Inkjet printer

1. An inkjet printer including a main body device that performs printing by discharging ink from a plurality of inkjet heads, and ink cartridges detachably mounted on the main body device, the inkjet printer comprising:

a maintenance unit configured to simultaneously perform a maintenance operation on the plurality of inkjet heads;

a storage unit configured to store, for each type of ink discharged from the plurality of inkjet heads, a manufacturing date or a start-of-use date of the ink cartridge, a normal consumption period from the manufacturing date or the start-of-use date of the ink cartridge to a recommended time limit before the expiration date, cycle and strength of a maintenance operation performed by the maintenance unit before the recommended time limit, and cycle and strength of the maintenance operation performed by the maintenance unit after the recommended time limit;

a determination unit configured to determine whether or not the recommended time limit of the ink cartridge has passed, based on the manufacturing date or the start-of-use date and the normal consumption period stored in the storage unit, and an elapsed period from the manufacturing date or the start-of-use date of the ink cartridge;

a maintenance setting value decision unit configured to select and decide, in a case where the determination unit determines that the recommended time limit has passed, the shortest cycle and the strongest strength as maintenance setting values for the maintenance unit configured to simultaneously perform the maintenance operation on the plurality of inkjet heads, from among (i) the cycle and the strength of the maintenance operation performed by the maintenance unit before the recommended time limit stored in the storage unit corresponding to the ink cartridge whose recommended time limit is determined to have not passed by the determination unit, and (ii) the cycle and the strength of the maintenance operation performed by the maintenance unit after the recommended time limit stored in the storage unit corresponding to the ink cartridge whose recommended time limit is determined to have passed by the determination unit; and

a controller configured to cause the maintenance unit to execute the maintenance operation, based on the maintenance setting values decided by the maintenance setting value decision unit.

2. The inkjet printer according to claim 1 , further comprising:

a thermometer that detects use-environment temperature of the inkjet printer; and

a period change unit configured to change the normal consumption period stored in the storage unit, based on the temperature detected by thermometer, and an elapsed time from when the ink cartridge is mounted on the main body device.

3. The inkjet printer according to claim 1 , further comprising:

a correction coefficient storage unit configured to store, for each type of sheet on which the ink is discharged, a correction coefficient of the cycle in association with a correction coefficient of the strength; and

a setting value correction unit configured to extract, from the correction coefficient storage unit, a correction coefficient of the cycle and a correction coefficient of the strength corresponding to the specified type of sheet, and to correct the maintenance setting values decided by the maintenance setting value decision unit with the extracted correction coefficient, wherein

the controller causes the maintenance unit to execute the maintenance operation, based on the maintenance setting values decided by the maintenance setting value decision unit and corrected by the setting value correction unit.