JP7382858B2 - Distance sensor - Google Patents

Description

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

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

By the way, in the above-mentioned dToF distance measuring sensor, the light receiving element receives reflected light (photons) from the emission of a single pulsed light and detects the reflected light. ), whether a photon arrives or not is a stochastic event. Therefore, a distance measurement sensor using a light receiving element improves distance measurement accuracy by creating a histogram that accumulates the reactions of the light receiving element due to multiple light emissions within a predetermined unit time for each time. Such a distance measurement sensor can obtain an imaging frame (distance image) having distance information for each pixel in real time by reading out photons for each pixel column arranged in a line.

In addition, in order to improve distance measurement accuracy even in environments with a lot of disturbance light and fluctuations, a distance measurement sensor that can select the light receiving element that forms the light receiving area used for photon measurement from among multiple light receiving elements. has also been proposed (for example, see Patent Document 1).

JP2018-44923A

Incidentally, even in the above-mentioned distance measuring sensor, higher resolution is strongly desired. With this increase in resolution, the amount of data read out at one time increases.

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

Furthermore, the data output band increases, and the distance measurement interval increases due to the output band rate.

The present disclosure has been made in view of the above circumstances, and aims to provide a ranging sensor that can reduce power consumption and alleviate data output band rate limiting even when the resolution is increased. .

One aspect of the present disclosure includes a light receiving unit including a plurality of pixels arranged in a matrix and each having a light receiving element that converts received reflected light from a target area into an electrical signal, and an electrical signal output for each pixel. a distance measurement processing unit that includes a plurality of signal processing modules that perform signal processing based on the input signal to calculate the distance to the target area and that can independently control power supply; The distance measuring sensor includes a control unit that controls power supply to the processing module.

Another aspect of the present disclosure is to receive reflected light from a target area by a light receiving unit including a plurality of pixels arranged in a matrix and each having a light receiving element, convert the reflected light into an electrical signal, and output the electrical signal; In an imaging frame formed by pixels, a distance measurement process is performed to calculate a distance to a region of interest in the imaging frame based on the electric signal outputted for each pixel by a distance measurement processing unit. outputting data regarding the distance for each pixel with respect to the imaging frame; controlling off a power supply unit belonging to a region other than the region of interest based on a determination result of the region of interest; The distance measurement method includes: controlling the distance measurement processing unit to input the electric signal corresponding to the distance measurement processing unit.

It is a block diagram showing an example of composition of a distance measuring device in a 1st embodiment of this art. FIG. 2 is a block diagram illustrating an example of the configuration of a light receiving section in the first embodiment of the present technology. It is a flowchart for explaining the distance measurement processing method by the distance measurement device in the first embodiment of the present technology. FIG. 3 is a diagram for explaining distance measurement processing during formation of an imaging frame by the distance measurement device according to the first embodiment of the present technology. FIG. 2 is a block diagram illustrating 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. FIG. 3 is a block diagram illustrating an example of a case where sampling circuits are switched in order to output data for the entire area in the first embodiment of the present technology. 7 is a block diagram illustrating an example of a case where sampling circuits are switched in order to output data for the entire area in the first embodiment of the present technology, following FIG. 6 above. FIG. FIG. 7 is a block diagram illustrating an example of a case where power is turned off for pixels other than the ROI region in the second embodiment of the present technology. FIG. 7 is a block diagram illustrating an example of a case where the number of histogram generation circuits is reduced in a third embodiment of the present technology. FIG. 12 is a block diagram illustrating an example of a case where areas that do not overlap in the scanning direction are simultaneously read out in the fourth embodiment of the present technology. FIG. 12 is a block diagram illustrating an example of a case where the light receiving section is of an array type and output terminals of a plurality of light receiving elements are shared for each pixel in the fourth embodiment of the present technology. FIG. 12 is a block diagram illustrating an example of a case in which power is turned off for a sampling circuit and a histogram generation circuit belonging to an area other than the ROI area in the fifth embodiment of the present technology. FIG. 12 is a block diagram illustrating an example of assigning ROI regions to sampling circuits and histogram generation circuits according to angles of view in a sixth embodiment of the present technology. FIG. 12 is a block diagram showing another example of a case where an area other than the ROI area is allocated to a sampling circuit and a histogram generation circuit according to the angle of view in the sixth embodiment of the present technology. FIG. 12 is a diagram illustrating an example of a case where processing is performed by a sampling circuit and a histogram generation circuit on a pixel in a three-layer structure according to a seventh embodiment of the present technology. FIG. 12 is a diagram illustrating an example of a case where processing is performed by a sampling circuit and a histogram generation circuit on a pixel in a two-layer structure according to a seventh embodiment of the present technology. It is a figure which shows an example of the case where it outputs one area at a time in the 8th embodiment of this technique. FIG. 12 is a diagram illustrating an example in which the region to which light is applied is narrowed down to the ROI region when distance measurement is performed line by line in the ninth embodiment of the present technology. FIG. 12 is a diagram illustrating an example of dividing the area to which light is applied into a plurality of areas and focusing on the divided areas when distance measurement is performed line by line in the ninth embodiment of the present technology. It is a figure which shows an example of the case where it outputs one area at a time in the 10th embodiment of this technique. It is a figure shown in order to explain an example when the communication interface part reads distance measurement data in a 10th embodiment of this technology. It is a figure shown in order to explain another example when the communication interface part reads distance measurement data in a 10th embodiment of this technology. It is a block diagram showing an example of composition of a distance measuring device in an 11th embodiment of this art. It is a block diagram showing an example of composition of a distance measuring device in a 12th embodiment of this art. It is a block diagram showing an example of composition of a light receiving part in a 12th embodiment of this art. FIG. 12 is a block diagram illustrating an example of a case where the number of AD converters is reduced in order to output data only in the ROI region in the twelfth embodiment of the present technology. FIG. 12 is a diagram illustrating an example of a case where V-scan (readout line designation) can be performed for each region in the thirteenth embodiment of the present technology. FIG. 7 is a diagram illustrating an example of a case in which pixels are connected line by line using pixel drive lines; FIG. 12 is a diagram illustrating an example of a case where one line is divided into regions and each region is connected by a different pixel drive line in the thirteenth embodiment of the present technology. FIG. 12 is a diagram showing an example in which the ROI region is divided into three frames in the fourteenth embodiment of the present technology. FIG. 12 is a diagram illustrating an example in which three frames of the ROI region are 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 where it outputs one area at a time in the 15th embodiment of this technique. FIG. 12 is a diagram shown to explain an example of a case where the communication interface section reads distance measurement data in the fifteenth embodiment of the present technology. FIG. 12 is a diagram shown to explain another example in which the communication interface section reads distance measurement data in the fifteenth embodiment of the present technology. It is a block diagram showing an example of composition of a distance measuring device in a 16th embodiment of this art.

