JP2006120619A - Color cathode-ray tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color cathode-ray tube with little peeling of a phosphor layer and which can be produced at low cost with proper yield. <P>SOLUTION: Optical filter layers 4B<SB>R</SB>, 4B<SB>G</SB>and 4B<SB>B</SB>only transmitting light with a desired wavelength are provided in a non-forming region of a light-absorbing layer 2 formed on the inner surface of a glass panel 12 and phosphor layers 6R, 6G or 6B that emit one among red, green or blue lights are provided on the optical filter layers. The optical filter layers 4B<SB>R</SB>, 4B<SB>G</SB>and 4B<SB>B</SB>transmit blue light. If the thickness of the optical filter layer 4B<SB>B</SB>underlying the phosphor layer 6B that emits blue light is set as t1, and the thickness of both the optical filter layers 4B<SB>R</SB>and 4B<SB>G</SB>underlying the phosphor layers 6R and 6G that emit red and green light is are set as t2, the relation t1>t2 is satisfied. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a color cathode ray tube.

  In the phosphor screen of the current color cathode ray tube, a method of providing an optical filter that transmits only light of a desired wavelength between the glass panel and the phosphor is widely adopted for the purpose of improving luminance and contrast. (For example, refer to Patent Document 1).

  This phosphor screen is manufactured as follows, for example. A dot-like or stripe-like optical filter layer that selectively transmits only red, green, or blue wavelengths is formed on the inner surface of a glass panel on which a light absorption layer such as a black matrix or black stripe is formed. Subsequently, a dot-like or stripe-like phosphor layer that emits red, green, or blue light corresponding to the color of light transmitted through the lower optical filter layer is formed on each optical filter layer.

  At this time, if the phosphor layer is directly formed on the optical filter layer, there arises a problem of so-called dot dropping, in which the phosphor is peeled off from the glass panel due to the unevenness of the base or the compatibility between the optical filter material and the phosphor material. This tendency is particularly remarkable in green and red phosphors.

  In order to solve this problem, a method has been proposed in which a colloidal silica solution is applied on an optical filter layer, dried to form a silica layer, and a phosphor layer is formed thereon (for example, Patent Document 2). 3). A method for forming this phosphor screen will be described with reference to FIGS. 4 (A) to 4 (G).

  First, the light absorption layer (black matrix or black stripe) 2 is formed on the inner surface of the glass panel 12 (FIG. 4A).

  Next, a blue pigment dispersion is applied to the inner surface of the glass panel 12 to form a blue pigment coating layer 3B (FIG. 4B).

  Next, a shadow mask (not shown) is mounted on the glass panel 12 and exposed through the shadow mask (FIG. 4C).

  Next, the shadow mask is removed, and a developing solution such as an alkaline aqueous solution is sprayed to remove the unexposed blue pigment coating layer 3B, thereby obtaining a blue pigment layer (blue filter layer) 4B (FIG. 4D).

  The green filter layer 4G and the red filter layer 4R are formed in the same manner as in the blue filter layer 4B formation process (FIG. 4E).

  Next, a colloidal silica liquid in which colloidal silica is dispersed is applied onto the optical filter layers 4B, 4G, and 4R on the inner surface of the glass panel 12, and dried to form the silica layer 5 (FIG. 4F).

  Next, the blue phosphor layer 6B is formed on the blue filter layer 4B, the green phosphor layer 6G is formed on the green filter layer 4G, and the red phosphor layer 6R is formed on the red filter layer 4R in order by a slurry method (FIG. 4 (G)).

  Thus, the phosphor screen 7 is obtained on the inner surface of the glass panel 12.

Thus, when the thin silica layer 5 is formed on the optical filter layers 4B, 4G, and 4R, the adhesion of the phosphor layers 6B, 6G, and 6R is improved, and the dropping of the phosphor layers 6B, 6G, and 6R is reduced. be able to.
JP-A-10-302668 Japanese Patent Laid-Open No. 10-64427 JP 11-2333018 A

  However, since the above method requires a step of applying a colloidal silica solution, there is a problem in that materials and equipment for that purpose are required, resulting in an increase in cost. In addition, after applying the colloidal silica solution, surplus colloidal silica solution scatters to the periphery, which dries and becomes foreign matter, causing various defects and reducing yield.

  The present invention provides a color cathode ray tube that eliminates the above-mentioned problems caused by applying a colloidal silica solution and has a phosphor screen with less dropping off of the phosphor layer, and as a result, is inexpensive and can be produced with high yield. The purpose is to do.

  The color cathode ray tube of the present invention transmits only light of a desired wavelength provided in a glass panel, a light absorption layer formed on the inner surface of the glass panel, and a non-formation region of the light absorption layer. An optical filter layer and a phosphor layer that is provided on the optical filter layer and emits light in any one of red, green, and blue. The optical filter layer transmits blue light. When the thickness of the optical filter layer below the phosphor layer emitting blue light is t1, and the thickness of the optical filter layer below the phosphor layer emitting red and green are both t2. , T1> t2 is satisfied.

