US Patent 7273272 Liquid supply device and image forming apparatus

The liquid supply device supplies ejection liquid to a plurality of ejection heads from a liquid tank, and comprises: a supply pipe which connects the liquid tank to the plurality of ejection heads, an upstream end portion of the supply pipe being connected to the liquid tank, a downstream side of the supply pipe being branched into a plurality of branch pipes having different numbers of branches by means of a plurality of ramifying sections, ends of the plurality of branch pipes being respectively connected to the plurality of ejection heads; and a flow path resistance altering device which alters a flow path resistance in at least one of flow paths from the plurality of ramifying sections to the plurality of ejection heads, wherein branch pipes having a relatively small number of branches among the plurality of branch pipes are connected to ejection heads having a relatively high ejection frequency among the plurality of ejection heads.