Patent Application
20170010701
1. Field of the Invention
The invention relates to a touch panel, and particularly relates to a layout structure of a capacitive touch panel.
2. Description of Related Art
Input devices of the information technology products have been changed from conventional keyboards and mice to touch panels so as to cope with the demands for convenience, miniaturization, and being user-friendly. At present, the touch panels can be generally classified into capacitive, resistive, optical, acoustic-wave and electromagnetic touch panels. Among these touch panels, the resistive touch panels and the capacitive touch panels are most common.
Taking capacitive touch panels as an example, the capacitive touch panel has a plurality of sensing electrodes, a plurality of signal lines, and a controller. When the user does not touch the touch panel, there is a capacitance initial value between the sensing electrodes. When the user touches the touch panel, the touched sensing electrode may generate a mutual capacitance, thereby changing the original capacitance initial value. At this time, the controller may determine the user's touch position by identifying the position of the electrode whose capacitance value is changed.
When the user holds the information technology product, a touch object (e.g., the user's finger) and the information technology product are connected to the same reference voltage (e.g., ground voltage). Thus, when the user holds the information technology product, the controller may easily identify the user's touch position. When the user does not hold the information technology product, the information technology product is likely in a floating-connecting state (i.e., low ground mode). Thus, the reference voltage of the information technology product may be different from the voltage of the touch object (e.g., the user's finger or a touch pen). Thus, when the user does not hold the information technology product, the controller may not easily identify the user's touch position.
The invention provides a touch panel capable of improving a touch sensitivity in a non-handheld environment.
According to an embodiment of the invention, the touch panel includes a lower film layer, an upper film layer, a protective layer, and a plurality of sensing units. The upper film layer is disposed on the lower film layer. The protective layer is disposed on the upper film layer. One of the sensing units includes a first sensing electrode, a second sensing electrode, and a charge-locked electrode. The first sensing electrode is disposed in the lower film layer. The second sensing electrode is disposed in the upper film layer, and at least partially overlaps the first sensing electrode. The charge-locked electrode is disposed in the upper film layer, and at least partially overlaps the second sensing electrode. The first sensing electrode, the second sensing electrode, and the charge-locked electrode do not contact each other. The charge-locked electrode 136 is coupled to or floating-connect to a constant voltage.
Based on above, in the touch panel according to the embodiments of the invention, the charge-locked electrode (an electrode floating-connected or coupled to a constant voltage) is additionally disposed between the first sensing electrode and the touch object, so as to absorb the capacitance of the first sensing electrode through the touch object. Accordingly, the touch sensitivity of the touch panel according to the embodiments may be improved in the non-handheld environment.
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.
Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
Throughout the specification (including claims), the term “coupling” may refer to any direct or indirect connection means. For example, if it is described that a first device is coupled to a second device, it shall be appreciated that the first device may be directly connected to the second device, or the first device may be indirectly connected to the second device through another device or a certain connection means. Moreover, wherever possible, elements/components/steps with same reference numerals represent same or similar parts in the drawings and embodiments. Elements/components/steps referred to by the same terms or reference numerals in different embodiment may be referred to each other for relevant description.
Any one of the sensing units 130 includes a first sensing electrode 132, a second sensing electrode 134, and a charge-locked electrode 136. Materials of the first sensing electrode 132, the second sensing electrode 134, and the charge-locked electrode 136 may be any conductive material, such as a transparent conductive material like indium tin oxide (ITO), or a non-transparent material like metal. The first sensing electrode 132 is disposed in the lower film layer F2. The second sensing electrode 134 is disposed in the upper film layer F1, and at least partially overlaps the first sensing electrode 132. The charge-locked electrode 136 is disposed in the upper film layer F1, and at least partially overlaps the second sensing electrode 132. The first sensing electrode 132, the second sensing electrode 134, and the charge-locked electrode 136 do not contact each other.
The first sensing electrode 132 and the second sensing electrode 134 are arranged in a staggered manner and insulated from each other. The first sensing electrode 132 and the charge-locked electrode 136 are arranged in a staggered manner and insulated from each other. In this embodiment, a width L132 of the first sensing electrode 132 may be 4.5 mm, and a width W134 of the second sensing electrode 134 and/or the charge-locked electrode 136 may be 1 mm. A position where the first sensing electrode 132 and the second sensing electrode 134 overlap has an overlapped area AB. Specifically, the overlapped area AB=L132*W134=4.5 mm2. The first sensing electrode 132 and the second sensing electrode 134 form a parallel-plate capacitor in the overlapped area AB. According to a formula of parallel-plate capacitor, a capacitance C=∈*A/d, wherein s represents a dielectric constant of a dielectric layer between the parallel plates (the first sensing electrode 132 and the second sensing electrode 134 in this embodiment), A represents the overlapped area AB of the first sensing electrode 132 and the second sensing electrode 134, and d represents a distance between the first sensing electrode 132 and the second sensing electrode 134. When the user does not touch the touch panel 100, the parallel-plate capacitor has a first capacitance initial value. The sensing unit 130 has a greater first capacitance initial value when the overlapped area AB is larger.
