JPH04218233A - Fluorescent screen forming method of color image tube - Google Patents

Abstract

PURPOSE:To improve the white uniformity, color balance, etc., of a color picture tube by uniforming the width and size of a photoabsorption layer or a tri-color phosphor layer. CONSTITUTION:When a pattern corresponding to the through hole 31 of a shadow mask is printed on the fluorescent-screen-forming member layer formed on the inside of a panel 1 in the forming method of the fluorescent screen of a color picture tube, the travel speed of a zone exposure shutter where an opening to partially expose the fluorescent screen forming member layer is made can be continuously changed.

Description

[Detailed description of the invention]

[Purpose of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a phosphor screen for a color picture tube, and more particularly to a method for forming a phosphor screen for a color picture tube by improving an exposure method.

0002

2. Description of the Related Art Generally, a color picture tube has an envelope consisting of a panel 1 and a funnel 2 integrally joined to the panel 1, as shown in FIG. A fluorescent screen 4 is provided opposite the attached shadow mask 3 having a large number of through holes. Three electron beams 7B, 7G, and 7R emitted from an electron gun 6 disposed inside the neck 5 of the funnel 2 are deflected by a magnetic field generated by a deflection device 8 attached to the outside of the funnel 2, and the above-mentioned shadow A structure is formed in which a color image is displayed on the phosphor screen 4 by horizontally and vertically scanning the phosphor screen 4 through the mask 3.

As the fluorescent screen 4, as shown in FIG.
Striped three-color phosphor layers 10B, 10G, and 10R that emit light in blue, green, and red elongated in the vertical direction (V-axis direction) are arranged in parallel in the horizontal direction (H-axis direction), and the three-color phosphor layer 10
B, 10G, 10R A black stripe type phosphor screen with a striped black light absorbing layer 11 provided between them, and as shown in FIG. dot-shaped three-color phosphor layer 10B, 1
0G, 10R are arranged, and the three color phosphor layers 10B, 1
Matrix-shaped black light absorption layer 11 between 0G and 10R
There is a black matrix type phosphor screen with a

Normally, these phosphor screens 4 are formed by a photoengraving method, in which a light absorption layer 11 is first formed, and then three color phosphor layers 10B, 10G, and 10R are formed. That is, first, a photosensitive agent layer is formed on the inner surface of the panel 1, and the photosensitive agent layer is exposed to light by irradiating the photosensitive agent layer with light from the light source section through the shadow mask 3. Burn the corresponding pattern. In this case, the light source section includes the three-color phosphor layer 1
This is performed by sequentially moving to the positions used to form 0B, 10G, and 10R. Next, develop the photosensitive agent layer,
A resist layer having a pattern corresponding to the through holes of the shadow mask 3 is formed. Next, a light-absorbing paint layer is formed on the inner surface of the panel 1 on which the resist layer is formed, and then the light-absorbing paint coated thereon is peeled off together with the resist layer to determine the position where the three-color phosphor layer will be formed. A light absorption layer 11 is formed to serve as a void.

[0005] Thereafter, a phosphor slurry layer containing a photosensitizer and a phosphor as main components is deposited on the inner surface of the panel 1 on which the light absorption layer 11 is formed, and the photosensitive agent layer is exposed to light. The phosphor slurry layer is exposed to light through the shadow mask 3, and a pattern corresponding to the holes in the shadow mask 3 is printed in the voids of the light absorption layer 11. Thereafter, this phosphor slurry layer is developed to form a phosphor layer having a pattern corresponding to the through holes of the shadow mask 3 in the voids of the light absorption layer 11. Then, the phosphor screen 4 is formed by repeating this phosphor layer forming method for three color phosphors.

Therefore, in this method of forming a phosphor screen, the size of the phosphor layer that is effective for light emission is determined by the void in the light absorption layer 11 that is formed first, and Exposure for printing a pattern corresponding to the through-holes of the shadow mask 3 on the photosensitive agent layer deposited on the inner surface of the panel 1 is largely involved in forming the voids.

