Patent ID: 12231776

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of the present disclosure will be described in detail on the basis of the drawings. Incidentally, in each of the following embodiments, the same reference numerals are given to the same portions, and duplicate description is not given.

Configuration Common to Each Embodiment

The present disclosure is suitable for use in a technology for performing distance measurement using light. Prior to the description of the embodiment of the present disclosure, an indirect time of flight (ToF) system will be described as one of distance measuring systems applied to the embodiment in order to facilitate understanding. The indirect ToF system is a technology of irradiating a measurement object with light source light (for example, laser light in an infrared region) modulated by, for example, pulse width modulation (PWM), receiving reflected light thereof by a light receiving element, and measuring a distance to the measurement object on the basis of a phase difference in the received reflected light.

FIG.1is a block diagram illustrating a configuration of one example of an electronic device using a distance measuring device applicable to each embodiment. InFIG.1, an electronic device1includes a distance measuring device10and an application unit20. The application unit20is realized, for example, by a program operating on a central processing unit (CPU), requests the distance measuring device10to execute distance measurement, and receives distance information or the like which is a result of the distance measurement from the distance measuring device10.

The distance measuring device10includes a light source unit11, a light receiving unit12, and a distance measurement processing unit13. The light source unit11includes, for example, a light emitting element that emits light having a wavelength in an infrared region, and a drive circuit that drives the light emitting element to emit light. For example, a light emitting diode (LED) can be applied as the light emitting element included in the light source unit11. The present invention is not limited thereto, and a vertical cavity surface emitting laser (VCSEL) in which a plurality of light emitting elements is formed in an array can also be applied as the light emitting element included in the light source unit11. Hereinafter, unless otherwise specified, “the light emitting element of the light source unit11emits light” will be described as “the light source unit11emits light” or the like.

The light receiving unit12includes, for example, a light receiving element capable of detecting light having a wavelength in an infrared region, and a signal processing circuit that outputs a pixel signal corresponding to the light detected by the light receiving element. A photodiode can be applied as the light receiving element included in the light receiving unit12. Hereinafter, unless otherwise specified, “the light receiving element included in the light receiving unit12receives light” will be described as “the light receiving unit12receives light” or the like.

The distance measurement processing unit13executes distance measurement processing in the distance measuring device10in response to a distance measurement instruction from the application unit20, for example. For example, the distance measurement processing unit13generates a light source control signal for driving the light source unit11and supplies the light source control signal to the light source unit11. Further, the distance measurement processing unit13controls light reception by the light receiving unit12in synchronization with the light source control signal supplied to the light source unit11. For example, the distance measurement processing unit13generates an exposure control signal for controlling an exposure period in the light receiving unit12in synchronization with the light source control signal, and supplies the exposure control signal to the light receiving unit12. The light receiving unit12outputs a valid pixel signal within the exposure period indicated by the exposure control signal.

The distance measurement processing unit13calculates distance information on the basis of the pixel signal output from the light receiving unit12according to the light reception. Further, the distance measurement processing unit13can also generate predetermined image information on the basis of the pixel signal. The distance measurement processing unit13passes the distance information and the image information calculated and generated on the basis of the pixel signal to the application unit20.

In such a configuration, for example, in accordance with an instruction to execute distance measurement from the application unit20, the distance measurement processing unit13generates a light source control signal for driving the light source unit11and supplies the light source control signal to the light source unit11. Herein, the distance measurement processing unit13generates a light source control signal modulated into a rectangular wave having a predetermined duty by the PWM, and supplies the light source control signal to the light source unit11. At the same time, the distance measurement processing unit13controls the light reception by the light receiving unit12on the basis of the exposure control signal synchronized with the light source control signal.

In the distance measuring device10, the light source unit11blinks and emits light according to a predetermined duty according to the light source control signal generated by the distance measurement processing unit13. The light emitted from the light source unit11is emitted from the light source unit11as emission light30. The emission light30is reflected by a measurement object31, for example, and is received as a reflected light32by the light receiving unit12. The light receiving unit12supplies a pixel signal corresponding to the reception of the reflected light32to the distance measurement processing unit13. Incidentally, in practice, the light receiving unit12receives surrounding ambient light in addition to the reflected light32, and the pixel signal includes a component of the ambient light together with a component of the reflected light32.

The distance measurement processing unit13executes light reception by the light receiving unit12a plurality of times in different phases. The distance measurement processing unit13calculates a distance D to the measurement object on the basis of a difference between pixel signals due to light reception at different phases. Further, on the basis of the difference between the pixel signals, the distance measurement processing unit13calculates first image information obtained by extracting the component of the reflected light32, and second image information including the component of the reflected light32and the component of the ambient light. Hereinafter, the first image information is referred to as directly reflected light information, and the second image information is referred to as RAW image information.

Distance Measurement by Indirect ToF System Applicable to Each Embodiment

Next, distance measurement by the indirect ToF system applicable to each embodiment will be described.FIG.2is a diagram for explaining a principle of the indirect ToF system. InFIG.2, light modulated by a sine wave is used as the emission light30emitted by the light source unit11. Ideally, the reflected light32is a sine wave having a phase difference phase corresponding to the distance D with respect to the emission light30.

The distance measurement processing unit13performs a plurality of times of sampling on the pixel signal obtained by receiving the reflected light32at different phases, and acquires a light amount value indicating a light amount for each sampling. In the example ofFIG.2, light amount values C0, C90, C180, and C270are acquired in respective phases of a phase of 0°, a phase of 90°, a phase of 180°, and a phase of 270° which are different by 90° in phase with respect to the emission light30. In the indirect ToF system, the distance information is calculated on the basis of a difference between light amount values of a set having phases different by 180° among the phases of 0°, 90°, 180°, and 270°.

A method of calculating the distance information in the indirect ToF system will be described more specifically with reference toFIG.3.FIG.3is a diagram illustrating an example of a case where the emission light30from the light source unit11is a rectangular wave modulated by the PWM. InFIG.3, the emission light30from the light source unit11and the reflected light32reaching the light receiving unit12are illustrated from an upper side. As illustrated in the upper side ofFIG.3, the light source unit11periodically blinks at a predetermined duty to emit the emission light30.

FIG.3further illustrates exposure control signals at the phase of 0° (described as Φ=0°), the phase of 90° (described as Φ=90°), the phase of 180° (described as Φ=) 180°, and the phase of 270° (described as Φ=270°) of the light receiving unit12. For example, a period during which the exposure control signal is in a high state is an exposure period during which the light receiving unit12outputs a valid pixel signal.

In the example ofFIG.3, the emission light30is emitted from the light source unit11at time t0, and the reflected light32obtained by reflecting the emission light30by the measurement object reaches the light receiving unit12at time t1after the delay according to the distance D from the time t0to the measurement object.

On the other hand, in the light receiving unit12, in accordance with the exposure control signal from the distance measurement processing unit13, the exposure period of the phase of 0° starts in synchronization with the time t0of the emission timing of the emission light30in the light source unit11. Similarly, in the light receiving unit12, the exposure periods of the phase of 90°, the phase of 180°, and the phase of 270° start in accordance with the exposure control signal from the distance measurement processing unit13. Herein, the exposure period in each phase follows the duty of the emission light30. Incidentally, in the example ofFIG.3, the exposure periods of the respective phases are illustrated as being temporally parallel for the sake of explanation. However, in practice, in the light receiving unit12, the exposure periods of the respective phases are sequentially specified, and the light amount values C0, C90, C180, and C270of the respective phases are acquired.

In the example ofFIG.3, the arrival timings of the reflected light32are times t1, t2, t3, and so on, and the light amount value C0at the phase of 0° is acquired as an integral value of the received light amount from the time t0to the end time of the exposure period including the time t0at the phase of 0°. On the other hand, in the phase of 180° which is different by 180° from the phase of 0°, the light amount value C180is acquired as an integral value of the received light amount from the start time of the exposure period at the phase of 180° to the time t2of the falling of the reflected light32included in the exposure period.

Also for the phase of C90 and the phase of 270° which is different by 180° from the phase of 90°, similarly to the case of the phases of 0° and 180° described above, the integral value of the received light amounts in the periods in which the reflected light32arrives within respective exposure periods are acquired as the light amount values C90and C270.

Among these light amount values C0, C90, C180, and C270, as shown in the following equations (1) and (2), a difference I and a difference Q are obtained on the basis of a combination of light amount values having phases different by 180°.
I=C0−C180(1)
Q=C90−C270(2)

The phase difference phase is calculated by the following equation (3) on the basis of these differences I and Q. Incidentally, in the equation (3), the phase difference phase is defined in a range of (0≤phase<2π).
phase=tan−1(Q/I)  (3)

Distance information Depth is calculated by the following equation (4) using the phase difference phase and a predetermined coefficient range.
Depth=(phase×range)/2π  (4)

The component (directly reflected light information) of the reflected light32can be extracted from the component of the light received by the light receiving unit12on the basis of the differences I and Q. Directly reflected light information DiRefl is calculated by the following equation (5) using the absolute values of the differences I and Q.
DiRefl=|I|+|Q|(5)

RAW image information RAW can be calculated as an average value of the light amount values C0, C90, C180, and C270as shown in the following equation (6).
RAW=(C0+C90+C180+C270)/4  (6)

FIG.4is a diagram illustrating an example of the amount of the light received by the light receiving unit12. As described above, the light receiving unit12also receives the ambient light to which the emission light30from the light source unit11does not contribute in addition to the reflected light32formed when the emission light30from the light source unit11is reflected by the measurement object31, that is, the directly reflected light. Therefore, the amount of the light received by the light receiving unit12is the sum of the amount of the directly reflected light and the amount of the ambient light. By the calculation of the above-described equations (1) to (3) and (5), the component of the ambient light is canceled, and the component of the directly reflected light is extracted.

