| 摘要 |
<p>1448385 Transferring powder images XEROX CORP 22 Nov 1973 [24 Nov 1972] 54229/73 Heading B6C [Also in Division H1] The transfer of a powder image 10 from an original support 11 (e.g. a xerographic belt) to a transfer member 16 (e.g. a sheet of copy paper) is effected by passing the support and the transfer member through a nip formed between a conductive member (e.g. a roller 12) and a roller electrode 15 which is biased by a constant current source 23 such that the field generated in the region immediately preceding the nip is below air-ionization potential and the field immediately following the nip is above air ionization potential. The roller electrode comprises a conductive core 22 and a layer 21 of an electrically relaxible material which takes long enough to transmit a charge from core 22 to the nip for a non-symmetrical voltage profile to be created about the nip. A "leaky" insulating layer 20 is provided on the relaxible material so that the charge acquired by the outer surface of the roller electrode is dissipated generally within one revolution. A control circuit maintains the current level constant so that the fields at the nip region are held at predetermined levels with respect to the air ionization level.</p> |
