Abstract: In a disc data store, wherein a read/write head is radially positionable by a feedback servomechanism to interact with a selectable one out of a plurality of radially equispaced data storage tracks on a rotary disc, the positioning errors resultant from phase errors between the plural signals available as the output of an optical grating head position transducer are eliminated by replacing one of the data storage tracks with a servo track by arranging that the period of the recursive, triangular wave position indicating signals from the transducer is equal to twice the radial spacing between tracks on the disc, by selecting as the exclusively-used position indicating signal that one of the plurality of transducer signals which brings the head to the center of the servo track with least offset, and, while employing that selected signal or its generated inverse as the feedback signal to the servomechanism applying that least offset as a correction when positioning the head over data storage tracks.

Abstract: A display panel comprising a gas-filled envelope containing an array of rows and columns of D.C. scan/address cells, each scan/address cell including a volume of gas and an anode electrode and a cathode electrode, and an array of rows and columns of display cells, each display cell including a volume of gas and two electrodes, one electrode being in the form of an apertured plate whose apertures are the display cells, the other electrode being an apertured electrode whose apertures are considerably smaller than the apertures in the one electrode and so numerous that the greater portion of the area of the other electrode is light-transmissive whereby the human eye does not see the solid portions of the other electrode which define the apertures therein.

Abstract: A servo track position detection system overcomes the measurement errors induced by the use of decoders employing two separate signal measuring circuits where the difference between the outputs of the circuits is indicative of the displacement of a signal-recovering transducer from central disposition over the servo track by using a servo track having opposed pairs of polarity transitions which sum the head to give a head output pulse whose polarity and magnitude are indicative of the distance and sense of displacement of the head from central disposition over the servo track and measured in a simple circuit.

Abstract: A wafer-scale integrated circuit has a plurality of data-processing cells disposed on a semiconductor wafer together with a port for providing communications with a controller. A branched spiral of inter-coupled working cells is grown starting at the port by testing cells and incorporating them into the branched spiral if found to be working, otherwise selecting alternative cells for testing. The growth of the branched spiral is such as to allow for the incorporation of cells trapped in cul-de-sacs. Each cell is operable to receive a unique cell name from the controller and is thereafter operable to respond to commands from the controller bearing its unique cell name to couple firstly to one neighbor and secondly, at any time thereafter, to couple to a further neighboring cell. The controller is provided with means for maintaining records of successful interconnections for later use.

Abstract: A very large scale integrated circuit, covering the entire surface of a semiconductor wafer, comprises a plurality of data processing cells and a port. Starting at the port, cells can be made to couple to neighboring cells which are then tested and incorporated into the overall working of the integrated circuit if functional to grow a functional array of interconnected cells on the wafer.Each cell is square and comprises a data processing element, four coupling sections and four link sections. The link sections allow the cell either to communicate with one of its four neighbors or to internally circulate data. The coupling sections join the link sections. The data processing element is associated with one of the link sections. The cells are divided into two groups, a first group with its cells all having the element associated with the coupling section in one corner and a second group with its cells all having the element associated with the coupling section in the opposite corner.

Abstract: A toner concentration sensor senses the concentration of toner in the toner system of an electro-photographic printer or copier. A novel circuit improves the toner concentration sensor. The novel circuit is composed of a resonant circuit, a frequency source, and a logic circuit. The resonant circuit is tuned to a selected frequency and has an inductor which creates a field into which the toner system is introduced. A frequency source excites the resonant circuit. A logic circuit receives a signal from the frequency source and an output from the resonant circuit. The logic circuit output is a signal representative of the phase shift between the signal from the frequency source and the output of the resonant circuit. The phase shift is representative of the inductance of the inductor in the presence of said toner system. The measurement of the inductance is representative of the concentration of toner in said toner system.

