This application claims the priority benefit of Taiwan application serial no. 102111715, filed on Apr. 1, 2013. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.
1. Technical Field
The invention relates to a touch panel. Particularly, the invention relates to a capacitive touch panel.
2. Related Art
Touch panels are approximately categorized into resistive touch panels, capacitive touch panels, optical touch panels, acoustic wave touch panels and electromagnetic touch panels according to different sensing manners. Compared to the other types of touch panel, since the capacitive touch panel has the advantages of fast response speed, high reliability and high definition, etc., it is widely applied in various handheld electronic devices. Moreover, a mutual capacitance sensing technology of the capacitive touch panel is quickly developed.
In detail, a mutual capacitive touch panel is configured with a touch electrode unit composed of a driving electrode and a sensing electrode. When a driving signal (voltage) is input to the driving electrode, the sensing electrode may obtain a sensing signal (voltage) based on a coupling effect. When no touch event occurs, a stable mutual capacitance is fonned between the driving electrode and the sensing electrode. When a touch event occurs, the mutual capacitance between the driving electrode and the sensing electrode correspondingly changes, and such change relates to a position and an area size of the touch event, a size of the touch electrode unit and a total length of adjacent side length between the driving electrode and the sensing electrode.
When the electrodes (the sensing electrode and the driving electrode) are designed, the size of the touch electrode unit is an important parameter. Theoretically, the smaller the size of the touch electrode unit is, the better signal linearity and sensitivity of the mutual capacitive touch panel are, though considering processing capability and fabrication cost, the size of the touch electrode unit is limited and cannot be unlimitedly decreased. Therefore, an area of the touch event probably cannot cross over the driving electrode and the sensing electrode, simultaneously (for example, an area of a touch point is too small), which causes inadequate mutual capacitance variation between the driving electrode and the sensing electrode to worsen the touch sensing capability. In other words, the signal linearity and sensitivity of the mutual capacitive touch panel is not ideal.
The invention is directed to a touch panel, which has ideal signal linearity and sensitivity without decreasing a size of a touch electrode unit.
The invention provides a touch panel including a carrier component, a plurality of first electrode series and a plurality of second electrode series. The first electrode series and the second electrode series are all carried by the carrier component. Each first electrode series includes a plurality of first connection patterns and a plurality of first electrodes connected in series along a first direction through the first connection patterns, where each of the first electrodes has a first main pattern extending along the first direction and a plurality of first sub patterns connected to the first main pattern. Each second electrode series includes a plurality of second connection patterns and a plurality of second electrodes connected in series along a second direction through the second connection patterns. The second electrode and the first electrode are separated by a gap. Each of the second electrodes has a second main pattern extending along the second direction and a plurality of second sub patterns connected to the second main pattern, where the first sub patterns and the second sub patterns are arranged in alternation. In a unit sensing area arbitrarily selected on the touch panel, a ratio of the unit sensing area occupied by each of the first electrodes to the unit sensing area occupied by each of the second electrodes is 1:1.2 to 1:1.4, where a length and a width of the unit sensing area are respectively equal to pitches of the first electrodes in the first direction and the second direction.
In an embodiment of the invention, a contour of the first electrodes and a contour of the second electrodes are complementary.
In an embodiment of the invention, each of the first electrode series further includes a plurality of first connection patterns for connecting the first electrodes along the first direction to form each of the first electrode series.
In an embodiment of the invention, each of the second electrode series further includes a plurality of second connection patterns for connecting the second electrodes along the second direction to form each of the second electrode series.
In an embodiment of the invention, the gap is from 200 μm to 300 μm.
In an embodiment of the invention, the touch panel further includes a plurality of dummy electrodes located between the first electrodes and the second electrodes. The dummy electrodes are arranged in multiple rows in the gap. A distance between the dummy electrodes and the first electrodes, a distance between the dummy electrodes and the second electrodes, and a distance between the dummy electrodes respectively are not greater than 30 μm.
