| 摘要 |
<p>The device comprises a substrate (3) on which are placed a series of electrodes (1, 2) connected to a high-voltage source (6). Another electrode (8) is formed by a coating deposited on an insulating sheet (7) which is normally rolled. Application of a potential between the electrodes (1, 2) on the one hand and the electrode (8) on the other causes the sheet to unroll, and selective earthing of the electrodes (1, 2) permits controlled rerolling of the sheet (7). In this example, the electrodes (1, 2) are alternated and connected in two series to the voltage source (6). Two sheets attached to two opposite edges of the substrate constitute a roller blind shutter for a camera.</p> |
