KR102429969B1 - Optical transmitter for lidar - Google Patents

Abstract

According to one aspect of the technical idea of the present disclosure, provided is an optical transmission unit, which includes a light source generating light, and an optical sheet forming lens disposed on one side of the light source, adjusting a vertical axis (Y) direction spreading angle of light incident from the light source through the inner surface within a first angle range, and generating an optical sheet by adjusting the spreading angle in the horizontal axis (X) direction through the outer surface within a second angle range.

Description

Optical transmitter for lidar

The technical idea of the present disclosure relates to a light transmitting unit for lidar, and more particularly, to a light transmitting unit for lidar, characterized in that it can form a light sheet including a light sheet forming lens made of a single lens.

LiDAR is a sensor that measures distance using laser light, enabling recognition of the surrounding environment and measuring the location of obstacles. Accordingly, lidar is being actively used to implement a distance sensing function in various fields such as intelligent mobile robots, drones, and unmanned vehicles.

On the other hand, among the methods of measuring the distance by the lidar, the method of calculating the distance by measuring the time it takes for the light output from the light transmitter to reach the target point and then to reach the light receiver (TOF, Time Of Flight), the light transmitter There is a method (triangulation) that calculates the arrival distance of the laser by triangulation using the distance difference and parallax of the light receiver.

The light transmitting unit of the lidar consists of a light irradiation optical system, and the light irradiation optical system is designed so that the light emitted from the light source has a specific distribution in the field of view of the light receiving unit using a plurality of refracting surfaces.

The light irradiation optical system of the light transmitter used for conventional two-dimensional distance measurement collects the light emitted from the light source at one point and passes it through a plurality of refracting surfaces to form a light sheet. At this time, light loss occurred due to reflection generated during the refraction process while passing through a number of refracting surfaces, and thus there is a problem in that the distance that the lidar can measure is limited.

In addition, if some or all of the plurality of refracting surfaces are removed from the light irradiation optical system, strong light is emitted in one direction and there is a risk of damaging the part of the user's body using the lidar, especially the retina and cornea of the eyeball. There are usability problems that exist.

In order to minimize the loss of light and solve the problem of safety in use, a method capable of forming the light sheet in a different way from the conventional light irradiation optical system of the light transmitter is required.

The problem to be solved by the technical idea of the present disclosure is to reduce light loss due to light reflected in the process of refraction passing through a plurality of refracting surfaces to form a light sheet, and some components constituting the light irradiation optical system forming the light sheet An object of the present invention is to provide a light sheet irradiation optical system in which light is focused in one direction and is not emitted even if it is dropped.

In order to achieve the above object, in the light transmitting unit for lidar according to an aspect of the technical idea of the present disclosure, a light source for generating light and a light source disposed on one side of the light source, the inner surface of the light incident from the light source It may include a light sheet forming lens for generating a light sheet by adjusting the vertical axis direction spread angle within the first angular range, and by adjusting the horizontal axis direction spread angle through the second angular range.

The optical sheet forming lens may be formed of a single lens having a refractive surface composed of the inner surface and the outer surface.

The inner surface of the optical sheet-forming lens may be adjusted to refract the light incident from the light source so that the spread angle in the vertical axis direction is in the range of 0° or more and 10° or less.

The outer surface of the optical sheet-forming lens can be adjusted to refract the light emitted to the outside from the optical sheet-forming lens so that the spreading angle in the horizontal axis direction is in the range of 0° or more and 200° or less.

The inner surface of the optical sheet-forming lens may be formed in the shape of a convex lens in cross section with respect to the optical axis-vertical axis plane.

The cross-section of the inner surface of the optical sheet forming lens with respect to the optical axis-vertical axis plane may be formed in a shape tangent to a curve such as a circle or an ellipse on the horizontal axis-optical axis plane.

The inner surface of the optical sheet forming lens has a z (r) distance with the cross section of the inner surface according to the distance (r) deviating from the optical axis with respect to the optical axis-vertical axis plane, based on the following [Equation 1], The cross-section of the side may have a shape in which one point is connected to each other while forming a distance z(r) from the cross-section of the inner surface of the optical sheet forming lens to the reference plane calculated based on Equation 1 below.

