Touch panel and driving device for the same

• US 9,013,443 B2
• Filed: 09/02/2011
• Issued: 04/21/2015
• Est. Priority Date: 04/18/2011
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lim, Seong-Taek
• Primary Examiner(s): Lee, Jr., Kenneth B
• Application Number:
  US13/224,422
• Publication Number:
  US 20120262410A1
• Time in Patent Office: 1,327 Days
• Field of Search: 345173-182, 178 1801- 1811
• US Class Current: 345/174
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• 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

Abstract

A driving device and a touch panel are provided. The driving device includes a first switcher and a second switcher. The first switcher is coupled to a first electrode of a capacitance node of the touch panel and is configured to selectively apply, to the first electrode, a driving voltage for generating an electric potential difference in the capacitance node. The second switcher is coupled to the first electrode and configured to selectively apply, to the first electrode, a sensing voltage for sensing a variation in the capacitance of the at least one capacitance node.

Claims

1. A driving device for a touch panel including at least one capacitance node, the driving device comprising:

a first switching element that is coupled to a first electrode of the at least one capacitance node and is configured to selectively apply, to the first electrode, a driving voltage for generating an electric potential difference in the at least one capacitance node; and

a second switching element that is coupled to the first electrode and is configured to selectively apply, to the first electrode, a sensing voltage for sensing a variation in the capacitance of the at least one capacitance node,

wherein at least one of the driving voltage, the sensing voltage, a voltage lower than the driving voltage, and a combination voltage obtained by subtracting the sensing voltage from the driving voltage or by adding the sensing voltage to the driving voltage is applied to the first electrode according to a combination of a driving selection signal for turning on or off the first switching element and a sensing selection signal for turning on or off the second switching element.

2. The driving device of claim 1, wherein:

first switching element comprises an output port,

the second switching element comprises an output port, and

the driving voltage is a high voltage of about 50V or higher, the sensing voltage is a low voltage of about 5V or lower, and the output ports of the first and second switching elements are connected in parallel to the first electrode.

3. A driving device for a touch panel including at least one capacitance node, the driving device comprising:

a first switching element that is coupled to a first electrode of the at least one capacitance node and is configured to selectively apply, to the first electrode, a driving voltage for generating an electric potential difference in the at least one capacitance node; and

a second switching element that is coupled to the first electrode and is configured to selectively apply, to the first electrode, a sensing voltage for sensing a variation in the capacitance of the at least one capacitance node,

wherein;

the first switching element comprises a first transistor that has a source coupled to a driving voltage source and a drain coupled to the first electrode, the first transistor being turned on or off according to whether the driving selection signal is applied, the driving voltage source generating the driving voltage, and

the second switching element comprises a second transistor that has a source coupled to a sensing voltage source and a drain coupled to the first electrode, the second transistor being turned on or off according to whether the sensing selection signal is applied, the sensing voltage source generating the sensing voltage.

4. The driving device of claim 3, further comprising a third transistor configured to turn off the first transistor in response to the driving selection signal being applied, and to turn on the first transistor in response to the driving selection signal not being applied.

5. The driving device of claim 4, further comprising a fourth transistor configured to be turned on in response to the second transistor being turned off, to be turned off in response to the second transistor being turned on, and to maintain a bias of the first electrode while the second transistor is turned off.

6. The driving device of claim 5, wherein:

the second transistor is turned on in response to the sensing selection signal being applied thereto and is turned off in response to the sensing selection signal not being applied thereto, and

the fourth transistor applies the driving voltage to the first electrode in response to the sensing selection signal not being applied to the fourth transistor and applies the subtracted voltage to the first electrode in response to the sensing selection signal being applied to the fourth transistor.

7. The driving device of claim 5, wherein the first through fourth transistors are high-voltage metal-oxide-semiconductor (MOS) transistors.

8. The driving device of claim 5, wherein the first through fourth transistors are laterally diffused MOS field-effect transistors (LD MOSFETs).

9. The driving device of claim 7, further comprising a breakdown prevention element configured to be coupled to the gate and the source of the first transistor.

10. The driving device of claim 9, wherein the breakdown prevention element comprises a diode and a capacity of the diode is greater than the sensing voltage and less than a breakdown voltage between the gate and the source of the first transistor.