On the other hand, an RAW image is an average value of the light amount values C0, C90, C180, and C270of the respective phases as shown in the above-described equation (6), and thus the RAW image includes a component of the ambient light as illustrated inFIG.4.

Next, a method for acquiring the light amount values C0, C90, C180, and C270 of respective phases and a method for calculating the distance information and the directly reflected light information DiRefl, which are applicable to each embodiment, will be described more specifically with reference toFIGS.5A,5B, and5C.

FIG.5Ais a diagram for explaining a first method of acquiring each light amount value and calculating each piece of information applicable to each embodiment. InFIG.5A, the light receiving unit12sequentially acquires light amount values C0, C90, C180, and C270for each phase. In the example ofFIG.5A, the light receiving unit12performs exposure with the phase of 0° in a period of time t10to time t11, and performs exposure with the phase of 90° in a period of time t12to time t13after a predetermined time (for example, processing switching time) from time t11. Similarly, light reception with the phase of 180° is performed in a period of time t14to time t15after a predetermined time from time t13, and exposure with the phase of 270° is performed in a period of time t16to time t17after a predetermined time from time t15.

At time t18after a predetermined time from time t17, the above-described operation from the time t10is executed again.

The method of sequentially acquiring the light amount values C0, C90, C180, and C270for each phase illustrated inFIG.5Ais referred to as a one-tap method.

Here, a sequence of performing exposure with each phase is assumed to be one microframe (μFrame). In the example ofFIG.5A, a period of time t10to time t18is a period of one microframe. The period of one microframe is shorter than one frame period (for example, 1/30 sec) of imaging, and processing of one microframe can be executed a plurality of times within one frame period.

The distance measurement processing unit13stores the light amount values C0, C90, C180, and C270acquired within the period of one microframe and acquired sequentially in each phase in, for example, a memory. The distance measurement processing unit13calculates the distance information Depth, the directly reflected light information DiRefl, and the RAW image information RAW on the basis of the light amount values C0, C90, C180, and C270stored in the memory.

In this case, the differences I and Q, the phase difference phase, and the distance information Depth can be calculated by the above-described equations (1) to (4). Further, the RAW image information RAW can be calculated using the above-described equation (6). On the other hand, here, the directly reflected light information DiRefl can be calculated using the following equation (7).
DiRefl=(I2+Q2)1/2(7)

FIG.5Bis a diagram for explaining a second method of acquiring each light amount value and calculating each piece of information applicable to each embodiment. In the second method, the light receiving unit12includes two reading circuits (taps A and B) for one light receiving element, and reading by the tap A and the tap B can be executed sequentially (alternately) (details will be described later).

InFIG.5B, the light receiving unit12sequentially executes the reading of the tap A and the tap B in each phase. Further, the light receiving unit12sequentially executes the reading of each phase within a period of one microframe.

That is, in the example ofFIG.5B, the light receiving unit12performs exposure with the phase of 0° in a period of time t20to time t21. The distance measurement processing unit13obtains a light amount value A0and a light amount value B0on the basis of the pixel signals read by the tap A and the tap B, respectively. The light receiving unit12performs exposure with the phase of 90° in a period of time t22to time t23after a predetermined time from time t21. The distance measurement processing unit13obtains a light amount value A90and a light amount value B90on the basis of the pixel signals read by the tap A and the tap B, respectively.

Similarly, exposure with the phase of 180° is performed in a period of time t24to time t25after a predetermined time from time t23. The distance measurement processing unit13obtains a light amount value A180and a light amount value B180on the basis of the pixel signals read by the tap A and the tap B, respectively. Further, the light receiving unit12performs exposure with the phase of 270° in a period of time t26to time t27after a predetermined time from time t25. The distance measurement processing unit13obtains a light amount value A270and a light amount value B270on the basis of the pixel signals read by the tap A and the tap B, respectively.

At time t28after a predetermined time from time t27, the above-described operation from the time t20is executed again.

The method of sequentially executing the reading by the taps A and B for each of the phases of 0°, 90°, 180°, and 270° and obtaining each light amount value based on the reading by the taps A and B for each phase as illustrated inFIG.5Bis referred to as a four-phase/two-tap method.

In the case of this second method, the differences I and Q are calculated by the following equations (8) and (9) using the light amount values A0and B0, A90and B90, A180and B180, and A270and B270.
I=C0−C180=(A0−B0)−(A180−B180)  (8)
Q=C90−C270=(A90−B90)−(A270−B270)  (9)

The phase difference phase, the distance information Depth, and the directly reflected light information DiRefl can be calculated by the above-described equations (3), (4), and (7) using the differences I and Q calculated by the equations (8) and (9). Further, the RAW image information RAW can be calculated as average values of the light amount values A0and B0, A90and B90, A180and B180, and A270and B270, following the above-described equation (6).

In the four-phase/two-tap method illustrated in FIG.5B, the exposure period in each phase is made redundant by the tap A and the tap B. Therefore, it is possible to improve the S/N ratios of the calculated distance information Depth, directly reflected light information DiRefl, and RAW image information RAW.

FIG.5Cis a diagram for explaining a third method of acquiring each light amount value and calculating each piece of information applicable to each embodiment. In the third method, the light receiving unit12includes the tap A and the tap B similarly to the above-described second method, and sequentially executes the reading by the tap A and the tap B. Further, the light receiving unit12sequentially executes the reading of the phases of 0° and 90° among the phases of 0°, 90°, 180°, and 270° described above. In the third method, the reading periods of the phases 0° and 90° are set as a period of one microframe.

In the case ofFIG.5C, the reading sequence is the same sequence as time t20to time t24inFIG.5Bdescribed above. That is, the light receiving unit12performs exposure with the phase of 0° in a period of time t30to time t31. The distance measurement processing unit13obtains a light amount value A0and a light amount value B0on the basis of the pixel signals read by the tap A and the tap B, respectively. The light receiving unit12performs exposure with the phase of 90° in a period of time t32to time t33after a predetermined time from time t31. The distance measurement processing unit13obtains a light amount value A90and a light amount value B90on the basis of the pixel signals read by the tap A and the tap B, respectively.

At time t34after a predetermined time from time t33, the above-described operation from the time t30is executed again.

The method of sequentially executing the reading by the taps A and B for each of the phases of 0° and 90° and obtaining each light amount value based on the reading by the taps A and B for each of the phases of 0° and 90° as illustrated inFIG.5Cis referred to as a two-phase/two-tap method.

Here, in the two-phase/two-tap method inFIG.5C, the reading by the tap A and the tap B is sequentially executed in each of the phases of 0° and 90°. This corresponds to, for example, executing reading of the phase of 0° and the phase of 180° having a phase different by 180° from the phase of 0° at the phase of 0°. Similarly, this corresponds to executing reading of the phase of 90° and the phase of 270° having a phase different by 180° from the phase of 90° at the phase of 90°.

The phase difference of reading by the tap A and the tap B in the light receiving unit12will be described with reference toFIG.6.FIG.6is a diagram illustrating an example of the exposure periods of the tap A and the tap B at each of the phases of 0°, 90°, 180°, and 270° for each light receiving unit12(for each light receiving element). Incidentally, inFIG.6, for the sake of explanation, the exposure periods of the respective phases are arranged in parallel with the phases aligned. In practice, as described with reference toFIGS.5A,5B, and5C, the exposure of each phase is sequentially executed.

InFIG.6, exposure (illustrated as the light amount values A0and B0, respectively) by the tap A and the tap B with the phase of 0° is executed sequentially (alternately). On the other hand, exposure by the tap A and the tap B with the phase of 180° is delayed by 180° with respect to the exposure by the tap A and the tap B with the phase of 0°, and the exposure by the tap A and the tap B is executed sequentially. At this time, the phases of the exposure period of the tap A at the phase of 0° and the exposure period of the tap B at the phase of 180° coincide with each other. Similarly, the phases of the exposure period by the tap B at the phase of 0° and the exposure period by the tap A at the phase of 180° coincide with each other.

That is, for example, the exposure periods by the tap A and the tap B at the phase of 0° can be considered as the exposure period at the phase of 0° and the exposure period at the phase of 180°. Therefore, in the case of the third method, the differences I and Q are calculated by the following equations (10) and (11) using the light amount values A0and B0and A90and B90.
I=C0−C180=(A0−B0)  (10)
Q=C90−C270=(A90−B90)  (11)

The phase difference phase, the distance information Depth, and the directly reflected light information DiRefl can be calculated by the above-described equations (3), (4), and (7) using the differences I and Q calculated by the equations (10) and (11). Further, the RAW image information RAW can be calculated as average values of the light amount values A0and B0and A90and B90, following the above-described equation (6).

In this manner, two reading circuits (taps A and B) are provided for one light receiving element, and reading by the tap A and the tap B is executed sequentially. As a result, an exposure period in which phases are different by 180° can be realized in one phase (for example, the phase of 0°). Therefore, in the two-phase/two-tap method illustrated inFIG.5C, a result equivalent to that of the one-tap method illustrated inFIG.5Acan be obtained in a shorter time than that of the one-tap method.

Configuration Applicable to Each Embodiment

Next, an example of a configuration applicable to each embodiment will be described.FIG.7is a block diagram illustrating a configuration of one example of an electronic device applicable to each embodiment. InFIG.7, an electronic device2includes a central processing unit (CPU)100, a read only memory (ROM)101, a random access memory (RAM)102, a storage103, a user interface (UI) unit104, and an interface (I/F)105. Further, the electronic device2includes a light source unit110and a sensor unit111corresponding to the light source unit11and the light receiving unit12inFIG.1, respectively.

