Composite lens with ring

Abstract

The utility model discloses a structure of a composite lens with a ring, the composite lens is formed by welding two glass materials, namely a lens with curvature at a light-transmitting part and an outer ring at a non-light-transmitting part, and the creativity of the composite structure is that the task of centering cutting of an outer circle is transferred to laser cutting of the glass outer ring; the size precision of centering cutting only depends on the equipment precision of a profiling mold and a laser cutting machine, many influences caused by centering and edge grinding operation during traditional optical machining do not exist, laser cutting can meet the quality requirements in the aspects of size precision, cylindrical surface quality, collapsing opening and the like for a tiny and precise mold pressing lens with the light transmission diameter being about 1 mm, and the production efficiency is greatly improved. And the splitting process is simple and easy to implement and low in cost.

Description

Technical Field

[0001] The present invention relates to the processing technology of optical lenses, and in particular to a compound lens with an outer ring structure. Background Art

[0002] For the processing of optical lenses, centering and edging (also called core cutting) is a basic process. Most lenses with a circular light-transmitting cross-section need centering and edging. While obtaining the required outer diameter, the line connecting the centers of the two end faces of the lens is made to coincide with the mechanical axis, and the eccentricity is controlled.

[0003] The molding manufacture of lenses is a modern process. Especially for small and precise lenses, large-scale manufacture can be achieved at low cost. However, the edges of the lenses extended by molding generally need to be edged. In CN202210394807, the inventor restricted the extension of the molded lens with a metal ring to obtain a lens with a metal ring, and then mechanically polished the outer cylindrical surface of the metal copper ring.

[0004] Laser cutting of glass is a modern process and can be used for the profile cutting of lenses to achieve the effect of "centering and edging" to replace the traditional process of mechanical grinding. Most laser cutting equipment uses fiber lasers, with various specifications, such as infrared, visible or ultraviolet wavelengths, and picosecond or femtosecond pulse widths. However, there are the following problems with using laser for centering and edging:

[0005] 1. Although lasers can cut some optical glass, they cannot cut many optical parts. Especially for small and precise molded lenses with a light-transmitting diameter of about 1 mm, the cutting quality often fails to meet the requirements, such as dimensional accuracy, cylindrical surface roughness, cylindrical surface perpendicularity, chipping, etc.;

[0006] 2. For the commonly used cutting method of small and precise lenses, a row of fine holes with a diameter and spacing in the micron range is drilled, and then "chip breaking" is performed. However, for most optical glass, chip breaking is very difficult, which is also one of the main difficulties in laser cutting lenses. Summary of the Invention

[0007] The technical problem solved by the present application is to provide a structure of a ringed compound lens. For small and precise lenses, laser cutting is used to perform centering and edging processing on the outer cylindrical surface of the outer ring, which can not only ensure the cutting quality, but also be easy to operate and low in cost.

[0008] The specific content is as follows:

[0009] A ringed compound lens, characterized in that it is composed of a curvature lens 1 for light transmission in the center and an outer ring 2 not for light transmission. The lens 1 is formed by molding low-melting-point glass in a preset inner hole of the outer ring 2. The lens 1 and the outer ring 2 are welded into one body, and the outer cylindrical surface of the outer ring 2 is an ablation and splitting surface formed after laser cutting and chipping.

[0010] Furthermore, the material of the outer ring 2 is glass, ceramic or crystal.

[0011] Preferably, a chamfer ring or a stepped ring is preset on one side or both sides of the preset inner hole of the outer ring 2.

[0012] Preferably, the outer cylindrical surface of the outer ring 2 is a cylindrical surface or a polygonal cylindrical surface, and the center of the cylindrical surface or the polygonal cylindrical surface is concentric or eccentric with respect to the center of the lens 1.

[0013] The present application discloses a structure of a ringed compound lens. Compared with the prior art, the beneficial effects that can be obtained are as follows: for a micro-precision molded lens with a light passing diameter of about 1 mm, laser cutting can meet the quality requirements in terms of dimensional accuracy, cylindrical surface quality, chipping, etc., and the chip splitting process is simple, easy to operate and low in cost; for the compound lens with a ringed structure, when it is adhered to the substrate of the optical system, the outer ring glass can play a role in thermal expansion matching. Description of the Drawings

[0014] Figure 1 It is a schematic diagram of a ringed compound lens;

[0015] Figure 2 It is a schematic diagram of a ringed compound lens;

[0016] Figure 3 It is a schematic diagram of a molded array large piece cut into single-piece square-ringed lenses. Detailed Embodiments

[0017] The present application will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present application, rather than limiting the present application.

[0018] In order to solve the problems in the background art, Figure 1 Exemplarily, a structure of a ringed compound lens is given. In the figure, 1 is a lens obtained by molding with the required curvature, and 2 is an outer ring formed of borosilicate glass. The preparation method of this compound lens is as follows: first, laser drill a round hole on a borosilicate glass flat plate, the aperture is the outer cylindrical diameter finally formed by the lens 1, put the preform of the lens 1 (usually a polished sphere) into the round hole, and then put the whole into a molding die for heating and molding. After molding, the preform is deformed into a lens 1 with a preset curvature and is welded to the borosilicate glass flat plate as a whole. Then, use a laser cutting machine to punch a series of "cutting" fine holes with a diameter and a pitch in the micron range on the borosilicate glass flat plate, and then through chip splitting, a finished compound lens with a cylindrical outer ring 2 is obtained. The outer cylindrical surface of the outer ring 2 is an ablated and split surface, and this ablated and split surface looks like a frosted surface in appearance, and the thickness of the rough layer is within ten microns, which is "fine" enough.

