| 摘要 |
<p>PURPOSE:To use various films different in form of the mark to perform a correct retrieval, by adjusting the variance of the characteristic of a mark detector. CONSTITUTION:One side ends of guide members 25 and 26 consisting of optical fiber bundles of a mark detector 11 are fitted to respective apertures of a mask 28 of the first block 22, and a length (l) between one end faces of members 25 and 26 is shorter than the length of the mark of a used film. The other ends of members 25 and 26 are inserted to through holes 291 and 292 of the second block 29 and are connected to photoelectric converting members 31 independent of each other through respective filters 30, and their output terminals are connected to a print board 32. The variance of characteristics of members 25 and 26 and members 31 is adjusted by changing the density of filters 30, and thus, output voltages of photoelectric converting members to a constant quantity of the incident light are kept constant.</p> |
