Aspheric prism and preparation method therefor

Abstract

The embodiments of the present invention relate to the technical field of optics. Provided are an aspheric prism and a preparation method therefor. The preparation method for the aspheric prism comprises: forming a wafer by using an integral molding process, wherein the wafer comprises a plurality of first prism strips sequentially arranged in a first direction; performing first cutting on the wafer, wherein 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 structures sequentially arranged in a second direction; performing second cutting on the second prism strips, wherein a cutting line in the second cutting is located between adjacent aspheric structures to form an initial prism; forming anti-reflection films on a surface where the aspheric structures are located and an emergent surface in the initial prism; and performing an ink coating operation on a surface other than the aspheric structures, the emergent surface and the inclined surfaces in the initial prism to obtain the aspheric prism. The embodiments of the present invention can at least improve the preparation efficiency and structural accuracy of the aspheric prism.

Description

Aspherical prisms and their preparation methods Technical Field

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

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

[0003] In the manufacturing process of aspherical prisms using relevant technologies, triangular prisms and lenses are typically assembled together. Different assembly methods are used for different applications; for example, the triangular prism and lens can be glued together. In the assembly of optical lenses, a support bracket can be used for assembly. However, regardless of the assembly method, the precision requirements for the fit between the triangular prism and lens, as well as the overall assembly precision, are extremely high.

[0004] Because triangular prisms and lenses are processed using different equipment, and their cutting, coating, and ink application processes are all completed separately on optical equipment, the entire process has a long preparation cycle, low preparation efficiency, and inconsistent control of structural precision.

[0005] Therefore, the fabrication efficiency and structural precision of aspherical prisms in related technologies need to be improved. Summary of the Invention

[0006] This invention provides an aspherical prism and its preparation method, which can at least improve the preparation efficiency of aspherical prisms and improve the structural accuracy.

[0007] This invention provides a method for fabricating an aspherical prism, comprising: forming a wafer using an integral molding process, the wafer having opposing first and second faces, the wafer including a plurality of first prism strips arranged sequentially along a first direction, each first prism strip including a plurality of aspherical structures convex relative to the first face, the plurality of aspherical structures being arranged in two columns along the first direction, and each column having a plurality of aspherical structures arranged sequentially along a second direction, each first prism strip further including two inclined surfaces convex relative to the second face, each inclined surface extending along the second direction; and performing a first dicing process on the wafer to make each first prism strip... The first prism strip is separated from the second prism strip and each first prism strip is cut into two second prism strips. Each second prism strip includes a bevel and a row of aspherical structures arranged sequentially along the second direction. The cutting surface of the first prism strip into two second prism strips is the exit surface. The second prism strip is subjected to a second cutting process, and the cutting line of the second cutting process is located between adjacent aspherical structures to form an initial prism. An anti-reflection film is formed on the surface of the aspherical structure and the exit surface in the initial prism. An ink coating operation is performed on the surface of the aspherical structure, the exit surface and the surface other than the bevel in the initial prism to obtain the aspherical prism.

[0008] In some embodiments, the integral molding process is a hot pressing molding process.

[0009] In some embodiments, the first prism strip is an axisymmetric shape, and the cutting line of the first prism strip into two second prism strips is the axis of symmetry of the first prism strip.

[0010] In some embodiments, after the first cutting process, the method further includes: grinding and polishing the exit surface so that the 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, prior to grinding the ejection 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 of the second prism strip to form a second chamfered surface.

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

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

[0016] In another aspect, the present invention provides an aspherical prism, which is prepared by the aspherical prism preparation method described in any of the above embodiments.

