| 摘要 |
<p>A cartridge (1) for an injection device carries a code represented by a number of bars (2, 3, 4, 5) mainly perpendicular to the axis of the cartridge. The bars (2, 3, 4, 5) are mainly transparent and are each along its whole length provided with an optical grating which diffracts and reflects light impinging the surface carrying the code so that a minor part of this light is reflected from the surface of the bar as a set of light beams of which beams at least one is detected for the indication of the presence of the bar when said bar passes a reading light field. The reflections from the bars may be interpreted as representing '1's and '0's in a binary code.</p> |
