JP2002050285A - Phosphor screen forming method of color picture tube and its exposing unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain means for a phosphor screen forming method and its exposing unit which can produce stripes in smooth lines by reducing zigzagging black non-luminous layer and a three-color phosphor layer which are formed corresponding to aperture lines consisting of a plurality of slit-like apertures in a shadow mask even if the inside surface of a useful screen area has complex curves. SOLUTION: In the phosphor screen forming method of color picture tubes, a line-like light source is laid as its major axis is parallel to a minor axis of a panel, and a cylindrical shape non-spherical surface lens 39 is arranged between the above light source and a shadow mask as the lens axis crosses the minor axis of a panel at right angles so that tilts of a pattern which is exposed on a photosensitive phosphor screen forming layer corresponding to slit-like apertures in the shadow mask can be compensated. Wherein, the lens axis is a cylinder axis because its basic shape is a cylinder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a fluorescent screen of a color picture tube and an exposure apparatus used for forming a fluorescent screen, and more particularly, to a method for forming a fluorescent screen on a photosensitive fluorescent screen formed on the inner surface of an effective portion of a panel. The present invention relates to a method of forming a phosphor screen of a color picture tube and an exposure apparatus which prevent the stripe pattern from meandering when printing a stripe pattern corresponding to an aperture row composed of a plurality of slit apertures.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 9, a color picture tube has a substantially rectangular panel 3 provided with a skirt portion 2 around an effective portion 1 having curved inner and outer surfaces, and a funnel-shaped funnel 4 as shown in FIG. And a three-color light emitting blue, green and red formed on the inner surface of the effective portion of the panel 3 so as to be embedded in the gap between the black non-light-emitting layers. A phosphor screen 5 including a phosphor layer is provided. Also, a mask body 6 having a large number of apertures formed in a predetermined arrangement on an effective surface formed of a curved surface facing the fluorescent surface 5.
A substantially rectangular shadow mask 8 comprising a mask frame 7 attached to a peripheral portion of the mask body 6 is attached to an elastic support 9 attached to the mask frame 7 to a stud pin 10 provided on the panel 3. It is supported by locking. On the other hand, an electron gun 14 for emitting three electron beams 13B, 13G, and 13R is disposed in the neck 12 of the funnel 4. The three electron beams 13B, 13G, and 13R emitted from the electron gun 14 are deflected by the deflection yoke 15 mounted outside the funnel 4, and the fluorescent screen 5 is horizontally and vertically scanned through the shadow mask 8. Thereby, it is formed in a structure for displaying a color image.

In such a color picture tube, there is a color picture tube in which a black non-emitting layer and a three-color phosphor layer constituting the phosphor screen 5 are formed as stripes. That is, as shown in FIG. 10, the openings 17 of the shadow mask 8 are slit-shaped, and a plurality of the openings 17 are arranged in the short axis direction (Y-axis direction) of the panel via the bridge 18. Multiple openings 1 in the direction
7 are arranged in parallel in the long-axis direction (X-axis direction), and the black non-light-emitting layer 20 and the three-color phosphor layers 21B and 21 correspond to the opening row 19 of the shadow mask 8.
G and 21R may be stripes long in the short axis direction.

In recent years, color picture tubes have been developed in which the curvature of the outer surface of the effective portion of the panel is reduced and the screen is flattened in order to improve the visibility. From the viewpoint of visibility and from the viewpoint of molding, such a panel needs to have a curved surface with a small curvature whose inner surface slightly changes in accordance with the flattening of the outer surface of the effective portion. Further, in general, the curvature of the inner surface of a panel made of glass changes due to rust and the like generated during molding. For this reason, even if the curvature of the inner surface is slightly changed, the black non-light-emitting layer or the phosphor layer is formed on the inner surface of the effective portion of the panel by a predetermined stripe regardless of the inner surface shape. Must be formed.

