Patent ID: 6733195
Filing Date: 2004-05-11
Classification: B41J

Abstract:
A head drive circuit for an impact dot printer which performs printing by driving a print wire, comprising:a DC power source for supplying a power source voltage; a head coil; a switching element which is on/off controlled to apply the power source voltage to the head coil for a predetermined time period; a voltage regulator for converting an input voltage having a value higher than the power source voltage into an output voltage having a value as substantially same as the power source voltage; a voltage introducer for inputting an inductive voltage, generated in the head coil when the switching element is turned off, into the voltage regulator as the input voltage; a voltage returner for feeding back the output voltage of the voltage regulator to the DC power source; a charger, which performs a first charging operation in which a condenser provided with the voltage regulator is initially charged when the DC power source is turned on, and a second charging operation in which the condenser is supplementally charged while the DC power source is turned on, wherein the condenser smoothes the input voltage of the voltage regulator, and a power saving mode in which the DC power source is temporarily turned off even though a main power for the impact dot printer is turned on, wherein the charger charges the condenser when the main power is turned on, and when the power saving mode is deactivated while the main power is turned on.