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. 14, 1987
Filed:
Aug. 19, 1986
Mikio Kobayashi, Kawasaki, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A input/output port for use in a device such as a central processing unit includes a common input/output terminal which serves as an input terminal when the port is set in a data input mode and as an output terminal when the port is set in a data output mode. The common terminal is connected to the junction between a pair of transistors connected in series between a high voltage source and ground. Also provided is a third transistor having a lower capability or power than the pair of first and second transistors and connected between the high voltage source and the common terminal. During data output mode, the pair of first and second transistors is turned on and off in a complementary fashion in accordance with data to be output. During data input mode, the pair of first and second transistors is maintained turned off and the third transistor is set either turned off or turned on.