JPH04127232U - Optical element mold - Google Patents

Abstract

(57) [Summary] [Purpose] To integrate each of the divided molds that make up one continuous molding surface so that they can be finely adjusted using screws, to eliminate the level difference that occurs in the parting part, and to facilitate mold assembly. . [Structure] An inner mold 5 is inserted into an outer mold 1 in which a through hole 3 is bored along the axis. The female thread 4 of the through hole 3 and the male thread 7 of the inner mold 5 are screwed together to form one continuous molding surface 2.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is an optical element with an inflection point on the molded surface by pressing a softened optical material. This invention relates to an optical element mold for press molding.

0002

[Conventional technology]

In recent years, heating and softening between a pair of high-precision molds has been used as a bequest method for manufacturing optical elements. Press molding is performed to obtain optical elements simply by inserting and arranging the prepared optical material and pressurizing it. It is being said.

0003 With the spread of this optical element molding technology and the expansion of its use, the conventional integrated type requires no processing. A need has arisen for possible irregularly shaped optical elements.

0004 For example, as shown in FIGS. 5 and 6, an illumination lens that uniformly illuminates a wide-angle area In the case of 71, the shape has an inverted conical space 72 at the center of the convex surface of the plano-convex lens; As shown in Figure 5, the cross section consists of two peaks with the valley point B as the center and the apex point A. It is a shaped shape.

[0005] The peak point a and the valley point b consist of an edge or a slight corner radius.

The mold 73 for molding this illumination lens (unusual-shaped lens) 71 has a cross-sectional shape that is an inversion of the lens surface of the illumination lens 71, as shown in FIG. Points corresponding to points a 1 and b 1 of the mold 73 are points corresponding to points a ₁ and b ₁ of the mold 73.

[0007]However, when machining the mold 73, the grinding tool does not enter the point _a1 and its vicinity, so it is practically impossible to machine the mold 73 as one piece.

[0008] Therefore, the following inventions have been proposed to solve the above drawbacks.

[0009] For example, the invention described in Japanese Patent Application Laid-Open No. 61-48801 previously proposed by the present applicant In this process, multifocal lenses are molded using a mold consisting of two parts: an outer mold and an inner mold. A method is disclosed.

0010

[Problem that the idea aims to solve]

However, in the invention described in JP-A-61-48801, the outer mold and When forming a mold with an inner mold, there is a difference in the position of the outer mold and the inner mold in the optical axis direction. If this occurs, the molded optical element may not be able to achieve its desired performance. It was.

[0011] Therefore, this invention was developed in view of the above problems, and it is possible to Each segment of the mold that forms one continuous molding surface can be assembled easily and accurately. The purpose of this invention is to provide a mold for molding optical elements that can

0012

[Means and actions for solving the problem]

The present invention uses at least two split molds on the optical functional surface of the optical element to be molded. They fit together at the inflection point part of the two parts, forming an optical element with an inflection point on the optical functional surface. In the optical element mold, the relative position of each split mold in the optical axis direction of the optical element to be molded is determined. It is equipped with a position adjustment means.

[0013] Further, the relative position adjustment means for each split mold includes a screw provided in each split mold, and a screw for adjusting the relative position of each split mold. It consists of a loosening preventer.

[0014] FIG. 1 is a conceptual diagram of an optical element mold according to the present invention.

[0015] 1 is a cylindrical outer mold, and a part 2a of a molding surface 2 is formed on this outer mold 1. . In addition, a through hole 3 is bored in the outer mold 1 along the axis, and the molding surface of the through hole 3 is A female thread is threaded on the opposite side of 2a.

[0016] 5 is an inner mold that fits into the outer mold 1, and a part of the molding surface 2 is attached to the tip of the protrusion 6 of the inner mold 5. 2b is formed, and the outer periphery of the protrusion 6 is threaded with the female thread 4 of the outer mold 1. A male screw 7 is engraved.

