| 摘要 |
<p>The sheet-holder has an electrode-supporting base, e.g. of rigid PVC, polyethylene or glass-reinforced epoxy and phenolic resins, with the electrodes connected in two sets. Electrical potential is applied to the electrodes to develop an electrostatic field adjacent the surface of the base and electrostatically attract a sheet to the surface. A cover plate over the electrodes is a thin sheet of semiconductor material which is stable under light when conductive and which has a bulk resistivity of no more than 1015 ohm- cms. A charge induced by the electrodes dissipates immediately when the electrode potential is removed in order to release the sheet. The third electrode is pref. PVC.</p> |