[0019] The above-mentioned compound lens refers to a compound-structured lens formed by fusing two glass materials, namely, the curved lens 1 in the light-transmitting part and the outer ring 2 in the non-light-transmitting part. The creativity of this compound structure lies in that there is no need to consider the centering cutting of the outer circle of the molded and extended glass lens 1, but the task of centering cutting of the outer circle is transferred to the cutting of the glass outer ring 2, and the dimensional accuracy and geometric tolerance accuracy of the centering cutting of the outer circle only depend on the equipment accuracy of the molding die and the laser cutting machine, and there are no many influences brought by the centering and edge grinding operations in traditional optical processing.

[0020] The material of the outer ring 2 is selected as borosilicate glass for the need of laser cutting and chipping. Borosilicate glass is a glass material that is relatively easy to chip and has a good chipping cross-section because it has the characteristic of "generating cracks rather than pulverizing" during stress fracture.

[0021] The thermal expansion coefficient of borosilicate glass is about 3 to 5 times lower than that of the low-melting-point glass used in molding. This brings a benefit to the compound lens, that is, when the cylindrical surface of the compound lens is bonded to the substrate or bracket of the optical path system (usually its thermal expansion coefficient is less than that of the lens 1), it is not the lens 1 that is directly glued to the substrate or bracket, but the outer ring 2 that is glued to the substrate or bracket, that is, a "thermal expansion performance matching layer" is added between the lens 1 and the substrate or bracket. This matching layer can effectively improve the bonding strength of the compound lens (in contrast, the copper ring used in the background technology CN202210394807 has a thermal expansion coefficient 3 times larger than that of the molded glass).

[0022] Figure 1 The typical dimensions and geometric precisions of the shown compound lens are as follows: the diameter of the lens 1 is 1.2 mm, the outer diameter of the outer ring 2 is 1.8 mm, the center deviation of the compound lens is less than 0.01 mm, the chipping of the outer cylindrical surface of the outer ring 2 is less than 0.05 mm, the perpendicularity of the cylindrical surface is 0.1°, and the surface roughness of the cylindrical surface is 0.01 mm. The cutting equipment selected is a picosecond fiber laser with a wavelength of 1064 nm and a power of 50 W.

[0023] In actual implementation, in the step of "laser-drilling round holes on the borosilicate glass plate", chamfered rings or stepped rings 3 can be pre-made on both sides of the round holes, as Figure 2 shown, so that the lens 1 and the outer ring 2 after molding and fusing are more firm.

[0024] The shape of the outer ring is not limited to a cylindrical ring, which can be determined according to the use occasion of the finished compound lens. It can be made into a polygonal cylindrical ring, such as a rectangular ring, leaving four flat cylindrical surfaces for subsequent bonding with the substrate. As Figure 3As shown, four round holes (taking a 2×2 matrix as an example) are first dug on the borosilicate glass plate 4, and a glass preform is placed and molded together. Then, a series of slitting fine holes are drilled along the dotted line by laser. After slitting, a compound lens with a rectangular outer ring 2 is obtained. Since the path change of the "series of fine holes" drilled by laser is very simple, it can be cut and slit into any cylindrical or polygonal column rings, and the centers of the cylindrical surface or the polygonal column surface can be concentric or eccentric with respect to the center of the lens 1.

[0025] It should be noted that the idea of this application is to add an outer ring 2 that is easy to be cut and slit by laser around the micro lens 1. It does not limit that the material of the outer ring 2 is borosilicate glass. It can also be other glasses, ceramics or crystals (such as sapphire) that are easy to be slit. Nor does it limit that the lens is spherical or aspherical. It can also be cylindrical or free-form surface.

[0026] The above is only the preferred embodiment of this application and the technical principles applied. For those skilled in the art, without departing from the inventive concept of the present invention, more other equivalent embodiments can be generated, and the protection scope of the present invention is determined by the scope of the appended claims.

Claims

1. A ring-shaped compound lens, characterized in that: The invention comprises a central lens (1) with curvature for transmitting light and an outer ring (2) not for transmitting light, wherein the lens (1) is low-melting-point glass and is formed by molding in a preset inner hole of the outer ring (2), the lens (1) and the outer ring (2) are fused into one, and the outer cylindrical surface of the outer ring (2) is an ablation cleavage surface formed by laser cutting of the cleavage pieces.

2. A ring-shaped composite lens as claimed in claim 1, characterized in that: The material of the outer ring (2) is glass, ceramic or crystal.

3. A ring-shaped composite lens as claimed in claim 1, characterized in that: A chamfered ring or a step ring is preset on one side or both sides of the preset inner hole of the outer ring (2).

4. A ring-shaped composite lens as claimed in claim 1, characterized in that: The outer cylindrical surface of the outer ring (2) is a cylindrical surface or a polygonal cylindrical surface, and the center of the cylindrical surface or the polygonal cylindrical surface is concentric or eccentric relative to the center of the lens (1).

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