CN104182102A - Mutual Capacitive Touch Sensing Device - Google Patents

Abstract

The invention provides a mutual capacitance type touch control induction device which comprises an induction electrode, a first driving electrode and a second driving electrode. The induction electrode is provided with an electrode trunk, a plurality of first electrode fingers and a plurality of second electrode fingers. The electrode trunk is in a strip shape in plane shape, and the long side of the electrode trunk is parallel to the first direction. The first electrode fingers extend from the electrode trunk toward a second direction perpendicular to the first direction. The second electrode fingers respectively extend from the electrode trunk in a direction opposite to the second direction. The first driving electrode includes a first body. The first main body is provided with a plurality of first concave parts which correspond to the plurality of first electrode fingers and are arranged in a staggered mode. The second drive electrode includes a second body. The second body is provided with a plurality of second concave parts which correspond to the second electrode fingers and are arranged in a staggered mode.

Description

Mutual Capacitive Touch Sensing Device

technical field

The present invention is related to the touch system, especially related to the electrode pattern design in the touch system.

Background technique

With the advancement of technology, the operation interfaces of various electronic products have become more and more user-friendly in recent years. For example, through a touch screen, users can directly operate programs and input messages/texts/patterns on the screen with fingers or a stylus, saving the trouble of using input devices such as keyboards or keys. In fact, the touch screen usually consists of a sensing panel and a display disposed behind the sensing panel. The electronic device judges the meaning of the touch according to the position touched by the user on the sensing panel and the picture displayed on the display at that time, and executes the corresponding operation result.

Existing capacitive touch technologies can be classified into two types: self-capacitance and mutual-capacitance. FIG. 1 is an electrode configuration diagram of a mutual capacitive touch panel adopting a single-layer electrode structure. The sensing electrodes S11-S1N correspond to the driving electrode D1, the sensing electrodes S21-S2N correspond to the driving electrode D2, the sensing electrodes S31-S3N correspond to the driving electrode D3, and the sensing electrodes S41-S4N correspond to the driving electrode D4. Taking the driving electrode D1 and its corresponding sensing electrode S11 as an example, when the driving electrode D1 carries a driving signal, the driving electrode D1 and the sensing electrode S11 have different potentials, so there are a certain number of electric lines between them. If the user's finger approaches the unit sensing area formed by the driving electrode D1 and the sensing electrode S11, the electric force line between the driving electrode D1 and the sensing electrode S11 will be attracted by the finger, resulting in a decrease in the mutual capacitance between the driving electrode D1 and the sensing electrode S11. The output signal of a receiver (not shown) connected to the sensing electrode S11 will reflect the mutual capacitance variation. According to the mutual capacity provided by the receiver connected to each sensing electrode and the timing of sending the driving signal, the subsequent circuit can determine the coordinates of the touch point.

The electrode configuration presented in Figure 1 has two disadvantages. First, the path lengths of the sensing electrodes to the corresponding receivers are different. For example, the length of the wire connecting the sensing electrode S11 is much shorter than the length of the wire connecting the sensing electrode S1N. Ideally, the impedance values formed by the sensing electrodes to the receiver should be equal, so as not to cause too much variation in the signal input to the receiver. Furthermore, the driving electrodes D1 , D2 , D3 , and D4 carry driving signals at different times and are staggered from each other, and these sensing electrodes are continuously in a state of receiving signals. Ideally, when the driving electrode D2 carries the driving signal, the sensing electrodes that may have mutual capacitance variation should be limited to the sensing electrodes S21 - S2N. However, as shown in FIG. 1, since the wire connecting the sensing electrode S1N is quite close to the driving electrode D2, the driving signal carried by the driving electrode D2 is likely to be coupled to the sensing electrode S1N, which may cause some mutual tolerance of the sensing electrode S1N. amount of change. This situation will cause subsequent circuits to misjudge the coordinates of the touch point.

