JPH04162332A - Cathode-ray tube with low reflection film - Google Patents

Abstract

PURPOSE:To reduce reflection and other influences from external light by providing an silica optical thin film, in which submicron particles of magnetism fluoride are diapered and mixed to lower the refractive index, with a particular film thickness on an outer surface of a face plate. CONSTITUTION:On an outer surface of a face plate 2, an anticharging optical selective absorption type low reflection film 10 is formed. In this low reflection film 10, in addition to organic or inorganic dye or color particles 8 and conductive filler particles 9, magnesium fluoride submicron-particles 11 are dispersed in a porous silica film 7 to lower the refractive index of the film 10. The average diameter of the magnesium fluoride submicron particles 11 is not larger than 1000Angstrom . The film thickness (d) (nm) and the refractive index (n) of the film 10 satisfy the condition of the expression I. External light reflection on the outer surface of the face plate 2 is therefore lowered, and also reflection and the other influences from the external light are reduced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a cathode ray tube with a low reflection film formed with a 71-s plate product number 9 [Prior Art] Maximum Power”, 7- The demand for picture quality of television receivers is constantly increasing, and for this reason the quality of cathode ray tubes is increasing.
Regarding the trust performance, it is hoped that the case will be defeated.The ability of trust P1 will be explained with reference to FIG. 25. Figure 23 is an enlarged schematic cross-section 1r+i of the fluorescent surface of a cathode ray tube. Black light absorbing film (61, 13G
An R3 color phosphor layer (4) and a metal back film (5) are formed in this order.

Now set the luminance of the fluorescent surface to No, and set the face plate (2).
) is 1・1, and the light transmittance of the face plate is i', , 13 (i R:
The reflectance of the phosphor film including the three-color phosphor layer (4), the black light absorption film (6), and the metal back film (5) is 1, and the aperture of the black light absorption film (6) is 11.ヰ is 1"□, and the intensity of the incoming external light is 1., 7.1-
--The intensity of surface reflected external light reflected by the outer surface of the face plate (21) is r5., and the intensity of surface reflected external light reflected by the inner surface of the face plate (2) and the surface of the phosphor layer (4) is r5. - If the intensity of external light reflected by the fluorescent surface coming out of the plate (2) is FA, then the contrast index C can be expressed by the following formula 0).

However, F + ”)'.・]゛,1・゛",...
・■G；1:0.041':o・・・・・・・・・・・・
......■1.: 2 = +0.961 F,
0-1'," (0,044(0,96) 'L) ・
...■. Here, since the material of the base plate (2) is glass, it is clear from 1 and 2 that the surface reflection at the interface with air and vacuum is estimated to be 4%.
Since El is constant from 2〇, the high number that increases the contrast performance, that is, the contrast index C, is r
', i, that is, the output brightness may be increased, or [.:2, that is, the intensity of external light reflected from the fluorescent surface may be reduced. In order to reduce l.;2, it can be seen from equation (2) that it is effective to lower the light transmission ratio of the face plate (Z). For this reason, as a method to improve the contrast performance of a cathode ray tube, it is often done to reduce the light transmittance of the space plate.In this case, the disadvantage is that the cathode ray tube It is clear from equation (2) that the output 11i of 1.1 is also low at the same time.

Figure 4 is a diagram for explaining the optical characteristics of the face plate and fluorescent surface. In the figure, H, G, and R are 130 +?
:', Relative luminescence intensity of luminescence from the color phosphor layer (4) i+i 4. ' is the sex curve, u, III, IV, V
The glass wall thickness of the fucose plate (2) is l 3
The spectral transmittance of the face plate (2) at m m is the IJ characteristic curve, and characteristic 11 is a clear type with a spectral transmittance of about 85% in the rI viewing region, and characteristic II+ is about 69%. % Gray type, Characteristic IV is about 50% Guinto type, ■ is about 38% Dark Tin! (The spectral transmittance of 21 is low, but it is disadvantageous for the brightness performance of the fluorescent surface of the cathode ray tube.) It is clear from the relationship with the spectral distribution of the relative emission intensity of the fluorescent surface of the cathode ray tube that the contrast performance l. , has become advantageous, and with the recent trend of emphasizing image quality in color television receivers, brightness performance of 1n
Tint type and dark tint type fucos plates (2), which emphasize contrast performance, have come to be used more frequently than the conventional clear type and gray type, and With the recent increase in the size of cathode ray tubes, their performance in l++ degrees, and changes in their face parts, the voltage applied to the fluorescent surface of cathode ray tubes, that is, the acceleration type J-J'g of the electron beam, has become higher. The problem of chassis and bumps on the face of Previsi TV receivers is becoming more and more serious.

