Optical device, in-vehicle system, and mobile device

Abstract

[Problem] To provide a small and high-resolution optical device. [Solution] An optical device (1) comprising: a light emitter (111) comprising at least one light emitting element (211); a light receiver (121) including a plurality of light receiving elements (125); an optical element (112) including a plurality of microlenses (231); an optical system comprising a first telecentric lens (131); and an acquisition unit (122, 123) configured to acquire distance information to the object based on a time required from when the light emitter emits the light until when the light receiver receives the light reflected by the object. The number of the microlenses is greater than the number of the light-emitting elements. The plurality of microlenses and the first telecentric lens form an afocal system.

Description

Technical Field

[0001] The invention relates to an optical device, a vehicle-mounted system and a movable device. Background Art

[0002] A time-of-flight (TOF) distance measurement method is known, which measures the distance to an object by measuring the time difference from when light is irradiated onto the object until when light reflected from the object is detected. Patent document 1 discloses a configuration including light-emitting elements and light-receiving elements arranged in a two-dimensional manner, wherein light is irradiated onto an object through an imaging lens, light reflected from the object is received, and three-dimensional distance information is acquired without a drive unit. This configuration requires that the viewing angle of the emitted light and the viewing angle of the received light are approximately equal. Therefore, in order to reduce the size of the distance measuring device, the light-emitting element array and the light-receiving element array can have approximately the same size and share an imaging lens.

[0003] Patent Document 2 discloses a configuration in which the resolution of projected light is increased by multiplying the number of light beams constituting a light emitter including a two-dimensional light emitting element array by using a diffractive optical element.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2019-60652

[0007] Patent Document 2: PCT International Publication No. 2019 / 043102 Summary of the invention

[0008] Problem that the invention aims to solve

[0009] The configuration disclosed in Patent Document 2 is to increase the size of the light receiving element array according to the increased viewing angle by diffraction. Therefore, since the diffractive optical element expands the viewing angle, this configuration makes it difficult to realize a compact and high-resolution distance measuring device.

[0010] Therefore, an object of the present invention is to provide a compact and high-resolution optical device.

[0011] Solutions for solving problems

[0012] An optical device according to one aspect of the present invention includes: a light emitter including at least one light emitting element; a light receiver including a plurality of light receiving elements; an optical element including a plurality of micro lenses; an optical system including a first telecentric lens; and an acquisition unit configured to acquire distance information to an object based on a time required from when the light emitter emits light until when the light receiver receives light reflected by the object. The number of the micro lenses is greater than the number of the light emitting elements. The plurality of micro lenses and the first telecentric lens form an afocal system.

[0013] Other objects and features of the present invention will be described in the following examples.

[0014] Effects of the Invention

[0015] The present invention can provide a compact and high-resolution optical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a block diagram of a distance measuring device according to the first embodiment.

[0017] Figure 2 is a schematic diagram of a light source unit according to various embodiments.

[0018] Figure 3 A method of dividing emission light according to each embodiment is described.

[0019] Figure 4 Illustrate how projection light is projected onto an object in each embodiment.

[0020] Figure 5 This is a modification of the method of dividing the emitted light according to each embodiment.

[0021] Figure 6 is a block diagram of a distance measuring device according to a second embodiment.

[0022] Figure 7 is a block diagram of a distance measuring device according to a third embodiment.

[0023] Figure 8 is a configuration diagram of an in-vehicle system having a distance measurement device according to any one of the above-described embodiments.

[0024] Fig. 9 is a schematic diagram of a movable device having a distance measuring device according to any one of the above-described embodiments.

[0025] Fig.10 is a flowchart illustrating an operation example of an in-vehicle system having a distance measurement device according to any one of the above-described embodiments. DETAILED DESCRIPTION

[0026] Embodiments according to the present invention will now be described in detail with reference to the accompanying drawings.

