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. 11, 2000
Filed:
Jan. 13, 1998
Noriyuki Suzuki, Tokyo, JP;
Sohei Tanaka, Kawasaki, JP;
Masafumi Wataya, Kawasaki, JP;
Hiroshi Uemura, Machida, JP;
Nobuyuki Tsukada, Fukushima, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An interface in accordance with IEEE 1284 has a signal output stage which is a totem pole circuit. The totem pole circuit may be damaged if its output signal line is left grounded for an extended period of time or if outputs are being delivered at both ends of the signal line. Drive by the totem pole circuit is limited to a case where a signal to be output is at a low level and to a length of time equivalent to, say, one clock period from the moment the signal makes a transition from the low to a high level. A high impedance is established at all other times during which the high level is in effect, with the high level being maintained by a pull-up resistor connected to the output signal line. As a result, the totem pole circuit will not be damaged even if the output line is grounded while at the high level.