JP3133418B2 - Exposure equipment for fluorescent screen formation of color picture tubes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus for forming a fluorescent screen of a color picture tube, and more particularly to a color picture tube provided with a correction filter function for a correction lens for correcting the trajectory of light emitted from a light source. The present invention relates to an exposure apparatus for forming a phosphor screen.

[0002]

2. Description of the Related Art Generally, in a color picture tube, a fluorescent screen is formed on an inner surface of a panel constituting an envelope, and an electron beam emitted from an electron gun is generated by a deflection yoke mounted outside the envelope. deflected by a magnetic field, and the horizontal the phosphor screen through the shadow mask to the vertical scanning, it is formed on the structure for displaying a color image on the phosphor screen
You.

As the phosphor screen, a phosphor screen composed of a three-color phosphor layer in the form of dots or stripes emitting blue, green, and red light, and a black light absorbing layer provided in the gap between the three-color phosphor layers are provided. There is a fluorescent screen called black matrix type or black stripe type.

[0004] These phosphor screens have conventionally been formed by photographic printing. That is, with respect to a phosphor screen composed of a three-color phosphor layer having no light absorbing layer, a phosphor slurry containing a phosphor and a photosensitive agent as main components is applied to the inner surface of the panel to form a phosphor slurry layer, This phosphor slurry layer is formed by exposing through a shadow mask and developing to form a phosphor layer, which is repeated for the three-color phosphor layer. For a black matrix type or black stripe type fluorescent screen having a light absorbing layer, a photosensitive agent is applied to the inner surface of the panel to form a photosensitive film before forming the three-color phosphor layer, and the photosensitive film is exposed. Then, development is performed to form a resist having a dot-like or stripe-like pattern at the phosphor layer forming position. Next, a black paint is applied to the inner surface of the panel on which the resist is formed to form a black paint layer. Next, the light-absorbing layer is formed by peeling off the black paint layer on the resist together with the resist. Thereafter, a phosphor layer is formed in the gap between the light absorbing layers by a method similar to the method of forming the three-color phosphor layer.

In this phosphor screen forming method, an exposure apparatus is used when exposing a phosphor slurry layer or a photosensitive film formed on the inner surface of the panel. Usually, as shown in FIG. 3, the exposure apparatus includes a support 2 for positioning and supporting the panel 1.
A light source 5 for irradiating a phosphor slurry layer 3 or a photosensitive film coated on the inner surface of the panel 1 with light through a shadow mask 4, and a light source 5 radiated from the light source 5. Correction lens 6a and second correction lens 6b for matching the trajectory of the light beam with the trajectory of the electron beam emitted from the electron gun, and a third correction lens 6c for correcting the effect of the vertical component of terrestrial magnetism on the electron beam. And three correction lenses 7 are arranged.

As the light source 5, an ultra-high pressure mercury lamp which normally emits light having a wavelength of 365 nm is used. Each of the correction lenses 7 is formed with a single-layer anti-reflection film on both sides to increase light transmittance.

When the phosphor slurry layer 3 and the photosensitive film coated on the inner surface of the panel 1 are exposed by such an exposure apparatus, the distance from the light source 5 to the center of the panel 1 becomes:
Since the distance from the light source 5 to the peripheral portion of the panel 1 is smaller, a light amount difference occurs between the central portion and the peripheral portion of the panel 1.
Therefore, for example, if the amount of exposure is adjusted so that the phosphor layer at the center of panel 1 has an appropriate size, the phosphor layer at the periphery of panel 1 becomes too small. Conversely, if the amount of exposure is adjusted so that the phosphor layer in the peripheral portion of the panel 1 has an appropriate size, the phosphor layer in the central portion of the panel 1 becomes too small, and a phosphor of a predetermined size is formed over the entire phosphor screen. Layer cannot be formed. Therefore, the exposure apparatus is provided with a correction filter 8 for lowering the transmittance of the central portion with respect to the transmittance of the peripheral portion in order to adjust the light amount distribution on the inner surface of the panel 1.

The correction filter 8 is formed by depositing a metal on a transparent substrate such as glass, and the thickness of the deposited film in the center is thicker and thinner toward the periphery.
As shown by, the transmittance is formed in a rotationally symmetrical shape with a transmittance distribution in which the transmittance decreases from the center to the periphery.

[0009]

As described above, the fluorescent screen of the color picture tube is formed by coating a phosphor slurry layer or a photosensitive film coated on the inner surface of the panel inside the lower part of the support for positioning and supporting the panel. A light source that irradiates light through a shadow mask, a correction lens that matches the trajectory of light emitted from this light source with the trajectory of the electron beam emitted from the electron gun, and the amount of light that irradiates the inner surface of the panel An exposure apparatus provided with a correction filter for correcting the distribution is used. However, since the correction filter is formed by evaporating metal on a transparent substrate and has a rotationally symmetrical shape with a transmittance distribution that decreases from the center to the periphery, the required transmittance distribution must be achieved. However, there is a problem that the tendency is more prominent as the difference in transmittance between the central portion and the peripheral portion is greater, and the film tends to peel off.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an improved means for correcting the light quantity distribution on the inner surface of a panel is provided. An object of the present invention is to configure an exposure apparatus capable of forming an absorption layer.

[0011]

In an exposure apparatus for forming a fluorescent screen of a color picture tube, comprising a light source and at least one correction lens for correcting the trajectory of light emitted from the light source, the light source is perpendicular to the correction lens. A multilayer film was formed to increase the transmittance of incident light obliquely with respect to the transmittance of incident light.

