Touch display panel and display device

A touch panel and a display device are disclosed. The touch panel comprises: a plurality of self-capacitance electrodes (04) disposed in a same layer and independent from each other; a plurality of wires (05) connecting the self-capacitance electrodes (04) to a margin frame of the touch panel; and periphery wirings (07) located at the margin frame of the touch panel and connected with the wires (05) one to one. Each of the wires (05) is electrically connected with at least two self-capacitance electrodes that are provided non-adjacent to each other (04) and self-capacitance electrodes (04) electrically connected with different wires (05) do not overlap each other. The touch panel can reduce touch dead zone in the touch panel utilizing self-capacitance principle.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the National Stage of PCT/CN2014/084575 filed on Aug. 16, 2014, which claims priority under 35 U.S.C. §119 of Chinese Application No. 201410157705.4 filed on Apr. 18, 2014, the disclosure of which is incorporated by reference.

TECHNICAL FIELD

At least one embodiment of the present invention relates to a touch display panel and a display device.

BACKGROUND

With the fast development of display technology, touch display panels have gradually become popular in people's life. At present, according to constitution structure, touch screens may be classified into add-on mode touch panels, on-cell touch panels and in-cell touch panels. For an add-on mode touch panel, the touch panel and the liquid crystal display (LCD) are produced separately and then attached together to form a liquid crystal display with touch function. Add-on mode touch panels suffer disadvantages such as high manufacturing cost, low light transmission rate and a big assembly thickness. For an in-cell touch panel, touch electrodes of the touch panel are embedded inside the liquid crystal display, which can reduce the overall thickness of the assembly, and can drastically reduce manufacturing cost of the touch panel. Therefore, in-cell touch panels have received more attention from panel manufacturers.

At present, an in-cell touch panel detects the touch position of a finger in accordance with the mutual capacitance or self-capacitance principle. For the self-capacitance principle, it is possible to provide a plurality of self-capacitance electrodes that are disposed in the same layer and insulated from each other in the touch panel. When a human body does not touch the screen, each self-capacitance electrode experiences a capacitance of fixed value. When the human body touches the screen, corresponding self-capacitance electrodes experience capacitance that is the fixed value plus the body capacitance. The touch sensing chip can determine the touch position by detecting capacitance value variation of self-capacitance electrodes in the touch period. Since the body capacitance can act on all the self-capacitances, as compared to the fact that the body capacity can only act on projection capacitance in mutual capacitance principle, the touch variation caused by the body touching the screen is greater than that of the touch panel manufactured in mutual capacitance principle. Therefore, as compared to touch panels utilizing the mutual capacitance principle, touch panels utilizing self-capacitance principle can effectively increase signal-to-noise ratio of the touch and thereby improve accuracy of touch sensing.

While designing a touch panel in the self-capacitance principle, each self-capacitance electrode is connected with the touch sensing chip via a separate lead-out wire. As shown inFIG. 1, for example, each lead-out wire comprises: a wire2for connecting a self-capacitance electrode1to the margin frame of the touch panel, and a periphery wiring4disposed in margin frame for connecting the self-capacitance electrode1to a connecting terminal3of a touch sensing chip.

SUMMARY

At least one embodiment of the present invention provides a touch panel and a display device to reduce touch dead zone of touch panels utilizing self-capacitance principle.

At least one embodiment of the present invention provides a touch panel comprising: a plurality of self-capacitance electrodes disposed in a same layer and independent from each other; a plurality of wires connecting the self-capacitance electrodes to a margin frame of the touch panel, wherein each of the wires is electrically connected with at least two self-capacitance electrodes that are provided non-adjacent to each other and self-capacitance electrodes electrically connected with different wires do not overlap with each other; and periphery wirings located at the margin frame of the touch panel and connected with the wires in a one-to-one manner.

At least one embodiment of the present invention provides a display device comprising the above-mentioned touch panel.

DETAILED DESCRIPTION

Thicknesses and shapes of layers in the accompanying drawings do not reflect real scale, and only serve to illustrate contents of the present invention.