[0017] A locking means such as a spring 8 is interposed between the outer mold 1 and the inner mold 5, and the outer mold 1 and the inner mold 5 are constructed so that they can be fixed.

[0018] Furthermore, when the inner mold 5 is fitted to the outer mold 1, the respective molding surfaces 2a and 2b form one continuous It is configured to form a continuous molding surface 2.

[0019] The optical element mold having the above-mentioned configuration has a female screw thread formed on the outer mold 1 and the inner mold 5. 4 and male screw 7, it is positioned and fixed with high precision, and each molding surface It is possible to prevent a step from occurring in the parting part 9, which is the boundary between the first part 2a and 2b. can.

[0020]

[Example 1] FIG. 2 is a longitudinal sectional view showing this embodiment.

[0021] 11 is a mold, and this mold 11 is inserted into an outer mold 12 and this outer mold 12. It is composed of an inner mold 13.

[0022] A through hole 14 is bored in the axis of the bottom mold 12, and one part of the molding surface 15 is formed at the upper end of the through hole 14. A portion 15a is formed. A coil heater 16 is wound around the upper part of the outer peripheral surface of the outer mold 12. It is worn.

[0023] A stepped portion 14a is formed at the center of the through hole 14 of the outer mold 12, and a step portion 14a is formed at the bottom of the through hole 14. A female thread 17 is threaded. A cooling pipe is installed near the center of the outer mold 12 and near the bottom. 18 are installed inside.

[0024] A portion 15b of the molding surface 15 is formed at the upper end of the inner mold 13, and the molding surface 15 is formed at the upper end of the inner mold 13. It is configured to form one continuous molding surface 15 with one part 15a of the surface. Inner mold 1 A sliding block 19 is attached to the lower part of the inner mold 13 so as to be rotatable about the central axis of the inner mold 13. It is.

[0025] The outer periphery of the sliding block 19 has a male thread that engages with the female thread 17 of the through hole 14. 20 is screwed on. The upper end of the sliding block 19 and the step 14a of the through hole 14. A spring 21 is loaded between them.

[0026] The mold 11 having the above-described configuration is first manufactured by starting from the lower part of the through hole 14 of the outer mold 12 into the inner mold. 13 is inserted.

[0027] Then, screw the male screw 20 of the sliding block 19 into the female screw 17 of the through hole 14. Then, the sliding block 19 is rotated to move the inner mold 13 in the axial direction. Inner mold 13 Due to the movement of This eliminates the step difference that occurs in the parting portion 22.

[0028] At this time, the sliding block 19 is constantly urged downward by the spring 21. The positional relationship between the outer mold 12 and the inner mold 13 can be adjusted without being affected by screw backlash. Can be held with high precision.

[0029] According to this embodiment, the difference in level between the outer mold 12 and the inner mold 13 at the parting part 22 is reduced to 2. It was possible to adjust the thickness to below μm.

[0030] In addition, the vicinity of the molding surface 15 of the mold 11 is heated by a coil heater; The area near the pipes 17 and 20 is cooled by cooling water flowing inside the cooling pipe 18, Jis 17 and 20 do not oxidize due to high temperatures, allowing for high positioning accuracy and mold assembly. Easy to use and can be maintained regardless of the usage time.

[0031]

[Example 2] Figures 3 and 4 show this example, with Figure 3 being a longitudinal cross-sectional view of the mold, and Figure 4 showing the lens. FIG.

[0032] The mold 31 of this embodiment shown in FIG. 3 has an irregularly shaped plano-concave lens 32 as shown in FIG. It is a mold for molding. The plano-concave lens 32 has a flat lens surface 33 and an inner curvature R. ₁ The lens surface 34 and the inner curvature R₁smaller curvature R₂lens surface 35 It has a shape that is effective as an illumination lens that uniformly illuminates a wide-angle area. Ru.

[0033] The mold 31 is composed of an inner mold 36, a middle mold 37, and an outer mold 38.

