| 摘要 |
<p>PURPOSE:To erase an image only by the operation of an applied voltage by providing a specific low dark resistance layer in the single crystal plate of the optical image element. CONSTITUTION:An insulation layer 2 is arranged on the incidence side of the single crystal plate 1 of the optical image element which has sillenate type crystal structure and performs writing operation by using photoconduction effect and electrooptic effect. Further, a low dark resistance layer 7 formed by adding a pentavalent element to a grown layer which has structure of the same kind with the single crystal plate 1 and enables lattice matching by crystal growth is provided on the production side of the crystal plate 1, and transparent electrodes 3 are provided on both sides of the element. When a power source 4 is removed and the transparent electrodes are short-circuited in this constitution, electrons are easily injected into the single crystal plate 1 from the low dark resistance layer 7 having large free carrier density to neutralize a positive charge distribution and to obtain a uniform potential distribution, so the need for blue-light irradiation is eliminated unlike before.</p> |
