Image forming apparatus and user registration method for allowing restriction of reuse of a login name

1 . An image forming apparatus comprising:

a processing device; and

an input device, wherein the processing device:

registers, in association with a user, a string serving as personal identification information for identifying the user,

determines, in response to a reception of a request for deletion of a registered user, via the input device, based on an attribute imparted to the registered user, whether to forbid reuse of the string associated with the registered user for which the request for deletion is received, the attribute including a period of forbiddance of reuse of the personal identification information,

refuses, in accordance with a result of the determination, a request for registration of the user associated with the string,

withdraws the forbiddance of reuse of the personal identification information according to the personal identification information or another attribute imparted to the user associated with the personal identification information, and

displays a warning message in response to a request for registration of a new user associated with the personal identification information for which the forbiddance of reuse has been withdrawn.

2 . The image forming apparatus according to claim 1 , wherein the attribute further includes at least one of:

a history of user identification performed based on the personal identification information,

a history of an operation performed by the user identified based on the personal identification information, and

a type of the personal identification information.

3 . The image forming apparatus according to claim 1 , wherein, if a block deletion of all registered users is requested, the processing device further permits a reuse with respect to all personal identification information associated with all the registered users.

4 . The image forming apparatus according to claim 1 , wherein the attribute further includes at least one of:

a history of a user identification performed based on the personal identification information,

a history of an operation performed by the user identified based on the personal identification information, and

a manager authority imparted to the user associated with the personal identification information.

5 . A user registration method for an image forming apparatus, the user registration method comprising:

registering, in association with a user, a string serving as personal identification information for identifying the user;

determining, in response to a reception of a request for deletion of a registered user, based on an attribute imparted to the registered user, whether to forbid reuse of the string associated with the registered user for which the request for deletion is received, the attribute including a period of forbiddance of reuse of the personal identification information;

refusing, in accordance with a result of the determination, a request for registration of the user associated with the string;

withdrawing the forbiddance of reuse of the personal identification information according to the personal identification information or another attribute imparted to the user associated with the personal identification information; and

displaying a warning message in response to a request for registration of a new user associated with the personal identification information for which the forbiddance of reuse has been withdrawn.

6 . The image forming apparatus according to claim 1 , wherein the attribute further includes on-registration authentication mode information.

7 . The image forming apparatus according to claim 1 , wherein the processing device further withdraws the forbiddance of reuse of the personal identification information when the period of forbiddance of reuse of the personal identification information has elapsed.

8 . The image forming apparatus according to claim 1 , wherein the warning message displays contents regarding the period of forbiddance of reuse of the personal identification information.

9 . The image forming apparatus according to claim 1 , wherein the attribute further includes a value corresponding to an operational history of the image forming apparatus, and the processing device determines, based on the value, whether to forbid the reuse of the string as a piece of the personal identification information.