. The illuminance measuring unit 151 measures the illuminance (brightness) outside the distance measuring device 1, that is, the illuminance of the ambient light, and outputs the illuminance value.

The set value storage unit 114 stores one or more distance measurement condition information used when the distance measurement device 1 executes distance measurement. The distance measurement condition information sets, for example, setting information including information indicating a unit time d when the generation unit 111 generates a histogram, a filter coefficient used by the signal processing unit 112 for filter processing, and a distance measurement pattern. Includes information to do. In addition, the set value storage unit 114 can further store information indicating the type of peak shape of the histogram data and output control information related to output control of distance measurement information. Each information stored in the set value storage unit 114 can be rewritten, for example, by the control of the overall control unit 103 according to the external control signal.

For example, the setting unit 113 reads out the distance measurement condition information from the set value storage unit 114 according to the control of the overall control unit 103, and sets parameters and the like for the generation unit 111 and the signal processing unit 112 based on the read distance measurement condition information. Do.

The output control unit 140 outputs the distance measurement data output from the signal processing unit 112 to the interface 106. At this time, the output control unit 140 can select and output the information specified by, for example, the setting unit 113, among the information included in the distance measurement data.

As described above, the output control unit 140 is supplied with distance measurement data from the signal processing unit 112. Further, the output control unit 140 supplies the temperature information output from the temperature measurement unit 150 and the illuminance information output from the illuminance measurement unit 151 as attribute data. Further, the output control unit 140 can acquire voltage value information indicating the voltage of the power supply supplied to the pixel array unit 100 from the pixel array unit 100 via a path (not shown) as attribute data. Furthermore, the output control unit 140 acquires, as attribute data, information (referred to as external output information) for output to the outside of the distance measuring device 1 among the information stored in the set value storage unit 114. Can be done.

The output control unit 140 controls the output of the distance measurement data and the attribute data to the interface 106. For example, the output control unit 140 controls the output timing of the distance measurement data and each information included in the attribute data based on the output control information stored in the set value storage unit 114. Further, the output control unit 140 can also control the output of the distance measurement data for each element 11 based on the output control information stored in the set value storage unit 114.

FIG. 16 is a diagram for explaining an output process in the ranging device 1a according to the first embodiment. Since the meaning of each part is the same as that of FIG. 8, the description thereof is omitted here. In FIG. 16, it is assumed that four types of attribute data p, q, r and s need to be output from the distance measuring device 1a from the distance measuring device 1a at least once in one frame period. In the example of FIG. 16, the output control unit 140 switches a plurality of attribute data p, q, r and s in a distance measurement unit (line unit). That is, the output control unit 140 outputs a plurality of attribute data p, q, r and s from the interface 106 for each type of data in a time division manner.

This will be described more specifically. In FIG. 16, for the sake of explanation, one frame includes eight lines, and distance measurement data X ₁ , X ₂ , ..., X ₈ are output in synchronization with each line according to the distance measurement in each line. To do. _{Distance measurement data X 1} and attribute data p are output according to the distance measurement of the first line (the left end of FIG. 16). _{Distance measurement data X 2} and attribute data q are output according to the distance measurement of the second line. Similarly, the distance measurement data X ₃ and the attribute data r are output according to the distance measurement of the third line, and the distance measurement data X ₄ and the attribute data s are output according to the distance measurement of the fourth line. ..

According to this, the data output in each line (distance measurement unit) becomes two systems, the distance measurement data and the attribute data of one system, and is compared with the example of the existing technology described with reference to FIG. , The pressure on the output band is suppressed.

The output control unit 140 switches the output of these attribute data p, q, r and s on / off for each distance measurement. For example, the output control unit 140 acquires each attribute data p, q, r and s at a predetermined timing, and stores the acquired attribute data p, q, r and s in a register provided in the output control unit 140, respectively. To do. The output control unit 140 switches a register for reading attribute data for each distance measurement (for each line). In this way, by switching the attribute data to be output among the plurality of attribute data inside the output control unit 140, faster output switching can be performed as compared with the example of the existing technique described with reference to, for example, FIG. realizable. Therefore, the distance measuring device 1a to which the first embodiment is applied can realize a higher speed distance measuring process.

(2-3. Example of information output from the distance measuring device)
Next, in the distance measuring device 1a according to the first embodiment, an example of the distance measuring data and the attribute data output by the output control unit 140 will be described.

First, an example of ranging data will be described with reference to FIGS. 17 and 18A to 18C. FIG. 17 is a diagram showing an example of a histogram based on the time when each element 11 (pixel circuit 10) receives a light. The histogram 50 shown in FIG. 17 is approximated by a curve, and the horizontal axis is time t.

In FIG. 17, for example, it is assumed that the _{left end is the time t 0} of the light emission timing by the light source unit 2. The light receiving timing is delayed toward the right, indicating that the light emitted by the light source unit 2 is reflected at a longer distance. That is, in FIG. 17, the distance D from the object to be measured increases toward the right.

In the example of FIG. 17, the time t _10, t ₁₁ and t _12, respectively histogram peak 51a, 51b and 51c are detected. _{The time t 10} , t ₁₁ and t _{12 at} which these peaks 51a, 51b and 51c are detected are referred to as peak positions, respectively. Further, the height obtained by subtracting the ambient light component shown in the range 311 as an offset in the histogram of FIG. 2 is called a peak intensity. Taking the peak 51a as an example, the time when the peak 51a starts is called the _{start position P st} , and the time when the peak 51a ends is called the end position P _ed. The start position P _st and the end position P _ed can be detected by, for example, differentiating the histogram 50 that approximates the curve.

The signal processing unit 112 acquires the above-mentioned peak position, peak intensity, start position P _st, and end position P _{ed based on the histogram generated by the generation unit 111.}

The signal processing unit 12 further acquires shape information indicating the shape of the peak of the histogram. 18A, 18B and 18C are diagrams schematically showing an example of the peak shape of the histogram. FIG. 18A shows an example in which one peak 51 is detected between a pair of start position P _st and end position P _{ed in the histogram 50.} The shape of the peak 51 is called a normal shape.

