| 摘要 |
PURPOSE:To make it possible to simply detect the shift of the speed difference between ink droplets, by detecting the shift of a charged droplet arrival time up to the detection electrode between heads by added output obtained by adding the detection outputs of the charged droplets of the heads. CONSTITUTION:When charge voltage is alternately applied to charge electrodes, for example, of Y and M of a recording head 4 and times Y, M reaching a detection electrode after charging coincide provisionally, the output voltage of the detection electrode comes to output almost only comprising a DC component because both outputs are alternately compensated to each other as shown by detection output 1. Detection output is cut in an implifier 23 by a condenser C and not transmitted to the side CPU. When the time reaching the detection electrode after charging becomes long as compared with M if the ink pressure of M is lowered, detection output is outputted as shown by detection output 2 and an AC component passes through the condenser C to be transmitted to CPU. By this method, the speed difference of ink droplets between two heads can be detected. |
