Liquid crystal display panel having integrated pressure sensing units

摘要

Capacitively actuated touch sensor units are integrated between subpixel light emitters of a liquid crystal display panel. In one embodiment, a sensor unit is monolithically integrated on a same substrate as are a plurality of associated subpixel units and the sensor unit includes a variable capacitor and a reference capacitor connected to define a voltage splitting circuit having a split voltage generating node. The sensor unit also includes a sensing transistor operatively coupled to the split voltage generating node and a voltage resetting transistor operatively coupled to the split voltage generating node. In one embodiment, one plate of the variable capacitor is defined by a touchwise flexed portion of a common electrode of the display and an opposed plate is defined by a spaced apart facing electrode provided on a TFT array substrate of the liquid crystal display.

主权项

1. A touch sensitive liquid crystal display panel comprising:
a plurality of subpixel units each comprising a liquid crystal capacitor having a pixel electrode and a common electrode of the display as two terminals with a liquid crystal layer interposed therebetween; a touch sensing unit for generating a sensing data signal in response to an external contact; a comparison signal generator for generating a comparison data signal regardless of the external contact; and a contact determining unit for comparing the sensing data signal and the comparison data signal to determine existence of contact, wherein the touch sensing unit comprises:
a voltage resetting transistor, a gate of the voltage resetting transistor being connected to a present gate line,a variable capacitor having a capacitance that is changed by pressure, and having a first sensing electrode and the common electrode as two terminals,a sensing element generating a detection signal based on a control voltage from the variable capacitor, anda reference capacitor connected to the variable capacitor, and having the first sensing electrode and a previous gate line as two terminals, the previous gate line being a gate line activated ahead of the present gate line, wherein the common electrode has a portion formed on a first protrusion, wherein the first sensing electrode include a transparent conductive material and a conductive material connected to the transparent conductive material through a contact hole, wherein the transparent conductive material does not overlap the first protrusion when the transparent conductive material and the first protrusion are projected onto a first substrate on which the transparent conductive material is disposed, wherein the first sensing electrode is connected to a first transistor, a gate of the first transistor being connected to the present gate line, wherein the comparison signal generator comprises:
a first comparison capacitor,a comparison element generating a detection signal based on the control voltage from the first comparison capacitor,a second comparison capacitor connected to the first comparison capacitor, anda second sensing electrode forming one terminal of a first comparison capacitor and a second comparison capacitor, andwherein the previous gate line forms the other terminal of the first comparison capacitor and the common electrode forms the other terminal of the second comparison capacitor.