JP2000162405A - Optical product and cathode-ray tube using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent reflection on a face panel of a cathode-ray by applying a coat of an antireflection film formed by laminating a metal film and a transparent dielectric film for the purpose of reducing reflection of outside light on the surface of the cathode-ray tube and enlarging a display contrast. SOLUTION: An outer surface of a face panel for this cathode-ray tube is coated with an antireflection film 3 comprising a praseodymium titanate film of 44.9 nm thickness as a first layer, an alloy film of nickel and iron of 4.9 nm thickness as a second layer, a praseodymium titanate film of 53.4 nm thickness as a third layer, an alloy film of nickel and iron of 3.9 nm thickness as a forth layer, a praseodymium titanate film of 20.6 nm thickness as a fifth layer, and a magnesium fluoride film of 84.7 nm thickness as a sixth layer, laminated in this order. Thereby, a double image cannot be generated, electrification and reflection of outside light in the surface of the cathode-ray tube can be prevented, and a video image contrast can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass article coated with an antireflection film having both conductivity and light absorption, and more particularly to a glass face panel used for a cathode ray tube or a glass face panel attached to a glass face panel. It relates to a glass plate used.

[0002]

2. Description of the Related Art In a display device using a cathode ray tube, such as a television, a display quality is improved by reducing the reflectance of external light on a display surface. Further, in a display device using this cathode ray tube, a high voltage is used by using an electron gun, so that the display surface is charged, thereby attracting dirt and dust in the air. In order to prevent the display surface from being charged, the surface of the cathode ray tube is made conductive. In addition, when an electromagnetic wave is generated by an electron beam accelerated by a high voltage, this may adversely affect a human body. Therefore, the front surface of the display unit is covered with a conductive film for the purpose of shielding electromagnetic waves. For this reason, a glass plate coated with a conductive anti-reflection film is bonded to the outer surface of the face panel of the cathode ray tube with a resin, or the outer surface of the face panel itself is directly coated with a conductive anti-reflection film. I have.

As a glass article used for the purpose of improving the display quality of the above-mentioned cathode ray tube, JP-A-6-2634 is known.
No. 83 discloses a laminate represented by glass plate / ITO / praseodymium titanate / magnesium fluoride / praseodymium titanate / magnesium fluoride.

Japanese Patent Application Laid-Open No. Sho 64-70 discloses a conductive antireflection film formed by laminating a metal layer and a transparent oxide layer.
No. 701 discloses a laminated body represented by a glass plate / metal / titanium oxide / silicon oxide;
No. 333 discloses a glass plate / magnesium fluoride / metal / titanium oxide / magnesium fluoride laminate, and a glass / praseodymium titanate / metal / titanium disclosed in Japanese Patent No. 25665538. There is a laminate that can be represented by praseodymium acid / magnesium fluoride. As the metal layer, stainless steel, titanium, chromium, zirconium, molybdenum, nickel, chromium alloy and the like are described.

Japanese Unexamined Patent Publication No. 1-200952 discloses a four-layer laminate having two metal layers such as glass plate / stainless alloy / praseodymium titanate / stainless alloy / magnesium fluoride. I have. Further, a light absorbing film other than metal and a transparent dielectric film are laminated to form a conductive antireflection film.
Discloses a laminate represented by a glass plate / titanium nitride / silicon nitride / silicon dioxide.

When the above-mentioned metal or metal nitride is used as a light absorbing film, and an antireflection film for laminating the light absorbing film and the transparent dielectric film is provided directly or indirectly on the front surface of the cathode ray tube, the transmittance can be reduced. Is known to be effective in increasing the contrast of the image.

[0007]

However, the antireflection film described in JP-A-6-263483 has no light absorbing property because all layers are made of a transparent oxide. Therefore, although having high conductivity and conductivity,
When the antireflection film was provided on the front surface of the cathode ray tube, there was no function of increasing the display contrast and making the screen easier to see.

On the other hand, in the conductive antireflection film in which the metal film and the transparent oxide film of the above-mentioned conventional technology are laminated, the transmittance can be adjusted by adjusting the thickness of the metal film. Therefore, the transmittance can be adjusted to 30% or more and 50% or less, which is convenient for increasing the display contrast. However, in these antireflection films, when the thickness of each film is adjusted so as to reduce the reflectance of the surface of the antireflection film viewed from the air side, the reflectance at the interface between the transparent substrate and the antireflection film increases. The problem came to be recognized.

If the reflectance at the interface between the glass and the antireflection film is high, the cathode ray tube is formed by using a glass panel directly coated with the antireflection film, or the glass substrate coated with the antireflection film is used as a cathode ray tube. In any of the cases in which the image is attached to the face panel, there is a problem that the image displayed on the cathode ray tube is doubled. The problem of the occurrence of the double image is particularly remarkable when the internal transmittance of the face panel of the cathode ray tube is high. Further, the above-mentioned prior art disclosed in JP-A-9-15
The above-described problem also occurs in the antireflection film in which the metal nitride film and the transparent dielectric film disclosed in Japanese Patent No. 6964 are laminated.

Further, the face panel of the cathode ray tube tends to be flat and large. In this case, in order to maintain the strength of the glass used for the face panel, the thickness of the glass at the periphery of the face panel is designed to be much larger than that at the center. In order to solve the above problem of the double image, it is conceivable to lower the internal transmittance of the glass. However, if such means is adopted, the image at the periphery of the cathode ray tube becomes darker than that at the center. In order to increase the thickness of the peripheral portion in order to secure mechanical strength and to make the brightness of the image in the peripheral portion equal to that in the central portion, it is necessary to increase the internal transmittance of the glass itself used for the face panel. When the outer surface of the face panel having a high internal transmittance is coated with an antireflection film including a conventional metal film or a metal nitride light absorbing film, the reflectance at the interface between the glass and the antireflection film increases. There is a problem that the display becomes a double image.

An object of the present invention is to provide an anti-reflection film containing a light absorbing film on the outer surface of a face panel of a cathode ray tube, or a glass plate coated with an anti-reflection film containing a light absorbing film on the face of the cathode ray tube. An object of the present invention is to solve the problem of a double image of a display which occurs when the display is attached to a panel. Another object of the present invention is to prevent reflection of external light on the display surface,
An object is to obtain a display having a large display contrast.