FIG. 2 is another electrode configuration diagram of a mutual capacitive touch panel adopting a single-layer electrode structure. As shown in FIG. 2, the sensing electrodes S11-S1N and S21-S2N are collectively arranged between the driving electrodes D1 and D2, while the sensing electrodes S31-S3N and S41-S4N are collectively arranged between the driving electrodes D3 and D4. The advantage of this electrode configuration is that the distance between the driving electrode D2 and the sensing electrodes S11 - S1N is relatively long, so its driving signal will not be coupled to the sensing electrodes S11 - S1N. On the other hand, since the driving electrode D3 can provide shielding for the sensing electrodes S31 - S3N, the sensing electrodes S31 - S3N will not be affected by the driving signal carried by the driving electrode D2. However, the electrode configuration presented in Figure 2 suffers from poor linearity. More specifically, the distances between the driving electrodes are not the same, and the distribution of the unit sensing area formed by the driving electrodes and the sensing electrodes is also uneven. In addition, the electrode configuration shown in FIG. 2 also has the problem that the impedance value formed by each sensing electrode to the receiver varies too much.

Contents of the invention

In order to solve the above problems, the present invention proposes a new electrode pattern suitable for a mutual capacitive touch sensing device. By adopting an electrode configuration method different from that of the prior art, the mutual capacitive touch sensing device according to the present invention can avoid the problems caused by the impedance mismatch of the sensing electrodes and the problem of poor linearity. In addition, by adding a shielding portion to each driving electrode, the mutual capacitive touch sensing device according to the present invention can reduce the probability of misjudgment of the coordinates of the touch point by the subsequent circuit.

A specific embodiment according to the present invention is a mutual capacitive touch sensing device, which includes a sensing electrode, a first driving electrode and a second driving electrode. The sensing electrode has an electrode trunk, a plurality of first electrode fingers and a plurality of second electrode fingers. The planar shape of the electrode trunk is roughly a strip shape, and its long side is roughly parallel to a first direction. The planar shape of each of the plurality of first electrode fingers is approximately a rectangle and extends from the electrode trunk toward a second direction. Each of the plurality of second electrode fingers has a planar shape approximately a rectangle and extends from the electrode trunk opposite to the second direction. The first direction is substantially perpendicular to the second direction. The first driving electrode includes a first body. The first body has a plurality of first recesses corresponding to the plurality of first electrode fingers and arranged alternately, forming a first sensing area with the plurality of first electrode fingers. The second driving electrode includes a second body. The second body has a plurality of second recesses corresponding to the plurality of second electrode fingers and arranged alternately, forming a second sensing area with the plurality of second electrode fingers.

Another specific embodiment of the present invention is a mutual capacitive touch sensing device, which includes a sensing electrode, a first driving electrode and a second driving electrode. The sensing electrode includes a first sensing region and a second sensing region. The first driving electrode includes a first body corresponding to the first sensing area and forming a first sensing area. The second driving electrode includes a second body corresponding to the second sensing area and forming a second sensing area. The first sensing area and the second sensing area are adjacent to each other and have an adjacent land. The first driving electrode further includes a shielding portion extending from the first body toward the adjacent land.

The advantages and spirit of the present invention can be further understood through the following detailed description of the invention and the accompanying drawings.

Description of drawings

FIG. 1 is an electrode configuration diagram of a mutual capacitive touch panel using a single-layer electrode structure in the prior art.

FIG. 2 is another electrode configuration diagram of a mutual capacitive touch panel using a single-layer electrode structure in the prior art.

FIG. 3A is a partial electrode configuration diagram of a single-layer mutual capacitive touch system according to a specific embodiment of the present invention.

FIG. 3B redraws the sensing electrodes and several driving electrodes in FIG. 3A to illustrate the definition of the unit sensing area.

The electrode pattern shown in FIG. 3C is the result of repeatedly arranging a plurality of electrode combinations as shown in FIG. 3A .

FIG. 3D shows an example in which the driving electrode further includes a shielding portion.

