| 摘要 |
PURPOSE:To enable removal of written electric-charge images or rewriting of electric-charge images by installing between a crystalline plate and an electron- image producing means, a secondary-electron catching electrode which is located so that it doesn't prevent any electric-charge image from being formed on the mirror surface of the crystalline plate, and a power source which can change a power source used for the electrode of the crystalline plate. CONSTITUTION:In an airtight glass case, a photoelectric screen 5, a focusing electrode 6, a micro-channel plate MCP7, a secondary-electron cathcing electrode 8 and an electrooptic crystalline plate 9 are arranged in that order. The electrode 8 and the plate 9 are placed parallel to each other so that they are spaced at a distance of, for example, 0.5mm.. The front surface of the plate 9 is provided with a transparent crystalline plate electrode 91. A power source (D) works as a power source for the electrode 8. Power sources (E-G), which are the elements of a crystalline-plate-electrode-power source, are used for determining the electric potential of the electrode 91 of the crystalline plate 9, and connected to the electrode 91 by the change-over-operation of a switch 15. |
