Ink jet recording apparatus and ink end judging method executed in the same

An ink jet recording apparatus comprising:

• a recording head, which ejects ink drops;
• a plurality of ink cartridges detachably mounted on the recording head to supply ink thereto, each associated with at least one color of ink;
• a consumed ink amount counter, which counts a consumed ink amount in each ink cartridge;
• a verifier, which adds a count value, when the counted consumed ink amount of one ink cartridge reaches a first value indicating an ink end state, to the counted consumed ink amounts of any other ink cartridges, in order to obtain verification count values;
• a determinant, which judges, when at least one of the verification count values reaches the first value, that the ink cartridge in which the verification count value reaches the first value is in the ink end state.

A method of judging an ink end state of at least one of ink cartridges detachably mounted on a recording head incorporated in an ink jet recording apparatus, comprising the steps of:

• counting a consumed ink amount in each ink cartridge;
• adding a count value, when the counted consumed ink amount of one ink cartridge reaches a first value indicating the ink end state, to the counted consumed ink amounts of any other ink cartridges, in order to obtain verification count values;
• and
• judging, when at least one of the verification count values reaches a second value which is less than the first value, that the ink cartridge in which the verification count value reaches the second value is in the ink end state.

A method of judging an ink end state of at least one of ink cartridges detachably mounted on a recording head incorporated in an ink jet recording apparatus, comprising the steps of:

• counting a consumed ink amount in each ink cartridge;
• adding a count value, when the counted consumed ink amount of one ink cartridge reaches a first value indicating an ink end state, to the counted consumed ink amounts of any other ink cartridges, in order to obtain verification count values;
• and
• judging, when at least one of the verification count values reaches the first value, that the ink cartridge in which the verification count value reaches the first value is in the ink end state.