[0012]

According to a first aspect of the present invention, a light-absorbing film and a second layer are formed on a light-transmitting substrate having a refractive index of 1.4 to 1.7 as a first layer in order from the light-transmitting substrate. The refractive index is 1.6
To 2.4, a light-absorbing film as a third layer,
A fourth layer is coated with a transparent dielectric film having a refractive index of 1.6 to 2.4 and a fifth layer is coated with an antireflection film formed by laminating a transparent dielectric film having a refractive index of 1.35 to 1.5. Optical article provided with an antireflection film.

The refractive index mentioned here is a refractive index at a wavelength of 550 nm. Metals, alloys, and metal nitrides can be used for forming the light absorbing film. Since the light absorbing film is laminated in two layers between the transparent dielectric films having a refractive index of 1.6 to 2.4, the light incident from the light transmitting substrate and the light transmitting substrate are prevented from being reflected. This is important for lowering the reflectance at the interface of the film. The two light absorbing films may be the same material or different from each other.

According to a second aspect, in the first aspect, the thickness of the transparent dielectric films of the second and fourth layers is 30 to 80 nm, and the thickness of the transparent dielectric film of the fifth layer is 60 to 100 nm. Features.

In order to reduce the reflectance when light incident from the light-transmitting substrate is reflected at the interface between the light-transmitting substrate and the antireflection film to more reliably prevent the occurrence of a double image, the second layer and the 4th
The thickness of the transparent dielectric film of the layer is 30 nm or more, and
nm or more, preferably 80 nm or less, and more preferably 6 nm or less.
It is preferably set to 0 nm or less.

In order to reduce the reflectance when the light incident from the light-transmitting substrate is reflected at the interface between the light-transmitting substrate and the antireflection film and to reliably prevent the occurrence of a double image, the fifth layer The thickness of the transparent dielectric film is preferably 60 nm or more, more preferably 65 nm or more, and preferably 100 nm or less, and more preferably 80 nm or less.

[0017] Claim 3 is based on claim 1 or 2,
The light absorbing film is a film of at least one kind or a mixture of two or more kinds selected from a metal group consisting of titanium, chromium, zirconium, molybdenum, iron, niobium, tantalum, hafnium, nickel, nickel iron alloy and stainless alloy. It is characterized by.

The films of these metals, alloys or mixtures thereof exhibit transmission colors with suppressed coloring and do not impair the color display of the cathode ray tube.

According to a fourth aspect of the present invention, when the light absorbing film is made of a metal nitride film, the first layer and the third
The thickness of each metal nitride of the layer is 5 nm to 18 nm.

When the thickness is less than 5 nm, the light absorption is small, the contrast of display is reduced, and the antistatic performance is undesirably deteriorated. From this viewpoint, the thickness is more preferably 6 nm or more. On the other hand, when the thickness exceeds 18 nm, the light absorption becomes large and the display image becomes dark, which is not preferable. From this viewpoint, the thickness is more preferably 12 nm or less. The thickness of the light absorbing film is preferably selected so that the visible light transmittance of the optical article is in the range of 30 to 50%.

A fifth aspect of the present invention relates to the third or fourth aspect,
The transparent dielectric film having a refractive index of 1.6 to 2.4 is formed of a chromium oxide film.

A sixth aspect of the present invention is based on the first or second aspect.
The light absorption film is a film of at least one kind or a mixture of two or more kinds selected from the group consisting of metal nitrides composed of titanium nitride, chromium nitride, zirconium nitride, hafnium nitride, and tantalum nitride.

These metal nitride films exhibit a transmission color in which coloring is suppressed, and do not impair the color of the color display of the cathode ray tube.

A seventh aspect of the present invention is characterized in that, in the sixth aspect, when the light absorbing film is formed of a metal or alloy film, the thickness of the first and third layers is 3 to 6 nm. When the thickness is less than 3 nm, the light absorption is small, the display contrast is reduced, and the antistatic performance is deteriorated.
On the other hand, if it exceeds 6 nm, the amount of light absorption increases and the display image becomes dark. The thickness of the light absorbing film is preferably selected so that the visible light transmittance of the optical article is in the range of 30 to 50%.

According to an eighth aspect of the present invention, a transparent layer having a refractive index of 1.6 to 2.4 is formed as a first layer on the transparent substrate having a refractive index of 1.4 to 1.7 in order from the transparent substrate side. A dielectric film, a light absorbing film as a second layer, a transparent dielectric film having a refractive index of 1.6 to 2.4 as a third layer, a light absorbing film as a fourth layer, and a refractive index of 1. as a fifth layer. An optical article with an antireflection film coated with an antireflection film formed by laminating 35 to 1.5 transparent dielectric films.

The refractive index mentioned here is a refractive index at a wavelength of 550 nm. Metals, alloys, and metal nitrides can be used for forming the light absorbing film. Since the light absorbing film is laminated in two layers between the transparent dielectric films having a refractive index of 1.6 to 2.4, the light incident from the light transmitting substrate and the light transmitting substrate are prevented from being reflected. This is important for lowering the reflectance at the interface of the film. The two light absorbing films may be the same material or different from each other.

According to a ninth aspect, in the eighth aspect, the refractive index between the fourth-layer absorbing film and the fifth-layer transparent dielectric film is 1.6.
The transparent dielectric films of (1) to (2) are interposed as the sixth layer.

According to a tenth aspect, in the eighth or ninth aspect, the thickness of the transparent dielectric film of the first and third layers is from 30 to 30.
80 nm, the thickness of the fifth transparent dielectric film is 60 to 100
nm.

The reflectance of light incident from the light-transmitting substrate at the interface between the light-transmitting substrate and the antireflection film is reduced, and
In order to more reliably prevent the occurrence of a superimposed image, the thicknesses of the first and third transparent dielectric films are 30 nm or more, and more preferably 4 nm or more.
It is preferably set to 0 nm or more. It is preferably at most 80 nm, more preferably at most 60 nm.

