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. 28, 1992
Filed:
Aug. 21, 1990
Tsutomu Ikehata, Sakado, JP;
Hirofumi Suzuki, Tokorozawa, JP;
Katsuya Masuda, Tokyo, JP;
Makoto Yasunaga, Kawagoe, JP;
Yoshimasa Tai, Kawasaki, JP;
Citizen Watch Co., Ltd., Tokyo, JP;
Abstract
A printing head includes solenoids arranged in an annular array for driving needles which are arranged in a zigzag array of two vertical columns. Solenoids corresponding to needles forming one of the columns are arranged on a semicircle of the annular array in the same order as that of the needles on the needle column. Two solenoids respectively corresponding to needles disposed at lower ends of the two needle columns are designed to generate magnetic fluxes whose directions are the same. During underline printing where these two solenoids are alternately energized, the magnetic flux generated by one of the solenoids never acts to increase an effective magnetic flux of the other solenoid at an initial stage of the excitation period thereof, so that the needle of the first solenoid reaches its forwardmost position at an appropriate time. The needle is rapidly restored and its tip prevented from being caught by the ink ribbon. After the forwardmost position is reached by the needle associated with the first solenoid, the magnetic flux generated by the second solenoid never acts to increase the magnetic flux of the first, permitting rapid restoration of the needle.