GB898043A - Improvements in or relating to image converters - Google Patents

Abstract

898,043. Static electricity. DICK CO., A.B. Jan. 20, 1961 [April 5, 1960], No. 2445/61. Class 35. [Also in Groups XXXVI and XL (b)] In an apparatus, Fig. 2, for recording an image as an electrostatic charge image on a dielectric material 26, the image 31 is formed lineby-line on an array of photo-diodes 20 (see Group XXXVI) constructed as shown in Fig. 1 of a suitably doped and shaped block of semiconductor material 10, the diodes being connected in a circuit 22 and associated with a backing plate 24 for the material so as to control, in accordance with the resistance valve established for each diode, the magnitude of the charge laid down or leaked away from the surface of the material 26. The charge pattern is subsequently rendered visible by dusting and fixing in known manner in apparatus 32 and 34. The photo-diodes may be arranged either as shown in Fig. 3 to control the charge laid down on the dielectric material from a source 42, or as shown in Fig. 4 to control the amount to which a charge laid down in a different position by a source 64 is leaked away. The arrangement of Fig. 4 produces a negative of the image produced by the arrangement of Fig. 3. In Fig. 3 it may be desirable to arrange a conductive path 48 to the tips of the diodes which engage the dielectric material. This may be provided by depositing a conductive film on block 10. An embodiment is described with reference to Fig. 5 (not shown) where the electrostatic charge pattern is formed on an intermediate carrier in the form of a conductive drum with a dielectric surface layer, developed and subsequently transferred to a paper record strip.