The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 25, 1978
Filed:
Sep. 22, 1975
Takahiro Kohashi, Hachioji, JA;
Motoo Akagi, Hachioji, JA;
Yoichi Oba, Hachioji, JA;
Saburo Nonogaki, Tokyo, JA;
Makoto Tanaka, Koganei, JA;
Tadao Kaneko, Tokyo, JA;
Yoshifumi Tomita, Mobara, JA;
Hitachi, Ltd., Tokyo, JA;
Abstract
The present invention affords a process for forming a pattern having a surface area substantially equal to or smaller than area of apertures of shadow-mask through which beams pass on a photoresist film, which contains an acrylamidediacetoneacrylamide copolymer and a water-soluble aromatic bisazide compound, by exposing said photoresist film to light through a mask having the pattern and then developing the film. The use of said photoresist film for the preparation of a phosphor screen of a color picture tube of a black matrix or black stripe type does not require a special technique such as post-etching of a shadow mask and makes it possible to form a three primary color phosphor pattern having a surface area substantially equal to or smaller than the area of apertures of the shadow mask through which lightbeams pass, without mutual 'bridging' between phosphor dots. Thus, an excellent phosphor screen of a color picture tube of a black matrix or black stripe type can be prepared.