FIG. 18B shows an example in which two peaks 51d and 51e whose positions are close to each other are detected between the pair of start position P _st and end position P _{ed in the histogram 50.} In the case of FIG. 18B, since the distance between the peaks 51d and 51e is higher than the offset height of the histogram 50 by a predetermined value or more, it is considered that one peak is broken at the peaks 51d and 51e, and the two peaks 51d and 51e whose positions are close to each other are considered to be broken. The shape according to is called a peak crack shape.

Further, FIG. 18C shows an example in which the peak 51f is detected in the histogram 50 including a large number of peaks that are extremely close to each other and are continuous between the _{pair of start position P st} and end position P _ed. The shape of the peak 51f including a large number of peaks that are extremely close to each other and is continuous is called a peak continuous generation shape.

The signal processing unit 112 analyzes the histogram 50 supplied from the generation unit 111 to determine whether the shape of the peak included in the histogram 50 is a normal shape, a peak cracking shape, or a peak continuous generation shape. The shape information indicating the shape of the peak is associated with the peak information.

In the first embodiment, the output control unit 140 outputs any one of the following information (1) to (3) as distance measurement data for each element 11.

(1) All information of the histogram 50 In this case, the total information of the histogram 50 is information indicating the frequency in each bin of the histogram 50. The output control unit 140 receives all the information of the histogram 50 generated by the generation unit 111 from the signal processing unit 112 and outputs it as distance measurement data.

(2) Information on the histogram 50 around the peak The signal processing unit 112 analyzes the histogram 50 received from the generation unit 111 to obtain the start position P _st and the end position P _ed of the peak. When a plurality of peaks are detected in one histogram 50, the start position P _st and the end position P _ed are obtained for each of the plurality of peaks. The signal processing unit 112 outputs _{information indicating the start position P st} and the end position P _ed of these peaks and information indicating the frequency in each bin between the start position P _st and the end position P _ed. Pass to. The output control unit 140 outputs these information received from the signal processing unit 112 as distance measurement data.

(3) Peak Information The signal processing unit 112 analyzes the histogram 50 received from the generation unit 111, and analyzes the peak position, the start position P _st and the end position P _ed of the peak at the peak position, and the peak intensity of the peak. And shape information. When a plurality of peaks are detected in one histogram 50, the information is obtained for each of the plurality of peaks. The signal processing unit 112 passes each of these pieces of information to the output control unit 140. The output control unit 140 outputs these information received from the signal processing unit 112 as distance measurement data.

Of the above-mentioned (1) all information of the histogram 50, (2) information of the histogram 50 around the peak, and (3) peak information, the amount of information obtained by receiving the data and the amount of output data are respectively. (1)> (2)> (3). Further, (1) all the information of the histogram 50, and (2) the information of the histogram 50 around the peak can be created. Further, (3) peak information can be created from (2) the information of the histogram 50 around the peak. That is, the amount of information can be compressed and the amount of output data can be reduced from (1) to (2) and (2) to (3).

Next, an example of attribute data output from the ranging device 1 will be described. The attribute data includes (4) information related to the pixel (element 11), (5) information related to ambient light, (6) information related to calibration of the pixel array unit 100, and (7) information related to the pixel array unit 100. It can be roughly divided into information on parameters that affect operation.

(4) Information related to pixels Header information such as pixel identification information for identifying pixels, that is, elements 11. For example, information for identifying the element 11 to be scanned by the pixel array unit 100, that is, the element 11 to which the pixel signal is output in the distance measuring device 1a is passed from the overall control unit 103 to the distance measuring processing unit 101. In the distance measuring processing unit 101, for example, the conversion unit 110 converts the pixel signal supplied from the pixel array unit 100 into time information, and adds pixel identification information as header information to this time information. The function for adding pixel identification information is always on or always off.

(5) Information on ambient light The ambient light is measured by the illuminance measuring unit 151. More specifically, the output control unit 140 measures the external illuminance of the distance measuring device 1 measured from the illuminance measuring unit 151 during the period when the light source unit 2 does not emit the laser light during the distance measuring process. Measured as the illuminance of ambient light. The distance measuring device 1a outputs the disturbance light information indicating the measured illuminance of the disturbance light at a frequency of about once in a few line period or once in a few frame period. Further, it can be considered that the disturbance light information does not change in the adjacent pixels (element 11), and depending on the scene, it is also possible to output the disturbance light information due to the disturbance light measured immediately before.

(6) Information Related to Calibration The pixel array unit 100 performs calibration, for example, periodically in order to accurately measure the light receiving timing. As an example of calibration, correction of wiring delay of the pixel array unit 100 can be mentioned. For example, a reference pulse is input to one end of the line of the pixel array unit 100, and the delay amount at the other end is measured. The accuracy can be further improved by measuring the delay amount multiple times on different lines during one frame period. Information related to calibration (calibration information) is acquired and output at a frequency of, for example, about once every several line periods. The distance measuring device 1a acquires, for example, wiring delay correction information for light receiving element detection and sampling, which is obtained based on the measured delay amount, as calibration information.

(7) Information on parameters that affect the operation of the pixel array unit 100 The temperature of the pixel array unit 100 and the voltage of the power supply supplied to the pixel array unit 100 are parameters that affect the operation of the pixel array unit 100. The distance measuring device 1a measures the temperature by, for example, a temperature measuring unit 150 provided in close contact with the pixel array unit 100. Further, the distance measuring device 1a measures the voltage of the power supply supplied to the pixel array unit 100 by, for example, the overall control unit 103 or the pixel control unit 102. The temperature and voltage of the pixel array unit 100 by the distance measuring device 1a are output at a frequency of, for example, about once in one frame period. The information indicating these temperatures and voltages can be used, for example, as the calibration information for correcting the distance measurement data based on the pixel signal output from the pixel array unit 100 described above.

