Display device and voltage adjusting method therefor

• US 20070200832A1
• Filed: 02/22/2007
• Published: 08/30/2007
• Est. Priority Date: 02/24/2006
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Cho, Man-Seung, Lee, Joo-Hyung, Park, Jong-Woung, Uh, Kee-Han, Kim, Hyung-Guel, Cha, Young-Ok, Lee, Myung-Woo
• Granted Patent: US 8,188,979 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/04184 Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally
• 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
• CPC Class Codes: G06F 3/0447 Position sensing using the local deformation of sensor cells

Abstract

A display device includes: a plurality of sensing data lines; a plurality of sensing units that output sensing signals through the plurality of sensing data lines; a signal selector that selects one sensing signal among the plurality of sensing signals; an automatic voltage adjusting unit that, when one sensing signal is selected by the signal selector, performs a controlling operation so as to allow a magnitude of the selected sensing signal to be in a predetermined range; and a voltage generator that adjusts the magnitude of the voltage applied to the sensing data lines based on a control signal output from the automatic voltage adjusting unit. According to the voltage adjusting operation, the sensing signal output through the sensing data line is always in an appropriate range. As a result, the touch determining operation on the sensing units can be accurately performed, so that it is possible to improve reliability of the sensing units.

Claims

1. A method of adjusting the voltage of a plurality of initial sensing signals output from a plurality of sensing units of a touch-sensitive display based on initial input sensing signals, the method comprising:

selecting an initial sensing signal from one of the initial sensing signals that is input;

determining whether the voltage of the selected initial sensing signal is in a predetermined range;

starting an adjusting operation for adjustment of the initial sensing signal;

when the voltage of the selected initial sensing signal is not in the predetermined range, commanding the adjusting of the initial sensing signal; and

determining whether the adjusting operation for the initial sensing signal according to the command starts;

when the adjusting operation for the initial sensing signal starts, stopping the commanding operation for the adjusting of the initial sensing signal; and

determining whether the adjusting operation for the initial sensing signal has placed the sensing signal in the predetermined range, and

stopping the adjustment of the initial sensing signal when the initial sensing signal is in the predetermined range.

2. The voltage adjusting method of claim 1, wherein the selected initial sensing signal is an initial sensing signal having a maximum value among the initial sensing signals.

3. The voltage adjusting method of claim 1, wherein the initial sensing signal is a vertical sensing signal.

4. The voltage adjusting method of claim 1, wherein the initial sensing signal is a horizontal sensing signal.

5. The voltage adjusting method of claim 1, wherein the initial sensing signal is made up of vertical and horizontal sensing signals.

6. The voltage adjusting method of claim 5, wherein, after the voltage of the vertical sensing signal is adjusted, the voltage of the horizontal sensing signal is adjusted.

7. The voltage adjusting method of claim 5, wherein, after the voltage of the horizontal sensing signal is adjusted, the voltage of the vertical sensing signal is adjusted.

8. The voltage adjusting method of claim 1, further comprising determining the occurrence of touch of the sensing units and the position of touch.

9. The voltage adjusting method of claim 8, wherein the determining of the occurrence of touch and the touched positions comprises:

when the operation of adjusting the initial sensing signal is completed, determining whether or not the voltage of the initial sensing signal is in the predetermined range;

when the voltage of the initial sensing signal is in the predetermined range, commanding calculation of the occurrence of touch and the touched positions on the sensing units; and

maintaining a standby state until the operation of calculating the occurrence of touch and the touched positions on the sensing units is finished.

10. The voltage adjusting method of claim 9, wherein, when the voltage of the initial sensing signal is not in the predetermined range, the step of the occurrence of touch and the touched positions further comprises commanding clearing of data stored in a storage unit so as to calculate the occurrence of touch and the touched positions on the sensing units.

11. A display device comprising:

a plurality of sensing data lines;

a plurality of sensing units that output a plurality of sensing signals through the sensing data lines;

a signal selector that selects one sensing signal among the sensing signals;

an automatic voltage adjusting unit that controls the magnitude of the selected sensing signal to be in a predetermined range; and

a voltage generator that applies a voltage to the sensing data line based on the output from the automatic voltage-adjusting unit.

12. The display device of claim 11, wherein the signal selector selects an initial sensing signal having a maximum value among a plurality of initial sensing signals output of the sensing units when there is no occurrence of touch.

13. The display device of claim 12, wherein, the automatic voltage-adjusting unit:

determines whether the magnitude of the input initial sensing signal is in a predetermined range and whether there is an operation of adjusting the initial sensing signal;

when the magnitude of the initial sensing signal is not in the predetermined range, commands the voltage generator to adjust the initial sensing signal, and determines whether the voltage generator completes the operation of adjusting the initial sensing signal.

14. The display device of claim 13, wherein the initial sensing signal is a vertical initial sensing signal.

15. The display device of claim 13, wherein the initial sensing signal is an initial horizontal sensing signal.

16. The display device of claim 13, further comprising a touch-determining unit that determines the occurrence of touch and the touched positions on the sensing units, wherein the automatic voltage-adjusting unit further controls an operation of determining the occurrence of touch and the touched positions on the sensing units performed by the touch-determining unit.

17. The display device of claim 16, wherein the determining of the occurrence of touch and the touched positions comprises:

when the adjusting of the sensing signal is completed,

determining whether or not the magnitude of the initial sensing signal is in a predetermined range;

when the magnitude of the initial sensing signal is in the predetermined range,

commanding the touch determining unit to calculate the occurrence of touch and the touched positions on the sensing units; and

maintaining a standby state until the touch-determining unit completes the calculation operation on the occurrence of touch and the touched positions on the sensing units.

18. The display device of claim 17, wherein, when the magnitude of the initial sensing signal is not in a predetermined range, the step of determining the occurrence of touch and the touched positions further comprises commanding the touch determining unit to clear data stored in a storage unit so as to calculate the occurrence of touch and the touched positions on the sensing units.

19. The display device of claim 18, further comprising an interface between the automatic voltage-adjusting unit and the voltage generator and between the automatic voltage-adjusting unit and the touch-determining unit.

20. The display device of claim 19, wherein the interface is an SPI (serial peripheral interface).

21. The display device of claim 11, further comprising a reset signal input unit that applies a predetermined voltage to the sensing data line to reset the sensing data line with the predetermined voltage.

22. The display device of claim 21, wherein the voltage generator adjusts the magnitude of the predetermined voltage.

23. A touch-sensitive display device having a viewing area, comprising:

a plurality of variable capacitance touch sensing units disposed throughout the viewing area of the display device;

a voltage generator for applying a predetermined voltage to the sensing units;

a touch-determining unit monitoring the voltage of the sensing units to determine the occurrence of touch and calculating the location of positions determined to have been touched; and

a voltage-adjusting unit for controlling the operation of the voltage generator.

24. A touch-sensitive display device according to claim 23 wherein the voltage-adjusting unit determines whether the voltage of the sensing units is in a predetermined range, the voltage-adjusting unit permitting the touch-determining unit to calculate the touched positions when the voltage is within the predetermined range and maintaining a standby state until the operation of calculating the occurrence of touch and the touched positions on the sensing units is finished.

25. A touch-sensitive display device according to claim 24 wherein when the voltage of the initial sensing signal is not in the predetermined range the voltage generator adjusts the magnitude of the voltage applied to the sensing at a line based on the output from the voltage-adjusting unit.