PURPOSE: To simplify a structure by providing a sequential judgment section sequentially judging the key ridge information read by a detecting means and recognizing a key ridge shape, and providing a controller outputting a command to an unlocking device when the judgment section judges the normal key ridge.
CONSTITUTION: When a key 1 is inserted into a key barrel 2 through a key hole 2a, the side face 1c of the key 1 enters between a light emitting element 3 and a light receiving element 4. Light is shielded by the quantity corresponding to the width (a) of the key 1, then signals for the light shielded quantities changed in response to the widths (b), (c)... are obtained sequentially, and the key ridge information which is electrical signals corresponding to heights of key ridges is obtained. A judgment section sequentially judges the key ridge information in the order of reading, and it outputs an unlocking command to a controller when the key ridge information coincides with the previously registered key ridge information. The controller outputs an unlocking action signal to an unlocking device.
AOKI HISASHI
MIZUNO YOSHIYUKI
MIZUNO HIROMITSU
