JPH04123747A - Manufacture of color picture tube - Google Patents

Abstract

PURPOSE:To form a phosphor screen of a dot type color picture tube with a good characteristic by moving a light source synchronously with the movement of a shutter, in parallel with the movement of the shutter, on a flat surface including a tube axis, and by varying the shape of the opening of the shutter. CONSTITUTION:An opening 50 of a shutter 23 is long in the direction of a long shaft or of a short shaft of a panel 1, and is moved in the direction that crosses with the long shaft of the opening, while an exposure region is limited. The landing of a correcting lens 22 is matched with that in the direction of the movement of the shutter 23 on a phosphor screen, when a light source 20 is at origin. The landing in the same direction with the shutter is adjusted in such a way that the shape of the opening 50 of the shutter is changed correspondent to the irradiation region where the landing in the same direction as the movement of the shutter of a light beam passing the opening from a moved light source, is almost the same with the case when the light source is at the origin. In this structure, the good landing characteristic over the entire surface of the phosphor screen for a dot type color picture tube, is obtained.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention relates to a method of manufacturing a color picture tube, in which a dot-shaped phosphor screen is formed so as to obtain particularly good landing characteristics. The present invention relates to a method of manufacturing a color picture tube.

(Prior Art) Generally, a color picture tube has an envelope consisting of a panel J and a funnel 2, as shown in FIG. A fluorescent screen 4 is formed on the inner surface of the panel 1, facing the shadow mask 3. The phosphor screen 4 is composed of a striped or dot-shaped three-color phosphor layer that emits blue, green, and red light. In addition, in order to improve the contrast of the screen, a non-luminous layer mainly composed of carbon or the like is provided in the gaps between the three-color phosphor layers, resulting in a so-called black stripe type or black matrix type.

The image is displayed on the phosphor screen 4 using three electron beams 6 emitted from an electron gun 5 built into the neck of the funnel 2.
B, 6G, and 6R are deflected in the horizontal and vertical directions by a magnetic field formed by a deflection yoke 7 attached to the outside of the funnel 2, and the phosphor screen 4 is scanned. Therefore, in order to display an image with good color purity on this phosphor screen 4, as shown in FIG.
, 6G, 6R correspond to phosphor layers 9B, 9G,
It is necessary to shoot at 9R correctly. In particular, the three-color phosphor layer 98 for the through hole 8 of the shadow mask
．． The positions of 9G and 9R are the respective electron beams 6B, 6G,
According to the deflection angle of 6R, its apparent injection position (
Since the deflection center) changes, each corresponding phosphor layer 9B,
In order for the electron beams 6B and 6G6R to strike correctly on the electron beams 9G and 9R, the three-color phosphor layer 9 must be aligned with the through hole 8 of the shadow mask 3 at each point on the inner surface of the panel l.
It is necessary to change the positions of B, 9G, and 9R.

On the other hand, conventionally, as shown in FIG. 12, a phosphor screen is made by coating the inner surface of the panel with a phosphor slurry mainly composed of phosphor and photosensitive resin, drying it, and then exposing the coating 40 to light through a shadow mask 3. By doing this, a pattern is printed in the through holes 8 of the shadow mask 3, and then developed and the unexposed portions are removed to form a phosphor layer of any one color. Then, this process is repeated for three color phosphor layers. In particular, for a phosphor screen having a non-emissive layer, a photosensitive resin is applied prior to the formation of the three-color phosphor layer,
After forming a photosensitive resin pattern corresponding to the through hole 8 of the shadow mask 3 at the position where the three-color phosphor layer is formed using a similar method, a non-luminescent paint is applied, and then this non-luminescent paint is made photosensitive. It is manufactured by peeling off the resin pattern together with the resin pattern to form a non-emissive layer having voids at the positions where the three-color phosphor layer is to be formed.

