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:
Sep. 28, 2004
Filed:
May. 21, 2002
Yu-Fan Fang, Taipei, TW;
Kuang-Huei Huang, Taipei, TW;
Hi-Touch Imaging Technologies Co., Ltd., Pan-Chiao, TW;
Abstract
A method is provided to increase the gray level resolution of a thermal print head. The thermal print head includes a plurality of heaters which are used to heat color dye so as to deposit the color dye on a paper to form a line image. The line image contains a plurality of pixels, each formed by one heater. When generating a pixel, a pulse sequence is fed to one heater to control the heater″s heating period. The pulse sequence contains first and second portions. The first portion contains a plurality of consecutive pulses which is used to generate a first gray level. And the second portion contains at least one empty pulse period followed by at least one pulse which is used to generate a second gray level. The combination of the first and second gray levels will determine the gray level of each pixel of the line image.