KR20090071374A - Position sensing display - Google Patents

Abstract

A position sensing display is provided to sense relatively high resolution power without connection of a corresponding number, thereby improving reliability. An accurate position sense operation is performed by using accurate x and y sensing electrodes(4,6). The accurate position sense operation determines a position of a sensed object as one of positions through accurate resolution power. An approximate position sense operation is performed. Results of the approximate position sense operation and the accurate position sense operation are combined to solely distinguish a position of the sensed object through the accurate resolution power.

Description

Position sensing display {POSITION SENSING DISPLAY}

This application claims priority to US Provisional Application No. 61 / 016,822, filed December 27, 2007, which is hereby incorporated by reference in its entirety.

This application claims priority to European Patent Application No. 08163204.4, filed August 28, 2008, which is hereby incorporated by reference in its entirety.

The present invention relates to a position sensitive display and a method of operating such a display.

The position sensor has been combined with the display in the form of a transparent position sensing overlay disposed on the display for recording touch or pen input. Such sensors may be composed of electrode arrays that are connected to a drive / sense circuit.

The sensors may be capacitive sensors with electrode sets connected to the drive and / or sensing circuit. The position of the object, such as a stylus or finger, is then determined by measuring the change in capacitance associated with the electrodes affected by the surrounding objects.

In order to provide increased resolution, an increase in the number of sensing electrodes is required. However, these sense electrodes need to be connected to a sense circuit or a drive circuit, and the number of connections required for a large array of high resolution can actually be very large. Connections are a relatively difficult manufacturing task and can reduce reliability because a large number of connections increase costs and, at the same time, increase the likelihood of failure.

Thus, relatively high resolution sensing is needed without a corresponding number of connections.

According to the present invention, a method of sensing the position of a detected object in front of a display is provided. The display has a front position sensing panel. The front position sensing panel has a plurality of sophisticated x sensing electrodes and a plurality of sophisticated y sensing electrodes. Sophisticated x sensing electrodes extend across the front position sensing panel and are combined into interdigitated groups. Sophisticated y sensing electrodes span across the sophisticated x sensing electrodes and extend across the front position sensing panel and are combined into interlocking groups. The method of sensing the position of the detected object includes performing a sophisticated position sensing operation using sophisticated x and y sensing electrodes, wherein the sophisticated position sensing operation determines the position of the detected object with a fine resolution among a plurality of positions. Performing a sophisticated position sensing operation, determining one; Performing an approximate position sensing operation to determine a position of the detected object as a unique position with an approximate resolution rather than an elaborate position sensing operation; And combining the results of the coarse position sensing operation with the sophisticated position sensing operation to uniquely identify the position of the object detected with the fine resolution.

The invention also relates to a position sensing panel for an active matrix display for sensing a sensed object. The position sensing panel comprises a plurality of elaborate x sensing electrodes, a plurality of elaborate y sensing electrodes and one means. Sophisticated x sensing electrodes extend in parallel across the active matrix display and are grouped into interlocking groups. Sophisticated y sense electrodes extend in parallel across the active x display across the sophisticated x sense electrodes and are grouped into interlocking groups. Sophisticated x sensing electrodes and sophisticated y sensing electrodes provide position detection of an object detected in one of a plurality of positions with sophisticated resolution. One means performs coarse position sensing to determine which of the plurality of positions is the position of the sensed object.

The invention also relates to a display. The display includes a back panel, a position sensing panel, a plurality of sophisticated sensing circuits, a plurality of approximate sensing circuits, and calculation means. The position sensing panel is mounted in front of the rear panel and includes a plurality of elaborate x sensing electrodes, a plurality of elaborate y sensing electrodes, and one means. Sophisticated x sensing electrodes extend in parallel across the active matrix display and are grouped into interlocking groups. Sophisticated y sense electrodes span across the sophisticated x sense electrodes and extend in parallel across the active matrix display and are grouped into interlocking groups. Sophisticated x sensing electrodes and sophisticated y sensing electrodes provide position detection of an object detected in one of a plurality of positions with sophisticated resolution. The means performs approximate position sensing to determine which of the plurality of positions corresponds to the position of the sensed object. The sophisticated sensing circuit is on the back panel attached to each sophisticated sensing connectors connected to the sophisticated sensing electrodes on the position sensing panel. The coarse sensing circuit is on the back panel attached to each coarse sensing connectors connected to means for performing coarse position sensing on the position sensing panel. The computing means is electrically connected to the coarse sense circuit and the coarse sense circuit, which are configured to output the only sophisticated position of the detected object based on the approximate sense circuit and the readings of the fine sense circuit.