The inventors of the present application have noted that in the case as shown inFIG. 1, since there are many self-capacitance electrodes, there will also be many corresponding lead-out wires. Considering an example in which each self-capacitance electrode occupies an area of 5 mm*5 mm, a 5-inch liquid crystal display needs 264 self-capacitance electrodes. If each self-capacitance electrode is designed smaller, there will be more self-capacitance electrodes, and more lead-out wires need to be provided. Because wires and self-capacitance electrodes in lead-out wires are generally disposed in the same layer in design to reduce the number of layers, more wires will produce a larger touch dead zone. The touch dead zone refers to a region in a touch panel, where wirings are concentrated and signals are relatively disordered, which means that touch performance can not be guaranteed in this area.FIG. 1is for explanation by taking 30 self-capacitance electrodes as an example. 30 self-capacitance electrodes need 30 wires for leading them out to the margin frame. 10 wires are needed for the place of densest wires, which can result in a large touch dead zone. In addition, many wires entail many periphery wirings connected one by one with wires disposed in the margin frame, which enlarges the margin frame of touch panel and is adverse to the narrow margin frame design.

At least one embodiment of the present invention provides a touch panel, as shown inFIG. 3, comprising: a plurality of self-capacitance electrodes04disposed in the same layer and mutually independent; a plurality of wires05connecting self-capacitance electrodes04to the margin frame of the touch panel; and periphery wirings07disposed in the margin frame of the touch panel and connect with wires05one by one. In one embodiment, the touch panel further comprises: a touch sensing chip for determining a touch position by detecting capacitance variation of the self-capacitance electrodes04in a touch period and electrically connected with periphery wirings07via connection terminals06. As shown inFIG. 3, each wire05is electrically connected with at least two self-capacitance electrodes04that are disposed non-adjacent to each other, and self-capacitance electrodes04electrically connected with different wires05do not overlap each other.FIG. 3shows an example in which every two self-capacitance electrodes are connected with one wire05. As shown inFIG. 4, the wire05connects the self-capacitance electrodes04to the touch sensing chip100via a periphery wiring07. The touch sensing chip100may be, for example, provided on a substrate or a flexible printed circuit board.

The above-mentioned touch panel provided in an embodiment of the present invention may be applied to add-on mode touch panels or in-cell touch panels. When applied to an in-cell touch panel, in one embodiment, as shown inFIG. 2, the touch panel may further comprise a top substrate01and a bottom substrate02disposed opposite to each other; and self-capacitance electrodes04that may be disposed on a side of the top substrate01facing the bottom substrate02or on a side of the bottom substrate02facing the top substrate01.FIG. 2shows an example in which both the black matrix layer03and the self-capacitance electrodes04are disposed on a side of the top substrate01facing the bottom substrate02. Of course, in another embodiment, it is also possible to dispose the black matrix layer03and the self-capacitance electrodes04on the bottom substrate02, which will not be described any more here.

In the above-mentioned touch panel provided in embodiments of the present invention, at least two self-capacitance electrodes04that are provided non-adjacent to each other are connected to the margin frame of the touch panel via a wire05and then connected to the touch sensing chip via a corresponding periphery wiring07for touch position detection. Connecting a plurality of self-capacitance electrodes04that are not adjacent to each other to one wire05can effectively reduce the overall number of wires05in the touch panel, thereby reducing the area occupied by a touch dead zone and guaranteeing touch performance. Furthermore, the number of corresponding periphery wirings07decreases along with the decrease of the number of wires05, which is also advantageous for the design of a narrow margin frame of the touch panel.

Furthermore, since a plurality of self-capacitance electrodes04that are provided non-adjacent to each other are connected via one wire05, and adjacent self-capacitance electrodes04are connected to the margin frame via different wires05, when a human body touches the screen, the touch sensing chip can determine touch position by determining capacitance variation of adjacent self-capacitance electrodes04connected with different wires05, which can avoid misjudgment and improve accuracy of touch sensing. Taking the connection of self-capacitance electrodes as shown inFIG. 3as an example, since self-capacitance electrodes04in x direction are not connected through the same one wire05, it is possible to accurately determine the position in x direction. Self-capacitance electrodes04in y direction are connected to each other in the configuration of two by two, and therefore the position in y direction needs to be determined through the signal change on different wires05. For example, when a finger touches position A, it is known from signal change on the wire d that both positions A and B may be touched. However, from the fact that the signal on the wire a changes while the signal on the wire b does not changes, it may be known that only position A is really touched.

In one embodiment, as shown inFIG. 2, the above-mentioned touch panel provided in the embodiment of the present invention may further comprise: a black matrix layer03disposed on a side of the top substrate01facing the bottom substrate02or a side of the bottom substrate02facing the top substrate01; the orthogonal projections of patterns of self-capacitance electrodes04and patterns of wires05onto the bottom substrate02are within the region correspondingly occupied by the pattern of black matrix layer03.

