Display Device

• US 20120075243A1
• Filed: 09/22/2011
• Published: 03/29/2012
• Est. Priority Date: 09/24/2010
• Status: Active Grant

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: Nagata, Koji, Doi, Koji
• Granted Patent: US 9,569,038 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G06F 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• 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
• CPC Class Codes: G06F 3/0447 Position sensing using the local deformation of sensor cells

Abstract

A touch panel of capacitance type includes plural X-electrodes, plural Y-electrodes, and a Z-electrode. Each of the X-electrode and the Y-electrode is formed to have pad portions and thin line portions alternately arranged in an extending direction. The pad portion of the X-electrode and the pad portion of the Y-electrode are arranged without being overlapped in a planar view. The Z-electrode is electrically in a floating state, and formed to be overlapped with both the adjacent X-electrode and the Y-electrode in a planar view. The touched position is calculated based on a local minimal point as an intersection with the interelectrode capacitance value that is equal to or smaller than each of the interelectrode capacitance values of four peripheral intersections among those at the intersections between the plural X-electrodes and the plural Y-electrodes.

Claims

1. A display device provided with a touch panel of capacitance type, wherein:

the touch panel of capacitance type includes a plurality of X-electrodes, a plurality of Y-electrodes, and a Z-electrode;

the X-electrode and the Y-electrode intersecting with each other via a first insulating layer, each of which is formed to have a pad portion and a thin line portion alternately arranged in an extending direction, and the pad portion of the X-electrode and the pad portion of the Y-electrode are arranged without being overlapped in a planar view; and

the Z-electrode is electrically in a floating state, and formed to be overlapped with both the adjacent X-electrode and the Y-electrode via a second insulating layer in a planar view, the display device comprising;

a measurement unit that measures an interelectrode capacitance at each intersection between the plurality of X-electrodes and the plurality of Y-electrodes by applying a pulse signal sequentially to one of the X-electrode and the Y-electrode, and detecting a signal from the other electrode;

a data storage unit that stores an interelectrode capacitance value measured by the measurement unit at each of the intersections between the plurality of X-electrodes and the plurality of Y-electrodes; and

a control unit that calculates a touched position on the touch panel of capacitance type based on a local minimal point as an intersection with the interelectrode capacitance value that is equal to or smaller than each of the interelectrode capacitance values of four peripheral intersections among those at the respective intersections to stored in the data storage unit.

6. The display device according to claim 1, wherein:

the control unit searches the intersections adjacent to the local minimal point as a start point in four directions sequentially among the interelectrode capacitance values at the respective intersections stored in the data storage unit;

when the searched intersection has the interelectrode capacitance value that is equal to or larger than the interelectrode capacitance value at a present intersection by a predetermined threshold value or larger, the searched data are added to a touched region to be extracted; and

the touched position on the touch panel of capacitance type is calculated based on the interelectrode capacitance value at each of the intersections in the touched region.

7. The display device according to claim 6, wherein:

the data storage unit stores a signal value;

the control unit calculates a difference value between the interelectrode capacitance value at each of the intersections in the touched region and the interelectrode capacitance value at each of the intersections around the touched region as a reference value after extracting the touched region, and inverts a sign of the calculated difference value to provide and store the signal value in the data storage unit; and

when a maximum value of the signal value in the touched region is equal to or larger than the threshold value, it is determined that the “

touched state is established”

, and the touched position on the touch panel of capacitance type is calculated.

10. The display device according to claim 1, wherein the second insulating layer has its thickness variable under depression.

11. The display device according to claim 1, wherein a thickness of the second insulating layer is held by a spacer.

12. The display device according to claim 1, wherein air is used for forming the second insulating layer.

2. A display device provided with a touch panel of capacitance type, wherein:

the touch panel of capacitance type includes a plurality of X-electrodes, a plurality of Y-electrodes, and a Z-electrode;

the X-electrode and the Y-electrode intersecting with each other via a first insulating layer, each of which is formed to have a pad portion and a thin line portion alternately arranged in an extending direction, and the pad portion of the X-electrode and the pad portion of the Y-electrode are arranged without being overlapped in a planar view; and

the Z-electrode is electrically in a floating state, and formed to be overlapped with both the adjacent X-electrode and the Y-electrode via a second insulating layer in a planar view, the display device comprising;

a measurement unit that measures an interelectrode capacitance at each intersection between the plurality of X-electrodes and the plurality of Y-electrodes by applying a pulse signal sequentially to one of the X-electrode and the Y-electrode, and detecting a signal from the other electrode;

a data storage unit that stores an interelectrode capacitance value measured by the measurement unit at each of the intersections between the plurality of X-electrodes and the plurality of Y-electrodes; and

a control unit that calculates a touched position on the touch panel of capacitance type based on a local minimal point as an intersection with the interelectrode capacitance value that is equal to or smaller than each of the interelectrode capacitance values of four peripheral intersections among those at the respective intersections stored in the data storage unit, and a local maximal point as an intersection with the interelectrode capacitance value that is equal to or larger than each of the interelectrode capacitance values of four peripheral intersections among those at the respective intersections stored in the data storage unit, and determines that the touch panel of capacitance type is touched with a human finger or a conductive pen when the touched position is calculated based on the local minimal point, and determines that the touch panel of capacitance type is touched with an insulating pen when the touched position is calculated based on the local maximal point.

