Abstract: An electronic article surveillance tag which is responsive to forces applied to the tag's housing. The tag has a piezoelectric film which is attached to the tag housing in such a way that forces which are applied to the tag housing are mechanically coupled to the piezoelectric film. The piezoelectric film generates a voltage which is proportional to the forces mechanically coupled thereto. An alarm detecting means compares the voltage generated by the piezoelectric film with a predetermined reference voltage, and initiates an audible alarm when the voltage generated exceeds the predetermined reference voltage.

Abstract: A tag for an electronic article surveillance system which includes a circuit means for reradiating a predetermined tag signal and voltage dependent means in circuit with the circuit means. The voltage dependent means has a capacitance which can be varied with a change in voltage to selectively enable the circuit means and disable the circuit means from being able to reradiate the predetermined tag signal.

Abstract: A resonant tag for an article surveillance system comprising a voltage dependent capacitance means whose capacitance can be varied with changes in voltage to selectively provide one or more resonant frequencies for the resonant tag.

Abstract: An electrostatic tag formed from an antenna and a capacitor is disclosed. The capacitor has a charge which changes from a first charge value to a second charge value when the voltage across the capacitor reaches a first threshold value and from the second charge value to the first charge value when the voltage reaches a second threshold value. The capacitor has a dielectric which changes from a first to second dielectric value and from the second to first dielectric value at the first and second voltage thresholds. The capacitor plates also are extended beyond the dielectric to form the antenna of the tag. The tag is used in an electronic article surveillance system which generates an electrostatic field which causes one or the other of the threshold voltages to be exceeded when a tag is exposed to the field. This results in a charge change in the capacitor and a detectable electrostatic pulse is generated.

Abstract: A theft detection tag is formed from first and second sections which define a loop for receipt of an article part and which are connected by a coupling adapted to be quickly activated so as to change the loop and thereby permit quick attachment and release of the tag and article. In a first form of the tag, the first tag section includes a body having an upper end and the second tag section includes wedge means movable within the body to form the loop with the upper body end. In a second form of the tag, the first section includes a flexible member having at one end teeth and the second member includes a body with a channel for receiving the one end of the flexible member.