The charge-locked electrode 136 is configured to be coupled to or floating-connect to a constant voltage. For example (however, the invention is not limited thereto), in some embodiments, the charge-locked electrode 136 may be constantly connected to a ground voltage. In some other embodiments, the charge-locked electrode 136 may be connected to any reference voltage having a constant level. In other embodiments, the charge-locked electrode 136 may be floating-connected. Namely, the charge-locked electrode 136 is not connected to any conductive material or electrical component. Thus, the charge-locked electrode 136 may not serve as a driving electrode or a receiving electrode.
The first sensing electrode 132 and the second sensing electrode 134 are respectively electrically connected to a controller (not shown) through different signal lines. Based on different design requirements, in some embodiments, the first sensing electrode 132 may be a driving electrode (also referred to as Tx electrode), while the second sensing electrode 134 may be a receiving electrode (also referred to as Rx electrode). In some other embodiments, the first sensing electrode 132 may be a receiving electrode, and the second sensing electrode 134 may be a driving electrode. When a touch object (e.g., the user's finger or a touch pen) touches the sensing array 220 to make a touched position (e.g., the position of the sensing unit 130 as indicated in
Exemplary data are provided in the following to demonstrate characteristics of the touch panel 100 shown in
Table 2 illustrates capacitance values of the sensing unit 130 when the touch object 200 touches the touch panel 100. When a diameter of the touch object 200 is 22 mm (22 phi), and the user holds the information technology product having the touch panel 100, a mutual capacitance variance ΔC of the sensing unit 130 having the charge-locked electrode 136 is 0.059 pF, and the mutual capacitance variance ΔC of the sensing unit without the charge-locked electrode 136 is 0.045 pF. When the diameter of the touch object is 22 mm (22 phi), and the user does not hold the information technology product having the touch panel 100, the mutual capacitance variance ΔC of the sensing unit 130 having the charge-locked electrode 136 is −0.08 pF, and the mutual capacitance variance ΔC of the sensing unit without the charge-locked electrode 136 is −0.19 pF. When the diameter of the touch object 200 is 7 mm (7 phi), and the user holds the information technology product having the touch panel 100, the mutual capacitance variance ΔC of the sensing unit 130 having the charge-locked electrode 136 is 0.02 pF, and the mutual capacitance variance ΔC of the sensing unit without the charge-locked electrode 136 is 0.007 pF. When the diameter of the touch object is 7 mm (7 phi), and the user does not hold the information technology product having the touch panel 100, the mutual capacitance variance ΔC of the sensing unit 130 having the charge-locked electrode 136 is −0.019 pF, and the mutual capacitance variance ΔC of the sensing unit without the charge-locked electrode 136 is −0.052 pF.
Table 3 illustrates mutual capacitance characteristic values of different sensing units 130 of the touch panel 100 when the touch object 200 of 22 phi (diameter thereof is 22 mm) touches the center of the touch panel 100 having the charge-locked electrode 136. Table 4 illustrates mutual capacitance characteristic values of different sensing units when the touch object 200 of 22 phi (diameter thereof is 22 mm) touches the center of the touch panel 100 without the charge-locked electrode 136. Here, Rx1, Rx2, Rx3, Rx4, Rx5, Rx6, Rx7, Rx8, Rx9, and Rx10 represent different second sensing electrodes 134, while Tx1, Tx2, Tx3, Tx4, Tx5, Tx6, Tx7, Tx8, Tx9, and Tx10 represent different first sensing electrodes 132. Based on Tables 3 and 4, it can be seen that the mutual capacitance characteristic values (e.g., the mutual capacitance characteristic values −50, −40, −42, and -38 at the position of the touch object 200) of the touch panel 100 having the charge-locked electrode 136 are greater than the mutual capacitance characteristic values (e.g., the mutual capacitance characteristic values −79, −110, −83, and -110) of the touch panel 100 without the charge-locked electrode 136. It can thus be known that the charge-locked electrode 136 may improve the mutual capacitance variance. Accordingly, the touch sensitivity of the touch panel 100 having the charge-locked electrode 136 in the non-handheld environment may be improved.
