| 摘要 |
PURPOSE:To eliminate the necessity of increasing the number of connector pins by setting the voltage of a power supply applied to a printer main body mechanism to a value keeping sufficient printing quality being a voltage level value executing division printing processing. CONSTITUTION:A shunt regulator 46 uses the voltage generated in a resistor 42 as reference voltage and controls an inflow current so that the reference voltage becomes a prescribed constant value. The control circuit 22 of a switching regulator 20 receives the control current of the shunt regulator 46 through a photocoupler light emitting element 45/photocoupler light detecting element 23 and makes the contact of a temp. switch 43 at the time of an overheating state to bypass a resistor to control the level of power supply voltage VOUT so as to form the relational expression of the resistance value of (resistance value of resistor 40 + resistance value of resistor 42).reference voltage/resistor 42. The power supply voltage VOUT drops in a heating state but is set to a value equal to or less than a threshold value wherein a printer main body mechanism 2 enters division printing processing ad capable of keeping printing quality. |
