JPH1027545A - Method for forming fluorescent screen of color picture tube and its aligner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorescent screen forming method and its aligner which can make a stripe form of non-luminous layer and a phosphor layer at a predetermined positions correctly, and can reduce the contraction of the stripe, without reducing the position accuracy of a light source. SOLUTION: In the fluorescent screen forming method of a color picture tube which prints a stripe form pattern to a photosensitive fluorescent screen forming member layer 40 formed on the inner surface of a panel 1 through the through holes of a shadow mask which has through hole line comprising a plurality of through holes arranged in a linear form through a bridge, the longitudinal direction of a long light source is made coinsident with the longitudinal direction of the through hole line, and an opaque cover 45 having a light penetration window 44 is provided on the long light source, and a stripe form pattern is to be printed to the photosensitive fluorescent screen forming member layer by the light penetrating through the light penetration part, while moving reciprocating the cover 45 in the longitudinal direction of the long light source.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a fluorescent screen of a color picture tube and an exposure apparatus therefor, and more particularly to a method of forming a fluorescent screen of a color picture tube which is effective for forming a stripe-shaped non-light-emitting layer and a phosphor layer. And its exposure apparatus.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 6, a color picture tube comprises a vacuum envelope comprising a substantially rectangular panel 1 having a curved surface and a funnel-shaped funnel 2 joined to the panel 1. A phosphor screen 4 having at least a three-color phosphor layer is formed on the inner surface of the panel 1 so as to face the shadow mask 3 in which a large number of through holes are formed in a predetermined arrangement. On the other hand, three electron beams 6 are placed in the neck 5 of the funnel 2.
Is provided. Then, the three electron beams 6 emitted from the electron gun 7 are deflected by a magnetic field generated by a deflecting device 8 mounted outside the funnel 2 to scan the fluorescent screen 4 horizontally and vertically via the shadow mask 3. Thus, a structure for displaying a color image is formed.

In such a color picture tube, as shown in FIG. 7, the shadow mask 3 is formed by arranging a plurality of through-holes formed of a plurality of through-holes 11 arranged in a straight line via a bridge 10 in parallel. The phosphor screen 4 is provided so as to be buried in a gap between the non-light-emitting layer 12 and the black non-light-emitting layer 12 having a stripe shape long in the longitudinal direction of the hole row. Striped three-color phosphor layer 13B
, 13G and 13R are widely used in practice.

Conventionally, the fluorescent screen 4 of the above color picture tube has
The shadow mask 3 is formed by a photo printing method using the photomask as a photomask. On the phosphor screen 4 of the black stripe type color picture tube, the non-light emitting layer 12 is first formed, and then the three-color phosphor layers 13B and 13G are formed. , 13R.

That is, first, a photosensitive film is formed on the inner surface of the panel 1. Next, the photosensitive film is exposed through the shadow mask 3, and a stripe pattern corresponding to the row of holes of the shadow mask 3 is printed on the photosensitive film. Then, the exposed photosensitive film of this pattern is developed to remove unexposed portions,
A striped resist is formed. Next, a black non-light-emitting layer forming paint layer is formed on the inner surface of the panel 1 on which the resist is formed. Next, the non-light-emitting layer forming paint layer applied on the resist is peeled off together with the resist to form a striped non-light-emitting layer 12.

Thereafter, a phosphor slurry layer containing a phosphor and a photosensitive agent as main components is formed on the inner surface of the panel 1 on which the non-light emitting layer 12 is formed. Next, this phosphor slurry layer is exposed through the shadow mask 3, and a stripe pattern corresponding to the row of holes of the shadow mask 3 is printed on the phosphor slurry layer. Next, the phosphor slurry layer having the pattern printed thereon is developed to remove unexposed portions, thereby forming a stripe-shaped phosphor layer of any one color. Then, the method of forming the phosphor layer of any one color is determined by the three-color phosphor layers 13B, 13G,
It is formed by repeating for 13R.

In this method of forming a phosphor screen by a photographic printing method, a shadow mask 3 is formed on the photosensitive film and the phosphor slurry layer.
When printing a stripe pattern corresponding to the row of through holes, an exposure apparatus is used. Conventionally, this exposure apparatus has a direct exposure system shown in FIG.
There is an exposure apparatus called a zone exposure method shown in FIG.

