Printing apparatus

1. A printing apparatus comprising:

a slot to and from which a memory unit storing permitted usage amount information of ink held in an ink holding unit can be attached and removed; and

a processing unit that carries out a process for updating estimated ink amount information that is information for estimating an amount of the ink in the ink holding unit,

wherein in the case where a first memory unit is attached to the slot, the processing unit carries out a charging process that updates the estimated ink amount information using the permitted usage amount information in the first memory unit; and

in the case where a second memory unit is attached to the slot after the charging process, the processing unit does not carry out the charging process using the second memory unit until a consumed ink amount expressed by the estimated ink amount information exceeds a prescribed threshold, and in the case where the consumed ink amount has exceeded the prescribed threshold, the processing unit carries out the charging process using the second memory unit.

2. The printing apparatus according to claim 1 ,

wherein the processing unit carries out a process for displaying state information of the permitted usage amount information of the memory unit in a first display region of a display unit and carries out a process for displaying state information of the estimated ink amount information updated by the processing unit in a second display region of the display unit.

3. The printing apparatus according to claim 2 ,

wherein the processing unit carries out a process for displaying information expressing that the second memory unit is in a reserved state in the display unit until the consumed ink amount expressed by the estimated ink amount information exceeds the prescribed threshold.

4. The printing apparatus according to claim 3 ,

wherein the processing unit carries out the process for displaying information expressing that the second memory unit is in the reserved state in the first display region of the display unit.

5. The printing apparatus according to claim 3 ,

wherein the processing unit carries out a process for displaying information identifying whether or not a reservation by the second memory unit succeeded in the display unit.

6. The printing apparatus according to claim 2 ,

wherein the processing unit carries out a process for displaying information identifying whether or not the charging process succeeded in the display unit.

7. The printing apparatus according to claim 2 ,

wherein in the case where the memory unit is not attached to the slot, the processing unit displays information expressing that the memory unit is not attached in the display unit.

8. The printing apparatus according to claim 1 , further comprising:

a storage unit that stores a charged flag and a reserved flag,

wherein in the case where the charging process using the first memory unit is carried out, the processing unit sets the charged flag to on; and

in the case where the second memory unit is attached to the slot before the consumed ink amount exceeds the prescribed threshold, the processing unit sets the reserved flag to on.

9. The printing apparatus according to claim 8 ,

wherein in the case where the charging process using the second memory unit is carried out, the processing unit sets the reserved flag to off.

10. The printing apparatus according to claim 1 ,

wherein in the case where the consumed ink amount expressed by the estimated ink amount information exceeds the prescribed threshold in a state where the second memory unit set to a valid state is attached to the slot, the processing unit carries out the charging process using the second memory unit; and

in the case where the consumed ink amount expressed by the estimated ink amount information exceeds the prescribed threshold in a state where the second memory unit set to an invalid state is attached to the slot, the processing unit does not carry out the charging process using the second memory unit.

11. The printing apparatus according to claim 1 ,

wherein the ink holding unit is an ink tank that can be filled with ink from the exterior.

12. The printing apparatus according to claim 11 ,

wherein the ink tank is a tank that can be filled with ink from an ink refill receptacle; and

the memory unit is packaged with the ink refill receptacle.

13. The printing apparatus according to claim 1 ,

wherein in the case where the charging process using the memory unit is carried out, the processing unit sets the memory unit to an invalid state.

14. The printing apparatus according to claim 1 ,

wherein the processing unit carries out a process for writing the estimated ink amount information as backup information into a region, of storage regions in the first memory unit, that is different from a region in which the permitted usage amount information is stored, after the charging process using the first memory unit.

15. The printing apparatus according to claim 14 ,

wherein in the case where the first memory unit that is attached to the slot is removed and it is detected that the second memory unit is attached to the slot, the processing unit carries out a process for writing the estimated ink amount information as backup information into a region, of storage regions in the second memory unit, that is different from a region in which the permitted usage amount information is stored.

16. The printing apparatus according to claim 15 ,

wherein in the case where the charging process using the memory unit is carried out, the processing unit sets the memory unit to an invalid state by writing invalidating data into a region, of storage regions in the memory unit, in which the permitted usage amount information is stored.

17. The printing apparatus according to claim 14 , further comprising:

a storage unit that stores the estimated ink amount information, wherein the backup information is information used to restore the estimated ink amount information in the case where an error has arisen in the estimated ink amount information in the storage unit.

18. The printing apparatus according to claim 13 ,

wherein the processing unit carries out a process for displaying information expressing that the memory unit becomes invalid in the first display region.

19. A printing apparatus comprising:

a slot to and from which a memory unit storing permitted usage amount information of ink held in an ink holding unit can be attached and removed; and

a processing unit that carries out a process for updating estimated ink amount information that is information for estimating an amount of the ink in the ink holding unit,

wherein in the case where a first memory unit is attached to the slot, the processing unit carries out a charging process that updates the estimated ink amount information using the permitted usage amount information in the first memory unit;

in the case where a second memory unit is attached to the slot after the charging process, the processing unit does not carry out the charging process using the second memory unit until a consumed ink amount expressed by the estimated ink amount information exceeds a prescribed threshold, and in the case where the consumed ink amount exceeds the prescribed threshold, the processing unit carries out the charging process using the second memory unit; and

the processing unit carries out a process for displaying information expressing that the second memory unit is in a reserved state in the display unit until the consumed ink amount expressed by the estimated ink amount information exceeds the prescribed threshold.