TWI442299B - Electrode structure of capacitive touch panel - Google Patents

Description

Electrode structure of capacitive touch panel

The invention is an electrode structure, in particular an electrode structure of a capacitive touch panel.

With the development of technology, more and more electronic devices on the market, such as notebook computers, tablet computers, mobile phones, various information appliances, etc., the operation control of mainstream products is no longer limited to the traditional Keyboard, button or mouse input mode, and more intuitive touch mode, users only need to move and touch the finger on the touch panel to input and operate. Features.

However, with the rapid development of touch technology and soft and hard technology, touch operations are becoming more and more user-friendly, and many touch operations are becoming more and more delicate. Therefore, the resolution requirements for touch tracks are becoming higher and higher. Otherwise, it is easy to misjudge or the touch track drawn is not as expected.

The way to improve the sensitivity of touch operation can be divided into software improvement and hardware improvement. The so-called software-based improvement refers to reducing the probability of error in the touch operation by changing the touch panel driver and algorithm; while the hardware method is to directly improve the components of the touch panel, one of which is to improve the electrode structure.

Taking a mutual-capacitive touch panel as an example, please refer to FIG. 1 , which is a schematic diagram of a conventional technology. The electrode structure of the touch panel is a matrix structure composed of staggered wires, and the material of the wires is basically a transparent conductive material such as ITO. The staggered wires may be divided into a plurality of driving lines in a first direction and a plurality of sensing lines in a second direction, and the driving lines and the sensing lines are insulated and staggered. After the driving signal is transmitted by the driving line, the capacitance value of the intersection (node) of the driving line and the sensing line can be measured from the sensing line. When a finger or other conductor approaches or touches the surface of the touch panel, the measured capacitance value at the node adjacent to the finger or the conductor changes significantly, thereby knowing the position of the object on the touch panel.

The driving lines and the sensing lines of the conventional touch panel are often formed by connecting the diamond electrode units in series. Such a diamond-shaped unit can easily perform basic finger sensing and positioning due to its structural symmetry. However, as today's touch applications are becoming more and more wide, not only single and two-finger touch gestures have developed more and more difficult to locate operations; when multi-finger touch, each finger signal interferes with each other and increases detection. Measuring the difficulty of the contact. This makes it necessary to accurately judge the touch track. In addition to having a good soft firmware algorithm, it also depends on the hardware design to provide a better signal-to-noise ratio.

In view of the above, the present invention provides an electrode structure of a capacitive touch panel, comprising a plurality of driving lines, a plurality of sensing lines, a plurality of star-shaped electrode units, a plurality of sensing electrode units, and a plurality of independent electrodes. The driving lines are spaced apart from each other and parallel to the first direction, the sensing lines are spaced apart from each other and parallel to the second direction, and the driving lines and the sensing lines are insulated from each other. The star electrode unit is serially connected to each of the driving lines, and each of the star electrode units includes six tapered protrusions, and each of the star electrodes is axisymmetric with the driving line as an axis of symmetry. The sensing electrode unit is serially connected to each sensing line, and each sensing electrode unit is surrounded by four star electrode units, each sense The electrode unit is axisymmetric with the sensing line as the axis of symmetry. The individual electrode is insulated between the star electrode unit and the sensing electrode unit.

The invention improves the electrode structure of the conventional capacitive touch panel by forming a plurality of star electrode units on the driving line, and each star electrode unit comprises six tapered protrusions, and the sensing electrodes complementary thereto are used The signal intensity of the unit when the finger is touched by the invention is significantly higher than the signal intensity of the conventional diamond electrode.

2 is a schematic view of a first embodiment of the present invention, and discloses an electrode structure 1 of a capacitive touch panel, comprising: a plurality of driving lines 10, a plurality of sensing lines 20, a plurality of star electrode units 11 and A plurality of sensing electrode units 21.

