Touch-sensing structure for touch panel and touch-sensing method thereof

In a touch-sensing structure for a touch panel and a touch-sensing method thereof, the touch-sensing structure includes a plurality of first conducting wires paralleled to each other and a first conductor. A terminal of each first conducting wire is electrically coupled to the first conductor, so as to divide the conductor into a plurality of first line segments. The resistance of each first conducting wire is smaller than that of each first line segment. Wherein, when the displaying area of the touch panel receives an external force, a first conducting wire corresponding to the position designated by the external force is electrically coupled to a reference potential.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from the prior Taiwan Patent Application No. 098130297, filed Sep. 8, 2009, the entire contents of which are incorporated herein by reference.

BACKGROUND

1. Technical Field

The present invention relates to a touch panel, and more particularly, to a touch-sensing structure for a touch panel, and a touch-sensing method thereof.

2. Description of the Related Art

With development of the touch screen, nowadays, two kinds of touch-sensing structures for embedded touch screen are used widely, one of which is a passive touch-sensing structure, and the other one is an active touch-sensing structure. The two kinds of touch-sensing structures are respectively shown inFIG. 1andFIG. 2.

FIG. 1is a schematic view of a touch screen employing the passive touch-sensing structure. Referring toFIG. 1, the touch screen includes a data driver110, a touch panel120, and a touch signal processing circuit130. The touch panel120includes a plurality of pixels; each pixel is consisted of a thin-film transistor (TFT), a storage capacitor Cst, and a pixel capacitor Clc. In addition, the touch panel120further includes a plurality of data lines140, a plurality of gate lines150, a plurality of common lines160, a plurality of sensing units170, a plurality of first touch-signal reading lines180-1, and a plurality of second touch-signal reading lines180-2. These sensing units170are used to detect a touch position corresponding to a touch action imposed in the touch panel by a user. Each sensing unit170is electrically coupled to the touch signal processing circuit130via one of the first touch-signal reading lines180-1and one of the second touch-signal reading lines180-2, so as to enable the touch signal processing circuit130to obtain X-axis and Y-axis coordinates of the touch position according to the signals transmitted through the touch-signal reading lines180-1and180-2.

It can be found fromFIG. 1that a sensing resolution of this kind of touch screen is determined by a distribution density of the sensing units170in the touch panel120. However, as each of the sensing units170is electrically coupled to the touch signal processing circuit130via the touch-signal reading lines180-1and180-2, and the distribution density of the sensing units170is usually limited by the channel number of the touch signal processing circuit130, and thereby the sensing resolution of the touch screen is always low. If the manufacturer wants to ensure the sensing resolution of the touch screen, a more expensive touch signal processing circuit130with more channels has to be adopted. This may increase the cost of the touch screen.

Moreover, because each of the sensing units170is electrically coupled to the touch signal processing circuit130via the touch-signal reading lines180-1and180-2, more external wires for the touch panel are needed with the increase of the distribution density of the sensing units170, and accordingly a width of the edge portion (not shown) for the touch panel120should also be increased. Furthermore, another deficiency arises in this kind of passive touch-sensing structure, specifically, the touch-sensing structure can only perform a so-called single touch sensing.

FIG. 2is a schematic view of a touch screen employing the active touch-sensing structure. Referring toFIG. 2, the touch screen includes a data driver210, a touch panel220, and a touch signal processing circuit230. The touch panel220includes a plurality of pixels. Each pixel is also consisted of a thin-film transistor (TFT), a storage capacitor Cst, and a pixel capacitor Clc. In addition, the touch panel220further includes a plurality of data lines240, a plurality of gate lines250, a plurality of common lines260, a plurality of sensing units270, and a plurality of touch-signal reading lines280. These sensing units270are also used to detect a touch position of a user in the touch panel. Each sensing unit270is electrically coupled to the touch signal processing circuit230via one of the touch-signal reading lines280, so as to enable the touch signal processing circuit230to obtain X-axis and Y-axis coordinates of the touch position according to the signals transmitted through the touch-signal reading lines280.

