| 摘要 |
<p>PROBLEM TO BE SOLVED: To limit a shift amount of a half-wave length voltage in continuous driving to a minimum level to always maintain a light quantity constant in terms of a solid scanning type optical shutter using a PLZT as an optical shutter means. SOLUTION: An optical shutter forms an image on a photosensitive body by turning on or off multiple optical shutter elements for printing each consisting of a PLZT and passing the light therethrough when the optical shutter element is turned on. While a printing mode is effective, an electric field is switched to be in a ratio of non-inversion/inversion. Optical shutter elements for monitoring are provided adjacent to the elements for printing. Each optical shutter element for monitoring is driven by being switched between non-inversion and inversion states similarly to the element for printing. At a non-printing mode, a half-wave length voltage of the element for monitoring is measured, then a ratio of non-inversion/inversion of the electric field in the next printing mode is determined.</p> |
