TOUCH DISPLAY CAPABLE OF ELIMINATING DISPLAY IMPACT ON TOUCH

• US 20120162133A1
• Filed: 03/09/2012
• Published: 06/28/2012
• Est. Priority Date: 09/27/2009
• Status: Abandoned Application

• Current Assignee: Inferpoint Systems Limited
• Original Assignee: Inferpoint Systems Limited
• Inventors: CHEN, Qiliang, LIU, Haiping, LI, Dehai
• Application Number:
  US13/416,549
• Publication Number:
  US 20120162133A1
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04184 Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes

Abstract

A touch display is provided, in which at least one substrate of an active LCD screen has an active device array and a row electrode group and a column electrode group connected to an active device array, and another substrate of the display screen has a common (COM) electrode; and after a normal display time ends, Liquid Crystal (LC) pre-driving signals are applied to a part or all of row and column electrode lines and the COM electrode of the display screen, an intensity of the LC pre-driving signal enables a potential difference between the row and the column electrode lines and the COM electrode with the applied LC pre-driving signals to be not smaller than an LC saturation driving voltage, such that LC molecules between the row and the column electrode lines and the COM electrode with the applied LC pre-driving signals are in a determined arrangement state.

Claims

1. A touch display capable of eliminating a display impact on touch, comprising an active Liquid Crystal Display (LCD) screen, a display driving circuit, a touch system circuit, and a display/touch signal gating-switch and output circuit or display/touch signal loading and merge circuit capable of enabling a display screen electrode to be used for both display driving and touch detection;

wherein the touch system circuit has a touch excitation source and a touch signal detection unit;

the display/touch signal gating-switch and output circuit enables the display screen electrode to communicate with the display driving circuit to transmit a display driving signal, or to communicate with a touch system circuit to transmit a touch signal, and the display driving and the touch detection time division multiplex the display screen electrode;

the display/touch signal loading and merge circuit enables the display screen electrode to simultaneously transmit the display driving signal and the touch signal, and the display driving and the touch detection simultaneously share the display screen electrode;

at least one substrate of the active LCD screen has an active device array and a row electrode group and a column electrode group connected to the active device array, and the other substrate of the display screen has a common (COM) electrode;

wherein after a normal display time ends, Liquid Crystal (LC) pre-driving signals are applied to a part or all of row and column electrode lines and the COM electrode of the display screen, an intensity of the LC pre-driving signal enables a potential difference between the row and the column electrode lines and the COM electrode with the applied LC pre-driving signals to be not smaller than an LC saturation driving voltage, such that LC molecules between the row and the column electrode lines and the COM electrode with the applied LC pre-driving signals are in a determined arrangement state, thereby eliminating an impact of changes of display content on detection of the touch signal.

2. The touch display according to claim 1, wherein

the LC pre-driving signals applied to a part or all of the row and the column electrode lines and the COM electrode of the display screen are simultaneously or non-simultaneously applied to the different row and column electrode lines;

and during a time when the row and the column electrode lines have the applied LC pre-driving signals, a moment that the COM electrode also has the applied LC pre-driving signal exists.

3. The touch display according to claim 1, wherein

for the LC pre-driving signals applied to a part or all of the row and the column electrode lines and the COM electrode of the display screen, after the LC pre-driving signals are applied to a part or all of the row and the column electrode lines and the COM electrode of the display screen, the touch signals are applied to the row and the column electrode lines with the applied LC pre-driving signals, and changes of the touch signals on the electrode lines are detected.

4. The touch display according to claim 1, wherein

for the LC pre-driving signals applied to a part or all of the row and the column electrode lines and the COM electrode of the display screen, when or after the touch signals are applied to the row and the column electrode lines, the LC pre-driving signals are applied to a part or all of the row and the column electrode lines and the COM electrode of the display screen;

and after the LC pre-driving signals are applied, changes of the touch signals on the electrode lines with the applied LC pre-driving signals are detected.

5. The touch display according to claim 1, wherein

the active device array of the display screen is a Thin Film Transistor (TFT) array, the row and the column electrode lines are respectively connected to gates and sources of TFTs, or respectively connected to the gates and drains of the TFTs, and a time that the LC pre-driving signals are simultaneously applied to the column electrode lines connected to the sources or the drains of the TFTs exists.

6. The touch display according to claim 1, wherein

when the LC pre-driving signals are applied to a part or all of the row and the column electrode lines and the COM electrode of the display screen, all or a part of active devices of the display screen connected to a display pixel are in an off state.

7. The touch display according to claim 1, wherein

the LC pre-driving signals are applied, when active devices of the display screen connected to a display pixel are in an on state.

8. The touch display according to claim 1, wherein

the LC pre-driving signals and the touch signals are simultaneously applied, when active devices of the display screen connected to a display pixel are in an on state.

9. The touch display according to claim 7, wherein

the active device array of the display screen is a TFT array, and when TFTs connected to the display pixel are in the on state, the LC pre-driving signals are applied to the column electrode lines connected to sources or drains of the TFTs and the COM electrode.

10. The touch display according to claim 8, wherein

the active device array of the display screen is a TFT array, and when TFTs connected to the display pixel are in the on state, the LC pre-driving signals are applied to the column electrode lines connected to sources or drains of the TFTs and the COM electrode.

11. The touch display according to claim 1, wherein

the LC pre-driving signal applied to the row or column electrode group or the COM electrode is an Alternating Current (AC) signal, a Direct Current (DC) signal, or a composite signal of an AC signal and a DC signal.

12. The touch display according to claim 7, wherein

the LC pre-driving signal applied to the row or column electrode group or the COM electrode is an Alternating Current (AC) signal, a Direct Current (DC) signal, or a composite signal of an AC signal and a DC signal.

13. The touch display according to claim 8, wherein

the LC pre-driving signal applied to the row or column electrode group or the COM electrode is an Alternating Current (AC) signal, a Direct Current (DC) signal, or a composite signal of an AC signal and a DC signal.

14. The touch display according to claim 1, wherein

the LC pre-driving signal and the touch signal applied to the same electrode of the display screen is an AC signal having the same frequency or the same waveform.

15. The touch display according to claim 7, wherein

the LC pre-driving signal and the touch signal applied to the same electrode of the display screen is an AC signal having the same frequency or the same waveform.

16. The touch display according to claim 8, wherein

the LC pre-driving signal and the touch signal applied to the same electrode of the display screen is an AC signal having the same frequency or the same waveform.

17. The touch display according to claim 1, wherein

a frequency of the LC pre-driving signal is 10 kHz or above 10 kHz.

18. The touch display according to claim 7, wherein

a frequency of the LC pre-driving signal is 10 kHz or above 10 kHz.

19. The touch display according to claim 8, wherein

a frequency of the LC pre-driving signal is 10 kHz or above 10 kHz.