CN116794844A - Optical system and detection system - Google Patents

Abstract

The application discloses an optical system and a detection system. The optical system includes: a collimating optical element that collimates the target beam into parallel light; a splitting optical element splitting the parallel light into a plurality of point light sources; and a diverging optical element diverging the plurality of point light sources to form a diverging light beam. The detection system comprises a receiving unit and the optical system, wherein the optical system emits the divergent light beam to a target scene, and the receiving unit receives the light beam of the divergent light beam reflected by the target scene. According to the optical system and the detection system provided by the embodiment of the application, the parallel light formed by collimating the target light beam through the collimating optical element can be divided into the plurality of point light sources through the dividing optical element, and then the diverging optical element diverges the point light sources to form the diverging light beam with a large emergent view angle, so that a high resolution can be obtained without adopting an emitting light source with a large light emitting area, and meanwhile, the cost is reduced.

Description

Optical system and detection system

Technical Field

The application relates to the technical field of optical elements, in particular to an optical system and a detection system.

Background

Lenses are an indispensable component in machine vision systems, and are widely used in many fields. For example, the reversing image, 360-degree panorama or automatic driving assistance, laser radar detection and the like in the automobile field can be used as lenses, and the positioning assembly, automatic detection and the like in the industrial field can also be used as optical lenses.

For laser radar detection, it is necessary to match the current emission lens with an emission light source with a larger light emitting area, such as a VCSEL (Vertical Cavity Surface Emitting Laser) area array light source, in order to obtain higher resolution. However, the larger the area of the emission light source, the more the number of point light sources, which not only results in significant increase in cost, but also is limited by the processing and manufacturing process, and the number of point light sources which fail during the process of manufacturing the emission light source is increased, thereby affecting the subsequent detection.

Disclosure of Invention

An optical system according to an embodiment of the first aspect of the present application includes:

a collimating optical element that collimates the target beam into parallel light;

a splitting optical element splitting the parallel light into a plurality of point light sources; and

and a divergent optical element for diverging the plurality of point light sources to form divergent light beams.

According to one embodiment of the present application, the plurality of point light sources are distributed in an area array.

According to one embodiment of the present application, the dividing optical element includes at least one microlens array, each of the microlens arrays includes a plurality of microlenses, and the plurality of point light sources are in one-to-one correspondence with the plurality of microlenses.

According to one embodiment of the present application, a ratio of a diameter of the microlens to a focal length of the microlens is not less than 0.1.

According to one embodiment of the present application, the diameter of the microlens and the focal length of the microlens satisfy the following formula:

wherein D is ₂ F is the diameter of the microlens ₂ Is the focal length of the microlens.

According to one embodiment of the application, the collimating optical element comprises at least one collimating lens.

According to one embodiment of the present application, the surface shape of the collimating lens is a spherical surface, an aspherical surface or a free-form surface.

According to one embodiment of the present application, the split optical element includes at least one microlens array including a plurality of microlenses, and the focal length of the collimating lens is not less than the focal length of the microlenses of the microlens array.

According to one embodiment of the application, the segmented optical element comprises at least one microlens array comprising a plurality of microlenses; the diameter of the micro lens is not more than 0.7 times of the diameter of the collimating lens.

According to one embodiment of the application, the diameter of the collimating lens and the exit field angle of the diverging optical element satisfy the following formula:

wherein D is ₁ And θ is the outgoing field angle of the divergent optical element, which is the diameter of the collimator lens.

According to one embodiment of the application, the optical system further comprises: and an emission light source for generating and emitting the target light beam.

According to one embodiment of the application, the collimating optical element comprises at least one collimating lens having a diameter not smaller than 3 times the emission diameter of the emitting light source.

According to one embodiment of the application, the collimating optical element comprises at least one collimating lens, the emitting diameter of the emitting light source being not more than half the focal length of the collimating lens.

According to one embodiment of the application, the collimating optical element comprises at least one collimating lens, the product of the emission diameter of the emitting light source and its divergence angle being not more than 7 times the diameter of the collimating lens or the focal length of the collimating lens.

According to one embodiment of the application, the collimating optical element comprises at least one collimating lens, the diameter of the collimating lens being not less than half the pitch between the first side of the collimating lens and the emitting light source, and the diameter of the collimating lens being not more than 2 times the pitch between the first side of the collimating lens and the emitting light source;

the first side of the collimating lens is the side of the collimating lens facing the emitting light source.

