Abstract: A packaged article is captured between a resilient film mounted on a frame, and a raised, planar, stationary platform. The frame surrounds, and is positioned below, the plane of the platform in use.

Abstract: A combined bipolar junction transistor and an optical modulator comprising a plurality of semiconductor layers providing an optical mirror for the modulator, a collector for the transistor formed upon the plurality of semiconductor layers, the collector also forming an optical absorber of the modulator, a base of the transistor formed upon the collector, an emitter of the transistor formed upon the base and a metallic contact for the base, the metallic contact providing a function of an optical reflector for the modulator.

Abstract: A semiconductor radio-frequency power detector comprises, in a stack, an ohmic contact layer, undoped layer of a first semiconductor material, such as GaAs, of thickness l.sub.1, an undoped layer of a second semiconductor material, such as AlGaAs, of larger band gap than the first semiconductor material, the thickness of the layer being such that transport in the layer is primarily by intraband tunnelling, a second undoped layer of the first semiconductor material of thickness l.sub.2, where l.sub.2 >20l.sub.1, and a second ohmic contact layer. The difference between the thicknesses of the layers of the first semiconductor material gives rise to asymmetry in the current density/applied voltage characteristic for the device. An n+ layer may be incorporated in the second layer of the intrinsic first material to reduce "band bending" and to increase the current density.

Abstract: In a method of driving liquid crystal cells in an active matrix addressed display of the resistively-coupled transistor type whereby interlacing of alternate rows of pixels is achieved, rows N-1, N+1, N+3, - - - of the cells are addressed in sequence in a first field period by applying transistor turn-on pulses to the associated row address lines while reference signals are applied to the row address lines associated with rows, N, N+2, N+4, - - - in sequence, the turn-on pulse for the row N-1 and the reference signal for the row N being coincident. During a second field period of the transistor turn-on pulses are applied to the address lines for rows N, N+2, N+4, - - - while reference signals are applied to the address lines for rows N-1, N+3, N+5, - - - the turn-on pulse for the row N and the reference signal for the row N+1 being coincident. The reference signal may be of two different magnitudes which alternate at the line rate or at the frame rate of a television video signal.

Abstract: A three-dimensional, heart-shaped, decorative bow has an elevated circular loop positioned above interconnected ends of a ribbon. The loop is formed by curling the ribbon in opposite directions, and is maintained in shape and in position by mutually interlocking slits formed in the ribbon.

Abstract: A charge pump circuit for a frequency/phase comparator in a phase locked loop oscillator arrangement, in which current sources utilizing only npn transistors provide currents of equal magnitude but of opposite sense to an input of an operational amplifier, the output of this amplifier charge-pumping a capacitor to control the frequency of oscillation of an oscillator. The use of npn transistors enables higher current levels and higher speed switching compared to circuits including pnp transistors.

Abstract: A device for detecting the presence of a chemical material, such as a gas, amongst a number of incident chemical materials comprises a group of sensors having overlapping broadband selectivities in respect of the incident materials, so that each sensor responds, to a greater or smaller extent, to each of the materials. The sensor outputs are fed to a signal processor which produces, for each material, a notional vector. These vectors are compared with stored reference vectors to identify the material under investigation. The responses to the various materials have a time-varying portion and a portion of constant value. Certain materials may produce the same constant value, but different time-varying portions. The latter portions are therefore also taken into account in identifying the materials. A chromatographic layer may be provided over the sensors to distinguish between chemical species in the materials under test.

Abstract: A wrinkled paper decoration is made by jointly coiling an elongated paper strip to which a bendable wire is attached in a continuous spiral. The coiled wire is bent, and the paper strip is simultaneously wrinkled. The bent wire retains the paper strip in a wrinkled configuration.

Abstract: A microwave synthesiser comprising: a plurality of oscillator sources (1, 13, 3, 15, 5, 17, 7), each for generating signals over a range of frequencies, said ranges of frequencies together extending over a total range of frequencies generated; phase locked loops (19, 31, 83, 37, 38, 41, 81) for phase-locking any selected one of said oscillator sources (1, 13, 3, 15, 5, 17, 7) so that it generates signals of a frequency at which it is set; a single low harmonic modulator (21) for modulating the signals generated by the selected one of said oscillator sources (1, 13, 3, 15, 5, 17, 7), the modulated signals passing to an output (27) of said synthesiser; and at said output (27) elements (25, 29) for detecting the power of the signals at said output (27), the modulation by said single low harmonic modulator (21) being controlled in dependence on the detected power thereby to control the power of the signals at said output (27).

Abstract: Arrangement for automatically introducing paper ribbons into a plurality of angle-bars of a printing press, comprising a plurality of endless chains, one for each angle-bar, for conveying a respective ribbon to a folder-stitcher unit. Each chain has a gripper for grasping a leading end of the respective ribbon. Each chain is independently driven by a motor drive.

Abstract: A radio receiver antenna arrangement incorporating an RF pre-amplifier (5) wherein circuitry (11 to 21) is provided for by-passing the pre-amplifier when strong signals are picked up by the antenna (1) to avoid overloading the pre-amplifier.

Abstract: In a method of forming a micron-size field emitter, an array of conductive tips is formed on a substrate. A layer of dielectric material is formed on the substrate to a thickness substantially equal to the height of the tips, but forming a protuberance over each tip. A conductive grid layer is deposited over the dielectric layer, forming corresponding protuberances, followed by a layer of resist material which is of sufficiently low viscosity so that it flows off the grid layer at the protuberances leaving the protuberances substantially unprotected. The grid and dielectric layers in the protuberances are then etched away to reveal the tips through the resulting apertures in the grid and dielectric layers. The apertures are thereby automatically aligned with the tips without the need for lithographic processes.