[Equation 1]

는 원뿔 상수(comic comstamt),

n는 비구면 계수).(where r is the distance off the optical axis, R is the radius of curvature at the point where r = 0,

is the conic constant,

n is the aspheric coefficient).

)에 따른 빛의 세기(

)와 상기 외측면을 통해 굴절되어 방출되는 각도(

)에 따른 빛의 세기(

)가 아래 수학식 2의 조건을 만족하도록, 아래 수학식 3을 기초로 계산된 입사각에 해당하는 지점에서의 곡면 기울기

를 형성하면서 각각의 일 지점이 서로 연결된 형태를 갖을 수 있다. The outer surface of the optical sheet-forming lens, the optical axis of the light passing through the inner surface of the optical sheet-forming lens - the angle projected on the horizontal axis (

) according to the light intensity (

) and the angle refracted and emitted through the outer surface (

) according to the light intensity (

) to satisfy the condition of Equation 2 below, the slope of the curved surface at a point corresponding to the angle of incidence calculated based on Equation 3 below.

Each point may have a shape connected to each other while forming.

[Equation 2]

은 내측면을 통과해 나온 빛의 광축-수평축 상에 투영된 빛의 각도,

는

에 따른 빛의 세기,

는 외측면을 통해 굴절되어 방출되는 빛의 각도,

는

에 대해 요구되는 빛의 세기)(here,

is the angle of the light projected on the optical axis-horizontal axis of the light passing through the inner surface,

Is

light intensity according to

is the angle of the light that is refracted and emitted through the outer surface,

Is

light intensity required for

[Equation 3]

은

에 해당하는 지점에서의 각 곡면의 기울기).(here,

silver

the slope of each surface at a point corresponding to ).

The light transmission unit for LiDAR according to an exemplary embodiment of the present disclosure includes a single light sheet forming lens to minimize light loss due to light reflected in the process of refraction during light sheet formation, and By minimizing the loss, it is possible to increase the distance that the lidar to which the transmitter is applied can measure.

The light transmitter for lidar according to an exemplary embodiment of the present disclosure may simplify the assembly process by simplifying the structure of the light irradiation optical system and minimizing the number of parts, and may reduce manufacturing costs.

Since the light transmitting unit for LiDAR according to an exemplary embodiment of the present disclosure generates a light sheet through a light sheet forming lens made of a single lens, the components constituting the existing light sheet irradiation optical system are dropped and light is focused in one direction. It can prevent problems from occurring and ensure user safety.

1 is a configuration diagram of a lidar to which a light sheet irradiation optical system according to an exemplary embodiment of the present disclosure is applied.
2 is a configuration diagram of an optical axis-horizontal axis of a light sheet irradiation optical system according to an exemplary embodiment of the present disclosure.
3 is a front perspective view of a lens for forming an optical sheet according to an exemplary embodiment of the present disclosure.
4 is a diagram schematically illustrating a cross-section of an inner surface for explaining an inner surface according to an exemplary embodiment of the present disclosure.
5 is a diagram schematically illustrating a cross-section of an inner surface on an optical axis-vertical axis plane to describe an inner surface according to an exemplary embodiment of the present disclosure.
6 is a rear perspective view of a lens for forming an optical sheet according to an exemplary embodiment of the present disclosure.
7 is a view for explaining an inclination of an outer surface according to an exemplary embodiment of the present disclosure.
8A is a view showing the vertical axis-optical axis of light passing through the light sheet forming lens according to an exemplary embodiment of the present disclosure, and FIG. 8B is light passing through the light sheet forming lens according to an exemplary embodiment of the present disclosure. is a diagram showing the horizontal axis-optical axis.
9 is a graph illustrating the intensity of output light in the horizontal axis direction according to the horizontal axis direction spreading angle of light passing through the optical sheet forming lens according to an exemplary embodiment of the present disclosure.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The embodiments of the present invention are provided to more completely explain the present invention to those of ordinary skill in the art. Since the present invention may have various changes and may have various forms, specific embodiments will be illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to the specific disclosed form, it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention. In describing each figure, like reference numerals are used for like components. In the accompanying drawings, the dimensions of the structures are enlarged or reduced than the actual size for clarity of the present invention.

