An interruptible variable power laser beam expander

Abstract

The utility model discloses an interruptible zoom laser beam expander lens, containing two groups of sliding mirror groups, a group of fixed mirror groups that are installed in main mirror barrel, and hand wheel and cam structure that are matched with sliding mirror group. The main mirror barrel is provided with the taper hole that can be accurate interruptible zoom, and the hand wheel of sliding mirror group is provided with the accurate positioning clamping groove structure. The first lens, third and fourth lenses that are installed in sliding mirror group are provided with accurate limit when axially translating. The utility model discloses an interruptible zoom laser beam expander lens, can realize 1-4x interruptible zoom, makes up the defect that fixed ratio beam expander cannot realize the adjustment of beam expansion ratio, also reduces the insufficient that continuous zoom beam expander has no accurate reference point when adjusting, so that some calibration, measurement application can quickly find the calibration position, and through the limiting function of mechanical design, the beam expansion ratio has good consistency, and the debugging process has higher repeatability.

Description

Technical Field

[0001] This utility model belongs to the field of laser lenses, specifically relating to a laser beam expander with intermittent zoom. Background Technology

[0002] With the rapid development of the laser industry, the application of laser lenses is becoming increasingly widespread, and various laser lenses are constantly being innovated, with continuous updates to their design concepts and quality. Mainstream laser beam expanders fall into two main categories: fixed magnification and continuously variable magnification. For example, Chinese patent CN101750745A discloses a laser beam expander system for urban lighting demonstrations, with a beam expansion ratio of 20x, which is non-adjustable and cannot be changed. While continuously variable magnification beam expanders have the advantage of continuously changing the beam expansion ratio, they do not provide a precise definition and marking for the specified magnification. For instance, Chinese patent CN118897370A discloses a variable magnification laser beam expander, which, although adjustable in magnification, lacks a precise limiting structure. Such designs require an extremely complex calibration process before use to find the specific position information corresponding to the beam expansion ratio, and then adjust each moving component to the specified position to obtain the specified beam expansion ratio. Utility Model Content

[0003] This invention discloses an intermittently variable magnification laser beam expander, which overcomes the limitation of fixed magnification beam expanders in adjusting the beam expansion ratio, and also compensates for the lack of a precise reference point during adjustment in continuous variable magnification beam expanders. This allows for rapid location of the calibration position in certain calibration and metrology applications, eliminating complex pre-calibration work. Furthermore, the mechanically designed limiting function ensures excellent consistency in the beam expansion ratio, exhibiting high repeatability (positioning repeatability error ±0.005mm) during repeated use, eliminating the need for repeated calibration. This lens is suitable for scenarios requiring rapid magnification switching, such as laser calibration and medical aesthetic equipment, replacing the original multi-lens configuration on a single machine.

[0004] According to the present invention, a laser beam expander capable of intermittent magnification is achieved through the following technical solution: A laser beam expander capable of precise intermittent magnification is provided. A magnification cam (4) and a magnification handwheel (3) are installed on the left side of the main lens barrel (5). A pin (2-1) passes through the magnification cam (4) and the main lens barrel (5) and is connected to the internal magnification sliding lens barrel (11). A magnification locking ring (1-1) is installed on the left side of the magnification cam (4), and a set screw (9-1) is installed on the magnification locking ring (1-1) to fix the magnification locking ring (1-1) to the main lens barrel (5), thereby restricting the axial translation of the magnification cam (4) and the magnification handwheel (3) during rotation. A compensation cam (7) and a compensation handwheel (6) are installed on the right side of the main lens barrel (5). A pin (2-2) passes through the compensation cam (7) and the main lens barrel (5) and is connected to the internal compensation sliding lens barrel (11). 8) Connected, a compensation locking ring (1-2) is installed on the right side of the compensation cam (7), and a set screw (9-2) is installed on the compensation locking ring (1-2) to fix the compensation locking ring (1-2) to the main lens barrel (5), thereby restricting the compensation cam (7) and the compensation handwheel (6) from axial translation when rotating; the first pin (2-1) drives the variable magnification sliding lens barrel (11) to axial translation, and the first lens (G1) and the first locking ring (10) are installed in the variable magnification sliding lens barrel (11); the second pin (2-2) drives the compensation sliding lens barrel (18) to axial translation, and the third lens (G3), the fourth lens (G4), the second spacer (17), and the third locking ring (16) are installed in the compensation sliding lens barrel (18); the second fixed lens (G2), the first spacer (15), and the second locking ring (14) are installed inside the main lens barrel (5).

