Mold for molding optical element

Abstract

An optical element molding die includes an upper die having an upper die neck and an upper surface molding surface provided to the upper die neck and molding an upper surface of an optical element, a lower die having a lower die neck and a lower surface molding surface provided to the lower die neck and molding a lower surface of the optical element, a side die into which the upper die neck and the lower die neck are inserted, and a sleeve that houses the upper die and the lower die, wherein a size relationship of a first gap and a second gap is determined according to a size relationship of a first distance and a second distance, the first gap indicating a gap between a hole portion of the side die and the lower die neck, the second gap indicating a gap between the hole portion of the side die and the upper die neck, the first distance indicating a distance between a curvature center of the lower surface molding surface and an outer diameter height of the optical element, and the second distance indicating a distance between a curvature center of the upper surface molding surface and the outer diameter height of the optical element.

Description

Technical Field

[0001] This invention relates to molds for forming optical components. Background Technology

[0002] A processing method has been proposed in which, in the molding of an optical element made of glass, an outer diameter portion is formed in addition to the upper and lower optical surfaces of the optical element, thereby eliminating the need for centering processing after molding (e.g., Patent Document 1).

[0003] In the method proposed in Patent Document 1, in order to make the upper and lower molds coaxial, a sleeve with an inner circumference formed in a straight line (without steps) is used as a sleeve to hold the mold, and the side mold for the outer diameter portion of the formed optical element is separately constructed from the upper and lower molds. In addition, the side mold is positioned by fitting with the sleeve, and a gap (slit) is provided between the inner circumference of the side mold and the neck of the upper and lower molds.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent No. 4549820 Summary of the Invention

[0007] The technical problem that the invention aims to solve

[0008] In the mold structure proposed in Patent Document 1, the following problem arises when molding optical elements with a short distance between the centers of curvature of the upper and lower surfaces. For example, in the molding of optical elements, such as... Figure 2 As shown, if the optical axis Ax is tilted, then at the outer diameter height H of the optical element... 13 In this case, the outer diameter deviation R of the optical element relative to the optical axis Ax increases.

[0009] It should be noted that "optical axis Ax" represents the curvature center C of the upper surface forming surface 112 of the upper mold 11. U The curvature center C of the lower surface forming surface 122 of the lower mold 12 L The connecting straight lines, wherein the upper surface forming surface 112 of the upper mold 11 forms the upper surface of the optical element, and the lower surface forming surface 122 of the lower mold 12 forms the lower surface of the optical element. Additionally, "the outer diameter height H of the optical element..." 13 "" indicates the height center of the outer diameter portion of the molded optical element and the height center of the side mold. Additionally, "Outer Diameter Deviation R" indicates the optical axis Ax and the central axis Ax of the side mold. 13 The distance between them.

[0010] The present invention was made in view of the above-mentioned problems, and the object is to provide a mold for molding optical elements that can reduce the deviation of the outer diameter of the optical element relative to the optical axis when molding optical elements.

[0011] Technical solutions for solving technical problems

[0012] To solve the aforementioned technical problems and achieve the objective, the optical element molding die of the present invention comprises: an upper die having an upper die neck and an upper surface molding surface, the upper surface molding surface being disposed on the upper die neck and molding the upper surface of the optical element; a lower die having a lower die neck and a lower surface molding surface, the lower surface molding surface being disposed on the lower die neck and molding the lower surface of the optical element; a side die for inserting the upper die neck and the lower die neck; and a sleeve for receiving the upper die and the lower die. The size relationship between a first gap and a second gap is determined according to the size relationship between a first distance and a second distance, wherein the first gap represents the gap between the hole of the side die and the neck of the lower die, the second gap represents the gap between the hole of the side die and the neck of the upper die, the first distance represents the distance between the center of curvature of the lower surface molding surface and the outer diameter height of the optical element, and the second distance represents the distance between the center of curvature of the upper surface molding surface and the outer diameter height of the optical element.

[0013] Furthermore, in the optical element forming mold of the present invention, the size relationship between the first gap and the second gap is the same as the size relationship between the first distance and the second distance.

[0014] Furthermore, in the optical element forming mold of the present invention, the gap between the inner surface of the sleeve and the upper mold and the gap between the inner surface of the sleeve and the lower mold are smaller than the gap between the inner surface of the sleeve and the side mold.

[0015] The effects of the invention

[0016] According to the mold for forming optical elements of the present invention, when forming optical elements, the deviation of the outer diameter of the optical element relative to the optical axis can be reduced. Attached Figure Description

[0017] Figure 1 This is a schematic diagram illustrating a structural example of a mold for forming optical elements according to an embodiment of the present invention.

