CN110865386B - Laser optical path system and laser distance measuring device - Google Patents

Abstract

The present invention provides a laser optical path system and a laser ranging device, which belong to the field of laser ranging technology. The laser optical path system includes: a laser interface, an off-axis parabolic mirror and a photoelectric converter; the optical axis of the laser interface is perpendicular to the quasi-plane of the off-axis parabolic mirror, a first through hole is formed on the mirror surface of the off-axis parabolic mirror, the laser interface is located at the opening on the side of the first through hole away from the mirror surface of the off-axis parabolic mirror, and the photoelectric converter is located at the focus of the off-axis parabolic mirror. The laser ranging device includes: a laser, a processor and any one of the above laser optical path systems, the processor is connected to the photoelectric converter signal of the laser optical path system, and the laser is connected to the laser interface of the laser optical path system. The purpose of the present invention is to provide a laser optical path system and a laser ranging device, which can omit the spectroscopic device corresponding to the laser in the laser optical path system, so as to simplify the structure of the laser optical path system, reduce the difficulty of assembly, and reduce space occupation.

Description

Laser light path system and laser ranging device

Technical Field

The invention relates to the technical field of laser ranging, in particular to a laser light path system and a laser ranging device.

Background

In the field of laser ranging, two main methods for realizing ranging are one of a time-of-flight ranging method and the other of a phase ranging method, wherein the common ranging method is a time-of-flight ranging method, and the basic principle is that the time of flight from the emission of a laser pulse to the reception of the laser pulse after the reflection of a target object is measured, and the distance between a transmitting device and the target position is obtained by calculating the time of flight according to the propagation speed of light in a corresponding medium.

The general laser ranging device comprises a laser, a return mirror, a condensing lens, a return light receiver and a reference light receiver. The laser device comprises a laser device, a reference light receiver, a return light receiver and a light source, wherein the laser device emits light beams which are subjected to light splitting treatment to form reference light beams and working light beams, the reference light receiver is used for receiving the reference light beams when the laser device emits laser pulses and converting the reference light beams into electric signals to mark the initial flight time emitted by the laser pulses, the return light receiver is used for receiving return light formed by the working light reflected by a target object and converting the working light into electric signals to mark the end flight time emitted by the laser pulses, and therefore the flight time returned by the target object after the laser pulses are emitted can be obtained according to the initial flight time and the end flight time.

However, in the existing structure, since a special beam splitting device is required to be arranged corresponding to the laser to split the laser pulse emitted by the laser into the reference light and the working light, and the beam splitting proportion is required to be controlled to ensure that the working light has higher intensity, the assembly difficulty is higher, the implementation is relatively difficult, and the occupation of the structure is relatively complex.

Disclosure of Invention

The invention aims to provide a laser light path system and a laser distance measuring device, which can omit a light splitting device corresponding to a laser in the laser light path system, so as to simplify the structure of the laser light path system, reduce the assembly difficulty and reduce the space occupation.

Embodiments of the present invention are implemented as follows:

In one aspect of the embodiment of the invention, a laser light path system is provided, which comprises a laser interface, an off-axis parabolic mirror and a photoelectric converter, wherein an optical axis of the laser interface is perpendicular to a quasi-plane of the off-axis parabolic mirror, a first through hole is formed in a mirror surface of the off-axis parabolic mirror, the laser interface is positioned at an opening at one side of the first through hole away from the mirror surface of the off-axis parabolic mirror, and the photoelectric converter is positioned at a focus of the off-axis parabolic mirror.

Optionally, a collimating mirror is arranged between the laser interface and the first through hole, and a collimating optical axis of the collimating mirror coincides with an optical axis of the laser interface.

Optionally, an optical filter is disposed on a side of the off-axis parabolic mirror away from the laser interface, and an optical axis of the laser interface passes through the optical filter.

Optionally, a second through hole is formed on the optical filter, and the second through hole is coaxially arranged with the first through hole.

Optionally, the sidewall roughness of the first via is between 3.2 microns and 12.5 microns.

