Optical devices, in-vehicle systems, and mobile devices

Abstract

To provide an optical device small in size and capable of reducing an effect of reflected light.SOLUTION: An optical device (1) includes: a light emission part (111) having a plurality of light emitting elements (201); a light reception part (121) having a light receiving elements (301); an imaging optical system (130); a light division part (155) having a reflection mirror (151); and acquisition parts (122 and 123) which acquire distance information on an object on the basis of the time required for the light emission part to emit light and the light reception part to receive the light reflected by the object. Light from the light emission part is reflected by the reflection mirror, passes through the imaging optical system and is reflected by the object. The light reflected by the object passes through the imaging optical system, penetrates the reflection mirror and is received by the light reflection part. A first light emitting element in the plurality of light emitting elements and a first light receiving element in the plurality of light receiving elements have a conjugate relation via the reflection mirror, and the light division part is configured to restrict incidence of the light from the first light emitting element to the first light receiving element.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The present invention relates to an optical device, an in-vehicle system, and a mobile device.

Background Art

[0002] A TOF (Time-Of-Flight) ranging method is known, in which the distance to a subject is measured by measuring the time difference from when light is irradiated until the reflected light is detected. Patent Document 1 discloses a configuration in which light-emitting elements and light-receiving elements are each arranged two-dimensionally, light is irradiated onto a subject through an imaging lens, and reflected light is received, thereby obtaining three-dimensional distance information without a driving unit. In such a configuration, it is necessary to make the light-emitting angle and the light-receiving angle substantially equal. Therefore, in order to miniaturize the ranging device, it is desirable to make the sizes of the light-emitting element array and the light-receiving element array substantially equal and to share the imaging lens.

[0003] Patent Document 2 discloses a configuration in which a third time-series luminance signal obtained by subtracting a second time-series luminance signal corresponding to reflected light from outside the measurement object from a first time-series luminance signal corresponding to reflected light from the measurement object is generated, and a distance value to the measurement object is generated based on the third time-series luminance signal.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the configuration disclosed in Patent Document 2, since a plurality of mirrors are arranged in the optical path, it is difficult to reduce the influence of reflected light without increasing the size of the device.

[0006] Therefore, an object of the present invention is to provide an optical device that is small-sized and capable of reducing the influence of reflected light.

Means for Solving the Problems

[0007] An optical device according to one aspect of the present invention includes a light emitting unit having a plurality of light emitting elements arranged two-dimensionally, a light receiving unit having a plurality of light receiving elements, an imaging optical system, and a light splitting unit disposed between the imaging optical system and the light receiving unit and having a reflecting mirror. The optical device also includes an acquisition unit that acquires distance information of an object based on a time required from when the light emitting unit emits light until the light receiving unit receives the light reflected by the object. Among the plurality of light emitting elements, the light emitting elements in the first row and the light emitting elements in the second row emit light at different times in a time division manner. The optical axis direction of the imaging optical system and the normal direction of the reflecting mirror are non-parallel. The light from the light emitting unit is reflected by the reflecting mirror, passes through the imaging optical system, is reflected by the object, and the light reflected by the object passes through the imaging optical system, passes through the reflecting mirror, and is received by the light receiving unit. Among the plurality of light emitting elements, the first light emitting element and the first light receiving element among the plurality of light receiving elements are in a conjugate relationship via the reflecting mirror. The light splitting unit is configured to suppress the light from the first light emitting element from entering the first light receiving element. The light splitting unit has a beam splitter including the reflecting mirror, and the beam splitter has a reflection suppression structure on the surface opposite to the surface facing the light-emitting unit, which has a periodic structure twice the spacing between the plurality of light-emitting elements, and the reflection suppression structure suppresses the incident light emitted by the first light-emitting element, transmitted through the reflecting mirror, and reflected by the reflection suppression structure, onto the first light-receiving element. 。

[0008] Other objects and features of the present invention will be described in the following embodiments.

Advantages of the Invention

[0009] According to the present invention, it is possible to provide an optical device that is small-sized and capable of reducing the influence of reflected light.

Brief Description of the Drawings

[0010] [Figure 1] It is a block diagram of a distance measuring device in each embodiment.​​​​​​​ [Figure 4] These are schematic diagrams of pixels in each embodiment. [Figure 5] These are schematic diagrams of the TDC array section in each embodiment. [Figure 6] These are schematic diagrams of oscillators in each embodiment. [Figure 7] This table shows the output signals of the buffers at each stage and the internal signals of the oscillator in each embodiment. [Figure 8] This diagram illustrates the changes in the cathode potential of the SPAD element, the pixel output signal, the synchronization clock, the synchronization clock count circuit, the output of the oscillation start / stop signal generation circuit, the oscillator output, and the oscillation count circuit in each embodiment. [Figure 9] This is a magnified view of the period from time 803 to 805 in Figure 8. [Figure 10] This is a block diagram of the oscillation adjustment voltage generation circuit in each embodiment. [Figure 11] This is a diagram showing the configuration of the main parts of the distance measuring device in the first embodiment. [Figure 12] This flowchart shows the distance measurement process in each embodiment. [Figure 13] This is a diagram showing the configuration of the main parts of the distance measuring device in the second embodiment. [Figure 14] This is a diagram showing the configuration of the main parts of the distance measuring device in the third embodiment. [Figure 15] This is a diagram showing the configuration of the main parts of the distance measuring device in the fourth embodiment. [Figure 16] This is a diagram showing the configuration of an in-vehicle system equipped with a distance measuring device in each embodiment. [Figure 17] These are schematic diagrams of mobile devices equipped with distance measuring devices in each embodiment. [Figure 18] This flowchart shows examples of operation of an in-vehicle system equipped with a rangefinder in each embodiment. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described in detail below with reference to the drawings. (First Embodiment) [Overall configuration of the rangefinder] First, with reference to Figure 1, the schematic configuration of the optical device (distance measuring device) 1 in the first embodiment will be described. Figure 1 is a block diagram of the optical device 1. In Figure 1, solid lines represent signal exchange, dashed lines represent projected light projected onto the subject (object), and dashed lines represent reflected light from the subject. The optical device 1 is an optical device (Light Detection and Ranging: LiDAR) that calculates the distance to an object based on the time it takes for light to arrive after it is emitted using the TOF method.

