TN liquid crystal display device and touch control method thereof

• US 9,494,815 B2
• Filed: 11/20/2013
• Issued: 11/15/2016
• Est. Priority Date: 12/24/2012
• Status: Active Grant

• Current Assignee: Shanghai Tianma Micro-Electronics Company Limited (Tianma Microelectronics Company Limited)
• Original Assignee: Shanghai Tianma Micro-Electronics Company Limited (Tianma Microelectronics Company Limited)
• Inventors: Ma, Jun, Zhao, Lijun
• Primary Examiner(s): Mengistu, Amare
• Assistant Examiner(s): Mathews, Crystal A
• Application Number:
  US14/085,766
• Publication Number:
  US 20140176465A1
• Time in Patent Office: 1,091 Days
• US Class Current: 1/1
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G02F 1/134318 having a patterned common electrode
• CPC Class Codes: G02F 1/1396 the liquid crystal being selectively controlled between a twisted state and a non-twisted state, e.g. TN-LC cell G02F1/141 takes precedence
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

A twisted nematic liquid crystal display device integrated with a touch control function is disclosed. The device includes an array substrate, a color film substrate disposed opposite the array substrate, and a liquid crystal layer disposed between the array substrate and the color film substrate. The device also includes a common electrode layer disposed on a surface of the color film substrate facing the liquid crystal layer. The common electrode layer includes a plurality of sensing electrodes, a plurality of driving electrodes, and a plurality of dummy electrodes located between the sensing electrodes and the driving electrodes. In addition, the sensing electrodes, the driving electrodes, and the dummy electrodes are insulated from one another.

Claims

1. A twisted nematic liquid crystal display device integrated with a touch control function, the device comprising:

an array substrate;

a color film substrate disposed opposite the array substrate;

a liquid crystal layer disposed between the array substrate and the color film substrate; and

a common electrode layer disposed on a surface of the color film substrate facing the liquid crystal layer, wherein the common electrode layer comprises;

a plurality of sensing electrodes,

a plurality of driving electrodes,

a plurality of dummy electrodes located between the sensing electrodes and the driving electrodes, wherein the sensing electrodes, the driving electrodes, and the dummy electrodes are insulated from one another;

a black matrix layer located between the color film substrate and the common electrode layer, wherein the sensing electrodes, the driving electrodes and the dummy electrodes are isolated and insulated from each other by gaps in the common electrode layer, and the gaps are covered by the black matrix layer;

a gate electrode layer disposed on a surface of the array substrate facing the liquid crystal layer, wherein the gate electrode layer comprises gate electrodes and scanning lines;

a first insulating layer disposed on the gate electrode layer;

a silicon island disposed on the first insulating layer;

a source/drain electrode layer disposed on the silicon island, wherein the source/drain electrode layer comprises source electrodes, drain electrodes and data lines,

wherein the gate electrode within the gate electrode layer, the first insulating layer, the silicon island, the source electrode, and the drain electrode collectively form a thin film transistor structure;

a second insulating layer disposed on the source/drain electrode layer;

a third insulating layer disposed on the second insulating layer;

a pixel electrode layer disposed on the third insulating layer;

a first transparent electrode layer disposed between the first insulating layer and the gate electrode layer, wherein the first transparent electrode layer covers the scanning lines of the gate electrode layer and does not cover an area of the gate electrodes at the gate electrode layer; and

a fourth insulating layer disposed between the first transparent electrode layer and the gate electrode layer.

2. The twisted nematic liquid crystal display device according to claim 1, wherein:

the driving electrodes in a particular row are connected to one another through a first wiring to form a driving line, and the sensing electrodes in a particular column are connected to one another through a second wiring to form a sensing line;

or

the driving electrodes in a particular column are connected to one another through a first wiring to form a driving line, and the sensing electrodes in a particular row are connected to one another through a second wiring to form a sensing line.

