Aspheric prism and manufacturing method therefor

Abstract

A manufacturing method for an aspheric prism, comprising the following steps: S1, using a hot-press molding method to integrally form a lens and a prism to obtain a molded glass body; S2, cutting the molded glass body into strip-shaped glass (20); S3, performing primary grinding and primary polishing on a right-angle surface; S4, machining a curved surface structure on the right-angle surface having undergone primary polishing; S5, performing secondary polishing on the molded curved surface structure; S6, machining a reflecting surface; S7, performing edge chamfering machining on the strip-shaped glass having undergone reflecting surface machining; S8, coating the strip-shaped glass having undergone chamfering machining; and S9, cutting the coated strip-shaped glass into single aspheric prisms. The manufacturing method for the aspheric prism can machine multiple aspheric prisms in a single operation, shorten the manufacturing period, improve the machining efficiency, and reduce dimensional variations to achieve uniformity. The present invention further relates to an aspheric prism manufactured by the manufacturing method for the aspheric prism.

Description

Aspherical prisms and their preparation methods Technical Field

[0001] This invention relates to the field of optical technology, and in particular to an aspherical prism and its manufacturing method. Background Technology

[0002] A three-in-one prism is mainly formed by combining lenses (spherical convex lenses or concave lenses) and prisms.

[0003] In the fabrication of three-in-one prisms, when assembling lenses and prisms, three-in-one prisms of different specifications can be obtained by assembling lenses and prisms of different specifications. The main assembly method is to bond the lens and prism together by gluing. In the assembly of optical lenses, a bracket support method can be used for assembly. However, regardless of whether a gluing or bracket support method is used, the requirements for the fit clearance between the lens and prism, the precision of the components, and the overall assembly precision are all very high.

[0004] In related technologies, the lens and prism of a three-in-one prism are processed using different equipment, and the grinding, polishing, chamfering, coating, and ink application processes are all carried out separately on optical equipment. This results in a long manufacturing cycle, low processing efficiency, and large fluctuations in dimensional accuracy, making it impossible to achieve uniformity in the three-in-one prism. Technical issues

[0005] The purpose of this invention is to provide a method for preparing an aspherical prism, so as to solve the problems of long preparation cycle, low processing efficiency, large fluctuations in dimensional accuracy and inability to achieve uniformity in the preparation method of three-in-one prism in related technologies. Technical solutions

[0006] To address the aforementioned problems, in a first aspect, the present invention provides a method for preparing an aspherical prism, comprising the following steps:

[0007] S1. Using a hot pressing molding method, the lens and prism that form the incident surface are integrally molded to obtain a molded glass body;

[0008] S2. Cut the molded glass into strips of glass;

[0009] S3. Adhere the strip glass to the fixture and perform the first grinding and first polishing of the right-angled surface according to the preset size; wherein, after the first grinding, reserve processing amount for the first polishing process;

[0010] S4. Machining curved surfaces on the right-angled surfaces after the first polishing, and reserving machining allowance for the second polishing process;

[0011] S5. Perform a second polishing on the shaped curved surface structure;

[0012] S6. The strip of glass that has been polished for the second time is flipped over and glued back onto the fixture and the reflective surface is processed.

[0013] S7. Chamfer the edges of the strip glass after the reflective surface has been processed;

[0014] S8. Apply a coating to the chamfered strip glass;

[0015] S9. Cut the coated strip of glass into individual aspherical prisms;

[0016] S10. Apply ink to the aspherical prism.

[0017] Preferably, in step S1, hot pressing is performed using an integrated mold; the formed glass has a spherical structure or an aspherical structure.

[0018] Preferably, in step S2, laser cutting or wire cutting is used for cutting; the single-sided processing allowance of the strip glass is greater than 0.3mm.

[0019] Preferably, in step S3, using the two opposing surfaces of the strip glass as reference surfaces, after the strip glass is bonded to the fixture, the centers of all spherical or aspherical structures on the same strip glass are on a horizontal line; the angular tolerance of the fixture is less than 1 minute; and the processing amount reserved for the first polishing process after the first grinding is greater than 20 μm.

[0020] Preferably, in step S4, the curved surface structure is any one of a spherical structure, an aspherical structure, and a freeform surface structure; the curved surface structure is processed using a computer numerical control machine tool, and mechanical positioning is used to ensure that the eccentricity of the curved surface structure is less than 10μm; the processing amount reserved for the second polishing process is greater than 5μm.

[0021] Preferably, in step S5, a second polishing is performed using an upper or lower swing machine to achieve the required surface shape, sagitta, and roughness of the curved surface structure.

