| 摘要 |
PURPOSE:To definitely detect a defective optical unit and to improve productiv ity. CONSTITUTION:The sensitivity of the optical unit is obtained based on the spectral sensitivity of an image sensor 109, the light transmittivity of a filter 107 and the standard value and tolerance of the spectral distribution of a light source 202. The illumination of an original surface irradiated by the optical unit is measured by an illuminometer 204. The range of the output value of the optical unit subject to the inspection is obtained from the sensitivity and illumination. Then the output value of the optical unit is obtained at a prescribed timing by inputting a timing signal to the optical unit. A calculator 207 judges whether or not the output value is included in the range of the output value obtained from the sensitivity and illumination, determines the pass or fail of the optical unit and displays the result on a display part 208. |
