KR20210116983A - Optical device - Google Patents

Abstract

According to an embodiment, an optical device comprises: a light irradiating unit irradiating light toward a target scene; a light receiving unit receiving the light reflected from the target scene; and a processor connected to the light irradiating unit and the light receiving unit. The light irradiating unit comprises: a light source array including a plurality of directional light sources; an actuator horizontally moving the light irradiated from the plurality of light sources in the same direction; and F-theta telecentric lenses concentrating the light for a plurality of light passing through the actuator to be irradiated to the target scene after passing one point.

Description

Optical device {OPTICAL DEVICE}

The present invention relates to an optical device. Specifically, it is applicable to the technical field of scanning a target scene with high resolution and acquiring depth information.

Existing and new applications are increasing the need for real-time 3D images. An optical device for acquiring a real-time 3D image is generally known as light detection and ranging (LiDAR).

Such an optical device may acquire depth information of the target scene by irradiating an optical beam to the target scene and analyzing the reflected optical signal. Here, the depth information may include a distance to a subject included in the target scene, external information of the subject, and distance information between subjects.

A technique commonly used to irradiate an optical beam onto a target scene and to obtain depth information of a target scene by analyzing a reflected optical signal is a Time of Fight (TOF) method. The TOF method refers to a method of converting a time when a light beam irradiated to a target scene is reflected and incident after being irradiated into distance information. An optical device that acquires depth information of a target scene in a TOF method is generally referred to as a TOF camera.

The TOF camera specifically includes a light irradiator for irradiating an optical beam to a target scene, and a light receiving unit for receiving an optical signal reflected on the target scene. Here, a single light source may be used for the light irradiation unit, but recently, a vertical cavity surface emitting laser (VCSEL) has been widely used. In addition, the light receiver may include an image sensor that converts the received optical signal into an electrical signal, and the image sensor may receive the optical signal from a plurality of pixels corresponding to resolution, respectively.

Currently, the technical issue of TOF cameras is to extend the measurement distance and improve the recognition resolution of the region of interest. In extending the measurement distance, there are limitations such as eye-safety issues in increasing the amount of irradiated light from the light irradiator. Therefore, it may be desirable to increase the recognition distance by increasing the Signal to Noise Ratio (SNR). As a method for improving SNR within a given optical power, there may be a method of forming and scanning a light beam array. For Light Beam Array, the beam must be scanned with distortion within the minimum or allowable limit in a given scan area.

When scanning a beam based on the existing imaging optical system, horizontal movement or tilting of the lens barrel can be used, but the following two issues may arise. When scanning a beam based on horizontal movement or inclination of the lens barrel, aberration occurs due to fluctuations in the optical system, which may cause an issue of obtaining distorted information because beam movement characteristics vary depending on the position in the object area. In addition, when the lens barrel is moved, the scan frequency is limited due to the large mass, so it may be difficult to obtain the desired scan speed.

An optical device according to an embodiment aims to improve resolution obtained by scanning a light beam.

An optical device according to an embodiment has an object of improving a scanning distance of a light beam.

An optical device according to an embodiment has an object to reduce distortion that may occur while scanning a light beam.

An optical device according to an embodiment has an object to improve a speed of scanning a light beam.

In order to achieve the above object, an optical device according to an embodiment includes a light irradiator for irradiating light toward a target scene, a light receiving unit for receiving light reflected from the target scene, and the light irradiator connected to the light receiving unit A processor, wherein the light irradiation unit includes a light source array including a plurality of directional light sources, an actuator that horizontally moves the light emitted from the plurality of light sources in the same direction, and a plurality of lights passing through the actuator pass through a point It may be characterized in that it comprises an eptheta telecentric lens for condensing to be irradiated to the target scene.

In addition, according to an embodiment, the actuator may include a glass plate driven with a variable inclination.

