Aspheric prism and preparation method thereof

Abstract

The embodiment of the invention relates to the technical field of optics, and provides an aspheric prism and a preparation method thereof.The preparation method of the aspheric prism comprises the steps that a wafer is formed through an integrated forming technology, the wafer comprises a plurality of first prism strips which are sequentially arranged in the first direction, the wafer is subjected to first cutting treatment, and a second prism strip is formed; each first prism strip is cut into two second prism strips, and each second prism strip comprises an inclined surface and a column of aspheric surface structures which are sequentially arranged along a second direction; second cutting processing is carried out on the second prism strip, and a cutting line of the second cutting processing is located between the adjacent aspheric surface structures so as to form an initial prism; an antireflection film is formed on the surface where the aspheric surface structure is located and the emergent surface in the initial prism; and ink coating operation is carried out on the surfaces except the aspheric structure, the emergent surface and the inclined surface in the initial prism to obtain the aspheric prism. According to the embodiment of the invention, the preparation efficiency and the structural precision of the aspheric prism can be improved at least.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of optical technology, and in particular to an aspherical prism and a method for preparing the same. Background Art

[0002] Aspheric prisms are usually composed of a lens (convex or concave) and a triangular prism.

[0003] In the steps of manufacturing aspheric prisms in related technologies, triangular prisms and lenses are usually used for assembly. Different assembly methods are used for different application scenarios. For example, the triangular prism and the lens can be glued together. In the process of assembling optical lenses, a bracket can be used for support to achieve assembly. However, no matter which assembly method is used, the precision requirements of the matching clearance between the triangular prism and the lens and the assembly precision requirements are very high.

[0004] Since the triangular prism and lens are processed by different equipment respectively, and their cutting, coating, inking and other processes are all completed separately on optical equipment, the preparation cycle of the whole process is relatively long, the preparation efficiency is low, and the structural precision control cannot be unified.

[0005] Therefore, the preparation efficiency and structural accuracy of aspheric prisms in the related art need to be improved. Summary of the invention

[0006] The embodiments of the present invention provide an aspheric prism and a method for manufacturing the same, which can at least improve the manufacturing efficiency and structural accuracy of the aspheric prism.

[0007] On one hand, the present invention provides a method for preparing an aspheric prism, comprising: forming a wafer by an integrated molding process, the wafer having a first surface and a second surface opposite to each other, the wafer comprising a plurality of first prism strips arranged in sequence along a first direction, each of the first prism strips comprising a plurality of aspheric structures protruding relative to the first surface, the plurality of aspheric structures being arranged in two rows along the first direction, and each row comprising a plurality of aspheric structures arranged in sequence along a second direction, each of the first prism strips further comprising two inclined surfaces protruding relative to the second surface, each of the inclined surfaces extending along the second direction; performing a first cutting process on the wafer so that each of the first prism strips is opposite to the first prism strip; The first prism strips are separated from each other, and each of the first prism strips is cut into two second prism strips, each of the second prism strips includes an inclined surface and a row of the aspheric structures arranged in sequence along the second direction, and the cutting surface of the first prism strip cut into two second prism strips is the exit surface; the second prism strips are subjected to a second cutting process, and the cutting line of the second cutting process is located between adjacent aspheric structures to form an initial prism; an anti-reflection film is formed on the surface of the initial prism where the aspheric structure is located and on the exit surface; and the surfaces other than the aspheric structure, the exit surface and the inclined surface in the initial prism are subjected to an ink coating operation to obtain the aspheric prism.

[0008] In some embodiments, the one-piece molding process is a hot pressing molding process.

[0009] In some embodiments, the first prism bar is an axisymmetric shape, and a cutting line of the first prism bar to cut the first prism bar into two second prism bars is a symmetry axis of the first prism bar.

[0010] In some embodiments, after the first cutting process is performed, the method further includes: grinding and polishing the exit surface so that the included angle between the exit surface and the inclined surface is 45°.

[0011] In some embodiments, the inclined surface of the first prism strip is a plane.

[0012] In some embodiments, before grinding the exit surface, the method further includes: placing the inclined surface on the tooling.