Terms used in the present disclosure are used only to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present disclosure, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification is present, but one or more other features It is to be understood that it does not preclude the possibility of the presence or addition of numbers, steps, operations, components, parts, or combinations thereof. Ordinal expressions such as "first ~" and "second ~" used in the present disclosure do not limit that "first ~" precedes "second ~", and are understood to be expressed differently in similar configurations. should be

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

1 is a configuration diagram of a lidar to which a light sheet irradiation optical system according to an exemplary embodiment of the present disclosure is applied.

Referring to FIG. 1 , a lidar 1 according to an exemplary embodiment of the present disclosure is a sensor capable of generating information on a target object 200 using laser light. The lidar 1 includes a light transmitter 100 and a light receiver 10 . The lidar 1 according to an embodiment of the present invention may transmit an optical signal generated by the optical transmitter 100 to the target object 200 . The optical signal reflected by the target object 200 may be received by the optical receiver 10 .

The lidar 1 according to an embodiment of the present invention determines the distance by using a round trip time in which the laser light signal transmitted from the light transmitter 100 is reflected from the object, and the reflected light signal is detected by the light receiver 10 . It may be a Time-of-Fight (ToF) type lidar that detects. However, the present invention is not limited thereto, and the lidar 1 may measure the distance in various ways, such as a method of calculating the distance using a triangulation method (Triangulation) and a method of calculating the distance by measuring the amount of phase change (Phase-shift).

The light transmitter 100 is configured to generate laser light and transmit it to the target object 200 . In this case, the light transmitter 100 may include a light source 110 for generating laser light and a light irradiation optical system for controlling a path of laser light incident from the light source 110 . The light transmission unit 100 for lidar according to an exemplary embodiment of the present disclosure may include a light irradiation optical system made of a light sheet forming lens.

The light transmitting unit 100 may include a light sheet forming lens 130 that is a single lens having a special shape for forming a light sheet. The light sheet forming lens 130 can form a light sheet having a wide angle (180° or more in the horizontal direction) with a small number of components compared to an optical system for forming an existing light sheet.

The light transmission unit 100 of the lidar 1 according to the present invention includes a light sheet forming lens 130 made of a single lens that minimizes the process of refraction of light when an optical signal is generated as a light irradiation optical system, so that light reflected in the process of refraction It is possible to improve the measurement distance of the lidar (1) by preventing the light loss due to the.

A detailed configuration of the optical transmitter 100 according to an embodiment of the present invention will be described below.

The light receiving unit 10 is configured to receive the laser light reflected from the target object 200 . For example, the light receiver 10 may convert light reflected and received from the target object 200 into an electrical signal (eg, current) using a photoelectric conversion element such as a photodiode. The light receiving unit 10 may include a light receiving optical system that adjusts the path of the reflected received light. For example, the light receiving optical system may include various lenses or mirrors, but is not limited thereto.

2 is a configuration diagram of the optical axis (Z)-horizontal axis (X) of the optical sheet irradiation optical system according to an exemplary embodiment of the present disclosure, and FIG. 3 is the front surface of the optical sheet forming lens according to an exemplary embodiment of the present disclosure. is a perspective view.

2 and 3 , the light transmission unit 100 for lidar according to an embodiment of the present invention may include a light source 110 and a light sheet forming lens 130 .

The light source 110 may be configured to emit pulsed light at regular time intervals. In addition, the light source 110 may be configured to emit light in an infrared band invisible to the human eye. For example, the light source 110 may be configured to emit light having a partial wavelength band selected from a band of about 800 nm to about 2,000 nm.

The light source 110 may be a pulse laser light source, but is not limited thereto. If the emission wavelength can be controlled within the tolerance range, the light source 110 may use an optoelectronic device that converts electrical energy such as a laser diode or a light emitting diode into light or a device having a similar light irradiation distribution as the light source 110. . These devices refer to devices in which the solid angle through which the emitted light spreads is not 0 in a state where there is no coupling of an additional optical system.

