GB1038801A - Improvements in developing electrostatic images - Google Patents

Abstract

1,038,801. Developing electrostatic images. RANK KEROX Ltd. Jan. 2, 1964 [Jan. 4, 1963], No. 232/64. Heading G2H. An apparatus for developing electrostatic images has a member of photoconductive material which serves as a donor member 50, Fig. 2, carrying developer or as a development electrode 90 Fig. 7. A donor member 50, Fig. 2, has a photoconductive layer 62 Fig. 6 (not shown) on an insulating translucent or transparent substrate 63. The layer 62 may be coated with a film forming dielectric material having triboelectric properties to charge toner particles positively or negatively. A plurality of lamps in a light tight box illuminate the layer 62 through slit 72 to render it more conductive when solid area development is required. A potential may be applied to shoe 65 of the same polarity of charged image areas on a photoconductive layer on drum 10. In another embodiment, Fig. 4 (not shown) lamps 81 illuminate the donor 50 before development and is exposed to an infra red lamp 82 after development. Development electrodes 90, Fig. 7, has a translucent or transparent substrate 92 carrying a photoconductive layer 91. A conductive strip 103 is connected to a D.C.power supply 112. An air supply 104 and powder cloud supply 93 are connected to block 96 to effect development of a latent electrostatic image on photoconductive layer 101. The conductivity of electrode 90 is controlled by energizing and de-energizing lamps 108. The lamps are de-energized for line copy and energized for solid area reproduction. In another embodiment Fig. 8 (not shown) developer liquid 110 is pumped by pump 115 through a conduit 116 to flow between electrode 90 and photoconductive layer 101