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:
Sep. 04, 1979
Filed:
Jan. 18, 1978
Toyoo Okamoto, Yokohama, JP;
Seiichi Miyakawa, Nagareyama, JP;
Ricoh Company, Ltd., , JP;
Abstract
A device for detecting toner concentration in a developing solution for developing an electrostatic image includes a casing having a small drainage hole formed at a top portion thereof so that a certain amount of a developing solution will always be present in the casing even when a tank containing a major portion of the developing solution used is made empty for some reason. A lamp and a lightsensitive element are mounted in the casing at locations below the drainage hole so that they may remain submerged in the solution within the casing at all times, thereby to prevent toner particles in the solution from adhering to the active surface of the former and hence errors in the detection due to the adhesion of toner particles. Alternatively, a pair of light transmission members in the form of bundles of optical fibers may be submerged in the solution within the casing, instead of the lamp and element, in order to allow the latter to be disposed externally of the casing.