Patent ID: 6974202

Claim:
A liquid jet apparatus comprising: a liquid jet head having nozzle openings through which liquid drops are ejected; a liquid storage unit configured to store plural kinds of liquids to be fed to said liquid jet head; a plurality of valve units capable of respectively closing a plurality of liquid feed paths interconnecting said liquid storage unit and said liquid jet head for each kind of said plural kinds of liquids; a capping unit configured to seal a nozzle forming face of said liquid jet head and form a single closed space, said single closed space being able to cover said nozzle openings for said plural kinds of liquids; a negative pressure generation unit configured to exhaust said single closed space formed by said capping unit and generate negative pressure in said single closed space; and control means for controlling a switching operation for an open state or a closed state of said plurality of valve units and an exhaust operation for said single closed space by said negative pressure generation unit so as to execute cleaning of said liquid jet head, wherein: said control means has a function for executing a pressure reduction step of putting a valve unit corresponding to a kind of liquid to be cleaned among said plurality of valve units into an open state and simultaneously putting other valve units into a closed state, and in this state, exhausting said single closed space by said negative pressure generation unit and generating a negative pressure state, a totally-closing step, after said pressure reduction step, almost simultaneously with stopping exhausting by said negative pressure generation unit or immediately before stopping exhausting, of switching said valve unit in said open state to said closed state and putting all said plurality of valve units into said closed state, a totally-opening step, after said totally-closing step and after a lapse of a predetermined time, of putting all said plurality of valve units into said open state after said totally-opening step, at a stage that negative pressure remains in said single closed space, a totally-re-closing step of putting all said plurality of valve units into said closed state again and a totally-re-opening step, after said totally-re-closing step and after a lapse of a predetermined time, for putting all said plurality of valve units into said open state again.