JP2021139836A - Distance measuring sensor and method for measuring distance - Google Patents

Abstract

To provide a distance measuring sensor that can consume less power and has a higher resolution at the same time, and can ease a data output band rate controlling.SOLUTION: The distance measuring device includes: a light receiving unit having a plurality of pixels arranged in a matrix and each having a light receiving element for converting a light reflected from a received target region to an electric signal; a distance measuring unit for performing signal processing on the basis of an electric signal output on a pixel-by-pixel basis and calculating the distance to the target region, the distance measuring unit having a plurality of signal processing modules capable of controlling power supply separately; and a control unit for executing power supply control of a plurality of signal processing modules according to an input signal.SELECTED DRAWING: Figure 2

Description

The technology according to the present disclosure (the present technology) relates to a distance measuring sensor and a distance measuring method.

As a Time of Flight (ToF) method that measures the distance to an object (object) based on the light flight time, the direct ToF (dToF) that measures the distance from the light flight time that is directly measured using a pulse wave. ) Method distance measurement sensor and indirect ToF (iToF) type distance measurement sensor that measures the distance from the optical flight time indirectly calculated by using the phase of the modulated light are known.

By the way, in the above-mentioned dToF type ranging sensor, since the light receiving element receives the reflected light (photons) for the emission of a single pulsed light and the light receiving element detects the reflected light, the distance to the object and the ambient light (turbulent light). ), It is a probabilistic event whether or not photons arrive. Therefore, the distance measuring sensor using the light receiving element improves the distance measuring accuracy by creating a histogram in which the reactions of the light receiving element due to a plurality of times of light emission within a predetermined unit time are accumulated for each time. Such a distance measuring sensor can obtain an imaging frame (distance image) having distance information for each pixel in real time by reading out photons for each pixel array arranged in a line.

A distance measuring sensor that can select a light receiving element that forms a light receiving region used for photon measurement from a plurality of light receiving elements in order to improve distance measurement accuracy even in an environment where there is a lot of ambient light and fluctuates. Has also been proposed (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2018-44923

By the way, even in the above-mentioned ranging sensor, it is strongly desired to increase the resolution. As the resolution increases, the amount of data read at one time increases.

Further, in order to process data within the time (short time) for distance measurement, the circuit scale and power consumption are increased because parallel processing of logic circuits is required.

Furthermore, the output band of data increases, and the distance measurement interval becomes longer due to the output band rate-determining.

The present disclosure has been made in view of such circumstances, and provides a distance measuring sensor and a distance measuring method capable of reducing power consumption and relaxing the rate-determining of the data output band even if the resolution is increased. The purpose.

One aspect of the present disclosure is a light receiving unit arranged in a matrix and having a plurality of pixels each having a light receiving element that converts the reflected light from the received target region into an electric signal, and an electric signal output for each of the pixels. The distance measuring unit having a plurality of signal processing modules capable of performing signal processing based on the above, calculating the distance to the target area, and independently controlling the power supply, and the plurality of signals according to the input signal It is a distance measuring sensor including a control unit that executes power supply control of the processing module.

Another aspect of the present disclosure is to receive the reflected light from the target region by a light receiving unit including a plurality of pixels arranged in a matrix and each having a light receiving element, convert it into an electric signal, and output the plurality of light signals. In an image pickup frame formed by pixels, performing distance measurement processing for calculating the distance to a region of interest in the image pickup frame based on the electric signal output for each pixel by the distance measurement processing unit. To output data related to the distance for each pixel with respect to the imaging frame, to control off the power supply unit belonging to a region other than the region of interest based on the determination result of the region of interest, and to control the region of interest to be off. It is a distance measuring method including performing at least one of controlling the distance measuring processing unit so as to input the electric signal corresponding to.

It is a block diagram which shows an example of the structure of the distance measuring apparatus in 1st Embodiment of this technique. It is a block diagram which shows an example of the structure of the light receiving part in the 1st Embodiment of this technique. It is a flowchart for demonstrating the distance measurement processing method by the distance measuring apparatus in 1st Embodiment of this technique. It is a figure for demonstrating the distance measurement processing during the formation of the image pickup frame by the distance measuring apparatus in the 1st Embodiment of this technique. FIG. 5 is a block diagram showing an example of a case where the number of sampling circuits is reduced in order to output data only in the ROI region in the first embodiment of the present technology. It is a block diagram which shows an example of the case where the sampling circuit is switched in order to output the data of the whole area in the 1st Embodiment of this technique. Following FIG. 6, it is a block diagram showing an example in the case of switching the sampling circuit in order to output the data of the entire region in the first embodiment of the present technology. It is a block diagram which shows an example of the case where the power of the pixel other than the ROI region is turned off in the second embodiment of this technique. It is a block diagram which shows an example in the case of reducing the number of histogram generation circuits in the 3rd Embodiment of this technique. FIG. 5 is a block diagram showing an example of a case where regions that do not overlap in the scanning direction are simultaneously read out in a fourth embodiment of the present technology. FIG. 5 is a block diagram showing an example in which the light receiving unit is an array type and the output terminals of a plurality of light receiving elements are shared for each pixel in the fourth embodiment of the present technology. It is a block diagram which shows an example of the case where the power of the sampling circuit and the histogram generation circuit belonging to the region other than the ROI region in the fifth embodiment of this technique is turned off. FIG. 5 is a block diagram showing an example of a case where the ROI region is assigned to the sampling circuit and the histogram generation circuit according to the angle of view in the sixth embodiment of the present technology. FIG. 5 is a block diagram showing another example in the case of allocating a region other than the ROI region to the sampling circuit and the histogram generation circuit according to the angle of view in the sixth embodiment of the present technology. It is a figure which shows an example of the case where the pixel is processed by the sampling circuit and the histogram generation circuit on the surface in the three-layer structure in the seventh embodiment of this technique. It is a figure which shows an example of the case where the pixel is processed by the sampling circuit and the histogram generation circuit on the surface in the two-layer structure in the seventh embodiment of this technique. It is a figure which shows an example of the case of outputting one region at a time in the eighth embodiment of this technique. In the ninth embodiment of the present technology, it is a figure which shows an example which narrows down the area to which light is applied to the ROI area when the distance is measured in line units. In the ninth embodiment of the present technology, it is a figure which shows an example of the case where the area to which light is applied is divided into a plurality of areas, and the area is narrowed down to the divided area at the time of measuring the distance in line units. It is a figure which shows an example of the case of outputting one region at a time in the tenth embodiment of this technique. It is a figure which shows for demonstrating an example of the case where the communication interface part in 10th Embodiment of this technique reads a distance measurement data. It is a figure which shows for demonstrating another example of the case where the communication interface part in 10th Embodiment of this technique reads a distance measurement data. It is a block diagram which shows an example of the structure of the distance measuring apparatus in eleventh embodiment of this technique. It is a block diagram which shows an example of the structure of the distance measuring apparatus in the twelfth embodiment of this technique. It is a block diagram which shows an example of the structure of the light receiving part in the twelfth embodiment of this technique. It is a block diagram which shows an example of the case where the number of AD conversion part is reduced in order to output data only in a ROI area in the twelfth embodiment of this technique. It is a figure which shows an example of the case where V scan (designation of a read line) can be performed for each area in the thirteenth embodiment of this technique. It is a figure which shows an example of the case where the pixel is connected to a pixel by a pixel drive line for each line in the past. In the thirteenth embodiment of the present technology, it is a figure which shows an example of the case where it is divided into the regions in one line, and each region is connected by a different pixel drive line. It is a figure which shows an example which the ROI area is divided into three frames in 14th Embodiment of this technique. FIG. 5 is a diagram showing an example in which each of the three frames of the ROI region is connected by different vertical signal lines in the fourteenth embodiment of the present technology. It is a figure which shows an example of the case of outputting one area at a time in the fifteenth embodiment of this technique. It is a figure which shows in order to explain an example of the case where the communication interface part reads out the distance measurement data in the fifteenth embodiment of this technique. It is a figure which shows for demonstrating another example of the case where the communication interface part reads out the distance measurement data in the fifteenth embodiment of this technique. It is a block diagram which shows an example of the structure of the distance measuring apparatus in the 16th Embodiment of this technique.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the description of the drawings referred to in the following description, the same or similar parts are designated by the same or similar reference numerals, and duplicate description will be omitted. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the plane dimensions, the ratio of the thickness of each device and each member, etc. are different from the actual ones. Therefore, the specific thickness and dimensions should be determined in consideration of the following explanation. In addition, it goes without saying that the drawings include parts having different dimensional relationships and ratios from each other.

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.

<First Embodiment>
<Structure of distance measuring device>
FIG. 1 is a block diagram showing an example of the configuration of the distance measuring device 1A according to the first embodiment of the present technology. The distance measuring device 1A emits pulsed light from a light emitting element and receives reflected light from an object OBJ (object or subject) irradiated with the pulsed light by a light receiving element, based on an electric signal obtained by the object OBJ. It is a distance measuring sensor that measures the distance to.