[0018] Figure 2 This is an explanatory diagram used to illustrate the outer diameter deviation of optical elements. Detailed Implementation

[0019] Hereinafter, embodiments of the mold for forming optical elements according to the present invention will be described with reference to the accompanying drawings. It should be noted that the present invention is not limited to the embodiments described below, and the feature elements in the embodiments below also include feature elements that can be easily replaced or are substantially the same by those skilled in the art.

[0020] Reference Figure 1 The structure of the optical element forming mold 1 according to an embodiment of the present invention will be described. The optical element forming mold 1 is, for example, a mold for forming optical elements made of glass. The optical element forming mold 1 includes an upper mold 11, a lower mold 12, a side mold 13, and a sleeve 14.

[0021] The upper mold 11 has a cylindrical neck 111 extending toward the lower mold 12. The neck 111 is the portion of the upper mold 11 that is inserted into the hole 131 of the side mold 13. At the end of the neck 111, an upper surface forming surface 112 for forming the upper optical functional surface of the optical element is provided. In addition, the upper mold 11 is placed on the upper end face of the sleeve 14.

[0022] The lower mold 12 has a cylindrical neck 121 extending toward the upper mold 11. The neck 121 is the portion of the lower mold 12 that is inserted into the hole 131 of the side mold 13. At the end of the neck 121, a lower surface forming surface 122 for forming the lower optical functional surface of the optical element is provided.

[0023] The side mold 13 is provided with a hole 131 that extends vertically through the side mold 13. A portion of the inner surface of the hole 131 constitutes a side molding surface for molding the side surface (outer diameter portion) of the optical element. It should be noted that, in this embodiment, the height center of the side mold 13 is defined as "the outer diameter height H of the optical element". 13 ".

[0024] The upper mold 11 and the lower mold 12 are positioned opposite each other on their forming surfaces, separated by the side mold 13. Furthermore, the upper mold 11, the lower mold 12, and the side mold 13 are disposed inside the sleeve 14. Additionally, the side mold 13 is mounted on a stepped portion 141 disposed inside the sleeve 14.

[0025] The sleeve 14 is a component used to house the upper mold 11, the lower mold 12, and the side mold 13. The sleeve 14 is cylindrical. In addition, a stepped portion 141 for mounting the sleeve 14 is formed inside the side mold 13. Furthermore, the gaps between the various parts of the mold 1 used to form the optical element are set to a range of several μm to tens of μm.

[0026] Here, in the case of molding optical elements using the mold 1 for molding optical elements, for example... Figure 1 As shown, ideally, the central axis Ax of the upper mold 11 is... 11 The central axis Ax of the lower mold 12 12 and the central axis Ax of the side mold 13 13They are identical. Under this ideal condition, the outer diameter deviation of the optical element relative to the optical axis Ax will be zero. It should be noted that... Figure 1 The optical axis Ax shown represents the straight line connecting the center of curvature of the upper surface molding surface 112 and the center of curvature of the lower surface molding surface 122.

[0027] On the other hand, for example Figure 2 As shown, when forming an optical element using the mold 1 for forming optical elements, if the curvature center C of the upper surface forming surface 112 is connected... U and the curvature center C of the lower surface forming surface 122 L The optical axis Ax is tilted at the height H of the outer diameter of the optical element. 13 The outer diameter deviation R of the optical element increases. It should be noted that, for example... Figure 2 As shown, the outer diameter deviation R represents the outer diameter height H. 13 The position P1 where it intersects with the optical axis Ax and the outer diameter height H 13 and the central axis Ax of the side mold 13 13 The distance between the intersecting positions P2.

[0028] Therefore, in the optical element molding mold 1 of the embodiment, the size relationship between L1 (hereinafter referred to as "first distance") and L2 (hereinafter referred to as "second distance") is considered, wherein L1 is the curvature center C of the lower surface molding surface 122. L and outer diameter height H 13 The distance between them, L2 is the center of curvature C of the upper surface forming surface 112. U and outer diameter height H 13 The distance between them.

[0029] In the optical element molding mold 1 of the embodiment, the size relationship between the gap (hereinafter referred to as "first gap") between the hole 131 of the side mold 13 and the neck 121 of the lower mold 12 and the gap (hereinafter referred to as "second gap") between the hole 131 of the side mold 13 and the neck 111 of the upper mold 11 is determined according to the size relationship between the first distance L1 and the second distance L2. In other words, in the optical element molding mold 1, the size relationship between the first gap and the second gap is set according to the size relationship between the first distance L1 and the second distance L2.

