| 摘要 |
PURPOSE:To record a record wherein the light and dark of an original are reproduced faithfully at high speed by providing an optical modulator which modulates the intensity of light at extremely fast speed on the optical path of projection. CONSTITUTION:The detected density information of a photodetector 7 is inputted to a controller 9 and the voltage applied to a PLZT modulator 8 from the controller 9 is varied successively according to the light and dark of the original M to vary the intensity of projection light to a photosensitive drum 6 to proper intensity with which an excellent record is obtained. When no voltage is applied to a PLZT plate 10, the rays of light passed through through one polarizing late 11a have only the component of the plane of polarization in a direction shown in figure A and are cut off by the other polarizing plate 11b having a polarization direction as shown in figure B. When a voltage is applied to the PLZT plate 10, the plane of polarization rotates by an angle corresponding to the applied voltage to generate a light component to be passed through the other polarizing plate 11b. |