According to one embodiment of the application, the collimating optical element comprises at least one collimating lens, the splitting optical element comprises at least one microlens array, and the spacing between the first side of the collimating lens and the emitting light source is not greater than the spacing between the first side of the microlens array and the emitting light source;

the first side of the collimating lens is the side of the collimating lens facing the emitting light source; the first side of the microlens array is the side of the microlens array facing the collimating lens.

According to one embodiment of the application, the collimating optical element comprises at least one collimating lens, the splitting optical element comprises at least one microlens array, the diameter of the collimating lens is not less than 0.2 times the spacing between the first side of the microlens array and the emitting light source, and the diameter of the collimating lens is not more than 3 times the spacing between the first side of the microlens array and the emitting light source;

the first side of the collimating lens is the side of the collimating lens facing the emitting light source; the first side of the microlens array is the side of the microlens array facing the collimating lens.

According to one embodiment of the application, the collimating optical element comprises at least one collimating lens, the splitting optical element comprises at least one microlens array, a spacing between a second side of the microlens array and the diverging optical element is not less than 0.1 times a spacing between a first side of the microlens array and the emitting light source, and a spacing between a second side of the microlens array and the diverging optical element is not more than 1.5 times a spacing between a first side of the microlens array and the emitting light source;

the first side of the micro lens array is the side of the micro lens array facing the collimating lens, and the second side of the micro lens array is the side of the micro lens array facing away from the collimating lens.

According to one embodiment of the application, the collimating optical element comprises at least one collimating lens, the splitting optical element comprises at least one microlens array comprising a plurality of microlenses, the diameter of the microlenses, the focal length of the microlenses, and the spacing between the first side of the microlens array and the emitting light source satisfying the following formula:

wherein D is ₂ Is the diameter of the micro lens, F ₂ L is the focal length of the microlens ₂ The first side of the microlens array is the side of the microlens array facing the collimating lens, which is the distance between the first side of the microlens array and the emitting light source.

An optical system according to an embodiment of the second aspect of the present application includes:

the optical system according to the first aspect of the present application is configured to emit the divergent light beam toward a target scene; and

and the receiving unit is used for receiving the beam of the divergent beam reflected by the target scene.

According to the optical system and the detection system provided by the embodiment of the application, the parallel light formed by collimating the target light beam through the collimating optical element can be divided into the plurality of point light sources through the dividing optical element, and then the diverging optical element diverges the point light sources to form the diverging light beam with a large emergent view angle, so that a high resolution can be obtained without adopting an emitting light source with a large light emitting area, and meanwhile, the cost is reduced.

It should be understood that the description in this section is not intended to identify key or critical features of the embodiments of the application or to delineate the scope of the application. Other features of the present application will become apparent from the description that follows.

Drawings

Other features, objects and advantages of the present application will become more apparent upon reading of the detailed description of non-limiting embodiments made with reference to the following drawings. The drawings are included to provide a better understanding of the present application and are not to be construed as limiting the application. In the drawings:

FIG. 1 is a schematic diagram of one of the optical systems according to the present application;

FIG. 2 is a schematic diagram of another optical system according to the present application;

FIG. 3 is a schematic diagram of the working principle of an optical system according to the present application;

fig. 4 is an enlarged view of fig. 3 at a;

fig. 5 is a schematic view of the structure of an emission light source according to the present application.

Reference numerals:

100. a collimating optical element; 200. dividing the optical element; 201. a microlens;

300. a diverging optical element; 400. an emission light source; 401. a semiconductor light source;

501. point light sources.

Detailed Description

In the description of the embodiments of the present application, it should be noted that the positional or state relation indicated by the terms "left", "right", etc. is based on the positional or state relation shown in the drawings, and is merely for convenience in describing the embodiments of the present application and simplifying the description, and does not indicate or imply that the apparatus or element referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the embodiments of the present application. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In describing embodiments of the present application, it should be noted that, unless explicitly stated and limited otherwise, the terms "coupled," "coupled," and "connected" should be construed broadly, and may be either a fixed connection, a removable connection, or an integral connection, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium. The specific meaning of the above terms in embodiments of the present application will be understood in detail by those of ordinary skill in the art.