By coupling the sensor electrodes together into groups, the increase in the number of connections usually resulting from the increase in resolution is minimized. Despite the reduced number of connections, improved resolution is still possible.

The panel is a position sensing panel, often referred to as a touch sensing panel. Strictly speaking, the term position sensing panel is used herein instead of the more common touch sensing panel because such a panel can operate using capacitive coupling and therefore does not require touch but only proximity.

The display may comprise an active matrix panel, such as an active matrix liquid crystal display (AMLCD) panel or an active matrix organic light emitting diode display (AMOLED) panel. In this way, all circuitry and processing can be provided on the position sensing electrodes provided on the active panel and the front panel, which facilitates manufacturing.

Detailed descriptions are given in the following embodiments with reference to the accompanying drawings.

A method of detecting the position of a detected object in front of the display is provided.

The following description is the best considered mode for carrying out the invention. This description is for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims.

The drawings are schematic and not drawn to scale. Similar or similar components are present in different figures and the same reference numerals are used, and descriptions thereof are not normally repeated.

Referring to FIG. 1, there is shown a front position sensing panel 1 for mounting on the front of the display.

The panel 1 comprises a transparent substrate 2 and a plurality of elaborate x sensing electrodes 4 arranged in parallel extending in the column direction on the substrate. A plurality of elaborate y electrodes 6 extends transversely across the substrate and insulated from the elaborate x sensing electrodes. They cover the sensing area 7 of the panel, indicated by the bold lines. Preferably, the sensing area corresponds to the display area.

Sophisticated x sense electrodes, like the y sense electrodes, are arranged in groups. There are n groups 8 of elaborate x sense electrodes, and all nth elaborate x sense electrodes are connected together as a group. Thus, a sophisticated group of x sensing electrodes meshes with each other effectively. Alternatively, the groups alternate or cycle the electrodes across the display belonging to each group in turn until all groups from the first group are used, and then the cycle starts again from the first group.

For clarity, four groups of x sensing electrodes are shown in the figure, each group having three electrodes. Groups are defined by connecting together. In a typical manufacturing apparatus there may be even more electrode groups, and there may be even more electrodes in each group.

Similarly, there are m groups 10 of elaborate y sensing electrodes, and all mth elaborate y sensing electrodes are connected together as a group.

Sophisticated x sense electrode 4 and y sense electrode 6 act as electrodes for sensing with fine resolution.

The electrodes themselves are transparent and can be made of a transparent conductor, for example indium tin oxide.

The front position sensing panel also includes four approximate sensing electrodes 12 and is located one at each corner 14 of the panel.

Each of the sophisticated groups of sensing electrodes 8, 10 is connected to a corresponding connector 16. Similarly, each of the approximate sensing electrodes 12 is individually connected to a corresponding connector 18.

The approximate sensing electrode 12 comprises a drive electrode 27 and a pick-up electrode 28. The drive electrode 27 is disposed at the opposite edges 14 of the panel and the detection electrode 28 is disposed at the other opposite edge 14.

Sophisticated connectors and coarse connectors 16, 18 are connected to corresponding sophisticated sense circuits and coarse sense circuits 20, 22 and are not on the transparent panel itself. The coarse drive unit 23 is also provided to be connected to the drive electrodes 27 for driving the electrodes.

The calculation unit 24 is connected to the coarse sense circuit and the sophisticated sense circuits 22, 20.

Referring to FIG. 2, in a particular embodiment the touch panel 1 is the front panel of an active matrix liquid crystal display having a back active panel 50, and the liquid crystal 52 is the touch panel 1 and the back active panel 50. And controlled to display using the rear active panel.

In the embodiment the sensing circuits 20, 22 are provided as part of the circuit of the rear active panel 50, and the calculation unit 24 is a separate circuit. In an alternative configuration, the calculation unit 24 may also be integrated into the rear active panel 50.

In use, as shown in FIGS. 3-5, the first sophisticated sensing operation of the position of the sensed object 30 is performed using a sophisticated sensing circuit and a group of sophisticated sensing electrodes. This can be done using capacitive coupling of sensed objects and adjacent sensing electrodes. The sensed object 30 itself may be, for example, a stylus or a finger. The signal measured on the sensing circuit is affected by the capacitive coupling of the delicate sensing electrode adjacent to the sensed object 30. Thus, a sensing circuit that detects a change in the signal displays sensing electrodes adjacent to the sensed object.

