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. 27, 1989
Filed:
Apr. 20, 1988
Mitutoyo Mfg. Co., Ltd., Tokyo, JP;
Abstract
A variable capacitance type encoder for measuring the length of an object to be measured on the basis of detecting the amount of movement of a probe as a function of the variation of electrostatic capacity between a rotary disk which is secured to a shaft and a pair of fixed disks which are secured to a frame body so as to be opposed to the rotary disk. On at least one fixed disk is provided first and second transmitting electrodes composed of a plurality of electrode elements to which voltages of different phases are applied. The rotary disk is provided with first and second receiving electrodes for receiving signals of a common phase by electrostatic coupling with both transmitting electrodes. Each fixed disk is further provided with an output electrode which is electrostatically coupled with the respective receiving electrode.