The driving lines 10 are spaced apart from each other and parallel to the first direction, the sensing lines 20 are spaced apart from each other and parallel to the second direction, and the sensing lines 20 and the driving lines 10 are insulated from each other. The star electrode unit 11 is serially connected to each of the driving lines 10, and each of the star electrode units 11 includes six first tapered protrusions 12, each of which is axially symmetric with the driving line 10 as an axis of symmetry. . The sensing electrode unit 21 is serially connected to each sensing line 20, each sensing electrode unit 21 is surrounded by four star electrode units 11, and each sensing electrode unit 21 has a sensing line 20 as an axis of symmetry. Axis symmetric. In addition, each of the sensing electrode units 21 includes an extension portion 214 in the forward direction and the reverse direction of the first direction.

In the electrode structure 1 of the capacitive touch panel, the star electrode unit 11 obviously has a longer circumference than the conventional rhombic electrode unit, and the shape of the sensing electrode unit 21 is complementary to the star electrode unit 11, and thus the sense The length of the edge of the line 20 adjacent to the driving line 10 is increased, which can significantly increase the capacitive coupling strength between the two, that is, to provide a stronger capacitive signal of nearby nodes. In addition, each of the first tapered protrusions 12 has two first edges 121, and the angle between the two first edges 121 is less than 90 degrees.

Please refer to FIG. 3 , which is a schematic view of a second embodiment of the present invention, illustrating an electrode structure 2 of a capacitive touch panel. The main difference between this embodiment and the first embodiment is that the driving line 10 includes a plurality of high-order star electrode units 11' which are connected in series with each other. The first tapered protrusions 12 of each of the high-order star-shaped electrode units 11' further include two second tapered protrusions 13 disposed at points in the two first edges 121. The angle between the first edges 121 of each of the first tapered protrusions 12 is 60 degrees. Each of the second tapered protrusions 13 has two second edges 131, and the angle between the second edges 131 is also 60 degrees.

In addition, in the electrode structure 2 of the capacitive touch panel, each of the high-order sensing electrode units 21' is complementary in shape to the high-order star electrode unit 11', except that the forward and reverse directions in the second direction respectively include a diamond-shaped extension. Outside the portion 211, each of the sensing electrode units 21' also includes three strip-shaped extensions 212 at two ends in the first direction. In this design, the edge of the high-order star electrode unit 11' adjacent to the high-order sensing electrode unit 21' is longer, providing a stronger capacitive signal.

Please refer to FIG. 4 , which is a schematic diagram of a third embodiment of the present invention, illustrating an electrode structure 3 of a capacitive touch panel. The sensing electrode unit 41 of the present embodiment does not have the protrusion in the first direction on the sensing electrode unit 21 of the first embodiment. This design helps to reduce the signal baseline when the multi-finger is simultaneously pressed against the same sensing line 20. The probability that the node touched by the finger is also pulled high, thereby reducing the probability of contact misjudgment. In addition, the present embodiment has an independent electrode 31 that is insulated between the star electrode unit 11 and the sensing electrode unit 41 and is not electrically connected to the star electrode unit 11 or the sensing electrode unit 41. The individual electrode 31 may employ the same or different conductive material as the star electrode unit 11 or the sensing electrode unit 41. In terms of optical effect, the individual electrodes 31 fill the vacancies other than the star electrode unit 11 or the sensing electrode unit 41, increase the uniformity of the surface of the substrate, keep the refractive index of the glass consistent, and reduce the visibility of the electrode pattern. Electrically, the individual electrodes 31 act to isolate adjacent sensing electrode units 41 to reduce the interaction between adjacent two parallel sensing electrode units 41.

In addition, in this embodiment, the longest length L1 of each sensing electrode unit 41 of the electrode structure 3 of the capacitive touch panel in the first direction is one third to thirty of the longest length L2 along the second direction. One of the points. However, the situation that the resistance is too large due to the narrowness of the sensing electrode unit should be avoided.