As shown in the figure, the distance measuring device 1A includes, for example, components such as a system control unit 10, a light emitting unit 20, a light emitting timing adjusting unit 30, a light receiving unit 40, and a distance measuring processing unit 50. These components can be integrally configured as, for example, a system-on-chip (SoC) such as a CMOS LSI, but for example, some components such as the light emitting unit 20 and the light receiving unit 40 are configured as separate LSIs. May be done. The distance measuring device 1A operates according to an operating clock (not shown). Further, the distance measuring device 1A includes a communication interface unit 60 for outputting data (distance measuring data) related to the distance calculated by the distance measuring processing unit 50 to the outside. Although not shown, the distance measuring device 1A is configured to be able to communicate with a host IC arranged outside via the communication interface unit 60.

The system control unit 10 is a component that comprehensively controls the operation of the distance measuring device 1A. Typically, the system control unit 10 is configured to include a microprocessor.

The light emitting unit 20 emits pulsed light such as infrared light (IR) toward the target area. The light emitting timing adjusting unit 30 is a circuit for adjusting the light emitting timing of the light emitting unit 20. For example, the light emitting timing adjusting unit 30 outputs a trigger pulse so as to synchronize with the reading timing for each line from the light receiving unit 40, which will be described later, and drives the light emitting unit 20.

The light receiving unit 40 is a sensor that outputs an electric signal in response to light incident from the target area. The incident light includes the reflected light from the object OBJ. In the present disclosure, the light receiving unit 40 is a CMOS image sensor composed of a plurality of pixels including a plurality of light receiving elements arranged in a two-dimensional matrix. In the present disclosure, for example, under the control of the system control unit 10, a specific pixel group (for example, a pixel group in the one-line direction in the imaging frame) is activated, whereby an electric signal is read out. Further, the pixel groups of each line are sequentially activated in one frame time, and one imaging frame for the target area is formed by the electric signals output from each of the activated pixel groups.

The distance measuring processing unit 50 is a component that calculates the distance to the object OBJ based on the pulsed light emitted by the light emitting unit 20 and the reflected light received by the light receiving unit 40. The ranging processing unit 50 is typically configured by a signal processing processor. In the present disclosure, the distance measuring processing unit 50 includes a sampling circuit 51, a histogram generation circuit 52, and a distance calculation circuit 53.

The sampling circuit 51 is a component that samples an electric signal output from a specific pixel group at a predetermined sampling frequency in response to the emission of pulsed light. The sampling circuit 51 outputs a High or Low value (sampling value) according to the value of the electric signal output from each of the activated pixel groups, for example.

The histogram generation circuit 52 is a component that generates a histogram showing the intensity of reflected light for each time based on the total value of the sampling values for each sampling time output by the sampling circuit 51. The histogram is stored, for example, in a memory (not shown) as a kind of data structure or table. Histograms are generated in the number corresponding to the number of pixels based on the pulsed light emitted for each readout line in the imaging frame. The histogram generated by the histogram generation circuit 52 is referred to by the distance calculation circuit 53.

The distance calculation circuit 53 is a component that refers to the generated histogram, detects the peak value in the histogram, and calculates the distance from the time corresponding to the peak value (that is, the arrival time). That is, if the reflected light when the emitted pulsed light irradiates the object OBJ is received, the time is the round-trip time to the object OBJ, so this is multiplied by c / 2 (c is the speed of light). By doing so, the distance to the object OBJ can be calculated for each pixel. Therefore, a distance image can be obtained from the distances calculated for all the pixels constituting the imaging frame. The distance calculation circuit 53 sequentially outputs data (distance measurement data) related to the distance calculated for each pixel in each imaging frame to the communication interface unit 60 and the interest (ROI (Region of Interest)) region determination unit 80.

The communication interface unit 60 is an interface circuit for outputting the calculated distance measurement data to an external host IC. For example, the communication interface unit 60 is an interface circuit compliant with MIPI (Mobile Industry Processor Interface), but is not limited to this. For example, SPI (Serial Peripheral Interface), LVDS, SLVS-EC, or the like may be used, or some of these interface circuits may be implemented.

The ROI area determination unit 80 determines, for example, the ROI area including the object OBJ based on the calculated distance measurement data. This determination result is output to the system control unit 10. The system control unit 10 is provided with pixels in the distance measuring processing unit 50 and the light receiving unit 40 so as to process an electric signal from the pixels corresponding to the ROI region based on the determination result of the ROI region by the ROI region determining unit 80. Controls the drive unit 70.

<Structure of light receiving part>
FIG. 2 illustrates a pixel 41 of one of a plurality of pixels arranged in a two-dimensional matrix in the light receiving unit 40, and a power supply 42 that supplies electric power to the pixels 41. The pixel 41 has a photoelectric conversion element that photoelectrically converts the received light and generates an electric charge according to the amount of light.

The pixel drive unit 70 is connected to the light receiving unit 40 via the pixel drive line 43. The pixel driving unit 70 drives each pixel of the light receiving unit 40 at the same time for all pixels, in units of rows, or the like. The pixel signals output from each pixel of the pixel line (pixel line) selectively scanned by the pixel drive unit 70 are supplied to the sampling circuit 51 through each of the vertical signal lines 44.

The sampling circuit 51 samples each pixel string of the light receiving unit 40 at a predetermined sampling frequency with respect to the pixel signal output from each pixel unit of the selection line (selection line) through the vertical signal line 44.

<Distance measurement processing method>
FIG. 3 is a flowchart for explaining a distance measuring processing method by the distance measuring device 1A in the first embodiment of the present technology.

That is, when the distance measuring device 1A starts the distance measuring process, it first selects the reading line in the imaging frame (step ST1a). For example, immediately after the start of the distance measuring process, the top line in the imaging frame is selected.

Subsequently, the distance measuring device 1A measures the distance to the pixel 41 in the selected read line (step ST1b). As a result, the light receiving unit 40 outputs the pixel signal from the pixel 41 to the distance measuring processing unit 50.

The distance measuring processing unit 50 determines a sampling value while sampling the pixel signal of each pixel 41 according to a predetermined sampling frequency, and generates a histogram based on the total value of the sampling values for each sampling time (step ST1c). ..

Subsequently, the distance measuring processing unit 50 detects the peak value in the generated histogram and calculates the distance from the time corresponding to the peak value (step ST1d). Then, the distance measuring device 1A determines whether or not there is an object OBJ from the calculated distance measurement data by the ROI area determination unit 80 (step ST1e), and if there is an object OBJ (Yes), pixel drive. The power supply 42 is turned on only in the ROI region by controlling the unit 70, or the pixel signal is sampled only in the ROI region by controlling the sampling circuit 51 (step ST1f). Regarding the process of step ST1f, in addition to the determination result by the ROI area determination unit 80, a signal indicating that there is an object OBJ is received from the outside even in image recognition using, for example, an external camera image. May be good. Further, even if the signal indicating that the object OBJ is present is not used, the area division and the power-on for each area may be determined in advance and input.

After that, the distance measuring device 1A determines whether or not the selected line has ended (step ST1g), and if it is not the end of the line (No), the process proceeds to the process of step ST1b, but if the line ends (Yes). ), The process proceeds to step ST1a and the next read line is selected.

In this way, as shown in FIG. 4, the distance measuring device 1A can measure a nearby obstacle (for example, another vehicle) with a higher distance measuring accuracy in a scene in front of the vehicle, for example. It becomes possible to avoid collisions more accurately. On the other hand, as a result of distance measurement, when there is no obstacle (for example, another vehicle) nearby, the pixel can be pixeled by turning off the power supply 42 that supplies power to the pixel 41 or masking the pixel signal output from the pixel 41. It will be possible to reduce the power consumption by reducing the driving voltage and the computing load of the processor.

<Reduction of sampling circuit>
FIG. 5 is a block diagram showing an example in which the number of sampling circuits 51 is reduced in order to output data only in the ROI region in the first embodiment of the present technology. In order to process high-resolution data at a high frame rate, the sampling circuit 51 needs to sample pixel signals output from a plurality of pixels 41 at the same time. In the example of FIG. 5, the sampling circuit 51 can simultaneously process the electric signals output from the plurality of pixels 41 corresponding to the ROI region on one line in the imaging frame (for example, three in FIG. 5). A module is provided (hereinafter, referred to as a sampling circuit (2, 3, 4) 51). When processing the electric signals output from all the pixels 41 on one line at the same time, in the example of FIG. 5, for example, five sampling circuits 51 are required. Further, one pixel 41 includes a plurality of light receiving elements. Further, each of the plurality of modules of the sampling circuit 51 can independently control the power supply.