Exemplary embodiments of the present application will now be described with reference to the accompanying drawings, in which various details of the embodiments of the present application are included to facilitate understanding, and are to be considered merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the application. Also, descriptions of well-known functions and constructions are omitted in the following description for clarity and conciseness.

It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other. The application will be described in detail below with reference to the drawings in connection with embodiments.

As shown in conjunction with fig. 1 to 4, an embodiment of the present application provides an optical system including a collimating optical element 100, a dividing optical element 200, and a diverging optical element 300; the collimating optical element 100 collimates the target beam into parallel light, the dividing optical element 200 divides the parallel light into a plurality of point light sources 501, and the diverging optical element 300 diverges the plurality of point light sources 501 to form a diverging beam.

The optical system of the application can divide the parallel light formed by the collimation of the target beam by the collimation optical element 100 into a plurality of point light sources 501 by arranging the dividing optical element 200, and then the divergent optical element 300 is used for diverging each point light source 501 to form a divergent light beam with a large emergent view angle theta, thereby obtaining higher resolution without adopting the emission light source 400 with a larger light emitting area, and reducing the cost.

It should be noted that the optical system in the embodiment of the present application may be applied to a general optical lens, a radar emission lens, or a projection lens. Of course, the optical system in the embodiment of the present application is not limited to the above-described several application objects. Taking different application objects as examples, the working principle of the optical system in the embodiment of the application is described below:

for example, the application object is a general optical lens. The general optical lens includes the above-described collimating optical element 100, dividing optical element 200, and diverging optical element 300. In this case, the side of the collimating optical element 100 facing away from the splitting optical element 200, i.e. the left side of the collimating optical element 100 in fig. 1, is the object side, and the side of the diverging optical element 300 facing away from the splitting optical element 200, i.e. the right side of the diverging optical element 300 in fig. 1, is the image side. As shown in fig. 3, after the target beam emitted from the external emission light source 400 is incident into the optical lens, the target beam irradiates the collimating optical element 100 and is collimated into parallel light by the collimating optical element 100, the parallel light irradiates the splitting optical element 200 and is split into a plurality of point light sources 501, and finally the plurality of point light sources 501 are diverged by the diverging optical element 300 to form a diverging beam having a large exit angle θ. It can be seen that, even though the light emitting area of the external light emitting source 400 is small, since the object beam emitted from the external light emitting source 400 is sequentially collimated and split after being incident into the optical lens, a plurality of point light sources 501 are formed, and each point light source 501 is diverged to form a divergent light beam having a large emission angle θ, and the area of the divergent light beam projected on the imaging surface is large, the resolution of the final imaging obtained by the divergent light beam is high. For example, if a photosensitive element, such as a photosensitive chip, is disposed on the side of the diverging optical element 300 facing away from the dividing optical element 200, a high resolution image can be obtained after the diverging light beam is projected onto the photosensitive chip, i.e., the imaging surface.

As another example, the application object is a radar-emitting lens of a radar system, which comprises, in addition to the above-described collimating optical element 100, dividing optical element 200 and diverging optical element 300, an emitting light source 400 for generating and emitting a target light beam. As shown in fig. 5, the emission light source 400 may include, but is not limited to, at least one semiconductor light source 401, and the semiconductor light source 401 includes a Laser Diode (LD) or a VCSEL light source. In this case, the side of the emission light source 400 facing away from the collimating optical element 100, i.e. the left side of the emission light source 400 in fig. 1, is the imaging side, and the side of the diverging optical element 300 facing away from the splitting optical element 200, i.e. the right side of the diverging optical element 300 in fig. 1, is the image source side. As shown in fig. 3, the emission light source 400 emits the generated target light beam, that is, the laser light, to the collimating optical element 100, the target light beam is collimated into parallel light by the collimating optical element and then emitted to the splitting optical element 200, the parallel light is split into a plurality of point light sources 501 by the splitting optical element 200 and emitted to the diverging optical element 300, the plurality of point light sources 501 are diverged by the diverging optical element 300 to form a diverging light beam having a large exit angle θ, and then emitted from the radar emission lens, and finally irradiated to the target scene, and the light beam reflected by the target scene is received by a receiving unit of the radar system, for example, a receiving lens. As can be seen, even though the light emitting area of the light emitting source 400 of the radar emission lens is small, due to the presence of the splitting optical element 200, the target light beam emitted from the light emitting source 400 is collimated into parallel light by the collimating optical element 100, and then split into multiple point light sources 501 by the splitting optical element 200, and each point light source 501 is diverged by the diverging optical element 300 to form a diverging light beam with a large exit field angle θ, and the area of the diverging light beam projected on the target scene after being emitted from the radar emission lens is large, so that the detection field of view can be enlarged and the resolution can be improved.