[0022] Preferably, in step S6, using the incident surface and right-angled surface of the strip glass as reference surfaces, after the strip glass is bonded to the fixture, the centers of the spherical or aspherical structures on the incident surface of the strip glass are on the same horizontal plane.

[0023] Preferably, in step S6, the processing of the reflective surface includes the following steps:

[0024] S61. Mill the reflective surface of the strip glass bonded to the tooling;

[0025] S62. Perform a second grinding on the milled reflective surface, and reserve machining allowance for a third polishing process; wherein the reserved machining allowance for the third polishing process is greater than 20μm;

[0026] S63. Perform a third polishing on the reflective surface after the second grinding to complete the processing of the reflective surface.

[0027] Preferably, in step S8, coating the chamfered strip glass specifically involves coating an anti-reflective film on the incident surface and the right-angled surface, and coating a high-reflective film on the reflective surface.

[0028] Preferably, in step S10, the process of applying ink to the aspherical prism specifically involves: applying ink to the outside of the light-transmitting apertures of the incident surface and right-angle surface of the aspherical prism using pad printing, and applying ink to the side surface and chamfer of the aspherical prism using screen printing.

[0029] Secondly, the present invention provides an aspherical prism, which includes an incident surface and a right-angled surface that are perpendicular to each other, and a reflecting surface connecting the incident surface and the right-angled surface, wherein at least one of the incident surface and the right-angled surface is an aspherical structure; the aspherical prism is manufactured using the aspherical prism preparation method described above. Beneficial effects

[0030] Compared with existing technologies, the aspherical prism manufacturing method of this invention integrates the lens and prism into one piece through hot pressing. This allows subsequent processes such as grinding, polishing, chamfering, coating, and ink application to be performed based on the same benchmark. This not only enables the processing of multiple aspherical prisms at once but also shortens the manufacturing cycle, improves processing efficiency, minimizes dimensional fluctuations, and achieves uniformity. Furthermore, the hot pressing process allows subsequent processing to be carried out in one step, eliminating assembly errors and improving the structural accuracy of the aspherical prism. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0032] Figure 1 is a flowchart of the method for preparing an aspherical prism according to an embodiment of the present invention;

[0033] Figure 2 is a schematic diagram of the structure of the array-shaped glass in step S1 of the method for preparing an aspherical prism provided in the embodiment of the present invention;

[0034] Figure 3 is a schematic diagram of the structure after the strip glass is installed into the tooling in step S6 of the method for preparing an aspherical prism provided in the embodiment of the present invention.

[0035] Figure 4 is a schematic diagram of the structure of the strip glass after the chamfering process is completed in step S7 of the method for preparing an aspherical prism provided in the embodiment of the present invention;

[0036] Figure 5 is a schematic diagram of the first perspective of the aspherical prism provided in the embodiment of the present invention;

[0037] Figure 6 is a schematic diagram of the second perspective of the aspherical prism provided in an embodiment of the present invention. Modes for Carrying Out the Invention

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] This invention provides a method for preparing an aspherical prism, as shown in Figure 1, which includes the following steps:

[0040] S1. Using a hot pressing molding method, the lens and prism that form the incident surface are integrally molded to obtain a molded glass.

[0041] Among them, a precision-machined array mold is used for hot pressing to mold the double-sided polished flat glass into an array-type molded glass 10 with an aspherical structure (or a spherical structure) (as shown in Figure 2), and to ensure that the warpage of the molded glass is less than 10μm, the core thickness is within ±10μm, the aspherical structure surface is less than 300nm, and the sagitta is within ±1μm.

[0042] S2. Cut the molded glass into strips of glass.

[0043] The cutting is performed using laser cutting (or wire cutting); the single-sided processing allowance of the strip glass is greater than 0.3mm.

[0044] S3. Adhere the strip glass to the tooling and perform the first grinding and first polishing of the right-angled surface according to the preset size.

[0045] Among them, a double-sided grinding machine is used to grind the strip glass bonded (glued) to the tooling, and the grinding process is strictly monitored for grinding size, roughness and surface finish of the strip glass.

[0046] After the first grinding, allowance is reserved for the first polishing process, which is greater than 20μm.

[0047] As shown in Figure 3, using the two opposing surfaces (or upper and lower surfaces) of the strip glass 20 as reference surfaces, after the strip glass 20 is bonded to the fixture 30, the centers of all spherical or aspherical structures on the same strip glass 20 are on the same horizontal line, and the height difference is less than 5μm; the angular tolerance of the fixture 30 is less than 1 minute.