In an embodiment of the invention, the carrier component includes a plate or a membrane. Moreover, the touch panel further includes a decoration layer, which is disposed at a peripheral area of the carrier component, and the first electrode series and the second electrode series are located at a same side of the carrier component.
In an embodiment of the invention, the carrier component includes a first plate/membrane and a second plate/membrane. The first electrode series and the second electrode series are located between the first plate/membrane and the second plate/membrane, and are separated by an insulation medium. Now, one of the first plate/membrane and the second plate/membrane is, for example, a cover plate. The first electrode series and the second electrode series are located at two opposite sides of the other one of the first plate/membrane and the second plate/membrane. Moreover, the first electrode series is disposed on the first plate/membrane, and the second electrode series is disposed on the second plate/membrane. Now, the first plate/membrane and the second plate/membrane are sequentially stacked, and one of the first electrode series and the second electrode series is located between the first plate/membrane and the second plate/membrane, and the other one is not located therebetween. The touch panel further includes a cover plate. The cover plate is adhered on the first plate/membrane and the second plate/membrane.
In an embodiment of the invention, the first sub patterns of each of the first electrodes extends outwards from the first main pattern, and an extending direction of the first sub patterns is not parallel to the first direction. The extending direction of the first sub patterns is parallel to the second direction. Alternatively, the extending direction of at least one of the first sub patterns extending outwards from the first main pattern points to a center of one of the adjacent second electrodes. Moreover, the extending direction of at least one of the first sub patterns extending outwards from the first main pattern is first parallel to the second direction and then points to the center of one of the adjacent second electrodes. The first sub patterns have different pattern widths.
In an embodiment of the invention, each of the first electrodes and each of the second electrodes respectively have a symmetric contour.
In an embodiment of the invention, each of the second sub patterns of each of the second electrodes includes a main branch and a plurality of sub branches. The sub branches are connected to the main branch, the main branch extends outwards from the second main pattern, and an extending direction of the main branch is not parallel to the second direction. An extending direction of each of the sub branches extending outwards from the main branch is first parallel to the second direction and then points to a center of one of the adjacent first electrodes. Alternatively, the extending direction of each of the sub branches extending outwards from the main branch is parallel to the second direction. Moreover, the extending direction of each of the sub branches extending outwards from the main branch first points to a center of one of the adjacent first electrodes and is then parallel to the second direction. In an embodiment, a width of the main branch is greater than a width of the sub branches.
In an embodiment of the invention, the first electrode series and the second electrode series are made of metal material and patterned in the form of mesh. Moreover, the carrier component comprises an indentation, and the first electrode series and the second electrode series are disposed within the indentation.
According to the above descriptions, in the touch panel according to the embodiments of the invention, the patterns of the first electrodes and the second electrodes have a plurality of branches arranged in alternation. Therefore, the unit sensing area arbitrarily selected on the touch panel covers partial areas of the first electrode and the second electrode, such that the sensing signal of the touch panel has an ideal linearity. Moreover, an area ratio of the first electrode to the second electrode is adjusted for improving sensitivity of touch sensing. Therefore, the first electrode and the second electrode have ideal sensing yield without decreasing the sizes thereof.
In order to make the aforementioned and other features and advantages of the invention comprehensible, several exemplary embodiments accompanied with figures are described in detail below.
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
In detail, the first electrode series 110 and the second electrode series 120 can be carried by a carrier component (not shown) made of organic material including SiOx, polyimide, polypropylene, polyethylene, polycarbonate, polyrnethyl methacrylate, polyether ketone, cyclic olefin copolymer, acrylic resin or epoxy resin. However, in order to clearly present the design of the electrodes, only the electrodes are illustrated in
In the present embodiment, each of the first electrodes 112 is composed of a first main pattern 112A and a plurality of first sub patterns 112B and 112C. The first main pattern 112A mainly extends along the first direction D1, and the ends of the first main pattern 112A are respectively connected to the first connection patterns 114. The first sub patterns 112B and 112C are all connected to the first main pattern 112A and extend outward from the first main pattern 112A. Here, each of the first electrodes 112 is substantially composed of a continuous or integral conductive pattern, and the aforementioned main pattern and the sub patterns are divided into different portions according to contours and extending directions of the portions. Therefore, in an actual design, the main pattern and the sub patterns have no boundary therebetween.
