Panasonic claims to have developed a new way to drastically increase the colour and light sensitivity of digital cameras.

The Osaka-based electronics company said Monday that its method replaces the colour filter arrays widely used in such devices to capture individual colours, using tiny prism-like colour splitters instead. The company said the new method can double the colour sensitivity of image sensors, leading to far brighter images under the same lighting conditions or similar image quality at half the light.

Most image sensors on the market detect only the intensity of light they are exposed to, and so must rely on filters to provide colour information. Each pixel in a sensor sits under a tiny filter that lets through only a single colour. In the widely used Bayer filter, light is filtered into red, blue and green, with green given half the total pixels and the remainder split between the other two colors.

But Panasonic said this filtering method blocks much of the light before it reaches the sensor pixels, letting only 25 to 50 per cent through. The company's "micro color splitters" use a super-thin transparent and refractive material to diffract light into combinations of white, red and blue, with no loss of light, which can then be translated back into standard colours mathematically.

Colour me good

The new filters can be used with existing image sensors, including the most commonly used CCD and CMOS varieties. The company said they can be manufactured using existing chip production techniques, and the computations involved are based on a newly developed method of analyzing the optics involved.

A Panasonic spokeswoman said the company doesn't have a schedule for commercializing the new technology.

The company said the new method for filtering colors is described in the latest issue of the publication Nature Photonics. It said it has obtained or applied for 21 Japanese patents and 16 overseas patents in regards to the new technology.