| 摘要 |
<p>1,186,775. Developing electrostatic images. RANK XEROX Ltd. May 24, 1967 [June 1, 1966], No. 24122/67. Heading G2H. The concentration of toner in developer material is controlled by a photo-cell P1 which in cooperation with a light source L-1 detects the accumulation of toner on a plate 42 across which developer is directed. The plate 42 is a thin glass sheet having a transparent layer of conductive oxide apart from areas 46 and 44. Developer material flows across the plate in the direction of arrow 42, but accumulates on the area 44 which is electrically connected to a supply by a switch 51, 52. The photo-cell P1 is included in a bridge circuit, imbalance of which due to a reduction in the density of the accumulation of toner on the area 44 as a result of toner depletion operates a Schmidt trigger 66 connected to an amplifier 67 which energizes a solenoid 68. Switch S-1 then closes to energize motor M to actuate a device 32 which effects toner replenishment.</p> |
