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Magnetic Bubble Domain Alphanumeric Display and Microfilm Printing Device

IP.com Disclosure Number: IPCOM000078311D
Original Publication Date: 1972-Dec-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 5 page(s) / 117K

Publishing Venue

IBM

Related People

Chang, H: AUTHOR [+2]

Abstract

A complete alphanumeric display and printing system, together with a character generator and a write decoder, is implemented using indented angelfish bubble domain devices. The angelfish patterns are etched into the bubble domain magnetic sheet. Since it is easier to move a domain wall into a shallower part of the sheet than out of it, bubble domain size variation over etched triangles in an oscillating bias field will result in unidirectional motion of the bubble domain.

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Magnetic Bubble Domain Alphanumeric Display and Microfilm Printing Device

A complete alphanumeric display and printing system, together with a character generator and a write decoder, is implemented using indented angelfish bubble domain devices. The angelfish patterns are etched into the bubble domain magnetic sheet. Since it is easier to move a domain wall into a shallower part of the sheet than out of it, bubble domain size variation over etched triangles in an oscillating bias field will result in unidirectional motion of the bubble domain.

The system is shown in Fig. 1. It consists of three major parts: character generators, a write decoder, and a display area comprising a plurality of closed- loop shift registers SR. All parts are made of indented angelfish bubble domain devices, which are driven by a common modulating bias field and controlled by local current loops.

A single character is composed by filling part of its 12 useable segments with elongated magnetic bubbles. Fig. 2A shows the meandering shift register while Fig. 2B shows one of the repetitive portions of the shift register. The 12 segments of each character are connected into the meandering shift register. All characters are then connected serially to form a recirculating shift register loop. This loop cam store, move, and display its information content. The input to the shift registers is obtained from the character generators, through the control of the write decoder.

The character generator is divided into 12 segment generators, each of which has control lines for the bubble domain generators, input signals, and bubble domain buster components. The character generator converts a 6-bit code in parallel into one of 64 (2/6/) prestored characters. The character, which is represented by 12 Partly filled segments, is generated by the 12 segment generators operating simultaneously. Each of the segment generators performs as a read-only memory and yields a bubble domain or a void to be assembled with the outputs from other segment generators into a character, which is then fed into the write decoder and from there into the shift registers SR.

Fig. 3 shows the details of a single-segment generator. Each segment generator consists of four parts: a controlled bubble generator, a switch tree, a read-only memory, and an OR tree. For a segment containing 9 bubble domain positions (Figs. 2A, 2B), the bubble generator is controlled to emit one bubble domain in every 9 field-oscillation cycles. The n-bit input signals to the switch tree select a unique propagation path in the switch tree and guide the bubble domain to the selected input of the read-only memory. This memory provides one bit position in each of the 2/n/ channels, corresponding to each of the 2/n/ characters. This position either propagates the bubble domain through or destroys the bubble domain on site, as determined by the character pattern. The 2/n/ channels are connected through the OR tree into the comm...