[0012] The optical device 1 comprises a light projection unit 110, a measurement unit 120, an imaging lens (imaging optical system) 130, an overall control unit 140, and an optical splitting unit 155 including a beam splitter 150. The light projection unit 110 comprises a light source unit 113 having an element-emitting array (light-emitting section) 111 and an element-emitting drive unit 112, and a light source control unit 114. The element-emitting array 111 has a plurality of element-emitting elements 201 (see Figure 2) arranged in two dimensions. The element-emitting array 111 is a sequential light-emitting section in which some of the element-emitting elements (first row) and other element-emitting elements (second row) of the plurality of element-emitting elements 201 emit light at different times in a time-division manner.

[0013] The measurement unit 120 comprises a photodetector array (photodetector) 121, a TDC (Time-to-Digital Converter) array 122, a signal processing unit 123, a measurement control unit 124, and a row selection circuit 125. The photodetector array 121 has a plurality of photodetectors arranged in two dimensions. The beam splitter 150 has a half-mirror (reflector) 151 that transmits a portion of the light and reflects the other portion, and a reflection suppression structure 152. In this embodiment, it is preferable to place a bandpass filter on the photodetector array 121 that transmits light of wavelengths including the wavelength emitted by the light-emitting element array 111 and reflects or absorbs light of other wavelengths.

[0014] Each of the light-emitting element arrays 111 (multiple light-emitting elements 201) in the light source unit 113 emits pulsed light, projecting pulsed light into space via the imaging lens 130. The pulsed light emitted from each of the separate light-emitting elements 201 is projected to different angles of view in space. The projected light irradiates a subject (object), and a portion of the light reflected by the subject is received by the photodetector array 121 via the imaging lens 130. The time from when the light-emitting element array 111 emits light until the photodetector array 121 receives the light is the time of flight (TOF). The TDC array unit 122 is a measurement unit that measures the time of flight (TOF). However, in a single measurement, it is difficult to remove noise components such as ambient light and dark count, and the distance measurement error becomes large due to the influence of noise in the measurement circuit. Therefore, the TDC array unit 122 repeatedly measures the time of flight (TOF) from light emission to light reception, and the signal processing unit 123 creates a histogram of the measurement results, removes noise components, and averages the measurement results. The TDC array unit 122 and the signal processing unit 123 constitute an acquisition unit that acquires distance information of the subject based on the time required from when the light-emitting element array 111 emits light until the light-receiving element array 121 receives the light reflected by the subject.

[0015] By substituting the time of flight (TOF) obtained in this way into equation (1) below, the distance L to the subject can be determined with high accuracy. In equation (1), c is the speed of light.

[0016] L = TOF × c / 2 ... (1) [Floodlight Unit] Next, the light-emitting unit 110 will be described with reference to Figure 2. Figure 2 is a schematic diagram of the light source unit 113 and the light source control unit 114 that constitute the light-emitting unit 110. The light-emitting element array 111 has a plurality of light-emitting elements 201. In this embodiment, the light-emitting elements 201 are VCSELs (Vertical Cavity Surface Emitting Lasers) arranged two-dimensionally on a substrate. The light-emitting element drive unit 112 has a plurality of light-emitting element row drive circuits 202 arranged one-dimensionally. In this embodiment, the light-emitting elements 201 are not limited to VCSELs, but it is preferable that they be end-emitting lasers or LEDs (light-emitting diodes) that can be integrated in one or two dimensions.

[0017] When an end-emitting laser is used as the light-emitting element 201 instead of a VCSEL array, the light-emitting element array 111 can be, for example, a laser bar arranged in a one-dimensional manner on a substrate, or a laser bar stack arranged in a two-dimensional manner by stacking these laser bars. When LEDs are used as the light-emitting elements 201, the light-emitting element array 111 can be a two-dimensional arrangement of LEDs on a substrate.

[0018] In this embodiment, the optical device 1 preferably has the wavelength of light emitted by the light-emitting element 201 in the near-infrared band in order to suppress the influence of ambient light. However, this embodiment is not limited to this. VCSELs are manufactured using semiconductor processes with materials used in conventional end-emitting lasers and surface-emitting lasers. When configuring a VCSEL to emit light in the near-infrared band, GaAs-based semiconductor materials can be used as the main material. In this case, the dielectric multilayer film forming the DBR (distributed reflection) mirror constituting the VCSEL can be constructed by alternately and periodically stacking two thin films (for example, GaAs / AlGaAs) made of materials with different refractive indices. The wavelength of the emitted light can be changed by adjusting the elemental combination or composition of the compound semiconductor.

[0019] Each VCSEL in the VCSEL array is provided with electrodes for injecting current and holes into the active layer. These electrodes are shared across the rows and connected to light-emitting element row drive circuits 202 located in each row. By operating only a specific light-emitting element row drive circuit 202 of the light-emitting element drive unit 112, current is injected only into the VCSELs belonging to that specific row, making it possible to emit light from the light-emitting elements 201 in that specific row. [Measurement Unit] Next, the measurement unit 120 will be described with reference to Figure 3. Figure 3 is a schematic diagram of the measurement unit 120. The measurement unit 120 includes a photodetector array 121, a TDC array section 122, a signal processing section 123, a measurement control section 124, a row selection circuit 125, a row selection pulse wiring 303, and a pixel output line 304. The photodetector array 121 has a plurality of pixels (photodetectors) 301 arranged in two dimensions. The row selection circuit 125 activates only a specific row. The row selection pulse wiring 303 outputs the output signal of the row selection circuit 125 to the pixels 301. The pixel output line 304 outputs the output signal of the pixels 301 to the TDC array section 122.

[0020] Now, with reference to Figure 4, the pixel 301 in this embodiment will be described. Figure 4 is a schematic diagram of the pixel 301. The pixel 301 has a SPAD element 401 as a light-receiving element, a load transistor 402, an inverter 403, a pixel output circuit 404, a row selection pulse wiring 303, and a pixel output line 304. The SPAD element 401 has a light-receiving region and an avalanche region.

[0021] When light is incident on the SPAD element 401, it is photoelectrically converted in the light-receiving region, generating electrons and holes. The positively charged holes are discharged through the anode electrode Vbd. The negatively charged electrons are transported as signal charges to the avalanche region by an electric field set to decrease in potential toward the avalanche region within the light-receiving region. Upon reaching the avalanche region, the signal charges undergo avalanche breakdown due to the strong electric field in the avalanche region, generating an avalanche current.

