Optical system antenna with large divergence angle and large receiving view field
Through the five-lens optical system antenna, the problem of small distance-measuring field of view in the prior art is solved, and a large divergence angle and a large receiving field of view are achieved, and dynamic target measurements of small targets can be performed in a large field of view.
Patent Information
- Application Number
- CN202421720478.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-19
- Publication Date
- 2025-07-04
- Estimated Expiration
- 2034-07-19
AI Technical Summary
The distance measurement field angle of existing optical systems is small, making it impossible to achieve dynamic target measurements within a large field of view.
It adopts a five-piece lens structure, including the first lens to form a transmitting antenna, and the other four lenses to form a receiving antenna. The lens material is H-ZF6 and H-K9L glass, and is coated with a 1535nm±5nm band resistant film. The filter film is used to improve transmittance. The lens surface is a spherical surface to achieve a large divergence angle and a large receiving field of view.
The large divergence angle is ≥2°, the receiving field of view is ±1.5°, and the distance-based field of view is 2°, so that dynamic target measurements of small targets can be performed in the large field of view.
Smart Images
Figure CN223065501U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of optical antennas of laser rangefinders, and particularly to an optical system antenna with a large divergence angle and a large receiving field of view. Background Art
[0002] When a solid-state laser is used in devices such as laser rangefinders and lidars, the laser beam emitted by the laser module needs to be collimated by a transmitting antenna and then projected onto the target to be measured, and the receiving antenna converges the laser echo reflected by the target to the photosensitive surface of the detector module. The existing optical system antennas generally have the problem of a small ranging field of view angle and cannot achieve the dynamic target measurement of small targets within a large field of view. Content of the Utility Model
[0003] Aiming at the defects of the existing technology, the utility model provides an optical system antenna with a large divergence angle and a large receiving field of view.
[0004] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:
[0005] An optical system antenna with a large divergence angle and a large receiving field of view includes a first lens, a second lens, a third lens, a fourth lens and a fifth lens. The first lens forms a transmitting antenna for collimating the laser beam emitted by the laser module and then projecting it onto the target to be measured. The remaining four lenses are coaxially arranged in sequence along the propagation direction of the target-reflected beam to form a receiving antenna. The receiving antenna is used to converge the laser beam reflected by the target to the detector. Among them, the first lens is a plano-concave lens, coaxially arranged with the laser, the incident surface is a plane, and the exit surface is a concave surface. The second lens is a plano-convex lens, the incident surface is a convex surface, and the exit surface is a plane. The third lens is a meniscus positive lens, the incident surface is a convex surface, and the exit surface is a concave surface. The fourth lens is a plano-concave lens, the incident surface is a concave surface, and the exit surface is a plane. The fifth lens is a meniscus positive lens, the incident surface is a convex surface, and the exit surface is a concave surface.
[0006] Further, the material of the first lens is H-ZF6 glass, and the materials of the second lens to the fifth lens are all H-K9L glass.
[0007] Further, both sides of the first lens, the second lens, the third lens, the fourth lens and the fifth lens are coated with an antireflection film in the 1535nm±5nm band to increase the transmittance of the antenna.
[0008] Further, a filter film with a central wavelength of 1535nm and a half-width of 50nm is coated on the plane side of the second lens.
[0009] Further, the curved surfaces of all lenses are spherical surfaces.
[0010] Advantageous Effects:
[0011] The optical system antenna of the present utility model has the characteristics of a large divergence angle and a large receiving field of view. The divergence angle is ≥2°, the effective clear aperture Φ = 43 mm, the system focal length is 35.63 mm, the receiving field of view is ±1.5°, and the ranging field of view angle is 2°. It can realize the dynamic target measurement of small targets within a large field of view. Description of the Drawings
[0012] Figure 1 Schematic diagram of the optical system antenna of the present utility model.
[0013] Reference numerals: 1, first lens; 2, second lens; 3, third lens; 4, fourth lens; 5, fifth lens; 6, laser; 7, detector. Detailed Embodiment
[0014] The following further describes the present utility model in detail with reference to the drawings and specific embodiments.
[0015] As Figure 1 shown, an optical system antenna with a large divergence angle and a large receiving field of view includes a first lens 1, a second lens 2, a third lens 3, a fourth lens 4, and a fifth lens 5. Among them, the first lens 1 forms a transmitting antenna, which is used to collimate the laser beam emitted by the laser 6 module and project it onto the target to be measured. The first lens 1 is a plano-concave lens, coaxially arranged with the laser 1, the incident surface is a plane, and the exit surface is a concave surface. The remaining four lenses are coaxially arranged in sequence along the propagation direction of the target-reflected light beam to form a receiving antenna. The receiving antenna is used to converge the laser beam reflected by the target to the detector 7. Among them, the second lens 2 is a plano-convex lens, the incident surface is a convex surface, and the exit surface is a plane. The third lens 3 is a meniscus positive lens, the incident surface is a convex surface, and the exit surface is a concave surface. The fourth lens 4 is a plano-concave lens, the incident surface is a concave surface, and the exit surface is a plane. The fifth lens 5 is a meniscus positive lens, the incident surface is a convex surface, and the exit surface is a concave surface.
[0016] The surfaces of the first lens 1, the second lens 2, the third lens 3, the fourth lens 4, and the fifth lens 5 all need to be coated with an antireflection film in the 1535 nm ± 5 nm band, which can increase the transmittance of the antenna.
