| 摘要 |
PURPOSE:To correct the irregularity of a printing position, by detecting the shift width of the rotary phase of a drum from an ink pulverizing phase and applying correction to charge quantity corresponding to the shift width. CONSTITUTION:In order to suppress a shift amount by half by changing the insert phase of a guard drop, a clock of 2.112MHz receives frequency dividing by a counter 11 to obtain the output of a clock (b) (66kHz) which is, in turn, latched by the output (c) of a drum sensor to make it possible to know the relation between therotary phase of a drum and an internal clock. A signal is selected on the basis of this latch output by a multiplexer 15 and the phase of the guard drop is controlled by a gate circuit 23. Next, the residual shift (corresponding to 1/2 dot) is corrected but, when the output (c) of the drum sensor becomes active (H), a counter 14 begins to count and the count value of the counter 14 is latched at the rising of a signal (d) [output obtained by latching the signal (c) by the clock (b)]. This count value is guided to ROM20 through a multiplexer 18 and a correction amount is fed out to an adder 21 and the deflection quantity of an ink droplet is controlled to correct shift of 1/2 dot or less. |
