JP2022163303A - Control device, receiving device, sensor device, control method, program, and storage medium - Google Patents

Abstract

To appropriately set the voltage to be applied to an APD.SOLUTION: A control unit 300 estimates a breakdown voltage VBR at timing when an amount of light incident on an APD 200 becomes equal to or less than a predetermined amount. The predetermined amount is, for example, practically zero. At timing when a reflected beam or scattered beam of a beam radiated by reflecting a beam emitted from a light source by a scanning unit 100 and external light such as sunlight do not enter the APD 200, the amount of light incident on the APD practically approaches zero. In detection of light by the APD 200, the control unit 300 operates the APD 200 with a voltage VM obtained by multiplying the estimated breakdown voltage VBR by a predetermined ratio VAPD/VBR.SELECTED DRAWING: Figure 4

Description

The present invention relates to a control device, a receiving device, a sensor device, a control method, a program and a storage medium.

In recent years, various sensor devices such as LiDAR (Light Detection And Ranging) have been developed. The sensor device includes a scanning unit such as a MEMS (Micro Electro Mechanical Systems) mirror and a polygon mirror for scanning a beam emitted from a light source such as a laser, and an avalanche photodiode ( APD) and

Current flows through the APD when light of a certain intensity is incident on the APD. The current flowing through the APD increases as the multiplication factor of the APD increases. The multiplication factor varies according to the reverse bias voltage applied to the APD. The multiplication factor sharply increases with increasing reverse bias voltage in the vicinity of the breakdown voltage of the APD.

The breakdown voltage may vary with temperature, as described in US Pat. Patent Document 1 describes a method for obtaining a constant multiplication factor regardless of variations in breakdown voltage due to temperature. In this method, the reverse bias voltage applied to the APD is changed to detect the reverse bias voltage at which a predetermined current flows through the APD, that is, the breakdown voltage. In the measurement using the APD, a voltage obtained by multiplying the breakdown voltage by a predetermined ratio is applied to the APD.

JP-A-2002-324909

As a method of controlling the voltage applied to the APD, for example, as described in Patent Document 1, a voltage obtained by multiplying the detected breakdown voltage by a predetermined ratio may be applied to the APD. However, in this method, if light is incident on the APD during breakdown voltage detection, the current due to the photons incident on the APD may be multiplied by the APD. Therefore, an error may occur in detecting the breakdown voltage. Moreover, in the method described above, the predetermined ratio for obtaining an arbitrary multiplication factor has not been clarified. Therefore, even if the breakdown voltage is detected, it may not be possible to set the APD to an arbitrary multiplication factor.

One example of the problem to be solved by the present invention is to appropriately set the voltage applied to the APD.

The invention according to claim 1,
A control comprising a control unit that estimates the breakdown voltage of the APD when the amount of light incident on the APD becomes equal to or less than a predetermined amount, and operates the APD with a voltage obtained by multiplying the estimated breakdown voltage by a predetermined ratio. It is a device.

The invention according to claim 3,
The control device includes a control unit that operates the APD at a voltage determined by referring to a predetermined relationship between the ratio of the operating voltage to the breakdown voltage and the multiplication factor.

The invention according to claim 5,
the APD;
the control device;
is a receiving device comprising

The invention according to claim 6,
a scanning unit;
the receiving device;
A sensor device comprising:

The invention according to claim 9,
The computer estimates the breakdown voltage of the APD at the timing when the amount of light incident on the APD becomes equal to or less than a predetermined amount, and operates the APD at a voltage obtained by multiplying the estimated breakdown voltage by a predetermined ratio. The method.

The invention according to claim 10,
A control method in which a computer operates the APD at a voltage determined by referring to a predetermined relationship between the ratio of the operating voltage to the breakdown voltage and the multiplication factor.

The invention according to claim 11,
A program that causes a computer to execute the control method.

The invention according to claim 11,
A storage medium storing the program.

It is a functional block diagram showing a receiving device according to an embodiment. 4 is a graph showing an example of temperature dependence of the relationship between the operating voltage V _APD and the multiplication factor M; 4 is a graph showing an example of the relationship between the ratio of the operating voltage V _APD to the breakdown voltage V _BR and the multiplication factor M; It is a figure which shows the sensor apparatus which concerns on an Example. It is the figure which looked at the opening and the light-shielding part which were shown in FIG. 4 from the negative direction of the 3rd direction. 5 is a diagram showing an example of a timing chart of control by a control unit in the sensor device shown in FIG. 4; FIG. It is a figure which illustrates the hardware constitutions of a control part.