Embodiments of the present disclosure will be described below with reference to the drawings. In the description of the drawings referred to in the following description, the same or similar parts are denoted by the same or similar symbols, and redundant description will be omitted. However, it should be noted that the drawings are schematic and the relationship between thickness and planar dimension, the ratio of the thickness of each device and each member, etc. may differ from the actual one. Therefore, specific thickness and dimensions should be determined with reference to the following explanation. Furthermore, it goes without saying that the drawings include portions with different dimensional relationships and ratios.

Note that the effects described in this specification are merely examples and are not limiting, and other effects may also exist.

<First embodiment>
<Configuration of distance measuring device>
FIG. 1 is a block diagram showing an example of the configuration of a 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 detects the object OBJ based on an electrical signal obtained by receiving reflected light from an object OBJ (object or subject) irradiated with the pulsed light with a light receiving element. This is a distance sensor that measures the distance to.

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

The system control unit 10 is a component that centrally controls the operation of the distance measuring device 1A. Typically, the system control unit 10 includes a microprocessor.

The light emitting unit 20 emits pulsed light such as infrared light (IR) toward a target area. The light emission timing adjusting section 30 is a circuit that adjusts the light emission timing of the light emitting section 20. For example, the light emission timing adjustment section 30 outputs a trigger pulse to drive the light emission section 20 in synchronization with the readout timing for each line from the light receiving section 40, which will be described later.

The light receiving unit 40 is a sensor that outputs an electrical signal in response to light incident from the target area. The incident light includes reflected light from the object OBJ. In the present disclosure, the light receiving unit 40 is a CMOS image sensor configured with 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 one line direction in an imaging frame) is enabled, and thereby an electrical signal is read out. Further, the pixel groups of each line are sequentially enabled in one frame time, and one imaging frame for the target area is formed by electrical signals output from each of the enabled pixel groups.

The distance measurement 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 distance measurement processing section 50 is typically composed of a signal processing processor. In the present disclosure, the distance measurement processing section 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 electrical signals output from a specific pixel group at a predetermined sampling frequency in response to emission of pulsed light. The sampling circuit 51 outputs a High or Low value (sampling value), for example, according to the value of the electrical signal output from each of the enabled pixel groups.

The histogram generation circuit 52 is a component that generates a histogram indicating the intensity of reflected light for each time based on the total value of sampling values for each sampling time output by the sampling circuit 51. The histogram is held, for example, in a memory (not shown) as some kind of data structure or table. The number of histograms corresponding to the number of pixels is generated based on 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 a peak value in the histogram, and calculates a distance from the time corresponding to the peak value (ie, arrival time). In other words, if the reflected light is received when the emitted pulsed light irradiates the object OBJ, 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, it is possible to obtain a distance image using the distances calculated for all pixels constituting the imaged 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 ROI (Region of Interest) region determination unit 80.

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

The ROI region determination unit 80 determines, for example, the ROI region including the object OBJ based on the calculated ranging data. This determination result is output to the system control unit 10. The system control unit 10 controls pixels provided in the ranging processing unit 50 and the light receiving unit 40 to process electrical signals from pixels corresponding to the ROI area based on the ROI area determination result by the ROI area determination unit 80. Controls the drive unit 70.

<Configuration of light receiving section>
FIG. 2 illustrates one pixel 41 of a plurality of pixels arranged in a two-dimensional matrix in the light receiving section 40, and a power source 42 that supplies power to the pixel 41. The pixel 41 includes a photoelectric conversion element that photoelectrically converts received light and generates charges according to the amount of light.

A pixel drive unit 70 is connected to the light receiving unit 40 via a pixel drive line 43. The pixel driving section 70 drives each pixel of the light receiving section 40 simultaneously for all pixels or in units of rows. A pixel signal output from each pixel of a pixel line (pixel row) selectively scanned by the pixel driving section 70 is supplied to the sampling circuit 51 through each of the vertical signal lines 44.

The sampling circuit 51 samples pixel signals output from each pixel unit of a selected line (selected row) through the vertical signal line 44 for each pixel column of the light receiving section 40 at a predetermined sampling frequency.

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

That is, when the distance measuring device 1A starts the distance measuring process, it first selects a read line in the imaged frame (step ST1a). For example, immediately after the start of distance measurement processing, the topmost line in the captured frame is selected.

Subsequently, the distance measuring device 1A measures the distance to the pixel 41 in the selected readout line (step ST1b). Thereby, the light receiving section 40 outputs a pixel signal from the pixel 41 to the distance measurement processing section 50.

The distance measurement 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 measurement processing unit 50 detects a peak value in the generated histogram, and calculates the distance from the time corresponding to the peak value (step ST1d). The distance measuring device 1A then uses the ROI region determination unit 80 to determine whether or not there is an object OBJ based on the calculated distance measurement data (step ST1e), and if there is an object OBJ (Yes), the pixel drive 70 to turn on the power supply 42 only in the ROI region, or control the sampling circuit 51 to perform sampling of pixel signals only in the ROI region (step ST1f). Note that in the process of step ST1f, in addition to the determination result by the ROI region determination unit 80, even if image recognition is performed using an external camera image, for example, a signal indicating that the object OBJ is present is received from the outside. Good too. Furthermore, without using the signal indicating that the object OBJ exists, it is also possible to decide in advance to divide the area and turn on the power for each area, and input the information.

Thereafter, the distance measuring device 1A determines whether or not the selected line has ended (step ST1g). If the line has not ended (No), the process proceeds to step ST1b, but if the line has ended (Yes). ), the process moves to step ST1a and selects the next read line.

In this way, as shown in FIG. 4, for example, in the scene in front of the vehicle, the distance measuring device 1A can measure nearby obstacles (for example, other vehicles) with higher distance measurement accuracy. Collisions and the like can be avoided more accurately. On the other hand, if there are no obstacles nearby (for example, other vehicles) as a result of distance measurement, the pixel It will be possible to reduce power consumption by lowering the drive voltage and calculation load on the processor.

