Display device and method of driving the same for alternately applying a reset voltage to row and column sensor data lines

• US 8,471,827 B2
• Filed: 07/16/2008
• Issued: 06/25/2013
• Est. Priority Date: 12/26/2007
• 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, Joo-Hyung, Uh, Kee-Han, Cho, Man-Seung
• Primary Examiner(s): Shalwala, Bipin
• Assistant Examiner(s): CRAWLEY, KEITH L
• Application Number:
  US12/174,095
• Publication Number:
  US 20090167718A1
• Time in Patent Office: 1,805 Days
• Field of Search: 345173-178, 341/5, 341/20, 341/33, 341/658, 341/663, 323/904
• US Class Current: 345/174
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• 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 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• 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

In a touch sensible display device, a first sensing unit is connected to a row sensor data line and outputs a first sensing signal according to a touch, and a second sensing unit is connected to a column sensor data line and outputs a second sensing signal according to the touch. A sensing signal processor alternately applies a reset voltage to the row sensor data line and the column sensor data line and generates a sensing data signal according to the first sensing signal and the second sensing signal, and a touch determiner processes a sensing data signal to generate touch information.

Claims

1. A display device, comprising:

at least one row sensor data line extending in a row direction;

at least one column sensor data line extending in a column direction;

a first sensing unit that is connected to the row sensor data line, the first sensing unit to output a first sensing signal on a first output terminal according to a touch;

a second sensing unit that is connected to the column sensor data line, the second sensing unit to output a second sensing signal on a second output terminal according to the touch;

a sensing signal processor to alternately apply a reset voltage to the row sensor data line and the column sensor data line, generate a sensing data signal according to the first sensing signal and the second sensing signal, initialize the first output terminal to a reference voltage while the reset voltage is applied to the row sensor data line, and initialize the second output terminal to the reference voltage while the reset voltage is applied to the column sensor data line; and

a touch determiner to process the sensing data signal to generate touch information,

wherein the sensing signal processor comprises;

a first output unit to process the first sensing signal during a first period and apply the reset voltage to the row sensor data line during a second period; and

a second output unit to process the second sensing signal during the second period and apply the reset voltage to the column sensor data line during the first period.

2. The display device of claim 1, wherein the first sensing unit is configured to form a first variable capacitor that is connected to the row sensor data line, the first variable capacitor having a capacitance that changes according to the touch, and

the second sensing unit is configured to form a second variable capacitor that is connected to the column sensor data line, the second variable capacitor having a capacitance that changes according to the touch.

3. The display device of claim 2, wherein a reference capacitor is formed by the row sensor data line and the column sensor data line,

the first sensing signal comprises a first current according to a difference between the reference voltage and a first junction point voltage between the first variable capacitor and the reference capacitor, and

the second sensing signal comprises a second current according to a difference between the reference voltage and a second junction point voltage between the second variable capacitor and the reference capacitor.

4. The display device of claim 3, wherein the first output unit generates a first output voltage by integrating the first current during the first period,

the second output unit generates a second output voltage by integrating the second current during the second period, and

the sensing signal processor processes the first output voltage and the second output voltage to generate the sensing data signal.

5. The display device of claim 1, wherein:

the first output unit comprises;

a first amplifier comprising the first output terminal, an inversion terminal, and a non-inversion terminal, the non-inversion terminal to receive the reference voltage,

a first switching element connected between the row sensor data line and the reset voltage,

a second switching element connected between the inversion terminal of the first amplifier and the row sensor data line,

a first capacitor connected between the inversion terminal and the first output terminal of the first amplifier, and

a third switching element connected in parallel to the first capacitor; and

the second output unit comprises;

a second amplifier comprising the second output terminal, an inversion terminal, and a non-inversion terminal, the non-inversion terminal to receive the reference voltage,

a fourth switching element connected between the column sensor data line and the reset voltage,

a fifth switching element connected between the inversion terminal of the second amplifier and the column sensor data line,

a second capacitor connected between the inversion terminal and the second output terminal of the second amplifier, and

a sixth switching element connected in parallel to the second capacitor.

6. The display device of claim 5, wherein the second switching element, the fourth switching element, and the sixth switching element are turned on during the first period, and the first switching element, the third switching element, and the fifth switching element are turned on during the second period.

7. The display device of claim 1, wherein the at least one row sensor data line, the at least one column sensor data line, the first sensing unit, and the second sensing unit are disposed in a touch screen panel, and

the display device further comprises a display panel that is aligned with the touch screen panel, the display panel to display an image.

20. The display device of claim 1, wherein the first output unit is configured to apply the reference voltage to the first output terminal during the second period;

and

the second output unit is configured to apply the reference voltage to the second output terminal during the first period.

