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:
Nov. 04, 2008
Filed:
Jul. 06, 2006
Tadashi Osaka, Kashiwa, JP;
Kazushi Yoshida, Kasumigaura, JP;
Ryoko Ichinose, Tsukuba, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
Disclosed is a linear actuator, including: a screw unit rotatably driven by a driving motor; a nut unit screwed to the screw unit; a slider attached to the nut unit, in which the slider and the nut unit move linearly by the rotation of the screw unit; a guide restricting both surfaces of the slider; a first antenna attached to a side wall of the guide opposite to the slider; a second antenna attached to a side wall of the guide opposite to the slider, and opposing the first antenna; and a third antenna attached to both side walls of the slider, being interposed between the first antenna and the second antenna, wherein position of the slider is detected based on a change in capacitance due to displacement of the third antenna with respect to the first antenna and the second antenna.