JPH06333501A - Fluorescent screen exposing method and exposing device of color picture tube - Google Patents

Abstract

PURPOSE:To regulate the exposing light quantity of each position of a fluorescent screen forming material layer on the inner surface of a panel with high accuracy, by controlling the operating time of each segment of a liquid crystal element, and regulating the exposing quantity to the position of the fluorescent screen forming material layer. CONSTITUTION:By dividing the illuminances of each position on the inner surface of a panel 4 obtained by the measurement of the illuminance distribution, by the illuminance at the center of the inner surface of the panel 4, and multiplied by 100, so as to calculate a noncorrecting light distribution value. Then, the necessary light distribution values at the positions of the inner surface of the panel 4 are found. The light distribution values are found by exposing the fluorescent screen forming material layer 20 formed at the inner surface of the panel 4 by making the exposing light amount as a parameter, developing them to form the phosphor layer, and measuring the sizes. And then, the time ratios of the positions of the inner surface of the panel 4 are found. Then, the exposing time at the center of the inner surface of the panel 4 can be decided, and the necessary exposing light amounts can be given to the positions of the inner surface of the panel 4. Consequently, the exposing light amounts of the positions of the fluorescent screen forming material layer of the panel inner surface can be regulated at a high accuracy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent screen exposure method and exposure apparatus for a color picture tube, and more particularly to a fluorescent screen exposure for a color picture tube in which a correction filter composed of a liquid crystal display element is arranged between a panel and a light source. A method and an exposure apparatus.

[0002]

2. Description of the Related Art Generally, a color picture tube has a dot-shaped or stripe-shaped three-color phosphor layer 1B, 1 which emits blue, green, and red light on the inner surface of the panel as shown in FIGS.
A phosphor screen composed of G, 1R, or, as shown in FIGS. 5 and 6, dot-shaped or stripe-shaped three-color phosphor layers 1B, 1G, 1R are formed in gaps between matrix-shaped or stripe-shaped light-absorbing layers 2. The fluorescent screen is provided so as to be embedded.

The fluorescent screen of such a color picture tube is conventionally formed by a photographic printing method. For example, the phosphor screen having the matrix-shaped or stripe-shaped light absorption layer 2 shown in FIGS. 5 and 6 will be described.
As shown in (a), polyvinyl alcohol (PVA) and ammonium dichromate (ADC) are provided on the inner surface of the panel 4.
The photosensitive film 5 is formed by applying a photosensitizer whose main component is.
Then, as shown in (b), the photosensitive film 5 is exposed through a shadow mask 6 to form a shadow mask 6 on the photosensitive film 5.
The pattern corresponding to the electron beam passage hole of is baked. In addition, 7 is an exposure light source. Then, the photosensitive film 5 having a pattern corresponding to the electron beam passage hole is developed to remove the unexposed portion, and a dot-shaped or stripe-shaped resist film 8 is formed as shown in FIG. . Next, as shown in (d), a black light absorbing paint is applied to the inner surface of the panel 4 having the resist film 8 formed thereon to form a light absorbing paint layer 9. Then, together with the resist film 8, the light absorbing paint on the resist film 8 is removed, and as shown in FIG. The stripe-shaped light absorption layer 2 is formed.

Thereafter, as shown in (f), a phosphor slurry containing PVA, ADC and an arbitrary one-color phosphor such as a blue phosphor as a main component is formed on the inner surface of the panel 4 on which the light absorption layer 2 is formed. Is applied to form a phosphor slurry layer 12. Then, as shown in (g), the phosphor slurry layer 12 is exposed through the shadow mask 6, and a pattern corresponding to the electron beam passage hole of the shadow mask 6 is printed on the phosphor slurry layer 12. Next, the phosphor slurry layer 12 having a pattern corresponding to the electron beam passage hole is developed to remove the unexposed portion, and as shown in (h) of FIG. Alternatively, the stripe-shaped phosphor layer 1B is formed. The method for forming this phosphor layer 1B is 3
By repeating the procedure for the color phosphors, as shown in (i), the three-color phosphor layers 1B, 1G,
Form 1R.

Further, the phosphor screen having no light absorption layer shown in FIGS. 3 and 4 is formed by repeating the step of forming the phosphor layer.

By the way, in the above-mentioned phosphor screen forming method, when a pattern corresponding to the electron beam passage hole of the shadow mask is printed on the phosphor screen forming member layer such as the photosensitive film or the phosphor slurry layer formed on the inner surface of the panel. The exposure apparatus shown in FIG. 8 is used. This exposure apparatus has a support portion 14 for positioning and supporting the panel 4, and a light source 7 is arranged below the support portion 14. Then, in the direction of the panel 4 positioned and supported by the support portion 14 from the light source 7, the lamp shutter 1 for blocking the light emitted from the light source 7 with respect to the fluorescent screen forming member layer 15 formed on the inner surface of the panel 4.
6, an optical lens system 17 including a correction lens for approximating the trajectory of the light emitted from the light source 7 to the trajectory of the electron beam emitted from the electron gun of the color picture tube, and the phosphor screen forming member layer 15 on the inner surface of the panel A correction filter 18 for correcting the illuminance distribution, that is, for adjusting the amount of exposure light for each part of the phosphor screen forming member layer 15 is arranged.

