Eastman-kodak Company

Cummins-allison Corporation

Jay D Freeman

Frederick J Jeffers

Tomasz Marek Jagielinski

Neil Smith

Danny D Yang

George S Krastev

Peter VanderSalm Koeppe

Frederick Rockwell Chamberlain, Iv

Kent R Gandola

Thomas D Carr

According to some embodiments of the invention, a magnetic sensor having a track width of greater than about 50 millimeters is provided. The magnetic sensor is adapted to detect a magnetic feature and produce a linear, analog output in response to the magnetic feature. The analog output is along a single data channel.

Currency discrimination system and method

A magnetic detection system for authenticating a document includes a first magnetic scanhead adapted to create a first magnetic field for saturating the magnetization of an area on each of the bills. The magnetic detection system further includes a second magnetic scanhead with an electromagnet. The electromagnet is capable of creating a second magnetic field of adjustable intensity. The second magnetic field is the opposite polarity of the first magnetic field. The intensity of the second magnetic field is adjusted by changing the amount of current supplied to the electromagnet. The amount of current supplied to the electromagnet is based upon a characteristic of the document to be authenticated.

Magnetic detection system for use in currency processing and method and apparatus for using the same

A single use camera is preloaded with a roll of magnetically coated film with defined image frames. The camera has an exposure system for selectively exposing an image frame of the film in one of a plurality of image formats. The camera also includes a manually actuated mechanism coupled to a mounted permanent magnet. The magnet is movable to record a magnetic mark on the magnetically coated film at a predetermined location relative to an exposed image frame. The location of the mark is indicative of the image format of the exposed image frame.

Advanced photo system format selector

A copyright protection system is provided in which copyrighted articles, such as documents and photos, have associated with the article magnetic material which is detected when the article is copied on a scanner/reproducing machine. The magnetic material may be secured to the article so that it cannot be removed without destroying the article, or the magnetic material may form part of the article. The scanner/reproducing machine is provided with a magnetic detection system for automatically detecting the copyrighted article.

Copyright protection for photos and documents using magnetic elements

A magnetically permeable 'cap' is deposited across the top face (the bottom face being the face at the head-medium interface), or on the end faces, or on both the top and the end faces of a DMR reproduce head. The top cap serves as a magnetic keeper which provides flux closure between the two MR elements of the DMR when they are transversely magnetized anti-parallel to each other. By means of a magnetic cap of only moderate effective permeability, the current density required to optimally bias a DMR head is reduced by a factor of from 3 to 4. The presence of the top cap layer also provides an increase in the intrinsic sensitivity (independent of the bias level) of the DMR by a factor of 2. Further, when the head is fully biased to also include longitudinal biasing of the MR elements, the caps at the longitudinal ends of the MR stripes magnetically stabilize the fully antisymmetric bias configuration providing optimal performance for a DMR head. The end caps also provide for establishing the necessary electrical conductive path between the two MR elements of the DMR. In an additional embodiment, an electrically insulating layer between the magnetically permeable layer and the MR elements breaks any exchange coupling between the magnetically permeable layer and the MR elements.

Magnetically capped dual magnetoresistive reproduce head

A magnetic assembly for detection and authentication of magnetic documents. The magnetic assembly includes a permanent magnet (PM), first and second magnetically soft high permeability pole pieces shaped to form a tapered, variable gap size magnetic circuit with the permanent magnet. The PM is located at a first gap between the first and second pole pieces. A magnetoresistive (MR) sensing element is located at or near the center of a second gap between said first and second pole pieces. The second gap and MR sensing element are proximate a magnetic document to be sensed. An electrical conductor is adjacent to the MR sensing element, but is electrically insulated therefrom. A direct current is passed through the electrical conductor to create a compensating bias field in the MR element which is combined with the bias field generated by the PM.

Permanent magnet assembly with MR and DC compensating bias

A magnetic assembly for detection and authentication of magnetic documents. The magnetic assembly includes a permanent magnet (PM), first and second magnetically soft high permeability pole pieces shaped to form a tapered, variable gap size magnetic circuit with the permanent magnet. The PM is located at a first gap between the first and second pole pieces. A magnetoresistive (MR) sensing element is located at or near the center of a second gap between said first and second pole pieces. The second gap and MR sensing element are proximate a magnetic document to be sensed. An electrical conductor is adjacent to the MR sensing element, but is electrically insulated therefrom.

MR sensor including calibration circuit wherein signals are averaged for

A shorted DMR reproduce head includes two substantially identical MR elements, separated by a thin film of titanium nitride having a resistivity of 1000 .mu..OMEGA.-cm. Signal loss due to current shunting in the shorted DMR head is significantly reduced by use of the titanium nitride film.

Shorted DMR reproduce head

A thin film magnetometer includes first and second thin film magnetoresistive elements and first and second thin film laminated flux collectors. The first magnetoresistive element is located in a gap formed by the flux collectors, and the second magnetoresistive element is subtantially magnetically shielded by the flux collectors, and acts as a thermistor. The magnetoresistive elements are connected in a bridge circuit whereby any signal component due to thermal effects on the magnetoresistive elements is removed from the signal produced by the first magnetoresistive element.

Growing community of inventors

Leucadia, CA, United States of America

Jay D Freeman