Further, in order to reduce the reflectance when light incident from the light-transmitting substrate is reflected at the interface between the light-transmitting substrate and the antireflection film and to reliably prevent the occurrence of a double image, the fifth method is adopted. The thickness of the transparent dielectric film of the layer is preferably at least 60 nm, more preferably at least 65 nm. Further, it is preferably 100 nm or less,
Further, the thickness is preferably 95 nm or less.

An eleventh aspect is characterized in that, in the ninth or tenth aspect, the thickness of the transparent dielectric film of the sixth layer does not exceed 100 nm.

The thickness of the sixth transparent dielectric film is 100 nm.
If it exceeds, the reflectivity increases, which is not preferable. From the viewpoint of reducing the reflectance, the thickness is preferably 70 nm or less,
More preferably, the thickness is 30 nm or less.

According to a twelfth aspect of the present invention, in any one of the eighth to eleventh aspects, the light absorption film is made of titanium, chromium, zirconium,
The film is characterized by being a film of at least one or a mixture of two or more metals selected from the group consisting of molybdenum, iron, niobium, tantalum, hafnium, nickel, nickel-iron alloys, and stainless steel alloys.

The films of these metals, alloys or mixtures thereof exhibit transmission colors with suppressed coloring and do not impair the color display of the cathode ray tube.

According to a thirteenth aspect, in the twelfth aspect, the thickness of the light absorbing film is 3 to 6 nm.

According to a fourteenth aspect, in the twelfth or thirteenth aspect, at least one of the transparent dielectric films having a refractive index of 1.6 to 2.4 is formed of a chromium oxide film.

When the light absorbing film is formed of a metal or alloy film, the thickness of the second and fourth light absorbing films is 3 to 6
It is preferably set to nm. When the thickness is less than 3 nm,
Light absorption is small, display contrast is reduced, and antistatic performance is deteriorated. On the other hand, if it exceeds 6 nm, the amount of light absorption increases and the displayed image becomes dark, which is not preferable. The thickness of the light absorbing film is preferably selected so that the visible light transmittance of the optical article is in the range of 30 to 50%.

According to a fifteenth aspect, in any one of the eighth to eleventh aspects, the light-absorbing film is at least one selected from the group consisting of titanium nitride, chromium nitride, zirconium nitride, hafnium nitride, and tantalum nitride. Alternatively, the film is a film of a mixture of two or more kinds.

These metal nitride films exhibit a transmission color in which coloring is suppressed, and do not impair the color of the color display of the cathode ray tube.

In a sixteenth aspect, in the fifteenth aspect, the thickness of the light absorbing film is 5 to 18 nm.

When the light absorbing film is formed of a metal nitride film, the thickness of the second and fourth metal nitride films is 5n.
m to 18 nm. When the thickness is less than 5 nm, the light absorption is small, the contrast of display is reduced, and the antistatic performance is undesirably deteriorated.
From this viewpoint, the thickness is more preferably 6 nm or more. On the other hand, when the thickness exceeds 18 nm, the amount of light absorption increases and the display image becomes dark, which is not preferable. From this perspective, 12
It is more preferable that the thickness be not more than nm. The thickness of the light absorbing film is preferably selected so that the visible light transmittance of the optical article is in the range of 30 to 50%.

The seventeenth aspect is the invention according to the first to sixteenth aspects.
The translucent substrate is a glass substrate.

The glass substrate is used by bonding it to the outer surface of a face panel for a cathode ray tube with an adhesive. Since the surface of the face panel usually has a gentle curved surface, it is preferable that the surface bend along the curved surface so that the glass substrate is bonded with an adhesive layer having a uniform thickness. Colorless or colored glass plates can be used. The composition of the glass is not particularly limited, and a soda-lime silicate composition, a borosilicate composition, an aluminosilicate composition, an aluminoborosilicate composition, or the like is used. The glass substrate may be air-cooled. Usually, float glass having a soda lime silica composition is often used because it is inexpensive.

According to an eighteenth aspect, in the seventeenth aspect, the translucent substrate is a glass face panel for a cathode ray tube.

A nineteenth aspect is characterized in that, in the seventeenth aspect or the eighteenth aspect, the glass has a light absorbing property by a coloring component contained therein.

Examples of the light-absorbing ion (colored ion) component contained in the glass include nickel, iron, cobalt, selenium, cerium, titanium and the like. By including one or more of these in the glass, a light-absorbing glass having a transmission color such as a gray system, a green system, or a bronze system can be obtained. It is preferable that the glass has a light-absorbing property, as described later, since light reaching the antireflection film from the glass substrate reduces the amount of light reflected at the interface. Further, the glass may contain barium, strontium, antimony, zinc, zirconium and the like as additives.

A cathode ray tube according to claim 20 is the cathode ray tube according to claims 17 to 1
9. The glass article according to any one of 9 above, wherein:

Throughout the specification, the refractive index is 1.6 to 2.
As the transparent dielectric film of No. 4, praseodymium titanate, praseodymium oxide, indium oxide, indium oxide doped with tin, niobium oxide, titanium oxide, bismuth oxide, aluminum oxide, tantalum oxide, zirconium oxide, silicon nitride, tin oxide and oxide A chromium film can be exemplified. Examples of the transparent dielectric film having a refractive index of 1.35 to 1.5 include films of magnesium fluoride and silicon dioxide. These transparent dielectric films can be coated by a known method such as a vacuum evaporation method, an ion plating method, and a sputtering method. Further, the translucent substrate may be a plastic plate or a film thereof.

In the present invention, when a metal film is used as the absorption film, the metal film has a larger light absorption coefficient on the long wavelength side in the visible light wavelength region of 340 to 780 nm than that on the short wavelength side. Optical article having low transmittance. Among the transparent dielectric films, the chromium oxide film has some absorption in the visible light wavelength range, and the light absorption on the short wavelength side is larger than that on the long wavelength side. Therefore, when a metal film is used as the absorbing film and a chromium oxide film is used as the transparent dielectric film, the transmittance can be made flat in the visible region or slightly increased on the long wavelength side. That is, since the spectral transmittance curve can be controlled to some extent by utilizing the difference in the wavelength dispersion characteristics of the two types of films, it is preferable to select a metal film as the absorbing film and a chromium oxide film as the transparent dielectric film. preferable.