In addition, according to an embodiment, the parallel movement distance of the light irradiated from the plurality of light sources may be determined by a thickness of the glass plate, a refractive index, and an inclination of an incident surface and an exit surface.

Also, according to an embodiment, the glass plate may include a grating pair that diffracts light from an incident surface and an exit surface.

In addition, according to an embodiment, the glass plate may be characterized in that the distance between the grating pairs provided on the incident surface is the same as the distance between the grating pairs provided on the exit surface.

In addition, according to an embodiment, the target scene includes a plurality of divided regions respectively corresponding to the plurality of light sources, and the light emitted from the light source is irradiated to the corresponding divided regions, and The irradiation area may be smaller than the corresponding divided area.

In addition, according to an embodiment, the processor may variably drive the inclination of the actuator to scan each of the divided regions corresponding to the light emitted from each of the light sources.

In addition, according to an embodiment, the processor may be characterized in that the actuator biaxially rotates so that the light irradiated from the light source moves in a vertical direction in the one direction.

In addition, according to an embodiment, the actuator includes a glass plate having a grating pair that diffracts light on an incident surface and an output surface, and the grating pair is a liquid crystal arranged in response to an applied electric field. It may be formed based on, and the horizontal movement of the light passing through the actuator may be characterized in that it is controlled in response to an electric field applied to the pair of gratings.

Also, according to an embodiment, the light receiving unit includes a unit pixel group corresponding to the divided area, and the processor sequentially drives the pixels included in the unit pixel group in response to the rotation direction of the actuator. can be characterized.

In addition, according to an embodiment, the image sensor includes the unit pixel group for each section, and synchronizes and sequentially drives the pixels included in the unit pixel group for each section in response to the rotation direction of the actuator. can do.

Also, according to an embodiment, the processor may obtain a depth image of a target scene by merging signals obtained by sequentially driving pixels included in each unit pixel group.

Also, according to an embodiment, the light receiving unit includes a unit pixel group corresponding to the divided area, and the processor simultaneously drives pixels included in the unit pixel group, and a pixel corresponding to a rotation direction of the actuator. It may be characterized in that the depth image of the target scene is obtained by merging the signals obtained from them.

Also, according to an embodiment, the processor obtains a signal corresponding to the reflected light and a signal corresponding to the ambient light from each pixel in response to the rotation direction of the actuator, and uses the signal corresponding to the ambient light to obtain the reflected light It may be characterized in that the depth image of the target scene is obtained by correcting the signal corresponding to , and merging the signal corresponding to the corrected reflected light.

Also, according to an embodiment, the light source array may include a VCSEL array.

The optical device according to an embodiment may improve resolution obtained by scanning a light beam.

The optical device according to an exemplary embodiment may improve a scanning distance of a light beam.

The optical device according to an embodiment may reduce distortion that may occur while scanning a light beam.

The optical device according to an embodiment may improve a speed of scanning a light beam.

1 is a schematic diagram of an optical device according to an embodiment;
2 illustrates a light irradiator of an optical device according to an exemplary embodiment.
3 is a view for explaining an actuator included in the light irradiation unit.
4 shows another embodiment of the actuator included in the light irradiation unit.
5 shows another embodiment of the actuator included in the light irradiation unit.
6 is a view for explaining an ftheta telecentric lens included in the light irradiation unit.
7 is a diagram for explaining a driving method of an optical device according to an exemplary embodiment.
FIG. 8 shows the light source array included in FIG. 7 .
FIG. 9 shows the image sensor included in FIG. 7 .
FIG. 10 illustrates a signal change obtained by each pixel in a unit pixel group of the image sensor included in FIG. 9 for a unit time.