Incidentally, it is conceivable to apply, for example, a smartphone (multifunctional mobile phone terminal) or a tablet personal computer as the electronic device2illustrated inFIG.7. The devices to which the electronic device2is applied are not limited to these smartphones and tablet personal computers.

The storage103is a nonvolatile storage medium such as a flash memory or a hard disk drive. The storage103can store various data and programs for operating the CPU100. Further, the storage103can store an application program (hereinafter, abbreviated as an application) for realizing the application unit20described with reference toFIG.1. The ROM101stores in advance programs and data for the CPU100to operate. The RAM102is a volatile storage medium that stores data.

According to the program stored in the storage103or the ROM101, the CPU100operates using the RAM102as a work memory and controls the entire operation of the electronic device2.

In the UI unit104, various operators for operating the electronic device2, a display element for displaying the state of the electronic device2, and the like are arranged. The UI unit104may further include a display which displays an image captured by the sensor unit111described later. Further, this display may be a touch panel in which a display device and an input device are integrally formed, and the various operators may be configured by components displayed on the touch panel.

The light source unit110includes a light emitting element such as an LED or a VCSEL, and a driver for driving the light emitting element. In the light source unit110, the driver generates a drive signal having a predetermined duty in response to an instruction from the CPU100. The light emitting element emits light according to the drive signal generated by the driver and emits light modulated by the PWM as the emission light30.

The sensor unit111includes a pixel array unit in which a plurality of light receiving elements is arranged in an array, and a drive circuit which drives the plurality of light receiving elements arranged in the pixel array unit and outputs a pixel signal read from each light receiving element. The pixel signal output from the sensor unit111is supplied to the CPU100.

Next, the sensor unit111applicable to each embodiment will be described with reference toFIGS.8to11.

FIG.8is a block diagram illustrating an example of a configuration of the sensor unit111applicable to each embodiment. InFIG.8, the sensor unit111has a laminated structure including a sensor chip1110and a circuit chip1120laminated on the sensor chip1110. In this laminated structure, the sensor chip1110and the circuit chip1120are electrically connected through a connection portion (not illustrated) such as a via (VIA) or a Cu—Cu connection. In the example ofFIG.8, a state where the wiring of the sensor chip1110and the wiring of the circuit chip1120are connected by the connection portion is illustrated.

A pixel area1111includes a plurality of pixels1112arranged in an array on the sensor chip1110. For example, an image signal of one frame is formed on the basis of pixel signals output from the plurality of pixels1112included in the pixel area1111. Each pixel1112arranged in the pixel area1111can receive, for example, infrared light, performs photoelectric conversion on the basis of the received infrared light, and outputs an analog pixel signal. Two vertical signal lines VSL1and VSL2are connected to each pixel1112included in the pixel area1111.

In the sensor unit111, a vertical drive circuit1121, a column signal processing unit1122, a timing control circuit1123, and an output circuit1124are further arranged on the circuit chip1120.

The timing control circuit1123controls the drive timing of the vertical drive circuit1121in accordance with an element control signal supplied from the outside via a control line50. Further, the timing control circuit1123generates a vertical synchronization signal on the basis of the element control signal. The column signal processing unit1122and the output circuit1124execute respective processing in synchronization with the vertical synchronization signal generated by the timing control circuit1123.

The vertical signal lines VSL1and VSL2are wired in the vertical direction inFIG.8for each column of the pixels1112. Assuming that the total number of columns in the pixel area1111is M columns (M is an integer of 1 or more), a total of 2×M vertical signal lines are wired in the pixel area1111. Although details will be described later, each pixel1112includes two taps A (TAP_A) and B (TAP_B) which accumulate electric charges generated by photoelectric conversion. The vertical signal line VSL1is connected to the tap A of the pixel1112, and the vertical signal line VSL2is connected to the tap B of the pixel1112.

In the vertical signal line VSL1, a pixel signal AINP1which is an analog pixel signal based on the electric charge of the tap A of the pixel1112in the corresponding pixel column is output. Further, in the vertical signal line VSL2, a pixel signal AINP2which is an analog pixel signal based on the electric charge of the tap B of the pixel1112in the corresponding pixel column is output.

The vertical drive circuit1121drives each pixel1112included in the pixel area1111in units of pixel rows in accordance with timing control by the timing control circuit1123, and outputs the pixel signals AINP1and AINP2. The pixel signals AINP1and AINP2output from each pixel1112are supplied to the column signal processing unit1122via the vertical signal lines VSL1and VSL2of each column.

The column signal processing unit1122includes, for example, a plurality of AD converters provided for each pixel column corresponding to the pixel column of the pixel area1111. Each AD converter included in the column signal processing unit1122executes AD conversion on the pixel signals AINP1and AINP2supplied via the vertical signal lines VSL1and VSL2, and supplies the pixel signals AINP1and AINP2converted into digital signals to the output circuit1124.

The output circuit1124executes signal processing such as correlated double sampling (CDS) processing on the pixel signals AINP1and AINP2converted into digital signals and output from the column signal processing unit1122, and outputs the pixel signals AINP1and AINP2subjected to the signal processing to the outside of the sensor unit111via an output line51as the pixel signal read from the tap A and the pixel signal read from the tap B, respectively.

FIG.9is a circuit diagram illustrating a configuration of one example of the pixel1112applicable to each embodiment. The pixel1112includes a photodiode231, two transfer transistors232and237, two reset transistors233and238, two floating diffusion layers234and239, two amplification transistors235and240, and two selection transistors236and241. The floating diffusion layers234and239correspond to the tap A (described as TAP_A) and the tap B (described as TAP_B) described above, respectively.

The photodiode231is a light receiving element which photoelectrically converts received light to generate an electric charge. With a surface on which a circuit is arranged in a semiconductor substrate as a front surface, the photodiode231is arranged on the back surface with respect to the front surface. Such a solid-state imaging element is called a back-illuminated solid-state imaging element. Incidentally, instead of the back-illuminated configuration, a front-illuminated configuration in which the photodiode231is arranged on the front surface can also be used.

An overflow transistor242is connected between the cathode of the photodiode231and a power supply line VDD, and has a function of resetting the photodiode231. That is, the overflow transistor242is turned on in response to an overflow gate signal OFG supplied from the vertical drive circuit1121, thereby sequentially discharging the electric charge of the photodiode231to the power supply line VDD.

The transfer transistor232is connected between the cathode of the photodiode231and the floating diffusion layer234. Further, the transfer transistor237is connected between the cathode of the photodiode231and the floating diffusion layer239. In accordance with a transfer signal TRG supplied from the vertical drive circuit1121, the transfer transistors232and237sequentially transfer the electric charges generated by the photodiode231to the floating diffusion layers234and239, respectively.

The respective floating diffusion layers234and239corresponding to the taps A and B accumulate the electric charges transferred from the photodiode231, convert the electric charges into voltage signals of voltage values corresponding to the accumulated electric charge amounts, and generate the pixel signals AINP1and AINP2which are analog pixel signals, respectively.

The two reset transistors233and238are connected between the power supply line VDD and the respective floating diffusion layers234and239. The reset transistors233and238are turned on in response to reset signals RST and RSTpsupplied from the vertical drive circuit1121, thereby extracting electric charges from the floating diffusion layers234and239and initializing the floating diffusion layers234and239, respectively.

The two amplification transistors235and240are connected between the power supply line VDD and the respective selection transistors236and241. The amplification transistors235and240amplify voltage signals obtained by converting electric charges into voltages in the floating diffusion layers234and239, respectively.

The selection transistor236is connected between the amplification transistor235and the vertical signal line VSL1. Further, the selection transistor241is connected between the amplification transistor240and the vertical signal line VSL2. The selection transistors236and241are turned on in response to the selection signals SEL and SELpsupplied from the vertical drive circuit1121, thereby outputting the pixel signals AINP1and AINP2amplified by the amplification transistors235and240to the vertical signal line VSL1and the vertical signal line VSL2, respectively.

The vertical signal line VSL1and the vertical signal line VSL2connected to the pixel1112are connected to the input end of one AD converter included in the column signal processing unit1122for each pixel column. The vertical signal line VSL1and the vertical signal line VSL2supply the pixel signals AINP1and AINP2output from the pixels1112to the AD converter included in the column signal processing unit1122for each pixel column.

The laminated structure of the sensor unit111will be schematically described with reference toFIGS.10and11.

As an example, the sensor unit111can be formed by a two-layer structure in which semiconductor chips are laminated in two layers.FIG.10is a diagram illustrating an example of the sensor unit111formed by a laminated complementary metal oxide semiconductor image sensor (CIS) having the two-layer structure applicable to each embodiment. In the structure ofFIG.10, the pixel area1111is formed in the first-layer semiconductor chip which is the sensor chip1110, and a circuit unit is formed in the second-layer semiconductor chip which is the circuit chip1120.

The circuit unit includes, for example, the vertical drive circuit1121, the column signal processing unit1122, the timing control circuit1123, and the output circuit1124. Incidentally, the sensor chip1110may include the pixel area1111and, for example, the vertical drive circuit1121. As illustrated on the right side ofFIG.10, the sensor chip1110and the circuit chip1120are bonded together while being in electrical contact with each other, so that the sensor unit111is configured as one solid-state imaging element.

