US20150346873A1 - Capacitive touch panel having improved response characteristics - Google Patents

Abstract

An apparatus is provided. The apparatus comprises a second layer disposed over a first layer. Each of the first and second layers have a set of detection electrodes that are spaced apart and electrically isolated from one another and an associated set of interleavers. Each interleaver is located between adjacent detection electrodes from its associated the set of detection electrodes, and each set of interleavers also includes a pair of complementary interleaving electrodes coupled to those that are electrically coupled to the adjacent detection electrodes from its associated set of detection electrodes. The detection electrodes and interleaving electrodes are also substantially transparent to visible spectrum light.

Description

CROSS-REFERENCE TO RELATED APPLICATION
• Under 35 U.S.C. §120, this continuation application claims priority to and the benefit of U.S. patent application Ser. No. 13/555,556, filed on Jul. 23, 2012 and entitled “CAPACITIVE TOUCH PANEL HAVING IMPROVED RESPONSE CHARACTERISTICS,” the entirety of which is incorporated herein by reference.
TECHNICAL FIELD
• The disclosure relates generally to a touch panel and, more particularly, to a capacitive touch panel having an improved response.
BACKGROUND
• Turning toFIGS. 1 and 2, an example of aconventional system100 can be seen.System100 generally comprises atouch panel102 andtouch panel controller104. Thetouch panel102 has an array of sensors formed by a set of column electrodes (e.g., electrode103), where each electrode of each column is coupled together by a strip electrode (e.g., strip electrode107), and a set of row electrodes (e.g., electrode109), where each electrode of each row is coupled together by a strip electrode (e.g., strip electrode107). Usually, the column and row electrodes (e.g.,electrodes103 and105) are formed in two separate layers with a dielectric or insulating layer formed therebetween, and these conductive layers which form the electrodes (e.g.,electrodes105 and109) are generally transparent to visible spectrum light (e.g., light having a wavelength from about 380 nm to about 750 nm). The strip electrodes for each column (e.g., strip electrode107) are then coupled to the interface or I/F106 of thetouch panel controller104 by terminals X-1 to X-N, while the strip electrodes for each row (e.g., strip electrode109) are coupled to theinterface106 by terminals Y-1 to Y-M. Theinterface106 is able to communicate with thecontrol circuit108. As shown in greater detail inFIG. 2, theinterface106 is generally comprised of a multiplexer ormux202 and anexciter204.
• In operation, the interface106 (which is usually controlled by the control circuit108) selects and excites columns of electrodes (e.g., electrode103) and “scans through” the rows of row electrodes (e.g., electrode105) so that a touch position from a touch event can be resolved. As an example,interface204 can excite two adjacent columns through terminals X-j and X-(j+1) with excitation signals EXCITE[j] and EXCITE[j+1], andinterface106 receives a measurement signal from a row associated with terminal Y-i. When an object (e.g., finger) is in proximity to the touch panel (which is generally considered to be a touch event), there is a change in capacitance due at least in part to the arrangement of electrodes (e.g.,electrodes103 and105), and thecontroller108 is able to resolve the position of the touch event.
• Most conventional touch panels (e.g., touch panel102) do, however, exhibit a non-uniform response characteristic, which is manifested as non-uniform signal strength across the panel. This non-uniformity is generally caused by natural variations in the patterns forming the column and row electrodes (e.g.,electrodes103 and105). In other words, the electrodes are arranged to have gaps or non-overlapping regions between the electrodes so that, as an object (e.g., finger) traverses the panel (e.g., panel102) and passes over these non-overlapping regions, the signal strength or measured capacitance changes. Therefore, there is a need for a touch panel having a more uniform response characteristic.
• Some examples of other conventional systems are: U.S. Patent Pre-Grant Publ. No. 2011/0095996; U.S. Patent Pre-Grant Publ. No. 2011/0095997; U.S. Patent Pre-Grant Publ. No. 2011/0102361; and U.S. Patent Pre-Grant Publ. No. 2011/0157079.
SUMMARY
• An embodiment of the present disclosure, accordingly, provides an apparatus. The apparatus comprises a first layer having: a first set of detection electrodes that are spaced apart and electrically isolated from one another, wherein each detection electrode from the first set of detection electrodes is substantially transparent to visible spectrum light; and a first set of interleavers, wherein each interleaver from the first set of interleavers is located between adjacent detection electrodes from the first set of detection electrodes, and wherein each interleaver from the first set of interleavers includes: a first set of interleaving electrodes that are electrically coupled to one of its adjacent detection electrodes from the first set of detection electrodes, wherein each interleaving electrode from the first set of interleaving electrodes is substantially transparent to visible spectrum light; and a second set of interleaving electrodes that are electrically coupled to the other of its adjacent detection electrodes from the first set of detection electrodes, wherein each interleaving electrode from the second set of interleaving electrodes is substantially transparent to visible spectrum light; and a second layer that is disposed over the first layer, wherein the second layer has: a second set of detection electrodes that are spaced apart and electrically isolated from one another, wherein each detection electrode from the second set of detection electrodes is substantially transparent to visible spectrum light; and a second set of interleavers, wherein each interleaver from the second set of interleavers is located between adjacent detection electrodes from the second set of detection electrodes, and wherein each interleaver from the second set of interleavers includes: a third set of interleaving electrodes that are electrically coupled to one of its adjacent detection electrodes from the second set of detection electrodes, wherein each interleaving electrode from the third set of interleaving electrodes is substantially transparent to visible spectrum light; and a fourth set of interleaving electrodes that are electrically coupled to the other of its adjacent detection electrodes from the second set of detection electrodes, wherein each interleaving electrode from the fourth set of interleaving electrodes is substantially transparent to visible spectrum light.
