Abstract:
An electro-optic display comprises a two dimensional array of liquid crystal cells (C11A,B to C44A,B) each switchable by means of electrical signals applied to respective pairs of address lines connected to the cell by respective transistors (T11 - T44). Each main electrode of each transistor is isolated from the rest of the array by a respective cell of the array.
Abstract:
A display device which is corrected for vibration, for example between screen (4) and the electron gun (2) in a C.R.T. (1). The device comprises an optical system (6) on the observer side of the screen (4) for directing the light from a small part of the screen (9), onto which the electron beam is directed at intervals, onto a photocell (10) which detects the position of the light spot. The output signal from the photocell is processed in a circuit (5) to provide a correction signal which is applied to the deflection system (3) of the C.R.T. to reduce the deviation of the light spot from the position it would have in a vibration-free environment.
Abstract:
A droplet generator for a continuous stream ink jet print head comprising: an elongate cavity (13) for containing the ink; nozzle orifices (15) in a wall of said cavity for passing ink from the cavity to form jets, said nozzle orifices extending along the length of said cavity; and actuator means for vibrating the ink in said cavity such that each said jet breaks up into ink droplets at the same predetermined distance from said wall of the cavity, said actuator means being disposed on the opposite side of said cavity to said wall and comprising vibration means which is divided up along the length of said cavity at least partially into at least two parts, characterised in that said actuator means further comprises a backing member (21) disposed further from said cavity than said vibration means and secured to and bridging said parts into which said vibration means is at least partially divided, said vibration means being interposed in line between said backing member and said cavity.
Abstract:
An integrated circuit includes a monitor circuit (1, 3) designed to fail prior to the rest of the integrated circuit whilst allowing the rest of the integrated circuit to function. A warning circuit provides an indication that the monitor circuit (1, 3) has failed.
Abstract:
Pleochroic fluorescent dyes of general formula (I), in which R is hydrogen or an aliphatic hydrocarbon radical containing not more than 20 carbon atoms and -CH2- between carbon atoms or adjacent to the bicyclo[2.2.2]octane residue may be replaced by -O-, may be dissolved in liquid crystal host material to form displays which are caused to fluoresce by incident low-energy ultraviolet initially absorbed by the liquid crystal host material and then internally transferred to the fluorophor. These dyes have greater stability to ultraviolet than other perylenedicarboxylic diesters while possessing good fluorescent properties and satisfactory order parameters. In formula (I), R is preferably a straight or branched alkyl and/or cycloalkyl group having 3 to 10 carbon atoms, preferably 5 to 7 carbon atoms. The liquid crystal host material preferably contains an energy-transfer agent such as a 4-substituted 4''-cyanoterphenyl. The 4-pentyl- and 4-propyl- bicyclo[2.2.2]oct-1-yl perylenedicarboxylates of formula I and solutions of these dyes in nematic liquid crystal host "E7" (a mixture based on cyanobiphenyls containing 8% 4-pentyl-4"-cyanoterphenyl) are described in examples.
Abstract:
An anti-dazzle filter (1) comprises a transparent substrate (2) to which are laminated a vertical polariser (3) and a yellow filter (4). The device may be incorporated into sunglasses or into a visor to reduce glare caused by bright sunlight. Alternatively, it may be used to reduce light back-scattered by fog or mist.
Abstract:
A method of manufacturing integrated circuits in which a number of conductive test structures (7) for monitoring electromigration are formed at different points on the wafer on which the integrated circuits (1) are being manufactured. Electrical connections (5) are formed between the test structures (7) on the wafer, and the resistance of the current path constituted by the structures (7) and connections (5) is monitored to determine whether any of the test structures (7) have failed.
Abstract:
A method of improving the electrical characteristics of a thin film (1 or 9) formed on a substrate (3 or 11) by a Langmuir-Blodgett process. The method comprises immersing the film (1 or 9) in a fluid (5 or 13) and applying an electrical potential to the substrate (1 or 9) such that a self limiting electrochemical reaction within the fluid (5 or 13) causes any voids in the film (1 or 9) to be preferentially filled.
Abstract:
A filter with a tailored output characteristic for example useable as a comb filter is fabricated by producing two or more biconical tapered portions in an optical fibre. The manufacture is controlled so that the resulting concatenated couplers have specified pass-band characteristics.
Abstract:
In a method of driving a matrix of ferroelectric liquid crystal devices in a TDM mode, each strobing signal comprises first and second pulses (20, 21) of opposite polarities and of different amplitudes, together with a dc voltage (26) which is applied from the end of the second pulse to the beginning of the first pulse of the next strobing signal on the same strobe line to cancel the dc level which would be caused by the unequal pulses. Data ON signals applied selectively to data lines of the matrix comprise two consecutive pulses (22, 23) of opposite polarities. Data OFF signals (24, 25) may be the inverse of the data ON signals or may comprise a constant dc level. The combination of the two pulses with a dc level to form each strobing signal means that only two strobe pulse time slots per frame are required for addressing each strobe line, as compared with the conventional systems in which four time slots per frame are required.