11. A touch panel comprising:

a first substrate;

a plurality of first electrode lines that are disposed on the first substrate and extend in parallel in a first direction;

a second substrate that is spaced apart from the first substrate by a distance;

a plurality of second electrode lines that are disposed on the second substrate and extend in parallel in a second direction that is perpendicular to the first direction;

an electrorheological fluid that is interposed between the first and second substrates;

a driving device configured to apply, to the first electrode lines, a combined signal obtained by combining a driving voltage for varying a viscosity of the electrorheological fluid with a sensing voltage; and

a sensing device that is connected to the second electrode lines and is configured to detect an input to the touch panel in response to the sensing voltage being applied to the first electrode lines,

wherein the driving device comprises;

a first switching element configured to selectively apply the driving voltage to the first electrode lines and a second switching element configured to selectively apply the sensing voltage to the first electrode lines, and

a controller configured to transmit a combination of a driving selection signal for turning on or off the first switching element and a sensing selection signal for turning on or off the second switching element to the driving device,

wherein the driving device selectively applies, to the first electrode lines, at least one of the driving voltage, the sensing voltage, a voltage lower than the driving voltage, and a combination voltage obtained by subtracting the sensing voltage from the driving voltage or by adding the sensing voltage to the driving voltage based on the combination of the driving selection signal and the sensing selection signal from the controller.

12. The touch panel of claim 11, wherein the touch panel comprises a plurality of driving devices that correspond to the first electrode lines and are configured to be respectively connected to the first electrode lines.

13. The touch panel of claim 11, wherein the controller is further configured to, in response to an input signal being received from the sensing device, select the driving selection signal and transmit the driving selection signal to the driving device to release the driving voltage from the first electrode lines.

14. The touch panel of claim 11, wherein the controller is further configured to select the sensing selection signal, and transmit the sensing selection signal to the driving device so that the sensing voltage is sequentially applied to the first electrode lines.

15. A touch panel comprising:

a first substrate;

a plurality of first electrode lines that are disposed on the first substrate and extend in parallel in a first direction;

a second substrate that is spaced apart from the first substrate by a distance;

a plurality of second electrode lines that are disposed on the second substrate and extend in parallel in a second direction that is perpendicular to the first direction;

an electrorheological fluid that is interposed between the first and second substrates;

a driving device configured to apply, to the first electrode lines, a combined signal obtained by combining a driving voltage for varying a viscosity of the electrorheological fluid with a sensing voltage;

a sensing device that is connected to the second electrode lines and is configured to detect an input to the touch panel in response to the sensing voltage being applied to the first electrode lines,

wherein the driving device comprises a first switching element configured to selectively apply the driving voltage to the first electrode lines and a second switching element configured to selectively apply the sensing voltage to the first electrode lines,

the first switching element comprises a first transistor that has a source coupled to a driving voltage source and a drain coupled to the first electrode lines, the first transistor being turned on or off according to whether the driving selection signal is applied thereto, and

the second switching element comprises a second transistor that has a source coupled to a sensing voltage source and a drain coupled to the first electrode lines, is the second transistor being turned on or off according to whether the sensing selection signal is applied thereto.

16. The touch panel of claim 15, wherein the driving device further comprises a third transistor configured to turn off the first transistor in response to the driving selection signal being applied to the third transistor, and to turn on the first transistor in response to the driving selection signal not being applied to the third transistor.

17. The touch panel of claim 16, wherein the driving device further comprises a fourth transistor configured to be turned on in response to the second transistor being turned off, to be turned off in response to the second transistor being turned on, and to maintain a bias of the first electrode lines while the second transistor is turned off.

18. A capacitive-type touch panel comprising:

a first substrate;

a first electrode that is disposed on the first substrate;

a second substrate that is spaced apart from the first substrate;

a second electrode that is disposed on the second substrate, the second electrode and the first electrode forming a capacitance node;

an electrorheological fluid that is interposed between the first and second substrates;

a driving device that is coupled to the first electrode and is configured to apply to the first electrode, a driving voltage, a sensing voltage, a voltage lower than the driving voltage, or a combination of the driving voltage and sensing voltage;

a sensing device that is coupled to the second electrode and is configured to detect an input at the capacitance node in response to the sensing voltage being applied to the first electrode; and

a controller that is configured to transmit a control signal comprising a combination of a driving selection signal for turning on or off a first switching element and a sensing selection signal for turning on or off a second switching element to the driving device,

wherein the driving device selectively applies, to the first electrode, based on the control signal from the controller, the driving voltage, the sensing voltage, the voltage lower than the driving voltage, or the combination of the driving voltage and the sensing voltage, the combination being generated by subtracting the sensing voltage from the driving voltage or by adding the sensing voltage to the driving voltage.