JP2004098654A - Die for molding optical element and molded optical element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a die for molding an optical element capable of removing the optical element without deformation while controlling an enlargement in size of a device and cost increase. <P>SOLUTION: The die for molding the optical element is used in molding a resin-made optical element 1 having an optical function surface and a side face 1a surrounding the optical function surface. A die member 5 having a mirror section in forming the optical function surface and the side face 1a are molded. A slide member 2 is provided in a movable manner to allow the optical element to expand when the optical element is removed from the die member 5. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a mold for molding an optical element and an optical element molded product molded by the mold.
[0002]
[Prior art]
Conventionally, as disclosed in Japanese Patent Application Laid-Open No. H10-180819, when a long optical element is released from the mold, when the mold is opened, of the two end faces substantially perpendicular to the optical functional surface of the optical element, The surface close to the outside of the mold is released first, so even if the mold release is performed in a state where the ejector plate is inclined due to uneven release force between or within the cavities during release, the optical There is known a technique capable of preventing deformation of a surface.
[0003]
[Patent Document 1]
JP-A-10-180819.
[0004]
[Problems to be solved by the invention]
However, the mold structure disclosed in the above-mentioned publication has problems such as an increase in the number of parts, an increase in mold manufacturing cost accompanying a complicated structure, and an extension of delivery time. In addition, there has been a problem that existing equipment cannot cope with the increase in the outer dimensions of the mold. In particular, if the mold structure described in the above publication is applied to molding of a long optical element such as a lens of a scanning optical system, the outer dimensions of the mold are likely to be large.
[0005]
Accordingly, the present invention has been made in view of the above-described problem, and an object of the present invention is to enable mold release without deforming an optical element while suppressing an increase in size and cost of an apparatus. .
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned problem and achieve the object, an optical element molding die according to the present invention is provided for molding a resin optical element having an optical function surface and a side surface surrounding the optical function surface. An optical element molding die, comprising: a mold member having a mirror portion for molding the optical function surface; and forming the side surface, and expanding the optical element when releasing the optical element from the mold member. And a slide member movably arranged to allow
[0007]
Further, in the optical element molding die according to the present invention, the amount of movement of the slide member is equal to or more than the amount of expansion of the optical element, and when the movable mold and the fixed mold close, the slide member is closed. Is set to an amount within a range capable of returning to the original position.
[0008]
Further, an optical element molded product according to the present invention is characterized by being molded by the above-mentioned mold.
[0009]
The optical element molded product according to the present invention is characterized in that it is a lens of a scanning optical system.
[0010]
Further, the optical element molded product according to the present invention is characterized in that it is a prism of a photographing optical system.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.
[0012]
FIG. 1 is a cross-sectional view of a mold according to an embodiment of the present invention cut at the center of a molded product, and shows one cavity of a multi-cavity mold. The mold of the present embodiment is for molding an optical element used in a laser scanning optical system as shown in FIG.
[0013]
1 is an optical element molded product which is a lens of a scanning optical system, and 2 is a slide member located on the opposite side of the gate and is accommodated in a groove provided in the movable mold plate 7 and moves only in the longitudinal direction of the molded product. Is possible. Numeral 3 denotes a regulating member which is fixed to the slide member 2 and regulates the movement of the slide member 2 in the longitudinal direction of the molded article. The regulating member 3 projects more toward the movable side mold plate than the slide member 2, and the projecting portion is It is stored with play in the holes of the movable mold plate. Reference numeral 4 denotes a regulating member that regulates the movement of the slide member 2 in a direction substantially horizontal to the release direction. Reference numerals 5 and 6 denote mirror-faced pieces for molding a molded product into a desired shape. Reference numeral 7 denotes a movable side mold plate. Denotes a fixed mold plate, 9, 10, 11 denote ejector pins, and 12, 13 denote ejector plates.
[0014]
