An Apple patent application dated Thursday has sparked speculation among bloggers that the computer maker may be planning an iPhone light that would focus only on voice communications and music.

Filed with the U.S. Patent and Trademark Office, the patent application covers the use of a scroll wheel, similar to what's used on the Apple iPod, as the control mechanism for the device.

"The invention pertains to a user interface for controlling an electronic device, particularly a multifunctional device that is capable of operating in multiple modes as for example a phone mode for communications and a media player mode for playing audio files, video files and the like," the application said.

The disclosure, first reported by the blog Unwired View, sparked speculation that Apple could be planning to release a cheaper version of the iPhone without the Web access, Wi-Fi support, e-mail, calendaring, and other functionality found in the original, which was released June 29.

Instead, the simpler version would use the scroll wheel to control only voice communications and the music player.

"While there is a huge market and a lot of happy potential iPhone users, the market for a cheap and simple device like iPhone Nano, that just makes calls, plays your music and does it really well, may be just as big," Unwired said. Nano is the brand Apple uses for the no-frills version of the iPod that only plays music and podcasts.

Blog and gadget guide Gizmodo went on to say that the patent application was an indication that Apple "is probably not going to abandon the click wheel just yet." The iPhone's biggest innovation, experts say, is its touch-screen interface.

Apple is unlikely to participate in the speculation over its recent patent application. The secretive company has a policy of not commenting on its plans for future products.