| 摘要 |
PURPOSE:To replenish accurate amounts of an ink and a solvent compensating a consumed ink amount and a volatile solvent loss for the maintenance of an ink density at a constant level in a charge deviation-type ink jet type printer, by detecting the number of ink drops used for type printing and also the surface level of an ink tank. CONSTITUTION:The number of ink drops, which are charged by a charging electrode 4 and used for type printing, among ink drops sprayed from an ink jet 3 is detected by counting the number of charging. If the counted value at a counter 17a reaches 2N, the counter 17a is replaced by a counter 17b and the counting operation is continued. An ink consumption amount determined by the value 2N is replenished into a tank 1 from a subsidiary tank 18 by opening a valve 20. On the other hand, an ink collected by a gutter 7 is returned to a tank 1, but the surface level is lowered by a height corresponding to the volatile loss of a solvent during the recovery period. If the difference is detected by the detecting end 23 of a surface level detector 22, a valve 21 is opened so as to replenish a diluent into the tank 1 from a diluent tank 19. |