• In accordance with an embodiment of the present disclosure, the first layer further comprises: a substrate that is substantially transparent to visible spectrum light; a conductive layer disposed over the substrate, wherein the conductive layer is patterned to form the first sets of detection electrodes and interleavers; and an insulating layer disposed over the conductive layer.
• In accordance with an embodiment of the present disclosure, the conductive layer further comprises a first conductive layer, and wherein the insulating layer further comprises a first insulating layer, and wherein the second layer further comprises: a second conductive layer disposed over the first layer, wherein the second conductive layer is patterned to form the second sets of detection electrodes and interleavers; and a second insulating layer disposed over the conductive layer.
• In accordance with an embodiment of the present disclosure, the first set of detection electrodes further comprises a first set of strip electrodes that are substantially parallel with one another and are oriented in a first direction, and wherein the second set of detection electrodes further comprises a second set of strip electrodes that are substantially parallel to one another and oriented in a second direction, and wherein the orientation of the first and second sets of strip electrodes with respect to one another forms a plurality of non-overlapping zones.
• In accordance with an embodiment of the present disclosure, the first direction is substantially perpendicular to the second direction.
• In accordance with an embodiment of the present disclosure, complementary pairs of interleaving electrodes from at least one of the first and second sets of interleaving electrodes and the third and fourth sets of interleaving electrodes are located in each non-overlapping zone.
• In accordance with an embodiment of the present disclosure, each interleaving electrode is substantially rectangular in shape.
• In accordance with an embodiment of the present disclosure, each interleaving electrode is substantially triangular in shape.
• In accordance with an embodiment of the present disclosure, the first and second sets of strip electrodes further comprise first and second sets of linear strip electrodes.
• In accordance with an embodiment of the present disclosure, the first and second sets of strip electrodes further comprise first and second sets of diamond strip electrodes.
• In accordance with an embodiment of the present disclosure, the complementary pairs of interleaving electrodes from the first and second sets of interleaving electrodes and from the third and fourth sets of interleaving electrodes are located in each non-overlapping zone.
• In accordance with an embodiment of the present disclosure, an apparatus is provided. The apparatus comprises a touch panel screen having a touch sensor disposed over a display, wherein the touch sensor has: a first layer having: a first set of detection electrodes that are spaced apart and electrically isolated from one another, wherein each detection electrode from the first set of detection electrodes is substantially transparent to visible spectrum light; and a first set of interleavers, wherein each interleaver from the first set of interleavers is located between adjacent detection electrodes from the first set of detection electrodes, and wherein each interleaver from the first set of interleavers includes: a first set of interleaving electrodes that are electrically coupled to one of its adjacent detection electrodes from the first set of detection electrodes, wherein each interleaving electrode from the first set of interleaving electrodes is substantially transparent to visible spectrum light; and a second set of interleaving electrodes that are electrically coupled to the other of its adjacent detection electrodes from the first set of detection electrodes, wherein each interleaving electrode from the second set of interleaving electrodes is substantially transparent to visible spectrum light; and a second layer that is disposed over the first layer, wherein the second layer has: a second set of detection electrodes that are spaced apart and electrically isolated from one another, wherein each detection electrode from the second set of detection electrodes is substantially transparent to visible spectrum light; and a second set of interleavers, wherein each interleaver from the second set of interleavers is located between adjacent detection electrodes from the second set of detection electrodes, and wherein each interleaver from the second set of interleavers includes: a third set of interleaving electrodes that are electrically coupled to one of its adjacent detection electrodes from the second set of detection electrodes, wherein each interleaving electrode from the third set of interleaving electrodes is substantially transparent to visible spectrum light; and a fourth set of interleaving electrodes that are electrically coupled to the other of its adjacent detection electrodes from the second set of detection electrodes, wherein each interleaving electrode from the fourth set of interleaving electrodes is substantially transparent to visible spectrum light; and a touch panel controller that is electrically coupled to the first and second sets of detection electrodes.
• In accordance with the present disclosure, the first set of interleaving electrodes form a first set of first serpentines with its detection electrodes, and wherein the second set of interleaving electrodes form a second set of serpentines with its detection electrodes, and wherein each first serpentine is interleaved with at least one second serpentine.
• In accordance with the present disclosure, the third and forth interleaving electrodes form a zig-zag pattern the overlaps the interleaved first and second serpentines.
BRIEF DESCRIPTION OF THE DRAWINGS
• For a more complete understanding of the present disclosure, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
• FIGS. 1 and 2 are diagrams of an example of a conventional system;
• FIG. 3 is a diagram of an example of a system in accordance with the present disclosure;
• FIG. 4 is a cross-sectional view of a touch panel ofFIG. 3 along section line I-I;
• FIGS. 5 and 6 are plan views of portions of the section of the touch panel depicted inFIG. 4; and
• FIGS. 7-20 are examples of the plan views shown inFIGS. 5 and 6.
