Printing apparatus and its control method, and expendable attached to printing apparatus and having memory

A printing apparatus comprising:

• detaching/attaching means for detaching or attaching an expendable unit having a recording agent and a memory capable of setting a locking state for inhibiting data writing with respect to a plurality of memory areas in the memory, said a plurality of memory areas including a first memory area storing data concerning a use state of the expendable unit a second memory area storing data concerning a use state of the recording agent and a setting area storing data for setting inhibition/permission of writing with respect to the first and second memory areas;
• detection means for detecting a state of the expendable unit and a state of the recording agent;
• write means for writing a result detected by said detection means to the memory;
• and
• locking state control means for controlling the locking state of the first memory area on the basis of the status of said expendable unit detected by detection means and controlling the locking state of the second memory area on the basis of the use status of the recording agent detected by said detection means.

A method of controlling a printing apparatus having detaching/attaching means for detaching or attaching an expendable unit having a recording agent and a memory, capable of setting a locking state for inhibiting data writing with respect to a plurality of memory areas in the memory, said a plurality of memory areas including a first memory area storing data concerning a initial use state of the expendable unit, a second memory area storing data concerning a use state of the recording agent and a setting area storing data for setting inhibition/permission of writing with respect to the first and the second memory areas, comprising the steps of:

• the detection step of detecting a use state of the expendable unit and a use state of the recording agent;
• the write step of writing the result detected in said detection step to the memory;
• and
• the locking state control step of controlling a locking state of the first memory area on the basis of the initial use status of the expendable unit detected in said detection step and controlling a locking state of the second memory area on the basis of the use sate of the recording agent detected in said detection step.

A memory unit provided to an expendable unit which can be detachably attached to a printing apparatus, said memory unit comprising:

• a first memory area to store data that concerns an initial use state of the expendable unit;
• and
• a second memory area to store data that concerns a use state of a recording agent of the expendable unit;
• a third memory area to store data for determining inhibition/permission of writing with respect to said first memory area and the second memory area.