This application claims all benefits accruing under 35 U.S.C. §119 from China Patent Application No. 201410031617.X, filed on Jan. 23, 2014, in the China Intellectual Property Office, the disclosure of which is incorporated herein by reference.
1. Technical Field
The present disclosure relates to a method for determining touch point coordinates, particularly to a method for determining touch point coordinates on capacitive type touch panel.
2. Description of Related Art
Touch panels or touch screens are widely applied in electronic apparatuses, particularly in portable or hand-held electronic apparatuses, such as personal digital assistants (PDA) or mobile phones. Touch panels involve integration of resistive-type, capacitive-type or optical touch technologies and display panels.
A conventional capacitive-type touch panel includes two pattern layers made of transparent conductive materials formed on two surfaces of a glass substrate respectively to detect two-dimensional coordinates on the pattern layers. The transparent conductive material of conventional touch panel is indium tin oxide (ITO). Recently, the research is focus on the capacitive-type touch panel with single layer of transparent conductive material. The single layer of transparent conductive material comprises a plurality of triangular electrodes extending along the same direction (X direction) and aligned side to side. Each two adjacent electrodes are coupled together to detect the touch point. However, the touch panel cannot distinguish the two points on the extending direction. Therefore, the touch panel is not suitable for multi-touching.
What is needed, therefore, is to provide a method for solving the problem discussed above.
Many aspects of the embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
The disclosure is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one.
Referring to
The insulating substrate 10 having a plane structure or a curved structure. The insulating substrate 10 can be transparent. The insulating substrate 10 can be formed using transparent material, such as polyethylene (PE), polycarbonate (PC), polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), polyimide (PI), polyether sulphone (PES), cellulose resin, polyvinylchloride (PVC), benzocyclobutene (BCB), acrylic resin, glass, or quartz, for example. In one embodiment, the insulating substrate 10 has a plane structure and is formed by polycarbonate.
The conductive layer 12 can be a carbon nanotube layer, an indium tin oxide (ITO) layer, or an antimony tin oxide (ATO) layer. The conductive layer 12 can have a thickness of about 0.5 nanometers (nm) to about 100 micrometers (um). In one embodiment, the conductive layer 12 has a thickness of about 100 nm to about 200 nm.
The plurality of first electrodes 122 and the plurality of second electrodes 124 can extend along X direction and aligned along Y direction perpendicular to the X direction. The plurality of first electrodes 122 and the plurality of second electrodes 124 are alternatively aligned along the Y direction. It means that each first electrode 122 is sandwiched between two adjacent second electrodes 124, and each second electrode 124 is sandwiched between two adjacent first electrodes 122.
Furthermore, the adjacent first electrode 122 and second electrode 124 are coupled together. The shape of the first electrode 122 and the shape of the second electrode 124 are complementary, thus the detection region of the touch panel can nearly cover the insulating substrate 100. A distance between the first electrode 122 and the second electrode 124 can be selected according to the touch resolution requirement of the touch panel 100 to meet the actual requirements of different devices.
Each of the plurality of first electrodes 122 comprises a first end and a second end along the X direction. A size of the first electrode 122 along the Y direction is defined as width of the first electrode 122. A first width on the first end is greater than a second width of the first electrode 122 on the second end. In one embodiment, the width of the first electrode 122 is gradually decreased from the first end to the second end. In one embodiment, each of the plurality of first electrodes 122 is in a shape of triangle.
In one embodiment, the first electrode 122 comprises three regions with different resistance along the X direction. The first electrode 122 comprises a first region N1, a second region N2, and a third region N3 from the first end to the second end. The first region Ni has a first resistance RN1, the second region N2 has a second resistance RN2, and the third region has a third resistance RN3. The first resistance RN1, the second resistance RN2, and the third resistance RN3 satisfy RN1≠RN2≠RN3.
Referring to
The two first recesses 1222 are spaced from each other and extend from the edge into inside of the first electrode 122. Thus the first electrode 122 is not broken up by the two first recesses 1222 along the X direction. The shape of each of the two first recesses 1222 can be rectangular, semi-circular, triangular, or other geometric shape. A length of each of the two first recesses 1222 along the X direction can be selected according to the charging time and discharging time of the driving and sensing circuit. During single charging cycle time, merely the capacity of the first region N1 can be fully charged by the driving and sensing circuit. During over 3 times charging cycle times, all of the capacity of the first region N1, the second region N2, and the third region N3 can be fully charged.
