JP4194426B2 - Mold for optical element molding - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical element molding die and an optical element molded product molded by the die.
[0002]
[Prior art]
Conventionally, as disclosed in Japanese Patent Application Laid-Open No. 10-180819, when releasing a long optical element, a mold is selected from two end faces substantially perpendicular to the optical function surface of the optical element when the mold is opened. By releasing the surface near the outside of the mold first, even if the mold is released while the ejector plate is tilted due to the unevenness of the mold release force between the cavities or in the cavity at the time of mold release, the optical There is known a technique capable of preventing the deformation of the surface.
[0003]
[Patent Document 1]
JP-A-10-180819.
[0004]
[Problems to be solved by the invention]
However, the mold structure as disclosed in the above publication has problems such as an increase in the number of parts, an increase in mold production cost due to a complicated structure, and an extended delivery time. In addition, there is a problem in that existing equipment cannot be used due to an increase in the outer dimensions of the mold. In particular, when the mold structure described in the above publication is applied to molding a long optical element such as a lens of a scanning optical system, the outer dimension of the mold is likely to be increased.
[0005]
Therefore, the present invention has been made in view of the above-described problems, 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 the apparatus. .
[0006]
[Means for Solving the Problems]
In order to solve the above-described problems and achieve the object, an optical element molding die according to the present invention is for molding a resin optical element having an optical functional surface and a side surface surrounding the optical functional surface. an optical element molding die, and a pair of mold members having a mirror surface part for forming the optically functional surface, and the molding surface for molding a portion of the side surface, opposite to the molded surface ; and a slide member having a slope portion located on the surface, the one of the pair of mold members are inclined surfaces formed for engagement with the inclined surface portion of the slide member, when the mold clamping The position of the slide member is regulated by engaging the inclined surface of the slide member with the inclined surface of the mold member, and the inclined surface and the inclined surface are separated at the same time as the mold opening operation starts, and the optical element expands. the scan in the mold opening direction perpendicular to allow Id member is characterized by comprising movable.
[0007]
In the optical element molding die according to the present invention, mold opening direction and further comprising a restricting means for restricting the moving range of the vertical direction of the sliding member, moving range of the sliding member, the optical element The amount of expansion is equal to or larger than the range in which the inclined surface of the mold member and the inclined surface of the slide member can be engaged with each other.
[0011]
DETAILED DESCRIPTION OF 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-piece mold. The mold of this 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 side mold plate 7 and moves only in the longitudinal direction of the molded product. Is possible. Reference numeral 3 denotes a restricting member that is fixed to the slide member 2 and restricts the movement of the slide member 2 in the longitudinal direction of the molded product. The restricting member 3 protrudes toward the movable side mold plate from the slide member 2, and the protruding portion is It is housed in a hole in the movable side mold plate with a backlash. 4 is a restricting member that restricts the movement of the slide member 2 in a direction substantially horizontal to the mold release direction, 5 and 6 are specular pieces for forming a molded product into a desired shape, 7 is a movable side mold plate, Is a fixed side template, 9, 10 and 11 are ejector pins, and 12 and 13 are ejector plates.
[0014]
FIG. 1 is a view in which the mold is cut at the center of the molded product in a state where the fixed mold plate 8 and the movable mold plate 7 are closed and 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 inclined surface 2 a coming into contact with the inner inclined surface 8 a of the fixed-side template 8. Note that the amount of movement of the slide member 2 to the outside is regulated by the regulating member 3 and is greater than or equal to the amount of expansion of the molded product 1 and the fixed side mold plate 8 and the movable side template 7 are open. When closed, the inner slope 8a of the fixed-side template 8 and the outer slope 2a of the moving member 2 are set in a range that does not exceed a position where the engagement is possible. Further, the amount of movement of the slide member 2 to the inside is set to a movement amount substantially equal to the amount of movement to the outside.
[0015]
2 is a cross-sectional view showing a state where the mold shown in FIG. 1 is opened, 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 along the line 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 inclined surface 2 a coming into contact with the inner inclined surface 8 a of the fixed-side mold plate 8 can move outward. It becomes.
[0017]
When shifting from the state of FIG. 2 to the state of FIG. 3, the optical element molded product 1 is released from the movable mirror piece 4 and the stress received from the cavity is released and the molded product starts to expand. Along with the expansion, the slide member 2 slides by the amount of expansion in the direction in which the molded product expands, and allows the optical element molded product 1 to expand. As a result, the mold can be released without receiving stress from the surface 1a in the direction substantially perpendicular to the mold release direction at the time of mold release, sufficiently satisfying the accuracy of the desired optical function surface and the reproducibility of the optical function surface. Therefore, it is possible to provide an optical element molded article with good quality.
[0018]
In addition to the long optical element molded product such as the scanning optical system lens shown in FIGS. 1 to 4, the present invention is a rectangular lens such as the prism 14 of the photographing optical system shown in FIGS. 5 and 7. It can also be applied to round and round lenses.
[0019]
As described above, according to the above-described embodiment, the slide member that can move in the direction perpendicular to the mold release direction of the optical element molded product at the time of mold release moves by the expansion amount of the molded product by the expansion force of the optical element molded product. By doing so, it is possible to obtain an optical element molded product that can minimize the distortion applied to the surface substantially perpendicular to the mold release direction of the molded product and obtain 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, and the mold production cost can be reduced accordingly.
[0021]
In addition, 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 a mold without deforming the optical element while suppressing an increase in 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 the ejector pin protrudes a molded product and the molded product is released from the mold in FIG. 2;
4 is a view taken in the direction of arrows AA in FIG. 3;
FIG. 5 is a cross-sectional view of a mold for forming a prism of a photographic optical system cut at the center of a molded product.
FIG. 6 is a perspective view of an optical element molded product used in a laser scanning optical system.
FIG. 7 is a perspective view of a prism used in the photographing optical system.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Optical element molded product 2 Slide member 3 Restriction member 4 Restriction member 5 Movable side specular piece 6 Fixed side specular piece 7 Movable side template 8 Fixed side template 9 Ejector pin 10 Ejector pin 11 Ejector pin 12 Ejector plate 13 Ejector plate 14 Optical element molded product

Claims (2)

An optical element molding die for molding a resin optical element having an optical functional surface and a side surface surrounding the optical functional surface,
A set of mold members having a mirror surface portion for molding the optical functional surface;
A slide member having a molding surface for molding a part of the side surface and an inclined surface located on the surface opposite to the molding surface;
Wherein the one of the pair of mold members are inclined surfaces formed for engagement with the inclined surface portion of said slide member,
Wherein during clamping slope portion of the slide member the position of the slide member by engaging is regulated on the inclined surface of the mold member, the mold opening operation start and said inclined surface portion and the inclined surface moves away simultaneously, the optical An optical element molding die, wherein the slide member is movable in a direction perpendicular to the mold opening direction so as to allow expansion of the element.   And a regulating means for regulating a movement range of the slide member in a direction perpendicular to a mold opening direction, the movement range of the slide member being equal to or larger than an expansion amount of the optical element, and an inclined surface of the mold member. 2. The optical element molding die according to claim 1, wherein the slope of the slide member is not more than a engageable range.

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