Portable electronic device, security system and method for determining allowable operating range of portable electronic device

A security system having a portable electronic device connected by radio with an item as a possession other than the portable electronic device owned by an owner of the portable electronic device, the portable electronic device comprising:

• a registering unit for registering item information for specifying the item in advance in memory;
• a judging unit for judging, based on the presence or absence of a signal from the item, whether an item specified by the registered item information can communicate with the portable electronic device or not when an event is generated in the portable electronic device;
• and
• an operating range determining unit for allowing a normal operation of the portable electronic device in response to an external access when the judging unit judges that the item can communicate with the portable electronic device, and for limiting the operating range of the portable electronic device in response to an external access when the judging unit judges that the item can not communicate with the portable electronic device.

A security system having a portable electronic device connected by radio with an item as a possession other than the portable electronic device owned by an owner of the portable electronic device, wherein:

• the item includes a function for enhancing a security;
• and
• the portable electronic device,
• judges, based on the presence or absence of a signal from the item, whether an item specified by the registered item information can communicate with the portable electronic device or not when an event is generated in the portable electronic device, and
• performs so as to enhance the security of the portable electronic device by using a function for improving the security provided in the item when it is judged that the item can communicate with the portable electronic device.

An allowable operating range determining method of portable electronic device radio communicating with an item as a possession other than the portable electronic device owned by an owner of the portable electronic device, the allowable operating range determining method comprising:

• registering item information to specify the item in advance in memory;
• judging, based on the presence or absence of a signal from the item, whether an item specified by the registered item information can communicate with the portable electronic device or not when an event is generated in the portable electronic device;
• and
• allowing a normal operation of the portable electronic device in response to an external access when it is judged that the item can communicate with the portable electronic device, and limiting the operating range of the portable electronic device in response to an external access when it is judged that the item can not communicate with the portable electronic device.