It can be found fromFIG. 2that a sensing resolution of this kind of touch screen is also determined by a distribution density of the sensing units270in the touch panel220. As the distribution density of the sensing units270is usually limited by the channel number of the touch signal processing circuit230, the sensing resolution of the touch screen is always low. If the manufacturer wants to ensure the sensing resolution of the touch screen, a more expensive touch signal processing circuit230with more channels has to be adopted. This may increase the cost of the touch screen. Moreover, because each of the sensing units270is electrically coupled to the touch signal processing circuit230via the touch-signal reading lines280, more external wires for the touch panel are needed with the increase of the distribution density of the sensing units270, and accordingly a width of the edge portion (not shown) for the touch panel220will also be increased.

Although this active touch-sensing structure can perform multi touch sensing, an aperture ratio of the pixel is reduced and thereby diminishing the light transmission rate of the pixel because the sensing units270in this structure are made up of TFTs. In addition, as the sensing units270in this structure are coupled to the gate lines250, and operate accompanying with scanning rate of the gate lines, a touch response speed of the touch screen is low.

What is needed, therefore, is a touch-sensing structure that can overcome the above-described deficiencies. What is also needed is a touch-sensing method.

BRIEF SUMMARY

The present invention relates to a touch-sensing structure for a touch panel. A touch screen using the touch-sensing structure can attain high sensing resolution without employing a touch signal processing circuit having a great number of channels. Moreover, peripheral wires for the touch panel of the touch screen can be reduced, and thereby it is unnecessary to enlarge the width of the edge portion for the touch panel. Further, compared with the conventional passive touch-sensing structure, the touch-sensing structure provided in the present invention has an ability of performing multi touch sensing. In addition, compared with the conventional active touch-sensing structure, the aperture ratio of the pixel in the touch-sensing structure provided in the present invention would not be reduced, and the touch-sensing response time thereof can also be faster.

The present invention also relates to a touch-sensing method corresponding to the touch-sensing structure.

In one aspect, the present invention provides a touch-sensing structure for a touch panel. The touch-sensing structure includes a first conductor and a plurality of first conducting wires paralleled to each other. A terminal of each first conducting wire is electrically coupled to the first conductor, so as to divide the first conductor into a plurality of first line segments. A resistance of each first conducting wire is smaller than that of each of the first line segments. When a display area of the touch panel receives an external force, the first conducting wire corresponding to a position designated by the external force is electrically coupled to a reference potential.

In another aspect, the present invention provides a touch-sensing method for a touch panel. The touch panel utilizes a touch-sensing structure including a first conductor and a plurality of parallel first conducing wires. A terminal of each first conducting wire is electrically coupled to the first conductor so as to divide the first conductor into a plurality of first line segments. A resistance of each first conducting wire is smaller than that of each of the first line segments. When a display area of the touch panel receives an external force, the first conducting wire corresponding to a position designated by the external force is electrically coupled to a reference potential. The method includes the steps of determining whether a touch action is performed; and calculating, when a touch action is performed, coordinates of a touch position according to resistances of two equivalent resistors respectively measured at two terminals of the first conductor.

In yet one aspect, the present invention provides a touch-sensing structure for a touch panel. The touch-sensing structure includes a conductor having N conducting structures paralleled to each other. Each of the conducting structures includes a first conducting wire and a second conducting wire in parallel. Each of the conducting wires includes a first terminal indicating a first direction and a second terminal indicating a second direction. The first terminal of the first conducting wire of the Kthconducting structure is electrically coupled to the first terminal of the second conducting wire of the Kthconducting structure, and the second terminal of the second conducting wire of the Kthconducting structure is electrically coupled to the second terminal of the first conducting wire of the (K+1)thconducting structure, where N and K are both natural numbers, 1≦K<N. Two touch-signal reading lines are configured to be electrically coupled to two ends of the conductor respectively. When a display area of the touch panel receives an external force, the first conducting wire corresponding to a position designated by the external force is electrically coupled to a reference potential.