  The color cathode ray tube of the present invention has a phosphor layer having good adhesion without going through the step of applying a colloidal silica solution. Therefore, it is possible to realize a color cathode ray tube that can be produced inexpensively and with high yield.

  One embodiment of the color cathode ray tube of the present invention is shown in FIG. The color cathode ray tube 10 includes an envelope 11 composed of a glass panel 12 having a phosphor screen 19 formed on the inner surface and a funnel 13. An electron gun 14 is housed in the neck portion 13 a of the funnel 13. A shadow mask 15 is provided facing the phosphor screen 19. The shadow mask 15 is supported by a frame 16 having a substantially rectangular frame shape, and the frame 16 is attached to a panel pin (not shown) provided on the inner wall of the glass panel 12 via a spring (not shown). A deflection yoke 18 is provided on the outer peripheral surface of the funnel 13 to deflect and scan the three electron beams 17 emitted from the electron gun 14.

FIG. 2 is a partial enlarged cross-sectional view of the phosphor screen 19. A light absorption layer (black matrix or black stripe) 2 is provided on the inner surface of the glass panel 12. The light absorption layer 2 of the dot or stripe-shaped non-forming region, selectively permeable to optical filter layers 4B _B only light of a specific wavelength, 4B _G, 4B _R is provided, the red on the green, Three color phosphor layers 6B, 6G, and 6R each emitting blue light are provided. Optical filter layers 4B _B, 4B _G, none 4B _R is blue filter layer that transmits blue light. That is, the blue filter layer is provided not only under the blue phosphor layer 6B that emits blue light but also as a lower layer of the green phosphor layer 6G that emits green light and the red phosphor layer 6R that emits red light. Then, it is provided blue filter layer 4B _B, 4B _G, directly onto 4B _R phosphor layers 6B, 6G, 6R, respectively. Thereby, even if the conventional silica layer 5 (see FIG. 4G) is not interposed, the adhesion of the phosphor layers 6B, 6G, and 6R can be improved and the drop-out can be prevented. Therefore, the manufacturing yield is improved. In addition, since the silica layer is not necessary, the problems of an increase in cost due to an increase in material cost and equipment cost and a decrease in yield due to scattering of the colloidal silica liquid, which are caused by performing the coating process of the colloidal silica liquid, are solved.

Optical filter layers 4B _B, 4B _G, but all the composition of 4B _R may be the same or different, it is preferable that the thickness is different. Specifically, the thickness of the lower of the blue filter layer 4B _B of the blue phosphor layer 6B t1, lower blue filter layer 4B _G of the green phosphor layer 6G and a red phosphor layer 6R, the thickness of the 4B _R In any case, it is preferable that t1> t2 is satisfied when t2. If this condition is not satisfied, the luminance and chromaticity of green and red are reduced, or the blue chromaticity improvement effect is not sufficiently obtained, and the color reproducibility of the image is lowered.

The thickness t1 of the lower blue filter layer 4B _B of the blue phosphor layer 6B is,
1.00μm ≦ t1 ≦ 3.50μm
Is preferably satisfied. If the thickness t1 of the blue filter layer 4B _B satisfies the above range, it is possible to obtain the most efficient filter characteristic for blue phosphor layer 6B.

Lower blue filter layer 4B _G of the green phosphor layer 6G and a red phosphor layer 6R, the thickness t2 of the 4B _R,
0.01 μm ≦ t2 ≦ 0.35 μm
Furthermore,
0.05μm ≦ t2 ≦ 0.25μm
Is preferably satisfied. If the blue filter layer 4B _G, thickness t2 of the 4B _R is smaller than the above numerical range, the phosphor layer 6G, the adhesion improving effect of 6R decreases. The thickness t2 is larger than the above range, blue filter layer 4B _G, the blue light transmission characteristic of 4B _R, affects the green and red luminance and chromaticity. Incidentally, the thickness of the lower layer of the blue filter layer 4B _G of the green phosphor layer 6G, may be the same as the thickness of the lower of the blue filter layer 4B _R of the red phosphor layer 6R, it may be different.

The reason why the blue filter layer improves the adhesion of the phosphor layers 6B, 6G, 6R is not clear, but pigment particles (for example, cobalt aluminate (CoO.Al ₂ O ₃ )) contained in the blue filter layer and fluorescence This may be because the compatibility with the phosphor particles contained in the body layers 6B, 6G, and 6R is good.

Example 1
A phosphor screen for a wide color cathode ray tube having a diagonal size of 76 cm and an aspect ratio of 16: 9 was produced as follows.