Conventionally, the fluorescent screen of a color picture tube has been formed by a photographic printing method using a shadow mask as an optical mask. That is, a photosensitive agent is applied to the inner surface of the effective portion of the panel and dried to form a photoresist. The photoresist is exposed through a shadow mask, and a pattern corresponding to an aperture row including a plurality of apertures of the shadow mask is formed. And then developed to form a striped resist corresponding to the row of apertures in the shadow mask. Next, a black non-light-emitting paint layer is applied to the inner surface of the effective portion of the panel on which the resist is formed, and dried to form a black non-light-emitting paint layer. The black non-light-emitting paint layer applied on the resist is formed together with the resist. By stripping and removing, a stripe-shaped black non-light-emitting layer is formed. Thereafter, a photosensitive phosphor slurry is applied to the inner surface of the effective portion of the panel on which the black non-light-emitting layer is formed, and dried to form a photosensitive phosphor slurry layer. Then, the photosensitive phosphor slurry layer is exposed through a shadow mask, and a pattern corresponding to the opening of the shadow mask is printed and developed. A phosphor layer, for example, a blue phosphor layer is formed. further,
This method of forming the blue phosphor layer is sequentially repeated for the green phosphor and the red phosphor to form green and red phosphor layers in predetermined gaps between the black non-light-emitting layers.

In this method of forming a phosphor screen by a photographic printing method, a photosensitive phosphor screen forming layer such as a photoresist or a photosensitive phosphor slurry layer for forming a black non-emitting layer and a three-color phosphor layer is exposed. A linear light source in the form of a straight tube such as an ultra-high pressure mercury lamp is used. In the formation of a striped black non-light-emitting layer and a three-color phosphor layer, the long axis (tube axis) of the linear light source is shadow masked. In the direction of the opening row.

Therefore, when the stripe-shaped black non-light emitting layer and the three-color phosphor layer are formed by the above-described method, the effective surface of the shadow mask is a curved surface. The apertures are inclined with respect to the light source, and the pattern to be printed on the photosensitive phosphor screen forming layer is inclined in accordance with the apertures. The body layers meander.

Several means have been developed as means for preventing the black non-light emitting layer and the three-color phosphor layer from meandering due to the slit-shaped opening being inclined with respect to the light source.

In one of them, a shielding plate for partially exposing the photosensitive phosphor screen forming layer is disposed between the linear light source and the shadow mask, and the shielding plate is moved in the direction of the aperture row of the shadow mask. In addition, there is an exposure apparatus called a partial exposure method, in which a light source is swung in a long axis direction so that an inclination of the light source and an inclination of a slit-shaped opening of a portion through which light from the light source passes coincide with each other for exposure. . However, such an exposure apparatus,
Compared with an exposure apparatus that exposes the entire surface of the photosensitive phosphor screen forming layer at the same time, the number of movable parts is increased and the partial exposure method is used, so that it takes time to expose the entire surface of the photosensitive phosphor screen forming layer.

As another means, a meniscus lens is arranged between the light source and the shadow mask so as to reduce the inclination of the pattern corresponding to the slit-shaped opening of the shadow mask printed on the photosensitive phosphor screen forming layer. There is an exposure device. However, the meniscus lens has a limit in reducing the inclination of the pattern corresponding to the slit-shaped opening theoretically.
It is not suitable for a color picture tube or a large color picture tube for flattening a screen.

[0011] Further, Japanese Patent Publication No. 6-40464 and Japanese Patent Application Laid-Open No. H8-17341 propose an exposure apparatus in which a simple cylindrical lens is arranged between a linear light source and a shadow mask. However, since these known simple cylindrical lenses have a constant radius of curvature in the long axis direction of the linear light source in the orthogonal direction, the inclination of the pattern corresponding to the slit-shaped apertures of the shadow mask covers the entire effective portion of the panel. Is difficult to satisfactorily correct.

