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. 28, 2000
Filed:
May. 27, 1999
Shigekazu Yanagisawa, Suwa, JP;
Susumu Takatsu, Suwa, JP;
Kenji Watanabe, Tokyo, JP;
Takanobu Kameda, Tokyo, JP;
Chieko Aida, Tokyo, JP;
Tomoyuki Shimmura, Tokyo, JP;
Seiko Epson Corporation, Tokyo, JP;
King Jim Co., Ltd., Tokyo, JP;
Abstract
The present invention provides a method and an apparatus for driving and controlling a thermal head used in a printing device, such as a tape printer, in response to the temperature variations of the printing device environment and the thermal head. According to the present invention, in the printing operation of the tape printer, measurements are made of the initial temperature T1 immediately after the power is switched on, the temperature prior to printing T2, and the ambient temperature of the thermal head each time the thermal head prints T3 (i). If the temperature difference between the initial temperature T1 and the temperature prior to printing T2 is small, the duration of the current signals provided to the thermal head is controlled in accordance with the temperature prior to printing T2, which is the most recently measured thermal head ambient temperature best reflecting the printing device environmental temperature. If the difference is large, the duration is controlled in accordance with the initial temperature T1 which then best reflects the environmental temperature. If the rate of the increase in temperature during printing T3(i) is large, the duration is controlled in accordance with the initial temperature T2 to reduce the duration. If the temperature during printing T3(i) exceeds a temperature which indicates overheating, the printing operation is aborted. Thus, the present invention allows for controlling the thermal head drive by means of the measured thermal head ambient temperature excluding the effect of the heat generation of the thermal head and in accordance with the thermal state of the thermal head.