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:
Nov. 03, 1992
Filed:
Apr. 23, 1991
Yoshihisa Fujiwara, Kadoma, JP;
Hirokazu Genno, Hirakata, JP;
Sanyo Electric Co., Ltd., Osaka, JP;
Abstract
A method of driving a thermal head enabling recording of multiple gradations and having a plurality of heating resistors, comprising: a first step of calculating an amount of density correction, corresponding to an amount of decrease of printed density of the specific ones of the heating resistors due to reduction of quantity of heat generated by the specific ones of the heating resistors, which reduction is caused by simultaneous heating of the specific ones of the heating resistors and the remaining heating resistors; and a second step of applying to the specific ones of the heating resistors, a print signal corrected on the basis of the amount of density correction so as to drive the specific ones of the heating resistors such that a desired printed density is obtained; in which in the first step, the amount of density correction is calculated on the basis of a weight factor, an imaginary number of the heating resistors and a maximum amount of density decrease.