JPS58175239A - Projection type cathode-ray tube - Google Patents

Abstract

PURPOSE:To fully show advantages of the faceplate of anti-browning glass and reduce the secular degradation of the optical output by using a terbium activated yttrium.aluminum.gallium garnet phosphor. CONSTITUTION:A phosphor screen is constituted by providing a phosphor layer on the inner surface of the faceplate glass that forms a part of a vacuum enclosure and X is regulated to 0<=x<=1 by incorporating lithium oxide (Li2O) of 0.3 to 3.0 weight percentage in the faceplate glass and making the said phosphor layer composed of terbium activated yttrium.aluminum.gallium garnet Y3(Al1-xGax)5O12:Tb.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a projection oak cathode-wrapped tube with a modified phosphor screen.

Zaihiro Todoroki<*#The TV set 1 using the shadow mask method that is wrapped in the shadow mask method is 30 as a childcare chair that can be obtained by its structural constraints as a lifetime. The depth of excavation in inches is considered to be the limit.

For this reason, as a means of receiving larger -[tf Bayesian television images, etc. . In this projection TV set (1), there are 9 B (Jf 1 color), 03m color), l
(Red) F) Achieving jll images ・Approximately 5 to 8 inches Ii 1 chair small throw 8 grip cathode ray tube (hereinafter referred to as monochrome cathode ray tube) ($) @ (1) , (4 )
The monochromatic image of
You can get color images of the surface. This screen (
6) Since the height of the chair is generally 40 to 70 inches, the image in 5 (4) is displayed on the screen (6). Approximately 50 to 10
Enlarge the image to 0x and take a picture.

These monochromatic cathode ray tubes tg)' a, (s) #'
(4) differs only in the type of phosphor broken inside.
Since they are structurally almost the same, monochromatic cathode ray tubes (
8), the structure of f will be briefly explained (see Figure 1112).

A phosphor layer (9) is formed on the inner surface of the face plate glass (8) constituting the -S of the outside vacuum Wi-(7) using a sedimentation coating method using am potassium (KljliOl) as a binder. - On this phosphor layer (9) there is a ^8E electrical reef and an aluminum layer as a light reflecting film.
) is formed as a metal back film. This, the phosphor layer (9) and the metal rose 1114 constitute a phosphor element (6). Also, this vacuum envelope - (
An electron gun (B) is sealed inside the 7), and the energy of the electron beam emitted from the electron gun (2) excites the phosphor layer (9), increasing the light output. is taken out.

In the case of such a G monochromatic polar tube (8), the phosphor layer (9
), traditionally, the luminous color tone of 1,000 is superior and %
The r41I property (a property that shows the combination of an increase in light output with an increase in the fluorescent surface stimulation current) and the one-time property (a property that shows a change in the luminous efficiency of the fluorescent surface due to an increase in the temperature of the fluorescent surface) are incomplete. However, sulfide-based phosphors (such as sulfide-based phosphors, which are widely used as G phosphors in conventional Simidum mass I color cathode ray tubes, etc.) are also superior.
FhiIIIJi ship with gun (1mm sto,
:iim) Use fluorescent physical strength i! tL ”C is here.

On the other hand, in the case of such a projection individual polarized tube, since the image is enlarged and projected onto the starne (6) as described above, it is necessary to realize an image of sufficient brightness on the starne (6). , it is essential that the light output of the projection #1 pole tube itself be sufficiently large (per unit area) to be This Lugi density (
11a+-'') is an order of magnitude larger than that of the fluorescent surface of a conventional shadow master type color tube.

However, when operating a single projection cathode-wrapped tube for a long time while applying a large load to the phosphor surface, the phenomenon of deterioration of the light output from the phosphor surface over time becomes important.
becomes.

The curve M (X) in Figure 113 has an average particle size of 31 mm ml (F
) N-8104: Mal phosphor was coated and formed on the inner surface of the face plate glass, which has been widely used in the past, with a coating density of 4Q by the coating method. Projection □Photographic cathode ray tube with high voltage 27a1
The graph shows the relative degradation of light output from a phosphor surface over time when operated at a constant phosphor load of 6 μm·51-” current density.
When lI41 after true &: aIJN light output of 40 &:
This phenomenon of deterioration of the optical output, which decreases to In cathode ray tubes, in order to increase the light output of the phosphor surface, it is difficult to provide too much eclipse to the phosphor surface from the viewpoint of the lifespan of the phosphor surface.