Hereinafter, the embodiments disclosed in the present specification will be described in detail with reference to the accompanying drawings, but the same or similar components are assigned the same reference numbers regardless of reference numerals, and redundant description thereof will be omitted. The suffixes "module" and "part" for the components used in the following description are given or mixed in consideration of only the ease of writing the specification, and do not have a meaning or role distinct from each other by themselves. In addition, in describing the embodiments disclosed in the present specification, if it is determined that detailed descriptions of related known technologies may obscure the gist of the embodiments disclosed in the present specification, the detailed description thereof will be omitted. In addition, the accompanying drawings are only for easy understanding of the embodiments disclosed in the present specification, and the technical spirit disclosed herein is not limited by the accompanying drawings, and all changes included in the spirit and scope of the present invention , should be understood to include equivalents or substitutes.

Terms including an ordinal number, such as first, second, etc., may be used to describe various elements, but the elements are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another.

When a component is referred to as being “connected” or “connected” to another component, it is understood that the other component may be directly connected or connected to the other component, but other components may exist in between. it should be On the other hand, when it is said that a certain element is "directly connected" or "directly connected" to another element, it should be understood that no other element is present in the middle.

The singular expression includes the plural expression unless the context clearly dictates otherwise.

In the present application, terms such as "comprises" or "have" are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

1 is a schematic diagram of an optical device 100 according to an embodiment.

The optical device 100 according to an embodiment includes a light irradiator 110 for irradiating light toward a surface scene 200 , a light receiver 120 for receiving light reflected from the surface scene 200 , and a light irradiator ( 110 ) and a processor (not shown) connected to the light receiver 120 .

The optical device 100 according to an embodiment may be a TOF camera. Here, the TOF Carrera may include both a Direction type and an In-direction type TOF camera. The Direction-type TOF camera detects a phase difference between the light irradiated from the light irradiation unit 110 and the light reflected by the target scene 200 and received by the light receiving unit 120, and converts it into a distance. The in-direction type TOF camera uses a method of converting the time the light irradiated from the light irradiation unit 110 reflects off the target scene 200 and arrives at the light receiver 120 into a distance. In general, a direction-type TOF camera has better resolution than an in-direction-type TOF camera, so it may be advantageous to apply the present invention to an in-direction-type TOF camera.

In order to increase resolution, the optical apparatus 100 according to an exemplary embodiment may collect the light emitted from the light irradiation unit 110 and scan the collected light to obtain depth information of the target scene 200 .

The light irradiation unit 110 includes a light source array 111 including a plurality of directional light sources, an actuator 112 that horizontally moves light irradiated from the plurality of light sources in the same direction, and a plurality of lights passing through the actuator 112 at one time. It may include an eptheta telecentric lens 113 that condenses to be irradiated to the target scene 200 through the point F. Here, the ftheta telecentric lens 113 may correspond to the Tx optical lens 113 that guides light from the light source array 111 to the target scene 200 .

The light receiver 120 may include an image sensor 121 that converts light reflected from the target scene 200 into an electrical signal, and an Rx optical lens 123 that guides the light to the image sensor 121 .

The light source array 111 may be a Vertical-Cavity Surface-Emitting Laser (VCSEL) array. The light source array 111 may include a plurality of light sources. A plurality of light sources included in the light source array 111 may respectively correspond to a plurality of divided regions 210 constituting the target scene 200 . Specifically, the plurality of light sources included in the light source array 111 may correspond one-to-one to the plurality of divided regions 210 constituting the target scene 200 , and may radiate light to the corresponding divided regions 210 . have.

In order to scan the target scene 200 with the light irradiated from the light source array 111 , a driving unit for changing the area to which the light is irradiated may be required. To this end, the Tx optical lens 113 may be moved or the light source array 111 may be moved. However, this may cause a problem of spherical spherical aberration, and may limit the scanning speed.

In order to solve the above problem, a method of scanning light in the light irradiation unit 110 will be described in FIGS. 2 to 5 below.

Additionally, sectional rolling operation of the light receiver 120 will be described in FIGS. 6 to 8 .

2 illustrates a light irradiator 110 of the optical device 100 according to an exemplary embodiment.

The light source array 111 included in the light irradiation unit 110 may include a plurality of directional light sources.