[0022] When no avalanche current is flowing, the voltage of the anode electrode Vbd is set so that a reverse bias greater than the breakdown voltage is applied to the avalanche region of the SPAD element 401. At this time, there is no current flowing through the load transistor 402, so the cathode potential Vc is close to the power supply voltage Vdd, and the inverter output signal is "0". When an avalanche current is generated in the SPAD element 401 due to the arrival of a photon, the cathode potential Vc drops, and the output of the inverter 403 inverts. That is, the inverter output changes from "0" to "1". As the cathode potential Vc decreases, the reverse bias applied to the SPAD element 401 becomes smaller, and the generation of avalanche current stops when the reverse bias falls below the breakdown voltage. Subsequently, a hole current flows from the power supply voltage Vdd to the cathode potential Vc through the load transistor 402, the cathode potential Vc rises, and the inverter output returns from "1" to "0", returning to the state before the arrival of the photon.

[0023] In pixels 301 where the row selection pulse wiring 303 is ON, the output signal of the inverter 403 is controlled to be output to the pixel output line 304. On the other hand, in pixels 301 where the row selection pulse wiring 303 is OFF, the output signal of the inverter 403 is controlled to be disconnected from the pixel output line 304. As a result, it is possible to detect only the light incident on a specific row selected by the row selection circuit 125. In this way, the light detection at pixels belonging to the row selected by the row selection circuit 125 is output to the TDC array unit 122 as a low-latency digital signal.

[0024] Next, the TDC array unit 122 will be described with reference to Figure 5. Figure 5 is a schematic diagram of the TDC array unit 122. The TDC array unit 122 measures the time from when the light source unit 113 emits light until the pixel output signal changes from "0" to "1" as the ToF time.

[0025] In the TDC array section 122, there are as many TDCs 501 as there are pixels in the horizontal direction of the pixel array, and each TDC 501 simultaneously measures the pixel output of one row. The TDC 501 includes an oscillator 511, an oscillation count circuit 521, and a synchronous clock count circuit 531. The count result from the synchronous clock count circuit 531 is the upper bit, the internal signal of the oscillator 511 is the lower bit, and the count result from the oscillation count circuit 521 is the bit in between. In other words, the synchronous clock count circuit 531 measures roughly, the internal signal of the oscillator 511 measures finely, and the oscillation count circuit 521 measures the bits in between. Alternatively, each of these may be configured to have redundant bits.

[0026] Next, the oscillator 511 of the TDC501 will be described with reference to Figure 6. Figure 6 is a schematic diagram of the oscillator 511. The oscillator 511 has an oscillation start / stop signal generation circuit 640, buffers 611-618, an oscillation switch 630, and a delay adjustment current source 620. The buffers 611-618 and the oscillation switch 630 are connected in a loop in an alternating manner in eight stages.

[0027] Here, with reference to Figure 7, the output signals of buffers 611 to 618 and the internal signals of oscillator 511 for each stage will be explained. Figure 7 is a table showing the output signals of buffers 611 to 618 and the internal signals of oscillator 511 for each stage at the time of reset, and the output signals of buffers 611 to 618 and the internal signals of oscillator 511 for each stage after a certain period of time has elapsed since the oscillation switch 630 was turned on.

[0028] At reset, the outputs of buffers 611-617 are "0", and the output of buffer 618 is "1". After the oscillator switch 630 is turned on, there is a delay time t equal to one buffer stage. buff After the specified time, the outputs of buffers 612-618, whose inputs and outputs are matched, remain unchanged, while only the output of buffer 611, which is not matched, changes from "0" to "1" (the signal advances by one stage). Additionally, there is a delay time t corresponding to one buffer stage. buff After the passage of time (2 × t) buffAfter that, the outputs of buffers 611, 613 to 618 with input-output matching do not change, and only the output of buffer 612 without input-output matching changes from "0" to "1" (the signal advances by one stage). In this way, for each delay time t of one buffer stage buff in sequence, the output of one buffer without input-output matching changes. After the oscillation switch 630 is turned on, after 8×t buff the outputs of all buffers change (the signal makes one round), and after 16×t buff all buffers change further (the signal makes two rounds) and return to the original state. After that, the same operation is repeated every 16×t buuf time.

[0029] As a result, time measurement with a time resolution of t buff is performed. Also, the time resolution t buff is adjusted to be 1 / 2 of the synchronization clock by the oscillation adjustment voltage generation circuit 541 described later. 7 Also, the output of the oscillator 511, which is the output of buffer 618, is input to the oscillation count circuit 521. The oscillation count circuit 521 counts the rising edge of the output of the oscillator 511, and time measurement with a time resolution of 16×t buff is performed.

[0030] FIG. 8 is an explanatory diagram of the cathode potential Vc of the SPAD element 401, the pixel output signal, the synchronization clock, the synchronization clock count circuit 531, the output of the oscillation start / stop signal generation circuit 640, the output of the oscillator 511, and the oscillation count circuit 521. FIG. 8 shows the state of change over time from when the light-emitting element 201 belonging to a specific row of the light-emitting element array 111 emits light until the SPAD element 401 receives the reflected light and the counting operation of the TDC ends.

[0031] The cathode potential Vc of the SPAD element 401 is an analog voltage, with the upper side of the page indicating a higher voltage. The synchronous clock, the output of the oscillation start / stop signal generation circuit 640, and the output of the oscillator 511 are digital signals, with the upper side of the page indicating the ON state and the lower side indicating the OFF state. The synchronous clock count circuit 531 and the oscillation count circuit 521 are digital values, shown as decimal numbers.

[0032] Figure 9 is an enlarged view of the period from time 803 to time 805 in Figure 8, showing the output of the oscillation start / stop signal generation circuit 640, the output of the oscillator 511, the oscillation count circuit 521, and the internal signals of the oscillator 511. The internal signals of the oscillator 511 are digital values ​​and are shown as decimal numbers.

[0033] Referring to Figures 8 and 9, the operation of measuring the time from time 801 when a light-emitting element 201 belonging to a specific row of the light-emitting element array 111 emits light to time 803 when a pixel receives a photon will be explained using TDC 501.

[0034] At time 801, which is synchronized with the rising edge of the synchronous clock supplied via the overall control unit 140, a specific light-emitting element row drive circuit 202 is driven so that a light-emitting element 201 belonging to a specific row of the light-emitting element array 111 lights up. The synchronous clock count circuit 531 starts counting the rising edge of the synchronous clock from the time the light-emitting element 201 lights up.

