| 摘要 |
<p>An optical scanner includes a hand-holdable housing having a scanner head for scanning a record medium (RM), a roller (15) engageable with and rotatable by the record medium when scanned by the scanner head, the roller including an optically-sensible marking for use in measuring rotary movement of the roller, a light source illuminating the roller and its marking, an optical sensor (4) for sensing information on the record medium and the marking of the roller, and a control system for periodically energizing the light source during predetermined time periods enabling the optical sensor to sense the marking of the roller during the predetermined time periods, and the information on the record medium during other time periods.</p> |
