Ink-jet recording apparatus, ink container, and method of filling ink container

An ink-jet recording apparatus comprising:

• at least an ink container that consists of an ink bag containing ink and a case holding said ink bag air-tightly;
• a recording head placed below said ink container and supplied with the ink from said ink bag through an ink supply path,
• said recording head discharging the ink through at least a nozzle by an amount variable in accordance with image data to print an image;
• a case internal pressure adjusting device for adjusting pressure in a room between said ink bag and said case by sucking or sending air from or into said case;
• an ink flow rate predictor that predicts a flow rate of the ink that will flows through said ink supply path in a given time, based on those image data to be used for printing later in the given time, while said recording head is printing the image;
• a temperature sensor for measuring temperature of the ink in said ink container;
• an ink viscosity calculator for calculating a viscosity of the ink based on the measured ink temperature;
• a pressure loss calculator for calculating a pressure loss through said ink supply path based on the predicted flow rate and the calculated viscosity of the ink;
• and
• a control device for controlling said case internal pressure adjusting device based on the calculated pressure loss, so as to keep pressure in said nozzle in a predetermined range.

A method of filling an ink container with ink, wherein said ink container is used for supplying the ink to a recording head of an ink-jet recording apparatus, and consists of an ink bag for containing the ink and a case holding said ink bag air-tightly, said case being provided with an ink port for feeding the ink from said ink bag out of said case, and a connecting portion for connecting said ink container to a pressure control device for controlling pressure in a room between said ink bag and said case, said method comprising steps of:

• connecting said pressure control device to said connecting portion;
• ejecting residuals from said ink bag through said ink port by raising the pressure in said room by use of said pressure control device;
• connecting, thereafter, an ink supply tank to said ink port;
• and
• sucking the ink from said ink supply tank into said ink bag through said ink port by reducing the pressure in said room by use of said air pump.