[0013] In some embodiments, after polishing the exit surface, the method further includes: chamfering the edges and corners of the second prism strip to form a second chamfered surface.

[0014] In some embodiments, the material refractive index of the initial prism is greater than or equal to 1.75.

[0015] In some embodiments, the refractive index of the material of the initial prism is less than 1.75, and the method for preparing the aspherical prism further includes: forming a high-reflection film on the inclined surface.

[0016] Another aspect of the present invention further provides an aspheric prism, wherein the aspheric prism is prepared by using the method for preparing an aspheric prism described in any of the above embodiments.

[0017] The beneficial effects of the present invention are: a wafer with an aspheric structure is formed by an integrated molding process, the aspheric structure of the wafer is equivalent to a lens, and then the wafer is subjected to a first cutting process, a second cutting process, and steps such as forming an anti-reflection film to form an aspheric prism, so that there is no need to first form an initial triangular prism and an initial lens, and then cut, coat, and ink the initial triangular prism and the initial lens to form a triangular prism and a lens, and then assemble the triangular prism and the lens, so that the preparation method of the aspheric prism provided by the present invention can shorten the preparation cycle and improve the processing efficiency. The wafer with an aspheric structure and an inclined surface is directly formed by an integrated molding process, so that the grinding process steps for preparing the aspheric structure and the inclined surface in the related art can be reduced, and the preparation cycle can also be shortened to improve the processing efficiency. In addition, the first prism strip in the wafer prepared by the integrated molding process includes two inclined surfaces and two rows of aspherical structures. When performing the first cutting process, one prism strip can be cut to form two second prism strips with one inclined surface and one row of aspherical structures, which reduces the grinding process steps directly taken on the wafer to form the second prism strip in the related art, thereby improving the utilization rate of the wafer material, shortening the preparation cycle, and improving the preparation efficiency. In addition, the wafer is formed by the integrated molding process, which can be carried out in one piece in the subsequent processing process, so there is no assembly error of the triangular prism and the lens, and the structural accuracy of the aspherical prism is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] One or more embodiments are exemplarily described by pictures in the corresponding drawings. These exemplified descriptions do not constitute a limitation on the embodiments. Unless otherwise specified, the pictures in the drawings do not constitute a scale limitation. In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the conventional technology, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A front view of a wafer formed by the integrated molding process provided by an embodiment of the present invention;

[0020] Figure 2 A bottom view of a wafer formed by the integrated molding process provided by an embodiment of the present invention;

[0021] Figure 3A top view of a wafer formed by the integrated molding process provided by an embodiment of the present invention;

[0022] Figure 4 A side view of a wafer formed by the integrated molding process provided by an embodiment of the present invention;

[0023] Figure 5 A three-dimensional diagram of a wafer formed by the integrated molding process provided by an embodiment of the present invention;

[0024] Figure 6 A schematic diagram of the structure after a first prism strip provided in an embodiment of the present invention is cut into two second prism strips;

[0025] Figure 7 A schematic diagram of the structure of a second prism strip provided by an embodiment of the present invention;

[0026] Figure 8 A schematic diagram of placing a second prism bar on a tooling provided in an embodiment of the present invention;

[0027] Fig. 9 A front view of a second prism strip after chamfering provided by an embodiment of the present invention;

[0028] Fig.10 A three-dimensional diagram of a second prism strip after chamfering provided by an embodiment of the present invention;

[0029] Fig.11 A perspective view of an initial prism provided for an embodiment of the present invention;

[0030] Fig.12 A side view of an aspheric prism provided by an embodiment of the present invention;

[0031] Fig.13 A schematic structural diagram of an aspheric prism provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] It can be seen from the background technology that the preparation efficiency and structural accuracy of aspheric prisms in the related art need to be improved.

