Magnetic domain detector arrangement

Claim 2

A magnetic arrangement comprising a layer of magnetic material in which single wall domains can be moved, a repetitive pattern of elements operative responsive to a magnetic field reorienting cyclically in the plane of said layer to advance domains one period along a channel defined thereby for each cycle of said field, at least one period of said channel being defined by elements operative first to enlarge and then to contract a domain being advanced thereby along said channel.

Claim 3

An arrangement in accordance with claim 1 wherein said first section comprises one stage of said multistage pattern.

Claim 4

An arrangement in accordance with claim 1 wherein said first section comprises a plurality of magnetically soft elements disposed to exhibit closely spaced attracting magnetic poles along the axis of domain propagation in said channel in a manner to define an extended diffuse pole there when said in-plane field is aligned with the long dimensions thereof.

Claim 5

An arrangement in accordance with claim 1 wherein said first section comprises a plurality of stages of said multistage pattern.

Claim 6

An arrangement in accordance with claim 4 wherein said pattern defines a serpentine channel including a turn and said first section of said first geometry includes a magnetically soft curved element for defining said turn.

Claim 7

An arrangement in accordance with claim 5 including a plurality of magnetically soft elements radiating outwardly from said curved element and a detector coupled to a pair of said plurality of elements for detecting the presence and absence of domains so expanded there.

Claim 8

An arrangement in accordance with claim 5 wherein said first geometry comprises a common magnetically soft element having a first thickness aligned with the axis of domain movement at said turn and includes magnetically soft elements each having a second thickness greater than said first radiating from said common element transverse to said axis.

Claim 9

An arrangement in accordance with claim 4 wherein said first geometry comprises a common magnetically soft element aligned with the axis of domain movement in said channel and includes magnetically soft elements radiating from said common element transverse to said axis.

Claim 10

An arrangement in accordance with claim 8 wherein said common element has a thickness substantially less than that of said elements radiating therefrom.

Claim 11

An arrangement in accordance with claim 1 including means for providing a bias field for maintaining said domains at a prescribed diameter.

Claim 12

An arrangement in accordance with claim 10 includes means for providing said reorienting in-plane field.

Claim 13

An arrangement comprising a layer of magnetic material in which single wall domains can be moved, a repetitive pattern of magnetically soft elements juxtaposed with a surface of said layer operative responsive to a magnetic field reorienting cyclically in the plane of said layer for moving said domains one period along a channel defined thereby for each cycle of said field from an input through an output position, means for maintaining said domains at a first diameter, said pattern at said output position having a geometry first to enlarge domains to a second diameter larger than said first diameter and thereafter to reduce domains to said first diameter, and means for detecting domains so enlarged at said output position.

Claim 14

An arrangement comprising a layer of magnetic material in which single wall domains can be moved, a repetitive pattern of magnetically soft elements juxtaposed with a surface of said layer operative responsive to a magnetic field reorienting cyclically in the plane of said layer for moving said domains one period along a channel defined thereby for each cycle of said field from an input through an output position, means for maintaining said domains at a first diameter, said pattern at said output position having a geometry first to enlarge domains to a second diameter larger than said first diameter and thereafter to reduce domains to said first diameter, and means for detecting domains so enlarged at said output position.