[0048] S4. Machining curved surfaces on the right-angled surfaces after the first polishing, and reserving machining allowance for the second polishing process.

[0049] The surface structure can be any one of a spherical structure, an aspherical structure, or a freeform surface structure.

[0050] The curved structure is processed using a computer numerical control machine tool. Specifically, the strip glass is fixed on the machine table of a three-axis computer numerical control machine tool, and then the spherical structure is processed. During the processing, the surface shape and position of the spherical structure are strictly monitored, and mechanical positioning is used to ensure that the eccentricity of the spherical structure is less than 10μm.

[0051] The allowable machining depth for the second polishing process is greater than 5μm.

[0052] S5. Perform a second polishing on the shaped curved surface.

[0053] The process involves a second polishing using a lower swing machine (or an upper swing machine) to achieve the required surface shape, elevation, and roughness of the curved surface structure. The surface shape, roughness, and smoothness of the spherical structure are strictly monitored during the polishing process.

[0054] S6. The strip of glass that has been polished for the second time is flipped over and glued back onto the fixture and the reflective surface is processed.

[0055] As shown in Figure 3, using the incident surface and right-angled surface of the strip glass 20 as reference surfaces, after the strip glass 20 is bonded to the fixture 30, the centers of the spherical or aspherical structures on the incident surface of the strip glass 20 are on the same horizontal plane; at the same time, the fixture 30 provides optical surface clearance for the incident surface and right-angled surface to ensure that the bonding and subsequent debonding processes will not damage the optical surface.

[0056] The processing of the reflective surface includes the following steps:

[0057] S61. Mill the reflective surface of the strip glass bonded to the tooling.

[0058] Among them, a milling machine is used to remove excess material.

[0059] S62. Perform a second grinding on the milled reflective surface and reserve processing space for a third polishing process.

[0060] The reserved third polishing process has a machining allowance of more than 20μm.

[0061] S63. Perform a third polishing on the reflective surface after the second grinding to complete the processing of the reflective surface.

[0062] Among them, a polishing machine is used to polish the reflective surface to form a mirror surface. The polishing process is strictly monitored for its surface shape, roughness and surface finish, and its surface shape tolerance is guaranteed to be λ / 20.

[0063] S7. Chamfer the edges of the strip glass after the reflective surface has been processed.

[0064] The chamfering process is carried out using a chamfering machine, and the dimensions and chipping data of the chamfer are strictly monitored during the process. The strip glass 20 after the chamfering process is completed is shown in Figure 4, which includes multiple incident surfaces 1 and multiple reflective surfaces 2.

[0065] S8. Apply a coating to the chamfered strip glass.

[0066] Specifically, the coating process for the chamfered strip glass involves depositing an anti-reflective coating (AR film) on the incident surface and the right-angled surface, and depositing a high-reflective coating (HR film) on the reflective surface.

[0067] The incident surface, right-angle surface and reflective surface are coated sequentially by vapor deposition, and the thickness of the coating and the reflectivity after coating are strictly monitored during the coating process.

[0068] S9. Cut the coated strip of glass into individual aspherical prisms.

[0069] The cutting process employs laser cutting (or wire cutting), and the perpendicularity and dimensional data must be strictly monitored during the cutting process.

[0070] S10. Apply ink to the aspherical prism.

[0071] Specifically, the aspherical prism is inked by: applying ink to the outer apertures of the incident surface and right-angle surface of the aspherical prism using pad printing; and applying ink to the sides and chamfers of the aspherical prism using screen printing. During the inking process, the inking range, ink layer thickness, and instances of insufficient or excessive ink application are strictly monitored. Furthermore, the transmittance and reflectance are monitored after inking.

[0072] The aspherical prism after ink coating is shown in Figures 5 and 6. It includes an incident surface 1 and a right-angled surface 2 that are perpendicular to each other, and a reflecting surface 3 that connects the incident surface 1 and the right-angled surface 2. At least one of the incident surface 1 and the right-angled surface 2 is an aspherical structure. Of course, depending on the actual needs, the right-angled surface 2 can also be an aspherical structure. Based on the above method steps, it is possible to make the right-angled surface 2 an aspherical structure.

[0073] In this embodiment, the aspherical prism is fabricated by integrally molding the lens and prism using hot pressing. This allows subsequent processes such as grinding, polishing, chamfering, coating, and ink application to be performed based on the same benchmark. This not only enables the simultaneous fabrication of multiple aspherical prisms but also shortens the fabrication cycle, improves processing efficiency, minimizes dimensional fluctuations, and achieves uniformity. Furthermore, the integral hot pressing process allows subsequent processing to be carried out as a single unit, eliminating assembly errors and improving the structural precision of the aspherical prism. It also simplifies the mold assembly process, reducing mold size and improving the optical performance of the mold.