<Reduction of sampling circuit>
FIG. 5 is a block diagram showing an example of a case where 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 simultaneously sample pixel signals output from the plurality of pixels 41. In the example of FIG. 5, the sampling circuit 51 has a number of electrical signals (for example, three in FIG. 5) that can simultaneously process electrical signals output from a plurality of pixels 41 corresponding to the ROI region on one line in the imaging frame. A module is provided (hereinafter referred to as sampling circuit (2, 3, 4) 51). Note that in the case of simultaneously processing the electrical signals output from all the pixels 41 on one line, in the example of FIG. 5, for example, five sampling circuits 51 are required. Moreover, one pixel 41 includes a plurality of light receiving elements. Furthermore, power supply to the plurality of modules of the sampling circuit 51 can be controlled independently.

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

In the line indicated by the thick frame in FIG. 5, pixel signals output from the third to sixth pixels 41 from the right end corresponding to the ROI region are input to the sampling circuit (4) 51 via the selector 54, and from the right end 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 illustrating an example of switching the sampling circuit 51 in order to output data for the entire area in the first embodiment of the present technology.

First, in the line indicated by the thick frame in FIG. . Then, the system control unit 10 switches the selector 54, and as shown in FIG. , 4) Input in 51.

<Operations and effects of the first embodiment>
As described above, according to the first embodiment, the circuit scale of the sampling circuit 51 is reduced relative to the number of pixels 41 in the line (row) direction of the imaging frame, and the area to be ranged by the selector 54 is 51, when a small number of sampling circuits 51 are shared by a larger number of pixels 41 in one line (row) direction, power consumption can be reduced by reducing the circuit scale of the sampling circuits 51.

Therefore, by activating only the necessary portions, even if the resolution is increased, power consumption can be reduced and data output band rate limiting can be alleviated.

Further, according to the first embodiment, since the ROI region determining section 80 is provided in the distance measuring device 1A, it is possible to process the ROI in the captured frame in real time.

<Second embodiment>
Next, a second embodiment will be described. The second embodiment is a modification of the first embodiment, and a case will be described in which the power supply 42 of the pixels 41 outside the ROI region is turned off.

FIG. 8 is a block diagram illustrating an example of turning off the power supply 42 of the pixels 41 other than the ROI region according to the second embodiment of the present technology. In the example of FIG. 8, in the third line (row) from the top, the system control unit 10 controls the power source 42 of the pixel 41 in the area other than the ROI area (the gray area in FIG. 8) among the areas to be read out at the same timing. Turn off. Then, pixel signals output from the 8th to 12th pixels 41 from the left end are input to the sampling circuit 51.

Furthermore, in the tenth line (row) from the top, the system control unit 10 turns off the power supply 42 of the pixels 41 outside the ROI region. Then, pixel signals output from the fifth to seventh and twelfth to fifteenth pixels 41 from the left end are input to the sampling circuit 51.

<Actions and effects of the second embodiment>
As described above, according to the second embodiment, by turning off the power supply 42 of the pixels 41 other than the ROI region, power consumption can be reduced without changing the circuit scale of the sampling circuit 51 and the histogram generation circuit 52. It 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 will be described in which the number of modules of the histogram generation circuit 52 is reduced in order to output data only in the ROI region.

FIG. 9 is a block diagram illustrating an example of reducing the number of modules of the histogram generation circuit 52 in the third embodiment of the present technology. 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 a switching instruction from the system control unit 10. Power supply to the plurality of modules of the histogram generation circuit 52 can be controlled independently.

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

<Operations and effects of the third embodiment>
As described above, according to the third embodiment, the circuit scale of the histogram generation circuit 52 is reduced relative to the number of pixels 41 in the line direction of the imaging frame, and the area to be measured by the selector 54 is converted into a histogram. By allocating it 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 size of the histogram generation circuit 52 can be reduced, and the consumption can be reduced. Can reduce power consumption.

Furthermore, in the third embodiment, a plurality of sampling circuits (1, 2, 3, 4, 5) Since 51 are fixedly prepared, sampling processing can be performed with high accuracy.

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

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

The light receiving section 40 is of 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. The pixel 41a shown in FIG. 10 is provided with, for example, 12 light receiving elements 45, as shown in FIG. The pixel 41b is equipped with, for example, twelve light receiving elements 46. The pixel 41c is equipped with, for example, twelve light receiving elements 46. Note that the light receiving element 45 is a light receiving element that does not read data simultaneously, and the light receiving element 46 is a light receiving element that reads data simultaneously.

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

Here, when outputting only ROI data 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 connects the light receiving element 45 belonging to the pixels 41b and 41c via the pixel drive line 43 to the light receiving element 45 belonging to the pixels 41b and 41c. , and simultaneously input pixel signals output from the light receiving element 46 to the sampling circuit 51 via the vertical signal lines 441, 442, 443, 444, 445, and 446, respectively.

<Operations and effects 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 are By turning off the power of 45 or performing an output mask, it becomes possible to simultaneously read out areas that do not overlap in different V directions.

<Fifth embodiment>
Next, a fifth embodiment will be described. The fifth embodiment is a modification of the first embodiment, and a case will be described in which the power of the sampling circuit 51 and the histogram generation circuit 52 belonging to an area other than the ROI area is turned off.

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

In the example of FIG. 12, the sampling circuit 51 and the histogram generation circuit 52 are provided with a number of modules that can simultaneously process electrical signals output from a plurality of pixels 41 on one line in an 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 each module and the power supply 55. Note that the configuration is not limited to one power source 55, and a configuration may be adopted in which a plurality of power sources and a plurality of modules are 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 outside the ROI region in the line (row). Then, the power gate cell 56 to the power supply 55 of the module (modules 2 and 3 in FIG. 12) belonging to the pixel 41 in the ROI region is turned on, and the pixel signal output from the pixel 41 is input to the sampling circuit 51. Note that in addition to the power gate cell 56, a clock gating cell may be used.

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

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

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

In the example of FIG. 13, in order to make the center granularity finer, the sampling circuit 51 and the histogram generation circuit 52 simultaneously process the electrical signals output from the 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) of sampling circuits (2, 3, 4, 5, 6, 7, 8) 51 and histogram generation circuits (2, 3, 4, 5, 6, 7, 8) 52). Two sampling circuits 51 and two histogram generation circuits 52 are provided in areas other than the ROI region (hereinafter referred to as sampling circuits (1, 9) 51 and histogram generation circuits (1, 9) 52).

