Patent ID: 7693990

Claim:
A multifunction device being communicatably connected with a control device for executing an application program, the multifunction device performing a device function according to a control command created by the application program, the device function being an appropriate combination of plural elemental functions including a communication function and at least one of an image reading function and an image forming function, wherein: the control command is attached with an access key; and the multifunction device comprises: control command receiving means for receiving the control command from the control device; a criterion storage section for storing criterion in which command type information indicating control command types is associated with information indicating whether an authentication process is necessary or not; determining means for determining, by using the criterion, whether the authentication process is necessary or not for the control command received by the control command receiving means; authentication process means for performing the authentication process by matching the access key with an authentication key stored in advance, the authentication process means performing the authentication process if the determining means determines that the authentication process is necessary; and process execution means for executing a process as instructed by the control command, the process execution means performing the process if the authentication process means determines that authentication is successful, or if the determining means determines that the authentication process is not necessary, further wherein: the access key includes identification information for identifying (a) the application program that created the control command, or (b) a manufacturer of the application program; and the multifunction device comprises: a usage frequency storage section for storing usage frequencies per application program or per manufacturer of the application program; and usage frequency updating means for updating, if the authentication process means determines that the authentication is successful, a usage frequency for the application program or the manufacturer of the application program identified by the identification information included in the access key.