[0017] The beneficial effects of this invention are as follows: A wafer with an aspherical structure is formed using a one-piece molding process. The aspherical structure of the wafer is equivalent to a lens. The wafer is then subjected to first dicing, second dicing, and anti-reflective coating formation to create an aspherical prism. This eliminates the need for methods like those in related technologies, which require first forming an initial triangular prism and an initial lens, then separately dicing, coating, and ink-coating the initial triangular prism and initial lens to form a triangular prism and a lens, and finally assembling them. Therefore, the aspherical prism fabrication method provided by this invention can shorten the fabrication cycle and improve processing efficiency. The one-piece molding process directly forms a wafer with an aspherical structure and bevels, thereby reducing the grinding steps required in related technologies to create the aspherical structure and bevels, further shortening the fabrication cycle and improving processing efficiency. Furthermore, the first prism strip in the wafer fabricated using a one-piece molding process includes two bevels and two rows of aspherical structures. During the first dicing process, one prism strip can be cut into two second prism strips, each with a bevel and a row of aspherical structures. This reduces the grinding steps directly performed on the wafer to form the second prism strips, as is done in related technologies, thus improving wafer material utilization, shortening the fabrication cycle, and increasing fabrication efficiency. Additionally, the one-piece molding process allows for integrated processing in subsequent steps, eliminating assembly errors associated with triangular prisms and lenses, and improving the structural precision of the aspherical prism. Attached Figure Description

[0018] One or more embodiments are illustrated by way of example with corresponding pictures in the accompanying drawings. These illustrative descriptions do not constitute a limitation on the embodiments. Unless otherwise stated, the pictures in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the conventional technology, the drawings used in 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.

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

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

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

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

[0023] Figure 5 is a perspective view of a wafer formed by the integral molding process provided in an embodiment of the present invention;

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

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

[0026] Figure 8 is a schematic diagram of the second prism strip placed on the tooling according to an embodiment of the present invention;

[0027] Figure 9 is a front view of the second prism strip after chamfering according to an embodiment of the present invention;

[0028] Figure 10 is a perspective view of the second prism strip after chamfering according to an embodiment of the present invention;

[0029] Figure 11 is a perspective view of the initial prism provided in an embodiment of the present invention;

[0030] Figure 12 is a side view of the aspherical prism provided in an embodiment of the present invention;

[0031] Figure 13 is a schematic diagram of the aspherical prism provided in an embodiment of the present invention. Embodiments of the present invention

[0032] As can be seen from the background technology, the fabrication efficiency and structural accuracy of aspherical prisms in related technologies need to be improved.

[0033] This invention provides a method for fabricating an aspherical prism. A wafer with an aspherical structure is formed using a one-piece molding process. The wafer is then processed to form the aspherical prism. The aspherical structure within the wafer acts as a lens, eliminating the need for methods like those in related technologies that first form an initial triangular prism and an initial lens, then process them separately to form a triangular prism and a lens, and finally assemble them. This method shortens the fabrication cycle and improves processing efficiency. The one-piece molding process directly forms the wafer with the aspherical structure and bevel, reducing the grinding steps required in related technologies to create the aspherical structure and bevel, further shortening the fabrication cycle and improving efficiency. Furthermore, during the first dicing process, one prism strip can be cut into two second prism strips, each with a bevel and a row of aspherical structures. This reduces the grinding steps required in related technologies to form the second prism strips, improving wafer material utilization, shortening the fabrication cycle, and increasing processing efficiency. In addition, the wafer is formed by a one-piece molding process, which can be carried out in one piece in subsequent processing. Therefore, there is no assembly error of triangular prism and lens, which improves the structural accuracy of aspherical prism.

[0034] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of the present invention to facilitate a better understanding of the invention. However, the technical solutions claimed in this invention can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0035] Figure 1 is a front view of a wafer formed by the integral molding process provided in an embodiment of the present invention; Figure 2 is a bottom view of a wafer formed by the integral molding process provided in an embodiment of the present invention; Figure 3 is a top view of a wafer formed by the integral molding process provided in an embodiment of the present invention; Figure 4 is a side view of a wafer formed by the integral molding process provided in an embodiment of the present invention; Figure 5 is a perspective view of a wafer formed by the integral molding process provided in an embodiment of the present invention.

[0036] It should be noted that Figures 1 to 5 illustrate the case where the wafer includes three first prism strips. In reality, the number of first prism strips on the wafer can be adaptively adjusted according to the needs of actual applications. The embodiments of the present invention do not limit the number of first prism strips in the wafer.

[0037] Referring to Figures 1 to 5, a wafer 100 is formed using an integral molding process. The wafer 100 has a first surface 110 and a second surface 120 opposite to each other. The wafer 100 includes a plurality of first prism strips 101 arranged sequentially along a first direction X. Each first prism strip 101 includes a plurality of aspherical structures 102 protruding relative to the first surface 110. The plurality of aspherical structures 102 are arranged in two columns along the first direction X, and each column has a plurality of aspherical structures 102 arranged sequentially along a second direction Y. Each first prism strip 101 also includes two inclined surfaces 103 protruding relative to the second surface 120. Each inclined surface 103 extends along the second direction Y.

