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:
Oct. 08, 1991
Filed:
Feb. 09, 1990
Kiyofumi Koike, Suwa, JP;
Minoru Tanaka, Suwa, JP;
Seiko Epson Corporation, Tokyo, JP;
Abstract
A drive circuit for a wire dot print head including a driving coil, a print lever attracted by the coil in a first direction, a spring for biasing the print lever in a second opposite direction and a damper includes a DC power source connected to a first end of the driving coil. A transistor is connected to the second end of the driving coil. An output circuit provides a gated output to the transistor. The output circuit receives as a first input a print data signal and as a second input a signal from a reference timing signal generator. The reference timing signal generator includes a drive pulse signal generator which provides an output in response to a print timing pulse which causes the output circuit to provide an output for the driving coil to attract the print lever. The reference timing signal generator also includes a brake pulse signal generator which provides an output when the print head temperature falls outside of a predetermined range after a predetermined interval so that current is caused to flow through the driving coil when the print lever is moving in the second direction and the print head temperature falls outside of the temperature range.