With respect to each of the above-mentioned attribute data, information indicating the attribute data to be output and information indicating the frequency of outputting the attribute data are stored in advance in, for example, the set value storage unit 114. Further, with respect to the distance measurement data, any of the above-mentioned (1) all information of the histogram 50, (2) information of the histogram 50 around the peak, and (3) peak information of the distance measurement data is stored in the set value storage unit 114. Information indicating whether to output can also be stored in advance.

The output control unit 140 acquires these information stored in the set value storage unit 114 via the setting unit 113, selects distance measurement data to be output according to the acquired information, and outputs timing of each attribute data. Control. Not limited to this, the output control unit 140 has a memory, and the distance measurement data to be output, the information indicating the attribute data to be output, and the information indicating the frequency of outputting the attribute data are stored in this memory in advance. You may leave it.

(2-4. Modification example)
Next, a modified example of the first embodiment will be described. In the modified example of the first embodiment, the output timing of the attribute data can be selected from a plurality of patterns. FIG. 19 is a diagram for explaining the output process in the ranging device 1a according to the modified example of the first embodiment. As shown in FIG. 19, with respect to the distance measurement data X output for each line period, the attribute data p, q, r and s are a plurality of attribute data p, q, r and s as shown as patterns (1) to (4). It is possible to output in a pattern.

In the example of FIG. 19, pattern (1) is a pattern in which each attribute data p, q, r and s are sequentially output for each line period. The pattern (2) is a pattern in which the attribute data p and q are alternately output for each line period. The pattern (3) is a pattern in which the attribute data p is output in one line, the attribute data q is output in a two-line period, and the attribute data r is output in a one-line period. Further, the pattern (4) is a pattern in which the attribute data p is output in a 3-line period, the attribute data q is output in a 4-line period, and the attribute data r is output in a 1-line period. Note that these patterns (1) to (4) are examples for explanation and are not limited thereto.

Of these patterns (1) to (4), information indicating a pattern used to output each attribute data p, q, r and s is stored in advance in, for example, the set value storage unit 114. The output control unit 140 acquires the information stored in the set value storage unit 114 via the setting unit 113, and stores the attribute data p, q, r and s according to the pattern shown in the acquired information. Select the register to read the attribute data from the register. As a result, the pressure on the output band is suppressed, and each attribute data p, q, r and s can be output at an appropriate timing.

[3. Second Embodiment]
Next, a second embodiment of the present disclosure will be described. The second embodiment of the present disclosure makes it possible to reduce the output ranging data. More specifically, in the second embodiment, when the first ranging data is output at the first frequency, the second ranging data is output at a second frequency lower than the first frequency. To do.

In the second embodiment, the configuration of the distance measuring device 1a according to the first embodiment described with reference to FIG. 15 can be applied as it is, and thus the description of the device configuration will be omitted.

FIG. 20 is a diagram for explaining the output processing of the ranging data according to the second embodiment. FIG. 20 is a diagram corresponding to FIG. 17 described above, and shows an example of a histogram 50 based on the time when each element 11 (pixel circuit 10) receives a light. In Figure 20, the time t _10, t ₁₁ and t _12, the peak 51a of each histogram 50, 51b and 51c are detected.

FIG. 21 is a diagram schematically showing an example of distance measurement processing by the entire pixel array unit 100. In FIG. 21, the area 340 corresponds to the frame in the pixel array unit 100. That is, FIG. 21 schematically shows the scene seen from the area 340. The ranging device 1a first horizontally scans the area 341a corresponding to the line at the lower end of the area 340, and when the scanning of the area 341a is completed, the horizontal scan is performed on each line included in the area 340. Switch vertically and repeat. When the scan of the area 341b, which is the uppermost line of the area 340, is completed, the scan of the area 340 is completed.

In the region 340, it is assumed that the target object 342 exists at a short distance and the target object 343 exists at a long distance. In this case, the target object 342 corresponds to, for example, the peak 51a in FIG. 20, and the target object 343 corresponds to, for example, the peak 51c in FIG.

Here, consider a predetermined distance D _th. In the example of FIG. 20, the distance D _th is longer than the distance corresponding to the time t ₁₀ and shorter than the distance corresponding to the times t ₁₁ and t ₁₂ . The distance data corresponding to a short distance (distance less than the distance D _th) with respect to the distance D _th, a first distance measurement data described above. On the other hand, long distance relative to the distance D _th (distance D _th or more distance), a second distance measurement data described above.

In the example of FIG. 20, the first ranging data _{includes the ranging data corresponding to the time t 10} , and the second ranging data includes the ranging data corresponding to the times t ₁₁ and t _12. Is included. The frequency of outputting the second ranging data is made lower than the frequency of outputting the first ranging data. That is, in general, there is less change in the scene at a long distance than at a short distance. Therefore, for example, define a distance D _th as the threshold value, the distance D is output by thinning the distance measurement data measured from a distance of the distance range for _th, the distance D _th output of the far distance measurement data to Suppress.

In the following, the distance _{measurement data measured from a long distance range with respect to the distance D th} is referred to as long distance region data, and the distance measurement data measured from a short distance range with respect to _{the distance D th is referred to as long distance area data.} It is called short-distance region data.

At this time, in the second embodiment, the thinning method is switched according to a predetermined pattern so that the distance measurement data of the thinned element 11 can be interpolated. For example, the output control unit 140 uses the element 11 at the odd-numbered position of the odd-numbered line and the even-numbered element 11 of the even-numbered line in the odd-numbered frame period (referred to as the frame (odd)). Do not output long-distance area data. Further, in the even-numbered frame period (referred to as an even), the output control unit 140 uses the element 11 at the even-numbered position of the even-numbered line and the odd-numbered element 11 of the even-numbered line. Do not output long-distance area data.