  First, as shown in FIG. 3A, a stripe-shaped light absorption layer (black matrix) 2 was formed on the inner surface of the glass panel 12 by a known method, and then a precoat treatment was performed. In the precoat treatment, a precoat agent containing a silane coupling agent as a main component was used. The silane coupling agent serves to increase the adhesion of the optical filter layer to the glass panel 12 and to prevent the light absorption layer 2 from peeling from the glass panel 12 when the optical filter layer is formed. Yes.

Next, as shown in FIG. 3B, a blue pigment dispersion was applied to the entire inner surface of the glass panel 12 and dried to form a blue pigment coating layer 3B. The blue pigment dispersion contains cobalt blue (CoO.Al ₂ O ₃ manufactured by Toyo Pigment) as a blue pigment, and ammonium bichromate (ADC) and polyvinyl alcohol (PVC) as a photoresist.

  Next, as shown in FIG. 3C, a shadow mask (not shown) was attached to the glass panel 12, and only the planned formation place of the blue phosphor layer was exposed through the shadow mask.

Next, the shadow mask was removed and developed. The development conditions were weaker than the conventional development conditions. The weak development conditions include, for example, shortening the development time, weakening the pressure of the developing water to be sprayed, and lowering the alkali concentration when an alkaline aqueous solution (for example, NaOH-containing aqueous solution) is used as the developer. Applicable. In this example, a 0.1% NaOH solution was used as a developer and immersed for 20 seconds, and then developed with a developing water pressure of 0.2 MPa and a time of 25 s. As a result, among the non-formation region of the light absorbing layer 2, the blue filter layer 4B _B in the exposed area is formed, further in the areas not exposed, and remaining blue pigment coated layer 3B blue filter layer 4B _G and 4B _R were formed. The thickness t1 of the blue filter layer 4B _B is 2.1 .mu.m, the blue filter layer 4B _G, thickness t2 of the 4B _R was 0.2 [mu] m (FIG. 3 (D)).

Next, a blue phosphor layer 6B in the blue filter layer 4B on _B, and the green phosphor layer 6G on the blue filter layer 4B _G, a red phosphor layer 6G on the blue filter layer 4B _R, a known slurry method These were formed in order (FIG. 3E).

  Thus, a phosphor screen 19 was obtained on the inner surface of the glass panel 12.

(Comparative Example 1)
In Example 1, the blue filter layer was obtained by developing under the development conditions generally used conventionally. That is, in Comparative Example 1, a 0.3% NaOH solution was used as a developing solution and immersed for 40 seconds, and then developed with a developing water pressure of 0.4 MPa and a time of 40 seconds. The development conditions, stronger than Example 1, the blue pigment coated layer 3B which is not exposed is almost completely removed, the blue filter layer 4B _G, 4B _R was not formed.

  Except for the above, a phosphor screen was obtained on the inner surface of the glass panel 12 in the same manner as in Example 1.

(Comparative Example 2)
A phosphor screen was formed by the conventional method shown in FIGS. 4 (A) to 4 (G). Details are as follows.

  First, as shown in FIG. 4A, the light absorption layer 2 was formed on the inner surface of the glass panel 12 in the same manner as in Example 1, and then the same precoat treatment as in Example 1 was performed.

  Next, as shown in FIG. 4B, the same blue pigment dispersion as in Example 1 was applied to the inner surface of the glass panel 12 and dried to form a blue pigment coating layer 3B.

  Next, as shown in FIG. 4C, a shadow mask (not shown) was attached to the glass panel 12, and only the planned formation place of the blue phosphor layer was exposed through the shadow mask.

  Next, the shadow mask was removed, development was performed under the same conditions as in Comparative Example 1, the unexposed blue pigment coating layer 3B was removed, and a blue filter layer 4B was obtained (FIG. 4D).

The green filter layer 4G and the red filter layer 4R were formed in the same manner as in the blue filter layer 4B formation process (FIG. 4E). The green pigment dispersion for forming the green filter layer 4G includes cobalt green (CoO · Cr ₂ O ₃ · TiO ₂ · Al ₂ O ₃ ) as a green pigment, ammonium dichromate (ADC) as a photoresist, and Contains polyvinyl alcohol (PVC). The red pigment dispersion for forming the red filter layer 4R contains Bengala (Fe ₂ O ₃ ) as a red pigment and ammonium bichromate (ADC) and polyvinyl alcohol (PVC) as a photoresist.

  Next, as shown in FIG. 4 (F), a colloidal silica liquid in which colloidal silica is dispersed is applied onto the optical filter layers 4B, 4G, and 4R on the inner surface of the glass panel 12, and dried to form the silica layer 5. Formed.

