Recording apparatus

A recording apparatus comprising:

• a recording head having liquid chamber for storing a liquid and at least one nozzle for discharging liquid;
• a tank for storing liquid which is to be supplied to the recording head;
• a liquid supply path for supplying liquid from the tank to the liquid chamber;
• a supply pump provided in the liquid supply path;
• a parallel supply path which is connected from the tank into the liquid supply path without passing through the supply pump;
• a valve arranged between the tank and the parallel supply path, the valve being configured to switch the tank into either a first state where the tank and the parallel path are connected or a second state where the tank and the parallel path are not connected;
• a liquid return path for returning liquid from the liquid chamber to the tank;
• a return pump provided in the liquid return path;
• and
• a control unit for controlling driving of the supply pump, the return pump and the valve;
• wherein, when liquid is initially to be introduced into the liquid chamber, the control unit is configured, in a first stage, to make the valve into the first state and drive the return pump so as to cause a negative pressure state in the liquid chamber via the liquid return path between the liquid chamber and the tank, and in a second stage after the first stage, to switch the valve into the second state and drive the supply pump to supply liquid from the tank to the liquid chamber.

A recording system comprising a plurality of recording apparatuses comprising:

• a first recording apparatus comprising:
• a first recording head having a first liquid chamber for storing a first liquid and at least one nozzle for discharging liquid;
• a first tank for storing the first liquid which is to be supplied to the first recording head;
• a first liquid supply path for supplying the first liquid from the first tank to the first liquid chamber;
• a first supply pump provided in the first liquid supply path;
• a first liquid return path for returning the first liquid from the first liquid chamber to the first tank;
• and
• a first return pump provided in the first liquid return path;
• and
• a second recording apparatus comprising:
• a second recording head having a second liquid chamber for storing a second liquid and at least one nozzle for discharging liquid;
• a second tank for storing the second liquid which is to be supplied to the second recording head;
• a second liquid supply path for supplying the second liquid from the second tank to the second liquid chamber;
• a second supply pump provided in the second liquid supply path;
• a second liquid return path for returning the second liquid from the second liquid chamber to the second tank;
• and
• a second return pump provided in the second liquid return path;
• a control unit for controlling driving of the supply pumps and the return pumps,
• wherein, when liquid is initially to be introduced into the liquid chambers, the control unit is configured, in a first stage, to drive the return pumps so as to cause a negative pressure state in the liquid chambers via the liquid return paths between the liquid chambers and the tanks, and in a second stage after the first stage, to drive the supply pump to supply liquid from the tanks to the liquid chambers, and
• a first driver motor for driving a group of pumps selected from:
• a supply group of pumps comprising the first and second supply pumps;
• and
• a return group of pumps comprising the first and second return pumps.