Abstract: An apparatus for driving a printhead has a timer, a power supply, and a controller. The power supply applies a drive voltage to the printhead to eject ink drops from the printhead. The timer counts an elapsed time during which the printhead does not eject ink drops. The controller performs an ejection test where the drive voltage drives the printhead a plurality of times to eject a plurality of ink drops. The controller drives the power supply to increase the drive voltage in accordance with a length of the elapsed time. The ejection test is performed at a predetermined length of the elapsed time, the drive voltage and the predetermined length of the elapsed time are selected in accordance with a decrease in an ejection speed of the ink drops. The controller controls the drive voltage such that the surface of meniscus of ink in the orifice is subjected to fine vibration before the ink drop is ejected.

Abstract: A method of cleaning is used for cleaning a print head used in an ink type recording apparatus. The head cleaning operation includes a suction operation in which a head cleaning mechanism performs suction of the tips of ink nozzles and an ejection operation in which ink is ejected through the ink nozzles. A first cleaning operation is performed if the print head is cleaned for the first time after the power-up of the recording apparatus. A second cleaning operation is performed if the print head has been cleaned at least one time after the power-up of the recording apparatus. The first operation includes a combination of cleaning conditions and the second operation includes a combination of cleaning conditions different from the first cleaning operation.

Abstract: An impact printer has a print head in which demagnetizing coils are embedded in a filling compound. A resistor or Zener diode is connected in series between the print head and the printer's frame ground, to prevent current flow through the filling compound from causing corrosion of the demagnetizing coils, while permitting discharge of static charge from the print head to ground.

Abstract: In a protective circuit for a printer driver energized from a drive power supply, and associated with a control circuit for controlling the current supply to the printer driver, and connected to a power supply, a first circuit detects a malfunction of the control circuit with a first predetermined time T1 and resets the control circuit, and a second circuit detects a breakdown of the motor drive transistor with a second predetermined time T2 longer than the first predetermined time, and interrupts an input power supply.

Abstract: A method and apparatus prevents the overheating of a line feed motor used in a printer. First and second timers are respectively provided to measure first and second time intervals. The second time interval includes a cessation period in which the line feed motor is not driven to allow for heat dissipation of the line feed motor. At the end of the first time interval, a determination is made as to whether the number of line feed pulses during the first time interval exceeds a predetermined limit. If the number of line feed pulses does not exceed the predetermined limit, the first time is reactivated. If the number of line feed pulses does exceed the predetermined limit, then the second timer is activated to allow for heat dissipation of the line feed motor.

Abstract: A printing system for a dot printer for printing matrix patterns in the form of aggregated dots which consist of orthogonal rows and columns, has a first memory having first and second memory areas for storing pattern data corresponding to the rows and columns of the dot matrix patterns. The data corresponding to successive columns of each one of the dot matrix patterns are stored in the first memory area and numerical data specifying a total number of times each respective successive column is to be repeated in the respective pattern are stored in the second memory area. A second memory temporarily stores the dot matrix patterns specified by the pattern data and a control means causes the dot matrix patterns to be generated in the second memory in accordance with the pattern data stored in the first memory.