Hereinafter, embodiments and examples of the present invention will be described with reference to the drawings. In addition, in all the drawings, the same constituent elements are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

In the present specification, ordinal numbers such as "first", "second", "third", etc., unless otherwise specified, are merely used to distinguish similarly named configurations. , does not imply any particular feature (eg, order or importance) of the configurations.

FIG. 1 is a functional block diagram showing the receiving device 20 according to the embodiment.

The receiving device 20 includes an APD (avalanche photodiode) 200 and a control section 300 .

APD 200 detects light incident on receiver 20 . A current flows through the APD 200 when light of a certain intensity is incident on the APD 200 . The current flowing through the APD 200 increases as the multiplication factor M of the APD 200 increases. The multiplication factor M varies according to the reverse bias voltage applied to the _APD 200, that is, the operating voltage VAPD of the APD 200. FIG. Regardless of whether light is incident on the APD 200 or not, the multiplication factor M sharply increases with increasing operating voltage V _APD in the vicinity of the breakdown voltage V _BR of the APD 200 .

The control unit 300 estimates the breakdown voltage _VBR at the timing when the amount of light incident on the APD 200 becomes equal to or less than a predetermined amount. The breakdown voltage _VBR is theoretically the voltage at which the multiplication factor M becomes infinite. However, the breakdown voltage V _BR in estimating the breakdown voltage V _BR may be a voltage at which the multiplication factor M is a relatively large predetermined value. In light detection by the APD 200, the control unit 300 operates the APD 200 at a voltage V _M obtained by multiplying the estimated breakdown voltage V _BR by a predetermined ratio V _APD /V _BR . The predetermined amount is, for example, substantially zero. In this example, the predetermined amount may not be strictly zero. For example, light may be incident on the APD 200 to the extent that current does not substantially flow through the APD 200 . Further, in the sensor device 10 according to the embodiment described later, a beam emitted from a light source (not shown) is reflected by the scanning unit 100 to emit a reflected beam or a scattered beam, and an external light such as sunlight. At the timing at which light and do not enter the APD 200, the amount of light entering the APD substantially approaches zero.

If the breakdown voltage V _BR is estimated at the timing when the amount of light incident on the APD 200 exceeds a predetermined amount, the current due to the photons incident on the APD 200 is multiplied by the APD 200, and the breakdown voltage V _BR is estimated. Errors can occur. On the other hand, according to the present embodiment, compared to the case where the breakdown voltage _VBR is estimated at the timing when the amount of light incident on the APD 200 becomes higher than the predetermined amount, the current caused by the photons incident on the APD 200 is Multiplication by the APD 200 can be suppressed, and errors in estimating the breakdown voltage V _BR can be suppressed.

FIG. 2 is a graph showing an example of the temperature dependence of the relationship between the operating voltage _VAPD and the multiplication factor M. In FIG. FIG. 3 is a graph showing an example of the relationship between the ratio of the operating voltage V _APD to the breakdown voltage V _BR and the multiplication factor M. In FIG.

In FIG. 2 , the horizontal axis of the graph indicates the operating voltage V _APD (unit: V) of the APD 200 . In FIG. 3, the horizontal axis of the graph indicates the ratio of operating voltage V _APD to breakdown voltage V _BR . 2 and 3, the vertical axis of the graph indicates the multiplication factor M of the APD 200. FIG. Each curve in FIG. 2 shows the characteristics for −20° C., −10° C., 0° C., 10° C., 15° C., 25° C., 40° C., 50° C., 60° C. and 85° C. per APD 200 temperature. Multiplication factor M is 1. In the range of E+02 or higher, the characteristics of each temperature are arranged in order of increasing temperature toward the high voltage side of the operating voltage _VAPD .

ただし、ｋは、イオン化率比であり、ｎは、不純物プロファイル等、ＡＰＤ２００の素子構造で決定される値である。イオン化率比ｋは、電子のイオン化率αに対する正孔のイオン化率βの比β／αによって表される。 The multiplication factor M is expressed by the following formula (1) according to Miller's approximation formula.

