On Cell touch technology that can be applied to a 10-inch or larger-area foldable panel with a single semiconductor chip (IC) has been developed in Korea. On Cell touch is a technology to make a touch-integrated panel by mounting a touch sensor on an organic light emitting diode (OLED) panel. The display size that OnCell Touch can cope with has been limited to 8 inches until now based on flexible OLEDs. Now that it is expected to work with 10-inches or larger, it will facilitate the development of foldable smartphones or tablets that can fold the screen twice.
G2 Touch announced on the 5th that it has developed a technology that can implement On Cell touch up to 12 inches with a single IC. The company explained it completed development and performance evaluation of customers for the past two years and prepared for mass production. In the display field, 8 inches had been considered the limit for On Cell Touch. The panel (7.6 inches) applied by Samsung Display to the Galaxy Fold 3 is the largest among the single IC applied on-cell touch OLEDs so far.
In general, when the display electrode (EL electrode) and the touch sensor electrode become closer or the touch pad area increases, the parasitic capacitance increasesand the touch performance is deteriorated. For this reason, the Add-On method of adding a touch sensor on the top of a display was mainly used for medium-sized sizes of 10 inches or more. However, this requires separate touch film to be made, raising the burden of cost increase and setting an obstacle in making thinner display.
G2 Touch announced that it has improved the size problem with a ‘Self-Dot’ touch sensor structure. They explained that they have chosen to increase the number of pads instead of touch sensor area to prevent an increase in parasitic capacitance between the display electrode and touch electrode.
Joo-chan Pyo, CEO of G2Touch, said, “The parasitic capacitance increases as the area of each pad increases, but Self-Dot increases the number without changing the area, so the parasitic capacitance is not affected.”
If On Cell touch becomes possible up to 12 inches, it is expected to be useful in development of new types of foldable smartphones and tablets. The larger screen makes advantageous for double-folding or implementing various design products with different proportions. Moreover, using two ICs makes it possible to cope with 20 inches or more.
CEO Joo-chan Pyo of G2Touch said “OnCell Touch technology can reduce the number of parts and simplify the structure to reduce costs. With this realization of large-area, we will support the acceleration of the development of various form factor displays and devices – in-folding, out-folding, and Z-folding.”
By Dong-jun Kwon, Staff Reporter djkwon@etnews.com