Clearer photos in a flash

An Australian study has shown that adding a thin supercapacitor to the LED flash in camera phones can provide sufficient light energy for high-resolution pictures in low light conditions without compromising slimline design.

Sydney-based CAP-XX compared camera-phone flash solutions for their ability to provide the light energy that camera phones of 2-megapixels or more need to take digital still-camera quality pictures in low light. Ten to fifteen lux seconds (lux sec) of light energy is said to be ideal for high-resolution pictures.

High-current LEDs need up to 400 per cent more power than a phone battery can provide to achieve full light intensity. CAP-XX claims its BriteFlash LED flash power architecture delivers the pulse power of more than 1A needed to drive high-current LEDs. The phone battery is only needed to recharge the supercapacitor for two seconds between flashes.

The study compared camera phones with xenon flash tubes driven by electrolytic storage capacitors against a supercapacitor-powered four-LED array at a current of 1A each. The supercapacitor delivers 15 watts of pulse power to the LEDs, compared to a battery which can only deliver 1 – 2 watts