| 摘要 |
<p>PURPOSE:To realize the noncontact type identification card which is extremely low in power consumption and eliminates the need for a start switch, etc., by driving a liquid crystal shutter, which is provided on the internal surface side of a surface plate and turns on and off at all times, with light from a reader and generating characteristic data. CONSTITUTION:The surface plate 1 of the ID card functions as a visible light cutting filter and also functions as a name plate which has a company name, an occupation, an individual name, etc., on the surface, and the liquid crystal shutter 4 formed by stacking a polarizing filter 2 and a liquid crystal plate 3, a retroreflection plate 8, a printed board where a one-chip microcomputer 6 is mounted, and a rear plate are superposed and fixed to form the ID card. When the read light from the card reader 15 is made incident on this card, the light is transmitted through the liquid crystal shutter 4 only while the liquid crystal shutter 4 which is driven according to internal characteristic data is open and then reflected toward the reader 15 by the retroreflection plate 8. Its reflected light is received by the reader to read the characteristic data.</p> |
