JP2016151857A - Touch panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a touch panel having a crosswise wiring group including a plurality of linear conductive wires arranged in parallel crosswise and a lengthwise wiring group including a plurality of linear conductive wires arranged in parallel lengthwise, respectively disposed in matrix on two sides of a transparent substrate, the touch panel capable of avoiding moire, reducing a development cycle, improving a production efficiency and coping with a high-definition display device, even if installed in a display device having pixels.SOLUTION: In a touch panel, the width of a conductive wire is equal to or smaller than the wavelength of visible light.SELECTED DRAWING: None

Description

  The present invention relates to a touch panel provided with a horizontal wiring group and a vertical wiring group in a matrix.

  In recent years, a product in which an image display unit of an image display device is provided with a touch panel having wiring patterns in the vertical and horizontal directions has been developed and provided to the market as a product. In an image display device provided with a touch panel, the device can be operated by touching the touch panel with a finger or pen at a position on a pattern such as a figure or a character displayed on the screen. It came to be used for the display device. Furthermore, with the increase in the size of display devices, large touch panels have been developed.

  3A and 3B are explanatory diagrams showing an example of a conventional capacitive touch panel, where FIG. 3A is an explanatory diagram viewed from above, and FIG. 3B is a cross-sectional view of the AA ′ portion of FIG. It is explanatory drawing.

  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 serves as an electrode that receives a change in capacitance between electric conduction or electric field when touched. In FIG. 3, the horizontal conductive lines are drive lines, and the vertical conductive lines are sensing lines. FIG. 4 is an explanatory view of the drive board 112 and the sensing board 111 as viewed from above. A drive substrate 112 (FIG. 4B) provided with a drive line electrode 114 on a glass substrate, a sensing substrate 111 (FIG. 4A) provided with a sensing line on a glass substrate, a drive line electrode 114 and a sensing substrate 111 Are laminated with an optical adhesive sheet OCA (Optically Clear Adhesive) 115. 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 grouped as a sensing electrode and a drive electrode in the black frame 116, and is electrically connected to the display device. Conventionally, the conductive wire is a transparent conductive wire using a transparent conductive film.

  In such a configuration, for example, when touched with a finger on the windshield 117, a change in capacitance at the contacted portion or a change in electric field thereby is output to the sensing electrode and the drive electrode, You can know the coordinate value. The operation content is specified from the display device provided with the touch panel. That is, reading of a signal from the touch panel gives a pulse waveform from the drive line and senses it with the sensing line. Each line is scanned to give a signal, sensed, and read the changed site. In general, the detected signal is processed and detected.

  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. Some use a resin film instead of the windshield.

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. For the metal mesh, for example, a thin metal wire such as copper (Cu) or chromium (Cr) is used.

Special table 2013-525918 gazette Special table 2013-529803 gazette Special table 2014-523599 gazette

  In such a panel usage situation, the following problems arise. That is, as a result of installing the panel on a display substrate having a large number of pixels vertically and horizontally, light interferes between the pixels and the conductive lines of the panel, and moire occurs. Therefore, it is necessary to perform an optimum design according to the display device. is there. For this reason, a fixed design period is required, and when the display device is different, the conductive line pattern may not be diverted. Furthermore, there is a problem that it becomes difficult to cope with an ultra-high definition display device.

  Other touch panels include, for example, a sensor having a resistance value, but a matrix wiring is formed, and the problem of generating moiré is the same.

  The present invention solves such a problem, and a horizontal wiring group composed of a plurality of linear conductive lines arranged in parallel in the horizontal direction, and a plurality of linear patterns arranged in parallel in the vertical direction. A touch panel in which vertical wiring groups made of conductive wires are provided in a matrix, and no moire occurs even when installed on a display device with pixels, while shortening the development period, improving production efficiency, and high-definition display It is an object of the present invention to provide a touch panel that can support a device.

The present invention has been made in view of the problems, and the invention of claim 1
A touch panel having a horizontal wiring group consisting of a plurality of linear conductive lines arranged in parallel in the horizontal direction and a vertical wiring group consisting of a plurality of linear conductive lines arranged in parallel to the vertical direction. There,
The touch panel is characterized in that the width of the conductive line is equal to or less than the wavelength of visible light.

The invention of claim 2 of the present invention
The touch panel according to claim 1, wherein the width of the conductive line is 0.4 μm or less.

The invention of claim 3 of the present invention
The touch panel according to claim 1 or 2, wherein the conductive wire has a thickness of 0.5 to 1 µm.

