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Apple Receives Patent for In-cell Touchscreen Technology

iPhone 4S

Source: iPhone 4S | Apple

Apple received a new patent last Tuesday for touchscreen LCD technology. This system enables the integration of touch-sensing elements and display circuitry to make a thinner and lighter panel. That being said, the in-cell touchscreen technology is likely to land on the company’s smartphone.

Touch Screen Liquid Crystal Display Patent

Also known as “Touch Screen Liquid Crystal Display,” the US patent 8,243,027 describes various ways of how a touchscreen’s touch-sensing elements can be integrated within the LCD. In fact, the filing cross-references a number of properties with regard to multi-touch and LCD technologies.

Currently, phone manufacturers employ placing the touch layer over a device’s screen. In iPhone 4S, the LCD touchscreen technology is glass-on-glass or “on cell.” This means that the touch-sensitive capacitive element of a screen is sandwiched between a display unit’s top glass and the Gorilla Glass protective layer. Beneath the LCD’s top glass is the liquid crystal array, bottom glass, and backlight assembly.

With in-cell technology, a top substrate or glass layer is no longer required. That’s because the liquid crystal and touch-sensing elements are now formed in a single structure. Furthermore, there are different ways to do this. As stated on Apple’s patent filing:

By integrating the layered structure of an LCD and a touch sensor, a variety of benefits can be achieved. This integration can include combining and 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.

In-cell IPS Panel

One of the methods mentioned in the patent filing is of particular interest for Apple, as it can be implemented either in conventional or in-plane switching panels. As of the moment, the IPS panels are used in iPhone 4S’ Retina Display and a bevy of other iDevices.

With regard to the company’s concept about in-cell IPS panel, it was mentioned that sharing the same electrodes for display updating and touch sensing can enable this technology to feature touch-sensing capabilities. This is important for IPS displays, as it lacks the needed layer to apply a touch drive or touch sensing elements.

In-cell Touch Display for Next-generation iPhone

Rumors that the next-generation iPhone will feature an in-cell touch display started to emerge in April. There were also claims that this technology can trim down the smartphone’s thickness, as it will allegedly boast a 4-inch screen, but whether the upcoming mobile phone will sport an in-cell touch panel or not remains to be seen.

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