JP2016151985A - Capacitance touch panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a capacitance touch panel having a crosswise wiring group including a plurality of conductive wires arranged in parallel in a crosswise direction and a lengthwise wiring group including a plurality of conductive wires arranged in parallel in a lengthwise direction respectively on both sides of a transparent substrate in matrix, the capacitance touch panel capable of avoiding deterioration of operability of the touch panel, with regard to a touch panel substrate with a curved surface.SOLUTION: In a capacitance touch panel, a surface having a wiring group is warped, and a wiring interval is changed in proportion to a vertical distance of a crosswise wiring group and a lengthwise wiring group.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a capacitive touch panel.

  The touch panel can operate the apparatus by touching a pattern such as a figure or a character displayed on the screen with a finger or a pen. In recent years, it has been provided and used on a display screen of a display device mainly including a mobile device. Furthermore, with the increase in the size of display devices, large touch panels have been developed.

  5A and 5B are explanatory views showing an example of a conventional capacitive touch panel, where FIG. 5A is an explanatory view seen from above, and FIG. 5B is a cross-sectional view of a part of AA ′ portion of FIG. It is explanatory drawing seen by.

  The capacitive touch panel 100 has a configuration in which a plurality of conductive lines arranged in parallel in the horizontal direction and a plurality of conductive lines arranged in parallel in the vertical direction are provided on a glass substrate in a matrix. Each conductive line is an electrode that receives a change in capacitance between the conductive when touched. In FIG. 5, the horizontal conductive lines are drive lines and the vertical conductive lines are sensing lines. FIG. 6 is an explanatory view of the drive substrate 112 and the sensing substrate 111 as viewed from above.

  A sensing line is provided on the glass substrate via an optical adhesive sheet OCA (Optically Clear Adhesive) 115 on the drive line electrode surface side of the drive substrate 112 (FIG. 6B) provided with the drive line electrode 114 on the glass substrate. The sensing substrate 111 (FIG. 6A) is laminated on the glass substrate side (FIG. 5B). The surface of the sensing substrate is covered with the windshield 117 through the OCA 115. The windshield 117 serves to form and protect the surface of the capacitive touch panel 100. A black frame 116 is provided on the back surface of the windshield 117 around the display portion. Each line electrode is gathered as a sensing electrode and a drive electrode in the black frame 116, and is electrically connected to the display device via a control circuit or the like. Conventionally, the conductive wire is a transparent conductive wire using a transparent conductive film.

  With such a configuration, when the finger touches the windshield 117, for example, the capacitance between the sensing electrode and the drive electrode at the contact position changes, and the coordinate value can be known from the change amount. I can do it. Thereby, the operation content is displayed on the display device.

  As a configuration of an actual touch panel, such a drive substrate or a sensing substrate often has a configuration in which a pattern is formed on a film-like base material to form a touch panel sensor and is attached to a glass substrate. Moreover, what formed the pattern in the film-form base material is made into a board | substrate, and is utilized as a touch panel. In that case, a sensing line and a drive line are provided on the film surface, respectively, to serve as a sensing surface and a drive surface.

  In recent years, such touch panels have been increased in size, and touch panels using metal mesh have been developed and put into practical use. This is a replacement of a conventional ITO (indium-tin-oxide) panel used as a transparent conductive wire with a metal mesh made of a mesh-like metal. Metal mesh has a lower sheet resistance than ITO and is suitable for increasing the size of touch panels.

  Each conductive line (electrode line) is shown as a single line in FIGS. 5 and 6, but is usually composed of a plurality of parallel conductive lines (wire lines).

JP 2013-045150 A

  In recent display devices, due to the versatility of display devices, a panel having a distorted shape has been required. On the other hand, the sensitivity varies due to the variation between the sensors on the panel.

  The capacitive touch panel sensor that forms the metal mesh sensor has a film with metal wires on the drive surface and sensing surface (hereinafter referred to as sensor film) facing each other with an insulator in between. It is composed. The intervals between the metal wires arranged on the sensor film (wire pitch L) are arranged at equal intervals, and the drive surface and the sensing surface are overlapped to form a uniform lattice (FIG. 7).

  FIG. 7 is a partial explanatory view of the central portion of the metal mesh capacitive touch panel as viewed in plan. The sensing wire 123 is arranged in the vertical direction, and the drive wire 124 is arranged in the horizontal direction. For such an arrangement, one electrode wire consists of a plurality of predetermined wires (four wires in the figure). From the electrical signal obtained by this sensor, the coordinate value of the panel is determined by sensing and driving. The intersection of the electrode lines is associated with one coordinate value (node... Node). In the figure, both the drive surface and the sensing surface correspond to one coordinate with four wires. Further, the wire pitch 126 on the drive surface and the wire pitch 125 on the sensing surface have the same value L, and the node pitch 128 on the drive surface and the node pitch 127 on the sensing surface have the same value N.