An analysis of the causes of such deterioration in the light output of the phosphor surface revealed that the main causes of deterioration were the decrease in the light output of the phosphor, the decrease in luminous efficiency and the 7Ace plate glass. It has become clear that coloring by electron beams (electron beam prawninda) is layered.

The mountain in Table 1 shown below is 1 described in curve (1) of Rattan 6.
This figure shows the results of analyzing the fluorescent surface after 14000 hours.

(Table 1) Notes 1 to 5 in the table refer to the following commutes.

(Note 1) The phosphor (light output ratio) is 10% of the light output of the phosphor.
000 hours to the initial C0 time).

(Note 2) Glass (transmission ratio) refers to the light output from the phosphor for face plate glass ti4. t71 (transmittance: ratio of R to the initial period (0 hours) after 10,000 hours (TSm/TE) t-amowase.

(Note 5) (4) = (Made x (O)! According to (1) of 11, the luminous efficiency of the phosphor decreased to 0.72 (as NliAt-1,0) after 10,000 hours. The transmission ratio of the face plate glass has been reduced to 0.56 (with WJM as 1,0), and the light output is as a composite of the reduced knot (0,72X O,56-0,40). It can be seen that the value has decreased to 0.40 from the initial value (1,0).

The mechanism by which the luminous efficiency of the phosphor decreases has not been clearly elucidated, but when the phosphor surface is operated for a long time under extremely harsh excitation conditions, as in projection cathode ray tubes, movement due to collisions with electron beams occurs. The light-emitting mechanism of the phosphor itself is gradually destroyed by the energy and incidental thermal energy, and these energies also act as a stopper when the sl phosphor is deposited. Used silicone potassium (chi B
It is thought that the luminous efficiency of the phosphor decreases due to the diffusion of 7N potash ions (such as ions) contained in the phosphor into the phosphor and giving a light-emitting mechanism &:s shadow.

Furthermore, the mechanism of coloring of the face plate glass, that is, electron beam browning, is considered to be approximately as follows. Table 2 below shows an example of the composition (IIIS) of conventional face plate glass.

3 Table 2) As raw materials for glass, sodium oxide (ilalo) and potassium saponide (1:, O) are indispensable materials in order to provide the characteristics of face plate glass.

These exist in the form of Ma (+silium ion) and 1+ (potassium ion) in the formed glass (referred to as fj decorative ions), and play an important role in maintaining the properties of glass. I have 1ilk.

On the other hand, as shown at 1128 m, in the phosphor layer (11) of the projection IITM polar ray tube, particulate phosphor with an average particle diameter of 5 to 20 mm settles on the inner surface of the face plate glass (8).
method), thin and porous coating (at most 2 to 6 particles)
layer)], and there is a gap between the phosphor particles. Therefore, when the phosphor layer (9) is excited by an electron beam from an electron gun, a portion of the electron beam passes through the impurities present between the phosphor particles.

The electron beam directly reaches the surface of the face plate glass (8), collides with the surface, and loses energy. The t-page enters to a depth of several micrometers. If the S load of the member is accumulated on the face play F glass surface for a long time, then -
Alkaline ions such as 2 and 4 are attracted to and move to the charged-up area, neutralize these charges, and generate colloidal metal particles of N& and 2.

For this purpose, the originally transparent faceplate glass (8
) is thought to cause coloring or browning of the surface.

One way to correct the phenomenon of deterioration of the optical output of the projection mmi tube over time is to use this face plate.
It is possible to reduce the electron beam blowing of glass. As mentioned above, this negative Browning beam is associated with M&+, which is a decorative ion in the glass. This is thought to occur because alkali ions such as ``1'' move easily in the glass, so electron beam browning can be reduced by making the glass #lf1', which does not easily cause this movement. Whether or not alkali gold cations are difficult to move in glass depends on its electrical resistance)
You can know. Electrical resistance or volume resistance ratio - (Ω
・It is thought that the larger 5) is, the more difficult it is for alkali metal cations to move.

Is Im+ a specific means of increasing the electrical resistance of glass? In addition to the conventional alkali ions, lithium ions (L
It is known that I (volume resistivity ratio) can be increased by adding ``i'') and adjusting the combination ratio of these appropriately.

This is called the mixed alkali effect.

Figure 4 shows a glass made by replacing barium oxide (LAO) in conventional face plate glass with the composition shown in (B) in Table 2 with lithium oxide (Li, O) in various amounts. The volume resistivity ratio ω) is indicated by −ρ.