As another example, the sensor unit111can be formed by a three-layer structure in which semiconductor chips are laminated in three layers.FIG.11is a diagram illustrating an example of the sensor unit111formed of a laminated CIS having the three-layer structure applicable to each embodiment. In the structure ofFIG.11, the pixel area1111is formed in the first-layer semiconductor chip which is the sensor chip1110. Further, the above-described circuit chip1120is formed to be divided into a first circuit chip1120aformed as the second-layer semiconductor chip and a second circuit chip1120bformed as the third-layer semiconductor chip. As illustrated on the right side ofFIG.11, the sensor chip1110, the first circuit chip1120a, and the second circuit chip1120bare bonded together while being in electrical contact with each other, so that the sensor unit111is configured as one solid-state imaging element.

Example of Distance Measuring Device According to Existing Technology

Next, processing by a distance measuring device according to an existing technology will be described.FIG.12is a functional block diagram illustrating one example of functions of the distance measuring device according to the existing technology. InFIG.12, the distance measuring device1000includes the light source unit11, the light receiving unit12, a control unit140, and a distance measuring unit141.

The control unit140generates a light source control signal and supplies the light source control signal to the light source unit11. The light source control signal includes, for example, information that specifies a duty in PWM modulation, intensity of light emitted by the light source unit11, light emission timing, and the like. The light source unit11emits the emission light30(seeFIG.1) modulated by the PWM in accordance with the light source control signal supplied from the control unit140. Further, the control unit140generates an exposure control signal and supplies the signal to the light receiving unit12. The exposure control signal includes information for controlling the light receiving unit12to perform exposure with an exposure length according to the duty of the light source unit11in each of different phases. Further, the exposure control signal further includes information for controlling the exposure amount in the light receiving unit12.

The pixel signal of each phase output from the light receiving unit12is supplied to the distance measuring unit141. The distance measuring unit141calculates the distance information Depth, the directly reflected light information DiRefl, and the RAW image information RAW by calculating the above-described equations (1) to (4), (6), and (7) on the basis of the pixel signal of each phase supplied from the light receiving unit12. The equation (5) may be used instead of the equation (7). The distance measuring unit141passes the calculated distance information Depth, directly reflected light information DiRefl, and RAW image information RAW to, for example, the application unit20.

Herein, the above-described control unit140generates a control signal for controlling the exposure amount in the light receiving unit12on the basis of each pixel signal of each phase (for example, the phases of 0°, 90°, 180° and 270°) supplied from the light receiving unit12. The control signal generated by the control unit140is used to enable the distance measuring unit141to appropriately calculate the distance information Depth regardless of the scene to be captured. For example, the control unit140generates a control signal to adjust each light amount value based on the pixel signal of each phase to a value within an appropriate range.

That is, more specifically, referring to the above-described equations (1) and (2), there is a possibility that the differences I and Q cannot be appropriately calculated in a case where one or more pixel signals among the pixel signals corresponding to the respective phases are saturated or at a level equal to or lower than a predetermined level. In this case, the reliability of the distance information Depth calculated on the basis of the differences I and Q in the distance measuring unit141is also low.

Therefore, the control unit140obtains a control signal for controlling each light amount value based on each pixel signal of each phase to a value within an appropriate range. On the basis of the obtained control signal, the control unit140controls the gain and the exposure time by the light receiving unit12and the duty and intensity of light emission by the light source unit11to adjust the amount of the light received by the light receiving unit12to be appropriate.

As an example, in a case where the reflectance of the measurement object31is low or a case where the distance indicated by the distance information Depth calculated by the distance measuring unit141is equal to or more than a predetermined value, the S/N of the calculated distance information Depth becomes low, and the accuracy of the distance information Depth decreases. In this case, in order to maintain the S/N of the distance information Depth calculated by the distance measuring unit141, the control unit140generates a control signal for controlling the light receiving unit12such that the exposure time by the light receiving unit12becomes long.

The control unit140stores the generated control signal in a register or the like. The control unit140executes the light emission by the light source unit11and the light reception by the light receiving unit12for each frame of a predetermined cycle. The control unit140performs processing for one frame on the basis of the control information stored in the register, obtains a control signal on the basis of a result of the processing, and updates the control signal stored in the register.

FIG.13is a flowchart illustrating one example of processing in the distance measuring device1000according to the existing technology. For example, when an imaging start instruction instructing to start imaging (distance measurement) is passed from the application unit20to the distance measuring device1000, the processing according to the flowchart inFIG.13is started.

In step S100, the distance measuring device1000causes the control unit140to control the light source unit11and the light receiving unit12on the basis of the control signal stored in the register to perform imaging. The pixel signal of each phase obtained by the imaging is passed from the light receiving unit12to the control unit140and the distance measuring unit141.

In the next step S101, the distance measuring device1000causes the distance measuring unit141to calculate the distance information Depth on the basis of the imaging result obtained by the imaging in step S100. More specifically, the distance measuring unit141calculates the distance information Depth by performing the calculation of the above-described equations (1) to (4) on the basis of each pixel signal of each phase obtained by imaging and supplied from the light receiving unit12. The distance measuring device1000outputs the distance information Depth calculated by the distance measuring unit141to, for example, the application unit20.

In the next step S102, the distance measuring device1000causes the distance measuring unit141to calculate the directly reflected light information DiRefl on the basis of the imaging result obtained by the imaging in step S100. More specifically, the distance measuring unit141calculates the directly reflected light information DiRefl by performing the calculation of the above-described equation (7) or (5) on the basis of the differences I and Q obtained at the time of calculating the distance information Depth in step S101. The distance measuring device1000outputs the directly reflected light information DiRefl calculated by the distance measuring unit141to, for example, the application unit20.

In the next step S103, the distance measuring device1000causes the distance measuring unit141to calculate the RAW image information RAW on the basis of the imaging result obtained by the imaging in step S100. More specifically, the distance measuring unit141calculates the RAW image information RAW by performing the calculation of the above-described equation (6) on the basis of each pixel signal of each phase acquired by the imaging in step S100. The distance measuring device1000outputs the RAW image information RAW calculated by the distance measuring unit141to, for example, the application unit20.

In the next step S104, the distance measuring device1000causes the control unit140to obtain a control signal for controlling the light source unit11and the light receiving unit12on the basis of each pixel signal of each phase obtained by the imaging in step S100. The control unit140stores the obtained control signal in the register or the like.

In the next step S105, the distance measuring device1000determines whether or not imaging is ended. For example, in a case where the distance measuring device1000receives an imaging end instruction instructing end of imaging from the application unit20, the distance measuring device determines that the imaging is ended (step S105, “Yes”). In this case, the distance measuring device1000ends a series of processing according to the flowchart ofFIG.13.

On the other hand, in a case where the distance measuring device1000does not receive the imaging end instruction from the application unit20and determines that the imaging is not ended (step S105, “No”), the processing returns to step S100. The processing of steps S100to S105is repeated, for example, in units of one frame.

Herein, the directly reflected light information DiRefl and the RAW image information RAW generated by the distance measuring unit141will be considered. When the gain and the exposure time by the light receiving unit12and the duty and intensity of the light emission by the light source unit11change on the basis of the above-described control signal, the signal values of the directly reflected light information DiRefl and the RAW image information RAW generated by the distance measuring unit141change.

On the other hand, the directly reflected light information DiRefl and the RAW image information RAW generated by the distance measuring unit141can be used for various purposes in addition to the distance measurement. For example, it is conceivable to use the directly reflected light information DiRefl and the RAW image information RAW for improving the accuracy of the distance information Depth. Further, it is also conceivable to apply the directly reflected light information DiRefl and the RAW image information RAW to face recognition, simultaneous localization and mapping (SLAM), or the like. Further, it is also conceivable that an image from a viewpoint as an indirect ToF sensor is important. Furthermore, it is also conceivable to use the directly reflected light information DiRefl and the RAW image information RAW when creating a composite image from an image captured by a multi-view camera in a case where the distance measuring device1000is applied to a smartphone and the multi-view camera is mounted on the smartphone.

As described above, in a case where the directly reflected light information DiRefl and the RAW image information RAW are secondarily used for calculation of the distance information Depth, it is not preferable that the signal values of the directly reflected light information DiRefl and the RAW image information RAW vary according to the control signal for calculation of the distance information Depth.

In the present disclosure, an adjustment value is generated according to a control signal generated such that the distance information Depth is appropriately calculated, and the scale (signal level) of the directly reflected light information DiRefl or the RAW image information RAW is adjusted on the basis of the adjustment value. As a result, even in a case where the pixel signal output from the light receiving unit12is controlled to appropriately calculate the distance information Depth, the signal value of the directly reflected light information DiRefl or the RAW image information RAW can be made stable.

First Embodiment

Next, a first embodiment of the present disclosure will be described.FIG.14is a functional block diagram illustrating one example of functions of a distance measuring device according to the first embodiment. InFIG.14, a distance measuring device10aincludes the light source unit11, the light receiving unit12, a control unit130, a distance measuring unit131, and an adjustment unit132. Among the light source unit11, the light receiving unit12, the control unit130, the distance measuring unit131, and the adjustment unit132, the control unit130, the distance measuring unit131, and the adjustment unit132are configured by, for example, operating a predetermined program on the CPU100(seeFIG.7). The present invention is not limited thereto, and some or all of the control unit130, the distance measuring unit131, and the adjustment unit132may be configured by hardware circuits that operate in cooperation with each other.

Incidentally, in the following description, for the sake of explanation, it is assumed that acquisition of each light amount value and calculation of each piece of information at each phase of 0°, 90°, 180°, and 270° in the light receiving unit12are executed by the one-tap method described with reference toFIG.5A. However, in practice, when the four-phase/two-tap method illustrated inFIG.5Bis applied to the acquisition of each light amount value and the calculation of each piece of information at each phase, it is possible to improve the S/N ratios of the calculated distance information Depth, directly reflected light information DiRefl, and RAW image information RAW, which is preferable.