Abstract: A data communications controller, for use intermediately between a data processor and a data communications link such as a modem driven land line, relieves the data processor of time-consuming supervisory and data preparation tasks, normally associated with the use of a data link, by means of a block loadable transmit queue, an automatic cyclic redundancy check generator, an automatic time fill generator and a parity generator, a block unloadable receive queue, an automatic character translator, an automatic character monitor and a received serial bit queue in conjunction with a byte synchronizing detector, the operation or non-operation of each of the above elements and, if operational, the manner of that operation, being selectable by commands from the data processor, the commands from the data processor being intermingled with but distinguishable from data to be sent over the data link.

Abstract: An electro-optical imaging system uses a charge-coupled bucket-brigade photo-sensitive image convertor where the necessity for light shielded shift registers and other measures for preventing the acquisition of additional incident-light induced charge by light-representative electrical charge packets as they pass to the output port of the convertor is removed by the use of a liquid crystal light transmission cell which can be made transparent for the acquisition of charge by the convertor and opaque for the shifting of the charges to the output port. The convertor can thus be made simpler and of smaller area to give a lower cost and higher production yield. The convertor is given an apparently increased spatial resolution by providing that the cell allows sub-areas of the total image to be transmitted one-by-one to the convertor by the sequential operation of four sub-cells of the main cell such that each sub-cell becomes transparent and has its through-passing image converted in turn.

Abstract: A display panel comprising an array of scan cells formed by an array of row scan anodes and an array of column cathodes, the scan anodes operating with the lower surfaces of the cathodes to provide cathode glow. The panel also includes an array of display cells formed by an array of row display anodes and the same cathodes, the display anodes operating with restricted areas on the top surfaces of the cathodes to provide cathode glow. The rows of display cells are offset from the rows of scan cells so that the glow transfer path and display glow cells are disposed in an optimum location for panel operation and life.

Abstract: Coupling apparatus comprising two plates to be coupled together, with each plate carrying a locking mechanism for receiving a coupling member, the coupling member having two ends, each end being adapted to engage and couple to the locking mechanism on one of the plates whereby the two plates can be rigidly coupled together. Each plate carries two flexible locking tabs which are offset from each other, and the coupling member carries two holes which are offset from each other and each of which is adapted to receive one locking tab of each plate.

Abstract: A composition for a conductor ink used in a screening process and including a nickel powder, a lead-free glass binder, and a vehicle suitable for firing at a temperature below about 590.degree. C. The conductor composition is designed for use in gas plasma display panels.

Abstract: A system for rotating a data storage disc in a disc drive and for rapidly bringing the disc to a halt comprises a brushless motor fed with direct current in its windings by a motor drive circuit which current is also fed to a solenoid to hold a spring loaded solenoid arm from pressing a brake against a shaft to brake the disc, the motor control circuit using the current caused by back emf in the windings of the motor to provide motor braking while passing the current through the solenoid which applies the brake when the motor speed falls below a predetermined limit, the solenoid also being employed as a current smoothing choke.

Abstract: A wafer-scale integrated circuit wherein a plurality of memory cells on a wafer are connectable from a port to form a chain memory looping away from and back to the port by means of a serial connection of forward moving data registers and a serial connection of backward moving data registers between cells, has a reduced risk of any individual, otherwise functional cell being non-functional as a result of a failure elsewhere on the wafer of an associated global signal line by achieving a reduction in the numbers of global lines by providing the clock signal for controlling the shifting of data in the registers between the cells in parallel with the data, the inter-cell clock operating a multiple clock pulse generator in each cell.

Abstract: A sheet item reloader-feeder wherein a pivoted item receiving tray is arcuately-angularly movable from a load position in which the tray is empty to a feed position in which the tray is full. A coiled spring biases the item tray vertically to bring the top most sheet item into the nip of a feeding device. A cable connected to the tray is interconnected to an over-center spring biased cam and an external tray handle whereby movement of the handle causes the tray to automatically move against the tension of the biasing spring from the empty position to the loaded position bring the top most sheet item into the nip of the feeding device for automatic feeding. Two such reloader-feeder devices are stacked in vertical offset relation to one another permitting operator reloading during feeding without stopping the operation of the apparatus.