[0027] (First embodiment)

[0028] [Overall configuration of distance measuring equipment]

[0029] Reference now Figure 1 , a schematic configuration of an optical device (distance measuring device) 1 according to a first embodiment will be described. Figure 1 1 is a block diagram of an optical device 1. The optical device 1 is an optical device (light detection and ranging: LiDAR) that calculates the distance to an object based on the time from when light is emitted until when light is received by the TOF method. The optical device 1 includes a light projection unit 110, a measuring unit 120, an image side telecentric lens (first telecentric lens) 131, an image side telecentric lens (second telecentric lens) 132, and an overall control unit 140. The light projection unit 110 includes a light source unit 113 having a light emitter 111 and an optical element 112, and a light source control unit 114.

[0030] The light emitter 111 includes a light emitting element array 210 having a plurality of light emitting elements 211 arranged in a two-dimensional manner (see Figure 2 ). However, the embodiment is not limited to this example, and the light emitter 111 may have only a single light emitting element 211. In other words, the light emitter 111 may have at least one light emitting element 211. The optical element 112 includes a microlens array 230 having a plurality of microlenses 231 arranged in a two-dimensional manner (see Figure 2 ), and splits the light emitted from the light emitter 111 into a plurality of split light beams.

[0031] The measuring unit 120 includes a light receiver 121, a time-to-digital converter (TDC) array unit 122, a signal processing unit 123, and a measurement control unit 124. The light receiver 121 includes a light receiving element array 125 having a plurality of light receiving elements.

[0032] Each of the plurality of light emitting elements 211 in the light source unit 113 emits pulsed light, and the pulsed light is projected toward space through the image side telecentric lens 131. The pulsed light beams emitted from different light emitting elements 211 are projected in space at different viewing angles. The projected light is irradiated onto the object, and a portion of the light reflected by the object is received by the photoreceiver 121 via the image side telecentric lens 132. The time from when the light emitting element 211 emits light until when the photoreceiver 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, it is difficult to remove noise components caused by noise light and dark counts such as ambient light in a single measurement, and the distance measurement error increases due to the influence of noise in the measurement circuit, etc. Therefore, the TDC array unit 122 repeatedly measures the time of flight TOF from when the light is emitted until when the light is received, and the signal processing unit 123 creates a histogram of the measurement results, removes the 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 to an object based on the time required from when the light emitter 111 emits light until when the light receiver 121 receives light reflected by the object.

[0033] By substituting the thus obtained time of flight TOF into the following equation (1), the distance L to the object can be obtained with high accuracy, where c is the speed of light:

[0034] L = TOF × c / 2 (1)

[0035] [Light source unit]

[0036] Reference now Figure 2 , an example of the light source unit 113 constituting the light projection unit 110 will be described. Figure 2 2 is a schematic diagram of the light source unit 113. The light emitting element array 210 is a VCSEL array including a plurality of vertical cavity surface emitting lasers (VCSELs) as a plurality of light emitting elements 211 arranged in a two-dimensional manner on a substrate. In this embodiment, the light emitting element 211 is not limited to the VCSEL, but is preferably a light emitting element that can be integrated in a one-dimensional array or a two-dimensional array, such as an edge emitting laser or an LED (light emitting diode).

[0037] In the case of using edge-emitting lasers instead of VCSEL arrays as light-emitting elements 211, light-emitting element array 210 is, for example, laser bars arranged in one dimension on a substrate, or a laser bar stack arranged in two dimensions by stacking laser bars. In the case of using LEDs as light-emitting elements 211, light-emitting element array 210 is LEDs arranged in two dimensions on a substrate.

[0038] In the optical device 1 according to this embodiment, in order to suppress the influence of ambient light, the wavelength of the light emitted by the light emitting element 211 is preferably in the near-infrared band. However, this embodiment is not limited to this example. VCSEL is manufactured using a semiconductor process, using materials used in conventional edge-emitting lasers and surface-emitting lasers. In the case where the VCSEL is configured to emit light having a wavelength in the near-infrared band, a GaAs-based semiconductor material can be used as the main material. In this case, a dielectric multilayer film forming a DBR (distributed reflective type) reflector constituting the VCSEL can be constructed by alternately and periodically stacking two thin films (e.g., GaAs / AlGaAs) made of materials with different refractive indices. The wavelength of the emitted light can be changed by adjusting the element combination or composition of the compound semiconductor.