The control unit130generates a light source control signal for controlling driving of the light source unit11and an exposure control signal for controlling exposure in the light receiving unit12. The control unit130stores the generated control signals (the light source control signal and the exposure control signal) in the register or the like.

Here, a parameter Param is supplied from the application unit20to the control unit130. The parameter Param includes, for example, a value indicating an operation mode of the application unit20. As an operation mode of the application unit20, an operation mode of an authentication system such as a mode in which face authentication is performed on the basis of the pixel signal output from the light receiving unit12and a mode in which person authentication is performed on the basis of the pixel signal can be considered. Further, as the operation mode of the application unit20, an operation mode of displaying an image based on the pixel signal can be also considered. Further, for example, the face authentication mode can include a three-dimensional face authentication mode using three-dimensional information based on the distance information Depth and a two-dimensional face authentication mode using two-dimensional information based on the directly reflected light information DiRefl.

The control unit130generates the light source control signal and the exposure control signal described above on the basis of the parameter Param supplied from the application unit20such that the pixel signal output from the light receiving unit12is appropriate for the operation mode of the application unit20.

For example, in a case where the parameter Param indicates the three-dimensional face authentication mode, the control unit130generates the light source control signal and the exposure control signal such that the distance information Depth calculated by the distance measuring unit131is appropriate for face authentication in the three-dimensional face authentication mode. Incidentally, the parameter Param can include, for example, parameters for the control unit130to generate the light source control signal and the exposure control signal.

The control unit130further generates an adjustment value for adjusting the scale of the directly reflected light information DiRefl and the RAW image information RAW on the basis of the light source control signal and the exposure control signal. The control unit130supplies the generated adjustment value to the adjustment unit132and stores the adjustment value in the register or the like.

The distance measuring unit131has a function corresponding to the distance measuring unit141described with reference toFIG.12. In other words, the distance measuring unit131calculates the distance information Depth, the directly reflected light information DiRefl, and the RAW image information RAW by calculating the above-described equations (1) to (4), (6), and (7) on the basis of the pixel signal of each phase supplied from the light receiving unit12. The distance information Depth, the directly reflected light information DiRefl, and the RAW image information RAW output from the distance measuring unit131are supplied to, for example, the application unit20. Further, the directly reflected light information DiRefl and the RAW image information RAW output from the distance measuring unit131are also supplied to the adjustment unit132.

The adjustment unit132adjusts the scales of the directly reflected light information DiRefl and the RAW image information RAW supplied from the distance measuring unit131on the basis of the adjustment value supplied from the control unit130. The adjustment unit132passes the directly reflected light information DiRefl, and directly reflected light information Scaled_DiRefl and RAW image information Scaled_RAW obtained by adjusting the scale of the RAW image information RAW to the application unit20.

Details of Configuration According to First Embodiment

FIG.15is a functional block diagram illustrating one example of functions of the control unit130applicable to the first embodiment. InFIG.15, the control unit130includes a control value generation unit1300, a storage unit1301, a drive signal generation unit1302, a light reception control unit1303, and a light reception amount detection unit1304.

In accordance with the light source control signal generated by the control value generation unit1300, the drive signal generation unit1302generates a drive signal modulated by the PWM with a predetermined duty and controlled to a predetermined level. The drive signal generation unit1302supplies the generated drive signal to the light source unit11. The light source unit11emits light on the basis of the supplied drive signal and emits the emission light30modulated by the PWM with a predetermined duty.

The light reception control unit1303controls the exposure period and the gain in the light receiving unit12according to the exposure control signal generated by the control value generation unit1300. The light receiving unit12is controlled to have an exposure period and a gain by the light reception control unit1303, and outputs the pixel signal corresponding to the light received during the exposure period.

The light reception amount detection unit1304is supplied with the pixel signal output from the light receiving unit12. Herein, the pixel signal output by the light receiving unit12is each pixel signal having each phase of 0°, 90°, 180°, and 270°. The light reception amount detection unit1304obtains light amount values C0, C90, C180, and C270of the light received in each phase on the basis of the pixel signal supplied from the light receiving unit12. The light reception amount detection unit1304passes the obtained light amount values C0, C90, C180, and C270to the control value generation unit1300.

The control value generation unit1300generates a light source control signal and an exposure control signal on the basis of the light amount values C0, C90, C180, and C270passed from the light reception amount detection unit1304. The present invention is not limited thereto, and the control value generation unit1300may generate at least one of the light source control signal and the exposure control signal. For example, in a case where the light amount value of at least one of the light amount values C0, C90, C180, and C270is a value outside a predetermined range, the control value generation unit1300generates one or both of the light source control signal and the exposure control signal such that the light amount value becomes a value within the predetermined range.

For example, the control value generation unit1300generates, for the light source unit11, a light source control signal for controlling the light amount of the emission light30emitted by the light source unit11. By controlling the amount of the emission light30emitted from the light source unit11, the amount of the reflected light32received by the light receiving unit12can be controlled. Further, the control value generation unit1300generates, for the light receiving unit12, an exposure control signal for controlling the amount of light received during the exposure period.

The storage unit1301is, for example, a register, and stores the light source control signal and the exposure control signal generated by the control value generation unit1300. The control value generation unit1300can supply the light source control signal and the exposure control signal stored in the storage unit1301to the drive signal generation unit1302and the light reception control unit1303, respectively.

FIGS.16A,16B, and16Care diagrams for schematically explaining the control signal generated by the control value generation unit1300applicable to each embodiment.

FIG.16Ais a diagram illustrating a first example of control by the control value generation unit1300. In the first example, the control value generation unit1300controls the light receiving unit12by the exposure control signal. InFIG.16A, for example, charts50aand51aillustrate examples of the light emission of the light source unit11and the exposure period of the light receiving unit12in a default state, respectively. More specifically, the chart50aillustrates an example of one cycle of the light emission of the light source unit11in the default state. Further, the chart51aillustrates an example of the exposure period (long exposure) in the light receiving unit12in the default state corresponding to the light emission cycle of the light source unit11.

For example, in a case where the amount of the light received by the light receiving unit12during the exposure period is controlled to a half of that in the default state, as illustrated in the chart51bofFIG.16A, the control value generation unit1300generates an exposure control signal such that the exposure period of the light receiving unit12is a half of the exposure period in the default state. The control value generation unit1300passes the generated exposure control signal to the light reception control unit1303. By this exposure control signal, the exposure time of the light receiving unit12becomes short exposure which is a half of the above-described long exposure, and the light reception amount decreases with respect to the default state.

In this case, as indicated by a solid line in chart50bofFIG.16A, the control value generation unit1300generates a light source control signal for setting the duty of the light emission of the light source unit11to a half of that in the default state, and synchronizes the period during which the light source unit11emits light with the exposure period of the light receiving unit12. The present invention is not limited thereto, and the duty of the light emission of the light source unit11may remain in the default state as indicated by a dotted line in the chart50b.

FIG.16Bis a diagram illustrating a second example of the control by the control value generation unit1300. In the second example, the control value generation unit1300controls the light source unit11by the light source control signal. InFIG.16B, for example, charts52aand53aillustrate examples of the light emission of the light source unit11and the exposure period of the light receiving unit12in the default state, respectively. More specifically, the chart52aillustrates an example of one cycle of the light emission of the light source unit11in the default state. In the default state, the light source unit11blinks and emits light according to duty=50%. Further, the chart53aillustrates an example of the exposure period in the light receiving unit12in the default state corresponding to the duty of the light source unit11.

In the second example, for example, in a case where the amount of the light received by the light receiving unit12during the exposure period is controlled to a half of that in the default state, the control value generation unit1300generates a light source control signal for setting the duty of the light emission in the light source unit11to 25% of a half of that in the default state as illustrated in the chart52binFIG.16B. The control value generation unit1300passes the generated light source control signal to the drive signal generation unit1302. The exposure period of the light receiving unit12remains in the default state as illustrated in the chart53b. By this light source control signal, the time during which the light source unit11emits light in one cycle of a PWM waveform becomes a half of that in the default state, and the light reception amount in the light receiving unit12decreases with respect to the default state.

FIG.16Cis a diagram illustrating a third example of the control by the control value generation unit1300. In the third example, the control value generation unit1300controls the light source unit11by the light source control signal. InFIG.16C, for example, charts54aand55aillustrate examples of the light emission of the light source unit11and the exposure period of the light receiving unit12in the default state, respectively. More specifically, the chart54aillustrates an example of one cycle of the light emission of the light source unit11in the default state. Further, the chart55aillustrates an example of the exposure period in the light receiving unit12in the default state corresponding to the light emission cycle of the light source unit11.

In the third example, for example, in a case where the amount of the light received by the light receiving unit12during the exposure period is controlled to a half of that in the default state, the control value generation unit1300generates a light source control signal for setting the light emission intensity in the light source unit11to a half of that in the default state as illustrated in the chart54bofFIG.16C. The control value generation unit1300passes the generated light source control signal to the drive signal generation unit1302. The exposure period of the light receiving unit12remains in the default state as illustrated in the chart55b. By this light source control signal, one cycle of light emission amount by the light source unit11becomes a half time of that in the default state, and the light reception amount in the light receiving unit12decreases with respect to the default state.

On the basis of each of the light amount values C0, C90, C180, and C270passed from the light reception amount detection unit1304, the control value generation unit1300generates a control signal for controlling the light reception amount in the light receiving unit12by any one of the first to third examples described above or a combination of two or more of the first to third examples. As described above, the control signal generated here is at least one of the exposure control signal and the light source control signal. The control value generation unit1300stores the generated control signal in the storage unit1301.