[0005] A further preferred technical solution of the intermittent zoom laser beam expander according to the present invention is as follows: The end faces of the main lens barrel (5) that connect with the zoom handwheel (3) and the compensation handwheel (6) are each provided with four precisely machined conical holes for indicating the accurate positions of different beam expansion ratios (1x, 2x, 3x, 4x). The cylindrical surface of the main lens barrel (5) is marked with indicator lines for different beam expansion ratios.

[0006] A further preferred technical solution of the intermittent zoom laser beam expander according to the present invention is as follows: the end face of the zoom handwheel (3) connected to the main lens barrel (5) is provided with a cylindrical spring slot hole, in which a compression spring (12-1) is installed, and a steel ball (13-1) is installed at the end of the compression spring (12-1); the end face of the compensation handwheel (6) connected to the main lens barrel (5) is also provided with a cylindrical spring slot hole, in which a compression spring (12-2) is installed, and a steel ball (13-2) is installed at the end of the compression spring (12-2). The compression spring and the steel ball are positioning and limiting devices for intermittent zoom.

[0007] A further preferred technical solution of the intermittently zoomable laser beam expander according to the present invention is as follows: the first lens (G1) can be translated along the optical axis, the second lens (G2) is a fixed lens, and the third lens (G3) and the fourth lens (G4) are translated synchronously, forming an overall "moving-fixed-moving" zoom structure.

[0008] A further preferred technical solution of the intermittent zoom laser beam expander according to the present invention is as follows: the first lens (G1) moves along the optical axis so that its interval with the second lens (G2) has four designated positions (d11 = 30.13 mm, d12 = 26.14 mm, d13 = 22.17 mm, d14 = 18.19 mm); the third lens (G3) and the fourth lens (G4) move synchronously along the optical axis so that their interval with the second lens (G2) moves to four designated positions (d21 = 40.29 mm, d22 = 46.95 mm, d23 = 49.18 mm, d24 = 50.29 mm) respectively, so as to achieve intermittent zoom of 1x, 2x, 3x, and 4x.

[0009] According to the present invention, a further preferred technical solution of the intermittent zoom laser beam expander is as follows: the left conical hole on the main lens tube (5) is engaged with the compression spring (12-1) and steel ball (13-1) in the zoom handwheel (3), and the right conical hole is engaged with the compression spring (12-2) and steel ball (13-2) in the compensation handwheel (6), so as to achieve a positioning accuracy of ±0.005mm at the four zoom positions.

[0010] Compared with the prior art, the technical solution of this utility model has the following advantages / benefits: This invention features intermittent variable magnification beam expansion, enabling intermittent changes in expansion ratios of 1x, 2x, 3x, and 4x. Through precise mechanical structure design—including a positioning cone hole on the main tube and a spring groove on the rotating handwheel, along with a compression spring and steel balls—precise positioning can be achieved at all four magnifications, with a measured positioning accuracy of 0.005mm, resulting in a magnification accuracy of 0.03%. Attached Figure Description

[0011] The following are accompanying drawings illustrating the technical solution of this utility model. It should be understood that the drawings only show some embodiments of this utility model and should not be considered as limiting the scope. Those skilled in the art can obtain other related drawings based on these drawings without any creative effort.

[0012] Figure 1This is a schematic diagram of the mechanical structure of an intermittently variable magnification laser beam expander according to the present invention. The variable magnification handwheel (3) and the compensation handwheel (6) are made transparent to more clearly show the cooperation between the internal variable magnification cam (4) and the compensation cam (7).

[0013] Figure 2 This is a schematic diagram of the internal structure of an intermittently variable magnification laser beam expander according to this utility model.

[0014] Figure 3 This is a schematic diagram of the optical design scheme of an intermittently variable magnification laser beam expander according to this utility model.

[0015] Figure 4 This is a schematic diagram of the intermittent zoom position points of a laser beam expander with intermittent zoom capability according to this utility model.

