| 摘要 |
1,209,115. Electrostatic recording heads. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. 3 May, 1968 [6 May, 1967], No. 21032/68. Heading G5R. Information is electrostatically recorded on, or erased from, an insulating carrier 2 by an electrode 5 housed in an insulating member 1 having a sharp edge, the electrode being located "upstream" of the edge; and a conducting layer 3, which may be attached to the carrier 2, being located on the side of the carrier remote from the member 1. The electrode is spaced from the edge slightly less than a critical distance d 1 below which charge density varies linearly with the applied voltage. Recording is effected with a D.C. bias of, e.g. 600 V and optionally a H.F. bias voltage. Erasing is effected by applying a H.F. bias voltage. Cleaning.-The member 1 may be oscillated at twice the H.F. bias frequency such that the sharp edge contacts the carrier at the maximum amplitude of the bias. This is said to remove impurities. |