An exposure apparatus shown in FIG. 7 is used for exposure to form the light absorption layer 11. In this exposure apparatus, a light source section 14 containing a high-pressure mercury lamp or the like is installed at the bottom of a panel mounting table 13 that positions and supports the panel 1, and the light source section 14 is connected to the panel 1 that is positioned and supported on the panel mounting table 13. In between, a correction lens 1 is provided which sequentially approximates the trajectory of light emitted from the light source section 14 to the trajectory of the electron beam.
5. A correction filter 16 that corrects the distribution of the amount of light emitted from the light source section 14, a zone exposure shutter 18 having an aperture 17 that partially exposes the photosensitive agent layer formed on the inner surface of the panel 1, etc. are arranged. has been done.

As shown in FIG. 8, the correction filter 16 is always moved so as to be coaxial with the light source section 14, corresponding to the position of the light source section 14 when forming the resist layer. That is, a resist layer is formed at the blue phosphor layer formation position based on the position of the light source 14G and the correction filter 16G when forming the resist layer at the green phosphor layer formation position shown in (b). At the same time (
When forming a resist layer at the positions indicated by 14B and 16B in a) and at the red phosphor layer formation position, follow the steps in (c) above.
They are placed at positions 14R and 16R.

This method corrects the amount of light reaching the photosensitive layer formed on the inner surface of the panel 1 so as to obtain an appropriate light distribution, and produces black stripe type or black matrix type fluorescent light. This is to form the width and size of the void portion of the light absorption layer over the entire surface to a predetermined width and size. Usually, as such a correction filter 16, a filter having an ultraviolet transmittance as shown by a curve 19 in FIG. 9 in all radiation directions such as horizontal, vertical, and diagonal axes is used. Filters having different ultraviolet transmittances in the horizontal, vertical, and diagonal directions may be used.

Further, as shown in FIG. 7(a), the zone exposure shutter 18 has a horizontal direction (H-axis It has an elongated rectangular opening 16 in the vertical direction (direction), and is attached to a panel position movement adjustment mechanism 21 (hereinafter abbreviated as PPC mechanism) that moves the panel 1 in the horizontal direction.
By moving at a constant speed in the V-axis direction), panel 1
The structure is such that the entire area of the inner photosensitive agent layer 22 is exposed to light. However, the moving speed of the zone exposure shutter 18 depends on the sensitivity of the photosensitive material layer, etc., as shown by the polygonal line 23 in FIG. It can be changed as appropriate (within a range of approximately ±15%).

The above-mentioned PPC mechanism 21 is intended to make the gap width of the light absorption layer uniform, especially when forming a phosphor screen having a striped phosphor layer such as a black stripe type phosphor screen.

By the way, even if the above-mentioned exposure device is used, the conventional correction filter 16 does not have an appropriate distribution of ultraviolet transmittance, and the amount of light reaching the photosensitive agent layer coated on the inner surface of the panel 1 varies, as shown in FIG. As shown, the light absorption layer 11
The width and size of the voids become uneven, deteriorating white uniformity and color balance.

Further, the width and size of the void in the light absorption layer should originally be formed at the grade shown by the curve 24 in FIG. 12, but it deviates from this curve 24 and is no longer formed at the predetermined grade. Therefore, conventionally, Figures 13(a) to (
As shown in d), the shape of the aperture 17 of the zone exposure shutter is changed from a rectangular shape. However, if a zone exposure shutter with such an opening 21 shape is used and the above PPC mechanism 21 is used to form the striped light absorbing layer 11, the opening 17 is not in an accurate rectangular shape, so that the opening shown in FIG. For example, in a zone exposure shutter 18 whose aperture 17 is hourglass-shaped, when the zone exposure shutter 18 is moved vertically at a constant speed to expose a corner of the approximately rectangular panel 1, the PPC mechanism 2
1 does not match the horizontal movement amount of panel 1,
As shown in FIG. 15, the striped light absorption layers 11 are grouped and deviated from the correct arrangement, deteriorating white uniformity and color balance.

