IMPLEMENTATION OF DRIVE OF TOUCH FLAT PANEL DISPLAY

• US 20110254795A1
• Filed: 06/27/2011
• Published: 10/20/2011
• Est. Priority Date: 05/21/2009
• Status: Abandoned Application

• Current Assignee: Inferpoint Systems Limited
• Original Assignee: Inferpoint Systems Limited
• Inventors: LIU, Haiping, CHEN, Qiliang
• Application Number:
  US13/169,506
• Publication Number:
  US 20110254795A1
• Time in Patent Office: Days
• US Class Current: 345/173
• 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 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

A touch screen and a flat panel display are provided, and more particularly a touch flat panel display is provided. The touch flat panel display includes a display screen and a driving circuit. A touch excitation source providing touch excitation energy is connected with a power end of a last-stage driving cell of the driving circuit, an output end of the last-stage driving cell is connected with an electrode line of the display screen, and the touch system circuit judges whether the electrode line of the display screen connected with the driving unit is touched by detecting a change of a touch signal flowing through the power end or the output end of the last-stage driving cell. The disclosed structural relation of circuits between the touch system circuit, the display driving circuit, and the display screen not only simplifies the connection between the touch system circuit, the display driving circuit, and electrodes of the display screen, but also can prevent the influence of a distributed capacitance within the display driving circuit on the touch signal.

Claims

1. A touch flat panel display, comprising a display screen and a driving circuit, wherein the driving circuit comprises a display driving circuit and a touch system circuit, and output ends of the driving circuit are connected with electrode lines of the display screen respectively, wherein

a touch excitation source providing touch excitation energy is connected with a power end of a last-stage driving cell of the driving circuit;

the last-stage driving cell at least has one active element, and an output end thereof is connected with an electrode line of the display screen; and

the touch system circuit judges whether the electrode line of the display screen connected with the driving unit is touched by detecting a change of a touch signal flowing through the power end or the output end of the last-stage driving cell.

2. The touch flat panel display according to claim 1, wherein

the power end of the driving unit in the driving circuit connected with the touch excitation source is a positive power end of the driving unit, or a negative power end of the driving unit.

3. The touch flat panel display according to claim 1, wherein

the power end of the last-stage driving cell in the driving circuit connected with the electrode lines of the display screen are connected with a display driving source providing display driving energy and the touch excitation source providing the touch excitation energy through a display/touch signal gating-switch and output circuit respectively, and the display/touch signal gating-switch and output circuit enables the power end of the driving unit to communicate with the display driving source, so that the driving circuit transmits a display driving signal to the connected electrode line of the display screen;

or to communicate with the touch excitation source, so that the driving circuit transmits a touch signal to the connected electrode line of the display screen.

4. The touch flat panel display according to claim 3, wherein

a detection point of the touch system circuit for detecting the touch signal is disposed between the touch excitation source and the display/touch signal gating-switch and output circuit, or disposed between the display/touch signal gating-switch and output circuit and the power end of the driving unit, or disposed between multi-stage multiplexers, or disposed at the output end of the driving unit.

5. The touch flat panel display according to claim 1, wherein

power ends of different driving units in the driving circuit connected with different electrode lines of the display screen are connected with a display driving source providing display driving energy and the touch excitation source providing the touch excitation energy through a display/touch signal loading and merge circuit unit respectively, and the driving circuit transmits a display driving signal and the touch signal to a connected next stage circuit and finally to the electrode lines of the display screen simultaneously.

6. The touch flat panel display according to claim 5, wherein

the display/touch signal loading and merge circuit is connected with the touch excitation source through a signal multiplexer or directly connected with the touch excitation source.

7. The touch flat panel display according to claim 6, wherein

a detection point of the touch system circuit for detecting the touch signal is disposed between the touch excitation source and the display/touch signal loading and merge circuit, or disposed between the signal multiplexer and the display/touch signal loading and merge circuit, or disposed between the display/touch signal loading and merge circuit and the power end of the driving unit, or disposed at the output end of the driving unit.

8. The touch flat panel display according to claim 1, wherein

the touch excitation source providing the touch excitation energy and the display driving source providing the display driving energy share the same power supply, the power end of the driving unit in the driving circuit is connected with a display driving and touch excitation sharing source, and the driving circuit transmits a display driving signal and the touch signal to a connected next stage circuit and finally to the electrode lines of the display screen simultaneously or in different time.

9. The touch flat panel display according to claim 8, wherein

the power end of the driving unit in the driving circuit connected with the electrode line of the display screen is connected with the display driving and touch excitation sharing source through a display/touch signal gating-switch and output circuit or directly connected with the display driving and touch excitation sharing source.

10. The touch flat panel display according to claim 9, wherein

a detection point of the touch system circuit for detecting the touch signal is disposed between the display driving and touch excitation sharing source and a multiplexer, or disposed between the display/touch signal gating-switch and output circuit and the power end of the driving unit, or disposed between the display driving and touch excitation sharing source and the power end of the driving unit, or disposed at the output end of the driving unit.

11. The touch flat panel display according to claim 1, wherein

the display driving and touch excitation sharing source is an independent power supply without being connected with other parts of the driving circuit, or an independent output end in a power output end without being connected with other parts of the driving circuit.

12. The touch flat panel display according to claim 3, wherein

the display/touch signal gating-switch and output circuit is a single-stage or multi-stage multiplexer at least having one active element.

13. The touch flat panel display according to claim 6, wherein

the display/touch signal gating-switch and output circuit is a single-stage or multi-stage multiplexer at least having one active element.

14. The touch flat panel display according to claim 9, wherein

the display/touch signal gating-switch and output circuit is a single-stage or multi-stage multiplexer at least having one active element.

15. The touch flat panel display according to claim 1, wherein

the touch excitation source is a direct current (DC) power supply, an alternating current (AC) power supply, or a hybrid AC/DC power supply.

16. The touch flat panel display according to claim 13, wherein

when the touch excitation source is a DC power supply, the output end of the last-stage driving cell in the driving circuit outputs a touch signal alternating with an alternating signal of an input end to the electrode line of the display screen.

17. The touch flat panel display according to claim 13, wherein

when the touch excitation source is an AC power supply, the output end of the last-stage driving cell in the driving circuit outputs an alternating touch signal coming from the power end and gated by an input end to the electrode line of the display screen.

18. The touch flat panel display according to claim 1, wherein

a touch signal sampling circuit of the touch system circuit is a passive element, or an active element, or a circuit unit formed by multiple elements.

19. The touch flat panel display according to claim 1, wherein

a frequency of the touch signal output to the electrode line of the display screen by the output end of the last-stage driving cell of the driving circuit is not smaller than 50 kHz,

20. The touch flat panel display according to claim 1, wherein

the touch system circuit detects the touch signal flowing into the power end of the driving unit connected with the touch excitation source by detecting at least one of a current signal and a voltage signal.

21. The touch flat panel display according to claim 1, wherein

the touch system circuit detects the touch signal flowing into the power end of the driving unit connected with the touch excitation source by detecting at least one of amplitude, time, phase, frequency signal, and pulse number.