The electrostatic protection 11- of the fuse part of such a color television receiver and the history of the contrast performance of the image are as follows.
Antistatic 11/light selective absorption film (
3) Cathode ray tube with anti-static + selective absorption film (l)
It has come to be used.

This antistatic 11-photoselective absorption film (3) is made of silica (S1
It is composed of a 0□) type film, and has both antistatic function and light selective absorption function.

In order to form such an antistatic 11° selective absorption film (3), silicon (Sl) Al: 1, which is generally a functional group and has a -011 group or an -OR group, is used. Let's use Gishito's one-lone 1-l melt as a varnish material, and use this base r!pf
In addition to dispersing and mixing fine particles of tin oxide (SnO7l and indium oxide ＼(I n +i 0 :+)) as conductive fillers in 4, a coating liquid containing 41 organic or inorganic dyes or pigments is applied to the cathode ray tube. 11 by coating the outer surface of the face plate (2) with 4J.
I can sleep.

The application 11 of such a coating liquid is generally performed by spin: j-tθ
, to obtain strong film strength after film formation Z) to 1
Cure the membrane at a temperature of 0 to 200°C.

Figure 6 shows the surface of the face plate (2).
It is an enlarged cross-sectional view of the 111 electric protection 11 light selective absorption film (3), and is a porous silica H! It has a structure in which organic or inorganic dye or pigment particles (8) and conductive filler particles (9) are dispersed in the particles 2 (71).

Figure 7 is a small graph showing changes in the surface potential of the face/breath part of a cathode ray tube.Characteristic curve 14 in the figure shows 11 when charged - when the power is turned on for a cathode ray tube that is not functioning. 1゜1 is the surface potential change characteristic when the power is OFF F', and the broken line characteristic curve M is when the power is turned on for a cathode ray tube with an antistatic function. M+ has a small surface potential change characteristic when the power source is 01;'F''.

A cathode ray tube, which has no function when charged, has a conductive film formed on the outer surface of its face plate (2), and this conductive film is connected to the ground, so that the surface charge does not occur. It can be seen that the charge-up has become significantly smaller because it constantly escapes towards the ground.

Next, the contrast performance achieved by the antistatic light selective absorption film (3) will be explained with reference to an enlarged sectional view of the fluorescent surface portion of the cathode ray tube in FIG.

・j;: Electroprotection 11 This is the same as the cross-sectional view of FIG. 21, except that a light selective absorption film (3) is added to the outer surface of the fucose plate (2). .

In addition, the glass material of the face plate (2) and...
1) Since the optical refraction angles of the electrical protection 11 and the light selective absorption film (3) are selected to be almost the same, light reflection at these interfaces can be almost ignored.

In this case, the :Jn trust index (:° can be expressed by the following formula (0) similarly to formula (l).

・・・・・・■ I11 1・-1: [・0・i゛. Pi゛、・Tc・・
・・・・■＋・： 、 = 0.0415゜・・・・・・
......■F,'+lO,96)"Eo-Tp"
i'c" (口、,044 (0,9612R,,1...
・It is ■.

In Equation 1, l.:1 is constant, and if i', , is also constant, then in order to make the last index C° towards history, from equations (5) and (8), .:1 :Electric protection 11 likely selective absorption; light transmission of model (3) small '1'. The 41 effect is to be able to see the difference in size. .

