An abutment type microlens array manufacturing method

Abstract

This invention discloses a method for manufacturing adjacent microlens arrays, relating to the field of microlens array manufacturing, comprising the following steps: Step 1, processing a pyramid array microstructure mold on a planar mold substrate; Step 2, placing a first glass preform on the upper part of a lower mold and heating it; Step 3, applying pressure to the pyramid array microstructure mold and the lower mold, causing the pyramid array microstructure mold to process a concave pyramid microstructure glass on the surface of the first glass preform; Step 4, placing a second glass preform on the upper part of the lower mold and heating it; Step 5, applying pressure to the upper mold and the lower mold, using the surface tension of the glass material to shape the second glass preform, thereby obtaining an adjacent microlens array. This method for manufacturing adjacent microlens arrays solves the problems of the inability of existing non-contact forming methods to process adjacent microlens arrays and the long manufacturing cycle and high cost of structural molds.

Description

Technical Field

[0001] This invention relates to the field of microlens array manufacturing, and in particular to a method for manufacturing adjacent microlens arrays. Background Technology

[0002] Adjacent microlens arrays are formed by arranging lens units adjacent to each other. Due to their unique arrangement, they feature high fill factor, high integration, and high light energy utilization, and are widely used in optical systems. Molding is a common method for fabricating microlens arrays, and its process is as follows: Figure 1 As shown. First, a microlens array structure is fabricated on a mold using an ultra-precision machining method. The structure shape is the same as the manufactured microlens array, thus obtaining the structural mold 12. Then, the lower plane mold 9, outer sleeve 10, inner sleeve 11, structural mold 12, and glass preform 13 are assembled. Pressure is applied to the structural mold 12 and the lower plane mold 9 at a temperature higher than the glass transition temperature (Tg) of the glass material, so that the glass preform 13 is shaped to be the same as the shape of the structural mold 12. After cooling, the glass microlens array 14 is obtained.

[0003] Non-contact forming processes are similar to compression molding and are often used to fabricate distributed microlens arrays. The process is as follows: Figure 2 As shown, firstly, an array of holes is machined on a mold. Then, the glass preform is heated and pressurized, utilizing the surface tension of the glass material at high temperatures to form the distributed microlens array 15. The structure of the distributed microlens array 15 is as follows: Figure 9 and Figure 10 As shown, there are gaps between the lenses of the distributed microlens array 15, and the gaps are planar. This method has low requirements for the machining accuracy of the mold, but due to the limitations of the principle, it cannot manufacture adjacent microlens arrays.

[0004] In microlens array manufacturing technology, the limitation of compression molding lies in the requirement for structural molds with high surface precision. During the compression molding process, the surface morphology of the glass preform will eventually be identical to that of the structural mold, almost completely replicating its shape. Therefore, high precision and good processing quality of the structural mold are required, resulting in long processing time and high cost. Existing non-contact forming processes have the disadvantage of being unable to process adjacent microlens arrays and having low fill rates. Summary of the Invention

[0005] To address the above technical problems, this invention provides a method for manufacturing adjacent microlens arrays, which solves the problems that the original non-contact forming method cannot process adjacent microlens arrays and that the manufacturing cycle of structural molds is long and costly.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] This invention provides a method for manufacturing an adjacent microlens array, comprising the following steps:

[0008] Step 1: Machining a pyramid array microstructure mold on a planar mold base;

[0009] Step 2: Place the first glass preform on the upper part of the lower mold, and place the pyramid array microstructure mold on top of the first glass preform. Heat the pyramid array microstructure mold, the first glass preform, and the lower mold to reach the molding temperature T1. The glass transition temperature of the first glass preform is Tg1, where T1 > Tg1.

[0010] Step 3: Apply pressure to the pyramid array microstructure mold and the lower mold, so that the pyramid array microstructure mold is processed on the surface of the first glass preform to obtain a concave pyramid microstructure glass;

[0011] Step 4: Remove the concave pyramid microstructured glass from the lower mold and place it at the bottom of the upper mold. Place the second glass preform on the upper part of the lower mold, and place the upper mold and the concave pyramid microstructured glass above the second glass preform. Heat the upper mold, the concave pyramid microstructured glass, the second glass preform, and the lower mold to reach the molding temperature T2. The glass transition temperature of the second glass preform is Tg2, where Tg1 > Tg2 and Tg2 < T2 < Tg1.