A selector 54 is interposed between the light receiving unit 40 and the sampling circuit (2, 3, 4) 51. The selector 54 selectively connects the light receiving unit 40 and the sampling circuit (2, 3, 4) 51 according to the switching instruction from the system control unit 10.
The system control unit 10 switches and controls the selector 54 so as to connect the plurality of pixels 41 corresponding to the ROI region and the plurality of sampling circuits 51, for example, based on the determination result by the ROI region determination unit 80.

In the line shown by the thick frame in FIG. 5, the pixel signal output from the third to sixth pixels 41 from the right end corresponding to the ROI region is input to the sampling circuit (4) 51 via the selector 54, and is input from the right end to the sampling circuit (4) 51. The pixel signal output from the seventh pixel 41 is input to the sampling circuit (3) 51 via the selector 54.

6 and 7 are block diagrams showing an example of switching the sampling circuit 51 in order to output data over the entire region in the first embodiment of the present technology.

First, in the line shown by the thick frame in FIG. 6, the pixel signal output from the first to tenth pixels 41 from the left end is input to the sampling circuit (2, 3, 4) 51 via the selector 54. .. Then, the system control unit 10 switches the selector 54 and, as shown in FIG. 7, samples the pixel signals output from the remaining pixels 41 (11th to 20th pixels 41 from the left end) in the sampling circuit (2, 3). , 4) Enter in 51.

<Action and effect of the first embodiment>
As described above, according to the first embodiment, the circuit scale of the sampling circuit 51 is reduced with respect to the number of pixels 41 in the line (row) direction of the imaging frame, and the area measured by the selector 54 is the sampling circuit. By allocating to 51, when a small number of sampling circuits 51 are shared by a larger number of pixels 41 in one line (row) direction, the circuit scale of the sampling circuit 51 can be reduced, and power consumption can be reduced.

Therefore, by activating only the necessary parts, it is possible to reduce the power consumption and relax the rate-determining of the data output band even if the resolution is increased.

Further, according to the first embodiment, since the ROI area determination unit 80 is provided in the distance measuring device 1A, it is possible to process the ROI in the imaging frame in real time.

<Second embodiment>
Next, the second embodiment will be described. The second embodiment is a modification of the first embodiment, and describes a case where the power supply 42 of the pixel 41 other than the ROI region is turned off.

FIG. 8 is a block diagram showing an example of a case where the power supply 42 of the pixel 41 other than the ROI region in the second embodiment of the present technology is turned off. In the example of FIG. 8, in the third line (row) from the upper end, the system control unit 10 reads out the power supply 42 of the pixel 41 other than the ROI area (gray area in FIG. 8) at the same timing. Turn off. Then, the pixel signal output from the 8th to 12th pixels 41 from the left end is input to the sampling circuit 51.

Further, in the tenth line (row) from the upper end, the system control unit 10 turns off the power supply 42 of the pixel 41 other than the ROI region. Then, the pixel signals output from the 5th to 7th and 12th to 15th pixels 41 from the left end are input to the sampling circuit 51.

<Action and effect of the second embodiment>
As described above, according to the second embodiment, by turning off the power supply 42 of the pixel 41 other than the ROI region, the power consumption can be reduced without changing the circuit scales of the sampling circuit 51 and the histogram generation circuit 52. Can be reduced.

<Third embodiment>
Next, a third embodiment will be described. The third embodiment is a modification of the first embodiment, and a case where the number of modules of the histogram generation circuit 52 is reduced in order to output data only in the ROI region will be described.

FIG. 9 is a block diagram showing an example in which the number of modules of the histogram generation circuit 52 according to the third embodiment of the present technology is reduced. In the example of FIG. 9, a selector 54 is interposed between the sampling circuit (1,2,3,4,5) 51 and the histogram generation circuit (2,3,4) 52. The selector 54 selectively connects the sampling circuit (1,2,3,4,5) 51 and the histogram generation circuit (2,3,4) 52 according to the switching instruction from the system control unit 10. The plurality of modules of the histogram generation circuit 52 can independently control the power supply.

The system control unit 10 connects the sampling circuit (1, 2, 3, 4, 5) 51 and the histogram generation circuit (2, 3, 4) 52, for example, based on the determination result by the ROI area determination unit 80. The selector 54 is switched and controlled.

<Action and effect of the third embodiment>
As described above, according to the third embodiment, the circuit scale of the histogram generation circuit 52 is reduced with respect to the number of pixels 41 in the line (row) direction of the imaging frame, and the region measured by the selector 54 is a histogram. By allocating to the generation circuit 52, when a small number of histogram generation circuits 52 are shared by a larger number of sampling circuits 51 in one line (row) direction, the circuit scale of the histogram generation circuit 52 can be reduced and consumed. Power can be reduced.

Further, in the third embodiment, a plurality of sampling circuits (1, 2, 3, 3) can simultaneously process pixel signals output from the plurality of pixels 41 in one line (one line) in the imaging frame. Since 4, 5) 51 are fixedly prepared, sampling processing can be performed with high accuracy.

<Fourth Embodiment>
Next, a fourth embodiment will be described. A fourth embodiment is a modification of the first embodiment, and when reading ROI data in an array type, an example of simultaneously reading regions that do not overlap in the scanning direction (V direction) will be described.

FIG. 10 is a block diagram showing an example of a case where regions that do not overlap in the scanning direction are simultaneously read out in the fourth embodiment of the present technology.

The light receiving unit 40 is an array type, and as shown in FIG. 11, the output terminals of the plurality of light receiving elements are shared for each pixel 41. As shown in FIG. 11, the pixel 41a shown in FIG. 10 is provided with, for example, 12 light receiving elements 45. The pixel 41b is provided with, for example, 12 light receiving elements 46. The pixel 41c is provided with, for example, 12 light receiving elements 46. The light receiving element 45 is a light receiving element that does not read at the same time, and the light receiving element 46 is a light receiving element that reads out at the same time.

The output terminal of the light receiving element 45 is connected to the vertical signal lines 444, 445 and 446 of the vertical signal lines 44. The output terminal of the light receiving element 46 belonging to the pixel 41b is connected to the vertical signal lines 441, 442, 443 of the vertical signal lines 44. The output terminal of the light receiving element 46 belonging to the pixel 41c is connected to the vertical signal lines 444, 445 and 446 of the vertical signal lines 44. The vertical signal lines 444, 445 and 446 are shared by the light receiving elements 45 and 46.

Here, when only the ROI data is output to the sampling circuit 51, the system control unit 10 turns off the power supply 42 of the light receiving element 45 belonging to the pixel 41a, and the light receiving element 46 belonging to the pixels 41b and 41c via the pixel drive line 43. Is driven, and the pixel signal output from the light receiving element 46 via each of the vertical signal lines 441, 442, 443, 444, 445, 446 is simultaneously input to the sampling circuit 51.

<Action and effect of the fourth embodiment>
As described above, according to the fourth embodiment, in order to reduce the number of wires, the output terminals of the plurality of light receiving elements 45 and 46 are shared for each pixel 41, so that the light receiving elements other than the light receiving element 46 to be read out are shared. By turning off the power of 45 or performing an output mask, it is possible to read out regions that do not overlap in different V directions at the same time.

<Fifth Embodiment>
Next, a fifth embodiment will be described. A fifth embodiment is a modification of the first embodiment, and describes a case where the power of the sampling circuit 51 and the histogram generation circuit 52 belonging to the region other than the ROI region is turned off.

FIG. 12 is a block diagram showing an example of a case where the power of the sampling circuit 51 and the histogram generation circuit 52 belonging to the region other than the ROI region in the fifth embodiment of the present technology is turned off.

In the example of FIG. 12, the sampling circuit 51 and the histogram generation circuit 52 are provided with a number of modules capable of simultaneously processing electrical signals output from a plurality of pixels 41 on one line in the imaging frame. The sampling circuit 51 and the histogram generation circuit 52 are modularized, and a power gate (registered trademark) cell 56 is interposed between the sampling circuit 51 and the power supply 55 for each module. In addition, the present invention is not limited to one power supply 55, and a plurality of power supplies and a plurality of modules may be connected via a power gate cell 56.

The system control unit 10 turns off the power gate cell 56 to the power supply 55 of the module (module 1 in FIG. 12) belonging to the pixel 41 other than the ROI region in the line (row). Then, the power gate cell 56 to the power supply 55 of the module belonging to the pixel 41 in the ROI region (modules 2 and 3 in FIG. 12) is turned on, and the pixel signal output from the pixel 41 is input to the sampling circuit 51. In addition to the power gate cell 56, a clock gating cell may be used.

<Action and effect of the fifth embodiment>
According to the fifth embodiment, by controlling the power supply 55 of the sampling circuit 51 and the histogram generation circuit 52 belonging to the region other than the ROI region to be off, the power consumption can be reduced without changing the circuit scale.