In another aspect, the present invention provides a touch-sensing method for a touch panel. The touch panel utilizes a touch-sensing structure including a conductor and two touch-signal reading lines. The conductor includes N conducting structures paralleled to each other. Each of the conducting structures includes a first conducting wire and a second conducting wire in parallel. Each of the conducting wires includes a first terminal indicating a first direction and a second terminal indicating a second direction. The first terminal of the first conducting wire of the Kthconducting structure is electrically coupled to the first terminal of the second conducting wire of the Kthconducting structure, and the second terminal of the second conducting wire of the Kthconducting structure is electrically coupled to the second terminal of the first conducting wire of the (K+1)thconducting structure, where N and K are both natural numbers, 1≦K<N. When a display area of the touch panel receives an external force, the first conducting wire corresponding to a position designated by the external force is electrically coupled to a reference potential. The two touch-signal reading lines are configured to be electrically coupled to two ends of the conductor respectively. The method includes the steps of determining whether a touch action is performed; and calculating, when a touch action is performed, a coordinate of a touch position according to a resistance of a equivalent resistor measured at an end of the first conductor.

The present invention utilizes a conductor and a plurality of parallel conducting wires to form a touch-sensing structure which is suitable for performing one-dimension coordinate sensing. As a resistance of each conducting wire is smaller than that of each line segment of the conductor, the resistance of each conducting wire can be ignored. Once the touch screen determines that a touch action is performed, resistances of the two equivalent resistors can be measured at two terminals of the conductor. The two measured resistances can be used to represent different numbers of line segments, and accordingly the one-dimension coordinate of the touch position can be calculated. By making use of two touch-sensing structures as described above, two-dimension coordinates of the touch position can be obtained so long as an extra process of determining the actual touch position is carried out.

Similarly, a plurality of conducting structures paralleled to each other can also be used to form a conductor, and thereby form another touch-sensing structure capable of performing two-dimension coordinates sensing in the present invention. As the farther a distance from the touch position to a terminal of the conductor, the greater the measured resistances of the equivalent resistor, once the touch screen determines that a touch action is performed, the two-dimension coordinates of the touch position can be calculated according to the resistance of the equivalent resistor measured at a terminal of the conductor.

As described above, the present invention mainly utilizes the above conductor to obtain the coordinates of the touch position, and the touch signal processing circuit can carry out such operation merely through being coupled to the terminals of the conductor. Thus, the touch screen using the touch-sensing structure provided in the present invention can attain high sensing resolution without employing a touch signal processing circuit having a great number of channels. Moreover, peripheral wires for the touch panel of the touch screen can be less, and thereby it is unnecessary to enlarge the width of the edge portion for the touch panel. Further, as the resistances of the two equivalent resistors can respectively be measured at the two terminals of a same conductor, so as to represent different numbers of line segments, or to calculate the distance between the touch position and the terminals of the conductors according to the resistances of the two equivalent resistors, the touch-sensing structure provided in the present invention has an ability of performing multi touch sensing, while compared with the conventional passive touch-sensing structure. In addition, compared with the conventional active touch-sensing structure, it is not necessary to employ any transistor to form the sensing unit in the touch-sensing structure provided in the present invention, and accordingly the aperture ratio of the pixel in the touch panel can be ensured, and the touch-sensing response time thereof can also be lowered.

Other novel features and advantages will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

DETAILED DESCRIPTION

Reference will now be made to the drawings to described preferred and exemplary embodiments in detail.

Referring toFIG. 3, a touch-sensing structure for a touch panel according to a first embodiment of the present invention is illustrated. The touch-sensing structure is applicable for sensing two-dimension coordinates of a touch position. AsFIG. 2shown, the touch-sensing structure includes a first conductor310, a second conductor320, and a plurality of conducting wires330-348. Moreover, the touch-sensing structure further includes touch-signal reading lines312,314,322, and324. The conducting wires330-336are disposed in parallel, and one terminal of each of the conducting wires330-336is electrically coupled to the first conductor310, so as to divide the first conductor310into a plurality of first line segments. The conducting wires338-348are disposed in parallel and substantially perpendicular to the conducting wires330-336. One terminal of each of the conducting wires338-348is electrically coupled to the second conductor320, so as to divide the second conductor320into a plurality of second line segments.