FIG. 3E shows an example of each driving electrode plus connecting wires in the electrode combination shown in FIG. 3D .

FIG. 3F shows another example of adding connecting wires to each driving electrode in the electrode combination shown in FIG. 3D .

FIG. 4A and FIG. 4B are used to present electrode patterns before and after adding shielding parts in an embodiment of the present invention.

Symbol Description

S11～S4N, S1～S4: Sensing electrodes

S1A: Electrode trunk

S1B: electrode fingers

D1～D6: Drive electrodes

U1～U3: Sensing area

D1A, D2A: shielding part

R: curved part

B: Adjacent zone

Detailed ways

A specific embodiment according to the present invention is a single-layer mutual capacitive touch system, and its partial electrode configuration is shown in FIG. 3A . The electrodes labeled S1 are sensing electrodes, and the electrodes labeled D1-D6 are independent driving electrodes. As shown in FIG. 3A , the planar shape of the trunk S1A of the sensing electrode S1 is roughly a long strip and its long side is roughly parallel to the Y direction. The sensing electrode S1 also includes a plurality of electrode fingers, such as the electrode finger S1B. These substantially rectangular electrode fingers respectively extend from the electrode trunk S1A toward the X direction or opposite to the X direction. As shown in FIG. 3A , the main bodies of the driving electrodes D1 - D6 each have a plurality of recesses corresponding to and interlaced with the plurality of electrode fingers of the sensing electrode S1 .

Theoretically, the electric force lines that will be affected by the user's touch are mainly distributed near the gap between the driving electrodes and the sensing electrodes. Taking the sensing electrode S1 and the driving electrodes D1, D2, and D3 redrawn in FIG. 3B as an example, the concave part of the driving electrode D1 and the corresponding electrode fingers in the sensing electrode S1 constitute a sensing area U1 shown in a dotted line frame, and the driving electrodes The concave portion of D2 and the corresponding electrode fingers in the sensing electrode S1 constitute another sensing area U2 , and the concave portion of the driving electrode D3 and the corresponding electrode fingers in the sensing electrode S1 constitute another sensing area U3 . By analogy, each driving electrode adjacent to the sensing electrode S1 in FIG. 3A corresponds to a unit sensing area.

It can be seen from FIG. 3A that the driving electrodes on the left side and the right side of the sensing electrode S1 are not symmetrically arranged in the Y direction. Taking the driving electrodes D1, D2, and D5 as examples, a part of the electrode fingers corresponding to the driving electrode D5 and a part of the electrode fingers corresponding to the driving electrode D1 have the same position in the X direction, while the other part of the electrode fingers corresponding to the driving electrode D5 A part of the electrode fingers is at the same position as a part of the electrode fingers corresponding to the driving electrode D2 in the X direction. Compared with the left-right symmetrical arrangement, the advantage of this approach is that it can improve the resolution of the sensing results.

The electrode pattern shown in FIG. 3C is a plurality of electrode combinations shown in FIG. 3A repeatedly arranged in the X direction. In order to keep the drawing clear, only the sensing electrodes S1 - S4 as the center of each electrode combination are marked in FIG. 3C . Comparing FIG. 3C with FIG. 1 and FIG. 2, it can be seen that, unlike the practice of using multiple sensing electrodes to cooperate with one driving electrode in the prior art (for example, as shown in FIG. 1, sensing electrodes S11-S1N cooperate with driving electrode D1), this implementation For example, a plurality of driving electrodes cooperate with one sensing electrode, and the driving electrodes are arranged on both sides of the sensing electrode. The advantage of this approach is that, since the total lengths of the sensing electrodes under this configuration are almost identical, the problem caused by the impedance mismatch of the sensing electrodes in the prior art can be solved. In addition, compared with the electrodes with straight edges in the prior art, the plurality of electrode fingers of the sensing electrodes and the corresponding recesses of the driving electrodes in this embodiment can increase the number of electric force lines that will be affected by the user's touch, thereby improving the interaction. The amount of capacitance change is to increase the signal-to-noise ratio of the sensing signal. Moreover, as shown in FIG. 3C , the distances between the sensing electrodes are quite even. As long as the widths of the driving electrodes and the sensing electrodes are properly designed, the problem of poor linearity in the prior art shown in FIG. 2 does not exist.