[0039] The VCSELs constituting the VCSEL array include electrodes for injecting current and holes into the active layer, and can emit arbitrary pulse light or modulated light by controlling the injection timing. Therefore, the light source control unit 114 can, for example, independently drive each VCSEL in the plurality of VCSELs as the plurality of light emitting elements 211, or drive the VCSELs for each specific area (such as a row or column of the VCSEL array, etc.).

[0040] Each light emitted from the VCSEL as the light emitting element 211 is generally a divergent light due to the diffraction phenomenon at the opening of the VCSEL. Therefore, the light source unit 113 includes a collimating lens array 220, in which a plurality of collimating lenses 221 are arranged in a two-dimensional manner to control the divergence angle of the divergent light or to convert the divergent light into parallel light. In this embodiment, the plurality of collimating lenses 221 constituting the collimating lens array 220 are arranged in a one-to-one correspondence with the plurality of light emitting elements 211. The light emitted from the VCSEL array that is collimated by the collimating lens array 220 is converted into, for example, parallel light perpendicular to the VCSEL array substrate. In the case where the radiation angle from the VCSEL is small due to the opening diameter, etc., the collimating lens 221 can be omitted.

[0041] The light source unit 113 includes a microlens array 230 having a plurality of microlenses 231 arranged in a two-dimensional manner to separate parallel light collimated by the plurality of collimating lenses 221 into a plurality of emission light beams.

[0042] [Method of separating (dividing) emitted light]

[0043] Reference now Figure 3 , a method of separating the light emitted from the light emitting element 211 into a plurality of emission light beams will be described. Figure 3 A method of separating emission light is described, illustrating as an example how to separate a single emission light beam into multiple (3×3) emission light beams. Figure 3 Example of a two-dimensional cross section.

[0044] The light emitted from the light emitting element 211 diverges due to diffraction, and is therefore collimated by the collimating lens 221 to become parallel light. The parallel light collimated by the collimating lens 221 is separated into a plurality of emission light beams by passing through the microlens array 230. The width (three-dimensional thickness) of the parallel light collimated by the collimating lens 221 is greater than the diameter of the microlens 231. The plurality of emission light beams separated by the microlens array 230 are projected onto the object via the image side telecentric lens 131.

[0045] The microlens 231 and the image side telecentric lens 131 form an afocal system (non-focusing optical system). Therefore, light is projected from the image side telecentric lens 131 at an angle according to the image height (the positional relationship between the microlens 231 and the image side telecentric lens 131), and is projected in parallel. Therefore, the width d (thickness in three dimensions) of the projected light is projected with the same width (thickness in three dimensions) at any distance from the image side telecentric lens 131 toward the object (regardless of the distance to the object), and is expressed by the following formula (2), where p is the pitch of the microlens 231, fM is the focal length of the microlens 231, and fL is the focal length of the image side telecentric lens 131. In the case where the width d of the projected light is greater than the pupil diameter of the image side telecentric lens 131, the width d of the projected light is limited by the pupil diameter.

[0046] d = p×(fL / fM) (2)

[0047] Reference now Figure 4 (a) to (c) will describe the observation on the object side. Figure 3 The state of the projected beam described in . Figure 4 (a) to (c) illustrate the states of the projection light beam projected onto the object 401. Figure 4 In (a) to (c), the projection light beams divided into 3×3 are projected onto the object 401 as a projection image 402. Figure 4 The projected image size d and Figure 3 The widths d of the projected lights in are equal to each other. Figure 4 (a), (b), and (c) are illustrated in the order of the position closer to the image-side telecentric lens 131 (the light emitter 111 or the light receiver 121 in the optical device 1 ) from the object 401 .

