91av

As the screens on mobile phones and PDAs get bigger and more colourful, they soak up more battery power. The Japanese consumer electronics company Matsushita which owns the Panasonic brand, has a simple idea that might help (GB 2384400). Many screens emulate computer displays by showing black text on a white background. This means switching on almost all of the LCD pixels to give the white background and leaving only a few pixels switched off to produce the black text. Matsushita’s idea is to reverse the display like a photographic negative when the user is talking. The text is displayed as white on black, thereby saving power. The reversal happens automatically when a call connects or when an infrared sensor detects that the phone is next to the ear.