This sophisticated sensing operation provides positional information with sophisticated resolution of the sophisticated sensing electrode, but grouping of electrodes means that the determined position is not unique.

In the simplified diagrams of FIGS. 3-5, each group of sophisticated sensing electrodes has two electrodes, so the sophisticated position sensing operation in FIG. 3 determines four candidate positions 32 with sophisticated resolution.

As shown in FIG. 4, an approximate sensing operation is performed using an approximate sensing circuit to uniquely determine the approximate position 34 with an approximate resolution. A signal is provided to the drive electrode 27 by the coarse drive unit 23, and the signal detected by the detection electrode 28 is measured by the coarse sensing circuit 22 to sense the object to the corners 14. Determine the approach of, and thus determine the coarse position 34.

Then, the calculation unit 24 selects the candidate position 32 that is closest to the approximate position 34 determined as the coarse resolution, so that the approximate sensing operation and the sophisticated sensing operation are shown as shown in FIG. Combining the results, the sensing position 36 is reached.

By grouping the sophisticated sensing electrodes, the number of sophisticated connectors 16 is much smaller than when each sophisticated sensing electrode has its own connector.

If this technique is not used, the number of connectors can be very large. In order to obtain fine resolution of the sense probe position, a sophisticated grid of sense electrodes needs to be provided. Unfortunately, a large number of sensing electrodes also require a large number of connections, and the reliability of the connection is a major problem of the reliability of the position sensing screen.

This is particularly true where the electrodes are integrated into the front side of the display device as in the embodiment described above. This approach means that the reliability of the connection between the front panel and the back panel is an important reliability problem, and the reliability is greatly reduced by reducing the number of connections.

Of course, the grouping of the electrodes makes it more difficult to uniquely determine the position of the sensed object 30, but this problem is solved using coarse sensing and sophisticated sensing techniques.

In the alternative embodiment shown in FIG. 6, an alternative configuration of the approximate sensing electrode is used. In this configuration, a plurality of coarse sense electrodes are used that extend across the panel and between the sophisticated sense electrodes. Approximate sense electrodes are lines like sophisticated sense electrodes. Thus, in this embodiment, there are as many approximate sense electrodes as sophisticated sense electrodes, but the approximate sense electrodes are grouped differently. The approximate groups of sensing electrodes 40, 42 are adjacent approximate sensing electrodes, including the approximate x sensing electrode group 40 and the approximate y sensing electrode group 42. In this case, therefore, each group 40, 42 of coarse sense electrodes is connected to a corresponding coarse sense connector 18. In this embodiment, the approximate sense electrodes 40, 42 operate in the same way as the sophisticated sense electrodes 4, 6, but differ in the way they are connected together in a group.

The approximate group of electrodes is configured to correspond to a sophisticated group of electrodes. Assuming the elaborate electrodes are divided into n groups, the elaborate electrodes make a repeating pattern with the first electrode, the second electrode, ... the nth electrode until starting again at the first electrode.

With regard to the repeatability of the group, the position sensing panel can be divided into sensing regions 44 as shown. Each sensing region begins with the x sensing electrode and the y sensing electrode of the first group and includes one sensing electrode of each group. The sensing area 44 then begins again with the next x sensing electrode and / or y sensing electrode of the first group.

With respect to the approximate sensing electrode, each sensing region 44 corresponds to a single group of approximate electrodes in both directions of x and y. Thus, in this embodiment, the coarse sense electrodes are divided into groups in response to a repeating cycle of elaborate sense electrodes, and n sense electrodes are present in each group of coarse sense electrodes, such as n groups of sophisticated sense electrodes. Will exist.

The manner in which the calculation unit determines the position will now be described in more detail with reference to FIGS. 7 and 8.

Sophisticated sensing operation essentially provides (xp, yp) position results within each high resolution sensing region. The detected object's position will be detected at this position within the high resolution sensing region, but from this sophisticated sensing operation it is not possible to know which sensing region contains the sensed object position.

The coarse sensing operation uses an approximate sensing electrode, indicates which of the sensing areas 44 senses the sensed object, and which of the groups of approximate x sensing electrode and approximate y sensing electrode is the object. Determine approximate positions (Xp, Yp) that indicate whether the detection is detected.

By combining these two pieces of information, the position of the object can be determined as the sensing position shown in FIG.