[0016] Figure 5 This is the output wavefront diagram of a discontinuous variable magnification laser beam expander of this invention at a beam expansion ratio of 1x and a wavelength of 405nm.

[0017] Figure 6 This is the output wavefront diagram of a discontinuous variable magnification laser beam expander of this invention at a beam expansion ratio of 2x and a wavelength of 405nm.

[0018] Figure 7 This is the output wavefront diagram of a discontinuous variable magnification laser beam expander of this invention at a beam expansion ratio of 3x and a wavelength of 405nm.

[0019] Figure 8 This is the output wavefront diagram of a discontinuous variable magnification laser beam expander of this invention at a beam expansion ratio of 4x and a wavelength of 405nm.

[0020] The markings in the diagram are as follows: 1-1-Magnification locking ring, 1-2-Compensation locking ring, 2-1-Pin one, 2-2-Pin two, 3-Magnification handwheel, 4-Magnification cam, 5-Main lens barrel, 6-Compensation handwheel, 7-Compensation cam, 8-1-Magnification handwheel locking pin, 8-2-Compensation handwheel locking pin, 9-1-Setting screw one, 9-2-Setting screw two, 10-Locking ring one, 11-Magnification sliding lens barrel, 121-Compression spring one, 12-2-Compression spring two, 13-1-Steel ball one, 13-2-Steel ball two, 14-Locking ring two, 15-Spacer one, 16-Locking ring three, 17-Spacer two, 18-Compensation sliding lens barrel; G1 - First lens, G2 - Second lens, G3 - Third lens, G4 - Fourth lens; The spacing between G1 and G2 at the d11-1x beam expansion ratio. The spacing between G3 and G2 at the d21-1x beam expansion ratio. The spacing between G1 and G2 at a beam expansion ratio of d12-2x The spacing between G3 and G2 at a beam expansion ratio of d22-2x The interval between G1 and G2 at the d13-3x beam expansion ratio. The interval between G3 and G2 at the d23-3x beam expansion ratio. The spacing between G1 and G2 at a beam expansion ratio of d14-4x The interval between G3 and G2 at a beam expansion ratio of d24-4x. Detailed Implementation

[0021] The technical solution of this utility model will be further described clearly, completely, and in detail below with reference to specific embodiments. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0022] Unless otherwise defined, the technical terms used in this invention should be understood in the ordinary sense by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity limitation, or importance, but are merely used to distinguish different components. Similarly, terms such as "connection" and "interlocking" used in this embodiment are not limited to physical mechanical connections, but can include electrical connections, spatial optical paths, fiber optic beam transmissions, and other connections.

[0023] Example 1:

[0024] This embodiment mainly describes the mechanical structure design method of an intermittently magnifying laser beam expander according to the present invention, and details its precise positioning and intermittent magnification structural design scheme.

[0025] Figure 1This is a schematic diagram of the mechanical structure of an intermittent zoom laser beam expander according to this utility model. A zoom cam (4) with a cam groove is installed at the left end of the main lens barrel (5). A zoom handwheel (3) is fixed to the outside of the cam. The zoom handwheel (3) and the zoom cam (4) are connected by a zoom handwheel locking pin (8-1) and are fixed with adhesive to prevent relative movement between them. When the zoom handwheel (3) is rotated around the main lens barrel (5), it drives the zoom cam (4) to rotate together. A zoom locking ring (1-1) is installed on the left side of the zoom cam (4), and the zoom locking ring (1-1) is fixed to the main lens barrel (5) by a set screw (9-1), thereby preventing axial translation when the zoom cam (4) and zoom handwheel (3) rotate. Similarly, the compensation cam (7) and compensation handwheel (6), compensation handwheel locking pin (8-2), compensation locking ring (1-2), and set screw (9-2) are all installed using the same principle.