A more specific description will be given with reference to FIGS. 22A and 22B. In FIGS. 22A and 22B, for the sake of explanation, in the pixel array unit 100, the element 11 includes (5 × 4) pixel circuits 10 in the row and column directions, and the frame includes 5 lines. Shown. Further, each line is defined as the first line L # 1, the second line L # 2, the third line L # 3, ... From the lower end of the frame, and the arrangement in the direction perpendicular to the line of the element 11 is arranged in the first column (column). ) Col # 1, the second column Col # 2, the third column Col # 3, ... Further, among the elements 11, the shaded elements 11 output short-distance region data and long-distance region data.

FIG. 22A is a diagram showing an example of thinning out in odd-numbered frame periods (odd numbers) according to the second embodiment. In the odd-numbered lines 1st line L # 1 and 3rd line L # 3, in the element 11 of the odd-numbered columns Col # 1, Col # 3, ... (That is, the odd-numbered element 11 in the line) , Do not output long-distance area data. On the other hand, in the second line L # 2 and the fourth line L # 4, which are even-numbered lines, the elements 11 of the even-numbered columns Col # 2, Col # 4, ... (That is, the even-numbered elements 11 in the line). ), The long-distance region data is not output.

FIG. 22B is a diagram showing an example of thinning out in even-numbered frame periods (even) according to the second embodiment. In the first line L # 1 and the third line L # 3, which are odd-numbered lines, in the element 11 of the even-numbered columns Col # 2, Col # 4, ... (That is, the even-numbered element 11 in the line). , Do not output long-distance area data. On the other hand, in the second line L # 2 and the fourth line L # 4, which are even-numbered lines, the odd-numbered columns Col # 1, Col # 3, ... Element 11 (that is, the odd-numbered element 11 in the line) ), The long-distance region data is not output.

In this way, by setting the element 11 that does not output the long-distance region data in each frame period in advance, it is possible to reduce the distance-finding data output from the distance-measuring device 1a, and the distance-finding can be performed at a higher speed. Processing is feasible.

Further, by alternately switching the element 11 that does not output the long-distance region data for each frame period and each line, the long-distance region data in the element 11 is interpolated in the frame with respect to the element 11 that does not output the long-distance region data. It is possible to interpolate using the adjacent element 11 of the element 11 and the element 11 whose positions correspond to each other in a plurality of frame periods adjacent in time.

In the above description, the element 11 that does not output the long-distance region data based on _{the threshold distance D th is provided, but this is not limited to this example.} For example, an element 11 that outputs up to n long-distance region data and an element 11 that outputs up to (n / 2) pieces of long-distance region data may be provided based on _{the distance D th.} Further, based on the distance D _th , the element 11 that does not output the peak information whose peak intensity in the long-distance region data is equal to or less than a predetermined value may be provided.

[4. Third Embodiment]
Next, a third embodiment of the present disclosure will be described. The third embodiment of the present disclosure makes it possible to reduce the output ranging data. More specifically, in the third embodiment, the element 11 that suppresses the output of the long-distance region data is determined based on the condition determination.

FIG. 23 is a schematic diagram for explaining the output process according to the third embodiment. Note that FIG. 23 shows the same scene as FIG. 21 described above. In FIG. 23, it is assumed that in the scan of the region 341c as a line, the target object 342 is detected at a _{short distance, for example, a distance less than the above-mentioned threshold distance D th, at the elements 11a, 11b and 11c.} Further, in the scan of the region 341c, it is assumed that the target object 343 is _{detected at a long distance, for example, a distance D th} or more of the above-mentioned threshold value, in the elements 11d and 11e.

Here, considering the output band of the distance measurement data, it is assumed that N distance measurement data can be output for each line within a certain output band. That is, when the line includes m elements 11, the average number of distance measurement data output by each element 11 is N / m [elements]. In this case, the number of distance measurement data output by each element 11 is adjusted based on the distance of the target object detected for each element 11.

For example, in the area 341c of FIG. 23, it is assumed that each element 11 can output four peaks (distance measurement data). In this case, the elements 11a, 11b and 11c in which the short-distance target object 342 is detected can output six peaks, while the elements 11d and 11e in which the long-distance target object 343 is detected can output six peaks. Two peaks can be output. That is, while maintaining the number of peaks that can be output in the entire region 341c within a certain output band, the number of outputs of long-distance peaks is reduced and the number of outputs of short-distance peaks is increased.

In this way, by adjusting the number of distance measurement data to be output for each element 11 based on the distance measurement result, the distance measurement data is appropriately output while avoiding the output band rate-determining in the line including the element 11. It becomes possible. Further, as a result, the distance measuring device 1a to which the third embodiment is applied can realize a higher speed distance measuring process.

FIG. 24 is a flowchart of an example showing the output processing according to the third embodiment. The process according to the flowchart of FIG. 24 is executed for each element 11, for example. In step S100, the output control unit 140 determines whether or not the target object detected by the element 11 is a long-distance object based on the distance measurement data of the target element 11 supplied from the signal processing unit 112. To do. When the output control unit 140 determines that the object is a long-distance object (step S100, “Yes”), the output control unit 140 shifts the process to step S101.

In step S101, the output control unit 140 sets the number of output data of the element 11 to a predetermined minimum value, and shifts the process to step S120.

On the other hand, when the output control unit 140 determines that the target object detected in step S100 is a short-distance object (step S100, “No”), the output control unit 140 shifts the process to step S110. In step S110, the output control unit 140 calculates the peak value (maximum value) of the number of output data that can be output within the output band. In the next step S111, the output control unit 140 sets the peak value calculated in step S110 to the number of output data, and shifts the process to step S120.

In step S120, the output control unit 140 outputs distance measurement data according to the number of output data set in step S101 or step S111.