The correction filter 18 is conventionally formed by depositing a metal vapor deposition film of Ni, Cr or the like on a transparent glass substrate as shown in FIG.
In order to obtain the transmittance distribution curve 20 as shown in (4), the film thickness of the metal vapor deposition film is thicker in the central portion and thinner in the peripheral portion. This is because the illuminance of the peripheral portion sharply drops with respect to the illuminance of the central portion of the inner surface of the panel, and the distribution of the light transmittance of the shadow mask must be taken into consideration in the actual exposure.

However, recently, in the color picture tube, the inner surface of the panel is not a single spherical surface as in the prior art but a curved surface expressed by a high-order formula and tends to be flat. On the other hand, many of the electron beam passage holes of the shadow mask have a variable pitch rather than a fixed pitch, and the fine pitch is being advanced in response to the higher definition of the color picture tube. Correspondingly, there are various requirements for the transmittance distribution of the correction filter, such as concentric circles, ellipses, and asymmetry of each axis, and a plurality of types of correction filters with higher accuracy are required.

When such a correction filter is formed of a metal vapor deposition film as in the conventional case, it is difficult to make its transmittance distribution a predetermined distribution, especially in a color picture tube in which the inner surface of the panel is flat and the deflection angle is large. Even with a slight change in the position of the light source, the illuminance distribution becomes non-uniform, and uneven exposure is likely to occur. This exposure unevenness changes the size of the gaps in the matrix- or stripe-shaped light absorbing layer or the size of the dot-shaped or stripe-shaped three-color phosphor layer, thereby degrading the image quality, especially white uniformity. In the case of a sharp appearance, the appearance quality is also deteriorated. In addition, defects such as chipping and dropping of the three-color phosphor layer occur in the phosphor screen forming step, which causes a decrease in yield.

[0010]

As described above, the fluorescent screen of the color picture tube is formed by the photo printing method, and as one of the steps, the photosensitive film and the phosphor slurry layer formed on the inner surface of the panel are formed. There is a step of exposing the phosphor screen forming member layer through a shadow mask and baking a pattern corresponding to the electron beam passage holes of the shadow mask on the phosphor screen forming member layer, and an exposure apparatus is used for the baking.

In this exposure apparatus, a light source is arranged below a supporting portion for positioning and supporting the panel, and a lamp shutter and a light source are provided for sequentially blocking the light emitted from the light source in the direction of the panel positioned and supported by the supporting portion from the light source. The optical lens system consisting of a correction lens that approximates the trajectory of the light emitted from the electron beam emitted from the electron gun of the color picture tube, the correction filter that corrects the illuminance distribution to the phosphor screen forming member layer on the inner surface of the panel. Etc. are formed in a structure in which they are arranged.

In the correction filter, a metal vapor deposition film of Ni, Cr or the like is conventionally formed on a transparent glass substrate, and the metal vapor deposition film is thick at the central portion and at the periphery so that a predetermined transmittance distribution can be obtained. It becomes thinner as it becomes a part.

However, recently, in the color picture tube, the inner surface of the panel is not a single spherical surface as in the prior art but a curved surface expressed by a high-order formula and tends to be flat. On the other hand, many of the electron beam passage holes of the shadow mask have a variable pitch rather than a fixed pitch, and the fine pitch is being advanced in response to the higher definition of the color picture tube. Correspondingly, the requirement for the transmittance distribution of the correction filter is
There is a wide variety of elliptical and asymmetrical axes, and multiple types of highly accurate correction filters are required. When such a correction filter is formed of a metal vapor deposition film as in the conventional case, it is difficult to make its transmittance distribution a predetermined distribution. Especially, in a color picture tube with a flat inner surface and a large deflection angle, a slight Even if the position of the light source changes, the illuminance distribution becomes non-uniform, and uneven exposure is likely to occur. This uneven exposure changes the size of the gap portion of the light absorption layer or the size of the three-color phosphor layer, resulting in image quality, especially white uniform. Deteriorates Miti. If you want to
It also reduces the appearance quality. Also, in the fluorescent screen forming step,
There is a problem that defects such as chipping and dropping of the three-color phosphor layer occur, which causes a decrease in yield.