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

Further, when inputting the pixel signal output from the pixel 41 of the face part of the ROI region on one line to the sampling circuit (3, 4, 5, 6, 7) 51, the system control unit 10 controls the sampling circuit (3, 4, 5, 6, 7). The power gate cells 56 to the power supplies 55 of the modules belonging to the histogram generation circuit (1, 2, 8, 9) 51 and the histogram generation circuit (1, 2, 8, 9) 52 are turned off.

Further, when inputting the pixel signal output from the pixel 41 on the right hand side of the ROI region on one line to the sampling circuit (2, 3) 51, the system control unit 10 controls the sampling circuit (1, 4, 5, The power gate cells 56 to the power supplies 55 of the modules belonging to the histogram generation circuits (1, 4, 5, 6, 7, 8, 9) 52 are turned off.

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

This makes it possible to block both ends of one line in the imaging frame in accordance with the general angle of view.

Note that, as shown in FIG. 14, the configuration may be such that the power supply can be shut off as needed in the use case of setting or reading out all pixels 41, in addition to ROI. In the example of FIG. 14, four sampling circuits 51 and four histogram generation circuits 52 are provided (hereinafter referred to as sampling circuits (1-1, 1-2, 2-1, 1 -2) 51 and histogram generation circuit (referred to as 1-1, 1-2, 2-1, 1-2) 52).

When inputting the pixel signal output from the pixel 41 in the ROI region on one line to the sampling circuit (3, 4, 5) 51, the system control unit 10 The power gate cells 56 to the power supplies 55 of the modules belonging to the histogram generation circuits (1, 1-2) 51 and the histogram generation circuits (1-1, 1-2, 2-1, 1-2) 52 are turned off. Further, when changing the angle of view of VGA to that of HVGA or QVGA, the system control unit 10 controls the sampling circuit (1-1, 1-2) 51 and the histogram generation circuit (1-1, 1-2). It is also possible to turn off the power gate cell 56 to the power supply 55 of the module belonging to the module 52.

<Seventh embodiment>
Next, a seventh embodiment will be described. The seventh embodiment is a modification of the first embodiment, and a case will be described in which, for example, processing is performed by the sampling circuit 51 and the histogram generation circuit 52 on the pixel 41 in a layered structure.

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

In the example of FIG. 15, the surface of the pulse changing circuit 200 is interposed between the surface of the light receiving section 40 and the surface of the ranging processing section 50. The pulse changing circuit 200 includes a plurality of power supply units that are provided for each pixel 41 arranged within the plane of the light receiving unit 40 or for each pixel group constituted by several pixels 41, and supply power to the light receiving element. Further, the pulse changing 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 a low level to a high level, the light receiving element in the pixel 41 lowers its quench voltage, thereby discharging the accumulated charge.

The system control unit 10 can control the pulse change circuit 200 to shut off power to logic other than the ROI area or stop clocks.

Note that a two-layer structure may be used instead of the three-layer structure. FIG. 16 is a diagram illustrating an example of a case where processing is performed by the sampling circuit 51 and the histogram generation circuit 52 on the pixel 41 in a 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 measurement processing section 50. Note that the pulse change circuit 200 may be provided on the surface of the light receiving section 40.

<Actions and effects of the seventh embodiment>
As described above, according to the seventh embodiment, when performing distance measurement processing on a surface of a pixel 41 in a layered structure, the power source 42 belonging to a region other than the ROI region within the surface of the light receiving section 40 is turned off. can do.

<Eighth embodiment>
Next, an eighth embodiment will be described. The eighth embodiment is a modification of the first embodiment, and a case where not all regions are output in one imaging frame but one region at a time will be described.

FIG. 17 is a diagram illustrating an example of outputting one area at a time in 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,” “right hand,” and “left hand,” and controls the light receiving unit 40 to read out the divided regions for each imaging frame. Note that it is assumed that the "right hand" and the "left hand" are areas that overlap when reading.

The system control unit 10 controls the light receiving unit 40 to read out the "right hand" in the first frame. Subsequently, the system control unit 10 controls the light receiving unit 40 to read out the "face" in the second frame. In the third frame, the system control unit 10 controls the light receiving unit 40 to read “left hand”.
Note that the readout process may be performed multiple times until the scene changes even if specified.

<Operations and effects of the eighth embodiment>
As described above, according to the eighth embodiment, by outputting one divided area at a time instead of outputting all areas in one imaging frame, when areas overlap, the size to be read out at the same time can be reduced. Distance measurement accuracy can be improved by limiting temperature rise and by irradiating light only within the area.

<Ninth embodiment>
Next, a ninth embodiment will be described. The ninth embodiment is a modification of the first embodiment, and a case will be described in which the region to which light is applied is narrowed down to the ROI region.

FIG. 18 is a diagram illustrating an example in which the region to which light is applied is narrowed down to the ROI region when distance measurement is performed line by line in the ninth embodiment of the present technology.

In the example of FIG. 18A, the system control unit 10 causes the light emission timing adjustment unit 30 to emit light in a focused manner on the ROI area on one line of the imaging frame based on the determination result by the ROI area determination unit 80. The light emitting unit 20 is controlled by the light emitting timing adjusting unit 30 by sending an instruction signal to.

In the example of FIG. 18(b), the system control unit 10 controls the light emission timing adjustment unit 30 to emit light with increased light emission intensity in the ROI region based on the determination result by the ROI region determination unit 80. Controls the light emitting section 20.

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

In the example of FIG. 19, the system control unit 10 divides the ROI region into, for example, “face,” “right hand,” and “left hand,” based on the determination result by the ROI region determination unit 80, and narrows it down to the divided regions. An instruction signal is sent to the light emission timing adjustment section 30 so that the light emission section 20 is controlled by the light emission timing adjustment section 30 so as to emit light.

For example, as shown in FIG. 19(a), the system control unit 10 sends an instruction signal to the light emission timing adjustment unit 30 to cause the light emission timing adjustment unit 30 to control the light emission unit 20 so that the light emission is focused on the “face”. Control. Further, as shown in FIG. 19(b), the system control unit 10 sends an instruction signal to the light emission timing adjustment unit 30 to cause the light emission timing adjustment unit 30 to control the light emission unit 20 so that the light emission is focused on the “right hand”. Control. Furthermore, as shown in FIG. 19(c), the system control unit 10 sends an instruction signal to the light emission timing adjustment unit 30 to cause the light emission timing adjustment unit 30 to control the light emission unit 20 so as to focus the light emission on the “left hand”. Control.