For another example, the application object is a projection lens, which includes an emission light source 400 for generating and emitting a target light beam, in addition to the above-described collimating optical element 100, dividing optical element 200, and diverging optical element 300. The emission light source 400 may include, but is not limited to, at least one semiconductor light source 401, and the semiconductor light source 401 includes a Laser Diode (LD) or a VCSEL light source. In this case, the side of the emission light source 400 facing away from the collimating optical element 100, i.e. the left side of the emission light source 400 in fig. 1, is the imaging side, and the side of the diverging optical element 300 facing away from the splitting optical element 200, i.e. the right side of the diverging optical element 300 in fig. 1, is the image source side. As shown in fig. 3, an emission light source 400 directs a generated target beam toward the collimating optical element 100; wherein the target beam may include, but is not limited to, at least one of red light, blue light, and green light. The target light beam is collimated by the collimating optical element 100, then directed to the dividing optical element 200, the parallel light is divided by the dividing optical element 200 into a plurality of point light sources 501, then directed to the diverging optical element 300, and the plurality of point light sources 501 are diverged by the diverging optical element 300 to form a diverging light beam having a large exit angle θ, then emitted from the projection lens, and finally projected to the target scene. It can be seen that, even though the light emitting area of the emission light source 400 of the projection lens is small, due to the presence of the splitting optical element 200, the target light beam emitted from the emission light source 400 is collimated into parallel light by the collimating optical element 100, and then split into multiple point light sources 501 by the splitting optical element 200, and each point light source 501 is diverged by the diverging optical element 300 to form a diverging light beam with a large exit field angle θ, and the projection area of the diverging light beam on the target scene after being emitted from the projection lens is large, so that the resolution can be improved.

In some embodiments, the multiple point light sources 501 are distributed in an area array, that is, the multiple point light sources 501 are located on the same plane or curved surface. As an example, as shown in fig. 3, a plurality of point light sources 501 are distributed in a rectangular array.

In some embodiments, diverging optical element 300 includes at least one diverging lens. When the number of divergent lenses is plural, the plural divergent lenses are sequentially arranged at intervals along the optical path direction of the point light source 501. The diverging lens can be either a spherical lens or an aspherical lens or a free-form surface lens, and the diverging lens can be, but is not limited to, a glass lens or a plastic lens. If the application scene has certain requirements on the quality of the divergent lens, the divergent lens can be an aspheric lens; if the application scene has certain requirements on the temperature resistance of the divergent lens, the divergent lens can be a glass lens.

As shown in fig. 1 and 3, the split optical element 200 may include, but is not limited to, at least one microlens array, each including a plurality of microlenses 201, a plurality of point light sources 501 corresponding one-to-one to the plurality of microlenses 201, that is, the same number of point light sources 501 as the number of microlenses 201. When the number of the microlens arrays is plural, the plural microlens arrays are sequentially arranged at intervals along the optical path direction of the parallel light. Wherein the plurality of microlenses 201 can be, but are not limited to, distributed in a rectangular array, a circular array, or an elliptical array. The center of the micro lens array is taken as an origin to establish a three-dimensional coordinate system, the z axis of the three-dimensional coordinate system is parallel to the optical axis of the micro lens array, the z axis, the x axis and the y axis are perpendicular to each other, and the number of micro lenses 201 of the micro lens array along the x axis direction can be the same as or different from the number of micro lenses 201 of the micro lens array along the y axis direction. For example, when the plurality of microlenses 201 are distributed in a rectangular array, the x-axis is parallel to one side of the rectangular array and the y-axis is parallel to the other side of the rectangular array: if the number of the microlenses 201 in the x-axis direction and the y-axis direction of the microlens array is the same, the rectangular array is a square array; if the number of microlenses 201 in the x-axis direction and in the y-axis direction of the microlens array is different, the rectangular array is a rectangular array. Further, the focal length of the microlens 201 in the x-axis direction and the focal length thereof in the y-axis direction may be the same or different, and the convergence of the point light sources 501 is similar to astigmatism when the two are different. As an example, the side of the micro-lens 201 facing the collimating optical element 100 is convex, and the side of the micro-lens 201 facing away from the collimating optical element 100 is planar or concave. Of course, both of the opposite surfaces of the microlens 201 may be convex.