The present invention has been made in order to solve the above-mentioned problems, and constitutes a correction filter which can obtain an optimum exposure light amount for each part of the phosphor screen forming member layer on the inner surface of the panel, and is always optimum. The purpose is to be able to perform various exposures.

[0015]

A phosphor screen forming member layer formed on the inner surface of a panel of a color picture tube and a light source for exposing the phosphor screen forming member layer to each part of the phosphor screen forming member layer. In a fluorescent screen exposure method of a color picture tube, in which a correction filter for adjusting the amount of exposure light is arranged, and the fluorescent screen forming member layer is exposed through the correction filter, a liquid crystal having a large number of segments in which the correction filters are arranged in a matrix. The liquid crystal display element is composed of a display element, and the operating time of each segment of the liquid crystal display element is controlled to adjust the exposure light amount for each part of the phosphor screen forming member layer.

Further, the exposure apparatus includes a support portion for positioning and supporting a panel having a phosphor screen forming member layer formed on the inner surface thereof.
The light source for exposing the phosphor screen forming member layer on the inner surface of the panel, which is positioned and supported by the supporting portion, and the exposure light amount for each part of the phosphor screen forming member layer on the inner surface of the panel, are positioned and supported by the light source and the supporting portion. A correction filter including a liquid crystal display element having a large number of segments arranged in a matrix arranged between a panel and a liquid crystal control device having means for controlling the operating time of each segment of the liquid crystal display element. Formed into a structure.

[0017]

As described above, the correction filter is composed of a liquid crystal display element having a large number of segments arranged in a matrix, and the operation time of each segment of the liquid crystal display element is controlled to control each of the phosphor screen forming member layers. By adjusting the amount of exposure light for each part, each part of the phosphor screen forming member layer can be exposed with an optimum amount of exposure light.

[0018]

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

FIG. 1 shows an exposure apparatus according to the embodiment. This exposure apparatus has a supporting portion 14 for positioning and supporting the panel 4, a light source 7 is arranged below the supporting portion 14, and the light source 7 is sequentially positioned in the direction of the panel 4 positioned and supported by the supporting portion 14. A lamp shutter 16 for blocking the emitted light from the light source 7 with respect to the panel 4 positioned and supported by the support portion 14 and an orbit of the emitted light from the light source 7 are set to the orbit of the electron beam emitted from the electron gun of the color picture tube. Exposure to each part of the phosphor screen forming member layer 20 such as a photosensitizer layer or a phosphor slurry layer formed on the inner surface of the panel 4 positioned and supported by the lens optical system 17 including a correction lens to be approximated and the supporting portion 14. A correction filter 21, which will be described later, that corrects the amount of light is arranged.

In FIG. 1, 6 is a shadow mask mounted on the panel 4.

The light source 7 corresponds to the three electron beams emitted from the electron gun by the light source shift mechanism at a position corresponding to the deflection center of the color picture tube with respect to the panel 4 positioned and supported by the support portion 14. It can be moved to the position and can be moved up and down together with the lens optical system 17 by the up-and-down mechanism according to the deflection angle of the color picture tube.

In the exposure apparatus of this example, the correction filter 21 is composed of a transmissive liquid crystal display element, and as shown in FIG. 2, a pair of transparent substrates 22a, 22a,
An X electrode 23X and a Y electrode 23Y composed of a large number of transparent electrode elements formed in parallel are formed on the facing surface of 22b, and each intersection point of these X, Y electrodes 23X, 23Y is set to 1
The pixels are arranged in a matrix composed of a large number of segments. The correction filter 21 is connected to a control device (not shown), and its operation is controlled by a program stored in the control device.

That is, at the time of non-exposure, the X and Y electrodes 23
A voltage is applied to all X and 23Y electrode elements to turn them on to block light, and the lamp shutter 1
6 is opened, all the electrode elements are turned off to allow the radiated light from the light source 7 to pass therethrough, and the phosphor screen forming member layer 20 formed on the inner surface of the panel 4 through the shadow mask 6
Irradiate. Then, when a preset time is reached, according to a program stored in the control device, the central segment selected from a large number of segments composed of the X and Y electrodes 23X and 23Y is sequentially turned on. The radiant light that irradiates the phosphor screen forming member layer 20 is sequentially blocked from the central portion. When the peripheral portion of the phosphor screen forming member layer 20 reaches a predetermined amount of exposure light, the lamp shutter 16 is closed and all the electrode elements are turned on to block the light, and the exposure is completed.

That is, when the operating time of each segment of the liquid crystal display element is controlled as described above, the exposure light amount for each portion of the phosphor screen forming member layer 20 on the inner surface of the panel 4 is controlled, and the entire inner surface of the panel 4 is controlled. A phosphor layer having a predetermined size can be formed.

The program stored in the control device, that is, the operating time of each segment of the liquid crystal display element is set as follows.