[0074] The above description is merely an embodiment of the present invention. It should be noted that those skilled in the art can make improvements without departing from the inventive concept of the present invention, but these improvements all fall within the protection scope of the present invention.

Claims

1. A method for preparing an aspherical prism, characterized in that, The method for preparing the aspherical prism includes the following steps: S1. Using a hot pressing molding method, the lens and prism that form the incident surface are integrally molded to obtain a molded glass body; S2. Cut the molded glass into strips of glass; S3. Adhere the strip glass to the fixture and perform the first grinding and first polishing of the right-angled surface according to the preset size; wherein, after the first grinding, reserve processing amount for the first polishing process; S4. Machining curved surfaces on the right-angled surfaces after the first polishing, and reserving machining allowance for the second polishing process; S5. Perform a second polishing on the shaped curved surface structure; S6. The strip of glass that has been polished for the second time is flipped over and glued back onto the fixture and the reflective surface is processed. S7. Chamfer the edges of the strip glass after the reflective surface has been processed; S8. Apply a coating to the chamfered strip glass; S9. Cut the coated strip of glass into individual aspherical prisms; S10. Apply ink to the aspherical prism.

2. The method for preparing an aspherical prism as described in claim 1, characterized in that, In step S1, hot pressing is performed using an integrated mold; the formed glass has a spherical or aspherical structure.

3. The method for preparing an aspherical prism as described in claim 1, characterized in that, In step S2, laser cutting or wire cutting is used for cutting; the single-sided processing allowance of the strip glass is greater than 0.3mm.

4. The method for preparing an aspherical prism as described in claim 2, characterized in that, In step S3, using the two opposing surfaces of the strip glass as reference surfaces, after the strip glass is bonded to the fixture, the centers of all spherical or aspherical structures on the same strip glass are on a horizontal line; the angular tolerance of the fixture is less than 1 minute; and the processing amount reserved for the first polishing process after the first grinding is greater than 20 μm.

5. The method for preparing an aspherical prism as described in claim 1, characterized in that, In step S4, the curved surface structure is any one of a spherical structure, an aspherical structure, and a freeform surface structure; the curved surface structure is processed using a computer numerical control machine tool, and mechanical positioning is used to ensure that the eccentricity of the curved surface structure is less than 10μm; the processing amount of the reserved second polishing process is greater than 5μm.

6. The method for preparing an aspherical prism as described in claim 1, characterized in that, In step S5, a second polishing is performed using an upper or lower swing machine to achieve the required surface shape, sagitta, and roughness of the curved surface structure.

7. The method for preparing an aspherical prism as described in claim 2, characterized in that, In step S6, using the incident surface and right-angled surface of the strip glass as reference surfaces, after the strip glass is bonded to the fixture, the centers of the spherical or aspherical structures on the incident surface of the strip glass are on the same horizontal plane.

8. The method for preparing an aspherical prism as described in claim 1, characterized in that, In step S6, the processing of the reflective surface includes the following steps: S61. Mill the reflective surface of the strip glass bonded to the tooling; S62. Perform a second grinding on the milled reflective surface, and reserve machining allowance for a third polishing process; wherein the reserved machining allowance for the third polishing process is greater than 20μm; S63. Perform a third polishing on the reflective surface after the second grinding to complete the processing of the reflective surface.

9. The method for preparing an aspherical prism as described in claim 1, characterized in that, In step S8, the coating process for the chamfered strip glass specifically involves coating an anti-reflective film on the incident surface and the right-angled surface, and coating a high-reflective film on the reflective surface.

10. The method for preparing an aspherical prism as described in claim 1, characterized in that, In step S10, the process of applying ink to the aspherical prism specifically involves: applying ink to the outside of the light-transmitting apertures of the incident surface and right-angle surface of the aspherical prism using pad printing, and applying ink to the side surface and chamfer of the aspherical prism using screen printing.

11. An aspherical prism, characterized in that, The aspherical prism includes an incident surface and a right-angled surface that are perpendicular to each other, and a reflecting surface connecting the incident surface and the right-angled surface, wherein at least one of the incident surface and the right-angled surface is an aspherical structure; characterized in that the aspherical prism is manufactured by the aspherical prism preparation method according to any one of claims 1 to 10.

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