<Sixth Embodiment>
Next, the sixth embodiment will be described. The sixth embodiment is a modification of the fifth embodiment, and the case where the power supply cutoff and the clock gating regions are not evenly spaced will be described.

FIG. 13 is a block diagram showing an example of a case where the power of the sampling circuit 51 and the histogram generation circuit 52 belonging to the region other than the ROI region in the sixth embodiment of the present technology is turned off.

In the example of FIG. 13, in order to make the central particle size finer, the sampling circuit 51 and the histogram generation circuit 52 simultaneously process electrical signals output from a plurality of pixels 41 corresponding to the ROI region on one line in the imaging frame. A possible number (for example, 7 in FIG. 13) is provided (hereinafter, sampling circuit (2,3,4,5,6,7,8) 51 and histogram generation circuit (2,3,4,5,6). 7, 8) 52). Two sampling circuits 51 and a histogram generation circuit 52 are provided except for the ROI region (hereinafter, referred to as a sampling circuit (1,9) 51 and a histogram generation circuit (1,9) 52).

When the pixel signal output from the pixel 41 in the ROI region on one line is input to the sampling circuit (2,3,4,5,6,7,8) 51, the system control unit 10 uses the sampling circuit (1,3,4,5,6,7,8) 51. 9) Turn off the power gate cell 56 to the power supply 55 of the module belonging to 51 and the histogram generation circuit (1, 9) 52.

Further, when the pixel signal output from the pixel 41 of the face portion of the ROI region on one line is input to the sampling circuit (3,4,5,6,7) 51, the system control unit 10 uses the sampling circuit (3,4,5,6,7). The power gate cell 56 to the power supply 55 of the module belonging to 1,2,8,9) 51 and the histogram generation circuit (1,2,8,9) 52 is turned off.

Further, when the pixel signal output from the pixel 41 on the right hand side of the ROI region on one line is input to the sampling circuit (2, 3) 51, the system control unit 10 uses the sampling circuit (1, 4, 5,). The power gate cell 56 to the power supply 55 of the module belonging to 6,7,8,9) 51 and the histogram generation circuit (1,4,5,6,7,8,9) 52 is turned off.

Further, when the pixel signal output from the pixel 41 on the right hand side of the ROI region on one line is input to the sampling circuit (6, 7, 8) 51, the system control unit 10 uses the sampling circuit (1, 2, 2, The power gate cell 56 to the power supply 55 of the module belonging to 3,4,5,9) 51 and the histogram generation circuit (1,2,3,4,5,9) 52 is turned off.

As a result, both ends on one line in the imaging frame can be blocked according to a general angle of view.

As shown in FIG. 14, in addition to the ROI, the power may be cut off as needed during a set or read-out use case of all pixels 41. In the example of FIG. 14, four sampling circuits 51 and four histogram generation circuits 52 are provided in order to reduce the particle size of the region other than the ROI (hereinafter, sampling circuits (1-1, 1-2, 2-1, 1). -2) 51 and the histogram generation circuit (referred to as 1-1, 1-2, 2-1, 1-2) 52).

When the pixel signal output from the pixel 41 in the ROI region on one line is input to the sampling circuit (3,4,5) 51, the system control unit 10 uses the sampling circuit (1-1, 1-2,2-). The power gate cell 56 to the power supply 55 of the module belonging to 1, 1-2) 51 and the histogram generation circuit (1-1, 1-2, 2-1, 1-2) 52 is turned off. Further, when the angle of view of VGA is set to the angle of view of HVGA or QVGA, the system control unit 10 uses a sampling circuit (1-1, 1-2) 51 and a histogram generation circuit (1-1, 1-2). The power gate cell 56 to the power supply 55 of the module belonging to 52 can also be turned off.

<7th Embodiment>
Next, a seventh embodiment will be described. A seventh embodiment is a modification of the first embodiment, and a case will be described in which, for example, in a laminated structure, the pixels 41 are processed by the sampling circuit 51 and the histogram generation circuit 52 on the surface.

FIG. 15 is a diagram showing an example of a case where the pixel 41 is processed by the sampling circuit 51 and the histogram generation circuit 52 on the surface in the three-layer structure according to the seventh embodiment of the present technology.

In the example of FIG. 15, the surface of the pulse change circuit 200 is interposed between the surface of the light receiving unit 40 and the surface of the distance measuring processing unit 50. The pulse change circuit 200 includes a plurality of power supply units provided for each pixel 41 arranged in the plane of the light receiving unit 40 or for each pixel group composed of some pixels 41 to supply electric power to the light receiving element. Further, the pulse change circuit 200 supplies a pixel output pulse that changes from a low level to a high level to an arbitrary pixel 41, and outputs the charge accumulated in the pixel 41 as a pixel signal. When the pixel output pulse supplied from the pulse change circuit 200 changes from the low level to the high level, the light receiving element in the pixel 41 lowers the quench voltage and discharges the accumulated charge.

The system control unit 10 can control the pulse change circuit 200 to shut off the power supply or stop the clock of the logic other than the ROI region.

In addition to the three-layer structure, a two-layer structure may be used. FIG. 16 is a diagram showing an example of a case where the pixel 41 is processed by the sampling circuit 51 and the histogram generation circuit 52 on the surface in the two-layer structure according to the seventh embodiment of the present technology.

In the example of FIG. 16, the pulse change circuit 200 is provided on the surface of the distance measuring processing unit 50. The pulse change circuit 200 may be provided on the surface of the light receiving unit 40.

<Action and effect of the seventh embodiment>
As described above, according to the seventh embodiment, when the pixel 41 is subjected to the distance measuring process on the surface of the pixel 41 in the laminated structure, the power supply 42 belonging to the area other than the ROI area is turned off in the surface of the light receiving unit 40. can do.

<8th Embodiment>
Next, the eighth embodiment will be described. The eighth embodiment is a modification of the first embodiment, and a case where not all areas are output in one imaging frame but one area at a time will be described.

FIG. 17 is a diagram showing an example in the case of outputting one region at a time according to the eighth embodiment of the present technology.

In the example of FIG. 17, the system control unit 10 divides the ROI region into, for example, a “face”, a “right hand”, and a “left hand”, and controls the light receiving unit 40 so as to read out the divided region for each imaging frame. It is assumed that the "right hand" and the "left hand" are areas that overlap at the time of reading.

The system control unit 10 controls the light receiving unit 40 so as to read the "right hand" in the first frame. Subsequently, the system control unit 10 controls the light receiving unit 40 so as to read out the "face" in the second frame. At the third frame, the system control unit 10 controls the light receiving unit 40 so as to read the "left hand".
The reading process may be specified or the distance may be measured a plurality of times until the scene changes.

<Action and effect of the eighth embodiment>
As described above, according to the eighth embodiment, by outputting not all the areas in one imaging frame but one divided area at a time, when the areas overlap, the size to be read at the same time is reduced. Distance measurement accuracy can be improved by limiting the temperature rise or irradiating light only within the area.

<9th embodiment>
Next, a ninth embodiment will be described. A ninth embodiment is a modification of the first embodiment, and a case where a region to which light is applied is narrowed down to an ROI region will be described.

FIG. 18 is a diagram showing an example in which, in the ninth embodiment of the present technology, the area to which light is applied is narrowed down to the ROI area when the distance is measured in line units.

In the example of FIG. 18A, the system control unit 10 emits light only in the ROI region on one line of the imaging frame based on the determination result by the ROI region determination unit 80. The light emitting unit 20 is controlled by the light emitting timing adjusting unit 30 by sending an instruction signal to.

Further, in the example of FIG. 18B, the system control unit 10 uses the light emission timing adjusting unit 30 to focus on the ROI region and increase the light emission intensity based on the determination result by the ROI area determination unit 80. The light emitting unit 20 is controlled.

FIG. 19 is a diagram showing an example in which a region to which light is applied is narrowed down to an ROI region when measuring a distance on a surface in a ninth embodiment of the present technology.

In the example of FIG. 19, the system control unit 10 divides the ROI area into, for example, a “face”, a “right hand”, and a “left hand” based on the determination result by the ROI area determination unit 80, and narrows down the ROI area to the divided areas. An instruction signal is sent to the light emitting timing adjusting unit 30 so that light is emitted, and the light emitting unit 20 is controlled by the light emitting timing adjusting unit 30.

For example, as shown in FIG. 19A, the system control unit 10 sends an instruction signal to the light emission timing adjustment unit 30 so that the light emission is focused on the “face”, and the light emission timing adjustment unit 30 causes the light emission unit 20 to emit light. Control. Further, as shown in FIG. 19B, the system control unit 10 sends an instruction signal to the light emission timing adjustment unit 30 so that the light emission is focused on the “right hand”, and the light emission timing adjustment unit 30 causes the light emission unit 20 to emit light. Control. Further, as shown in FIG. 19C, the system control unit 10 sends an instruction signal to the light emission timing adjustment unit 30 so that the light emission is focused on the “left hand”, and the light emission timing adjustment unit 30 causes the light emission unit 20 to emit light. Control.