[0012]

In recent years, color picture tubes have been
Panels have been developed that flatten the screen by reducing the curvature of the outer surface of the effective part of the panel.However, such a color picture tube has a smaller and more subtle curvature on the inner surface corresponding to the curvature of the outer surface of the effective part. It consists of a changing curved surface, and as a fluorescent screen,
It is necessary to form a striped black non-light emitting layer or phosphor layer corresponding to the inner surface shape. However, in the case of a shadow mask in which the effective surface is a curved surface corresponding to the curved surface of the inner surface of the effective portion of the panel, as the slit-shaped apertures move away from the long axis and the short axis of the shadow mask, the linear light source used for forming the fluorescent screen becomes more difficult. The pattern to be printed is inclined corresponding to the apertures, and the stripe-shaped black non-light emitting layer or the three-color phosphor layer formed corresponding to the aperture rows meanders to form a predetermined stripe. Can not do it.

Conventionally, some means (exposure apparatus) for preventing the black non-light emitting layer and the three-color phosphor layer from meandering have been proposed. However, in the exposure apparatus of the partial exposure system, the number of movable parts increases, Exposure takes time. Further, in an exposure apparatus in which a meniscus lens is arranged, there is a limit in reducing the inclination of the pattern corresponding to the slit-shaped aperture, and it is not suitable for a color picture tube or a large color picture tube having a flat screen. Also,
An exposure apparatus having a simple cylindrical lens has a problem that it is difficult to satisfactorily correct the inclination of a pattern corresponding to a slit-shaped opening of a shadow mask.

That is, in a color picture tube in which the fluorescent surface is composed of a black non-light-emitting layer having a stripe shape and a three-color phosphor layer, the black non-light-emitting layer and the three-color phosphor layer are formed into predetermined stripes on the inner surface of the effective portion of the panel. However, if the effective surface of the shadow mask that faces the inner surface of the effective portion of the panel is a curved surface, the fluorescent surface becomes more distant from the long and short axes of the shadow mask. The pattern is inclined with respect to the linear light source used for the formation, and the pattern corresponding to the opening is inclined. In addition, when the curvature of the inner surface of the effective part of the panel is small and it is composed of a complicated curved surface that changes slightly,
Corresponding to the curved surface, the inclination of the pattern corresponding to the aperture also changes, and there is a problem that the black non-light emitting layer and the three-color phosphor layer cannot be formed into predetermined stripes.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and is applicable to a row of apertures composed of a plurality of slit-shaped apertures of a shadow mask even when the inner surface of an effective portion of the panel is formed of a complicated curved surface. It is an object of the present invention to obtain a phosphor screen forming method and an exposure apparatus which reduce the meandering of the black non-light emitting layer and the three-color phosphor layer formed by forming the phosphor screen into smooth stripes.

[0016]

Means for Solving the Problems (1) The light emitted from the linear light source is applied to the photosensitive phosphor screen forming layer formed on the inner surface of the effective portion of the substantially rectangular panel through the bridge in the short axis direction of the panel. In a method for forming a fluorescent screen of a color picture tube, the method includes a step of printing a stripe pattern corresponding to an aperture row of a shadow mask in which a plurality of slit-shaped apertures are arranged. The cylindrical aspheric lens is arranged between the linear light source and the shadow mask, and the axis in the same direction as the cylinder axis of the cylinder which is the basis of the lens is arranged as a direction orthogonal to the long axis of the light source. The inclination with respect to the long axis of the light source of the pattern corresponding to the slit-shaped aperture to be printed on the photosensitive phosphor screen forming layer by the cylindrical aspheric lens is corrected.

(2) A plurality of slit-like openings are formed in the photosensitive phosphor screen forming layer formed on the inner surface of the effective portion of the substantially rectangular panel through a bridge in the short axis direction of the panel by light emitted from the linear light source. In the method for forming a fluorescent screen of a color picture tube having a step of printing a stripe pattern corresponding to the aperture row of the shadow mask in which the holes are arranged, the long axis of the linear light source is arranged as the short axis direction of the panel, A cylindrical aspheric lens is arranged between the linear light source and the shadow mask, and an axis in the same direction as the cylindrical axis of the cylinder which is the basis of the lens is arranged as a direction orthogonal to the long axis of the light source. The shield is provided with a barrel-shaped opening in which the direction perpendicular to the opposite long side is set and the interval between the center portions of the opposite long sides is wider than the interval between the ends, and the photosensitive phosphor screen is formed by a cylindrical aspheric lens. Baking on cambium At the same time as correcting the inclination of the pattern corresponding to the slit opening to the long axis of the light source,
The length of the light source in the major axis direction of the pattern corresponding to the slit-shaped opening to be printed on the photosensitive phosphor screen forming layer by the opening of the shield is corrected.

