| 摘要 |
PURPOSE:To reduce uneven illumination, by providing an illuminating control plate uniforming the luminous intensity on an objective on an optical path formed between a light source and the objective. CONSTITUTION:To an objective 1 carried toward the arrow A, an illuminated light irradiated from illumination light sources 2, 2 is irradiated on light collecting optical systems 3, 3, the reflected light from the objective 1 is received on a photodetector 5 via an image forming optical system 4 and converted into an electric signal. Between the systems 3, 3 and the objective 1, an optical scattering plate 8 as the luminous intensity controlling plate is arranged. Thus, the illumination pattern without uneven luminous intensity can be obtained on the objective 1, allowing to accurately read character information described on the objective 1. |