The conductors310and320are made from special material, such that a resistance of each line segment is greater than that of each conducting wire. In ideal, a resistance of each line segment in the conductor310,320should be far greater than that of each conducting wire. In this embodiment, the conductors310and320are made from conductive material Indium Tin Oxide (ITO), and the conductors310and320are perpendicular to each other. As for the touch-signal reading lines312and314, each of these two lines has a terminal electrically coupled to an end of the first conductor310, and the other terminal of each of the touch-signal reading lines312and314is configured to be electrically coupled to a touch signal processing circuit (not shown) or other similar processing circuit. Similarly, each of touch-signal reading lines322and324has a terminal electrically coupled to an end of the first conductor320, and the other terminal of each of the touch-signal reading lines322and324is configured to be electrically coupled to the touch signal processing circuit or other similar processing circuit.

The touch-sensing structure as shown inFIG. 3is suitable for cooperating with a color filter of the touch panel, which is described as follow accompanying withFIG. 4andFIG. 5.FIG. 4illustrates a configuration relation in space between a color filter of the touch panel and the touch-sensing structure. AsFIG. 4shown, the color filter is disposed upon the touch-sensing structure. Referring toFIG. 5, a cross-sectional view of the touch panel is illustrated. AsFIG. 5shown, a plurality of photo spacers are distributed at a lower surface502of the color filter, and a layer of conductive material ITO (labeled with504) covers both the photo spacers and the lower surface of the color filter. Besides, the layer of conductive material ITO504is further electrically coupled to a reference potential Vcom (not shown). A first metal layer508and a second metal layer510are disposed on an upper surface506of an array substrate. The first metal layer508is configured to form the conducting wires330-336ofFIG. 3, while the second metal layer510is configured to form the conducting wires338-348ofFIG. 3. Alternatively, the first metal layer508can also be configured to form the conducting wires338-348ofFIG. 3, while the second metal layer510is configured to form the conducting wires330-336ofFIG. 3.

Each conductive line formed by the first metal layer508extends to a position under the corresponding photo spacers via conductive material ITO (labeled with512), and each conductive line formed by the first metal layer510also extends to a position under the corresponding photo spacers via conductive material ITO (labeled with514). With this configuration, when the displaying area (not shown) of the touch panel receives an external force (labeled with520), the photo spacer corresponding to the position designated by the external force is forced to lower down. This causes the conductive material ITO504to touch the conductive material512and514corresponding to the photo spacer, such that conductive wires in both X-direction and Y-direction, which corresponds to the photo spacer, are electrically coupled to the reference potential Vcom. That is, conducting the conductive wires in both X-direction and Y-direction corresponding to the position designated by the external force is electrically coupled to the reference potential Vcom.

FIG. 6illustrates how the touch-sensing structure ofFIG. 3performs a single touch sensing. Referring toFIG. 6, when an external force is applied to an display area604of the touch panel602, the conducting wires334and342, which corresponds to the position (labeled with606, hereinafter, the touch position) designated by the external force, are electrically coupled to a reference potential Vcom. As the touch position is where the conducting wires334and342electrically coupled to the reference potential Vcom, a line segment from the touch position606to the first conductor310can be equivalent to a first resistor608, and a line segment from the touch position606to the second conductor602can also be equivalent to a second resistor610.

Because the resistance of each conducting wire is far less than that of each line segment of the conductors310and320, the resistances of the first and second resistors608and610are so smaller that can be ignored. Thus, if the resistance of each line segment of the conductor310and320is Rsa resistance of an equivalent resistor measured from a terminal Y1is about 2Rsand a resistance of an equivalent resistor measured from a terminal Y2is about 3Rs. Similarly, a resistance of an equivalent resistor measured from a terminal X1is about 3Rs, and a resistance of an equivalent resistor measured from a terminal Y2is about 4Rs. Therefore, an X-axis coordinate of the touch position606can be calculated according to the two measured resistances respectively obtained at both terminals of the first conductor310, and a Y-axis coordinate of the touch position606can be calculated according to the two measured resistances respectively obtained at both terminals of the second conductor320. As such, the two-dimension coordinates of the touch position606can be sensed.