In the case where the diameter of the microlens 201 is constant, the diameter D of the microlens 201 is used for convenience in matching with other components in the optical system ₂ And microlens 201Of F (F) (focal length of F) ₂ At least one of the following conditions may be satisfied:

condition one, diameter D of microlens 201 ₂ Focal length F with microlens 201 ₂ The ratio is not less than 0.1, i.e. D ₂ /F ₂ Not less than 0.1, wherein D ₂ F is the diameter of the microlens 201 ₂ Is the focal length of the microlens 201. This has the advantage that the range of focal lengths of the microlenses 201 can be limited with a certain diameter of the microlenses 201, thereby further facilitating matching of the microlenses 201 with other components within the optical system. As an example, D ₂ /F ₂ And is more than or equal to 0.2. For example, as shown in FIG. 1, D ₂ ＝1.1mm，F ₂ ＝1.965mm，D ₂ /F ₂ = 0.2799. As another example, as shown in fig. 2, D ₂ ＝1.1mm，F ₂ ＝2.063mm，D ₂ /F ₂ ＝0.267。

Condition two, diameter D of microlens 201 ₂ Focal length F with microlens 201 ₂ The following formula is satisfied:

wherein D is ₂ F is the diameter of the microlens 201 ₂ Is the focal length of the microlens 201. This has the advantage of facilitating the mating of the split optical element 200 with the diverging optical element 300.

As an example of this, the number of devices,for example, as shown in FIG. 1, D ₂ ＝1.1mm，As another example, as shown in fig. 2, D ₂ ＝1.1mm，

In some embodiments, the collimating optical element 100 includes at least one collimating lens. When the number of the collimating lenses is plural, the plural collimating lenses are sequentially arranged at intervals along the optical path direction of the target beam. The present application can collimate a plurality of point light sources 501 formed by dividing the dividing optical element 200 into a plurality of parallel light beams having different light path directions by using the collimating optical element 100 including at least one collimating lens, thereby realizing long-distance detection.

The surface shape of the collimating lens can be, but is not limited to, a spherical surface, an aspherical surface or a free-form surface. The present application is not limited to the type of the collimator lens, and the collimator lens may be of a rotationally symmetrical structure or a biconic structure, that is, the type of the collimator lens is not limited to the above types. And establishing a three-dimensional coordinate system by taking the center of the collimating lens as an origin, wherein the z-axis of the three-dimensional coordinate system is parallel to the optical axis of the collimating lens, and the z-axis, the x-axis and the y-axis are perpendicular to each other. The collimating lens is in a rotationally symmetrical structure, namely the collimating lens is a revolution body taking a z axis as a symmetry axis, and the focal length of the collimating lens along the x axis direction is equal to the focal length of the collimating lens along the y axis direction; the collimating lens is of a biconic structure, namely, the collimating lens is symmetrical with respect to the z axis in the x axis direction and the y axis direction respectively, but the focal length of the collimating lens along the x axis direction is unequal to the focal length of the collimating lens along the y axis direction. As shown in fig. 1 and 2, the side of the collimator lens facing away from the dividing optical element 200 may be a flat surface or a convex surface. The collimating lens may be a spherical lens, an aspherical lens, or a free-form surface lens, and may be, but not limited to, a glass lens or a plastic lens. If the application scene has certain requirements on the quality of the collimating lens, the collimating lens can be an aspheric lens; if the application scene has a certain requirement on the temperature resistance of the collimating lens, the collimating lens can be a glass lens.

