Apparatus and method for a multilayer pixel structure
AssigneeTouch Biometrix Limited
InventorsHenricus Derckx, Wilhelmus Van Lier, Michael A. Cowin
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Abstract
The present disclosure provides a pixel structure comprising a plurality of layers for providing a touch sensitive pixel of a sensing array. The layers comprising: a thin film transistor; and a conductive layer deposited on a dielectric shield to be touched by an object to be sensed and arranged to provide a capacitive sensing electrode coupled to the thin film transistor. The present disclosure also provides methods of manufacturing such a pixel structure.
Claims18
A pixel structure comprising a plurality of layers for providing a touch sensitive pixel of a sensing array, the pixel comprising:
- a sense thin film transistor (TFT);
- a select TFT coupled to the sense TFT;
- and
- a capacitive sensing electrode coupled to the sense TFT;
- wherein each TFT comprises:
- (i) a gate layer comprising a gate region of the TFT, (ii) a source-drain layer comprising a source region and a drain region of the TFT, and (iii) a channel region which connects the source region and the drain region to provide a conduction path therebetween when the TFT is in an on state;
- wherein the pixel structure comprises a conductive layer arranged to provide the capacitive sensing electrode;
- wherein a gate layer of the sense TFT is connected to the capacitive sensing electrode;
- wherein the conduction path of the sense TFT is connected to the conduction path of the select TFT;
- and
- wherein the conduction path of the sense TFT is connected between:
- (i) the conduction path of the select TFT, and (ii) a read-out line for the pixel.
A pixel structure comprising a plurality of layers for providing a touch sensitive pixel of a sensing array, the pixel comprising:
- a sense thin film transistor (TFT);
- a reset TFT coupled to the sense TFT;
- and
- a capacitive sensing electrode coupled to the sense TFT;
- wherein each TFT comprises:
- (i) a gate layer comprising a gate region of the TFT, (ii) a source-drain layer comprising a source region and a drain region of the TFT, and (iii) a channel region which connects the source region and the drain region to provide a conduction path therebetween when the TFT is in an on state;
- wherein the pixel structure comprises a conductive layer arranged to provide the capacitive sensing electrode;
- wherein the gate layer of the sense TFT is connected to the capacitive sensing electrode and the conduction path of the reset TFT;
- and
- wherein the conductive path of the reset TFT is connected between a reset voltage provider and the gate region of the sense TFT, and wherein the reset voltage provider is configured to reset the voltage at the gate region of the sense TFT to a reset voltage value selected to provide a selected pixel sensitivity.
A pixel structure comprising a plurality of layers for providing a touch sensitive pixel of a sensing array, the pixel comprising:
- a sense thin film transistor (TFT);
- a reference capacitor comprising a first plate and a second plate, wherein the reference capacitor is coupled to the sense TFT;
- and
- a capacitive sensing electrode coupled to the sense TFT;
- wherein the sense TFT comprises:
- (i) a gate layer comprising a gate region of the TFT, (ii) a source-drain layer comprising a source region and a drain region of the TFT, and (iii) a channel region which connects the source region and the drain region to provide a conduction path therebetween when the TFT is in an on state;
- wherein the pixel structure comprises a conductive layer arranged to provide the capacitive sensing electrode;
- wherein the gate layer of the sense TFT is connected to the capacitive sensing electrode and the second plate of the reference capacitor;
- and
- wherein one of the plates of the reference capacitor is provided in the same layer which provides the gate layer of the sense TFT, and the other of the plates of the reference capacitor is provided in the same layer which provides the source-drain layer of the sense TFT.
Dependencies are inferred from the claim text.