However, k is the ionization rate ratio, and n is a value determined by the device structure of the APD 200 such as the impurity profile. The ionization rate ratio k is represented by the ratio β/α of the ionization rate β of holes to the ionization rate α of electrons.

As shown in FIG. 2, the relationship between the operating voltage V _APD and the multiplication factor M varies depending on the temperature of the APD 200. FIG. On the other hand, as shown in FIG. 3, the relationship between the ratio of the operating voltage V _APD to the breakdown voltage V _BR and the multiplication factor M is theoretically constant regardless of the temperature of the APD 200 .

The control unit 300 determines the voltage V _M to be applied to the APD 200 with reference to a predetermined relationship between the ratio of the operating voltage V _APD to the breakdown voltage V _BR and the multiplication factor M, such as the relationship shown in FIG. ing. When the breakdown voltage V _BR has already been estimated, the control unit 300 refers to the relationship to obtain a predetermined ratio V _APD /V _BR for obtaining an arbitrary multiplication factor M, that is, the voltage to be applied to the APD 200 _VM can be determined.

FIG. 4 is a diagram showing the sensor device 10 according to the embodiment. FIG. 5 is a view of the opening 510 and the light shielding portion 520 shown in FIG.

In FIGS. 4 and 5, for arrows indicating the first direction X, the second direction Y, or the third direction Z, the direction from the proximal end to the distal end of the arrow is the positive direction of the direction indicated by the arrow, and It indicates that the direction from the tip of the arrow to the base is the negative direction of the direction indicated by the arrow. In FIG. 4, the white dot with a black dot indicating the first direction X indicates that the direction from the back to the front of the paper is the positive direction of the first direction X, and the direction from the front to the back of the paper is the negative direction of the first direction X. It shows that In FIG. 5, the white circle with X indicating the third direction Z indicates that the direction from the front to the back of the paper is the positive direction of the third direction Z, and the direction from the back to the front of the paper is the negative direction of the third direction Z. It shows that

The first direction X is one direction parallel to the horizontal direction orthogonal to the vertical direction. When viewed from the negative direction of the third direction Z, the positive direction of the first direction X is from right to left in the horizontal direction, and the negative direction of the first direction X is from left to right in the horizontal direction. It is the direction to go. The second direction Y is a direction parallel to the vertical direction. The positive direction of the second direction Y is the direction from bottom to top in the vertical direction, and the negative direction of the second direction Y is the direction from top to bottom in the vertical direction. A third direction Z is a direction parallel to the horizontal direction and perpendicular to the first direction X. As shown in FIG. When viewed from the positive direction of the first direction X, the positive direction of the third direction Z is from right to left in the horizontal direction, and the negative direction of the third direction Z is from left to right in the horizontal direction. It is the direction to go.

The relationship between the first direction X, the second direction Y, the third direction Z, the horizontal direction, and the vertical direction is not limited to the relationship according to this embodiment. The relationship between the first direction X, the second direction Y, the third direction Z, the horizontal direction, and the vertical direction varies depending on the arrangement of the sensor device 10 . For example, the third direction Z may be parallel to the vertical direction.

The sensor device 10 includes a scanning section 100 , an APD 200 , a control section 300 , a voltage source 310 and a housing 500 . The scanning unit 100 , the APD 200 , the control unit 300 and the voltage source 310 are housed inside the housing 500 . The controller 300 may be provided outside the housing 500 .

The scanning unit 100 reflects a plurality of beams temporally repeatedly emitted from a light source such as a laser (not shown). Specifically, the scanning unit 100 reflects a plurality of beams toward scanning lines L shown in FIG. Further, the scanning unit 100 reflects light toward the scanning unit 100 from the direction in which the scanning line L is positioned toward the APD 200 . A scanning line L is a scanning line projected onto a virtual plane that is perpendicular to the third direction Z and on which an opening 510 (to be described later) is located. In one example, the scanning unit 100 is a MEMS mirror that can rotate or swing about two predetermined orthogonal rotation axes. In this example, the scanning unit 100 rotates or oscillates one of the two rotation axes to scan the beam incident on the scanning unit 100 in the first direction X on the virtual plane. The scanning unit 100 scans the beam incident on the scanning unit 100 in the second direction Y on the virtual plane by rotating or swinging the other of the two rotation axes. In each frame of scanning by the scanning unit 100, the scanning unit 100 reflects a plurality of beams from the positive direction side of the scanning line L in the second direction Y toward the negative direction side of the scanning line L in the second direction Y. there is The scanning unit 100 may be a scanning unit different from the MEMS mirror, such as a polygon mirror or a galvanomirror.