Table 5 illustrates mutual capacitance characteristic values of different sensing units 130 of the touch panel 100 when the touch object 200 of 7 phi (diameter thereof is 7 mm) touches the touch panel 100 having the charge-locked electrode 136. Table 6 illustrates mutual capacitance characteristic values of different sensing units when the touch object 200 of 7 phi (diameter thereof is 7 mm) touches the touch panel 100 without the charge-locked electrode 136. Based on Tables 5 and 6, it can be seen that the mutual capacitance characteristic values (e.g., the mutual capacitance characteristic values −17, −11, −9 and -2 at the position of the touch object 200) of the touch panel 100 having the charge-locked electrode 136 are greater than the mutual capacitance characteristic values (e.g., the mutual capacitance characteristic values −11, −39, −14 and −40) of the touch panel 100 without the charge-locked electrode 136. It can thus be known that the charge-locked electrode 136 may improve the mutual capacitance variance. Accordingly, the touch sensitivity of the touch panel 100 having the charge-locked electrode 136 in the non-handheld environment may be improved, and a coaxial effect may be reduced.
The first sensing electrode 432 and the second sensing electrode 434 are arranged in a staggered manner and insulated from each other. The first sensing electrode 432 and the charge-locked electrode 436 are arranged in a staggered manner and insulated from each other. Here, to make the description clear and avoid overlapping of lines, only half of components disposed in symmetry in
The second sensing electrode 434 includes two sensing pads 434a arranged in parallel and a second connection portion 434b. In addition, shapes of the second sensing pads 434a and the second connection portion 434b are rectangular. As shown in
Specifically, the second connection portion 434b and the first connection portion 432b of this embodiment intersect (overlap) each other, and a position where the second connection portion 434b and the first connection portion 432b overlap has an overlapped area AC. In this embodiment, the first connection portion 432b and the second connection portion 434b perpendicularly intersect each other, while the first sensing pads 432a and the second sensing pads 434a do not overlap each other. In addition, there are a plurality of first gaps G1 between the first sensing pads 432a and the second sensing pads 434a, and there are a plurality of second gaps G2 between the first sensing pads 432a and the second connection portion 434b. In this embodiment, a width of the first gap is in a range from 0.1 mm to 0.3 mm. However, the invention is not limited thereto.
In addition, the touch panel 400 of this embodiment further includes a plurality of signal lines 440 and a controller 450. The first sensing electrode 432 and the second sensing electrode 434 are respectively electrically connected to the controller 450 through different signal lines 440. It should be noted that a relative electrical connection relation between each of the signal lines 440 and the first sensing electrode 432 and the second sensing electrode 434 is illustrated in
The charge-locked electrode 436 is configured to be coupled to or floating-connect to a constant voltage. For example (however, the invention is not limited thereto), in some embodiments, the charge-locked electrode 436 may be constantly connected to a ground voltage. In some other embodiments, the charge-locked electrode 436 may be connected to any reference voltage having a constant level. In other embodiments, the charge-locked electrode 436 may be floating-connected. Namely, the charge-locked electrode 436 is not connected to any conductive material or electrical component. Thus, the charge-locked electrode 436 may not serve as a driving electrode or a receiving electrode.
Referring to
Exemplary data are provided in the following to demonstrate characteristics of the touch panel 400 shown in
Table 8 illustrates capacitance values of the sensing unit 430 when the touch object 200 touches the touch panel 400. When a diameter of the touch object 200 is 22 mm (22 phi), and the user holds the information technology product having the touch panel 400, a mutual capacitance variance ΔC of the sensing unit 430 having the charge-locked electrode 436 is 0.17 pF, and the mutual capacitance variance ΔC of the sensing unit without the charge-locked electrode 436 is 0.19 pF. When the diameter of the touch object is 22 mm (22 phi), and the user does not hold the information technology product having the touch panel 400, the mutual capacitance variance ΔC of the sensing unit 430 having the charge-locked electrode 436 is −0.02 pF, and the mutual capacitance variance ΔC of the sensing unit without the charge-locked electrode 436 is −0.1 pF. When the diameter of the touch object 200 is 7 mm (7 phi), and the user holds the information technology product having the touch panel 400, the mutual capacitance variance ΔC of the sensing unit 430 having the charge-locked electrode 436 is 0.1 pF, and the mutual capacitance variance ΔC of the sensing unit without the charge-locked electrode 436 is 0.14 pF. When the diameter of the touch object is 7 mm (7 phi), and the user does not hold the information technology product having the touch panel 400, the mutual capacitance variance ΔC of the sensing unit 430 having the charge-locked electrode 436 is 0.06 pF, and the mutual capacitance variance ΔC of the sensing unit without the charge-locked electrode 436 is 0.07 pF.