In another embodiment, as shown in FIG. 3D , in addition to the main body, each driving electrode further includes at least one shielding portion (separated from the main body by a dotted line) extending from the main body in the Y direction. The shield portion D1A of the drive electrode D1 and the shield portion D2A of the drive electrode D2 will be described. As shown in FIG. 3B , the sensing area U1 and the sensing area U2 are adjacent to each other and have an adjacent land. The shielding portion D1A of the driving electrode D1 extends from its electrode body toward the adjacent land. Correspondingly, the shielding portion D2A of the driving electrode D2 also extends from the electrode body toward the adjacent land. When the driving electrode D1 carries a driving signal, the shielding portion D2A can provide shielding for the sensing electrode S1 in the sensing area U2, preventing the sensing electrode S1 in the sensing area U2 from contributing to the mutual capacitance variation. Similarly, when the driving electrode D2 carries a driving signal, the shielding part D1A can provide shielding for the sensing electrode S1 in the sensing area U1 to prevent the sensing electrode S1 in the sensing area U1 from contributing to the mutual capacitance variation. In this way, the possibility of misjudging the coordinates of the touch point by the subsequent circuit can be reduced.

FIG. 3E shows an example of each driving electrode plus connecting wires in the electrode combination shown in FIG. 3D . It is worth noting that in FIG. 3E , the widths of the main bodies of the driving electrodes D3 and D6 in the X direction are slightly reduced. This approach is applicable to the case where the driving electrodes D3 and D6 are adjacent to the edge area of the entire touch panel. In FIG. 3(E), the edge area is located not far below the drawing. By appropriately reducing the width of certain electrodes, the widths and line spacings of the connecting wires of all the driving electrodes in the vicinity of the edge regions are approximately equal. It can also be clarified that, in the embodiment according to the present invention, the widths of the driving electrodes that cooperate with the same sensing electrode do not have to be equal. It can also be seen from FIG. 3E that the main body of the driving electrode D2 can shield the wires of the driving electrode D1 from possibly affecting the sensing area U2 . The designer of the electrode pattern can determine the width of the driving electrodes in the X direction according to the shielding effect required in practice.

FIG. 3F shows another example of adding connecting wires to each driving electrode in the electrode combination shown in FIG. 3D . In this embodiment, the sensing electrode S1 which is generally elongated is slightly curved within the range R indicated by the dotted line. In addition, as shown in FIG. 3F , the width of the upper half of the driving electrode D6 is greater than the width of the lower half thereof. The goal of these adjustments is to make the widths and pitches of the connecting wires of all the driving electrodes approximately equal in the adjacent edge regions. It should be noted that the line widths, line distances, and length-to-width ratios of the electrodes in the above illustrations are for illustration only, and the scope of the present invention is not limited thereto.

Those with ordinary knowledge in the technical field of the present invention can understand that the concept of adding a shielding portion to provide shielding for adjacent sensing areas proposed by the present invention can also be applied to other mutual capacitance types in which one sensing electrode cooperates with multiple driving electrodes other than FIG. 3A electrode combination. FIG. 4A shows the electrode pattern before adding the shielding portion, and FIG. 4B shows the electrode pattern after adding the shielding portion (separated from the main body by a dotted line). The sensing electrode S1 includes a plurality of sensing segments corresponding to the driving electrodes D1 - D4 . Taking the first driving electrode D1 and the second driving electrode D2 in this embodiment as an example, the first driving electrode D1 and its corresponding sensing area constitute the first sensing area U1, and the second driving electrode D2 and its corresponding sensing area The segments constitute the second sensing area U2. The first sensing area U1 and the second sensing area U2 are adjacent to each other and have an adjacent zone, which is roughly the area B indicated by the dotted line in FIG. 4(A). The first driving electrode D1 includes a shielding portion D1A extending from its main body toward the adjacent land zone. The shielding part D1A can provide a shielding effect for the first sensing region U1 to reduce the influence of the second driving electrode D2. In contrast, the second driving electrode D2 includes a shielding portion D2A extending from its main body toward the adjacent land. The shielding part D2A can provide a shielding effect for the second sensing region U2 to reduce the influence of the first driving electrode D1.

