JPH04281414A - Molding method for lens barrel - Google Patents

Abstract

PURPOSE:To mold plural lenses integrally with the lens barrel by accurately setting the optical axes of the lenses. CONSTITUTION:A 1st lens 2 and a 1st relay cylinder 6 are molded out of light- transmissive resin 21 by using a 1st mold 10 and a 2nd lens 3 and a 2nd relay cylinder 7 are molded out of light-transmissive resin 21 by a 2nd mold 11 and then the 2nd mold 11 is moved to align the axes 22 and 23 of cavities 12 and 16 with each other and then the 1st lens 2 and 2nd lens 3 are so arranged that optical axes 4 and 5 are aligned with each other. Then a cavity 24 is provided outside the 1st and 2nd relay cylinders 6 and 7 and light-nontransmissive resin 25 is filled and solidified in a 3rd cavity 24. Consequently, the optical axes 4 and 5 are aligned by aligning the 22 and 23 of the cavities 12 and 16, thereby accurately molding the 1st and 2nd lenses 2 and 3.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of molding a lens barrel manufactured by plastic molding.

0002

[Prior Art] Conventionally, a plurality of lenses are held through a lens barrel, and as a lens barrel used for a photo camera or a video camera, Japanese Patent Laid-Open No. 62-2219 discloses that the lens barrel is attached to other parts. A flange for fixing is provided integrally, and a plurality of separately molded lenses are inserted into the lens barrel, and the lenses are positioned by a spacing ring and fixed by being pressed to one side by a screw ring. A lens barrel has been proposed. Furthermore, instead of using the screw ring, fixation is also performed by adhesive or the like.

0003

[Problems to be Solved by the Invention] In the above-mentioned prior art, a plurality of separately molded lenses are each inserted into a lens barrel and then fixed with a screw ring or adhesive, so that the optical axes of the lenses are not aligned with each other. It required skill to match the numbers.

[0004] As a means to solve such problems,
A gas-filled molding method, a parison blow molding method, a method in which an evanescent core is inserted into a mold, and a covering molding is performed thereon are known.

However, the above-mentioned means have limitations in making the wall thickness uniform and controlling the dimensions.
Further, extra steps such as heating and dissolving and washing were required.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for molding a lens barrel, which solves the above-mentioned problems and easily manufactures a lens barrel with high precision with respect to eccentricity of the optical axis of the lens.

[0007]

[Means for Solving the Problems] A method for molding a lens barrel according to the present invention is a method for molding a lens barrel in which a plurality of lenses are attached to the lens barrel with their optical axes aligned. a first lens and a first lens surrounding the first lens by a first mold provided on one side as a boundary;
A second relay tube surrounding the second lens and the second lens is molded with a light-transmitting resin using a second mold provided on the other side of the dividing surface. After molding, the first and second molds are relatively moved using the dividing surface as a sliding surface to align the axes of the first and second molds, A lens barrel is integrally molded by filling cavities provided in the first and second molds so as to communicate with the outsides of the first and second relay barrels, respectively. This is what I did.

[0008]

[Operation] With the above configuration, after the first lens is molded using the first mold and the second lens is molded using the second mold, the axes of the first mold and the second mold are By matching, the optical axes of the first lens and the second lens can be made to match, and the lens barrels are integrated into the first relay barrel and the second relay barrel.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a lens barrel 1 molded according to this embodiment. This lens barrel 1 has a first lens 2 which is a convex lens and a second lens 3 which is a concave lens. 5, the first and second lenses 2 and 3 are integrally molded with first and second relay tubes 6 and 7, respectively, and the outer side of the relay tubes 6 and 7 is lens barrel 8
is provided.

FIG. 2 shows the first step, in which a first mold 10 is provided on one side of the dividing surface 9, and a second mold 11 is provided on the other side of the dividing surface 9. The first and second molds 11 and 12 can be moved relative to each other using the dividing surface 9 as a sliding surface. A first cavity 12 for molding the first lens 2 and the first relay tube 6 is formed in the first mold 10, and a first cavity 12 for molding the lower surface of the first lens 2 is formed. A first moving core 13 is provided on the second mold 11 side. Furthermore, the lens barrel 8 is located outside the first cavity 12.
First ring-shaped movable split core 1 for molding the upper part of
4, and the first cavity 12 is provided with resin passages 15 such as injection molding nozzles and runner holes.
is set up in front of you. Similarly, the second mold 11
A second cavity 16 for molding the second lens 3 and the second relay tube 7 is formed in the first mold 10 side for molding the upper surface of the second lens 3. A second moving core 17 is provided. Further, a second ring-shaped movable split core 18 for molding the lower part of the lens barrel 8 is provided outside the second cavity 16, and a resin passage 19 faces the second cavity 16. It is set in. Incidentally, facing the first ring-shaped movable split core 14, there is a resin passage 20 for injection molding.
is provided.