The structure of the second electrode 124 is similar with the first electrode 122, except that the width of the second electrode 124 is gradually increased along the X direction to form an inverted triangle along the X direction. In detail, the second electrode 124 comprises a third end and a forth end along the X direction. A third width of the third end is smaller than a fourth width of the fourth end of the second electrode 124. Thus the third end of the second electrode 124 can complementary to the first end of the first electrode 122, and the fourth end of the second electrode 124 can complementary to the second end of the first electrode 122. Therefore, the inverted triangular second electrode 124 is coupled with the triangular first electrode 122 to form a rectangle.
The second electrode 124 comprises a third region M3, a second region M2, and a first region M1 from the third end to the fourth end. The first region M1 has a first resistance RM1, the second region M2 has a second resistance RM2, and the third region has a third resistance RM3. The first resistance RM1, the second resistance RM2, and the third resistance RM3 satisfy Rm1≠Rm2≠Rm3.
Two second recesses 1242 can be defined between the third end and the fourth end in the second electrode 124. The two second recesses 1242 are formed on two opposite edges of the second electrode 124 and opposite with each other along the Y direction. The region on one side of the two second recesses 1242 is defined as the first region M1, the region on another side of the two second recesses 1242 is defined as the third region M3, and the region between the two second recesses 1242 is defined as the second region M2. Because the first region M1, the second region M2, and the third region M3 have different width, thus the resistance of the first region M1, the second region M2, and the third region M3 are different from each other. Furthermore, the two second recesses 1242 and the two first recesses 1222 are aligned along the Y direction. Thus the two second recesses 1242 and the two first recesses 1222 have the same X-coordinates.
Furthermore, both the first electrode 122 and the second electrode 124 can have more than three different regions with different resistance along X direction. In one embodiment, both the first electrode 122 and the second electrode 124 can have five different regions. In another embodiment, both the first electrode 122 and the second electrode 124 have seven different regions.
Because both the first electrode 122 and the second electrode 124 have at least three different regions with at least three different resistances along X direction, the two touch points coordinates on the touch panel along X direction can be detected and determined.
Furthermore, the touch panel 100 comprises a plurality of first electrode leads 1221 and a plurality of second electrode leads 1241 distributed on two opposite sides of the conductive layer 12. The plurality of first electrode leads 1221 are electrically connected to the plurality of first electrode 122, and the plurality of second electrode leads 1241 are electrically connected to the plurality of second electrode 124.
Furthermore, the touch panel 100 comprises a driving and sensing unit 14 to inputs driving electrical signals to conductive layer 12 and read out sensed electrical signals of the touch points on the touch panel. The driving and sensing unit 14 is electrically connected to the conductive layer 12 via the plurality of first electrodes 122 and the plurality of second electrodes 124.
The charging cycle time T of the driving and sensing unit 14 is determined by the RC loading of the driving and sensing unit 14. During single charging cycle time 1T, merely the capacity of the first region can be fully charged. During double times charging cycle time 2T, both the capacity of the first region and the second region can be fully charged. Above three times charging cycle time 3T, the capacity of the first region, the second region, and the third region can be fully charged.
Referring to
step (S10), obtaining a first signal value A1T by inputting driving electrical signals to each of the plurality of first electrodes 122 for single charging cycle time 1T, and sensing the plurality of first electrodes 122;
step (S20), getting a second signal value B1T by inputting driving electrical signals to each of the plurality of second electrodes 124 for single charging cycle time 1T, and sensing the plurality of second electrodes 124;
step (S30), reading out a third signal value A2T by inputting driving electrical signals to each of the plurality of first electrodes 122 again for three charging cycle time 3T; and
step (S40), obtaining a fourth signal value B2T by inputting driving electrical signals to each of the plurality of second electrodes 124 again for three charging cycle time 3T.
