JP2001170970A - Photographing device, optical part, method for manufacturing photographing device, and method for manufacturing optical part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photographing device with which useless discarding of expensive optical materials in large quantities is and dispensing with gate cutting. SOLUTION: A hot runner type mold is used and a nozzle for injecting a molten resin is arranged on an optical axis to mold an optical part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photographing apparatus having an optical part molded without waste of material, an optical part, a method of manufacturing the photographing apparatus, and a method of manufacturing the optical part.

[0002]

2. Description of the Related Art Optical components such as a photographic lens and a finder lens used in a film unit with a lens are molded with resin.

[0003] A conventional optical component molding method is a so-called cold runner type, in which a plurality of cavities corresponding to the shape of the optical component to be molded are provided in a mold, and a parting line is formed substantially at the center of the cavities. The molten resin is injected into the sprue provided in the fixed mold at right angles to the sprue, and the molten resin is injected into the side gate provided in each cavity through the runner communicating with the plurality of cavities in parallel with the parting line. I was After cooling the molded optical component, the movable mold is separated from the fixed mold, and the optical component is protruded by the ejector pin, and then the optical component, the runner, and the sprue are taken out in an integrated state.

[0004]

As described above, when molding an optical component in the cold runner type, it is common to use a side gate. However, the thickness of the optical component at the central portion and the peripheral portion is large. In contrast, when the molten resin was injected from the peripheral portion, the resin did not flow sufficiently, and rapid molding was difficult. However, if the gate is provided at the center, a cut surface is generated by the gate cut, which has a great effect on optical performance, and this is not practical at all.

[0005] In the case of molding an optical component in a cold runner format, a runner or a sprue that is considerably larger than the size of the optical component to be molded is required. Runners and sprues were separated and discarded. For discarding a large amount of such an expensive optical material, an improvement has been demanded for environmental reasons and cost. In addition, since post-processing of the gate cut is required, productivity is not good and the cost is high.

SUMMARY OF THE INVENTION The present invention has been made in view of the foregoing problems, and has been made in consideration of the above circumstances. In order to improve the flow of resin by molding an optical component in a hot runner format, rapid molding can be performed. It is an object of the present invention to provide a photographic lens device, an optical component, a method of manufacturing an image capturing device, and a method of manufacturing an optical component, which are not provided. In addition, by molding in a hot runner type, wasteful disposal of a large amount of expensive optical materials is eliminated, and gate cutting is not required.

[0007]

The above object is achieved by any of the following means.

[0008] An imaging apparatus characterized by having an optical component molded by using a hot runner type mold and disposing a nozzle for injecting a molten resin on an optical axis.

An optical component characterized in that a hot runner type mold is used and a nozzle for injecting molten resin is arranged on the optical axis and molded.

In a method of manufacturing a photographing apparatus, there is provided a step of molding an optical component by using a hot runner type mold, disposing a nozzle from which molten resin is injected on an optical axis, and molding the optical part. Production method.

[0011] A method of manufacturing an optical component, characterized in that a hot runner type mold is used, and a nozzle into which a molten resin is injected is arranged on the optical axis and molded.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a film unit with a lens according to the present invention will be described in detail with reference to the drawings.

First, a hot runner type mold will be described with reference to FIGS. FIG. 1 is an exploded perspective view of a mold,
FIG. 2 is a partially detailed sectional view of a mold.

In FIGS. 1 and 2, a molten resin is filled in a fixed mold 11, a movable movable mold 12, and a plurality of cavities 12 a formed by the fixed mold 11 and the movable mold 12. A hot runner section 20 to be supplied and an ejector plate 30 having ejector pins 31 for separating the molded optical component 1 from the movable mold 12 are provided.

In practice, a plurality of ejector pins 31 are provided for each cavity 12a. However, in FIG. 1, only one ejector pin 31 is drawn for simplification.

The hot runner section 20 is provided above the stationary mold 11 and includes an air cylinder 21, a plurality of needles 22, a nozzle holding ring 23, and a plurality of nozzle sections 24. Are provided corresponding to each cavity 12a.

The needles 22 inserted into each of the plurality of nozzle portions 24 are driven by one air cylinder 21. Each nozzle 24 has a heater 25 and a temperature sensor 2
6 are provided, and the temperature is controlled independently of each other.
The needle 22 is slidably held by a guide 27, and when the needle 22 slides upward, the molten resin guided from the passage 28 to the nozzle 29 is formed by the cavity 12 a formed by the fixed mold 11 and the movable mold 12. Injected into. When the cavity 12a is sufficiently filled with the molten resin, the needle 22 slides downward and seals the nozzle 29.

Here, the injection position of the molten resin from the nozzle 29 into the cavity 12a is on the optical axis of the optical component 1 to be molded. The injection direction is parallel to the movable direction of the movable mold 12.

The tip of the needle 22 is desirably a spherical surface along the optical surface of the optical component 1 to be molded.
However, the needle 22 is finer than the optical surface,
When the curvature of the optical surface is loose, the tip of the needle 22 may be a plane orthogonal to the optical axis of the optical component 1.

