Laser optical path system and laser ranging device

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 light splitting 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

Technical Field

[0001] The present invention relates to the technical field of laser ranging, and more particularly, to a laser optical path system and a laser ranging device. Background Art

[0002] In the field of laser ranging, there are two main methods for realizing ranging. One is the time-of-flight ranging method, and the other is the phase ranging method. Among them, the commonly used ranging method is the time-of-flight ranging method. Its basic principle is to measure the time of flight of a laser pulse from emission to being received after being reflected by the target object, and use this time of flight to calculate according to the propagation speed of light in the corresponding medium to obtain the distance between the emission device and the target position.

[0003] Generally, a laser ranging device includes a laser, a retroreflector, a condenser lens, a retroreceiver, and a reference light receiver. Among them, the beam emitted by the laser is split into a reference beam and a working beam through beam splitting processing; the reference light receiver is used to receive the reference beam when the laser emits a laser pulse, and convert it into an electrical signal to mark the starting time of flight of the laser pulse; the retroreceiver is used to receive the retroreflection formed by the working light reflected by the target object, and convert it into an electrical signal to mark the ending time of flight after the laser pulse is emitted; thus, the time of flight of the laser pulse after being reflected by the target object and returning can be obtained according to the starting time of flight and the ending time of flight.

[0004] However, in the existing above structure, since a dedicated beam splitting device needs to be provided corresponding to the laser to split the laser pulse emitted by the laser into a reference light and a working light, and the beam splitting ratio needs to be controlled to ensure that the working light has a high intensity, its assembly difficulty is relatively high, the implementation is relatively difficult, and the structure is relatively complex and occupies a large space. Summary of the Invention

[0005] The purpose of the present invention is to provide a laser optical path system and a laser ranging device, which can eliminate the beam splitting 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 assembly difficulty, and reduce the space occupation.

[0006] The embodiments of the present invention are implemented as follows:

[0007] On the one hand, an embodiment of the present invention provides a laser optical path system, including: a laser interface, an off-axis paraboloid mirror, and a photoelectric converter; the optical axis of the laser interface is perpendicular to the quasi-plane of the off-axis paraboloid mirror, a first through hole is formed on the mirror surface of the off-axis paraboloid 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 paraboloid mirror, and the photoelectric converter is located at the focus of the off-axis paraboloid mirror.

[0008] Optionally, a collimating mirror is disposed between the laser interface and the first through hole, and the collimating optical axis of the collimating mirror coincides with the optical axis of the laser interface.

[0009] Optionally, a filter is disposed on a side of the off-axis parabolic mirror away from the laser interface, and the optical axis of the laser interface passes through the filter.

[0010] Optionally, a second through hole is formed in the filter, and the second through hole is coaxially disposed with the first through hole.

[0011] Optionally, the surface roughness of the side wall of the first through hole is between 3.2 microns and 12.5 microns.

[0012] Optionally, the difference between the aperture of the first through hole and the spot diameter of the laser beam is between 0 mm and 0.3 mm.

[0013] Optionally, the difference between the aperture of the second through hole and the spot diameter of the laser beam is between 0 mm and 0.3 mm.

[0014] On the other hand, an embodiment of the present invention provides a laser ranging device, including: a laser, a processor, and the laser optical path system of any one of the above, the processor is signal-connected to the photoelectric converter of the laser optical path system, and the laser is connected to the laser interface of the laser optical path system.

[0015] Optionally, the laser is connected to the laser interface through an optical fiber.

[0016] Optionally, the laser ranging device further includes an operation terminal, and the operation terminal is respectively signal-connected to the processor and the laser.

[0017] The beneficial effects of the embodiments of the present invention include:

