JPH03266801A - Antireflection filter - Google Patents

Abstract

PURPOSE:To facilitate the complete wiping away of the traces of finger prints without application of strong force by providing the thin flm of fluoroplastic on the surface of the antireflection film of the antireflection filter. CONSTITUTION:A plastic film is stuck via a tacky adhesive layer to a transparent base material, such as glass plate or plastic plate to form the antireflection film. A material having the refractive index lower than the refractive index of the base material is used for this film. Further, the thin film of the fluoroplastic is provided on this antireflection film. Polytetrafluoroethylene, polyvinyl fluoride or the like is provided at about 3 to 100nm thickness as this thin film. The traces of finger prints are hardly stuck on the surface. In case of the trace of the finger prints sticking thereto, the coefft. of friction of the fluoroplastic surface is small and, therefore, the slipperiness and non- tackiness are high and the traces of the finger prints are completely wiped away without the application of the strong force.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an antireflection filter on which fingerprint marks are easily wiped off.

(Prior art) Displays for office automation equipment are difficult to see due to reflected light from the display surface, so conventionally CRT,
Anti-reflection filters have been used for anti-glare applications such as liquid crystal displays. This type of filter includes a type in which an inorganic multilayer thin film is installed as an anti-reflection layer on a glass plate or a display board, and a type in which an inorganic multilayer thin film is installed on the front of the display as an anti-reflection layer, and a type in which an inorganic multilayer thin film is provided on a plastic film and this film is attached to a glass plate or plastic plate. There are two types: one type in which it is installed in front of the display, and another type in which a plastic film coated with an inorganic multilayer film is bonded directly to the display surface.

By using these filters, the amount of light reflected from the display surface is reduced, greatly reducing glare.

(Problem M to be Solved by the Invention) The surfaces of these antireflection filters are often touched by hands and fingers, and fingerprint marks and the like are often deposited thereon.

If you try to wipe away fingerprints etc. with cloth, paper, etc.
The antireflection layer on the filter surface is softer and more easily scratched than the surface of a glass plate, so it cannot be wiped off with strong force. For this reason, there was a problem in that fingerprint marks could not be completely removed from the filter surface, making the screen extremely difficult to see.

Accordingly, an object of the present invention is to provide an antireflection filter that has a good effect of preventing fingerprints from being attached and which can be easily wiped off.

(Means of rounding to solve the problem) As a result of intensive study to achieve the above object, the inventor has found that
If the outermost surface of the anti-reflection filter is made of a thin layer of fluororesin, which has a low coefficient of friction and is highly slippery and non-adhesive, fingerprint marks will be less likely to adhere without impairing the anti-reflection effect. This invention was completed after learning that even if fingerprint marks were left on the body, they could be easily wiped off with a small amount of force.

That is, in this invention, an antireflection layer consisting of a single layer or multilayer inorganic dielectric thin film is formed on the surface of a transparent base material,
5 further relates to an antireflection filter comprising a fluororesin thin film formed thereon.

Examples of the base material in this invention include a single glass plate, a single plastic plate, a glass plate with a plastic film pasted through an adhesive layer, and a plastic plate with a plastic film pasted through an adhesive layer. Examples include. Any material may be used as long as it has transparency; in the case of a plastic plate,
Specific examples include haphoryester resin, triacetyl cellulose resin (TAC), polycarbosoot resin, polyamide resin, acrylic resin, and polyimide resin.

The thickness of plastic plates made of these materials is:
Although not particularly limited, generally 0.5111~20m1
It is better to be at a certain level.

In the case of glass plates, examples include soda lime glass, potash crown glass, borosilicate glass, aluminum silicate glass, and quartz glass. The thickness of the glass plate made of these materials is the same as that of the plastic plate described above.

Further, in the case of the Puwo Snack Film, the specific example of the material is the same as that of the plastic plate, and the thickness is not particularly limited, but it is generally good to be about 25 to 200 μm.