The tip of the needle 22 needs to be polished, and in some cases, it is desirable that the needle 22 be plated.

The inner diameter of the nozzle 29 is desirably 0.5 mm or more and 2.0 mm or less, and the lower limit is more desirably 0.8 mm or more, and the upper limit is 1.0 mm.
More preferably, it is 2 mm or less. The nozzle 2
If the inner diameter of the nozzle 9 is 0.5 mm or less, the needle 22 may bend, the durability is reduced, and the maintainability of the nozzle 29 is also reduced. On the other hand, when the inner diameter of the nozzle 29 is 2.
If it is 0 mm or more, the optical performance of the molded optical component is reduced.

The ejector plate 30 is provided with an ejector pin 31. When the optical component 1 is molded, the movable mold 12 is separated from the fixed mold 11, and the molded optical component 1 adheres to the movable mold 12. Therefore, the ejector pins 31 protrude from the optical component 1 and are separated from the movable mold 12. The cooling ports 11b and 12b are for cooling the molten resin.

The optical component 1 is preferably a photographic lens, a finder objective lens or an eyepiece, a strobe panel, an indexer window, etc., which are components used in film units with lenses and cameras having an optical surface. . However, it can also be used for binoculars and telescope lenses.

As described above, by molding an optical component using a hot runner type mold for directly injecting a molten resin into an optical component to be molded, a runner and a sprue become unnecessary and expensive optical materials are discarded. This almost eliminates the need for a post-gate cut operation, which has been conventionally performed.

FIG. 3 shows a photographing lens as an example of the optical component molded as described above. As shown in the figure,
A circular trace 2a by the needle 22 remains at the tip of the taking lens 2 on the optical axis. However, by specifying the inner diameter of the nozzle as described above, the influence of the circular trace 2a can be reduced, and the image quality performance on the photographing screen can be made practically no problem at all.

When the photographing lens is molded, in a photographing apparatus equipped with the photographing lens, when the diameter of the aperture is set to be a minimum, an area through which light reaching the imaging surface (film surface) passes. Circular trace 2a corresponding to
When the effective diameter of the lens surface on the side (nozzle side) where remains is D, it is desirable that the upper limit of the inner diameter of the nozzle 29 be D × 0.25 or less. When the inner diameter of the nozzle 29 exceeds D × 0.25, the lens performance deteriorates. Note that the upper limit of the inner diameter of the nozzle 29 is more desirably D × 0.15 or less. D
Is generally 6 mm to 8 mm.

FIG. 4 is a view of the objective lens of the finder. A circular mark 3a formed by the needle 22 on the objective lens 3
However, by molding such that the mark 3a appears strongly, the mark 3a can be used as a center mark indicating the center position when looking through the finder.

When the diagonal length of the effective lens surface in the use state on the side where the circular mark 3a of the objective lens 3 remains (nozzle side) is L, the inner diameter of the nozzle 29 is L × 0.25.
It is desirable to do the following. When the inner diameter of the nozzle 29 is L × 0.
If it exceeds 25, the ratio of the center mark becomes large with respect to the entire visual field range, and the visibility of the subject decreases. L is generally between 10 mm and 14 mm.

The photographing device used in the claims is preferably a film unit with a lens, but may be a camera loaded with a silver halide film or a digital camera.

[0030]

According to the present invention, the photographing apparatus according to any one of claims 1 to 9, the optical component according to claims 10 to 17, the method for manufacturing the photographing apparatus according to claims 18 to 26, and the method according to claims 27 to 34. According to the method of manufacturing an optical component, the effect of the nozzle has no practical effect on the optical performance, and rapid molding can be performed. In addition, since wasteful disposal of a large amount of expensive optical materials is eliminated and gate cutting is not required, the cost is reduced and the environment is not affected.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a hot runner type mold.

FIG. 2 is a partially detailed sectional view of a hot runner type mold.

FIG. 3 is a perspective view of a photographic lens molded with a hot runner type mold.

FIG. 4 is a perspective view of a finder objective lens molded by a hot runner type mold.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical component 2 Shooting lens 2a, 3a Trace 3 Objective lens 11 Fixed mold 12 Movable mold 22 Needle 29 Nozzle

Claims (34)