(3) A shadow mask in which a plurality of slit-shaped apertures are arranged on a photosensitive phosphor screen forming layer formed on an inner surface of an effective portion of a substantially rectangular panel through a bridge in a short axis direction of the panel. In an exposure apparatus for forming a fluorescent screen of a color picture tube having a linear light source for printing a stripe pattern corresponding to an aperture row, the long axis of the linear light source is arranged as the short axis direction of the panel, and the linear light source and A cylindrical aspherical lens that corrects the inclination of the pattern corresponding to the slit-shaped apertures printed on the photosensitive phosphor screen forming layer with respect to the long axis of the light source between the shadow mask and the cylindrical cylindrical axis that is the basis of this lens. The axis in the same direction was arranged as a direction orthogonal to the long axis of the light source.

(4) A shadow mask in which a plurality of slit-shaped openings are arranged on a photosensitive phosphor screen forming layer formed on an inner surface of an effective portion of a substantially rectangular panel through a bridge in a short axis direction of the panel. In an exposure apparatus for forming a fluorescent screen of a color picture tube having a linear light source for printing a stripe pattern corresponding to an aperture row, the long axis of the linear light source is arranged as the short axis direction of the panel, and the linear light source and The cylindrical aspherical lens that corrects the inclination of the pattern corresponding to the slit-shaped aperture printed on the photosensitive phosphor screen forming layer between the shadow mask and the long axis of the light source is the same as the basic cylindrical axis of the lens. The axis in the same direction is arranged as a direction orthogonal to the long axis of the light source, and the direction orthogonal to the long axis of the light source is the opposite long side, and the interval between the central portions of the opposite long sides is wider than the interval between the ends. Photosensitive phosphor screen formation A shield provided with a barrel-shaped opening for correcting the length of the light source in the long axis direction in a pattern corresponding to the slit-shaped opening to be burned in the layer was arranged.

(5) The color image of (3) or (4)
In an exposure system for forming a fluorescent screen on a tube, a cylindrical aspherical lens
The light source side is a flat surface and the shadow mask side is a curved surface.
The center of the curved surface is the origin of the coordinates, the direction perpendicular to the long axis of the light source.
The coordinates are x, the coordinates in the major axis direction of the light source are y, and a1 to a8 are related.
When expressed as a number, the curved surface on the shadow mask side is
Formula Z (x, y) = a1 x^Two + A2 x^Four + A3 y^Two + A4 x
^Two y^Two + A5 x^Four y ^Two + A6 y^Four + A7 x^Two y^Four + A8
x^Four y^Four Aspheric surface represented by

(6) In the exposure apparatus for forming a fluorescent screen of a color picture tube as described in (5), the average curvature in the major axis direction of the light source on the curved surface on the shadow mask side of the cylindrical aspherical lens is determined by using the center of the cylindrical aspherical lens and the light source. The shape takes the maximum value or the minimum value between the long axis and the end in the direction orthogonal to the long axis.

(7) In the exposure apparatus for forming a fluorescent screen of a color picture tube as described in (5), the major axis curvature of the curved surface on the shadow mask side of the cylindrical aspherical lens is set to the axis perpendicular to the major axis of the light source. The shape takes the maximum value or the minimum value between the light source and the longitudinal end of the light source.