[0018] A laser optical path system provided by an embodiment of the present invention includes a laser interface, an off-axis paraboloid mirror, and a photoelectric converter. A first through hole is formed on the mirror surface of the off-axis paraboloid mirror. The laser interface is located at the opening on one side of the first through hole away from the mirror surface of the off-axis paraboloid mirror, and the photoelectric converter is located at the focus of the mirror surface of the off-axis paraboloid mirror. Among them, the optical axis of the laser interface is perpendicular to the quasi-plane of the off-axis paraboloid mirror. In actual use, a laser can be connected to the laser optical path system through the laser interface. When the laser emits laser pulses, the laser pulses can enter the laser optical path system along the optical axis of the laser interface through the laser interface. After passing through the first through hole on the off-axis paraboloid mirror, the laser pulses can be emitted from the laser optical path system to the target object. Since a small part of the laser (about 5% or so) emitted by the laser will inevitably be distributed outside the beam divergence angle, this part of the laser will irradiate on the side wall of the first through hole. Under the diffuse reflection of the side wall of the first through hole, it is directed to the photoelectric converter. This part of the laser is converted into an electrical signal by the photoelectric converter and can be used as a reference light to mark the initial flight time of the laser pulse. When the laser within the beam divergence angle in the laser pulse finally passes through the first through hole and is reflected by the target object to form a return light, the light beam perpendicular to the quasi-plane of the off-axis paraboloid mirror in the return light can be reflected by the off-axis paraboloid mirror to the photoelectric converter at the focus. The return light is converted into an electrical signal by the photoelectric converter and can be used as a working light to mark the end flight time of the laser pulse. By sending the electrical signal converted by the photoelectric converter to devices such as a processor for calculation, the distance between the target object and the laser optical path system can finally be obtained. With the above structure, the laser optical path system can omit the beam splitting device corresponding to the laser, thereby simplifying the overall structure of the laser optical path system, reducing the assembly difficulty, and reducing the space occupied by the laser optical path system.

[0019] A laser ranging device provided by an embodiment of the present invention adopts the above laser optical path system, has a more compact structure, lower assembly difficulty, and smaller space occupation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0021] Figure 1 It is a schematic structural diagram of the laser ranging device provided by the embodiment of the present invention;

[0022] Figure 2 It is a schematic structural diagram of the laser optical path system provided by the embodiment of the present invention.

[0023] Icons: 110 - Laser interface; 120 - Off-axis paraboloid mirror; 121 - First through hole; 130 - Photoelectric converter; 140 - Collimating mirror; 150 - Filter; 151 - Second through hole; 210 - Laser; 220 - Optical fiber. Detailed implementation manners

[0024] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in 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. Obviously, the described embodiments are some but not all of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0026] It should be noted that like reference numerals and letters denote like items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0027] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the present invention is usually placed when in use. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive distinction and cannot be understood as indicating or implying relative importance.

[0028] In addition, terms such as "horizontal" and "vertical" do not mean that the components are required to be absolutely horizontal or hanging vertically, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0029] In the description of the present invention, it should also be noted that unless otherwise clearly specified and defined, the terms "arrangement", "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] An embodiment of the present invention provides a laser optical path system, as Figure 1 shown, including: a laser interface 110, an off-axis parabolic mirror 120, and a photoelectric converter 130; 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 located at the opening on the 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 the focus of the off-axis parabolic mirror 120.

[0031] When the laser 210 is connected to the laser optical path system through the laser interface 110, the laser pulses emitted by the laser 210, the laser (as the working light) distributed within the beam divergence angle can be reflected by the target object after passing through the first through hole 121 and then reflected by the off-axis parabolic mirror 120 to the photoelectric converter 130, and the laser (as the 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.

[0032] It should be noted that, first, the quasi-plane of the off-axis parabolic mirror 120 refers to the plane formed by the directrices corresponding to the countless parabolas that form the parabolic mirror surface of the off-axis parabolic mirror 120.

[0033] Second, the optical axis of the laser interface 110 refers to the light ray direction of the laser emitted by the laser 210 after the laser interface 110 is connected to the laser 210.

[0034] Third, generally, the aperture of the first through hole 121 is not less than the spot diameter of the laser pulses emitted by the laser 210, so as to prevent the laser within the beam divergence angle from being reflected by the side wall of the first through hole 121 to the photoelectric converter 130 and reducing the intensity of the laser (i.e., the working light) directed at the target object.

[0035] A laser optical path system provided by an embodiment of the present invention includes a laser interface 110, an off-axis parabolic mirror 120, and a photoelectric converter 130. A first through hole 121 is formed on the mirror surface of the off-axis parabolic mirror 120. The laser interface 110 is located at the opening on one 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 the focus of the mirror surface of the off-axis parabolic mirror 120. Among them, the optical axis of the laser interface 110 is perpendicular to the reference plane of the off-axis parabolic mirror 120. Combining Figure 1 and Figure 2 As shown, in actual use, the laser 210 can be connected to the laser optical path system through the laser interface 110. When the laser 210 emits laser pulses, the laser pulses can enter the laser optical path system along the optical axis of the laser interface through the laser interface. After passing through the first through hole 121 on the off-axis parabolic mirror 120, the laser pulses can be emitted from the laser optical path system to the target object. Since a small part of the laser (about 5% or so) emitted by the laser 210 will inevitably be distributed outside the beam divergence angle, this part of the laser will irradiate on the side wall of the first through hole 121. Under the diffuse reflection of the side wall of the first through hole 121, it is directed to the photoelectric converter 130. This part of the laser is converted into an electrical signal by the photoelectric converter 130 and can be used as a reference light to mark the initial flight time of the laser pulse. When the laser in the laser pulse that is distributed within the beam divergence angle finally passes through the first through hole 121 and is reflected by the target object to form a return light, the light beam perpendicular to the reference 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. The return light is converted into an electrical signal by the photoelectric converter 130 and can be used as a working light to mark the end flight time of the laser pulse. By sending the electrical signal converted by the photoelectric converter 130 to devices such as a processor and performing calculations, the distance between the target object and the laser optical path system can finally be obtained. The laser optical path system adopts the above structure, which can eliminate the beam splitter device corresponding to the laser 210, thereby simplifying the overall structure of the laser optical path system, reducing the assembly difficulty, and reducing the space occupied by the laser optical path system.