A plurality of light sources included in the light source array 111 may radiate light toward the actuator 112 positioned in front of the light source array 111 . Here, the light irradiated from the light source array 111 toward the actuator 112 may be parallel to each other.

The actuator 112 may include a glass plate through which the light irradiated from the light source array 111 passes. Here, the glass plate may be driven so that the inclination is changed in response to the light irradiated from the light source array 111 . The light passing through the glass plate may pass through the Tx optical lens 113 of the light irradiation unit 111 to be irradiated to the target scene 200 (refer to FIG. 1 ).

The actuator 112 may be configured to horizontally move a plurality of parallel lights irradiated from the light source array 111 . Specifically, when the inclination of the glass plate constituting the actuator 112 is changed, the plurality of parallel lights irradiated from the light source array 111 may be moved in parallel. Here, the actuator 112 may be configured to move the plurality of parallel lights irradiated from the light source array 111 in parallel in the same direction and the same distance h1, respectively.

The Tx optical lens 113 may be an eptheta telecentric lens that condenses a plurality of parallel lights passing through the actuator 112 so that a point F passes. Here, one point F may maintain a fixed point even if the plurality of parallel lights move in parallel due to the driving of the actuator 112 . That is, the plurality of parallel lights that have moved in parallel by the driving of the actuator 112 pass through a point F through the Tx optical lens 113, respectively, and correspond to the incident direction to the point F in the target scene 200 ) can be irradiated to the moving point.

The distance h1 moved through the actuator 112 may correspond to a distance h2 that the light point moves in the target plane 200 . Specifically, as the distance h1 moved by the parallel light through the actuator 112 increases, the distance h2 moved in the target plane 200 may increase. The moving distance ratio may correspond to a distance ratio with a point F condensed through the Tx optical lens 113 .

3 is a view for explaining the actuator 112 included in the light irradiation unit.

The actuator 112 may include a glass plate made of a transparent material through which the light irradiated from the light source array 111 passes. The glass plate may be controlled to have a variable inclination. Corresponding to the inclination of the glass plate, the plurality of parallel lights passing through the glass plate may move in parallel.

The parallel movement distance h1 of the plurality of parallel lights irradiated from the light source array 111 passing through the glass plate is determined by the thickness d1 of the glass plate, the refractive index n, and the inclination θ between the incident surface and the exit surface. can be decided.

Specifically, as the inclination θ of the glass plate increases, the parallel movement h1 may increase. Here, the plurality of parallel lights irradiated from the light source array 111 may move in parallel in a direction opposite to the inclined direction of the glass plate.

In addition, as the thickness d1 of the glass plate increases, the parallel movement distance h1 may increase. However, the thickness d1 of the glass plate is a factor that affects the volume of the light irradiator 110, and the thickness d1 is used as a factor other than adjusting the sensitivity to parallel movement versus the change in the inclination θ using the thickness d1. θ) It may be desirable to adjust the translation sensitivity versus change.

Specifically, it is possible to adjust the translation sensitivity versus the change in the slope (θ) by using the refractive index (n). Here, the larger the refractive index n, the greater the translation sensitivity versus the change in the slope θ, and the smaller the refractive index n, the greater the translation sensitivity versus the change in the slope θ.

4 shows another embodiment of the actuator 112 included in the light irradiation unit. Specifically, FIG. 3 describes an embodiment in which parallel light emitted from the light source array 111 is moved in parallel using only refraction of light. On the other hand, in FIG. 4 , an embodiment in which parallel light irradiated from the light source array 111 is moved in parallel using diffraction will be described.

The actuator 112 may include a transparent glass plate through which a plurality of parallel lights irradiated from the light source array 111 pass. A plurality of parallel lights irradiated from the light source array 111 may move in parallel as the inclination of the glass plate is changed.