[0023]

FIG. 1 shows an exposure apparatus for forming a fluorescent screen of a color picture tube according to an embodiment of the present invention. This exposure apparatus has a striped black non-light-emitting layer and three colors on the inner surface of a substantially rectangular panel corresponding to an aperture row composed of a plurality of slit-shaped apertures arranged via a bridge of a shadow mask. An exposure apparatus for forming a phosphor layer, a support 30 for positioning and supporting the panel 3, and an effective portion 1 of the panel 3 positioned and supported by the support 30
A light source unit 32 for emitting light for printing a pattern corresponding to the row of apertures of the shadow mask 8 on a photosensitive phosphor screen forming layer 31 such as a photoresist or a photosensitive phosphor slurry formed on the inner surface of the light source unit 32; A plurality of correction lenses 33 such as a ΔS correction lens and a γ-ΔP correction lens for correcting the trajectory of light emitted in the direction of the panel 3 positioned and supported on the support base 30 from above, and the photosensitive phosphor screen forming layer 3
And a correction filter 34 for correcting the light amount distribution for the light source 1.

As shown in FIG. 2, the light source section 32 includes a straight tubular linear light source 36 such as an ultra-high pressure mercury lamp disposed inside a lamp house 35, and a photosensitive phosphor screen on the inner surface of the effective portion of the panel. And a shield 38 having an opening 37 for substantially regulating the size of the light source with respect to the formation layer. Further, in this embodiment, the slit-shaped opening formed in the effective surface of the curved surface of the shadow mask is formed outside the lamp house 35 through the opening 37 of the shield 38 so as to have the length of the linear light source 36. A cylindrical aspheric lens 39 for correcting the inclination of the pattern corresponding to the opening of the shadow mask which is printed on the photosensitive phosphor screen forming layer so as to incline with respect to the axis (tube axis) is arranged.

The linear light source 36 has a major axis extending from the support base 3.
It is arranged as the short axis direction of the panel positioned and supported at 0. For this linear light source 36, a shield 38
As shown in FIG. 3, the long axis direction of the panel 37, that is, the direction orthogonal to the long axis of the linear light source 36, is defined as the opposing long side, and the interval between the center portions of the opposing long sides is the interval between the end portions. It is formed in a barrel shape wider than that.

The cylindrical aspheric lens 39 is a quartz glass.
The linear light source 36 side is flat as shown in FIG.
Surface, the panel side positioned and supported by the support table,
The shadow mask side is made aspherical curved surface, and the basic of cylindrical lens
The axis in the same direction as the cylinder axis direction of the cylindrical
It is arranged as a direction orthogonal to the axis. The panel side
The aspherical surface of is the center of the curved surface (the intersection of the lens axis and the curved surface).
Point) is the origin of the coordinates, and is orthogonal to the long axis of the linear light source 36.
The coordinates of the direction are x, the coordinates of the long axis of the light source are y, a1 to a
When 8 is a coefficient, a fourth-order polynomial of the following equation (1) Z (x, y) = a1 x^Two + A2 x^Four + A3 y^Two + A4 x^Two y^Two + A5 x^Four y ^Two + A6 y^Four + A7 x^Two y^Four + A8 x^Four y^Four ... (1)

More specifically, the coefficient a of the fourth-order polynomial
By setting 1 to a8 as appropriate, as shown in FIG. 5, the average radius of curvature in the major axis direction of the light source of the aspheric curved surface on the panel side is the center of the lens and the cylindrical axis of the cylindrical lens which is the basis of the cylindrical lens. And a curved surface having a maximum value or a minimum value between the end and the end in the same direction.

Further, by appropriately setting the coefficients a1 to a8 of the fourth-order polynomial, as shown in FIG. 6, the major axis direction curvature of the light source of the aspherical curved surface on the panel side is perpendicular to the major axis. Is formed on a curved surface having a maximum value or a minimum value between the axis of the light source and the longitudinal end of the light source.

The phosphor screen is formed by a photo printing method using the above exposure apparatus and using a shadow mask as an optical mask.

