JP3095396B2 - Compound lens - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compound lens in which a plurality of resin lenses are closely arranged.

[Conventional technology]

Conventionally, as this kind of composite lens made of resin, as shown in FIG. 1, a composite lens in which a single convex lens 2 and a concave lens 3 are fitted and overlapped inside a cylindrical body 1 is used. Are known.

[Problems to be solved by the invention]

However, in the above-mentioned conventional resin composite lens, since it is composed of three parts, ie, the cylindrical body 1, the convex lens 2 and the concave lens 3, it takes time and effort to assemble, and the cost is increased. It is difficult to join them with a sufficient degree of adhesion, and a space is easily created at the interface between the two lenses 2 and 3, which reduces the lens performance and causes moisture to enter the space due to the moisture entering this space. There was a problem that it was easy.

The present invention has been made in view of the above circumstances, and an object of the present invention is to achieve good adhesion at a boundary surface between a plurality of lenses, greatly improving lens performance, and further improving lens performance. It is an object of the present invention to provide a compound lens that can prevent the occurrence of troubles such as cloudiness and can be manufactured easily at low cost.

[Means for solving the problem]

In the composite lens of the present invention, a plurality of resin lenses are housed in a resin cylinder, and these lenses are closely contacted with each other.
Further, at least the entire outer peripheral portion of each of the lenses is a composite lens configured to be in close contact with the cylindrical body, and the cylindrical body and each lens are overlapped by sequentially filling the cylindrical body with resin. It is molded integrally with the cylinder in the fitted state.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS.

The basic structure of the compound lens of the present invention is the same as that of the conventional compound lens shown in FIG. 1, but the difference is that the cylindrical body 1, convex lens 2, and concave lens 3 are integrally molded by using a multicolor molding technique. It is. The cylindrical body 1, convex lens 2 and concave lens 3 will be described in detail. The cylindrical body 1 includes a large cylindrical portion 1a, a small cylindrical portion 1b connected thereto, and a ring formed at the tip of the small cylindrical portion 1b. The convex lens 2 is composed of a pair of convex curved surfaces 2a and 2b.
c, a flange portion 2d provided on the outer edge portion of the convex lens portion 2c and in close contact with the inner peripheral surface of the small cylindrical portion 1b and the receiving portion 1c, and formed between the collar portion 2d and the convex curved surface 2a. And a ring-shaped recess 2e. The concave lens 3
Is a concave lens portion 3c composed of a pair of concave curved surfaces 3a and 3b.
And a flange 3d provided on the outer edge of the concave lens portion 3c. The concave curved surface 3a of the concave lens 3 and the annular surface and the outer peripheral surface of the flange 3d connected thereto are respectively the upper surface of the convex lens 2 and the cylindrical body. It is formed in close contact with the inner peripheral surface of one small cylindrical portion 1b.

When integrally forming the compound lens configured as described above, first, as shown in FIG. 2, a fixed mold 10 forming an end surface of the large cylindrical portion 1a, and a large cylindrical portion fitted into the fixed mold 10 A bush 11 forming the inner peripheral surface of 1a, and this bush 11
A first fixing member which is fitted to the inside so as to be freely detachable and forms the inner peripheral surface of the small cylindrical portion 1b, the back surface of the receiving portion 1c (the annular surface of the flange portion 2d of the convex lens 2) and the convex curved surface 2b of the convex lens 2. Side insert 12
, Is provided so as to approach and separate from the fixed mold 10,
A movable mold 13 forming the outer surface of the cylindrical body 1;
The cylindrical body 1 is inserted into the cylindrical body 13 using an injection mold that is fitted into the inside 13 and includes the inner peripheral surface of the receiving portion 1c, the convex curved surface 2a of the convex lens 2, and the movable side insert 14 forming the concave portion 2e. Forming (primary forming). That is, the resin (primary injection material) for forming the cylinder 1 is filled into the cavity from the primary injection material supply passage 15 formed in the movable mold 13. In this case, the first fixed-side insert 12 is provided with a passage 16 for supplying a secondary injection material, but is not supplied with a resin. Also, the first
Because the lower surface of the fixed-side insert 12 and the upper surface of the movable-side insert 14 are in close contact with each other at the annular portion, the resin does not enter the space formed at the center between them.