[0012] Step 5: Apply pressure to the upper mold and the lower mold. By controlling the forming pressure of the upper mold and the displacement of the concave pyramid microstructure glass, the second glass preform is formed using the surface tension of the glass material to obtain an adjacent microlens array.

[0013] Preferably, in step one, a first V-groove microstructure array is processed on a planar mold base at a fixed cycle, the planar mold is rotated 90°, and a second V-groove microstructure array is processed in the same cycle in a direction perpendicular to the first V-groove microstructure array, thereby obtaining the pyramid array microstructure mold.

[0014] Preferably, in step four, Tg1 > Tg2 + 200℃.

[0015] Preferably, in step two, Tg1 is 400℃~700℃ and T1 is 500℃~800℃; in step four, Tg2 is 200℃~350℃ and T2 is 300℃~450℃.

[0016] Preferably, in step three, the pressure applied is 0.01 MPa to 0.9 MPa, and the pressurization time is 30 seconds to 10 minutes.

[0017] Preferably, in step five, the pressure applied is 0.01 MPa to 0.9 MPa, and the pressurization time is 30 seconds to 10 minutes.

[0018] Preferably, in step five, the downward displacement distance of the concave pyramid microstructure glass after contact with the second glass preform is 0.01mm to 0.5mm.

[0019] The present invention achieves the following technical effects compared to the prior art:

[0020] The present invention discloses a method for manufacturing adjacent microlens arrays. It utilizes a first glass preform and a second glass preform with different glass transition temperatures. A concave pyramidal microstructure glass is obtained by processing the surface of the first glass preform using a pyramidal array microstructure mold. This concave pyramidal microstructure glass serves as an intermediate mold placed on an upper mold. The second glass preform is then processed to obtain the adjacent microlens array. This invention utilizes the cavity of the concave pyramidal microstructure glass and employs a non-contact molding method. By controlling the surface tension of the glass material, the adjacent microlens array is obtained. The method of this invention solves the problem that traditional non-contact forming methods cannot process adjacent microlens arrays due to low fill rate. Furthermore, the microlens array produced by the non-contact forming method only contacts the frame of the intermediate mold, not the microstructure surface of the intermediate mold. Compared to the molding method, which relies on mold precision, this method solves the problems of long manufacturing cycles and high costs associated with structural molds. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, 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.

[0022] Figure 1 A flowchart illustrating the manufacturing of adjacent microlens arrays using compression molding in existing technologies;

[0023] Figure 2 A flowchart illustrating the fabrication of distributed microlens arrays using a non-contact forming process in existing technologies;

[0024] Figure 3 A flowchart of the adjacent microlens array manufacturing method provided by the present invention;

[0025] Figure 4 This is a three-dimensional structural diagram of the pyramid array microstructure mold in the adjacent microlens array manufacturing method provided by the present invention;

[0026] Figure 5A three-dimensional structural diagram of the concave pyramid microstructure glass in the adjacent microlens array manufacturing method provided by the present invention;

[0027] Figure 6 This is a front view of the concave pyramid microstructure glass in the adjacent microlens array manufacturing method provided by the present invention;

[0028] Figure 7 This is a top view of the concave pyramid microstructure glass in the adjacent microlens array manufacturing method provided by the present invention.

[0029] Figure 8 This is a three-dimensional structural diagram of an adjacent microlens array fabricated using the adjacent microlens array manufacturing method provided by the present invention.

[0030] Figure 9 This is a three-dimensional structural diagram of a distributed microlens array manufactured using a non-contact forming process in the prior art;

[0031] Figure 10 This is a front view of a distributed microlens array manufactured using a non-contact forming process in the prior art.

[0032] Explanation of reference numerals in the attached drawings: 1. Planar mold; 2. Pyramid array microstructure mold; 3. Lower mold; 4. First glass preform; 5. Concave pyramid microstructure glass; 6. Upper mold; 7. Second glass preform; 8. Adjacent microlens array; 9. Lower planar mold; 10. Outer sleeve; 11. Inner sleeve; 12. Structural mold; 13. Glass preform; 14. Glass microlens array; 15. Distributed microlens array. Detailed Implementation

[0033] 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 some embodiments of the present invention, and not all embodiments. 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.

[0034] The purpose of this invention is to provide a method for manufacturing adjacent microlens arrays, which solves the problems that the original non-contact forming method cannot process adjacent microlens arrays and that the manufacturing cycle of structural molds is long and costly.

