A PHOSPHOR FIXED-QUANTITY SUPPLYING SYSTEM OF DEVELOPING DEVICE FOR MANUFACTURING A DRY-TYPE ELECTRO-PHOTOGRAPHICAL SCREEN OF CRT

摘要

The present invention provides a phosphor quantitative supply system of a developing device for producing a dry electrophotographic screen of a cathode ray tube.;The phosphor quantitative supply system of the developing apparatus charges the inner surface of the panel 12 on which the volatile conductive film 132 and the photoconductive film 134 are formed with a predetermined electrostatic charge and supplies the shadow mask 16 with a charge latent image of a predetermined arrangement. After exposure through, a dry electrophotographic screen of a cathode ray tube for attaching phosphor powders charged at the discharge electrode 144a in the developing container 142 and sprayed by air pressure at the nozzle 144b in an arrangement structure of the latent charge image thereof. A phosphor supply apparatus for a developing process, comprising: a hopper 148 in which phosphor powder is stored; A load cell 151 supporting the hopper 148 to generate a weight signal according to the weight; By rotating the screw 149 of the tongue powder in the hopper 148 connected to the lower portion of the hopper 148 by the variable speed motor 150, the phosphor powder is transferred to the phosphor supply pipe 147 via the venturi tube 146. Feeding means (146, 149, 150) for feeding; And the controller for controlling the variable speed motor 150 of the feeding means (146, 149, 150) at a relatively low speed when the weight is large, and a relatively high speed when the weight is low, according to the weight signal of the load cell 151 ( 152).;Accordingly, the supply of the phosphor powder can be varied according to the weight of the phosphor powder remaining or newly added to the hopper 148 storing the phosphor powder in the developing step, thereby feeding the quantitative phosphor powder regardless of the pressure. There is an effect that the supply of the phosphor powder and the developing density can be made uniform.