DETAILED DESCRIPTION
• Refer now to the drawings wherein depicted elements are, for the sake of clarity, not necessarily shown to scale and wherein like or similar elements are designated by the same reference numeral through the several views.
• Turning toFIG. 3, an example of asystem200 in accordance with an embodiment of the present disclosure can be seen.System200 is similar in construction tosystem100 except thattouch panel102 has been replaced bytouch panel202. Additionally,interconnect204 has been provided to provide communication channels between thetouch panel controller104 and thetouch panel202.
• InFIG. 4, a cross sectional view forsection206 of touch panel can be seen. As shown in this example, thetouch panel202 is generally comprised of atouch sensor322 disposed over or positioned over a display316 (which can, for example be a liquid crystal display or LCD) so as to allow the light from the display to project through thesensor322. This means that each layer of thesensor322 is substantially transparent to visible spectrum light. As shown, thetouch sensor322 is a dual or two layer sensor, having arow layer320,column layer318, andcover plate314. The column androw layers318 and320, in this example, each have aconductive layer304 and310 (respectively) disposed on asubstrate302 and308 (respectively), but one of thesubstrates302 or308 may be used instead of two. Typically, thesubstrates302 and308 are formed of glass (which is substantially transparent to visible spectrum light), and theconductive layers310 and304 are usually formed of a conductive material that is generally transparent to visible spectrum light (such as indium tin oxide, aluminum doped zinc oxide, gallium doped zinc oxide, or indium doped zinc oxide).Conductive layers304 and310 are also usually formed by electron beam evaporation, physical vapor deposition (PVD), or sputter deposition on thesubstrates302 and308, which can, for example, then be patterned using laser ablation or etching so to form the detection electrodes. The row andcolumn layers320 and318 can then be secured to one another and thecover plate314, using an insulating or dielectric material (which can be an adhesive, like epoxy).
• In order to achieve a more uniform response characteristic for thetouch sensor322, the patterns for theconductors304 and310 should be modified. As shown in the example ofFIGS. 5 and 6, row andcolumn interleavers404 and504 (respectively) are introduced between adjacent rows (e.g., rows402-1 and402-2) and adjacent columns (e.g., columns502-1 and502-2) across thetouch sensor322. The interleavers (e.g.,404 and504) can vary in configuration based on the shape or configuration of theconductors304 and310 but are intended to reduce the size (and, thus, the impact) of the non-overlapping zones and produce a generally uniform response characteristic across thetouch sensor322.
• InFIGS. 7-9, an example of an arrangement for the row and column interleavers404 and504 is shown (which are labeled404-A and504-A, respectively) for section206-A. In this example, row electrodes402-A1 and402-A2 are combined with row interleaver404-A so as to form serpentine electrodes that are interleaved with one another. The row layer320-A can also (optionally) include floating regions (e.g., floating region406) interspersed between sections of the row interleaver404-A, which can improve optical characteristics and response of the sensor (e.g.,322). Overlapping the row electrodes402-A1 and402-A2 and row interleaver404-A are the column electrodes502-A1 and502-A2 and column interleaver504-A that are arranged in a zig-zag or “fishbone” pattern.
• Turning toFIGS. 10-12, another example of an arrangement for the row and column interleavers404 and504 (which are labeled404-B and504-B, respectively) for section206 (which is labeled206-B) can be seen. For this example, column electrodes502-B1 and502-B2 and row electrodes402-B1 and402-B2 are linear strip conductors that are oriented in different directions so as to be perpendicular to one another. Because linear strip electrodes are employed, the non-overlapping region602-B is large. So, the row and column interleavers404-A and502-A are each formed of complementary pairs of interleaving electrodes that are each electrically coupled to a corresponding electrode (e.g.,402-A1) and that extend into the non-overlapping region602-B. These complementary pairs of interleaving electrodes, however, remain electrically isolated from one another. By doing this, the effect that the non-overlapping region has on the performance of thetouch sensor322 can be greatly reduced. Alternatively, as shown inFIGS. 13 and 14, all of the complementary pairs of interleaving electrodes do not need to be within the non-overlapping region (as shown with region602-C), but some (e.g., interleaving electrodes for column interleaver504-C in column layer318-C) may be in proximity or substantially over/under corresponding electrodes (e.g., row electrode402-1) in a staggered pattern.
• Additionally, as shown inFIGS. 15-17, the interleaving electrodes may take a variety of shapes. With section206-B and206-C (which are described above), the interleaving electrodes are substantially rectangular in shape, but it may be advantageous to employ other shapes. In the example shown inFIGS. 15-17, row interleaver404-D and column interleaver504-D employ triangular shaped interleaving electrodes.
• The interleaving electrodes may also be employed with various detection electrode shapes as well. In the example shown inFIGS. 18-20, the column electrodes502-E1 and502-E2 and row electrodes402-E1 and402-E2 are arranged as diamond strip electrodes (similar to the configuration shown with touch panel102) that are oriented in different directions so as to be perpendicular to one another. In this example, the interleaving electrodes for the column interleaver504-E and row interleaver404-E are positioned on the edges of the diamonds in the column electrodes502-E1 and502-E2 and row electrodes402-E1 and402-E2. This allows the performance of atouch sensor322 with good response characteristics (e.g., use of diamond strip electrodes) can be further improved.
• Having thus described the present disclosure by reference to certain of its preferred embodiments, it is noted that the embodiments disclosed are illustrative rather than limiting in nature and that a wide range of variations, modifications, changes, and substitutions are contemplated in the foregoing disclosure and, in some instances, some features of the present disclosure may be employed without a corresponding use of the other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the disclosure.

