Display device for use with e.g. telephone, has light source including electroluminescent diode whose emission spectrum is controlled by modulation unit which varies spectral bands of light rays reaching pad filters

摘要

The device has a key board with pads equipped with respective filters (612-614, 622-624) and electrical switches (616, 626). A light source has an electroluminescent diode (630) whose emission spectrum is controlled by a modulation unit (640) via the diode`s supply voltage. The filters are placed in an optical path of light rays coming from the light source. The unit (640) varies spectral bands of light rays reaching the filters. An independent claim is also included for a display process.