The glass plate included in the actuator 112 may include grating pairs 112a and 112b that diffract light from the light source array 111 to the incident surface on which the light is incident and the light outgoing surface. . Light diffracted through the grating pair on the incident surface may be diffracted on the output surface and emitted as parallel light.

In this case, the grating pair 112a provided on the incident surface of the glass plate may have the same grid spacing as the grating pair 112b provided on the exit surface.

5 shows an embodiment of the actuator 112 included in the light irradiation unit.

An embodiment in which the actuator 112 of FIG. 5 controls the pattern of the grating pair 112a and 112b without changing the inclination to move the parallel light irradiated from the light source array 111 in parallel will be described.

The actuator 112 may include a glass plate having a grating pair 112a, 112b diffracting light on an incident surface and an exit surface. The grating pairs 112a and 112b may be formed based on liquid crystals arranged in response to an applied electric field. Specifically, the pattern of the grating pair 112a and 112b may vary according to the direction and magnitude of the applied electric field.

Using the electric field, the grating pair 112a provided on the incident surface and the grating pair 112b provided on the exit surface may be controlled, respectively. The pattern may be controlled by an electric field applied to at least one of the grating pair 112a provided on the incident surface and the grating pair 112b provided on the exit surface.

As the arrangement of the grating pairs 112a and 112b is changed, the parallel movement direction and degree of the light irradiated from the light source array 111 may be controlled. Specifically, Fig. 5 (a) shows an embodiment in which the light irradiated from the light source array 111 is moved in parallel in one direction by the arranged grating pairs 112a and 112b, and Fig. 5 (b) is a grating. An embodiment in which the light irradiated from the light source array 111 is moved in parallel in the opposite direction by changing the arrangement of the pairs 112a and 112b is shown.

The actuator 112 is laminated on one surface of the body portion 1121 and the body portion 1121 and is stacked on the other surface of the incident portion 1122 and the body portion 1121 to which the light irradiated from the light source array 111 is incident. It may include an emitting unit 1123 from which the light is emitted. The incident surface grating pair 112a may be provided between the incident part 1122 and the body part 1121 , and the exit surface grating pair 112b may be provided between the output part 1123 and the body part 1121 . .

The body portion 1121 and the incident portion 1122 may include an electrode pattern for controlling the pattern of the incident surface grating pair 112a. In some cases, the electrode pattern may be provided between the body portion 1121 and the incident portion 1122 , and may be provided to surround the incident surface grating pair 112a. In this case, the electrode pattern may be formed of a transparent electrode. In addition, the body portion 1121 and the emission portion 1123 may include an electrode pattern for controlling the pattern of the emission surface grating pair 112b. In some cases, the electrode pattern may be provided between the body portion 1121 and the emission portion 1123 and may be provided to surround the emission surface grating pair 112b. In this case, the electrode pattern may be formed of a transparent electrode.

FIG. 6 is a view for explaining the ftheta telecentric lens 113 included in the light irradiation unit.

The ftheta telecentric lens 113 is a lens designed to refract and diffract irradiated laser light (parallel light) to focus F in the irradiation direction. The ftheta telecentric lens 113 must include both a refractive element for refracting laser light and a diffraction element for correcting aberration. In general, the ftheta telecentric lens is composed of a combination of several concave and convex lenses, but in some cases, one optical system injection molded with plastic may be configured. Specifically, although FIG. 5 shows the eftheta telecentric lens 113 composed of a plurality of lenses, the embodiment of the eftheta telecentric lens 113 is not limited to the configuration of FIG. 6 .

The plurality of parallel lights irradiated from the light source array 111 of the light irradiation unit 110 may be incident on the f-theta lens 113 and may be irradiated to the target scene 220 through the focal point F. A plurality of parallel lights incident to the ftheta telecentric lens 113 all pass through a fixed focal point F, but the irradiated position to the target scene 220 may be different depending on the incident position.