An axis passing through the center of the light emission surface through which light is emitted from the light source 110 and perpendicular to the light emission surface is defined as the optical axis Z. In addition, an arbitrary direction passing through the center of the light emission plane and perpendicular to the optical axis (Z) is defined as the horizontal axis (X), and an axis passing through the center of the light emission plane and perpendicular to the optical axis (Z) and the horizontal axis (X) is defined as the vertical axis (Y). . Here, when the distribution of the radiation intensity is not rotationally symmetrical about the optical axis (Z), the horizontal axis (X), the horizontal axis (X) and the optical axis (Z) are the directions with the widest spread angle measured based on the radiation intensity distribution. ) can be set as the vertical axis (Y) in a direction perpendicular to each other.

The light sheet forming lens 130 may form the light sheet 135 by adjusting the path of light generated from the light source 110 and incident to the light sheet forming lens 130 .

On the other hand, the light source 110 and the light sheet forming lens 130 may be formed in a shape fixed or coupled by the housing, but is not limited thereto. In addition, the light source 110 and the optical sheet forming lens 130 may be sequentially arranged to have the same optical axis Z. The optical axis Z refers to an axis that allows light to travel in the same direction regardless of the refractive index of the lens.

The optical sheet forming lens 130 refracts the laser light 115 emitted from the light source 110 in order to send the optical signal implemented by the optical sheet 135 to the target object 200, so that the vertical axis (Y) direction light spread angle A light sheet in which (θ1, see FIG. 8A ) is adjusted within the first angle range and the horizontal axis (X) direction light spread angle (θ2, see FIG. 8B ) is adjusted within the second angle range may be output.

Here, the spreading angle means an angle measured based on the full width at half maximum in terms of the light intensity according to the angle in the plane formed by the optical axis (Z), the horizontal axis (X), the optical axis (Z), and the vertical axis (Y).

The optical sheet forming lens 130 is refracted from the inner surface 131 into which the laser light 115 emitted from the light source 110 is refracted into the optical sheet forming lens 130 and the optical sheet forming lens 130 and emitted to the outside. It may be provided with an outer surface 133 that is.

The light source 110 may be disposed in the direction of the inner surface 131 , and the inner surface 131 may be disposed at a position facing the outer surface 133 .

The light sheet forming lens 130 may be formed as a single lens to minimize the refraction process in which light is refracted to form the light sheet 135 . The optical sheet forming lens 130 may define a refracting surface for refracting light by dividing the inner surface 131 and the outer surface 133 .

The optical sheet forming lens 130 may have a shape for mechanical fixing in addition to the refractive surface composed of the inner surface 131 and the outer surface 133 .

The light transmitting unit 100 for lidar according to an embodiment of the present disclosure includes a light sheet forming lens 130 composed of a single lens to form a light sheet, simplifying the structure of the light irradiation optical system and the number of parts It is possible to miniaturize the entire optical transmitter by minimizing

In addition, the light transmitting unit 100 for LiDAR according to an embodiment of the present disclosure is a light sheet (with only two refractions of the inner surface 131 and the outer surface 133) through the light sheet forming lens 130 made of a single lens. 135), it is possible to minimize the refraction process compared to the light irradiation optical system that transmits the light sheet through a plurality of refracting surfaces to form the light sheet. As the light transmitting unit 100 for lidar according to an embodiment of the present disclosure includes the optical sheet forming lens 130 with a minimized refractive surface, it is possible to reduce light loss due to reflection occurring in the refraction process, and this light transmitting unit ( Lidar (1) with 100) has the advantage that it is possible to measure a greater distance.

In the conventional optical system for generating a light sheet, a light sheet is formed by collecting light in the horizontal and vertical directions using a convex lens, and then diffusing the light again in the horizontal direction. In the conventional optical system for generating a light sheet, when a component is partially removed, light of strong intensity is emitted in one direction, and there is a risk of damaging a part of the body, particularly the retina and cornea of the eye. On the other hand, since the optical sheet forming lens 130 according to an embodiment of the present disclosure is made of a single lens, a problem in which a part of the components is dropped does not occur, so the light transmitting unit 100 according to an embodiment of the present disclosure It is possible to increase the safety of use of the applied lidar. In addition, even if the optical sheet forming lens 130 itself according to an embodiment of the present disclosure is removed, the light source 110 projects the laser light 115 traveling in parallel, so that light of strong intensity focused in one direction is not emitted. In this respect, it is possible to prevent safety problems caused by emitting light of strong intensity in one direction in the conventional light irradiation optical system.

