Abstract: A radar for a terminally-guided sub-munition is capable of differentiating between spatial depositions of target scatterers and clutter. The radar frequency f is swept, in stepwise manner, over a frequency range F, the frequency of 2N successive batches of M pulses being incremented in steps of f = F 2 ? N . To minimise variability of hybrid spectrum with relative target velocity, v, a duplexer transmits the 2 NM pulses with a monotonic frequency sequence derived from control circuit and the returns being reordered.

Abstract: An imaging system for the generation of an apparent three-dimensional (3-D) image suspended in space for direct vieiwing includes a beamsplitter and a retroreflector. The optical property of reflecting light back along its original path enable the system to generate such an apparent 3-D image based on the perception of depth cues present in the original scene for viewing.

Abstract: Apparatus for use with an autocorrelation technique for characterizing fingerprints includes an imaging device for providing an image of a fingerprint. The image so produced is then utilized by a microprocessor in order to generate an autocorrelation pattern for statistical comparison with stored data so as to determine whether the image of the fingerprint under test is derived from the fingerprint representated by the stored data.

Abstract: A directly viewable fingerprint image is formed by illuminating a transparent planar substrate from one surface with collimated light, the substrate having pressed against the other surface a fingerprint to be imaged. Light striking the surface against which ridges of the fingerprint are in contact undergoes internal reflection within the substrate and causes a directly viewable image of the fingerprint to be formed by a direct image producing means.

Abstract: An optical modulation device includes first (1,4,6) and second (2,5,7) optically transmissive parallel plates having a ferroelectric liquid crystal material sandwiched between them. A plurality of spacer members (10), each secured to one of the plates, are located between the plates to maintain the plate spacing. The spacer members form walls defining parallel liquid crystal material-containing channels (11) which extend parallel to the plates. These channels communicate along their lengths with cavities (12) at least partly defined by the spacer members (10). These cavities may be created by segmenting each wall, the separations between the successive segments constituting the respective cavities. Alternatively, each wall may be provided with a parallel auxiliary wall of lesser height close to it but spaced from it, the space between the two walls forming a cavity.

Abstract: A method of analysing clusters of bearings (A, B, C, D) taken of distant sources by an array of direction finding stations. Each bearing has an error +E and a triangulation process is used to fix the position of the sources. A combination of bearings is taken one each from the stations. Each bearing of the combination is taken in turn as a spoke (3) directed at a source. The triangulation process generates a bar (31, 32, 33) of intersection points along the spoke for each other bearing of the combination, each bar corresponding to the error +E of each bearing. The number of overlaps between pairs of bars along a spoke is totalled to give a spoke score. The spoke scores of all spokes of the combination is summed to form a fix confidence score for a source which may be associated with the combination, or cluster, of bearings. Methods are also provided for rejecting redundant fixes associated with subsets of bearings within a cluster.

Abstract: A channelised bearing processor comprises a channelised receiver consisting of a plurality of i.f. receivers (34 to 42) covering contiguous parts of a predetermined frequency range. Each of the receivers (34 to 42) is connected to a respective, continuously energised local oscillator (35 to 43). A plurality of direction finding antennas (10 to 15) are coupled to respective receiving channels for producing an amplitude signal. Each receiving channel includes a tunable i.f. receiver (24A to 24F) having an input (26A to 26F) for a local oscillator signal. A local oscillator selector (50) is responsive to an output from one of the channelised receivers (34 to 42) to connect the local oscillator (35 to 43) connected to that one of the channelised receivers (34 to 42) to the local oscillator signal inputs (26A to 26F) of the tunable i.f. receivers (24A to 24F) in the receiving channels.

Abstract: A thermal imaging device includes detector pixels A, B, C provided by a pyroelectric layer 1 arranged between electrode structures 3 and 4. A photoconductive layer 7 is provided between the electrode structure 5 and a further electrode structure 9. The device also includes an illumination source 11 for illuminating the photoconductive layer 7 for enabling pyroelectric charge developed by the detector pixels A, B, C to be optically addressed via the electrode structure 9. Optical addressing of the detector pixels obviates the need for solid state switching connections to each pixel, providing an imaging device readily capable of large scale fabrication.

Abstract: An apparatus for calculating the root square sum of a plurality of values includes a serial commutator for receiving input signals indicative of the values, serially coupled with a root mean square to direct current circuit for providing an output signal indicative of the root square sum of the values. The apparatus may include a plurality of magnetometers for measuring the total value of the magnetic field.

Abstract: A color sequential illumination system, such as, for example, a backlighting system for a liquid crystal display (LCD), comprises lamps for emitting blue, red and green light. The red and green light is provided by lamps including fluorescent dyes having optical decay times similar to a phosphor material used to provide the blue light. In this manner, the blue, red and green emissions can be fully synchronized with electrical signals used to energise the lamps, enhancing color range and color quality. Furthermore, if the fluorescent dyes are carried in plastics materials, then trapping and concentration of the light generated may also be achieved, providing enhanced brightness for the LCD for a given power input.

