Patent ID: 8882244

Claim:
An image forming apparatus comprising: plural head holders, each head holder holding one or more recording heads, wherein at least one head holder amongst the plural head holders includes plural recording heads which are disposed in an offset manner in a sub scanning direction, and each recording head amongst the plural recording heads includes plural nozzles to discharge liquid droplets, an integrally formed head tank to supply liquid to the recording head, and an open air valve provided at the head tank to expose an inside of the head tank to air; a carriage configured to exchangeably support the plural head holders; a main tank configured to store liquid to be supplied to the head tanks of the plural recording heads; and plural relay members corresponding to the plural recording heads and to the plural head tanks and plural open air valves of the plural recording heads; and an actuator unit provided at an apparatus main body side to drive a selected open air valve amongst the plural open air valves via a corresponding relay member amongst the plural relay members, so that the open air valve exposes the inside of the corresponding head tank to air, wherein each relay member amongst the plural relay members has a length corresponding to the position of the corresponding head tank in the sub scanning direction, and the plural relay members have respective lengths depending on the positions of the corresponding head tanks on the head holder.