In the case of either the phosphor layer or the non-emissive layer, in the exposure process, as shown in FIG. An exposure apparatus is used in which a correction lens 12 is arranged to approximate the trajectory of the light 11 to the trajectory of the electron beam. Note that 13 is a shutter for partially exposing the film, and 14 is an opening for controlling the exposed area. Using an orthogonal coordinate system in which the reference position of the light source 10 is the origin, the optical axis that coincides with the tube axis is the X axis, and the short and long axes of the panel I are the y and Z axes, the shutter 13 is usually It has a long frontage 14 in two directions and moves in the y direction without restricting the exposure area.

A spherical lens was once used as the correction lens 12, but as the structure of color picture tubes has become more complex, it has become impossible to correct the trajectory of light with a simple lens. An aspherical lens having a shape is used.

The surface height X from the lens bottom surface at any point on the surface of this aspherical lens is generally expressed by a polynomial of y and z. Correction lens I made using such a polynomial
The design of 2 is based on the light source IO for the amount of change of each coefficient of the polynomial.
It is designed to track how the light 11 emitted from the phosphor screen 4 changes over the entire surface of the phosphor screen 4, and to keep the error between the incident position of the electron beam and the entire surface of the phosphor screen 4 below a certain value (usually 10 microns). be done. However, even if designed using this method, it is relatively easy to reduce the error at a limited number of points on the correction lens I2, but it is possible to reduce the error at any point on the correction lens by setting a coefficient. Even if you set
Since the coefficient generally acts to increase the error at most other points, it is extremely difficult to design the error so that it is less than a desired error at all points on the phosphor screen. Even if a high-performance, ultra-high-speed computer is used, not only is it time-consuming to design, but changing the coefficients often requires judgment based on extensive experience. Furthermore, there is a limit to the correction that can be made using continuous curved surfaces.

In other words, a continuous curved surface generally only has the degree of freedom to match the landing in only the y direction or only in two directions. Therefore, for a striped color picture tube where the landing in the y direction can be ignored, correction can be made using a continuous curved surface, but for a dot type color picture tube where the landing in both the y direction and two directions needs to be matched. It is generally impossible to correct only continuous curved surfaces. However, if the deflection is approximately 90°, the characteristics of the deflection magnetic field are close to those that can be expressed by a continuous curved surface, so that a somewhat satisfactory correction can be performed. However, for color picture tubes with wide deflection angles such as 110° deflection, it has been impossible to perform sufficient correction using continuous curved surfaces.

In addition, as a design method for other correction lenses,
40983 and Japanese Patent Publication No. 49-22770, as shown in FIGS. 14(a) and (b), a correction lens 1 is provided.
2 into multiple parts and determine the slope of the surface for each part. Such a method is
It is possible to precisely match the trajectory of light during exposure to the trajectory of the electron beam for each divided portion. However, since a step 15 is formed at the boundary between the divided parts, this is particularly difficult for a black stripe type or black matrix type phosphor screen 4 in which a non-emissive layer is provided between the three color phosphor layers. The phosphor screen 4 is likely to have unevenness due to non-uniform light intensity caused by the step 15. As a way to solve this,
There are methods of swinging the correction lens 12 during exposure and methods of shielding the step portion from light, but neither of these methods can reduce the unevenness of the phosphor screen 4 to a sufficiently satisfactory quality.

(Problems to be Solved by the Invention) As mentioned above, in general, in manufacturing the phosphor screen 4 of a color picture tube, a coating of phosphor slurry or photosensitive resin formed on the inner surface of the panel 1 is coated with the through holes of the shadow mask. The light 11 emitted from the light source 10 when printing the corresponding pattern
A correction lens 12 is used to approximate the trajectory of the electron beams 6B, 6G, and 6R deflected by the magnetic field formed by the deflection yoke.

However, when a continuous curved surface expressed by a polynomial or the like is used as the surface shape of the correction lens 12, it is insufficient to correct a dot-type color picture tube, and especially 110
For wide deflection angles such as ° deflection, it has generally been impossible to perform corrections. In the case of a dot-type color picture tube, it is necessary to match the landing in both the y direction and two directions, but in general, for continuous curved surfaces, only the y direction or two directions are required.
This is because the only degree of freedom is adjusting the landing in one direction.