Since both patterns of self-capacitance electrodes04and patterns of wires05are disposed in the region corresponding to the pattern of black matrix layer03, electric field generated by self-capacitance electrodes04will not influence electric field in the pixel opening region, and therefore will not influence the normal display. Self-capacitance electrodes04disposed in the region blocked by the pattern of the black matrix layer03may also avoid influencing transmittance of the touch panel.

The resolution for a touch panel is generally on the order of millimeter. Therefore, in one embodiment, it is possible to choose the density of and the area occupied by self-capacitance electrodes04according to the required touch resolution to ensure the required touch resolution. Generally, self-capacitance electrodes04are designed as square electrodes having the size of 5 mm*5 mm. The resolution for display screen is generally on the order of micron, and therefore one self-capacitance electrode04generally may correspond to a plurality of pixel units in the display screen. In order to ensure that the patterns of self-capacitance electrodes04do not occupy opening areas for pixel units, as shown inFIG. 4, in one embodiment, it is possible to cut out patterns at positions corresponding to the opening areas of pixel units (i.e., forming blank parts in pixel regions) within the patterns of self-capacitance electrodes04, that is, patterns of self-capacitance electrodes04can designed such that their orthogonal projections on the bottom substrate02are of a mesh structure in regions where the pattern of black matrix layer03is located. Furthermore, in order to ensure display uniformity, patterns of self-capacitance electrodes04are generally disposed in gaps between sub-pixel units in a pixel unit. InFIG. 4, each group of RGB sub-pixel units constitute a pixel unit. The density or resolution as referred to in embodiments of the present invention means the pitch between self-capacitance electrodes of the touch panel or the pitch between pixel units of the display screen.

In a different embodiment, wires05and self-capacitance electrodes04may be disposed on the same substrate, that is, both are disposed on the top substrate01or on the bottom substrate02; and periphery wirings07and connection terminals06of the touch sensing chip may be disposed on the bottom substrate02. For example, when wires05and self-capacitance electrodes04are disposed on the top substrate01, wires05may be electrically connected with periphery wirings07on the bottom substrate02by the conduction effect of conducting particles such as gold balls in sealant. For example, when wires05and self-capacitance electrodes04are disposed on the bottom substrate02, wires05may be electrically connected with periphery wirings07of the bottom substrate02directly.

In one embodiment, In order to reduce the number of layers and patterning processes in the touch panel as many as possible, it is possible to dispose wires05and self-capacitance electrodes04on the same layer. Because patterns of self-capacitance electrodes04and wires05are designed with one layer of metal, in order to avoid short circuit between self-capacitance electrodes04, wires05for connecting self-capacitance electrodes04should not cross each other. Therefore, in this case it is possible to adopt the manner as shown inFIG. 3in which two self-capacitance electrodes04that are provided non-adjacent to each other are electrically connected with one wires05. In this way, as compared to the connection manner as shown inFIG. 1in which self-capacitance electrodes04and wires05are connected in a one-to-one manner, the number of wires05may be reduced by a half, which drastically reduces the area of touch dead zone.

In one embodiment, in designing extension directions of wires05, it is possible to design the extension directions of all wires05to be identical. Generally, the margin frame of a touch panel is of a rectangle shape. In one embodiment, in order to reduce the area of a touch dead zone, it is possible to configure the extension direction of wires05to be consistent with the direction of the short side of the margin frame of the touch panel so as to reduce the area of the touch dead zone by shortening the length of wires05connecting the self-capacitance electrodes04as much as possible.

In one embodiment, in order to reduce the area of the touch dead zone as much as possible, the margin frame of the touch panel generally have four sides and it is possible to connect self-capacitance electrodes04to the closest side via corresponding wires05as well as ensure wires05do not cross each other. This can shorten the length of wires05connecting self-capacitance electrodes04as much as possible, and reduce the area of the touch dead zone as much as possible as a whole.