Table 9 illustrates mutual capacitance characteristic values of different sensing units 430 of the touch panel 400 when the touch object 200 of 22 phi (diameter thereof is 22 mm) touches the center of the touch panel 400 having the charge-locked electrode 436. Table 10 illustrates mutual capacitance characteristic values of different sensing units when the touch object 200 of 22 phi (diameter thereof is 22 mm) touches the center of the touch panel 400 without the charge-locked electrode 436. Here, Rx1, Rx2, Rx3, Rx4, Rx5, Rx6, Rx7, Rx8, Rx9, and Rx10 represent different second sensing electrodes 434, while Tx1, Tx2, Tx3, Tx4, Tx5, Tx6, Tx7, Tx8, Tx9, and Tx10 represent different first sensing electrodes 432. Based on Tables 9 and 10, it can be seen that the mutual capacitance characteristic values (e.g., the mutual capacitance characteristic values −11, 1, −12, and -3 at the position of the touch object 200) of the touch panel 400 having the charge-locked electrode 436 are greater than the mutual capacitance characteristic values (e.g., the mutual capacitance characteristic values −38, −53, −39, and -16) of the touch panel 400 without the charge-locked electrode 436. It can thus be known that the charge-locked electrode 436 may improve the mutual capacitance variance. Accordingly, the touch sensitivity of the touch panel 400 having the charge-locked electrode 436 in the non-handheld environment may be improved.
Table 11 illustrates mutual capacitance characteristic values of different sensing units 430 of the touch panel 400 when the touch object 200 of 7 phi (diameter thereof is 7 mm) touches the touch panel 400 having the charge-locked electrode 436. Table 12 illustrates mutual capacitance characteristic values of different sensing units when the touch object 200 of 7 phi (diameter thereof is 7 mm) touches the touch panel 400 without the charge-locked electrode 436. Based on Tables 11 and 12, it can be seen that the mutual capacitance characteristic values (e.g., the mutual capacitance characteristic values 41, 57, 31, and 51 at the position of the touch object 200) of the touch panel 400 having the charge-locked electrode 436 are greater than the mutual capacitance characteristic values (e.g., the mutual capacitance characteristic values 43, 33, 40, and 36) of the touch panel 400 without the charge-locked electrode 436. It can thus be known that the charge-locked electrode 436 may improve the mutual capacitance variance. Accordingly, the touch sensitivity of the touch panel 400 having the charge-locked electrode 436 in the non-handheld environment may be improved, and a coaxial effect may be reduced.
The first sensing electrode 532 and the second sensing electrode 534 are arranged in a staggered manner and insulated from each other. The first sensing electrode 532 and the charge-locked electrode 536 are arranged in a staggered manner and insulated from each other. In an identical sensing unit 530, the first sensing electrode 532 includes a first sensing pad 532a, a second sensing pad 532c, a third sensing pad 532e, a first connection portion 532b, and a second connection portion 532d. Shapes of the first sensing pad 532a, the second sensing pad 532c, the third sensing pad 532e, the first connection portion 532b, and the second connection portion 532d are rectangular. As shown in
The second sensing electrode 534 includes a fourth sensing pad 534b, a fifth sensing pad 534c, a third connection portion 534a, and a fourth connection portion 534d. Shapes of the fourth sensing pad 534b, the fifth sensing pad 534c, the third connection portion 534a, and the fourth connection portion 534d are rectangular. Two short sides of the third connection portion 534a are respectively electrically connected to a long side of the fourth sensing pad 534b and a long side of the fifth sensing pad 534c, and two short sides of the fourth connection portion 534d are respectively electrically connected to the long side of the fourth sensing pad 534b and the long side of the fifth sensing pad 534c. The third connection portion 534a and the first connection portion 532b may intersect each other, and the fourth connection portion 534b and the second connection portion 532d intersect each other.
As shown in
In addition, the touch panel 500 of this embodiment further includes a plurality of signal lines 540 and a controller 550. The first sensing electrode 532 and the second sensing electrode 534 are respectively electrically connected to the controller 550 through different signal lines 540. It should be noted that a relative electrical connection relation between each of the signal lines 540 and the first sensing electrode 532 and the second sensing electrode 534 is illustrated in
The charge-locked electrode 536 is configured to be coupled to or floating-connect to a constant voltage. For example (however, the invention is not limited thereto), in some embodiments, the charge-locked electrode 536 may be constantly connected to a ground voltage. In some other embodiments, the charge-locked electrode 536 may be connected to any reference voltage having a constant level. In other embodiments, the charge-locked electrode 536 may be floating-connected. Namely, the charge-locked electrode 536 is not connected to any conductive material or electrical component. Thus, the charge-locked electrode 536 may not serve as a driving electrode or a receiving electrode.
