Switching circuitry for touch sensitive display

• US 8,922,521 B2
• Filed: 08/21/2009
• Issued: 12/30/2014
• Est. Priority Date: 02/02/2009
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Hotelling, Steven Porter, Yousefpor, Marduke, Chang, Shih Chang
• Primary Examiner(s): Young, Wayne
• Assistant Examiner(s): BUTCHER, BRIAN M
• Application Number:
  US12/545,754
• Publication Number:
  US 20100194698A1
• Time in Patent Office: 1,957 Days
• Field of Search: None
• US Class Current: 345/174
• CPC Class Codes: G06F 1/3218 of display devices
• 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 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads
• 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
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3666 with the matrix divided into sections

Abstract

A circuit for switching an LCD between display and touch modes is disclosed. The circuit can include one or more switches configured to switch one or more drive, sense, and data lines in LCD pixels according to the mode. During touch mode, the circuit switches can be configured to switch one or more drive lines to receive stimulation signals, one or more sense lines to transmit touch signals, and one or more data lines to transmit residual data signals. During display mode, the circuit switches can be configured to switch one or more drive lines and sense lines to receive common voltage signals and one or more data lines to receive data signals. The circuit can be formed around the border of the LCD chip or partially or fully on a separate chip.

Claims

1. A circuit for switching an integrated touch screen between different modes, comprising:

one or more switches configured to switch a data line, a sense line, and a drive line between a first configuration associated with a display mode and a second configuration associated with a touch mode, wherein during the touch mode, the data line is coupled to receive a common voltage and the drive line is configured to stimulate one or more drive regions during the touch mode, the data line, sense line, and drive line being distinct lines.

2. The circuit of claim 1, wherein the first configuration comprises at least one drive line being switched to receive a common voltage signal.

3. The circuit of claim 1, wherein the first configuration comprises the data line being switched to receive a data signal.

4. The circuit of claim 1, wherein the first configuration comprises the sense line being switched to receive a common voltage signal.

5. The circuit of claim 1, wherein the second configuration comprises drive lines being switched to receive a stimulation signal.

6. The circuit of claim 5, wherein the first configuration comprises the sense line coupled to receive a common voltage signal.

7. The circuit of claim 1, comprising:

a controller configured to control the one or more switches.

8. The circuit of claim 1 incorporated into an integrated touch screen.

9. The circuit of claim 1 incorporated into at least one of a mobile telephone, a digital media player, or a personal computer.

10. A touch sensitive display switchable between different modes, the device comprising:

a display pixel having a drive line, a sense line, and a data line, the drive line, sense line, and data line being distinct lines; and

a circuit having one or more switches configured to switch the data line and drive line between a display mode and a touch mode, wherein in the touch mode, the data line is coupled to receive a common voltage and the drive line is configured to stimulate one or more drive regions during the touch mode.

11. The touch sensitive display of claim 10, comprising:

a drive region comprising the display pixel,

wherein the drive line of the display pixel is coupled to receive a stimulation signal during the touch mode and to receive a common voltage signal during the display mode.

12. The touch sensitive display of claim 11, comprising:

a drive region comprising the display pixel,

wherein the data line is coupled to receive a data signal during the display mode.

13. The touch sensitive display of claim 10, comprising:

a ground region comprising the display pixel,

wherein in the display mode, the circuit is configured to couple the data line to receive a data signal.

14. The touch sensitive display of claim 10, comprising:

a ground region comprising the display pixel,

wherein in the touch mode, the circuit is configured to couple the sense line to receive a common voltage.

15. The touch sensitive display of claim 10, comprising:

a touch circuit configured to receive a touch signal from the sense line and to send a stimulation signal to the drive line during the touch mode.

16. The touch sensitive display of claim 10, comprising:

a display circuit configured to send a data signal to the data line during the display mode.

17. A method for switching between different modes in a touch sensitive display, comprising:

providing a plurality of pixels in a touch sensitive display having a display mode and a touch mode; and

switching a data line, a sense line, and a drive line between the display mode and the touch mode, wherein in the touch mode, the data line is coupled to receive a common voltage and the drive line is configured to stimulate one or more drive regions during the touch mode, the data line, sense line, and drive line being distinct lines.

18. The method of claim 17, wherein the switching comprises:

for the touch mode, switching the sense line to connect to a touch circuit for sensing a touch or near touch and switching drive line to connect to the touch circuit for driving a stimulation signal.

19. The method of claim 17, wherein the switching comprises:

for the display mode, switching the sense line to receive a common voltage, switching drive line to receive the common voltage, and switching the data line to connect to a display circuit for displaying graphics or data.

20. An integrated touch screen switchable between different modes, comprising:

a plurality of pixels having different modes including a touch mode and a display mode; and

a circuit comprising at least one switch configured to switch at least one of a drive line, a sense line, or a data line between the display mode and the touch mode, wherein the data line, drive line, and sense line are distinct lines and the at least one switch is configured to couple the data line to receive a common voltage in the touch mode and at least one switch configured to couple the drive line to stimulate one or more drive regions during the touch mode.

21. A touch sensitive display having a display mode and a touch mode comprising:

at least a first and second drive region;

each drive region having a plurality of pixels having data lines and common electrodes, the plurality of pixels in each of the first and second drive regions having the common electrodes thereof coupled together;

at least a first sense region disposed between the first and second drive regions;

the first sense region having a plurality of pixels having data lines and common electrodes and sense lines distinct from the data lines, the plurality of pixels in the first sense region having the common electrodes thereof coupled together;

a plurality of drive lines coupling the common electrodes of the first and second drive regions together while bypassing the common electrodes of the first sense region;

the data lines of the first and second drive regions coupled to receive a common voltage during the touch mode.

22. The touch sensitive display of claim 21, further comprising at least one ground region disposed between the first and second drive regions, the ground region having a plurality of pixels having data lines and common electrodes;

the data lines and common electrodes coupled to receive the common voltage during the touch mode.

23. The touch sensitive display of claim 22, wherein the at least one ground region comprises a first ground region disposed between the first drive region and the at least one sense region and a second ground region disposed between the at least one sense region and the second drive region.

24. The touch sensitive display of claim 23 wherein each of the first and second ground regions have a plurality of pixels having data lines and common electrodes;

the data lines and common electrodes coupled to receive the common voltage during the touch mode.

25. The touch sensitive display of claim 22, wherein the data lines of the ground region are coupled to display circuitry during the display mode.

26. The touch sensitive display of claim 21, wherein the data lines of the first and second drive regions are coupled to display circuitry during the display mode.