The advantage of the f-theta telecentric lens 113 is that it can uniformly scan the dots irradiated to the target scene 220 irrespective of the position of the incident parallel light. For example, parallel light irradiated from the first light source of the light source array 111 and parallel light irradiated from the second light source are parallelly moved in the same direction and the same distance by the actuator 112 described with reference to FIGS. It may be incident to the centric lens 113 . In this case, the parallel light irradiated from the first light source and the parallel light irradiated from the second light source may have different positions to be incident on the ftheta telecentric lens 113 . Since the incident parallel light passes through the fixed focal point F regardless of the incident position of the ftheta telecentric lens 113, the parallel light emitted from the first light source and the parallel light emitted from the second light source are the same. When moving in the same direction and the same distance, it is possible to control the corresponding dots to move in the same direction and the same distance even in the target scene 220 . That is, the ftheta telecentric lens 113 may prevent distortion caused by differently moving dots in the target scene 220 .

7 is a diagram for explaining a driving method of an optical device according to an exemplary embodiment.

The target scene 200 may include a plurality of divided regions 210 to correspond to the plurality of light sources provided in the light source array 111 . The plurality of light sources and the plurality of divided regions 210 may correspond one-to-one, and each of the light sources may irradiate light to the corresponding divided regions.

When one light source irradiates light to the corresponding divided area 210 , the light may be irradiated to one area of the divided area 210 , instead of irradiating light to the entire divided area 210 . The light irradiator 110 may control the light irradiated from one light source to move and scan within the divided area 210 by driving the actuator 112 .

The light receiver 120 may include an image sensor 121 that converts light reflected from the target scene 220 into an electrical signal and an Rx optical lens 123 that guides the light to the image sensor 121 . The image sensor 121 may include a plurality of pixels corresponding to the resolution. The image sensor 121 may include a group of divided unit pixels to respectively correspond to the divided regions 210 . The unit pixel group may include a plurality of pixels.

Looking at the driving of the optical device according to the embodiment in a unit configuration, one light source included in the light source array 111 may irradiate light to the corresponding divided area 210 . The actuator 112 may adjust a position where the light irradiated from the light source is incident on the eptheta telecentric lens 113 to scan the entire corresponding divided region 210 . The unit pixel group corresponding to the divided area 210 may receive light respectively or sequentially corresponding to the light irradiated position to obtain depth information of the light irradiated area.

A manner in which the light irradiated from one light source scans within the divided area 210 may be determined by driving the actuator 112 . In one embodiment, when the actuator 112 is uniaxially rotationally driven, the light irradiated from the light source may move only in one direction or the opposite direction in the divided area 210 . The movement of the dots on the target scene 200 by uniaxial rotational actuation of the actuator 112 is illustrated in FIG. 6 . In another embodiment, when the actuator 112 is driven to rotate in two axes, the light irradiated from the light source may move in one direction or the opposite direction and the vertical direction in the divided area 210 . The movement of the dot on the target scene 200 with the biaxial rotational actuation of the actuator 112 is illustrated in FIG. 1 .

When the actuator 112 is driven to rotate in two axes, there is an advantage that one light source can scan a wider divided area 210 . However, it may take a long time to scan one divided region 210 , and a driving unit for biaxially rotating the actuator 112 may require a complex and large volume.

Accordingly, manufacturing the actuator 112 to uniaxially rotate may be advantageous in terms of structure simplicity, scan time reduction, and size reduction. Hereinafter, an embodiment of scanning the target scene 200 by driving the actuator 112 uniaxially will be described in detail.

FIG. 8 shows the light source array 111 included in FIG. 7 .

FIG. 9 shows the image sensor 121 included in FIG. 7 .

In order to scan the target scene 200 by driving the actuator 112 uniaxially, the light sources 111 of the light source array 111 of the light irradiation unit 110 are arranged along the first direction A, and the first direction ( A group of light sources 111 listed in A) needs to be provided apart by a preset distance h3 in the second direction B perpendicular to the first direction A.