Note that instead of dividing the ROI region into, for example, a "face," "right hand," and "left hand," and emitting light in the divided regions, the light may be emitted in a focused manner in the entire ROI region.

<Operations and effects of the ninth embodiment>
As described above, according to the ninth embodiment, by narrowing the area to which light is applied to the ROI area, the amount of light is enhanced, the consumption of the light emitting unit 20 is reduced, and the safety function is improved by not irradiating light to unnecessary areas. can be expected.

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

FIG. 20 is a diagram illustrating an example of outputting one area at a time in the tenth embodiment of the present technology.

In the example of FIG. 20, the system control unit 10 divides the ROI region into, for example, frame 1 (face), frame 2 (right hand), and frame 3 (left hand), and reads the data of frame 1, frame 2, and frame 3. The light receiving section 40 is controlled as follows.

As shown in FIG. 21, the communication interface section 60 adds the PH and PF identified for each line to the distance measurement data of frame 1 output from the distance measurement processing section 50, and then adds the PH and PF identified for each line. The PH and PF identified for each line are added to the distance measurement data of No. 3.

Furthermore, as shown in FIG. 22, when reading out areas in different V directions at the same time, the communication interface unit 60 arranges the distance measurement data of frames 1, 2, and 3 on one line, and also arranges the distance measurement data of frames 1, 2, and 3 on one line, and PH and PF are added to the distance measurement data of frames 2 and 3.

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

<Eleventh embodiment>
Next, an eleventh embodiment will be described. In the eleventh embodiment, the distance calculation circuit 53 is removed from the distance measurement processing section 50, and an external host IC that receives the distance measurement data calculated by the distance measurement processing section 57 is used. Disclosed is a distance measuring device 1B that makes it possible to determine an ROI region. Here, the term "external host IC" is used to mean 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 a distance measuring device 1B according to the eleventh embodiment of the present technology. As shown in the figure, the host IC 2 executes processing by the distance calculation circuit 53 based on the distance measurement data received from the distance measurement processing section 57 via the communication interface section 60, and determines the ROI region. This embodiment is different from that shown in the first embodiment in that it is configured as follows. Note that in FIG. 23, components having the same functions or configurations as those already illustrated 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 region determination section 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 section. Similar to the first embodiment, when the distance measurement calculation circuit of the host IC 2 receives the distance measurement data from the distance measurement processing section 50 via the communication interface section 60, it calculates the distance to the object OBJ. Then, the ROI region determination unit of the host IC 2 determines the ROI region based on the distance measurement data. The ROI region 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) that can hold distance measurement data for one imaging frame. The ROI region determination unit of the host IC 2 refers to the frame buffer and determines the ROI region for each read line in the next captured frame.

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

<Description 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 configured to include a plurality of light receiving elements (SPADs) arranged in a two-dimensional array. That is, each SPAD detects incoming light (photons) and converts 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 one line direction in an imaging frame) is enabled, and thereby an electrical signal The pulse is read out. Further, the SPAD groups of each line are sequentially enabled in one frame time, and one imaging frame for the target area is formed by electrical signal pulses output from each of the enabled SPAD groups.

<Twelfth embodiment>
<Configuration of distance measuring device>
FIG. 24 is a block diagram showing an example of the configuration of a 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 converted by a plurality of transfer transistors. This is a distance measuring sensor that measures the distance to an object OBJ based on the amount of charge that is distributed to a plurality of charge storage sections and accumulated in the plurality of charge storage sections.

As shown in the figure, the distance measuring device 1C differs from the first embodiment in that it includes a distance measuring processing section 90, an AD (analog-to-digital) converting section 91, and a distance calculating circuit 92. This is different from the one shown in the figure. Note that in FIG. 24, components having the same functions or configurations as those already illustrated are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

The AD converter 91 converts a pixel signal corresponding to the amount of charge output and accumulated for each pixel 41 from an analog signal to a digital signal. A pixel signal for each pixel 41 is output to a distance calculation circuit 92. The distance calculation circuit 92 calculates the distance to the object OBJ based on the pixel signal of each pixel 41. The distance calculation circuit 92 can obtain a distance image based on the distances calculated for all 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 section 60 and the ROI region determination section 80.

The ROI region determination unit 80 determines, for example, the ROI region including the object OBJ based on the calculated ranging 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 ROI area determination result by the ROI area determination unit 80. Note that when controlling the pixel drive unit 70, the system control unit 10 may use a V (vertical) control determination unit 100 that determines whether to skip the readout area or the like.

<Configuration of light receiving section>
FIG. 25 illustrates one pixel 41 among a plurality of pixels arranged in a two-dimensional matrix in the light receiving section 40. The pixel 41 includes a photoelectric conversion element that photoelectrically converts received light and generates charges according to the amount of light.

A pixel drive unit 70 is connected to the light receiving unit 40 via a pixel drive line 43. The pixel driving section 70 drives each pixel of the light receiving section 40 simultaneously for all pixels or in units of rows. A pixel signal output from each pixel of a pixel line (pixel row) selectively scanned by the pixel driving section 70 is supplied to the AD converting section 91 through each of the vertical signal lines 44.

The AD conversion unit 91 converts the pixel signals output from each pixel unit of the selected line (selected row) through the vertical signal line 44 from analog signals to digital signals for each pixel column of the light receiving unit 40 .

<Reduction of AD converter>
FIG. 26 is a block diagram illustrating an example of a case where the number of AD converters 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 converter 91 needs to simultaneously convert the pixel signals output from the plurality of pixels 41 from analog signals to digital signals. In the example of FIG. 26, the AD converter 91 can simultaneously process the number of pixel signals output from a plurality of pixels 41 corresponding to the ROI region on one line in the imaged frame (for example, three in FIG. 26). (hereinafter referred to as AD conversion unit (2, 3, 4) 91). Note that in the case of simultaneously processing the electrical signals output from all the pixels 41 on one line, in the example of FIG. 26, for example, five AD conversion units (1, 2, 3, 4, 5) 91 are required. Become. Moreover, one pixel 41 includes a plurality of light receiving elements.

