CN218567598U

CN218567598U - Transmit-receive paraxial optical system of laser scanner

Info

Publication number: CN218567598U
Application number: CN202222691613.7U
Authority: CN
Inventors: 黄泰来
Original assignee: Wuhan Xiangyin Technology Co ltd
Current assignee: Wuhan Xiangyin Technology Co ltd
Priority date: 2022-06-10
Filing date: 2022-10-13
Publication date: 2023-03-03
Anticipated expiration: 2032-10-13

Abstract

The utility model relates to the technical field of optical systems, in particular to a laser scanner receiving and emitting paraxial optical system, which comprises a fiber laser and a collimator, wherein the fiber laser is connected with the collimator through a single mode fiber; it also includes a receiving lens and a photodetector, the optical axis of the collimator being parallel to but not coaxial with the optical axis of the receiving lens. The utility model adopts the paraxial form of the transmitting and receiving light path, namely the transmitting light path and the receiving light path are completely separated and do not overlap in parallel, and the transmitting light path and the receiving light path are completely separated, so that the problem of internal stray light can be effectively eliminated; the utility model discloses a paraxial light path compare and can have certain blind area in coaxial light path, can effectively reduce closely the high reflectivity target and cause the risk of damage to photoelectric detector.

Description

Transmit-receive paraxial optical system of laser scanner

Technical Field

The utility model relates to an optical system technical field especially relates to a laser scanner receives and dispatches other axle optical system.

Background

In an optical system of an existing laser scanner, a receiving and transmitting optical path is coaxial, namely, an optical axis of a transmitting optical path is superposed with an optical axis of a receiving optical path.

For example, chinese patent application publication No. CN 216083083U, entitled coaxial optical system for laser ranging, introduces one or more mirrors by turning the transmitting or receiving optical path, which complicates the structure and increases the cost; in addition, because the actually output collimated light beam is not a completely parallel light beam, most of the energy is mainly distributed in a small divergence angle range, and a small amount of energy is distributed outside the divergence angle, however, laser light outside the small amount of divergence angle is scattered on the surfaces of structural components and optical elements in the transmitting-receiving optical path coaxial optical system to form stray light, and the stray light is transmitted to a photoelectric detector to be converted into an electric signal, so that the test result is interfered. In addition, the damage threshold of the photoelectric detector is low, a blind area does not exist in a coaxial mode of a transmitting-receiving optical path, and the photoelectric detector is easy to damage when facing a short-distance high-reflection-rate target.

SUMMERY OF THE UTILITY MODEL

Aiming at the defects in the prior art, the utility model provides a laser scanner receiving and transmitting paraxial optical system, which adopts the paraxial form of a receiving and transmitting optical path, namely, the transmitting optical path and the receiving optical path are completely separated and do not overlap in parallel, thus effectively eliminating the internal stray light problem; in addition, paraxial light path compares and has certain blind area in coaxial light path can effectively reduce the risk that the high reflectivity target of closely makeed the damage to photoelectric detector.

In order to solve the technical problem, the utility model discloses a technical scheme is: the laser scanner transmitting and receiving paraxial optical system comprises a fiber laser and a collimator, wherein the fiber laser is connected with the collimator through a single mode fiber; it also includes a receiving lens and a photodetector, the optical axis of the collimator being parallel to but not coaxial with the optical axis of the receiving lens.

In a preferred embodiment, the collimator divergence angle is in the range of 0-5 mrad.

In a preferred embodiment, the receiving lens is a convex lens.

In a preferred embodiment, the receiving lens is a plano-convex lens.

In a preferred scheme, two light-transmitting surfaces of the receiving lens are plated with antireflection films.

In a preferred scheme, a clamping groove is formed in the receiving lens, and the collimator is installed in the clamping groove.

In a preferred embodiment, an optical filter is further disposed between the receiving lens and the photodetector.

Compared with the prior art, the utility model discloses mainly have following beneficial effect:

1. the utility model discloses a receiving and dispatching light path paraxial form, the emission light path separates completely, parallel misalignment promptly with the receiving light path, and the emission light path separates completely with the receiving light path and can effectively eliminate inside stray light problem.

2. The utility model discloses a paraxial light path compare and can have certain blind area in coaxial light path, can effectively reduce closely the high reflectivity target and cause the risk of damage to photoelectric detector.

3. The utility model discloses receiving and dispatching range finding optical system compact structure, the assembly is simple.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

Fig. 2 is the schematic diagram of the blind area optical principle of the present invention.

Fig. 3 is a schematic structural diagram of a preferred embodiment of the present invention.

Fig. 4 is a schematic structural diagram of a receiving lens according to a preferred embodiment of the present invention.

In the drawings, wherein: 1. an emission optical axis; 2. receiving an optical axis; 10. a fiber laser; 20. a collimator; 30. a single mode optical fiber; 40. a receiving lens; 41. a card slot; 50. a photodetector; 60. an anti-reflection film; A. a target object; B. a blind area; alpha, receiving field angle; beta, divergence angle.

Detailed Description

The technical solution of the present invention will be further explained with reference to the accompanying drawings and embodiments.

Referring to fig. 1 and 2, as a preferred embodiment of the present invention, a laser scanner transmitting and receiving paraxial optical system is provided, which includes a fiber laser 10 and a collimator 20, wherein the fiber laser 10 is connected to the collimator 20 through a single mode fiber 30; it further comprises a receiving lens 40 and a photodetector 50, the optical axis of the collimator 20 being parallel to but not coaxial with the optical axis of the receiving lens 40.

