Electronic shelf label with photosensitive standby wakeup function

摘要

An electronic shelf label comprises a photosensitive wakeup unit for generating a wakeup voltage when light from a light source is incident upon a light sensor to awaken the unit from a power saving standby / sleep mode. In particular, the light sensor is responsive to light from a scanner, e.g. a barcode scanner, used with labels 130 also forming part of the electronic shelf label. A light transmitting unit 140 may be provided to transmit light incident on the front of the label to the light sensor. The light sensor may comprise a light sensitive thin film transistor TFT device which in combination with a capacitor generates the wakeup voltage.