  Next, a blue phosphor layer 6B was formed on the blue filter layer 4B, a green phosphor layer 6G on the green filter layer 4G, and a red phosphor layer 6R on the red filter layer 4R (FIG. 4 (G )). The materials and forming methods of the blue phosphor layer 6B, the green phosphor layer 6G, and the red phosphor layer 6R are the same as those in the first embodiment.

  Thus, the phosphor screen 7 was obtained on the inner surface of the glass panel 12.

[Evaluation]
100 samples of glass panels 12 each having a phosphor screen formed on the inner surface under the conditions of Example 1 and Comparative Examples 1 and 2 were produced. Each phosphor screen was examined for the presence or absence of dot drop in the green and red phosphor layers 6G and 6R. The dot drop is one of the evaluation items of the phosphor screen, and refers to a phenomenon in which the phosphor layer material in the non-formation region of the light absorption layer 2 falls off during the phosphor layer formation process. When dot dropping occurs, the color of the phosphor dropped off at that portion does not emit light, and the color reproducibility deteriorates. The results are shown in Table 1.

As shown in Table 1, with respect to dot dropping, Example 1 is equivalent to Comparative Example 2 in which the silica layer 5 is provided between the filter layers 4B, 4G, and 4R and the phosphor layers 6B, 6G, and 6R. Good results were obtained, and Comparative Example 1 was inferior to these. This blue filter layer 4B _G, 4B _R directly onto the phosphor layer 6G, by forming respectively 6R, phosphor layer 6G, adhesion 6R is the equivalent to that obtained by interposing a conventional silica layer 5 It shows improvement. Therefore, according to the present invention, the silica layer 5 becomes unnecessary, and various problems associated with providing the silica layer 5 can be solved.

In the first embodiment, the blue filter layer 4B _B thickness are different from each other and the blue filter layer 4B _G, in order to obtain 4B _R, is adopted weak development conditions, the present invention is not limited thereto. For example, concentrations of two different blue pigment dispersion liquid separately coated, exposed, and developed to the blue filter layer 4B _B and blue filter layers 4B _G, it may be formed 4B _R.

(Comparative Example 3)
In the exposure step of FIG. 3C of Example 1, not only the planned formation site of the blue phosphor layer but also the planned formation sites of the red phosphor layer and the green phosphor layer were exposed through the shadow mask. Except for the above, a phosphor screen was obtained on the inner surface of the glass panel 12 in the same manner as in Example 1. The thickness t1 and blue filter layers 4B _G and blue filter layers 4B _B, thickness t2 of the 4B _R was either a 2.1 .mu.m.

[Evaluation]
A color cathode ray tube was prepared using the glass panel 12 having a phosphor screen formed on the inner surface, obtained in Example 1 and Comparative Example 3. Each color cathode ray tube was operated under predetermined conditions, and the luminance at the center of the screen was measured using a CRT color analyzer “CA-100” manufactured by Minolta Co., Ltd., which is an industry standard. The results are shown in Table 2. In Table 2, the luminance data of Comparative Example 3 is shown as a relative value with the luminance of Example 1 as 100.

As in Comparative Example 3, if the same as the blue filter layer 4B _G, 4B thickness of the thickness t2 of the _R blue filter layer 4B _B t1 the red and green luminance is significantly deteriorated.

  The field of use of the present invention is not particularly limited, and can be widely used for television receivers, computer displays, and the like.

It is sectional drawing which showed schematic structure of the color cathode ray tube which concerns on one Embodiment of this invention. It is a partial expanded sectional view of the phosphor screen of the color cathode ray tube which concerns on one Embodiment of this invention. It is sectional drawing which showed the formation method of the phosphor screen which concerns on Example 1 of this invention in order. It is sectional drawing which showed the formation method of the conventional phosphor screen in order.

Explanation of symbols

Second light absorbing layer 3B blue pigment coated layer 4B _B, 4B _G, 4B _R optical filter layer (blue filter layer)
5 Silica layer 6B, 6G, 6R Phosphor layer 10 Color cathode ray tube 11 Envelope 12 Glass panel 13 Funnel 13a Neck 14 Electron gun 15 Shadow mask 16 Frame 17 Electron beam 18 Deflection yoke 19 Phosphor screen

Claims (2)

  A glass panel, a light absorption layer formed on the inner surface of the glass panel, an optical filter layer provided in a non-formation region of the light absorption layer, and transmitting only light of a desired wavelength, and the optical filter A color cathode ray tube having a phosphor layer that emits red, green, or blue light provided on the layer, wherein the optical filter layer transmits blue light and emits blue light T1> t2 is satisfied, where t1 is the thickness of the lower optical filter layer, and t2 is the thickness of the lower optical filter layer of the phosphor layer that emits red and green light. Color cathode ray tube. 1.00μm ≦ t1 ≦ 3.50μm
0.01 μm ≦ t2 ≦ 0.35 μm
The color cathode ray tube according to claim 1, wherein:

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