JPS5918401Y2 - lens holding frame - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a lens holding frame that can be produced inexpensively and lightweight using synthetic resin.

For example, a lens for a copying machine is shown in Fig. 1, in which left and right lens groups are arranged inside a lens holding frame a consisting of a cylindrical body with a uniform outer diameter, and concave surfaces of L2 face each other. Assemble both lens groups L1. The inner outer peripheral edge of L2 is respectively locked in the groove of the intermediate inward protrusion a1 of the holding frame a, and the outer peripheral surface is brought into contact with the inner surface of the holding frame a, and the outer outer peripheral edge is pressed by the retaining ring r to separate both lenses. Group L1. I try to keep L2.

By the way, the above-mentioned lens holding frame a is made of metal, and the inner surface shape is not uniform, and each lens group L1. The central portion where L2 is disposed is thick, making it heavy and expensive.

Therefore, if it is made of synthetic resin, it can be made lighter and at a lower cost, but generally when molding a synthetic resin product, the parts of the product, as shown in the graph in Figure 2 A, are The cooling and hardening time of the resin in the mold differs depending on the target wall thickness (in the figure, P1 is a thermoplastic resin, P2
(shown for thermosetting resin), therefore, the degree of shrinkage varies depending on each part, and as a result, it is said that the product is likely to be distorted.When this is applied to the lens holding frame a as shown in Figure 1, Distortion appears in the thick part of the center,
It is not suitable for being incorporated into optical equipment.

In this case, as shown in the opening in the same figure, a two-stage stepped portion is formed at the center of the holding frame a between the barrel c2 that should abut the outer periphery of the lens group and the inward protrusion c1 that should lock the inner outer periphery. do,
The above problem can be solved by making the wall thickness the same as the thickness of the fitting abutment parts C3 to the equipment on both sides, but with such a configuration, when it is installed on the aircraft, it will not be supported. The contact area is limited to the large-diameter contact portions C3 on both sides, and the joint surface is small, making it difficult to sit.

This invention was developed in view of these circumstances, and is intended to provide a lens holding frame that is made of synthetic resin, is lightweight, can be produced at low cost, and is stable when attached to the aircraft body.

Fig. 3 shows an embodiment of this invention, in which 1 is a cylindrical lens holding frame to be incorporated into a copying machine, and is made of synthetic resin, and the central part of its peripheral wall is similar to Fig. 2A. Left and right lens groups L1. An inward protrusion 1a having grooves 2 on both sides to which the inner outer peripheral edge of L2 is to be locked, and each lens group L1. The receiving part 1b that should come into contact with the outer circumferential surface of L2 is formed in two stages, deep and shallow, and the wall thickness of these parts is equal to the wall thickness of the fitting contact part IC for the copying machine on both sides. A large number of annular fin plates 3 are integrally provided on the outer peripheral surfaces of the left and right receiving portions 1b and the inwardly directed protrusions 1a with a required gap,
Their outer diameters are made equal to the outer diameters of the fitting abutting portions on both sides.

Inside, there are left and right lens groups L1. L2 is assembled in such a way that each inner outer circumferential edge is engaged with the groove 2 on both sides of the inwardly directed protrusion 1a, and each outer circumferential surface is in contact with the inner surface of the receiving part 1b,
It is held under pressure by retaining rings 4 on both sides.

In use, the lens holding frame 1 is fitted into a mounting portion of a copying machine and is attached using fastening means such as screws or bands.

At that time, not only the outer surfaces of the fitting contact sections 1C on both sides but also the outer surfaces of the many fin plates 3 come into contact with the inner surface of the mounting section, thereby improving the seating of the lens holding frame 1.

As described above, in this invention, the lens group on the peripheral wall of the cylindrical body molded from synthetic resin is shaped into a stepped part to be attached, and the thickness of the stepped part is adjusted to the thickness of the fitting contact part to the fuselage. and a number of annular fin plates whose outer diameter matches the outer diameter of the fitting abutment part are integrally provided on the outer periphery of the step, making it lighter and cheaper to produce than conventional ones. The circumferential wall has a uniform thickness and is cooled and hardened at the same time during the molding process, so no distortion occurs.Moreover, the joint surface to the fuselage is wide, and the installation is stable and does not cause any problems.

[Brief explanation of the drawing]

FIG. 1 is a half-sectional view of a conventional lens holding frame. Figure 2A is a rough graph showing the relationship between cooling hardening time and wall thickness of synthetic resin. The opening in Figure 2 is an imaginary half-sectional view of a synthetic resin molded with uniform wall thickness. FIG. 3 is an upper half-cut side view of an embodiment of this invention.

Claims (1)

[Scope of utility model registration request] Forming a stepped portion on the peripheral wall of the cylinder made of synthetic resin to which the lens group is attached, and making the thickness of the stepped portion equal to the thickness of the fitting contact portion 1C to the fuselage, and the stepped portion. A lens holding frame integrally provided with a large number of annular fin plates 3 whose outer diameters match the outer diameters of the fitting contact portions 1C.