[0034] A portion 39a of the molding surface 39 is formed at the upper end of the inner mold 36, and a portion 39a of the molding surface 39 is formed at the lower end of the inner mold 36. A sliding block 40 is rotatably attached to the central axis. A male screw 41 is threaded on the outer periphery of the hole 40.

[0035] A through hole 42 into which the inner mold 36 can be inserted is bored in the axis of the middle mold 37. A portion 39b of the molding surface 39 is formed at the upper end of the middle mold 37. In addition, through hole 4 A female screw 43 is screwed into the lower part of the inner mold 36 to be screwed into the male screw 41 of the inner mold 36. difference Furthermore, there is a gap between the step portion 42a of the through hole 42 and the upper end of the sliding block 40 of the inner mold 36. A spring 44 is loaded to constantly urge the inner mold 36 downward.

[0036] In addition, a sliding block 45 is attached to the lower part of the medium size 37 so as to be rotatable about the central axis. A male thread 46 is threaded on the outer periphery of the sliding block 45.

[0037] A through hole 47 is bored in the axis of the outer mold 38, into which the middle mold 37 can be inserted. A portion 39c of the molding surface 39 is formed at the upper end of the outer mold 38. In addition, through hole 4 A female screw 48 is screwed into the lower part of the medium-sized screw 37 to be engaged with a male screw 46 of the medium size 37. difference Furthermore, there is a gap between the step portion 47a of the through hole 47 and the upper end of the sliding block 45 of the medium size 37. A spring 49 is loaded to constantly urge the medium 37 downward.

[0038] In the mold 31 having the above configuration, first, the middle mold 37 is placed in the outer mold 38, and the inner mold 37 is placed in the middle mold 37. Insert the molds 36 into each other, and screw each male screw 41, 46 and each female screw 43, 48. match. Then, each sliding block 40, 45 is rotated to form the inner mold 36 and the middle mold. 37 in the direction of their respective central axes, and remove a portion of each molding surface of the inner mold 36 and the middle mold 37. Parting part 50 which is the boundary between 39a and 39b and between the middle mold 37 and the outer mold 38 The difference in level that occurs in the parting part 51, which is the boundary between the first parts 39b and 39c of each molding surface, is It can be dissolved to form one continuous molding surface 39.

[0039] In addition, each sliding block 40, 45 is always maintained by each loaded spring 44, 49. It is pressed downward and is not affected by the backlash of the screw, and the inner mold 36 and the middle mold 3 7 and the outer mold 38 can be maintained with high precision.

[0040] According to this embodiment, each part that is the boundary between the inner mold 36, the middle mold 37, and the outer mold 38 It was possible to adjust the level difference occurring in the ring parts 50 and 51 to 2 μm or less.

[0041]

【Effect of the invention】

As explained above, according to the optical element mold according to the present invention, one continuous product can be formed. It is possible to eliminate the difference in level that occurs in the parting parts of each split mold that makes up the shape, and An optical element mold that is easy to assemble can be obtained.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram showing the present invention.

FIG. 2 is a longitudinal cross-sectional view showing Example 1.

FIG. 3 is a longitudinal cross-sectional view showing Example 2.

FIG. 4 is a cross-sectional view of the lens.

FIG. 5 is a sectional view showing a conventional example.

FIG. 6 is a perspective view showing a conventional example.

FIG. 7 is a sectional view showing a conventional example.

[Explanation of symbols]

1 Outer mold 2 Molding surface 3 Through hole 4 Female thread 5 Inner mold 7 Male thread 8 Spring 9 Parting part

Claims (2)

[Scope of utility model registration request] Claim 1. An optical element in which at least two or more split molds are fitted together at an inflection point portion on an optical functional surface of the optical element to be molded to mold an optical element having an inflection point on the optical functional surface. An optical element mold, characterized in that the mold is configured by providing relative position adjustment means for each of the split molds in the optical axis direction of the optical element to be molded. 2. The optical element mold according to claim 1, wherein the means for adjusting the relative position of each divided mold includes a screw provided on each divided mold and a locking device for the screw.