In the case of the 11-like selective absorption film (3) when charged, the optimum spectral transmittance distribution of this film in the visible light region and the relative emission intensity distribution of the light emission from the 13 G R three-color phosphor layer (4) are determined. By doing so, it is possible to suppress the low level of the output luminance r='' shown in 20 as much as possible and raise the contrast index C' in the direction of 1.

The characteristic curve l in FIG.
1. An example of the spectral transmittance distribution characteristics of the light-selective absorption film (3) is shown, and between 535 nm and 625 nm of the spectral distribution of the relative emission intensity of G, F<1.
If there is an absorption peak of this antistatic light selective absorption film (3) in a portion of m that is close to this toss vector wavelength, the brightness performance of the fluorescent surface of the cathode ray tube will be disadvantageous. Considering hair value range etc., usually 570nm or 610nm.
The absorption peak 8 is placed in the range of m. This is because light with a wavelength within this range corresponds to a relatively high visual sensitivity region of 11 for humans.

Of the external light (usually white light) component, this region of light is absorbed,
When removed:] Contrast Performance 1 - Favorable. That is, when charging 11--when charging the cathode ray tube (l) with a light selective absorption film 11. The optical properties of the light selective absorption film (3) include high visibility of 1-'I for humans, and 570'nm or rII, which has as little influence on light emission from the fluorescent surface as possible.
The absorption peak of absorption (l) is placed within the Onm range to maintain the luminance performance of the fluorescent surface, while absorbing external light to an E1 effect to improve contrast performance. .

It is very important to select an organic or inorganic dye or pigment that has such optical properties, and the characteristic curve I is
An example is shown in which the absorption band has eight absorption peaks at 580 nm. In cathode ray tubes (+) with antistatic function and selective absorption film, the optical light absorption characteristics of the organic and inorganic dyes and pigments mixed in the base paint are relatively broad, so the luminescence of the fluorescent surface is Among them, for example, the other part on the longer wavelength side of the + spectral wavelength of green emission and the sub-peak part on the shorter wavelength side of 1 spectral wavelength of red emission are absorbed by this light selective absorption film (3), and the color tone of the emitted light changes. Improvements can also be made at the same time.

The small diagram in Figure 9 shows cathode ray tubes a~ [“
When external light with an intensity of 100 [·, 0] is incident on the outer surface of the face plate (2) of the face plate (
2) Intensity of surface reflected external light reflected on the outer surface of 1.
7, the intensity of the external light reflected by the fluorescent film reflected by the inner surface of the ace plate (2) and the fluorescent film and coming out of the face plate (2), and the total internal reflection external light. In the light,
The ratio of external light reflected from the surface to the surface (t-: l/ (l.
+ + l': 2) Since C and " are reflections on the outer surface of the antistatic 11 light selective absorption film (3) whose optical refractive index is almost the same as that of the glass material, the intensity is approximately 4.0. Naru 3,
In addition, the fluorescent film (strength 1., 2 at the outer tip of the radiation is the antistatic 1! ) depends on the light transmittance of
When these light transmittances become low, they decrease rapidly.

When these characteristics were measured and evaluated, an incandescent lamp was used that provided external light lJ and a relative luminous intensity /1+ as shown in FIG.

It is clear from each face plate in the diagram of FIG. 1
ni ratio he (l・, 2 or J1 normal ζ high <<= 1, that is, it can be ignored, but 7J-1-S plate (・and (lo)
As the light transmittance decreases, 1.:1 and 1.
:2 is always close to J1 (-J ends up being 1・:1's influence is 1!
1 (cannot be seen and has low light transmittance to begin with) If a light absorbing film is formed on the outer surface 1° as shown in upper grade c and [, this tendency will become more noticeable. ] is a phenomenon that the more the light transmittance of the fucose plate (2) is increased in order to improve the contrast performance of the cathode ray tube, (2)
The more the light transmission = tt is increased by providing a light absorption film on the outer surface of the Fucose Spray 1121, the more light reflection from the surface of the fucose spray 1121 becomes. I could clearly see Kangen's face reflected in the sky,
For the viewer, it becomes extremely tiring, and if you continue to watch the video for a long time, you will feel tired and wandering around.

