CN215867099U

CN215867099U - Adjusting lens cone type laser light source angle expanding lens

Info

Publication number: CN215867099U
Application number: CN202121903202.9U
Authority: CN
Inventors: 王起维; 张�浩; 李向春
Original assignee: Institute of Oceanographic Instrumentation Shandong Academy of Sciences
Current assignee: Institute of Oceanographic Instrumentation Shandong Academy of Sciences
Priority date: 2021-08-16
Filing date: 2021-08-16
Publication date: 2022-02-18
Anticipated expiration: 2031-08-16

Abstract

The application discloses adjust lens barrel type laser source angle expanding lens, including having the internal screw thread lens cone, fixed lens, zoom lens and back fixed lens before setting gradually in the lens cone, be equipped with the zoom lens snap ring on the zoom lens, it is rotatory zoom lens snap ring, zoom lens snap ring move along the lens cone internal thread, a lens cone tip is equipped with the adaptor. The angle expanding lens has the advantages of large adjustment range of the divergence angle of the light beam, continuously adjustable spot size, good linearity, compact structure, small volume, simple assembly and adjustment and the like.

Description

Adjusting lens cone type laser light source angle expanding lens

Technical Field

The invention relates to the field of laser active illumination imaging detection and laser illumination optics, in particular to a manually-adjusted lens barrel type laser light source angle expanding lens.

Background

In recent years, the underwater range-gated laser active imaging detection technology becomes a research hotspot in the field of computational imaging. The structure and the working principle of the underwater range gating laser active imaging detection system are basically the same as those of a laser radar, and all or key characteristic parts of a target object at a certain distance underwater are illuminated by adjusting the divergence angle of emitted laser beams, so that the imaging detection of the underwater target object is realized. At present, the optical and mechanical design and manufacture of the laser zoom beam expander are relatively mature, the technology is suitable for the condition of collimated light illumination, and the divergence angle of a laser beam needs to be changed in order to change the spot size of laser emitted by an imaging detection system to a certain distance. The purpose of adjusting the divergence angle of the laser beam can be achieved by adjusting the distance between the beam expanding objective lens and the ocular lens, at present, the adjustment range of the divergence angle of the laser beam expanding objective lens on the market is generally small, the system structure is complex, the adjustment process is complex, the adjustment efficiency is low, and the linearity of the change of the spot size is poor.

SUMMERY OF THE UTILITY MODEL

Based on the problems, the application provides a manual adjustment lens barrel type laser light source angle expanding lens aiming at a 532nm pulse laser light source of a laser underwater imaging detection system, and the size change range of the aperture of a laser spot at 30m in the air can reach 300-3000mm by manual adjustment of a laser beam with the diameter of 10mm incident to the angle expanding lens. The angle expanding lens has the advantages of large adjustment range of the divergence angle of the light beam, continuously adjustable spot size, good linearity, compact structure, small volume, simple assembly and adjustment and the like. The technical proposal is that the method comprises the following steps,

the utility model provides an adjust lens cone formula laser light source angle expanding mirror, is including having the internal screw thread lens cone, fixed lens before setting gradually, zoom lens and back fixed lens in the lens cone, be equipped with the zoom lens snap ring on the zoom lens, it is rotatory zoom lens snap ring, zoom lens snap ring move along the lens cone internal thread, a lens cone tip is equipped with the adaptor.

Further, the front fixed lens is a concave lens, a front lens clamping ring is arranged on the front fixed lens, an external thread matched with the internal thread of the lens barrel is arranged on the front lens clamping ring, and the front fixed lens clamping ring is positioned at the front end of the lens barrel; the rear fixed lens is a convex lens, a rear lens clamping ring is arranged on the rear fixed lens, an external thread matched with the internal thread of the lens barrel is arranged on the rear lens clamping ring, and the rear fixed lens clamping ring is positioned at the rear end of the lens barrel.

Furthermore, the zoom lens is a concave lens, and an external thread matched with the internal thread of the lens barrel is arranged on the zoom lens clamping ring.

Furthermore, a groove is formed in the lens barrel, and the zoom lens clamping ring is rotated through the groove.

Furthermore, a scale is arranged on the lens barrel.

Furthermore, a laser beam with the diameter of 10mm passes through the front fixed lens, the zoom lens and the rear fixed lens in sequence, and the distance between the zoom lens and the front fixed lens is adjusted, so that the size change range of the aperture of the laser spot at 30m in the air reaches 300-3000 mm.

Advantageous effects

The angle expanding lens has the advantages of large adjustment range of the divergence angle of the light beam, continuously adjustable spot size, good linearity, compact structure, small volume, simple assembly and adjustment and the like.

Drawings

The invention is further described below with reference to the accompanying drawings and embodiments:

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

FIG. 2 is a schematic cross-sectional view of the present invention. Wherein, 1-front fixed lens; 101-front lens retainer ring; 2-a zoom lens; 201-zoom lens snap ring, 3-rear fixed lens; 4-a lens barrel; 5-an adapter; 6-a groove; 7-scale, 8-laser beam.

