Touch screen flat panel display

• US 8,610,680 B2
• Filed: 01/12/2011
• Issued: 12/17/2013
• Est. Priority Date: 07/21/2008
• Status: Active Grant

• Current Assignee: FocalTech Electronics (Shenzhen) Co., Ltd.
• Original Assignee: Solution Depot (Shenzhen) Limited
• Inventors: Chen, Qiliang, Liu, Haiping, Chen, Meiying
• Primary Examiner(s): Zhou, Hong
• Application Number:
  US13/005,203
• Publication Number:
  US 20110102360A1
• Time in Patent Office: 1,070 Days
• Field of Search: 345173- 17, 345173-174, 345/179, 345/182, 178 1801- 2004
• 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 flat panel display (FPD) is provided, which includes a display screen, a display driving circuit, a touch system circuit, and the like. Related circuits in the touch screen FPD enable electrodes of the display screen to transmit display driving signals as well as touch signals, that is to say, the display driving and the touch detection multiplex the electrodes of the display screen, such that the FPD is not only used for normal display but also used for realizing touch detection. By applying the touch signal simultaneously to detecting lines and non-detecting lines, the flow of the touch signal between the detecting lines and between the detecting line and the non-detecting line is reduced, thus controlling the flow direction of the touch signal, and increasing the accuracy of determining touched electrodes.

Claims

1. A touch screen flat panel display (FPD), comprising a display screen, a display driving circuit, a touch system circuit, and a multiplexer or a signal loading and merge circuit enabling electrodes of the display screen to be used for display driving as well as touch detection;

wherein the multiplexer enables the electrodes of the display screen to be communicated with the display driving circuit for transmitting display driving signals or to be communicated with the touch system circuit for transmitting touch signals, and the display driving and the touch detection time-division multiplex the electrodes of the display screen;

the signal loading and merge circuit enables the electrodes of the display screen to transmit the display driving signals and the touch signals simultaneously, and the display driving and the touch detection share the electrodes of the display screen simultaneously;

wherein;

during a period that the electrodes of the display screen transmit the touch signals, the touch signals are applied to more than two electrode lines of the display screen at least one moment, the touch system circuit selects at least one electrode line of the display screen having shielding protection as a detecting line from them;

when the touch signal is applied to the detecting line, a change of the touch signal flowing through the electrode is also detected;

the electrode line of the display screen having the shielding protection refers to an electrode line of the display screen having electrode lines at two adjacent sides or two non-adjacent sides applied with the touch signal or intersected electrode lines applied with the touch signal, and

wherein when the touch signal is applied to the detecting line, the same touch signal is also applied to non-detecting lines around the detecting line to provide shielding functions.

2. The touch screen FPD according to claim 1, wherein:

the electrode lines of the display screen comprise all electrodes of the display screen including row electrode lines and column electrode lines of a passive display screen, or row electrode lines and column electrode lines of an active display screen.

3. The touch screen FPD according to claim 2, wherein when the touch signal is applied to at one least of the row electrode lines as the detecting line, the touch signal is also applied to the remaining row electrode lines as non-detecting lines, and when the touch signal is applied to at one least of the column electrode lines as the detecting line, the touch signal is also applied to the remaining column electrode lines as non-detecting lines.

4. The touch screen FPD according to claim 1, wherein:

during the period that the touch signal is applied to the electrodes of the display screen, when applying the touch signal on the detecting line and detecting the change of the touch signal flowing through the detecting line, the touch signal is also applied to other electrodes of the display screen being intersected with the detecting line; and

the other electrodes of the display screen being intersected with the detecting line are all electrodes being intersected with the detecting line or a part of the electrodes being intersected with the detecting line.

5. The touch screen FPD according to claim 1, wherein:

during the period that the touch signal is applied to the electrodes of the display screen, when applying the touch signal on the detecting line and detecting the change of the touch signal flowing through the detecting line, the touch signal is also applied to other electrodes of the display screen not intersected with the detecting line; and

the other electrodes of the display screen not intersected with the detecting line are all electrodes not intersected with the detecting line or a part of the electrodes not intersected with the detecting line.

6. The touch screen FPD according to claim 1, wherein:

during the period that the touch signal is applied to the electrodes of the display screen, when applying the touch signal on the detecting line and detecting the change of the touch signal flowing through the detecting line, the touch signal is also applied to other electrodes of the display screen being or not intersected with the detecting line; and

the other electrodes of the display screen being or not intersected with the detecting line are all electrodes being or not intersected with the detecting line or a part of the electrodes being or not intersected with the detecting line.

