Apparatus and method of identifying touch area

• US 9,710,112 B2
• Filed: 01/13/2012
• Issued: 07/18/2017
• Est. Priority Date: 01/13/2011
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Han, Dong-Kyoon
• Primary Examiner(s): Chang, Kent
• Assistant Examiner(s): Ghafari, Sepideh
• Application Number:
  US13/350,168
• Publication Number:
  US 20120182259A1
• Time in Patent Office: 2,013 Days
• Field of Search: 345173
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• 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
• CPC Class Codes: H04B 1/707 using direct sequence modulation

Abstract

Methods and apparatus are provided for identifying coordinates of a touch area on a touch screen panel based on a capacitive scheme. The touch screen panel has a first electrode layer having first electrode lines aligned in a first direction and a second electrode layer having second electrode lines aligned in a second direction. A signal generation unit generates a spread spectrum signal and supplies the spread spectrum signal to the first electrode layer. A signal restoration unit processes a band restoration for a signal input from the second electrode layer. A touch area coordinate identification unit identifies the coordinates of the touch area on the touch screen panel from a signal input from the signal restoration unit.

Claims

1. An apparatus for identifying coordinates of a touch area on a touch screen panel based on a capacitive scheme, the apparatus comprising:

the touch screen panel comprising a first electrode layer having first electrode lines aligned in a first direction and a second electrode layer having second electrode lines aligned in a second direction, wherein the second direction is different from the first direction, and wherein an electric field exists between the first electrode layer and the second electrode layer;

a signal generation unit for generating a spread spectrum signal and supplying the spread spectrum signal to the first electrode layer;

a signal restoration unit for processing a band restoration for a signal input from the second electrode layer, and

a touch area coordinate identification unit for identifying the coordinates of the touch area on the touch screen panel by using a signal input from the signal restoration unit,

wherein the signal generation unit comprises;

an input signal generator for generating an input signal required for identifying the coordinates of the touch area,

a spread spectrum code generator for generating a spread spectrum code for generating the spread spectrum signal with a higher frequency spectrum than a frequency spectrum of the input signal, and

a spread spectrum processor for combining the input signal and the spread spectrum code and generating the spread spectrum signal.

2. The apparatus as claimed in claim 1, wherein the signal generation unit further comprises a signal amplifier for amplifying the spread spectrum signal.

3. The apparatus as claimed in claim 1, wherein the signal generation unit further comprises an electrode selector that sequentially supplies the spread spectrum signal to the first electrode lines.

4. The apparatus as claimed in claim 1, wherein the signal generation unit further comprises an electrode selector that simultaneously supplies two or more different spread spectrum signals to two or more of the first electrode lines.

5. The apparatus as claimed in claim 4, wherein the two or more different spread spectrum signals are generated based on differently generated input signals required for identifying the coordinates of the touch area.

6. The apparatus as claimed in claim 4, wherein the signal restoration unit comprises:

a plurality of spread spectrum restoration units for processing a band restoration for signals input from the second electrode layer by using a spread spectrum code used for generation of the spread spectrum signal; and

a plurality of differential amplifiers each for amplifying a difference value between at least two signals input from at least two of the plurality of spread spectrum restoration units.

7. The apparatus as claimed in claim 6, wherein the signal restoration unit further comprises a plurality of filters for removing a predetermined frequency band including a noise component from a plurality of signals input from the plurality of differential amplifiers.

8. The apparatus as claimed in claim 4, wherein the signal restoration unit further comprises:

a plurality of spread spectrum restoration units for processing a band restoration for a plurality of signals input from the second electrode layer by using a spread spectrum code used for generation of the spread spectrum signal;

a plurality of differential amplifiers, each receiving a respective signal input from the plurality of spread spectrum restoration units as a first input signal and a signal being a reference of a differential amplification as a second input signal;

a reference signal input unit for providing the second input signal to each of the plurality of differential amplifiers; and

a reference signal controller for controlling a voltage value of the second input signal in response to a voltage value of a signal which is output from one of the plurality of differential amplifiers and identified in the touch area coordinate identification unit.

9. The apparatus as claimed in claim 1, wherein the signal restoration unit comprises a plurality of spread spectrum restoration units for processing a band restoration for each of a plurality of signals input from the second electrode layer by using a spread spectrum code used for generation of the spread spectrum signal.

