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:
May. 05, 1981
Filed:
Jul. 16, 1979
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A powdered developer (26) comprising carrier and toner particles is caused to flow by gravity downwardly through a passageway (71). A transparent electrode (62) is disposed in the passageway (71). A light source (64) and photosensor (66) are arranged on opposite sides of the electrode (62) for sensing an amount of attracted toner. The electrode (62) is first de-energized and cleaned by aprtially restricting the passageway (71) below the electrode (62) and allowing developer (26) to accumulate in the passageway (71) from the restriction upwardly past the electrode (62) while a restricted amount of developer (26) flows downwardly through the restriction. Then, the restriction is removed and the passageway (71) blocked above the electrode (62), allowing the accumulated developer (26) to flow downwardly past the electrode (62). Then, the passageway (71) is completely unblocked and the electrode (62) energized with an electric potential causing toner to be attracted thereto. After a predetermined length of time the passageway (71 ) above the electrode (62) is blocked and the output of the photosensor (66) indicates the amount of toner attracted to the electrode (62) and thereby the developing ability of the developer (26). The output of the photosensor (66) after cleaning the electrode (62) may be compared with the final output to provide a reference valve which is compensated for variables such as electrode contamination, electric potential variation and the like.