GB1464863A - Production of electrostatic images - Google Patents

Abstract

1464863 Image converter tubes AGFAGEVAERT 8 May 1974 [21 May 1973] 24167/73 Heading H1D An electron discharge image in an evacuated envelop-produced, for example, by the incidence of an X-ray, ultra-violet, visible, or infrared image, corresponding to scanned information, on a photocathode 50-is recorded as an electrostatic charge image by accelerating it through a channel electron multiplier 51 on to the inner surface of a conductive pin matrix 56 forming part of the envelope, to be transferred thereby to the outer side of the envelope, which at the exterior ends of the pins contacts, or is in close proximity to, an insulating surface of a receiving material which is moved in synchronism with the information scanning. The channel multiplier is mounted by members 60 in close proximity to the lead or uranium photocathode 50, to obviate the need for focusing elements, and may have its channels tilted at an angle of up to 10 degrees with respect to the normal to the photocathode surface, to increase multiplication. The photocathode may contact a fluorescent screen (63, Fig. 4, not shown), sensitive to an incident X-ray, gamma ray, beta ray, or neutron image. A modified arrangement (Fig. 2, not shown), for document reproduction employs a strip photocathode 36, a multiplier having a single row of channels 35, and a single row of pins 33, the charge pattern being produced line-wise by progressive line-wise exposure of the photocathode with visible light. A variety of known methods for effecting the development of the electrostatic charge pattern are referred to.