In-cell type touch panel

• US 8,780,078 B2
• Filed: 12/28/2011
• Issued: 07/15/2014
• Est. Priority Date: 04/27/2011
• Status: Expired due to Fees

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Kim, Cheol-Se, Han, Man-Hyeop
• Primary Examiner(s): OLSON, JASON C
• Application Number:
  US13/339,027
• Publication Number:
  US 20120274603A1
• Time in Patent Office: 930 Days
• Field of Search: None
• US Class Current: 345/174
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes

Abstract

The present invention relates to an in-cell type touch panel includes first and second substrates opposite to each other, gate and data lines crossed each other to define a plurality of pixel regions, a pixel electrode at each of the pixel region, a pixel thin film transistor connected to the gate and data lines, and a pixel overlapped with the pixel electrode to have a common electrode, formed in a surface of the first substrate, a sensor electrode on a back side of the second substrate, and a touch sensor between the sensor electrode and the pixel, and a capacitance change between the sensor electrode and a touch object over the sensor electrode.

Claims

1. An in-cell type touch panel comprising:

a first substrate and a second substrate opposing each other with a liquid crystal layer disposed therebetween;

a gate line and a data line that cross each other to define a pixel region, a pixel electrode at the pixel region, a pixel thin film transistor connected to the gate line and the data line that drives the pixel electrode, and a pixel overlapped with the pixel electrode to have a common electrode divided by patterning in a surface of the first substrate;

a sensor electrode on a back side of the second substrate; and

a touch sensor that senses a capacitance change between the sensor electrode and the pixel, and a capacitance change between the sensor electrode and a touch object over the sensor electrode, and outputs a sensing signal.

2. The in-cell type touch panel as claimed in claim 1, further comprising a sensor driving line that supplies a sensing driving voltage to the touch sensor at the time of touch sensing, and a read out line that outputs the sensing signal from the touch sensor.

3. The in-cell type touch panel as claimed in claim 2, wherein at least one of the sensor driving line and the read out line is formed of metal on the same layer with one of the gate line or the data line.

4. The in-cell type touch panel as claimed in claim 3, wherein the sensor driving line is formed of the same metal, and on the same layer, with the gate line, and the read out line is formed of the same metal, and on the same layer, with the data line.

5. The in-cell type touch panel as claimed in claim 2, wherein the common electrode is driven divided in the touch sensing and the display, wherein, in the display, a common voltage is applied to the common electrodes.

6. The in-cell type touch panel as claimed in claim 2, wherein the gate line is used as the sensor driving line.

7. The in-cell type touch panel as claimed in claim 2, wherein the common electrode includes a first common electrode and a second common electrode arranged alternately, wherein each of the first and second common electrodes is arranged for a block of pixels.

8. The in-cell type touch panel as claimed in claim 7, wherein the sensor electrode is in an island shape in which the sensor electrode overlaps with one first common electrode and a portion of each of the second common electrodes adjacent to the one first common electrode.

9. The in-cell type touch panel as claimed in claim 7, wherein each of the first common electrode and the second common electrode has at least one slit.

10. The in-cell type touch panel as claimed in claim 7, wherein the first common electrode is connected to the sensor driving line, and the second common electrode is connected to the read out line.

11. The in-cell type touch panel as claimed in claim 10, further comprising a protective film provided between the read out line and the first and second common electrodes, and a stack of a gate insulating film and a protective film between the sensor driving line and the first and second common electrodes.

12. The in-cell type touch panel as claimed in claim 10, wherein the capacitance between the pixel and the sensor electrode is a sum of capacitance between the first common electrode and the sensor electrode, and capacitance between the second common electrode and the sensor electrode.

13. The in-cell type touch panel as claimed in claim 2, wherein the common electrode is divided taking the sensor driving line as a boundary.

14. The in-cell type touch panel as claimed in claim 13, wherein the common electrode is connected to the read out line.

15. The in-cell type touch panel as claimed in claim 14, wherein the sensor electrode is formed in a direction to cross the common electrodes in an island shape in which the sensor electrode overlaps with an entire width of one center common electrode and a portion of a width of each of the common electrodes adjacent to both of the one center common electrode.

16. The in-cell type touch panel as claimed in claim 13, wherein the capacitance between the pixel and the sensor electrode is a sum of capacitance between the sensor driving line and the sensor electrode, and capacitance between the common electrode and the sensor electrode.

17. The in-cell type touch panel as claimed in claim 1, wherein the sensor electrode is in a floating state.

18. The in-cell type touch panel as claimed in claim 1, further comprising a protective member between the sensor electrode and the touch object.

19. The in-cell type touch panel as claimed in claim 18, wherein the protective member is formed of glass or a transparent film.

20. The in-cell type touch panel as claimed in claim 1, further comprising a polarizing plate on a back side of the second substrate, and the sensor electrode is attached on a top side of the polarizing plate.

21. The in-cell type touch panel as claimed in claim 20, further comprising a transparent protective film on the polarizing plate, and the sensor electrode is formed on the transparent protective film by patterning.