This problem of external light reflection becomes extremely noticeable when the light transmittance of the face plate (2) becomes 5% or more. The problem becomes even more serious when a light absorption film such as the antistatic 11-photoselective absorption film (3) is formed on the surface.

[Problems to be Solved by the Invention] This invention was made to solve the problems mentioned in item L4, and in order to improve the contrast performance of the cathode ray tube, the light transmittance of the face plate is increased. To provide a cathode ray tube with a low reflection film which causes little reflection due to external light even if a light absorption film is provided on its outer surface.

. [Means for solving the problem] The cathode ray tube according to the present invention has a light transmittance of 50% or more.
100 formed on the outer surface of the fucose plate
Ultrafine particle magnesium fluoride with a diameter of less than 0 people (
It is characterized by having a silica (S102)-based optical thin film with a constant thickness in which MgFz) is dispersed and mixed.

[Function] In the optics-:+71 model of silica (sio, l-based, constant yield II) according to the present invention, magnesium fluoride with an average f1'I diameter of more than +000 is dispersed. ,
The reflection of external light on the outer surface of the fucose plate is reduced, and the influence of reflection etc. on external light is reduced. I'll explain next. FIG. 1 is an enlarged sectional view of the face plate portion of the cathode ray tube with a low reflection film according to this embodiment.
Antistatic 11 on the outer surface of 121 - Light selective absorption type low reflection 11
110) is formed. This anti-static 11 light-selective absorption type low reflection film (l0) has organic or inorganic dye or pigment powder r (81 and In addition to the proprietary f1 filler (9), this film (l0)
Conventional static protection 1 is characterized by the dispersion of ultrafine 1:t, r magnesium fluoride\(l1) to lower the refractive index of
1-Different from light selective absorption film (3).

The average particle size of this ultrafine magnesium fluoride (l1) is 1
1,000 or more people, preferably 300 or more people.
1+i It is more preferable than Mi+ in terms of effective transmission and uniformity of j.

In the case of the conventional electric protection 11 light selective absorption film (3),
Organic or inorganic dye or pigment particles (8) and conductive filler particles (9) are dispersed and mixed in a porous silica membrane (7), but depending on the type of these mixed materials, The refractive index of the formed film was 1.5 to 1.54, which was the same as that of the glass material of the blank face plate (2).

However, in this example, magnesium fluoride (MgF2
Since 1 itself is a material with a very low refractive index (n' = 1.3B), by adding ultrafine particles of magnesium fluoride made of this material to -11, the refractive index is reduced to approximately 1.
An optical thin film with a low refractive index that can be increased up to 4? It is well known that anti-Q・t on the glass surface can be reduced by providing a thin film with a constant thickness and a refractive index lower than that of the glass on the surface of the glass1. The refractive index of the thin film provided on the surface of If (d) is selected, the surface reflection can be suppressed to the minimum, and the surface reflection [<
is R= (rl2no nap” / (rl2+
rlo ria12. However, rlo is the refractive index of air, and n G is the refractive index of glass.

In this example, anti-static 11" light selective absorption type low reflection 1 model (l
0) is provided on the outer surface of a fucose plate (2) made of glass with a refractive index of 1.5 to 1.54, and its refractive index is ultrafine magnesium fluoride (If), which is a low refractive material.
? , R can be reduced to about 1.4 by dispersion mixing.
It is possible to reduce the surface reflection of external light on the face prolate (2) surface by maintaining a constant contrast of the film thickness d. Among (white light), it is desirable to effectively reduce light in the range of 480 nm to 620 nm, which has relatively high visual sensitivity for the human mouth, so please note 7. It is preferable that m is selected so as to satisfy the relational expression of an integer of 1F less than or equal to l.

In addition, in order to control the film thickness of the coating film to be constant in this way, the coating film 11 of the coating liquid is prepared using the spin code method, and the rotation speed during the spin code, the shake-off time, the viscosity of the coating liquid, the solid content, and the temperature. It is necessary to strictly control the surface temperature of the face plate (2), the temperature and humidity of the coating/drying booth, etc.