In this way, when the primary molding is completed and the cylindrical body 1 is formed, as shown in FIG.
Is separated from the movable side insert 14 by a predetermined distance. Then, in this state, using the secondary injection material supply passage 16,
The resin (secondary injection material) for molding the convex lens 2 is supplied into the space between the first fixed-side insert 12, the movable-side insert 14, and the cylindrical body 1 formed by the primary molding, and the convex lens 2 is formed. (Secondary molding).

Next, when the secondary molding is completed and the convex lens 2 is molded, as shown in FIG. 4, the first fixed side insert 12 is pulled out, and the second fixed side insert 17 is inserted into the bush 11. insert.
The second fixed side insert 17 is for forming the concave curved surface 3b of the concave lens 3 and the annular surface of the flange portion 3d connected thereto.
A passage 18 for supplying a resin (tertiary injection material) for molding the concave lens 3 is formed therein. Then, using the tertiary injection material supply passage 18, the resin for forming the concave lens is placed in the space formed by the already molded cylindrical body 1 and convex lens 2 and the second fixed side insert 17. The concave lens 3 is molded by filling (tertiary molding).

In the composite lens formed in this way, since the cylindrical body 1, the two lenses 2, 3 are fused and joined, there is no gap between the lenses 2, 3, and the lens performance is improved. In addition to the improvement, it is possible to completely prevent problems such as clouding at the interface between the lenses 2 and 3. The cylindrical body 1 formed by the primary molding is still attached to the movable mold 13 side after the secondary molding, and the first and second fixed side inserts 12 are formed along the inner surface of the cylindrical body 1. , 17 are sequentially moved or mounted, the cylindrical body 1 and the movable mold 13 (movable side insert 14) to which the cylindrical body 1 is attached and the fixed side inserts 12, 17
Can be easily matched with each other, and the center of each of the lenses 2 and 3 can be smoothly and reliably matched with the center of the cylindrical body 1 of the multicolor molded compound lens.

In this embodiment, an example in which the cylindrical body 1, the convex lens 2, and the concave lens 3 are integrally formed has been described. However, it goes without saying that three or more lenses can be stacked.

〔The invention's effect〕

As described above, since the present invention is obtained by integrally molding a plurality of resin lenses, the lenses can be easily and surely brought into close contact with each other, so that the adhesion between the lenses can be improved. Therefore, not only can the lens performance be significantly improved, but also problems such as clouding between the lenses can be prevented, and the lens can be manufactured at low cost and easily. Moreover, according to the present invention, it is possible to form a cylindrical body by multicolor molding and then integrally mold a plurality of lenses in the cylindrical body in close contact with each other, whereby the inner wall surface of the cylindrical body is used as a reference. Each lens can be molded with high precision, and a high-quality compound lens in which the axis of the cylindrical body and the optical axis of each lens match can be easily obtained.

Furthermore, the present invention can improve the adhesion between the cylinder and the outer periphery of each lens and the cylinder by tightly contacting the cylinder and the plurality of lenses by integral molding, and therefore, The cylindrical body can completely prevent light from entering the outer periphery of each lens, further prevent moisture, foreign matter, and the like from entering the interface between the lenses, and ensure that each lens is Can be held.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of a compound lens, FIGS. 2 to 4 show a procedure for integrally forming the compound lens of the present invention, and FIG. 2 is a cross-sectional view when a cylindrical body is formed. FIG. 3 is a cross-sectional view of a convex lens during molding, and FIG. 4 is a cross-sectional view of a concave lens during molding. 1 ... cylindrical body, 2 ... convex lens, 3 ... concave lens.

Continuation of the front page (56) References JP-A 1-263034 (JP, A) JP-A 62-70810 (JP, A) JP-A 3-230920 (JP, A) JP-A 2-299824 (JP) , A) JP-A-2-99912 (JP, A) JP-A-59-162025 (JP, A) JP-A-58-26003 (JP, U)

Claims (1)

(57) [Claims] A plurality of resin lenses are housed in a resin cylinder, the lenses are closely contacted, and at least the entire outer peripheral portion of each lens is closely contacted with the cylinder. A composite lens, wherein the cylindrical body and each of the lenses are formed by integrally filling the cylindrical body with the resin by sequentially filling the cylindrical body with a resin.