Specifically, the inner surface 131 of the optical sheet forming lens 130 refracts the laser light 115 incident from the light source 110 to focus the light in the vertical axis (Y) direction, and The outer surface 133 may be formed to refract light emitted to the outside from the optical sheet forming lens 130 to diffuse the light in the horizontal axis (X) direction.

When the laser light 115 projected by the light source 110 is incident on the inner surface 131 of the optical sheet forming lens 130 in parallel to the optical axis Z, the spreading angle in the vertical axis Y direction is in the first angle range. The light in the horizontal axis (X) direction may be focused so as to be collected.

Since the optical sheet forming lens 130 according to an embodiment of the present disclosure collects light in the vertical direction on the inner surface 131, it is not necessary to provide a separate convex lens to form the light sheet, thereby simplifying the light irradiation optical system. can do.

The light passing through the inner surface 131 of the optical sheet forming lens 130 may be focused so that a spreading angle of the light in the vertical axis (Y) direction may be collected within the first angle range. Here, the first angle range represents a range of 0° or more and 10° or less.

That is, the laser light 115 emitted from the light source 110 is refracted while passing through the inner surface 131 of the optical sheet forming lens 130 to be focused so that the spreading angle of the vertical axis Y is 0° or more and 10°. can

To this end, the inner surface 131 of the optical sheet forming lens 130 may be formed in the shape of a convex lens cross-section with respect to the vertical axis (Y)-optical axis (Z) plane. However, the present invention is not limited thereto and may be formed in various shapes capable of focusing parallel incident light.

The outer surface 133 of the optical sheet forming lens 130 has a horizontal axis (X) direction so that when the light passing through the inner surface 131 is emitted to the outside, the spreading angle in the horizontal axis (X) direction spreads to a second angle range. light can be diffused.

The light passing through the outer surface 133 of the optical sheet forming lens 130 may be diffused so that the spreading angle of the light in the horizontal axis (X) direction may be spread in the second angle range. Here, the second angle range represents a range of 0° or more and 200° or less.

That is, the light sheet 135 , which is light emitted to the outside from the light sheet forming lens 130 , is refracted while passing through the outer surface 133 of the light sheet forming lens 130 so that the spreading angle of the horizontal axis X is 0° or more It can be diffused to be 200°.

At this time, the outer surface 133 of the optical sheet forming lens 130 may be formed in various shapes that can diffuse incident light in parallel with a cross section with respect to the horizontal axis (X)-optical axis (Z) plane.

The existing optical sheet generating optical system collects the laser light emitted from the light source in the horizontal and vertical directions using a convex lens, and then spreads the light in the horizontal direction using a diffusion lens having a plurality of refracting surfaces. The components for generating the light sheet are complex, and there are many problems with the refraction process. In contrast, in the optical sheet forming lens 130 according to an embodiment of the present disclosure, the inner surface 131 collects the light in the vertical direction of the laser light 115 emitted from the light source 110 , and the outer surface 133 . The light irradiation optical system can be simplified in that the light sheet 135 can be generated by diffusing the light in the horizontal direction, thereby minimizing light lost in the refraction process.

On the other hand, the optical sheet forming lens 130 capable of forming a light sheet with only a single lens according to an exemplary embodiment of the present disclosure may be combined with an additional refractive and reflective optical system if necessary. The light transmitter 100 may further include an optical system capable of changing the path of the light of the light sheet emitted from the light sheet forming lens 130 . For example, by combining an additional diffusion lens with the optical sheet-forming lens 130, the spreading angle of the light sheet generated from the optical sheet-forming lens 130 can be increased, and the optical sheet-forming lens 130 by combining an additional reflective mirror. You can change the angle of the light sheet generated from

4 is a diagram schematically illustrating an inner surface cross-section on an optical axis (Z)-vertical axis (Y) plane to describe an inner surface according to an exemplary embodiment of the present disclosure, and FIG. 5 is an exemplary embodiment of the present disclosure; It is a diagram schematically showing a cross-section of an inner surface for explaining an inner surface according to an example.