The direction from the base end to the tip end of each of the first arrow BA1, the second arrow BA2, and the third arrow BB shown in FIG. The scanning unit 100 can irradiate a beam in a beam irradiation direction by reflecting a beam emitted from a light source (not shown). By adjusting the emission timing of the beam from the light source, the scanning unit 100 may or may not actually irradiate the beam in the beam irradiation direction of the scanning unit 100 . The beam irradiation direction of the scanning unit 100 changes with time as the scanning unit 100 is driven. The beam irradiation by the scanning unit 100 is not limited to the example described above. For example, the scanning unit 100 may be a light source whose beam irradiation direction is variable.

The direction from the tip to the base of each of the first arrow BA1, the second arrow BA2, and the third arrow BB shown in FIG. The scanning unit 100 reflects the light directed toward the scanning unit 100 from the light receiving direction toward the APD 200 . The light receiving direction of the scanning unit 100 changes with time as the scanning unit 100 is driven.

An opening 510 is provided on the side surface of the housing 500 on the positive direction side in the third direction Z. As shown in FIG. A beam emitted from a light source (not shown) is reflected by the scanning unit 100, as exemplified by the beam irradiation direction indicated by the first arrow BA1 or the second arrow BA2 in FIG. The beam irradiated toward the opening 510 in is irradiated toward the outside of the housing 500 through the opening 510 . In the example shown in FIG. 5, the opening 510 is rectangular when viewed from the negative direction side of the third direction Z. As shown in FIG. The shape of the opening 510 viewed from the negative side of the third direction Z is not limited to the example shown in FIG.

A beam emitted from the scanning unit 100 toward the outside of the housing 500 through the opening 510 is reflected or scattered by an object (not shown) existing outside the housing 500 . In this embodiment, the beam reflected or scattered by the object is reflected or scattered by the scanning unit, as exemplified by the direction of light reception indicated by the direction from the tip of the first arrow BA1 or the second arrow BA2 in FIG. 100 and is reflected by the scanning unit 100 toward the APD 200 . That is, the optical axis of the beam transmitted from the sensor device 10 and the optical axis of the beam received by the sensor device 10 after being reflected or scattered by an object existing outside the sensor device 10 are coaxial. The optical system of the sensor device 10 is not limited to the optical system according to this embodiment. For example, a beam reflected or scattered by an object (not shown) existing outside the housing 500 may enter the APD 200 without entering the scanning unit 100 . In this case, the optical axis of the beam transmitted from the sensor device 10 and the optical axis of the beam received by the sensor device 10 after being reflected or scattered by objects present outside the sensor device 10 are offset from each other.

As shown in FIG. 5, the light blocking portion 520 partially overlaps the scanning line L when viewed from the negative direction of the third direction Z. As shown in FIG. In the example shown in FIG. 5 , the light shielding portion 520 is positioned on the positive side in the second direction Y with respect to the opening 510 . The position where the light blocking portion 520 is provided is not limited to the example shown in FIG. For example, the light blocking portion 520 may be positioned on the negative direction side in the second direction Y with respect to the opening 510, or may be positioned on the positive or negative direction side in the first direction X with respect to the opening 510. may be Furthermore, when viewed from the negative direction of the third direction Z, the light blocking portions 520 may be provided at a plurality of positions around the opening 510 . For example, the two light blocking portions 520 may be positioned on both the positive direction side and the negative direction side of the second direction Y with respect to the opening 510, or may be positioned on the positive direction side of the first direction X with respect to the opening 510. and the negative direction side.

In this embodiment, the control unit 300 estimates the breakdown voltage V _BR at the timing when the light receiving direction of the scanning unit 100 is directed toward the light shielding unit 520 . As exemplified by the direction of light reception indicated by the direction from the tip of the third arrow BB in FIG. Light outside the housing 500 , such as sunlight, is less likely to enter the scanning unit 100 than when the direction is directed toward the opening 510 . Therefore, estimating the breakdown voltage V _BR at the timing when the light receiving direction of the scanning unit 100 is directed toward the light shielding unit 520 is compared with estimating the breakdown voltage V _BR at the timing when the light receiving direction of the scanning unit 100 is directed toward the opening 510. As a result, light outside the housing 500 can be prevented from entering the APD 200 via the scanning unit 100 . The timing at which control unit 300 estimates breakdown voltage V _BR is not limited to the timing according to the present embodiment. For example, the control unit 300 may estimate the breakdown voltage V _BR at the timing when the light receiving direction of the scanning unit 100 is directed toward the aperture 510 .

