| 摘要 |
PURPOSE:To attempt to enlarge the range of correction by controlling the output of a high-voltage generating circuit by a reference signal when light is spot-irradiated on a material to be measured of a light permeative movable body thereby to measure the reflection and permeation ratio. CONSTITUTION:Light from a luminous source 1 is spot-irradiated on the material to be measured held on the main surface of the movable body 4 such as a light- permeative drum or the like, through an aperture 2, and projected light is received by a photoelectric converting element 6 to obtain an analog signal 9. The signal of permeative light at a reference point is held at a comparison circuit 8 and compared with a signal generated with the rotation of the movable body 4. The output from the comparison circuit 8 is applied to a control circuit 13 and a high voltage from a high voltage generating circuit 12 thereby to control the photo current quantity of the photoelectric current. By the adjustment of spot light due to the aperture 2, the photoelectric conversion can be followed even when the quantity of incident light is greatly increased or decreased, and hence the range of correction can be widened on a large scale. |