First, as shown in FIG. 7A, a photosensitive agent is applied to the inner surface of the effective portion 1 of the panel and dried to form a photoresist 41. Then, the plurality of openings 17 of the shadow mask 8 are formed in the photoresist 41 by using the above-described exposure apparatus.
The pattern corresponding to the row of apertures consisting of is printed. Next, the photoresist 41 on which the pattern has been baked is developed to form a striped resist 42 corresponding to the row of apertures of the shadow mask as shown in FIG. Next, as shown in FIG.
Then, a black non-light-emitting paint is applied to the inner surface of the effective portion 1 of the panel on which the black non-light-emitting paint is applied and dried to form a black non-light-emitting paint layer 43. Next, the black non-light-emitting paint layer 43 applied and formed on the resist 42 is peeled off together with the resist 42, and as shown in FIG.
To form

Thereafter, as shown in (e), a photosensitive phosphor slurry containing a photosensitive agent and a phosphor as main components is applied to the inner surface of the effective portion 1 of the panel on which the black non-light-emitting layer 20 is formed, and dried. Thus, a photosensitive phosphor slurry layer 45 is formed. Then, a pattern corresponding to the opening 17 of the shadow mask 8 is printed on the photosensitive phosphor slurry layer 45 using an exposure device. Next, the photosensitive phosphor slurry layer 45 on which the pattern is baked is developed, and a stripe phosphor layer of any one color is provided in a predetermined gap of the black non-light-emitting layer 20 as shown in FIG. For example, a green phosphor layer 21G is formed. Further, the method of forming the green phosphor layer 21G is sequentially repeated for the blue phosphor and the red phosphor, and as shown in FIG.
The red phosphor layers 21B and 21R are formed.

When the fluorescent screen is formed as described above, the shadow mask which is burned on the photosensitive fluorescent screen forming layer 31 such as the photoresist 41 and the photosensitive phosphor slurry layer 45 as the distance from the long axis and the short axis of the panel 3 increases. 8 holes 1
The length of the pattern corresponding to No. 7 is reduced and the inclination with respect to the short axis of the panel 3 is eliminated, so that the meandering of the striped black non-light-emitting layer 20 and the three-color phosphor layers 21B, 21G and 21R is effectively eliminated and smoothed. Stripes.

That is, on the linear light source 36, a direction perpendicular to the major axis is defined as a facing long side, and a barrel-shaped opening 37 is formed in which the distance between the centers of the facing long sides is wider than the distance between the ends. When the angle of light radiated from the linear light source 36 through the opening 37 with respect to a normal line perpendicular to the shield 38 increases, the linear light source viewed from the panel 3 side along the light increases. 36 becomes shorter. Therefore, FIG.
As shown in (b), the distance from the long axis and the short axis of the panel 3 corresponding to the length of the linear light source 36 corresponds to the opening of the shadow mask printed on the photosensitive phosphor screen forming layer. As for the length of the pattern 47, the length of the light source becomes shorter.

On the other hand, when the cylindrical aspherical lens 39 is not provided, as shown in FIG. 8A, a shadow mask which is printed on the photosensitive phosphor screen forming layer as the distance from the long axis and short axis of the panel increases. Pattern 4 corresponding to opening
7 is inclined with respect to the short axis of the panel, but when the cylindrical aspheric lens 39 is arranged, the trajectory of light from the linear light source 36 is corrected, and as shown in FIG. The pattern 4 corresponding to the opening of the shadow mask which is printed on the photosensitive phosphor screen forming layer as the distance from the axis and the minor axis increases.
7 is reduced.

That is, the aspherical surface of the cylindrical aspherical lens 39 is calculated using the coefficients a1 to a8 of the fourth-order polynomial shown in equation (1).
In a conventional simple cylindrical lens, the radius of curvature in the long axis direction of the light source is constant in the orthogonal direction, so that the inclination of the pattern corresponding to the aperture of the shadow mask can be reduced. When the inclination of the pattern 47 corresponding to the opening of the shadow mask is reversed from the short axis end to the middle of the long side to the diagonal end of the panel, the correction cannot be sufficiently made. Pattern 4 corresponding to the opening of these shadow masks.
7 can be effectively corrected.