[0026] Figure 2 This is a schematic diagram of the internal structure design of an intermittent zoom laser beam expander according to the present invention. Pin 1 (2-1) is connected to the zoom sliding lens barrel (11) and passes through the straight slot hole on the main lens barrel (5), tangent to the cam on the zoom cam (4). The zoom sliding lens barrel (11) is equipped with a first lens (G1) and a locking ring 1 (10). When the zoom handwheel (3) rotates, it drives the zoom cam (4) to rotate, while simultaneously constraining pin 1 (2-1) to move in the cam groove of the zoom cam (4) and the straight slot hole of the main lens barrel (5). That is, the rotational motion of the zoom handwheel (3) is transmitted as the first lens (G1) to translate axially along the straight slot hole on the main lens barrel (5). Similarly, pin 2 (2-2) is connected to the compensation sliding lens barrel (18) and passes through the straight slot hole on the main lens barrel (5), tangent to the cam on the compensation cam (7). The compensating sliding lens barrel (18) houses a third lens (G3), a fourth lens (G4), a spacer ring two (17), and a locking ring three (16). The third lens (G3) and the fourth lens (G4) are fixed relative to each other. When the compensating handwheel (6) rotates, it drives the compensating cam (7) to rotate. At the same time, the constraint pin two (2-2) moves in the cam groove of the compensating cam (7) and the straight slot hole of the main lens barrel (5). That is, the rotational motion of the compensating handwheel (6) is transmitted to the third lens (G3) and the fourth lens (G4) to translate axially along the straight slot hole on the main lens barrel (5).

[0027] When the first lens (G1) moves to a distance of 30.13mm from the second lens (G2), and the compensation lens group consisting of the third lens (G3) and the fourth lens (G4) moves to a distance of 40.29mm from the second lens (G2), the intermittent zoom laser beam expander of this invention achieves a 1x beam expansion ratio output. At this position, a cylindrical spring slot hole with a depth of 5mm is provided on the right end face of the zoom handwheel (3) for installing the compression spring (12-1) (diameter 3mm, wire diameter 0.3mm, free height 6mm). A steel ball (13-1) with a diameter of 3mm is installed at the end of the compression spring, and a conical hole with a depth of 1mm and a diameter of about 2.8mm is provided on the main lens tube (5) corresponding to the position of the steel ball (13-1). At this time, the steel ball (13-1) falls exactly into the conical hole on the main lens tube (5) and is locked, completing the precise positioning of the 1x zoom position. Similarly, the movement of the compensating lens group composed of the third lens (G3) and the fourth lens (G4) in the main lens tube (5) is also achieved using the same principle, which will not be elaborated here.

[0028] In this embodiment, four precisely machined conical holes are provided on the end face of the main lens barrel (5) to indicate the accurate positions of different lens expansion ratios (1x, 2x, 3x, 4x). The positioning of the four conical holes is calculated using the following method: the difference Δ between the lens spacing dll and d12, the pitch p of the zoom cam (4), and the rotation angle α of the zoom handwheel (3) when rotating from 1x to 2x expansion ratio have the following relationship: That is, the angle between the second conical hole and the first conical hole: By analogy, the positions of the remaining conical holes can be accurately located, and the positioning method of the compensation handwheel (6) is the same. By giving high-precision tolerance requirements to the machining of each conical hole, the machining accuracy of the included angle of each conical hole can reach 0.05° as tested by a coordinate measuring machine. The pitch p of the zoom cam (4) is 33mm. According to the above relationship formula, the axial positioning accuracy of the moving lens group can be calculated to be 0.005mm. Then, the zoom accuracy of the entire lens is simulated to be 0.03% by optical simulation software.

[0029] In this embodiment, the initial positions of the compression spring 1 (12-1) and the steel ball 1 (13-1) on the magnification handwheel (3) are located at the first conical hole position (1x position). Since the compression spring 1 (12-1) has a certain amount of extension and contraction, when the magnification handwheel (3) is rotated continuously with a slightly larger force, the steel ball 1 (13-1) is squeezed into the cylindrical hole of the compression spring 1 (12-1) and the magnification handwheel (3), so that the magnification handwheel (3) can continue to rotate. When the steel ball 1 (13-1) reaches the second conical hole position (2x position), the compression spring 1 (12-1) is released, and the steel ball 1 (13-1) is ejected and falls into the second conical hole. The magnification handwheel (3) reaches the 2x expansion ratio position. If the magnification handwheel (3) is rotated continuously, it will go through the 3x and 4x expansion ratio positions. Similarly, the movement mode of the compensation handwheel (6) is the same. At these four positions, the lens exhibits good stability and repeatability due to the ingenious constraints of its mechanical structure design.