Incidentally, the control value generation unit1300can also control the gain in the light receiving unit12, for example, in addition to the first to third examples described with reference toFIGS.16A,16B, and16C. By controlling the gain in the light receiving unit12, the level of the pixel signal output from the light receiving unit12is controlled. The control value generation unit1300generates a gain control signal for controlling a gain in the light receiving unit12and passes the gain control signal to the light reception control unit1303. The light reception control unit1303controls, for example, an output gain of the output circuit1124(seeFIG.8) in the light receiving unit12according to the gain control signal passed from the control value generation unit1300.

The control value generation unit1300generates an adjustment value for adjusting the scale (signal level) of the directly reflected light information DiRefl and the RAW image information RAW on the basis of the generated control signal. The control value generation unit1300outputs the generated adjustment value from the control unit130.

FIG.17is a functional block diagram illustrating one example of functions of the distance measuring unit131applicable to the first embodiment. InFIG.17, the distance measuring unit131includes a distance measurement calculation unit1310, a memory1311, a directly reflected light information calculation unit1312, and a RAW image information calculation unit1313.

Each pixel signal of each phase output from the light receiving unit12is supplied to the distance measurement calculation unit1310. The distance measurement calculation unit1310obtains the light amount values C0, C90, C180, and C270of the light received in each phase on the basis of the pixel signal supplied from the light receiving unit12. The distance measurement calculation unit1310stores the obtained light amount values C0, C90, C180, and C270in the memory1311.

When all the light amount values C0, C90, C180, and C270are stored in the memory1311, the distance measurement calculation unit1310calculates the differences I and Q on the basis of the above-described equations (1) and (2). Further, the distance measurement calculation unit1310calculates the distance information Depth by the above-described equations (3) and (4) on the basis of the calculated differences I and Q. The distance measurement calculation unit1310outputs the calculated distance information Depth from the distance measuring unit131.

The distance measurement calculation unit1310passes the calculated differences I and Q to the directly reflected light information calculation unit1312. The directly reflected light information calculation unit1312calculates the directly reflected light information DiRefl on the basis of the above-described equation (7) using the differences I and Q passed from the distance measurement calculation unit1310. The directly reflected light information calculation unit1312is not limited thereto, and may calculate the directly reflected light information DiRefl on the basis of the above-described equation (5). The directly reflected light information calculation unit1312outputs the calculated directly reflected light information DiRefl from the distance measuring unit131.

Further, the distance measurement calculation unit1310passes the light amount values C0, C90, C180, and C270stored in the memory1311to the RAW image information calculation unit1313. The RAW image information calculation unit1313calculates the RAW image information RAW on the basis of the above-described equation (6). The RAW image information calculation unit1313outputs the calculated RAW image information RAW from the distance measuring unit131.

FIG.18is a functional block diagram illustrating one example of functions of the adjustment unit132applicable to the first embodiment. InFIG.18, the adjustment unit132includes a coefficient generation unit1320D and a multiplier1321D as a configuration for adjusting the directly reflected light information DiRefl. Further, the adjustment unit132includes a coefficient generation unit1320R and a multiplier1321R as a configuration for adjusting the RAW image information RAW.

InFIG.18, the adjustment value output from the control value generation unit1300and the parameter Param output from the application unit20are input to the coefficient generation units1320D and1320R, respectively.

Herein, the parameter Param further includes the directly reflected light information DiRefl requested by the application unit20and target information target indicating the signal level of the RAW image information RAW with respect to the information indicating the above-described operation mode. The parameter Param may include the target information target for each of the directly reflected light information DiRefl and the RAW image information RAW. Hereinafter, unless otherwise specified, the target information target corresponds to the directly reflected light information DiRefl. In this case, the target information target is, for example, a value normalized on the basis of the signal level of the directly reflected light information DiRefl in a predetermined default state.

In the configuration for adjusting the directly reflected light information DiRefl, the coefficient generation unit1320D obtains a coefficient kDfor adjusting the signal level (scale) of the directly reflected light information DiRefl on the basis of the adjustment value output from the control value generation unit1300and the target information target included in the parameter Param.

Herein, a scale Scale is defined by a following equation (12) on the basis of the target information target and the adjustment value.
Scale=target/adjustment value  (12)

Incidentally, the adjustment value indicates a ratio of the light reception amount in a case where at least one of the light source unit11and the light receiving unit12is controlled by the control signal with respect to the light reception amount in a predetermined default state of the light receiving unit12. For example, in the case of the example ofFIG.16Bdescribed above, since the duty of the light emission of the light source unit11is controlled from 50% to 25%, and the light reception amount becomes a half, the adjustment value is set to ½.

According to the equation (12), the signal level of the directly reflected light information DiRefl is scaled on the basis of the scale Scale after canceling the controlled amount of the light reception amount of the light receiving unit12. For example, when the adjustment value=½ and the target information target=1, the scale Scale=2 and the coefficient kD=2 are calculated. The coefficient generation unit1320D inputs the calculated coefficient kDto the multiplication value input end of the multiplier1321D.

The directly reflected light information DiRefl output from the directly reflected light information calculation unit1312is input to the multiplication target value input end of the multiplier1321D. The multiplier1321D multiplies the directly reflected light information DiRefl input to the multiplication target value input end by the coefficient kDinput to the multiplication input end, and outputs the scale-adjusted directly reflected light information Scaled_DiRefl.

The configuration for adjusting the RAW image information RAW also has a function equivalent to that of the configuration for adjusting the directly reflected light information DiRefl described above. That is, the coefficient generation unit1320R calculates the coefficient kRfor adjusting the signal level of the RAW image information RAW by the above-described equation (12) on the basis of the adjustment value output from the control value generation unit1300and the target information target for the RAW image information RAW included in the parameter Param. The coefficient generation unit1320R inputs the calculated coefficient kRto the multiplication value input end of the multiplier1321R.

The RAW image information RAW output from the RAW image information calculation unit1313is input to the multiplication target value input end of the multiplier1321R. The multiplier1321R multiplies the RAW image information RAW input to the multiplication target value input end by the coefficient kRinput to the multiplication input end and outputs the scaled-adjusted RAW image information Scaled_RAW.

(Example of Each Piece of Information According to First Embodiment)

The distance information Depth, the directly reflected light information DiRefl, and the scale-adjusted directly reflected light information Scaled_DiRefl will be described more specifically with reference toFIGS.19A,19B,19C, and19D.FIG.19Ais a view illustrating an example of the measurement object31captured by the light receiving unit12. In the example ofFIG.19A, the head of a mannequin is used as the measurement object31.

FIG.19Bis a diagram illustrating an example of the distance information Depth. InFIG.19B, the distance information Depth is expressed as an image based on the distance information Depth corresponding to each pixel position. In the example ofFIG.19B, the distance information Depth to each portion of the measurement object31is expressed by the brightness of the pixel. For example, the closer the distance is, the brighter the image is expressed, and the farther the distance is, the darker the image is expressed. The face authentication in the three-dimensional face recognition mode using the three-dimensional information can be executed on the basis of the distance information Depth as illustrated inFIG.19B.

FIG.19Cis a diagram illustrating an example of the directly reflected light information DiRefl. Since the image is obtained by extracting the reflected light32obtained by reflecting the emission light30from the light source unit11from the measurement object31, a portion of the measurement object31having a high reflectance, for example, a skin portion of the face is displayed brighter than the surroundings. Further, a fine portion (eyes, lips, eyebrows, or the like) of the head of the mannequin is unclear.

FIG.19Dis a diagram illustrating an example of the directly reflected light information Scaled_DiRefl subjected to scale adjustment according to each embodiment. A portion of the measurement object31having a high reflectance is displayed more clearly as compared with the example ofFIG.19Cdescribed above. For example, portions, such as eyes, lips, and eyebrows, which are unclear in the example ofFIG.19Ccan be more clearly recognized. For example, in the two-dimensional face authentication mode using the two-dimensional information in the face authentication, the recognition processing can be executed with higher accuracy by using the scale-adjusted directly reflected light information Scaled_DiRefl illustrated inFIG.19Dthan the directly reflected light information DiRefl illustrated inFIG.19Cdescribed above.

Processing in Distance Measuring Device According to First Embodiment

FIG.20is a flowchart illustrating one example of processing in the distance measuring device10aaccording to the first embodiment. Similarly to the flowchart ofFIG.13, for example, when an imaging start instruction instructing to start imaging (distance measurement) is passed from the application unit20to the distance measuring device10a, the processing according to the flowchart ofFIG.20is started. At the same time, the application unit20passes the parameter Param including the information indicating the operation mode of the application unit20and the target information target for the directly reflected light information DiRefl and the RAW image information RAW to the distance measuring device10a.

In the flowchart ofFIG.20, the processing of steps S100to S104is similar to the corresponding processing ofFIG.13described above. That is, in step S100, the distance measuring device10acauses the control unit130to control the light source unit11and the light receiving unit12on the basis of the control signal stored in the register to perform imaging. The pixel signal of each phase obtained by the imaging is passed from the light receiving unit12to the control unit140and the distance measuring unit141.

In the next step S101, the distance measuring device10acauses the distance measuring unit131to calculate the distance information Depth on the basis of the imaging result obtained by the imaging in step S100. The distance measuring device10aoutputs the distance information Depth calculated by the distance measuring unit141to, for example, the application unit20. In the next step S102, the distance measuring device10acauses the distance measuring unit131to calculate the directly reflected light information DiRefl on the basis of the imaging result obtained by the imaging in step S100. The distance measuring device10aoutputs the directly reflected light information DiRefl calculated by the distance measuring unit131to, for example, the application unit20. In the next step S103, the distance measuring device10acauses the distance measuring unit131to calculate the RAW image information RAW on the basis of the imaging result obtained by the imaging in step S100. The distance measuring device10aoutputs the RAW image information RAW calculated by the distance measuring unit131to, for example, the application unit20.

