Liquid crystal display device integrated with touch sensor

• US 9,715,293 B2
• Filed: 06/02/2014
• Issued: 07/25/2017
• Est. Priority Date: 08/01/2013
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Chung, Jae-Mo
• Primary Examiner(s): Faragalla, Michael
• Assistant Examiner(s): BIBBEE, CHAYCE R
• Application Number:
  US14/293,868
• Publication Number:
  US 20150035766A1
• Time in Patent Office: 1,149 Days
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• 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 liquid crystal display device includes as a monolithically integrated part thereof, a touch sensor that operates during a blanking period of the display device. In one embodiment, the LCD device includes a first substrate, a second substrate, a plurality of common electrodes, a plurality of sensing electrodes, a data driver, a gate lines driver, a common electrodes driver, a touch controller and a display controller. A plurality of pixels coupled to gate lines and data lines are formed on the first substrate. The second substrate is positioned opposite to the first substrate. The plurality of common electrodes corresponding to the respective pixels are formed on the second substrate. The plurality of sensing electrodes are also formed on the second substrate to cross with the common electrodes. The data lines driver outputs data signals to the data lines during a display period. The gate lines driver includes a plurality of stages receiving first and second clock signals. The gate lines driver outputs a gate-on signal to the gate lines during the display period, and outputs a gate-off signal to the gate lines during the blanking period. The common electrodes driver supplies touch driving signals to the common electrodes during a touch driving period included within the blanking period. The touch controller supplies the touch control signal to the common electrode driver during the touch driving period. The display controller supplies the first and second clock signals to the gate lines driver, in synchronization with the touch control signal, during the touch driving period.

Claims

1. A liquid crystal display (LCD) device having monolithically integrated as a part thereof, a touch sensor, the LCD device comprising:

a first substrate on which there is disposed a plurality of pixels respective coupled to respective ones of gate lines and data lines also formed on the first substrate;

a plurality of electrically separate common electrodes configured to correspond to, and to be operative portions of respective subsets of the pixels, the common electrodes being integrally formed as part of the LCD device and extending longitudinally in a first direction;

a plurality of sensing electrodes integrally formed as part of the LCD device and extending longitudinally in a second direction crossing with the first direction;

a data lines driver configured to output respective data signals to respective ones of the data lines during an image forming portion of a display period;

a gate lines driver including a plurality of stages configured for receiving first and second clock signals, wherein the gate lines driver outputs gate-on signals to the gate lines during the image forming portion of the display period, and outputs gate-off signals to the gate lines during a blanking period that is separate from the display period;

a common electrodes driver configured to supply touch driving signals to the common electrodes during a touch driving subperiod included within the blanking period and in synchronism with a touch control signal;

a touch controller configured to supply the touch control signal to the common electrodes driver during the touch driving subperiod; and

a display controller configured to supply the first and second clock signals to the gate lines driver, in synchronization with the touch control signal, during the touch driving subperiod,

wherein the display controller supplies the first and second clock signals as having a first frequency to the gate lines driver during the display period, and supplies the first and second clock signals as having a second frequency different from the first frequency to the gate lines driver during the touch driving subperiod.

2. The LCD device of claim 1 and configured to cause the blanking period and the display period to be alternately repeated.

3. The LCD device of claim 1, wherein the common electrodes driver supplies the same common voltage to the common electrodes during the display period.

4. The LCD device of claim 1, wherein the blanking period further includes one or more margin periods in which the touch control signal is not supplied.

5. The LCD device of claim 4, wherein at least one of the margin periods is positioned between the display period and the touch driving subperiod.

6. The LCD device of claim 4, wherein the display controller supplies the first and second clock signals as having the first frequency to the gate lines driver during at least one of the margin periods.

12. The LCD device of claim 1, wherein the second frequency is a frequency lower than the first frequency.

13. The LCD device of claim 1, wherein the first and second clock signals have phases opposite to each other.

14. The LCD device of claim 1, wherein the common electrodes are positioned on either the first substrate or on a second substrate that faces but is spaced apart from the first substrate.

15. The LCD device of claim 1, further comprising a backlighting unit positioned to supply backlighting from below and into the first substrate.

16. The LCD device of claim 1, further comprising a liquid crystal layer positioned between the first substrate and a second substrate that is provided to face but be spaced apart from the first substrate.

17. The LCD device of claim 1, wherein the common electrodes and the sensing electrodes respectively include respective light-passing materials.

7. A liquid crystal display (LCD) device having monolithically integrated as a part thereof, a touch sensor, the LCD device comprising:

a first substrate on which there is disposed a plurality of pixels respective coupled to respective ones of gate lines and data lines also formed on the first substrate;

a plurality of electrically separate common electrodes configured to correspond to, and to be operative portions of respective subsets of the pixels, the common electrodes being integrally formed as part of the LCD device and extending longitudinally in a first direction;

a plurality of sensing electrodes integrally formed as part of the LCD device and extending longitudinally in a second direction crossing with the first direction;

a data lines driver configured to output respective data signals to respective ones of the data lines during an image forming portion of a display period;

a gate lines driver including a plurality of stages configured for receiving first and second clock signals, wherein the gate lines driver outputs gate-on signals to the gate lines during the image forming portion of the display period, and outputs gate-off signals to the gate lines during a blanking period that is separate from the display period;

a common electrodes driver configured to supply touch driving signals to the common electrodes during a touch driving subperiod included within the blanking period and in synchronism with a touch control signal;

a touch controller configured to supply the touch control signal to the common electrodes driver during the touch driving subperiod; and

a display controller configured to supply the first and second clock signals to the gate lines driver, in synchronization with the touch control signal, during the touch driving subperiod, wherein each stage of the gate lines driver includes;

a first transistor coupled between a first clock terminal and an output terminal, the first transistor having a gate electrode coupled to a first node;

a second transistor coupled between a first input terminal and the first node, the second transistor having a gate electrode coupled to the first input terminal;

a third transistor coupled between the first node and a voltage terminal, the third transistor having a gate electrode coupled to a second input terminal;

a fourth transistor coupled between the output terminal and the voltage terminal, the fourth transistor having a gate electrode coupled to a second clock terminal;

a fifth transistor coupled between the output terminal and the voltage terminal, the fifth transistor having a gate electrode coupled to a second node;

a sixth transistor coupled between the second node and the voltage terminal, the sixth transistor having a gate electrode coupled to the first node; and

a seventh transistor coupled between the first node and the voltage terminal, the seventh transistor having a gate electrode coupled to the second node.

8. The LCD device of claim 7, wherein each stage of the gate lines driver further includes:

a first capacitor coupled between the first node and the output terminal; and

a second capacitor coupled between the first clock terminal and the second node.

9. The LCD device of claim 8, wherein the first and second clock signals are respectively input to the first and second clock terminals of an odd-numbered stage, and

wherein the second and first clock signals are respectively input to the first and second clock terminals of an even-numbered stage.

10. The LCD device of claim 9, wherein a scan start signal or the gate-on signal of a previous stage is input to the first input terminal, and

wherein the gate-on signal of a next stage is input to the second input terminal.

11. The LCD device of claim 10, wherein a gate-off voltage is applied to the voltage terminal.