3m Innovative Properties Company

Minnesota Mining and Manufacturing Company

3m Innovative Properties

Anthony Michael Belka

Peter J Zarembo

Thomas J Brace

Ronald David Jesme

Edward D Goff

John E Nelson

William R Weber, Iii

Walter J ReMine

Samuel H Tao

Dennis L Sando

Philip E Edstrom

Mark R Crellin

In general, the invention is directed to techniques for creating and controlling a magnetic field for use with electronic article surveillance (EAS) markers. In particular, the techniques make use of current switching devices to generate a signal having one or more current pulses for creating the magnetic field. An electronic article surveillance (EAS) system includes a coil to create a magnetic field for changing a status of an EAS marker and a drive unit to output a signal having one or more current pulses for energizing the coil. A programmable processor within the EAS system controls the drive unit to generate the output signal according to a desired profile. By selectively activating and deactivating current switching devices within the drive unit, the processor can direct the drive unit to generate the output signal according to a desired profile having a number of current pulses of different amplitudes and direction.

Field creation in a magnetic electronic article surveillance system

A device is disclosed for activating and deactivating magnetic electronic article surveillance (EAS) markers. In one embodiment, the device includes control circuitry comprising a coil, such as a solenoid-type coil, that provides a magnetic field in one direction and another coil that provides a magnetic field in a substantially perpendicular direction, so that EAS markers that pass through the device are positioned generally in the plane defined by the first and second directions.

Dual axis magnetic field EAS device

A device is disclosed for activating and deactivating magnetic electronic article surveillance (EAS) markers, and particularly those EAS markers that are associated with magnetically recorded media. In one embodiment, the device includes control circuitry comprising a coil, such as a solenoid-type coil, that provides a substantially uniform magnetic field that reliably activates and deactivates the marker, yet doesn't damage the magnetically-recorded media.

Device for changing the status of dual status magnetic electronic article surveillance markers

An article inventory tracking and control system tracks and controls removal of articles from a secured facility. Exemplary facilities in which the system may be useful include libraries, rental stores and retail stores. Each article is marked with an EAS marker to prevent unauthorized removal. In the system, each user of a facility and each article in the facility is uniquely identifiable. Upon receiving the user and article information, the system queries a central database to ensure that the user is a valid user and that the desired transaction is authorized. A receiving compartment is specifically designed to receive a particular type of article, such as a video or audio cassette. Sensors in the receiving compartment ensure that the article is properly placed within the receiving compartment. Proper placement of the article within the receiving compartment ensures that the marker is properly re/desensitized, and also ensures that only one transaction on one article can be performed at a time.

Article inventory tracking apparatus and method

An apparatus for detecting the presence of multiple items includes a platform upon which one or more items may be placed and a detector positioned with respect to the platform to receive an image of a profile of the one or more items on the platform. The detector is configured and arranged to generate a signal corresponding to the profile. The signal indicates whether multiple items are on the platform. The detector may be, for example, a moving point detector, a linear detector, or a two-dimensional array detector. This apparatus can be used in conjunction with an inventory control device, such as an automated library check-out device, to prevent the unauthorized removal of inventory items.

Apparatus and method for the optical detection of multiple items on a

Article inventory tracking and control system

The present re/desensitizer is an apparatus for changing the status of a magnetic marker of an electronic article surveillance system. The markers are attached to or otherwise associated with an object to be protected, such has a book, CD, etc. The device can be set up as a resensitizer, a desensitizer, or with the inclusion of a mode switch, a combination re/desensitizer. The apparatus includes a magnetic field generator for generating a marker status changing magnetic field, detection means for detecting presence of an object, a control means for controlling the activation time of the magnetic field generator such that the marker status changing magnetic field is generated when an object is present. The magnetic field generator includes an offset core designed for continuous operation without excessive heat build up. The offset core is oriented such that the marker status changing magnetic field is substantially horizontal and adjacent to the mounting surface, thus reducing the complexity of movement of the hands and arms required when operating the device. The re/desensitizer also includes a control circuit which controls power to the magnetic field generator such that the marker status changing magnetic field is produced only when an object containing a marker is present. The control circuit also controls the duty cycle of the device by controlling the amount of time that the device is activated and by controlling the amount of time between successive activations.

Apparatus for changing the status of magnetic markers in an electronic

Markers in different portions of the interrogation zone of an electromagnetic article surveillance system produce signals with waveforms of different character. In one embodiment, a false alarm minimization method determines the character of the waveform of the signal induced in the detection antenna. A requirement that signals with waveforms of different character be sensed provides greater confidence that the marker is passing through, as opposed to being near one portion of, the interrogation zone. Also, false alarms produced by stationary objects such as metallic door and window frames are eliminated. In another embodiment, the direction in which the marker passes through the interrogation zone is determined.

Growing community of inventors

Stillwater, MN, United States of America

Anthony Michael Belka