[0050]

FIG. 1 is a sectional view of an embodiment of the optical article of the present invention. In FIG. 1A, the optical article 10a
In FIG. 1, an antireflection film 3 is coated on the surface of a glass substrate 2a. This optical article is used by being adhered to the face panel of a cathode ray tube with an adhesive so that the antireflection film is on the inside. Optical article 10 according to another embodiment of the present invention
1B, as shown in the cross-sectional view of FIG. 1B, the outer surface of a glass face panel 2b for a cathode ray tube is directly coated with an antireflection film 3.

FIG. 2 is an external view of one embodiment of the cathode ray tube 11 of the present invention. The glass article 10 (b) coated with the phosphor 1 on the inside shown in FIG. 13
The glass frit 12 is attached to the funnel 14 where the
Sealed by.

FIG. 3 is a cross-sectional view for explaining an antireflection film according to one embodiment of the present invention. On the surface of the transparent substrate 2 having a refractive index of 1.4 to 1.7, a transparent dielectric film 31 having a refractive index of 1.6 to 2.4, a metal film 32, and a refractive index of 1.6 to 2. 4, the transparent dielectric film 31, the metal film 32, and the refractive index of 1.6 to 2.
4 and a refractive index of 1.35 to 1.5
Of transparent dielectric films 33 are sequentially laminated.

FIG. 4 is an explanatory diagram for optically explaining a double image displayed. FIG. 5 is an explanatory diagram for explaining the internal transmittance T _int , the reflectance r _{1 of the} side face not coated with the antireflection film, and the transmittance T ₁ of the glass substrate of the glass substrate of the present invention. FIG. 6 shows the reflectance r _{2 of} the light incident on the anti-reflection film from the glass substrate of the optical article of the present invention at the interface between the anti-reflection film and the glass and the reflectance R ₁ of the light incident from the non-reflection coating uncoated surface. It is an explanatory view for explaining.
FIG. 7 is a diagram illustrating spectral characteristics of the glass plate used in Example 1. FIG. 8 is a diagram illustrating spectral characteristics of the optical article obtained in Example 1.

In FIG. 4, light emitted from the phosphor 1 passes through the glass substrate 2a and reaches the interface between the glass substrate 2a and the antireflection film 3. At this time, a part of the light passes through the antireflection film 3 and the transmitted light 4 appears as an image. The reflected light 5 is further reflected at the interface between the glass substrate 2a and the phosphor 1, and becomes reflected light 6. The reflected light 6
The light passes through the glass substrate 2a and the antireflection film 3 and reaches the observer, and the transmitted light 7 can be visually confirmed as an image. Since the observer can visually confirm the two lights of the transmitted light 4 and the transmitted light 7 at the same time, there is a problem of a double image in which two images are seen.

The double image tends to be more remarkable as the internal transmittance of the glass is higher. Conversely, in glass having a low internal transmittance, the reflected light 5 and the reflected light 6 are absorbed while passing through the inside of the glass, and as a result, the amount of the transmitted light 7 decreases, and the observer cannot observe the transmitted light 7. No double image is generated.

In this specification, the definition is made as follows. 1) Surface reflectance of the glass substrate: r ₁ 2) Transmittance of the glass substrate: T ₁ 3) Internal transmittance T _int of the glass substrate 4) Reflectivity at incidence from the side of the optical article where the antireflection film is not coated : R ₁ 5) reflectance on the interface between the glass substrate and the antireflection film of the optical article: r ₂ 6) anti-reflection film coating side surface reflectance of the optical article: r ₃ 7) transmittance of the optical article: T _Two

A method for measuring the reflectance r ₂ at the interface between the glass substrate and the antireflection film in the optical article of the present invention shown in FIG. 6 will be described. First, before forming the anti-reflection film,
The transmittance T ₁ of the glass substrate formed into a parallel plate shape is measured. Next, one surface 12 of the glass substrate is processed by sandblasting into a surface such as “ground glass”, and the processed surface is painted with a black oil pen (this processing is referred to as non-reflection processing). Light is incident and the reflectance is measured. This reflectance is defined as surface reflectance r _{1 as} shown in FIG. The transmittance T ₁ of the glass substrate and the surface reflectance r ₁ measured by the spectrophotometer are substituted into the equation (1), and the internal transmittance T of the glass substrate is obtained.
Calculate _int . FIG. 5 shows the internal transmittance T _{int of} the glass substrate, the transmittance T ₁ of the glass substrate, and the surface reflectance r ₁ of the glass substrate.

[0058]

[Number 1] _{T int = 2T 1 / ((} (1-r 1) 4 + 4T 1 2 · r 1 2) 0.5 + (1-r 1) 2) ···· ( Equation 1)

Next, with respect to a sample of a glass article in which an antireflection film is coated on a glass substrate having the same optical characteristics as the above glass substrate, the reflectance spectrum R ₁ for incident light from the non-reflection film non-coated side of the glass substrate. (See FIG. 6). From the reflectance R ₁ on the non-reflection surface side of the antireflection film of the glass article, the surface reflectance r _{1 of} the glass substrate, and the internal transmittance T _int of the glass substrate, using the (Equation 2), The reflectance r ₂ at the interface of the antireflection film is calculated.

[0060]

R ₂ = (R ₁ −r ₁ ) / ((R ₁ −r ₁ ) · r ₁ + (1−r ₁ ) ² ) · T _int ² ) (Equation 2)

The reflectance r ₂ of the glass substrate and the antireflection film of the optical article determined as described above is determined. Shows the reflectance R ₁ of the non-antireflection film-coated surface of the reflectance r ₂ and the glass article at the interface between the glass substrate and the antireflection film of the optical article in FIG.

