JP2002189422A - Film and protective filter for plasma display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve color reproducibility based on the light emitting characteristics of a plasma display. SOLUTION: The film for a plasma display is obtained by uniformly coating the top of a transparent film with a resin coating solution containing a dye having the absorption maximum at 575-595 nm wavelength and removing the solvent by drying to form a film containing the dye and having 1-50 μn thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color reproducibility improving film for improving the image quality of a plasma display.
The present invention relates to a film directly attached to the front surface of a panel of a plasma display, a front protection filter set on the front surface of the panel, and an electromagnetic wave shielding front protection filter.

[0002]

2. Description of the Related Art Conventionally, a display has been CR
T (Cathode Ray Tube) was the mainstream, but recently FPD (Flat Panel Di)
spray) has been developed and commercialized. However,
LCD (Liquid Crystal Di), which is expanding its market by utilizing functions such as thinness, light weight, and low power consumption
Spray is widely used, but PDP (Plasma Display) which is thin and is applied to a large screen.
y Panel) is attracting attention.

However, for example, the basic structure of a DC-type plasma display is to selectively discharge and emit phosphors in a large number of display cells separated between two glass plates. A partition, a display cell, an auxiliary cell, and the like are arranged therebetween, and a red phosphor, a green phosphor, and a blue phosphor are provided in a film on the inner wall of each display cell.
These phosphors emit light when discharged by the voltage applied to the cathode, display anode, and auxiliary anode.

[0004] As described above, a plasma display panel utilizes a light emission phenomenon caused by gas discharge, so that a large current flows and a magnetic field is generated. Therefore, there is a concern that the electromagnetic waves generated from the plasma display panel may affect the human body and other electronic devices, and an electromagnetic wave shielding filter is generally attached. In parallel with this, improvement in color reproducibility has also been a major issue due to emission characteristics associated with gas discharge.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to improve the color reproducibility based on the light emission characteristics of a plasma display. Conventionally, unnecessary light emission derived from neon gas of a plasma display has been selected for this purpose. Improvement of color reproducibility using a dye that absorbs chemically has been studied. Specifically, a film containing a selective absorption dye is used.However, in a method in which a dye is mixed with a film resin to form a film by extrusion molding, it is necessary to melt the resin at a temperature of at least 200 degrees C. There has been a problem that the pigment deteriorates or discolors even with time.

[0006]

The first aspect of the present invention is characterized in that:
A plasma display in which a binder resin coating solution containing a dye having an absorption maximum wavelength at 75 to 595 nm is uniformly applied on a transparent film, and then the solvent is dried to form a film having a thickness of 1 to 50 microns containing the dye. It depends on the film for use. And especially, it is a film having a light transmittance of 585 nm of 50% or less.

Further, a feature of the second invention is a front protective filter for a plasma display, comprising an antireflection layer on one side of the film of the first invention via an adhesive layer,
More specifically, it is a filter in which the film is bonded to a transparent substrate. Above all, particularly preferably, the filter has a visible light transmittance of 35% or more and 850 to 100.
The transmissivity at 0 nm is 15% or less, and the transmissivity at 585 nm is 35% or less.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION As described above, the present invention applies a coating solvent containing an organic solvent, a binder resin and a dye uniformly on a transparent film, and then dries the solvent to obtain a film having a thickness of 1 to 50 containing the dye. The most distinctive feature is that a micron film was formed, and as a result, a film with little deterioration was produced without being exposed to high temperatures.

Examples of the binder resin constituting the film include an acrylic resin represented by polymethyl methacrylate (PMMA), a polycarbonate resin, an ABS resin, and the like, but are not limited thereto.

[0010] As a selective absorption dye of neon emission used for cutting unnecessary light peculiar to neon gas, cyanine type, squarylium type, anthraquinone type, phthalocyanine type, polymethyl type and polyazo type are mentioned. That is, the selective absorption dye is 585 n
It is necessary that the selective absorption of neon emission near m and the absorption be small for other visible light wavelengths, and that the absorption maximum wavelength is 575-595 nm and the half width of the absorption spectrum is 40 nm or less. It is preferably used. And
As the selective absorption, the transmittance of a 585 nm film is 5
Desirably, it is 0% or less. Of course, as long as it does not significantly affect the optical properties, a coloring dye,
You may add an ultraviolet absorber and an antioxidant.

Furthermore, among the fluorescent emission colors of the plasma display, the peak around 590 nm is close to vermilion, which causes deterioration of color reproducibility and causes poor color purity and color reproducibility. I have. Therefore, by using the above-mentioned dye, the peaks near the wavelengths of 590 and 600 nm are canceled out, whereby the redness of the RED spectrum can be improved.

