Patent ID: 6014079
Filing Date: 2000-01-11
Classification: G08B

Abstract:
A burglar alarm system for an electronic apparatus with a slot arranged to receive a removable interface device or information storage medium, comprising:a radio transmitter unit for insertion into the slot of said electronic apparatus, said radio transmitter unit comprising a casing fitting the slot of said electronic apparatus, a transmitting circuit mounted in said casing, and an on/off switch, said transmitting circuit comprised of an encoder, a radio signal transmitter, a transmitting antenna, and a transmitting control device, said encoder being controlled by said transmitting control device to output a code signal to said radio signal transmitted when said on/off switch is switched on, enabling the code signal to be transmitted into the air by radio by said radio signal transmitter through said transmitting antenna, wherein said on/off switch of said radio transmitter unit is arranged to be switched off when said radio transmitter unit is removed from the slot of said electronic apparatus and switched on when said radio transmitter unit is inserted in the slot of the electronic apparatus; anda radio receiver unit, said radio receiver unit comprising a receiving antenna which receives the code signal from said radio transmitter unit, a decoder which recognizes the code signal received by said receiving antenna, an alarm device, a receiving control unit which drives said alarm device to output an alarm signal when said receiving antenna receives no signal from said radio transmitter unit, and switch means to turn on/off said radio receiver unit.