In each of these exposure apparatuses, a straight tubular ultra-high pressure mercury lamp is provided below a table 15 for positioning and supporting the panel 1 with the longitudinal direction of the row of holes of the shadow mask 3 mounted on the panel 1 as the longitudinal direction. A light source unit 6 having a long light source as a light source is provided. Between the light source unit 16 and the shadow mask 3, the orbit of the radiated light 17 from the light source unit 16 is sequentially transmitted from the light source unit 16 side. A correction lens optical system 18 composed of one or more lenses approximating the orbit, and a correction filter 19 for correcting the light quantity distribution on the inner surface of the panel 1 positioned and supported on the table 15 are arranged. Further, in a zone exposure type exposure apparatus, the correction filter 19 and the panel 1
An opening 2 having a longitudinal direction perpendicular to the longitudinal direction of the long light source 16 between the opening 2 and the shadow mask 3 mounted inside the
A light-shielding plate 21 in which 0 is formed is arranged.

In the direct exposure method, the light source 16
Are fixedly provided, and the radiated light 17
Accordingly, the entire inner surface of panel 1 is exposed simultaneously. On the other hand, in the zone exposure method, the light source 16
3 and the light-shielding plate 21 is moved in synchronization with the swing of the long light source 16 in the longitudinal direction of the light source 16 indicated by the arrow 24 (longitudinal direction of the through-hole row of the shadow mask 3), that is, the aperture is opened. By moving the panel 20 in the width direction, the irradiation area on the inner surface of the panel 1 is moved, and the inner surface of the panel 1 is scanned and exposed. Therefore, the exposure apparatus of the zone exposure system has a complicated structure and a longer exposure time than the exposure apparatus of the direct exposure system.

Further, in any of the exposure apparatuses, the stripe-shaped non-light-emitting layer or the stripe-shaped non-light-emitting layer 3 is formed due to the difference in light intensity between the portion corresponding to the bridge of the shadow mask 3 and the portion corresponding to the through hole. As shown for the non-light emitting layer 12 in FIG.
Constriction occurs.

In order to eliminate the constriction in this stripe,
As shown in FIG. 10, the length L of the long light source 27 of the light source section 16
e is a positive integer (n) with respect to the distance L to the inner surface of the panel 1, the distance q between the inner surface of the panel 1 and the shadow mask 3, and the arrangement pitch Pv of the through holes in the through hole array of the shadow mask 3. = 1, 2, 3,...) And Le = n · (L / q) · Pv.

However, as described above, the length Le of the long light source 27 is
Is set, the length of the long light source 27 actually required is
Different from each other on the inner surface of the panel 1, in the direct exposure method, the entire surface is simultaneously exposed, so that the length between the central portion and the peripheral portion must be compromised. Therefore, the constriction cannot be eliminated. On the other hand, the zone exposure method has a structure in which the length of the long light source 27 is changed in synchronization with the movement of the light-shielding plate, but it is still insufficient to eliminate the constriction. That is, in each of the exposure methods, the required length of the light source is different at each point on the inner surface of the panel, so it is difficult to eliminate the constriction over the entire inner surface of the panel.

As a result, in the phosphor screen formed by the conventional exposure apparatus, color unevenness occurs due to the constriction of the stripe and white uniformity is deteriorated. The contrast due to external light differs between the constricted portion and the non-constricted portion. Furthermore, in a high-resolution tube in which the shadow mask has a small through-hole and an arrangement pitch thereof, and a correspondingly small arrangement pitch of the non-light-emitting layer and the three-color phosphor layer, the phosphor layer is likely to protrude or chip, and the phosphor screen quality is high. And the occurrence of defective phosphor screens increases.

As a method for eliminating the above constriction, Japanese Patent Publication No. 4-18412 discloses that a long light source of an exposure apparatus is vibrated in the longitudinal direction. According to this method, it is possible to reduce the difference in light intensity between the portion corresponding to the bridge and the portion corresponding to the through hole in the through hole row, thereby reducing the constriction amount of the stripe. However, in such a method, a complicated operation is required for the long light source, so that the structure of the exposure apparatus is complicated. In addition, if the position of the long light source is shifted, the position of the stripe to be formed is shifted, resulting in deterioration of color purity. In other words, the position accuracy of the long light source is important,
It is necessary to always keep the correct position at a predetermined position. However, when the long light source is vibrated as described above, a positional shift is likely to occur.