Hereinafter, the present invention will be described with reference to Examples and Comparative Examples. The coating of the film was performed by the following method.・ Praseodymium titanate (PrTiO ₃ ) layer: evaporation using PrTiO ₃ pellet as evaporation material ・ Nickel iron alloy (NiFe) layer: evaporation using nickel iron alloy piece as evaporation material ・ Magnesium fluoride (MgF ₂ ) layer: MgF ₂ Stainless steel (NiFeCr) layer: Deposition using stainless steel flakes as the evaporation material. Silicon nitride (SiNx) layer: Reactive sputtering using Si as target. Titanium nitride (TiNx) layer: Using Ti as target. Reactive sputtering ・ Silicon dioxide (SiO ₂ ) layer: Sputtering with Si target ・ Aluminum dioxide (Al ₂ O ₃ ) layer: Sputtering with Al target

Example 1 The surface reflectance r ₁ and the transmittance T ₁ of a colored glass plate having a size of 100 mm × 100 mm × 14 mm were set to 340 nm to 780 nm.
Was measured in the wavelength range. The transmittance and the surface reflectance were substituted into (Equation 1) to calculate the internal transmittance T _int of the glass substrate. Fig. 7 shows the wavelength spectra of internal transmittance and surface reflectance.
Shown in

Next, the glass substrate whose internal transmittance and surface reflectance were determined as described above was placed in a vacuum evaporation apparatus, and heated to 300 ° C. by a substrate heater installed in the evaporation apparatus. Sample 1 of the optical article of the present invention was produced by coating the antireflection film having the multilayer structure shown in FIG. The evaporation material was evaporated by an electron beam evaporation method, the distance from the evaporation crucible to the glass substrate was 100 cm, and the evaporation was performed while rotating the glass substrate. The ultimate vacuum degree before the start of vapor deposition was 0.003 Pa with an oil diffusion pump for each film.
The air was exhausted until. Nickel iron alloy (NiFe) film, praseodymium titanate (PrTiO ₃ ) film (refractive index 2.
14) A magnesium fluoride (MgF ₂ ) film (refractive index: 1.38) was deposited without introducing oxygen gas.

The obtained optical article was taken out of the vapor deposition apparatus, and the composition of the NiFe film was chemically analyzed.
= 81: 19 (weight%).

The transmittance of the obtained sample and the reflectance on the non-reflection surface side of the antireflection film were measured in the wavelength range of 340 to 780 nm. By substituting these values into (Equation 2), the reflectance r ₂ at the interface between the glass substrate and the antireflection film was determined. Further, the surface on the non-reflection film-uncoated side was subjected to non-reflection treatment with sandblasting and a black oil-based pen, and then the surface reflectance r ₃ on the anti-reflection film-coated surface was measured. FIG. 8 shows the wavelength spectrum of the transmittance T ₂ of the optical article, the reflectance r ₂ at the interface between the glass substrate and the anti-reflection film, and the surface reflectance r ₃ on the anti-reflection film-coated surface side, obtained as described above. .

From each spectrum shown in FIG.
3106 (1998) to determine the visible light transmittance T
v, the visible light reflectance r ₃ v on the side of the anti-reflection coating surface, and the visible light reflectance r ₂ v at the interface between the glass substrate and the anti-reflection coating were calculated. Table 2 shows the results.

Under the same film-forming conditions as the above-mentioned anti-reflection film, an anti-reflection film was coated on the outer surface of a face panel for a cathode ray tube having substantially the same glass composition as the glass substrate used. The visible light transmittance including the face panel was 35.7%. An image of a cathode ray tube manufactured using this face panel was observed in a dark room. The display contrast of the cathode ray tube was good.

The visible light reflectance at the interface between the face panel and the antireflection film was as low as 0.19%, and the image was doubled and could not be seen. In addition, the surface reflectance of the anti-reflection film-coated surface side is as low as 0.26%. Even when the cathode ray tube is observed under a fluorescent lamp in a room, the fluorescent lamp is not reflected on the face panel surface, and visibility is high. It was excellent.

In order to impart an antistatic function to the antireflection film, the antireflection film preferably has a sheet resistance of 2 kΩ / □ or less. Further, in order to block electromagnetic waves harmful to the human body generated from the cathode ray tube, it is considered that the sheet resistance of the antireflection film is preferably 500Ω / □ or less. Therefore, the sheet resistance of the antireflection film of Sample 1 was measured. Table 2 shows the measurement results. The sheet resistance was 112 Ω / □, indicating that it had an antistatic function and an electromagnetic wave shielding function.

Example 2 Using the same glass substrate as used in Example 1, an antireflection film having a laminated structure shown in Table 1 was coated by a vacuum deposition method. As a result of chemically analyzing the composition of the nickel-iron-chromium alloy film used for the light absorption film, Ni: Fe: Cr = 77.0:
7.8: 15.2 (weight% ratio).

The transmittance of the sample of the obtained optical article and the reflectance on the non-reflection surface side of the anti-reflection film were measured, and the visible light reflectance at the interface between the glass substrate and the anti-reflection film was measured in the same manner as in Example 1. I asked. Further, after the anti-reflection film non-coated surface side was subjected to anti-reflection treatment, the surface reflectance on the anti-reflection film coated surface side was measured.

Regarding these measurement results, JIS R
Using 3106, the visible light transmittance Tv, the visible light reflectance r ₃ v on the coated surface side, and the visible light reflectance r ₂ v at the interface between the glass substrate and the antireflection film were calculated. Table 2 shows the results.

The visible light transmittance was 35.6%. This value is a transmittance that is convenient for increasing the contrast of the display. The surface reflectance of the anti-reflection film-coated surface side is as low as 0.32%, and there is almost no reflection of reflected images. Further, the reflectance at the interface between the glass substrate and the anti-reflection film was as low as 0.14%, and the double image was hardly visible.

The sheet resistance of the antireflection film was 268 Ω / □, and it was found that the antireflection film had a practically antistatic function and an electromagnetic wave shielding function.