FIG. 7illustrates how the touch-sensing structure ofFIG. 3performs a multi touch sensing. Two touch positions, labeled with606and612respectively, are shown inFIG. 7. Equivalent resistors from the touch positions to line segments of corresponding conductors in the corresponding conducting wires are labeled with608,610,614, and616, respectively. If a resistance of each line segment of the conductor310and320is Rsand resistances of the equivalent resistors608,610,614, and616are respectively Rm1, Rn1, Rm2, and Rn2, and theoretically, a resistance RY1of an equivalent resistor measured from a terminal Y1, a resistance RY2of an equivalent resistor measured from a terminal Y2, a resistance RX1of an equivalent resistor measured from a terminal X1, and a resistance RX2of an equivalent resistor measured from a terminal X2can respectively expressed by the following formulae (1)-(4).

As the resistance Rm1, Rn1, Rm2, and Rn2are so small that can be ignored, the actual measured resistances RY1, RY2, RX1, and RX2are respectively about 2Rs, 2Rs, 3Rs, and 2Rs.

Following with the above description, from the four values of 2Rs, 2Rs, 3Rs, and 2Rs, it can be found that a length about two line segments of the first conductor310counted from the terminal Y1can be treated as corresponding to a touch position, and a length about two line segments of the first conductor310counted from the terminal Y2can also be treated as corresponding to another touch position. Similarly, a length about three line segments of the second conductor320counted from the terminal X1can be treated as corresponding to another touch position, and a length about two line segments of the second conductor320counted from the terminal X2can also be treated as corresponding to another touch position. Thus, there may be four possible touch positions, including touch positions606and612, a cross point for the conducting wires334and336, and a cross point for the conducting wires332and342. Because only two of the above four possible touch positions are actual touch positions, a further determination for the actual touch positions is needed, so as to obtain the two-dimension coordinates of the actual touch positions.

Two methods for determining the actual touch positions are provided as follows. It should be noted that these two illustrated methods should not be treated as limitation of the present invention.

Referring toFIG. 7again, one of the methods is to calculate the values of Rm1and Rm2according to the above formulae (1) and (2), and to calculate the values of Rn1and Rn2according to the above formulae (3) and (4). Alternatively, the resistance Rm1can also be calculated out according to a known fixed value Rs, for example, through subtracting 2Rsfrom the actual measured resistance RY1directly, and the resistance Rm2can be calculated out through subtracting 2Rsfrom the actual measured resistance RY2directly. Similarly, the resistance Rm3can be calculated out through subtracting 3Rsfrom the actual measured resistance RX1directly, and the resistance Rm4can be calculated out through subtracting 2Rsfrom the actual measured resistance RX2directly. Then, the actual touch positions can be determined according to a relationship between the two resistances Rm1and Rm2, as well as a relationship between the two resistances Rn1and Rn2. For this example, as the resistance Rm1is smaller than Rm2, and the resistance Rn1is greater than Rn2, the touch positions606and612should be regarded as the actual touch positions. Therefore, the two-dimension coordinates of these two actual touch positions can be obtained.

Referring toFIG. 7again, in a second method, the actual touch positions are determined according to the touch time difference. Assuming the touch position606is sensed first, coordinates of the touch position606in an X-axis direction (namely, a first dimension direction) and a Y-axis direction (namely, a second dimension direction) can be recorded. After that, the touch position612is then be sensed. Thereby, the touch position612, a cross point of the conducting wires334and346, and a cross point of the conducting wires332and342are all regarded as possible touch positions. As such, the actual touch position can be determined from these latterly sensed possible touch positions according to the recorded coordinates.

