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US 5,179,268 AGranted
Apparatus for detecting inclination of an optical card
AssigneeOmron Tateisi Electronic Co.
InventorsKouji Nitto, Yoshihito Koshiba, Kazuo Tsuboi, Keiichi Tsutsui, Koji Sogo
Life of this patent
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Abstract
The present invention relates to an optical card reader that detects any relative inclination of the card by measuring the relative motion of the optical tracks themselves. The optical card reader comprises a card holding portion, an optical head having the ability follow data tracks on the optical card, and a detector that measures the angle of inclination of the optical card from a tracking signal generated from a one-dimensional relative movement of the card holder and the optical card.
Claims6
An optical card inclination detecting apparatus comprising:
- a card holder having a card holding portion for holding an optical card which is provided on a surface thereof with a plurality of parallel information containing tracks;
- a card transfer means for moving said card holder in opposing directions which are substantially parallel to the direction of said tracks provided on a card held by said card holding portion;
- an optical head, supported to be movable in a direction perpendicular to the movement direction of said card holder and comprising:
- a light projecting optical system for projecting light onto said surface of said card, photodetecting means for receiving light reflected from said surface of said card and for generating a tracking error signal on the basis of a signal representing the received light, the tracking error signal representing a deviation of the light projected onto a card from a track on the card, and an actuator means for adjusting said light projecting optical system for tracking control;
- servo-control means responsive to said tracking error signal for producing a tracking drive signal based on said tracking error signal to drive said actuator means such that the light projected onto said card follows along the track provided on said card;
- means for detecting said tracking drive signal produced in said servo-control means while said card holder is being moved in at least one of said opposing directions by said card transfer means and said servo-control means is executing a tracking operation;
- and
- means for generating a signal representing a change in said tracking drive signal detected by said detecting means, said change in the tracking drive signal representing an angle of inclination of said card held by said card holder relative to a direction of motion of said card holder.
5 more elements
A method for detecting optical card inclination comprising the steps of:
- holding an optical card with a card holder, said card having on a surface thereof a plurality of parallel information containing tracks;
- moving said holder relative to an optical head in opposing directions which are substantially parallel to the direction of said tracks provided on said held card;
- using said optical head to:
- project light onto said surface of said card, receive light reflected from said surface of said card;
- generate a tracking error signal on the basis of a signal representing the received light, the tracking error signal representing a deviation of the light projected onto a card from a track on the card, and adjust said projected light for tracking control;
- producing a tracking drive signal based on said tracking error signal which is used by said optical head to adjust said projected light such that the light projected onto said card follows along the track provided on said card;
- detecting said tracking drive signal produced while said card is being moved in at least one of said opposing directions and said projected light is being adjusted by said optical head based on said tracking drive signal;
- and
- generating a signal representing a change in said tracking drive signal, said change in the tracking drive signal representing an angle of inclination of a card held by said card holder relative to a direction of motion in said opposing directions.
6 more elements
Dependencies are inferred from the claim text.