In the above description, the determination is made for the element 11 immediately after the distance measurement process is executed, but this is not limited to this example. For example, it is possible to determine the number of output data in the target element 11 based on the distance measurement result in the element 11 around the target element 11. Further, the target element 11 corresponds to the target element 11, for example, based on the distance measurement result of the element 11 in the immediately preceding frame or the distance measurement result of the elements 11 around the target element 11 in the immediately preceding frame. It is also possible to determine the number of output data in.

Further, in the above description, for the element 11 in which the target object is detected, the number of distance measurement data to be output is adjusted according to the distance to the target object, but this is not limited to this example. For example, for the element 11 in which only a long-distance target object is detected as a target object, distance measurement data is always output (for example, every line period), and other information (for example, attribute data) is thinned out, for example, in a period of several frames. It can also be output once. In this case, it is also possible to switch the element 11 that outputs other information in the odd-numbered and even-numbered frame periods or lines. At this time, it is preferable that the number of distance measurement data outputs per frame is constant.

[5. Fourth Embodiment]
Next, as a fourth embodiment, the first embodiment and its modification according to the present disclosure, and the application example of the distance measuring device 1a according to the second and third embodiments will be described. FIG. 25 is a diagram showing a first embodiment and a modification thereof, and a usage example using the distance measuring device 1a according to the second and third embodiments.

The distance measuring device 1a according to the first embodiment and its modifications described above and the second and third embodiments described above includes, for example, visible light, infrared light, ultraviolet light, X-rays, and the like as follows. It can be used in various cases to sense the light of.

-A device that captures images used for viewing, such as digital cameras and mobile devices with camera functions.
・ For safe driving such as automatic stop and recognition of the driver's condition, in-vehicle sensors that photograph the front, rear, surroundings, inside of the vehicle, etc., surveillance cameras that monitor traveling vehicles and roads, inter-vehicle distance, etc. A device used for traffic, such as a distance measuring sensor that measures the distance.
-A device used for home appliances such as TVs, refrigerators, and air conditioners in order to take a picture of a user's gesture and operate the device according to the gesture.
-Devices used for medical treatment and healthcare, such as endoscopes and devices that perform angiography by receiving infrared light.
-Devices used for security, such as surveillance cameras for crime prevention and cameras for personal authentication.
-Devices used for beauty, such as a skin measuring device that photographs the skin and a microscope that photographs the scalp.
-Devices used for sports, such as action cameras and wearable cameras for sports applications.
-Agricultural equipment such as cameras for monitoring the condition of fields and crops.

(5-1. A more specific example of mounting the ranging device of the present disclosure on a vehicle)
As an application example of the distance measuring device 1a according to the present disclosure, a more specific example in the case where the distance measuring device 1a is mounted on a vehicle and used will be described. FIG. 26 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a mobile control system to which the technique according to the present disclosure can be applied.

The vehicle control system 12000 includes a plurality of electronic control units connected via the communication network 12001. In the example shown in FIG. 26, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an outside information detection unit 12030, an in-vehicle information detection unit 12040, and an integrated control unit 12050. Further, as a functional configuration of the integrated control unit 12050, a microcomputer 12051, an audio image output unit 12052, and an in-vehicle network I / F (interface) 12053 are shown.

The drive system control unit 12010 controls the operation of the device related to the drive system of the vehicle according to various programs. For example, the drive system control unit 12010 provides a driving force generator for generating the driving force of the vehicle such as an internal combustion engine or a driving motor, a driving force transmission mechanism for transmitting the driving force to the wheels, and a steering angle of the vehicle. It functions as a control device such as a steering mechanism for adjusting and a braking device for generating a braking force of a vehicle.

The body system control unit 12020 controls the operation of various devices mounted on the vehicle body according to various programs. For example, the body system control unit 12020 functions as a keyless entry system, a smart key system, a power window device, or a control device for various lamps such as headlamps, back lamps, brake lamps, blinkers or fog lamps. In this case, the body system control unit 12020 may be input with radio waves transmitted from a portable device that substitutes for the key or signals of various switches. The body system control unit 12020 receives inputs of these radio waves or signals and controls a vehicle door lock device, a power window device, a lamp, and the like.

The vehicle exterior information detection unit 12030 detects information outside the vehicle equipped with the vehicle control system 12000. For example, the image pickup unit 12031 is connected to the vehicle exterior information detection unit 12030. The vehicle outside information detection unit 12030 causes the image pickup unit 12031 to capture an image of the outside of the vehicle and receives the captured image. The vehicle exterior information detection unit 12030 may perform object detection processing or distance detection processing such as a person, a vehicle, an obstacle, a sign, or characters on the road surface based on the received image.

The imaging unit 12031 is an optical sensor that receives light and outputs an electric signal according to the amount of the light received. The image pickup unit 12031 can output an electric signal as an image or can output it as distance measurement information. Further, the light received by the imaging unit 12031 may be visible light or invisible light such as infrared light.

The in-vehicle information detection unit 12040 detects information in the vehicle. For example, a driver state detection unit 12041 that detects the driver's state is connected to the in-vehicle information detection unit 12040. The driver state detection unit 12041 includes, for example, a camera that images the driver, and the in-vehicle information detection unit 12040 determines the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 12041. It may be calculated, or it may be determined whether the driver is dozing.

The microcomputer 12051 calculates the control target value of the driving force generator, the steering mechanism, or the braking device based on the information inside and outside the vehicle acquired by the vehicle exterior information detection unit 12030 or the vehicle interior information detection unit 12040, and the drive system control unit. A control command can be output to 12010. For example, the microcomputer 12051 realizes ADAS (Advanced Driver Assistance System) functions including vehicle collision avoidance or impact mitigation, follow-up driving based on inter-vehicle distance, vehicle speed maintenance driving, vehicle collision warning, vehicle lane deviation warning, and the like. It is possible to perform cooperative control for the purpose of.