Optionally, the difference between the aperture of the first through hole and the spot diameter of the laser beam is between 0mm and 0.3 mm.

Optionally, the difference between the aperture of the second through hole and the spot diameter of the laser beam is between 0mm and 0.3 mm.

In another aspect of the embodiment of the invention, a laser ranging device is provided, which comprises a laser, a processor and any one of the laser light path systems, wherein the processor is in signal connection with a photoelectric converter of the laser light path system, and the laser is in interface connection with the laser of the laser light path system.

Optionally, the laser is interfaced with the laser via an optical fiber.

Optionally, the laser ranging device further comprises an operation terminal, and the operation terminal is respectively connected with the processor and the laser in a signal mode.

The beneficial effects of the embodiment of the invention include:

The embodiment of the invention provides a laser light path system which comprises a laser interface, an off-axis parabolic mirror and a photoelectric converter. A first through hole is formed on the mirror surface of the off-axis parabolic mirror, the laser interface is positioned on an opening of one side of the first through hole away from the mirror surface of the off-axis parabolic mirror, and the photoelectric converter is positioned on a focus of the mirror surface of the off-axis parabolic mirror, wherein an optical axis of the laser interface is perpendicular to the quasi-plane of the off-axis parabolic mirror. When the laser device emits laser pulses, the laser pulses can be incident into the laser light path system along the optical axis of the laser interface through the laser interface, and the laser pulses can be emitted from the laser light path system to a target object after passing through the first through hole on the off-axis parabolic mirror. Because the laser pulse emitted by the laser device must have a small part of laser (about 5 percent) distributed outside the beam divergence angle, the part of laser irradiates on the side wall of the first through hole, and is emitted to the photoelectric converter under the diffuse reflection of the side wall of the first through hole, and the part of laser is converted into an electric signal by the photoelectric converter and can be used as a reference light to mark the initial flight time of the laser pulse. When laser distributed in the beam scattering angle in the laser pulse finally passes through the first through hole and is emitted by the target object to form return light, the light beam perpendicular to the quasi-plane of the off-axis parabolic mirror in the return light can be reflected to the photoelectric converter at the focus by the off-axis parabolic mirror, and the return light is converted into an electric signal through the photoelectric converter, so that the electric signal can be used as a working light to mark the end flying time of the laser pulse. The distance between the target object and the laser light path system can be finally obtained by sending the electric signals converted by the photoelectric converter to a processor and other devices and calculating. The laser light path system adopts the structure, and a light splitting device corresponding to a laser can be omitted, so that the integral structure of the laser light path system is simplified, the assembly difficulty is reduced, and the space occupation of the laser light path system can be reduced.

The laser ranging device provided by the embodiment of the invention adopts the laser light path system, so that the structure is more compact, the assembly difficulty is lower, and the space occupation is smaller.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

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

fig. 2 is a schematic structural diagram of a laser optical path system according to an embodiment of the present invention.

The icons are 110-laser interface, 120-off-axis parabolic mirror, 121-first via, 130-photoelectric converter, 140-collimator mirror, 150-filter, 151-second via, 210-laser, 220-optical fiber.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It should be noted that like reference numerals and letters refer to like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.

In the description of the present invention, it should be noted that, directions or positional relationships indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., are directions or positional relationships based on those shown in the drawings, or are directions or positional relationships conventionally put in use of the inventive product, are merely for convenience of describing the present invention and simplifying the description, and are not indicative or implying that the apparatus or element to be referred to must have a specific direction, be constructed and operated in a specific direction, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used merely to distinguish between descriptions and should not be construed as indicating or implying relative importance.

Furthermore, the terms "horizontal," "vertical," and the like do not denote a requirement that the component be absolutely horizontal or overhang, but rather may be slightly inclined. As "horizontal" merely means that its direction is more horizontal than "vertical", and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

In the description of the present invention, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, integrally connected, mechanically connected, electrically connected, directly connected, indirectly connected through an intermediary, or in communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

The embodiment of the invention provides a laser light path system, as shown in fig. 1, which comprises a laser interface 110, an off-axis parabolic mirror 120 and a photoelectric converter 130, wherein the optical axis of the laser interface 110 is perpendicular to the quasi-plane of the off-axis parabolic mirror 120, a first through hole 121 is formed on the mirror surface of the off-axis parabolic mirror 120, the laser interface 110 is positioned at an opening at one side of the first through hole 121 far away from the mirror surface of the off-axis parabolic mirror 120, and the photoelectric converter 130 is positioned at the focus of the off-axis parabolic mirror 120.