As a method for preventing the displacement of the light source, Japanese Patent Application Laid-Open No. 3-55741 discloses a method of vibrating a panel instead of a long light source. However, such a method is disadvantageous because the weight of the panel is generally large, especially for a large tube.

[0016]

As described above, the fluorescent screen of the color picture tube is formed by a photographic printing method. In particular, the fluorescent screen formed of a non-light-emitting layer or a phosphor layer in the form of a stripe has a long light source. Is formed using an exposure apparatus described above. However, even if a long light source is used, simply setting the length cannot eliminate the constriction of the stripe corresponding to the bridge of the through-hole array of the shadow mask over the entire surface of the phosphor screen. Deterioration of white uniformity, deterioration of the level of unevenness in appearance caused by differences in contrast due to external light, and furthermore, the apertures of the shadow mask and the arrangement pitch thereof are small, and accordingly the arrangement of the non-light emitting layer and the three-color phosphor layer In a high-resolution tube having a small pitch, there is a problem that the phosphor layer is easily protruded or chipped, and the quality of the phosphor screen is deteriorated and the occurrence of defective phosphor screen is increased. In recent years, with the progress of multimedia, color picture tubes have been increasing in size and increasing in resolution with the progress of multimedia.

As a method for eliminating the constriction of the stripe, there is a method of exposing while oscillating a long light source in the longitudinal direction. According to this method, the difference in light intensity between the portion corresponding to the bridge and the portion corresponding to the through-hole of the shadow mask can be reduced, and constriction of the stripe can be reduced. However, this method has a problem that the position of the long light source is likely to shift due to the repetition of the vibration, and as a result, the position of the stripe to be formed is shifted, resulting in deterioration of color purity.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and a non-light-emitting layer or a phosphor layer having a stripe shape can be correctly positioned at a predetermined position without deteriorating the positional accuracy of a light source.
Further, it is an object of the present invention to configure a phosphor screen forming method capable of reducing the constriction of the stripe and an exposure apparatus therefor.

[0019]

SUMMARY OF THE INVENTION Light emitted from a long light source is applied to a panel through each through hole of a shadow mask having a plurality of through holes arranged linearly through a bridge. Irradiating the photosensitive phosphor screen forming member layer formed on the inner surface of the photosensitive phosphor screen forming member layer with a stripe pattern corresponding to the row of holes on the photosensitive phosphor screen forming member layer; And the opaque cover having a light transmitting window is arranged on the long light source, and the cover is transmitted through the light transmitting portion while reciprocating the cover in the longitudinal direction of the long light source. Light was used to print a stripe pattern on the photosensitive phosphor screen forming member layer.

Also, a photosensitive fluorescent screen forming member layer formed on the inner surface of the panel through each through hole of a shadow mask having a plurality of through holes arranged linearly through a bridge. In the exposure apparatus for forming a fluorescent screen of a color picture tube having a long light source that emits light for printing a stripe pattern corresponding to a row of holes on the photosensitive fluorescent screen forming member layer by irradiating the long light source, Was arranged in a direction corresponding to the longitudinal direction of the row of through holes, and an opaque cover having a light transmitting portion reciprocating in the longitudinal direction of the long light source was arranged on the long light source.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the main steps of forming a phosphor screen of a black-strip type color picture tube, which is one embodiment of the present invention. The phosphor screen of the color picture tube is formed by a photo printing method,
First, as shown in FIG. 1A, a photosensitive agent containing polyvinyl alcohol (PVA) and ammonium bichromate (ADC) as main components is applied to the inner surface of the panel 1, and dried to form a photosensitive film 30. Next, a shadow mask 3 is mounted on the panel 1 on which the photosensitive film 30 is formed, and a plurality of through-holes 11 are linearly arranged via a bridge by a radiation light from a light source unit of an exposure apparatus described later. Mask 3
The stripe pattern corresponding to the through-hole row (formed in parallel with a plurality of rows) is printed. Next, the photosensitive film on which the pattern is baked is developed to remove the unexposed portions, and a resist 31 having a stripe shape (a plurality of rows of stripes are arranged in parallel) is formed as shown in FIG.