[0035] At time 803, photons reflected from the subject are received by the pixels, causing the SPAD cathode potential Vc to drop, and the pixel output signal changes from "0" to "1". Upon receiving the pixel output signal as "1", the output of the oscillation start / stop signal generation circuit 640 changes from "0" to "1", and the oscillation switch 630 turns on. When the oscillation switch 630 turns on, the oscillation operation begins, and a signal loop starts inside the oscillator as shown in Figure 9. Every two loops of the signal inside the oscillator, a rising edge appears at the oscillator output, and the oscillation count circuit 521 measures its number. Also at time 803, the synchronous clock count circuit 531 stops counting and holds the value.

[0036] The first time the synchronous clock rises after oscillator 511 is turned on is at time 805. In response to the rising edge of the synchronous clock, the output of the oscillation start / stop signal generation circuit 640 becomes "0", and the oscillation switch 630 turns off. When the oscillation switch 630 becomes "0", oscillation ends, and the internal signal of the oscillation circuit is retained. Also, since oscillation stops, the count of the oscillation count circuit 521 also stops.

[0037] As a result, the count result D of the synchronous clock count circuit 531 Gclk This is the time from 801 to 802. 7 ×t buff This is the value counted over that time. Also, the count result D of the oscillation count circuit 521. ROclk The time from 8:03 to 8:04 is 2 4 ×t buff This is the value counted over that time. Also, the internal signal D of oscillator 511 ROin The time from 8:04 to 8:05 is t buff This is the value counted over that time. After performing the following processing on these signals, they are output to the signal processing unit 123, completing one TDC operation.

[0038] Count result D of oscillation count circuit 521 ROclk and oscillator D ROin Add them together using the following equation (2).

[0039] D RO =2 4 ×D ROclk +D ROin ...(2) D RO The time from 18:04 to 18:05 buff This is the value counted, and the time from time 802 to time 805 is the period of the synchronous clock, 2 7 ×t buff This is equivalent to the following equation (3): RO Subtracting D Gclk By adding this together, the time of light's flight (from time 801 to time 803) is calculated as t buff The value D counted by ToF This is required.

[0040] D ToF =2 7 ×D Gclk +(2 7 -D RO ) =2 7 ×D Gclk +(2 7 -24×D ROclk -D ROin )···(3) Delay time t for one buffer stage buff Because this can vary due to process factors such as transistor manufacturing tolerances, fluctuations in the voltage applied to the TDC circuit, and temperature, an oscillation adjustment voltage generation circuit 541 is provided for each TDC.

[0041] Figure 10 is a block diagram of the oscillation adjustment voltage generation circuit 541. The oscillation adjustment voltage generation circuit 541 consists of a dummy oscillator 1001, 1 / 2 3 It has a frequency divider 1002 and a phase comparator 1003. The dummy oscillator 1001 is the same oscillator as the oscillator 511 mounted on the TDC501.

[0042] The output of the dummy oscillator 1001 is 1 / 2 3 Input to frequency divider 1002: 1 / 2 3The frequency divider 1002 divides the input clock frequency by 1 / 2. 3 This is a circuit that outputs a clock signal with a clock frequency. Phase comparator 1003 has a synchronous clock and 1 / 2 3 The output of frequency divider 1002 is input. Phase comparator 1003 divides the frequency of the synchronous clock by 1 / 2. 3 The frequency of the output signal of the frequency divider 1002 is compared with that of the phase comparator. If the frequency of the synchronous clock is high, the output voltage is increased, and if the frequency of the synchronous clock is low, the output voltage is decreased. The output voltage of the phase comparator is input to the oscillator's delay adjustment current source 620, so that the oscillator's oscillation frequency is 2 times that of the synchronous clock. 3 The voltage is adjusted to double the original voltage.

[0043] Thus, the oscillation frequency is determined based on the synchronous clock frequency. Therefore, by generating the synchronous clock using an external IC that can output a constant frequency regardless of process / voltage / temperature changes, frequency variations due to process / voltage / temperature changes can be suppressed. For example, by inputting a 160MHz clock to the synchronous clock frequency, the oscillation frequency becomes 1.28GHz, which is 8 times the synchronous clock frequency. The time resolution is the delay time t of one buffer stage. buff This translates to 48.8 ps. [Suppression of reflected light in beam splitters] Next, the suppression of reflected light by the beam splitter 150 of this embodiment will be explained with reference to Figures 11(A) to (C). Figures 11(A) to (C) are configuration diagrams of the main parts of the optical element 1, showing cross-sections of the beam splitter 150, light-emitting element array 111, light-receiving element array 121, and imaging lens 130.

[0044] In Figure 11(A), the light-emitting element array 111 and the light-receiving element array 121 are conjugate via the half-mirror 151 of the beam splitter 150, and each light-emitting element and each light-receiving element are also conjugate. In Figure 11(A), both the light-emitting element array 111 and the light-receiving element array 121 are shown with 8 rows, but the number of rows is not limited to this. In this embodiment, the light-emitting elements and light-receiving elements are configured to be one-to-one conjugate, but this is not limited to this, and the number of light-receiving elements may be n × n times the number of light-emitting elements, so that one light-emitting element is conjugate to n × n light-receiving elements. The row numbers of the light-emitting element array 111 are assigned in ascending order from the smallest to the largest Yv in Figure 11(A). The row numbers of the photodetector array 121 are assigned in ascending order from the smallest to the largest Y value in Figure 11(A), and the light-emitting element array 111 and the photodetector array 121 with the same row number are in a conjugate relationship.

[0045] Figure 11(B) shows the optical path of the light emitted by the light-emitting element in row 1 of the light-emitting element array 111. The light ray 1110 emitted from the light-emitting element array 111 is divided into two rays: one ray 1111 that is reflected by the half mirror 151 and illuminates the subject, and another ray 1112 that passes through the half mirror 151 and travels toward the reflection suppression structure 152.

[0046] Figure 11(C) shows the reflected light 1113 from the subject and the reflected light 1114 from the reflection suppression structure 152. The reflected light 1113 from the subject is incident on the photodetector which is conjugate to the emitted light-emitting element.

