On-cell touch architecture
Integrated touch screens are provided including drive lines formed of grouped-together circuit elements of a thin film transistor layer and sense lines formed between a color filter layer and a material layer that modifies or generates light. The common electrodes (Vcom) in the TFT layer can be grouped together during a touch sensing operation to form drive lines. Sense lines can be formed on a separate layer dedicated to only touch hardware.
1. An organic light emitting diode touch sensitive device including a plurality of display pixels, the device comprising:
an encapsulation layer;
a cathode layer, the cathode layer containing circuit elements that can be configured to operate as drive lines in a mutual capacitance touch sensor during a touch mode of the device and as display hardware during a display mode of the device;
an anode layer, the anode layer containing circuit elements that can be configured to be stimulated when the drive lines of the cathode layer are stimulated during the touch mode of the device; and
an ITO layer, the ITO layer disposed above the encapsulation layer.
2. The touch sensitive device of claim 1 , wherein the cathode layer is configured to act as cathodes in an OLED display during a display mode of the device.
3. The touch sensitive device of claim 1 , wherein the cathode layer can switchably operate as display circuitry during a display mode of the device, and as touch circuitry during a touch mode of the device, and wherein the display and touch modes are time multiplexed.
4. The touch sensitive device of claim 1 , wherein the ITO layer is configured to act as sense lines in a mutual capacitance touch sensor during a touch mode of the device.
5. The touch sensitive device of claim 4 , wherein the drive lines are arranged in vertical columns, while a plurality of sense lines of the device are arranged in horizontal rows.
6. The touch sensitive device of claim 4 , wherein the drive lines are stimulated with signals that are based on elements of a matrix stored in a memory of the touch sensitive device.
7. The touch sensitive device of claim 6 , wherein the matrix is a Hadamard matrix.
8. The touch sensitive device of claim 6 , wherein the matrix is a circulant matrix.
9. The touch sensitive device of claim 6 , wherein the matrix is an identity matrix.