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:
Jul. 20, 2004
Filed:
Feb. 17, 2003
Kouji Nishi, Kyoto, JP;
Takaya Nagahata, Kyoto, JP;
Rohm Co., Ltd., Kyoto, JP;
Abstract
A thermal printhead is disclosed which prevents an undesired color from being generated around the periphery of a desired color, even when a two-color thermo-sensitive paper is used as the recording medium. A plurality of variable electric potential regions are formed on top of a heating resistor. Each region is disposed between two adjacent projections, and has an individual electrode that intersects therewith. The variable electric potential regions generate colors due to electric potential differences that are produced between a common electrode and individual electrodes. The width of each variable electric potential region corresponds to one dot, and is set such that the temperature of the entire region is substantially uniform when heated. A plurality of fixed electric potential regions are formed on top of the heating resistor, and each region has a fixed electric potential even when an electric potential difference is produced between the common electrode and the individual electrodes. Each adjacent pair of fixed electric potential regions have at least one variable electric potential region disposed therebetween.