When the laser 210 is connected to the laser light path system through the laser interface 110, the laser pulse emitted by the laser 210, the laser light (as working light) distributed in the beam divergence angle can be reflected by the target object after exiting through the first through hole 121, and then reflected to the photoelectric converter 130 through the off-axis parabolic mirror 120, and the laser light (as reference light) distributed outside the beam divergence angle can be reflected to the photoelectric converter 130 through the side wall of the first through hole 121.

The quasi-plane of the first off-axis parabolic mirror 120 refers to a plane formed by innumerable parabolas forming the parabolic mirror of the off-axis parabolic mirror 120 and corresponding quasi-lines.

Second, the optical axis of the laser interface 110 refers to the direction of the laser beam emitted by the laser 210 after the laser interface 110 is connected to the laser 210.

Third, the aperture of the first through hole 121 is generally not smaller than the spot diameter of the laser pulse emitted by the laser 210, so as to avoid that the laser light within the beam divergence angle is reflected by the sidewall of the first through hole 121 to the photoelectric converter 130 to reduce the intensity of the laser light (i.e., working light) emitted to the target object.

The embodiment of the invention provides a laser light path system, which comprises a laser interface 110, an off-axis parabolic mirror 120 and a photoelectric converter 130. A first through hole 121 is formed in the mirror surface of the off-axis parabolic mirror 120, the laser interface 110 is located at an opening of a side of the first through hole 121 away from the mirror surface of the off-axis parabolic mirror 120, and the photoelectric converter 130 is located at a focal point of the mirror surface of the off-axis parabolic mirror 120, wherein an optical axis of the laser interface 110 is perpendicular to an alignment surface of the off-axis parabolic mirror 120. As shown in fig. 1 and fig. 2, in practical use, the laser 210 can be connected to the laser light path system through the laser interface 110, and when the laser 210 emits a laser pulse, the laser pulse can be incident to the laser light path system through the laser interface along the optical axis of the laser interface, and the laser pulse can be emitted from the laser light path system to the target after passing through the first through hole 121 on the off-axis parabolic mirror 120. Since a small portion of the laser light (about 5%) emitted from the laser 210 is necessarily distributed outside the beam divergence angle, the portion of the laser light irradiates the sidewall of the first through hole 121, and is emitted to the photoelectric converter 130 under diffuse reflection of the sidewall of the first through hole 121, and the portion of the laser light is converted into an electrical signal by the photoelectric converter 130, so that the electrical signal can be used as a reference light to mark the initial flight time of the laser light pulse. When the laser light distributed in the beam dispersion angle in the laser pulse finally exits through the first through hole 121 and is reflected by the target object to form return light, the light beam perpendicular to the quasi-plane of the off-axis parabolic mirror 120 in the return light can be reflected by the off-axis parabolic mirror 120 to the photoelectric converter 130 at the focus, and the return light is converted into an electric signal through the photoelectric converter 130, so that the electric signal can be used as the working light to mark the end flying time of the laser pulse. The distance from the target object to the laser beam path system can be finally obtained by calculating the electric signal converted by the photoelectric converter 130 and sent to a processor or the like. The laser light path system adopts the structure, and a light splitting device corresponding to the laser 210 can be omitted, so that the whole structure of the laser light path system is simplified, the assembly difficulty is reduced, and the space occupation of the laser light path system can be reduced.

Optionally, as shown in fig. 1, a collimating mirror 140 is disposed between the laser interface 110 and the first through hole 121, and a collimating optical axis of the collimating mirror 140 coincides with an optical axis of the laser interface 110.