Further, the collimator 20 has a divergence angle in the range of 0-5 mrad.

Further, the receiving lens 40 is a plano-convex lens.

Further, both surfaces of the receiving lens 40 are coated with antireflection films.

In this embodiment, the wavelength of the fiber laser 10 may be any wavelength within any range of visible light band, near infrared band and short wave infrared band, and is used to emit pulsed laser to detect the target object a; the single-mode fiber 30 is used for transmitting the pulse laser to the collimator 20; the divergence angle range of the collimator 20 is within the range of 0-5mrad, and the collimator is used for compressing the divergence angle of a laser beam emitted by the optical fiber laser 10 to enable the laser beam to be close to a parallel beam, so that remote detection is realized; the two surfaces of the receiving lens 40 are plated with antireflection films of working wave bands, are completely separated from the collimator and are placed in parallel to the collimator 20, the direction angle of the collimator or the receiving lens can be adjusted to enable the optical axis of the receiving lens 40 to be parallel to the transmitting optical axis of the collimator 20, and the receiving lens 40 is used for receiving optical signals of pulse laser returned by scattering through the surface of a target object A; a photodetector 50 is placed at the focal point of the receiving lens 40 for converting the return light signal into an electrical signal for the back end to calculate the distance of the target object a.

The fiber laser sends pulse laser light, the pulse laser light is transmitted to the collimator through the single-mode fiber, the pulse laser light is compressed into light beams with small divergence angles close to parallel through the collimator and irradiates the surface of a target object at a distance, the laser light is scattered on the surface of the object, a part of return light is received and converged by the receiving lens, ambient light except for working wavelength is filtered through the optical filter, the converged focus is located on the surface of the photoelectric detector, the photoelectric detector converts received return light signals into electric signals, and the electric signals are transmitted to the rear end to calculate distance information of the target object to be measured.

Referring to fig. 2, the damage threshold of the photodetector 50 is low, and the collimator 20 and the receiving lens 40 are not coaxially arranged at all, so that the damage of the photodetector can be avoided when facing a near-distance high-reflectivity target due to the existence of the blind zone B.

As another preferred embodiment of the present invention, referring to fig. 3 and 4, for convenience of arrangement and installation, a clamping groove 41 is formed on the receiving lens 40, and the collimator 20 is installed in the clamping groove 41. The size of draw-in groove 41 and collimator external diameter phase-match install collimator 20 in the draw-in groove 41 of receiving lens 40, and collimator 20 direction angle can freely be adjusted through auxiliary fixtures, is convenient for make emission optical axis 1 parallel with receiving optical axis 2, fixes through the form of gluing, and this installation form is favorable to further reducing transceiver module volume size and helps reducing the size of front end scanning mechanism.

According to the embodiment, the receiving and transmitting optical path paraxial arrangement is adopted, so that the influence of internal stray light on the performance and the test result of the photoelectric detector in an optical system can be effectively eliminated, and the damage risk of the near-distance high-reflectivity target on the photoelectric detector can be effectively reduced. The transmitting-receiving distance measuring optical system is compact in structure and simple to assemble. The transmitting light path is completely separated from the receiving light path, so that the problem of internal stray light can be effectively solved; in addition, referring to fig. 2, there is an incomplete overlapping region between the receiving field angle α and the emission beam divergence angle β, that is, the paraxial optical path has a certain blind zone B compared to the coaxial optical path, so that the risk of damage to the photodetector caused by a near-distance high-reflectivity target can be effectively reduced, and the range of the blind zone mainly depends on the offset of the receiving and transmitting optical axes, the emission beam divergence angle β, and the receiving field angle α.

Further, an optical filter 60 is further disposed between the receiving lens 40 and the photodetector 50, and the optical filter 60 is disposed between the receiving lens 40 and the photodetector 50, and is configured to filter light with a wavelength other than the operating wavelength, so as to reduce the influence of ambient light on the effective optical signal.

Finally, it is noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should be covered by the scope of the claims of the present invention.

Claims

1. The laser scanner transmitting and receiving paraxial optical system comprises a fiber laser and a collimator, wherein the fiber laser is connected with the collimator through a single mode fiber; it still includes receiving lens and photoelectric detector, characterized by: the optical axis of the collimator is parallel to but not coaxial with the optical axis of the receive lens.

2. The transmit-receive paraxial optical system of a laser scanner of claim 1, wherein: the collimator divergence angle is in the range of 0-5 mrad.

3. The transmit-receive paraxial optical system of a laser scanner of claim 1, wherein: the receiving lens is a convex lens.

4. The transmitting/receiving paraxial optical system of a laser scanner according to claim 3, wherein: the receiving lens is a plano-convex lens.

5. The transmit-receive paraxial optical system of a laser scanner of claim 2, wherein: and two light transmission surfaces of the receiving lens are plated with antireflection films.

6. The transmit-receive paraxial optical system of a laser scanner of claim 1, wherein: the receiving lens is provided with a clamping groove, and the collimator is arranged in the clamping groove.

7. The transmitting/receiving paraxial optical system of a laser scanner according to claim 1, wherein: and an optical filter is also arranged between the receiving lens and the photoelectric detector.