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. 20, 2001
Filed:
Oct. 20, 1998
Nobuo Katsuma, Saitama, JP;
Fuji Photo Film Co., Ltd., Kanagawa, JP;
Abstract
A thermal head of a thermal printer has plural heating elements arranged along a line and connected in parallel with one another. A respective one of the heating elements is connected to one of plural heat control switches, which are selectively turned on/off for driving the heating elements individually by applying electrical energy to generate heat. To measure resistance data of at least one of the heating elements, a capacitor is connected in parallel with the plural heating elements. A reference resistor is connected in parallel with the plural heating elements and the capacitor. The capacitor is charged, and then discharged via the reference resistor or the one of the heating elements. A capacitor voltage across the capacitor is detected. Discharging time elapsed in a decrease of the capacitor voltage is measured from a predetermined high voltage to a predetermined low voltage while the capacitor is discharged, in association respectively with the reference resistor and the heating elements. Resistance data of the heating elements is determined in accordance with the discharging time respectively of the heating elements with reference to the discharging time of the reference resistor.