Referring to FIG. 4 , the inner surface 131 of the optical sheet forming lens 130 may be formed to reduce the light spread angle in the vertical axis (Y) direction. To this end, the inner surface 131 may be formed in the shape of a convex lens having a cross-section (C) with respect to the optical axis (Z)-vertical axis (Y) plane. The cross-section (C) of the inner surface 131 with respect to the optical axis (Z)-vertical axis (Y) plane may be expressed in the form of the following [Equation 1] of a spherical surface, an aspherical surface, or a free-form lens.

The inner surface 131 of the optical sheet forming lens has a cross-section (C) and z (r) of the inner surface 131 according to a distance (r) deviating from the optical axis (Z) with respect to the optical axis (Z)-vertical axis (Y) plane It may be formed to have a distance. The optical axis (Z) of the inner surface 131 - the cross section (C) with respect to the vertical axis (Y) plane forms a distance z (r) to the reference plane calculated based on [Equation 1] below, while one point is connected to each other It may be formed to have a shape.

[Equation 1]

는 원뿔 상수(comic comstamt),

n는 비구면 계수를 의미한다.where r is the distance away from the optical axis (Z), R is the radius of curvature at the point where r = 0,

is the conic constant,

n means an aspherical coefficient.

에서

까지를 시뮬레이션에 사용)를 시뮬레이션에 사용할 수 있고, 내측면(131)이 자유형 렌즈로 형성된 경우에는 광축(Z)에서 거리 r 값에 따른 거리

을 임의의 수식 혹은 포인트 별 데이터 값으로 사용할 수 있다. 구면<비구면<자유형의 순으로 곡면의 형상을 나타내는 파라미터의 수가 늘어난다. 내측면(131)의 곡면의 형상에 따라 즉, 구면<비구면<자유형 순으로 내측면(131)의 퍼짐각 조절 범위가 커질 수 있다.Mathematically, when the inner surface 131 is formed as a spherical surface, one coefficient may be used for simulation. When the inner surface 131 is formed as an aspherical surface, the parameters shown in Equation 1 are part of the coefficient (

at

up to) can be used for the simulation, and when the inner surface 131 is formed of a free-form lens, the distance according to the distance r value from the optical axis (Z)

can be used as an arbitrary formula or data value for each point. The number of parameters representing the shape of the curved surface increases in the order of spherical <aspheric <freestyle. According to the shape of the curved surface of the inner surface 131 , that is, the range of adjusting the spreading angle of the inner surface 131 may be increased in the order of spherical <aspheric <freestyle.

Referring to FIG. 5 , the cross section C of the inner surface 131 with respect to the optical axis (Z)-vertical axis (Y) plane is a circle or ellipse on the optical axis (Z)-horizontal axis (X) plane shown by a dotted line in FIG. 5 . It may be formed in a shape tangent to a curve such as

6 is a rear perspective view of a lens for forming a light sheet according to an exemplary embodiment of the present disclosure, and FIG. 7 is a view for explaining an inclination of an outer surface according to an exemplary embodiment of the present disclosure.

6 and 7 , the outer surface 133 of the optical sheet forming lens 130 may be formed to adjust the spreading angle of light in the horizontal axis (X) direction.

)를 갖는 각각의 일 지점이 서로 연결된 형태로 형성될 수 있다.The outer surface 133 of the optical sheet forming lens 130 is the slope of the curved surface obtained through [Equation 2] and [Equation 3] (

) may be formed in a form in which each point having a point is connected to each other.

에 따른 세기를

이라 하고, 외측면(133)을 통해 굴절되어 방출되는 광의 각도

에 대해 요구되는 빛의 세기를

이라 할 때, 각도

과 각도

은 다음 [수학식 2]을 만족한다.The angle of the light that has passed through the inner surface 131 is projected on the optical axis (Z)-horizontal axis (X)

century according to

The angle of the light refracted and emitted through the outer surface 133

the required light intensity for

When , the angle

and angle

satisfies the following [Equation 2].