A selector 93 is interposed between the light receiving section 40 and the AD converting section (1, 2, 3, 4, 5) 91. The selector 93 selectively connects, for example, the light receiving section 40 and the AD converting section (2, 3, 4) 91 in accordance with a switching instruction from the system control section 10.

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

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

<Operations and effects of the twelfth embodiment>
As described above, according to the twelfth embodiment, the number of AD converters 91 is reduced relative to the number of light receiving elements and pixels in the line direction of the imaging frame, and the area to be measured by the selector 93 is set to the AD converter 91. By allocating the AD converters 91 to a larger number of pixels 41 in one line direction, a smaller number of AD converters 91 can be shared by a larger number of pixels 41, and power consumption can be reduced by reducing the number of AD converters 91.

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

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

In the example of FIG. 27, when outputting a pixel signal from the pixel 41 in the third line from the top of the ROI region (the first row is shown in FIG. 27), the pixel drive line 43(1) shown in FIG. Pixel signals are output from all pixels 41 of the eye at the same timing. Furthermore, when outputting a pixel signal from the pixel 41 in the ROI region on the fourth line from the top (in FIG. 27, the second row is shown), all pixels on the fourth line are Pixel signals from 41 are output at the same timing.

Therefore, in the thirteenth embodiment of the present technology, as shown in FIG. 29, areas within one line are divided and 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 on the third line from the top end are connected by the pixel drive line 431, and the ninth pixel from the left end is connected by the pixel drive line 431. The twelfth pixel 412 is connected by a pixel drive line 432. Then, the 13th to 16th pixels 413 from the left end are connected by a pixel drive line 433, and the 17th to 20th pixels 414 from the left end are connected by a pixel drive line 434.

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

When reading out the pixel 412 in the ROI region on the third line (in FIG. 27, the first line of the face part), the pixel driving unit 70 drives the pixel 412 via the pixel driving line 432, and the pixel 412 is outputted from the pixel 412. The pixel signal is input to the AD converter 91.

When reading out the pixel 416 in the ROI region on the fourth line (in FIG. 27, the second line of the face part), the pixel driving unit 70 drives the pixel 416 via the pixel driving line 436, and the pixel 416 is outputted from the pixel 416. The pixel signal is input to the AD converter 91.

<Operations and effects of the thirteenth embodiment>
As described above, according to the thirteenth embodiment, by configuring the readout line so that it can be specified for each area, the output is output from a plurality of pixels 41 in areas that do not overlap in the V (scanning) direction of the imaging frame. By simultaneously reading out the pixel signals and inputting them to the AD converter 91, the processing time of the AD converter 91 can be shortened, and power consumption can be reduced accordingly.

<Fourteenth embodiment>
Next, a fourteenth embodiment will be described. The fourteenth embodiment is a modification of the twelfth embodiment, and a configuration in which the AD converter 91 has many vertical signal lines 44 will be described.

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

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

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

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

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

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

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

<Operations and effects of the fourteenth embodiment>
As described above, according to the fourteenth embodiment, by having many vertical signal lines 44 for the AD conversion unit 91, the ROI region can be divided and set into, for example, frame 1, frame 2, and frame 3, and V When the directions do not overlap, it becomes possible to simultaneously input a plurality of pixel signals to the AD converter 91 using different vertical signal lines 44 for each frame 1, frame 2, and frame 3, thereby reducing processing time. , power consumption can be reduced accordingly.

<Modification of the fourteenth embodiment>
Note that as a modification of the fourteenth embodiment of the present technology, a switch can be interposed between the vertical signal line 44 and the AD conversion section 91. In this way, the system control unit 10 can turn on and off the switch according to the ROI region.

<Fifteenth embodiment>
Next, a fifteenth embodiment will be described. The fifteenth embodiment is a modification of the twelfth embodiment, and a case will be described in which data on different lines are simultaneously and consecutively output.

FIG. 32 is a diagram illustrating an example of outputting one area at a time in the fifteenth embodiment of the present technology.

In the example of FIG. 32, the system control unit 10 divides the ROI region into, for example, frame 1 (face), frame 2 (right hand), and frame 3 (left hand), and reads the data of frame 1, frame 2, and frame 3. The light receiving section 40 is controlled as follows.

As shown in FIG. 33, the communication interface section 60 outputs the distance measurement data of the frame 1, frame 2, and frame 3 outputted from the distance measurement processing section 50 in a line-by-line manner.

Furthermore, as shown in FIG. 34, when reading out different V-direction areas at the same time, the communication interface unit 60 outputs the distance measurement data of frame 1, frame 2, and frame 3 arranged on one line.

<Sixteenth embodiment>
Next, a sixteenth embodiment will be described. In the sixteenth embodiment, a distance measuring device 1D is disclosed that makes it possible to determine an ROI region using an external host IC that receives distance measurement data calculated by a distance measurement processing unit 90. Here, the term "external host IC" is used to mean that it is provided outside the distance measuring device 1D as the SoC described in the twelfth embodiment.

FIG. 35 is a block diagram illustrating an example of the configuration of a distance measuring device 1D according to the sixteenth embodiment of the present technology. As shown in the figure, the distance measurement device 1D has a distance measurement processing section 94 obtained by removing the distance calculation circuit 92 from the distance measurement processing section 90, and the host IC 2 extracts the communication interface section 60 from the distance measurement processing section 94. This embodiment differs from that shown in the twelfth embodiment in that it is configured to determine the ROI region based on distance measurement data received via the twelfth embodiment. Note that in FIG. 35, components having the same functions or configurations as those already illustrated 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 region determination section 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 section. Similar to the first embodiment, when the distance measurement calculation circuit of the host IC 2 receives the distance measurement data from the distance measurement processing section 94 via the communication interface section 60, it calculates the distance to the object OBJ. Then, the ROI region determination unit of the host IC 2 determines the ROI region based on the distance measurement data. The ROI region 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) that can hold distance measurement data for one imaging frame. The ROI region determination unit of the host IC 2 refers to the frame buffer and determines the ROI region for each read line in the next captured frame.

<Operations and effects of the 16th embodiment>
In this way, the sixteenth embodiment can also provide the same effects or advantages as the eleventh embodiment and the twelfth embodiment. Furthermore, according to the sixteenth embodiment, since the processing by the distance measurement calculation circuit and the ROI region determination processing can be omitted in the distance measuring device 1D, advanced processing becomes possible.

