An analysis of a clear-view angelfish bubble-domain shift register

A clear-view display and printing device is proposed utilizing a new bubble-domain shift register which has triangular patterns etched into the surface of a magnetic crystal. The geometrical and materials requirements for the clear-view shift register are analyzed. The etched-out triangular pattern is shown to provide the unidirectionality of bubble motion under an oscillating bias field just as the triangular Permalloy overlay does. An etched depth of one-tenth of the plate thickness and an etched gradient of about unity are shown to be sufficient for the expected shift-register operation.