Optical encoder system and method
AssigneeMichael Naor
InventorMichael NAOR
Life of this patent
Estimating the term…
Abstract
An improved optical encoder uses an optical pick-up unit that provides for degrees of freedom in the tracking and focus axes that are unavailable in conventional optical encoders thereby improving the encoders' performance. In an embodiment the encoder employs an optical disc marked with pits and lands which may be arranged in a spiral pattern. The optical disc is mounted on the shaft whose motion is to be monitored by the optical encoder. The encoder may be arranged to read the markings on the optical disc using the three-beam pickup method.
Claims30
An optical encoder, comprising:
- a light focusing element;
- a light detector that receives light from a substrate containing markings via the light focusing element and converts the received light into at least one electrical signal;
- a servomechanism that adjusts a position of the light focusing element based on the at least one electrical signal;
- and
- a processor receiving the at least one electrical signal and adapted to report motion of the substrate based on the received at least one electrical signal.
An optical encoder, comprising:
- an optical disc mounted on a shaft, the optical disc containing pit and land markings;
- an optical pickup unit for an optical disc that receives light from the optical disc and supplies as an output an electrical signal representative of the received light, comprising:
- a reading head objective lens, and
- dynamic steering actuators that control the focus and tracking of the reading head objective lens;
- a processor that receives as an input the electrical signal from the optical pickup unit and reports motion of the substrate based on the received at least one electrical signal.
A method for use in an optical encoder comprising:
- a light focusing element;
- a light detector that receives light from a substrate containing markings via the light focusing element and converts the received light into at least one electrical signal;
- and
- a servomechanism adapted to adjust a position of the light focusing element based on the at least one electrical signal;
- the method comprising:
- responsive to the at least one electrical signal, adjusting the position of the light focusing element;
- and
- providing an electrical indication of motion of the substrate, the motion being determined based on the received at least one electrical signal.
Dependencies are inferred from the claim text.