In a change of this approach, the approximate sensing position can be adjusted based on the sophisticated sensing position.

For example, if an object is located near a boundary between sensing areas, the coordinates determined from the low resolution sensing are likely to place the object in the wrong sensing area. This possibility can be avoided by using more complex algorithms for determining the position of the object. In particular, the approximate position determination for determining (Xp, Yp) can use sophisticated position information (xp, yp) by identifying whether xp and yp are large or small values. Consider the case where the approximate position determination appears as the approximate position is adjacent to the boundary between the two sensing regions. If xp is a large value, the position will be close to the right side of the sensing region (in the figure), and therefore, if the approximate position is adjacent to the boundary between the sensing regions, the sensing region with a lower Xp is selected. In contrast, if xp is a small value, the position will be close to the left side of the sensing area and thus the sensing area with a high Xp is selected.

Similar approaches can be used for y detection.

The above embodiments are merely examples.

For example, although the above description describes an embodiment using the integrated touch panel 1, in the alternative embodiment shown in FIG. 9 the touch panel 1 is mounted separately on top of the display 54. In this embodiment, the active matrix display 54 is mounted on the support substrate 56. The sense circuits 20, 22 and the calculation unit 24 are shown to be in a single integrated unit 58 mounted on the support substrate 56.

Alternatively, sensing circuits 20 and 22 may be included in the drive circuit of the active matrix panel.

In the embodiment of FIG. 6 above, the sensing regions 44 correspond to both a coarse group of electrodes and a group of sophisticated electrodes, corresponding to the size of the repeating unit of the group of sophisticated electrodes and the coarse group of electrodes. However, this is not essential, and as long as the determination of the approximate electrode is sufficiently accurate, the approximate electrode group and the elaborate electrode group need not be fitted in this way. In some configurations, in particular, still having lower resolution than fine resolution, it may be useful to have a better approximate resolution.

In addition, coarse and elaborate sensing operations may occur simultaneously or sequentially upon request.

In the configuration of FIG. 6, the approximate number of electrodes is equal to the number of elaborate sensing electrodes. This is not required and it is also possible to use fewer approximate electrodes.

In the above embodiment related to Fig. 6, the approximate sensing electrode and the sophisticated sensing electrode are separate electrodes, but it is also possible to use the same electrode as the approximate electrode and the sophisticated electrode. This can be done, for example, by simply grouping the electrodes together as a fine sense electrode on one edge with every nth electrode in the group, and as an approximate sense electrode on the other edge of the group of n electrodes. In this case, a switch, for example a thin film transistor switch, can be used to change the connection of the electrodes to perform coarse positioning and then to change the connection to perform fine positioning. The switch can be operated to alternate between coarse and sophisticated arrangements.

Although this embodiment relates to a conventional active matrix liquid crystal display, the invention is equally applicable to alternative active matrix devices such as, for example, active matrix organic light emitting diode displays (AMOLED).

The electrodes do not necessarily all have to be transparent.

The calculation means 24 may be on a separate panel if required. A general purpose computer may be used.

While the invention has been described by way of example with respect to preferred embodiments, it will be understood that the invention is not limited to the disclosed embodiments. In contrast, it is intended to include various modifications and similar arrangements (as those skilled in the art will understand). Accordingly, the scope of the appended claims should follow the broadest interpretation so as to encompass all such modifications and similar arrangements.

The above detailed description and examples can be more fully understood by referring to the accompanying drawings.

1 is a front view of a first embodiment according to the present invention.

2 is a side view of a first embodiment according to the present invention.

3 to 5 are diagrams showing operations of the first embodiment of the present invention.

6 is a front view of a second embodiment according to the present invention.

7 and 8 are views showing the operation of the second embodiment of the present invention.

9 shows a third embodiment according to the present invention.

Claims (11)