The ROI region may be divided into, for example, a "face", a "right hand", and a "left hand", and the light may be focused on the entire ROI region in addition to the divided regions to emit light.

<Action and effect of the ninth embodiment>
As described above, according to the ninth embodiment, by narrowing the area to which the light is applied to the ROI area, the amount of light is strengthened, the consumption of the light emitting unit 20 is low, and the safety function is improved by not irradiating the useless area with light. Can be expected.

<10th Embodiment>
Next, a tenth embodiment will be described. A tenth embodiment is a modification of the first embodiment, and a case where a packet header (PH) and a packet footer (PF) are added to data for each line according to the MIPI standard will be described. In the case of dToF, since there is a lot of data information per pixel, PH and PF may be added in units of a plurality of pixels, or PH and PF may be added for each pixel when outputting histogram data. PH and PF show different values for each line.

FIG. 20 is a diagram showing an example in the case of outputting one region at a time according to the tenth embodiment of the present technology.

In the example of FIG. 20, the system control unit 10 divides the ROI area into, for example, a frame 1 (face), a frame 2 (right hand), and a frame 3 (left hand), and reads out the data of the frame 1, the frame 2, and the frame 3. The light receiving unit 40 is controlled in this way.

As shown in FIG. 21, the communication interface unit 60 adds PH and PF identified for each line to the distance measurement data of the frame 1 output from the distance measurement processing unit 50, and subsequently, the frame 2 and the frame. PH and PF identified for each line are added to the distance measurement data of 3.

Further, as shown in FIG. 22, when reading different regions in the V direction at the same time, the communication interface unit 60 arranges the ranging data of the frame 1, the frame 2, and the frame 3 on one line, and arranges the distance measurement data of the frame 1, each frame 1, and each frame 1. PH and PF are added to the distance measurement data of the frames 2 and 3.

<Action and effect of the tenth embodiment>
As described above, according to the tenth embodiment, by adding PH and PF for each line of the imaging frame in the ROI region, the PH and PF identified for each line on the external device side such as the host IC can be obtained. Based on this, it becomes possible to manage the distance measurement data in the ROI area.

<11th Embodiment>
Next, the eleventh embodiment will be described. In the eleventh embodiment, the distance measurement processing unit 57 is obtained by deleting the distance calculation circuit 53 from the distance measurement processing unit 50, and an external host IC that has received the distance measurement data calculated by the distance measurement processing unit 57 is used. The distance measuring device 1B capable of determining the ROI region is disclosed. Here, the external host IC is used in the sense that it is provided outside the distance measuring device 1B as the SoC described in the first embodiment.

FIG. 23 is a block diagram showing an example of the configuration of the distance measuring device 1B according to the eleventh embodiment of the present technology. As shown in the figure, the host IC 2 executes the process by the distance calculation circuit 53 based on the distance measurement data received from the distance measurement processing unit 57 via the communication interface unit 60, and determines the ROI area. It is different from the one illustrated in the first embodiment above in that it is configured in. In FIG. 23, components having the same function or configuration as the components already shown are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

As shown in the figure, in this example, the distance calculation circuit 53 shown in FIG. 1 and the ROI area determination unit 80 shown in FIG. 1 are provided in the host IC 2 instead of being provided in the distance measuring device 1A. There is. Although not shown, the host IC 2 includes a corresponding communication interface unit. Similar to the first embodiment, the distance measurement calculation circuit of the host IC 2 calculates the distance to the object OBJ when the distance measurement data is received from the distance measurement processing unit 50 via the communication interface unit 60. Then, the ROI area determination unit of the host IC 2 determines the ROI area based on the distance measurement data. The ROI area determination unit of the host IC 2 transmits the determination result to the system control unit 10 via the communication interface unit 60.

As an example, the host IC 2 may include a frame buffer (not shown) capable of holding distance measurement data for one imaging frame. The ROI area determination unit of the host IC 2 refers to the frame buffer and determines the ROI area for each read line in the next imaging frame.

<Action and effect of the eleventh embodiment>
In this way, the eleventh embodiment can also exhibit the same effects or advantages as those of the first embodiment. Further, according to the eleventh embodiment, the processing by the distance measuring calculation circuit and the determination processing of the ROI region can be omitted in the distance measuring device 1B, so that advanced processing becomes possible. In particular, during the formation of the current imaging frame, the power supply 42 belonging to an area other than the ROI area is turned off based on the determination result of the ROI area, and the distance measurement is performed so as to input the pixel signal corresponding to the ROI area. At least one of controlling the processing unit 50 can be executed.

<Explanation of SPAD used in the first to eleventh embodiments>
In the first to eleventh embodiments of the present disclosure, the light receiving unit 40 is a CMOS image sensor including a plurality of light receiving elements (SPADs) arranged in a two-dimensional array. That is, each SPAD detects incoming light (photons) and converts the carriers generated thereby into electrical signal pulses using avalanche multiplication. In the first to eleventh embodiments of the present disclosure, for example, under the control of the system control unit 10, a specific SPAD group (for example, a SPAD group in the one-line direction in the imaging frame) is activated, whereby an electric signal is activated. The pulse is read out. Further, the SPAD group of each line is sequentially activated in one frame time, and one imaging frame for the target area is formed by the electric signal pulses output from each of the activated SPAD groups.

<12th Embodiment>
<Structure of distance measuring device>
FIG. 24 is a block diagram showing an example of the configuration of the distance measuring device 1C according to the twelfth embodiment of the present technology. The distance measuring device 1C emits light from a light emitting element, the reflected light from an object OBJ (object or subject) is photoelectrically converted by a photoelectric conversion unit, and the electric charge generated by the photoelectric conversion unit is generated by a plurality of transfer transistors. It is a distance measuring sensor that is distributed to a plurality of charge storage units and measures the distance to the object OBJ based on the amount of charges accumulated in the plurality of charge storage units.

As shown in the figure, the distance measuring device 1C is configured to include an AD (analog / digital) conversion unit 91 and a distance calculation circuit 92 in the distance measuring processing unit 90, and is the first embodiment described above. It is different from the one shown in. In FIG. 24, components having the same function or configuration as the components already shown are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

The AD conversion unit 91 converts a pixel signal corresponding to the amount of electric charge output and accumulated for each pixel 41 from an analog signal to a digital signal. The pixel signal for each pixel 41 is output to the distance calculation circuit 92. The distance calculation circuit 92 calculates the distance to the object OBJ based on the pixel signal for each pixel 41. In the distance calculation circuit 92, a distance image can be obtained from the distances calculated for all the pixels constituting the imaging frame. The distance calculation circuit 92 sequentially outputs data (distance measurement data) related to the distance calculated for each pixel in each imaging frame to the communication interface unit 60 and the ROI area determination unit 80.

The ROI area determination unit 80 determines, for example, the ROI area including the object OBJ based on the calculated distance measurement data. This determination result is output to the system control unit 10. The system control unit 10 controls the pixel drive unit 70 provided in the light receiving unit 40 based on the determination result of the ROI region by the ROI area determination unit 80. When controlling the pixel drive unit 70, the system control unit 10 may use the V (vertical) control determination unit 100 that determines skipping of the read region or the like.

<Structure of light receiving part>
FIG. 25 illustrates one pixel 41 of a plurality of pixels arranged in a two-dimensional matrix in the light receiving unit 40. The pixel 41 has a photoelectric conversion element that photoelectrically converts the received light and generates an electric charge according to the amount of light.

The pixel drive unit 70 is connected to the light receiving unit 40 via the pixel drive line 43. The pixel driving unit 70 drives each pixel of the light receiving unit 40 at the same time for all pixels, in units of rows, or the like. The pixel signals output from each pixel of the pixel line (pixel line) selectively scanned by the pixel drive unit 70 are supplied to the AD conversion unit 91 through each of the vertical signal lines 44.

The AD conversion unit 91 converts an analog signal into a digital signal for each pixel string of the light receiving unit 40 with respect to a pixel signal output from each pixel unit of the selection line (selection line) through the vertical signal line 44.

<Reduction of AD conversion unit>
FIG. 26 is a block diagram showing an example in which the number of AD conversion units 91 is reduced in order to output data only in the ROI region in the twelfth embodiment of the present technology. In order to process high-resolution data at a high frame rate, the AD conversion unit 91 needs to simultaneously convert pixel signals output from a plurality of pixels 41 from analog signals to digital signals. In the example of FIG. 26, the AD conversion unit 91 can simultaneously process the pixel signals output from the plurality of pixels 41 corresponding to the ROI region on one line in the imaging frame (for example, three in FIG. 26). It is provided (hereinafter, referred to as AD conversion unit (2, 3, 4) 91). When processing the electric signals output from all the pixels 41 on one line at the same time, in the example of FIG. 26, for example, five AD conversion units (1, 2, 3, 4, 5) 91 are required. Become. Further, one pixel 41 includes a plurality of light receiving elements.

