Microsoft has filed a patent application covering a technique for creating a tactile touch screen that changes its shape to make a textured surface, circumventing the need for a traditional keyboard.

The system relies on tiny pixel-shaped plastic cells that protrude from the screen's surface when cued by different wavelengths of ultra violet light directed from below the screen. The wavelengths turn on and off as the user touches the screen's surface and light is reflected off the fingers to sensors below.

While other attempts at tactile screens give only the illusion of texture, Redmond, Washington-based Microsoft's approach is to create real texture, according to New Scientist, which reported on Monday the company's patent application.

The system would allow users to type on a screen without looking and could also help those with limited vision to feel braille.

The innovation is designed for Microsoft's table-sized computing display called the Surface, which is used in schools and businesses, but the potential exists for it to be transferred to mobile devices such as phones and tablets.

However, the company never comments on its patent applications so it's not clear how close it is to commercialization.