An extending direction of the first sub pattern 112B or the first sub pattern 112C extending outwards from the first main pattern 112A is not parallel to the first direction D1. Therefore, the first sub pattern 112B approximately extends along the second direction D2 from the first main pattern 112A to the first electrode 112 of the adjacent first electrode series 110. Moreover, the first sub pattern 112C approximately extends along the second direction D2 from the first main pattern 112A to a central line of the adjacent second electrode 122.
The pattern of the second electrode 122 is, for example, composed of a second main pattern 122A and a plurality of second sub patterns 122B connected to the second main pattern 122A. Here, a main extending direction of the second main pattern 122A is approximately parallel to the second direction D2, and the ends of the second main pattern 122A are respectively connected to the corresponding second connection patterns 124. Moreover, in the present embodiment, each of the second sub patterns 122B includes a main branch 122B1 and a plurality of sub branches 122B2, where the sub branches 122B2 extend outwards from the main branch 122B1 and are indirectly connected to the second main pattern 122A through the main branch 122B1. In other words, the sub branches 122B2 do not contact the second main pattern 122A. Moreover, in the design of the present embodiment, a width of the main branch 122B1 can be selectively greater than a width of the sub branches 122B2.
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In the touch panel 100, the first electrode series 110 can be regarded as sensing electrodes, and the second electrode series 120 can be regarded as driving electrodes. When a user touches the touch panel 100 by a finger, the touch panel 100 determines a touch position of the finger according to a mutual capacitance variation between the first electrode series 110 and the second electrode series 120. Since the first electrodes 112, the sensing electrodes, are used to receive signals, the larger the area of the first electrodes 112 is, the more external noise is received. Therefore, when the electrodes are designed, the area of the second electrodes 122 is designed to be larger and the area of the first electrodes 112 is designed to be smaller. However, small area of the first electrodes 112 leads to problems of excessively high resistance of the first electrode series 110, inadequate signal coupling amount, etc. Therefore, an area ratio of the first electrodes 112 and the second electrodes 122 can be adjusted according to the design of the touch panel 100.
In the present embodiment, in a unit sensing area A arbitrarily selected on the touch panel 100, a ratio of an area occupied by the first electrode 112 to an area occupied by the second electrode 122 is 1:1.2 to 1:1.4, where a length and a width of the unit sensing area A are respectively equal to a pitch P1 and a pitch P2 of the first electrodes 112 in the first direction D1 and the second direction D2. When the user directly operates the touch panel 100 by fingers, a size of the unit sensing area A is, for example, set to 5 mm2. Now, regardless of any position where the finger touches the touch panel 100, a contact area of the finger may cover partial areas of the first electrode 112 and the second electrode 122, and an area ratio of the contacted first electrode 112 to the second electrode 122 is 1:1.2 to 1:1.4. Therefore, the touch panel 100 may effectively perform touch sensing. Particularly, when a conductor, for example, the finger moves on the touch panel 100 along a specific track (for example, a track R), the signals received by the first electrode series 110 may present a good linearity to achieve better touch sensing sensitivity. However, the aforementioned values are only used as an example, and the invention is not limited thereto.
Each of the first electrodes 212 has a first main pattern 212A extending along the first direction D1 and a plurality of first sub patterns 212B and 212C connected to the first main pattern 212A. The first main pattern 212A is, for example, a pattern having double arrows, and the first main pattern 212A mainly extends along the first direction D1. Extending directions of the first sub patterns 212B and 212C are not parallel to the first direction D1. The first sub pattern 212B can be connected to a central portion of the first main pattern 212A, and approximately extends outwards from the first main pattern 212A along the second direction D2. The first sub pattern 212C is, for example, connected to an end portion of the first main pattern 212A, and approximately extends from the first main pattern 212A towards a center of the adjacent second electrode 222. Now, an extending direction of the first sub pattern 212C is neither parallel to the first direction D1 nor parallel to the second direction D2. However, such pattern design is only used as an example, and the invention is not limited thereto.
