MINI coaxial movement

Abstract

The invention discloses a MINI coaxial movement, which relates to the field of laser ranging and comprises a laser, a reflector, a transmitting and receiving lens and a receiving assembly. The laser, the small hole area on the reflecting mirror and the transmitting and receiving lens form a transmitting reflector path; the transmitting and receiving lens, a non-small-hole area on the reflecting mirror and the receiving assembly form a receiving light path; the optical axis of the laser coincides with the optical axis of the transmitting-receiving lens. During working, a light beam emitted by the laser device penetrates through the small hole area on the reflecting mirror, emergent light spots are screened through the small hole area on the reflecting mirror, then collimation is carried out through the emitting and receiving lens, and parallel light is formed and emitted to a target object; the light reflected by the surface of the target object is focused by the transmitting and receiving lens and then is focused to the receiving assembly by the non-small hole area on the reflector; and the receiving assembly calculates the distance between the receiving assembly and the target object according to the received optical signal. According to the invention, miniaturized and low-cost distance measurement can be realized.

Description

Technical Field

[0001] The present application relates to the field of laser ranging, and in particular to a MINI coaxial movement. Background Art

[0002] In recent years, laser ranging technology has been widely used in self-driving cars, drones, robots, and geographic survey equipment. Laser ranging technology can quickly measure long distances, detect obstacles, and navigate, thereby promoting the rapid development of industries such as transportation and industrial manufacturing. However, the current laser ranging technology still has the problem of being difficult to balance the three aspects of R&D and manufacturing costs, system weight and volume, and measurement accuracy. For example, when a focusing lens is used between the reflector and the light source, it will increase costs and is not conducive to miniaturization; when two reflectors plus a laser shaping device are used, it will increase costs. Summary of the invention

[0003] The purpose of this application is to provide a MINI coaxial movement that can achieve miniaturized and low-cost distance measurement.

[0004] To achieve the above objectives, this application provides the following solutions: The present application provides a MINI coaxial movement, including a laser, a reflector, a transmitting and receiving lens, and a receiving assembly; the laser, the reflector, and the transmitting and receiving lens are arranged in sequence, and a small hole is arranged on the reflector; The laser, the pinhole area on the reflector and the transmitting and receiving lens constitute an external transmitting optical path; the transmitting and receiving lens, the non-pinhole area on the reflector and the receiving component constitute a receiving optical path; the optical axis of the laser coincides with the optical axis of the transmitting and receiving lens; When working, the laser emits a light beam through the pinhole area on the reflector to filter the emitted light spot through the pinhole area on the reflector, and then collimates it through the transmitting and receiving lens to form parallel light that is emitted to the target object; the light reflected from the surface of the target object is focused through the transmitting and receiving lens, and then focused to the receiving component by the non-pinhole area on the reflector; the receiving component calculates the distance to the target object based on the received light signal.

[0005] According to the specific embodiments provided by the present application, the present application has the following technical effects: the present application provides a MINI coaxial movement, the optical axis of the laser coincides with the optical axis of the transmitting and receiving lens, the laser, the small hole area on the reflector and the transmitting and receiving lens constitute the transmitting external optical path, the transmitting and receiving lens, the non-small hole area on the reflector and the receiving component constitute the receiving optical path, compared with the off-axis ranging technology, only one transmitting and receiving lens is set in the present application, which can effectively compress the volume of the device and reduce the cost. In addition, a small hole is set on the reflector, and the small hole is used to screen the light spot emitted by the laser, and then the transmitting and receiving lens can achieve the collimation effect within the entire measuring range, so there is no need to add a lens between the laser and the reflector to shape the laser beam, which further saves space and cost and achieves miniaturization. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0007] Figure 1 It is a schematic diagram of a MINI coaxial movement in one embodiment of the present application.

[0008] Figure 2 Schematic diagram of the internal light path of the emission in one embodiment of the present application.

[0009] Explanation of symbols: 1-laser, 2-reflector, 3-transmitting and receiving lenses, 4-filter, 5-light detector, 6-target object, 7-internal light path reflective plug. DETAILED DESCRIPTION

[0010] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0011] In order to make the purpose, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0012] In an exemplary embodiment, Figure 1As shown, a MINI coaxial movement is provided, including a laser 1, a reflector 2, a transmitting and receiving lens 3 and a receiving component; the laser 1, the reflector 2 and the transmitting and receiving lens 3 are arranged in sequence, and a small hole is arranged on the reflector 2.

[0013] The laser 1, the small hole area on the reflector 2 and the transmitting and receiving lens 3 constitute an external transmitting optical path; the optical axis of the laser 1 coincides with the optical axis of the transmitting and receiving lens 3; the angle between the optical axis of the reflector 2 and the optical axis of the laser 1 is 45°. In a specific application, the laser 1 is a semiconductor laser.

[0014] The transmitting and receiving lens 3, the non-pinhole area on the reflector 2 and the receiving component constitute a receiving optical path; in a specific application, the receiving component includes a filter 4 and a light detector 5 arranged in sequence, and the light detector 5 can be an avalanche photodiode (APD).

[0015] In a specific application, the transmitting and receiving lens 3 is a lens with an aspherical structure, and the focal length and back focal length of the transmitting and receiving lens 3 are both in a preset short focal range, that is, the focal length and back focal length of the transmitting and receiving lens 3 are relatively small, and the distance between the laser 1 and the transmitting and receiving lens 3, and between the transmitting and receiving lens 3 and the avalanche photodiode are effectively limited, thereby achieving the purpose of miniaturization.