First, the illuminance distribution on the inner surface of the panel 4 positioned and supported by the support portion 14 is measured without the correction filter 21 being arranged. Then, the illuminance of each part on the inner surface of the panel 4 obtained by the measurement of the illuminance distribution is measured by the panel 4
An uncorrected light distribution value is calculated by dividing by 100 times the illuminance of the central part of the inner surface of. Next, the required light distribution value of each part on the inner surface of the panel 4 is obtained. This required light distribution value is obtained by exposing and developing the phosphor screen forming member layer 20 actually formed on the inner surface of the panel 4 using the amount of exposure light as a parameter to form a phosphor layer, and determine the size of the phosphor layer. Obtained by measuring. Next, the required light distribution value thus obtained is divided by the non-corrected light distribution value to obtain the time ratio of each part to the central portion of the inner surface of the panel 4. Therefore, the exposure time of the central portion of the inner surface of the panel 4 is determined, and the operating time of each segment of the liquid crystal display element is set according to the time ratio of each portion of the inner surface of the panel 4. As a result, a desired amount of exposure light can be given to each part of the inner surface of the panel 4.

In the above embodiment, the case where the liquid crystal display element is operated in segment units in order to adjust the exposure light amount of each portion of the inner surface of the panel 4 has been described. The same effect can be obtained by operating a plurality of segments of the device as a block and operating in a block unit.

[0028]

EFFECTS OF THE INVENTION The correction filter is composed of a liquid crystal display element consisting of a large number of segments arranged in a matrix, and the operating time of each segment of the liquid crystal display element is controlled to expose each part of the phosphor screen forming member layer. When the light amount is adjusted, the exposure light amount of each part of the phosphor screen forming member layer on the inner surface of the panel can be adjusted with high precision, and a high quality phosphor screen can be formed. In the past, a different correction filter was required for each tube type, and a mechanism for moving the correction filter vertically and horizontally and its adjustment work were required, but the correction filter was composed of a liquid crystal display element and By controlling the operation and adjusting the exposure light amount of each part on the inner surface of the panel, it is possible to optimally adjust the exposure light amount of each part on the inner surface of the panel required for each tube type with one liquid crystal display element.

[Brief description of drawings]

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

FIG. 2A and FIG. 2B are diagrams showing a configuration of a liquid crystal display element used as a correction filter thereof.

FIG. 3 (a) is a plan view showing the structure of a phosphor screen in which a three-color phosphor layer is composed of dots, and FIG. 3 (b) is a bb sectional view thereof.

FIG. 4 (a) is a plan view showing the structure of a phosphor screen in which a three-color phosphor layer is a stripe, and FIG. 4 (b) is its bb.
FIG.

FIG. 5 (a) is a plan view showing the structure of a phosphor screen including a light absorption layer formed of dots in a three-color phosphor layer, FIG. 5 (b).
Is a bb sectional view thereof.

6 (a) is a plan view showing the structure of a phosphor screen including a light absorption layer in which a three-color phosphor layer is a stripe, FIG.
(B) is the bb sectional drawing.

7 (a) to 7 (i) are views for explaining a phosphor screen forming method of a color picture tube.

FIG. 8 is a diagram showing a configuration of a conventional exposure apparatus.

FIG. 9 is a diagram showing a transmittance distribution of a correction filter of the exposure apparatus.

[Explanation of symbols]

 4 ... Panel 7 ... Light source 20 ... Phosphor screen forming member layer 21 ... Correction filter 22a, 22b ... Transparent substrate 23X ... X electrode 23Y ... Y electrode

Claims (2)

[Claims] 1. An exposure light amount for each part of the phosphor screen forming member layer is adjusted between a phosphor screen forming member layer formed on the inner surface of the panel of the color picture tube and a light source for exposing the phosphor screen forming member layer. In a fluorescent screen exposure method of a color picture tube, in which a correction filter is arranged and the fluorescent screen forming member layer is exposed through the correction filter, the correction filter is a liquid crystal display device having a large number of segments arranged in a matrix. A method of exposing a fluorescent screen of a color picture tube, wherein the operating time of each segment of the liquid crystal display device is controlled to adjust the amount of exposure light to each site of the fluorescent screen forming member layer. 2. A support part for positioning and supporting a panel having a phosphor screen forming member layer formed on the inner surface thereof, a light source for exposing the phosphor screen forming member layer on the inner surface of the panel positioned and supported by the supporting part, and the panel inner surface. A liquid crystal display device having a large number of segments arranged in a matrix arranged between the light source and a panel positioned and supported by the supporting part in order to adjust the amount of exposure light to each part of the phosphor screen forming member layer. And a liquid crystal control device having means for controlling the operation time of each segment of the liquid crystal display element, and a fluorescent screen exposure device for a color picture tube.