The internet is the most popular media for social networking and the sharing of pictures and videos. Media-centric phones are gaining market share over voice-centric phones, causing a migration to larger size and higher resolution color displays. The backlighting of these displays demand higher power from portable battery sources. Beyond the display, the mobile handset is becoming a high quality digital still camera requiring special lighting functions for video-recording and photography in low light environments and consuming more battery peak power and energy.

Light-emitting-diode (LED) technology is widely used to provide illumination for the pixels in small format liquid crystal displays (LCDs) in battery-powered applications. White light, emitted by the LEDs, is transmitted through a polarizer to the LCD where the light can be blocked or attenuated and sent on to RGB color filters to create colored light.

The very same LED technology can be used to illuminate a scene when taking a picture with a camera phone in dim light conditions. How much light is needed? How much current will the flash unit consume? Answering these questions can guide the designer in the selection of the appropriate LED flash unit.

Read the full article by clicking here (no registration required)