[0048] like Figure 4As illustrated in (a) to (c), as the distance from the image side telecentric lens 131 increases, the distance between the projected light beams increases, but the projected image size d remains unchanged. In other words, the distance between the multiple separated lights separated by the optical element 112 and irradiated onto the object 401 after passing through the image side telecentric lens 131 (projected light interval) varies according to the distance to the object 401. On the other hand, the width of each of the multiple separated lights (projected image size d) does not vary according to the distance to the object 401. Thus, the light emitted from a certain light-emitting element 211 can be received only by a specific light-receiving element (not illustrated) in the light-receiving element array 125, and the light-emitting element 211 and the light-receiving element can have a one-to-one correspondence. This configuration can provide sequential driving, in which only a portion of the multiple light-emitting elements 211 are caused to emit light, and only the light-receiving elements corresponding to the light-emitting element 211 that emits light among the multiple light-receiving elements are driven. Thus, multiple light-receiving elements can share a TDC, reduce the pixel size, and achieve high resolution.

[0049] In this embodiment, light emitted from one light emitting element 211 is divided into 3×3, but the number of divisions of the emitted light is not limited to 3×3. Figure 5 A variation of the method of dividing the emitted light is illustrated. Figure 5 As illustrated, the microlenses are not necessarily arranged in a square array, as in the microlens array 230 in which the microlenses are arranged in a 3×2 array. The microlenses constituting the microlens array 230 may be not only circular microlenses 501 but also elliptical microlenses 502 .

[0050] (Second embodiment)

[0051] Reference now Figure 6 , an optical device (distance measuring device) 1a according to a second embodiment will be described. Figure 6 is a block diagram of an optical device 1a. The optical device 1a is different from the optical device 1 according to the first embodiment in that, instead of two image side telecentric lenses 131 and 132, the optical device 1a has one image side telecentric lens 133 and a beam splitter (light division unit) 150. That is, the optical device 1a uses the beam splitter 150 to share the same image side telecentric lens 133 for light emission and light reception.

[0052] In reference Figure 1 In the first embodiment described, the dual-lens optical device 1 in which the light emitting optical system and the light receiving optical system are separate systems is exemplified. In this case, in the case where light emitted from a certain light emitting element 211 is projected through the image side telecentric lens 131, reflected by the object, and returned through the image side telecentric lens 132, the optical path of the reflected light changes depending on the object distance. Therefore, the imaging position on the light receiving element changes depending on the object distance, and the distance measurement accuracy is likely to depend on the object distance.

[0053] On the other hand, in the optical device 1a according to this embodiment, the same optical path can be used for light emission and light reception. Therefore, this embodiment can eliminate the dependency of distance measurement accuracy on the object distance caused by the dual lens configuration as described above.

[0054] (Third Embodiment)

[0055] Reference now Figure 7 , an optical device (distance measuring device) 1b according to a third embodiment will be described. Figure 7 1 is a block diagram of an optical device 1b. The optical device 1b is different from the optical device 1a according to the second embodiment in that the optical device 1b includes a converter (viewing angle changing unit) 160. The optical device 1b according to this embodiment includes the converter 160, and arbitrarily changes the viewing angle. In this embodiment, the converter 160 can change the viewing angle according to the object distance using a telephoto converter or a wide-angle converter. The converter 160 according to this embodiment is applicable to the configuration of the first embodiment.

[0056] [In-vehicle system]

[0057] Figure 8 1 is a configuration diagram of an optical device 1 (1a, 1b) and an in-vehicle system (driving assistance device) 1000 including the optical device 1 (1a, 1b) according to each embodiment. The in-vehicle system 1000 is a system that is held by a movable unit (movable device) such as a car (vehicle) and is configured to support driving (operation) of the vehicle based on distance information to objects such as obstacles and pedestrians around the vehicle acquired by the optical device 1. Fig. 9 1 is a schematic diagram of a vehicle 500 as a movable device including an in-vehicle system 1000. Fig. 9 , the distance measurement range (detection range) of the optical device 1 is set to the front of the vehicle 500 , but the distance measurement range may be set to the rear or side of the vehicle 500 .