Next, a black non-light-emitting layer forming paint is applied to the inner surface of the panel 1 on which the resist 31 is formed, and dried to form a black non-light-emitting layer forming paint layer 32 as shown in FIG. To form Next, the non-light-emitting layer forming paint layer 32 applied on the resist 31 is peeled off together with the resist 31 by a stripping agent, and as shown in FIG. 3D, a striped non-light-emitting layer 33 (a plurality of rows of stripes are arranged in parallel). To form

Thereafter, a photosensitive phosphor slurry containing a phosphor, PVA and ADC as a main component is applied to the inner surface of the panel 1 on which the non-light emitting layer 33 is formed, dried, and dried as shown in FIG. Thus, the photosensitive phosphor slurry layer 35 is formed. Next, a shadow mask 3 is mounted on the panel 1 on which the phosphor slurry layer 35 is formed, and a stripe pattern corresponding to the row of holes of the shadow mask 3 is printed by light emitted from a light source unit of an exposure apparatus described later. wear. Then, the phosphor slurry layer 35 having the printed pattern is developed to remove the unexposed portions, and as shown in FIG.
A phosphor layer in the form of a stripe, for example, a blue phosphor layer 36
B is formed so as to be embedded in a predetermined gap of the non-light-emitting layer 33. Thereafter, the method of forming the blue phosphor layer 36B is repeated for the green and red phosphors, so that the green phosphor layer 36G and the red phosphor layer 36R.

FIG. 2A shows an exposure apparatus used for printing a stripe pattern corresponding to the row of holes of the shadow mask 3 on the photosensitive film and the photosensitive phosphor slurry layer. This exposure apparatus is a direct exposure type exposure apparatus, and a table 15 for positioning and supporting the panel 1.
A light source unit 38 is disposed below the light source unit.
A correction lens optical system 18 comprising one or more lenses for approximating the trajectory of the emitted light 39 from the light source unit 38 to the trajectory of the electron beam, and a correction for correcting the light quantity distribution on the inner surface of the panel 1 positioned and supported on the table 15. A filter 19 is provided. Note that, in FIG.
Reference numeral 0 denotes a phosphor screen forming member layer such as a photosensitive film or a photosensitive phosphor slurry layer formed on the inner surface of the panel 1.

The light source section 38 uses a long light source such as a straight tube ultra-high pressure mercury lamp as a light source, and the long light source has a longitudinal direction of a row of holes of the shadow mask 3 mounted inside the panel 1 as a longitudinal direction. As shown in FIG. 2B, a glass tube 41 is arranged around the long light source. Furthermore, in this exposure apparatus,
An opaque cover 45 having a light transmission window 44 which is reciprocally moved (vibrated) in the longitudinal direction of the long light source indicated by an arrow 43 in close contact with the glass tube 41 by a driving mechanism 42 (shown in FIG.
Is arranged. The moving distance (amplitude) of the opaque cover 45 does not exceed the length of the long light source, and the constriction of the stripe of the non-light emitting layer and the three-color phosphor layer formed for each tube type is minimized. Adjusted. The reciprocating speed is appropriately selected for each pipe type.

By arranging the opaque cover 45 having the light transmitting portion 44 that reciprocates along the longitudinal direction of the long light source in the light source portion 38 and appropriately adjusting the moving distance, at each point on the inner surface of the panel 1, The difference in light intensity between the portion corresponding to the bridge and the portion corresponding to the through hole of the shadow mask 3 can be reduced, and as shown for the non-light-emitting layer 33 in FIG. The width of the stripe can be made uniform as shown by a straight line by reducing the stripe-shaped gap 26 of the light-emitting layer 33 and the constriction of the stripe-shaped three-color phosphor layer.

