Abstract: A method for improving the memory effect and brightness of an alternating current (AC) excited thin film electroluminensence (ACTEL) device is described. A typical ACTEL device has a thin luminescent layer made of ZnS thin film doped with Mn which is sandwiched between two dielectric layers. ACTEL devices exhibit a brightness versus voltage amplitude hysteresis loop which is commonly referred to as the memory effect. The application of a hybrid AC excitation waveform to the ACTEL device provides increased brightness and improved memory effect stability. The hybrid waveform has an initial portion that is sufficiently high for efficient carrier generation and a remaining waveform portion that is at a lower level than the initial portion for charge collection and holding purposes.

Abstract: An interactive projection display system having a light pen device for use thereon is described. The projection display system has an image of a light valve on a projection screen which is formed by visible light of specified wavelengths. The projection screen also has a translatable crosswire image thereon which is formed by radiation which includes the visible light used to form the light valve image and an additional spectral component. The light pen device is sensitive to this additional spectral component. In a preferred embodiment, the image of the light valve and the crosswires are formed with white light (0.3 to 0.7 microns). The additional spectral component used for the crosswire image and the light pen sensing is a band of near-IR radiation (0.7 to 1 micron).

Abstract: A method of treating the surface of substrates used in liquid crystal display cells so that the surface forces the liquid crystal director to be aligned uniformly over the entire surface and parallel to the substrate surface. The method includes the step of forming a plasma beam containing oxygen free-radicals, inert gas free-radicals such as argon, neon and helium, and free radicals of a compound containing the element to be deposited, for example, silicon, tin, indium, etc. Preferably a volatile organo-silicon or an organo-tin compound is used to supply the silicon or tin. The plasma beam is then directed at the substrate surface at an angle, preferably of about 30.degree., for a time sufficient to deposit a film. The liquid crystal display cell utilizing a substrate formed in this manner has a high contrast ratio as well as a sharp threshold in its electro-optical characteristics.

Abstract: A magnetic bubble Y-bar corner for use at the end of a minor loop. The Y-bar corner includes a Y-bar corner element and a canted I-bar positioned between the Y-bar corner element and each of the two adjacent storage elements in the minor loop. The ends of the arm of the Y-bar corner element are positioned adjacent the apex portions of the canted I-bars. The distance between the ends of the arms of the Y-bar is larger than the distance between the opposing ends of the two canted I-bars. With this corner a bubble propagates in either direction along a path from a minor loop storage element to the end of the canted I-bar and then to the apex portion of the canted I-bar and from there across to the end of the arm of the Y-bar.

Abstract: An electrochromic display device comprises a single counter electrode and a plurality of display electrodes. The counter electrode is charged and is maintained at a given potential by a donor electrode which transfers charge to the counter electrode in response to the action of a reference electrode. A potentiostat operates to supply current to the donor electrode in accordance with the potential of the counter electrode as sensed by the reference electrode. Both the donor electrode and the counter electrode are preferably of platinum black. The donor electrode is preferably arranged in the manner of a frame about the display area. The counter electrode is preferably grid-shaped.

Abstract: An electrochromic display device, preferably employing an organic electrochromic material such as heptyl viologen, has display electrodes with a rough surface in contact with the electrochromic material. The device is operated at a sufficiently high current density so that the diffusion depth of the material conforms to the contours of the electrodes.

Abstract: An approach for maintaining the identification of the defective minor loops of a bubble domain memory system having one or more major/minor loop arrays is disclosed. The bubble domain memory system has a plurality of minor loops for the storage of data bits including some minor loops which are defective. There is a plurality of pointers that identify the defective minor loops. At least one block of bits in each major/minor loop array is reserved for the storage of the pointers. The pointer block is associated with a fast access read/write memory, for example, a volatile random-access read/write memory system, to which the pointer information is transferred during power-on initialization of the bubble domain memory system. During the read/write operations of the bubble domain memory system, the read/write memory system enables the data positions to be skipped that correspond to the defective loops.

Abstract: An improved potentiostat for use with electrochemical cells provides dynamic protection of both the electrochemical cell elements and the sensitive potentiostat components from any significant voltage or current overload. A comparator compares the potentiostat input voltage with the electrochemical cell reference electrode voltage. When the reference electrode voltage becomes substantially different from the potentiostat input voltage and exceeds a certain preset value, the comparator activates a control means that causes the cell current to go to zero. This system provides dynamic protection even as the input voltage varies.

Abstract: A plasma process for forming a polymer film containing metal therein includes the steps of providing an electrode of a metal that can be etched by a halogen, providing a substrate for the polymer film to be deposited thereon, and passing a halocarbon monomer through a plasma system so that the metal etched from the electrode forms a volatile halide and is incorporated in the polymer film that is deposited on the substrate.

Abstract: A method of forming an improved liquid phase epitaxial film on a wafer. The resultant film has improved uniformity of magnetic properties, such as the collapse field (H.sub.o), across the surface of the wafer as well as being substantially free of mesa defects on the surface. The method includes the step of growing the liquid phase epitaxial film while the wafer is in the horizontal plane. The wafer is removed from the melt while the wafer is tilted at an angle from the horizontal plane so that the melt may drain from the wafer. Then the wafer is positioned in a horizontal plane again and rotated to remove the remaining melt droplets from the edge of the wafer. In a preferred embodiment, a plurality of wafers are positioned in a wafer holding means so that the wafers are arranged in a stacked manner having substantially the same space between adjacent wafers. Wafers may also be stacked in pairs that are back-to-back while carrying out this method.