[0058] like Figure 8 As illustrated, the in-vehicle system 1000 includes an optical device 1, a vehicle information acquisition device 200, a control device (controller or electronic control unit (ECU)) 300, and a warning device (warning unit) 400. In the in-vehicle system 1000, the control unit 60 in the optical device 1 is used as a distance acquisition unit and a collision determination unit. However, if necessary, the in-vehicle system 1000 may include a distance acquisition unit and a collision determination unit separated from the control unit 60, or the distance acquisition unit and the collision determination unit may each be provided outside the optical device 1 (e.g., inside the vehicle 500). Alternatively, the control device 300 may be used as the control unit 60.

[0059] Fig.10 1 is a flowchart illustrating an example operation of the in-vehicle system 1000 according to the embodiment. The operation of the in-vehicle system 1000 will now be described with reference to this flowchart.

[0060] First, in step S1, the light source unit 10 in the optical device 1 illuminates an object around the vehicle, and the light receptor 40 receives light reflected from the object, and the control unit 60 acquires distance information to the object based on a signal output by the light receptor 40. In step S2, the vehicle information acquisition device 200 acquires vehicle information including vehicle speed, yaw rate, steering angle, etc. In step S3, the control unit 60 uses the distance information acquired in step S1 and the vehicle information acquired in step S2 to determine whether the distance to the object is within a previously set distance range.

[0061] This configuration can determine whether an object exists within a set distance around the vehicle and the possibility of a collision between the vehicle and the object. Step S1 and step S2 may be performed in the reverse order of the above, or may be processed in parallel with each other. The control unit 60 determines that there is a possibility of a collision when the object exists within the set distance (step S4), and determines that there is no possibility of a collision when there is no object within the set distance (step S5).

[0062] Next, in the case where the control unit 60 determines that there is a possibility of a collision, the control unit 60 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 of the control unit 60 (step S6), and the warning device 400 issues a warning to the user (driver, passenger) of the vehicle based on the determination result of the control unit 60 (step S7). The notification of the determination result may be sent to at least one of the control device 300 and the warning device 400.

[0063] The control device 300 can control the movement of the vehicle by outputting a control signal to a driving unit (engine, motor, etc.) of the vehicle. For example, the control device 300 performs control such as applying brakes in the vehicle, releasing the accelerator, turning the steering wheel, and generating a control signal for generating a braking force in each wheel to suppress the output of the engine or motor. In addition, the warning device 400 issues a warning to the user by, for example, emitting a warning sound, displaying a warning message on a screen of a car navigation system, etc., and applying vibration to a seat belt or a steering wheel.

[0064] As described above, the vehicle-mounted system 1000 according to this embodiment can detect and measure the distance to the object through the above-mentioned processing, and can avoid the collision between the vehicle and the object. In particular, applying the optical device 1 according to each embodiment to the vehicle-mounted system 1000 can achieve high distance measurement accuracy, and detect the object with high accuracy and determine the collision.

[0065] In this embodiment, the vehicle-mounted system 1000 is applied to driving assistance (collision damage reduction), but the embodiment is not limited to this example, and the vehicle-mounted system 1000 can be applied to cruise control (including adaptive cruise control function) and automatic driving. The vehicle-mounted system 1000 is not limited to vehicles such as cars, but can be applied to movable units such as ships, aircraft, and industrial robots. The vehicle-mounted system 1000 is not limited to movable units, but is applicable to various devices using object recognition such as intelligent transportation systems (ITS) and surveillance systems.

[0066] The in-vehicle system 1000 and the vehicle (movable device) 500 may include a notification device (notification unit) for notifying the manufacturer (producer) of the in-vehicle system or the dealer (seller) of the movable device that the vehicle 500 has collided with an obstacle (if any). For example, the notification device may be a device that transmits information (collision information) related to the collision between the vehicle 500 and the obstacle to a preset external notification destination via e-mail or the like.