Claims (20)

What is claimed is:

1. A touch panel sensor comprising:

a first detection electrode extending longitudinally;

a second detection electrode extending longitudinally and parallel with the first detection electrode, the second detection electrode spaced apart and electrically isolated from the first detection electrode;

a first set of interleaving electrodes extending from the first detection electrode without contacting the second detection electrode; and

a second set of interleaving electrodes extending from the second detection electrode without contacting the first detection electrode, the second set of interleaving electrodes interleaving with the first set of interleaving electrodes.

2. The touch panel sensor ofclaim 1, wherein the first detection electrode, the second detection electrode, the first set of interleaving electrodes, and the second set of interleaving electrodes are substantially transparent to visible spectrum light.

3. The touch panel sensor ofclaim 1, wherein:

the first set of interleaving electrodes are substantially perpendicular to the first and second detection electrodes; and

the second set of interleaving electrodes are substantially parallel with the first set of interleaving electrodes and substantially perpendicular to the first and second detection electrodes.

4. The touch panel sensor ofclaim 1, wherein the first set of interleaving electrodes from a first serpentine conductor with the first detection electrode, and the second set of interleaving electrodes from a second serpentine conductor with the second electrode.

5. The touch panel sensor ofclaim 1, wherein each of the first and second set of interleaving electrodes is substantially rectangular in shape.

6. The touch panel sensor ofclaim 1, wherein each of the first and second set of interleaving electrodes is substantially triangular in shape.

7. The touch panel sensor ofclaim 1, further comprising:

a first detection layer having:

a first substrate substantially transparent to visible spectrum light; and

a first conductive layer disposed on the first substrate and patterned to form the first and second detection electrodes and the first and second interleave electrodes in a horizontal direction; and

a second detection layer aligned with the first detection layer in a vertical direction perpendicular to the horizontal direction, the second detection layer having:

a second substrate substantially transparent to the visible spectrum light; and

a second conductive layer disposed on the second substrate and pattern to form third and fourth detection electrodes partially overlapping with the first and second electrodes along the horizontal direction.