[0033] The embodiment of the present invention provides a method for preparing an aspheric prism, which uses an integrated molding process to form a wafer with an aspheric structure, and then processes the wafer to form an aspheric prism. The aspheric structure in the wafer is equivalent to a lens, so there is no need to first form an initial triangular prism and an initial lens, and then process the initial triangular prism and the initial lens to form a triangular prism and a lens, and then assemble the triangular prism and the lens, as in the related art. Thus, the method for preparing an aspheric prism provided by the present invention can shorten the preparation cycle and improve the processing efficiency. The wafer with an aspheric structure and an inclined surface is directly formed by an integrated molding process, so that the grinding process steps for preparing the aspheric structure and the inclined surface in the related art can be reduced, and the preparation cycle can also be shortened to improve the processing efficiency. In addition, when performing the first cutting process, a prism strip can be cut to form two second prism strips with an inclined surface and a column of aspheric structures, which can reduce the grinding process steps directly taken on the wafer in order to form the second prism strip in the related art, and can improve the utilization rate of the wafer material, shorten the preparation cycle, and improve the processing efficiency. In addition, the wafer is formed by an integrated molding process, so that it can be processed in one piece in the subsequent processing, so there is no assembly error between the triangular prism and the lens, which improves the structural accuracy of the aspheric prism.

[0034] The following will describe the various embodiments of the present invention in detail with reference to the accompanying drawings. However, it will be appreciated by those skilled in the art that, in the various embodiments of the present invention, many technical details are provided in order to enable the reader to better understand the present invention. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in the present invention can be implemented.

[0035] Figure 1 A front view of a wafer formed by the integrated molding process provided by an embodiment of the present invention; Figure 2 A bottom view of a wafer formed by the integrated molding process provided by an embodiment of the present invention; Figure 3 A top view of a wafer formed by the integrated molding process provided by an embodiment of the present invention; Figure 4 A side view of a wafer formed by the integrated molding process provided by an embodiment of the present invention; Figure 5 A three-dimensional diagram of a wafer formed by the integrated molding process provided in an embodiment of the present invention.

[0036] It should be noted that Figures 1 to 5 The schematic diagram shows a case where the wafer includes three first prism strips. In fact, the number of first prism strips on the wafer can be adaptively adjusted according to the needs of actual applications. The embodiment of the present invention does not limit the number of first prism strips in the wafer.

[0037] Combined with reference Figures 1 to 5, a wafer 100 is formed by an integrated molding process, the wafer 100 has a first surface 110 and a second surface 120 relative to each other, the wafer 100 includes a plurality of first prism strips 101 arranged in sequence along a first direction X, each first prism strip 101 includes a plurality of aspheric structures 102 protruding relative to the first surface 110, the plurality of aspheric structures 102 are arranged in two rows along the first direction X, and each row has a plurality of aspheric structures 102 arranged in sequence along a second direction Y, each first prism strip 101 also includes two inclined surfaces 103 protruding relative to the second surface 120, and each inclined surface 103 extends along the second direction Y. In some embodiments, the integrated molding process can be a hot press molding process, which refers to a processing method in which pre-processed raw materials are pressed and molded under high temperature and high pressure conditions. This process is generally suitable for manufacturing high-precision and high-strength products. In the hot press molding process, multiple processes are required, such as raw material pretreatment, hot pressing, cooling, polishing, etc. These processes can be combined into one process, and the use of hot press molding can improve the production efficiency of wafers.

[0038] In some embodiments, a precision tungsten steel mold may be used for hot pressing molding process, so that the formed wafer 100 has sufficiently high precision. The hot pressing molding process usually performs molding near the sag temperature of the wafer material.

[0039] The material of the wafer 100 is optical glass, which has the characteristics of high uniformity, no cracks, isotropy, good light transmittance, high dispersion, and small temperature coefficient.

[0040] The first prism strip 101 includes two rows of aspheric structures 102 arranged along a first direction X. Each aspheric structure 102 is used as a light-transmitting area of ​​an incident surface of a subsequently manufactured aspheric prism. The aspheric structure 102 is equivalent to a lens in an aspheric prism in the related art, and the lens can reduce the aberration of the aspheric prism and improve the imaging quality.

[0041] The first prism strip 101 further includes two inclined surfaces 103 protruding relative to the second surface 120 , and the inclined surfaces 103 are used as reflecting surfaces of the aspheric prisms manufactured subsequently.