A selector 93 is interposed between the light receiving unit 40 and the AD conversion unit (1, 2, 3, 4, 5) 91. The selector 93 selectively connects, for example, the light receiving unit 40 and the AD conversion unit (2, 3, 4) 91 according to the switching instruction from the system control unit 10.

The system control unit 10 switches the selector 93 so as to connect the plurality of pixels 41 corresponding to the ROI area and the AD conversion unit (2, 3, 4) 91 based on the determination result by the ROI area determination unit 80, for example. Control.

In the line shown by the thick frame in FIG. 26, the pixel signal output from the fourth to sixth pixels 41 from the left end corresponding to the ROI region is input to the AD conversion unit (2) 91 via the selector 93, and is input to the AD conversion unit (2) 91 at the left end. The pixel signal output from the 11th to 14th pixels 41 is input to the AD conversion unit (4) 91 via the selector 93.

<Action and effect of the twelfth embodiment>
As described above, according to the twelfth embodiment, the number of AD conversion units 91 is reduced with respect to the number of light receiving elements and the number of pixels in the line direction of the imaging frame, and the area measured by the selector 93 is the AD conversion unit 91. By allocating to, a small number of AD conversion units 91 can be shared by a larger number of pixels 41 in one line (row) direction, and power consumption can be reduced by the amount that the number of AD conversion units 91 can be reduced.

<13th Embodiment>
Next, the thirteenth embodiment will be described. The thirteenth embodiment is a modification of the twelfth embodiment, and describes a configuration in which a V scan (designation of a read line) can be performed for each area.

FIG. 27 is a diagram showing an example of a case where V scan (designation of a read line) can be performed for each area in the thirteenth embodiment of the present technology.

In the example of FIG. 27, when the pixel signal is output from the pixel 41 of the ROI region (the first line is shown in FIG. 27) of the third line from the upper end, the pixel drive line 43 (1) shown in FIG. 28 has three lines. Pixel signals are output from all the pixels 41 of the eye at the same timing. Further, when the pixel signal is output from the pixel 41 of the ROI region (the second line is shown in FIG. 27) of the fourth line from the upper end, all the pixels of the fourth line are output by the pixel drive line 43 (2) shown in FIG. 28. The pixel signal is output from 41 at the same timing.

Therefore, in the thirteenth embodiment of the present technology, as shown in FIG. 29, the regions in one line are divided so that they can be read out at different timings.

Returning to FIG. 27, in the thirteenth embodiment of the present technology, among the pixels 41, the first to eighth pixels 411 from the left end of the third line from the upper end are connected by the pixel drive line 431, and the ninth from the left end. The twelfth pixel 412 is connected by the pixel drive line 432. Then, the 13th to 16th pixels 413 from the left end are connected by the pixel drive line 433, and the 17th to 20th pixels 414 from the left end are connected by the pixel drive line 434.

Further, in the thirteenth embodiment of the present technology, among the pixels 41, the first to eighth pixels 415 from the left end of the fourth line from the upper end are connected by the pixel drive line 435, and the ninth to twelfth pixels from the left end. Pixels 416 are connected by pixel drive lines 436. Then, the 13th to 16th pixels 417 from the left end are connected by the pixel drive line 437, and the 17th to 20th pixels 418 from the left end are connected by the pixel drive line 438.

When reading out the pixel 412 in the ROI region of the third line (the first line of the face portion in FIG. 27), the pixel drive unit 70 drives the pixel 412 via the pixel drive line 432 and outputs the pixel 412 from the pixel 412. The pixel signal is input to the AD conversion unit 91.

When reading out the pixel 416 of the ROI region of the fourth line (the second line of the face portion in FIG. 27), the pixel drive unit 70 drives the pixel 416 via the pixel drive line 436 and outputs the pixel 416 from the pixel 416. The pixel signal is input to the AD conversion unit 91.

<Action and effect of the thirteenth embodiment>
As described above, according to the thirteenth embodiment, by configuring so that the read line can be specified for each area, output is output from a plurality of pixels 41 in a region that does not overlap in the V (scanning) direction of the imaging frame. By simultaneously reading out the pixel signals to be generated and inputting them to the AD conversion unit 91, the processing time of the AD conversion unit 91 can be shortened, and the power consumption can be reduced accordingly.

<14th Embodiment>
Next, the fourteenth embodiment will be described. The fourteenth embodiment is a modification of the twelfth embodiment, and the configuration in the case where a large number of vertical signal lines 44 are provided with respect to the AD conversion unit 91 will be described.

FIG. 30 is a diagram showing an example in which the ROI region is divided into a frame 1, a frame 2, and a frame 3 in the 14th embodiment of the present technology. FIG. 31 is a diagram showing an example in which the frame 1, the frame 2, and the frame 3 are connected by different vertical signal lines 44.

In the example of FIG. 31, among the pixels 41, for example, the pixel 4111 in the first row of the frame 1 is connected by the pixel drive line 4311 and is connected by the vertical signal line 4411. The pixels 4112 in the second row of the frame 1 are connected by the pixel drive line 4312 and are connected by the vertical signal line 4412.

The pixels 4121 in the first row of the frame 2 are connected by the pixel drive line 4321 and are connected by the vertical signal line 4421. The pixels 4122 in the second row of the frame 2 are connected by the pixel drive line 4322 and are connected by the vertical signal line 4422.

The pixels 4131 in the first row of the frame 3 are connected by the pixel drive line 4331 and are connected by the vertical signal line 4431. The pixels 4132 in the second row of the frame 3 are connected by the pixel drive line 4332 and are connected by the vertical signal line 4432.

When reading the frame 1 (first and second rows of the face portion in FIG. 30), the pixel drive unit 70 drives the pixels 4111 and 4112 via the pixel drive lines 4311 and 4312, and from the pixels 4111 and 4112. The output pixel signal is input to the AD conversion unit 91 via the vertical signal lines 4411 and 4412.

When reading the frame 2 (the first and second rows of the right-hand portion in FIG. 30), the pixel drive unit 70 drives the pixels 4121 and 4122 via the pixel drive lines 4321 and 4322, and from the pixels 4121 and 4122. The output pixel signal is input to the AD conversion unit 91 via the vertical signal lines 4421 and 4422.

When reading the frame 3 (the first and second rows of the left-hand portion in FIG. 30), the pixel drive unit 70 drives the pixels 4131 and 4132 via the pixel drive lines 4331 and 4332, and from the pixels 4131 and 4132. The output pixel signal is input to the AD conversion unit 91 via the vertical signal lines 4431 and 4432.

<Action and effect of the 14th embodiment>
As described above, according to the fourteenth embodiment, by having a large number of vertical signal lines 44 with respect to the AD conversion unit 91, the ROI region is divided into, for example, frame 1, frame 2, and frame 3 and set, and V When the directions do not overlap, it is possible to input a plurality of pixel signals to the AD conversion unit 91 at the same time using different vertical signal lines 44 for each of the frames 1, frame 2, and frame 3, which can shorten the processing time. , Power consumption can be reduced accordingly.

<Modified example of the 14th embodiment>
As a modification of the 14th embodiment of the present technology, a switch can be interposed between the vertical signal line 44 and the AD conversion unit 91. In this way, the system control unit 10 can control the switch on / off according to the ROI region.

<Fifteenth Embodiment>
Next, the fifteenth embodiment will be described. A fifteenth embodiment is a modification of the twelfth embodiment, and a case where data on different lines are continuously output at the same time will be described.

FIG. 32 is a diagram showing an example in the case of outputting one region at a time according to the fifteenth embodiment of the present technology.

In the example of FIG. 32, the system control unit 10 divides the ROI area into, for example, a frame 1 (face), a frame 2 (right hand), and a frame 3 (left hand), and reads out the data of the frame 1, the frame 2, and the frame 3. The light receiving unit 40 is controlled in this way.

As shown in FIG. 33, the communication interface unit 60 outputs the distance measurement data of the frame 1, the frame 2 and the frame 3 output from the distance measurement processing unit 50 side by side for each line.

Further, as shown in FIG. 34, when reading different regions in the V direction at the same time, the communication interface unit 60 outputs the ranging data of the frame 1, the frame 2, and the frame 3 side by side on one line.

<16th Embodiment>
Next, the sixteenth embodiment will be described. In the sixteenth embodiment, a distance measuring device 1D that makes it possible to determine the ROI region by using an external host IC that has received the distance measuring data calculated by the distance measuring processing unit 90 is disclosed. Here, the external host IC is used in the sense that it is provided outside the distance measuring device 1D as the SoC described in the twelfth embodiment.