In this embodiment, the scanning unit 100 does not irradiate the beam at the timing when the light receiving direction of the scanning unit 100 is directed toward the light shielding unit 520 . If the beam of the scanning unit 100 is not irradiated at the timing when the light receiving direction of the scanning unit 100 is directed toward the light shielding unit 520, the beam of the scanning unit 100 is irradiated at the timing when the light receiving direction of the scanning unit 100 is directed toward the light shielding unit 520. Compared to the case of irradiation, the beam irradiated by the scanning unit 100 and reflected or scattered by the light shielding unit 520 is suppressed from entering the APD 200 at the timing when the control unit 300 estimates the breakdown voltage _VBR . be able to. The timing at which the beam is emitted by the scanning unit 100 is not limited to the example described above. For example, the scanning unit 100 may irradiate the beam at the timing when the light receiving direction of the scanning unit 100 is directed toward the light shielding unit 520 .

FIG. 6 is a diagram showing an example of a timing chart of control by the control unit 300 in the sensor device 10 shown in FIG.

The arrow extending from the left side to the right side in the upper part of FIG. 6 indicates the time axis. A first non-measurement time interval TB1 indicated by an arrow attached to the left part of the time axis in FIG. A measurement time interval TA indicated by an arrow attached to the central portion of the time axis in FIG. 6 indicates a time interval after the first non-measurement time interval TB1 in which the light receiving direction of the scanning unit 100 is directed toward the aperture 510. ing. A second non-measurement time interval TB2 indicated by an arrow attached to the right part of the time axis in FIG. showing.

The middle timing chart in FIG. 6 shows the timing chart of the voltage V applied to the APD 200 by the voltage source 310 . In the timing chart showing the voltage V, the dashed line with "0" indicates zero voltage. In the timing chart showing the voltage V, the voltage V is positive above the dashed line indicating zero voltage, and the voltage V is negative below the dashed line indicating zero voltage.

The lower timing chart in FIG. 6 shows the timing chart of the statistical value S of the signal output from the APD 200 based on the voltage V applied to the APD 200. FIG. When no beam is emitted by the scanning unit 100 during the first non-measuring time interval TB1 or the second non-measuring time interval TB2, the statistical value S is, for example, is the average value of the signal output from the APD 200 in at least a part of the time interval of . The statistical value S may be a statistical value different from the average value. For example, the statistical value S may be a variance value of the signal output from the APD 200 in at least a part of the first non-measurement time interval TB1 or the second non-measurement time interval TB2. When the beam is emitted by the scanning unit 100 during a partial time interval of the first non-measuring time interval TB1 or the second non-measuring time interval TB2, the statistical value S is, for example, the first non-measuring time interval TB1 or the second non-measuring It is the average value of the signal output from the APD 200 in at least a part of the measurement time interval TB2 excluding the time interval in which the beam is irradiated by the scanning unit 100. FIG. The statistical value S may be a statistical value different from the average value. For example, the statistical value S is a signal output from the APD 200 in at least a part of the first non-measurement time interval TB1 or the second non-measurement time interval TB2, excluding the time interval during which the beam is irradiated by the scanning unit 100. may be the variance of In the timing chart showing the statistical value S, the dashed line with "D" indicates the default value D. FIG. In the timing chart showing the statistic value S, the statistic value S is greater than the default value D above the dashed line indicating the default value D, and the statistic value S is greater than the default value D below the dashed line indicating the default value D. is getting smaller. The default value D is the value that the statistic S takes if the voltage V applied to the APD 200 is the breakdown voltage _VBR .

An example of control by the control unit 300 will be described with reference to FIG.

First, the control unit 300 causes the voltage source 310 to apply the voltage V to the APD 200 until the time t1 of the first non-measurement time interval TB1. The statistical value S is smaller than the default value D until time t1 of the first non-measurement time interval TB1. The voltage V applied until time t1 of the first non-measurement time interval TB1 is a voltage near the breakdown voltage _VBR .

