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:
Jul. 30, 1991
Filed:
Dec. 21, 1989
Yasunori Ichikawa, Kanagawa, JP;
Hiroshi Ohnishi, Kanagawa, JP;
Shigeharu Urabe, Kanagawa, JP;
Akira Kojima, Kanagawa, JP;
Akira Katoh, Kanagawa, JP;
Fuji Photo Film Co., Ltd., Kanagawa, JP;
Abstract
A control process and apparatus for the formation of silver halide grains comprising a mixer disposed outside of a reaction vessel containing an aqueous protective colloid solution and causing a nucleus formation (nucleation) and/or a crystal growth of silver halide grains. The process and apparatus further include: supplying an aqueous solution of a water-soluble silver salt, an aqueous solution of water-soluble halide(s), and an aqueous solution of a protective colloid to the mixer through supply conduits while controlling the flow rates of the solutions; mixing them while controlling the rotational speed of a stirrer of the mixer to form fine, silver halide grains; and immediately supplying the fine grains into the reaction vessel through a conduit connecting the mixer to the reaction vessel to perform the nucleus formation and/or the crystal growth of the silver halide grains in the reaction vessel. The control process and apparatus further comprise measuring the silver ion potential of the fine grains formed in the mixer or the silver ion potential in the reaction vessel with an electrode, and controlling the flow rate of at least one of the aqueous silver salt solution, the aqueous halide solution, and the aqueous protective colloid solution being added to the mixer, such that the measured value equals a predetermined value.