Integrated touch panel for a TFT display

• US 20100144391A1
• Filed: 12/05/2008
• Published: 06/10/2010
• Est. Priority Date: 12/05/2008
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Zhong, John Z., Chang, Shih Chang
• Granted Patent: US 8,749,496 B2
• Time in Patent Office: Days
• US Class Current: 455/566
• CPC Class Codes: G02F 1/13312 Circuits comprising photodetectors for purposes other than feedback
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• 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 3/0443 using a single layer of sensing electrodes

Abstract

This relates to displays for which the use of dual function capacitive elements does not result in any decreases of the aperture of the display. Thus, touch sensitive displays that have aperture ratios that are no worse than similar non-touch sensing displays can be manufactured. More specifically, this relates to placing touch sensing opaque elements so as to ensure that they are substantially overlapped by display related opaque elements, thus ensuring that the addition of the touch sensing elements does not substantially reduce the aperture ratio. The touch sensing display elements can be, for example, common lines that connect various capacitive elements that are configured to operate collectively as an element of the touch sensing system.

Claims

1. A touch screen configured to perform both a display and a touch sensing functionality comprising:

a plurality of pixels, each pixel including a storage capacitor comprising a first electrode and a second electrode;

one or more opaque display elements used to perform the display functionality of the touch screen; and

a plurality of common lines made from a non-transparent conductor, connected to the first electrode of one or more of the plurality of pixels and positioned at a different layer in the touch screen than the opaque display elements such that the opaque display elements substantially overlap the common lines,

wherein the first electrodes connected to the common lines are used for both the display and touch sensing functionalities of the touch screen.

2. The touch screen of claim 1, wherein the common lines are connected to touch circuitry and are used to carry touch sensing signals.

3. The touch screen of claim 1, wherein the common lines include a first plurality of parallel common lines (xVcom lines) and a second plurality of parallel common lines (yVcom lines), the first and second pluralities being positioned perpendicular to one another at the same layer to form a lattice structure.

4. The touch screen of claim 3, wherein the opaque display elements include a plurality of parallel gate lines and a plurality of parallel data lines, the gate and data lines being positioned perpendicular to each other to form a lattice structure, wherein:

the xVcom lines are substantially overlapped by the gate lines; and

the yVcom lines are substantially overlapped by the data lines.

5. The touch screen of claim 1, wherein the opaque display elements include display gate and data lines.

6. The touch screen of claim 1, wherein the opaque display elements include pixel transistors.

7. The touch screen of claim 1, wherein the plurality of common lines are configured to connect the pixels in a plurality of sets of pixels, each set of pixels having all first electrodes connected to each other by the common lines, and wherein the common lines are interrupted at the boundaries between different adjacent sets of pixels.

8. The touch screen of claim 7, wherein each set of pixels comprises a touch region, and wherein selected pairs of touch regions form touch pixels capable of indicating a touch event thereon by changes in a capacitance between said pair of touch regions.

9. The touch screen of claim 7, wherein each set of pixels covers a contiguous region of the touch screen.

10. A mobile media player including the touch screen of claim 1.

11. A mobile telephone including the touch screen of claim 1.

12. A personal computer including the touch screen of claim 1.

13. A digital media player including a touch screen configured to perform both a display and a touch sensing functionality, comprising:

a plurality of pixels, each pixel including a storage capacitor comprising a first electrode and a second electrode;

one or more opaque display elements used to perform the display functionality of the touch screen; and

a plurality of common lines made from a non-transparent conductor, connected to the first electrode of one or more of the plurality of pixels and positioned at a different layer in the touch screen than the opaque display elements such that the opaque display elements substantially overlap the common lines,

wherein the first electrodes connected to the common lines are used for both the display and touch sensing functionalities of the touch screen.

14. A mobile telephone including a touch screen configured to perform both a display and a touch sensing functionality, comprising:

a plurality of pixels, each pixel including a storage capacitor comprising a first electrode and a second electrode;

one or more opaque display elements used to perform the display functionality of the touch screen; and

a plurality of common lines made from a non-transparent conductor, connected to the first electrode of one or more of the plurality of pixels and positioned at a different layer in the touch screen than the opaque display elements such that the opaque display elements substantially overlap the common lines,

wherein the first electrodes connected to the common lines are used for both the display and touch sensing functionalities of the touch screen.

15. A touch screen configured to perform both a display and a touch sensing functionality, comprising:

a plurality of pixels including a plurality of sets of pixels, each set of pixels comprising two or more pixels;

a plurality of common electrodes, each common electrode serving as a storage capacitor electrode for a respective set of pixels;

one or more opaque display elements used to perform the display functionality of the touch screen; and

a plurality of common lines made from a non-transparent conductor, connected to the plurality of common electrodes and positioned at a different layer in the touch screen than the opaque display elements such that the opaque display elements substantially overlap the common lines,

wherein the common electrodes are used for both the display and touch sensing functionalities of the touch screen.