[0047] The surface of the reflection suppression structure 152, which is irradiated with light rays 1112, uses a surface structure that transmits, absorbs, or both transmits light at wavelengths of light emitted by the light-emitting element array 111, thereby reducing its reflectivity. The surface structure may be a stacked structure of dielectrics with different refractive indices, or an anti-reflective structure consisting of multiple structures finer than the wavelength. It may also be an absorbing material such as a metal. The shape of the reflection suppression structure 152 is a periodic structure (e.g., rectangular) with a period twice the spacing between light-emitting elements in the row direction of the light-emitting elements, and the shape is the same in the depth direction of the cross-sectional view. Alternatively, it may be a cylindrical lens shape with a period twice the spacing between light-emitting elements. With a reflection suppression structure 152 having such a shape, the reflected light 1114 from the reflection suppression structure 152 is incident on the half mirror 151 with a shift of one row, and incident on the photodetector in a row that is not conjugate to the emitted light-emitting element.

[0048] As described later in the distance measurement process, the pixel output of the photodetector in the row that is conjugate to the row of the light-emitting element is output to the TDC. Therefore, the TDC detects the time from the time of light emission to the incidence of light on the photodetector in the row that is conjugate to the row of the light-emitting element, and does not react to light incidence on other rows. This suppresses false detection caused by light rays 1112 incident on photodetectors that are not conjugate to the light-emitting element. The explanation above regarding the first row also applies to the other rows. [Distance measurement processing] Next, with reference to Figure 12, we will explain the distance measurement process for acquiring three-dimensional distance information using the optical device 1. Figure 12 is a flowchart of the distance measurement process.

[0049] First, in step S1201, the overall control unit 140 (measurement control unit 124) resets the row counter j and sets it to 1. Next, in step S1202, the measurement control unit 124 uses the row selection circuit 125 to select the row corresponding to the row counter and sets it so that the pixel signal of the corresponding row is output to the TDC array unit 122 via the pixel output line 304. Next, in step S1203, the measurement control unit 124 resets the histogram circuits, which are arranged in the same number as the TDC 501 in the signal processing unit 123, and resets the measurement counter i.

[0050] Next, in step S1204, the overall control unit 140 (light source control unit 114) operates the light-emitting element row drive circuit 202 for the row corresponding to row counter j, causing the light-emitting element 201 belonging to the corresponding row to emit a short pulse of light. Next, in step S1205, the light source control unit 114 determines whether the time since emission is less than or equal to the time Tmax corresponding to the longest distance measurement distance. If it is determined that the time since emission is greater than time Tmax, the process proceeds to step S1209. On the other hand, if it is determined that the time since emission is less than or equal to time Tmax, the process proceeds to step S1206. In step S1206, the light source control unit 114 determines whether the pixel output is "1". If it is determined that the pixel output is "1", the process proceeds to step S1207. On the other hand, if it is determined that the pixel output is not "1", the process returns to step S1205. That is, the process waits until the time since emission is greater than time Tmax, or until the pixel output becomes "1".

[0051] While in standby mode, the light reflected back from the subject enters the photodetector, which is conjugate to the light-emitting element that emitted the light. When the pixel output signal becomes "1" due to the reception of light, in step S1207, the overall control unit 140 measures the time since emission using TDC 501. Subsequently, in step S1208, the overall control unit 140 stores (adds) the TDC result to the histogram and returns to the standby state.

[0052] When the time since emission exceeds time Tmax, in step S1209, the light source control unit 114 increments the emission count counter i by 1. Subsequently, in step S1210, the light source control unit 114 sets the emission count counter i to a pre-set emission count N. total Determine whether it is greater than or equal to N. total If it is determined to be smaller than N, the process proceeds to step S1204. Meanwhile, the flash count counter i is less than the flash count N total If it is determined to be greater than that, proceed to step S1211.

[0053] In step S1211, the measurement control unit 124 performs histogram signal processing to calculate distance measurement results such as distance, signal strength, and ambient light intensity from the histogram of TDC results. Subsequently, in step S1212, the measurement control unit 124 outputs the distance measurement results calculated in step S1211 from the measurement unit 120 (row signal output). In steps S1202 to S1212, the distance measurement processing for one row is completed and the distance measurement results are output. Subsequently, in step S1213, the measurement control unit 124 increments the row counter j by 1.

[0054] Next, in step S1214, the measurement control unit 124 determines that the row counter j is equal to the number of rows N. row (In the case of Figure 11, N row Determine whether it is greater than (=8). The measurement count counter j is set to N. row If it is determined that the following is true, the process proceeds to step S1202, and the overall control unit 140 performs the distance measurement process for the next row. Meanwhile, the measurement count counter j is set to the number N row If it is determined to be greater than the specified value, the distance measurement process is terminated as the measurement of all rows has been completed. Through the above distance measurement process, a distance measurement result in the form of a two-dimensional array, similar to image information, can be obtained.

[0055] In this embodiment, the light-emitting element array 111 is made to emit light at different times for each row, and only the light-emitting elements of the rows emitting light within the light-emitting element array 111 and the conjugate light-receiving elements via the half mirror 151 are activated. In addition, a reflection suppression structure 152 is provided on the side of the beam splitter 150 opposite to the light-emitting element array 111, with the half mirror 151 in between. This enables distance measurement processing that suppresses false detection (false distance measurement) due to reflected light. (Second Embodiment) Next, a second embodiment of the present invention will be described with reference to Figures 13(A) to (C). Figures 13(A) to (C) are configuration diagrams of the main parts of the optical device (distance measuring device) in this embodiment. This embodiment differs from the first embodiment in that it has a reflection suppression structure 1301 instead of the reflection suppression structure 152. Note that the other configurations are the same as in the first embodiment, so their description will be omitted.

[0056] Figure 13(A) shows a cross-section of the beam splitter 150, the light-emitting element array 111, the photodetector array 121, and the imaging lens 130. Figure 13(B) shows the optical path of the light emitted by the light-emitting element in row 1 of the light-emitting element array 111. Figure 13(C) shows the reflected light 1113 from the subject and the reflected light 1302 from the reflection suppression structure 1301.