<Other embodiments>
As mentioned above, although the present technology has been described using the first to sixteenth embodiments, the statements and drawings that form part of this disclosure should not be understood as limiting the present technology. After understanding the spirit of the technical content disclosed by the above-described embodiments, it will be apparent to those skilled in the art that various alternative embodiments, implementations, and operational techniques may be included in the present technology. Furthermore, the configurations disclosed in the first to sixteenth embodiments and the modifications of the first to sixteenth embodiments can be combined as appropriate within a range that does not cause any contradiction. For example, configurations disclosed by a plurality of different embodiments may be combined, or configurations disclosed by a plurality of different modifications of the same embodiment may be combined.

Note that the present disclosure can also have the following configuration.
(1)
a light receiving unit including a plurality of pixels arranged in a matrix and each having a light receiving element that converts received reflected light from a target area into an electrical signal;
a plurality of power supply units that are provided for each pixel or for each pixel group constituted by several pixels and supply power to the light receiving element;
A distance measurement process for calculating a distance to a region of interest in the image capture frame based on the electrical signal output for each pixel in the image capture frame formed by the plurality of pixels. Department and
an output interface unit that is output by the distance measurement processing unit and outputs data regarding the distance for each pixel with respect to the imaging frame;
a control unit that performs at least one of on/off control of the plurality of power supply units, output masking of the light receiving element, and control of distance measurement processing by the distance measurement processing unit;
Equipped with
The control unit is configured to control off a power supply unit belonging to a region other than the region of interest based on the determination result of the region of interest, and perform the distance measurement process to input the electrical signal corresponding to the region of interest. performing at least one of the following:
Distance sensor.
(2)
The distance measurement processing section
a sampling circuit that samples the electrical signal output for each pixel at a predetermined sampling frequency and outputs a sampled value;
a histogram generation unit that generates a histogram indicating the intensity of the reflected light for each time based on the plurality of sampling values obtained by performing the light reception;
a distance calculation unit that detects a peak value in the histogram and calculates a distance from the peak value to the region of interest;
The ranging sensor according to (1) above.
(3)
comprising a selection circuit connected between the light receiving section and the sampling circuit,
The sampling circuit is provided with a plurality of 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 to connect a plurality of pixels corresponding to the region of interest and a plurality of the sampling circuits.
(4)
comprising a selection circuit connected between the sampling circuit and the histogram generation section,
The sampling circuit includes a plurality of sampling circuits capable of simultaneously processing electrical signals output from a plurality of pixels constituting one line in the imaging frame,
The histogram generation unit includes a plurality of units capable of simultaneously processing 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 to connect the plurality of sampling circuits and the plurality of histogram generation units in order to process electrical signals from a plurality of pixels corresponding to the region of interest. 2) The distance measuring sensor described in 2).
(5)
The light receiving section is of an array type,
The distance measuring sensor according to (1) above, wherein the output terminals of the plurality of light receiving elements are shared for each pixel.
(6)
A plurality of the sampling circuits and the histogram generation unit are provided 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 power off of the sampling circuit and the histogram generation unit that belong to a region other than the region of interest.
(7)
The light receiving section and the distance measurement processing section have a laminated structure belonging to different layers,
The distance measuring sensor according to (1), wherein the control unit controls off a power supply unit that belongs to a region other than the region of interest on a plane made up of the plurality of pixels.
(8)
The distance measuring sensor according to (1), wherein the control unit controls the light receiving unit to divide the region of interest into a plurality of regions and read out the divided regions for each imaging frame.
(9)
comprising a light emitting unit that irradiates light to the target area,
The distance measuring sensor according to (1), wherein the control unit controls the light emitting unit to irradiate only the region of interest with the light based on the determination result of the region of interest.
(10)
The distance measurement processing section
an analog/digital conversion unit that converts the electrical signal output for each pixel from an analog signal to a digital signal;
a distance calculation unit that calculates a distance to the region of interest based on the digital signal;
The ranging sensor according to (1) above.
(11)
comprising a selection circuit connected between the light receiving section and the analog/digital conversion section,
The analog/digital conversion unit is provided with a plurality of 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 section switches and controls the selection circuit to connect a plurality of pixels corresponding to the region of interest and a plurality of the analog/digital conversion sections.
(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 an area that does not overlap in a scanning direction of the imaging frame to the analog/digital conversion unit. The distance measuring sensor according to (10).
(13)
The pixels and the analog/digital converter are connected by a plurality of signal lines 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 electrical signal to the analog/digital conversion unit using a different signal line for each frame. distance sensor.
(14)
comprising a switch connected between the plurality of signal lines and the analog/digital conversion section,
The distance measuring sensor according to (13), wherein the control unit controls on/off the switch according to the region of interest.
(15)
comprising a region of interest determination unit that determines the region of interest from the output from the distance measurement processing unit;
The control unit controls to turn off a power supply unit belonging to a region other than the region of interest based on a 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. The distance measurement sensor according to any one of (1) to (14), wherein the distance measurement sensor executes at least one of controlling the distance measurement processing unit as follows.
(16)
The control unit controls off a power supply unit belonging to a region other than the region of interest based on a determination result of the region of interest provided from an external device, and inputs the electrical signal corresponding to the region of interest. The distance measurement sensor according to any one of (1) to (14), wherein the distance measurement sensor executes at least one of controlling the distance measurement processing unit as follows.
(17)
The distance measuring sensor according to any one of (1) to (10), wherein the output interface section adds header information and footer information to each line of the imaging frame for the region of interest.
(18)
Receiving reflected light from the target area by a light receiving unit including a plurality of pixels arranged in a matrix and each having a light receiving element, converting it into an electrical signal and outputting it;
In the imaging frame formed by the plurality of pixels, a distance measurement process is performed to calculate a distance to a region of interest in the imaging frame based on the electrical signal output for each pixel by a distance measurement processing unit. to carry out and
outputting data regarding the distance for each pixel with respect to the imaged frame;
Based on the determination result of the region of interest, controlling a power supply unit belonging to an area other than the region of interest to be turned off, and controlling the distance measurement processing unit to input the electric signal corresponding to the region of interest. carrying out at least one of the following;
Distance measurement method.
(19)
a light receiving unit including a plurality of pixels arranged in a matrix and each having a light receiving element that converts received reflected light from a target area into an electrical signal;
a distance measurement processing unit that performs signal processing based on the electrical signal output for each pixel to calculate the distance to the target area, and includes a plurality of signal processing modules that can independently control power supply;
A ranging sensor comprising: a control unit that controls power supply to the plurality of signal processing modules according to an input signal.
(20)
The distance measurement processing unit performs distance measurement processing for calculating a distance to a region of interest in the image capture frame based on the electrical signal output for each pixel in the image capture frame formed by the plurality of pixels. 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)
comprising a selection circuit connected between the light receiving section and the plurality of signal processing modules,
As described in (20) above, the control unit switches and controls the selection circuit to connect a plurality of pixels corresponding to the region of interest and a signal processing module corresponding to a plurality of pixels corresponding to the region of interest. ranging sensor.
(22)
The distance measuring sensor according to (21), wherein the light receiving element is an avalanche photodiode.
(23)
The distance measurement processing unit includes a sampling circuit that samples the electrical signal output for each pixel at a predetermined sampling frequency and outputs a sampled value,
The distance measuring sensor according to (22), wherein the selection circuit is disposed between the light receiving section and the sampling circuit.
(24)
The distance measurement processing section
a sampling circuit that samples the electrical signal output for each pixel at a predetermined sampling frequency and outputs a sampled value;
a histogram generation unit that generates a histogram indicating the intensity of the reflected light for each time based on the plurality of sampling values obtained by performing the light reception;
The distance measuring sensor according to (22), wherein the selection circuit is disposed between the sampling circuit and the histogram generation section.