  The wire pitch L is related to the sensitivity P, and as L increases, the sensitivity P defined by Equation 1 increases (FIG. 3). 3A and 3B are explanatory diagrams schematically showing the characteristics of capacitance and sensitivity P. FIG. 3A is a diagram illustrating characteristics with respect to the wire pitch L, and FIG. 3B is a diagram illustrating characteristics with respect to the drive-sensing interval R. It is.

Sensitivity P = (C−C ′) / C (Equation 1)
C: Capacitance when there is no touch C ′: Capacitance when touching Capacitance when touching with a finger is assumed to be touched by a 9 mmφ conductor rod.
The drive-sensing gap R is uniform, and the sensitivity P when touching the panel is uniform.

  However, when either (or both) of the drive surface and the sensing surface of the capacitive touch panel are curved surfaces (FIG. 4), the drive-sensing gap R varies depending on the touch position. FIG. 4 is an explanatory diagram schematically showing an example in which the drive surface and the sensing surface are curved surfaces. Figures (a) and (b) show examples where the sensing surface is a curved surface, Figures (c) and (d) show examples where the drive surface is a curved surface, and Figures (e) and (f) show examples where the drive surface and the sensing surface are curved. Since the drive-sensing gap R also affects the sensitivity P (FIG. 3B), if the metal mesh pattern is the same as that of the flat surface, the sensitivity P changes depending on the touch position, and the operability as a touch panel is impaired. It is.

  This invention solves such a problem, and makes it a subject to provide the electrostatic capacitance touch panel with which the operativity of a touch panel is not impaired with respect to a curved-surface-shaped touch panel board | substrate.

The present invention has been made in view of the problems, and the invention of claim 1
A horizontal wiring group consisting of a plurality of conductive lines arranged in parallel in the horizontal direction and a vertical wiring group consisting of a plurality of conductive lines arranged in parallel in the vertical direction are arranged on both surfaces of the transparent substrate in a matrix form, respectively. A capacitive touch panel provided,
The capacitive touch panel is characterized in that the surface on which the wiring group is provided is distorted and the wiring interval is changed in proportion to the vertical distance between the horizontal wiring group and the vertical wiring group.

The invention of claim 2 of the present invention
The capacitive touch panel according to claim 1, wherein the wiring interval is such that the capacitance at each matrix intersection when not touched is uniform.

The invention of claim 3 of the present invention
The capacitive touch panel according to claim 1 or 2, wherein the wiring interval is wired so that the sensitivity at each matrix intersection is uniform.

The invention of claim 4 of the present invention
4. The capacitive touch panel according to claim 1, wherein the conductive wire is a metal conductor.

The invention of claim 5 of the present invention
The node representing the coordinates of the matrix is composed of a plurality of conductive lines, the node pitch width varies depending on the vertical distance between the horizontal wiring group and the vertical wiring group, and the pitch of the conductive lines belonging to the same node is the same. The capacitive touch panel according to any one of claims 1 to 4, wherein the capacitive touch panel is provided.

  Since the capacitive touch panel of the present invention is configured as described above, it can be a capacitive touch panel that does not impair the operability of the touch panel with respect to a curved touch panel substrate.

It is typical explanatory drawing which looked at the example of an embodiment of the metal mesh capacitive touch panel of the present invention in the perspective view. It is the typical partial explanatory view which looked at the metal mesh touch panel sensor of the embodiment of the present invention in the plane. FIG. 4A is an explanatory diagram schematically showing characteristics of capacitance and sensitivity P. FIG. 5A is a diagram illustrating characteristics with respect to the wire pitch L, and FIG. 5B is a diagram illustrating characteristics with respect to the drive-sensing interval R. FIG. It is explanatory drawing which showed typically the example whose drive surface and sensing surface of a touchscreen are curved surfaces. It is explanatory drawing which showed an example of the conventional electrostatic capacitance type touch panel, (a) is explanatory drawing seen from upper direction, (b) is the description which looked at a part of AA 'part of FIG. FIG. It is explanatory drawing which looked at the drive board | substrate and sensing board | substrate of FIG. 5 in the upper surface. It is the partial explanatory view which looked at the center part of the metal mesh capacitive touch panel in the plane.

  Hereinafter, modes for carrying out the present invention will be described.

  In this embodiment, a horizontal wiring group composed of a plurality of conductive lines arranged in parallel in the horizontal direction and a vertical wiring group composed of a plurality of conductive lines arranged in parallel in the vertical direction are transparent in a matrix form The present invention can be preferably applied to a capacitive touch panel provided on both sides of a substrate, particularly a metal mesh capacitive touch panel in which a wiring group uses wires. The transparent base material is distorted, and the wiring is arranged with the wiring interval changed in proportion to the vertical distance between the horizontal wiring group and the vertical wiring group.