Further, the microcomputer 12051 controls the driving force generator, the steering mechanism, the braking device, and the like based on the information around the vehicle acquired by the vehicle exterior information detection unit 12030 or the vehicle interior information detection unit 12040, so that the driver can control the driver. It is possible to perform coordinated control for the purpose of automatic driving, etc., which runs autonomously without depending on the operation.

Further, the microcomputer 12051 can output a control command to the body system control unit 12020 based on the information outside the vehicle acquired by the vehicle exterior information detection unit 12030. For example, the microcomputer 12051 controls the headlamps according to the position of the preceding vehicle or the oncoming vehicle detected by the external information detection unit 12030, and performs coordinated control for the purpose of anti-glare such as switching the high beam to the low beam. It can be carried out.

The audio-image output unit 12052 transmits an output signal of at least one of audio and an image to an output device capable of visually or audibly notifying the passenger of the vehicle or the outside of the vehicle. In the example of FIG. 26, an audio speaker 12061, a display unit 12062, and an instrument panel 12063 are exemplified as output devices. The display unit 12062 may include, for example, at least one of an onboard display and a heads-up display.

FIG. 27 is a diagram showing an example of the installation position of the imaging unit 12031. In FIG. 27, the vehicle 12100 has image pickup units 12101, 12102, 12103, 12104, 12105 as the image pickup unit 12031.

The imaging units 12101, 12102, 12103, 12104, 12105 are provided at positions such as, for example, the front nose, side mirrors, rear bumpers, back doors, and the upper part of the windshield in the vehicle interior of the vehicle 12100. The imaging unit 12101 provided on the front nose and the imaging unit 12105 provided on the upper part of the windshield in the vehicle interior mainly acquire an image in front of the vehicle 12100. The imaging units 12102 and 12103 provided in the side mirrors mainly acquire images of the side of the vehicle 12100. The imaging unit 12104 provided on the rear bumper or the back door mainly acquires an image of the rear of the vehicle 12100. The images in front acquired by the imaging units 12101 and 12105 are mainly used for detecting a preceding vehicle or a pedestrian, an obstacle, a traffic light, a traffic sign, a lane, or the like.

Note that FIG. 25 shows an example of the photographing range of the imaging units 12101 to 12104. The imaging range 12111 indicates the imaging range of the imaging unit 12101 provided on the front nose, the imaging ranges 12112 and 12113 indicate the imaging ranges of the imaging units 12102 and 12103 provided on the side mirrors, respectively, and the imaging range 12114 indicates the imaging range of the imaging units 12102 and 12103. The imaging range of the imaging unit 12104 provided on the rear bumper or the back door is shown. For example, by superimposing the image data captured by the imaging units 12101 to 12104, a bird's-eye view image of the vehicle 12100 as viewed from above can be obtained.

At least one of the imaging units 12101 to 12104 may have a function of acquiring distance information. For example, at least one of the image pickup units 12101 to 12104 may be a stereo camera composed of a plurality of image pickup elements, or may be an image pickup element having pixels for phase difference detection.

For example, the microcomputer 12051 has a distance to each three-dimensional object within the imaging range 12111 to 12114 based on the distance information obtained from the imaging units 12101 to 12104, and a temporal change of this distance (relative velocity with respect to the vehicle 12100). By obtaining, it is possible to extract as the preceding vehicle a three-dimensional object that is the closest three-dimensional object on the traveling path of the vehicle 12100 and that travels in substantially the same direction as the vehicle 12100 at a predetermined speed (for example, 0 km / h or more). it can. Further, the microprocessor 12051 can set an inter-vehicle distance to be secured in front of the preceding vehicle in advance, and can perform automatic braking control (including follow-up stop control), automatic acceleration control (including follow-up start control), and the like. In this way, it is possible to perform coordinated control for the purpose of automatic driving or the like in which the vehicle runs autonomously without depending on the operation of the driver.

For example, the microcomputer 12051 converts three-dimensional object data related to a three-dimensional object into two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects based on the distance information obtained from the imaging units 12101 to 12104. It can be classified and extracted and used for automatic avoidance of obstacles. For example, the microprocessor 12051 identifies obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. Then, the microcomputer 12051 determines the collision risk indicating the risk of collision with each obstacle, and when the collision risk is equal to or higher than the set value and there is a possibility of collision, the microcomputer 12051 via the audio speaker 12061 or the display unit 12062. By outputting an alarm to the driver and performing forced deceleration and avoidance steering via the drive system control unit 12010, driving support for collision avoidance can be provided.

At least one of the imaging units 12101 to 12104 may be an infrared camera that detects infrared rays. For example, the microcomputer 12051 can recognize a pedestrian by determining whether or not a pedestrian is present in the captured image of the imaging units 12101 to 12104. Such pedestrian recognition includes, for example, a procedure for extracting feature points in an image captured by an imaging unit 12101 to 12104 as an infrared camera, and pattern matching processing for a series of feature points indicating the outline of an object to determine whether or not the pedestrian is a pedestrian. It is done by the procedure to determine. When the microcomputer 12051 determines that a pedestrian is present in the captured images of the imaging units 12101 to 12104 and recognizes the pedestrian, the audio image output unit 12052 outputs a square contour line for emphasizing the recognized pedestrian. The display unit 12062 is controlled so as to superimpose and display. Further, the audio image output unit 12052 may control the display unit 12062 so as to display an icon or the like indicating a pedestrian at a desired position.

The example of the vehicle control system to which the technique according to the present disclosure can be applied has been described above. The technique according to the present disclosure can be applied to, for example, the imaging unit 12031 among the configurations described above. Specifically, as the image pickup unit 12031, the first embodiment of the present disclosure and its modifications, and the distance measuring device 1a according to the second and third embodiments can be applied to the image pickup unit 12031. By applying the technique according to the present disclosure to the imaging unit 12031, it is possible to perform distance measurement at a higher speed, and it is possible to perform distance measurement from a traveling vehicle with higher accuracy.

