US Patent 7581810 Inkjet recording apparatus and maintenance method thereof

For a recording apparatus capable of supplying a plurality of different color inks to a plurality of recording element substrates, when a condition for performing maintenance on a first recording element substrate is met, it is determined whether or not to perform maintenance on a second recording element substrate according to how close the second recording element substrate is to meeting the condition. Since maintenance is performed on the first and second recording element substrates in such a manner, unnecessary maintenance operations will be prevented from being carried out multiple times within a short period of time. Accordingly, the total amount of time required for maintenance is reduced.