JPH0574345A - Manufacture of color cathode-ray tube - Google Patents

Abstract

PURPOSE:To reduce the correction quantity of a correcting lens and manufacture a highly precise dot type color fluorescent screen easy to manufacture by properly regulating the distance from the slit opening position of a douser to the central axis of a long arc mercury lamp. CONSTITUTION:A long arc mercury lamp 2 of a light source is provided so that its longitudinal direction is parallel to the horizontal direction of a panel, and a douser 5 having a slit is provided so that the slit is parallel to the vertical direction of the panel 1. A fluorescent screen-completed panel is placed on this exposing device, and the distance between the light source and the panel is regulated while microscopically observing the light spot 3 emitted by the mercury lamp 2 to be conformed with the hole 4 of a black matrix film situated in the corresponding position thereto on the end parts of the vertical and horizontal directional lines passing the panel center. Further, the difference in position between the light spot 3 and the hole 4 is measured in four corner positions of the panel 1, and on the basis of the resulting average, the lateral end position of the slit 5 is corrected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shading plate which is used in combination with a fixed long arc mercury lamp light source when a fluorescent surface for a color cathode ray tube in which dots of three primary color phosphors are arranged is formed by an exposure method. By appropriately defining the distance from the slit opening position to the central axis of the mercury lamp, the correction amount for the exposure light rays to be shared and corrected by the correction lens is reduced.
The present invention relates to a method for manufacturing a color cathode ray tube that uses a correction lens that is easy to make and has high accuracy.

[0002]

2. Description of the Related Art In a color cathode ray tube having a dot-type fluorescent surface, an electron beam for a specific primary color which has passed through a specific hole of a shadow mask has dots of three primary color phosphors on a back surface of a panel. The dots of the specific primary color of the arrayed color cathode ray tube must be projected to emit light. The three electron beams dedicated to the three primary colors, which have passed through the same hole of the shadow mask, strike the fluorescent dots of the respective colors due to the different trajectories of the respective electron beams. Therefore, when performing an exposure operation for forming a black matrix film for antireflection and contrast enhancement or a phosphor dot by the photolithography technique, the inclination angle of the light ray when the exposure light ray passes through the hole of the shadow mask and The direction should be the same as when each electron beam passed through its hole in the shadow mask. On the other hand, since the electron beam of the color cathode ray tube is electromagnetically bent by the deflection magnetic field of the deflection yoke, it does not go straight like a light beam, but has a curve that gradually curves. In the exposure device for forming the fluorescent surface of the color cathode ray tube, the inclination angle and direction of the exposure light beam when passing through the shadow mask should be the same as the electron beam, as described above. The correction lens is used to correct the direction of the light beam incident on each part of the correction lens. As can be easily understood from the above description, the correction lens is a surface having a very complicated curved surface, or a set of minute planes having inclinations that change the direction of the light ray at each incident / emission site of the light ray as desired. Have.

The exposure device for forming the fluorescent surface of the color cathode ray tube uses, in addition to the correction lens, a light amount for canceling the influence of the difference in the distance from the light source to the exposure surface and making the light amount per unit area uniform. It must also have a correction filter. Also, the color cathode ray tube is a mass-produced product, and the exposure time must be short. Therefore, it is necessary to select a light source with as high brightness as possible, and currently high-pressure or ultra-high-pressure mercury lamps are generally used. There are various types such as a plate which is brought close to a point light source by combining plates and a short arc mercury lamp which has extremely high brightness due to direct current lighting and is close to a point light source. Under the circumstances as described above, many proposals have been made for the exposure apparatus. For example, combining a long arc mercury lamp with a shading plate with a relatively large slit width, rotating it about an axis perpendicular to the mercury lamp axis, and providing a movable slit plate opened in a direction parallel to the mercury lamp axis to rotate the mercury lamp. A technique for changing the distance between the slit plate and the mercury lamp in synchronism with the above-mentioned technique to obtain a large amount of light and close to a point light source is disclosed in Japanese Patent Laid-Open No. 2-9.
No. 4227 discloses a method of exposing a fixed long arc mercury lamp light source with a slit having a width substantially equal to the effective arc diameter. Cover with a wide slit, move intermittently in the slit direction, give swinging motion or elliptical motion,
A technique for producing a large amount of light and a light source close to that of a point light source is disclosed in JP-A-61-99245 and JP-A-63-28974.
It is disclosed in Japanese Patent Publication No. 2 and the like.