FIG. 35 is a block diagram showing an example of the configuration of the distance measuring device 1D according to the 16th embodiment of the present technology. As shown in the figure, the distance measuring device 1D is a distance measuring processing unit 94 in which the distance calculation circuit 92 is deleted from the distance measuring processing unit 90, and the host IC 2 transfers the communication interface unit 60 from the distance measuring processing unit 94. It is different from the one illustrated in the twelfth embodiment in that it is configured to determine the ROI region based on the distance measurement data received via the device. In FIG. 35, components having the same function or configuration as the components already shown are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

As shown in the figure, in this example, the distance calculation circuit 92 shown in FIG. 24 and the ROI area determination unit 80 shown in FIG. 24 are provided in the host IC 2 instead of being provided in the distance measuring device 1C. There is. Although not shown, the host IC 2 includes a corresponding communication interface unit. Similar to the first embodiment, the distance measurement calculation circuit of the host IC 2 calculates the distance to the object OBJ when the distance measurement data is received from the distance measurement processing unit 94 via the communication interface unit 60. Then, the ROI area determination unit of the host IC 2 determines the ROI area based on the distance measurement data. The ROI area determination unit of the host IC 2 transmits the determination result to the system control unit 10 via the communication interface unit 60.

As an example, the host IC 2 may include a frame buffer (not shown) capable of holding distance measurement data for one imaging frame. The ROI area determination unit of the host IC 2 refers to the frame buffer and determines the ROI area for each read line in the next imaging frame.

<Action and effect of the 16th embodiment>
In this way, the sixteenth embodiment can also exhibit the same effects or advantages as those of the eleventh embodiment and the twelfth embodiment. Further, according to the 16th embodiment, the processing by the distance measuring calculation circuit and the determination processing of the ROI region can be omitted in the distance measuring device 1D, so that advanced processing becomes possible.

<Other Embodiments>
As mentioned above, the present technology has been described in accordance with the first to sixteenth embodiments, but the statements and drawings that form part of this disclosure should not be understood as limiting the present technology. Understanding the gist of the technical content disclosed in the above embodiments will make it clear to those skilled in the art that various alternative embodiments, examples and operational techniques may be included in the present technology. In addition, the configurations disclosed by the first to sixteenth embodiments and the modifications of the first to sixteenth embodiments can be appropriately combined within a range that does not cause a contradiction. For example, configurations disclosed by a plurality of different embodiments may be combined, or configurations disclosed by a plurality of different variations of the same embodiment may be combined.

The present disclosure may also have the following structure.
(1)
A light receiving unit arranged in a matrix and having a plurality of pixels each having a light receiving element that converts the reflected light from the received target region into an electric signal, and a light receiving unit.
A plurality of power supply units provided for each pixel or each pixel group composed of several pixels to supply electric power to the light receiving element, and
In an image pickup frame formed by the plurality of pixels, a distance measurement process for executing a distance measurement process for calculating a distance to a region of interest in the image pickup frame based on the electric signal output for each pixel. Department and
An output interface unit that is output by the distance measuring processing unit and outputs data related to the distance for each pixel with respect to the imaging frame.
A control unit that executes at least one of on / off control of the plurality of power supply units, an output mask of the light receiving element, and control of distance measurement processing by the distance measurement processing unit.
With
Based on the determination result of the region of interest, the control unit turns off the power supply unit belonging to the region other than the region of interest, and performs the distance measuring process so as to input the electric signal corresponding to the region of interest. Perform at least one of controlling the parts,
Distance measurement sensor.
(2)
The distance measuring processing unit
A sampling circuit that samples the electrical signal output for each pixel at a predetermined sampling frequency and outputs a sampling value.
A histogram generation unit that generates a histogram showing the intensity of the reflected light for each time based on a plurality of the sampling values obtained by performing the light reception.
A distance calculation unit that detects the peak value in the histogram and calculates the distance from the peak value to the region of interest.
The distance measuring sensor according to (1) above.
(3)
A selection circuit connected between the light receiving unit and the sampling circuit is provided.
The sampling circuit is provided with a plurality of sampling circuits capable of simultaneously processing electrical signals output from a plurality of pixels corresponding to the region of interest on one line in the imaging frame.
The distance measuring sensor according to (2), wherein the control unit switches and controls the selection circuit so as to connect the plurality of pixels corresponding to the region of interest and the plurality of sampling circuits.
(4)
A selection circuit connected between the sampling circuit and the histogram generator is provided.
The sampling circuit is provided with a plurality of sampling circuits capable of simultaneously processing electrical signals output from a plurality of pixels constituting one line in the imaging frame.
A plurality of the histogram generation units are provided, which can simultaneously process the outputs of a plurality of sampling circuits corresponding to the region of interest on one line in the imaging frame.
The control unit switches and controls the selection circuit so as to connect the plurality of sampling circuits and the plurality of histogram generation units in order to process electrical signals from the plurality of pixels corresponding to the region of interest. The ranging sensor according to 2).
(5)
The light receiving unit is an array type.
The distance measuring sensor according to (1), wherein the output terminals of the plurality of light receiving elements are shared for each pixel.
(6)
The sampling circuit and the histogram generator are provided with a plurality of electrical signals that can simultaneously process electrical signals output from a plurality of pixels constituting one line in the imaging frame.
The distance measuring sensor according to (2), wherein the control unit controls off the power of the sampling circuit and the histogram generation unit that belong to a region other than the region of interest.
(7)
The light receiving unit and the distance measuring processing unit have a laminated structure in which they belong to different layers.
The distance measuring sensor according to (1), wherein the control unit turns off a power supply unit that belongs to a region other than the region of interest on a surface composed of the plurality of pixels.
(8)
The distance measuring sensor according to (1), wherein the control unit controls the light receiving unit so as to divide the region of interest into a plurality of regions and read out the divided regions for each imaging frame.
(9)
A light emitting unit that irradiates the target area with light is provided.
The distance measuring sensor according to (1), wherein the control unit controls the light emitting unit so as to irradiate only the area of interest with the light based on the determination result of the area of interest.
(10)
The distance measuring processing unit
An analog / digital converter that converts the electrical signal output for each pixel from an analog signal to a digital signal.
A distance calculation unit that calculates the distance to the region of interest based on the digital signal,
The distance measuring sensor according to (1) above.
(11)
A selection circuit connected between the light receiving unit and the analog / digital conversion unit is provided.
The analog / digital conversion unit is provided with a plurality of analog / digital conversion units capable of simultaneously processing electrical signals output from a plurality of pixels corresponding to the region of interest on one line in the imaging frame.
The distance measuring sensor according to (10), wherein the control unit switches and controls the selection circuit so as to connect a plurality of pixels corresponding to the region of interest and the plurality of analog / digital conversion units.
(12)
The control unit specifies a readout line in the region of interest, and simultaneously inputs electrical signals output from a plurality of pixels in a region that does not overlap in the scanning direction of the imaging frame to the analog / digital conversion unit. The distance measuring sensor according to (10).
(13)
The pixel and the analog / digital conversion unit are connected by a plurality of signal lines that are different for each line of the imaging frame.
The measurement according to (10) above, wherein the control unit divides and sets the region of interest into a plurality of frames, and transfers the electric signal to the analog / digital conversion unit using different signal lines for each frame. Distance sensor.
(14)
A switch connected between the plurality of signal lines and the analog / digital converter is provided.
The distance measuring sensor according to (13), wherein the control unit controls on / off of the switch according to the region of interest.
(15)
It is provided with an area of interest determination unit that determines the area of interest from the output from the distance measurement processing unit.
The control unit turns off the power supply unit belonging to a region other than the region of interest based on the determination result of the region of interest by the region of interest determination unit, and inputs the electric signal corresponding to the region of interest. The distance measuring sensor according to any one of (1) to (14) above, which executes at least one of controlling the distance measuring processing unit as described above.
(16)
Based on the determination result of the region of interest provided by the external device, the control unit turns off the power supply unit belonging to the region other than the region of interest, and inputs the electric signal corresponding to the region of interest. The distance measuring sensor according to any one of (1) to (14) above, which executes at least one of controlling the distance measuring processing unit as described above.
(17)
The distance measuring sensor according to any one of (1) to (10), wherein the output interface unit adds header information and footer information to each line of the imaging frame for the region of interest.
(18)
The light receiving unit provided with a plurality of pixels arranged in a matrix and each having a light receiving element receives the reflected light from the target area, converts it into an electric signal, and outputs it.
In an image pickup frame formed by the plurality of pixels, distance measurement processing for calculating the distance to a region of interest in the image pickup frame is performed based on the electric signal output for each pixel by the distance measurement processing unit. To do and
To output data regarding the distance for each pixel with respect to the imaging frame,
Based on the determination result of the region of interest, the power supply unit belonging to the region other than the region of interest is controlled to be turned off, and the distance measuring processing unit is controlled so as to input the electric signal corresponding to the region of interest. To perform at least one of the, including,
Distance measurement method.
(19)
A light receiving unit arranged in a matrix and having a plurality of pixels each having a light receiving element that converts the reflected light from the received target region into an electric signal, and a light receiving unit.
A distance measuring processing unit having a plurality of signal processing modules capable of performing signal processing based on the electric signal output for each pixel, calculating the distance to the target area, and independently controlling the power supply.
A distance measuring sensor including a control unit that executes power supply control of the plurality of signal processing modules in response to an input signal.
(20)
The distance measuring processing unit calculates the distance to the region of interest in the imaging frame based on the electric signal output for each pixel in the imaging frame formed by the plurality of pixels. And run
The distance measuring sensor according to (19), wherein the control unit supplies power to the signal processing module corresponding to a plurality of pixels corresponding to the region of interest.
(21)
A selection circuit connected between the light receiving unit and the plurality of signal processing modules is provided.
The control unit switches and controls the selection circuit so as to connect a plurality of pixels corresponding to the region of interest and a signal processing module corresponding to the plurality of pixels corresponding to the region of interest. Distance measurement sensor.
(22)
The distance measuring sensor according to (21) above, wherein the light receiving element is an avalanche photodiode.
(23)
The distance measuring processing unit includes a sampling circuit that samples the electric signal output for each pixel at a predetermined sampling frequency and outputs a sampling value.
The distance measuring sensor according to (22), wherein the selection circuit is arranged between the light receiving unit and the sampling circuit.
(24)
The distance measuring processing unit
A sampling circuit that samples the electrical signal output for each pixel at a predetermined sampling frequency and outputs a sampling value.
A histogram generation unit that generates a histogram showing the intensity of the reflected light for each time based on a plurality of the sampling values obtained by performing the light reception is provided.
The distance measuring sensor according to (22), wherein the selection circuit is arranged between the sampling circuit and the histogram generation unit.

