Method for forming partial films on uneven surfaces of objects
First Claim
1. A method for forming partial films over an uneven surface of an object having spaced apart ridge portions, comprising the steps of:
- applying a photosensitive agent onto the entire uneven surface of the object;
projecting light rays emitted from a light source obliquely against said uneven surface of said object in such a manner that only the surface portions of the ridge portions which face said light source are exposed while the remaining surface portions which do not face said light source are left unexposed to said light rays;
etching the photosensitive film thus treated; and
washing the uneven surface, whereby a film is left over only said surface portions exposed to said light rays or over said remaining surface portions which have not been exposed to said light rays.
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Accused Products
Abstract
In order to form a minute light shielding film at a specific portion of an uneven surface of an object such as a Fresnel lens, a Fresnel plate, or a compound lens and more particularly of an optical-path-varying element, a photosensitive film (10) is previously applied onto the uneven surface and is irradiated with the light rays (11) emitted from an obliquely disposed light source. As a result, the surface of the ridge portion of the uneven surface which faces the light source is exposed to the light rays, while the remaining surface which does not face the light source is left unexposed to the light rays, whereby the portion (10a) of the light sensitive film exposed to light rays or that (10b) unexposed to light rays changes its properties. Thereafter the photosensitive film is subjected to etching and washing so that part of the photosensitive film is removed while the remaining light sensitive film remains as a light shielding film because of the difference in properties between the exposed and unexposed light sensitive film portions (10a, 10b).
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Citations
15 Claims
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1. A method for forming partial films over an uneven surface of an object having spaced apart ridge portions, comprising the steps of:
- applying a photosensitive agent onto the entire uneven surface of the object;
projecting light rays emitted from a light source obliquely against said uneven surface of said object in such a manner that only the surface portions of the ridge portions which face said light source are exposed while the remaining surface portions which do not face said light source are left unexposed to said light rays;
etching the photosensitive film thus treated; and
washing the uneven surface, whereby a film is left over only said surface portions exposed to said light rays or over said remaining surface portions which have not been exposed to said light rays. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
- applying a photosensitive agent onto the entire uneven surface of the object;
Specification