In addition, this exposure apparatus differs from the above-mentioned known exposure apparatus (Japanese Patent Publication No. 4-18412).
Since the opaque cover 45 is arranged on the light source without moving the light source and the opaque cover 45 is moved, the non-light-emitting layer 33 and the three-color phosphor layer 36B can be maintained accurately without displacing the light source. , 36G, 36R can be correctly formed at predetermined positions. As a result, the white uniformity is deteriorated due to the occurrence of color unevenness, the appearance unevenness level is deteriorated due to the difference in contrast due to external light, and the through holes of the shadow mask and the arrangement pitch thereof are small. By applying the present invention to the formation of the fluorescent screen of a high-resolution tube having a small arrangement pitch of the layers and the three-color phosphor layers, the phosphor layer can be prevented from protruding or chipping, and a high-quality fluorescent screen can be formed.

Next, a description will be given of an exposure apparatus having a structure different from that of the exposure apparatus shown in FIG. 2 used for forming the fluorescent screen.

The exposure apparatus shown in FIG. 3A is an exposure apparatus of a zone exposure system, similar to the exposure apparatus shown in FIG. 2, between the panel 1 positioned and supported on the table 15 and the light source section 38. In addition, a correction lens optical system 18 and a correction filter 19 are arranged from the light source unit 38 side. Further, in this exposure apparatus, a long distance is provided between the correction filter 19 and the shadow mask 3 mounted inside the panel 1. A light-shielding plate 21 having an opening 20 whose longitudinal direction is perpendicular to the longitudinal direction of the light source is disposed. This light shielding plate 21
Is moved in the longitudinal direction of the long light source, that is, in the width direction of the aperture 20, as indicated by the arrow 24, in synchronization with the swinging of the light source unit 38 described later.

As shown in FIG. 3B, the light source section 38 uses a long light source such as a straight tube ultra-high pressure mercury lamp as a light source, similarly to the light source section of the exposure apparatus shown in FIG. The light source is arranged with the longitudinal direction of the row of through holes of the shadow mask 3 mounted inside the panel 1 as a longitudinal direction, and a glass tube 41 is arranged around the long light source. Further, an opaque cover 4 having a light transmitting window 44 along the glass tube 41.
5 are arranged. The opaque cover 45 is reciprocated in the longitudinal direction of the long light source indicated by the arrow 43 by the drive mechanism 42 (shown in FIG. 7A). The whole 38 swings about an axis 46 orthogonal to the tube axis of the long light source as a rotation center axis as shown by an arrow 47.

Also in this exposure apparatus, the moving distance of the opaque cover 45 is set so as not to exceed the length of the long light source, and the non-light-emitting layer and the stripe of the three-color phosphor layer formed for each tube type. Adjusted to minimize constriction. The reciprocating speed is appropriately selected for each pipe type.

This exposure apparatus has the same effects as those of the exposure apparatus shown in FIG. 2.
As compared with the direct type exposure apparatus shown in FIG. 2, the structure is complicated and the position of the light source is easily shifted by the swing of the light source unit 38, so that a more remarkable effect can be obtained.

FIG. 4 shows a light source unit 38 of a different exposure apparatus.
Is shown. In this light source section 38, a plate-shaped opaque cover 45 having a light transmission window 44 is disposed at a position distant from a glass tube 41 disposed around the long light source, and reciprocates in the longitudinal direction of the long light source indicated by an arrow 43. It is something to do.

Even if the opaque cover 45 is arranged as described above, the same effects as those of the above-described respective exposure apparatuses can be obtained. However, the opaque cover 45 can be easily moved by disposing the opaque cover 45 away from the glass tube 41. .

[0036]