  Further, the wiring intervals are arranged so that the capacitance at each matrix intersection when not touched is uniform and the sensitivity is uniform.

  The example of embodiment of this invention is shown concretely. FIG. 1 is a schematic explanatory view of an embodiment of a metal mesh capacitive touch panel according to the present invention as seen in perspective. Drawing 2 is a typical fragmentary explanatory view which looked at the metal mesh touch panel sensor of an embodiment in the plane. In the example illustrated in FIG. 1, the touch panel 10 has a sensing surface 11 having a concave shape and a drive surface 12 having a planar shape. FIG. 2 shows an example of a touch panel in which wires having such a shape and uniform sensitivity are arranged, and the number of wires is determined for each node to be conductive lines. In this example, the metal mesh wire patterns of the drive surface 12 and the sensing surface 11 are changed from the outer periphery of the sensor toward the center by changing the node pitch and the wire pitch interval, and the two are combined. The number of driver wires 14 and sensing wires 13 for each node is M1 for node 2 at the center of the touch panel and M2 for node 1 at the periphery of the touch panel, but here, specifically, M1 = M2 = 3.

  As a method of forming such an arrangement of shapes, it is effective to arrange the arrangement of wires for simulation data at a temporary pitch value, perform an electromagnetic field simulation, and rearrange the arrangement. To illustrate the method below, from the drive-sensing gap R on the center line 15 of the sensing surface 11 so that the sensitivity P becomes a constant value based on the data shown in FIG. 3 and the previous data, The provisional value of the wire pitch L is determined. That is, based on the fact that the sensitivity P and the capacitance are inversely proportional to the gap R and proportional to the wire pitch L, the provisional values are determined. At this time, in this example, the gap R is selected from the outer circumference of the sensor toward the center, and the value of the wire pitch L is determined for each of the number of wires M1 and M2 for each node with respect to the value of one gap R. Similarly, the pitch L is determined with respect to the drive surface center line 18. This is arranged in a matrix. Then, a simulation is performed, and when the sensitivity P shift occurs, the value of the wire pitch L is corrected at any time, and is repeated until the sensitivity P shift falls within an allowable range. For the simulation, commercially available electromagnetic field simulation software can be used.

In this example, the number of wires for each node (conductive wire) is the same, but this is not particular.
The correspondence between the number of wires and the node (conductive line) can be processed by software in the signal output from the touch panel sensor.

  Further, the number of wires is not limited for each node, and the wire pitch L may be determined in accordance with the value of the gap R. In this case, for example, as in the above example, the correspondence between the signal from each wire output from the touch panel sensor and the conductive line may be coordinate-processed by software.

DESCRIPTION OF SYMBOLS 10 ... Capacitive touch panel 11 ... Sensing surface 12 ... Drive surface 13 ... Sensing wire 14 ... Drive wire 15 ... Sensing surface center line 16 ... Node wire (drive side) )
17 ... Node wire (sensing side)
18 ... Drive surface center line 100 ... Capacitive touch panel 111 ... Sensing line substrate 112 ... Drive line substrate 113 ... Sensing line electrode 114 ... Drive line electrode 115 ... OCA
116 ... black frame 117 ... windshield 123 ... sensing wire 124 ... drive wire 125 ... sensing wire pitch 126 ... drive wire pitch 127 ... sensing node pitch 128 ... drive node pitch

Claims (5)

A horizontal wiring group consisting of a plurality of conductive lines arranged in parallel in the horizontal direction and a vertical wiring group consisting of a plurality of conductive lines arranged in parallel in the vertical direction are arranged on both surfaces of the transparent substrate in a matrix form, respectively. A capacitive touch panel provided,
A capacitive touch panel, wherein a surface provided with a wiring group is distorted, and a wiring interval is changed in proportion to a vertical distance between a horizontal wiring group and a vertical wiring group.   The capacitive touch panel according to claim 1, wherein the wiring interval is such that the capacitance at each matrix intersection when not touched is uniform.   The capacitive touch panel according to claim 1, wherein the wiring interval is wired so that the sensitivity at each matrix intersection is uniform.   4. The capacitive touch panel according to claim 1, wherein the conductive wire is a metal conductor.   The node representing the coordinates of the matrix is composed of a plurality of conductive lines, the node pitch width varies depending on the vertical distance between the horizontal wiring group and the vertical wiring group, and the pitch of the conductive lines belonging to the same node is the same. The capacitive touch panel according to claim 1, wherein the capacitive touch panel is characterized in that:

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