FIG. 3 is a schematic diagram of a laser beam with a diameter of 10mm after passing through a lens barrel of an angle expanding lens. The concave surface of the front fixed lens is a first refraction surface, and the other surface of the front fixed lens is a second refraction surface; the concave surface of the zoom lens is a third refraction surface, and the other surface of the zoom lens is a fourth refraction surface; rear endThe convex surface of the fixed lens is a fifth refractive surface, and the other surface of the fixed lens is a sixth refractive surface, wherein d₁-the distance between the second refractive surface and the third refractive surface in the coaxial optical system; d₂-the distance between the fourth to the fifth refractive surface in the coaxial optical system.

FIG. 4 is a schematic view of an adaptor having internal and external threads.

FIG. 5 is a schematic diagram of a coaxial optical system of the manual adjusting lens barrel type laser source angle expanding lens of the invention.

Among them, the symmetry axis (i.e., optical axis) of the PP' -coaxial system, the incident laser beam (caliber)

) Propagating along the axis of symmetry; after PQ (representing the half-aperture of incident light) in the object space passes through the angle expanding mirror of the invention, images P ' Q ' are generated in the image space, y and y ' represent the object height and the image height respectively, namely the half-aperture size (y is 5mm) of the incident light beam and the half-aperture size (y is D/2, and the spot diameter at D-30 m) of the emergent light beam reaching the target object; l and l' represent the system object distance and image distance, respectively; o is₁And O_mRespectively representing the centers of the 1 st refracting surface and the m (m is 6 in the invention) th refracting surface; n is₁And n'_mRespectively representing the refractive index of the image space medium of the 1 st refraction surface and the refractive index of the image space medium of the m-th refraction surface; the refractive index of the medium mentioned in the invention except the lens material is 1; u. of₁Representing the incident angle of the incident beam, parallel light incident u₁＝0；-u′_m(m in the present invention is 6) represents the exit angle of the exiting light beam.

FIG. 6 is a diagram illustrating adjustment of the distance d between the zoom lens and the front fixed lens₁A linear fit of the results was calculated for the change in spot diameter D at 30m in air.

Detailed Description

The following detailed description is exemplary and is intended to provide further explanation of the invention as claimed. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application.

As shown in fig. 1, 2 and 3, the manual adjustment barrel type laser light source angle expanding lens of the present invention comprises a cylindrical barrel 4 with internal threads, wherein a front fixed lens 1, a zoom lens 2 and a rear fixed lens 3 are installed in the barrel 4; laser beams are incident from the left end of an angle expanding lens barrel 4 and sequentially pass through a front fixed lens 1, a zoom lens 2 and a rear fixed lens 3, wherein the front fixed lens 1 and the zoom lens 2 are both plano-concave lenses, and the rear fixed lens 3 is a plano-convex lens; the front fixed lens 1 is fixed at the left end of the lens barrel 4 through a front lens clamping ring 101, the rear fixed lens 3 is fixed at the right end of the lens barrel 4 through a rear lens clamping ring 301, and the zoom lens 2 is fixed between the front fixed lens 1 and the rear fixed lens 3 through a zoom lens clamping ring 201 and moves along the internal thread of the lens barrel 4; the front lens snap ring 101, the zoom lens snap ring 201, and the rear lens snap ring 301 are all provided with external threads that match the internal threads of the lens barrel 4. The outer side wall of the lens barrel 4 is provided with a scale 7.

The lens barrel 4 is provided with two symmetrical grooves 6 along the axial direction, and the two symmetrical grooves 6 are utilized to manually rotate the zoom lens clamping rings 201 fixed at two ends of the zoom lens, move left and right to change the position of the zoom lens 2, change the divergence angle of the emergent light beam and achieve the purpose of obtaining the required light spot size in the light field of a target object at a certain distance; as shown in fig. 5 and 6, an adaptor 5 with internal and external threads is mounted at the left end of the angle expanding lens barrel through threaded connection, and the angle expanding lens can be directly mounted on the laser light-emitting window through the adaptor 5.

The invention relates to a principle of an optical system of a manual adjusting lens cone type laser light source angle expanding lens, which comprises the following steps:

as shown in fig. 3, the manual adjustment barrel type angle expanding mirror optical system of the invention adopts a 'concave-convex' three-lens structure, and a coaxial optical system with 6 refraction surfaces (3 spherical surfaces and 3 planes) is formed by 2 plano-concave lenses and 1 plano-convex lens. The principle of the coaxial optical system is shown in FIG. 5. in FIG. 5, the first refracting surface (concave spherical surface) and the sixth refracting surface (flat surface) of the coaxial optical system of the angle expanding lens from left to right are drawn, and the middle part of the coaxial optical system isIts refracting surface is slight; as shown in FIG. 3, when the zoom lens 2 is manually adjusted to move left and right, the distance d between the second refractive surface and the third refractive surface in the coaxial optical system₁And the distance d between the fourth and fifth 5 refractive surfaces₂With a consequent change.

