Patent ID: 8035478

Claim:
An easy-to-retrofit, electronically controlled door lock system, comprising: a door lock configured to be mounted to a door for locking and unlocking the door in response to an input signal from a key means, the door lock having predetermined inherent functions; and a function expanding device selected from a plurality of function expanding devices each having additional functions other than the predetermined inherent functions of the door lock and each configured to be removably attached to the door lock at the door; wherein the door lock configured to be mounted to the door comprises an authentication unit for authenticating the key means of the door lock, a multi-purpose interface device for removably connecting the function expanding device to the door lock, a multi-purpose interface device control unit for identifying and controlling an operation of the function expanding device, a controller unit for controlling the door lock, and a driving unit for causing the door lock to perform the locking and unlocking under the control of the controller unit; and wherein the multi-purpose interface device control unit identifies the function expanding device connected to the multi-purpose interface device by use of electric characteristics including at least one of a voltage, a frequency and a timing of signals, mechanical characteristics of connector pins, and logical characteristics including a command response.