According to reports, solar powered Apple products are coming soon. The company have just applied for a patent for utilising solar cells in portable devices.

Since much of the surface of a handheld device is occupied by buttons and similar components, the patent specifies putting the solar panels under the display. Devices described in the application include both handheld and portable computers.

Phones like the iPhone have a large screen and the larger the surface area, the better for catching solar rays. According to the patent, the solar panels would be stacked behind the LCD display, absorbing light rays that pass through the display. This makes the iPhone and iPod candidates.

An analyst for Jupiter Research, noted that some small devices, such as wristwatches or calculators, are solar-powered, but otherwise the potential has only recently emerged for larger portable devices to be energized by the sun.

The analyst, Michael Gartenberg suggested that solar power, at least in the short term, may be employed for short-term recharging or in other supplementary ways, rather than as the exclusive power source.

Other mobile phone companies are also starting to think of the sun as more than just a warm, fiery star. Last month, for example, Vodafone said its plans to dramatically cut its greenhouse-gas emissions included solar-powered phone chargers.

Motorola has already received a patent, originally filed in 2001, for a screen that lets more light through than other designs.

As an LCD is a reflective screen (only six percent of rays get through), Motorola claim to have developed a screen that allows 75 percent ray absorption.

In recent years solar power has begun to be used in a variety of settings as a source of electricity, but there are still substantial technical issues for mobile devices. The Motorola patent, for instance, notes the limited area for solar-panel surfaces, the durability of the panels, and other issues.

If Apple’s patent is approved, it could be quite a few years before we see solar powered gadgets. Apple has already applied for a patent for a new messaging interface for touchscreens, which has media features that the iPhone can’t currently perform. It has also recently filed patents for head-mounted displays and a three-dimensional display system.