IMAGE FORMING APPARATUS

PROBLEM TO BE SOLVED: To solve a problem that supply failure occurs due to simultaneous driving of a solution sending pump when supply control to a head tank is performed with a sensor on a carriage.SOLUTION: Ink supply to the head tank 5 is started after an ink consumption from the time when a displacement member 205 which displaces in a reduction direction is detected by a first sensor 251 on the carriage 3 reaches a predetermined amount. During a difference supply time t corresponding to a difference supply amount after the first sensor 251 detects the displacement member 205 which displaces in an increase direction, the solution sending pump 241 is driven to continue filling. If the filling continues, when supply operations from one main tank 10 to two head tanks 5a and 5b conflict with each other, a supply flow rate supplied by the solution sending pumps 241a and 241b is increased more than a supply flow rate supplied by the one solution pump 241a or 241b.