[0030] In this embodiment, all lenses have strict processing tolerance requirements, such as a diameter tolerance of <0.02mm and eccentricity controlled within 1 minute. The mechanical lens barrel tolerance is <0.02mm, and the coaxiality is <0.01mm. These measures can effectively ensure the coaxiality of the assembly and ensure good beam pointing stability (<1mrad) of the emitted beam during the zoom process. The beam pointing stability test employed the following method: A beam profilometer was used to collect the center coordinates of the output beam at different magnification ratios at a specified distance (10 meters), and the maximum deviation *c* from 1x to 4x beam expansion ratios was calculated. Then, using… The following formula calculates the beam pointing stability angle range: The measured value of c is less than 10 mm. According to the calculation, θ is less than 0.057°, which is less than 1 mrad.

[0031] Example 2:

[0032] This embodiment mainly describes the optical system implementation scheme of the intermittently zoomable laser beam expander of this utility model, details the cooperation relationship of each optical component, and the optical principle of realizing intermittent zoom.

[0033] Figure 3 This is a schematic diagram of the optical design scheme of an intermittently magnifying laser beam expander according to the present invention, including a first lens (G1), a second lens (G2), a third lens (G3), and a fourth lens (G4) arranged sequentially from the incident end to the exit end; the first lens (G1) can be translated along the optical axis; the second lens (G2) is a fixed lens, directly mounted on the main lens barrel (5) and with a coaxiality of <0.01mm; the third lens (G3) and the fourth lens (G4) are translated together as a whole. The first lens (G1) has positive optical power and is made of crown glass H-K9L, with a convex surface facing the beam input direction and a convex surface facing away from the beam input direction; the second lens (G2) has negative optical power and is made of flint glass H-ZF2, with a concave surface facing the beam input direction and a concave surface facing away from the beam input direction; the third lens (G3) has negative optical power and is made of flint glass H-ZF2, with a convex surface facing the beam input direction and a concave surface facing away from the beam input direction; the fourth lens (G4) has positive optical power and is made of crown glass H-K9L, with a convex surface facing the beam input direction and a convex surface facing away from the beam input direction.

[0034] In this embodiment, the second lens (G2) is a fixed lens, and the first lens (G1) is translated along the optical axis, such that the intervals (d11, d12, d13, d14) between the first lens (G1) and the second lens (G2) have four designated positions (30.13mm, 26.14mm, 22.17mm, 18.19mm); the third lens (G3) and the fourth lens (G4) form a relatively stationary lens group, which is translated along the optical axis as a whole, and its intervals (d21, d22, d23, d24) with the second lens (G2) correspond to four designated positions (40.29mm, 46.95mm, 49.18mm, 50.29mm). When each lens and lens group reaches the designated position, the lens magnification ratios are 1x, 2x, 3x, and 4x, respectively, as shown in the attached figure. Figure 4 As shown.

[0035] In this embodiment, all lenses are meticulously designed, and their materials and radii of curvature are optimized using the effective damping least squares method, enabling the entire lens to achieve extremely high wavefront quality in the output beam, as shown in the attached figure. Figure 5-8 As shown.

[0036] In this embodiment, all lenses are spherical lenses and coated with anti-laser damage anti-reflection coatings. The single-sided transmittance is T > 99.8% @ 405nm, and the damage threshold is > 5J @ 532nm, 10Hz, 10ns (the test wavelength is the standard wavelength 532nm).

[0037] Table 1 shows the curvature radius, thickness, material, and spacing data of each lens surface of the intermittently zoomable laser beam expander of this invention. The units for curvature radius, thickness, and air spacing are all millimeters (mm).

