JPH0136081B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plastic lens having a shape that facilitates painting when painting outside the effective curved surface.

Generally, lenses are coated with a matte black paint on the outside of their effective curved surface to reduce flare and ghosts in order to prevent reflections and the like. However, ordinary glass lenses have a simple lens shape and are therefore easy to paint. Even if it takes a certain amount of time to hand-paint a glass lens with a complicated shape, it is still expensive and profitable. However, since plastic lenses often have more complex shapes and are inexpensive, there is a demand for reducing the time required for painting as much as possible. In addition, if the part near the outer periphery outside the effective curved surface of the lens is painted, the thickness of the coating will affect the fit with the inner diameter of the lens barrel or the distance between the lenses. The lens cannot be fitted into the lens barrel to which it should be fitted, and as a result, the regular dimensions of the lenses vary. Therefore, it is necessary to prevent the formation of irregularities on the surface of the plastic lens on the side closer to the outer periphery outside the effective curved surface of the lens.

The present invention provides a plastic lens used in an optical system with a coating liquid reservoir groove that prevents the internal reflection prevention coating liquid applied to the painted surface outside the effective curved surface of the lens from dripping onto the non-painted surface. The present invention provides a plastic lens characterized in that the coating solution is applied to the coating surface of the lens, which is formed between the coating surface and the non-coating surface and has the liquid reservoir groove formed therein.

Hereinafter, the content of the present invention will be described in detail with reference to the drawings. 1 to 4 all show cross sections of plastic lenses according to embodiments of the present invention, in which 1 is the effective curved surface of the lens, 2 is the painted surface outside the effective curved surface, and 4 is the painted surface outside the effective curved surface.
is the unpainted surface on the outer circumferential side outside the effective curved surface. A coating liquid reservoir groove 3 is provided at the boundary line between the painted surface 2 and the non-painted surface 4. Therefore, the paint 5 protruding from the painted surface 2 will coat the paint liquid reservoir groove 3, so the possibility of contaminating the non-painted surface 4 is extremely reduced, which not only reduces the number of painting failures, but also Painting work efficiency can be greatly improved. Here, the coating liquid reservoir groove 3 may be continuous with the coating surface 2 as shown in FIG. 2, for example, or may be a V-shaped groove as shown in FIG. can be achieved. Furthermore, the painted surface 2 and the non-painted surface 4 are not limited to intersecting surfaces having a certain angle as shown in the embodiments of FIGS. Surface 2 and non-painted surface 4
There is no problem even if the surface is continuous in nature, such as.

As shown in the above examples, the plastic lens of the present invention is extremely easy to paint on surfaces outside the effective curved surface, and has a very effective shape not only for hand painting but also for automatic painting. It is. In addition, since flatness can be maintained at the contact portion between the lens fixing frame and the subsequent lens, the lens has good adhesion and can be securely fixed. Another advantage is that this part does not need to be polished as in the conventional method.

[Brief explanation of drawings]

1 to 4 each show a cross section of a plastic lens according to an embodiment of the present invention. 1... Effective curved surface, 2... Painted surface, 4... Non-painted surface, 3... Paint liquid reservoir groove, 5... Paint.

Claims (1)

[Claims] 1. In a plastic lens used in an optical system, a liquid reservoir groove for preventing internal reflection prevention coating liquid applied to the painted surface outside the effective curved surface of the lens from dripping onto the non-painted surface is installed on the painted surface. and a non-painted surface, and the coating liquid is applied to the painted surface of the lens in which the liquid reservoir groove is formed.