Liquid droplet jetting apparatus and image forming apparatus

An image forming apparatus comprising:

• a liquid droplet jetting apparatus comprising:
• a jetting unit equipped with plural head modules, each of the plural head modules including plural nozzles that jet liquid droplets and plural pressure chambers that jet a supplied liquid from the nozzles in response to applied pressure;
• a supply channel equipped with plural branching channels that supply, to each of the plural head modules, liquid that is stored in a storage chamber that stores the liquid;
• circulation limiting units that are disposed in each of the plural branching channels, that allow circulation of the liquid in a direction from the storage chamber to the plural head modules and that limit circulation of the liquid in an opposite direction of the circulating direction;
• liquid storage units that are disposed between the circulation limiting units in each of the plural branching channels and the plural head modules, that store the liquid, and whose volumes change because of external force;
• and
• external force applying units that apply the external force to the liquid storage units such that the volumes of the liquid storage units become smaller, and that cause liquid droplets to be jetted from the nozzles.