Abstract: A document interpreting system comprises a graphics tablet on which a stack of documents, e.g., a book, to be interpreted are stacked, a pointer associated with the graphics tablet and operable through the stack of documents whereby the co-ordinates of an area of the topmost document to which the pointer is directed may be determined, speech storage typically in the form of a compact disc, for storing speech relating to the different areas of the documents being interpreted and speech reproduction meas, typically in the form of a compact disc player for reproducing speech relating to an area of the topmost document to which the pointer is directed.

Abstract: A signal processing system for time varying band-limited signals such as speech comprises signal coding means for affording a time encoded signal symbol stream, a matrix generator for generating a fixed size, typically "A" matrix from the symbol stream, and an artificial neural network to which the matrix elements are applied for network training and subsequently for affording an output indicative of the nature of an input signal.

Abstract: A voice recognition system for time encoded speech (TES). The TES coded stream is divided into time frames. Each time frame is fed to a number of seeker circuits, each seeker circuit being optimized to detect an acoustic event of the voice signals, such as voiced or unvoiced events, amplitude or silence (ambient noise). Segmentation boundaries in the TES symbol stream are then determined from the acoustic events sensed as present or absent. These events are compared with stored events to determine the voice signals. By using this parallel comparison technique, comparison is made using distinct boundaries determined from the voice signal content and not by arbitrary boundaries which may contain acoustic events from, for example, more than one word in the voice signals. The implementation of the TES recognizer in low cost complimentary metal-oxide semiconductor (CMOS) technology makes this parallel comparison technique feasible at a reasonable cost.

Abstract: An analog waveform such as speech is encoded by dividing the data stream into successive time frames consisting of Time Encoded Speech (TES) symbols. The distribution of the TES symbols in each frame is compared for successive frames whereby a small change causes a repeat code in place of a frame of corresponding digital signal data.

Abstract: There is provided an automatic voice recognition system which utilizes time encoded speech. Through the determination of zero crossing information and waveform parameters of an input voice signal, a stream of time encoded speech symbols is obtained. The stream of time encoded speech symbols is then converted into a matrix format for comparison with reference matrices formatted from time encoded symbols of reference words thereby to provide an output signal indicative of the content of the input voice signal.

Abstract: A speech waveform is encoded to reduce storage capacity or transmission bandwidth requirements. The invention encodes two features of the time waveform, for example (1) duration of half-cycle, and (2) shape, e.g. number of maxima or minima of the waveform within that half cycle. The duration of each half cycle and the associated shape data constitute a pair of primary-code symbols. Each pair of primary code symbols may be represented by a single secondary code symbol using a mapping table. The number of secondary symbols may be reduced by grouping within the mapping table. Redundant sequences and inefficient transmission codes are deleted for further data reduction. Envelope peak value may be stuffed with the mapped signal for storage or transmission. Corresponding decoding provides speech synthesis.

Abstract: To permit panning and tilting of the foreground camera when composite images are being produced by the color separation overlay or chroma-key technique, signals representing the panning and tilting motions of the foreground camera are used to control the movement of the background image in front of the background camera in two mutually perpendicular directions.

Abstract: In the casting of aluminium and other metals having a relatively low melting point, the metal is cast between a pair of belts, which are caused to move along precisely defined paths by means of externally applied attractive forces, which hold the outer surface of at least the upper of the belts against closely spaced support surfaces. The attractive force is preferably achieved by sub-atmospheric pressure conditions on the reverse side of the belts, although magnetic forces may be employed for the same purpose. The belts are preferably arranged to provide a casting cavity of decreasing thickness to maintain close contact between the belt and the solidifying metal to secure rapid transfer of heat from the metal to the belts throughout the length of the casting zone. The cooling of the belts is preferably achieved by directing jets of coolant substantially normally to the belt at closely spaced localities.