CN210894688U

CN210894688U - Laser emission device and laser radar system

Info

Publication number: CN210894688U
Application number: CN201921019069.3U
Authority: CN
Inventors: 罗佳林; 黄杰凡; 刘超
Original assignee: Shenzhen Oradar Technology Co Ltd
Current assignee: Shenzhen Oradar Technology Co Ltd
Priority date: 2019-07-02
Filing date: 2019-07-02
Publication date: 2020-06-30
Anticipated expiration: 2029-07-02

Abstract

The utility model relates to a laser radar technical field especially relates to a laser emission device and laser radar system. The laser emitting device includes: a laser emitting unit and a reflecting unit. The laser emitting unit is used for generating a laser beam. The reflecting unit comprises a prism and a reflecting film, the prism is arranged opposite to the laser emitting unit, the prism is provided with an incident surface, a first reflecting surface and a second reflecting surface which are sequentially arranged, the first reflecting surface is perpendicular to the second reflecting surface, and the reflecting film is arranged on the first reflecting surface. The laser beam emitted from the laser emitting unit is emitted into the triangular prism at the incident surface and is transmitted to the first reflecting surface in the triangular prism; the first reflecting surface reflects the laser beam to the second reflecting surface, and the laser beam exits the triple prism from the second reflecting surface. The utility model discloses an optimization to the inside light path of laser emission device realizes the compactification of laser radar system structure and the simplification of assembly.

Description

Laser emission device and laser radar system

Technical Field

The utility model relates to a laser radar technical field especially relates to a laser emission device and laser radar system.

Background

A laser radar system is a system that emits a laser beam to detect information such as a position, a velocity, and the like of a target object. The laser radar system has the characteristics of long detection distance, high resolution, small environmental interference and the like, so that the laser radar system is widely applied to the technical fields of intelligent robots, unmanned aerial vehicles, unmanned driving and the like.

The laser radar system firstly transmits laser beams to a target object through the laser transmitting device, the target object reflects laser signals to the laser receiving device, and after the laser signals are properly processed by the laser receiving device, relevant information of the target object can be obtained, so that the target object is detected, tracked and identified. With the market demand of the laser radar system expanding, the laser radar system needs to meet the performances of small size, high reliability, high imaging frame frequency, high resolution, long-distance ranging and the like. Many components and parts that contain in the laser radar system, for example laser instrument, speculum, receiver, integrated circuit board, lead wire etc. all need carry out reasonable structural design to do not influence other indexes when satisfying the volume reduction.

However, it is difficult for the existing laser emitting device to achieve a balance between the compactness of the structure and multiple performance parameters, and how to reasonably arrange the internal space of the laser emitting device, so that the improvement of the space utilization rate, the compactness of the structure, the simplicity of assembly and the stability of the structure is an aspect which needs to be improved urgently at present on the premise of meeting the light path design.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a laser emission device aims at solving the propagation light path of how to optimize the inside laser beam of laser emission device to realize the problem of laser emission device compact structure and assembly simplification.

The utility model provides a laser emission device for to target object transmission laser beam, laser emission device includes:

a laser emitting unit for generating the laser beam; and

the laser emitting unit comprises a laser emitting unit, a reflecting unit and a control unit, wherein the laser emitting unit comprises a laser source, a laser source and a laser source, the reflecting unit comprises a prism and a reflecting film, the prism is arranged opposite to the laser emitting unit, the prism is provided with an incident surface, a first reflecting surface and a second reflecting surface which are sequentially arranged, the first reflecting surface is vertical to the second reflecting surface, and the reflecting film is arranged on the first reflecting surface;

the laser beam emitted from the laser emitting unit is incident into the triangular prism at the incident surface and is transmitted to the first reflecting surface in the triangular prism; the first reflecting surface reflects the laser beam to the second reflecting surface, and the laser beam exits the triangular prism from the second reflecting surface.

In one embodiment, the second reflecting surface is also provided with the reflecting film, the reflecting film provided on the second reflecting surface is provided with a light-transmitting hole, and the laser beam exits the triangular prism at the light-transmitting hole.

In one embodiment, the laser emitting device further includes an antireflection film for improving the transmittance of the laser beam, and the antireflection film is disposed on the incident surface.

In one embodiment, the laser light emitting device further includes a first lens unit located between the laser light emitting unit and the triangular prism and disposed on a propagation light path of the laser beam.

In one embodiment, the reflective film is a dielectric film or a metal film.

