JP2011003169A - Capacitive touch panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a capacitive touch panel whose electrodes are not visible.SOLUTION: The capacitive touch panel includes: an upper electrode on which a glass plate or a resin plate coated on the whole surface with ink matched with the same color as a transparent conductive polymer with a touch plate on the rear side is stuck on the uppermost part and which is made of thin stripes printed with conductive ink containing PEDOT/PSS (polyethylene dioxythiophene/polystyrene sulfonate); and a lower electrode which is made of the same PEDOT/PSS and is made of thin stripes perpendicular to the upper part. Alternately, a film coated on the whole surface with ink matched with the same color as a conductive polymer may be stuck on the lower side of the touch plate as a design sheet. The capacitive touch panel uses the ink containing the PEDOT/PSS as the conductive polymer with the thin strips of the upper electrode and the lower electrode.

Description

    The present invention relates to a transparent capacitive touch panel.

Conventional technology

  Conventionally, there is a capacitive touch panel as one of display panels and ticket machines for portable devices such as game machines, mobile phones, and car navigation systems for automobiles. Conventional transparent touch panels have often used ITO (Indium Tin Oxide), which is a metal oxide, but there is a problem that it is vulnerable to bending and expensive. The conductive polymer is resistant to bending and has heat resistance, but it has a disadvantage that since it is light blue, the pattern is easily visible and it is difficult to produce a product.

    The present invention provides a light blue transparent touch panel that is difficult to see an electrode in a capacitive touch panel composed of transparent and light blue conductive polymer electrodes.

  In the present invention, since the conductive polymer has a light blue color, the electrode pattern is easy to see and it is difficult to make it into a product. Therefore, the pattern can be made invisible by coating the design plate with ink that is toned in the same color as the conductive polymer. It is characterized by doing.

  Hereinafter, the present invention will be described in detail. As the base material of the touch plate used in the present invention, glass or plastics plate can be used. Specifically, any glass can be used as long as it is an insulating material such as soda lime glass and heat resistant glass. Thickness is 0.3-5 mm, and the plastics plate can be a transparent acrylic plate, polycarbonate (PC), polyimide (PI), etc. having a thickness of 0.2-5 mm. A transparent film of ~ 0.2 mm can be used. If the thickness is 0.2 mm or less, the strength does not exist, and if it is 5 mm or more, the sensitivity becomes dull and input becomes difficult.

  As a design film, a transparent film having a thickness of 0.025 to 0.2 mm, such as polyethylene terephthalate (PET), polyimide (PI), polyethylene naphthalate (PEN), polyethersulfone (PES), polyimide (PI), etc. Can be used. If the thickness is 0.025 mm or less, the strength is not obtained. If the thickness is 0.2 mm or more, the sensitivity becomes low and input becomes difficult.

The design plate or film may be provided with a normal printing method such as a gravure printing method, a screen printing method, or an offset printing method.
Ink used for patterning is made of polyvinyl resin, polyamide resin, polyester resin, acrylic resin, polyurethane resin, polyvinyl acetal resin, polyester urethane resin, cellulose ester resin, alkyd resin, epoxy resin It is preferable to use a colored ink containing a resin such as a binder and an appropriate color pigment or dye as a colorant.
The film may be patterned and affixed to glass or plastics plates, or printed directly on glass or plastics plates.

  The conductive ink used for the electrode is preferably an ink containing PEDOT / PSS (polyethylenedioxythiophene / polystyrene sulfonic acid). This is because it is a light blue transparent ink that can be screen printed. Moreover, since the resistance value of the ink containing PEDOT / PSS can be lowered, an electrode power supply line can also be formed. The power supply line may be a silver paste having a low resistance value.