[0057] The reflection suppression structure 1301 in this embodiment is not a periodic structure with twice the period of the light-emitting element 201, but rather a diffuse reflecting surface with suppressed reflectivity. By using the reflection suppression structure 1301 for diffuse reflection, it is possible to suppress the incident of reflected light from the beam splitter 150 on the photodetector which is conjugate to the emitted light-emitting element, thereby suppressing erroneous distance measurement. (Third embodiment) Next, a third embodiment of the present invention will be described with reference to Figures 14(A) to (C). Figures 14(A) to (C) are configuration diagrams of the main parts of the optical device (distance measuring device) in this embodiment. This embodiment differs from the first and second embodiments in that it uses the polarization information of light to suppress the incidence of light on the light-receiving element that is conjugate to the emitted light-emitting element. That is, in this embodiment, a polarizing plate (first polarizing plate) 1401 is placed between the light-emitting element array 111 and the beam splitter 150, and a polarizing plate (second polarizing plate) 1402 is placed between the beam splitter 150 and the light-receiving element array 121. Note that the other configurations are the same as in the first and second embodiments, so their description will be omitted.

[0058] Figure 14(A) shows cross-sections of the beam splitter 150, light-emitting element array 111, photodetector array 121, imaging lens 130, and polarizers 1401 and 1402. Polarizers 1401 and 1402 are composed of polarizers oriented orthogonally to each other, for example. Figure 14(B) shows the optical path of light emitted by the light-emitting element in row 1 of the light-emitting element array 111. Light that has passed through polarizer 1401 becomes light with linear polarization in the X direction (or Y direction). Figure 14(C) shows the optical paths 1403 of reflected light 1113 from the subject and reflected light from the surface 1410 of the beam splitter 150. The reflected light from the subject has little polarization bias. On the other hand, the reflection at the surface 1410 of the beam splitter 150 is specular reflection, so it is light with linear polarization in the X direction (or Y direction). A portion of the reflected light from the subject passes through polarizer 1402. On the other hand, the reflected light from the surface 1410 of the beam splitter 150 does not pass through the polarizing plate 1402 and does not enter the photodetector array 121.

[0059] In this embodiment, a polarizing plate 1401 is placed between the light-emitting element array 111 and the beam splitter 150, and a polarizing plate 1402 is placed between the beam splitter 150 and the light-receiving element array 121. This suppresses the incidence of reflected light from the beam splitter 150 onto the light-receiving element array 121, thereby suppressing erroneous distance measurement. (Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to Figures 15(A) to (C). Figures 15(A) to (C) are configuration diagrams of the main parts of the optical device (distance measuring device) in this embodiment. This embodiment differs from the first to third embodiments in that it uses the polarization information of light and the reflection suppression structure 1502 of the beam splitter 150 to suppress the incidence of light on a photodetector that is conjugate to the emitted light-emitting element. That is, in this embodiment, a polarizing plate 1501 is placed between the light-emitting array 111 and the beam splitter 150, and the reflection suppression structure 1502 is formed on the beam splitter 150. Note that the other configurations are the same as in the first to third embodiments, so their description will be omitted.

[0060] Figure 15(A) shows cross-sections of the beam splitter 150, light-emitting element array 111, photodetector array 121, imaging lens 130, polarizer 1501, and reflection suppression structure 1502. The shape of the reflection suppression structure 1502 is a repeating structure of planes parallel to the YZ plane and planes oblique to the YZ plane, at the same interval as the row spacing of the light-emitting elements. Figure 15(B) shows the optical path of light emitted by the light-emitting element in row 1 of the light-emitting element array 111. Figure 15(C) shows the reflected light 1113 from the subject.

[0061] The polarizing plate 1501 is configured such that light passing through it becomes p-polarized with respect to a plane oblique to the YZ plane constituting the reflection suppression structure 1502. The angle of the plane oblique to the YZ plane constituting the reflection suppression structure 1502 is set such that the angle between the normal to the plane and the light ray 1112 after passing through the half mirror is the Brewster angle. This configuration makes it possible to suppress reflection in the reflection suppression structure 1502. [In-vehicle systems] Figure 16 is a configuration diagram of the optical device 1 and the in-vehicle system (driving assistance device) 1000 equipped therewith according to each embodiment. The in-vehicle system 1000 is held by a movable mobile body (mobile device) such as an automobile (vehicle) and is a system for assisting the driving (operation) of the vehicle based on distance information of objects such as obstacles and pedestrians around the vehicle acquired by the optical device 1. Figure 17 is a schematic diagram of the vehicle 500 as a mobile device including the in-vehicle system 1000. In Figure 17, the case in which the distance measurement range (detection range) of the optical device 1 is set to the front of the vehicle 500 is shown, but the distance measurement range may also be set to the rear or side of the vehicle 500.

[0062] As shown in Figure 16, the in-vehicle system 1000 comprises an optical device 1, a vehicle information acquisition device 200, a control device (control unit, ECU: electronic control unit) 300, and a warning device (warning unit) 400. In the in-vehicle system 1000, the overall control unit 140 provided in the optical device 1 has the functions of a distance acquisition unit (acquisition unit) and a collision determination unit (determination unit). However, if necessary, the in-vehicle system 1000 may provide a distance acquisition unit and a collision determination unit separate from the overall control unit 140, and each may be provided outside the optical device 1 (for example, inside the vehicle 500). Alternatively, the control device 300 may be used as the overall control unit 140.

[0063] Figure 18 is a flowchart showing an example of the operation of the in-vehicle system 1000 according to this embodiment. The operation of the in-vehicle system 1000 will be described below in accordance with this flowchart.

[0064] First, in step S1, the light source unit 113 of the optical device 1 illuminates the object around the vehicle, and the overall control unit 140 acquires distance information of the object based on the signal output by the light receiving element array 121, which receives reflected light from the object. In step S2, the vehicle information acquisition device 200 acquires vehicle information, including the vehicle speed, yaw rate, and steering angle. Then, in step S3, the overall control unit 140 uses the distance information acquired in step S1 and the vehicle information acquired in step S2 to determine whether the distance to the object falls within a preset distance range.

[0065] This allows the system to determine whether or not an object exists within a set distance around the vehicle and to determine the possibility of a collision between the vehicle and the object. Steps S1 and S2 may be performed in the reverse order of the above, or they may be processed in parallel. The overall control unit 140 determines "possibility of collision" if an object exists within the set distance (step S4), and determines "no possibility of collision" if an object does not exist within the set distance (step S5).

[0066] Next, if the overall control unit 140 determines that there is a possibility of collision, it notifies (transmits) the determination result to the control device 300 and the warning device 400. At this time, the control device 300 controls the vehicle based on the determination result from the overall control unit 140 (step S6), and the warning device 400 issues a warning to the vehicle's user (driver, passengers) based on the determination result from the overall control unit 140 (step S7). Note that notification of the determination result only needs to be made to at least one of the control device 300 and the warning device 400.

