Touch panel having reduced number of interconnects and touch input/output apparatus having the same

• US 8,648,833 B2
• Filed: 03/04/2010
• Issued: 02/11/2014
• Est. Priority Date: 09/03/2009
• Status: Expired due to Fees

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Lee, Su-Mi, Lee, Yong-Woo, Lee, Sung-Kyu, Hwang, Seong-Mo, Kang, Sung-Wook
• Primary Examiner(s): Lao, Lun-Yi
• Assistant Examiner(s): Abebe, Sosina
• Application Number:
  US12/717,827
• Publication Number:
  US 20110050624A1
• Time in Patent Office: 1,440 Days
• Field of Search: 345156-184, 178 1801- 2004
• US Class Current: 345/174
• 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 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

A touch panel includes first and second normally spaced apart substrates. The first substrate includes first spaced apart touch electrodes extended in a first direction and each having a first width (W1). The second substrate includes second spaced apart touch electrodes extended in a different second direction and each having a second width (W2) which is substantially narrower than the first width. One of the substrates can be flexed so that momentary shorting contact is established between corresponding first and second touch electrodes at positions where pressing touch is provided. A combination of interconnect wirings and interrogation circuits are provided for automatically determining where and when the temporary shorting contacts were made, even if plural ones are simultaneously made. The disclosed embodiments include ones where the number of interconnect wirings are reduced.

Claims

1. A touch panel comprising:

a first substrate comprising a plurality of first touch electrodes formed on a first base substrate, the first touch electrodes each having a first width, where the first touch electrodes are elongated along a first direction and arranged in parallel one next to the other so as to thereby be distributed along a second direction crossing the first direction; and

a second substrate comprising a plurality of second touch electrodes formed on a second base substrate that is in spaced apart facing relationship with the first base substrate, where the second touch electrodes each have a second width narrower than the first width, and where the second touch electrodes are elongated primarily along the second direction and arranged in parallel one next to the other so as to thereby be distributed along the first direction, the respective narrower second widths of the respective second touch electrodes allowing development in each of the second touch electrodes of a respective and detectable plurality of different voltages between opposed terminal ends of the respective and elongated second electrode;

a plurality of first wirings each respectively connected to only a first among respective first and second terminal ends of a respective one of the first touch electrodes; and

respective pairs of second wirings, each pair having two wires that are respectively connected to the opposed terminal ends of a respective one of the narrower and elongated second electrodes.

2. The touch panel of claim 1, wherein each of the plural second touch electrodes is not entirely a linear structure, but rather comprises:

a first electrode portion extended in the second direction;

a second electrode portion spaced apart from and substantially parallel to the first electrode portion;

a third electrode portion extended in the first direction and connecting a first end of the first electrode portion with an adjacent first end of the second electrode portion so as to form a substantially U shaped structure; and

wherein for each substantially U shaped structure, the touch panel has a corresponding pair of second wirings connected to corresponding second ends of the first and second electrode portions.

3. The touch panel of claim 2, wherein at least one of a first electrode portion or a second electrode portion of a correspondingly one or two adjacent second touch electrodes is disposed between the first electrode portion and the second electrode portion of the first recited and substantially U shaped second touch electrode.

4. The touch panel of claim 2, wherein the third electrode portion overlaps with and is electrically insulated from a respective second wiring of at least one of the first and second touch electrode portions that are adjacent to the third electrode portion.

5. The touch panel of claim 4, wherein the second substrate comprises an insulating layer disposed between the third electrode portion and the second wiring of the second touch electrode portion that is adjacent to the third electrode portion.

6. The touch input/output apparatus of claim 1, wherein the respective second ones of the opposed first and second terminal ends of the first touch electrodes are not connected to any wirings.

7. A touch input/output apparatus comprising:

a touch panel assembly comprising a touch panel, the touch panel comprising;

a first substrate comprising a plurality of first touch electrodes formed on a first base substrate, the first touch electrodes each having a first width (W1) and being elongated along a first direction, the first touch electrodes being arranged one after the other in a different second direction; and

a second substrate comprising a plurality of second touch electrodes formed on a second base substrate facing the first base substrate, the second touch electrodes each having a second width (W2) narrower than the first width and being elongated primarily along the second direction, the second electrodes being arranged one after the other in the first direction, the respective narrower second widths (W2) of the respective second touch electrodes allowing development in each of the second touch electrodes of a respective and detectable plurality of different voltages between opposed terminal ends of the respective and elongated second electrode; and

a touch position controller operatively coupled to the first and second substrates for determining one or more touch positions corresponding to touchings on the panel that cause one or more of the first touch electrodes to come into shorting contact at the touch positions with a corresponding one or more of the second touch electrodes, the touch position controller being responsive to a developed voltage developed as part of said respective and detectable plurality of different voltages that can be developed along a contacted one of the plural second touch electrodes.

