Ink bubble removal from ink jet printer

An ink jet printer comprising:

• a carriage movable on a body frame, including a plurality of printing heads, each printing head printing data on a printing medium by jetting ink through a nozzle;
• a plurality of ink tanks, each ink tank storing the ink to be supplied to a corresponding printing head;
• and
• a plurality of ink paths, each ink path supplying the ink from the ink tank to the corresponding printing head,
• wherein for each printing head the carriage has a bubble collecting chamber that collects bubbles produced in the respective ink path, a discharge path which is communicated with the bubble collecting chamber, and an opening and closing valve which is arranged in the discharge path and is normally closed, wherein each discharge path has a different bubble discharge resistance when bubbles collected in the bubble collecting chamber are discharged and
• wherein the body frame has an opening and closing member for opening and closing the opening and closing valve, a discharge cap which can be brought into tight contact with the carriage to cover an outlet of the discharge path so that an airtight space communicated with the outlet is defined between the discharge cap and the carriage, and a suction member that sucts air from the airtight space;
• wherein discharge of bubbles by the suction member is independently implemented for each printing head.