10. The apparatus as claimed in claim 9, wherein the signal restoration unit further comprises a plurality of filters for removing a predetermined frequency band that includes a noise component from band restored signals which are input from the plurality of spread spectrum restoration units.

11. The apparatus as claimed in claim 10, wherein the signal restoration unit further comprises a plurality of signal amplifiers for amplifying a plurality of signals input from the plurality of filters in which the predetermined frequency band is removed.

12. The apparatus as claimed in claim 11, wherein the second electrode layer of the touch screen panel comprises a reference electrode formed in an area where a touch is not input by a user and configured to output a reference spread spectrum signal transmitted from the first electrode layer, and

the signal restoration unit further comprises:

a reference spread spectrum restoration unit for processing a band restoration for a signal input from the reference electrode by using the spread spectrum code; and

a reference filter for removing the predetermined frequency band including the noise component from a band restored signal which is input from the reference spread spectrum restoration unit,

wherein the plurality of signal amplifiers comprise a plurality of differential amplifiers for amplifying a difference value between a signal output from the reference filter and each of signals input from the plurality of filters in which the predetermined frequency band is removed.

13. The apparatus as claimed in claim 1, wherein the touch area coordinate identification unit comprises:

an Analog-Digital Converter (ADC) processor for analog-digital converting a signal input from the signal restoration unit;

a moving average filter for averaging the analog-digital converted signal in a predetermined time unit; and

a touch input identifier for identifying a level change of the signal averaged in the predetermined time unit, and determining whether the touch is input and the coordinates of the area in which the touch is input.

14. The apparatus as claimed in claim 1, wherein the touch screen panel is overlapped with a display panel, and the first electrode layer and the second electrode layer are disposed on a lower surface of the display panel.

15. The apparatus as claimed in claim 1, wherein the touch screen panel is overlapped with a display panel, and at least one of the first electrode layer and the second electrode layer is disposed on an upper surface of the display panel.

16. A method of identifying coordinates of a touch area on a touch screen panel based on a capacitive scheme, the method comprising the steps of:

generating a spread spectrum signal and supplying the generated spread spectrum signal to a first electrode layer, wherein the first electrode layer is formed in the touch screen panel and has first electrode lines aligned in a first direction;

processing a band restoration for a signal input from a second electrode layer, which is formed in the touch screen panel and has second electrode lines aligned in a second direction, wherein the second direction is different from the first direction, and wherein an electric field exists between the first electrode layer and the second electrode layer;

identifying the coordinates of the touch area on the touch screen panel by using a band restored signal,

wherein supplying the spread spectrum signal to the first electrode layer comprises;

generating an input signal required for identifying the coordinates of the touch area,

generating a spread spectrum code for generating the spread spectrum signal with a higher frequency spectrum than a frequency spectrum of the input signal, and

combining the input signal and the spread spectrum code and generating two or more different spread spectrum signals; and

simultaneously supplying the two or more different spread spectrum signals to the first electrode lines.

17. The method as claimed in claim 16, wherein supplying the spread spectrum signal to the first electrode layer comprises sequentially supplying the spread spectrum signal to the first electrode lines.

18. An article of manufacture for identifying coordinates of a touch area on a touch screen panel based on a capacitive scheme, comprising a machine non-transitory readable medium containing one or more programs which when executed implement the steps of:

generating a spread spectrum signal and supplying the generated spread spectrum signal to a first electrode layer, wherein the first electrode layer is formed in the touch screen panel and has first electrode lines aligned in a first direction;

processing a band restoration for a signal input from a second electrode layer, which is formed in the touch screen panel and has second electrode lines aligned in a second direction, wherein the second direction is different from the first direction, and wherein an electric field exists between the first electrode layer and the second electrode layer; and

identifying the coordinates of the touch area on the touch screen panel by using a band restored signal,

wherein supplying the spread spectrum signal to the first electrode layer comprises;

generating an input signal required for identifying the coordinates of the touch area,

generating a spread spectrum code for generating the spread spectrum signal with a higher frequency spectrum than a frequency spectrum of the input signal, and

combining the input signal and the spread spectrum code and generating two or more different spread spectrum signals; and

simultaneously supplying the two or more different spread spectrum signals to the first electrode lines.