Furthermore, a method has been proposed in which the correction lens 12 is divided into a plurality of parts and the slope of the surface is determined for each divided part, but in this case, although it is possible to perform the necessary correction for each part, Since the step 15 is formed at the boundary, the phosphor screen 4 becomes uneven. Even if a method of swinging the correction lens 12 or shielding the stepped portion is used to avoid this, the unevenness of the phosphor screen 4 cannot be reduced to a sufficiently satisfactory quality.

The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a means for forming a phosphor screen of a dot-type color picture tube, which has conventionally been difficult to manufacture, in a sufficiently satisfactory manner.

[Structure of the Invention (Means for Solving the Problems)] In order to achieve the above object, the present invention forms a film of photosensitive resin or phosphor slurry on the inner surface of the panel, and a light source is applied to this film through a shadow mask. A phosphor screen is formed on the inner surface of the panel by irradiating it with light from above to print a pattern corresponding to the through holes of the shadow mask on the film, and then developing it to form a non-emissive layer or a phosphor layer. In the method of manufacturing a color picture tube, a shutter is moved in one direction while limiting the irradiation area of the light from the light source to the coating formed on the inner surface of the panel, and is provided with a shutter for a long time in a direction perpendicular to the direction of movement. , is placed between this shutter and the upper W1 light source, and the light source is the origin number on the tube axis.

At some point, a correction lens having a shape that has a q-landing in the same direction as the shutter movement direction is used to move the light source in synchronization with the movement of the shutter into a position parallel to the movement direction of the shutter and including the tube axis. The shape of the aperture of the shutter is changed so that the light ray from the moved light source that passes through the aperture of the shutter lands in the same direction as the moving direction of the shutter. The coating is determined to correspond to an irradiation area that is approximately the same as when it was at the origin, and the landing in the direction perpendicular to the moving direction of the shutter in the irradiation area is adjusted by the amount of movement of the light source. The method is characterized in that a pattern corresponding to the through-holes of the shadow mask is printed.

(Function) The light emitted from the light source is refracted by the correction lens, passes through the opening of the shutter and the through hole of the shadow mask, and reaches a predetermined point on the curved surface of the panel. Here, the opening of the shutter is long in the long or short axis direction of the panel, and moves in a direction perpendicular to the long axis of the opening while limiting the exposure area.

When the surface shape of the correction lens is a continuous curved surface, it is generally impossible to align the landings in both the long axis and short axis directions of the panel, assuming that a shutter is not used and the light source is not moved. However, it is generally possible to design a continuous curved surface that can accommodate unidirectional landings only in the long sleeve direction or short axis direction of the panel. Therefore, the correction lens is designed so that when the light source is at the origin, the landing of the shutter in the moving direction matches the fluorescent screen.

On the other hand, the landing in the direction perpendicular to the moving direction of the shutter is adjusted by moving the light source. In other words, the light source is synchronized with the movement of the shutter so that the landing in the same direction as the movement direction of the shutter in the irradiation area limited by the shutter is not changed, and the landing deviation in the direction perpendicular to the movement direction of the shutter is corrected. and move the shutter in a plane parallel to the moving direction of the shutter and including the tube axis.

However, if the shape of the shutter aperture is constant, it is generally impossible to prevent the landing from changing in the same direction as the shutter movement throughout the corresponding irradiation area, and as it approaches the edge of the shutter, The landing gradually shifts. This is mainly because the cross shape of the planar light passing through the curved panel and the shutter opening is a curve.

Therefore, the shape of the shutter aperture is adjusted to correspond to the irradiation area where the landing of the light ray passing through the shutter aperture from the moved light source in the same direction as the shutter movement direction is approximately the same as when the light source is at the origin. By changing the shape, it is possible to adjust the landing in the same direction as the shutter movement direction.

In this way, by moving the shutter and determining the position of the light source and simultaneously changing the shape of the aperture, it is possible to form a phosphor screen for a dot-type color picture tube so that good landing characteristics can be obtained over the entire surface. .

(Example) Hereinafter, the present invention will be described based on an example with reference to the drawings.

