Display apparatus with touch detection functions and with driving electrodes shared by two more pixels in the same column, driving method for same, and mobile device with same

• US 9,804,711 B2
• Filed: 04/15/2011
• Issued: 10/31/2017
• Est. Priority Date: 04/28/2010
• Status: Active Grant

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: Noguchi, Koji, Kida, Yoshitoshi
• Primary Examiner(s): LANDIS, LISA S
• Application Number:
  US13/087,439
• Publication Number:
  US 20110267293A1
• Time in Patent Office: 2,391 Days
• Field of Search: 345 84-104, 345173-179, 313498-512, 3151691-1694
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G06F 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads
• 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

A display apparatus with a substrate having a long side and a short side, a plurality of driving electrodes arranged on the substrate parallel to the long side of the substrate, a plurality of touch detection electrodes arranged on the substrate parallel to the short side of the substrate, a control unit electrically coupled to each of the plurality of driving electrodes and which sequentially drives the plurality of driving electrodes, and a detection unit electrically coupled to each of the touch detection electrodes.

Claims

1. A display apparatus comprising:

a first substrate;

a second substrate facing the first substrate;

a plurality of pixels arranged in columns and rows, the columns extending along a first direction and the rows extending along a second direction orthogonal to the first direction, and each of the pixels having a pixel electrode having a width in the second direction;

a plurality of driving electrodes on the first substrate and extending lengthwise only in the first direction, each of the driving electrodes having a stripe shape and overlapping widthwise two or more columns of the pixel electrodes, the driving electrodes being disposed on a layer other than a layer of the pixel electrodes, each pixel electrode width being less than a half of a width of each of the driving electrodes in the second direction, and the pixels in a same column sharing one of the driving electrodes;

a plurality of pixel signal lines extending in the first direction;

a plurality of touch detection electrodes on the second substrate and extending in the second direction and forming a capacitance at each intersection of the driving electrodes and the touch detection electrodes;

a polarizing film on the touch detection electrodes;

a control unit electrically coupled to each of the driving electrodes and which sequentially drives the driving electrodes; and

a detection unit electrically coupled to each of the touch detection electrodes and configured to detect variances in the capacitances,

wherein,

the driving electrodes, the pixel electrodes, the second substrate, the touch detection electrodes, and the polarizing film are in that order proceeding from the first substrate in a direction perpendicular from a surface of the first substrate,

each pixel of a given column is coupled to the other pixels belonging to the given column by means of one of the pixel signal lines,

in a display period, the control unit applies a fixed common voltage to all of the driving electrodes and transmits a pixel signal to each of the pixel signal lines to cause the pixels to display an image,

in a touch detection period that is different from the display period, the control unit applies driving signals to less than all of the driving electrodes to cause the detection unit to detect variances in the capacitances, and

the detection unit includes an analog to digital converter configured to conduct analog to digital conversion in the touch detection period and to not conduct the analog to digital conversion in the display period.

2. The display apparatus of claim 1 wherein:

each intersection has a corresponding touch detection electrode and a corresponding driving electrode, and

each of the touch detection electrodes transmits a touch detection signal to the detection unit when the control unit drives a corresponding driving electrode.

3. The display apparatus of claim 2, wherein the driving signals are pulsed touch driving signals and the control unit sequentially drives the plurality of driving electrodes with the pulsed touch driving signals in the touch detection period.

4. The display apparatus of claim 1 wherein:

each intersection has a corresponding driving electrode and a corresponding touch detection electrode,

in the touch detection period, the control unit transmits a touch driving signal to one of the pixel signal lines after putting the corresponding driving electrode into a floating state, thereby propagating the touch driving signal to the corresponding driving electrode via capacitive coupling between the pixel signal line and the corresponding driving electrode, and

the touch detection electrode receives the touch driving signal from the corresponding driving electrode and outputs a touch detection signal in response to the touch driving signal.

5. The display apparatus of claim 1 wherein the detection unit further includes an analog low pass filter, a signal processor, a coordinate extractor, and a detection timing controller.

6. The display apparatus of claim 1 wherein in the display period the pixels arranged in columns and rows are sequentially scanned in the first direction that differs from a direction in which the driving electrodes are sequentially scanned in the touch detection period.

7. The display apparatus of claim 6 wherein:

in the display period the control unit sequentially scans each of a plurality of units to be driven along a long side of the display apparatus, and

in the touch detection period the control unit sequentially scans each of a plurality of units to be driven along a short side of the display apparatus.

8. The display apparatus of claim 1 wherein the pixels are liquid crystal display elements having a liquid crystal layer.

21. The display apparatus of claim 1 wherein the driving electrodes extend exclusively in one direction.

22. The display apparatus of claim 1, wherein in the display period, the control unit applies the fixed common voltage of a same value to adjacent driving electrodes.