[0012]

In general, a multilayer film has a characteristic that the transmittance with respect to the wavelength is different and the transmittance varies with the incident angle. By arbitrarily selecting the transmittance of the multilayer film with respect to the wavelength, an arbitrary transmittance distribution is obtained. be able to. Therefore, when a multilayer film is formed on the correction lens as described above, a required correction filter function can be given to the correction lens.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings based on embodiments.

FIG. 1 shows an exposure apparatus according to one embodiment. The exposure apparatus has a support 2 for positioning and supporting the panel 1, and irradiates a phosphor slurry layer 3 or a photosensitive film formed on the inside of the lower portion of the support 2 with a light through a shadow mask 4. A light source 5 and first, second, and third correction lenses 10a, 10a for matching the trajectory of light emitted from the light source 5 with the trajectory of an electron beam emitted from an electron gun.
Three correction lenses 11 composed of b and 10c are arranged. As the light source 5, an ultra-high pressure mercury lamp that emits light having a wavelength of 365 nm is used. In the exposure apparatus of this example, a multilayer film 12 for correcting the light quantity distribution of light illuminating the inner surface of the panel 1 positioned and supported on the support table 2 is formed on both surfaces of the correction lenses 10a to 10c. .

Now, the multilayer film formed on both surfaces of each of the correction lenses 10a to 10c has a laminated structure of nine layers, and one of the multilayer films has an incident angle of light of 0 as shown in FIG. In other words, if the transmittance at a vertical incidence is curve 13, and the transmittance at an oblique incidence angle of 45 ° is a curve 14, the 365 nm wavelength light emitted from the light source 5 and effective for exposure is Is that when the incident angle is 0 °, the transmittance is 87%, and when the incident angle is 45 °, the transmittance is 98%.
Becomes Accordingly, in this case, the transmittance of the six multilayer films 12 formed on both surfaces of the three correction lenses 10a to 10c with respect to the light having a wavelength of 365 nm is as follows when the incident angle is 0: (87/100) = 43 % When the incident angle is 45 °, (98/100) = 90%. This is because, as the incident angle of light on the multilayer film increases, the transmittance curve with respect to wavelength shifts to the shorter wavelength side as shown by curves 13 and 14. The transmittance characteristic with respect to the wavelength of the multilayer film cannot be obtained with a single-layer film, but can be obtained only by stacking a plurality of single-layer films.

Accordingly, the material and thickness of each single-layer film constituting the multilayer film 12 and the number of stacked single-layer films are appropriately selected to change the transmittance curve to form the correction lenses 10a to 10c on both surfaces. As a result, a correction filter having a required transmittance distribution can be obtained, and the correction lens 11 can be provided with a required correction filter function. A body layer and a light absorbing layer can be formed.

Moreover, in the case of obtaining a transmittance distribution by changing the thickness of the deposited film as in a conventional correction filter, it is difficult to obtain a required transmittance distribution and to form a symmetric (rotationally symmetric) one. However, in the multilayer film 12, a required transmittance distribution can be obtained simply by forming the multilayer film uniformly on the surface of the correction lens, and the multilayer film 12 can be easily formed symmetrically.

In the above embodiment, a multi-layer film is formed on both surfaces of the three correction lenses to provide a correction filter function. However, this multi-layer film may be combined with a correction filter. That is, when a correction lens is provided with a correction filter function and a correction filter is used together,
The correction amount of the transmittance of the correction filter itself can be reduced to reduce the variation, and the light amount distribution on the inner surface of the panel can be optimized as in the above embodiment.

In the above embodiment, a multilayer film is formed on both surfaces of each of the three correction lenses.
It is not necessary to form the correction lens on all the correction lenses, and it is not necessary to form the correction lens on both surfaces.

[0020]

According to the present invention, it is possible to form a multilayer film in which the transmittance of light obliquely incident on at least one correction lens for correcting the trajectory of light emitted from a light source is higher than the transmittance of light obliquely incident. In addition, a difference can be made between the transmittance of vertically incident light and the transmittance of obliquely incident light, and a correction filter function can be provided to the correction lens. Therefore, it is easy to change the transmittance curve by appropriately selecting the material and thickness of each single-layer film constituting the multilayer film and the number of layers of the single-layer film to obtain a required transmittance distribution, and it is easy to obtain the inner surface of the panel. A phosphor layer or a light absorbing layer having a predetermined size can be formed on the substrate.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an exposure apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a relationship between a wavelength of light incident on a multilayer film formed on the correction lens and transmittance.

FIG. 3 is a diagram illustrating a configuration of a conventional exposure apparatus.

FIG. 4 is a diagram showing a transmittance distribution of the correction filter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Panel 2 ... Support base 3 ... Phosphor slurry layer 5 ... Light source 11 ... Correction lens 12 ... Multilayer film

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-122545 (JP, A) JP-A-62-169097 (JP, A) Japanese Utility Model Sho 54-42463 (JP, U) Japanese Utility Model Utility Model No. Sho 56- 9028 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01J 9/227

Claims (1)

(57) [Claims] 1. An exposure apparatus for forming a fluorescent screen of a color picture tube comprising a light source and at least one correction lens for correcting the trajectory of light emitted from the light source, comprising: An exposure apparatus for forming a fluorescent screen of a color picture tube, wherein a multi-layer film for increasing the transmittance of light obliquely incident on the transmittance is formed.