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:
Jun. 22, 1993
Filed:
Feb. 28, 1992
Seiji Kawasumi, Shizuoka, JP;
Akio Uesugi, Shizuoka, JP;
Fuji Photo Film Co., Ltd., Kanagawa, JP;
Abstract
In a process of surface-roughening of an aluminum support for a printing plate using an AC electrolytic etching apparatus, changes of the current waveform, particularly changes of the time required for the current to reach its peak value due to variations of the load on the power supply are prevented. Also, the voltage load on the gate turn-off thyristors used for generating an alternating current is prevented from going beyond the withstanding voltage capacity of the thyristors. In accordance with the invention, an electrolytic surface-roughening treatment apparatus is provided in which an alternating current is supplied by a power supply having a circuit for generating the alternating current using a current inversion control circuit so as to perform electrochemical treatment, wherein the electrolytic surface-roughening treatment is performed with either a parallel circuit or a series circuit of a capacitor and a diode bridge inserted in parallel with the load on the power circuit.