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:
Nov. 08, 1994
Filed:
Aug. 18, 1993
Naoki Obi, Tokyo, JP;
Kiyoshi Suematsu, Tokyo, JP;
Yasuhiko Kojima, Saitama, JP;
Masatoshi Katayama, Saitama, JP;
Yasuo Shigemitsu, Saitama, JP;
Dainippon Ink and Chemicals, Inc., Tokyo, JP;
Abstract
A direct positive silver halide photographic material and a method for forming a high contrast image using the same are disclosed, in which a pre-fogged direct positive silver halide emulsion layer contains a salt of a nitrogen-containing compound having at least one pyridine nucleus and at least one pyridinium nucleus. The photographic material, after imagewise exposure, is developed with an alkaline developer containing a developing agent, preferably a reductance compound. The photographic material provides high contrast characteristics having a gamma exceeding 10.