Motorola has been awarded a patent for technology the company says will make it possible to recharge the battery of mobile phones through solar cells embedded within the liquid crystal display.
The idea is not new, but Motorola claims in the patent that it has solved the problem of getting enough light to the solar cells to recharge the battery.
If Motorola were to successfully go to market with such a product, then the company would effectively eliminate the need to recharge a cellular phone's battery through a separate transformer that plugs into an electrical socket. The phone would always be charged.
Motorola believes it can get 75% or more of the light entering through the front of an LCD to the solar cell by using a different type of liquid crystal. By switching from nematic crystals to cholesteric or polymer disbursed, Motorola says it can eliminate the use of a metallic reflector that's used in LCDs to illuminate the screen. The use of such reflectors reduces the amount of light that could reach a solar cell to less than 6%, which is insufficient to recharge the battery.
While technologies addressing the problem have been patented before, Motorola's invention is a "more commercially acceptable solution," the company said in the patent.
"Relatively ordinary and cost-effective liquid crystal display technologies can now be utilized successfully to provide an acceptable display and nevertheless provide an acceptable level of light to a stacked solar cell," the company said.
The patent appears to have been awarded last month. Motorola was unavailable for comment. Solar cells are used today to power very low-power electronic gadgets, such as calculators.