| 摘要 |
PURPOSE:To reduce a noize of the picture signal by making the F number of the lens system a value smaller than the proper value, and also attenuating a light beam which has passed through this lens system, to the proper exposure value by means of the filter. CONSTITUTION:A reflected ray from the original 2 is made incident to the solid image sensor 5 through the filter 10 and the lens system 4. The lens system 4 has the F number which is smaller than the proper F number. And, the exposure amount which has increased by using this lens system 4 is attenuated by the filter 10. Accordingly, since the F number of the lens system 4 has been made small, a noise of the picture signal caused by dirt of the lens system, etc. can be reduced. |