Furthermore, the use of a wide variety of zone exposure shutters with varying apertures 17, as shown in FIG. 13, complicates the management of exposure equipment in the formation of phosphor screens.

[0015]

[Problems to be Solved by the Invention] As mentioned above, the phosphor screen of a color picture tube is formed by the photoengraving method, and especially for black stripe type and black matrix type phosphor screens, a light absorption layer is first formed. A phosphor layer is then formed in the voids of the light absorption layer. Therefore, in this method for forming a phosphor screen, the size of the phosphor layer that is effective for light emission is determined by the voids in the light absorption layer that are formed first, and in forming the voids in the light absorption layer, Exposure is largely involved in printing a pattern corresponding to the through holes of the shadow mask on the photosensitive layer formed on the inner surface of the panel. Conventionally, for exposure to form this light absorption layer, a light source section is installed at the bottom of a panel mounting table, and a correction lens and a correction filter are sequentially placed between the panel positioned and supported on the panel mounting table and the light source section. , a zone exposure shutter, etc. are arranged, and an exposure apparatus is used that moves the zone exposure shutter at a constant speed. In particular, an exposure apparatus for forming a striped light absorption layer is equipped with a PPC mechanism that horizontally moves a panel positioned and supported on a panel mounting table, and the exposure apparatus is equipped with a zone exposure shutter attached to this PPC mechanism. It is used.

However, in conventional exposure equipment, the distribution of the ultraviolet transmittance of the correction filter is not appropriate, the amount of light reaching the photosensitive agent layer coated on the inner surface of the panel varies, and the width and size of the gap in the light absorption layer varies. becomes uneven, deteriorating white uniformity and color balance. Further, the width and size of the void in the light absorption layer from the center of the panel to the periphery should be formed at a predetermined grade, but they are no longer formed at the predetermined grade. As a countermeasure against this shift, a zone exposure shutter with a changed aperture shape is used. However, by using a zone exposure shutter with a changed aperture shape and using a PPC mechanism, a striped light absorption layer can be formed. When a hole is formed, the opening is not in an accurate rectangular shape, so the amount of movement of the zone exposure shutter at a constant speed and the amount of horizontal movement of the panel by the PPC mechanism do not match, causing the light absorption layer to deviate from the correct alignment. white uniformity and color balance. Furthermore, the use of zone exposure shutters with a wide variety of aperture shapes poses problems such as complicating the management of exposure equipment in forming a phosphor screen.

The present invention has been made in view of the above-mentioned problems, and includes a gap in the light absorption layer of a phosphor screen having a light absorption layer, a three-color phosphor layer formed in the gap, or a light absorption layer. Even if the three-color phosphor layer of a phosphor screen without a layer can be formed to a predetermined width and size, and even if the aperture of the zone exposure shutter is made as close to a rectangular shape as possible, the amount of horizontal movement of the panel by the PPC mechanism can be sufficiently reduced. The objective is to improve the white uniformity and color balance of a color picture tube by matching the color picture tube with the color picture tube.

[Configuration of the invention]

[0019]

[Means for Solving the Problems] Light is irradiated from a light source section through a shadow mask to a phosphor screen forming member layer formed on the inner surface of a panel consisting of a photosensitive agent layer or a phosphor slurry layer, and the transparent holes in the shadow mask are irradiated with light from a light source section. When forming a striped or matrix-like light absorption layer or a striped or dot-like phosphor layer on the inner surface of the panel through an exposure process of printing a pattern corresponding to the phosphor layer between the shadow mask and the light source section, A color picture tube in which a zone exposure shutter having an opening for partially exposing the surface forming member layer is arranged, and the zone exposure shutter is exposed while moving in the longitudinal direction of the striped light absorption layer or the striped phosphor layer. In the method for forming a phosphor screen, the moving speed of the zone exposure shutter is continuously changed.