The above-mentioned design for reducing a touch dead zone provided in the embodiment of the present invention will be described with respect to a 5-inch touch panel as an example in which about 22*12=264 self-capacitance electrodes04are needed. As shown inFIG. 5, in order to lead each self-capacitance electrode04to the margin frame and reduce the area of touch dead zone as far as possible, it is possible to partition all self-capacitance electrodes04into8regions, namely Part A-Part H, and self-capacitance electrodes04in each region are connected individually to the connection terminals of the touch sensing chip under the display area (Panel). As shown inFIG. 6, the connection relationship of a portion of self-capacitance electrodes04is shown for each region. Self-capacitance electrodes in region, Part A, are led out from the top left region of the display area and led to the connection terminals of the touch sensing chip through the left margin frame of the display area. Self-capacitance electrodes in region, Part B, are led out from the top of the display area and then led to the connection terminals of the touch sensing chip through the left margin frame of the display area. Self-capacitance electrodes in region, Part C, are led out from the top of the display area and then led to the connection terminals of the touch sensing chip through the right margin frame of the display area. Self-capacitance electrodes in region, Part D, are led out from the top right of the display area and then led to connection terminals of the touch sensing chip through the right margin frame of the display area. Similarly, self-capacitance electrodes in region, Part E, are led out from the bottom left region of the display area and led to connection terminals of the touch sensing chip through the left margin frame of the display area. Self-capacitance electrodes in region, Part F, are led out from the bottom of display area and then directly connected to the connection terminals of the touch sensing chip. Self-capacitance electrodes in region, Part G, are led out from the bottom of display area and then directly connected to the connection terminals of the touch sensing chip. Self-capacitance electrodes in region, Part H, are led out from the lower right region of the display area and then led to the connection terminals of the touch sensing chip through the right margin frame of the display area.

In the touch panel provided in one embodiment of the present invention, as shown inFIG. 2, the black matrix layer03may be on a side of the top substrate01facing the bottom substrate02, and a color filter layer may be further provided on the black matrix layer03(RGB inFIG. 2denotes the color filter layer that may generally cover the black matrix layer). When self-capacitance electrodes04and wires05are disposed on the same layer, it is possible to dispose self-capacitance electrodes04and wires05between the black matrix layer03and the color filter layer, or on the color filter layer.

In the touch panel provided in one embodiment of the present invention, as shown inFIG. 7, a first planarization layer08and a spacer layer09over the first planarization layer08may be further provided in order over the black matrix layer03and the color filter layer. The self-capacitance electrodes04and wires05are located between the first planarization layer08and the spacer layer09. This can eliminate the patterning of the first planarization layer08, and wires05disposed on the same layer as self-capacitance electrodes04may be connected with periphery wirings07which are located at the bottom substrate02and electrically connected with the touch sensing chip directly via the margin frame sealant, and this saves the manufacturing process.

In one embodiment, in order to eliminate the touch dead zone in the touch panel, it is possible to dispose self-capacitance electrodes04and wires05in different layers and electrically connect self-capacitance electrodes04with corresponding wires05through via holes. When self-capacitance electrodes04and wires05are disposed in different layers, in order to reduce interference of body capacitance with respect to signals that are transmitted on wires, it is possible to dispose self-capacitance electrodes04between the black matrix layer03and the color filter layer and dispose wires05on the color filter layer. Wires05are connected with self-capacitance electrodes04through via holes in the color filter layer such that self-capacitance electrodes04may shield signal interference invoked by wires05covered by themselves.

In the above-mentioned touch panel provided in the embodiment of the present invention, since patterns of self-capacitance electrodes04are blocked by the pattern of black matrix layer, the total area of the pattern of the mesh structure of the self-capacitance electrodes04is limited by the area of the pattern of a black matrix layer03. In order to increase the area of patterns of self-capacitance electrodes04as much as possible so as to enhance the touch sensitivity, in at least one embodiment, as shown inFIGS. 8aand 8b, it is also possible to provide a second planarization layer10between the black matrix layer03and the color filter layer, and the second planarization layer10has through holes or grooves (blind holes) of for example trapezoid shape at least in regions corresponding to patterns of self-capacitance electrodes04.FIG. 8ashows that the second planarization layer10has through holes of a trapezoid shape in regions corresponding to the patterns of self-capacitance electrodes04, andFIG. 8bshows that the second planarization layer10has grooves of a trapezoid shape in regions corresponding to the patterns of self-capacitance electrodes04. Patterns of self-capacitance electrodes04fill at least in through holes or grooves, and the surface area of self-capacitance electrodes04filled in through holes or grooves is greater than the trapezoid basal area of through holes or grooves. It is possible to increase the area of the patterns of self-capacitance electrodes04in the above-mentioned way. Furthermore, self-capacitance electrodes04disposed in through holes or grooves have a concave-convex structure, and the convex parts as seen from the finger side can aggregate more charges since they are tips. When a finger touches the panel, it is possible to enhance the touch variation and in turn improve the effect of touch sensing.

