JPH0628104A - Transparent touch panel - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention relates to a transparent touch panel mounted on the upper surface of a display and used as an input switch, and the resistance value of the transparent electrode used when the transparent touch panel is irradiated with light. Prevent decline,
The purpose is to prevent erroneous input of the input position. [Structure] By adding an ultraviolet absorber to the upper panel 1, the ultraviolet rays radiated to the transparent electrodes 3a and 3b are prevented, the resistance value of the transparent electrodes 3a and 3b is prevented from lowering, and the erroneous input of the transparent touch panel is prevented. It is a thing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent touch panel which is mounted on a display such as a liquid crystal and enables input while corresponding to the displayed contents.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to the transparent touch panel shown in FIG.

Reference numeral 21 denotes a polyethylene terephthalate film (hereinafter referred to as PET) having a transparent electrode 3a formed of an indium tin oxide (hereinafter referred to as ITO) film.
2 is a bottom panel made of a glass substrate on which a transparent electrode 3b made of an ITO film is formed.
The upper panel 21 and the lower panel 2 are connected to the transparent electrodes 3a, 3
b are arranged so as to face each other, and are bonded with an adhesive 6. The upper panel 21 and the lower panel 2 are separated by a dot spacer 4 so as not to come into contact with each other when no pressure is applied. As a general method for forming an ITO film for forming the transparent electrodes 3a and 3b on a substrate, a method of forming an inorganic thin film by vapor deposition or sputtering has been known for a long time.
Alternatively, the transparent electrode may be made of tin oxide (SnO ₂ ).

[0004]

In the transparent touch panel having the above structure, when sunlight or the like is applied to the transparent touch panel, the resistance value of the ITO film forming the transparent electrodes 3a and 3b is significantly lowered, and sometimes the operation is performed. When it causes an abnormality or when the panel surface of the transparent touch panel is partially irradiated with light, the resistance value of the ITO film partially decreases and the area resistance value becomes non-uniform. There is a problem in quality such as not being in a true position when converted and input as an input signal.

[0005]

In order to solve the above-mentioned problems, the present invention adds or coats an ultraviolet absorber to an insulating base material constituting at least the light incident side of the upper and lower panels, or Alternatively, a transparent substrate having an ultraviolet absorber is attached to the above panel.

[0006]

As described above, it is possible to provide a transparent touch panel free from erroneous input of position by preventing the ultraviolet ray from being irradiated by the ultraviolet ray absorbent which causes the resistance value of the ITO film to decrease.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Prior to the description of the transparent touch panel of the present invention, the cause of the problem solved by the present invention will be described with reference to FIGS.

FIG. 6 is a graph showing the resistance change rate ((resistance value after light irradiation / resistance value before light irradiation) × 100 (%)) of the ITO film forming the transparent electrode with respect to light irradiation. According to this FIG. 7, the wavelength of the light to be irradiated is 200 to 400.
It is clear that the resistance change is remarkable between nm.

FIG. 7 is a graph showing the light transmittance of a glass substrate used for the upper and lower panels and a transparent insulating material such as PET.

According to the above FIGS. 6 and 7, wavelengths 200 to 400
It is obvious that the change of the resistance value of the ITO film can be prevented by preventing the incidence of ultraviolet rays of nm, and one embodiment of the transparent touch panel of the present invention will be described below with reference to FIG.

The same parts as those in the prior art are designated by the same reference numerals, and the explanation will be omitted. In the figure, 1 is a top panel made of PET to which 70% of benzophenone-based 2-hydroxybenzophenone is added as an ultraviolet absorber. Yes,
As shown in FIG. 7, the light transmittance of this top panel 1 is 4
At 50 nm, it was about 50%, at 380 nm was 2%, and at 360 nm or less, it was almost 0%, and the effect of blocking ultraviolet rays was very large. Results When this transparent touch panel was irradiated with sunlight for 5 hours, the change in resistance value could be suppressed to 5% or less. Since the touch panel of the conventional example has a resistance value change of 35%, it can be greatly improved.

2 to 5 show another embodiment of the present invention. In each of the embodiments shown in FIGS. 2 to 5, the same parts as those in the prior art are designated by the same reference numerals and the description thereof will be omitted. And explain.

According to FIG. 2, reference numeral 1 is the same as the embodiment of FIG. 1, and is a top panel in which a transparent electrode 3a is formed by sputtering an ITO film on PET containing an ultraviolet absorber.
Reference numeral 2 is a bottom panel in which an ITO film is formed as a transparent electrode 3b on a conventional PET that does not contain an ultraviolet absorber. Reference numeral 7 is an acrylic plate that is attached to the bottom of the lower panel 12 to prevent bending.