Abstract: A major/minor loop bubble memory configuration that provides gap free serial access to the data in the minor loops and which maintains the non-volatility of data when subjected to a power-on-off-on sequence. The configuration includes a timing minor loop in combination with the data storage minor loops in the major/minor loop array. The placement of a single timing bubble within the timing loop permits gap free serial access to the data in the remaining storage minor loops.

Abstract: A random access bubble memory directs a plurality of continuous streams of bubbles toward a plurality of storage loops. A write decoder selects one continuous stream of bubbles. An annihilator then transforms this one continuous stream of bubbles into the desired data pattern which is then stored in a selected loop. While the data pattern is being formed, a read decoder directs the data which had been stored in the selected loop to a bubble detector. This memory has a unified read/write cycle which permits intermixed read and write, read/modify/write, and swap operations. This bubble memory allows a user to remove power abruptly during a read/write cycle without returning a partially processed block to its storage loop and without saving the identity of the block. In a preferred embodiment, the read and write decoders are operated simultaneously by identical control currents.

Abstract: A magnetic bubble switch operates in a drive-to-transfer mode when a rotating magnetic field is applied. The switch has a magnetic element in the shape that defines the letter "Y" having two arms and a stem. The switch has at least one serration on the arm of the Y in the vicinity of the stem. The switch has a conductor which is positioned across the end of the stem of the Y. A magnetic element is positioned so as to form a gap with the stem of the Y.

Abstract: A bubble storage system includes a closed loop propagation pattern suitable for use with a bubble lattice. The closed loop propagation pattern is folded and contains, for example, segments of a hexagonal lattice connected by 60.degree. turns to obtain a close pack bubble storage configuration. The bubbles are propagated along the pattern consisting, preferably, of C-bar or chevron type permalloy elements by a rotating magnetic field in the plane of the pattern. In a preferred embodiment, the folded closed loop propagation pattern is surrounded by a region of non-propagating bubbles retained by permalloy dot confinement means. There are substantially the same number of elements in the propagation pattern as there are bubbles in the lattice that are affected by the propagation elements.

Abstract: A major/minor loop bubble domain memory system maintains the non-volatility of data when subjected to a power on-off-on sequence. A bubble domain shift register is associated with the major/minor loop array and indicates when a block of data in the major loop is in position to be transferred into the minor loops. The length of the shift register is related to the propagation delay of the path over which a bubble is propagated along the major loop from a minor loop read transfer switch to the write transfer switch for the same minor loop.

Abstract: An electrochromic display device adapted to be accurately erased has an opaque counter electrode in the shape of a pattern of lines, preferably reticulate, on the underside of the face of the display device through which the display is viewed. The counter electrode is brought to a predetermined potential either by trapping a suitable material capable of a reversible redox reaction at the counter electrode or by initially charging the counter electrode with heptyl vilogen cation radical. This enables voltage erase to be used.

Abstract: An electrochromic display device has an improved counter electrode arrangement. The device has a plurality of display elctrodes and a counter electrode in contact with a first electrolyte of a primary redox system. The counter electrode is charged to a predetermined potential. A secondary redox system is associated with the primary redox system. A secondary electrode in the secondary redox system is electrically connected to the counter electrode to maintain the charge on the counter electrode at a predetermined potential.

Abstract: A drive system for a bubble memory consists of a drive assembly and an electrically conducting surface enclosing the drive assembly. In a preferred embodiment, the drive assembly consists of a ferrite picture frame with two pairs of drive coils and the conducting surface is the interior surface of a metallic box.

Abstract: An optical modulator suitable for use with a collimated light beam having a moderate cross section and a fast response time and operational at relatively low voltage includes, for example, a glass prism and a smooth metal surface that are separated by an adjustable gap. The gap is filled with a medium, for example, air, having an index of refraction lower than the prism. A beam of monochromatic light is passed into the prism at a specific angle of incidence to undergo total internal reflection at the glass prism-gap interface. A change of approximately 1 micron in the thickness of the gap is sufficient to change the reflectivity from greater than 95% to essentially zero. The size of the gap is mechanically adjusted and this mechanical device determines the frequency response of the light modulation.

Abstract: A current access bubble memory system includes a method and device for propagating and switching isolated bubbles within a plurality of orthogonal propagation channels. The device includes two orthogonal arrays of parallel current conductors oriented at 45.degree. angles to the two orthogonal bubble translation axes. The conductors in each array are regularly spaced a distance S apart from center to center. The first array of conductors are connected in parallel to a first current source and the second array of conductors are connected in parallel to a second current source. The propagation channels are defined by confining means to have a width d where d is the bubble diameter. The centerline of the channels are spaced a distance of about .sqroot.2 S/8 from the center of adjacent conductor intersections. Bubble translation occurs through sequential activation of the two bipolar current sources.