As a result, when the fluorescent screen is formed by using the exposure device in which the shield 38 in which the barrel-shaped opening 37 is formed and the cylindrical aspherical lens 39 are arranged, as the distance from the long axis and the short axis of the panel 3 increases. The length of the pattern 47 corresponding to the resulting slit-shaped opening of the shadow mask is reduced and the inclination is eliminated, so that the stripe-shaped black non-light-emitting layer and the three-color phosphor layer are formed in a smooth stripe that does not meander effectively. It can be.

[0037]

As described above, according to the present invention, the pattern corresponding to the opening of the shadow mask which is printed on the photosensitive phosphor screen forming layer as the distance from the long axis and the short axis of the panel increases, increases with respect to the short axis of the panel. By eliminating the inclination, the stripe-shaped black non-light-emitting layer and the three-color phosphor layer can be effectively formed into smooth stripes without meandering.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an exposure apparatus for forming a fluorescent screen of a color picture tube according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration of a light source unit of the exposure apparatus.

FIG. 3 is a diagram showing a relationship between an opening of a shield of the exposure apparatus and a linear light source.

FIG. 4 is a diagram showing a relationship between a light source of the exposure apparatus and a cylindrical aspheric lens.

FIG. 5 is a diagram showing a specific curved surface of the cylindrical aspheric lens.

FIG. 6 is a diagram showing specific different curved surfaces of the cylindrical aspherical lens.

FIGS. 7A to 7G are diagrams showing main steps of a method of forming a fluorescent screen of a color picture tube, respectively.

FIG. 8 is a view for explaining the operation of the shield and the cylindrical aspherical lens. FIG. 8A is a view of a pattern corresponding to the opening of a shadow mask by a conventional exposure apparatus shown for comparison. FIG. 8B is a diagram of a pattern corresponding to the opening of the shadow mask by the exposure apparatus according to the embodiment of the present invention.

FIG. 9 is a diagram showing a configuration of a color picture tube.

FIG. 10 is a diagram showing the relationship between a black non-light-emitting layer and a three-color phosphor layer constituting a phosphor screen of the color picture tube and the openings of a shadow mask.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Effective part 3 ... Panel 8 ... Shadow mask 17 ... Opening of shadow mask 31 ... Photosensitive fluorescent screen forming layer 36 ... Linear light source 37 ... Shield opening 38 ... Shield 39 ... Cylindrical aspheric lens 47 ... Shadow mask Pattern corresponding to the opening of

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Fumito Suzuki 1-9-2, Hara-cho, Fukaya-shi, Saitama F-term in Toshiba Fukaya Plant (reference) 5C028 GG03

Claims (7)

