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:
Jun. 08, 1993
Filed:
Sep. 18, 1991
Dainippon Ink and Chemical, Inc., Tokyo, JP;
Abstract
A process of forming superhigh-contrast negative images is disclosed. The process comprises the steps of imagewise exposing a substantially surface latent image-type silver halide photographic material which is spectrally sensitized with a sensitizing dye and then developing said photographic material with a developer, wherein said photographic material contains a heterocyclic thione compound and said developer comprises (a) an aminophenol derivative developing agent, (b) a reductone compound, (c) a quaternary ammonium salt, and (d) a compound represented by formula (I): ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3, which may be the same or different, each represents a hydrogen atom, a nitro group, a halogen atom, or a cyano group, and wherein said development processing is carried out in the existence of at least one kind of a polyalkylene oxide or a derivative thereof. The process provides negative images of superhigh contrast having gamma over 10 substantially free from appearance of pepper.