Apple was today granted a patent for LCD touchscreens that integrate the touch sensing equipment right within the display circuitry. Present LCD touch screens require an extra layer of touch sensing components, which make the screen and as a consequence the whole phone thicker.

In-cell displays, another name for the technology described in the patent, due to their low space requirements have been rumored to be included on the new iPhone since the past few months. The patent, though, was filed way back in June 2007.

Traditional LCDs involve a number of layers sandwiched between the top and bottom glass, including the liquid crystals and a layer to detect touch.

Apple’s description of in-cell displays:

By integrating the layered structure of an LCD and a touch sensor, a variety of benefits can be achieved. This integration can include combining or interleaving the layered structures described above. Integration can further include eliminating redundant structures and/or finding dual purposes (e.g., one purpose for the touch function and another for the display function) for particular layers or structures. This can permit some layers to be eliminated, which can reduce cost and thickness of the touch screen LCD, as well as simplify manufacturing.

There can be various possible ways to fuse the touch sensing and the display layer together. Of particular interest to Apple is a way which uses electrodes to do both tasks, since it works with IPS panels found in many iOS devices and conventional displays found in other Apple devices. AppleInsider explains:

In one of Apple’s patent concepts regarding an in-cell IPS panel, the technology can “provide touch-sensing capabilities by allowing the same electrodes used for display updating to also be used for touch sensing.” This sharing of electrodes is necessary as IPS displays lack the requisite layer to apply a touch drive or touch sensing elements. The patent goes on to say the additional circuitry can help augment the shared electrodes and in some cases “touch pixels can overlap a large number of display pixels.”

The new display technology could cut the iPhone’s thickness by as much as 15 percent. Although the iPhone 4, at 9.3 mm thickness, was one of the thinnest smartphones when it debuted, new smartphones have beaten the iPhone in both slimness as well as weight.