In the case where the split optical element 200 includes a microlens array, in order to be able to improve resolution, the parameters related to the microlenses 201 and the collimator lenses may satisfy at least one of the following conditions:

focal length F of the collimator lens ₁ Not less than the focal length F of the microlens 201 of the microlens array ₂ I.e. F ₁ /F ₂ 1 or more; wherein F is ₁ To collimate the focal length of the lens, F ₂ Is a microlens 201Focal length. The arrangement can increase the number of microlenses 201 that participate in splitting parallel light, thereby increasing the number of point light sources 501 and improving resolution. As an example, F ₁ /F ₂ And is more than or equal to 1.5. For example, as shown in FIG. 1, F ₁ ＝9.08mm，F ₂ ＝1.965mm，F ₁ /F ₂ = 4.621. As another example, as shown in FIG. 2, F ₁ ＝8.4mm，F ₂ ＝2.063mm，F ₁ /F ₂ ＝4.072。

Condition two, diameter D of microlens 201 ₂ Not greater than diameter D of collimating lens ₁ Is 0.7 times, i.e. D ₂ /D ₁ Less than or equal to 0.7; wherein D is ₁ D is the diameter of the collimating lens ₂ Is the diameter of the microlens 201. This arrangement can increase the number of microlenses 201 and the number of point light sources 501, thereby improving resolution. As an example, D ₂ /D ₁ Less than or equal to 0.5. For example, as shown in FIG. 1, D ₂ ＝1.1mm，D ₁ ＝10mm，D ₂ /D ₁ =0.11. As another example, as shown in fig. 2, D ₂ ＝1.1mm，D ₁ ＝10mm，D ₂ /D ₁ ＝0.11。

In addition, in order to further increase the emission field angle θ of the divergent light emitted from the divergent optical element 300, the diameter D of the collimator lens ₁ The exit field angle θ with the diverging optical element 300 satisfies the following equation:

wherein D is ₁ The diameter of the collimator lens, θ, is the exit field angle of the diverging optical element 300. As an example, D ₁ And/(2 tan (θ/2)). Ltoreq.5. For example, as shown in fig. 1, θ=120°, D ₁ ＝10mm，D ₁ /(2 tan (θ/2))=2.887. As another example, as shown in fig. 2, θ=120°, D ₁ ＝10mm，D ₁ /(2tan(θ/2))＝2.887。

In the case where the optical system includes the emission light source 400 and the collimating optical element 100 includes at least one collimating lens, in order to improve the degree of collimation of the collimating lens, the relevant parameters of the emission light source 400 and the collimating lens may satisfy at least one of the following conditions:

condition one, diameter D of collimating lens ₁ Not smaller than the light emitting diameter D of the emission light source 400 ₃ 3 times, i.e. D ₁ /D ₃ Not less than 3, wherein D ₁ D is the diameter of the collimating lens ₃ For emitting the light of the diameter of the light source 400. As an example, D ₁ /D ₃ And is more than or equal to 5. For example, as shown in FIG. 1, D ₁ ＝10mm，D ₃ ＝0.5mm，D ₁ /D ₃ =20. As another example, as shown in fig. 2, D ₁ ＝10mm，D ₃ ＝0.5mm，D ₁ /D ₃ ＝20。

Second condition, light emitting diameter D of the light emitting source 400 ₃ Not greater than the focal length F of the collimating lens ₁ Half of (D), i.e. D ₃ /F ₁ Less than or equal to 0.5, wherein D ₃ F for emitting the light of the light source 400 ₁ Is the focal length of the collimating lens. As an example, D ₃ /F ₁ Less than or equal to 0.2. For example, as shown in FIG. 1, F ₁ ＝9.08mm，D ₃ ＝0.5mm，D ₃ /F ₁ =0.055. As another example, as shown in FIG. 2, F ₁ ＝8.4mm，D ₃ ＝0.5mm，D ₃ /F ₁ ＝0.059。

Condition three, light emitting diameter D of the emission light source 400 ₃ The product of the angle gamma of divergence is not greater than the diameter D of the collimating lens ₁ Is 7 times, i.e. D ₃ γ/D ₁ Not more than 7, wherein D ₃ For the luminous diameter of the emission light source 400, γ is the divergence angle of the emission light source 400, D ₁ Is the diameter of the collimating lens. This has the advantage that the larger the diameter of the collimating lens, the higher the degree of collimation in case the light emitting area and the divergence angle of the emitting light source 400 are fixed. As an example, D ₃ y/D ₁ And is less than or equal to 5. For example, as shown in FIG. 1, D ₁ ＝10mm，D ₃ ＝0.5mm，γ＝59°，D ₃ γ/D ₁ =2.950. As another example, as shown in fig. 2, D ₁ ＝10mm，D ₃ ＝0.5mm，γ＝59°，D ₃ γ/D ₁ ＝2.950。