In step (S10), during the time of 1T, the driving and sensing unit 14 can merely fully charge the capacity of the first region N1. Because of the resistance, the second region N2 and the third region N3 are not charged or fully charged. Thus during the sensing process, the touch point on the first region N1 can be read out as the first signal value A1T through the plurality of first electrodes 122. During sensing each of the plurality of first electrodes 122, the plurality of second electrodes 124 and other first electrodes 122 which are not sensed can be grounded, floating, or supplied with a potential. In one embodiment, the plurality of second electrodes 124 and other first electrodes 122 which are not sensed are floating.
In step (S20), during the time of 1T, merely the capacity of the first region M1 can be fully charged. Because of the resistance, the second region M2 and the third region M3 are not charged or fully charged. Thus during the sensing process, the touch point on the first region M1 can be read out as the first signal value B1T through the plurality of second electrodes 124. During sensing each of the plurality of second electrodes 124, the plurality of first electrodes 122 and other second electrodes 124 which are not sensed can be grounded, floating, or supplied with a potential.
In step (S30), during the time of 3T, all of the first region N1, the second region N2, and the third region N3 can be fully charged by the driving and sensing unit 14. During the sensing process, the touch point on the first region N1, the second region N2, or the third region N3 can be read out as the third signal value A2T through the plurality of first electrodes 122. During sensing each of the plurality of first electrodes 122, the plurality of second electrodes 124 and other first electrodes 122 which are not sensed can be grounded, floating, or supplied with a potential. In one embodiment, the plurality of second electrodes 124 and other first electrodes 122 which are not sensed are floating.
In step (S40), during the time of 3T, all of the first region M1, the second region M2, and the third region M3 can be fully charged by the driving and sensing unit 14. During the sensing process, the touch point on the first region M1, the second region M2, or the third region M3 can be read out as the third signal value B3T through the plurality of second electrodes 124. During sensing each of the plurality of second electrodes 124, the plurality of first electrodes 122 and other second electrodes 124 which are not sensed can be grounded, floating, or supplied with a potential. In one embodiment, the plurality of first electrodes 122 and other second electrodes 124 which are not sensed are floating.
Referring to
The coordinates of the first touch point TP1 and the second touch point TP2 can be calculated through the first signal value A1T, the second signal value B1T, the third signal value A2T, and the fourth signal value B2T as follows:
A
1T
=A
1P;
A
2T
=A
1P
+A
2P,
B
1T
=B
1P;
B
2T
=B
1p
+B
2P;
wherein A1p is the touch point signal caused by the first touch point TP1 and sensed by the plurality of first electrodes 122, and B1 is the touch point signal caused by the first touch point TP1 and sensed by the plurality of second electrodes 124. A2P is the touch point signal caused by the second touch point TP2 and sensed by the plurality of first electrodes 122, and B2P is the touch point signal caused by the second touch point TP2 and sensed by the plurality of second electrodes 124.
Thus the A1P, B1P, A2P, B2P can be expressed as:
A
1P
=A
1T;
B
1P
=B
2T
−B
2P
=B
2T
−B
1T;
A
2P
=A
2T
−A
1P
=A
2T
−A
1T;
B
2P
=B
1T.
Thus the coordinate X1 of the first touch point TP1 and the coordinate X2 of the second touch point TP2 can be calculated as:
wherein PX is a resolution of the X direction of the touch panel 100. In one embodiment, the value of the resolution can be set by the driving detecting unit 14, for example, the value is in the range of 480 to 1024.
Furthermore, the X1 and X2 can be used to determine whether there are two touch points or there is single touch point on the touch panel. l0 is set as the threshold value which the touch panel 100 can recognize along the X direction. While |X1−X2|<l0, the two touch points TP1 and TP2 cannot be recognized by the touch panel, thus the first touch point TP1 and the second touch point TP2 will be recognized as single touch point. Then the touch panel 100 can be responded to the single touch point in the following process. l0 can be selected according to the resolution along the X direction.
In one embodiment, the first electrode 122 is divided into n regions. Thus the n regions will be fully charged after a time of nT. The second electrode 124 is divided into m regions, and the m regions will be fully charged after a time of mT. Then the coaxial touch points can be obtained through more than two groups of signals as described above.
The method of determining touch point coordinates on touch panel has following advantages. The conductive layer has been patterned by the recesses, thus the plurality of regions with different resistance can be formed, and the two different touch points on the X direction can be obtained. Thus the detection accuracy and the sensitivity of the touch can be improved.