By adding Lil0 by about 1.0%, the volume resistivity ratio (4k conventional face plate glass cLt=o is 0%) also becomes much larger (
This effect is remarkable when the LLIO is 0.6 to 5.0 weight s'ic, but when the amount of Li1O exceeds 6°0 weight s'ic, the effect is reduced and the glass itself Glass with greatly improved electrical resistance causes the undesirable M1+ phenomenon in the glass.
It is thought that alkaline cations such as blue and blue 1 are difficult to detect and cause electron beam browning.

In Table 2, (η is Li*Ok1.0, jli≦ plus electron −
This is an example of a new face plate glass composition that is resistant to browning. Glass of this composition is hereinafter referred to as browning-resistant glass.

Using this type of browning-resistant glass, we can create a unique face plate glass that is exactly the same as the conventional one, with an average grain size of 6 mm.
: The Mn phosphor was deposited and deposited on the JJ411F-Kuni Ichimaro's idea: 4. At once, it was coated and formed on the inner surface of this new face plate glass, and then the projection #1 separation tube was formed. Figure 113 shows the relative temporal deterioration characteristics of the light output from the phosphor surface when the phosphor surface is moved under a constant load of 27 ff high pressure and a flow density of 6 m/am, as in the conventional case. The song, ILI (II de) 1. Also, the analysis results of t are shown in Table 1 (
1), the light output (initial ratio) for 10,000 hours bales is a curve (0.40 when using the conventional face plate glass of p, whereas this new face plate・0.42 if glass is required
However, despite the use of browning-resistant glass, the phenomenon of light output deterioration was not alleviated.

As a result of extensive investigation into the reasons why this deterioration phenomenon cannot be improved, it has become clear that the functions between the browning-resistant glass and the phosphor are the same.

This invention was made in view of the problems that occur when using a browning-resistant glass such as Kamiayu as the face plate glass of a projection-mounted pole ray tube.・Projection that fully takes advantage of the advantages of plate glass and reduces the phenomenon of deterioration of the light output of the phosphor screen over time a! It provides a separate tube.

Hereinafter, the dormitory arrangement of this invention will be explained. i&3 first
(1) in Table 1 shows the face plate glass made of plow-resistant glass and 1II as described in Figure 6.
LIIi04: This shows the analysis results of the cause of light output deterioration after 10,000 hours of the fluorescent surface in combination with Mll phosphor, and it is clear from this result that the use of browning-resistant glass is not recommended. ), the coloring phenomenon of face plate glass is conventionally Q, 5 in terms of glass transmission ratio.
6 was changed to 0.70. Although it has been significantly modified as intended, on the contrary, when using this new 1 series plate glass, the phosphor The luminous efficiency of the phosphor surface has decreased from the conventional 0.72 to 0.60), but as a result of combining both 1-*, the phenomenon of deterioration of the light output of the phosphor surface has not been significantly improved. That is to say, there was no such thing.

As a result of investigating the cause of this problem, we added -1, O is 2 town 1 to the new 6L face plate glass.
It has been revealed that i104: promotes the deterioration of the luminous efficiency of the Mn phosphor. The mechanism of accelerated deterioration in this case cannot be definitively determined, but it is thought to be a gradual process. In other words, since the Li ions themselves in the glass are very mobile, the areas where the face plate glass and the 2S104:Mlk phosphor are in contact are susceptible to shocks caused by electron beams and temperature rises caused by electron beams. As the L-ions become very active, they move and diffuse from the glass surface into the phosphor, and as a result, 5ZO4:
It is thought that the light emitting mechanism f of the M1 phosphor is affected in some way, accelerating the deterioration of the optical output. We also carried out a thorough examination of measures to prevent the acceleration of deterioration, and found that such deterioration can be prevented by adding Li and O (07:C-2m7).
It has become clear that the combination of glass and Zn@BLO4:M* phosphor is unavoidable as long as it is used sparingly.

For this reason, an analytical study was conducted on the deterioration of the light output of the phosphor surface by combining a face plate glass made of Browning-resistant glass with LL and O additions and phosphors of various GCm colors. At this time, the G phosphor under consideration not only has an initial light output that is not much different from that of the ZyhHBioa:Mm 1i nine bodies, but also has the above-mentioned performance that is particularly strongly required as a phosphor for projection mm polar tubes. Regarding the r characteristics and temperature characteristics, 1m1ii04: Mm & equivalent
The one above was selected.

As a result of this analysis, terbium-activated yttrium
Aluminum gallium gallium percentage Y, MU1 heat”mO
tm:Tb phosphor is used in this new face plate.
It has become clear that it exhibits very good compatibility with glass.