Condition four, light emission diameter D of the emission light source 400 ₃ The product of the angle gamma of divergence is not greater than the focal length F of the collimating lens ₁ Is 7 times, i.e. D ₃ γ/F ₁ Not more than 7, wherein D ₃ For the luminous diameter of the emission light source 400, γ is the divergence angle of the emission light source 400, F ₁ Is the focal length of the collimating lens. This has the advantage that the larger the focal length of the collimating lens, the higher the degree of collimation, given the light emitting area and the divergence angle of the emitting light source 400. As an example, D ₃ γ/F ₁ And is less than or equal to 5. For example, as shown in FIG. 1, F ₁ ＝9.08mm，D ₃ ＝0.5mm，γ＝59°，D ₃ γ/F ₁ = 3.249. As another example, as shown in FIG. 2, F ₁ ＝8.4mm，D ₃ ＝0.5mm，γ＝59°，D ₃ γ/F ₁ ＝3.512。

In the case where the optical system includes the emission light source 400, the collimating optical element 100 includes at least one collimating lens, and the dividing optical element 200 includes at least one microlens array, in order to enhance miniaturization of the optical system, the relevant parameters of the emission light source 400, the collimating lens, and/or the microlens array may satisfy at least one of the following conditions:

condition one, diameter D of collimating lens ₁ Not smaller than the distance L between the first side of the collimating lens and the emitting light source 400 ₁ Half of, and diameter D of the collimating lens ₁ Not greater than the distance L between the first side of the collimating lens and the emitting light source 400 ₁ The first side of the collimating lens is the side of the collimating lens facing the emitting light source 400, i.e. 0.5. Ltoreq.D ₁ /L ₁ Not more than 2, wherein D ₁ For collimating lens diameter, L ₁ Is the spacing between the first side of the collimating lens and the emitting light source 400. As an example, 1.ltoreq.D ₁ /L ₁ Less than or equal to 1.5. For example, as shown in FIG. 1, L ₁ ＝8.020mm，D ₁ ＝10mm，D ₁ /L ₁ = 1.247. As another example, as shown in FIG. 2, L ₁ ＝7.835mm，D ₁ ＝10mm，D ₁ /L ₁ ＝1.276。

Condition two, the spacing L between the first side of the collimating lens and the emitting light source 400 ₁ No greater than the first side and the microlens arraySpacing L between the emission light sources 400 ₂ The method comprises the steps of carrying out a first treatment on the surface of the The first side of the collimating lens is the side of the collimating lens facing the emission light source 400; the first side of the microlens array is the side of the microlens array facing the collimator lens, i.e. L ₁ /L ₂ Not more than 1, wherein L ₁ L is the distance between the first side of the collimating lens and the emitting light source 400 ₂ Is the spacing between the first side of the microlens array and the emitting light source 400. By way of example, L ₁ /L ₂ Less than or equal to 0.8. For example, as shown in FIG. 1, L ₁ ＝8.020mm，L ₂ ＝12.755mm，L ₁ /L ₂ = 0.6288. As another example, as shown in FIG. 2, L ₁ ＝7.835mm，L ₂ ＝13.60mm，L ₁ /L ₂ ＝0.576。

Condition III, diameter D of collimating lens ₁ Not smaller than the interval L between the first side of the microlens array and the emitting light source 400 ₂ Is 0.2 times of the diameter D of the collimating lens ₁ Not greater than the spacing L between the first side of the microlens array and the emission light source 400 ₂ 3 times of (3); the first side of the microlens array is the side of the microlens array facing the collimating lens, i.e., 0.2.ltoreq.D ₁ /L ₂ Not more than 3, wherein D ₁ For collimating lens diameter, L ₂ Is the spacing between the first side of the microlens array and the emitting light source 400. As an example, 0.5.ltoreq.D ₁ /L ₂ And is less than or equal to 2. For example, as shown in FIG. 1, L ₂ ＝12.755mm，D ₁ ＝10mm，D ₁ /L ₂ =0.784; as another example, as shown in FIG. 2, L ₂ ＝13.60mm，D ₁ ＝10mm，D ₁ /L ₂ ＝0.735。

