FPC-free LCD panel with capacitive coupling for transmission of signals and power

A flexible-printed-cable (FPC) free liquid-crystal-display (LCD) panel by using a capacitive-coupling technique has been developed. AQQVGA eight-color image was successfully displayed for the first time without attaching any signal or power cables to the panel. The receiving circuitry and capacitive-coupling electrodes were integrated on the LCD panel using a low-temperature polysilicon (LTPS) fabrication process. In the proposed digital coding method, the receiving circuit converts derivative waveform signals via the capacitive coupling to conventional logic-level signals. The maximum data rate of 2.4-Mbps x 3ch (RGB) was achieved. In addition, LTPS low-capacitance diode bridge and regulator enabled us to obtain stable DC power of 2.4 mWon the panel from the AC-power signal. This study is the first step towards integrating the wireless-communication function on the display panel to achieve a high-value-added flat-panel display (FPD).