In one embodiment, the laser emitting device further includes a scanning unit, the scanning unit receives the laser beam from the second reflecting surface and reflects the laser beam to the target object, and the scanning unit further receives the laser beam reflected by the target object and reflects the laser beam to the second reflecting surface again.

In one embodiment, the scanning unit includes a scanning mirror that receives and reflects the laser beam and a scanning driver for driving the scanning mirror to rotate.

Another object of the present invention is to provide a laser radar system, which includes: in the laser transmitter and the laser receiver as described above, the second reflecting surface reflects the received laser beam toward the laser receiver.

In one embodiment, the laser receiving device includes a laser receiving unit disposed opposite to the triangular prism and receiving the laser beam, a second lens unit disposed between the laser receiving unit and the triangular prism, and a filter disposed between the second lens unit and the laser receiving unit.

In one embodiment, the lidar system further comprises a laser control device; the laser control device is electrically connected with the laser emitting device and the laser receiving device and is used for controlling the laser emitting device to emit the laser beam and controlling the laser receiving device to receive the laser beam.

The technical effects of the utility model are that: the triangular prism is arranged in the reflecting unit, and the laser beam of the laser transmitting device is incident into the triangular prism from the inclined surface of the triangular prism, so that the propagation light path of the laser beam in the laser transmitting device is optimized, the effects of easy assembly, easy integration, controllable angle and compact structure of the laser transmitting device are facilitated by the triangular prism, and the contradiction between structure miniaturization and unchanged performance parameters in a laser radar system is solved.

Drawings

Fig. 1 is a schematic structural diagram of a laser radar system according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a laser transmitter and a laser receiver according to an embodiment of the present invention.

The correspondence between reference numbers and names in the drawings is as follows:

100. a laser radar system; 104. a target object; 101. a laser emitting device; 102. a laser receiving device; 103. a laser control device; 208. an anti-reflection film; 209. a reflective film; 201. a laser emitting unit; 202. a first lens unit; 204. a scanning unit; 207. a laser receiving unit; 205. a second lens unit; 206. an optical filter; 303. a prism; 3031. an incident surface; 3032. a first reflective surface; 3033. a second reflective surface; 20. a light-transmitting hole;

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present invention, and should not be construed as limiting the present invention.

In the description of the present invention, it is to be understood that the terms "thickness", "upper", "lower", "vertical", "parallel", "bottom", "angle", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted" and "connected" are to be construed broadly, e.g., as meaning either a fixed connection or a removable connection, or as an integral part; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship.

Referring to fig. 1, an embodiment of the present invention provides a laser transmitter 101 and a laser radar system 100 having the same. Laser radar system 100 further includes a laser receiving device 102 and a laser control device 103. The laser control device 103 is electrically connected to the laser emitting device 101, and controls the laser emitting device 101 to emit a laser beam to the target 104. The laser control device 103 is further electrically connected to the laser receiving device 102, and controls the laser receiving device 102 to receive the echo signal reflected by the target 104, and obtains the related information of the target 104 after internal processing of the laser receiving device 102.

Referring to fig. 2, the laser emitting device 101 includes: a laser emitting unit 201 and a reflecting unit. The laser emitting unit 201 is used to generate a laser beam 31. The reflection unit comprises a triangular prism 303 and a reflection film 209 arranged on the triangular prism 303, the triangular prism 303 is arranged opposite to the laser emission unit 201, the cross section of the triangular prism 303 is triangular, the triangular prism 303 is provided with an incidence surface 3031, a first reflection surface 3032 and a second reflection surface 3033 which are sequentially arranged, the first reflection surface 3032 is perpendicular to the second reflection surface 3033, and the reflection film 209 is arranged on the first reflection surface 3032. The laser beam 31 emitted from the laser emitting unit 201 enters the triangular prism 303 at the entrance surface 3031, and the incident laser beam 31' propagates to the first reflecting surface 3032 in the triangular prism 303; the first reflective surface 3032 reflects the laser beam 31 ″ to the second reflective surface 3033, and the laser beam 32 exits the triangular prism 303 at the second reflective surface 3033. It is understood that the reflective film 209 increases the reflectivity of the laser beam 31 within the triangular prism 303, so that the energy of the laser beam 32 exiting the triangular prism 303 is increased. By arranging the triangular prism 303 in the reflection unit and making the laser beam 31 of the laser emitting device 101 enter the triangular prism 303 from the inclined surface of the triangular prism 303, not only is the propagation light path of the laser beam 32 inside the laser emitting device 101 optimized, but also the triangular prism 303 is arranged, so that the effects of easy assembly, easy integration, controllable angle and compact structure of the laser emitting device 101 are realized, and the contradiction between structure miniaturization and unchanged performance parameters in the laser radar system 100 is solved.