  As a method for forming the electrode, a normal printing method such as a gravure printing method, a screen printing method, or an offset printing method can be used. The thickness of the conductive ink layer is desirably 1 to 50 μm. This is because if the thickness is less than 1 μm, there is a fear of disconnection of the power supply line, and if it exceeds 50 μm, the bluish color is strong and the transparency is deteriorated. The line width is preferably 20 μm to 500 μm. When the line width is less than 20 μm, the resistance value is too high, and when it is thicker than 500 μm, the line is too visible and the transparency is deteriorated.

  The electrode film may be bonded by bonding the upper electrode and the lower electrode with a notch, or may be bonded on the surface or on the back. The connectors should be installed accordingly.

  According to the capacitive touch panel of the present invention, a pattern can be formed directly by screen printing without using an expensive ITO (indium tin oxide) film, so that a capacitive touch panel using the static electricity of the human body can be obtained. However, although the conductive ink is transparent, it has a light blue color and the pattern is visible, so it is printed with the same color as the ink except for the pattern, so it does not seem that there is a pattern at all in appearance. become. Moreover, it can function as a capacitive touch panel.

As shown in FIG. 1, an acrylic plate having a thickness of 3 mm is used as the touch plate 1, and the entire surface is printed with an acrylic ink toned in the same color as that of the conductive ink.
125 μm PET (polyethylene terephthalate) is used as the upper electrode film 4, and 50 μm line width stripes are screen printed with conductive ink containing PEDOT / PSS (polyethylenedioxythiophene / polystyrene sulfonic acid) in the X direction. To do. On the other hand, a stripe having a line width of 50 μm is screen-printed with the conductive ink containing PEDOT / PSS in the Y direction orthogonal to the upper electrode as the lower electrode film 5.
The touch plate 1, the upper electrode film 4, and the lower electrode film 5 are bonded together with a double-sided adhesive film as shown in FIG. When viewed from above, the resulting touch panel has electrodes intersecting at right angles as shown in Fig. 1, and since the entire surface is coated with the same color as the electrode, the pattern is completely invisible. It worked when touched.

  As shown in FIG. 3, the ink is toned in the same color as the ink containing PEDOT / PSS on the upper surface of the PET film having a thickness of 25 μm through the double-sided adhesive sheet 3 under the touch plate 1 made of a glass plate having a thickness of 2 mm. The design film 2 printed on the entire screen is pasted, and the upper electrode film 4 on which a 20 μm stripe line is screen printed in the X direction with an ink containing PEDOT / PSS is pasted on the upper surface of a 125 μm thick PET film. On the other hand, a lower electrode film 5 obtained by screen-printing a stripe having a line width of 20 μm in the Y direction perpendicular to the upper surface of a 125 μm-thick PET film with an ink containing PEDOT / PSS is pasted through a double-sided adhesive film 3. In addition, a capacitive touch panel was made. When viewed from the top, the entire surface is light blue and the pattern is completely invisible. When touched with a finger as a touch panel, it functions and is completed as a capacitive panel.

Is the top view of the product from above Is a cross-sectional view of the product from the side Is a cross-sectional view of a product with a design film pasted under the touch panel

DESCRIPTION OF SYMBOLS 1 Touch board, such as acrylic or glass 2 Design film 3 Double-sided adhesive sheet 4 Upper electrode film 5 Lower electrode film 6 Electrode 7 Feed line

Claims (3)

  A conductive ink containing PEDOT / PSS (polyethylenedioxythiophene / polystyrene sulfonic acid), with a glass plate or resin plate coated on the entire surface with an ink toned in the same color as the transparent conductive polymer on the back as a touch plate on the top. A transparent capacitive touch panel consisting of an upper electrode made of thin stripes printed on and an upper electrode made of a transparent conductive polymer containing PEDOT / PSS and a lower electrode of thin stripes orthogonal to the upper electrode   A film coated entirely with an ink toned in the same color as the conductive polymer may be attached as a design sheet under the touch plate of claim 1. Capacitive touch panel characterized by using an ink containing PEDOT / PSS (polyethylenedioxythiophene / polystyrene sulfonic acid) as a conductive polymer for thin stripes of upper and lower electrodes

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