8. The touch panel sensor ofclaim 7, wherein:

the third detection electrode is substantially perpendicular to the first and second detection electrodes along the horizontal direction and has a first extended electrode extending parallel with the first and second detection electrodes along the horizontal direction; and

the fourth detection electrode is arranged parallel with the third detection electrode, the fourth detection electrode is substantially perpendicular to the first and second detection electrodes along the horizontal direction and has a second extended electrode extending parallel with the first and second detection electrodes along the horizontal direction.

9. The touch panel sensor ofclaim 8, wherein:

the first extended electrode partially overlaps with the first and second sets of interleaving electrodes along the horizontal direction; and

the second extended electrode partially overlaps with the first and second sets of interleaving electrodes along the horizontal direction.

10. A display panel comprising:

a display screen operative to project visible light;

a first detection layer vertically aligned with the display screen and substantially transparent to the projected visible light, the first detection layer having:

a first detection electrode extending longitudinally along a first horizontal direction parallel with the display screen;

a second detection electrode extending longitudinally and parallel with the first detection electrode, the second detection electrode spaced apart and electrically isolated from the first detection electrode;

a first set of interleaving electrodes extending from the first detection electrode without contacting the second detection electrode; and

a second set of interleaving electrodes extending from the second detection electrode without contacting the first detection electrode, the second set of interleaving electrodes interleaving with the first set of interleaving electrodes; and

a second detection layer vertically aligned with the display screen and the first detection layer, the second detection layer substantially transparent to the projected visible light and configured to sense a touch event along a second horizontal direction substantially perpendicular to the first horizontal direction.

11. The display panel ofclaim 10, further comprising:

an insulation layer positioned between the first detection layer and the second detection layer.

12. The display panel ofclaim 10, wherein:

the first set of interleaving electrodes are substantially perpendicular to the first and second detection electrodes; and

the second set of interleaving electrodes are substantially parallel with the first set of interleaving electrodes and substantially perpendicular to the first and second detection electrodes.

13. The display panel ofclaim 10, wherein the first set of interleaving electrodes from a first serpentine conductor with the first detection electrode, and the second set of interleaving electrodes from a second serpentine conductor with the second electrode.

14. The display panel ofclaim 1, wherein each of the first and second set of interleaving electrodes is substantially rectangular in shape.

15. The display panel ofclaim 1, wherein each of the first and second set of interleaving electrodes is substantially triangular in shape.

16. The display panel ofclaim 1, wherein the second detection layer includes:

a third detection electrode isolated from and substantially perpendicular to the first and second electrodes, the third detection electrode having a first extended electrode extending parallel with the first and second detection electrodes; and

a fourth detection electrode isolated from and substantially perpendicular to the first and second electrodes, the fourth detection electrode having a second extended electrode extending parallel with the first and second detection electrodes without interleaving with the first extended electrode.

17. A display system comprising:

a display screen operative to project visible light;

a touch panel vertically aligned with the display screen and substantially transparent to the projected visible light, the touch panel having:

a first detection electrode extending longitudinally along a horizontal direction parallel with the display screen;

a second detection electrode extending longitudinally and parallel with the first detection electrode, the second detection electrode spaced apart and electrically isolated from the first detection electrode;

a first set of interleaving electrodes extending from the first detection electrode without contacting the second detection electrode; and

a second set of interleaving electrodes extending from the second detection electrode without contacting the first detection electrode, the second set of interleaving electrodes interleaving with the first set of interleaving electrodes; and

a control circuit coupled with the touch panel to detect a capacitance change in the first detection electrode and the second detection electrode.

18. The display system ofclaim 17, wherein:

the first set of interleaving electrodes are substantially perpendicular to the first and second detection electrodes; and

the second set of interleaving electrodes are substantially parallel with the first set of interleaving electrodes and substantially perpendicular to the first and second detection electrodes.

19. The display system ofclaim 17, wherein the first set of interleaving electrodes from a first serpentine conductor with the first detection electrode, and the second set of interleaving electrodes from a second serpentine conductor with the second electrode.

20. The display system ofclaim 17, further comprising:

a row detection layer having:

a first substrate substantially transparent to the projected visible light; and

a first conductive layer disposed on the first substrate and patterned to form the first and second detection electrodes and the first and second interleave electrodes along a row direction; and

a column detection layer vertically aligned with the row detection layer, the column detection layer having:

a second substrate substantially transparent to the projected visible light; and

a second conductive layer disposed on the second substrate and pattern to form third and fourth detection electrodes partially overlapping with the first and second electrodes along a column direction perpendicular to the row direction.

Images