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:
Jan. 04, 2000
Filed:
Nov. 25, 1997
Yutaka Tatsumi, Kyoto, JP;
Rohm Co., Ltd., Kyoto, JP;
Abstract
A thermal head producing method in which dispersion of resistance values of heating resistors in each thermal head and dispersion of the resistance values of the heating resistors per dot unit are made uniform to improve printing quality. A glaze layer is formed on a substrate and a heating resistor composed of a thin film resistor material of a mixed composition of a high melting point metal and an insulating material is formed on the glaze layer. First and second pattern conductors for providing common and separate electrodes are formed on the heating resistor and, after a protective film is formed to cover the first and second pattern conductors and the heating resistor, the heating resistor is heated so as to be a higher temperature than a dot temperature required for a printing operation. Preferably, after a resistor film formed on the glaze layer is annealed under vacuum to prepare the heating resistor, the first and second pattern conductors are formed on the heating resistor, and the protective film is formed in the same manner as described above.