Patent GB-1333194-A (GB)
Title: Electrica comparison systems
IPC: G10L15/24
Filed: 1972-03-07
Abstract: 1333194 Comparator; selective signalling; voice and character recognition A P PEDRICK 7 March 1972 10443/72 Headings G4H G4M and G4R In an electrical comparison system, e.g. searching technical data, a filing system, comparing "voice-prints" to operate a typewriter, scanning written words and, by comparing them with stored tape-recorded words, producing them as spoken words, or translating spoken words into a selected foreign language by comparison with stored foreign words, electrical impulses from one of the signals to be compared are transformed into pressure impulses by a transducer at the base of a column (the left-hand one in Fig. 4, not shown) containing a fluid and a series of apertured plates (30) movable between fixed pairs of contacts (31) in the column. Plates (30) have electrically conductive upper faces and non-conductive lower faces. The impulses moving upwardly through the fluid lift a corresponding number of the plates (30) so that they bridge corresponding contacts (31), a diaphragm switch at the top of the column also being closed by the impulses to connect one terminal of a battery to the lefthand contacts (31). The right-hand contacts (31) are connected to condenser plates (1-7), and the condenser plates connected to the bridged contacts are charged by the battery. A second column (the right-hand one in Fig. 4) has contacts (31<SP>1</SP>), and plates (30<SP>1</SP>) with non- conductive upper surfaces and conductive lower surfaces. When impulses are fed into the right-hand column by a transducer operated by a second signal to be compared with the first signal, a number of the plates (30<SP>1</SP>) corresponding to the signal are lifted, and the remaining plates bridge their corresponding contacts, the diaphragm switch at the top of the right-hand column being actuated to connect the other battery terminal to charge the condenser plates (2-7) connected to the bridged contacts. The plates (1-7) charged by the previous signal in the left-hand column remain charged, and if the second signal in the righthand column is the same as the first, the corresponding plates (2-7) will not be charged, so that no current will flow through a solenoid (3), and a switch (4) will remain closed. If the signals are not the same, some of the plates (2-7) corresponding to the charged plates (1-7) will be charged, and a current will flow to energize solenoid (3) and open switch (4). In the voice-print application, Fig. 1 (not shown), the voices to be compared are converted into square tooth waves which are used to actuate the transducers of the fluid columns. In the technical data search application, Fig. 2 (not shown), a coded signal corresponding to the required data is fed into one comparison column, and into an identification signal producing device, Fig. 3 (not shown) comprising a plurality of fluid-filled vertical columns with spring finger contacts (21) at regular intervals. Each column has a ball (20) of conductive material which is moved up the column by pressure pulses applied at the bottom of the column by a transducer (22) actuated by a particular frequency pulse separated from the signal by frequency discriminators (23). The balls rise to different heights in the columns according to the number of pulses of each frequency in the signal. A delay switch device (25) is connected between the contacts of adjacent columns at each level, the time delay being different at each level, so that when a circuit including the delay switches, contacts and balls is closed by a correct "match" in the comparison system, a signal is produced comprising a series of "pips" with delays between them corresponding to the different heights of the balls. The system for scanning words and "speaking" them, Fig. 6 (not shown), comprises a slide (41) with glass fibre tubes (42) which scan a slotted plate placed over the word, the tubes being connected to a drum scanned by a photo-electric cell (44) connected to a pressure transducer (46) of the comparison system, a store of recorded words also being connected to the comparison system, and the selected word fed to a loudspeaker. In the system for translating spoken words into a selected foreign language, Fig. 8 (not shown), the word spoken into a microphone is compared with stored tape-recorded words in the selected foreign language using the comparison system.