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. 22, 1980
Filed:
Jan. 05, 1979
Mistuo Akiyama, Hachioji, JP;
Shunichi Abe, Hachioji, JP;
Konishiroku Photo Industry Co., Ltd., Tokyo, JP;
Abstract
A bias voltage switching circuit for an electrophotographic copying apparatus includes a series-connected string of resistors,, a constant bias voltage source in parallel with the string of resistors and a plurality of switching transistors. Each of the transistors is connected between a different junction of the series connected resistors and a common reference potential to which the constant voltage source and one end of the string of resistors is connected. Selective operation of the transistors varies the voltage output of the bias voltage switching circuit for use in controlling the concentration of the image produced by the copying apparatus.