The light radiated from the long light source is formed on the inner surface of the panel through each through hole of a shadow mask having a plurality of through holes arranged linearly through a bridge. Irradiating the light-sensitive phosphor screen forming member layer thus formed with a fluorescent phosphor screen forming member layer to print a stripe pattern corresponding to a row of holes in the phosphor screen of the color picture tube. Is aligned with the longitudinal direction of the row of through holes, and an opaque cover having a light transmitting window is arranged on the long light source, and the cover is reciprocated in the longitudinal direction of the long light source while transmitting light through the light transmitting portion. A stripe pattern is printed on the photosensitive phosphor screen forming member layer, and through each through hole of a shadow mask having a through hole array composed of a plurality of through holes arranged linearly via a bridge. panel Fluorescent light from a color picture tube having a long light source that emits light that irradiates a photosensitive phosphor screen forming member layer formed on an inner surface with a stripe pattern corresponding to a row of holes in the photosensitive phosphor screen forming member layer In the surface-forming exposure apparatus, the longitudinal direction of the long light source is arranged in a direction coincident with the longitudinal direction of the row of through holes, and an opaque cover having a light transmitting portion that reciprocates in the longitudinal direction of the long light source is arranged on the long light source. With this structure, the light source can be accurately maintained at the correct position, the stripe-shaped non-light-emitting layer and the phosphor layer can be formed at predetermined positions, and the constriction of the stripe can be effectively reduced over the entire phosphor screen. Can be reduced. As a result, the white uniformity is deteriorated due to the occurrence of color unevenness, the appearance unevenness level is deteriorated due to the difference in contrast due to external light, and the through holes of the shadow mask and the arrangement pitch thereof are small. In addition, the present invention can be applied to the formation of the fluorescent screen of a high-resolution tube having a small arrangement pitch of the three-color phosphor layers, thereby eliminating protrusion and chipping of the phosphor layer and forming a high-quality phosphor screen.

[Brief description of the drawings]

FIGS. 1A to 1G are diagrams showing main steps of a method of forming a phosphor screen of a black stripe type color picture tube according to an embodiment of the present invention.

FIG. 2A is a diagram illustrating a configuration of an exposure apparatus used for forming the fluorescent screen, and FIG. 2B is a diagram illustrating a configuration of a light source unit.

FIG. 3 is a view showing a shape of a gap between stripe-like non-light-emitting layers formed by the above-mentioned phosphor screen forming method.

FIG. 4A is a diagram showing a configuration of another exposure apparatus used for forming the fluorescent screen, and FIG. 4B is a diagram showing a configuration of a light source unit.

FIG. 5 is a diagram showing a configuration of a light source unit of another different exposure apparatus used for forming the fluorescent screen.

FIG. 6 is a diagram showing a configuration of a color picture tube.

FIG. 7 is a diagram showing a main configuration of a color picture tube.

8A is a diagram showing a configuration of a conventional direct exposure type exposure apparatus used for forming a fluorescent screen of a black stripe type color picture tube, and FIG. 8B is a view of a zone exposure type exposure apparatus. FIG. 3 is a diagram illustrating a configuration.

FIG. 9 is a view showing a shape of a gap between stripe-shaped non-light-emitting layers formed by using the conventional exposure apparatus.

FIG. 10 is a view for explaining the length of a long light source of an exposure apparatus used for forming a fluorescent screen of a black stripe type color picture tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Panel 3 ... Shadow mask 11 ... Through-hole 30 ... Photosensitive film 33 ... Non-light emitting layer 35 ... Photosensitive phosphor slurry layer 36B, 36G, 36R ... 3 color phosphor layer 38 ... Light source part 40 ... Photosensitive phosphor screen formation Member layer 42 Drive mechanism 44 Light transmitting window 45 Opaque cover

Claims (2)

[Claims] A light emitted from a long light source is formed on an inner surface of a panel through each through hole of a shadow mask having a plurality of through holes arranged linearly through a bridge. Irradiating the photosensitive phosphor screen forming member layer with a stripe pattern corresponding to the row of holes on the photosensitive phosphor screen forming member layer by irradiating the photosensitive phosphor screen forming member layer. The direction is aligned with the longitudinal direction of the row of through holes, and an opaque cover having a light transmitting window is arranged on the long light source, and the cover passes through the light transmitting portion while reciprocating in the longitudinal direction of the long light source. And b. Printing the stripe pattern on the photosensitive phosphor screen forming member layer with light. 2. A photosensitive phosphor screen forming member layer formed on an inner surface of a panel through each through hole of a shadow mask having a plurality of through holes arranged linearly via a bridge. An exposure apparatus for forming a fluorescent screen of a color picture tube having a long light source that emits light for printing a stripe pattern corresponding to the row of through holes on the photosensitive fluorescent screen forming member layer by irradiating the photosensitive fluorescent screen forming member layer; Is characterized in that an opaque cover having a light-transmitting portion that is reciprocated in the longitudinal direction of the long light source is disposed on the long light source, the longitudinal direction being arranged in a direction corresponding to the longitudinal direction of the through-hole row. An exposure apparatus for forming a fluorescent screen of a color picture tube.