[0042] Figure 6 A schematic diagram of a structure after a first prism strip provided in an embodiment of the present invention is cut into two second prism strips, Figure 7 A schematic diagram of the structure of a second prism strip provided by an embodiment of the present invention, wherein: Figure 6 The dotted line in the figure is the cutting line for cutting the first prism strip. For the convenience of illustration, the subsequent processing of the second prism strip is as follows. Figure 6 The first prism strip to the left of the middle dashed line is an example.

[0043] Combined with reference Figure 6 and Figure 7, a first cutting process is performed on the wafer 100, so that each first prism strip 101 is separated from each other, and each first prism strip 101 is cut into two second prism strips 104, each second prism strip 104 includes an inclined surface 103 and a row of aspheric structures 102 arranged in sequence along the second direction Y, and the cutting surface of the first prism strip 101 into the two second prism strips 104 is the exit surface 105. In order to make the first prism strip 101 be cut into two second prism strips 104 including an inclined surface 103, the cutting surface of the first prism strip 101 into the two second prism strips 104 should be perpendicular to the surface where the aspheric structure 102 is located, so that during the first cutting process, the cutting surface of the second prism strip 104 is directly converted into the exit surface 105 perpendicular to the surface where the aspheric structure 102 is located, which can improve the preparation efficiency of the aspheric prism. In addition, during the first cutting process, the cutting surface for separating each first prism bar 101 is the first chamfered surface 115 .

[0044] The first cutting process can be laser cutting or water cutting and other cutting processes, and the first cutting process needs to monitor the verticality and size data of the cutting surface (i.e., the exit surface 105 and the first chamfered surface 115) to ensure the accuracy and uniformity of the second prism strip 104 finally formed.

[0045] In some embodiments, the first prism bar 101 is an axisymmetric figure, and the cutting line of the first prism bar 101 into two second prism bars 104 is the symmetry axis of the first prism bar 101. In this way, when the first prism bar 101 is subjected to the first cutting process, two identical second prism bars 104 can be formed, which can improve the utilization rate of wafer materials, shorten the preparation cycle, and improve the preparation efficiency.

[0046] In other embodiments, the first prism strip may not be an axisymmetric shape, so that the aspheric structures on the two second prism strips formed by cutting the first prism strip may be different, so that the wafer formed by integral molding can simultaneously produce aspheric prisms with two different specifications of aspheric structures, and the preparation efficiency of aspheric prisms can also be improved.

[0047] Figure 8 A schematic diagram of placing a second prism bar on a tooling provided in an embodiment of the present invention.

[0048] Combined with reference Figure 7 and Figure 8 In some embodiments, the inclined surface 103 of the second prism bar 104 can be a plane. After the inclined surface 103 is placed on the tooling 11, the exit surface 105 is ground and polished so that the angle between the exit surface 105 and the inclined surface 103 is 45°.

[0049] In order to make the angle between the exit surface 105 and the inclined surface 103 be 45°, the exit surface 105 needs to be ground first and then polished. Before grinding and polishing, the inclined surface 103 opposite to the exit surface 105 needs to be placed on the tooling 11, and the inclined surface 103 in contact with the tooling 11 needs to be flat to ensure the bonding effect between the inclined surface 103 and the tooling 11. The inclined surface 103 prepared by the one-piece molding process is a plane, and the inclined surface 103 is flat enough to ensure the bonding effect between the inclined surface 103 and the tooling 11, thereby avoiding the movement of the second prism strip 104 caused by the insufficient flatness of the inclined surface 105 during the grinding and polishing process, which causes processing errors, thereby improving the reliability of grinding and polishing.

[0050] Fig. 9 A front view of a second prism strip after chamfering provided by an embodiment of the present invention; Fig.10 A three-dimensional diagram of a second prism strip after chamfering according to an embodiment of the present invention.

[0051] Combined with reference Fig. 9 and Fig.10 After polishing the exit surface 105, the method further includes: chamfering the corners of the second prism strip 104 to form a second chamfered surface 106. Chamfering the corners ensures that the edges of the subsequently manufactured aspheric prism are smooth and burr-free, thereby avoiding scratches or damage to other components during the use of the subsequently manufactured aspheric prism, which is beneficial to improving the safety of the aspheric prism.