[0036] Optionally, as Figure 1 shown, a collimating mirror 140 is provided between the laser interface 110 and the first through hole 121, and the collimating optical axis of the collimating mirror 140 coincides with the optical axis of the laser interface 110.

[0037] In this laser optical path system, a collimating mirror 140 is also provided. When the laser 210 is connected to this laser optical 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 this laser optical path system can have better directivity. Of course, limited by the material and principle characteristics of the collimating mirror 140, there will still be some laser light outside the beam divergence angle in the laser pulse collimated by the collimating mirror 140. This laser light can also be reflected by the side wall of the first through hole 121 on the off-axis paraboloid mirror 120 to the photoelectric converter 130 as reference light.

[0038] Optionally, as Figure 1 shown, a filter 150 is provided on the side of the off-axis paraboloid mirror 120 away from the laser interface 110, and the optical axis of the laser interface 110 passes through the filter 150.

[0039] By providing the filter 150 on the side of the off-axis paraboloid mirror 120 away from the laser interface 110 and making the optical axis of the laser interface 110 pass through the filter 150, the ambient light outside this laser optical path system can be filtered by the filter 150 (the ambient light usually has a different wavelength from the laser pulse emitted by the laser 210), so as to avoid the ambient light coinciding with the optical axis of the laser interface 110 being reflected by the off-axis paraboloid mirror 120 to the photoelectric converter 130, reducing the interference of the ambient light on marking the end flight moment of the laser pulse by the photoelectric converter 130, and improving the measurement accuracy of the laser ranging device using this laser optical path system.

[0040] Optionally, in combination with Figure 1 and Figure 2 shown, a second through hole 151 is formed on the filter 150, and the second through hole 151 is coaxially arranged with the first through hole 121.

[0041] By forming the second through hole 151 on the filter 150, the laser pulse (the part within the beam divergence angle in the laser pulse) emitted by the laser 210 can be emitted through the coaxially arranged first through hole 121 and second through hole 151, avoiding the reflection of the laser pulse by the filter 150, reducing the attenuation of the laser pulse generated by the filter 150, increasing the intensity of the laser pulse finally shooting at the target object, increasing the effective emission distance of the laser pulse, and enabling the laser ranging device using this laser optical path system to have a larger measurement range.

[0042] Optionally, the surface roughness of the side wall of the first through hole 121 is between 3.2 microns and 12.5 microns.

[0043] The sidewall roughness of the first through hole 121 may be, for example, 3.2 microns, 4.5 microns, 6 microns, 12.5 microns, etc. By setting the roughness within this range, the first through hole 121 can perform relatively good large-angle diffuse reflection on the laser of the part of the laser pulse distribution outside the beam divergence angle, which is more conducive to the laser of this part shooting towards the photoelectric converter 130.

[0044] Optionally, the difference between the aperture of the first through hole 121 and the spot diameter of the laser beam is between 0 mm and 0.3 mm.

[0045] For example, the aperture of the first through hole 121 may be increased by 0 mm, 0.1 mm, 0.2 mm, 0.3 mm, etc. compared to the spot diameter of the laser beam at the first through hole 121.

[0046] When the aperture of the first through hole 121 is set within the above range, the laser pulse within the beam divergence angle of the working light can pass through the first through hole 121 relatively completely without being reflected by the sidewall of the first through hole 121, enabling it to have relatively good intensity and avoiding the situation where the effective reflection area of the off-axis paraboloid mirror 120 decreases due to the first through hole 121 being too large. Of course, in practical applications, the aperture of the first through hole 121 can also be calculated and determined to obtain a relatively accurate value according to the beam divergence angle and the distance between the light output port of the laser 210 and the first through hole 121, so as to ensure that the part within the beam divergence angle of the laser pulse of the working light can pass through the first through hole 121 well and avoid the situation where the effective reflection area of the off-axis paraboloid mirror 120 decreases due to the first through hole 121 being too large.