The second reflecting surface 3033 is also provided with a reflecting film 209, the reflecting film 209 arranged on the second reflecting surface 3033 is also provided with a light transmission hole 20, and the laser beam 31 ″ is emitted out of the triangular prism 303 at the light transmission hole 20. The laser beam 31 ″ is emitted in a proper alignment with the light transmission hole 20 by adjusting the orientation of the laser emitting unit 201 such that the incident direction of the laser beam 31 forms a predetermined angle with the incident surface 3031. Wherein, an included angle between the incident surface 3031 and the first reflecting surface 3032 is 45 degrees.

Alternatively, the laser emitting unit 201 includes a laser emitting end for generating the laser beam 31, a laser modulator for modulating the laser beam 31, and a laser driving circuit for driving the laser emitting end. Wherein, the laser emitting end comprises a combination of a laser and an optical device, such as: the light cone is not limited herein.

In one embodiment, the laser emitting device 101 further includes a first lens unit 202, and the first lens unit 202 is located between the laser emitting unit 201 and the triangular prism 303 and is disposed on the propagation path of the laser beam 31. The first lens unit 202 is a common optical lens, which may be a convex lens, a concave lens or a combination of various lenses, and the first lens unit 202 is used for collimating and converging the laser beam 31, thereby making the laser beam 31 more optimized.

In one embodiment, the laser emitting device 101 further includes an anti-reflection film 208 for increasing the transmittance of the laser beam 31, and the anti-reflection film 208 is disposed on the incident surface 3031 and is used for increasing the incidence rate of the laser beam 31 and further increasing the energy of the scanning laser beam 32'.

In some embodiments, the anti-reflective film 208 is a high temperature resistant, acid and alkali resistant material that reduces the reflectance of visible and near infrared light to 0.3% -0.5%, and comprises H₄、SiO₂、MgF₂And the like.

In one embodiment, the reflective film 209 is a dielectric film, and the material of the dielectric film may be magnesium fluoride or the like. In another embodiment, the reflective film 209 is a metal film, and the material of the metal film may be silver or aluminum. It is noted that both antireflection film 208 and reflection film 209 may include one or more layers.

In some embodiments, the antireflection film 208 and the reflective film 209 may be coated by magnetron sputtering, electron beam thermal evaporation, vapor deposition, and chemical coating. It should be noted that the materials, the number of layers, and the coating method of the antireflection film 208 and the reflection film 209 can be set according to the wavelength of the laser beam 31 and the specific requirements, and are not limited herein.

In this embodiment, the reflective film 209 plated on the second reflective surface 3033 facing the scanning unit 204 may be replaced by a transflective film, a polarization splitting film, and a splitting film with different splitting ratios. It can be understood that when the film plated on the second reflection surface 3033 is a transflective film, a polarization splitting film, or a splitting film with different splitting ratios, the light hole 20 does not need to be opened, but other factors need to be considered, such as the polarization direction of the laser light when the polarization splitting film is used. Therefore, the present embodiment is described by taking the reflective film 209 as an example, and it is necessary to select which optical film is used appropriately according to specific requirements, which is not limited herein.

Referring to fig. 2, the laser emitting device 101 further includes a scanning unit 204 for receiving the laser beam 32 from the light hole 20, and the scanning unit 204 reflects the laser beam 32' toward the target 104. Generally, the scanning unit 204 includes a scanning mirror that receives the laser beam 32 from the light transmissive hole 20 and reflects the laser beam 32' to the target 104, and a scanning driver for driving the scanning mirror to rotate. The laser beam 33 returned from the target 104 is reflected by the scanning unit 204 and the reflection unit in sequence, and then emitted to the second lens unit 205, and is collected by the second lens unit 205, filtered by the filter 206, and finally emitted to the laser receiving unit 207.

In some embodiments, the scanning unit 204 is a MEMS galvanometer, and when the rotation angle of the MEMS galvanometer is changed, the incident angle of the laser beam 32 is changed, so that the corresponding reflected laser beam 32' is deflected to different degrees, thereby greatly increasing the scanning field of view of the laser emitting device 101.