Referring to FIG. 5, a schematic diagram of a fourth embodiment of the present invention discloses an electrode structure 4 of a capacitive touch panel. Compared with the first embodiment, each of the star electrode units 51 of the present embodiment has no acute angle. Further, a rectangular protrusion 14 is placed at the apex of each of the first tapered protrusions 12 of the star electrode unit 51, that is, at the intersection of the first edges 121 of each of the first tapered protrusions 12, so that the star The outer periphery of the electrode unit 51 does not have an acute angle to avoid electron accumulation problems; the rectangular protrusion 14 widens the first tapered protrusion 12 in the axial direction in the second direction, so that the impedance of the drive line can be effectively reduced.

Please refer to FIG. 6 , which is a schematic diagram of a fifth embodiment of the present invention. The electrode structure 5 of the capacitive touch panel is disclosed. The star electrode unit 61 of the embodiment has not only an acute angle. In the present embodiment, the rectangular protrusions 14 are placed at the apexes of the first tapered protrusions 12 of the star electrode unit 61 on the axis of the drive line 10, and the four first tapered protrusions 12 in the non-axial direction are along the first direction. It is modified to be rounded so that the outer circumference of the star electrode unit 61 does not have an acute angle to avoid electron accumulation problem; the rectangular protrusion 14 widens the first first tapered protrusion 12 in the axial direction, thereby effectively reducing the driving line Impedance.

Please refer to FIG. 7 , which is a schematic diagram of a sixth embodiment of the present invention, illustrating an electrode structure 6 of a capacitive touch panel. The star electrode unit 71 of the present embodiment does not have an acute angle. In the present embodiment, the rectangular protrusions 14 are placed at the apexes of the first tapered protrusions 12 of the star electrode unit 71 on the axis of the drive line 10, and the four first tapered protrusions 12 in the non-axial direction are along the first direction. The part is cut off so that the outer circumference of the star electrode unit 71 does not have an acute angle to avoid the electron accumulation problem; the rectangular protrusion 14 widens the first first tapered protrusion 12 in the second direction, thereby effectively reducing the impedance of the driving line. . In addition, the embodiment has a separate electrode 31 ′, and the independent electrode 31 ′ is insulated between the star electrode unit 71 and the sensing electrode unit 21 , and does not form electrical properties with the star electrode unit 71 or the sensing electrode unit 21 . connection. The individual electrode 31' may employ the same or different conductive material as the star electrode unit 71 or the sensing electrode unit 21. In terms of optical effect, the individual electrodes 31' fill the vacancies other than the star electrode unit 71 or the sensing electrode unit 21, increase the uniformity of the surface of the substrate, keep the refractive index of the glass uniform, and reduce the visibility of the electrode pattern. Electrically, the individual electrodes 31' act to isolate adjacent sensing electrode units 21 to reduce the interaction between adjacent two parallel sensing electrode units 21.

Please refer to FIG. 8 , which is a schematic diagram of a seventh embodiment of the present invention, and discloses an electrode structure 7 of a capacitive touch panel. The main difference between this embodiment and the sixth embodiment is that the first tapered protrusion of each star electrode unit 81 along the axial direction of the driving line 10 is not provided with a rectangular protrusion at the vertex and the sensing electrode 41 does not have the extension in the first direction. unit. The four first tapered protrusions 12 of the star electrode unit 81 in the non-axial direction are cut off in the first direction as in the sixth embodiment, so that the apexes of the four first tapered protrusions 12 are not acute. Avoid electronic accumulation problems. The sensing electrode unit 41 of the present embodiment is like the third embodiment. When the multi-finger is simultaneously pressed against the same sensing line 20, the design helps to reduce the signal baseline from being pulled up at the node that is not touched by the finger. Probability, which in turn reduces the probability of contact misjudgment. In addition, the present embodiment further provides an independent electrode 31 ′′ in a region other than the star electrode unit 81 and the sensing electrode unit 41. The individual electrode 31 ′′ is insulated between the star electrode unit 81 and the sensing electrode unit 41, and The electrical connection is not made with the star electrode unit 81 or the sensing electrode unit 41. The individual electrode 31" may employ the same or different conductive material as the star electrode unit 81 or the sensing electrode unit 41. In terms of optical effect, the individual electrode 31" fills the vacancy outside the star electrode unit 81 or the sensing electrode unit 41. Increase the uniformity of the surface of the substrate and reduce the visibility of the electrode pattern. Electrically, the individual electrodes 31" act to isolate the adjacent sensing electrode units 41 to reduce the interaction between the adjacent two parallel sensing electrode units 41. In addition, the individual electrodes 31" of the same block are broken. The shape, that is, the independent electrode does not need to fill the vacancy in a monolithic form, but multiple small-area independent electrodes can be used to fill the same vacancy.

