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:
Mar. 22, 1994
Filed:
Feb. 09, 1993
Jiro Tanuma, Tokyo, JP;
Naoji Akutsu, Tokyo, JP;
Takao Uchida, Tokyo, JP;
Chihiro Komori, Tokyo, JP;
Masaru Ito, Fukushima, JP;
Oki Electric Industry Co., Ltd., Tokyo, JP;
Abstract
In a wire-dot impact printer having a capacitance detector for detecting a displacement of each armature by a sensor electrode arranged opposite the armature, a space is formed between each sensor electrode and its associated armature, and a shield pattern is formed with a small space left around each sensor electrode. The shield pattern is fed with a potential at least equal to the potential of each sensor electrode. This makes it possible to reduce the influence of noise upon detection of a capacitance by the capacitance detector. A noise canceling electrode is also disposed around each sensor electrode and is connected to the sensor electrode, whereby a noise canceling circuit is further provided to eliminate noise voltage. The noise canceling circuit can eliminate a noise voltage picked up by the sensor electrode and the noise canceling electrode.