8. A display device, comprising:

an insulator having a first surface that can be touched by a user and a second surface at an opposite side thereof;

first sensing signal lines that are disposed on the second surface of the insulator and that extend in a first direction;

second sensing signal lines that are disposed on the second surface of the insulator and that extend in a second direction;

a sensing signal processor to alternately apply a reset voltage to the first sensing signal lines and the second sensing signal lines and generate a sensing data signal according to a first sensing signal flowing through first sensing signal lines, and a second sensing signal flowing through the second sensing signal lines; and

a touch determiner to process the sensing data signal to generate touch information,

wherein each first sensing signal line comprises;

first sensor electrodes, and

first connectors that connect the first sensor electrodes and that have a smaller width than the first sensor electrodes,

wherein each second sensing signal line comprises;

second sensor electrodes that are adjacent to the first sensor electrodes, and

second connectors that connect the second sensor electrodes, that cross the first connectors, and that have a smaller width than the second sensor electrodes, and

wherein the sensing signal processor comprises;

a first output unit to process the first sensing signal during a first period and apply the reset voltage to the first sensing signal lines during a second period; and

a second output unit to process the second sensing signal during the second period and apply the reset voltage to the second sensing signal lines during the first period.

9. The display device of claim 8, wherein the first sensor electrodes and the second sensor electrodes have a rhombus shape,

the first sensor electrodes and the second sensor electrodes are alternately disposed with respect to each other in a third direction, and

the first connector and the second connector are connected to a vertex of the rhombus shape.

10. The display device of claim 8, wherein each first sensor electrode and an adjacent second sensor electrode form a reference capacitor.

11. The display device of claim 10, wherein the first sensor electrodes and the second sensor electrodes together with a touch object that is touched with the first surface of the insulator form a capacitor.

21. The display device of claim 8, wherein the sensing signal processor is configured to receive the second sensing signal while the reset voltage is applied to the first sensing signal lines and the second sensing signal lines are floated, and receive the first sensing signal while the reset voltage is applied to the second sensing signal lines and the first sensing signal lines are floated.

22. The display device of claim 21, wherein the sensing signal processor comprises a first output unit to receive the first sensing signal and output a first output voltage on a first output terminal, and a second output unit to receive the second sensing signal and output a second output voltage on a second output terminal;

and the sensing signal processor is configured to alternately apply the first output terminal and the second output terminal to a reference voltage.

23. The display device of claim 22, wherein the sensing signal processor is configured to apply the reference voltage to the first output terminal while the reset voltage is applied to the first sensing signal lines and the second sensing signal lines are floated, and apply the reference voltage to the second output terminal while the reset voltage is applied to the second sensing signal lines and the first sensing signal lines are floated.

12. A method of driving a display device comprising at least one row sensor data line extending in a row direction and at least one column sensor data line extending in a column direction, the method comprising:

applying a reset voltage to the column sensor data line during a first period;

generating a first output voltage on a first output terminal by processing a first sensing signal that is output through the row sensor data line according to a touch during the first period;

initializing a second output terminal to a reference voltage during the first period;

applying the reset voltage to the row sensor data line during a second period;

generating a second output voltage on the second output terminal by processing a second sensing signal that is output through the column sensor data line according to the touch during the second period;

initializing the first output terminal to the reference voltage during the second period;

generating a sensing data signal by processing the first output voltage and the second output voltage; and

generating touch information from the sensing data signal.

13. The method of claim 12, wherein the generating of the first output voltage comprises changing capacitance of a first variable capacitor that is connected to the row sensor data line according to the touch, and

the generating of the second output voltage comprises changing capacitance of a second variable capacitor that is connected to the column sensor data line according to the touch.

14. The method of claim 13, wherein a reference capacitor is formed by the at least one row sensor data line and the at least one column sensor data line,

the first sensing signal comprises a first current according to a difference between the reference voltage and a junction point voltage between the first variable capacitor and the reference capacitor, and

the second sensing signal comprises a second current according to a difference between the reference voltage and a junction point voltage between the second variable capacitor and the reference capacitor.

15. The method of claim 14, wherein the generating of the first output voltage further comprises generating the first output voltage by integrating the first current, and

the generating of the second output voltage further comprises generating the second output voltage by integrating the second current.

16. The method of claim 14, wherein the at least one row sensor data line comprises a first row sensor data line, a second row sensor data line, and a third row sensor data line, and

the generating of the first output voltage further comprises generating the first output voltage by processing the first sensing signal from the first row sensor data line and the second row sensor data line during a third period and generating the first output voltage by processing the first sensing signal from the second row sensor data line and the third row sensor data line during a fourth period.

17. The method of claim 16, wherein the generating of touch information comprises generating the touch information by comparing the first output voltage in the third period and the first output voltage in the fourth period.

18. The method of claim 17, wherein the generating of touch information further comprises generating the touch information based on the first row sensor data line and the second row sensor data line, when the first output voltage in the third period is higher than the first output voltage in the fourth period.

19. The method of claim 14, wherein the at least one column sensor data line comprises a first column sensor data line, a second column sensor data line, and a third column sensor data line,

the generating of the second output voltage further comprises generating the second output voltage by processing the first sensing signal from the first column sensor data line and the second column sensor data line during a third period and generating the second output voltage by processing the first sensing signal from the second column sensor data line and the third column sensor data line during a fourth period, and

the generating of touch information comprises generating the touch information by comparing the second output voltage in the third period and the second output voltage in the fourth period.