JPH06332606A - Analog type transparent touch panel - Google Patents

Abstract

PURPOSE:To provide the analog type transparent touch panel which can execute smoothly a writing input of a character and a line with a pen without spoiling an external appearance. CONSTITUTION:In the transparent touch panel constituted so that a pair of transparent conductive panels 1, 11 constituted by forming conductive films 3, 13 are arranged adjacently through a spacer on insulating base materials 2, 12 so that each conductive film 3, 13 is opposed to each other, and also, a two-dimensional coordinate corresponding to a conducting point of both the conductive films 3, 13 generated by a touch operation is detected as an analog signal, the spacer scatters plastic beads 5 whose diameter is 5-30mum, covered with a thermal adhesive resin 4 onto one conductive film 3, and also, is formed by heating adhesion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is to bond two-dimensional coordinates to a computer or the like by touching them on a display surface of a liquid crystal flat panel display, plasma display, CRT display or the like and touching them with a finger or an input device. The present invention relates to a transparent touch panel used for the purpose, particularly an analog type transparent touch panel.

[0002]

2. Description of the Related Art Liquid crystal displays, plasma displays and CRs are used as input devices for computers, word processors, handy terminals, remote control switches and the like.
A transparent touch panel used on a display device such as a T display is roughly classified into a digital transparent touch panel whose input location is predetermined and an analog transparent touch panel whose entire surface is continuous.

As an analog type transparent touch panel, a pair of transparent conductive panels each having a conductive film formed on an insulating base material are closely arranged via spacers so that the conductive films face each other, and both conductive films generated by a touch operation. It is widely known that two-dimensional coordinates corresponding to the conduction point of the film are detected as an analog signal.

As a spacer used in the transparent touch panel, a transparent resin paste is printed in dots on one conductive film to obtain a clearance at the height of that dot, or a conductive film is formed on one conductive film. In general, a resin is applied and fine glass beads are scattered and fixed on the resin to obtain clearance at the height of the beads.

However, a spacer formed by printing a transparent resin paste in a dot pattern usually has a diameter of 100 μm or more and is visible to the naked eye, thus impairing the appearance.
Also, when writing characters or lines with the pen, there is a problem in that the pen rides up, which hinders the input. Further, in the spacer formed by spraying and fixing the glass beads on the applied conductive resin, it is difficult to obtain glass beads of a uniform size, and it is expensive to have uniform particle diameters by repeating classification. There was a problem.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide an analog type transparent touch panel capable of smoothly writing and writing characters and lines with a pen without damaging the appearance.

[0007]

According to an analog type transparent touch panel of the present invention, a pair of transparent conductive panels each having a conductive film formed on an insulating base material are arranged in proximity to each other with spacers so that the conductive films face each other. In a transparent touch panel arranged to detect two-dimensional coordinates corresponding to conduction points of both conductive films generated by a touch operation as an analog signal, the spacer is coated on one conductive film with a thermal adhesive resin. It is characterized in that plastic beads having a diameter of 5 to 30 μm are dispersed and heat-bonded.

As the plastic beads, for example, vinylbenzene type, styrene type, melamine type, benzoguanamine type, acrylic type resin and the like are used, and the heat-adhesive resin for coating the same is selected from the group consisting of epoxy type resin and acrylic type resin. A selected resin or the like is preferably used.
Also, the plastic beads coated with the heat-adhesive resin are
For example, it is manufactured by a known microencapsulation technique or the like.

As the basic structure of the touch panel, a known structure or a design modified version thereof may be adopted. For example, in the transparent conductive panel, a flexible transparent film made of a plastic film such as polyester, polyether sulfone or the like is used as the insulating base material on the side provided for the input surface for touch operation, and In addition to the flexible transparent film, a hard plastic transparent sheet, a transparent glass plate, or the like is used as the insulating base material on the side facing the display surface. An electrode for applying a potential gradient in a predetermined direction to the conductive film and detecting two-dimensional coordinates corresponding to the conduction point is connected to each transparent conductive panel at a side end of the conductive film.

A transparent metal thin film made of, for example, indium tin oxide (ITO) is suitable for the conductive film.
This is formed on the insulating base material by a method such as vacuum deposition, sputtering, or ion plating.

[0011]

By spraying the plastic beads coated with the thermo-adhesive resin on one conductive film and heating it, the thermo-adhesive resin is cured and the plastic beads are adhered as spacers on the conductive film.

The usable plastic beads have a diameter of 5 to
The size is limited to 30 μm, and if it is less than 5 μm in diameter, insulation failure between both conductive films due to discharge or the like is likely to occur, and if it exceeds 30 μm, it becomes visible to the naked eye and damages the appearance. There is a possibility that it will interfere with the handwriting input by. The spray density of the plastic beads varies depending on the diameter of the plastic beads used, the setting range of the input pressure by touch operation, etc., and is usually adjusted to 5 to 30 beads / mm ² .

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional view of the essential parts of an analog type transparent touch panel according to an embodiment of the present invention.

In the figure, the lower transparent conductive panel 1 is formed by depositing a conductive film 3 made of indium tin oxide on the upper surface of an insulating substrate 2 made of a transparent glass plate having a thickness of 1100 μm by sputtering or the like. Divinylbenzene-based plastic beads 5 having a diameter of 10 μm and coated with an epoxy-based thermo-adhesive resin 4 were sprayed on the film 3 at an average density of 20 particles / mm ² and heated at 180 ° C. for 1 hour to be bonded. Spacers made of beads 5 are formed.

In the upper transparent conductive panel 11, a conductive film 13 made of indium tin oxide is deposited by sputtering on the lower surface of the flexible insulating substrate 12 made of a polyester film having a thickness of 175 μm. Becomes
The conductive films 3 and 13 are arranged close to each other on the lower transparent conductive panel 1 via plastic beads 5 as spacers, and the upper surface of the upper transparent conductive panel 11 serves as an input surface for touch operation. To be done.

Although not shown and described because it is well known, the transparent conductive panels 1 and 11 are provided with a potential gradient in a required direction on the conductive films 3 and 13 and two-dimensional coordinates corresponding to conduction points are detected. Electrodes for this purpose are provided at both ends of the conductive films 3 and 13 by silver paste or the like, and external lead terminals are connected to them.

[0017]

Since the analog type transparent touch panel according to the present invention is configured as described above, it is possible to smoothly write and input characters and lines with a pen without damaging the appearance.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of essential parts of an analog type transparent touch panel according to an embodiment of the present invention.

[Explanation of symbols]

 1 Transparent Conductive Panel 2 Insulating Base Material 3 Conductive Film 4 Thermal Adhesive Resin 5 Plastic Beads 11 Transparent Conductive Panel 12 Insulating Base Material 13 Conductive Film

Claims (3)

[Claims] 1. A pair of transparent conductive panels, each having a conductive film formed on an insulating base material, are closely arranged via a spacer so that the conductive films face each other, and a conductive point of both conductive films generated by a touch operation. In a transparent touch panel configured to detect a two-dimensional coordinate corresponding to the above as an analog signal, the spacer sprays plastic beads with a diameter of 5 to 30 μm coated with a heat-adhesive resin on one conductive film and heat-bonds them. An analog type transparent touch panel characterized by the following. 2. The heat adhesive resin is a resin selected from the group consisting of epoxy resins and acrylic resins.
The analog type transparent touch panel described. 3. Plastic beads 5 to 30 pieces / mm
The analog type transparent touch panel according to claim 1, which is dispersed on the conductive film at a density of ² .