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. 21, 1987
Filed:
Jan. 18, 1985
Applicant:
Inventor:
Mikio Kyomasu, Hamamatsu, JP;
Assignee:
Ricoh Company Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03K / ; H03K / ;
U.S. Cl.
CPC ...
307361 ; 307264 ; 307451 ; 307473 ; 307475 ;
Abstract
An input buffer circuit comprised of MOS transistors includes an input terminal for receiving a tri-state input signal capable of taking any one of three potential levels, such as V.sub.pp, V.sub.cc and V.sub.ss. The input buffer circuit also includes a first detecting circuit having a first threshold level located between V.sub.pp and V.sub.cc and a second detecting circuit having a second threshold level located between V.sub.cc and V.sub.ss. Also provided is a third detecting circuit connected to the first and second detecting circuits to determine the level of the input signal applied to the input terminal.