Next, control unit 300 controls the absolute value of the difference between statistical value S and default value D to be smaller than the absolute value of the difference between statistical value S and default value D up to time t1 in first non-measurement time interval TB1. Additionally, the voltage V applied to the APD 200 by the voltage source 310 is controlled. Specifically, the control unit 300 increases the voltage V at the time t1 of the first non-measurement time section TB1. The statistical value S increases at time t1 due to the increase in voltage V at time t1. The absolute value of the difference between the statistic value S and the default value D after time t1 in the first non-measurement time interval TB1 is the difference between the statistic value S and the default value D up to time t1 in the first non-measurement time interval TB1. smaller than the absolute value. By varying the voltage V, the control unit 300 detects the voltage V at which the statistical value S approaches the default value D, thereby estimating the breakdown voltage _VBR .

Next, control unit 300 applies voltage V _M obtained by multiplying estimated breakdown voltage V _BR by a predetermined ratio V _APD /V _BR to APD 200 by voltage source 310 from first non-measurement time interval TB1 to measurement time interval TA. is applied to With the voltage _VM applied to the APD 200 , the beam emitted by the scanning unit 100 through the opening 510 toward the outside of the housing 500 is reflected or scattered by an object existing outside the housing 500 . Also, in a state in which the voltage _VM is applied to the APD 200 , the beam reflected or scattered by the object enters the scanning unit 100 and is reflected by the scanning unit 100 toward the APD 200 . In this way, the sensor device 10 measures the object while the voltage _VM is applied to the APD 200 . Therefore, the object can be measured while the multiplication factor of the APD 200 is set to a desired multiplication factor.

Next, the control section 300 increases the voltage V applied to the APD 200 by the voltage source 310 from the measurement time interval TA to the second non-measurement time interval TB2. In the second non-measurement time interval TB2, the control section 300 estimates the breakdown voltage _VBR in the same manner as in the first non-measurement time interval TB1.

In the example shown in FIG. 6, the voltage V applied to the APD 200 is increased by one update in the first non-measurement time interval TB1. However, the number of times the voltage V is updated in the first non-measurement time interval TB1 is not limited to once, and may be a plurality of times.

The control unit 300 performs the same operation as described above regarding the first non-measurement time interval TB1 or the second non-measurement time interval TB2 in a plurality of time intervals in which the light receiving direction of the scanning unit 100 is directed toward the light shielding unit 520. By repeating the operation, the estimation of the breakdown voltage _VBR is repeated. Therefore, control unit 300 can set the multiplication factor of APD 200 to a desired multiplication factor in a time interval in which the light receiving direction of scanning unit 100 is directed toward opening 510 .

In the examples shown in FIGS. 5 and 6, the control section 300 estimates the breakdown voltage V _BR in the initial time period of one frame of scanning by the scanning section 100 . However, the timing at which breakdown voltage _VBR is estimated by control unit 300 is not limited to this example. For example, when the light shielding part 520 is located on the negative direction side of the second direction Y with respect to the opening 510, the control part 300 reduces the breakdown voltage V _BR in the final time period of one frame of the scanning of the scanning part 100. can be estimated. Further, for example, when the light shielding portion 520 is positioned on the positive or negative direction side of the first direction X with respect to the opening 510, the control unit 300 controls the beam irradiation of the scanning unit 100 in one frame of the scanning of the scanning unit 100. The breakdown voltage V _BR can be estimated each time a direction is directed toward the light shield 520 .

In the example shown in FIG. 5, the width in the first direction X of the light shielding portion 520 located on the positive side in the second direction Y with respect to the opening 510 is the width in the first direction X of the scanning range in which the scanning lines L are formed. It is more than wide. In this case, compared to the case where the width in the first direction X of the light shielding portion 520 positioned on the positive side in the second direction Y with respect to the opening 510 is less than the width in the first direction X of the scanning range, the control The time interval over which the breakdown voltage V _BR estimation by unit 300 is performed can be lengthened. The width in the first direction X of the light shielding portion 520 located on the positive side in the second direction Y with respect to the opening 510 is not limited to the example shown in FIG. For example, the width in the first direction X of the light blocking portion 520 positioned on the positive side in the second direction Y with respect to the opening 510 may be less than the width in the first direction X of the scanning range.