[0020]

[Effect] As mentioned above, when the moving speed of the zone exposure shutter is continuously changed, the width and size of the voids in the light absorption layer and the phosphor layer will change for the portion where the moving speed is increased. A portion that has been made smaller or slower can be made larger. Therefore, there is no need for zone exposure shutters with various aperture shapes, which were conventionally used to control the width and size of the voids in the light absorption layer, and zone exposure with a simple aperture shape close to a rectangle is now possible. A shutter can be used to form the required phosphor screen. In addition, when forming a striped light absorption layer, the opening width of the zone exposure shutter can be narrowed to better match the amount of movement of the panel by the PPC mechanism, and the striped light absorption layer grouping can be resolved. Furthermore, it is possible to eliminate the need for a correction filter for the complicated ultraviolet transmittance distribution that was conventionally required.

[0021]

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

FIG. 1 shows a method for forming a phosphor screen of a black stripe type color picture tube, which is an embodiment of the present invention. The phosphor screen of a color picture tube is usually formed by a photoengraving method, by first forming a light absorption layer and then forming a three-color phosphor layer.

First, as shown in FIG. 1(a), a photosensitizer whose main components are polyvinyl alcohol (hereinafter abbreviated as PVA) and ammonium dichromate (hereinafter abbreviated as ADC) is applied to the inner surface of the panel 1. and photosensitive agent layer 30 (
A phosphor screen forming member layer) is deposited on the photosensitive agent layer 30, and the photosensitive agent layer 30 is exposed by irradiating light from a light source section through the shadow mask 3, so that the photosensitive agent layer 30 corresponds to the through holes 31 of the shadow mask 3. Burn a striped pattern. Then the same (b
), the photosensitive layer with the pattern baked thereon is developed to form a striped resist layer 33 having a pattern corresponding to the through holes of the shadow mask. Next, the inner surface of the panel 1 on which the resist layer 33 has been formed is coated with a light-absorbing paint containing, for example, carbon as a main component to form a light-absorbing paint layer 34 . And the same (c
), the resist layer 33 and the light-absorbing paint layer 34 deposited thereon are peeled off to form a striped light-absorbing layer 1 with voids 35 at the positions where the three-color phosphor layers are formed.
form 1.

Thereafter, PVA, ADC, and a phosphor of an arbitrary color are applied to the inner surface of the panel 1 on which the light absorption layer 11 is formed.
For example, a phosphor slurry containing blue phosphor as a main component is applied, a phosphor slurry layer 36 (phosphor screen forming member layer) is deposited and the photosensitive agent layer is exposed as shown in (d). In the same way as when exposing the phosphor slurry layer 36 to light through the shadow mask 3, the through holes 3 of the shadow mask 3
Print a striped pattern corresponding to 1. Next, this phosphor slurry layer 36 is developed, and as shown in FIG. form. The phosphor layer is formed by repeating this phosphor layer forming method for three color phosphors.

For exposure to form the light absorbing layer 11, a light source section is installed at the bottom of a panel mounting table that positions and supports the panel 1, and radiation is emitted from this light source section, as in the conventional exposure apparatus (see FIG. 7). A correction lens that approximates the trajectory of the emitted light to the trajectory of the electron beam, a correction filter that corrects the distribution of the amount of light emitted from the light source, and a photosensitive agent layer 30 formed on the inner surface of the panel 1 are partially exposed. An exposure apparatus equipped with a zone exposure shutter having rectangular openings and a PPC mechanism is used. At step 30, a pattern corresponding to the through hole 31 of the shadow mask 3 is printed.

However, in the phosphor screen forming method of this example, whereas in the conventional phosphor screen forming method the zone exposure shutter was moved at a constant speed, the zone exposure shutter was moved according to the exposed area as shown in FIG. Exposure is performed by accelerating and decelerating continuously. In other words, curve 38a
As shown in the figure, for the exposure of the photosensitive agent layer in the center of the panel,
When exposing the photosensitive layer at the periphery, the speed is reduced continuously, or as shown in curve 38b, the photosensitive layer at the periphery on one end side is exposed while the photosensitive layer at the center of the panel is exposed. When exposing the photosensitive layer at the periphery of the other end, the speed is continuously accelerated, or when exposing the photosensitive layer at the center of the panel, as shown in curve 38c. On the other hand, when exposing the photosensitive agent layer in the peripheral area, the exposure is performed by continuously accelerating the exposure.