For instance, based on the recorded coordinates, the one among the latterly sensed possible touch positions, which has an X-axis coordinate the same as that of the recorded coordinates, can be removed, such that the cross point of the conducting wires334and346can be excluded from the actual touch positions. Then, the one among the latterly sensed possible touch positions, which has a Y-axis coordinate the same as that of the recorded coordinates, can also be removed, such that the cross point of the conducting wires332and342can be excluded from the actual touch positions. The rest one of the latterly sensed possible touch positions, i.e., the touch position612, can accordingly be treated as another actual touch position. In an alternative embodiment, the possible touch positions having a Y-axis coordinate the same as that of the recorded coordinates can be removed firstly, and after that, the possible touch positions having an X-axis coordinate the same as that of the recorded coordinates is removed. As such, the two-dimension coordinates of both of the actual touch positions can be obtained.

Further, when a pressing object providing the external force slides, each actual touch position obtained in a first time instance can be taken to find touch positions respectively having shortest distances thereto from the possible touch positions obtained in a second time instance (later than the first time instance). The found touch positions can be regarded as the actual touch positions at the second time instance, and thereby a group of coordinates can be obtained. Accordingly, a sliding trail of the press object can be presented in accordance with the above group of coordinates.

From the first embodiment, it can be taught that the sensing of touch positions may also be implemented merely based on the first conductor310and the conducting wires330-336, or based on the second conductor320and the conducting wires338-348. While sensing a one-dimension coordinate of the touch position, only two resistances respectively measured at the two terminal of the corresponding conductor are needed, and the one-dimension coordinate can be calculated according to these two resistances. However, while sensing two-dimension coordinates of the touch position, the formulae (1)-(2), or (3)-(4) would be applied to calculate the other coordinate.

It should be noted that the above embodiment is one of the exemplary modes of the first embodiment. Referring toFIG. 8, a touch-sensing structure for a touch panel according to another embodiment of the present invention is shown. InFIG. 8, labels810and820represent conductors, labels812,814,822, and824represent touch-signal reading lines, and labels830-856represent conducting wires. In this embodiment, a width of each conducting wires830-856is increased, such that resistances of the conducting wires are lessened.

The above embodiment is also only one of the exemplary modes of the first embodiment. Referring toFIG. 9, a touch-sensing structure for a touch panel according to another embodiment of the present invention is shown. InFIG. 9, labels910and920represent conductors, labels912,914,922, and924represent touch-signal reading lines, and labels930-952represent conducting wires inFIG. 9. In this embodiment, each of the conductors910and920has continual folds, such that resistances of the conductors910and920are increased.

The above embodiment is also only one of the exemplary modes of the first embodiment. Referring toFIG. 10, a touch-sensing structure for a touch panel according to another embodiment of the present invention is shown. InFIG. 10, labels1010and1020represent conductors, labels1012,1014,1022, and1024represent touch-signal reading lines, and other lines in both X-direction and Y-direction represent conducting wires inFIG. 10. In this embodiment, the conductors1010and1020cross to each other, and all the conducting wire in the X-direction are electrically coupled to the conductor1010, all the conducting wires in the Y-direction are electrically coupled to the conductor1020.

The above embodiment is also only one of the exemplary modes of the first embodiment. Referring toFIG. 11, a touch-sensing structure for a touch panel according to another embodiment of the present invention is shown. InFIG. 11, labels1110,1120,1130, and1140represent conductors, labels1112,1114,1122,1124,1132,1134,1142, and1144represent touch-signal reading lines, and other lines in both X-direction and Y-direction represent conducting wires inFIG. 11. In this embodiment, the conductor1130is parallel to the conductor1110, and the conductor1140is parallel to the conductor1120. Besides, two terminals of each conducting wire in the X-direction are respectively electrically coupled to the conductor1110and the conductor1130, and two terminals of each conducting wire in the Y-direction are respectively electrically coupled to the conductor1120and the conductor1140.

