| 摘要 |
PURPOSE:To solve the problem of noises of a cooling fan and enable wasteful electric power consumption to be suppressed, by setting a printing-controlling circuit into the state of waiting for reception by a power source voltage for a data source when waiting for reception of a printing command, and supplying a printing mechanism with a voltage of a main power source in response to the printing command. CONSTITUTION:When a printing command is not supplied from a personal computer 2, both switching circuits 11, 12 are turned OFF, so that no voltage is supplied from a transformer 6 to a printing-controlling circuit 7 or a printing mechanism 8. On the other hand, a power source voltage is supplied from the personal computer 2 to the printing-controlling circuit 7 to set the latter into the state of waiting for reception of a printing command, while the printing mechanism 8 is not supplied with any source power. Therefore, electric power is not wastefully consumed, it is unnecessary to rotate a cooling fan, and a noise problem is solved. When a printing command from a personal computer 2 at the other end of a communication line is received, a power source switching command is supplied from the printing-controlling circuit 7 to a power source controlling circuit 13, the switching circuits 11, 12 are turned ON by an output from the circuit 13, and a power source voltage is supplied from the transformer 6 to the circuit 7 and the mechanism 8. |
