Title:
ROTARY ENCODER AND ROTATION MECHANISM COMPRISING SAME
Document Type and Number:
WIPO Patent Application WO/2011/074103
Kind Code:
A1
Abstract:
In order to correct the eccentric error while increasing the allowable eccentric amount, provided is a rotary encoder comprising two first detection means (21, 22) which are disposed at positions symmetric with respect to the center of rotation and respectively output incremental signals having a plurality of cycles with respect to one rotation of a scale (1), and a second detection means (23) which outputs an absolute signal (φA) indicating the rotation angle during one rotation of the scale, said rotary encoder comprising a storage means (3) which stores a plurality of calculation expressions that are different according to the value of the signal (φA) and used for correcting the error of the incremental signal due to eccentricity, a calculation means (17) which calculates the phases (φ1, φ2) of the two incremental signals using the calculation expression corresponding to the value of the signal (φA) outputted from the second detection means and finds one corrected phase (φI), and a generation means (48) which generates the rotation angle (θout) of the scale on the basis of the phase (φI) and the value (φA).
Inventors:
NAKAMURA HITOSHI (JP)
Application Number:
PCT/JP2009/071063
Publication Date:
June 23, 2011
Filing Date:
December 17, 2009
Export Citation:
Assignee:
CANON KK (JP)
NAKAMURA HITOSHI (JP)
NAKAMURA HITOSHI (JP)
International Classes:
G01D5/244
Foreign References:
| JP2007178320A | 2007-07-12 | |||
| JPH10227658A | 1998-08-25 | |||
| JPH06102055A | 1994-04-12 |
Attorney, Agent or Firm:
ABE, Takuma et al. (JP)
Takuma Abe (JP)
Takuma Abe (JP)
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