| 摘要 |
<p>A product pricing system for supermarket shelf labels (14) comprises an electronic data transmission system which transmits pricing information to electronic shelf labels (14) by modulating a data information signal (33) in the electric supply to artificial lighting (13) in the environment of the labels. The labels have a solar cell (16) for providing operating power and a photodetector (15) for detecting the data information signal in the artificial light. The data contains address information and data relevant to pricing, storage and sale of items and is displayed by a shelf label LCD display (17). The modulation is by way of phase modulation in a central contol unit (12). Each module incorporates a re-chargeable battery (18) and an adjustable timer for timing the interval between broadcasts to the particular module whereby the particular module is caused to flash its LCD display in the event that a broadcast is not received within a predetermined time to alert personnel of a possible fault in the module or system.</p> |