As mentioned above, the present invention proposes a new electrode pattern suitable for a mutual capacitive touch sensing device. By adopting an electrode configuration method different from that of the prior art, the mutual capacitive touch sensing device according to the present invention can avoid the problems caused by the impedance mismatch of the sensing electrodes and the problem of poor linearity. In addition, by adding a shielding portion to each driving electrode, the mutual capacitive touch sensing device according to the present invention can reduce the probability of misjudgment of the coordinates of the touch point by the subsequent circuit.

Through the above detailed description of the preferred embodiments, it is hoped that the features and spirit of the present invention can be described more clearly, rather than limiting the scope of the present invention by the preferred embodiments disclosed above. On the contrary, the intention is to cover various changes and equivalent arrangements within the scope of the claimed patent scope of the present invention.

Claims (7)

1. A mutual capacitive touch sensing device, comprising: An induction electrode has an electrode trunk, a plurality of first electrode fingers and a plurality of second electrode fingers. The planar shape of the first electrode fingers is approximately rectangular and respectively extends from the electrode trunk toward a second direction, and the planar shape of the plurality of second electrode fingers is approximately rectangular and respectively extends from the electrode trunk toward the second direction extends so that the first direction is substantially perpendicular to the second direction; A first driving electrode, including a first main body, the first main body has a plurality of first recesses corresponding to and interlaced with the plurality of first electrode fingers, the first driving electrode and the plurality of first electrode fingers forming a first sensing area; and A second driving electrode, including a second main body, the second main body has a plurality of second recesses corresponding to and interlaced with the plurality of second electrode fingers, the second driving electrode and the plurality of second electrode fingers A second sensing area is formed. 2 . The mutual capacitive touch sensing device according to claim 1 , wherein the electrode trunk further comprises a plurality of third electrode fingers, the planar shape of the plurality of third electrode fingers is roughly rectangular, and they respectively extend from the The electrode trunk extends toward the second direction; the mutual capacitive touch sensing device further includes: A third drive electrode, including a third body, the third body has a plurality of third recesses corresponding to and interlaced with the plurality of third electrode fingers, the third drive electrode and the plurality of third electrode fingers A third sensing area is formed. 3. The mutual capacitive touch sensing device according to claim 2, wherein the first sensing area and the third sensing area are adjacent to each other and have an adjacent land, and the first driving electrode further includes A shielding portion extending from the first body toward the adjacent land. 4. The mutual capacitive touch sensing device according to claim 2, wherein at least a part of the plurality of second electrode fingers and a part of the plurality of first electrode fingers are on the first side The upward position is different. 5. The mutual capacitive touch sensing device according to claim 2, wherein the first body has a first width in the second direction, and the third body has a first width in the second direction. Two widths, the first width is different from the second width. 6. A mutual capacitive touch sensing device, comprising: A sensing electrode, including a first sensing region and a second sensing region; a first driving electrode corresponding to the first sensing area and forming a first sensing area; and A second driving electrode, including a second body, corresponding to the second sensing region and forming a second sensing region; Wherein the first sensing area and the second sensing area are adjacent to each other and have an adjacent land, the first driving electrode further includes a first shielding portion extending from the first body toward the adjacent land. 7 . The mutual capacitive touch sensing device according to claim 6 , wherein the second driving electrode further comprises a second shielding portion extending from the second body toward the adjacent land.