In order to drive such a zone exposure shutter, as shown in FIG. 3, the computer 39 of the control unit that controls the PPC mechanism is instructed to set the shutter position and shutter speed corresponding to the relationship between the shutter position and shutter speed shown in FIG. The relationship with the pulse value of the pulse motor that drives the zone exposure shutter of the PPC mechanism, that is, the shutter position/pulse value, is stored, and the data signal is appropriately selected and called to the pulse control unit 41 that controls the pulse motor 40. This is done by

By the way, when forming the striped light absorption layer 11 on the inner surface of the panel 1 as described above, if the movement speed of the zone exposure shutter is continuously changed, the light absorption layer 11 will be formed over the entire area of the phosphor screen. The width can be formed uniformly. That is, if the moving speed of the zone exposure shutter when exposing the photosensitive agent layer 30 on the inner surface of the panel 1 is continuously changed, the portion where the moving speed is fast receives relatively less light from the light source compared to the portion where the moving speed is slow. The irradiation time becomes shorter, and the width of the gap in the light absorption layer 11 becomes smaller. Conversely, in a portion where the moving speed is slow, the irradiation time of the light from the light source section is relatively longer than in a fast moving portion, and the width of the gap in the light absorption layer 11 is increased. Therefore, in Figure 2, 3
By appropriately selecting the relationship between the shutter position and shutter speed shown in 8a to 38c and continuously changing the moving speed of the zone exposure shutter, the width of the light absorption layer 11 can be made uniform over the entire area of the phosphor screen, and the width of the light absorption layer 11 can be made uniform over the entire area of the phosphor screen. As shown in 12, for the phosphor screen that has a grade from the center to the periphery, the voids in the light absorption layer 11 can be formed with a predetermined grade, resulting in white uniformity and well-balanced phosphor. A surface can be formed.

Moreover, in this case, the aperture of the zone exposure shutter may be a simple rectangular shape, and the aperture width is narrower than before, for example, for a rectangular panel 1, it is 15 to 20% of the short side dimension of the rectangular panel 1. It is effective to do so to a certain degree. Also,
By narrowing the aperture width in this manner, grouping of the light absorption layer 11, which occurs due to mismatching with the horizontal movement of the panel 1 by the conventional PPC mechanism, is prevented. Furthermore, the complicated ultraviolet transmittance correction filter required in the past is no longer necessary, and sufficient results can be obtained with a relatively simple ultraviolet transmittance correction filter.

The case of forming a striped light absorption layer of a black stripe type phosphor screen has been described above, but this phosphor screen forming method is applicable not only to the light absorption layer but also to forming striped light absorption layers in the voids of the light absorption layer. It can also be applied when forming a three-color phosphor layer. Furthermore, the present invention can be applied not only to black stripe type phosphor screens but also to forming dot-shaped three-color phosphor layers in matrix-like light absorption layers of black matrix type phosphor screens and gaps in the light absorption layers. Furthermore, the present invention can be applied not only to black stripe type or black matrix type phosphor screens, but also to phosphor screens consisting of three color phosphor layers in the form of stripes or dots in which no light absorption layer is formed between the three color phosphor layers.