Referring to
Exemplary data are provided in the following to demonstrate characteristics of the touch panel 500 shown in
Table 14 illustrates capacitance values of the sensing unit 530 when the touch object 200 touches the touch panel 500. When the diameter of the touch object 200 is 22 mm (22 phi), and the user holds the information technology product having the touch panel 500, the mutual capacitance variance ΔC of the sensing unit 530 having the charge-locked electrode 536 is 0.24 pF, and the mutual capacitance variance ΔC of the sensing unit without the charge-locked electrode 536 is 0.29 pF. When the diameter of the touch object is 22 mm (22 phi), and the user does not hold the information technology product having the touch panel 500, the mutual capacitance variance ΔC of the sensing unit 530 having the charge-locked electrode 536 is −0.02 pF, and the mutual capacitance variance ΔC of the sensing unit without the charge-locked electrode 536 is −0.03 pF. When the diameter of the touch object 200 is 7 mm (7 phi), and the user holds the information technology product having the touch panel 500, the mutual capacitance variance ΔC of the sensing unit 530 having the charge-locked electrode 536 is 0.15 pF, and the mutual capacitance variance ΔC of the sensing unit without the charge-locked electrode 536 is 0.12 pF. When the diameter of the touch object is 7 mm (7 phi), and the user does not hold the information technology product having the touch panel 500, the mutual capacitance variance ΔC of the sensing unit 530 having the charge-locked electrode 536 is 0.09 pF, and the mutual capacitance variance ΔC of the sensing unit without the charge-locked electrode 536 is 0.05 pF.
Table 15 illustrates mutual capacitance characteristic values of different sensing units 530 of the touch panel 500 when the touch object 200 of 22 phi (diameter thereof is 22 mm) touches the center of the touch panel 500 having the charge-locked electrode 536. Table 16 illustrates mutual capacitance characteristic values of different sensing units when the touch object 200 of 22 phi (diameter thereof is 22 mm) touches the center of the touch panel 500 without the charge-locked electrode 536. Here, Rx1, Rx2, Rx3, Rx4, Rx5, Rx6, Rx7, Rx8, Rx9, and Rx10 represent different second sensing electrodes 534, while Tx1, Tx2, Tx3, Tx4, Tx5, Tx6, Tx7, Tx8, Tx9, and Tx10 represent different first sensing electrodes 532. Based on Tables 15 and 16, it can be seen that the mutual capacitance characteristic values (e.g., the mutual capacitance characteristic values −7, −5, −13, and -10 at the position of the touch object 200) of the touch panel 500 having the charge-locked electrode 536 are greater than the mutual capacitance characteristic values (e.g., the mutual capacitance characteristic values −14, −13, −8, and -15) of the touch panel 500 without the charge-locked electrode 536. It can thus be known that the charge-locked electrode 536 may improve the mutual capacitance variance. Accordingly, the touch sensitivity of the touch panel 500 having the charge-locked electrode 536 in the non-handheld environment may be improved.
Table 17 illustrates mutual capacitance characteristic values of different sensing units 530 of the touch panel 500 when the touch object 200 of 7 phi (diameter thereof is 7 mm) touches the touch panel 500 having the charge-locked electrode 536. Table 18 illustrates mutual capacitance characteristic values of different sensing units when the touch object 200 of 7 phi (diameter thereof is 7 mm) touches the touch panel 500 without the charge-locked electrode 536. Based on Tables 17 and 18, it can be seen that the mutual capacitance characteristic values (e.g., the mutual capacitance characteristic values 48, 50, 43, and 45 at the position of the touch object 200) of the touch panel 500 having the charge-locked electrode 536 are greater than the mutual capacitance characteristic values (e.g., the mutual capacitance characteristic values 41, 37, 37, and 25) of the touch panel 500 without the charge-locked electrode 536. It can thus be known that the charge-locked electrode 536 may improve the mutual capacitance variance. Accordingly, the touch sensitivity of the touch panel 500 having the charge-locked electrode 536 in the non-handheld environment may be improved, and a coaxial effect may be reduced.
In view of foregoing, in the touch panel (touch panel 100, 400, or 500) according to the embodiments of the invention, the charge-locked electrode (charge-locked electrode 136, 436, or 536) is additionally disposed between the first sensing electrode (first sensing electrode 132, 432, or 532) and the touch object to absorb the capacitance of the first sensing electrode through the touch object. Accordingly, the touch sensitivity of the touch panel according to the embodiments may be improved in the non-handheld environment.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.