It should be noted that the effects described in the present specification are merely examples and are not limited, and other effects may be obtained.

The present technology can also have the following configurations.
(1)
A light receiving part including a light receiving element and a light receiving part
A time measuring unit that measures the time from the light emitting timing when the light source emits light to the light receiving timing when the light receiving element receives light and acquires the measured value.
A generator that generates a histogram of the measured values and
An output unit that outputs data indicating the distance to the object to be measured based on the histogram, and an output unit.
An output control unit that controls the data to be output to the output unit,
With
The output control unit
Of the data indicating the distance, the data indicating the first distance is output to the output unit at the first frequency, and the data indicating the second distance is output to the output unit at the second frequency.
Distance measuring device.
(2)
The first distance is a distance included in the first distance range.
The second distance is a distance included in a second distance range that is farther than the first distance range.
The output control unit
The data indicating the second distance is output to the output unit at the second frequency lower than the first frequency.
The distance measuring device according to (1) above.
(3)
The time measuring unit
The measured value is acquired for each pixel including one or more light receiving elements, and the measured value is acquired.
The output control unit
The data indicating the first distance and the data indicating the second distance are switched for each pixel and output to the output unit.
The distance measuring device according to (1) or (2) above.
(4)
The output control unit
The data indicating the first distance to be output to the output unit and the data indicating the second distance are switched according to a predetermined pattern.
The distance measuring device according to any one of (1) to (3) above.
(5)
The light receiving elements included in the light receiving unit are arranged in a matrix-like arrangement.
The output control unit
The pattern for outputting the data indicating the first distance and the data indicating the second distance is switched for each frame period.
The distance measuring device according to (4) above.
(6)
The output control unit
Based on the measured value, it is determined whether the data indicating the distance for each pixel is output to the output unit at the first frequency or the second frequency.
The distance measuring device according to (3) above.
(7)
The output control unit
Based on the measured values of the pixels around the target pixel among the pixels, data indicating the distance of the target pixel is output to the output unit at either the first frequency or the second frequency. Determine if you want to
The distance measuring device according to (3) above.
(8)
The light receiving elements included in the light receiving unit are arranged in a matrix-like arrangement.
The output control unit
All the effective light receiving signals included in the array, which were measured immediately before, as to whether the data indicating the distance for each pixel is output to the output unit at the first frequency or the second frequency. Judgment is made based on the measured value of the frame including the element.
The distance measuring device according to (3) above.
(9)
The output control unit
The data indicating the first distance and the data different from the data indicating the second distance are further output by the output unit at a third frequency lower than the first frequency.
The distance measuring device according to any one of (1) to (8).
(10)
The different data
It includes one or more light receiving elements, and includes identification information for identifying a pixel, which is a unit for the time measuring unit to acquire the measured value.
The distance measuring device according to (9) above.
(11)
An illuminance measuring unit for measuring the illuminance outside the distance measuring device is further provided.
The different data
Includes information indicating the illuminance measured by the illuminance measuring unit.
The distance measuring device according to (9) or (10) above.
(12)
The different data
Includes calibration information to correct the measurements.
The distance measuring device according to any one of (9) to (11).
(13)
The calibration information is
Including information on wiring delay in the light receiving unit,
The distance measuring device according to (12) above.
(14)
A thermometer side portion for measuring the temperature of the light receiving portion is further provided.
The calibration information is
Contains information indicating the temperature measured by the thermometer side.
The distance measuring device according to (12) or (13).
(15)
The calibration information is
Includes information indicating the voltage of the power supply supplied to the light receiving unit.
The distance measuring device according to any one of (12) to (14).
(16)
A light receiving part including a light receiving element and a light receiving part
A time measuring unit that measures the time from the light emitting timing when the light source emits light to the light receiving timing when the light receiving element receives light and acquires the measured value.
A generator that generates a histogram of the measured values and
An output unit that outputs data indicating the distance to the object to be measured based on the histogram, and an output unit.
An output control unit that controls the output unit and
With
The output control unit
The output unit is controlled so that the data indicating the distance is output at the first frequency and the data different from the data indicating the distance is output at the second frequency.
Distance measuring device.
(17)
The output control unit
The different data is output to the output unit at the second frequency lower than the first frequency.
The distance measuring device according to (16) above.
(18)
The output control unit
The different data is output to the output unit in a time-division manner for each type of the different data.
The distance measuring device according to (16) or (17).
(19)
The output control unit
The output unit outputs the different data at a timing based on a predetermined pattern.
The distance measuring device according to any one of (16) to (18).
(20)
The time measuring unit
The measured value is acquired for each pixel including one or more light receiving elements, and the measured value is acquired.
The different data
Includes identification information that identifies the pixel
The distance measuring device according to any one of (16) to (19).
(21)
An illuminance measuring unit for measuring the illuminance outside the distance measuring device is further provided.
The different data
Includes information indicating the illuminance measured by the illuminance measuring unit.
The distance measuring device according to any one of (16) to (20).
(22)
The different data
Includes calibration information to correct the measurements.
The distance measuring device according to any one of (16) to (21).
(23)
The calibration information is
Including information on wiring delay in the light receiving unit,
The distance measuring device according to (22) above.
(24)
A thermometer side portion for measuring the temperature of the light receiving portion is further provided.
The calibration information is
Contains information indicating the temperature measured by the thermometer side.
The distance measuring device according to (22) or (23).
(25)
The calibration information is
Includes information indicating the voltage of the power supply supplied to the light receiving unit.
The distance measuring device according to any one of (22) to (24).
(26)
The output control unit
Data indicating a distance different from the data indicating the distance is output to the output unit at a third frequency lower than the first frequency.
The distance measuring device according to any one of (16) to (25).
(27)
The distance is a distance included in the first distance range.
The other distance is a distance included in a second distance range that is farther than the first distance range.
The distance measuring device according to (26) above.