[0035] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] like Figures 3-8 As shown, the present invention provides a method for manufacturing an adjacent microlens array, comprising the following steps:

[0037] Step 1: Machining a pyramid array microstructure mold 2 on a planar mold 1 substrate;

[0038] Step 2: Place the first glass preform 4 on the upper part of the lower mold 3, and place the pyramid array microstructure mold 2 on the upper part of the first glass preform 4. Heat the pyramid array microstructure mold 2, the first glass preform 4 and the lower mold 3 to reach the molding temperature T1. The glass transition temperature of the first glass preform 4 is Tg1, T1 > Tg1.

[0039] Step 3: Pressurize the pyramid array microstructure mold 2 and the lower mold 3 so that the pyramid array microstructure mold 2 is processed on the surface of the first glass preform 4 to obtain the concave pyramid microstructure glass 5.

[0040] Step 4: Remove the concave pyramid microstructure glass 5 from the lower mold 3 and place it at the bottom of the upper mold 6. Specifically, remove the concave pyramid microstructure glass 5 from the lower mold 3 and rotate it 180° before placing it at the bottom of the upper mold 6. Place the second glass preform 7 on the upper part of the lower mold 3, and place the upper mold 6 and the concave pyramid microstructure glass 5 above the second glass preform 7. Heat the upper mold 6, the concave pyramid microstructure glass 5, the second glass preform 7, and the lower mold 3 to reach the molding temperature T2. The glass transition temperature of the second glass preform 7 is Tg2, where Tg1 > Tg2. This allows the concave pyramid microstructure glass 5, which has a higher glass transition temperature, to process the second glass preform 7, which has a lower glass transition temperature. At the same time, the molding temperature T2 must also meet the following requirement: Tg2 < T2 < Tg1.

[0041] Step 5: Apply pressure to the upper mold 6 and the lower mold 3. The upper mold 6 can drive the concave pyramid microstructure glass 5 to move together. By controlling the forming pressure of the upper mold 6 and the displacement of the concave pyramid microstructure glass 5, the surface tension of the glass material is used to form the second glass preform 7, resulting in the adjacent microlens array 8.

[0042] Specifically, in step one, a first V-groove microstructure array is processed on the base of the planar mold 1 at a fixed period. The planar mold 1 is rotated 90°, and a second V-groove microstructure array is processed in the same period in the direction perpendicular to the first V-groove microstructure array, thereby obtaining a pyramid array microstructure mold 2. The shape and period of the V-groove of the first V-groove microstructure array and the second V-groove microstructure array can be adjusted according to the specific requirements of the pyramid array microstructure mold 2.

[0043] In this embodiment, the processing of the first V-groove microstructure array and the second V-groove microstructure array results in the pyramid array microstructure mold 2 having multiple square pyramids. The pyramid array microstructure mold 2 is used to process a concave pyramid microstructure glass 5 with multiple inverted square pyramid cavities. At this time, the openings of the inverted square pyramid cavities are set upwards. The concave pyramid microstructure glass 5 is removed from the lower mold 3 and rotated 180°, and then placed at the bottom of the upper mold 6. At this time, the openings of the inverted square pyramid cavities are set downwards. When the concave pyramid microstructure glass 5 moves down to process the second glass preform 7, the second glass preform 7 contacts the bottom frame of the concave pyramid microstructure glass 5. The second glass preform 7 does not contact the entire inverted square pyramid cavity of the concave pyramid microstructure glass 5, which reduces the requirement for the morphological accuracy of the concave pyramid microstructure glass 5, and thus a rectangular aperture adjacent microlens array 8 is obtained.

[0044] Specifically, in step four, Tg1 > Tg2 + 200℃.

[0045] In this specific implementation, in step two, Tg1 is 400℃~700℃, T1 is 500℃~800℃, and T1 is generally about Tg1+100℃; in step four, Tg2 is 200℃~350℃, T2 is 300℃~450℃, and T2 is generally about Tg2+100℃.

[0046] In this specific implementation, in step three, the pressurization pressure and pressurization time are determined based on the conditions of the pyramid array microstructure mold 2, the first glass preform 4, and the lower mold 3. Specifically, the pressurization pressure is 0.01MPa to 0.9MPa, and the pressurization time is 30s to 10min.

[0047] In this specific implementation, in step five, the pressurization pressure and pressurization time are determined based on the conditions of the upper mold 6, the concave pyramid microstructure glass 5, the second glass preform 7, and the lower mold 3. Specifically, the pressurization pressure is 0.01MPa to 0.9MPa, and the pressurization time is 30s to 10min.