[0038] In some embodiments, the integral molding process can be a thermoforming process, which refers to a processing method in which pre-processed raw materials are pressed into shape under high temperature and high pressure. This process is generally suitable for manufacturing high-precision and high-strength products. The thermoforming process requires multiple steps, such as raw material pretreatment, hot pressing, cooling, and polishing. These steps can be combined into a single process, and using thermoforming can improve wafer production efficiency.

[0039] In some embodiments, a precision tungsten carbide mold can be used for hot pressing to achieve sufficiently high precision in the formed wafer 100. The hot pressing process is typically performed near the sag temperature of the wafer material.

[0040] The material of wafer 100 is optical glass, which has the characteristics of high uniformity, no cracks, isotropy, good light transmittance, high dispersion and small temperature coefficient.

[0041] The first prism strip 101 includes two rows of aspherical structures 102 arranged along a first direction X. Each aspherical structure 102 serves as the light-transmitting area of ​​the incident surface of a subsequently manufactured aspherical prism. The aspherical structure 102 is equivalent to a lens in an aspherical prism in the related art, which can reduce the aberrations of the aspherical prism and improve the imaging quality.

[0042] The first prism strip 101 also includes two inclined surfaces 103 that protrude relative to the second surface 120, the inclined surfaces 103 serving as the reflecting surfaces of the aspherical prism subsequently manufactured.

[0043] Figure 6 is a schematic diagram of the structure of the first prism strip after being cut into two second prism strips according to an embodiment of the present invention. Figure 7 is a schematic diagram of the structure of the second prism strip according to an embodiment of the present invention. In Figure 6, the dotted line is the cutting line of the first prism strip. For ease of illustration, the subsequent processing of the second prism strip is based on the first prism strip to the left of the dotted line in Figure 6.

[0044] Referring to Figures 6 and 7, the wafer 100 undergoes a first dicing process to separate each first prism strip 101 from the others, and each first prism strip 101 is diced into two second prism strips 104. Each second prism strip 104 includes a bevel 103 and a row of aspherical structures 102 arranged sequentially along the second direction Y. The cutting surface from which the first prism strip 101 is diced into two second prism strips 104 is the exit surface 105. Specifically, to diced the first prism strip 101 into two second prism strips 104 including a bevel 103, the cutting surface from which the first prism strip 101 is diced into two second prism strips 104 should be perpendicular to the surface where the aspherical structures 102 are located. Thus, during the first dicing process, the cutting surface of the second prism strip 104 is directly converted into an exit surface 105 perpendicular to the surface where the aspherical structures 102 are located, which can improve the fabrication efficiency of the aspherical prism. In addition, during the first cutting process, the cutting surface that separates each first prism strip 101 is the first chamfer surface 115.

[0045] The first cutting process can be laser cutting or water jet cutting, and the first cutting process needs to monitor the perpendicularity and size data of the cutting surface (i.e., the exit surface 105 and the first chamfer surface 115) to ensure the accuracy and uniformity of the final formed second prism strip 104.

[0046] In some embodiments, the first prism strip 101 is an axisymmetric shape, and the cutting line from which the first prism strip 101 is cut into two second prism strips 104 is the axis of symmetry of the first prism strip 101. With this configuration, when the first prism strip 101 undergoes a first cutting process, two identical second prism strips 104 can be formed, which can improve the utilization rate of wafer materials, shorten the fabrication cycle, and increase fabrication efficiency.

[0047] In other embodiments, the first prism strip may not be an axisymmetric shape, so that the aspherical structures on the two second prism strips formed by cutting the first prism strip may be different. Thus, the wafer formed by integral molding can simultaneously produce aspherical prisms with two different specifications of aspherical structures, which can also improve the manufacturing efficiency of aspherical prisms.

[0048] Figure 8 is a schematic diagram of the second prism strip provided in an embodiment of the present invention being placed on the tooling.

[0049] Referring to Figures 7 and 8, in some embodiments, the inclined surface 103 of the second prism strip 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°.