[Equation 2]

은 내측면을 통과해 나온 빛의 광축(Z)-수평축(X) 상에 투영된 빛의 각도,

는

에 따른 빛의 세기,

는 외측면을 통해 굴절되어 방출되는 빛의 각도,

는

에 대해 요구되는 빛의 세기를 나타내고,

은

에 해당하는 지점에서의 곡면의 기울기를 나타낸다.here,

is the angle of the light projected on the optical axis (Z)-horizontal axis (X) of the light passing through the inner surface,

Is

light intensity according to

is the angle of the light that is refracted and emitted through the outer surface,

Is

represents the required light intensity for

silver

It represents the slope of the curved surface at the point corresponding to .

의 관계를 함수

를 얻을 수 있고, 이를 이용해

에 해당하는 지점에서의 각 곡면의 기울기(

)를 하기 [수학식 3]을 통해 찾을 수 있다.In addition, from the above [Equation 2]

the relationship of the function

can be obtained, and using

The slope of each surface at the point corresponding to (

) can be found through the following [Equation 3].

[Equation 3]

)를 갖는 각각의 일 지점이 서로 연결된 형태로 형성될 수 있다.The shape of the outer surface 133 of the optical sheet forming lens 130 is the slope of the curved surface obtained using [Equation 3] (

) may be formed in a form in which each point having a point is connected to each other.

에 따른 빛의 세기 함수

에 포함된다. 예를 들어

에서 빛의 세기가 0이 아닌 각도를

가 되도록

의 함수 값을 설정해주면,

과

의 관계가 함수

와 같이 계산이 될 수 있다. 이러한 수식을 만족시키기 위한 외측면(133)의 기울기(

))는 [수학식 3]을 통해서 계산될 수 있다.The horizontal spread angle controlled by the outer surface 133 is the emission angle used in [Equation 2]

light intensity function according to

included in for example

At an angle where the light intensity is non-zero

to become

If you set the function value of

class

the relationship of the function

can be calculated as The slope of the outer surface 133 to satisfy this formula (

)) can be calculated through [Equation 3].

8A is a view showing light passing through the optical sheet forming lens according to an exemplary embodiment of the present disclosure with respect to the vertical axis (Y)-optical axis (Z), and FIG. 8B is a light sheet according to an exemplary embodiment of the present disclosure. It is a view showing the light passing through the forming lens with respect to the horizontal axis (X)-optical axis (Z).

Referring to FIGS. 8A and 8B , in the light sheet 135 emitted from the light sheet forming lens 130 according to an embodiment of the present disclosure, the spreading angle θ1 in the vertical axis Y direction is the first angle range. , and a spreading angle θ2 in the horizontal axis (X) direction may spread in the second angle range.

In the vertical axis (Y)-optical axis (Z) plane, light incident on the optical sheet forming lens 130 is refracted to be condensed by the inner surface 131 , so that the vertical axis (Y) direction spread angle θ1 is in the first angle range It is possible to form a light sheet 135 having a. Here, the first angle range represents a range of 0° or more and 10° or less.

In the horizontal axis (X)-optical axis (Z) plane rotated by 90° with respect to the optical axis (Z) in the vertical axis (Y)-optical axis (Z) plane, the light emitted from the optical sheet forming lens 130 to the outside is the outer surface ( 133) to form a light sheet 135 having a horizontal axis (X) direction spread angle θ2 having a second angle range. Here, the second angle range represents a range of 0° or more and 200° or less.

As an example, the light sheet 135 may have a vertical axis (Y) direction spread angle θ1 of 0°, and a horizontal axis (X) direction spread angle θ2 may be formed of 110°.

9 is a graph illustrating the intensity of output light in the horizontal axis (X) direction according to the horizontal axis (X) direction spreading angle of light passing through the optical sheet forming lens according to an exemplary embodiment of the present disclosure.