In one embodiment, the MEMS galvanometer includes a scan mirror and a scan driver coupled to the scan mirror and configured to drive the scan mirror in rotation in two directions that are non-parallel to each other. For convenience of description, two directions of rotation of the scanning mirror are respectively referred to as a first direction and a second direction, and the first direction and the second direction are not parallel. Alternatively, the first direction and the second direction are perpendicular to each other and are respectively referred to as an X direction (corresponding to a transverse direction) and a Y direction (corresponding to a longitudinal direction), a plane defined by the X direction and the Y direction is a plane in which the laser emitting unit 201 and the scanning unit 204 are located, and the scanning driver drives the scanning mirror to rotate in the X direction and/or the Y direction, so that the laser beam 32' can be deflected in the X direction and/or the Y direction, and a large field of view scanning of the laser emitting device 101 is realized.

It should be understood that in other embodiments, the scanning unit 204 may include two or more scanning mirrors, and the scanning driver drives each scanning mirror to rotate so as to deflect the laser beam 32', which is not limited herein.

In one embodiment, laser beam 33 reflected by target 104 is reflected to a scan mirror, which reflects laser beam 33' to second reflective surface 3033, and second reflective surface 3033 reflects laser beam 34 to laser receiving device 102. The laser receiving apparatus 102 includes a second lens unit 205 for collimating and condensing the laser beam 34, a laser receiving unit 207 for receiving the collimated laser beam 34 from the second lens unit 205, and a filter 206 between the second lens unit 205 and the laser receiving unit 207. The receiving processor of the laser receiving unit 207 obtains the relevant information of the target 104 through corresponding data processing, thereby completing one laser radar scan. Meanwhile, the reflective film 209 increases the reflectivity of the laser beam 33' reflected from the scanning unit 204, thereby increasing the energy of the laser beam 34 received by the laser receiving device 102.

In some embodiments, the second lens unit 205 is a common optical lens, which may be a convex lens, a concave lens, or a combination of various lenses, and the second lens unit 205 is used to collimate and focus the laser beam 34, thereby making the laser beam 34 more optimal.

In some embodiments, the optical filter 206 includes a narrow-band optical filter and a wide-band optical filter, and the optical filter 206 is used for filtering stray light, background light, and the like, and reducing the noise signal received by the laser receiving unit 207, thereby improving the test signal-to-noise ratio of the laser radar system 100.

In some embodiments, the laser receiving unit 207 comprises a receiver, such as a PIN diode, a SPAD, an APD photodetector, etc., for converting the received optical signal into an electrical signal, and processing the electrical signal by a corresponding receiving processor to obtain the information of the target 104.

The above description is only exemplary of the present invention and should not be construed as limiting the present invention, and any modifications, equivalents and improvements made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.

Claims

1. A laser transmitter for transmitting a laser beam to a target object, comprising:

a laser emitting unit for generating the laser beam; and

2. The laser transmitter of claim 1, wherein: the second reflecting surface is also provided with the reflecting film, the reflecting film arranged on the second reflecting surface is provided with a light transmitting hole, and the laser beam is emergent from the light transmitting hole to the prism.

3. The laser transmitter of claim 1, wherein: the laser emitting device further comprises an antireflection film used for improving the transmissivity of the laser beam, and the antireflection film is arranged on the incident surface.

4. The laser transmitter of claim 1, wherein: the laser emitting device further comprises a first lens unit, wherein the first lens unit is located between the laser emitting unit and the triple prism and is arranged on a propagation light path of the laser beam.

5. The laser transmitter of claim 1, wherein: the reflecting film is a dielectric film or a metal film.

6. The laser transmitter as claimed in any one of claims 1 to 5, wherein: the laser emitting device further comprises a scanning unit, the scanning unit receives the laser beam from the second reflecting surface and reflects the laser beam to the target object, and the scanning unit further receives the laser beam reflected by the target object and reflects the laser beam to the second reflecting surface again.

7. The laser transmitter of claim 6, wherein: the scanning unit includes a scanning mirror that receives and reflects the laser beam and a scanning driver for driving the scanning mirror to rotate.

8. A lidar system, comprising: the laser transmitter and receiver of claim 6, wherein the second reflecting surface reflects the received laser beam toward the laser receiver.

9. The lidar system of claim 8, wherein: the laser receiving device comprises a laser receiving unit, a second lens unit and an optical filter, wherein the laser receiving unit is arranged opposite to the triangular prisms and receives the laser beams, the second lens unit is arranged between the laser receiving unit and the triangular prisms, and the optical filter is arranged between the second lens unit and the laser receiving unit.

10. The lidar system of claim 8, wherein: the laser radar system further comprises a laser control device; the laser control device is electrically connected with the laser emitting device and the laser receiving device and is used for controlling the laser emitting device to emit the laser beam and controlling the laser receiving device to receive the laser beam.