[0067] The configuration of the notification device automatically notifying the collision information in this way can take measures such as inspection and repair immediately after the collision occurs. The notification destination of the collision information can be an insurance company, a medical institution, the police, or any other party arbitrarily set by the user. The notification device can be configured to notify the notification destination not only of the collision information, but also of the failure information related to each part and the consumption information related to the consumables. The presence or absence of the collision can be detected using the distance information obtained based on the output from the light receiver 2, or can be detected by other detectors (sensors).

[0068] Embodiments may provide small and high-resolution optical devices, vehicle-mounted systems, and mobile devices.

[0069] Disclosure of the embodiments includes the following configurations.

[0070] (Configuration 1)

[0071] An optical device comprising:

[0072] a light emitter comprising at least one light emitting element;

[0073] A light receiver, comprising a plurality of light receiving elements;

[0074] an optical element comprising a plurality of microlenses;

[0075] an optical system comprising a first telecentric lens; and

[0076] an acquisition unit configured to acquire distance information to the object based on a time required from when the light emitter emits light until when the light receiver receives light reflected by the object,

[0077] wherein the number of the microlenses is greater than the number of the light emitting elements, and

[0078] Wherein, the plurality of microlenses and the first telecentric lens form an afocal system.

[0079] (Configuration 2)

[0080] The optical device of claim 1, wherein the first telecentric lens is an image-side telecentric lens.

[0081] (Configuration 3)

[0082] The optical device according to claim 1 or 2, wherein light emitted from one of the light emitting elements passes through at least two microlenses of the plurality of microlenses.

[0083] (Configuration 4)

[0084] The optical device according to any one of claims 1 to 3, wherein the light emitting element is a VCSEL.

[0085] (Configuration 5)

[0086] The optical device according to any one of claims 1 to 4, wherein the optical system further comprises a second telecentric lens,

[0087] wherein light emitted from the light emitter passes through the first telecentric lens and is reflected by the object, and

[0088] The light reflected by the object passes through the second telecentric lens and is received by the light receiver.

[0089] (Configuration 6)

[0090] The optical device according to any one of claims 1 to 4, wherein the optical system further comprises a beam splitter,

[0091] wherein light emitted from the light emitter is guided by the beam splitter, passes through the first telecentric lens, and is reflected by the object, and

[0092] The light reflected by the object passes through the first telecentric lens, is guided by the beam splitter, and is received by the light receiver.

[0093] (Configuration 7)

[0094] The optical device according to claim 6, wherein the optical system is shared by the light emitter and the light receiver.

[0095] (Configuration 8)

[0096] The optical device according to any one of claims 1 to 7, wherein the optical system comprises a viewing angle changing unit configured to change the viewing angle.

[0097] (Configuration 9)

[0098] The optical device according to any one of claims 1 to 8, wherein the optical element separates the light emitted from the light emitter into a plurality of separate beams,

[0099] wherein the distances between the plurality of separated beams passing through the first telecentric lens and irradiated onto the object vary according to the distance to the object, and

[0100] The width of each of the plurality of separate beams does not vary according to the distance to the object.

[0101] (Configuration 10)

[0102] A vehicle-mounted system, comprising:

[0103] The optical device according to any one of claims 1 to 9,

[0104] The vehicle-mounted system determines the possibility of a collision between the vehicle and the object based on the distance information to the object obtained by the optical device.

[0105] (Configuration 11)

[0106] The in-vehicle system according to claim 10, further comprising a control device configured to output a control signal to generate a braking force in the vehicle when it is determined that there is a possibility of a collision between the vehicle and the object.

[0107] (Configuration 12)

[0108] The in-vehicle system according to claim 10 or 11, further comprising a warning device configured to issue a warning to a user of the vehicle when it is determined that there is a possibility of a collision between the vehicle and the object.

[0109] (Configuration 13)

[0110] The in-vehicle system according to any one of claims 10 to 12, further comprising a notification device configured to notify an external party of information related to the collision between the vehicle and the object.

[0111] (Configuration 14)

[0112] A movable device comprising:

[0113] The optical device according to any one of claims 1 to 9,

[0114] The movable device is capable of moving while holding the optical device.

[0115] (Configuration 15)

[0116] The movable device according to claim 14, further comprising a determination unit configured to determine a possibility of collision with the object based on the distance information to the object acquired by the optical device.