[Claims] 1. An imaging apparatus comprising: a hot runner type mold; and an optical component molded by arranging a nozzle for injecting a molten resin on an optical axis. 2. The photographing apparatus according to claim 1, wherein the optical component is a photographing lens or a finder lens. 3. The method according to claim 1, wherein a tip of the needle for opening and closing the nozzle is formed into a curved surface along a curved surface of the optical component, and is polished. The imaging device according to the above. 4. A tip of a needle for opening and closing the nozzle is formed on a plane substantially orthogonal to an optical axis of the optical component,
2. A grinding process is performed.
Or the imaging device according to claim 2. 5. An inner diameter of the nozzle is 0.5 mm or more,
The photographing apparatus according to claim 1, wherein the distance is 2.0 mm or less. 6. The nozzle has an inner diameter of 0.8 mm or more,
The photographing apparatus according to claim 5, wherein the distance is 1.2 mm or less. 7. The optical component is a photographic lens, and when the effective diameter of the lens surface on the nozzle side in a state where the diameter of the stop is minimum is D (mm), the inner diameter of the nozzle is 0.1 mm.
The photographing apparatus according to claim 1, wherein the distance is 5 mm or more and D × 0.25 or less. 8. The optical component is a finder objective lens. When the diagonal length of the effective lens surface on the nozzle side of the objective lens is L (mm), the inner diameter of the nozzle is 0.5 mm or more, and L × L. The photographing apparatus according to any one of claims 1 to 4, wherein the photographing apparatus is set to 0.25 or less. 9. The photographing apparatus according to claim 1, wherein the photographing apparatus is a film unit with a lens. 10. An optical component, characterized in that a hot runner type mold is used, and a nozzle from which a molten resin is injected is arranged on the optical axis and molded. 11. The optical component according to claim 10, wherein the optical component is a photographing lens or a finder lens. 12. The tip of a needle for opening and closing the nozzle is formed in a curved surface along the curved surface of the optical component, and is polished.
Or the optical component according to claim 11. 13. The nozzle according to claim 10, wherein a tip of the needle for opening and closing the nozzle is formed on a plane substantially perpendicular to an optical axis of the optical component, and is polished. 12. The optical component according to item 11. 14. An inner diameter of the nozzle is 0.5 mm or more,
The thickness is 2.0 mm or less.
4. The optical component according to any one of 3. 15. The nozzle has an inner diameter of 0.8 mm or more,
The optical component according to claim 14, wherein the optical component is 1.2 mm or less. 16. The optical component is a photographic lens, and when the effective diameter of the lens surface on the nozzle side in a state where the diameter of the diaphragm is minimum is D (mm), the inner diameter of the nozzle is 0.5 mm or more. The optical component according to claim 10, wherein D × 0.25 or less. 17. The optical component is a finder objective lens. When the diagonal length of an effective lens surface on the nozzle side of the objective lens is L (mm), the inner diameter of the nozzle is 0.5 mm or more, and L × L. The optical component according to claim 10, wherein the optical component is 0.25 or less. 18. A method for manufacturing an imaging apparatus, comprising: using a hot runner type mold, arranging a nozzle on which a molten resin is injected on an optical axis to mold an optical component. Device manufacturing method. 19. The method according to claim 18, wherein the optical component is a photographic lens or a finder lens. 20. The tip of a needle for opening and closing the nozzle, the tip of which is formed into a curved surface along the curved surface of the optical component, and is polished.
20. A method for manufacturing a photographing device according to claim 19. 21. The tip of a needle for opening and closing the nozzle is formed on a plane substantially perpendicular to an optical axis of the optical component, and is polished. 20. The method for manufacturing an imaging device according to claim 19. 22. An inner diameter of the nozzle is 0.5 mm or more,
The thickness is 2.0 mm or less.
The method for manufacturing the imaging device according to claim 1. 23. An inner diameter of the nozzle is 0.8 mm or more,
23. The method according to claim 22, wherein the distance is 1.2 mm or less. 24. The optical component is a photographic lens, and when the effective diameter of the lens surface on the nozzle side in a state where the diameter of the diaphragm is minimum is D (mm), the inner diameter of the nozzle is 0.5 mm or more. 22. The method according to claim 18, wherein D * 0.25 or less. 25. The optical component is a finder objective lens. When the diagonal length of the effective lens surface on the nozzle side of the objective lens is L (mm), the inner diameter of the nozzle is 0.5 mm or more and L × L. 22. The method according to claim 18, wherein the value is 0.25 or less. 26. The method according to claim 18, wherein the photographing device is a film unit with a lens. 27. A method for manufacturing an optical component, comprising using a hot runner type mold, and arranging a nozzle on which an molten resin is injected on an optical axis to perform molding. 28. The method according to claim 27, wherein the optical component is a photographing lens or a finder lens. 29. The tip of a needle for opening and closing the nozzle is formed into a curved surface along the curved surface of the optical component, and is polished.
29. A method for manufacturing an optical component according to claim 28. 30. The tip of a needle that opens and closes the nozzle is formed on a plane substantially perpendicular to an optical axis of the optical component, and is polished. 29. The method for producing an optical component according to 28. 31. An inner diameter of the nozzle is 0.5 mm or more,
The thickness is not more than 2.0 mm.
0. The method for manufacturing an optical component according to any one of items 0 to 10. 32. An inner diameter of the nozzle is 0.8 mm or more,
The method for producing an optical component according to claim 31, wherein the optical component is 1.2 mm or less. 33. The optical component is a photographic lens, and when the effective diameter of the lens surface on the nozzle side in a state where the diameter of the diaphragm is minimum is D (mm), the inner diameter of the nozzle is 0.5 mm or more; 31. The method for manufacturing an optical component according to claim 27, wherein D * 0.25 or less. 34. The optical component is an objective lens of a finder. When the diagonal length of the effective lens surface on the nozzle side of the objective lens is L (mm), the inner diameter of the nozzle is 0.5 mm or more, and L × 31. The method for manufacturing an optical component according to claim 27, wherein the value is 0.25 or less.