[0076]

[Table 1] =============================== Example Laminating Structure of Antireflection Film and Thickness of Each Layer (nm) -------------------------------- example 1 Ca Bu Las _{/ PrTiO 3 / NiFe / PrTiO 3} / NiFe / PrTiO 3 / MgF ₂ 44.9 4.9 53.4 3.9 20.6 84.7 Example 2 Glass / PrTiO ₃ / NiFeCr / PrTiO ₃ / NiFeCr / MgF ₂ 54.1 5.6 57.6 3.3 90.3 Example 3 Glass / SiNx / TiNx / SiNx / TiNx / SiNx / SiO ₂ 52.1 11.1 54.9 8.5 1.2 79.2 example 4 Ca Bu Las / SiNx / TiNx / SiNx / TiNx / SiO 2 51.6 11.1 55.2 8.5 79.6 example 5 Ca Bu Las _{/ Al 2 O 3 / TiNx /} Al 2 O 3 / TiNx / SiO 2 39.5 8.0 69.8 8.4 86.4 embodiment example 6 Ca Bu Las _{/ TiO 2 / TiNx / TiO 2} / TiNx / SiO 2 39.5 17.5 39.0 8.3 81.4 example 7 Ca Bu Las / SiNx / TiNx / SiNx / TiNx / SiNx / SiO 2 31.0 10.5 50.1 10.8 20.3 60.3 example 8 Ca Bu Las / SiNx / TiNx / SiNx / TiNx / SiO ₂ 80 .0 9.9 67.8 6.9 100.0 Example 9 Ca Bu Las / SiNx / TiNx / SiNx / TiNx / SiNx / SiO 2 60.0 10.0 60.0 10.0 100.0 100.0 Example 10 Ca Bu Las / TiNx / SiNx / TiNx / SiNx / SiO 2 6.3 61.1 13.1 28.6 66.9 Embodiment example 11 Ca Bu Las _{/ PrTiO 3 / NiFe / PrTiO 3} / NiFe / PrTiO 3 / MgF 2 31.9 6.4 61.4 3.8 28.8 100.0 example 12 Ca Bu Las _{/ PrTiO 3 / NiFe / CrOx /} NiFe / PrTiO 3 / MgF 2 50.5 8.4 47.7 5.5 16.9 68.9 Example 13 Glass / NiFe / CrOx / NiFe / PrTiO ₃ / MgF ₂ 4.1 60.1 9.6 38.9 60.5 =============================== ===

Example 3 An antireflection film having a laminated structure shown in Table 1 was coated on a glass having the same optical characteristics as the colored glass substrate used in Example 1 by magnetron sputtering. The transmittance of the obtained glass article and the reflectance on the non-reflection film-uncoated surface side were measured, and the visible light reflectance at the interface between the glass substrate and the antireflection film was determined. Further, after the anti-reflection film non-coated surface side was subjected to anti-reflection treatment, the surface reflectance on the anti-reflection film coated surface side was measured. According to JIS R 3106, the measurement result was converted into a visible light transmittance T.
v, the visible light reflectance r ₃ v on the side of the anti-reflection coating surface and the visible light reflectance r ₂ v at the interface between the glass substrate and the anti-reflection coating were calculated. Table 2 shows the results.

The visible light transmittance was 36.6%. This value is a favorable transmittance for increasing the contrast of the display. The surface reflectance on the side of the anti-reflection film-coated surface is as low as 0.48%, and there is almost no reflection image. Further, the reflectivity at the interface between the glass substrate and the antireflection film was as low as 0.23%, and the double image was hardly visible. Further, the sheet resistance of the antireflection film was 182 Ω / □, which had a practically antistatic function and an electromagnetic wave shielding function.

Examples 4 to 10 In the same manner as in Example 3, an antireflection film having a laminated structure shown in Table 1 was coated on a glass substrate to obtain a sample of an optical article.
Table 2 shows their optical performance and sheet resistance. The visible light transmittance of each sample is 35% to 40%,
The transmittance was favorable for increasing the contrast of the display, the surface reflectance on the side of the anti-reflection film coated side was as low as 1% or less, and the reflected image was hardly reflected. Further, the visible light reflectance at the interface between the glass substrate and the antireflection film was as low as 1% or less, and the double image had a reflectance that was almost invisible. In each sample, the sheet resistance of the antireflection film was 208 Ω / □ or less, which was a sufficiently low value for the antistatic function and the electromagnetic wave shielding function.

[0080]

[Table 2] =============================== Visible Light Visible Light Visible Sheet Resistance at Interface Example Transmittance Tv Reflection Rate r ₃ v Light reflectance r ₂ v (%) (%) (%) (Ω / □) −−−−−−−−−−−−−−−−−−−−−−−−−−− −−−−− Example 1 35.7 0.26 0.19 112 Example 2 35.6 0.32 0.14 268 Example 3 36.6 0.48 0.23 182 Example 4 36.6 0.47 0.23 196 Example 5 36.7 0.64 0.52 201 Example 6 36.5 0.76 0.29 135 Example 7 34.6 0.35 0.70 164 Example 840 0.0 0.93 0.54 208 Example 9 35.0 0.62 0.68 175 Example 10 38.0 0.39 0.67 185 Example 11 31.4 0.21 2.61 98 Example 12 39.2 0.38 1.77 330 Example 13 38.9 0.69 1.25 420 ================ =============== _{Note) Tv, r 3 v, r} 2 v is above 5), 6), the measured values defined in 7), seen by JIS R 3106 This is the result of integration processing based on sensitivity characteristics.

Example 11 In the same manner as in Example 1, an antireflection film having a laminated structure shown in Table 1 was formed. Table 2 shows their optical performance. The transmittance is 35% to 40%, which is a convenient transmittance for increasing the display contrast. The surface reflectance on the side of the antireflection film-coated surface is as low as 1% or less, and there is almost no reflection image. Further, the reflectance at the interface between the glass substrate and the antireflection film was as low as 3% or less, and the reflectance of the double image was hardly seen. The sheet resistance of the antireflection film of this sample is 98Ω /
□, which was a sufficiently low value as an antistatic function and an electromagnetic wave shielding function.