The antireflection coating provided on the surface of these substrates is composed of a single layer or multiple layers of inorganic dielectric thin films, and in the case of multilayers, the number of layers is generally about 42 to 3 per layer. In the case of a single layer, the refractive index "4" (usually refractive index) is 1.3 to 1.
5). In the case of two layers, from the base material side, in the order of high refractive index material (usually φ is 1.9 to 2.4)/low refractive index material, '! In the case of three layers, from the base material side, medium refractive index materials (usually m is 1.5 to 1.9/high refractive index material/low refractive index material are formed in this order).

Regarding the thickness of each inorganic dielectric thin film, in the case of a single layer,
For example, set the optical film thickness to λ/ for the design wavelength (λ).
4. In the case of two layers, for example, λ/2 from the material on the base material side, human/
4. In the case of three layers, for example, λ/4, λ/
2. It is desirable to satisfy the relationship λ/4.

Specific examples of inorganic dielectric thin film materials for refractive overprinting include ZrO*, Ta z 0H1Ti, and high refractive index materials.
Examples include es, ZnS, Cent, etc. As a medium refractive index material, AmO = % Y dew 0-, Mg 01C
eF, etc.

In addition, as low refractive index materials, SiO, MgF snow, L
Examples include iF, N1M AIRs NaF, and the like.

Furthermore, the fluororesin thin film provided on this antireflection layer is specifically made of polytetrafluoroethylene (
PTF'E), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (
FEP), polychlorotrifluoroethylene (PCTF
E), tetoffluoroethylene-ethylene copolymer (
ETFE), chlorotrifluoroethylene-ethylene copolymer (ECTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF)
Examples include. The thickness of the fluorine IR fat film made of these materials is limited to an extent that does not impair the antireflection effect of the antireflection film, and is preferably about 3 to 1100 nm.

(Effects of the Invention) As described above, according to the present invention, by providing the fluororesin thin film on the surface of the antireflection film of the antireflection filter, it becomes difficult for fingerprint marks to adhere to the surface, and it also prevents fingerprint marks from adhering to the surface. The fluororesin surface has a small coefficient of friction, so even if it gets stuck, the anti-reflection filter is highly slippery and non-adhesive, making it possible to completely wipe away finger squeeze marks without applying strong force. be.

(Examples) Below, examples of the present invention will be described and explained more specifically.

Example 1 In order to configure the base material by laminating a plastic film to a plastic plate via an adhesive layer, a transparent acrylic resin plate with a thickness of 8111J1 was used as the plastic plate.
A transparent polyethylene terephthalate (PET) film with a thickness of 1004 m was used as the plastic film.

A Zr0t film with a thickness of 124 fP and a 5ins film with a thickness of 87 nm were successively formed on one side of this PET film as an antireflection film by electron gun vacuum evaporation.

Next, a PFA thin film with a thickness of 5 nm was formed on this Stow film by a resistance heating vacuum evaporation method. This antireflection filter was obtained.

This anti-reflection filter has a wavelength of 400 to 700 nm.
The average reflectance of visible light is approximately 1.0%, which means that the anti-reflection effect is not impaired even when compared to an anti-reflection filter that does not have a PFA thin film (average visible light reflectance of approximately 09%). Fingerprint marks could be easily erased by wiping them with gauze.

Example 2 On one side of a 100 μm thick transparent TAC film, in the same manner as in Example 1, Y with a film thickness of 75 nm, 0. Film, film thickness 1
10nm 'pio snow film and film thickness g7nm 5ins
The films were sequentially formed, and then a film thickness of tonm was formed on the 5-ins film.
The anti-reflection filter of the present invention was obtained by forming a PTFE film and further laminating a 3U thick transparent acrylic resin plate to the other surface of this TAC film using a transparent adhesive. The average visible light reflectance of this filter is approximately 0.
At 6%, it was not significantly inferior to an anti-reflection filter without a PTFE thin film (visible light average reflectance of approximately 0.58%) as a finger squeeze prevention layer, and it was less likely to attract fingerprint marks. .

Claims (1)

[Claims] An anti-reflection filter comprising an anti-reflection film made of an inorganic dielectric thin film formed on the surface of a transparent base material, and a fluororesin thin film further formed on this anti-reflection film.