Condition four, spacing L between the second side of the microlens array and the diverging optical element 300 ₃ Not smaller than the interval L between the first side of the microlens array and the emitting light source 400 ₂ And the spacing L between the second side of the microlens array and the diverging optical element 300 is 0.1 times ₃ Not greater than the spacing L between the first side of the microlens array and the emission light source 400 ₂ 1.5 times of (2); the first side of the micro lens array is the side of the micro lens array facing the collimating lens, and the second side of the micro lens array is the side of the micro lens array facing away from the collimating lensOne side of the lens, i.e. 0.1.ltoreq.L ₃ /L ₂ Not more than 1.5, wherein L ₂ L is the spacing between the first side of the microlens array and the emitting light source 400 ₃ Is the spacing between the second side of the microlens array and the diverging optical element 300. As an example, 0.3.ltoreq.L ₃ /L ₂ And is less than or equal to 1. For example, as shown in FIG. 1, L ₂ ＝12.755mm，L ₃ ＝9.22mm，L ₃ /L ₂ =0.723. As another example, as shown in FIG. 2, L ₂ ＝13.60mm，L ₃ ＝8.82mm，L ₃ /L ₂ ＝0.649。

Condition five, diameter D of microlens 201 ₂ Focal length F of microlens 201 ₂ And a spacing L between the first side of the microlens array and the emission light source 400 ₂ The following formula is satisfied:

wherein D is ₂ F is the diameter of the microlens 201 ₂ L is the focal length of the microlens 201 ₂ The first side of the microlens array is the side of the microlens array facing the collimating lens, which is the distance between the first side of the microlens array and the emitting light source 400. This has the advantage of facilitating the cooperation of the split optical element 200 with the diverging optical element 300, and of reducing the distance between the split optical element 200 and the diverging optical element 300.

As an example of this, the number of devices,for example, as shown in FIG. 1, L ₂ ＝12.755mm，F ₂ ＝1.965mm，As another example, as shown in FIG. 2, L ₂ ＝13.60mm，F ₂ ＝2.063mm，/>

In addition, the embodiment of the application also provides a detection system, which comprises a receiving unit and the optical system, wherein the optical system comprises a collimation optical element 100, a splitting optical element 200, a divergence optical element 300 and an emission light source 400; the optical system is used for emitting divergent light beams to the target scene, and the receiving unit receives the light beams of the divergent light beams reflected by the target scene. The detection system may be, but not limited to, a laser radar system, and the receiving unit may be, but not limited to, a laser receiving lens in the case where the detection system is a laser radar system. The detection system in the embodiment of the application remarkably improves the detection capability and resolution by adopting the optical system.

The above embodiments do not limit the scope of the present application. It will be apparent to those skilled in the art that various modifications, combinations, sub-combinations and alternatives are possible, depending on design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the scope of the present application.

Claims (10)

1. An optical system, comprising:

a collimating optical element that collimates the target beam into parallel light;

a splitting optical element splitting the parallel light into a plurality of point light sources; and

and a divergent optical element for diverging the plurality of point light sources to form divergent light beams.

2. The optical system of claim 1, wherein the plurality of point light sources are distributed in an area array.

3. The optical system of claim 2, wherein the split optical element comprises at least one microlens array, each microlens array comprising a plurality of microlenses, the plurality of point light sources being in one-to-one correspondence with the plurality of microlenses.

4. An optical system according to claim 3, wherein a ratio of a diameter of the microlens to a focal length of the microlens is not less than 0.1.

5. The optical system of claim 3, wherein the diameter of the microlens and the focal length of the microlens satisfy the following formula:

wherein D is ₂ F is the diameter of the microlens ₂ Is the focal length of the microlens.

6. The optical system of claim 1, wherein the collimating optical element comprises at least one collimating lens.

7. The optical system of claim 6, wherein the collimating lens has a spherical, aspherical or freeform surface.

8. The optical system of claim 6, wherein the segmented optical element comprises at least one microlens array comprising a plurality of microlenses, the focal length of the collimating lens being no less than the focal length of the microlenses of the microlens array.

9. The optical system of claim 6, wherein the segmented optical element comprises at least one microlens array comprising a plurality of microlenses; the diameter of the micro lens is not more than 0.7 times of the diameter of the collimating lens.

10. The optical system of claim 6, wherein the diameter of the collimating lens and the exit field angle of the diverging optical element satisfy the following formula:

wherein D is ₁ And θ is the outgoing field angle of the divergent optical element, which is the diameter of the collimator lens.