  Since the capacitive touch panel of the present invention is configured as described above, moire does not occur even when it is installed in a display device having pixels, shortening the development period, improving production efficiency, and achieving a high-definition display device. It can be set as the touch panel which can respond | correspond.

It is typical explanatory drawing which observes generation | occurrence | production of the moire of the touchscreen of embodiment of this invention. It is explanatory drawing which looked at the evaluation panel used for evaluation of moire in the cross section. It is explanatory drawing which showed an example of the conventional electrostatic capacitance type touch panel. It is explanatory drawing which looked at the drive board and sensing board | substrate of FIG. 3 on the upper surface.

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

  In the panel of the present embodiment, a horizontal wiring group composed of a plurality of linear conductive lines arranged in parallel in the horizontal direction and a vertical wiring composed of a plurality of linear conductive lines arranged in parallel in the vertical direction. The group is a panel provided on both sides of the transparent substrate in a matrix, and the width of the conductive line is set to be equal to or less than the wavelength of visible light. As a result of arranging the panel of the present embodiment in the image display unit of the image display device and examining the occurrence of moire, the present inventors have determined that the width of the linear conductive line is less than or equal to the wavelength of visible light. It was confirmed that moire does not occur. Furthermore, moire does not occur at all when the width of the conductive wire is 0.4 μm or less, and the conductive wire itself cannot be seen visually.

  The thickness of the conductive wire is preferably 0.5-1 μm. In this way, the resistance value of the conductive line is reduced, and the signal delay when touched can be eliminated.

  The example of the moire evaluation of embodiment of this invention is shown concretely. FIG. 1 is a schematic explanatory diagram for observing the occurrence of moire in the capacitive touch panel of this embodiment. The evaluation panel 10 of the capacitive touch panel of the present embodiment is disposed on an LCD panel 20 as an image display device. At this time, the evaluation panels 10 and the LCD panel 20 were arranged so as to be parallel to each other, and the evaluation panel 10 was further rotated to observe moire. FIG. 1A is a schematic explanatory view of a state in which the evaluation panel 10 and the LCD panel 20 are arranged in a perspective view, and FIG. 1B is a plan view of a state in which moire is generated in parallel. A schematic explanatory diagram viewed, FIG. 1C is a schematic explanatory diagram viewed from above in a state where moire is not generated by overlapping in parallel. Figures (d) and (e) are schematic diagrams showing the matrix portions of the LCD panel in Figures (b) and (c), and Figures (f) and (g) in the evaluation panel of Figures (b) and (c). FIG. The drawings in FIG. 1 are all shown schematically for explanation, and do not necessarily show actual moiré patterns or matrix patterns.

  FIG. 2 is an explanatory view of the evaluation panel used for the evaluation of moire in a cross section. The evaluation panel 10 includes a horizontal wiring group (not shown) composed of a plurality of linear conductive wires (Cu) 13 arranged in parallel in the horizontal direction on one surface of a transparent substrate (quartz) 11 and a vertical direction. A vertical wiring group composed of a plurality of linear conductive wires 13 arranged in parallel with each other was provided in a matrix by an etching method (FIGS. 2A and 2B). Further, an adhesive (OCA) 15 was applied and adhered thereon with a resin film (PET) 17 (FIG. 2 (b)).

  The transparent substrate 11 had a thickness Ts of 0.7 mm, the conductive wire 13 had a thickness Tf of 0.5 μm, and the conductive wire 13 had a pitch Pf of 420 μm. The film thickness Toca of the adhesive 15 was 50 μm, and the film thickness Tp of the resin film 17 was 100 μm.

Table 1 shows the line width Wf of the conductive wire 13 of the created evaluation sample. The values of the conductive line width Wf were 0.3 μm, 0.4 μm, 0.5 μm, 0.75 μm, 1.0 μm, and 3.0 μm. FIG. 2C shows electron micrographs of the conductive lines in the vertical line, horizontal line, and cross line portions of the sample having a conductive line width Wf design value of 0.3 μm.

  The evaluation results are shown in Table 1 for each evaluation sample. In the evaluation, “line appearance” indicates whether or not the conductive wire (Cu) was visible with the naked eye, ○: not visible, Δ: slightly visible, ×: visible. . The results of moire indicate that ◯: no moiré, Δ: slight moiré occurred, x: moiré occurred. As an evaluation combination, seven image display panels were selected, and the specifications (number of inches, resolution, pixel pitch) are shown in the table.