[0052] Specifically, a chamfering machine is used to perform the chamfering process, and the size and edge collapse data of the second chamfered surface 106 are monitored during the process.

[0053] Fig.11 A perspective view of an initial prism provided for an embodiment of the present invention.

[0054] Combined with reference Fig.10 and Fig.11 After the chamfering process, the second prism strip 104 is subjected to a second cutting process, and the cutting line of the second cutting process is located between adjacent aspherical structures 102 to form an initial prism 107 .

[0055] The second cutting process may be a cutting process such as laser cutting or water jet cutting, and the second cutting process requires monitoring of the verticality and size data of the cutting surface.

[0056] Each of the initial prisms 107 after the second cutting process has an aspherical structure 102 .

[0057] Fig.12 A side view of an aspheric prism provided by an embodiment of the present invention, Fig.13Schematic diagram of the structure of the aspheric prism provided by the embodiment of the present invention. It should be noted that for the convenience of illustration, the anti-reflection film, high-reflection film and ink layer in the aspheric prism are only Fig.12 There is a display in Fig.13 Not shown.

[0058] Combined with reference Figure 11-13 An anti-reflection film (AR film) 108 is formed on the surface of the initial prism 107 where the aspherical structure 102 is located and on the exit surface 105 .

[0059] The surface where the aspherical structure 102 is located is the incident surface 117. Anti-reflection films 108 are formed on the incident surface 117 and the exit surface 105 to reduce the reflectivity of the aspherical prism, improve imaging quality, and reduce glare and light loss.

[0060] In some embodiments, the refractive index of the initial prism 107 is less than 1.75, and the method for preparing the aspherical prism further includes: forming a high-reflection film (HR film, high-reflection film) 118 on the inclined surface 103. Since the refractive index of the initial prism 107 is relatively small, in order to improve the reflectivity of the inclined surface 103, the high-reflection film 118 is plated on the inclined surface 103 to improve the reflectivity of the inclined surface 103 as a reflection surface.

[0061] In some embodiments, the refractive index of the material of the initial prism 107 is greater than or equal to 1.75. In this case, the refractive index of the material of the initial prism 107 is large enough to meet the reflectivity requirements of the reflective surface in the aspheric prism, and there is no need to plate a high reflective film on the inclined surface 103, which can save the manufacturing cost of the aspheric prism.

[0062] The ink coating operation is performed on the surfaces other than the aspheric structure 102, the exit surface 105 and the inclined surface 103 in the initial prism 107 to obtain the aspheric prism 109. Specifically, the surface where the aspheric structure 102 is located is the incident surface 117, and the initial prism 107 includes the incident surface 117, the inclined surface 103, the exit surface 105, the first chamfered surface 115, the second chamfered surface 106 and the two side surfaces 127. The ink coating operation is performed on the second chamfered surface 106, the side surface 127 and the portion other than the aspheric structure 102 in the incident surface 117. When ink coating, the first chamfered surface 115 and the second chamfered surface 106 can be firstly ink coated, and then the portion of the incident surface 117 other than the aspheric structure 102 can be ink coated, and finally the two side surfaces 127 can be ink coated. The ink layer 128 formed by ink coating can reduce the absorption of light at the edge of the aspheric prism, reduce the stray light coefficient of the optical system, and help reduce unnecessary light reflection and scattering, thereby improving the clarity and contrast of the aspheric prism imaging.