8. The touch input/output apparatus of claim 7, wherein

the touch position controller can apply a first interrogating voltage signal to one or more of the first touch electrodes through corresponding first wirings connected only to respective first ones of opposed first and second terminal ends of the first touch electrodes, and wherein the touch position controller can detect corresponding voltages developed on the first touch electrodes through the first wirings, which first wirings are connected only to the respective first ones of the opposed first and second terminal ends of the first touch electrodes.

9. The touch input/output apparatus of claim 8, wherein the respective second ones of the opposed first and second terminal ends of the first touch electrodes are not connected to any wirings.

10. The touch input/output apparatus of claim 7, wherein the touch position controller comprises:

a voltages applying circuit structured for applying a first interrogating voltage signal (V1) to the respective first touch electrodes by way of respective ones of the first wirings, for applying a second interrogating voltage signal (V2) to the respective second touch electrodes by way of respective ones of the second wirings, and for additionally applying a third interrogating voltage signal (V3) by way of respective others of the second wirings while continuing to or reapplying the second interrogating voltage signal (V2) to the second touch electrodes in response to detection of touchings on the touch panel when only the first and second interrogating voltage signals (V1,V2) are applied; and

a position determining circuit structured for determining a second position using a position of the second touch electrode experiencing a change of developed voltage in response to touchings, and for determining a first position using a position of the first touch electrode experiencing a change of developed voltage in response to touchings.

11. The touch input/output apparatus of claim 10, wherein each of the second touch electrodes comprises:

a first electrode portion extended in the second direction;

a second electrode portion substantially parallel with the first electrode portion; and

a third electrode portion extended in the first direction and connecting substantially adjacent first ends of the first and second electrode portions;

wherein wirings are connected to respective second ends of the first and second electrode portions.

12. The touch input/output apparatus of claim 11,

wherein a first electrode portion or a second electrode portion of an adjacent second touch electrode is disposed between the first electrode portion and the second electrode portion of at least one of said each second touch electrode, and

the third electrode portion of the at least one of said each second touch electrode overlaps with and is electrically insulated from a wiring connecting to the second touch electrode.

13. The touch input/output apparatus of claim 11, wherein

the position determining circuit is further structured for determining as a crude first position of a contact inducing touch, an area having a side dimension and location corresponding to the first width (W1) of a corresponding first touch electrode when a voltage sensed to be developed on the first touch electrode is substantially equal to a midpoint voltage expected to be developed at a central portion of the length of the second touch electrode.

14. The touch input/output apparatus of claim 7, wherein

the first substrate further comprises a plurality of first pulse-delaying circuit elements respectively coupled one to the next and also respectively interconnecting adjacent first ends of the first touch electrodes one to the next so that an interrogating first electrical pulse supplied to a first of the adjacent first ends will be sequentially next applied to others of the adjacent first ends one after another, and

the second substrate further comprises a plurality of second pulse-delaying circuit elements respectively coupled one to the next and also respectively interconnecting adjacent second ends of the second touch electrodes one to the next so that an interrogating second electrical pulse supplied to a first of the adjacent second ends will be sequentially next applied to others of the adjacent second ends one after another.

15. The touch input/output apparatus of claim 14, wherein the touch position controller comprises:

a pulse generator structured and connected to supply the interrogating first electrical pulse to the first of the adjacent first ends of the first touch electrodes, wherein the pulse generator is further structured and connected to supply the interrogating second electrical pulse to the first of the adjacent second ends of the second touch electrodes,

said pulse generator being further structured and connected to automatically supply, in response to detection of a voltage change on one of the second touch electrodes, an interrogating third electrical pulse to a corresponding third end of the second touch electrode whose voltage was detected as being changed, where the third end is opposed to the second end of that voltage-change experiencing second touch electrode; and

a position determining circuit structured for determining a second position using a position of the second touch electrode experiencing a change of developed voltage in response to touchings, and for determining a first position using a position of the first touch electrode experiencing a change of developed voltage in response to touchings.

16. The touch input/output apparatus of claim 7, wherein the second substrate further comprises a common electrode disposed on a second surface facing a first surface on which the second touch electrodes are disposed.

17. The touch input/output apparatus of claim 16, wherein

the touch panel assembly further comprises a third substrate comprising a plurality of pixels and combined with the second substrate to receive a liquid crystal layer,

and each of the pixels comprises a switching element electrically connected to a gate line and a data line and a pixel electrode electrically connected to the switching element.

18. The touch input/output apparatus of claim 17, wherein the second width of each of the second touch electrodes is substantially equal to a length of a side of the pixel corresponding to the first direction.

19. The touch input/output apparatus of claim 17, wherein the second width of each of the second touch electrodes is substantially a whole number multiple of a length of a side of the pixel corresponding to the first direction.

20. The touch input/output apparatus of claim 17, wherein the touch panel assembly further comprises a polarizer disposed under the third substrate and having a first polarizing axis.

21. The touch input/output apparatus of claim 20, wherein the first base substrate of the first substrate includes a polarizer having a second polarizing axis which crosses the first polarizing axis.