According to the theory of physics, under the condition of paraxial approximation, as shown in fig. 5, the object-image relationship of the coaxial optical system can be expressed as the following equation system:

L′_Q′＝T_Q′m S T_1Q L_Q (1)

wherein L is_QIncident ray QM through object point Q₁Is determined by the state matrix of (a),

L′_Q′outgoing ray M through object point Q_mThe state matrix of Q' is then used,

T_1Qfrom point Q to M₁The translation matrix of the points is then,

T_Q′mslave M_mThe translation matrix from point to point Q',

s-extended angle mirror system transfer matrix, S ═ R_mT_(m)(m-1)R_m-1……R₃T₃₂R₂T₂₁R₁(in the present invention, m is 6). Wherein R is_m(m 1 … 6) -the refractive matrix of the mth refractive surface; t is_(m)(m-1)(m-1 … 6) -a translation matrix between the m-1 th and the m-th refractive surfaces.

Wherein the translation matrix

Translation matrix

The technical parameters of the optical elements of the manual regulation lens barrel type laser source angle expanding lens system are shown in the table 1. As shown in fig. 3 and 5, in the coaxial optical system of the magnifier, d is the distance between the front fixed lens and the rear fixed lens is determined, except when the zoom lens 2 is manually adjusted to move left and right₁And d₂Is out of a variable quantity (i.e. translation matrix T)₃₂And translation matrix T₅₄Is a variable) and the other parameters are constants, the distance d between the zoom lens and the front fixed lens can be solved according to the above principle by using the formula (1)₁And the light spot diameter D of the light field of the target object at a certain distance.

TABLE 1 Manual adjustment of technical parameters of elements of mirror cylinder type laser light source angle expanding mirror optical system

The invention relates to a manual regulation lens barrel type laser light source angle expanding lens, which has the following specific design requirements:

light source characteristics of the angle expanding mirror: laser center wavelength: 532 nm; aperture of laser beam: 10 mm; laser beam divergence angle: 1 mrad;

the designed angle expanding mirror has the following technical indexes: 30m in the air (l)^′30m) the diameter of the light spot can be changed within 300-3000 mm.

According to the principle of the manually-adjusted barrel type laser light source angle expanding lens optical system, the distance from the first refraction surface to the sixth refraction surface of a coaxial system of the angle expanding lens is set to be 71.3mm according to the technical index to be reached by the designed angle expanding lens, the distance between the zoom lens 2 and the front fixed lens 1 is adjusted, and the calculation result and the linear fitting result of the change of the diameter of a light spot at a position of 30m in the air are respectively shown in a table 2 and a figure 6.

TABLE 2 adjusting zoom lens and frontDistance d of fixed lens₁Change of spot diameter D at 30m in air

According to the manual adjustment lens barrel type laser light source angle expanding lens disclosed by the invention, as shown in fig. 2 and 3, the divergence angle of an emergent light beam is changed by moving the zoom lens 2 left and right along the optical axis direction, the light field of a target object at 30m in the air is obtained, the change range of the obtained light spot size reaches 300-3000mm, and as can be seen from fig. 6, the change of the light spot size has better linearity.

When the aperture or irradiation distance of the incident laser beam of the angle expanding mirror of the invention (namely the system object distance l) is changed^′) The size of the light spot obtained in the light field of the target object is changed along with the change of the size of the light spot; if the caliber or the irradiation distance of the incident laser beam is increased, the spot size of the light field of the target object is correspondingly increased, and otherwise, the spot size is reduced.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. The utility model provides an adjust lens cone formula laser light source angle expanding mirror, its characterized in that, is including having the internal screw thread lens cone, fixed lens before setting gradually, zoom lens and back fixed lens in the lens cone, be equipped with the zoom lens snap ring on the zoom lens, it is rotatory zoom lens snap ring, zoom lens snap ring move along the lens cone internal thread, a lens cone tip is equipped with the adaptor.

2. The adjustable lens barrel type laser light source angle expanding lens according to claim 1, wherein the front fixed lens is a concave lens, a front lens clamping ring is arranged on the front fixed lens, an external thread matched with the internal thread of the lens barrel is arranged on the front lens clamping ring, and the front fixed lens clamping ring is arranged at the front end of the lens barrel; the rear fixed lens is a convex lens, a rear lens clamping ring is arranged on the rear fixed lens, an external thread matched with the internal thread of the lens barrel is arranged on the rear lens clamping ring, and the rear fixed lens clamping ring is positioned at the rear part of the lens barrel.

3. The adjustable barrel type laser light source expander according to claim 1, wherein the zoom lens is a concave lens, and the zoom lens snap ring is provided with an external thread matching with the internal thread of the barrel.

4. The adjustable barrel type laser light source expander according to claim 1, wherein the barrel has a groove, and the zoom lens snap ring is rotated through the groove.

5. The adjustable barrel type laser light source angle expanding lens according to claim 1, wherein a scale is provided on the barrel.