| 摘要 |
PURPOSE:To permit a target to be continuously operated by forming it with a sheet having low resistance at the normal temperature and resistance value increased rapidly at a certain temperature or higher to permit the leakage of negative charge produced on the electron beam scanned surface of the target. CONSTITUTION:An pyroerectric vidicon target for picking up thermal images is formed by a sheet or film having high resistance at high temperature to polarize the target with sufficient electrofocusing effect and low resistance at low temperature operation to remove accumulated negative charge by leakage resistance. For materials of the sheet are used, for example, macromolecular substrate having pyroerectric powder material such as PbTiO3 spreaded thereon with a proper mixing ratio or material such as polyvinyl chloride film having resistance value increased at high temperature. Thus the accumulated negative charge can be removed by an electron beam scanning approximately at the normal operating temperature to facilitate the polarization of the target since the high resistance is obtained at high temperature. |