In the method for detecting the position of the detected object in front of the display, The display includes a plurality of fine x sense electrodes coupled in interdigitated groups extending across the panel and interlocked groups extending across the panel across the fine x sense electrode. A method of sensing a position of an object, comprising a plurality of sophisticated y sensing electrodes coupled Performing a sophisticated position sensing operation using the sophisticated x and y sensing electrodes, wherein the sophisticated position sensing operation determines the position of the detected object as one of a plurality of positions with precise resolution. Performing an operation; Performing a coarse position sensing operation to determine the position of the detected object as a unique position with coarse resolution than the sophisticated position sensing operation; And Combining the results of the coarse and fine position sensing operations to uniquely identify the position of the detected object with the fine resolution. Position detection method of an object comprising a. The method of claim 1, wherein performing the coarse position sensing operation comprises using a plurality of coarse sensing electrodes, driving at least one of the coarse sensing electrodes using driving signals, and other coarse sensing. Sensing the signals detected at the electrodes. The method of claim 1, Performing the coarse position sensing operation utilizes a plurality of coarse x sense electrodes and a plurality of coarse y sense electrodes extending across the display, and the plurality of coarse x sense electrodes and a plurality of coarse x sense electrodes. Approximate y sense electrodes are divided into at least one approximate x sense electrode group and at least one approximate y sense electrode group, Combining the results of the coarse sensing operation with the sophisticated position sensing operation, Either of the at least one approximate group of x sensing electrodes and any of the at least one approximate group of y sensing electrodes is capable of detecting the object using the determined precise position as well as the result of the approximate position sensing operation. Determining whether it corresponds to a location; And Selecting the elaborate position as an output among one of a plurality of positions corresponding to the determined group of at least one approximate x sense electrode and the determined group of at least one approximate y sense electrode. How to detect your location. The display of claim 1, wherein the display further comprises a rear active panel, The performing of the sophisticated position sensing operation may include generating a driving signal on the rear active panel, transmitting the driving signal to at least one of the sophisticated sensing electrodes, and other electrodes of the sophisticated sensing electrodes. Detecting signals on the sophisticated sensing electrodes using sophisticated sensing circuitry on the rear active panel; The performing of the approximate position sensing operation may include generating a driving signal on the rear active panel, transmitting the driving signal to at least one of the approximate sensing electrodes, and among the approximate sensing electrodes. Detecting a sensing signal on the other electrodes, and sensing signals on the approximately sensing electrodes using an approximate sensing circuit on the rear active panel. A position sensing panel for active matrix display for detecting a detected object, A plurality of sophisticated x sensing electrodes extending in parallel across the display, the plurality of sophisticated x sensing electrodes grouped into interdigitated groups of sophisticated x sensing electrodes, A plurality of elaborate y sense electrodes that cross the elaborate x sense electrodes and extend in parallel across the display, comprising a plurality of elaborate y sense electrodes grouped into interdigitated groups of elaborate y sense electrodes, The sophisticated x sensing electrodes and the sophisticated y sensing electrodes provide position detection of a sensed object at one of a plurality of positions with sophisticated resolution, Means for performing coarse position sensing to determine which of a plurality of positions is the position of the sensed object. 6. The position sensing panel of claim 5, wherein each of the groups of sophisticated x sensing electrodes and each of the groups of sophisticated y sensing electrodes is connected to one individual connector. The method of claim 5, There are n groups of sophisticated x sensing electrodes and m groups of sophisticated y sensing electrodes, where n and m are integers, All nth elaborate x sensing electrodes are connected together as a group, Wherein all mth elaborate y sensing electrodes are connected together as a group. 6. The position sensing panel of claim 5, wherein the means for performing coarse position sensing is a plurality of position sensing electrodes. 9. The apparatus of claim 8, wherein the approximate sense electrodes are parallel to the elaborate y sense electrodes across the panel and to the plurality of approximate x sense electrodes extending parallel to the elaborate x sense electrodes across the panel. A plurality of coarse y sensing electrodes extending to The approximate sense electrodes are alternately arranged with the sophisticated sense electrodes, the x sense electrodes are connected together in groups of n approximate x sense electrodes, and the approximate y sense electrodes are n approximate y Connected together within groups of sense electrodes, wherein each of the groups of approximate x sense electrodes and each of the groups of approximate y sense electrodes is connected to one individual connector. The position sensing panel of claim 8, wherein the plurality of approximate sensing electrodes comprise at least one pair of drive electrodes and at least one pair of detection electrodes. Rear panel; A position sensing panel according to claim 5 mounted on a front surface of the rear panel; A plurality of sophisticated sensing circuits on the back panel attached to individual sophisticated sensing connectors connected to sophisticated electrodes on the position sensing panel; A plurality of coarse sensing circuits on the back panel attached to respective coarse sensing connectors connected to means for performing coarse position sensing on the position sensing panel; And Calculation means electrically connected to the coarse sense circuit and the coarse sense circuit, configured to output a unique sophisticated position of a detected object based on the approximate sense circuit and the readings of the sophisticated sense circuit. Display comprising a.

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