| 摘要 |
<p>1293586 Electro-photographic developing apparatus; automatic concentration control CANON K K 5 Nov 1969 [5 Nov 1968] 54246/69 Headings G2H and G3R A pump 3 circulates liquid developer between a reservoir 1, a developing trough 8 and a vessel 9; toner concentrate being siphoned from a container 19 to vessel 9 when the concentration of the liquid falls. As shown, when concentration falls, a detector comprising a lamp 11 and photoconductor 12 energizes an electromagnetic 14 via a transistor circuit, Fig.2 (not shown). This opens a valve 17 to divert incoming liquid down a pipe 18, and closes a duct 16 so that liquid discharged through a pipe 10 produces a negative pressure in vessel 9 which siphons toner concentrate from container 19.</p> |
