JP2001125724A - Touch panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a touch panel with single-sided electrodes capable of constituting an X side driving electrode and a Y side driving electrode on the conductive film of a lower electrode sheet, reducing the influence of the Y side driving electrode in the case of detecting X coordinates, and reducing the influence of the X side driving electrode in the case of detecting Y coordinates. SOLUTION: This touch panel is composed of the lower electrode sheet, on which a driving electrode 3 and an auxiliary electrode 4 of a conductor having an overlapped part on a lower transparent conductive film 2 are located with the number of potential changes predetermined to make a potential gradient linear, an upper electrode sheet provided with a coordinate detecting electrode on an upper transparent conductive film 9, and an insulating sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a touch panel which is attached to a display device or a liquid crystal display device of a personal computer, and which can be easily input with a fingertip or a pen.

[0002]

2. Description of the Related Art In a conventional touch panel, as shown in FIG. 10, an X-side drive electrode 16 is provided on a lower transparent conductive film 2 on a lower transparent plate 1 and an upper transparent conductive film 9 on an upper transparent plate 6 is provided. It was composed of two electrode sheets provided with the Y-side drive electrodes 17 and an insulating sheet. Usually, the lower electrode sheet is made of glass, and the upper electrode sheet is made of a film.

[0003] However, the transparent conductive film on the film side has a drawback that the life is significantly shorter than that on the glass side, and the life of the touch panel is determined by the life on the film side. Therefore,
In recent years, a method of driving the X coordinate and the Y coordinate on only the glass surface has been proposed.

[0004]

However, since the X-side drive electrode and the Y-side drive electrode are formed on the glass transparent conductive film, the Y-side drive electrode is affected when the X coordinate is detected. Is detected by the X-side drive electrode,
Practical application was difficult.

An object of the present invention is to form an X-side drive electrode and a Y-side drive electrode on a glass conductive film, reduce the influence of the Y-side drive electrode when detecting the X coordinate, and detect the Y coordinate. An object of the present invention is to provide a single-sided electrode touch panel that can reduce the influence of the X-side drive electrode in such a case.

[0006]

In order to achieve this object, the drive electrode 3 and the auxiliary electrode 4 of a conductor having an overlapping portion on the lower transparent conductive film 2 are predetermined so that the potential gradient becomes linear. The lower electrode sheet arranged at the number of potential changes, the upper electrode sheet provided with the coordinate detection electrodes 8 on the upper transparent conductive film 9, and the insulating sheet.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described based on embodiments with reference to the drawings. FIG. 1 shows an embodiment of the present invention. FIG. 1A shows a lower electrode sheet 1 and a lower transparent plate made of glass or a transparent resin plate. Reference numeral 2 denotes a lower transparent conductive film formed by forming a metal oxide film, a composite film mainly composed of a metal oxide, or a metal film by vacuum deposition, sputtering, or the like. 3a, 3b, 3c, 3d drive electrodes and 4a,
4b, 4c, 4d, 4e, 4f, 4g, 4h, 4i, 4
j, 4k, and 4l auxiliary electrodes are formed using a metal paste such as gold, silver, or copper, or a conductive paste such as carbon.
For example, a pattern is formed such that the potential gradient becomes linear as shown in FIG. Reference numeral 5 denotes a spacer which forms dots by printing or a photo process using a transparent resin such as urethane acrylate resin.

FIG. 1B shows an upper electrode sheet, 6 an upper transparent plate, and a transparent resin plate (transparent film) is used. 7
Reference numerals a, 7b, 7c, and 7d denote electrode bonding portions, which are bonded to the drive electrodes 3a, 3b, 3c, and 3d of FIG. 1A with a conductive adhesive.
Reference numeral 8 denotes a coordinate detection electrode which prints a metal paste or the like as shown in FIG. Reference numeral 9 denotes an upper transparent conductive film, and reference numeral 10 denotes an insulating portion which insulates a routing circuit and the like from the transparent conductive film. Reference numeral 11 denotes a routing circuit, and reference numeral 12 denotes a terminal connected to a control circuit by a lead line portion.

FIG. 1C uses an insulating film as the insulating sheet 13. It is set between FIG. 1 (a) and FIG. 1 (b) and insulates the upper and lower adhesive holes 14 and the input area 15 other than the input area 15. The upper electrode sheet and the lower electrode sheet are bonded to the insulating sheet 13 via a double-sided tape or an adhesive to complete the touch panel. Further, the insulating sheet can be replaced with an insulating material such as an insulating tape or a resist, and similar results can be obtained.

