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US 6,958,468 B2Granted
Beam rotation angle detecting apparatus, rotation detecting apparatus and beam rotation angle detecting method
AssigneeCanon Kabushiki Kaisha
InventorKenichi Kataoka
Life of this patent
Estimating the term…
Abstract
A beam rotation angle detecting apparatus includes a light receiving portion for detecting the incidence positions of at least two beams moving on concentric circles while describing a circle or an arc, and an arithmetic system for calculating and outputting the angle between a straight line linking at least two incidence positions detected by the light receiving portion together and a predetermined reference line.
Claims31
A rotation detecting apparatus comprising:
- two members rotatable relative to each other, at least one of said two members forming on the other member at least two beams moving on concentric circles while forming a track as a circle or an arc in conformity with a relative rotation of said two members;
- a light receiving portion provided on said other member, said light receiving portion detecting incidence positions of said at least two beams;
- and
- an arithmetic system for calculating angle information respectively corresponding to at least two incidence positions selected from among a plurality of light incidence positions detected by said light receiving portion, calculating corrected angle information in which a decentered amount of a beam is corrected by adding the calculated angle information, calculating and outputting the angle between a straight line linking together at least two incidence positions detected by said light receiving portion and a predetermined reference line based on the calculation results, and detecting information concerning the relative rotation of said two members based on the output angle.
1 more element
A rotation detection apparatus comprising:
- a first member and a second member disposed rotatable relative to each other;
- a light source fixed with respect to the first member;
- light deflection means provided on the second member, for deflecting a beam from the light source into at least two directions in accordance with relative rotation with respect to the first member, and forming two beams of which illuminating points rotate on concentric circles to form a circle or an arc;
- a ring-like sensor which is provided on the first member and receives the two beams;
- and
- arithmetic means which calculates rotation angles of two beams, wherein a decentered amount between a rotation center of the two beams and a center of the ring-like sensor is corrected.
3 more elements
A rotation detection apparatus comprising:
- a first member and a second member disposed rotatable relative to each other;
- a light source fixed with respect to the first member;
- light deflection means provided on the second member, for deflecting into at least two directions a beam from the light source in accordance with relative rotation with respect to the first member, and forming two beams on which illuminating points rotate on concentric circles to form a circle or an arc;
- a two-dimensional position sensor which is provided on the first member, receives the two beams, and detects an incident position;
- and
- arithmetic means which calculates an angle formed between a straight line linking together two incident positions of the two beams on the two-dimensional position sensor and a predetermined reference line.
3 more elements
Dependencies are inferred from the claim text.