Abstract: A set of three input, three output bubble logic gates forms all of the possible distinct output functions for conservative three variable gates. The magnetic interaction between single wall domains propagating through separate channels defined by closely spaced circuit element paths causes the domains to switch to or remain on alternate paths via between-path transfer means in a predetermined fashion. In addition to vertically graded element transfer means, several new circuit arrangements are introduced including non-graded elements, strong and weak S-curves, elements having uneven gradation, and other circuit techniques. A group of primitive realizations are described which can be combined to produce other gates having output functions in each of 31 equivalence classes. A methodology for using the gates in logic design is suggested, and several new building block gates producing functions of two variables are presented.

Abstract: Composite mutually exclusive field-accessed circuit elements common to a plurality of bubble paths. A channel composed of mutually exclusive circuit elements is linked to an adjacent parallel channel of mutually exclusive circuit elements by means of circuit element portions common to both channels. The interconnected channels are operated mutually exclusively by means of corresponding pulsed field sequences. Transfer between the linked channels is via the common circuit element portion. Several new types of propagation circuits are also discussed along with organizations for mutually exclusive major and minor closed loops featuring controlled transfer via common circuit element portions.

Abstract: A composite semiconductor light-emitting display array. Light is emitted and observed through a light-transmissive planar array of LED devices formed in a monolithic transparent single crystal such as GaP. Light is generated at the back of the single crystal, but is observed through the front of the crystal. The crystal with its array of LED's is directly interconnected with a monolithic circuit having circuit elements for energizing the LED devices. The result is a composite sandwich structure with interconnections sandwiched between the LED array and the integrated circuit.

Abstract: Closed loop propagation channels for magnetic bubbles are mutually exclusively accessed by means of two different sets of repeating sequences of discrete, pulsed magnetic drive field orientations. A closed loop bubble propagation circuit is driven by a repeating sequence of pulsed orientations in which a plurality of interlaced subsets of the sequence operate corresponding sections of the circuit. A closed loop zigzag circuit traversing sections of the loop parallel to the sides of an equilateral triangle is driven by a sequence of pulsed field orientations aligned respectively with the sides of the equilateral triangle. Continuous overlay circuits are introduced driven by sequences of discrete nonorthogonal, pulsed drive field orientations repetitively realigning with consecutive segments of the overlay circuit.

Abstract: Magnetic bubble logic circuits performing the functions of various forms of flip-flops and decoders are presented. Set-reset and trigger flip-flops are constructed from specialized 3--3 conservative bubble logic circuits. Two forms of tree-type decoders employing crossovers of bubble tracks are illustrated for generating all possible product permutations of a plurality of input variables. Planar decoders and cross point circuits without crossovers are combined in matrix form to provide a multi-variable decoder without internal crossovers.

Abstract: A technique for enhancing readout of magnetic bubble data by producing two separate, complementary multiplicities of bubbles representing respectively the presences and the absences of bubbles in a data stream. A pair of detectors register the presence of the respective multiplicities of bubbles. The outputs of the detectors are compared to produce a single output indicative of the presence or absence of the original data bubble. In one embodiment a bubble logic gate causes a single bubble bit in the data stream to logically influence a train of bubbles in a separate closed circuit operating at a rate which is a multiple of the rate of the data stream. Depending on the presence or absence of a bubble in the data stream, the train of bubbles is directed to one or the other of a pair of magnetoresistive elements spanning the length of the train of bubbles. The magnetoresistive elements form part of a balanced bridge circuit.

Abstract: An integrated LED display array wherein light is emitted and observed through a light-transmissive substrate, i.e., single crystal, which carries a plurality of optically isolated LED assemblies. Scattering of light from individual assemblies is prevented by an optically absorbing doped region which optically isolates each assembly. Light is generated at the back of the single crystal and viewed through the crystal. The LED assemblies, preferably multicolor, are directly mated to energizing electronic circuitry, e.g., a monolithic integrated circuit, via appropriate interconnections sandwiched between the two. The energizing electronic circuitry comprise an array of circuit elements which provide the energizing currents for respective ones of the LED assemblies.

Abstract: Three magnetic bubble logic gates are disclosed in this application. One gate produces the AND and NAND logic functions, one gate produces the OR and NOR logic functions, and the third gate produces the majority function. In the gate providing the AND and NAND functions and in the gate providing the OR and NOR functions, a bubble generator applies magnetic bubbles at the binary variable rate to a first bubble propagation track, which diverges into two downstream tracks with the bubble being transmitted through the point of divergence to a preferred one of the two downstream tracks unless repelled to the unpreferred downstream track. Bubbles representing the binary variables are applied to data propagation tracks which approach the point of divergence in the first track. In the gate providing the AND and NAND functions, this approach is only close enough so that simultaneous bubbles representing both binary variables are required to repel a bubble at the point of divergence to the unpreferred track.

Abstract: Overlay patterns of discrete circuit elements for field-accessed, magnetic bubble propagation are driven by repetitive sequences of pulsed magnetic fields directed along axes which are parallel to consecutive overlay elements or segments with different orientations. A chevron circuit is driven by a series of reversing pairs of pulsed fields aligned alternately with the legs of the chevron elements. Two opposite parallel chevron circuits are driven in the same direction by the same sequence of pulsed fields. A broken element circuit, resembling a chevron circuit with the vertices removed, is driven in a similar manner.