In the next step S104, the distance measuring device10acauses the control unit130to obtain control information for controlling the light source unit11and the light receiving unit12on the basis of each pixel signal of each phase obtained by the imaging in step S100. The control unit140stores the obtained control information in the register or the like.

In the next step S110, the distance measuring device10acauses the control unit130to calculate an adjustment value for performing scale adjustment on the directly reflected light information DiRefl and the RAW image information RAW on the basis of the control information obtained in step S104and the parameter Param passed from the application unit20. The calculated adjustment value is passed to the adjustment unit132.

In the next step S111, the distance measuring device10acauses the adjustment unit132to adjust the directly reflected light information DiRefl calculated in step S102and the RAW image information RAW calculated in step S103on the basis of the adjustment value calculated in step S110, and acquire the scale-adjusted directly reflected light information Scaled_DiRefl and RAW image information Scaled_RAW. The distance measuring device10aoutputs the acquired scale-adjusted directly reflected light information Scaled_DiRefl and RAW image information Scaled_RAW to, for example, the application unit20.

In the next step S105, the distance measuring device10adetermines whether or not the imaging is ended. For example, in a case where the distance measuring device10areceives an imaging end instruction from the application unit20, the distance measuring device determines that the imaging is ended (step S105, “Yes”), and ends a series of processing according to the flowchart ofFIG.20.

On the other hand, in a case where the distance measuring device1000does not receive the imaging end instruction from the application unit20and determines that the imaging is not ended (step S105, “No”), the processing returns to step S100. The processing of steps S100to S105including steps S110and S111is repeated, for example, in units of one frame.

As described above, in the first embodiment, on the basis of the control signal for controlling the amount of the light received by the light receiving unit12for the calculation of the distance information Depth, scale adjustment is performed on the directly reflected light information DiRefl and the RAW image information RAW calculated on the basis of the pixel signal. Therefore, even in a case where the light reception amount of the light receiving unit12changes in order to calculate the distance information Depth, it is possible to suppress the luminance change of the directly reflected light information DiRefl and the RAW image information RAW and output a moving image with a constant luminance based on the directly reflected light information DiRefl and the RAW image information RAW. As a result, for example, it is possible to improve convenience when the application unit20uses the directly reflected light information DiRefl and the RAW image information RAW.

Incidentally, in the above description, the distance measuring device10acalculates the directly reflected light information DiRefl and the RAW image information RAW, and performs scale adjustment on the calculated directly reflected light information DiRefl and RAW image information RAW. However, this is not limited to this example. For example, the distance measuring device10amay calculate only one of the directly reflected light information DiRefl and the RAW image information RAW and perform scale adjustment on the calculated information.

The distance measuring device10amay calculate the directly reflected light information DiRefl and the RAW image information RAW, and the calculated distance measuring device10amay perform scale adjustment on only one of the directly reflected light information DiRefl and the RAW image information RAW. Among the directly reflected light information DiRefl and the RAW image information RAW, information to be calculated or scaled can be included in the parameter Param and specified with respect to the distance measuring device10aby the application unit20, for example.

Second Embodiment

Next, a second embodiment of the present disclosure will be described. The second embodiment is an example in which one of the directly reflected light information DiRefl and the RAW image information RAW which are not subjected to scale adjustment and the directly reflected light information DiRefl_Scale and the RAW image information RAW_Scale which are subjected to scale adjustment can be selected and output to the application unit20.

FIG.21is a functional block diagram illustrating one example of functions of a distance measuring device according to the second embodiment. InFIG.21, in a distance measuring device10b, a selector133is added to the distance measuring device10adescribed with reference toFIG.14. The selector133may be configured by operating a program on the CPU100(seeFIG.7) or may be realized by a hardware circuit.

A set of the directly reflected light information DiRefl and the RAW image information RAW output from the distance measuring unit131and a set of the directly reflected light information Scaled_DiRefl and the RAW image information Scaled_RAW which are output from the adjustment unit132and subjected to scale adjustment are input to the selector133. The selector133selects one of these two sets on the basis of, for example, information which is included in the parameter Param output from the application unit20and indicates the operation mode of the application unit20. The selector133supplies the selected set of the directly reflected light information and the RAW image information to the application unit20as directly reflected light information DiRefl′ and RAW image information RAW′, respectively.

As described above, in the distance measuring device10baccording to the second embodiment, the selector133selects one of the set of the directly reflected light information DiRefl and the RAW image information RAW which are not subjected to scale adjustment and the set of the directly reflected light information Scaled_DiRefl and the RAW image information Scaled_RAW which are subjected to scale adjustment, and supplies the selected set to the application unit20. Therefore, in the distance measuring device10b, it is possible to provide the application unit20with a wider variety of usage modes of the directly reflected light information and the RAW image information and to improve convenience when the application unit20uses the directly reflected light information DiRefl and the RAW image information RAW.

Third Embodiment

Next, a third embodiment of the present disclosure will be described. In the third embodiment, a specific subject is detected on the basis of the pixel signal output from the light receiving unit12. Then, scale adjustment is performed on the directly reflected light information DiRefl and the RAW image information RAW in a subject area including the subject detected in the captured frame.

FIG.22is a functional block diagram illustrating one example of functions of a distance measuring device according to the third embodiment. InFIG.22, in a distance measuring device10c, a subject detection unit134is added to the distance measuring device10adescribed with reference toFIG.14, and the function of an adjustment unit132′ is changed. The subject detection unit134may be configured by operating on of a program on the CPU100(seeFIG.7), or may be realized by a hardware circuit.

The distance information Depth output from the distance measuring unit131and the directly reflected light information DiRefl are supplied to the subject detection unit134. The subject detection unit134detects a specific subject (for example, a face) included in one frame on the basis of at least one of the distance information Depth and the directly reflected light information DiRefl of the frame. The subject to be detected is not limited to the face. That is, when the three-dimensional or two-dimensional shape pattern of the subject is known, another type of subject may be set as the detection target.

As an example, in the case of performing face detection, the subject detection unit134detects a face area in a frame on the basis of the distance information Depth (seeFIG.19B), for example, and further performs pattern matching of three-dimensional information or the like on the detected face area to detect the position and shape of each portion of the face as the three-dimensional information. Further, for example, the subject detection unit134performs image analysis on the directly reflected light information DiRefl to detect a face area (seeFIG.19D), and further performs pattern matching of two-dimensional information or the like to detect the position and shape of each portion of the face as the two-dimensional information. Further, the subject detection unit134can also perform face detection using both the face detection result based on the distance information Depth and the face detection result based on the directly reflected light information DiRefl.

The subject detection unit134obtains, as the subject area, an area in the frame in which the specific subject is detected, and acquires coordinate information of the subject area. As the coordinate information, for example, information indicating the position of each pixel1112in the pixel area1111can be applied with reference toFIG.8. The subject detection unit134supplies the acquired coordinate information of the subject area as subject area information Subj to the adjustment unit132′. On the basis of the subject area information Subj, the adjustment unit132′ performs scale adjustment on the information of the area indicated by the subject area information Subj in the directly reflected light information DiRefl and the RAW image information RAW supplied from the distance measuring unit131.

FIG.23is a functional block diagram illustrating one example of functions of the adjustment unit132′ according to the third embodiment. InFIG.23, similarly to the adjustment unit132described with reference toFIG.18, the adjustment unit132′ includes a coefficient generation unit1320D′ and the multiplier1321D as a configuration for adjusting the directly reflected light information DiRefl. Further, the adjustment unit132includes a coefficient generation unit1320R′ and a multiplier1321R as a configuration for adjusting the RAW image information RAW.

The subject area information Subj supplied from the subject detection unit134is input to the coefficient generation unit1320D′ and the coefficient generation unit1320R′. For example, similarly to the description usingFIG.18, the coefficient generation unit1320D′ obtains the coefficient kDfor adjusting the signal level (scale) of the directly reflected light information DiRefl by the above-described equation (12) on the basis of the adjustment value output from the control value generation unit1300and the target information target included in the parameter Param.

The coefficient generation unit1320D′ further receives the directly reflected light information DiRefl, and applies the obtained coefficient kDto the area indicated by the subject area information Subj in the directly reflected light information DiRefl input to the adjustment unit132′. The coefficient generation unit1320D′ applies, for example, the coefficient “1” to an area other than the area indicated by the subject area information Subj in the directly reflected light information DiRefl. As a result, in the multiplier1321D′, multiplication by the coefficient kDis selectively executed on the area indicated by the subject area information Subj, and scale adjustment can be performed on the area indicated by the subject area information Subj in the directly reflected light information DiRefl.

The same processing as that of the above-described coefficient generation unit1320D′ can be applied to the coefficient generation unit1320R′ which generates the coefficient kRfor the RAW image information RAW, and thus, detailed description thereof is not given here.

Processing in Distance Measuring Device According to Third Embodiment

FIG.24is a flowchart illustrating one example of processing in the distance measuring device10caccording to the third embodiment. Similarly to the flowchart ofFIG.20, for example, when an imaging start instruction instructing to start imaging (distance measurement) is passed from the application unit20to the distance measuring device10c, the processing according to the flowchart ofFIG.24is started. At the same time, the application unit20passes the parameter Param including the information indicating the operation mode of the application unit20and the target information target for the directly reflected light information DiRefl and the RAW image information RAW to the distance measuring device10c.