[0031]

Effects of the Invention: By continuously changing the moving speed of the zone exposure shutter used for exposure to form a striped or matrix-like light absorption layer or a striped or dot-like phosphor layer on the inner surface of the panel, The width and size of the voids in the light absorption layer and the phosphor layer can be reduced in areas where the movement speed is increased, and conversely, they can be increased in areas where the movement speed is increased. Therefore, (a)
It is possible to make the width and size of the voids in the light absorption layer and the phosphor layer uniform across the entire phosphor screen, greatly improving the white uniformity and color balance of color picture tubes (b) Light. For phosphor screens in which the voids in the absorbing layer or the phosphor layer have a grade from the center to the periphery, the grade can be easily adjusted to a predetermined grade.
The white uniformity and color balance of color picture tubes can be greatly improved (c) A simple rectangular aperture can be used as a zone exposure shutter, making it possible to use various complex aperture shapes that were previously required. Zone exposure shutter becomes unnecessary (d)
The width of the rectangular opening of the zone exposure shutter is narrowed,
As a result, it is possible to prevent the grouping of light absorption layers and phosphor layers that occur due to mismatching with the movement of the panel by the PPC mechanism when conventionally forming striped light absorption layers and striped phosphor layers, and to improve the landing characteristics of electron beams. (e) The complicated transmittance correction filter that was conventionally required is no longer necessary, and a relatively simple transmittance correction filter can provide sufficient results.

[Brief explanation of the drawing]

1A to 1E are diagrams for explaining a method for forming a phosphor screen of a black stripe type color picture tube, which is an embodiment of the present invention; FIG.

FIG. 2 is a diagram for explaining the moving speed of a zone exposure shutter used for exposure to form a striped light absorption layer in the phosphor screen forming method.

FIG. 3 is a diagram for explaining a method of moving the zone exposure shutter.

FIG. 4 is a diagram showing the configuration of a color picture tube.

FIG. 5(a) is a plan view showing the structure of a black stripe type phosphor screen of a color picture tube, and FIG. 5(b) is a sectional view thereof.

FIG. 6(a) is a plan view showing the structure of a black matrix type phosphor screen, and FIG. 6(b) is a sectional view thereof.

FIG. 7(a) is a plan view showing the configuration of an exposure apparatus used for forming a conventional black matrix type phosphor screen, and FIG. 7(b) is a front view thereof.

8(a) to 8(c) are for explaining the positional relationship between the light source section and the correction filter during exposure to form the striped light absorption layer of the black matrix type phosphor screen, respectively; FIG. This is a diagram.

FIG. 9 is a diagram showing the ultraviolet transmittance of a correction filter used for exposure to form a conventional light absorption layer.

FIG. 10 is a diagram for explaining the moving speed of a conventional zone exposure shutter.

FIG. 11(a) is a diagram showing the grouping of conventional stripe-like light absorbing layers, and FIG. 11(b) is a diagram showing the grouping of matrix-like light absorbing layers.

FIG. 12 is a diagram showing the grade of voids in a striped light absorption layer from the center to the periphery of a black matrix type phosphor screen.

13(a) to 13(d) are diagrams each showing the aperture shape of a conventional zone exposure shutter. FIG.

FIG. 14 is a diagram for explaining problems when using a zone exposure shutter with an hourglass-shaped aperture.

FIG. 15 is a diagram illustrating grouping of striped light absorption layers in various parts of the phosphor screen that occur when the zone exposure shutter with the above-mentioned hourglass-shaped apertures is used.

[Explanation of symbols]

1...Panel 3...Shadow mask 10B...Blue phosphor layer 11...Light absorption layer 30...Photosensitive agent layer 31...Through hole 35...Void part of light absorption layer 36...phosphor slurry layer

Claims (1)

[Claims] 1. A phosphor screen forming member layer made of a photosensitive agent layer or a phosphor slurry layer formed on the inner surface of a panel is irradiated with light from a light source through a shadow mask to form a pattern corresponding to the through holes of the shadow mask. When forming a stripe-like or matrix-like light absorption layer or a stripe-like or dot-like phosphor layer on the inner surface of the panel through an exposure process of printing, the phosphor screen forming member layer is placed between the shadow mask and the light source section. A phosphor screen of a color picture tube is formed by arranging a zone exposure shutter having an aperture that partially exposes the area, and exposing the area while moving the zone exposure shutter in the longitudinal direction of the striped light absorption layer or the striped phosphor layer. A method for forming a phosphor screen of a color picture tube, characterized in that the moving speed of the zone exposure shutter is continuously changed.