Song 411 (2) in Figure 11115 is Y1 with an average grain size of 3 to Oboro.
MujlG & 1011: This new face plate glass (1.0 wt. The projection type cathode ray tube equipped with the coating is coated on the inner surface of a browning-resistant glass (containing external material) and operated at a high voltage of 2-7D, current density of 6 m, and a constant fluorescent surface load of country-1 (F). This figure shows the relative aging characteristics of the optical output from the fluorescent surface compared to the conventional case. When looking at the light output (initial ratio) for 10,000 hours of bales, it is 0.42 when combining the new face play F glass with a curve 1) and "s" Oi: '+a phosphor. Well, this new face plate glass and Y1 Galotm
: In combination with Tb phosphor, it is 0.52, about 2
5. Deep improvements will be made.

(2) of Table 6 shown below shows the new face plate glass with plow resistance = :y/glass and Y1'l''l'11 :Tb phosphor and This is an analysis result of the cause of optical output deterioration after 10,000 hours of the fluorescent surface due to the combination of !Ik.

(Table 5) Note 1 in Table 5. Note 2. Note 5 is the same as that in Table 1, and Note 4 in Table 5 is as follows.

(Note 4) YlAJIGalOll: Indicates the light output ratio of the 10,000 hour bale phosphor when combining the YlAJIGalOll:DbgI phosphor with a conventional face plate glass.

According to the results in Table 5), by using browning-resistant glass, the coloring phenomenon of the face plate glass was reduced to 0.56 (Table 1) in the glass transmission ratio of 0°71. In addition, the luminous efficiency of the same phosphor was 0.72 for the combination of conventional face plate glass and YgAJIG&10□:Tb phosphor. This new face
The combination of plate glass and ysmujlGalo11:T'b phosphor is 0.75, YlAJIGa
It is clear that the lOll:Tb phosphor is not affected at all in combination with this new face plate glass.

In this case, both the deterioration of the phosphor and the coloring of the glass fc*
As a result of combining, the light output of the cathode 11f is 0.5 with respect to the initial value (1,0) as (0,73X0.71-0.52).
2 and 1, major improvements have been made.

In addition, the initial light output of the YamujmG&*otm :Tb g1 light body is equivalent to that of the Zn1iii04 :Mll, and the r and temperature characteristics, which are important for the performance of the phosphor of a projection cathode ray tube, are Mo2 town 8
104: It has become clear that Mu-hai Kotai-yo-yo is rather unfaithful.

Note that the above explanation is based on terbium-activated yttrium Al R.
Of the two-limb, gallium-garnet phosphors, Y, MuJ
1GalOH:! Although the present invention is not limited to this composition and can be applied to a wide range of
Yl (mul@-xGax)10u:Tkl (but-
The same effect can be obtained even when applied to a terbium-activated yttrium alkali-gallium garnet phosphor having a lit composition of 0≦X≦1).

As described above, even if Browning-resistant glass with added Li5O is used as the 7-Ace plate glass of the projection gripping cathode tube, due to this emission, the phenomenon of accelerated deterioration of the luminous efficiency of the phosphor occurs. This will not occur, and the advantages of browning-resistant glass will be fully utilized, and the deterioration of the light output of the teeth and fluorescent surfaces over time will be greatly improved! High quality projection shadow 4iiiA
It becomes possible to provide a tube.

[Brief explanation of the drawing]

Figure 1m1 is an explanatory diagram of the basics of a conventional projection lid television set. Figure 2 is a schematic cross-sectional view of a conventional projection lid cathode ray tube. Figure 5Ii1 is an illustration of the light from the fluorescent surface of a conventional projection lid cathode ray tube. Diagram showing deterioration of output over time, No. 4111! Figure 5 shows the relationship between the doping type of I, Ilo and the resistance ratio of the glass body (0).
The figure is a diagram showing a comparison between the aging deterioration of the optical output of the fluorescent surface of the power projection I# core ray tube in one embodiment of the present invention and the conventional deterioration. (7) ...
Fluorescent surface. In addition, the same reference numerals in the figures indicate the same parts or parts corresponding to 6. Agent: 151 Figure 2 Figure 3 0200040006000800010000 (hours) □ Weight % of Li10 in glass □

Claims (1)

[Claims] (1) A phosphor layer is provided on the inner surface of the face plate glass to form a phosphorescent surface, and the face plate glass has a 0.3
Lithium oxide (Li, O) with a weight of 5.0 to 5.0
Damn it, and replace the above phosphor layer with terbium-activated yttrium, aluminum, gallium, etc.! , (Mu4
l-XGax) Gun 011:? 'ni+nyo), mouth ≦X
≦1.