| 摘要 |
PURPOSE:To hold the output of a photoelectric transducer constant approximately, by controlling a modulator so that the output of the photoelectric transducer becomes constant and leading out a strong beam from a modulator for a part corresponding to black and leading out a weak beam from it for a part corresponding to white. CONSTITUTION:A beam 12 from a laser generator 11 is modulated in an optical modulator 13 in accordance with a voltage applied to the modulator, and a beam 12' is condensed by a lens 17 and is irradiated to a beam splitter 14 and is separated to two beams, and a beam 16 is irradiated onto a material 18 having a picture. The reflected light is converted to an electric signal by a photoelectric transducer 20 and is applied to a modulated signal forming circuit 21. Consequently, such control is performed that a large quantity of beam is emitted from the optical modulator 13 when the picture on the material reflects weak light and a small quantity of beam is emitted from the modulator 13 when the picture is white to reflect strong light, and the beam emitted from the modulator has picture information; and therefore, a beam 15 separated by the beam splitter 14 is used for information recording as it is. |
