Touch detecting apparatus and touch detecting method using pixel or pixels in display devices

• US 10,474,261 B2
• Filed: 12/09/2016
• Issued: 11/12/2019
• Est. Priority Date: 12/15/2015
• Status: Active Grant

• Current Assignee: G2touch Co Ltd
• Original Assignee: G2touch Co Ltd
• Inventors: Lee, Sung Ho
• Primary Examiner(s): Mehmood, Jennifer
• Assistant Examiner(s): Nokham, James S
• Application Number:
  US15/375,011
• Publication Number:
  US 20170168623A1
• Time in Patent Office: 1,068 Days
• CPC Class Codes: G06F 2203/04107 Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• 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 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• CPC Class Codes: G09G 2310/0291 Details of output amplifiers or buffers arranged for use in a driving circuit
• CPC Class Codes: G09G 3/3208 organic, e.g. using organic light-emitting diodes [OLED]
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3688 suitable for active matrices only
• CPC Class Codes: G09G 3/3696 Generation of voltages supplied to electrode drivers

Abstract

Disclosed herein are a touch detecting apparatus and a touch detecting method using a pixel or pixels in display devices including a means for applying an AC input voltage to a drive IC of the display device and detecting a change in touch capacitance between the pixel and an object in synchronization with a change in amplitude of the AC input voltage. In particular, the touch detecting apparatus using a pixel or pixels in display devices according to an exemplary embodiment of the present invention includes: a grayscale voltage generator applying a grayscale voltage to a source line and a sensing signal processor detecting a touch signal based on a feedback voltage of the grayscale voltage applied to the source line.

Claims

1. A touch detecting apparatus using a pixel or pixels in display devices, comprising:

a grayscale voltage generator configured to generate a first grayscale voltage applied to the pixel or the pixels in the display devices; and

a sensing signal processor configured to detect a touch signal based on a second grayscale voltage fed back from a touch capacitance that is formed between the pixel and a touch input means, and based on a preset reference value,

wherein the touch capacitance is generated by direct cooperation between the touch input means and the pixel or the pixels without being intervened by a common electrode of the display devices.

2. The touch detecting apparatus of claim 1, wherein the sensing signal processor compares the second grayscale voltage with the preset reference value to detect the touch signal.

3. The touch detecting apparatus of claim 1, wherein the sensing signal processor includes a comparator that compares the second grayscale voltage with the preset reference value.

4. The touch detecting apparatus of claim 3, wherein an input terminal of the comparator is provided with a circuit element temporarily storing the second gray scale voltage.

5. The touch detecting apparatus of claim 1, wherein the sensing signal processor includes a plurality of comparators that compare the second grayscale voltage with a plurality of preset reference values.

6. The touch detecting apparatus of claim 1, wherein the sensing signal processor includes:

a mux configured to select one of a plurality of second grayscale voltages; and

a plurality of comparators configured to compare the selected one second grayscale voltage with a plurality of preset reference values.

7. The touch detecting apparatus of claim 6, further comprising:

a touch &

display drive IC (TDDI) configured to set or adjust the plurality of reference values to be different values.

8. The touch detecting apparatus of claim 1, further comprising:

a CPU configured to perform a fingerprint recognition operation based on the detected touch signal.

9. The touch detecting apparatus of claim 1, further comprising:

a CPU or a logic configured to group at least two pixels present on the display devices and simultaneously control them to increase the touch capacitance of the touch signal.

10. The touch detecting apparatus of claim 1, wherein a guard layer is disposed over or under a source line of the pixel to which the first grayscale voltage is applied.

11. A touch detecting method using a pixel or pixels in display devices, comprising:

generating a first grayscale voltage applied to the pixel or the pixels in the display devices; and

detecting a touch signal based on a second grayscale voltage fed back from a touch capacitance that is formed between the pixel and a touch input means, and based on a preset reference value,

wherein the touch capacitance is generated by direct cooperation between the touch input means and the pixel or the pixels without being intervened by a common electrode of the display devices.

12. The touch detecting method of claim 11, wherein in the detecting, the second grayscale voltage is compared with the preset reference value to detect the touch signal.

13. The touch detecting method of claim 11, wherein in the detecting, a comparator compares the second grayscale voltage with the preset reference value.

14. The touch detecting method of claim 13, wherein an input terminal of the comparator is provided with a circuit element temporarily storing the second gray scale voltage.

15. The touch detecting method of claim 11, wherein in the detecting, a plurality of comparators compare the second grayscale voltage with a plurality of preset reference values.

16. The touch detecting method of claim 11, wherein the detecting includes:

selecting, by a mux, one of a plurality of second grayscale voltages, and

comparing, by a plurality of comparators, the selected one second grayscale voltage with a plurality of preset reference values.

17. The touch detecting method of claim 16, wherein the plurality of reference values are set or adjusted to be different values by a touch &

display drive IC (TDDI).

18. The touch detecting method of claim 11, further comprising:

recognizing, by a CPU, a fingerprint based on the detected touch signal.

19. The touch detecting method of claim 11, further comprising:

grouping, by a CPU or a logic, at least two pixels present on the display devices and simultaneously controlling them to increase the touch capacitance of the touch signal.

20. The touch detecting method of claim 11, wherein a guard layer is disposed over or under a source line of the pixel to which the first grayscale voltage is applied.