[0050] To ensure that the angle between the ejection surface 105 and the inclined surface 103 is 45°, the ejection surface 105 needs to be ground and then polished. Before grinding and polishing, the inclined surface 103 opposite to the ejection surface 105 needs to be placed on the fixture 11. The inclined surface 103 in contact with the fixture 11 needs to be flat to ensure the bonding effect between the inclined surface 103 and the fixture 11. The inclined surface 103 prepared by the one-piece molding process is flat. The inclined surface 103 is flat enough to ensure the bonding effect between the inclined surface 103 and the fixture 11. This can avoid the problem of the second prism strip 104 moving due to insufficient flatness of the inclined surface 105 during the grinding and polishing process, which would lead to processing errors. This can improve the reliability of grinding and polishing.

[0051] Figure 9 is a front view of the second prism strip after chamfering according to an embodiment of the present invention; Figure 10 is a perspective view of the second prism strip after chamfering according to an embodiment of the present invention.

[0052] Referring to Figures 9 and 10, after polishing the exit surface 105, the process further includes chamfering the edges of the second prism strip 104 to form a second chamfered surface 106. Chamfering the edges ensures that the edges of the subsequently manufactured aspherical prism are smooth and burr-free, thereby preventing scratches or damage to other components during the use of the aspherical prism and improving the safety of the aspherical prism.

[0053] Specifically, a chamfering machine is used for chamfering, and the dimensions and chipping data of the second chamfered surface 106 are monitored during the process.

[0054] Figure 11 is a perspective view of the initial prism provided in an embodiment of the present invention.

[0055] Referring to Figures 10 and 11, after chamfering, the second prism strip 104 is subjected to a second cutting process. The cutting line of the second cutting process is located between adjacent aspherical structures 102 to form the initial prism 107.

[0056] The second cutting process can be laser cutting or water jet cutting, and the perpendicularity and dimensional data of the cut surface need to be monitored during the second cutting process.

[0057] Each initial prism 107 after the second cutting process has an aspherical structure 102.

[0058] Figure 12 is a side view of the aspherical prism provided in an embodiment of the present invention, and Figure 13 is a schematic diagram of the structure of the aspherical prism provided in an embodiment of the present invention. It should be noted that, for ease of illustration, the anti-reflection film, high-reflection film, and ink layer in the aspherical prism are only shown in Figure 12 and are not shown in Figure 13.

[0059] Referring to Figures 11-13, an anti-reflection film (AR film, anti-reflection film) 108 is formed on the surface of the aspherical structure 102 in the initial prism 107 and on the exit surface 105.

[0060] The surface where the aspherical structure 102 is located is the incident surface 117. An anti-reflection coating 108 is formed on the incident surface 117 and the exit surface 105, which can reduce the reflectivity of the aspherical prism, improve the imaging quality, and reduce glare and light loss.

[0061] In some embodiments, the refractive index of the initial prism 107 is less than 1.75, and the method for fabricating the aspherical prism further includes forming a high-reflection film (HR film, high-reflection film) 118 on the inclined surface 103. Since the initial prism 107 has a low refractive index, in order to improve the reflectivity of the inclined surface 103, a high-reflection film 118 is deposited on the inclined surface 103 to improve the reflectivity of the inclined surface 103 as a reflecting surface.

[0062] In some embodiments, the refractive index of the initial prism 107 is greater than or equal to 1.75. In this case, the refractive index of the initial prism 107 is relatively large, which is sufficient to meet the reflectivity requirements of the reflecting surface in the aspherical prism. There is no need to coat the inclined surface 103 with a high-reflectivity film, which can save the manufacturing cost of the aspherical prism.

[0063] A blackening operation is performed on the surfaces of the initial prism 107 other than the aspherical structure 102, the exit surface 105, and the inclined surface 103 to obtain the aspherical prism 109. Specifically, the surface containing the aspherical structure 102 is the incident surface 117. 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 two side surfaces 127. The blackening operation is performed on the second chamfered surface 106, the side surfaces 127, and the parts of the incident surface 117 other than the aspherical structure 102. During blackening, the first chamfered surface 115 and the second chamfered surface 106 can be blackened first, then the parts of the incident surface 117 other than the aspherical structure 102 can be blackened, and finally the two side surfaces 127 can be blackened. The ink layer 128 formed by the ink coating can reduce the absorption of light from the edge of the aspherical 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 aspherical prism imaging.