In the above embodiment, the conductors1130and1140are back-up conductors, and the touch-signal reading lines1132,1134,1142, and1144are back-up touch-signal reading lines. When any of the conductors1110,1120and the corresponding touch-signal reading lines thereof suffers damage, for example, being impaired by electrostatics upon the condition that an electrostatic discharge (ESD) which may disable the sensing of touch positions made use of the conductors1110and1120occurs, the back-up conductors1130and1140can be applied to sense the touch positions. Alternatively, the conductors1110and1120may also serve as back-up conductors. By using the back-up conductors and the back-up touch-signal reading lines, the sensing process of the touch-sensing structure is more stable and reliable, and can prevent from the impairment of ESD.

The above embodiment is also only one of the exemplary modes of the first embodiment. Referring toFIG. 12, a touch-sensing structure for a touch panel according to another embodiment of the present invention is shown. InFIG. 12, labels1210and1120represent conductors, labels1212,1214,1216,1218,1222,1224,1226, and1228represent touch-signal reading lines, and other lines in both X-direction and Y-direction represent conducting wires inFIG. 12. In this embodiment, the conductor1210includes components1210-1and1210-2, and the component1210-1and the component1210-2are separated to each other. The component1210-1is configured to electrically couple to part of the conducting lines in the X-direction, and the component1210-2is configured to electrically couple to the rest of the conducting lines in the X-direction.

Similarly, the conductor1220includes components1220-1and1220-2, and the component1220-1and the component1220-2are also separated to each other. The component1220-1is configured to electrically couple to part of the conducting lines in the Y-direction, and the component1220-2is configured to electrically couple to the rest of the conducting lines in the Y-direction. From the above description aboutFIG. 3, it can be found that an X-direction conductor, together with a Y-direction conductor, can at least perform the sensing of two touch positions. Thus it can be inferred that the touch-sensing structure as illustrated inFIG. 12can used for perform the sensing of more than two touch positions, and thereby being capable of multiple point sensing.

Based on the teaching of the above first to seventh embodiments, a basic operation method can be summarized asFIG. 13.FIG. 13is a flow chart of a touch-sensing method according to an embodiment of the present invention, which can be applied in a touch panel. The touch panel has a touch-sensing structure, and the touch-sensing structure includes a first conductor and a plurality of parallel first conducting wires. A terminal of each first conducting wire is electrically coupled to the first conductor, so as to divide the conductor into a plurality of first line segments. The resistance of each first conducting wire is smaller than that of each first line segment. When an external force is applied to the displaying area of the touch panel, one of the first conducting wires corresponding to the position designated by the external force is electrically coupled to a reference potential. The method includes the steps of determining whether a touch action is performed (as shown in step S1302); calculating coordinates of the touch position according to two equivalent resistances respectively measured at two terminals of the first conductor when a touch action is performed (as shown in step S1304).

Referring toFIG. 14, a touch-sensing structure for a touch panel according to another embodiment of the present invention is shown. The touch-structure is adapted to sense two-dimension coordinates of a touch position. As shown inFIG. 14, the touch-sensing structure includes touch-signal reading lines1420and1430, other than a conductor1410. The conductor1410includes N conducting structures (labeled with1412) paralleled to each other. Each conducting structure includes a first conducting wire and a second conducting wire in parallel, which are labeled with1414and1416. Each conducting wire includes a first terminal (as shown by an arrow1440) and a second terminal (as shown by an arrow1450).

The first terminal of the first conducting wire of the Kthconducting structure is electrically coupled to the first terminal of the second conducting wire of the Kthconducting structure, and the second terminal of the second conducting wire of the Kthconducting structure is electrically coupled to the second terminal of the first conducting wire of the (K+1)th conducting structure, where N and K are both natural numbers, and 1≦K<N. The above two touch-signal reading lines are respectively electrically coupled to the two terminal of the conductor1410. When an external force is applied to the display area of the touch panel, a portion of conductor1410corresponding to the position designated by the external force is electrically coupled to a reference potential Vcom.