[0067] The control device 300 can control the movement of a vehicle by outputting control signals to the vehicle's drive unit (such as the engine or motor). For example, it can control the vehicle by applying the brakes, releasing the accelerator, turning the steering wheel, and generating control signals to apply braking force to each wheel, thereby suppressing the output of the engine or motor. The warning device 400 can also warn the user by, for example, emitting a warning sound, displaying warning information on a screen such as a car navigation system, or vibrating the seat belt or steering wheel.

[0068] As described above, the in-vehicle system 1000 according to this embodiment can detect objects and measure their distance through the above-described process, making it possible to avoid collisions between the vehicle and the objects. In particular, by applying the optical device 1 according to each embodiment described above to the in-vehicle system 1000, high distance measurement accuracy can be achieved, making it possible to detect objects and determine collisions with high accuracy.

[0069] In this embodiment, the in-vehicle system 1000 is applied to driver assistance (collision damage mitigation), but it is not limited to this, and the in-vehicle system 1000 may also be applied to cruise control (including with full-speed following function) or autonomous driving. Furthermore, the in-vehicle system 1000 is not limited to automobiles and other vehicles, but can be applied to mobile objects such as ships, aircraft, and industrial robots. Moreover, it is not limited to mobile objects, but can be applied to various devices that utilize object recognition, such as intelligent transportation systems (ITS) and surveillance systems.

[0070] Furthermore, the in-vehicle system 1000 and the vehicle (mobility device) 500 may be equipped with a notification device (notification unit) to notify the manufacturer of the in-vehicle system or the dealer of the mobility device if the vehicle 500 collides with an obstacle. For example, the notification device may be one that sends information regarding the collision between the vehicle 500 and the obstacle (collision information) to a pre-set external notification destination via email or the like.

[0071] In this way, by adopting a configuration in which collision information is automatically notified by the notification device, it is possible to promptly take action such as inspection and repair after a collision occurs. The recipients of the collision information may be insurance companies, medical institutions, the police, or any other name set by the user. Furthermore, the notification device may be configured to notify recipients not only of collision information, but also of malfunction information of various parts and information on the wear and tear of consumables. The detection of whether or not a collision has occurred may be performed using distance information acquired based on the output from the light receiving unit 2 described above, or it may be performed by other detection units (sensors).

[0072] According to each embodiment, it is possible to provide a compact optical device, an in-vehicle system, and a mobile device that can reduce the effects of reflected light.

[0073] Each embodiment disclosed includes the following configuration:

[0074] (Composition 1) A light-emitting section having multiple light-emitting elements arranged in a two-dimensional manner, A light-receiving unit having multiple light-receiving elements, Imaging optical system, An optical segment having a reflecting mirror is positioned between the imaging optical system and the light receiving unit, The system includes an acquisition unit that acquires distance information of an object based on the time required from the time the light-emitting unit emits light until the light-receiving unit receives the light reflected by the object. Of the plurality of light-emitting elements, the light-emitting elements in the first row and the light-emitting elements in the second row emit light at different times in a time-division manner. The optical axis direction of the imaging optical system and the normal direction of the reflecting mirror are non-parallel. The light from the light-emitting unit is reflected by the reflecting mirror, passes through the imaging optical system, and is reflected by the object. The light reflected by the object passes through the imaging optical system, through the reflecting mirror, and is received by the light receiving unit. The first light-emitting element among the plurality of light-emitting elements and the first light-receiving element among the plurality of light-receiving elements are in a conjugate relationship via the reflector. The optical device is characterized in that the light splitting section is configured to suppress light from the first light-emitting element from entering the first light-receiving element. (Configuration 2) The aforementioned light splitting unit has a beam splitter including the reflecting mirror, The beam splitter has a reflection suppression structure on the surface opposite to the surface facing the light-emitting section. The optical device according to configuration 1, characterized in that the reflection suppression structure suppresses the light emitted by the first light-emitting element, transmitted through the reflector, and reflected by the reflection suppression structure from entering the first light-receiving element. (Composition 3) The optical device according to configuration 2, characterized in that the reflection suppression structure has a periodic structure twice the interval between the plurality of light-emitting elements. (Composition 4) The optical device according to configuration 3, characterized in that the reflection suppression structure has the same shape in the row direction cross-section of the plurality of light-emitting units, and the column direction cross-section has a periodic structure that is twice the spacing between the plurality of light-emitting units. (Composition 5) The optical device according to configuration 3 or 4, characterized in that the periodic structure has a rectangular shape. (Composition 6) The optical device according to configuration 3 or 4, characterized in that the periodic structure is cylindrical in shape. (Composition 7) The optical apparatus according to any one of configurations 2 to 6, characterized in that the reflection suppression structure has a multilayer film that transmits the wavelength of the light emitted by the light-emitting part. (Composition 8) The optical device according to any one of configurations 2 to 7, characterized in that the reflection suppression structure has a plurality of structures that are finer than the wavelength of the light emitted by the light-emitting part. (Composition 9) The optical device according to any one of configurations 2 to 8, characterized in that the reflection suppression structure has an absorbing material that absorbs the wavelength of the light emitted by the light-emitting part. (Composition 10) The aforementioned optical splitting unit is A beam splitter including the aforementioned reflector, A first polarizing plate is disposed between the light-emitting unit and the beam splitter, It has a second polarizing plate disposed between the light receiving unit and the beam splitter, The optical apparatus according to configuration 1, characterized in that the first polarizing plate and the second polarizing plate extinguish the light from the light-emitting portion that is reflected from the surface of the beam splitter opposite to the surface facing the light-emitting portion. (Composition 11) The aforementioned optical splitting unit is A beam splitter including the aforementioned reflector, It has a first polarizing plate disposed between the light-emitting unit and the beam splitter, Of the light emitted from the light-emitting unit, the light transmitted through the reflecting mirror is p-polarized with respect to the surface opposite to the surface in the beam splitter that faces the light-emitting unit across the reflecting mirror. The optical device according to configuration 1, characterized in that the angle between the light that has passed through the reflecting mirror and the normal to the surface opposite to the surface facing the light-emitting part in the beam splitter is a Brewster angle. (Composition 12) An in-vehicle system comprising an optical device according to any one of configurations 1 to 10, characterized in that it determines the possibility of collision between the vehicle and the object based on the distance information of the object obtained by the optical device. (Composition 13) The in-vehicle system according to configuration 12, characterized in that it includes a control device that outputs a control signal to generate braking force on the vehicle when it is determined that there is a possibility of collision between the vehicle and the object. (Composition 14) The in-vehicle system according to configuration 12 or 13, characterized in that it includes a warning device that warns the user of the vehicle when it is determined that there is a possibility of collision between the vehicle and the object. (Composition 15) An in-vehicle system according to any one of configurations 12 to 14, characterized in that it includes a notification device for notifying the outside of information regarding a collision between the vehicle and the object. (Composition 16) A mobile device comprising an optical device described in any of configurations 1 to 11, and characterized in that it is capable of holding and moving the optical device. (Composition 17) The moving device according to configuration 16, characterized in that it has a determination unit that determines the possibility of collision with the object based on distance information of the object obtained by the optical device. (Composition 18) The moving device according to configuration 17, further comprising a control unit that outputs a control signal to control movement when it is determined that there is a possibility of collision with the aforementioned object. (Composition 19) The mobile device according to configuration 17 or 18, further comprising a warning unit that warns the user of the mobile device when it is determined that there is a possibility of collision with the aforementioned object. (Composition 20) A mobile device according to any one of configurations 17 to 19, characterized in that it includes a notification unit for notifying the outside of information relating to a collision with the aforementioned object.