Example 12 The same laminated structure as in Example 11 was adopted except that praseodymium oxide of the third layer was changed to chromium oxide. The characteristic values of the obtained sample satisfied the object of the present invention as shown in Table 2. Moreover, spectral transmittance characteristics of the sample, as shown in the transmittance T ₂ of the FIG. 9, there is no tendency of upward-sloping transmission curves shown in FIG. 8, be one having a flat transmittance characteristic generally in the visible range Was. That is, it is considered that chromium oxide has an effect of canceling large light absorption on the longer wavelength side than on the shorter wavelength side of the nickel-iron alloy film based on the fact that chromium oxide has the effect.

Example 13 An optical article sample was obtained according to the lamination structure shown in Table 1. The sheet resistance of the antireflection film of this sample is 420Ω.
/ □, which is a sufficiently low value as in Example 12 for the antistatic function and the electromagnetic wave shielding function. Further, it can be seen that it has low reflection characteristics. Further, this sample had a flat transmission characteristic in the visible region as in Example 12.

Comparative Examples 1 to 6 An antireflection film having a laminated structure shown in Table 3 was coated on the same glass substrate as used in Example 1. The coating of the antireflection film was performed by magnetron sputtering in Comparative Examples 1 to 3 as in Example 3, and the same vacuum deposition method as in Example 1 in Comparative Examples 4 to 6.

Table 4 shows the optical performance and sheet resistance of the obtained comparative sample. Visible light transmittance is 25% to 65%
And the contrast of the display when used for the face panel of a cathode ray tube was good. However, at least one of the surface reflectance on the side of the antireflection film-coated surface or the reflectance at the interface between the glass substrate and the antireflection film is 1% or more, and there is a reflection of a fluorescent lamp or a double image of display. None of the samples had both the reflection of external light and the generation of a double image, and it was recognized that the characteristics had practical problems.

[0086]

[Table 3] =============================== Example Lamination Configuration of Antireflection Film and Thickness of Each Layer (nm) −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− Comparative Example 1 Glass / TiNx / SiNx / SiO ₂ 21.5 41.3 40.2 Comparative Example 2 Glass / SiNx / TiNx / SiNx / SiO 2 72.7 11.3 3.8 82.4 Comparative example 3 Ca Bu Las / SiNx / TiNx / SiNx / TiNx / SiNx / SiO 2 24.9 2.1 19.8 2.1 124.2 116.1 Comparative example 4 Ca Bu Las _{/ NiFe / PrTiO 3 / NiFe /} MgF 2 1.3 39.6 3.4 110.7 Comparative example 5 Ca Bu Las _{/ SiO 2 / NiFe / SiO 2} / NiFe / SiO 2 / MgF 2 40.2 2.9 92.4 3.0 29.5 95.8 Comparative example 6 months Bu Las _{/ TiO 2 / NiFe / TiO 2} / NiFe / TiO 2 / PrTiO 3 39.5 7.6 52.1 5.6 86.3 67.6 =================================

[0087]

================================ Visible Light Visible Light Visible Sheet Resistance at Interface Example Transmittance Tv Reflection Rate r ₃ v Light reflectance r ₂ v (%) (%) (%) (Ω / □) −−−−−−−−−−−−−−−−−−−−−−−−−−− −−−−−− Comparative Example 1 37.2 0.45 25.4 150 Comparative Example 2 54.3 4.06 1.43 320 Comparative Example 3 64.2 1.56 1.43 2100 Comparative Example 4 48. 3 4.98 2.10 101 Comparative Example 5 35.8 1.37 0.34 164 Comparative Example 6 26.3 6.30 1.38 74 ================== ================ _{Note) Tv, r 3 v, r} 2 v is above 5), 6), the measured values defined in 7), by JIS R 3106 Integral processing by visibility characteristics One in which the.

[0088]

According to the optical article of the present invention, an antireflection film covering a glass substrate is formed by sequentially forming a first light absorbing film, a high refractive index transparent dielectric film having a predetermined refractive index, 2 has a light absorbing film and a low refractive index transparent dielectric film having a predetermined refractive index as a basic laminated structure. Since a high-refractive-index transparent dielectric film having a predetermined refractive index is provided between one of the films and between the second light-absorbing film and the low-refractive-index transparent dielectric film or both, The reflectance of the incident light at the interface between the translucent substrate and the antireflection film is small. Thus, when the optical article of the present invention is provided on the display surface of a cathode ray tube, a high-contrast display image can be obtained without generating a double image.

The light absorbing film may be made of at least one or a mixture of two or more metals selected from the group consisting of titanium, chromium, zirconium, molybdenum, iron, niobium, tantalum, hafnium, nickel, nickel-iron alloy and stainless steel alloy. By using this film, the display image of the cathode ray tube can be provided with favorable light absorbing property with high contrast, and the antistatic property and the electromagnetic wave shielding property can be provided by its conductivity.

Further, by forming the light absorbing film as a film of at least one kind or a mixture of two or more kinds selected from the group consisting of metal nitrides of titanium nitride, chromium nitride, zirconium nitride, hafnium nitride and tantalum nitride, Light absorption that is favorable for increasing the contrast of the display image of the cathode ray tube can be provided. In addition, antistatic properties and electromagnetic wave shielding properties can be imparted by its conductivity.

Further, by forming the translucent substrate of the present invention from a colored glass containing a coloring component, the occurrence of a double image can be further prevented.

A cathode ray tube using the optical article of the present invention as a display unit can display a high-contrast image in which a reflected image of external light is not reflected and a double image is not generated.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an embodiment of the optical article of the present invention.

FIG. 2 is an external view of an embodiment of a cathode ray tube of the present invention.

FIG. 3 is a cross-sectional view for explaining a laminated structure of an antireflection film according to an example of the optical article of the present invention.

FIG. 4 is a diagram for explaining the principle of generating a double image.

FIG. 5 is a diagram for explaining T ₁ , T _int and r ₁ of a glass substrate.

FIG. 6 is a view for explaining R _1, r ₂ and r ₃ of the optical article of the present invention.

FIG. 7 shows the internal transmittance T of the glass substrate used in Example 1.
FIG. 4 is a spectral characteristic diagram of _int and surface reflectance r ₁ .

