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. 02, 2010
Filed:
Aug. 25, 2006
Yutaka Nakamura, Ashigarakami-gun, JP;
Satoshi Yanobe, Ashigarakami-gun, JP;
Yutaka Nakamura, Ashigarakami-gun, JP;
Satoshi Yanobe, Ashigarakami-gun, JP;
Sokkia Co., Ltd., Atsugi-shi, Kanagawa, JP;
Abstract
[Problems to be Solved] To provide a rotary encoder capable of carrying out self-calibration for a horizontal encoder as well as a vertical encoder without requiring special equipment and simply and inexpensively with a high degree of accuracy while reducing the burden on a worker. [Means for Solving the Problems] In a rotary encoder including: a rotary disk () with an angle code (); a light source that irradiates the angle code; a CCD linear sensor () that reads the angle code; and a processing unit that acquires a reading value f(θ) based on the angle code read by the CCD linear sensor, every time the rotary disk is rotated by a predetermined angle, where a rotation angle of the rotary disk is provided as θ and an angle from the rotation angle θ is provided as φ, based on a change in a difference g(θ,φ) between reading values f(θ+φ) and f(θ) within a reading range on the CCD linear sensor, the difference g(θ,φ) is determined as a Fourier series, and self-calibration of the reading value f(θ) of 0 to 360° is carried out based on the result.