Infrared transmission/reception unit used for acquiring goods information in supermarket, is switched to transmit high frequency modulated IR signal and low frequency modulated IR signal through same path

摘要

The IR transmission/reception unit (11) mounted in housing (10) installed on floor surface, communicates with IR transmission/reception unit (21) mounted on shopping carts (2) and the electronic price indicators (41-46) mounted on shelves (3). The IR transmission/reception units are sequentially switched to transmit high frequency modulated IR signal and low frequency modulated IR signal through the same path.