[0063] In the above-mentioned method for preparing an aspheric prism, an integrated molding process is used to form a wafer with an aspheric structure, and then the wafer is processed to form an aspheric prism. The aspheric structure in the wafer is equivalent to a lens, so there is no need to first form an initial triangular prism and an initial lens, and then process the initial triangular prism and the initial lens to form a triangular prism and a lens, and then assemble the triangular prism and the lens, as in the related art. Thus, the method for preparing an aspheric prism provided by the present invention can shorten the preparation cycle and improve the processing efficiency. An integrated molding process is used to directly form a wafer with an aspheric structure and an inclined surface, so that the grinding process steps for preparing the aspheric structure and the inclined surface in the related art can be reduced, and the preparation cycle can also be shortened to improve the processing efficiency. In addition, when performing the first cutting process, a prism strip can be cut to form two second prism strips with an inclined surface and a column of aspheric structures, which can reduce the grinding process steps directly taken on the wafer in order to form the second prism strip in the related art, and can also improve the utilization rate of the wafer material, shorten the preparation cycle, and improve the processing efficiency. In addition, the wafer is formed by an integrated molding process, so that it can be processed in one piece in the subsequent processing, so there is no assembly error between the triangular prism and the lens, which improves the structural accuracy of the aspheric prism.

[0064] Correspondingly, another embodiment of the present invention further provides an aspheric prism prepared by the aspheric prism preparation method in the above embodiment. For the parts that are the same or corresponding to the previous embodiment, reference can be made to the corresponding description of the above embodiment, and will not be described in detail below.

[0065] refer to Fig.13 The aspherical prism 109 includes a lens 119 and a triangular prism 129 .

[0066] It can be understood by those skilled in the art that the above-mentioned embodiments are specific examples for realizing the present invention, and in practical applications, various changes can be made to them in form and details without departing from the spirit and scope of the present invention. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, so the protection scope of the present invention shall be subject to the scope defined in the claims.

Claims

1. A method for preparing an aspherical prism, characterized in that: include: A wafer is formed by an integrated molding process, wherein the wafer has a first surface and a second surface opposite to each other, wherein the wafer comprises a plurality of first prism strips sequentially arranged along a first direction, wherein each of the first prism strips comprises a plurality of aspheric structures protruding relative to the first surface, wherein the plurality of aspheric structures are arranged in two rows along the first direction, and each row comprises a plurality of aspheric structures sequentially arranged along a second direction, and each of the first prism strips further comprises two inclined surfaces protruding relative to the second surface, and each of the inclined surfaces extends along the second direction; Performing a first cutting process on the wafer, so that each of the first prism strips is separated from each other, and each of the first prism strips is cut into two second prism strips, each of the second prism strips includes an inclined surface and a row of the aspheric structures arranged in sequence along the second direction, and the cutting surface of the first prism strip into the two second prism strips is an exit surface; Performing a second cutting process on the second prism strips, wherein a cutting line of the second cutting process is located between adjacent aspherical structures, so as to form an initial prism; forming an anti-reflection film on the surface of the initial prism where the aspherical structure is located and on the exit surface; The aspheric prism is obtained by performing ink coating operation on the surfaces other than the aspheric structure, the exit surface and the inclined surface in the initial prism.

2. The method for preparing an aspheric prism according to claim 1, characterized in that: The one-piece forming process is a hot pressing forming process.

3. The method for preparing an aspheric prism according to claim 1, characterized in that: The first prism strip is an axisymmetric shape, and a cutting line of the first prism strip being cut into two second prism strips is a symmetry axis of the first prism strip.

4. The method for preparing an aspheric prism according to claim 1, characterized in that: After performing the first cutting process, the method further includes: The exit surface is ground and polished so that the angle between the exit surface and the inclined surface is 45°.

5. The method for preparing an aspheric prism according to claim 4, characterized in that: The inclined surface of the second prism strip is a plane.

6. The method for preparing an aspheric prism according to claim 5, characterized in that: Before grinding the exit surface, the method further includes: placing the inclined surface on the tooling.

7. The method for preparing an aspheric prism according to claim 4, characterized in that: After polishing the exit surface, the method further comprises: The corners of the second prism strip are chamfered to form a second chamfered surface.

8. The method for preparing an aspheric prism according to claim 1, characterized in that: The material refractive index of the initial prism is greater than or equal to 1.

75.

9. The method for preparing an aspheric prism according to claim 1, characterized in that: The material refractive index of the initial prism is less than 1.75, and the method for preparing the aspherical prism further comprises: A high reflection film is formed on the inclined surface.

10. An aspherical prism, characterized in that: The aspheric prism is prepared by the method for preparing an aspheric prism according to any one of claims 1 to 9.

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