3. The twisted nematic liquid crystal display device according to claim 2, wherein:

the common electrode layer and the first wiring for electrically connecting the driving electrodes to one another are on a same conductive layer, and the second wiring for electrically connecting the sensing electrodes to one another is a conductive bridging which is on a different conductive layer from the common electrode layer;

or

the common electrode layer and the second wiring for electrically connecting the sensing electrodes to one another are on a same conductive layer, and the first wiring for electrically connecting the driving electrodes to one another is a conductive bridging which is on a different conductive layer from the common electrode layer.

4. The twisted nematic liquid crystal display device according to claim 2, wherein the driving electrodes and sensing electrodes are rhombic and are arranged in an array, the dummy electrode are disposed between the driving electrode and the sensing electrode adjacent to each other, and the dummy electrode is a hollowed-out rhombic electrode having a hollowed-out part in which driving electrode or sensing electrode is disposed.

5. The twisted nematic liquid crystal display device according to claim 4, wherein the dummy electrodes in a particular row or in a particular column are electrically connected to one another through a conductive bridging which is on a different conductive layer from the common electrode layer.

6. The twisted nematic liquid crystal display device according to claim 1, wherein the dummy electrodes are electrically connected to one another.

7. The twisted nematic liquid crystal display device according to claim 1, wherein:

the plurality of driving electrodes are square and are arranged in a array, strip-shaped sensing electrodes are disposed between every two adjacent columns of driving electrodes, the dummy electrodes are disposed between the driving electrode and the sensing electrode adjacent to the driving electrode, each of the dummy electrodes is in an H shape, and the H-shaped dummy electrodes in each row are connected to one another;

or

the plurality of sensing electrodes are square electrodes arranged in an array, strip-shaped driving electrodes are disposed between every two adjacent columns of sensing electrodes, the dummy electrodes are disposed between the sensing electrode and the driving electrode adjacent to the driving electrode, each of the dummy electrodes is in an H-shape, and the H-shaped dummy electrodes in each row are connected to one another.

8. The twisted nematic liquid crystal display device according to claim 7, wherein the dummy electrodes in a particular row are electrically connected to one another through a third wiring, and the common electrode layer and the third wiring are on a same conductive layer.

9. The twisted nematic liquid crystal display device according to claim 1, wherein the first transparent electrode layer is disposed opposite the common electrode layer, and plan views of the areas of the first transparent electrode layer and the common electrode layer which are opposite to each other are the same except for an area of the thin film transistors.

10. The twisted nematic liquid crystal display device according to claim 9, wherein the dummy electrode block of the first transparent electrode layer is connected to the sensing electrode block which is located in a hollowed-out part of the dummy electrode block.

11. A method of controlling a twisted nematic liquid crystal display device, for performing detection of touch signal, the method comprising:

dividing a time-sharing period during display into a first duration and a second duration, wherein during the time-sharing period, the common electrode layer is configured to detect a touch signal and to provide a common electrode signal, wherein the second duration is shorter than a retention time of liquid crystal molecules and is longer than or equal to a scanning time for one detection of the touch signal by the common electrode layer, and wherein the retention time of liquid crystal molecules is a time period during which the liquid crystal molecules maintain a previous state when a driving voltage of the common electrode layer changes;

during the first duration, applying a same common potential to a plurality of sensing electrodes, to a plurality of driving electrodes, and to a plurality of dummy electrodes of the common electrode layer to achieve normal display;

during the second duration, grounding the dummy electrodes and applying a driving voltage for touch detection to the sensing electrodes and to the driving electrodes of the common electrode layer;

wherein during the first duration of the time-sharing period, a first transparent electrode layer is grounded, wherein during the second duration, parts of the first transparent electrode layer opposite the driving electrodes and the corresponding driving electrodes are applied a same signal, and parts of the first transparent electrode layer opposite the sensing electrodes and the dummy electrodes are grounded.

12. The control method of claim 11, wherein the duration of the time-sharing period is equal to the duration of a scanning period of the liquid crystal display device.

13. The control method of claim 12, wherein the duration of the first duration is greater than half of the duration of the time-sharing period, and the duration of the second duration is less than half of the duration of the time-sharing period.

14. The control method according to claim 13, wherein the second duration is less than 8 ms.

15. The control method according to claim 14, wherein the second duration is equal to 3 ms.