1~7. . . Electrode structure of capacitive touch panel

10. . . Drive line

11. . . Star electrode unit

11’. . . High-order star electrode unit

12. . . First tapered protrusion

121. . . First edge

13. . . Second tapered protrusion

131. . . Second edge

14. . . Rectangular protrusion

20. . . Sensing line

21, 21’. . . Sensing electrode unit

211. . . Diamond extension

212. . . Strip extension

214. . . Extension

31, 31', 31"... independent electrode

41. . . Sensing electrode unit

51. . . Star electrode unit

61. . . Star electrode unit

71. . . Star electrode unit

81. . . Star electrode unit

90. . . Drive line

91. . . Diamond electrode

92. . . Sensing line

Figure 1 is a schematic diagram of a prior art.

Figure 2 is a schematic view of a first embodiment of the present invention.

Figure 3 is a schematic view of a second embodiment of the present invention.

Figure 4 is a schematic view of a third embodiment of the present invention.

Figure 5 is a schematic view of a fourth embodiment of the present invention.

Figure 6 is a schematic view showing a fifth embodiment of the present invention.

Figure 7 is a schematic view of a sixth embodiment of the present invention.

Figure 8 is a schematic view of a seventh embodiment of the present invention.

3. . . Electrode structure of capacitive touch panel

10. . . Drive line

11. . . Star electrode unit

12. . . First tapered protrusion

121. . . First edge

20. . . Sensing line

41. . . Sensing electrode unit

31. . . Independent electrode

Claims (9)

An electrode structure of a capacitive touch panel, comprising: a plurality of driving lines spaced apart from each other and parallel to a first direction; a plurality of sensing lines spaced apart from each other and parallel to a second direction, the sensing lines and the driving The wires are insulated from each other; a plurality of star electrode units are serially connected to each of the driving lines, each of the star electrode units comprising six first tapered protrusions, each of the star electrode units having the driving line as an axis of symmetry And the plurality of sensing electrode units are serially connected to each of the sensing lines, and the sensing electrode units are individually surrounded by four of the star electrode units, and each of the sensing electrode units is The sensing line is axisymmetric with respect to the axis of symmetry. The electrode structure of the capacitive touch panel of claim 1, wherein each of the first tapered protrusions has two first edges, and the two first edges have an angle of less than 90 degrees. The electrode structure of the capacitive touch panel of claim 2, wherein an angle between the two first edges of each of the first tapered protrusions is 60 degrees, and each of the star electrode units further comprises The second second tapered protrusion is disposed at a point among the two first edges, and each of the second tapered protrusions has two second edges, and the two second edges have an angle of 60 degrees. The electrode structure of the capacitive touch panel of claim 3, wherein each of the sensing electrode units includes a dihedral extension in the first direction, and each of the two ends along the second direction Three strip extensions. The electrode structure of the capacitive touch panel according to claim 1, wherein the outer peripheral edge of each of the star electrode units does not have an acute angle. The electrode structure of the capacitive touch panel of claim 1, wherein each of the sensing electrode units includes an extension portion at each of the two ends of the first direction. The electrode structure of the capacitive touch panel of claim 1, wherein the longest length of each of the sensing electrode units along the first direction is a third of the longest length along the second direction. One to thirty-one. The electrode structure of the capacitive touch panel of claim 1, further comprising a plurality of independent electrodes, the insulation being disposed between the star electrode units and the sensing electrode units. The electrode structure of the capacitive touch panel according to claim 8, wherein the independent electrodes of the same block are shredded.