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:
Mar. 01, 1994
Filed:
Feb. 19, 1993
Hiroshi Shirotori, Nagano, JP;
Katsuhiko Nishizawa, Nagano, JP;
Seiko Epson Corporation, Tokyo, JP;
Abstract
The disclosed invention achieves a proper speed control of a sheet feeding motor for a serial printer that uses an astable power supply with a simple operation irrespective of variations in power supply voltage. The invention provides a method of and an apparatus for controlling the frequency of a sheet feeding pulse motor for a printer in accordance with the power supply voltage during sheet feeding. The apparatus of the invention is composed of a sheet feeding motor controller for use in a printer, the controller controlling a driving signal used to drive a motor in accordance with the level of a printer power supply voltage within the printer, the controller includes a device for detecting a power supply voltage; a first memory device for storing information representing the characteristic voltage restoration curve of the printer power supply; a second memory device for storing information representing the relationship between a rotational speed of the motor and the plurality of voltages making up the characteristic printer power supply restoration curve; a device for estimating a current power supply voltage on the characteristic restoration curve from the information stored in the first memory device; a device for reading a rotational speed from said second memory device corresponding to the current power supply voltage estimated by said estimating means; and a device for changing the speed of the motor in accordance with the read rotational speed.