There is described an array of charging electrodes such as are used in ink jet printers. At least portions of the exposed surfaces of such electrodes, used to charge passing ink drops, are overcoated with a continuous coating substantially free of cracks of a semiconductive material doped to have a resistance, at room temperature, when measured transverse to the electrode, of between 10.sup.8 and 10.sup.11 ohms, such material being essentially insoluble in the ink.
A method of synchronizing digitized audio information and digitized picture information establishes a reference time base based on timecodes included with the audio and picture information. The reference time base may be used to synchronize output between a digitized source and one which may be digitized or undigitized.