[0030] For example Figure 2 As shown, when the first distance L1 is less than the second distance L2, the first gap is set to be less than the second gap. In this case, for example, the outer periphery tolerance of the neck 121 of the lower mold 12 is set to -2μm to -1μm, and the inner periphery tolerance of the hole 131 of the side mold 13 is set to 0μm to 1μm, thereby setting the first gap to a maximum of 1μm. Furthermore, the second gap is set to a few μm.

[0031] On the other hand, with Figure 2 Conversely, when the first distance L1 is greater than the second distance L2, the first gap is set to be greater than the second gap. In this case, for example, the first gap is set to several μm. Furthermore, the second gap is set to a maximum of 1 μm. Thus, the relationship between the size of the first gap and the second gap becomes the same as the relationship between the size of the first distance L1 and the second distance L2.

[0032] Furthermore, in the mold 1 for forming optical components, the gap between the inner surface of the sleeve 14 and the upper mold 11 and the lower mold 12 (hereinafter referred to as the "third gap") is set to be smaller than the gap between the inner surface of the sleeve 14 and the side mold 13 (hereinafter referred to as the "fourth gap"). In this case, for example, the third gap is set to a few μm and the fourth gap is set to tens of μm.

[0033] It should be noted that the sizes of the first gap and the second gap do not depend on the dimensions (e.g., outer diameter and height) of the molded optical element. That is, regardless of whether a large or small optical element is being molded, the first gap and the second gap are set based on the first distance and the second distance. This greatly suppresses the deviation R of the outer diameter of the optical element relative to the optical axis Ax.

[0034] However, for example, in the case of molding tiny optical elements with a diameter of 5 mm, compared to the case of molding large optical elements, the central axis Ax of the lower mold 12 is... 12 Relative to the central axis Ax of the upper mold 11 11 The deviation of the outer diameter R increases. Therefore, the method of this embodiment is particularly effective when molding tiny optical elements. In addition, the method of this embodiment is also particularly effective when molding optical elements with a short distance between the centers of curvature of the upper and lower surfaces.

[0035] In the optical element molding die 1 of this embodiment described above, the curvature center C of the lower surface molding surface 122 is used as the reference. L and the curvature center C of the upper surface molding surface 112 U With outer diameter and height H 13 The distances between them (first distance L1, second distance L2) are used to set the gaps (first gap, second gap) between the hole 131 of the side mold 13 and the neck 121 of the lower mold 12 and the neck 111 of the upper mold 11. As a result, when molding optical elements, the outer diameter deviation R of the optical element relative to the optical axis Ax can be reduced.

[0036] The mold for forming optical elements according to the present invention has been specifically described above through embodiments for carrying out the invention. However, the essence of the present invention is not limited to the above description and should be interpreted broadly based on the scope of protection. In addition, various modifications and alterations based on these descriptions are naturally included in the essence of the present invention.

[0037] Symbol Explanation

[0038] 1. Mold for forming optical components

[0039] 11. Upper mold

[0040] 111 Neck

[0041] 112 Upper surface molding surface

[0042] 12 Lower mold

[0043] 121 Neck

[0044] 122 Lower surface molding surface

[0045] 13 Side mold

[0046] Hole 131

[0047] 14 Sleeves

[0048] 141 Step section

[0049] Ax optical axis

[0050] Ax 11 Ax 12 Ax 13 Central axis

[0051] C L C U Center of curvature

[0052] H 13 outer diameter height

[0053] R outer diameter deviation.

Claims

1. A mold for forming optical components, wherein, have: An upper mold has an upper mold neck and an upper surface forming surface, wherein the upper surface forming surface is disposed on the upper mold neck and forms the upper surface of an optical element; The lower mold has a lower mold neck and a lower surface forming surface, wherein the lower surface forming surface is disposed on the lower mold neck and forms the lower surface of the optical element; A side mold for inserting the neck of the upper mold and the neck of the lower mold; A sleeve is used to house the upper mold and the lower mold. The size relationship between the first gap and the second gap is determined according to the size relationship between the first distance and the second distance. The first gap represents the gap between the hole of the side mold and the neck of the lower mold, the second gap represents the gap between the hole of the side mold and the neck of the upper mold, the first distance represents the distance between the curvature center of the lower surface molding surface and the outer diameter height of the optical element, and the second distance represents the distance between the curvature center of the upper surface molding surface and the outer diameter height of the optical element.

2. The mold for forming optical elements according to claim 1, wherein, The size relationship between the first gap and the second gap is the same as the size relationship between the first distance and the second distance.

3. The mold for forming optical elements according to claim 1 or 2, wherein, The gap between the inner surface of the sleeve and the upper mold, and the gap between the inner surface of the sleeve and the lower mold, are smaller than the gap between the inner surface of the sleeve and the side mold.

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