| 摘要 |
PURPOSE:To prevent a faulty action of a head circuit and enable correct recording operation by connecting the same potential line from each power supply to recording head units independently. CONSTITUTION:A GND line of power supply lines extending from a control circuit 1 to a head circuit 2 is separated into a GND line which connects X and Z points of a +5V power supply 3 system and a GND line 57 which connects Y and Z points of a +24V power supply 4 system. Further under this wiring arrangement, these separate lines are commonly connected only at the head circuit 2 or its connector. In the section from head heaters 27 to 30 or from 31 to 34 is energized simultaneously, the potential of Y point is lower than that of Z point on account of an impedance between Z and Y points. However, no change occurs in X point, if it is based on Z point as a reference due to the current between Z and Y points not running to X point. Accordingly the voltage between GND and Vcc of a shift register 10 does not fluctuate regardless of the application of an electric current, thus eliminating the possibility of faulty action. |
