| 摘要 |
<p>PURPOSE:To measure the amount of dampening water on a plate picture stably with high precision, by splitting light from a light source into two, guiding the reflected light of measurement light projected on the plate picture and reference light to a photoelectric converting element through an optical chopper and alternately through a filter, and processing its output. CONSTITUTION:The white light from the light source 1 is split into two by a half-mirror 8, and the measurement light 3 is guided into an optical fiber tube 4 through a condenser lens 9 and projected on the plate picture 41 through the projection lens 6 of an optical head 5. Its reflected light is guided into the optical fiber tube 4 through a photodetection lens 7 and then converged onto the optical chopper 3 through a condenser lens 12. The reference light 2, on the other hand, is converged onto the optical chopper 13 through an intensity adjusting filter 10. The measurement light passed through the optical chopper 13 and the reflected light is made incident to the photoelectric converting element 19 through a lens 17 and an infrared filter 18 and its output is split again by a signal detecting mechanism 23 to measure the amount of dampening water ont the plate picture 41 from the ratio of the splitting stably with high precision.</p> |
