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:
Nov. 22, 1988
Filed:
Nov. 05, 1986
Kenichi Kanai, Kumagaya, JP;
Osamu Shimoe, Kumagaya, JP;
Hitachi Metals Ltd., Tokyo, JP;
Abstract
A toner level sensor for detecting the presence or absence or the level of residual amount of the toner of an electronic copier or the like. In order to secure stable operation regardless of changes of external environmental conditions such as temperature and humidity, a pair of transformers are provided with primary coils and secondary coils respectively wound on magnetic cores having a magnetic gap. When a magnetic member is present in the vicinity of a magnetic gap, the phases of the outputs of the secondary coils are opposite to each other, so that the differential output of the secondary coils is phase detected to determine the presence or absence of the residual toner amount or the level of residual amount.