[0016] When working, the laser 1 emits a laser beam through the pinhole area on the reflector 2 to filter the emitted light spot through the pinhole area on the reflector 2, and then collimates it through the transmitting and receiving lens 3 to form parallel light that is emitted to the target object 6; the light reflected from the surface of the target object 6 is focused through the transmitting and receiving lens 3, and then focused to the receiving component by the non-pinhole area on the reflector 2; the receiving component calculates the distance to the target object 6 based on the received light signal.

[0017] In the above working process, since the small hole on the reflector 2 is used to screen the direct light spot emitted by the laser 1, and the lens with an aspherical structure is used to collimate it within the entire measuring range, there is no need to add a lens between the laser 1 and the reflector to shape the laser beam, saving space and cost. At the same time, the use of a short-focus aspherical lens can compress the volume of the entire movement while meeting the measuring range, thus meeting the miniaturization requirements.

[0018] Specifically, the light is focused by the transmitting and receiving lens 3 , passes through the non-pinhole area on the reflector 2 and the filter 4 in sequence, and is focused on the avalanche photodiode.

[0019] In another specific application example, by setting the size and shape of the small hole on the reflector 2, the spot size of the light beam emitted by the laser 1 reaching the transmitting and receiving lens 3 and the angle of the fast and slow axes are adjusted, so that the outgoing laser spot is in a good size and energy distribution throughout the entire range.

[0020] In another specific application example, the MINI coaxial movement further includes an inner light path reflective plug 7; when in operation, part of the light beam emitted by the laser 1 passes through the inner light path reflective plug 7, through the small hole area on the reflector and is transmitted to the receiving component (specifically, it is focused on the avalanche photodiode via the filter 4, and the avalanche photodiode is the light detector 5) to form an emission inner light path, such as Figure 2 The receiving component is used to calculate the internal and external time difference based on the received optical signal corresponding to the transmitting internal optical path and the received optical signal corresponding to the receiving optical path, and then calculate the distance to the target object according to the internal and external time difference. Specifically, the internal and external time difference is multiplied by the speed of light to calculate the distance to the target object.

[0021] In summary, the present application provides a MINI coaxial movement, which uses a semiconductor laser, a reflector with a small hole, and a transmitting and receiving lens to form a transmitting optical path, and the area on the reflector except the small hole and the transmitting and receiving lens form a receiving optical path. The small hole on the reflector is used to filter the light spot directly emitted by the laser, and by controlling the size and shape of the hole, the long and short axis light spots of the semiconductor laser tend to be consistent and the divergence angles tend to be consistent. At the same time, a lens with an aspherical structure is used to collimate the light spot filtered by the small hole to form a nearly parallel light emission. The present application is the smallest movement currently on the market within the same measuring range. Compared with the off-axis system, the present application can achieve miniaturization while improving measurement accuracy.

[0022] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0023] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A MINI coaxial movement, characterized in that: The MINI coaxial movement includes a laser, a reflector, a transmitting and receiving lens and a receiving assembly; the laser, the reflector and the transmitting and receiving lens are arranged in sequence, and a small hole is arranged on the reflector; The laser, the pinhole area on the reflector and the transmitting and receiving lens constitute an external transmitting optical path; the transmitting and receiving lens, the non-pinhole area on the reflector and the receiving component constitute a receiving optical path; the optical axis of the laser coincides with the optical axis of the transmitting and receiving lens; When working, the laser emits a light beam through the small hole area on the reflector to filter the emitted light spot through the small hole area on the reflector, and then collimates it through the transmitting and receiving lens to form parallel light to be emitted to the target object; The light reflected by the surface of the target object is focused by the transmitting and receiving lens, and then focused by the non-pinhole area on the reflector to the receiving component; The receiving component calculates the distance to the target object based on the received light signal.

2. The MINI coaxial movement according to claim 1, characterized in that: The angle between the optical axis of the reflector and the optical axis of the laser is 45°.

3. The MINI coaxial movement according to claim 1, characterized in that: The laser is a semiconductor laser.

4. The MINI coaxial movement according to claim 1, characterized in that: The transmitting and receiving lens is a lens with an aspherical structure.

5. The MINI coaxial movement according to claim 1, characterized in that: The focal length and back focal length of the transmitting and receiving lenses are both within a preset short focal range.

6. The MINI coaxial movement according to claim 1, characterized in that: The receiving component includes a filter and a light detector which are arranged in sequence.

7. The MINI coaxial movement according to claim 6, characterized in that: The light detector is an avalanche photodiode.

8. The MINI coaxial movement according to claim 1, characterized in that: The MINI coaxial movement also includes an inner light path reflective plug; When working, part of the light beam emitted by the laser passes through the inner light path reflective plug, through the small hole area on the reflector and is transmitted to the receiving component to form an emission inner light path; The receiving component is used to calculate the internal and external time difference based on the received light signal corresponding to the transmitting internal light path and the received light signal corresponding to the receiving light path, and then calculate the distance to the target object according to the internal and external time difference.

9. The MINI coaxial movement according to claim 1, characterized in that: By setting the size and shape of the small hole on the reflector, the spot size of the light beam emitted by the laser and reaching the transmitting and receiving lens and the angle of the fast and slow axes are adjusted.

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