As an evaluation result, no moiré was generated with a Cu width of 0.5 μm or less. In addition, the Cu width was 0.4 μm or less, and the Cu line was not visible. Even in the image display panel having the highest resolution (440.6 ppi) in this evaluation, moire-free was realized with a line width of 0.5 μm or less, and considering the line appearance, a line width of 0.4 μm or less was a preferable result.

  From this, it can be seen that the touch panel of the present invention can be a touch panel that does not cause moiré even when installed in a display device having pixels, can shorten the development period, improve production efficiency, and can cope with a high-definition display device. It was.

  In addition, in order to confirm the occurrence of moiré for each liquid crystal panel with different definition, the effect of changing the wiring pitch of the touch panel to be superimposed on several types of panels was experimentally confirmed.

<Experiment method>
The three colored pixels of red (R), green (G), and blue (B) are made into one block, and the periphery of each colored pixel is surrounded by a black matrix for shading. Is approximately 3: 1, and three types of liquid crystal panels having a substantially square block were prepared. As the liquid crystal panel, the blocks that are substantially square in three colors,
96 ppi (p = 0.2645 mm), 150 ppi (p = 0.1693 mm), 364 ppi (p = 0.0698 mm)
The three types of liquid crystal panels are two-dimensionally arranged at the pitch p. On the display screen of this liquid crystal panel, a capacitive touch panel having a mesh electrode having a rectangular unit composed of a combination of row wiring and column wiring is overlapped by rotating the touch panel and the display screen to overlap each other. The situation to be visually recognized was evaluated.

As the capacitive touch panel, a sample was prepared in which the pitch P (rectangular side length) of the mesh electrode was changed from 0.20 mm to 0.50 mm every 0.05 mm.

<Experimental result>
96 ppi liquid crystal panel Mesh electrode pitch P (rectangular side length) with a rectangular unit consisting of a combination of row and column wirings in the range of 0.300 to 0.355 mm or 0.410 to 0.450 mm The generation of moire was reduced.
150 ppi liquid crystal panel Generation of moire was reduced when the mesh electrode pitch P was in the range of 0.265 to 0.315 mm.
364 ppi liquid crystal panel The generation of moire was reduced only when the pitch P of the mesh electrode was 0.22 mm, 0.260 mm, and 0.265 mm.

  The effect of the touch panel of the present invention that does not cause moiré will be described in detail.

(1) First, the pattern can be used.
When the size and pixel pitch of the image display unit of the image display device are different, it is basically impossible to use the same touch panel, and it is necessary to individually apply a pattern without moire. However, the touch panel of the present invention can be applied to products of different sizes and pixel pitches, and the design time can be shortened and the production efficiency can be improved.

(2) Moreover, it can respond to high definition.
Since the pixel pitch of the high-definition panel is small, the area where moire does not occur is narrow, and this area may disappear. However, the touch panel of the present invention can cope with future high definition.

(3) The evaluation time can be further shortened.
Currently, in order to design a pattern that does not cause moiré, moiré is evaluated using a TEG (Test Element Group) pattern and the actual image display device. However, in the touch panel of the present invention, it is not necessary to prepare an image display device and evaluate it with the actual product.

  As described above, in the touch panel wiring in which the width of the conductive line is less than or equal to the visible light wavelength (0.4 μm or less), it becomes impossible to resolve the wiring with human eyes, and the wiring pattern itself is difficult to identify. Moire caused by the relationship with the pixels is difficult to be visually recognized. Further, not only the moire but also the occurrence of shading of the wiring and the unevenness of the shade according to the coloring of the wiring can be prevented.

  In the embodiment, the capacitance type touch panel in which conductive wires are provided on both surfaces of the transparent substrate is described. However, the present invention can be applied to a touch panel that reads a change in resistance value, and the same effect can be obtained. It is done. A touch panel in which conductive wires are provided in a matrix on one side of the transparent substrate can also be applied.

10 ... Evaluation panel 11 ... Transparent substrate (quartz)
13 ... Conductive wire (Cu)
15 ... Adhesive (OCA)
17 ... Resin film (PET)
18 ... Drive surface center line 20 ... LCD panel 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

Claims (3)

A touch panel having a horizontal wiring group consisting of a plurality of linear conductive lines arranged in parallel in the horizontal direction and a vertical wiring group consisting of a plurality of linear conductive lines arranged in parallel to the vertical direction. There,
A touch panel characterized in that the width of the conductive wire is equal to or less than the wavelength of visible light.   The touch panel according to claim 1, wherein the width of the conductive line is 0.4 μm or less.   The touch panel according to claim 1 or 2, wherein the conductive wire has a thickness of 0.5 to 1 µm.