The actuator 112 may be uniaxially rotated to be inclined in the second direction (B).

Each of the plurality of divided regions 210 constituting the target scene 220 may be set to be short in the first direction (A) and long in the second direction (B).

The image sensor 121 of the light receiver 120 may include a plurality of pixels 1211 . The image sensor 121 may include a unit pixel group D corresponding to each divided area 210 . The unit pixel group D may include a plurality of pixels along the dot movement direction (the second direction or the opposite direction) in the divided area 210 .

The image sensor 121 may convert an optical signal received by sequentially driving the plurality of pixels 121 in one direction into an electrical signal. Specifically, in the image sensor 121 , the pixels 121 arranged in the first direction A may be sequentially driven in the second direction or the opposite direction.

The image sensor 121 is divided into a plurality of sections C, and the pixels 121 may be sequentially driven in each of the sections C1 to C4. That is, while the pixels 121 arranged in the first direction A in the first section C1 are sequentially driven in the second direction B or the opposite direction, the remaining sections C2 to C4 follow the same pattern. The pixels 121 may be sequentially driven. This may be referred to as driving the image sensor 121 Sectional Rolling.

Here, the sections C1 to C4 may be arranged in the second direction B or the opposite direction.

In the image sensor 121 , the pixels 121 may be sequentially driven in response to the actuator 112 being driven. The pixels 121 may be sequentially driven in response to a direction in which the dots move in response to a change in inclination of the actuator 112 .

As the pixels 121 are sequentially driven at the same time for each section, the time required for scanning the target scene 200 may be reduced. The image sensor 121 may acquire a full depth image by merging signals obtained from respective sequentially driven pixels.

In some cases, the plurality of pixels 121 in the image sensor 121 may be simultaneously driven. In this regard, reference is made to the graph of FIG. 9 .

FIG. 10 illustrates a signal change obtained by each pixel 1211 in a unit pixel group D (refer to FIG. 9 ) of the image sensor 121 included in FIG. 9 for a unit time.

Here, the unit time may be a time required to scan the divided area 210 with one light source.

The image sensor 121 may detect a position to which a dot is irradiated and a position of a corresponding pixel 121 by using a rate of change in inclination of the actuator 112 . The image sensor 121 may acquire a full depth image by merging signals respectively obtained from pixels 121 corresponding to the inclination of the actuator 112 during unit time. For example, it takes 0.4 s for one light source to scan the divided area 210 , and four pixels 1211a to 1211d are included in the unit pixel group D corresponding to one divided area 210 . In this case, the entire image may be merged by acquiring a signal received from the corresponding pixel (one of 1211a to 1211d) every 0.1s time interval.

When the pixels of the image sensor 121 are simultaneously driven, each pixel 121 may receive ambient light at a time other than the time when the reflected light is received. For example, if it is possible to obtain a signal corresponding to the reflected light from the first pixel 1211a at t1, while at other times t2 to t4, the first pixel 1211a may obtain a signal corresponding to the ambient light have. (refer to FIG. 10( a )) In addition, if a signal corresponding to the reflected light can be obtained from the second pixel 1211b at t2 , while at other times t1 , t3 and t4 , the second pixel 1211b receives ambient light A signal corresponding to can be obtained. (See FIG. 10( b )) Also, if a signal corresponding to the reflected light can be obtained at t3 at the third pixel 1211c , while at other times t1 , t2 and t4 , the third pixel 1211c receives ambient light A signal corresponding to can be obtained. (See FIG. 10( c )) Also, at t5, if a signal corresponding to the reflected light can be obtained from the fourth pixel 1211d, while at other times t1 to t3, the fourth pixel 1211c corresponds to the ambient light. signal can be obtained. (See Fig. 10(c))

That is, the reflected light signal received by each of the pixels 1211a to 1211d may be corrected by using the ambient light signal obtained at different times. For example, when a signal a is obtained at a time t1 when a reflected light signal is received from the first pixel 1211a and a signal b is obtained at other times t2 to t4, the reflected light signal is corrected to ab. can In this case, the optical device according to an exemplary embodiment may cancel the effect of reflected light, so that a more accurate depth image may be obtained.