[Claims] 1. A light emitting device according to claim 1, wherein a plurality of slits are formed on a photosensitive phosphor screen forming layer formed on an inner surface of an effective portion of the substantially rectangular panel through a bridge in a short axis direction of the panel by light emitted from a linear light source. In a method for forming a phosphor screen of a color picture tube, comprising a step of printing a stripe pattern corresponding to a row of apertures of a shadow mask in which holes are arranged, a long axis of the linear light source is arranged as a short axis direction of the panel. A cylindrical aspheric lens is disposed between the linear light source and the shadow mask, and an axis in the same direction as the cylindrical axis of the cylinder which is the basis of the lens is arranged as a direction orthogonal to the long axis of the light source. The fluorescent light of a color picture tube, wherein the inclination of a pattern corresponding to the slit-shaped aperture to be printed on the photosensitive phosphor screen forming layer by a cylindrical aspherical lens with respect to a long axis of the light source is corrected. Forming method. 2. A light emitting device according to claim 1, wherein a plurality of slits are formed on a photosensitive phosphor screen forming layer formed on an inner surface of an effective portion of the substantially rectangular panel through a bridge in a short axis direction of the panel by light emitted from the linear light source. In a method for forming a phosphor screen of a color picture tube, comprising a step of printing a stripe pattern corresponding to a row of apertures of a shadow mask in which holes are arranged, a long axis of the linear light source is arranged as a short axis direction of the panel. A cylindrical aspheric lens is arranged between the linear light source and the shadow mask, and an axis in the same direction as the cylindrical axis of the cylinder which is the basis of the lens is arranged as a direction orthogonal to the long axis of the light source. The shield is provided with a barrel-shaped opening in which a direction perpendicular to the long axis of the light source is a long side and a space between central portions of the long sides is wider than a space between the ends. Up by lens At the same time as correcting the inclination of the pattern corresponding to the slit-shaped aperture to be printed on the photosensitive phosphor screen forming layer with respect to the major axis of the light source, the slit-shaped aperture to be printed on the photosensitive phosphor screen forming layer by the opening of the shield. A method of forming a phosphor screen for a color picture tube, comprising: correcting a length of a pattern corresponding to a hole in a major axis direction of the light source. 3. A shadow mask in which a plurality of slit-shaped openings are arranged on a photosensitive phosphor screen forming layer formed on an inner surface of an effective portion of a substantially rectangular panel through a bridge in a short axis direction of the panel. In an exposure apparatus for forming a fluorescent screen of a color picture tube having a linear light source for printing a stripe pattern corresponding to a row of apertures, the linear light source is disposed with a long axis as a short axis direction of the panel. This lens is basically a cylindrical aspheric lens that corrects the inclination of the pattern corresponding to the slit-shaped apertures to be printed on the photosensitive phosphor screen forming layer between the light source and the shadow mask with respect to the long axis of the light source. An exposure apparatus for forming a fluorescent screen of a color picture tube, wherein an axis in the same direction as a cylinder axis of a certain cylinder is arranged as a direction orthogonal to a long axis of the light source. 4. A shadow mask in which a plurality of slit-shaped openings are arranged on a photosensitive phosphor screen forming layer formed on an inner surface of an effective portion of a substantially rectangular panel through a bridge in a short axis direction of the panel. In an exposure apparatus for forming a fluorescent screen of a color picture tube having a linear light source for printing a stripe pattern corresponding to a row of apertures, the linear light source is disposed with a long axis as a short axis direction of the panel. This lens is basically a cylindrical aspheric lens that corrects the inclination of the pattern corresponding to the slit-shaped apertures to be printed on the photosensitive phosphor screen forming layer between the light source and the shadow mask with respect to the long axis of the light source. An axis in the same direction as the cylinder axis of a certain cylinder is arranged as a direction orthogonal to the long axis of the light source, and a direction orthogonal to the long axis of the light source is an opposing long side. end A shield provided with a barrel-shaped opening that corrects the length of the light source in the long axis direction of a pattern corresponding to the slit-shaped opening that is printed on the photosensitive phosphor screen forming layer wider than the gap between the light source and the light-emitting layer is disposed. An exposure apparatus for forming a fluorescent screen of a color picture tube. 5. A cylindrical aspherical lens having a flat light source side.
The shadow mask side is a curved surface, and the center of this curved surface is
The origin of the mark, the coordinate in the direction orthogonal to the long axis of the light source is x,
The coordinates of the light source in the major axis direction are y, and a1 to a8 are coefficients.
When the curved surface on the shadow mask side is expressed by the following fourth-order polynomial Z (x, y) = a1 x^Two + A2 x^Four + A3 y^Two + A4 x
^Two y^Two + A5 x^Four y ^Two+ A6 y^Four + A7 x^Two y^Four + A8
x^Four y^Four 4. An aspherical surface represented by the following formula:
Or an exposure apparatus for forming a fluorescent screen of a color picture tube according to 4. 6. An average curvature in the major axis direction of the light source of the curved surface on the shadow mask side of the cylindrical aspherical lens is the largest between the center of the cylindrical aspherical lens and the end in the direction orthogonal to the long axis of the light source. 6. A value or a minimum value.
The exposure apparatus for forming a fluorescent screen of a color picture tube according to the above. 7. The light source according to claim 1, wherein the curvature of the curved surface of the cylindrical aspherical lens on the shadow mask side in the major axis direction is a maximum value between an axis perpendicular to the major axis of the light source and the major axis end of the light source. 6. The exposure apparatus for forming a fluorescent screen of a color picture tube according to claim 5, wherein the minimum value is taken.