As the farther a distance from the touch position to the conductor1410, the greater the resistance of the measured equivalent resistor, thus, while the touch screen determines that a touch action is performed, the two-dimension coordinates of the touch position can be calculated according to the resistance of the equivalent resistor measured at a terminal of the conductor1410, such that a single touch sensing can be realized. Moreover, a multi touch sensing can be achieved while calculating the two-dimension coordinates of the touch positions according to the resistances of the two equivalent resistors respectively measured at the two terminals of the conductor1410.

Based on the teaching of the eighth embodiment, a basic operation method can be summarized asFIG. 15.FIG. 15is a flow chart of a touch-sensing method according to another embodiment of the present invention, which can be applied in a touch panel. The touch panel has a touch-sensing structure, and the touch-sensing structure includes a first conductor and tow touch-signal reading lines. The conductor includes N parallel conducting structures, each of which includes a first terminal and a second terminal. The first terminal and the second terminal point to a first direction and a second direction, respectively. The first terminal of the first conducting wire of the Kthconducting structure is electrically coupled to the first terminal of the second conducting wire of the Kthconducting structure, and the second terminal of the second conducting wire of the Kthconducting structure is electrically coupled to the second terminal of the first conducting wire of the (K+1)thconducting structure, where N and K are both natural numbers, and 1≦K<N.

When an external force is applied to the displaying area of the touch panel, a portion of the conductor corresponding to the position designated by the external force is electrically coupled to a reference potential, and the above two touch-signal reading lines are electrically coupled to the two terminals of the conductor, respectively. The method includes the steps of determining whether a touch action is performed (as shown in step S1502); calculating a coordinate of the touch position according to an equivalent resistance measured at a terminal of the first conductor when a touch action is performed (as shown in step S1504).

It should be noted that, from the various embodiments as described above, the touch-sensing structure provided by the present invention may also be a passive touch-sensing structure, and is extremely suitable for being applied in an embedded touch screen. In addition, the present invention can be achieved by modifying the layout of the touch panel, and thereby no extra process is needed.

In summary, the present invention utilizes a conductor and a plurality of parallel conducting wires to form a touch-sensing structure which is suitable for performing one-dimension coordinate sensing. As a resistance of each conducting wire is smaller than that of each line segment of the conductor, the resistance of each conducting wire can be ignored. Once the touch screen determines that a touch action is performed, resistances of the two equivalent resistors can be measured at two terminals of the conductor. The two measured resistances can be used to represent different numbers of line segments, and accordingly the one-dimension coordinate of the touch position can be calculated. By making use of two touch-sensing structures as described above, two-dimension coordinates of the touch position can be obtained so long as an extra process of determining the actual touch position is carried out.

Similarly, a plurality of conducting structures paralleled to each other can also be used to form a conductor, and thereby form another touch-sensing structure capable of performing two-dimension coordinates sensing in the present invention. As the farther a distance from the touch position to a terminal of the conductor, the greater the measured resistances of the equivalent resistor, once the touch screen determines that a touch action is performed, the two-dimension coordinates of the touch position can be calculated according to the resistance of the equivalent resistor measured at a terminal of the conductor.

With the above description, it can be found that the present invention mainly utilizes the above conductor to obtain the coordinates of the touch position, and the touch signal processing circuit can carry out such operation merely through being coupled to the terminals of the conductor. Thus, the touch screen using the touch-sensing structure provided in the present invention can attain high sensing resolution without employing a touch signal processing circuit having a great number of channels. Moreover, peripheral wires for the touch panel of the touch screen can be less, and thereby it is unnecessary to enlarge the width of the edge portion for the touch panel. Further, as the resistances of the two equivalent resistors can respectively be measured at the two terminals of a same conductor, so as to represent different numbers of line segments, or to calculate the distance between the touch position and the terminals of the conductors according to the resistances of the two equivalent resistors, the touch-sensing structure provided in the present invention has an ability of performing multi touch sensing, while compared with the conventional passive touch-sensing structure. In addition, compared with the conventional active touch-sensing structure, it is unneeded to employ any transistor to form the sensing unit in the touch-sensing structure provided in the present invention, and accordingly the aperture ratio of the pixel in the touch panel can be ensured, and the touch-sensing response time thereof can also be improved.