The above detailed description should not be construed as restrictive in all respects and should be considered as illustrative. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present invention are included in the scope of the present invention.

100: optical device 110: light irradiation unit
111: light source array 112: actuator
113: ftheta telecentric lens (Tx optical lens)
120: light receiving unit 121: image sensor
123: Rx optical lens 200: target scene
210: partition area

Claims (15)

a light irradiator for irradiating light toward a target scene;
a light receiving unit for receiving light reflected from the target scene; and
a processor connected to the light irradiator and the light receiver;
The light irradiation unit
a light source array including a plurality of directional light sources;
an actuator that horizontally moves the light irradiated from the plurality of light sources in the same direction; and
and an eptheta telecentric lens for condensing the plurality of lights passing through the actuator to be irradiated to the target scene through one point. According to claim 1,
The actuator is
An optical device comprising a glass plate driven with a variable inclination. 3. The method of claim 2,
A distance traveled by the light irradiated from the plurality of light sources in parallel
The optical device according to claim 1, wherein the thickness of the glass plate, the refractive index, and the inclination of the incident surface and the exit surface are determined. 4. The method of claim 3,
The glass plate is
An optical device comprising a grating pair rotating light on an incident surface and an exit surface. 5. The method of claim 4,
The glass plate is
An optical device, characterized in that the grating spacing of the grating pair provided on the incident surface is the same as the grating spacing of the grating pair provided on the exit surface. According to claim 1,
The actuator is
A glass plate having a grating pair diffracting light on an incident surface and an output surface,
The grid pair is
It is formed based on liquid crystals arranged in response to an applied electric field,
The horizontal movement of light passing through the actuator is
An optical device, characterized in that controlled in response to an electric field applied to the grating pair. According to claim 1,
The target scene is
A plurality of divided regions respectively corresponding to the plurality of light sources,
The light irradiated from the light source is irradiated to the corresponding divided area, and an irradiation area of the light irradiated from the light source is smaller than the corresponding divided area. 8. The method of claim 7,
the processor
An optical device, characterized in that the inclination of the actuator is variably driven so that the light irradiated from each light source scans the entire divided area corresponding thereto. 9. The method of claim 8,
the processor
An optical device, characterized in that the actuator is uniaxially rotationally driven so that the light irradiated from the light source moves in one direction or the opposite direction. 10. The method of claim 9
the processor
An optical device, characterized in that the actuator is biaxially rotationally driven so that the light emitted from the light source moves in the vertical direction in the one direction. 9. The method of claim 8,
The light receiving unit
a unit pixel group corresponding to the divided area;
the processor
and sequentially driving the pixels included in the unit pixel group according to the rotation direction of the actuator. 12. The method of claim 11,
the image sensor
The optical device comprising the unit pixel group for each section, and synchronizing and sequentially driving the pixels included in the unit pixel group for each section in response to the rotation direction of the actuator. 13. The method of claim 12,
the processor
An optical device, characterized in that a depth image of a target scene is obtained by merging signals obtained by sequentially driving pixels included in each unit pixel group. 9. The method of claim 8,
The light receiving unit
a unit pixel group corresponding to the divided area;
the processor
simultaneously driving pixels included in the unit pixel group;
and acquiring an image of a target scene by merging signals from pixels corresponding to the rotation direction of the actuator. 15. The method of claim 14,
the processor
In response to the rotation direction of the actuator, a signal corresponding to the reflected light and a signal corresponding to the ambient light are respectively obtained from each pixel,
Correcting the signal corresponding to the reflected light by using the signal corresponding to the ambient light,
An optical device, characterized in that by merging a signal corresponding to the corrected reflected light to obtain a depth image of the target scene.

Images