[0047] Optionally, the difference between the aperture of the second through hole 151 and the spot diameter of the laser beam is between 0 mm and 0.3 mm.

[0048] Setting the aperture of the second through hole 151 within the above range has a similar function and effect to the setting of the first through hole 121 above, which will not be elaborated here.

[0049] On the other hand, an embodiment of the present invention provides a laser ranging device, as Figure 1 shown, including: a laser 210, a processor (not shown), and the laser optical path system of any one of the above. The processor is signal-connected to the photoelectric converter 130 of the laser optical path system, and the laser 210 is connected to the laser interface 110 of the laser optical path system.

[0050] The processor can process the signal generated by the photoelectric converter 130 to finally obtain the measured distance of the target object.

[0051] This laser ranging device adopts the above laser optical path system, has a more compact structure, lower assembly difficulty, and smaller space occupation.

[0052] Optionally, as Figure 1 shown, the laser 210 is connected to the laser interface 110 through the optical fiber 220.

[0053] Connecting the laser 210 to the laser interface 110 using the optical fiber 220 enables the laser 210 to be arranged relatively flexibly, no longer limited to the vicinity of the laser interface 110, which can make the structural arrangement of the laser ranging device more flexible and facilitate custom settings.

[0054] Optionally, the laser ranging device further includes an operation terminal, and the operation terminal is respectively signal-connected to the processor and the laser 210.

[0055] By setting the operation terminal, it is possible to facilitate the user to perform centralized and intelligent operations on the processing of the processor and the on / off control of the laser 210, etc. Exemplarily, the operation terminal can be a computer, and the processor and the laser 210 can be processed in an intelligent and visual manner using a computer program. Of course, the operation terminal can also be other devices, which are not limited here.

[0056] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A laser optical path system, characterized in that, Comprising: A laser interface, an off-axis paraboloid mirror, and a photoelectric converter; the optical axis of the laser interface is perpendicular to the reference plane of the off-axis paraboloid mirror, a first through-hole is formed on the mirror surface of the off-axis paraboloid 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 paraboloid mirror, and the photoelectric converter is located at the focus of the off-axis paraboloid mirror; The laser is connected to the laser optical path system through the laser interface. A part of the laser pulses emitted by the laser that is distributed outside the beam divergence angle can be diffusely reflected by the side wall of the first through-hole and then directed to the photoelectric converter. The part of the laser is converted into an electrical signal by the photoelectric converter, which can be used as a reference light to mark the initial flight time of the laser pulse. The laser pulses emitted by the laser that are distributed within the beam divergence angle can pass through the first through-hole and be reflected by the target to form a return light. The light beam perpendicular to the reference plane of the off-axis paraboloid mirror in the return light can be reflected by the off-axis paraboloid mirror to the photoelectric converter. The return light is converted into an electrical signal by the photoelectric converter, which can be used as a working light to mark the end flight time of the laser pulse. By sending the electrical signal converted by the photoelectric converter to a processor for calculation, the distance between the target and the laser optical path system can be obtained.

2. The laser optical path system according to claim 1, wherein A collimating mirror is provided between the laser interface and the first through-hole, and the collimating optical axis of the collimating mirror coincides with the optical axis of the laser interface.

3. The laser optical path system according to claim 1 or 2, characterized in that A filter is provided on the side of the off-axis paraboloid mirror away from the laser interface, and the optical axis of the laser interface passes through the filter.

4. The laser optical path system according to claim 3, characterized in that, A second through-hole is formed on the filter, and the second through-hole is coaxially arranged with the first through-hole.

5. The laser optical path system according to claim 1, wherein, The surface roughness of the side wall of the first through-hole is between 3.2 microns and 12.5 microns.

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

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

8. A laser ranging device, characterized in that, Comprising a laser, a processor, and a laser optical path system according to any one of claims 1 to 7, the processor is signal-connected to the photoelectric converter of the laser optical path system, and the laser is connected to the laser interface of the laser optical path system.

9. The laser ranging device according to claim 8, characterized in that, The laser is connected to the laser interface through an optical fiber.

10. The laser ranging device according to claim 8 or 9, characterized in that, The laser ranging device further includes an operation terminal, and the operation terminal is respectively signal-connected to the processor and the laser.

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