Figure 2 shows the surface spectral reflectance (a) of the conventional static protection 11" light selective absorption film (3) provided on the outer surface of the face plate (2) of a cathode ray tube, and the static protection II-2 according to this embodiment.
Surface spectral reflectance (n) of selective absorption type low reflection film (l0)
This figure shows a comparison between the conventional type and the conventional type, which had a surface reflection of about 4% in the +iJ viewing light range, but the surface reflection of this example was reduced to about 1.5%.

Fucose plates C° to f° in the diagram shown in Figure 9
are the intensity of reflected light E+, Eg and surface reflection 1.:1 ratio of external light ( X100) j ■, ζ, +1'
:.

Compared to the conventional face plates (2 to 2) under the same conditions, the proportion of external light reflected on the surface is about 1/2, indicating a significant improvement.

In the first embodiment, the anti-static 11 - light selective absorption type low 1 or projection film (l0) is described as one unit, but the present invention is not limited to this, and the face plates c' and d' A J-S plate (2) that has a light transmittance of 50% or more as a film that has only an antistatic function on its outer surface, and a film that has only a low reflection ability. It can be similarly applied to forming.

[Effects of the Invention] As described above, according to the present invention, ultrafine particles of magnesium fluoride (MgF21) having a mean particle diameter of 1,000 or more are coated on the outer surface of the face plate to reduce the refractive index. (It is characterized by the provision of a SiOzl-based optical thin film with a constant thickness, which reduces the reflection of external light on the outer surface of the face plate, resulting in a cathode ray tube that is less affected by external light reflections. C) It has a positive effect.

[Brief explanation of drawings]

FIG. 1 is a partially enlarged sectional view of the face plate of a cathode ray tube with a low reflection film according to an embodiment of the present invention, and FIG. 2 is a diagram showing the surface spectral reflectance of the outer surface of the face plate of this embodiment. Figure 3 is a partially enlarged cross-sectional view of the face plate including the fluorescent surface of the cathode ray tube, and Figure 4 is a cross-sectional view of the face plate including the fluorescent surface and the fluorescent surface.
Figure 5 is a partially cutaway side view of a cathode ray tube with antistatic 11 and light selective absorption film, and Figure 6 is a view showing the optical characteristics of the face of the cathode ray tube, which is smaller than that shown in Figure 5. Figure 7 is an enlarged cross-sectional view of the plate portion, and Figure 7 shows changes in the surface potential of the face plate portion of the cathode ray tube. FIG. 9 is a partial enlarged sectional view of the face plate including the fluorescent surface, and FIG. 9 shows the reflection characteristics f1 of the conventional example and the embodiment of the present invention.
FIG. 0 is a diagram showing the relative luminescence intensity distribution of the incandescent light used to measure the anti-Q.1 characteristic f1 of the Kokunijin shown in FIG. 9. (2)...Full plate, (7)...Porous silica plate, (ill...Organic or inorganic dye or pigment $1'/J', (91... conductivity fl-)
Trir, 110) - (i: Electric protection 1) Light-selective absorption type low-reflection film, (II)...Ultrafine particle magnesilate fluoride l\.In addition, in the valley diagram, the same symbol is the same, or Cut a considerable portion into small pieces.

Claims (1)

Scope of Claims: (l) An alcoholic solution of silicon (Si) alkoxide having -OH and -OR groups as functional groups is used as a base paint, and ultrafine magnesium fluoride particles with an average particle size of 1000 Å or less are added to this base paint. Equipped with a low reflection film formed by applying and forming a coating liquid containing (MgF_2) dispersedly mixed on the face plate surface of the cathode ray tube with a light transmittance of 50% or less.
The film thickness d (nm) of this low reflection film and its refractive index n are configured so as to satisfy the following formula: 480 nm≦4nd/(2m-1)≦620 nm (where m is a positive integer of 1 or less). A cathode ray tube with a low reflection film that is characterized by: