Touch detectable display device and driving method thereof

• US 7,755,612 B2
• Filed: 09/23/2005
• Issued: 07/13/2010
• Est. Priority Date: 09/24/2004
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Myung-Woo, Lee, Joo-Hyung, Uh, Kee-Han, Park, Sang-Jin
• Primary Examiner(s): Lefkowitz; Sumati
• Assistant Examiner(s): Moon; Seokyun
• Application Number:
  US11/234,720
• Publication Number:
  US 20060077186A1
• Time in Patent Office: 1,754 Days
• Field of Search: 345173-176, 345/207, 345/104, 345/102, 178/18.09, 178/18.11
• US Class Current: 345/173
• CPC Class Codes: G06F 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/042 by opto-electronic means

Abstract

A display device is disclosed which includes: a display panel; a lighting unit to illuminate the display panel and having a state in response to a lighting control signal; a pressure sensing unit generating a first sensor output signal according to a touch on the display panel; a light sensing unit receiving light from the lighting unit and ambient light and generating a second sensor output signal according to the touch on the display panel; a sensor scanning driver outputting sensor scanning signals to the pressure sensing unit and the light sensing unit in response to a sensor scanning control signal; and a sensing controller generating the lighting control signal and the sensor scanning control signal based on the first and the second sensor output signals and outputting the lighting control signal to the lighting unit and the sensor scanning control signal and the sensor scanning driver.

Claims

1. A display device comprising:

a display panel;

a lighting unit adapted to illuminate the display panel in response to receipt of a lighting control signal;

a pressure sensing unit adapted to generate a first sensor output signal in response to a touch on the display panel;

a light sensing unit positioned to receive light from the lighting unit and ambient light and in response thereto to generate a second sensor output signal in response to a touch on the display panel;

a sensor scanning driver adapted to generate and supply sensor scanning signals to the pressure sensing unit and to the light sensing unit in response to receipt of a sensor scanning control signal; and

a signal controller being operable to generate the lighting control signal and the sensor scanning control signal in response to receipt of the first and the second sensor output signals, the signal controller being further operable to transmit the lighting control signal and the sensor scanning control signal to the lighting unit and the sensor scanning driver, respectively, the signal controller comprising;

a pressure calculation unit being operable to generate a pressure information signal in receipt of the first sensor output signal;

a position calculation unit being operable to determine where a touch occurred to generate a position information signal in response to the second sensor output signal; and

a sensing controller, wherein the sensing controller receives the pressure information signal and the position information signal and generates the lighting control signal in response to a failure to detect the touched position in the received position information signal.

2. The display device of claim 1, wherein the lighting control signal is operable to control a luminance of the lighting unit.

3. The display device of claim 2, wherein the lighting control signal causes the lighting unit to be in either an operable or nonoperable state.

4. The display device of claim 2, wherein the lighting control signal controls a magnitude of a current driving the lighting unit.

5. The display device of claim 1, wherein the lighting control signal controls a phase of a driving voltage of the lighting unit.

6. The display device of claim 5, wherein the lighting control signal is operable to vary a duty ratio of the driving voltage of the lighting unit from 40% to 60%.

7. The display device of claim 5, wherein the phase of the driving voltage ranges from −

10°

to 10° and

form 170°

to 190°

if the phase of the driving voltage is defined to be 0°

when the phase of the driving voltage is synchronized with the sensor scanning signals.

8. The display device of claim 1, wherein the sensing controller controls a light sensing period of the light sensing unit according to an on/off state of the lighting unit in the dead zone.

9. The display device of claim 1, wherein the pressure sensing unit and the light sensing unit are disposed on the display panel.

10. The display device of claim 1, wherein the display device is a liquid crystal display.

11. A method of driving a display device including a display panel and a lighting unit, the method comprising:

generating a first sensing signal based on a pressure exerted on a display panel;

generating a pressure information signal as a function of the first sensing signal;

generating a second sensing signal responsive to receipt of light from the lighting unit and ambient light;

generating a position information signal as a function of the second sensing signal;

determining whether the display device is under a condition for a dead zone based on the pressure information signal and the position information signal; and

performing a control operation by controlling the lighting unit or by controlling a timing for generating the second sensing signal when the display device is under a condition for the dead zone,

wherein the determination of whether the display device is under a condition for the dead zone comprises;

determining that the display device is under a condition for the dead zone when the pressure information signal indicates that a touch exists but the position information signal fails to indicate the touched position.

12. The method of claim 11, wherein the control of the lighting unit comprises:

controlling a luminance of the lighting unit.

13. The method of claim 12, wherein the control of the luminance of the lighting unit comprises:

changing an on/off state of the lighting unit.

14. The method of claim 11, wherein the control of the luminance of the lighting unit comprises:

changing a current driving the lighting unit.

15. The method of claim 11, wherein the control of the lighting unit comprises:

changing a phase of a driving voltage of the lighting unit relative to the timing for generating the second sensing signal.

16. The method of claim 11, wherein the control of the timing for generating the second sensing signal comprises:

changing the timing for generating the second sensing signal relative to a phase of a driving voltage of the lighting unit.