FIG. 8 is a spectral characteristic diagram of the transmittance T ₂ of the optical article obtained in Example 1, the surface reflectance r ₃ on the side of the anti-reflection coating surface, and the reflectance r ₂ at the interface between the glass substrate and the anti-reflection coating. .

FIG. 9 is a spectral characteristic diagram of the transmittance T ₂ of the optical article obtained in Example 12, the surface reflectance r ₃ on the side of the anti-reflection coating surface, and the reflectance r ₂ at the interface between the glass substrate and the anti-reflection coating. .

[Explanation of symbols]

1: Phosphor 2: Translucent substrate 2a: Glass substrate 2b: Glass face panel 3: Antireflection film 10a: Optical article of the present invention using glass substrate 10b: Optical of the present invention using glass face panel Article 11: cathode ray tube of the present invention 12: glass frit sealing layer 13: electron gun unit 14: funnel 31: transparent dielectric film having a refractive index of 1.6 to 2.4 32: light absorbing film 33: refractive index 1.35 to 1.5 transparent dielectric film

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Chihiro Sakai 3-5-1-11 Doshomachi, Chuo-ku, Osaka-shi, Osaka Inside Nippon Sheet Glass Co., Ltd. (72) Koji Nakanishi 3 Doshomachi, Chuo-ku, Osaka-shi, Osaka 5-11-11 Nippon Sheet Glass Co., Ltd. (72) Yasunori Yanaka 3-5-1-11 Doshomachi, Chuo-ku, Osaka-shi, Osaka F-term in Nippon Sheet Glass Co., Ltd. 2H048 CA05 CA14 CA19 CA23 CA29 2K009 AA09 AA12 BB02 CC02 CC03 CC14 EE01 5C032 AA02 DD02 DE01 DE03 DF05 DG01 DG02 EE01 EE02 EF01

Claims (20)

[Claims] 1. A light-absorbing film as a first layer and a second film on a light-transmitting substrate having a refractive index of 1.4 to 1.7 as a first layer from the light-transmitting substrate side.
A transparent dielectric film having a refractive index of 1.6 to 2.4 as a layer;
The third layer has a light absorption film, and the fourth layer has a refractive index of 1.6 to 1.6.
An optical article with an anti-reflection film coated with an anti-reflection film formed by laminating a transparent dielectric film of 2.4 and a transparent dielectric film having a refractive index of 1.35 to 1.5 as a fifth layer. 2. The antireflection method according to claim 1, wherein the thickness of the second and fourth transparent dielectric films is 30 to 80 nm, and the thickness of the fifth transparent dielectric film is 60 to 100 nm. Optical article with a film. 3. The light-absorbing film according to claim 1, wherein the light-absorbing film is at least one or two or more metals selected from the group consisting of titanium, chromium, zirconium, molybdenum, iron, niobium, tantalum, hafnium, nickel, nickel-iron alloy and stainless steel alloy. The optical article with an antireflection film according to claim 1 or 2, which is a film of a mixture. 4. The optical article with an antireflection film according to claim 3, wherein the thickness of the light absorbing film is 5 to 18 nm. 5. The optical system according to claim 3, wherein at least one of the transparent dielectric films having a refractive index of 1.6 to 2.4 is formed of a chromium oxide film. Goods. 6. The light-absorbing film is a film of at least one kind or a mixture of two or more kinds selected from the group consisting of metal nitrides consisting of titanium nitride, chromium nitride, zirconium nitride, hafnium nitride, and tantalum nitride. 3. The optical article with an antireflection film according to 1 or 2. 7. The optical article with an antireflection film according to claim 6, wherein the thickness of the light absorbing film is 3 to 6 nm. 8. A first layer having a refractive index of 1.6 on a light-transmitting substrate having a refractive index of 1.4 to 1.7 as a first layer from the light-transmitting substrate side.
To 2.4, a light-absorbing film as a second layer,
A transparent dielectric film having a refractive index of 1.6 to 2.4 as a third layer, a light absorbing film as a fourth layer, and a transparent dielectric film having a refractive index of 1.35 to 1.5 as a fifth layer are laminated. An optical article with an anti-reflection film coated with the anti-reflection film. 9. A transparent dielectric film having a refractive index of 1.6 to 2.4 is interposed as a sixth layer between the fourth layer absorbing film and the fifth layer transparent dielectric film. 9. The optical article with an antireflection film according to 8. 10. The transparent dielectric film of the first layer and the third layer has a thickness of 30 to 80 nm, and the transparent dielectric film of the fifth layer has a thickness of 60 to 100 nm. Optical article with anti-reflection coating. 11. The transparent dielectric film interposed as said sixth layer has a thickness not exceeding 100 nm.
3. The optical article with an antireflection film according to item 1. 12. The light-absorbing film is formed of at least one or two or more metals selected from the group consisting of titanium, chromium, zirconium, molybdenum, iron, niobium, tantalum, hafnium, nickel, nickel-iron alloy and stainless steel alloy. The optical article with an antireflection film according to any one of claims 8 to 11, which is a film of a mixture. 13. The optical article with an antireflection film according to claim 12, wherein the thickness of the light absorbing film is 3 to 6 nm. 14. The optical system according to claim 12, wherein at least one of the transparent dielectric films having a refractive index of 1.6 to 2.4 is formed of a chromium oxide film. Goods. 15. The light-absorbing film is a film of at least one kind or a mixture of two or more kinds selected from the group consisting of metal nitrides consisting of titanium nitride, chromium nitride, zirconium nitride, hafnium nitride, and tantalum nitride. An optical article with an antireflection film according to any one of 8 to 11. 16. The optical article with an antireflection film according to claim 15, wherein the thickness of the light absorbing film is 5 to 18 nm. 17. The optical article with an antireflection film according to claim 1, wherein the light-transmitting substrate is a glass substrate. 18. The optical article with an antireflection film according to claim 17, wherein the translucent substrate is a glass face panel for a cathode ray tube. 19. The optical article with an antireflection film according to claim 17, wherein the light-transmitting substrate is made light-absorbing by a coloring component in glass. 20. A cathode ray tube using the optical article with an antireflection film according to claim 17.