Abstract: An infrared imaging arrangement using a chopping device for periodically blocking exposure of an array of detector elements responsive to infrared energy by using a plurality of individually-mounted cells. There is a non-reciprocating rotary mechanism used for moving the cells substantially orthogonal to the array in such a manner that constant orientation of the cells is maintained in order to expose the array to energy via the cells. Since the cells orientation is maintained, the shift of energy relative to the array increases the arrays ability to resolve spatially sources of energy. There is also an infrared blocking piece used for blocking the infrared energy from impinging on the array.

Abstract: A color sequential liquid crystal display, such as a television display, includes a lattice of selectably settable pixel elements which are time multiplexed addressed and illuminated during addressing to produce sequential red green and blue light outputs in any display period. The addressing of pixel elements in successive frame periods is arranged to occur in opposing directions so as to compensate spatial intensity variation which would otherwise arise from illumination of the pixel elements during the addressing.

Abstract: In a method of forming a solid article of predetermined shape from a liquid which can be cured by exposure to radiation, a surface upon which the article is to be formed is provided. A predetermined region of the surface is exposed to a beam of radiation. Liquid is then supplied to an unexposed region of the surface such that a solid barrier, defining a surface of the solid article, is created at the interface of the liquid and the beam. The solid barrier is effective as a mold to contain the liquid which has been supplied but not yet cured until this liquid is cured. Such a method can be used to encapsulate a microelectronic device.

Abstract: An apparatus is provided for measuring the concentration of a substance in a sample solution. The apparatus comprises first electrode means, second electrode means and an enzyme channel between the first and second electrode means. The enzyme channel contains an enzyme for catalyzing a reaction of the substance whose concentration is to be measured. In use, a known volume of the sample solution is presented to the first electrode means in a test solution including an excess of a mediator, one of reduction or oxidation of the mediator being coupled to the reaction of the substance. The first electrode means is arranged to ensure that the mediator is respectively completely oxidized or reduced, and also to remove any interferent species. The test solution is then passed through the enzyme channel so as to permit reaction of all of the substance present in the solution, whereby a quantity of the mediator is respectively reduced or oxidized.

Abstract: A thermal imaging device comprising a pyroelectric layer having on one major surface an array of interconnected electrodes forming an entrance face, and on the opposite major surface an array of discrete electrodes connected to electrical circuitry formed on a semiconductive substrate. Between the entrance faces of individual detector elements in a network of further electrodes of high thermal conductance which provides a high degree of thermal isolation for the detector elements and prevents significant thermal cross-talk between adjacent detector elements.

Abstract: A screen for use in a front projection system includes a section capable of reflecting light of certain, predetermined wavelengths more than light of other wavelengths. The screen appears black or dark gray when viewed in broadband light. The screen provides for enhanced contrast between incident projected and ambient light. A projector for use with the screen has a light source capable of emitting the predetermined wavelengths.

Abstract: A flow sensing device includes a semiconductor substrate 31 and a pivoted beam 1. Below one half of the beam is a channel 7 running throughout the substrate 31, and below the other half of the beam is a cavity 8. During operation, a differential force exists across the beam, and the amount of force required to compensate for this differential force is indicative of the rate of fluid flow.

Abstract: The display has a video signal receiver and a store with a capacity to hold one picture of the video signal. Row-output devices enable the video information for respective rows of pixels to be taken out from picture store, and each has a bit extractor to separate out one bit of the information for each pixel of the respective row. The resultant signal is passed to pixel drivers which operates on a lattice formed of ferroelectric liquid crystal pixel-elements, which are time-multiplex addressed according to a predetermined sequence, each row being addressed a plurality of times for each picture. In the addressing groups of the rows are set simultaneously, each group consisting of a plurality of rows spaced apart in the addressing sequence such that the rows in a group form a series with adjacent rows having a temporal separation in the addressing sequence exhibiting a geometric progression with the common ratio N being an integer corresponding to 2 or more.

Abstract: A liquid crystal display cell comprises first and second substrates located in a substantially parallel relative arrangement to define an active display region therebetween when filled with liquid crystal material. The cell further includes means to effect filling of the active display region with liquid crystal material from at least a part of an edge of the active display region.

Abstract: Column circuitry for a CMOS static RAM includes a bit line clamp combined with a bit line current source regulated by a voltage reference which tracks changes in transistor characteristics. Separate data read and data write lines are provided, with a differential amplifier for each pair of bit lines. The data read lines are coupled to compensated current source loads, and the differential amplifiers are couplled to switching transistors which are also compensated for transistor characteristic changes, Each bit line pair has a sneak capacitance prevention transistor so that in non-selected columns the bit line pairs are coupled together allowing the memory cells therein to pull down all of the bit lines. This isolates the read lines from unwanted capacitance in the differential amplifiers of each of the non-selected columns, Further, a VCC protection circuit is provided.