FIG. 1 shows a configuration of an exposure apparatus used in the present invention. This exposure apparatus has a support stand 30 that positions and supports a panel l having a coating 40 of photosensitive resin or phosphor slurry formed on its inner surface, and an exposure light source 20 is installed below this support stand 30. . As the light source 20, a water-cooled or air-cooled ultra-high pressure mercury lamp is usually used, but a laser beam or one that emits laser light through a light guide such as an optical fiber can also be used. A shutter 23 is disposed below the support 30, and a correction lens 22 is disposed between the shutter 23 and the light source 20.

A rack 32 is attached to the lower part of the light source 20, and a pinion 34 attached to the light source support 33 allows the X
It is possible to move freely in any direction.

A rack 35 is attached to both ends of the light source support 33, and can be freely moved in the X direction by a pinion 36. Such a mechanism allows the light source 20 to be moved within the xy plane.

The correction lens 22 is designed so that when the light source 20 is at the origin 0, the landing in the X direction is aligned with the entire inner surface of the panel. Furthermore, it is possible to match the landings in two directions on the z-axis, and the design is designed to do so.

A rack 41 is attached to the shutter 23 and can be moved in the X direction by a pinion 42. Further, the shutter 23 is provided with an opening 50 that is long in two directions, and an opening shape control mechanism 60 is arranged to change the shape of the opening 50 that is long in two directions.

This opening shape control mechanism 60 will be explained with reference to FIGS. 2 and 3. The opening 50 is formed by a rubber film 61 that blocks light. An aperture shape control rod 62 is fixed to the end of the membrane 61. A rack 63 is provided on a part of the control rod 62, and is movable in the X direction by a pinion 64. Furthermore, by moving the plurality of control rods 62, the rubber membrane 61 expands and contracts, and the opening 5
The shape of 0 can be changed.

In this embodiment, the number of control rods 62 is three on each side, but in general, any number may be used, and the more control rods 62, the more delicate control becomes possible. It may be determined as appropriate depending on the required landing characteristics. Pinion 64 is driven by motor 65. Although not shown, the pinions 34 and 36 for moving the light source and the pinion 42 for moving the shutter are also driven by the motor.

All motors are digitally controlled so that the movement of the light source 20, the movement of the shutter 23, and the change in the shape of the aperture 50 are coordinated.

Next, the amount of movement of the light source 20 and the change in shape of the aperture 50 of the shutter 23 will be explained using FIGS. 4 to 9.

Now, the shutter 23 has a long frontage 5 in two directions as described above.
0 and moves in the X direction. In FIG. 4, light 21 emitted from a light source 20 is refracted and refracted by a correction lens 22, and reaches a predetermined point on the curved surface of the panel l through an aperture of a shutter (not shown) and a through hole of a shadow mask.

When the surface shape of the correction lens 22 is a continuous curved surface, it is generally impossible to match the landings in both the X direction and the two directions, assuming that a shutter is not used and the light source is not moved. However, it is generally possible to design a continuous curved surface that can match the landings in only the X direction or in only two directions. Now, let us assume that the correction lens 22 is designed so that when the light source 20 is at the origin 0, the landing of the panel in the X direction is aligned with the entire surface of the phosphor screen. Also,
It is possible to match the landings in two directions on the z-axis, and it is assumed that this is done.

At this time, the landing generally looks like the one shown in FIG. Normally, the landing pattern is symmetrical with respect to the y-axis and the z-axis, so the figure shows an area of 2≧0 and y≧0. An arrow 71 indicates a landing, and the difference between the arrival points of a light ray passing through the same shadow mask hole and an electron beam is shown on an arbitrary scale with respect to the light ray from the light source. If the design is such that the landing in the
Landing direction does not match.

Therefore, in order to align the landings in these two directions, the light source 20 is moved in a plane that is parallel to the moving direction (X direction) of the shutter 23 and includes the tube axis (X direction). This will be explained using FIG. 6. Now, for simplicity, panel l
It is assumed that the inner coating 40 and the mask 3 are parallel to each other, and there is no correction lens.