The collimating mirror 140 is further disposed in the laser light path system, when the laser 210 is connected to the laser light path system through the laser interface 110, the laser pulse emitted by the laser 210 can be collimated by the collimating mirror 140 after passing through the laser interface 110, so that the finally emitted light beam of the laser light path system can have better directivity. Of course, due to the material and principle characteristics of the collimator 140, the laser light pulse collimated by the collimator 140 still has a portion of the laser light distributed outside the beam divergence angle, and the laser light may be reflected as reference light by the side wall of the first through hole 121 on the off-axis parabolic mirror 120 to the photoelectric converter 130.

Optionally, as shown in fig. 1, a filter 150 is disposed on a side of the off-axis parabolic mirror 120 away from the laser interface 110, and an optical axis of the laser interface 110 passes through the filter 150.

A filter 150 is disposed on the side of the off-axis parabolic mirror 120 remote from the laser interface 110 and allows the optical axis of the laser interface 110 to pass through the filter 150. The ambient light outside the laser light path system can be filtered by the optical filter 150 (the ambient light is usually different from the wavelength of the laser pulse emitted by the laser 210), so that the ambient light coinciding with the optical axis of the laser interface 110 is prevented from being reflected to the photoelectric converter 130 by the off-axis parabolic mirror 120, the interference of the ambient light on the photoelectric converter 130 when the laser pulse is marked to be ended is reduced, and the measurement accuracy of the laser ranging device adopting the laser light path system can be improved.

Alternatively, as shown in fig. 1 and 2, the filter 150 is formed with a second through hole 151, and the second through hole 151 is disposed coaxially with the first through hole 121.

The second through hole 151 is formed on the optical filter 150, so that the laser pulse (the part of the laser pulse within the beam scattering angle) emitted by the laser 210 can be emitted through the first through hole 121 and the second through hole 151 which are coaxially arranged, the reflection of the optical filter 150 on the laser pulse is avoided, the reduction of the optical filter 150 on the laser pulse can be reduced, the intensity of the laser pulse finally emitted to the target object is improved, the effective emitting distance of the laser pulse is improved, and the laser ranging device adopting the laser light path system has a larger range.

Optionally, the sidewall roughness of the first via 121 is between 3.2 microns and 12.5 microns.

The sidewall roughness of the first via 121 may be, for example, 3.2 microns, 4.5 microns, 6 microns, 12.5 microns, etc. By setting the roughness in this range, the first through hole 121 can perform relatively good large-angle diffuse reflection of the laser light of the portion of the laser light pulse that is distributed outside the beam divergence angle, which is more advantageous for the portion of the laser light to be directed to the photoelectric converter 130.

Alternatively, the difference between the aperture of the first through hole 121 and the spot diameter of the laser beam is between 0mm and 0.3 mm.

Illustratively, the aperture of the first through hole 121 may be increased by 0mm, 0.1 mm, 0.2 mm, 0.3mm, etc. as compared to the spot diameter of the laser beam at the first through hole 121.

When the aperture of the first through hole 121 is set within the above range, the laser pulse within the beam divergence angle as the working light can pass through the first through hole 121 relatively completely without being reflected by the side wall of the first through hole 121, so that it can have relatively good intensity, and it can be avoided that the effective reflection area of the off-axis parabolic mirror 120 is reduced due to the excessively large first through hole 121. Of course, in practical applications, the aperture of the first through hole 121 may also determine a relatively accurate value according to the beam divergence angle and the distance between the light outlet of the laser 210 and the first through hole 121, so as to ensure that the portion in the beam divergence angle of the laser pulse as the working light can well exit through the first through hole 121, and avoid the occurrence of the situation that the effective reflection area of the off-axis parabolic mirror 120 is reduced due to the oversized first through hole 121.

Alternatively, the difference between the aperture of the second through hole 151 and the spot diameter of the laser beam is between 0mm and 0.3 mm.

The aperture of the second through hole 151 is set to the above range, and its function and effect are similar to those of the above-described first through hole 121, and will not be described here.