FIGS. 2 and 3 show Embodiments 1 and 2 when the touch panel size becomes large. As the size of the touch panel increases, the potential at the center decreases and there is a concern that the voltage utilization rate will decrease, and the linearity of the potential gradient will also decrease. Then, when the size becomes large, the drive electrodes 3e, 3e
By adding f, 3g, and 3h at the center, it is possible to prevent a decrease in the voltage utilization rate. Further, the linearity of the potential gradient can be maintained by increasing the number of auxiliary electrodes.

FIG. 4 is a principle view of the present invention, in which the drive electrode 3 and the auxiliary electrode 4 are printed on the lower transparent conductive film 2 with a conductive paste. Drive electrode 3b and auxiliary electrodes 4a, 4b, 4
If the distance c is small, the current flowing between the electrodes is concentrated on the overlapping portions L1, L2, L3, and L4 of the electrodes to correct the linearity of the potential gradient. For example, when the voltage V1 is applied to the drive electrode 3b and the voltage V2 is applied to the auxiliary electrode 4a, the voltage V3 of the auxiliary electrode 4c is
It is expressed as in Equation 1.

[0012]

(Equation 1)

FIG. 5 shows an embodiment of the present invention in which the number of auxiliary electrodes 4 is increased to further finely correct the potential gradient inside the electrodes. The potential gradient inside the electrode is smoothed by the effects of 4a1, 4b1, and 4c1 in the drawing.

FIG. 6 is an explanatory view of one embodiment (X-side driving) in which the number of potential change points formed on the lower transparent conductive film 2 is six. The lengths of the driving electrode 3 and the auxiliary electrode 4 are ＮN, 1 / N.
N, 1 / 2N can be derived as a reference, and the length of the overlapping portion of the electrodes is such that the potential of the central portion of the auxiliary electrode 4 (upward arrow) is equal to the potential of the central portion of the lower transparent conductive film 2 (downward arrow). Determined by matching. The potential gradient inside the auxiliary electrode is as shown in FIG.

FIG. 7 is a diagram showing a potential gradient inside the transparent conductive film, and FIG. 8 is an explanatory diagram of one embodiment (Y-side drive), showing a potential gradient inside the auxiliary electrode similar to FIG. . FIG.
The potential gradient inside the transparent conductive film during driving on the Y side is shown.

The present invention has been described with reference to the embodiments.
In the present invention, a conductive film (carbon or the like) other than the transparent conductive film can be used, and changing the lower electrode sheet to a film is not excluded from the present invention. Furthermore, various modifications of the form of the drive electrode and the auxiliary electrode are possible within the scope of the present invention, and these are not excluded from the present invention.

[0017]

As described above, according to the present invention,
The following effects are obtained.

By disposing the X-side drive electrode and the Y-side drive electrode on the glass conductive film, the film surface becomes a coordinate detection electrode, and the upper transparent conductive film on the film surface does not affect the coordinate accuracy. Can be greatly extended.

Since the upper transparent conductive film on the film surface does not affect the coordinate accuracy, an inexpensive film can be used, so that the cost of the touch panel can be reduced.

[Brief description of the drawings]

FIG. 1 is an embodiment of the present invention.

FIG. 2 is a first embodiment when the touch panel size is increased.

FIG. 3 shows a second embodiment when the touch panel size is increased.

FIG. 4 is a diagram illustrating the principle of the present invention.

FIG. 5 is an embodiment for further finely correcting the potential gradient inside the electrode.

FIG. 6 is an explanatory diagram of one embodiment (X-side drive).

FIG. 7 is a diagram showing a potential gradient inside a transparent conductive film.

FIG. 8 is an explanatory diagram of one embodiment (Y-side drive).

FIG. 9 is a diagram showing a potential gradient inside a transparent conductive film during Y-side driving.

FIG. 10 is a diagram of a conventional touch panel.

[Explanation of symbols]

 1, lower transparent plate 2, lower transparent conductive film 3, drive electrode 4, auxiliary electrode 5, spacer 6, upper transparent plate 7, electrode bonding part 8, coordinate detection electrode 9, upper transparent conductive film 10, insulating part 11 , Routing circuit 12, lead wire portion 13, insulating sheet 14, adhesive hole 15, input area 16, X-side drive electrode 17, Y-side drive electrode

Claims (1)

[Claims] A lower electrode in which a drive electrode and an auxiliary electrode of a conductor having an overlapping portion on a lower transparent conductive film are arranged at a predetermined number of potential changes such that a potential gradient is linear. A touch panel comprising a sheet, an upper electrode sheet provided with coordinate detection electrodes 8 on an upper transparent conductive film 9, and an insulating sheet.