A contour of each second electrode 222 can be approximately divided into a second main pattern 222A and a plurality of second sub patterns 222B connected to the second main pattern 222A, where each of the second sub patterns 222B is further composed of a main branch 222B1 and a plurality of sub branches 222B2. The second main pattern 222A is defined as a pattern extending along the second direction D2, and two ends of the second main pattern 222A are respectively connected to the corresponding second connection patterns 224. The main branch 222B1 in the second sub pattern 222B extends outwards from the second main pattern 222A, and an extending direction of the main branch 222B1 can be selectively parallel to the first direction D1. The sub branches 222B2 are connected to the main branch 222B1 and extend outwards from the main branch 222B1. Each of the sub branches 222B2, for example, first extends towards the center of the adjacent first electrode 212 and then extends along the second direction D2. In this way, contours of the first electrode 212 and the second electrode 222 are approximately complementary to implement a planar sensing electrode distribution. Here, the first electrodes 212 and the second electrodes 222 respectively have a symmetric pattern design.
In a unit sensing area A arbitrarily selected on the touch panel 200, a ratio of an area occupied by the first electrode 212 to an area occupied by the second electrode 222 is 1:1.2 to 1:1.4, where a length and a width of the unit sensing area A are respectively equal to a pitch P1 and a pitch P2 of the first electrodes 212 in the first direction D1 and the second direction D2. In the present embodiment, a size of the unit sensing area A is set to 5 mm2, though the invention is not limited thereto. As that described in the aforementioned embodiments, regardless of any position where the finger touches the touch panel 200, a contact area of the finger may cover a certain area proportion of the first electrode 112 and the second electrode 122 to implement effective touch sensing. Particularly, when the finger moves on the touch panel 200 along a specific track, the signals received by the first electrode series 210 may present a good linearity to achieve better touch sensing sensitivity. Here, the size of the unit sensing area A is only used as an example, and the invention is not limited thereto. Actually, the sizes of the first electrode 212 and the second electrode 222 can be determined according to a size, a resolution requirement and a using method of the touch panel 200. Therefore, the size of the unit sensing area A can be greater than or equal to 5 mm2.
Each second electrode series 320 includes a plurality of second electrodes 322 and a plurality of second connection patterns 324 connecting the second electrodes 322 in series along the second direction D2. The first connection patterns 314 and the second connection patterns 324 are intersected and are electrically isolated to each other. Moreover, the second electrodes 322 and the first electrodes 312 are spaced by a gap G, and the first electrodes 312 are not overlapped with the second electrodes 322. Each of the first electrodes 312 has a first main pattern 312A extending along the first direction D1 and a plurality of first sub patterns 312B and 312C connected to the first main pattern 312A. The first main pattern 312A is, for example, a long stripe pattern having tips at both ends, and the first main pattern 312A mainly extends along the first direction D1. Extending directions of the first sub patterns 312B and 312C are not parallel to the first direction D1. The first sub pattern 312B can be connected to a central portion of the first main pattern 312A, and approximately extends outwards from the first main pattern 312A along the second direction D2. The first sub pattern 312C is, for example, connected to an end portion of the first main pattern 312A, and approximately extends outwards from the first main pattern 312A along the second direction D2 and then extends towards a center of the adjacent second electrode 322. However, such pattern design is only used as an example, and the invention is not limited thereto.
A contour of each second electrode 322 can be approximately divided into a second main pattern 322A and a plurality of second sub patterns 322B connected to the second main pattern 322A, where each of the second sub patterns 322B is further composed of a main branch 322B1 and a plurality of sub branches 322B2. The second main pattern 322A is defined as a pattern extending along the second direction D2, and two ends of the second main pattern 322A are respectively connected to the corresponding second connection patterns 324. The main branch 322B1 of the second sub pattern 322B extends outwards from the second main pattern 322A, and an extending direction of the main branch 322B1 can be selectively parallel to the first direction D1. The sub branches 322B2 are connected to the main branch 322B1 and extend outwards from the main branch 322B1 along the second direction D2. In this way, contours of the first electrode 312 and the second electrode 322 are approximately complementary to implement a planar sensing electrode distribution.