FIG. 1 is a view in which the mold is cut at the center of a molded product in a state where the fixed mold plate 8 and the movable mold plate 7 are closed, the resin is injected into the cavity, and then cooled and solidified. In this figure, the position of the slide member 2 is regulated by the outer slope 2 a contacting the inner slope 8 a of the fixed mold plate 8. The amount of movement of the slide member 2 to the outside is regulated by the regulating member 3 and is equal to or larger than the expansion amount of the molded product 1 and from the state where the fixed mold plate 8 and the movable mold plate 7 are opened. When closed, the inner slope 8a of the fixed mold plate 8 and the outer slope 2a of the movable member 2 are set so as not to exceed a position where they can be engaged. Further, the amount of movement of the slide member 2 inward is set to be substantially the same as the amount of movement outward.
[0015]
2 is a cross-sectional view showing a state in which the mold shown in FIG. 1 is open, FIG. 3 is a cross-sectional view immediately after the mold is opened and an optical element molded product is protruded, and FIG. 4 is a view taken in the direction of arrows AA in FIG. .
[0016]
When the mold is opened from the state of FIG. 1 to the state of FIG. 2, the slide member 2 whose position is regulated by the outer slope 2a abutting against the inner slope 8a of the fixed mold plate 8 can move outward. It becomes.
[0017]
When the state shown in FIG. 2 shifts to the state shown in FIG. 3, when the optical element molded product 1 is released from the movable mirror piece 4, the stress received from the cavity is released, and the molded product starts expanding. With the expansion, the slide member 2 slides by the amount of expansion in the direction in which the molded product has expanded, and allows the optical element molded product 1 to expand. This makes it possible to release the mold without receiving stress from the surface 1a in a direction substantially perpendicular to the release direction at the time of release, sufficiently satisfying the accuracy of the desired optical functional surface and the reproducibility of the optical functional surface It is possible to provide an optical element molded product with good performance.
[0018]
The present invention is not limited to a long optical element molded product such as a scanning optical system lens shown in FIGS. 1 to 4, but also a square lens such as a prism 14 of an imaging optical system shown in FIGS. It can also be applied to round lenses and round lenses.
[0019]
As described above, according to the above-described embodiment, at the time of release, the slide member movable in the direction perpendicular to the mold release direction of the optical element molded product moves by the expansion amount of the molded product due to the expansion force of the optical element molded product. By doing so, it is possible to minimize distortion on a surface substantially perpendicular to the mold release direction of the molded product, and obtain an optical element molded product with desired optical performance.
[0020]
In addition, the number of parts can be reduced and the structure can be simplified as compared with the conventional mold, so that the mold manufacturing cost can be reduced accordingly.
[0021]
Further, with the simplification of the mold structure, the outer dimensions of the mold can be reduced, and the conventional apparatus can be used.
[0022]
【The invention's effect】
As described above, according to the present invention, it is possible to release the optical element without deforming the optical element while suppressing an increase in the size and cost of the apparatus.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a mold according to an embodiment of the present invention, cut at the center of a molded product.
FIG. 2 is a view showing a state immediately before the mold shown in FIG. 1 is opened and a molded product is ejected.
FIG. 3 is a view showing a state immediately after an ejector pin projects a molded product in FIG. 2 and the molded product is released from the mold.
FIG. 4 is a view as viewed in the direction of arrows AA in FIG. 3;
FIG. 5 is a cross-sectional view of a mold for molding a prism of a photographing optical system, which is cut at the center of a molded product.
FIG. 6 is a perspective view of an optical element molded product used for a laser scanning optical system.
FIG. 7 is a perspective view of a prism used in a photographing optical system.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 optical element molded product 2 slide member 3 regulating member 4 regulating member 5 movable-side mirror piece 6 fixed-side mirror piece 7 movable-side mold plate 8 fixed-side mold plate 9 ejector pin 10 ejector pin 11 ejector pin 12 ejector plate 13 ejector plate 14 Optical element molding

Claims (5)

An optical element molding die for molding a resin optical element having an optical function surface and a side surface surrounding the optical function surface,
A mold member having a mirror portion for molding the optical function surface,
An optical element molding apparatus, comprising: a slide member configured to form the side surface and movably disposed so as to allow expansion of the optical element when the optical element is released from the mold member. Mold. The amount of movement of the slide member is set to an amount not less than the amount of expansion of the optical element, and within a range in which the slide member can return to the original position when the movable mold and the fixed mold are closed. The mold for molding an optical element according to claim 1, wherein: An optical element molded product formed by the mold according to claim 1. The optical element molded product according to claim 3, which is a lens of a scanning optical system. The optical element molded product according to claim 3, which is a prism of a photographing optical system.

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