Referring to
A method of one embodiment for determining touch panel coordinates on the touch panel comprises:
step (S10), obtaining a plurality of first signal values A1T, A2T, A1T by inputting driving electrical signals to each of the plurality of first electrodes 122 for 1T, 3T, . . . , iT respectively, and sensing the plurality of first electrodes 122 for each time; and
step (S20), getting a plurality of second signal values B1T, B1T, . . . , BiT by inputting driving electrical signals to each of the plurality of second electrodes 124 for 1T, 3T, iT respectively, and sensing the plurality of second electrodes 124 for each time.
The two touch point coordinates of the two touch points along the X direction can be calculated through the plurality of first signal values A1T, A2T, A1T and the plurality of second signal values B1T, B1T, . . . , BiT. A first group values of relationship between the two touch point coordinates can be deduced by making difference between each adjacent two of the plurality of first signal values A1T, A2T, . . . , AiT one by one. A second group values of relationship between the two touch point coordinates can be deduced by making difference between each adjacent two of the plurality of second values B1T, B1T, BiT one by one. Then the touch point coordinates of TP1 and TP2 can be calculated through the first group values and the second group values.
In one embodiment, the first touch point TP1 is located at the region Nj, and the second touch point TP2 is located at the region Nk in the first electrode 122. Thus for the second electrode 122, the first touch point TP1 is located at the region Ni-j, and the second touch point TP2 is located at the region Ni-k.
A first signal value AT sensed by the first electrode 122 while the first electrode 122 sensing the region Nj wherein the first touch point TP1 is located can be expressed as:
A
jT
=A
1P
+A
(j-2)T;
A second signal value AkT sensed by the first electrode 122 while the first electrode 122 sensing the region Nk wherein the second touch point TP2 is located can be expressed as:
A
kT
=A
2P
+A
(k-2)T;
wherein A2P is the signal value caused by the second touch point TP2 in region Nk and sensed by the first electrode 122, and A(k-2)T is the signal value of the regions from N1 to Nk-2 sensed by the first electrode 122 during (k−2)T.
A third signal value B(i-k)T sensed by the second electrode 124 while the second electrode 124 sensing the region N(i-k) wherein the second touch point TP2 is located can be expressed as:
B
(i-k)T
=B
2P
+B
(i-k-2)T;
wherein B2P is the signal value caused by the second touch point TP2 in region Ni-k and sensed by the second electrode 124, and B(i-k-2)T is the signal value of the regions from N1 to Nk-2 sensed by the second electrode 124 during (i−k−2)T.
A fourth signal value B(i-j)T sensed by the second electrode 124 while the second electrode 124 sensing the region N(i-j) wherein the first touch point TP1 is located can be expressed as:
B
(i-j)T
=B
2P
+B
(i-j-2)T;
wherein B2P is the signal value caused by the first touch point TP1 and sensed by the first electrode 122, and B(i-j-2)T is the signal value of the regions from N1 to Ni-j-2 sensed by the first electrode 122 during (i−j−2)T.
Therefore, the A1P, B1P, A2P, B2P can be expressed as:
A
1P
=A
jT
−A
(j-2)T;
A
2P
=A
kT
−A
(k-2)T;
B
1P
=B
(i-k)T
−B
(i-k-2)T,
B
2P
=B
(i-j)T
−B
(i-j-2)T.
Thus the coordinate X1 of the first touch point TP1 and the coordinate X2 of the second touch point TP2 can be calculated as:
wherein PX is a resolution of the X direction of the touch panel 200. In one embodiment, the value of the resolution can be set by the driving detecting unit 14, for example, the value is in the range of 480 to 1024.
Depending on the embodiment, certain of the steps of methods described may be removed, others may be added, and the sequence of steps may be altered. It is also to be understood that the description and the claims drawn to a method may include some indication in reference to certain steps. However, the indication used is only to be viewed for identification purposes and not as a suggestion as to an order for the steps.
It is to be understood that the described embodiments are intended to illustrate rather than limit the disclosure. Any elements described in accordance with any embodiments is understood that they can be used in addition or substituted in other embodiments. Embodiments can also be used together. Variations may be made to the embodiments without departing from the spirit of the disclosure. The disclosure illustrates but does not restrict the scope of the disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201410031617.X | Jan 2014 | CN | national |