GB1398497A - Method of and means for rapid development of electrostatic images - Google Patents

Abstract

1398497 Electrographic liquid development RESEARCH LABORATORIES OF AUSTRALIA PTY Ltd 20 March 1973 [27 March 1972] 13454/73 Heading G2H An electrostatic latent image 37 on the front surface of a recording member 36 is developed, without wetting the rear surface of the member 36, by applying thereto a developer 32 comprising electroscopic marking particles suspended in an insulating carrier liquid by means of a roller 34, and subsequently contacting said front surface with a roller 39 carrying a layer 47 of insulating carrier liquid 44, the roller 39 constituting one of a pair of squeegee rollers 39, 40. The feeds of the developer 32 and the carrier liquid 44 to the rollers 34, 39 respectively, are controlled to maintain a layer 42 or 47 of 1-5 microns thickness of the appropriate liquid on each roller 34, 39. This may be effected in the manner illustrated in Fig. 2 or, as described in another embodiment, Fig. 1 (not shown), by metering each liquid into a separate trough each of which is closed along its bottom by a narrow porous compressed open cell wiper blade of such length that it contacts the whole width of the respective applicator roller which, in this other embodiment, is sited below it and above the front surface of the recording member. Optionally, the rollers 34, 35 may be electrically biased.