1,1a, 300 Distance measuring device 10 pixel circuit 11, 11a, 11b, 11c, 11d, 11e Element 50 Histogram 51a, 51b, 51c, 51d, 51e, 51f Peak 100 pixel Array unit 101 Distance measurement processing unit 102 pixel control unit 103 Overall control unit 104 Clock generation unit 105 Light emission timing control unit 106 Interface 111 Generation unit 112 Signal processing unit 113 Setting unit 114 Setting value storage unit 140 Output control unit 150 Temperature measurement unit 151 Illumination measurement unit 340, 341a, 341b, 341c area 342,343 Target object

Claims (27)

A light receiving part including a light receiving element and a light receiving part
A time measuring unit that measures the time from the light emitting timing when the light source emits light to the light receiving timing when the light receiving element receives light and acquires the measured value.
A generator that generates a histogram of the measured values and
An output unit that outputs data indicating the distance to the object to be measured based on the histogram, and an output unit.
An output control unit that controls the data to be output to the output unit,
With
The output control unit
Of the data indicating the distance, the data indicating the first distance is output to the output unit at the first frequency, and the data indicating the second distance is output to the output unit at the second frequency.
Distance measuring device. The first distance is a distance included in the first distance range.
The second distance is a distance included in a second distance range that is farther than the first distance range.
The output control unit
The data indicating the second distance is output to the output unit at the second frequency lower than the first frequency.
The ranging device according to claim 1. The time measuring unit
The measured value is acquired for each pixel including one or more light receiving elements, and the measured value is acquired.
The output control unit
The data indicating the first distance and the data indicating the second distance are switched for each pixel and output to the output unit.
The ranging device according to claim 1. The output control unit
The data indicating the first distance to be output to the output unit and the data indicating the second distance are switched according to a predetermined pattern.
The ranging device according to claim 1. The light receiving elements included in the light receiving unit are arranged in a matrix-like arrangement.
The output control unit
The pattern for outputting the data indicating the first distance and the data indicating the second distance is switched for each frame period.
The distance measuring device according to claim 4. The output control unit
Based on the measured value, it is determined whether the data indicating the distance for each pixel is output to the output unit at the first frequency or the second frequency.
The distance measuring device according to claim 3. The output control unit
Based on the measured values of the pixels around the target pixel among the pixels, data indicating the distance of the target pixel is output to the output unit at either the first frequency or the second frequency. Determine if you want to
The distance measuring device according to claim 3. The light receiving elements included in the light receiving unit are arranged in a matrix-like arrangement.
The output control unit
All the effective light receiving signals included in the array, which were measured immediately before, as to whether the data indicating the distance for each pixel is output to the output unit at the first frequency or the second frequency. Judgment is made based on the measured value of the frame including the element.
The distance measuring device according to claim 3. The output control unit
The data indicating the first distance and the data different from the data indicating the second distance are further output by the output unit at a third frequency lower than the first frequency.
The ranging device according to claim 1. The different data
It includes one or more light receiving elements, and includes identification information for identifying a pixel, which is a unit for the time measuring unit to acquire the measured value.
The distance measuring device according to claim 9. An illuminance measuring unit for measuring the illuminance outside the distance measuring device is further provided.
The different data
Includes information indicating the illuminance measured by the illuminance measuring unit.
The distance measuring device according to claim 9. The different data
Includes calibration information to correct the measurements.
The distance measuring device according to claim 9. The calibration information is
Including information on wiring delay in the light receiving unit,
The distance measuring device according to claim 12. A thermometer side portion for measuring the temperature of the light receiving portion is further provided.
The calibration information is
Contains information indicating the temperature measured by the thermometer side.
The distance measuring device according to claim 12. The calibration information is
Includes information indicating the voltage of the power supply supplied to the light receiving unit.
The distance measuring device according to claim 12. A light receiving part including a light receiving element and a light receiving part
A time measuring unit that measures the time from the light emitting timing when the light source emits light to the light receiving timing when the light receiving element receives light and acquires the measured value.
A generator that generates a histogram of the measured values and
An output unit that outputs data indicating the distance to the object to be measured based on the histogram, and an output unit.
An output control unit that controls the output unit and
With
The output control unit
The output unit is controlled so that the data indicating the distance is output at the first frequency and the data different from the data indicating the distance is output at the second frequency.
Distance measuring device. The output control unit
The different data is output to the output unit at the second frequency lower than the first frequency.
The distance measuring device according to claim 16. The output control unit
The different data is output to the output unit in a time-division manner for each type of the different data.
The distance measuring device according to claim 16. The output control unit
The output unit outputs the different data at a timing based on a predetermined pattern.
The distance measuring device according to claim 16. The time measuring unit
The measured value is acquired for each pixel including one or more light receiving elements, and the measured value is acquired.
The different data
Includes identification information that identifies the pixel
The distance measuring device according to claim 16. An illuminance measuring unit for measuring the illuminance outside the distance measuring device is further provided.
The different data
Includes information indicating the illuminance measured by the illuminance measuring unit.
The distance measuring device according to claim 16. The different data
Includes calibration information to correct the measurements.
The distance measuring device according to claim 16. The calibration information is
Including information on wiring delay in the light receiving unit,
The distance measuring device according to claim 22. A thermometer side portion for measuring the temperature of the light receiving portion is further provided.
The calibration information is
Contains information indicating the temperature measured by the thermometer side.
The distance measuring device according to claim 22. The calibration information is
Includes information indicating the voltage of the power supply supplied to the light receiving unit.
The distance measuring device according to claim 22. The output control unit
Data indicating a distance different from the data indicating the distance is output to the output unit at a third frequency lower than the first frequency.
The distance measuring device according to claim 16. The distance is a distance included in the first distance range.
The other distance is a distance included in a second distance range that is farther than the first distance range.
The distance measuring device according to claim 26.

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