Floating aperture encoder
AssigneeHewlett-Packard Development Company, L.P.
InventorsSteven E. Soar, Michael A. Viselli
Life of this patent
Estimating the term…
Abstract
An encoder includes a housing, a light source coupled to the housing, and a light sensor coupled to the housing and positioned to receive a light beam from the light source. The encoder also includes a wheel having opaque and transmissive sections which may be positioned to pass through the light beam before it reaches the light sensor. The encoder further includes a floating aperture piece, which defines at least one aperture. The aperture is positioned so that the light beam must pass through it before reaching the light sensor. The floating aperture piece slidably engages the housing while allowing a loose tolerance between a position of the wheel and a position of the housing, thereby substantially eliminating a positioning error between the aperture and the wheel.
Claims16
An encoder, comprising:
- a housing;
- a light source coupled to the housing;
- a light sensor coupled to the housing and positioned to receive a light beam from the light source;
- a wheel having opaque and transmissive sections which may be positioned to pass through the light beam before it reaches the light sensor;
- and
- a floating aperture piece, which defines at least one aperture, wherein:
- the aperture is positioned so that the light beam must pass through it before reaching the light sensor;
- and
- the floating aperture piece slidably engages the housing while allowing a loose tolerance between a position of the wheel and a position of the housing, thereby substantially eliminating a positioning error between the aperture and the wheel.
A method of positioning an encoder housing relative to an encoder wheel mounted on a shaft in order to reduce or eliminate a positioning error, comprising:
- engaging the shaft adjacent to the encoder wheel with a floating aperture piece;
- slidably engaging the floating aperture piece with the encoder housing;
- and
- fixing the encoder housing in position without adjusting a location of the floating aperture piece.
An imaging mechanism, comprising:
- means for media positioning in an imaging zone;
- and
- an encoder, comprising:
- a housing;
- a light source coupled to the housing;
- a light sensor coupled to the housing and positioned to receive a light beam from the light source;
- a wheel having opaque and transmissive sections which may be positioned to pass through the light beam before it reaches the light sensor;
- and
- a floating aperture piece, which defines at least one aperture, wherein:
- the aperture is positioned so that the light beam must pass through it before reaching the light sensor;
- and
- the floating aperture piece slidably engages the housing while allowing a loose tolerance between a position of the wheel and a position of the housing, thereby substantially eliminating a positioning error between the aperture and the wheel.
An encoder, comprising:
- means for positioning an aperture piece relative to an encoder wheel so that a positioning error between the aperture and the encoder wheel is minimized;
- and
- means for slidably positioning an encoder housing including a light source and a light sensor relative to the aperture piece.
Dependencies are inferred from the claim text.