[0048] In this specific embodiment, in step five, the downward displacement distance of the concave pyramid microstructure glass 5 after contacting the second glass preform 7 is determined by the structure of the concave pyramid microstructure glass 5 and the morphology of the designed adjacent microlens array 8. Specifically, the downward displacement distance of the concave pyramid microstructure glass 5 after contacting the second glass preform 7 is 0.01 mm to 0.5 mm.

[0049] In this embodiment, a first glass preform 4 and a second glass preform 7 with different glass transition temperatures are used. A concave pyramidal microstructure glass 5 is obtained by processing the surface of the first glass preform 4 using a pyramidal array microstructure mold 2. The concave pyramidal microstructure glass 5 is set as an intermediate mold on the upper mold 6, and the second glass preform 7 is processed to obtain an adjacent microlens array 8. Specifically, in this embodiment, the cavity of the concave pyramidal microstructure glass 5 is used, and the adjacent microlens array 8 is obtained by non-contact molding and by controlling the surface tension of the glass material.

[0050] As can be seen, the method in this embodiment can solve the problem that the original non-contact forming method cannot process adjacent microlens arrays 8 due to low filling rate. At the same time, the microlens array morphology accuracy processed by the non-contact forming method only contacts the frame of the intermediate mold, and does not contact the microstructure surface of the intermediate mold, which reduces the requirements for the morphology accuracy of the intermediate mold. Compared with the compression molding method which depends on the mold accuracy, it solves the problems of long manufacturing cycle and high cost of structural mold, that is, it improves work efficiency and reduces costs. In addition, the compression molding method requires the use of structural mold 12 for each microlens array processing, while the method in this embodiment uses concave pyramid microstructure glass 5 for each microlens array processing. Multiple microlens arrays can be processed by processing one concave pyramid microstructure glass 5 with pyramid array microstructure mold 2. Compared with the structural mold 12 in the compression molding method, the pyramid array microstructure mold 2 in this embodiment is used less frequently, resulting in reduced wear and longer service life.

[0051] This specification uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for manufacturing an adjacent microlens array, characterized in that, Includes the following steps: Step 1: A pyramid array microstructure mold is obtained by processing a planar mold base; a first V-groove microstructure array is processed on the planar mold base at a fixed period; the planar mold is rotated 90°, and a second V-groove microstructure array is processed in the same period in the direction perpendicular to the first V-groove microstructure array, thereby obtaining the pyramid array microstructure mold. Step 2: Place the first glass preform on the upper part of the lower mold, and place the pyramid array microstructure mold on top of the first glass preform. Heat the pyramid array microstructure mold, the first glass preform, and the lower mold to reach the molding temperature T1. The glass transition temperature of the first glass preform is Tg1, where T1 > Tg1. Step 3: Apply pressure to the pyramid array microstructure mold and the lower mold, so that the pyramid array microstructure mold is processed on the surface of the first glass preform to obtain a concave pyramid microstructure glass; Step 4: Remove the concave pyramid microstructured glass from the lower mold and place it at the bottom of the upper mold. Place the second glass preform on the upper part of the lower mold, and place the upper mold and the concave pyramid microstructured glass above the second glass preform. Heat the upper mold, the concave pyramid microstructured glass, the second glass preform, and the lower mold to reach the molding temperature T2. The glass transition temperature of the second glass preform is Tg2, where Tg1 > Tg2 and Tg2 < T2 < Tg1. Step 5: Apply pressure to the upper mold and the lower mold. By controlling the forming pressure of the upper mold and the displacement of the concave pyramid microstructure glass, the second glass preform is formed using the surface tension of the glass material to obtain an adjacent microlens array.

2. The abutment type microlens array manufacturing method according to claim 1, wherein In step four, Tg1 > Tg2 + 200℃.

3. The abuttable microlens array manufacturing method according to claim 2, wherein In step two, Tg1 is 400℃~700℃ and T1 is 500℃~800℃; in step four, Tg2 is 200℃~350℃ and T2 is 300℃~450℃.

4. The method of claim 1, wherein In step three, the pressure applied is 0.01 MPa to 0.9 MPa, and the pressurization time is 30 seconds to 10 minutes.

5. The method of claim 1, wherein In step five, the pressure applied is 0.01 MPa to 0.9 MPa, and the pressurization time is 30 seconds to 10 minutes.

6. The method of claim 1, wherein In step five, the downward displacement distance of the concave pyramid microstructure glass after contact with the second glass preform is 0.01mm~0.5mm.

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