| 摘要 |
An information system comprises a master station controlling information to be displayed on a number of information units arranged remotely from said master station. The master station broadcasts instructions by modulated infrared signals, and these signals are detected by a photodiode within each information unit, said information unit also comprising a receiver and logic circuitry. The information unit further comprises an emitter diode in order that it is capable of acknowledging the receipt of instructions. Information is presented on LCD-type displays, e.g. digits, a graphic field, or other information fields, all being implemented in LCD-type displays. The display units are, in particular, applicable in shops or warehouses, e.g. supermarkets, where a display unit may be arranged adjacent each item of merchandise, serving the purpose of displaying e.g. the unit price on the information unit. The system according to the invention permits an automatic updating of prices and guarantees a reliable functioning through the facility of requesting verification signals to be transmitted from the individual information units.
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