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:
Dec. 22, 1987
Filed:
Apr. 04, 1986
Applicant:
Inventor:
Kazuhiko Muto, Kawasaki, JP;
Assignee:
Canon Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06G / ; H03K / ; H03K / ;
U.S. Cl.
CPC ...
307494 ; 328145 ; 333 14 ; 307571 ;
Abstract
A logarithmic compression circuit comprising an operational amplifier and a transistor for logarithmic compression. One of the emitter and collector of the transistor is connected to the inverting input of the amplifier and the other of the emitter and collector of the transistor is connected to the output of the amplifier. A switching device is selectively connected between the base of the transistor and the non-inverting input of the amplifier and between the base and the said one of the emitter and collector of the transistor in accordance with the magnitude of a signal current input.