1A, 1B, 1C, 1D... distance measuring device, 2... host IC, 10... system control unit, 20... light emitting unit, 30... light emission timing adjustment unit, 40... light receiving unit, 41, 41a, 41b, 41c, 411, 412, 413, 414, 415, 416, 417, 418, 4111, 4112, 4121, 4122, 4131, 4132... Pixel, 42... Power supply section, 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, 4411, 4412, 4421, 4422, 4431, 4432... Vertical signal line, 45, 46 ... Light receiving element, 50, 90... Distance processing unit, 51... Sampling circuit, 52... Histogram generation circuit, 53, 63, 92... Distance calculation circuit, 54, 93... Selector, 55... Power source, 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 (19)

a light receiving unit including a plurality of pixels arranged in a matrix and each having a light receiving element that converts received reflected light from a target area into an electrical signal;
a distance measurement processing unit that performs signal processing based on the electrical signal output for each pixel to calculate the distance to the target area, and includes a plurality of signal processing modules that can independently control power supply;
A ranging sensor comprising: a control unit that controls power supply to the plurality of signal processing modules according to an input signal. The distance measurement processing unit performs distance measurement processing for calculating a distance to a region of interest in the image capture frame based on the electrical signal output for each pixel in the image capture frame formed by the plurality of pixels. Run
The ranging 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. comprising a selection circuit connected between the light receiving section and the plurality of signal processing modules,
3. The control unit switches and controls the selection circuit 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 sensor. The distance measuring sensor according to claim 3, wherein the light receiving element is an avalanche photodiode. The distance measurement processing unit includes a sampling circuit that samples the electrical signal output for each pixel at a predetermined sampling frequency and outputs a sampled value,
The distance measuring sensor according to claim 4, wherein the selection circuit is arranged between the light receiving section and the sampling circuit. The distance measurement processing section
a sampling circuit that samples the electrical signal output for each pixel at a predetermined sampling frequency and outputs a sampled value;
a histogram generation unit that generates a histogram indicating the intensity of the reflected light for each time based on the plurality of sampling values obtained by performing the light reception;
The distance measuring sensor according to claim 4, wherein the selection circuit is arranged between the sampling circuit and the histogram generation section. The distance measurement processing section
a sampling circuit that samples the electrical signal output for each pixel at a predetermined sampling frequency and outputs a sampled value;
a histogram generation unit that generates a histogram indicating the intensity of the reflected light for each time based on the plurality of sampling values obtained by performing the light reception;
a distance calculation unit that detects a peak value in the histogram and calculates a distance from the peak value to the region of interest;
The distance measuring sensor according to claim 4, comprising: The light receiving section is of an array type,
commonizing the output terminals of the plurality of light receiving elements for each pixel;
The distance measuring sensor according to claim 1. further comprising a plurality of power supply units provided for each pixel or for each pixel group constituted by several pixels and supplying power to the light receiving element,
The light receiving section and the distance measurement processing section have a laminated structure belonging to different layers,
The control unit controls off a power supply unit that belongs to a region other than a region of interest on a plane made up of the plurality of pixels.
The distance measuring sensor according to claim 1. The control unit controls the light receiving unit 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. comprising a light emitting unit that irradiates light to the target area,
The control unit controls the light emitting unit to irradiate the light only to the region of interest based on the determination result of the region of interest.
The distance measuring sensor according to claim 2. The distance measurement processing section
an analog/digital conversion unit that converts the electrical signal output for each pixel from an analog signal to a digital signal;
a distance calculation unit that calculates a distance to the region of interest based on the digital signal;
The distance measuring sensor according to claim 2, comprising: comprising a selection circuit connected between the light receiving section and the analog/digital conversion section,
The distance measuring sensor according to claim 12, wherein the control section switches and controls the selection circuit to connect a plurality of pixels corresponding to the region of interest and the analog/digital conversion section. The control unit specifies a readout line in the region of interest, and simultaneously inputs electrical signals output from a plurality of pixels in areas that do 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 pixels and the analog/digital converter are connected by a plurality of signal lines 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 electrical signal to the analog/digital conversion unit using a different signal line for each frame.
The distance measuring sensor according to claim 12. comprising a switch connected between the plurality of signal lines and the analog/digital conversion section,
the control unit controls on/off the switch according to the region of interest;
The distance measuring sensor according to claim 15. comprising a region of interest determination unit that determines a region of interest from the output from the distance measurement processing unit;
The control section is configured to turn off a power supply section belonging to a region other than the region of interest based on a determination result of the region of interest by the region of interest determination section, and to input the electrical signal corresponding to the region of interest. performing at least one of controlling the distance measurement processing unit to
The distance measuring sensor according to any one of claims 1 to 16. The control unit is configured to turn off a power supply unit belonging to a region other than the region of interest based on a determination result of the region of interest provided from an external device, and to input the electrical signal corresponding to the region of interest. performing at least one of controlling the distance measurement processing unit;
The distance measuring sensor according to any one of claims 1 to 16. comprising an output interface unit that adds header information and footer information to each line of the imaging frame regarding the region of interest;
The distance measuring sensor according to claim 2.

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