16. The touch screen of claim 15, wherein the common lines are positioned at the same or adjacent layer to the plurality of common electrodes.

17. The touch screen of claim 15, wherein each common electrode is connected to a respective set of plurality of common lines from the plurality of common lines, and wherein the common lines are interrupted at the boundaries between different adjacent common electrodes.

18. The touch screen of claim 17, wherein the common lines include breaks at the borders of the common electrodes.

19. The touch screen of claim 17, wherein each common electrode comprises a touch region and selected pairs of touch regions form touch pixels capable of indicating a touch event thereon by changes in a capacitance between said pair of touch regions.

20. The touch screen of claim 15, wherein the touch screen comprises an FFS TFT LCD.

21. A method for manufacturing a touch screen configured to perform both a display and a touch sensing functionality comprising:

forming a plurality of pixels, each pixel including a storage capacitor comprising a first electrode and a second electrode;

forming one or more opaque display elements used to perform the display functionality of the touch screen;

forming a plurality of common lines from a non-transparent conductor, the common lines being positioned at a different layer in the touch screen than the opaque display elements such that the opaque display elements substantially overlap the common lines; and

connecting respective ones of the plurality of common lines to one or more of the first electrodes of the plurality of pixels,

wherein the first electrodes connected to the common lines are used for both the display and touch sensing functionalities of the touch screen.

22. The method of claim 21, wherein the common lines are connected to touch circuitry and are used to carry touch sensing signals.

23. The method of claim 21, wherein the forming of the common lines comprises:

forming a first plurality of parallel common lines (xVcom lines); and

forming a second plurality of parallel common lines (yVcom lines),

the first and second pluralities being positioned perpendicular to one another at the same layer to form a lattice structure.

24. The method of claim 23, wherein the forming of the opaque display elements comprises:

forming a plurality of parallel gate lines;

forming a plurality of parallel data lines; and

positioning the gate and data lines perpendicular to each other to form a lattice structure, wherein

the xVcom lines are respectively substantially overlapped by respective gate lines, and

the yVcom lines are respectively substantially overlapped by respective data lines.

25. The method of claim 21, wherein forming the opaque display elements comprises forming display gate and data lines.

26. The method of claim 21, wherein the forming of the opaque display elements comprises forming of pixel transistors.

27. The method of claim 21, wherein the plurality of common lines are configured to connect the pixels in a plurality of sets of pixels, each set of pixels having all first electrodes connected to each other by the common lines and wherein the common lines are interrupted at the boundaries between different adjacent sets of pixels.

28. The method of claim 27, wherein each sets of pixels comprises a touch region, and selected pairs of touch regions form touch pixels capable of indicating a touch event thereon by changes in a capacitance between said pair of touch regions.

29. The method of claim 27, wherein each set of pixels covers a contiguous region of the touch screen.

30. A method for manufacturing a touch screen configured to perform both a display and a touch sensing functionality including:

forming a plurality of pixels including a plurality of sets of pixels, each set of pixels comprising two or more pixels;

forming a plurality of common electrodes, each common electrode serving as a storage capacitor electrode for a respective set of pixels;

forming one or more opaque display elements used to perform the display functionality of the touch screen;

forming a plurality of common lines from a non-transparent conductor and positioned at a different layer in the touch screen than the opaque display elements such that the opaque display elements substantially overlap the common lines; and

connecting the plurality of common lines to the plurality of common electrodes,

wherein the common electrodes are used for both the display and touch sensing functionalities of the touch screen.

31. The method of claim 30, wherein forming the common lines comprises positioning the common lines at the same or adjacent layer to the plurality of common electrodes.

32. The method of claim 30, wherein each common electrode is connected to a set of plurality of common lines from the plurality of common lines and wherein the common lines are interrupted at the boundaries between different adjacent common electrodes.

33. The method of claim 32, wherein forming the common lines includes ensuring there are breaks of the common lines at the borders of the common electrodes.

34. The touch screen of claim 32, wherein each common electrode comprises a touch region, and selected pairs of touch regions form touch pixels capable of indicating a touch event thereon by changes in a capacitance between said pair of touch regions.

35. The method of claim 30, wherein the touch screen comprises an FFS TFT LCD.

36. A personal computer including a touch screen configured to perform both a display and a touch sensing functionality, comprising:

a plurality of pixels, each pixel including a storage capacitor comprising a first electrode and a second electrode;

one or more opaque display elements used to perform the display functionality of the touch screen; and

a plurality of common lines made from a non-transparent conductor, connected to the first electrode of one or more of the plurality of pixels and positioned at a different layer in the touch screen than the opaque display elements such that the opaque display elements substantially overlap the common lines,

wherein the first electrodes connected to the common lines are used for both the display and touch sensing functionalities of the touch screen.