[0017] The curved surfaces of each lens, that is, the exit surface of the first lens 1, the incident surface of the second lens 2, the incident surface and the exit surface of the third lens 3, the incident surface of the fourth lens 4, and the incident surface and the exit surface of the fifth lens 5, are all spherical surfaces.
[0018] The plane side of the second lens 2 needs to be coated with a filter film with a central wavelength of 1535 nm and a half-width of 50 nm to filter out stray visible light.
[0019] The specific parameters of the optical system in this embodiment are as follows:
[0020] The outer diameter of the first lens 1 is D = 6 mm, the radius of curvature R1 = 15 mm ± 0.5 mm, the radius of curvature R2 = ∞, the central thickness d = 1.8 mm ± 0.1 mm, and the material is H-ZF6.
[0021] The outer diameter of the second lens 2 is D = 44 mm, the radius of curvature R1 = 43.698 mm ± 0.5 mm, the radius of curvature R2 = ∞, the central thickness d = 8.5 mm ± 0.1 mm, and the material is H-K9L.
[0022] The air gap between the second lens 2 and the third lens 3 is: 0.6 mm.
[0023] The outer diameter of the third lens 3 is D = 39 mm, the radius of curvature R1 = 27.04 mm ± 0.5 mm, the radius of curvature R2 = 91.783 mm ± 0.5 mm, the central thickness d = 10 mm ± 0.1 mm, and the material is H-K9L.
[0024] The air gap between the third lens 3 and the fourth lens 4 is: 4.27 mm.
[0025] The outer diameter of the fourth lens 4 is D = 35 mm, the radius of curvature R1 = -120.682 mm ± 0.5 mm, the radius of curvature R2 = ∞, the central thickness d = 4.2 mm ± 0.1 mm, and the material is H-K9L.
[0026] The air gap between the fourth lens 4 and the fifth lens 5 is 6.48 mm.
[0027] The outer diameter of the fifth lens 5 is D = 21 mm, the radius of curvature R1 = 11.844 mm ± 0.5 mm, the radius of curvature R2 = 20.206 mm ± 0.5 mm, the central thickness d = 5 mm ± 0.1 mm, and the material is H-K9L.
[0028] The present utility model uses the first lens 1 to form a transmitting antenna to collimate the laser beam emitted by the laser module and project it onto the target to be measured, and the second lens 2, the third lens 3, the fourth lens 4, and the fifth lens 5 form a receiving antenna to converge the laser beam reflected from the target using a telephoto system.
[0029] The divergence angle of the antenna of this optical system is ≥2°, the effective clear aperture Φ = 43 mm, the system focal length is 35.63 mm, the receiving field of view is ±1.5°, and the ranging field of view angle is 2°, thus enabling the dynamic target measurement of small targets within a 2° field of view.
[0030] The above are only the preferred embodiments of the present utility model, and do not impose any form of limitation on the present utility model. Although the present utility model has been disclosed above with the preferred embodiments, it is not intended to limit the present utility model. Any person skilled in the art can make some changes or modifications to equivalent embodiments with equivalent changes by using the disclosed technical content within the scope of the technical solution of the present utility model. However, as long as it does not depart from the content of the technical solution of the present utility model, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present utility model still fall within the scope of the technical solution of the present utility model.
Claims
1. An optical system antenna with a large divergence angle and a large receiving field of view, characterized in that It includes a first lens (1), a second lens (2), a third lens (3), a fourth lens (4) and a fifth lens (5). The first lens (1) forms a transmitting antenna, which is used to collimate the laser beam emitted by the laser (6) module and project it onto the target to be measured. The remaining four lenses are coaxially arranged in sequence along the propagation direction of the target reflected beam to form a receiving antenna. The receiving antenna is used to converge the laser beam reflected by the target to the detector (7). Among them, the first lens (1) is a plano-concave lens, coaxially arranged with the laser (6), with the incident surface being a plane and the exit surface being a concave surface. The second lens (2) is a plano-convex lens, with the incident surface being a convex surface and the exit surface being a plane. The third lens (3) is a meniscus positive lens, with the incident surface being a convex surface and the exit surface being a concave surface. The fourth lens (4) is a plano-concave lens, with the incident surface being a concave surface and the exit surface being a plane. The fifth lens (5) is a meniscus positive lens, with the incident surface being a convex surface and the exit surface being a concave surface.
2. The optical system antenna with a large divergence angle and a large receiving field of view according to claim 1, wherein The material of the first lens (1) is H-ZF6 glass, and the materials of the second lens (2), the third lens (3), the fourth lens (4) and the fifth lens (5) are all H-K9L glass.
3. An optical system antenna with a large divergence angle and a large receiving field of view according to claim 1, characterized in that, The incident surfaces and the exit surfaces of the first lens (1), the second lens (2), the third lens (3), the fourth lens (4) and the fifth lens (5) are all coated with an antireflection film in the 1535nm±5nm band to increase the antenna transmittance.
4. The optical system antenna with a large divergence angle and a large receiving field of view according to claim 1, characterized in that, The plane side of the second lens (2) is coated with a filter film with a central wavelength of 1535nm and a half-width of 50nm.
5. An optical system antenna with a large divergence angle and a large receiving field of view according to claim 1, characterized in that, The curved surfaces of each lens are all spherical surfaces.