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. 06, 1993
Filed:
Aug. 08, 1991
Fuji Photo Film Co., Ltd., Kanagawa, JP;
Abstract
A method of forming a black-and-white image of very high contrast having a gamma value of 8 or above is disclosed, using a negative imagewise exposed photosensitive material comprising a support having thereon at least one hydrophilic colloid layer, at least one layer which is a silver halide emulsion layer, at least one of said hydrophilic colloid layer containing a hydrazine derivative represented by formula (I), comprising processing the photosensitive material with a developer having a pH of 11.2 or lower, said developer being substantially free from benzotriazoles to thereby provide a wide exposure latitude and steady image formability: ##STR1## wherein R.sub.1 represents an aliphatic group or an aromatic group; R.sub.2 represents a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an amino group, a carbamoyl group or an oxycarbonyl group; G.sub.1 represents a carbonyl group, a sulfonyl group, a sulfoxy group, ##STR2## or an iminomethylene group; and each of A.sub.1 and A.sub.2 represents a hydrogen atom, or one of A.sub.1 and A.sub.2 is a hydrogen atom and the other is an alkylsulfonyl group, an arylsulfonyl group, or an acyl group.