When this film is directly bonded to a plasma display, a general acrylic pressure-sensitive adhesive or adhesive can be used. When using an anti-reflection film from the viewpoint of improving image quality, a multilayer anti-reflection layer may be directly formed on the surface opposite to the coating surface of the film, and the film on which the anti-reflection film is formed is further laminated. Is also good.

This film can be used as a front protective filter for a plasma display by bonding it to a transparent substrate having a thickness of about 2 to 6 mm. Glass, an acrylic plate, and a polycarbonate plate are suitable as the transparent substrate. If anti-reflective property, electromagnetic wave shielding property, and near-infrared cut property are required as the function of the front protective filter, attach an anti-reflection (AR) film, anti-glare film, transparent conductive film, conductive mesh, near-infrared absorbing film, etc. May be combined.

It is desirable that the final optical characteristics of this protective filter be adjusted so that the visible light characteristics are 35% or more and the near-infrared absorption characteristics are 15% or less in the range of 850 nm to 1000 nm. Further, as the selective absorption characteristic, it is desirable that the transmittance at 585 nm is 35% or less.

[0015]

[Example] Tetrahydrofuran, methyl ethyl ketone,
A methacrylic resin (PMMA) was dissolved in a mixed solvent of toluene and cyclohexanone at a ratio of 8% by weight to prepare a paint base.

To this, a near-infrared absorbing dye is added to form a paint.
Obtained. This paint is applied to a transparent polyester with a gravure coater.
Apply it evenly to the steal equipment and apply the solvent in a drying oven at 12 ° C.
And dried to form a resin layer having a thickness of 5 μm. What
The pigment amount is about 0.15g / m ^Two Met.

The selective absorption dye is Aquarylium Dye A in Example 1, Aquarylium Dye B in Example 2, and Cyanine Dye C in Example 3, and any binder resin is used. It was PMMA, and the film thickness was 5 μm in each case.

FIGS. 1, 2, and 3 are graphs showing the absorption spectra of squarylium dyes A and B and cyanine dye C, respectively.

FIGS. 4, 5 and 6 are graphs showing transmission spectra of the films of Examples 1 to 3, respectively.

As can be seen from FIGS. 4 to 6, the film transmission spectrum has a characteristic that the transmittance is greatly reduced at 575 to 595 nm.

However, the emission spectrum of the RED system has a peak near a wavelength of 590 to 600 nm in addition to a peak near a wavelength of 630 nm which originally corresponds to bright red.
For example, the peak near 590 nm is close to orange and causes deterioration in color reproducibility. Also, GREE
The emission spectra of N and BLUE also include red-based noise having a high wavelength, and thus deteriorate color reproduction. These are spectra specific to plasma light emission, and it is impossible to control the light emission state by changing the design of the plasma display panel itself. The filter of the present invention can absorb the orange spectrum, improve the emission spectrum from the plasma display panel, and improve the color purity and color reproducibility.

[0022]

According to the present invention, a coating solvent containing an organic solvent, a binder resin, and a pigment is uniformly applied on a transparent film, and the solvent is dried to obtain a pigment containing a pigment having a thickness of 1 to 50.
By forming a micron film, it was possible to produce a film with little deterioration without exposing it to high temperatures.
As a result, it is possible to provide a filter which is particularly effective in improving color purity and color reproducibility.

[Brief description of the drawings]

FIG. 1 is an absorption spectrum of squarylium dye A.

FIG. 2 is an absorption spectrum of squarylium dye B.

FIG. 3 is an absorption spectrum of cyanine dye C.

FIG. 4 is a transmission spectrum of the film of Example 1.

FIG. 5 is a transmission spectrum of the film of Example 2.

FIG. 6 is a transmission spectrum of the film of Example 3.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5G435 AA04 AA14 BB06 GG11 GG33 HH03

Claims (5)

[Claims] 1. A resin coating solution containing a dye having an absorption maximum wavelength at 575 to 595 nm is uniformly applied on a transparent film, and then the solvent is dried to form a film having a thickness of 1 to 50 microns containing the dye. A film for a plasma display, which is formed. 2. The plasma display film according to claim 1, which has a light transmittance at 585 nm of 50% or less. 3. A front protective filter for a plasma display, comprising an antireflection layer on one side of the film according to claim 1 via an adhesive layer. 4. A front protective filter for a plasma display, wherein the film according to claim 1 is bonded to a transparent substrate. 5. A visible light transmittance of 35% or more, 850 to 10
5. The front protective filter for a plasma display according to claim 3, wherein the near-infrared transmittance at 00 nm is 15% or less, and the transmittance at 585 nm is 35% or less.