[0075] Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of its gist. [Explanation of symbols]

[0076] 1 Optical device (distance measuring device) 111 Light-emitting element array (light-emitting part) 121 Light-receiving element array (light-receiving section) 122 TDC Array Unit (Acquisition Unit) 123 Signal Processing Unit (Acquisition Unit) 130 Imaging lens (imaging optical system) 151 Half-mirror (reflector) 155 Light splitting section 201 Light-emitting element 301 pixels (photodetector)

Claims

1. A light-emitting section having multiple light-emitting elements arranged in a two-dimensional manner, A light-receiving unit having multiple light-receiving elements, Imaging optical system, An optical segment having a reflecting mirror is positioned between the imaging optical system and the light receiving unit, The system includes an acquisition unit that acquires distance information of an object based on the time required from the time the light-emitting unit emits light until the light-receiving unit receives the light reflected by the object. Of the plurality of light-emitting elements, the light-emitting elements in the first row and the light-emitting elements in the second row emit light at different times in a time-division manner. The optical axis direction of the imaging optical system and the normal direction of the reflecting mirror are non-parallel. The light from the light-emitting unit is reflected by the reflecting mirror, passes through the imaging optical system, and is reflected by the object. The light reflected by the object passes through the imaging optical system, through the reflecting mirror, and is received by the light receiving unit. The first light-emitting element among the plurality of light-emitting elements and the first light-receiving element among the plurality of light-receiving elements are in a conjugate relationship via the reflector. The light splitting unit is configured to suppress light from the first light-emitting element from entering the first light-receiving element. The aforementioned light splitting unit has a beam splitter including the reflecting mirror, The beam splitter has a reflection suppression structure on the surface opposite to the surface facing the light-emitting portion, which has a periodic structure twice the spacing between the plurality of light-emitting elements. The reflection suppression structure is characterized in that it suppresses the incidence of light emitted by the first light-emitting element, transmitted through the reflector, and reflected by the reflection suppression structure, onto the first light-receiving element.

2. The optical device according to claim 1, characterized in that the reflection suppression structure has the same shape in the row direction cross-section of the plurality of light-emitting elements, and the column direction cross-section has a periodic structure that is twice the spacing between the plurality of light-emitting elements.

3. The optical device according to claim 1, characterized in that the periodic structure has a rectangular shape.

4. The optical device according to claim 1, characterized in that the periodic structure is in the shape of a cylinder lens.

5. The optical device according to claim 1, characterized in that the reflection suppression structure has a multilayer film that transmits the wavelength of the light emitted by the light-emitting part.

6. The optical device according to claim 1, characterized in that the reflection suppression structure has a plurality of structures that are finer than the wavelength of the light emitted by the light-emitting part.

7. The optical device according to claim 1, characterized in that the reflection suppression structure has an absorbing material that absorbs the wavelength of the light emitted by the light-emitting part.

8. The aforementioned optical splitting unit is A first polarizing plate is disposed between the light-emitting unit and the beam splitter, The system further includes a second polarizing plate disposed between the light receiving unit and the beam splitter, The optical apparatus according to claim 1, characterized in that the first polarizing plate and the second polarizing plate extinguish the light from the light-emitting portion that is reflected from the surface of the beam splitter opposite to the surface facing the light-emitting portion.

9. The aforementioned optical splitting unit is The system further includes a first polarizing plate positioned between the light-emitting unit and the beam splitter. Of the light emitted from the light-emitting unit, the light transmitted through the reflecting mirror is p-polarized with respect to the surface opposite to the surface of the beam splitter that faces the light-emitting unit across the reflecting mirror. The optical apparatus according to claim 1, characterized in that the angle between the light that has passed through the reflecting mirror and the normal to the surface opposite to the surface facing the light-emitting part in the beam splitter is a Brewster angle.

10. An in-vehicle system comprising an optical device according to any one of claims 1 to 8, characterized in that it determines the possibility of a collision between a vehicle and the object based on the distance information of the object obtained by the optical device.

11. The in-vehicle system according to claim 10, further comprising a control device that outputs a control signal for generating braking force on the vehicle when it is determined that there is a possibility of collision between the vehicle and the object.

12. The in-vehicle system according to claim 10, further comprising a warning device that warns the user of the vehicle when it is determined that there is a possibility of collision between the vehicle and the object.

13. The in-vehicle system according to claim 10, further comprising a notification device for notifying an external party of information relating to a collision between the vehicle and the object.

14. A mobile device comprising an optical device according to any one of claims 1 to 9, characterized in that it is capable of holding and moving the optical device.

15. The moving device according to claim 14, further comprising a determination unit that determines the possibility of collision with the object based on distance information of the object obtained by the optical device.

16. The moving device according to claim 15, further comprising a control unit that outputs a control signal to control movement when it is determined that there is a possibility of collision with the aforementioned object.

17. The mobile device according to claim 15, further comprising a warning unit that warns the user of the mobile device when it is determined that there is a possibility of collision with the aforementioned object.

18. The mobile device according to claim 15, further comprising a notification unit for notifying the outside of information relating to a collision with the aforementioned object.

Images