1A, 1B, 1C, 1D ... Distance measuring device, 2 ... Host IC, 10 ... System control unit, 20 ... Light emitting unit, 30 ... Light emitting timing adjustment unit, 40 ... Light receiving unit, 41, 41a, 41b, 41c, 411, 421, 413, 414, 415, 416,417, 418, 4111, 4112, 4121, 4122, 4131, 4132 ... Pixels, 42 ... Power supply unit, 43,431,432,433,434,435,436,437,438 , 4311, 4312, 4321, 4322, 4331, 4332 ... Pixel drive line, 44,441,442,443,444,445,446,441,4412,4421,4422,4431,4432 ... Vertical signal line, 45,46 ... light receiving element, 50, 90 ... distance measurement processing unit, 51 ... sampling circuit, 52 ... histogram generation circuit, 53, 63, 92 ... distance calculation circuit, 54, 93 ... selector, 55 ... power supply, 56 ... power gate cell, 60 ... communication interface unit, 70 ... pixel drive unit, 80 ... ROI area determination unit, 91 ... AD conversion unit, 100 ... V (vertical) control determination unit, 200 ... pulse change circuit

Claims (20)

A light receiving unit arranged in a matrix and having a plurality of pixels each having a light receiving element that converts the reflected light from the received target region into an electric signal, and a light receiving unit.
A distance measuring processing unit having a plurality of signal processing modules capable of performing signal processing based on the electric signal output for each pixel, calculating the distance to the target area, and independently controlling the power supply.
A distance measuring sensor including a control unit that executes power supply control of the plurality of signal processing modules in response to an input signal. The distance measuring processing unit calculates the distance to the region of interest in the imaging frame based on the electric signal output for each pixel in the imaging frame formed by the plurality of pixels. And run
The distance measuring sensor according to claim 1, wherein the control unit supplies power to the signal processing module corresponding to a plurality of pixels corresponding to the region of interest. A selection circuit connected between the light receiving unit and the plurality of signal processing modules is provided.
The second aspect of claim 2, wherein the control unit switches and controls the selection circuit so as to connect a plurality of pixels corresponding to the region of interest and a signal processing module corresponding to the plurality of pixels corresponding to the region of interest. Distance measurement sensor. The distance measuring sensor according to claim 3, wherein the light receiving element is an avalanche photodiode. The distance measuring processing unit includes a sampling circuit that samples the electric signal output for each pixel at a predetermined sampling frequency and outputs a sampling value.
The distance measuring sensor according to claim 4, wherein the selection circuit is arranged between the light receiving unit and the sampling circuit. The distance measuring processing unit
A sampling circuit that samples the electrical signal output for each pixel at a predetermined sampling frequency and outputs a sampling value.
A histogram generation unit that generates a histogram showing the intensity of the reflected light for each time based on a plurality of the sampling values obtained by performing the light reception is provided.
The distance measuring sensor according to claim 4, wherein the selection circuit is arranged between the sampling circuit and the histogram generation unit. The distance measuring processing unit
A sampling circuit that samples the electrical signal output for each pixel at a predetermined sampling frequency and outputs a sampling value.
A histogram generation unit that generates a histogram showing the intensity of the reflected light for each time based on a plurality of the sampling values obtained by performing the light reception.
A distance calculation unit that detects the peak value in the histogram and calculates the distance from the peak value to the region of interest.
The distance measuring sensor according to claim 4. The light receiving unit is an array type.
The output terminals of the plurality of light receiving elements are shared for each pixel.
The distance measuring sensor according to claim 1. A plurality of power supply units provided for each pixel or each pixel group composed of several pixels to supply electric power to the light receiving element are further provided.
The light receiving unit and the distance measuring processing unit have a laminated structure in which they belong to different layers.
The control unit turns off the power supply unit that belongs to a region other than the region of interest on the surface composed of the plurality of pixels.
The distance measuring sensor according to claim 1. The control unit controls the light receiving unit so as to divide the region of interest into a plurality of regions and read out the divided regions for each imaging frame.
The distance measuring sensor according to claim 2. A light emitting unit that irradiates the target area with light is provided.
The control unit controls the light emitting unit so as to irradiate only the region of interest with the light based on the determination result of the region of interest.
The distance measuring sensor according to claim 2. The distance measuring processing unit
An analog / digital converter that converts the electrical signal output for each pixel from an analog signal to a digital signal.
A distance calculation unit that calculates the distance to the region of interest based on the digital signal,
2. The distance measuring sensor according to claim 2. A selection circuit connected between the light receiving unit and the analog / digital conversion unit is provided.
The distance measuring sensor according to claim 12, wherein the control unit switches and controls the selection circuit so as to connect a plurality of pixels corresponding to the region of interest to the analog / digital conversion unit. The control unit specifies a readout line in the region of interest, and simultaneously inputs electrical signals output from a plurality of pixels in a region that does not overlap in the scanning direction of the imaging frame to the analog / digital conversion unit.
The distance measuring sensor according to claim 12. The pixel and the analog / digital conversion unit are connected by a plurality of signal lines that are different for each line of the imaging frame.
The control unit divides and sets the region of interest into a plurality of frames, and transfers the electric signal to the analog / digital conversion unit using a signal line different for each frame.
The distance measuring sensor according to claim 12. A switch connected between the plurality of signal lines and the analog / digital converter is provided.
The control unit controls the on / off of the switch according to the region of interest.
The distance measuring sensor according to claim 15. It is equipped with an area of interest determination unit that determines the area of interest from the output from the distance measurement processing unit.
The control unit controls off the power supply unit belonging to a region other than the region of interest based on the determination result of the region of interest by the region of interest determination unit, and inputs the electrical signal corresponding to the region of interest. To perform at least one of controlling the ranging processing unit,
The distance measuring sensor according to any one of claims 1 to 16. Based on the determination result of the region of interest provided by the external device, the control unit turns off the power supply unit belonging to the region other than the region of interest, and inputs the electrical signal corresponding to the region of interest. Performing at least one of controlling the ranging processing unit,
The distance measuring sensor according to any one of claims 1 to 16. An output interface unit for adding header information and footer information to each line of the imaging frame for the region of interest is provided.
The distance measuring sensor according to claim 2. The light receiving unit provided with a plurality of pixels arranged in a matrix and each having a light receiving element receives the reflected light from the target area, converts it into an electric signal, and outputs it.
In the image pickup frame formed by the plurality of pixels, distance measurement processing for calculating the distance to the region of interest in the image pickup frame is executed based on the electric signal output for each pixel by the distance measurement processing unit. To do and
To output data regarding the distance for each pixel with respect to the imaging frame,
Based on the determination result of the region of interest, the power supply unit belonging to the region other than the region of interest is controlled to be turned off, and the distance measuring processing unit is controlled so as to input the electric signal corresponding to the region of interest. To do at least one, including,
Distance measurement method.

Images