[0038]

[0039] The overall parameters of the intermittent zoomable laser beam expander matched with Table 1 above are as follows: Operating wavelength: 405nm; Variation ratio: 1x, 2x, 3x, 4x discontinuous variation; Maximum incident beam aperture (for obtaining the diffraction-limited wavefront): 4 mm; Output wavefront quality: PV < 0.005λ @ 405nm; Output beam pointing stability during zoom process: <1 mrad; One-sided transmittance of coating: T > 99.8% @ 405nm ; Damage threshold: >5J@532nm, 10Hz, 10ns (test wavelength is standard wavelength 532nm); Lens diameter: Φ34mm Lens length: 123mm

[0040] Although the present invention has been specifically described with reference to the above embodiments, it should be understood by those skilled in the art that modifications or improvements can be made based on the content disclosed in the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A laser beam expander with intermittent zoom, characterized in that: The system includes a main lens barrel (5), on the left side of which a zoom cam (4) and a zoom handwheel (3) are mounted. A pin (2-1) passes through the zoom cam (4) and the main lens barrel (5) and is connected to an internal zoom sliding lens barrel (11). A zoom locking ring (1-1) is mounted on the left side of the zoom cam (4), and a set screw (9-1) is mounted on the zoom locking ring (1-1) to fix the zoom locking ring (1-1) to the main lens barrel (5), thereby preventing axial translation when the zoom cam (4) and the zoom handwheel (3) rotate. A compensation cam (7) and a compensation handwheel (6) are mounted on the right side of the main lens barrel (5). A pin (2-2) passes through the compensation cam (7) and the main lens barrel (5) and is connected to an internal compensation sliding lens barrel (18). A compensation lock is mounted on the right side of the compensation cam (7). The compensation locking ring (1-2) is fitted with a set screw (9-2) to fix the compensation locking ring (1-2) to the main lens barrel (5), thereby preventing the compensation cam (7) and compensation handwheel (6) from axially translating when they rotate; the pin (2-1) drives the variable magnification sliding lens barrel (11) to axially translate, and the variable magnification sliding lens barrel (11) is fitted with a first lens (G1) and a locking ring (10); the pin (2-2) drives the compensation sliding lens barrel (18) to axially translate, and the compensation sliding lens barrel (18) is fitted with a third lens (G3), a fourth lens (G4), a spacer (17), and a locking ring (16); the main lens barrel (5) is fitted with a fixed second lens (G2), a spacer (15), and a locking ring (14).

2. The intermittently magnifying laser beam expander as described in claim 1, characterized in that: The end face of the main lens tube (5) that connects with the magnification handwheel (3) and the compensation handwheel (6) is provided with four precisely machined conical holes, and marked with indicator lines for different beam expansion ratios (1x, 2x, 3x, 4x).

3. The intermittently magnifying laser beam expander as described in claim 1, characterized in that: The end face of the zoom handwheel (3) connected to the main lens barrel (5) is provided with a cylindrical spring slot hole, in which a compression spring (12-1) is installed, and a steel ball (13-1) is installed at the end of the compression spring (12-1); the end face of the compensation handwheel (6) connected to the main lens barrel (5) is also provided with a cylindrical spring slot hole, in which a compression spring (12-2) is installed, and a steel ball (13-2) is installed at the end of the compression spring (12-2); the compression spring and the steel ball are positioning and limiting devices for intermittent zoom.

4. The intermittently magnifying laser beam expander as described in claim 1, characterized in that: The first lens (G1) can be translated along the optical axis, the second lens (G2) is a fixed lens, and the third lens (G3) and the fourth lens (G4) are translated synchronously, forming a "moving-fixed-moving" zoom structure.

5. The intermittently magnifying laser beam expander as described in claim 1, characterized in that: The first lens (G1) moves along the optical axis so that its distance from the second lens (G2) has four designated positions (d11 = 30.13 mm, d12 = 26.14 mm, d13 = 22.17 mm, d14 = 18.19 mm); the third lens (G3) and the fourth lens (G4) move synchronously along the optical axis so that their distance from the second lens (G2) moves to four designated positions (d21 = 40.29 mm, d22 = 46.95 mm, d23 = 49.18 mm, d24 = 50.29 mm).

6. The intermittently magnifying laser beam expander as described in claim 1, characterized in that: The left conical hole on the main lens tube (5) engages with the compression spring 1 (12-1) and steel ball 1 (13-1) in the zoom handwheel (3), and the right conical hole engages with the compression spring 2 (12-2) and steel ball 2 (13-2) in the compensation handwheel (6), achieving a positioning accuracy of ±0.005mm and a zoom accuracy of 0.03% at the four zoom positions.

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