5. The display device according to claim 2, wherein:

the data storage unit includes a touched state management table which manages a touched position and a touch type; and

the control unit determines that the touch panel of capacitance type is touched with the human finger or the conductive pen when the touched position calculated based on the local maximal point is stored in the touched state management table, and the touch type stored in the touched state management table is set to the human finger or the conductive pen even if the touched position is calculated based on the local maximal point.

8. The display device according to claim 2, wherein:

the control unit searches the intersections adjacent to the local maximal point as a start point in four directions sequentially among the interelectrode capacitance values at the respective intersections stored in the data storage unit;

when the searched intersection has the interelectrode capacitance value that is equal to or smaller than the interelectrode capacitance value at a present intersection by a predetermined threshold value or smaller, the searched data are added to a touched region to be extracted; and

the touched position on the touch panel of capacitance type is calculated based on the interelectrode capacitance value in the touched region.

9. The display device according to claim 8, wherein:

the data storage unit stores a signal value;

the control unit calculates a difference value between the interelectrode capacitance value in the touched region and the interelectrode capacitance value at each of the intersections around the touched region as a reference value after extracting the touched region to store the difference value in the data storage unit as the signal value; and

when a maximum value of the signal value at the intersection in the touched region is equal to or larger than the threshold value, it is determined that the “

touched state is established”

, and the touched position on the touch panel of capacitance type is calculated.

3. A display device provided with a touch panel of capacitance type, wherein:

the touch panel of capacitance type includes a plurality of X-electrodes, a plurality of Y-electrodes, and a Z-electrode;

the X-electrode and the Y-electrode intersecting with each other at an intersection portion via a first insulating layer, each of which is formed to have a pad portion and a thin line portion alternately arranged in an extending direction, and the pad portion of the X-electrode and the pad portion of the Y-electrode are arranged without being overlapped in a planar view; and

the Z-electrode is electrically in a floating state, and formed to be overlapped with both the adjacent X-electrode and the Y-electrode via a second insulating layer in a planar view, the display device comprising;

a measurement unit that measures an interelectrode capacitance at each intersection between the plurality of X-electrodes and the plurality of Y-electrodes by applying a pulse signal sequentially to one of the X-electrode and the Y-electrode, and detecting a signal from the other electrode;

a data storage unit that stores an interelectrode capacitance value measured by the measurement unit at each of the intersections between the plurality of X-electrodes and the plurality of Y-electrodes; and

a control unit that calculates a touched position on the touch panel of capacitance type based on a local minimal point as an intersection with the interelectrode capacitance value that is equal to or smaller than each of the interelectrode capacitance values of four peripheral intersections among those at the respective intersections stored in the data storage unit.

4. A display device provided with a touch panel of capacitance type, wherein:

the touch panel of capacitance type includes a plurality of X-electrodes, a plurality of Y-electrodes, and a Z-electrode;

the X-electrode and the Y-electrode intersecting with each other at an intersection portion via a first insulating layer, each of which is formed to have a pad portion and a thin line portion alternately arranged in an extending direction, and the pad portion of the X-electrode and the pad portion of the Y-electrode are arranged without being overlapped in a planar view; and

the Z-electrode is electrically in a floating state, and formed to be overlapped with both the adjacent X-electrode and the Y-electrode via a second insulating layer in a planar view, the display device comprising;

a measurement unit that measures an interelectrode capacitance at each intersection between the plurality of X-electrodes and the plurality of Y-electrodes by applying a pulse signal sequentially to one of the X-electrode and the Y-electrode, and detecting a signal from the other electrode;

a data storage unit that stores an interelectrode capacitance value measured by the measurement unit at each of the intersections between the plurality of X-electrodes and the plurality of Y-electrodes; and

a control unit that calculates a touched position on the touch panel of capacitance type based on a local minimal point as an intersection with the interelectrode capacitance value that is equal to or smaller than each of the interelectrode capacitance values of four peripheral intersections among those at the respective intersections stored in the data storage unit, and a local maximal point as an intersection with the interelectrode capacitance value that is equal to or larger than each of the interelectrode capacitance values of four peripheral intersections among those at the respective intersections stored in the data storage unit, and determines that the touch panel of capacitance type is touched with a human finger or a conductive pen when the touched position is calculated based on the local minimal point, and determines that the touch panel of capacitance type is touched with an insulating pen when the touched position is calculated based on the local maximal point.