In the touch panel provided in the embodiment of the present invention, because the body capacitance act on the self-capacitance of self-capacitance electrodes04in a direct coupling mode, when a human body touches the screen, only the self-capacitance electrodes04directly under the touch position is subjected to significant change in their capacitance value, while self-capacitance electrodes04adjacent to self-capacitance electrodes04directly under the touch position is subjected to very slight change their capacitance value. In this way, when the human body touches an area smaller than that of one self-capacitance electrode, the touch position might not be located accurately. Therefore, in the touch panel provided in one embodiment of the present invention, it is possible to configure opposite sides of two adjacent self-capacitance electrodes04as fold lines such that the touch position of the human body can always cover the areas of a plurality of self-capacitance electrodes, therefore it is possible to determine the touch position in the way provided in the embodiment of the present invention.

For example, it is possible to set the overall shape of self-capacitance electrodes04in one of the following ways or in the combination thereof.

(1) The opposite sides of two adjacent self-capacitance electrodes04that are fold lines may be configured as step-like structures such that two opposite step-like structures have consistent and matching structural shapes as shown inFIG. 9a.FIG. 9ashows 2*2 self-capacitance electrodes04.

(2) The opposite sides of two adjacent self-capacitance electrodes04that are fold lines may be configured as concave-convex structures such that two opposite concave-convex structures have consistent and matching structural shapes as shown inFIG. 9b.FIG. 9bshows 2*2 self-capacitance electrodes04.

In one embodiment, in order to reduce mutual interference between display signals and touch signals and enhance picture quality and touch accuracy, in the above-mentioned touch panel provided in the embodiment of the present invention, time-division driving mode may be employed for touch and display phases. Also, in one embodiment, it is also possible to integrate the display driving chip and the touch sensing chip as one chip to further reduce the production costs.

In one embodiment, For example, in the driving timing sequence diagram shown inFIG. 10, the time period for the touch panel to display each frame (V-sync) is divided into a display interval (Display) and a touch interval (Touch). For example, in the driving timing sequence diagram as shown inFIG. 10, the time period for the touch panel to display one frame is 16.7 ms in which 5 ms is selected for the touch interval and the rest 11.7 ms for the display interval. Of course, it is also possible to appropriately adjust durations of both intervals according to processing capacity of the IC chip, which is not specifically limited in embodiments of the present invention. In the display interval (Display), gate signal lines Gate1, Gate2, . . . Gate n in the touch panel are applied with gate scanning signals successively and data signal lines Data is applied with gray scale signals to implement liquid crystal display function. In the touch interval (Touch), the touch sensing chip connected with self-capacitance electrodes Cx1. . . Cxn applies driving signals to touch driving electrodes Cx1. . . Cxn respectively and receives feedback signals from self-capacitance electrodes Cx1. . . Cxn, and determine whether touch occurs by analyzing feedback signals to implement touch function.

Based on the same inventive concept, at least one embodiment of the present invention further provides a display device comprising the above-mentioned touch panel provided in embodiments of the present invention. The display device may be any product or component having display function such as a cell phone, a tablet computer, a TV set, a display, a notebook computer, a digital picture frame and a navigator. The above-mentioned embodiments of the touch panel may be referred to for implementations of the display device, and redundant descriptions will not be repeated any more.

For the touch panel and display device provided in embodiments of the present invention, self-capacitance principle is utilized to dispose a plurality of self-capacitance electrodes arranged in the same layer and independent from each other, at least two self-capacitance electrodes that are provided non-adjacent to each other are connected to the margin frame of touch panel via one wire and then connected to the touch sensing chip for touch position detection via one corresponding periphery wiring. Connecting a plurality of self-capacitance electrodes that are not adjacent to each other to one wire can effectively reduce the overall number of wires in the touch panel, thereby reducing the area of the touch dead zone and guaranteeing touch performance. Furthermore, the number of corresponding periphery wirings decreases with the decrease of the number of wires, which is also advantageous for the design of a narrow margin frame of the touch panel. Furthermore, since a plurality self-capacitance electrodes that are provided non-adjacent to each other are connected via one wire, and adjacent self-capacitance electrodes are connected to the margin frame via different wires, when a human body touches the screen, the touch sensing chip can determine the touch position by determining capacitance variation of adjacent self-capacitance electrodes connected with different wires, which can avoid misjudgment and realize accuracy of touch sensing.

It is understood that one skilled in the art can make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of claims and their equivalents of the present invention, it is intended that the present invention contains these modifications and variations.

The present application claims priority of China Patent application No. 201410157705.4 filed on Apr. 18, 2014, the content of which is incorporated by reference herein in its entirety as part of the present application.