7. The touch screen FPD according to claim 1, wherein:

during the period that the touch signal is applied to the electrodes of the display screen, when applying the touch signal on the detecting line and detecting the change of the touch signal flowing through the detecting line, the touch signal is also applied to a common electrode of the display screen.

8. The touch screen FPD according to claim 1, wherein:

the touch signal is an alternating current (AC) signal including zero amplitude or a direct current (DC) signal including zero potential.

9. The touch screen FPD according to claim 1, wherein:

when the touch system circuit selects the detecting lines, the touch system circuit selects a part of the electrode lines of the display screen at the same time as a group of detecting lines.

10. The touch screen FPD according to claim 9, wherein:

the touch system circuit selects the detecting lines in a scanning manner, and selects different parts of the electrode lines of the display screen at different times as the detecting lines.

11. The touch screen FPD according to claim 9, wherein:

each group of detecting lines is composed of one or more electrode lines of the display screen.

12. The touch screen FPD according to claim 1, wherein:

when the touch system circuit selects the detecting lines, the touch system circuit selects two or more parts of the electrode lines of the display screen at the same time as two or more groups of detecting lines respectively, the touch signal is applied to each group of detecting lines simultaneously, and the changes of the touch signals flowing through each group of detecting lines are detected.

13. The touch screen FPD according to claim 12, wherein:

the touch system circuit selects the detecting lines in a scanning manner, and selects different parts of the electrode lines of the display screen at different times as the detecting lines.

14. The touch screen FPD according to claim 12, wherein:

each group of detecting lines is composed of one or more electrode lines of the display screen.

15. A touch screen flat panel display (FPD), comprising a display screen, a display driving circuit, a touch system circuit, and a multiplexer or a signal loading and merge circuit enabling electrodes of the display screen to be used for display driving as well as touch detection;

wherein the multiplexer enables the electrodes of the display screen to be communicated with the display driving circuit for transmitting display driving signals or to be communicated with the touch system circuit for transmitting touch signals, and the display driving and the touch detection time-division multiplex the electrodes of the display screen;

the signal loading and merge circuit enables the electrodes of the display screen to transmit the display driving signals and the touch signals simultaneously, and the display driving and the touch detection share the electrodes of the display screen simultaneously;

wherein;

during a period that the electrodes of the display screen transmit the touch signals, the touch signals are applied to more than two electrode lines of the display screen at least one moment, the touch system circuit selects at least one electrode line of the display screen having shielding protection as a detecting line from them;

when the touch signal is applied to the detecting line, a change of the touch signal flowing through the electrode is also detected;

the electrode line of the display screen having the shielding protection refers to an electrode line of the display screen having electrode lines at two adjacent sides or two non-adjacent sides applied with the touch signal or intersected electrode lines applied with the touch signal,

wherein the touch signals applied to the electrodes have the same frequency or code, and

wherein when the touch signal is applied to the detecting line, the same touch signal is also applied to non-detecting lines around the detecting line to provide shielding functions.

16. A touch screen flat panel display (FPD), comprising a display screen, a display driving circuit, a touch system circuit, and a multiplexer or a signal loading and merge circuit enabling electrodes of the display screen to be used for display driving as well as touch detection;

wherein the multiplexer enables the electrodes of the display screen to be communicated with the display driving circuit for transmitting display driving signals or to be communicated with the touch system circuit for transmitting touch signals, and the display driving and the touch detection time-division multiplex the electrodes of the display screen;

the signal loading and merge circuit enables the electrodes of the display screen to transmit the display driving signals and the touch signals simultaneously, and the display driving and the touch detection share the electrodes of the display screen simultaneously;

wherein;

during a period that the electrodes of the display screen transmit the touch signals, the touch signals are applied to more than two electrode lines of the display screen at least one moment, the touch system circuit selects at least one electrode line of the display screen having shielding protection as a detecting line from them;

when the touch signal is applied to the detecting line, a change of the touch signal flowing through the electrode is also detected;

the electrode line of the display screen having the shielding protection refers to an electrode line of the display screen having electrode lines at two adjacent sides or two non-adjacent sides applied with the touch signal or intersected electrode lines applied with the touch signal,

wherein the touch signals applied to the electrodes have the same frequency or code,

wherein the electrode lines of the display screen comprise all electrodes of the display screen including row electrode lines and column electrode lines of a passive display screen, or row electrode lines and column electrode lines of an active display screen, and

wherein when the touch signal is applied to at one least of the row electrode lines as the detecting line, the same touch signal is also applied to the remaining row electrode lines as non-detecting lines, and when the touch signal is applied to at one least of the column electrode lines as the detecting line, the same touch signal is also applied to the remaining column electrode lines as non-detecting lines.