9. A method of detecting an object in contact with a display apparatus, the method comprising the steps of:

providing a display comprising (a) a first substrate, (b) a second substrate facing the first substrate, (c) a plurality of pixels arranged in columns and rows with the columns extending along a first direction and the rows extending along a second direction orthogonal to the first direction, and each of the pixels having a pixel electrode having a width in the second direction, (d) a plurality of driving electrodes on the first substrate and extending lengthwise only in the first direction, each of the driving electrodes having a stripe shape and overlapping widthwise two or more columns of the pixel electrodes, the driving electrodes being disposed on a layer other than a layer of the pixel electrodes, each pixel electrode width being less than a half of a width of each of the driving electrodes in the second direction, and the pixels in a same column sharing one of the driving electrodes, (e) a plurality of pixel signal lines extending in the first direction, each pixel of a given column being coupled to the other pixels belonging to the given column by means of one of the pixel signal lines, (f) a plurality of touch detection electrodes on the second substrate and extending in the second direction and forming a capacitance at each intersection of the driving electrodes and the touch detection electrodes, (g) a polarizing film disposed on the touch detection electrodes, wherein the driving electrodes, the pixel electrodes, the second substrate, the touch detection electrodes, and the polarizing film are in that order proceeding from the first substrate in a direction perpendicular from a surface of the first substrate, (h) a control unit electrically coupled to each of the driving electrodes and which sequentially drives the driving electrodes, and (i) a detection unit electrically coupled to each of the touch detection electrodes and configured to detect variances in the capacitances, the detection unit including an analog to digital converter to conduct analog to digital conversion;

in a display period, applying a fixed common voltage to all of the driving electrodes and transmitting a pixel signal to each of the pixel signal lines by the control unit to cause the pixels to display an image without conducting the analog to digital conversion by the analog to digital converter; and

in a touch detection period that is different from the display period, applying driving signals to less than all of the driving electrodes by the control unit to cause the detection unit to detect variances in the capacitances and conducting the analog to digital conversion by the analog to digital converter.

10. The method of claim 9 wherein:

each touch detection electrode has a corresponding driving electrode, and

each of the touch detection electrodes transmits a touch detection signal to the detection unit when the control unit drives the corresponding driving electrode.

11. The method of claim 10, wherein the driving signals are pulsed touch driving signals, and the control unit sequentially drives the plurality of driving electrodes with the pulsed touch driving signals in the touch detection period.

12. The method of claim 9 including the step of electrically coupling each of a plurality of signal electrodes to at least one of a plurality of pixels, wherein the signal electrodes are disposed in parallel to a corresponding driving electrode.

13. The method of claim 12 wherein:

in the display period the control unit transmits a pixel signal to each of the plurality of signal electrodes to cause the pixels to display an image.

14. The method of claim 12 including, in the touch detection period, the steps of:

transmitting a touch driving signal to one of the signal electrodes after putting a driving electrode that corresponds to a touch detection electrode into a floating state, thereby propagating the touch driving signal to the driving electrode via capacitive coupling between the signal electrode and the driving electrode, and

receiving the touch driving signal from the corresponding driving electrode and outputting a touch detection signal in response to the touch driving signal.

15. The method of claim 9 wherein the detection unit further includes an analog low pass filter, a signal processor, a coordinate extractor, and a detection timing controller.

16. The method of claim 9 wherein in the display period the pixels arranged in columns and rows are sequentially scanned in the first direction that differs from a direction in which the driving electrodes are sequentially scanned in the touch detection period.

17. The method of claim 9 wherein intersecting electrode patterns between the driving electrodes and the touch detection electrodes form a capacitor at each intersection site.

18. The method of claim 12 wherein:

in the display period the control unit sequentially scans each of a plurality of units to be driven along a long side of the display apparatus; and

in the touch detection period the control unit sequentially scans each of a plurality of units to be driven along a short side of the display apparatus.

19. The method of claim 9 wherein the pixels are liquid crystal display elements having a liquid crystal layer.

20. A mobile device comprising:

a display apparatus including;

a first substrate;

a second substrate facing the first substrate;

a plurality of pixels arranged in columns and rows, the columns extending along a first direction and the rows extending along a second direction orthogonal to the first direction, and each of the pixels having a pixel electrode having a width in the second direction;

a plurality of driving electrodes on the first substrate and extending lengthwise only in the first direction, each of the driving electrodes having a stripe shape and overlapping widthwise two or more columns of the pixel electrodes, the driving electrodes being disposed on a layer other than a layer of the pixel electrodes, each pixel electrode width being less than a half of a width of each of the driving electrodes in the second direction, and the pixels in a same column sharing one of the driving electrodes;

a plurality of pixel signal lines extending in the first direction;

a plurality of touch detection electrodes on the second substrate and extending in the second direction and forming a capacitance at each intersection of the driving electrodes and the touch detection electrode;

a polarizing film disposed on the touch detection electrodes;

a control unit electrically coupled to each of the driving electrodes and which sequentially drives the driving electrodes; and

a detection unit electrically coupled to each of the touch detection electrodes and configured to detect variances in the capacitances,

wherein,

the driving electrodes, the pixel electrodes, the second substrate, the touch detection electrodes, and the polarizing film are in that order proceeding from the first substrate in a direction perpendicular from a surface of the first substrate,

each pixel of a given column is coupled to the other pixels belonging to the given column by means of one of the pixel signal lines,

in a display period, the control unit applies a fixed common voltage to all of the driving electrodes and transmits a pixel signal to each of the pixel signal lines to cause the pixels to display an image, and

in a touch detection period that is different from the display period, the control unit applies driving signals to less than all of the driving electrodes to cause the detection unit to detect variances in the capacitances,

the detection unit includes an analog to digital converter configured to conduct analog to digital conversion during the touch detection period and to not conduct the analog to digital conversion during the display period.