Therefore, the first cavity 12 is filled with a molten translucent resin 21 from the resin passage 15 and solidified to integrally mold the first lens 2 and the first relay tube 6, and the second A molten translucent resin 22 is filled into the second cavity 16 through the runner hole 19 and solidified to integrally mold the second lens 3 and the second relay tube 7. After this, the first and second
The movable cores 13 and 17 are moved back from the dividing surface 9, and the mold clamping is released.

Next, as shown in the second step in FIG. 3, the second mold 11 is moved in the direction of arrow A by a moving device (not shown), and the first lens 2 and the second lens 3 are separated. optical axis 4,
After aligning the axes 22 and 23 of the first cavity 12 of the first mold 10 and the second cavity 13 of the second mold 11 so that the molds 5 coincide with each other, the molds are clamped.

Next, as shown in the third step in FIG. 4, the first and second ring-shaped movable split cores 14 and 18 are each moved outward via a moving device (not shown) to perform the first molding process. Type 1
0 and the second mold 11 communicate with each other.
form. Then, a molten non-transparent resin 25 of black color, for example, is filled from the third runner hole 20 through the resin passage 24 and solidified, thereby forming a non-transparent resin 25 on the outside of the first and second relay tubes 6 and 7. The lens barrel 1 is formed by integrally molding a lens barrel 8 made of a translucent resin 25.

Next, as shown in the fourth step in FIG. ) etc. to take out the lens barrel 1.

As described above, in the embodiment, the first
In the process, the first lens 2 and the first relay tube 6 are molded from the transparent resin 21 using the first mold 10, and the second lens 3 and the second relay tube 6 are molded using the second mold 11.
The optical axis 4 is formed by molding the relay tube 7 with a translucent resin 22, and then moving the second mold 11 in the second step to align the axes 22 and 23 of the cavities 12 and 16. , 5 to match the first lens 2
and a second lens 3. After that, in a third step, a third cavity 24 is provided outside the first and second intermediate barrels 6 and 7, and the third cavity 24 is filled with non-transparent resin 25 and solidified. first and second lenses 2, 3, first and second relay tubes 6,
7 and the lens barrel 8 can be provided integrally. Therefore, by aligning the axes 22 and 23 of the cavities 12 and 16, the optical axes 4 and 5 can be aligned and the optical axes 4 and 5 of the first and second lenses 2 and 3 can be accurately shaped. can.

Furthermore, in the embodiment, when the molds of the cavities 12 and 16 are matched, the molds can be easily matched by sliding the second mold 12 using the dividing surface 9 as a boundary. It is possible to accurately set the optical axes 4 and 5 of the second lenses 2 and 3, and
Can be easily molded.

Furthermore, by providing the first and second relay barrels 6, 7 and the lens barrel 8 on the outside of the first and second lenses 2, 3, the strength is improved and the lens barrel 1 can be relatively large.
can be molded.

Further, since the lens barrel 8 is molded from a non-transparent resin 25, light leakage in the lens barrel can be prevented.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and various modifications can be made, for example, in the combination of lenses.

[0021]

Effects of the Invention The present invention provides a method for molding a lens barrel in which a plurality of lenses are attached to a lens barrel with their optical axes aligned, and a first A first lens and a first relay tube surrounding the first lens are molded from a transparent resin using a mold, and a second mold provided on the other side of the dividing surface is used to mold a second lens and a first relay tube surrounding the first lens. After molding a second relay tube surrounding the second lens with a transparent resin, the first and second molds are relatively moved using the dividing surface as a sliding surface to mold the first relay tube. and a second mold so that their axes coincide with each other, and a non-transparent mold is formed in a cavity provided in the first and second molds, communicating with the outside of the first and second relay tubes, respectively. By configuring the lens barrel to be filled with photoresist and integrally molded, it is possible to accurately and easily set the optical axes of the first and second lenses and mold the lens barrel. .

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a molded product showing an embodiment of the present invention.

FIG. 2 is a sectional view showing a first step showing an embodiment of the present invention.

FIG. 3 is a sectional view showing a second step showing an embodiment of the present invention.

FIG. 4 is a sectional view showing a third step showing an embodiment of the present invention.

FIG. 5 is a sectional view showing a fourth step showing an embodiment of the present invention.

[Explanation of symbols]

1 Lens barrel 2 First lens 3 Second lens 4, 5 Optical axis 6 First relay tube 7 Second relay tube 8 Lens barrel 9 Dividing plane 10 First mold 11 Second mold 21 Translucent resin 22, 23 Axis line 24 Cavity 25 Non-transparent resin

Claims (1)

[Claims] 1. A method for molding a lens barrel in which a plurality of lenses are attached to a lens barrel with their optical axes aligned, wherein a first
A first lens and a first relay tube surrounding the first lens are molded from a transparent resin using a mold, and a second lens is molded using a second mold provided on the other side of the dividing surface. and a second relay tube surrounding the second lens is molded from a transparent resin, and then the first and second molds are relatively moved using the dividing surface as a sliding surface to mold the second relay tube surrounding the second lens. The first and second molds are aligned so that their axes coincide, and a cavity provided in the first and second molds is connected to the outside of the first and second relay tubes. A method for molding a lens barrel, characterized in that the lens barrel is filled with a translucent resin and integrally molded.