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.

Date of Patent:
Apr. 20, 1999

Filed:

Jun. 11, 1996
Applicant:
Inventors:

Takaaki Yagi, Kawasaki, JP;

Mitsuchika Saito, Kawasaki, JP;

Assignee:

Hewlett-Packard Company, Palo Alto, CA (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01B / ; G01D / ; G01R / ; G01G / ;
U.S. Cl.
CPC ...
324660 ; 324686 ; 324 7671 ; 361292 ;
Abstract

A small position detection and positioning device detects relative displacement between two members with high precision. A moving medium-type memory device using such positioning device is also provided. The position detection device includes a linear array of first electrodes at equal pitches on one of the two members that have relative displacement in at least one dimension, and a linear array of at least one second electrode on the other member. The first electrodes are positioned opposite the second electrodes and separated from them by a minute gap. The first electrodes are divided into a first electrode set composed of alternate ones of the first electrodes, and a second electrode set composed of alternate ones of the first electrodes not in the first electrode set. A signal source which applies a first alternating signal to the first electrode set and a second alternating signal that differs in phase by 180.degree. from the first alternating signal to the second electrode set is connected to the first electrodes. A current detecting device that measures the current flowing in the at least one second electrode is connected to the at least one second electrode.


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