[0117] (Configuration 16)

[0118] The movable device according to claim 15, further comprising a control unit configured to output a control signal for controlling movement of the movable device if it is determined that there is a possibility of collision with the object.

[0119] (Configuration 17)

[0120] The movable device according to claim 15 or 16, further comprising a warning unit configured to issue a warning to a user of the movable device if it is determined that there is a possibility of collision with the object.

[0121] (Configuration 18)

[0122] The movable device according to any one of claims 15 to 17, further comprising a notification unit configured to notify an external party of information related to the collision with the object.

[0123] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the gist.

Claims

1. An optical device, comprising: a light emitter comprising at least one light emitting element; A light receiver, comprising a plurality of light receiving elements; an optical element comprising a plurality of microlenses; an optical system comprising a first telecentric lens; as well as an acquisition unit configured to acquire distance information to the object based on a time required from when the light emitter emits light until when the light receiver receives light reflected by the object, wherein the number of the microlenses is greater than the number of the light emitting elements, and Wherein, the plurality of microlenses and the first telecentric lens form an afocal system.

2. The optical device according to claim 1, wherein: The first telecentric lens is an image-side telecentric lens.

3. The optical device according to claim 1 or 2, wherein: Light emitted from one of the light emitting elements passes through at least two microlenses of the plurality of microlenses.

4. The optical device according to any one of claims 1 to 3, wherein: The light emitting element is a VCSEL.

5. The optical device according to any one of claims 1 to 4, wherein: The optical system further comprises a second telecentric lens, wherein light emitted from the light emitter passes through the first telecentric lens and is reflected by the object, and The light reflected by the object passes through the second telecentric lens and is received by the light receiver.

6. The optical device according to any one of claims 1 to 4, wherein: The optical system further comprises a beam splitter, wherein light emitted from the light emitter is guided by the beam splitter, passes through the first telecentric lens, and is reflected by the object, and The light reflected by the object passes through the first telecentric lens, is guided by the beam splitter, and is received by the light receiver.

7. The optical device according to claim 6, wherein: The optical system is shared by the light emitter and the light receiver.

8. An optical device according to any one of claims 1 to 7, wherein: The optical system includes a viewing angle changing unit configured to change a viewing angle.

9. The optical device according to any one of claims 1 to 8, wherein: The optical element separates the light emitted from the light emitter into a plurality of separate beams, wherein the distances between the plurality of separated beams passing through the first telecentric lens and irradiated onto the object vary according to the distance to the object, and The width of each of the plurality of separate beams does not vary according to the distance to the object.

10. A vehicle-mounted system, comprising: The optical device according to any one of claims 1 to 9, The vehicle-mounted system determines the possibility of a collision between the vehicle and the object based on the distance information to the object obtained by the optical device. 11 . The in-vehicle system according to claim 10 , further comprising a control device configured to output a control signal to generate a braking force in the vehicle when it is determined that there is a possibility of a collision between the vehicle and the object.

12. The in-vehicle system according to claim 10 or 11, further comprising a warning device configured to issue a warning to a user of the vehicle when it is determined that there is a possibility of a collision between the vehicle and the object. 13 . The in-vehicle system according to claim 10 , further comprising a notification device configured to notify an external party of information related to the collision between the vehicle and the object.

14. A movable device comprising: The optical device according to any one of claims 1 to 9, The movable device is capable of moving while holding the optical device. 15 . The movable device according to claim 14 , further comprising a determination unit configured to determine a possibility of collision with the object based on the distance information to the object acquired by the optical device. 16 . The movable device according to claim 15 , further comprising a control unit configured to output a control signal for controlling movement of the movable device if it is determined that there is a possibility of a collision with the object. 17 . The movable device according to claim 15 , further comprising a warning unit configured to issue a warning to a user of the movable device if it is determined that there is a possibility of a collision with the object. 18 . The movable device according to claim 15 , further comprising a notification unit configured to notify an external party of information related to the collision with the object.

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