FIG. 7 is a diagram illustrating the hardware configuration of the control unit 300. As illustrated in FIG. The controller 300 is implemented using an integrated circuit 400 . The integrated circuit 400 is, for example, a SoC (System-on-a-Chip).

Integrated circuit 400 includes bus 402 , processor 404 , memory 406 , storage device 408 , input/output interface 410 and network interface 412 . The bus 402 is a data transmission path through which the processor 404, memory 406, storage device 408, input/output interface 410 and network interface 412 exchange data with each other. However, the method of connecting processor 404, memory 406, storage device 408, input/output interface 410 and network interface 412 together is not limited to bus connections. The processor 404 is an arithmetic processing device implemented using a microprocessor or the like. The memory 406 is a memory implemented using a RAM (Random Access Memory) or the like. The storage device 408 is a storage device implemented using a ROM (Read Only Memory), flash memory, or the like.

The input/output interface 410 is an interface for connecting the integrated circuit 400 with peripheral devices. The input/output interface 410 is connected to the scanning unit 100 , the APD 200 and the voltage source 310 .

Network interface 412 is an interface for connecting integrated circuit 400 to a network. This network is, for example, a CAN (Controller Area Network) network. A method for connecting the network interface 412 to the network may be a wireless connection or a wired connection.

The storage device 408 stores program modules for realizing the functions of the control unit 300 . The processor 404 implements each function of the control unit 300 by reading these program modules into the memory 406 and executing them.

The hardware configuration of integrated circuit 400 is not limited to the configuration shown in FIG. For example, program modules may be stored in memory 406 . In this case, integrated circuit 400 may not include storage device 408 .

Although the embodiments and examples of the present invention have been described above with reference to the drawings, these are examples of the present invention, and various configurations other than those described above can be adopted.

For example, the control unit 300 may determine the voltage V _M applied to the APD 200 without referring to a predetermined relationship between the ratio of the operating voltage V _APD to the breakdown voltage V _BR and the multiplication factor M.

For example, the controller 300 may estimate the breakdown voltage _VBR at the timing when the amount of light incident on the APD 200 exceeds a predetermined amount.

10 sensor device 20 receiving device 100 scanning unit 200 APD
300 control unit 310 voltage source 400 integrated circuit 402 bus 404 processor 406 memory 408 storage device 410 input/output interface 412 network interface 500 housing 510 opening 520 light shield BA1 first arrow BA2 second arrow BB third arrow L scanning line TA measurement Time section TB1 First non-measurement time section TB2 Second non-measurement time section X First direction Y Second direction Z Third direction

Claims (12)

A control comprising a control unit that estimates the breakdown voltage of the APD when the amount of light incident on the APD becomes equal to or less than a predetermined amount, and operates the APD with a voltage obtained by multiplying the estimated breakdown voltage by a predetermined ratio. Device. The control device according to claim 1,
The controller determines the voltage for operating the APD by referring to a predetermined relationship between the ratio of the operating voltage to the breakdown voltage and the multiplication factor. A control device comprising a control unit that operates an APD at a voltage determined by referring to a predetermined relationship between a ratio of an operating voltage to a breakdown voltage and a multiplication factor. In the control device according to any one of claims 1 to 3,
The control device, wherein the control unit estimates the breakdown voltage based on a signal output from the APD by applying a voltage to the APD. the APD;
A control device according to any one of claims 1 to 4;
receiving device. a scanning unit;
a receiving device according to claim 5;
A sensor device comprising: In the sensor device according to claim 6,
The sensor device, wherein the control unit estimates the breakdown voltage at a timing when the light receiving direction of the scanning unit is directed toward the light shielding unit. In the sensor device according to claim 7,
The sensor device according to claim 1, wherein the scanning section does not emit a beam at a timing when the light receiving direction of the scanning section is directed toward the light shielding section. The computer estimates the breakdown voltage of the APD at the timing when the amount of light incident on the APD becomes equal to or less than a predetermined amount, and operates the APD at a voltage obtained by multiplying the estimated breakdown voltage by a predetermined ratio. Method. A control method in which the computer operates the APD at a voltage determined by referring to a predetermined relationship between the ratio of the operating voltage to the breakdown voltage and the multiplication factor. A program that causes a computer to execute the control method according to claim 9 or 10. A storage medium storing the program according to claim 11 .

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