[0064] In the aforementioned method for fabricating aspherical prisms, a wafer with an aspherical structure is formed using an integral molding process. The wafer is then processed to form the aspherical prism. The aspherical structure within the wafer acts as a lens, eliminating the need for the initial triangular prism and initial lens to be formed first, then processed separately to form a triangular prism and a lens, and finally assembled, as in related technologies. Therefore, the method provided by this invention can shorten the fabrication cycle and improve processing efficiency. The integral molding process directly forms a wafer with an aspherical structure and a bevel, reducing the grinding steps required in related technologies to form the aspherical structure and bevel, further shortening the fabrication cycle and improving processing efficiency. Furthermore, during the first dicing process, one prism strip can be cut into two second prism strips, each with a bevel and a row of aspherical structures. This reduces the grinding steps required in related technologies to form the second prism strips, improving wafer material utilization, shortening the fabrication cycle, and increasing processing efficiency. In addition, the wafer is formed by a one-piece molding process, which can be carried out in one piece in subsequent processing. Therefore, there is no assembly error of triangular prism and lens, which improves the structural accuracy of aspherical prism.

[0065] Accordingly, another embodiment of the present invention also provides an aspherical prism prepared using the aspherical prism preparation method described in the above embodiments. For parts that are the same as or corresponding to the previous embodiment, please refer to the corresponding descriptions of the foregoing embodiments, which will not be repeated in detail below.

[0066] Referring to Figure 13, the aspherical prism 109 includes a lens 119 and a triangular prism 129.

[0067] Those skilled in the art will understand that the above embodiments are specific examples of implementing the present invention, and in practical applications, various changes in form and detail can be made without departing from the spirit and scope of the present invention. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of the present invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A method for preparing an aspherical prism, comprising: A wafer is formed using an integral molding process. The wafer has a first face and a second face. The wafer includes a plurality of first prism strips arranged sequentially along a first direction. Each first prism strip includes a plurality of aspherical structures protruding relative to the first face. The plurality of aspherical structures are arranged in two columns along the first direction, and each column has a plurality of aspherical structures arranged sequentially along a second direction. Each first prism strip also includes two inclined surfaces protruding relative to the second face. Each inclined surface extends along the second direction. The wafer is subjected to a first dicing process to separate each of the first prism strips from each other, and each of the first prism strips is diced into two second prism strips. Each second prism strip includes a bevel and a row of aspherical structures arranged sequentially along the second direction. The dicing surface from which the first prism strip is diced into two second prism strips is the exit surface. The second prism strip is subjected to a second cutting process, wherein the cutting line of the second cutting process is located between adjacent aspherical structures to form an initial prism; An anti-reflection coating is formed on the surface where the aspherical structure is located and on the exit surface of the initial prism; The aspherical prism is obtained by applying ink to the aspherical structure, the exit surface, and the surface other than the inclined plane in the initial prism.

2. The method for preparing an aspherical prism according to claim 1, wherein, The integral molding process is a hot pressing molding process.

3. The method for preparing an aspherical prism according to claim 1, wherein, The first prism strip is an axisymmetric shape, and the cutting line of the first prism strip into two second prism strips is the axis of symmetry of the first prism strip.

4. The method for preparing an aspherical prism according to claim 1, wherein, After the first cutting process, the process also 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 aspherical prism according to claim 4, wherein, The inclined surface of the second prism strip is a plane.

6. The method for preparing an aspherical prism according to claim 5, wherein, Before grinding the ejection surface, the process further includes placing the inclined surface on the tooling.

7. The method for preparing an aspherical prism according to claim 4, wherein, After polishing the exit surface, the process further includes: The edges of the second prism strip are chamfered to form a second chamfered surface.

8. The method for preparing an aspherical prism according to claim 1, wherein, The initial prism is made of a material with a refractive index greater than or equal to 1.

75.

9. The method for preparing an aspherical prism according to claim 1, wherein, The initial prism is made of a material with a refractive index of less than 1.75, and the method for preparing the aspherical prism further includes: A high-reflectivity film is formed on the inclined surface.

10. An aspherical prism, wherein, The aspherical prism is prepared using the aspherical prism preparation method as described in any one of claims 1 to 9.

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