Abstract: A gas-filled display panel comprising a glass base plate and a glass face plate hermetically sealed together along a perimeter seal area to form an envelope which is filled with an ionizable gas, the base plate having an array of longitudinal slots in which anode wires are seated and having an array of cathode electrodes on the top surface thereof. The base plate has cross grooves transverse to the slots and positioned one near each end of the base plate, and a glass rod is secured in each cross groove with the ends of each rod lying within the seal area between the base plate and the face plate, the top surface of each insulating member being generally coplanar with the top surface of the base plate in the seal area, to insure the formation of a hermetic seal between the base plate and face plate at the cross grooves.

Abstract: A digital memory system comprises a wafer full of uncomitted but interconnectable memory cells and a controller acting as an interface between the wafer and a host system. Each cell comprises input logic to allow coupling thereto from just one other neighboring cell and output logic allowing a cell to be commanded by the controller to couple to any selectable one other neighboring cell not already so coupled to. The controller accesses the wafer via a port and successively tests and couples cells from the port to form a chain of memory cells. Each cell comprises a plurality of individually selectably usable data storage loops and allows a cell to be used even if the loops are not fully functional by the provision of through-passing data transfer path.

Abstract: A monitor (9) for determining the amount of metal which has been removed during the course of a chemical etching process comprises an etch resistant substrate (10) whereon are affixed a plurality of metal foil areas (12A to 12H) each with its own, known substantially uniform thickness prior to the start of the etching process, indication of the progressive depth of etching being provided by which out of the plurality of areas of foil (12A to 12H) remain at any particular time after the commencement of etching.

Abstract: A pivotal feed head for feeding non-rigid paper sheets individually from a feed hopper to a photo-optical utilization station at high speed without interruption, overlap or collision between sheets including oppositely disposed members for applying a normal force between an enlarged resilient tired feed wheel adapted for unidirectional rotation and a conjointly movable, engageable retard roller. The feed head is mounted for pivotal movement about an outboard drive member. A frictional brake for the retard roller is adjustable to provide a preset load at the nip between the feed wheel and the retard roller while a solenoid-actuated one-way clutch operably engages the feed wheel mounting shaft for incremental signal controlled paper feed. A vertical, signal-controlled latching member locks the feed head in a vertical pivoted position at the end of the vertical upward movement of the paper stack platform as the paper is fed into the nip between the feed wheel and the retard roller.

Abstract: Molded optical waveguide switching apparatus wherein a flat, planar light transmissive plastic member of a refractive index N.sub.2 is premolded with orthogonally arranged obverse and reverse grooves or channels and wherein each such channel or groove is filled-in or molded with a light transmissive plastic of a refractive index N.sub.1 (where N.sub.1 >N.sub.2) effectively forming front and back light conducting channels or waveguides at right angles to one another on the flat planar member. A gently curved tap is molded into the intersecting area of each row and column waveguide with a through opening or aperture formed adjacent each intersection. The taps of the obverse side are curved downwardly to meet the upwardly curved taps of the reverse side of the planar member. Light blocking and unblocking members are operably disposed in respective apertures to interrupt light from light generating to light receiving receptors.

Abstract: A multi-plane optical membrane switch for use for example in a keyboard matrix is formed by two flat, planar, clear, plastic members disposed in parallel, separated relationship and each having individual light conducting guides or channels thereon. The channels of the lower plane are disposed at right angles to the channels of the upper plane. The upper set of light guides includes integral, gently curving coupler taps disposed at the intersection of the upper and lower guides for coupling the light from the lower planar guide channels into the upper guide channels when the two channel intersections are pressed together by the key top effectively switching the light from the lower to the upper channels.