In the flowchart ofFIG.24, the processing of steps S100to S104is similar to the corresponding processing ofFIG.20described above, and thus the detailed description thereof is not given here. When obtaining a control signal for controlling the light source unit11and the light receiving unit12in step S104, the distance measuring device10cshifts the processing to step S110. The processing in step S110is the same as the processing in step S110inFIG.20described above, and thus the detailed description thereof will be not given here.

In step S110, the distance measuring device10ccalculates an adjustment value for performing scale adjustment on the directly reflected light information DiRefl and the RAW image information RAW on the basis of the control information and the parameter Param. After passing the calculated adjustment value to the adjustment unit132, the distance measuring device10cshifts the processing to step S120.

In step S120, the distance measuring device10ccauses the subject detection unit134to detect a specific subject included in one frame on the basis of at least one of the distance information Depth and the directly reflected light information DiRefl of the frame output from the distance measuring unit131. The subject detection unit134obtains, as the subject area, an area in the frame in which the specific subject is detected, and acquires coordinate information of the subject area. The subject detection unit134passes the subject area information Subj indicating the subject area to the adjustment unit132′.

In the next step S121, the distance measuring device10ccauses the adjustment unit132′ to perform scale adjustment on the area indicated by the subject area information Subj passed from the subject detection unit134in step S120in the directly reflected light information DiRefl supplied from the distance measuring unit131on the basis of the adjustment value calculated in step S110. The adjustment unit132′ can further perform scale adjustment on the area indicated by the subject area information Subj passed from the subject detection unit134in step S120in the RAW image information RAW supplied from the distance measuring unit131on the basis of the adjustment value calculated in step S110.

The directly reflected light information Scaled_DiRefl in which the area indicated by the subject area information Subj is scale-adjusted is output from the adjustment unit132′ and supplied to the application unit20. In a case where scale adjustment is performed on the area indicated by the subject area information Subj in the RAW image information RAW, the adjustment unit132′ supplies the scale-adjusted RAW image information Scaled_RAW to the application unit20.

In the next step S105, the distance measuring device10cdetermines whether or not imaging is ended. For example, in a case where the distance measuring device10creceives an imaging end instruction from the application unit20, the distance measuring device determines that the imaging is ended (step S105, “Yes”), and ends a series of processing according to the flowchart ofFIG.24.

On the other hand, in a case where the distance measuring device10cdetermines that the imaging is not ended (Step S105, “No”), the processing returns to step S100. The processing of steps S100to S105including steps S110, S111, S120, and S121is repeated, for example, in units of one frame.

As described above, in the third embodiment, scale adjustment can be selectively performed on the area indicated by the subject area information Subj in the frame in the directly reflected light information DiRefl and the RAW image information RAW. Therefore, a specific subject can be emphasized in the frame. As a result, for example, it is possible to improve convenience when the application unit20uses the directly reflected light information DiRefl and the RAW image information RAW.

Incidentally, in the above description, the distance measuring device10ccalculates the directly reflected light information DiRefl and the RAW image information RAW, and performs scale adjustment on each area indicated by the subject area information Subj in the calculated directly reflected light information DiRefl and RAW image information RAW. However, this is not limited to this example. For example, the distance measuring device10cmay calculate only one of the directly reflected light information DiRefl and the RAW image information RAW, and perform scale adjustment on the area indicated by the subject area information Subj of the calculated information.

The distance measuring device10cmay calculate the directly reflected light information DiRefl and the RAW image information RAW, and the calculated distance measuring device10amay perform scale adjustment on the area indicated by the subject area information Subj of any one of the directly reflected light information DiRefl and the RAW image information RAW. Among the directly reflected light information DiRefl and the RAW image information RAW, information to be calculated or scale-adjusted can be specified with respect to the distance measuring device10cby the application unit20, for example.

Fourth Embodiment

Next, a fourth embodiment of the present disclosure will be described. The fourth embodiment is an example in which the second embodiment and the third embodiment described above are combined.FIG.25is a functional block diagram illustrating one example of functions of a distance measuring device according to the fourth embodiment. InFIG.25, in a distance measuring device10d, the selector133in the distance measuring device10bdescribed usingFIG.21is added to the distance measuring device10cdescribed usingFIG.22.

Similarly to the distance measuring device10binFIG.21, the distance measuring device10daccording to the fourth embodiment inputs, to the selector133, a set of the directly reflected light information DiRefl and the RAW image information RAW output from the distance measuring unit131and a set of the directly reflected light information Scaled_DiRefl and the RAW image information Scaled_RAW which are output from the adjustment unit132and subjected to scale adjustment. The selector133selects one of these two sets on the basis of, for example, information which is included in the parameter Param output from the application unit20and indicates the operation mode of the application unit20. The selector133supplies the selected set of the directly reflected light information and the RAW image information to the application unit20as directly reflected light information DiRefl′ and RAW image information RAW′, respectively.

According to the distance measuring device10daccording to the fourth embodiment, the selector133selects one of the set of the directly reflected light information DiRefl and the RAW image information RAW which are not subjected to scale adjustment and the set of the directly reflected light information Scaled_DiRefl and the RAW image information Scaled_RAW in which the respective areas indicated by the subject area information Subj are selectively subjected to scale adjustment, and supplies the selected set to the application unit20. Therefore, in the distance measuring device10d, it is possible to provide the application unit20with a wider variety of usage modes of the directly reflected light information and the RAW image information and to improve convenience when the application unit20uses the directly reflected light information DiRefl and the RAW image information RAW.

Fifth Embodiment

In the first embodiment described above, in the description, the distance measuring device10ais configured as a hardware device by the electronic device2including the CPU100, the ROM101, the RAM102, the UI unit104, the storage103, the I/F105, and the like, but this is not limited to this example. For example, the sensor unit111configured by laminating semiconductor chips illustrated inFIG.10or11can be configured to be one semiconductor element as a whole of the distance measuring device10aincluding the control unit130, the distance measuring unit131, and the adjustment unit132illustrated inFIG.14. This is similarly applicable to the distance measuring devices10b,10c, and10daccording to the second to fourth embodiments.

Incidentally, the effects described in this specification are merely examples and are not limited, and other effects may be present.

Incidentally, this technology may also be configured as below.(1) A distance measuring device comprising:a distance measuring unit that calculates, when a light receiving unit performs light reception for each phase according to light emission of a light source unit, distance information on the basis of a light reception signal for each phase output by the light receiving unit according to the light reception for each phase;a control unit that controls a level of the light reception signal for each phase in accordance with the calculation of the distance information based on the light reception signal for each phase;a generation unit that generates an image signal on the basis of the light reception signal for each phase; andan adjustment unit that adjusts a level of the image signal according to an adjustment value, whereinthe control unit generates the adjustment value on the basis of the light reception signal for each phase controlled according to the calculation of the distance information.(2) The distance measuring device according to the above (1), further comprising:a detection unit that detects a subject area including a predetermined subject in an image area based on the image signal on the basis of the distance information calculated by the distance measuring unit and the image signal generated by the generation unit, whereinthe adjustment unit adjusts the level of the image signal in the subject area on the basis of the adjustment value.(3) The distance measuring device according to the above (1) or (2), further comprising:a selection unit that selects one of the image signal generated by the generation unit and an adjusted image signal obtained by the adjustment unit adjusting the level of the image signal.(4) The distance measuring device according to any one of the above (1) to (3), whereinthe generation unit generates the image signal based on a component of reflected light, which is received by the light receiving unit, of light emitted by light emission of the light source unit among components of light received by the light receiving unit.(5) The distance measuring device according to the above (4), whereinthe generation unit further generates the image signal based on components of the reflected light and the ambient light received by the light receiving unit.(6) The distance measuring device according to any one of the above (1) to (5), whereinthe control unit controls the level of the light reception signal for each phase by controlling an exposure length in the light receiving unit.(7) The distance measuring device according to any one of the above (1) to (6), whereinthe control unit controls the level of the light reception signal for each phase by controlling a duty of the light emission of the light source unit.(8) The distance measuring device according to any one of the above (1) to (7), whereinthe control unit controls the level of the light reception signal for each phase by controlling intensity of the light emission of the light source unit.(9) The distance measuring device according to any one of the above (1) to (8), whereinthe control unit controls the level of the light reception signal for each phase by controlling a gain of the light reception signal for each phase output by the light receiving unit.(10) The distance measuring device according to any one of the above (1) to (9), whereinthe control unit generates the adjustment value for canceling the control of the level of the light reception signal for each phase by the control unit on the basis of the light reception signal for each phase.

REFERENCE SIGNS LIST

1ELECTRONIC DEVICE10,10a,10b,10c,10d,1000DISTANCE MEASURING DEVICE11LIGHT SOURCE UNIT12LIGHT RECEIVING UNIT13DISTANCE MEASUREMENT PROCESSING UNIT20APPLICATION UNIT30EMISSION LIGHT31MEASUREMENT OBJECT32REFLECTED LIGHT100CPU110LIGHT SOURCE UNIT111SENSOR UNIT130,140CONTROL UNIT131,141DISTANCE MEASURING UNIT132,132′ ADJUSTMENT UNIT133SELECTOR134SUBJECT DETECTION UNIT1110SENSOR CHIP1111PIXEL AREA1120CIRCUIT CHIP1120aFIRST CIRCUIT CHIP1120bSECOND CIRCUIT CHIP1300CONTROL VALUE GENERATION UNIT1301STORAGE UNIT1310DISTANCE MEASUREMENT CALCULATION UNIT1312DIRECTLY REFLECTED LIGHT INFORMATION CALCULATION UNIT1313RAW IMAGE INFORMATION CALCULATION UNIT1320D,1320D′,1320R,1320R′ COEFFICIENT GENERATION UNIT1321D,1321R MULTIPLIER