In FIG. 6(a), the light source 20 is connected to the light beam 2 on the xy plane.
Even if the light ray 21 is moved from the origin O to OI along the direction 1, the arrival point of the light ray 21 in the X direction remains unchanged and the landing does not change. At this time, regarding landing in two directions, the arrival point of the light ray 21 moves from P to Pl, as shown in FIG. 6(b) representing the AB plane of FIG. 6(a). In this way, by changing the light source 20 along the direction of the light ray toward the point on the y-axis corresponding to the position of the shutter 23, it is possible to adjust the landing in the y-direction.

However, in reality, the correction lens and panel have complex curved surfaces, so even if you move the light source so that the landing in the y direction does not change on the y axis, the landing in the y direction will change as you move away from the y axis. It's changing. This is mainly because, as shown in FIG. 7, the intersection of the curved panel l and the planar light 70 passing through the opening 50 of the shutter 23 forms a curve. However, y
There is a region where the landing direction does not change, and it is possible to determine this by simulating the trajectory of the light using a computer. This is illustrated in FIG. 8. FIG. 8 shows the yz plane at the position of the shutter 23 in FIG.
The changes in the landing of the light rays that have passed through the aperture 50 are shown in arbitrary units with reference to when the light source 20 is at the origin. If the shape of the opening 50 of the shutter 23 is linear like 81, the landing will change not only in the two directions but also in the y direction. Therefore, by making the shape of the opening 50 of the shutter 23 like the shape 82 determined by a computer, it is possible to eliminate the change in the landing in the y direction. Furthermore, since the landing shift in the y direction varies depending on the position of the shutter 23, the shape of the opening is changed in synchronization with the movement of the shutter 23. Due to this change in the shape of the frontage 50, the shutter 23 moves in the same direction (y direction).
The landing can be adjusted. Furthermore, since the landing 73 in the direction (two directions) orthogonal to the movement of the shutter 23 also changes due to the movement of the light source 20 as described above, by adjusting the amount of movement of the light source 20,
Mislanding when the light source 20 shown in the figure is at the origin 0 can be offset.

Therefore, by determining the shape of the opening 50 of the shutter 23 corresponding to the curve 82 and performing exposure, it is possible to match the landing in both the y and z directions. In this way, by moving the shutter 23 and determining the position of the light source 20, at the same time changing the shape of the aperture 50 to correspond to the area where the landing in the y direction does not change,
Good landing characteristics can be obtained over the entire surface.

Note that, in general, it is not necessary to set the characteristics of the correction lens so that the landing in the y direction is zero.

The amount of movement of the light source and the change in the shape of the aperture may be determined in accordance with the characteristics of the correction lens. However, the above method is preferable because it is easier to move the light source and determine the shape of the aperture.

FIG. 9 shows how the shape of the opening 50 changes. The shape of the opening 50 of the shutter 23 is indicated by the position of the center of the opening 50, and since it is symmetrical about two axes, the y-axis, 2≧0 and y≧0 are illustrated. It is better to make the width of the opening 50 small from the viewpoint of landing, but it is better to make it large in consideration of the time required for exposure, and the width is determined by taking these points into consideration. Additionally, in order to adjust the amount of light, it is generally necessary to increase the width toward the ends. This shape is created in this embodiment by a control rod 62 shown in FIG. If the position of the center of the opening 50 is YA (0) and the position of the opening 50 in the long axis direction is YA (Z), then U (z) = Y (Z) YA (0) 8
^ represents the difference between the center and the periphery of the aperture at the moved position, that is, the change in the curvature of the aperture shape.

If the X+V coordinates of the moving light source are xo, yo, then 20
In the case of an inch color picture tube, the values of UA (z)"o"o are as shown in Table 1.

This is shown in Table 1. At this time, the difference between the two directions and the target landing characteristics in the y direction is δ2. When δy is taken as δy, δ2 and δy could be set to a maximum of 9 μm and 12 μm, respectively. This is δ2 in the case where the aperture shape is not changed. It can be seen that the landing characteristics are improved compared to the maximum value of δy of 12 μm and 49 μm.