Referring to FIG. 9 , looking at the light intensity distribution of the light sheet formed by the light sheet forming lens 130 according to an exemplary embodiment of the present disclosure, the horizontal spread angle is within the range of -50° or more and +50° or less. An optical signal is being emitted. Accordingly, the optical sheet forming lens 130 may form the optical sheet 135 having a horizontal spreading angle of 100°, and depending on the shape of the optical sheet forming lens 130 , the vertical axis Y of the optical signal or The spreading angle in the horizontal axis (X) direction can be adjusted.

Exemplary embodiments have been disclosed in the drawings and specification as described above. Although embodiments have been described using specific terms in the present specification, these are used only for the purpose of explaining the technical spirit of the present disclosure and not used to limit the meaning or the scope of the present disclosure described in the claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Accordingly, the true technical protection scope of the present disclosure should be defined by the technical spirit of the appended claims.

1: lidar 100: optical transmitter
110: light source 130: optical sheet forming lens
131: inner surface 133: outer surface

Claims (8)

In the light transmitter for lidar,
a light source for generating light; and
It is disposed on one side of the light source, adjusts the vertical axis (Y) direction spreading angle through the inner surface of the light incident from the light source within the first angle range, the horizontal axis (X) direction spread angle through the outer surface is a second Including; a light sheet forming lens for generating a light sheet by adjusting within the angle range;
When the incident light is incident parallel to the optical axis (Z) on the inner surface, the optical axis (Z)- A cross section with respect to the vertical axis (Y) plane is formed in the shape of a convex lens,
The outer surface, when the light passing through the inner surface is emitted to the outside, the optical axis (Z)- The light transmitter for lidar, characterized in that the central portion in the horizontal axis (X) plane is formed in a flat shape closer to the inner surface than the other portions of the outer surface. According to claim 1,
The optical sheet forming lens,
Light transmission unit for lidar, characterized in that it consists of a single lens having a refracting surface consisting of the inner surface and the outer surface. According to claim 1,
The inner surface of the optical sheet forming lens,
The light transmitting unit for lidar, characterized in that by refracting the light incident from the light source to adjust the spread angle in the vertical axis (Y) direction to be in the range of 0° or more and 10° or less. According to claim 1,
The outer surface of the optical sheet forming lens,
A light transmitting unit for lidar, characterized in that by refracting the light emitted to the outside from the optical sheet forming lens to adjust the spreading angle in the horizontal axis (X) direction to be in the range of 0° or more and 200° or less. delete According to claim 1,
The cross section of the inner surface of the optical sheet forming lens with respect to the optical axis (Z)-vertical axis (Y) plane is,
A light transmitter for lidar, characterized in that it is formed in a shape in contact with a curve such as a circle or an ellipse on the horizontal axis (X)-optical axis (Z) plane. According to claim 1,
The inner surface of the optical sheet forming lens,
Optical axis (Z) - Based on the following [Equation 1], the inner surface to have a z (r) distance from the cross section of the inner surface according to the distance r away from the optical axis (Z) with respect to the vertical axis (Y) plane The cross-section of has a form in which one point is connected to each other while forming a distance z(r) from the cross-section of the inner surface of the optical sheet forming lens to the reference plane calculated based on the following [Equation 1]
[Equation 1]

(where r is the distance away from the optical axis (Z), R is the radius of curvature at the point where r = 0,

is the conic constant,

n is the aspheric coefficient)
Light transmitter for lidar, characterized in that. According to claim 1,
The outer surface of the optical sheet forming lens,
The angle projected on the optical axis (Z)-horizontal axis (X) of the light passing through the inner surface of the optical sheet forming lens (

) according to the light intensity (

) and the angle refracted and emitted through the outer surface (

) according to the light intensity (

) to satisfy the condition of Equation 2 below, the slope of the curved surface at a point corresponding to the angle of incidence calculated based on Equation 3 below.

Each point has a shape connected to each other while forming
[Equation 2]

(here,

is the angle of the light projected on the optical axis (Z)-horizontal axis (X) of the light passing through the inner surface,

Is

light intensity according to

is the angle of the light that is refracted and emitted through the outer surface,

Is

light intensity required for
[Equation 3]

(here,

silver

slope of each surface at a point corresponding to )
Light transmitter for lidar, characterized in that.

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