Also in this embodiment, as shown in FIG. 7, the light transmittance has a large effect of blocking ultraviolet rays at wavelengths of 300 to 380 nm, and the rate of change in resistance when irradiated with sunlight can be greatly improved. It was

According to FIG. 3, reference numeral 11 is an upper panel made of a glass substrate (thickness: 0.2 mm), and a transparent electrode 3a of an ITO film is formed on the lower surface of the upper panel. The PET8 containing the same UV absorber as in the embodiment of FIG.

According to FIG. 4, 11a is a top panel made of a glass substrate (thickness: 0.2 mm), a transparent electrode 3a of an ITO film is formed on the bottom surface, and a PET 18 is bonded to the top surface of the top panel 11. Numeral 19 is an adhesive 19 in which 0.7% of benzophenone-based 2,4 dihydrooxybenzophenone is added as an ultraviolet absorber, and has the above-mentioned constitution to block the ultraviolet rays having a wavelength of 300 to 380 nm in the embodiment of FIG. Can be obtained in the same way as.

According to FIG. 5, 21 is a top panel,
A hard coat layer 22 to which about 0.5% of benzophenone-based 2,4 dihydrooxybenzophenone, which is an ultraviolet absorber, is added is provided on the upper panel 21. The hard coat layer 22 also has an effect of preventing scratches on the surface of the upper panel 21.

In each of the above embodiments, the ultraviolet absorbing function is provided on the upper panel side because the influence of the cathode ray tube located below the lower panel and the backlight of the liquid crystal display is relatively small. In the case of a display with high accuracy or strong irradiation energy, it is also possible to provide a high-performance transparent touch panel by providing the lower panel side with the same ultraviolet ray absorbing function as in the above embodiments. .

[0019]

As is apparent from the above embodiment, the transparent touch panel of the present invention has a transparent upper panel, a transparent electrode provided on the lower side of the upper panel, and an upper side of the lower panel facing the transparent electrode. Since another transparent electrode provided on the above and the upper surface panel facing the incident light or at least one of the lower surface panel is added or coated with an ultraviolet absorber or a transparent substrate having an ultraviolet absorber is laminated, It is possible to provide a high quality transparent touch panel by absorbing ultraviolet rays contained in sunlight and backlight light with an ultraviolet absorber to prevent the above-mentioned transparent electrodes from deteriorating (reduction in resistance value).

[Brief description of drawings]

FIG. 1 is a side sectional view of an embodiment of a transparent touch panel of the present invention.

FIG. 2 is a side sectional view of the other embodiment.

FIG. 3 is a side sectional view of the other embodiment.

FIG. 4 is a side sectional view of the other embodiment.

FIG. 5 is a side sectional view of the other embodiment.

FIG. 6 is a diagram showing the relationship between the wavelength of light of the ITO film and the resistance change.

FIG. 7 is a relational diagram showing the relationship between each wavelength of light of PET and glass used in the conventional example and the top panel which is the main part of the present invention, and the light transmittance at each wavelength.

FIG. 8 is a side sectional view of a conventional transparent touch panel.

[Explanation of symbols]

 1 top panel 2 bottom panel 3a, 3b transparent electrodes

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[Procedure amendment]

[Submission date] September 4, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction content]

The same parts as those in the prior art are designated by the same reference numerals, and the explanation will be omitted. In the description, 1 is an upper surface made of PET to which 0.7% of benzophenone-based 2-hydroxybenzophenone is added as an ultraviolet absorber. As shown in FIG. 7, the light transmittance of the upper panel 1 is about 50% at a wavelength of 400 nm and 2% at 380 nm, 360 nm.
In the following, the effect of blocking ultraviolet rays was greatly increased to almost 0%. Results When this transparent touch panel was irradiated with sunlight for 5 hours, the change in resistance value could be suppressed to 5% or less. Since the touch panel of the conventional example has a resistance value change of 35%, it can be greatly improved.

Claims (1)

[Claims] 1. A transparent upper panel, a transparent electrode provided on the lower side of the upper panel, another transparent electrode provided on the upper side of the lower panel facing the transparent electrode, and a surface for incident light. A transparent touch panel in which a transparent substrate having an ultraviolet absorber added or coated or a transparent substrate having an ultraviolet absorber is bonded to at least one of the upper panel and the lower panel.