As described above, according to the present invention, by moving the shutter and changing the shape of the shutter opening, the exposure area of the coating on the inner surface of the panel is restricted, and the light source is adjusted in accordance with the exposure area. It is possible to form a phosphor screen for a dot-type color picture tube that is movable and has good landing characteristics.

Note that in the above embodiment, a shutter with long openings in two directions is moved in the y direction, and the light source is moved within the xy plane. The light source may be moved within the xz plane.

In addition, the correction lens used does not have to have a continuous curved surface,
A correction lens having a step on its surface may also be used.

Furthermore, the shutter 23, light source 2θ, and control rod 62 are moved by a rack, pinion, and motor.
The movement method is not limited to this. A belt or wire may be used, or pneumatic pressure or hydraulic pressure may be used.

As long as you can make the necessary move, you can choose any means you like.

[Effects of the Invention] According to the present invention, the phosphor screen of a dot-type color picture tube can be formed with good characteristics. In particular, it is possible to form, with good quality, a phosphor screen for a color picture tube with a wide deflection angle, which was impossible to manufacture using only a correction lens using a continuous curved surface, and its industrial value is great.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the exposure apparatus used in the present invention, FIG. 2 is a schematic plan view showing the shutter aperture shape control mechanism in FIG. 1, and FIG. 3 is the aperture shape in FIG. 2. 4 is a schematic perspective view showing the principle of the correction lens in FIG. 1; FIG. 5 is a diagram explaining the landing in FIG. 4; FIGS. 6(a) to (b)
) is a diagram explaining the change in landing when the light source is moved, Figure 7 is a diagram showing the change in landing due to the movement of the shutter, Figure 8 is a diagram showing the change in the shutter aperture shape and landing, and Figure 9 is a diagram showing the change in landing when the light source is moved. The figure shows changes in the shape of the shutter aperture, Figure 10 is a cross-sectional view showing the configuration of a color picture tube, and Figure 11 is a diagram explaining the landing of three electron beams on the three-color phosphor layer of the phosphor screen. , FIG. 12 is a block diagram for explaining the manufacturing method of the phosphor screen, the first
FIG. 3 is a sectional view showing a conventional exposure apparatus, and FIGS. 14(a) and 14(b) are a plan view and a sectional view, respectively, of a correction lens divided into a plurality of parts. l...Panel 3...Shadow mask 10, 20...Light source 12.22...Correction lens H, 23...Shutter 50...Aperture 40...Coating 61...Rubber film 6
2...Aperture shape control rod agent Patent attorney Nori Ken Yudo Chika Kikuo Takehana Figure bl Figure Figure Figure (a) (b) Figure Figure Figure Figure Figure Figure Figure Figure ( b Figure ［〉） ``Figure

Claims (1)

[Claims] A film of photosensitive resin or phosphor slurry is formed on the inner surface of the panel, light from a light source is irradiated to this film through a shadow mask, and the film corresponds to the through holes of the shadow mask. In a method for manufacturing a color picture tube, in which a phosphor screen is formed on the inner surface of the panel by printing a pattern and then developing it to form a non-emissive layer or a phosphor layer, the light source for the coating formed on the inner surface of the panel. A shutter is placed between the shutter and the light source, which moves in one direction while limiting the irradiation area of the light, and has a long opening in a direction perpendicular to the direction of movement. Using a correction lens having a shape that matches the landing in the same direction as the moving direction of the shutter when it is at the origin, the light source is directed in synchronization with the movement of the shutter into a plane parallel to the moving direction of the shutter and including the tube axis. The shape of the aperture of the shutter is changed so that the light ray from the moved light source that passes through the aperture of the shutter lands in the same direction as the moving direction of the shutter. By determining the irradiation area to correspond to an irradiation area that is approximately the same as when it was at the origin, and adjusting the landing in the direction perpendicular to the moving direction of the shutter in the irradiation area by the amount of movement of the light source, the above-mentioned A method of manufacturing a color picture tube, comprising printing a pattern corresponding to the through holes of the shadow mask on the film.