In another aspect of the embodiments of the present invention, as shown in fig. 1, a laser ranging apparatus is provided, which includes a laser 210, a processor (not shown) and any of the above laser light path systems, where the processor is in signal connection with a photoelectric converter 130 of the laser light path system, and the laser 210 is connected with a laser interface 110 of the laser light path system.

The signals generated by the photoelectric converter 130 can be processed by the processor, and finally the measured distance of the target object is obtained.

The laser ranging device adopts the laser light path system, has more compact structure, lower assembly difficulty and smaller space occupation.

Alternatively, as shown in FIG. 1, the laser 210 is connected to the laser interface 110 by an optical fiber 220.

The laser 210 is connected with the laser interface 110 by the optical fiber 220, so that the laser 210 can be arranged relatively flexibly, is not limited to the vicinity of the laser interface 110, and the laser ranging device can be arranged more flexibly in structure and is convenient for user-defined setting.

Optionally, the laser ranging device further includes an operation terminal, and the operation terminal is respectively in signal connection with the processor and the laser 210.

By setting the operation terminal, the user can conveniently perform centralized and intelligent operations on the processing of the processor, the switch control of the laser 210 and the like. The operation terminal may be a computer, for example, and the processor and the laser 210 may be intelligently and visually processed by using a computer program, or the operation terminal may be another device, which is not limited herein.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. The laser light path system is characterized by comprising a laser interface, an off-axis parabolic mirror and a photoelectric converter, wherein the optical axis of the laser interface is perpendicular to the quasi-plane of the off-axis parabolic mirror, a first through hole is formed in the mirror surface of the off-axis parabolic mirror, the laser interface is positioned at one side of the first through hole far away from the mirror surface of the off-axis parabolic mirror and is opened, and the photoelectric converter is positioned at the focus of the off-axis parabolic mirror;

The laser device is connected into the laser light path system through the laser device interface, part of laser light distributed outside the beam scattering angle in laser pulses emitted by the laser device can be emitted to the photoelectric converter under diffuse reflection of the side wall of the first through hole, the part of laser light can be converted into an electric signal through the photoelectric converter and can be used as an initial flight time of a reference mark laser pulse, the laser light distributed in the beam scattering angle in the laser pulses emitted by the laser device can be emitted out of the first through hole and reflected by a target object to form return light, a beam perpendicular to the quasi-surface of the off-axis parabolic mirror in the return light can be reflected to the photoelectric converter through the off-axis parabolic mirror, the return light is converted into an electric signal through the photoelectric converter, the electric signal can be used as an end time of a working light mark laser pulse, and the distance from the target object to the laser light path system can be obtained through calculation by sending the electric signal converted by the photoelectric converter to a processor.

2. The laser light path system of claim 1, wherein a collimating mirror is disposed between the laser interface and the first through hole, and a collimating optical axis of the collimating mirror coincides with an optical axis of the laser interface.

3. The laser light path system of claim 1 or 2, wherein a side of the off-axis parabolic mirror remote from the laser interface is provided with a filter through which an optical axis of the laser interface passes.

4. The laser light path system according to claim 3, wherein a second through hole is formed in the optical filter, and the second through hole is disposed coaxially with the first through hole.

5. The laser light path system of claim 1, wherein a sidewall roughness of the first via is between 3.2 microns and 12.5 microns.

6. The laser light path system of claim 1, wherein the difference between the aperture of the first through hole and the spot diameter of the laser beam is between 0mm and 0.3 mm.

7. The laser light path system of claim 4, wherein the difference between the aperture of the second through hole and the spot diameter of the laser beam is between 0mm and 0.3 mm.

8. A laser ranging device, comprising a laser, a processor, and a laser light path system according to any one of claims 1 to 7, wherein the processor is in signal connection with a photoelectric converter of the laser light path system, and wherein the laser is in interface connection with the laser of the laser light path system.

9. The laser range finder device of claim 8, wherein the laser is interfaced with the laser via an optical fiber.

10. The laser ranging device of claim 8 or 9, further comprising an operating terminal in signal connection with the processor and the laser, respectively.