Similar to the aforementioned embodiment, in a unit sensing area A arbitrarily selected on the touch panel 300, a ratio of an area occupied by the first electrode 312 to an area occupied by the second electrode 322 is 1:1.2 to 1:1.4, where a length and a width of the unit sensing area A are respectively equal to a pitch P1 and a pitch P2 of the first electrodes 312 in the first direction D1 and the second direction D2. In this way, the touch panel 300 may have ideal touch sensing sensitivity. Actually, the sizes of the first electrode 312 and the second electrode 322 can be determined according to a size, a resolution requirement and a using method of the touch panel 300. Therefore, the size of the unit sensing area A can be greater than or equal to 5 mm2.
In the aforementioned embodiments, since contours of the first electrodes 112, 212 and 312 and the second electrodes 122, 222 and 322 are respectively patterns having a plurality of branches, a perimeter of each electrode contour is obviously increased. Now, capacitance coupling effects between the first electrodes 112, 212 and 312 and the second electrodes 122, 222 and 322 are obviously increased based on increase of the perimeter of the contour, which leads to an obvious increase of a load of a driving chip. In order to decrease the load of the driving chip, the gaps G between the first electrodes 112, 212 and 312 and the second electrodes 122, 222 and 322 can be suitably adjusted. A following table 1 lists the influences on the loads of the driving chip and capacitance variation rates received by the driving chip caused by the gaps G between the first electrodes 112, 212 and 312 and the second electrodes 122, 222 and 322. In other embodiment, the aforementioned first electrode series and second electrode series are made of metal material and patterned in the form of mesh with 0.8 μm-10 μm line width. Moreover, the first electrode series and second electrode series can be disposed within the indentation on the carrier component to provide another type of the touch panel.
According to the table 1, it takes the embodiment of gap G of 30 μm for standard, and the gap G comparative relation of percentage is based thereon for illustration. Increasing the gap G can reduce the load of the driving chip, but also reduce the capacitance variation rate wherein the higher capacitance variation rate brings the superior touch accuracy. When the gap G is increased to be greater than 200 μm, the load can be decreased by about 50%, and the capacitance variation rate is still maintained to be above 95%. Therefore, in the electrode designs of the aforementioned embodiments, the gaps G can be selectively set to a size between 200 μm and 300 μm to maintain ideal touch sensing sensitivity. However, the increased gaps G result in a fact that the user perceives the existence of the gaps G, which is unfavorable to visual effects of the touch panels 100-300. Therefore, dummy electrodes can be selectively disposed between the first electrodes 112, 212 and 312 and the second electrodes 122, 222 and 322 to improve the visual effects of the touch panels 100-300. Embodiments are provided below with reference of figures to describe designs and layouts of the first electrodes, the second electrodes and the dummy electrodes, though the invention is not limited thereto.
According to the table 2, by disposing the dummy electrode Ed between the first electrode E1 and the second electrode E2, the load of the driving chip is slightly increased, though the ideal capacitance variation rate can still be achieved. Therefore, configuration of the dummy electrode Ed can indeed improve the visual effects of the touch panels 100-300 effectively, and keep ideal sensing yields of the touch panels 100-300.
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In summary, in the touch panel of the invention, the electrode patterns have a plurality of branches arranged in alternation. When the unit sensing area is arbitrarily selected on the touch panel, the unit sensing area covers a part of the driving electrode and a part of the sensing electrode, and the sensing electrode and the driving electrode in the unit sensing area have a certain area ratio. In this way, the touch panel of the invention has ideal touch sensing sensitivity and better signal linearity.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.
Number | Date | Country | Kind |
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102111715 | Apr 2013 | TW | national |