Sharp Realizes 'Invisible' NFC Antenna on Entire Display Screen

- Apr 22, 2019-

Sharp Corp developed a display that has an NFC (near field communication) function on the entire screen.

Currently, most smartphones function as NFC cards, and the number of NFC-compatible credit cards is increasing. On the other hand, the number of users that have NFC card readers for electronic payment is not increasing. Therefore, it is not possible to say that the use of NFC for electronic payment via a network is not becoming common. Sharp developed the display to address this problem.

The new technology supports display sizes of up to 42 inches, and the company plans to commercialize it in or after fiscal 2019.


Advanced touch panel technology


The new display technology consists of a (1) technology to make an NFC antenna almost transparent and (2) technology to place the antenna on the entire display.

At this point, with the first technology, the light transmittance of the antenna is 80% or higher. This was realized by applying the "metal mesh technology for touch panels," Sharp said. Though the company did not disclose further details, silver (Ag) fine lines are probably used for transparent electrodes and transparent electric wiring.

There is a trade-off between the light transmittance and electric conductivity of ITO (indium tin oxide), which is commonly used for transparent electrodes. But Ag fine lines are not influenced by the trade-off much.

The communication range, which is an indicator of antenna performance, is 3.0-3.5cm on most parts of the screen. It is longer than 2.5cm, which is required for common NFC antennas, Sharp said.