Touch panel and display device comprising the same

• US 9,766,756 B2
• Filed: 01/07/2014
• Issued: 09/19/2017
• Est. Priority Date: 01/15/2013
• Status: Active Grant

• Current Assignee: Tianma Microelectronics Company Limited
• Original Assignee: NLT Technologies, Ltd.
• Inventors: Yoshida, Hitoshi
• Primary Examiner(s): FARAGALLA, MICHAEL A
• Application Number:
  US14/149,213
• Publication Number:
  US 20140198066A1
• Time in Patent Office: 1,351 Days
• Field of Search: 349 58, 349 59, 361799-818
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 2203/04107 Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G06F 3/0444 using a single conductive element covering the whole sensing surface, e.g. by sensing the electrical current flowing at the corners

Abstract

To shield the noise generated due to deformation or the like of the conductive frame. The touch panel includes: a detection region which generates detection signals according to a contact position of a conductor; a plurality of detection electrodes which output detection signals generated in the detection region; a conductive frame which covers above the outer side of the detection region and above the detection electrode; and shield electrodes formed on the outer side of the detection region on the CF substrate and between each of the plurality of detection electrodes, to which shield signals for shielding the electric influence on the detection region and the detection electrodes are supplied. Further, the distance between the shield electrodes and the detection region is shorter than distance between the conductive frame and the detection region.

Claims

1. A display device including a touch panel, the touch panel comprising:

a substrate;

a detection region formed on the substrate, for generating a detection signal according to a contact position of a conductor;

a plurality of detection electrodes formed on the substrate outside the detection region, for outputting the detection signal generated in the detection region;

a transparent conductive frame above an outer perimeter of the detection region on the substrate; and

a transparent shield electrode formed on a same surface on the touch panel as the detection region, on the outer perimeter of the detection region and between each of the plurality of detection electrodes,

wherein a distance from the detection region to the shield electrode is shorter than a distance from the detection region to the transparent conductive frame.

2. The display device as claimed in claim 1, wherein a shield signal is applied to the transparent shield electrode, and

the shield signal is a signal that is of an equivalent frequency and voltage level as those of a reference signal that corresponds to the detection signal when there is no contact of the conductor.

3. The display device as claimed in claim 1, wherein a shield signal is applied to the transparent shield electrode, and

the shield signal is a ground potential.

4. The display device as claimed in claim 1, wherein the display device is a liquid crystal display device, comprising:

as the touch panel, a color filter substrate on which a color filter is formed;

a thin film transistor substrate on which thin film transistors are formed; and

a liquid crystal layer sandwiched between the color filter substrate and the thin film transistor substrate.

5. The display device as claimed in claim 4, further comprising a shield signal wiring formed on the thin film transistor substrate for supplying a shield signal to the shield electrode, wherein

the shield signal wiring is electrically connected to the shield electrode by a conductive material provided between the thin film transistor substrate and the color filter substrate.

6. The display device as claimed in claim 5, further comprising a detection signal wiring which is formed on the color filter substrate, electrically connected to the detection electrodes, and covered by an insulating material for electrically insulating it from the shield electrode and the conductive material, wherein

a distance from the detection region to the shield electrode is shorter than a distance from the detection region to the detection signal wiring.

7. The display device as claimed in claim 1, wherein

the distance from the detection region to the transparent conductive frame is changed by deformation of the transparent conductive frame or the substrate.

8. The display device as claimed in claim 1, wherein

the distance from the detection region to the transparent conductive frame is changed by weight added to the detection region at a time of a touch operation.

9. The display device as claimed in claim 1, wherein

a space from the detection region to the transparent conductive frame is hollow.

10. The display device as claimed in claim 7, wherein

an insulating material is filled between the substrate and the transparent conductive frame.

11. The display device as claimed in claim 10, wherein

the insulating material has a hardness of an extent with which the deformation is lightened.

12. The display device as claimed in claim 1, wherein

capacitance between the shield electrode and the detection region is larger than capacitance between the transparent conductive frame and the detection region.