Image forming apparatus

A method for controlling servicing of a recording head included in an image forming apparatus comprising:

• the recording head having a nozzle surface in which nozzles to eject liquid droplets in a horizontal direction or a direction slanted from the horizontal direction are formed, the nozzle surface being disposed in a vertical direction or a direction slanted from the vertical direction;
• a head tank to supply liquid to the recording head;
• a suction cap to cap the nozzle surface of the recording head;
• a suction member connected to the suction cap to suck out liquid from the nozzles by the suction cap;
• a valve member to open or close a sealed space formed by capping the nozzle surface with the suction cap to atmosphere;
• a liquid supplier to supply the liquid to the head tank and return the liquid from the head tank;
• and
• a control unit to control the servicing of the recording head,
• the method comprising the steps of:
• sucking out liquid from the nozzles by capping the nozzle surface with the suction cap and driving the suction member;
• pressurizing the head tank by supplying the liquid using the liquid supplier after the sucking step;
• opening the sealed space to atmosphere using the valve member;
• discharging liquid remaining in the suction cap using the suction member after the opening of the sealed space to atmosphere;
• forming negative pressure in the head tank by returning the liquid from the head tank using the liquid supplier after the discharging step;
• and
• removing the suction cap from the nozzle surface after the step of forming negative pressure in the head tank.