[0004]

As described above, in order to approximate the trajectory of the light beam from the exposure light source to the trajectory of the deflected electron beam, a correction lens is used in the exposure apparatus. The trajectory of the electron beam varies depending on the type and specifications of the deflection yoke used in combination with the color cathode ray tube. Therefore, it is necessary to use a correction lens that is suitable for the type and specifications of the deflection yoke. In the conventional general deflection yoke, a so-called saddle winding coil was used for horizontal deflection and a toroidal winding coil was used for vertical deflection. In recent years, a large number of terminal displays for information processing are closely arranged and used. In some cases, a deflection yoke using a saddle winding has been used both horizontally and vertically so that the leakage magnetic field of the deflection yoke does not affect a nearby display. In the deflection yoke, the inside (panel side) of a funnel-shaped holder that is usually called a so-called separator is used.
The horizontal deflection coil is arranged on the outer side of the holder (on the side of the electron gun) to hold the vertical deflection coil. This is because the horizontal deflection angle is generally larger than the vertical deflection angle. But,
In recent years, a vertically long screen may be used in some terminal displays for information processing. However, when the vertical deflection angle is larger than the horizontal deflection angle, the vertical deflection coil is attached to the panel side of the separator. Then, the horizontal deflection coil is arranged on the electron gun side of the separator. Since the positions of the horizontal and vertical deflection coils are displaced in the tube axis direction in this way, the position of the horizontal deflection center is usually on the panel side, the position of the vertical deflection center is on the electron gun side, and in the case of a vertically long screen, On the contrary, there is a shift (this shift is hereinafter referred to as HV shift). The HV shift tends to be large in the deflection yoke in which the saddle winding is used for both the horizontal deflection and the vertical deflection. In the conventional exposure light source, the correction lens of the exposure apparatus for forming a fluorescent surface was designed so as to correspond to the trajectory of the light beam from the point light source emitted from almost one point. If it is attempted to correct the correction including the HV shift, the specification of the correction lens becomes very strict, which causes problems such as difficulty in manufacturing the lens and poor accuracy of the finished lens.

The present invention solves the above-mentioned conventional problems, and provides a method of manufacturing a color cathode ray tube capable of manufacturing a dot type color fluorescent surface with high accuracy even if the HV shift is considerably large. The purpose is to

[0006]

In order to achieve the above object, in the present invention, photolithography is performed on a fluorescent surface for a color cathode ray tube in which dots of three primary color fluorescent materials are repeatedly arranged in a predetermined order on the back surface of the panel. In the method of manufacturing a color cathode ray tube to be used as an exposure light source by passing a light beam emitted by a fixed long arc mercury lamp through a light shielding plate provided with a slit in a direction orthogonal to the mercury lamp axis and approaching a point light source when forming by a technique, When the target color cathode ray tube is used in combination with a horizontally long screen, when the horizontal deflection center of the deflection yoke is separated from the panel side and the vertical deflection center is separated into the electron gun side, the mercury lamp axis of the exposure light source is parallel to the horizontal direction of the panel. To
When the direction of the light source slit is arranged parallel to the vertical direction of the panel, the cathode ray tube is a vertically long screen, and the horizontal deflection center of the deflection yoke is separated to the electron gun side and the vertical deflection center is separated to the panel side, the mercury lamp of the exposure light source is The axis is parallel to the vertical direction of the panel,
The direction of the light source slit is arranged parallel to the horizontal direction of the panel.The distance from the slit opening of the light blocking plate through which the exposure light to the center of the panel passes to the central axis of the mercury lamp of the light source is combined with the target color cathode ray tube. The distance between the center of horizontal deflection and the center of vertical deflection of the deflection yoke used as the same, that is, the HV shift, or the difference from it, is set to ± 2 mm or less.

Alternatively, the conventional correction lens of the exposure apparatus is replaced with a flat glass plate having a thickness equal to the thickness of the central portion of the lens, and then, first, in the case of a horizontally long screen where the horizontal deflection center is on the panel side, In the case of a vertically long screen where the vertical deflection center is on the panel side at both ends of the vertical line passing through the center, the size and position of the light spot by the light beam that actually passed through the shadow mask is at the both ends of the horizontal line passing through the center of the panel. Adjust the light source position so that it exactly matches the desired size and position of the holes in the black matrix film, and then determine the position. Next, in the case of a horizontally long screen, at both ends of the horizontal line passing through the center of the panel, and in the case of a vertically long screen. Is at both ends of a vertical line passing through the center of the panel, so that the position of the light spot by the light beam that actually passed through the shadow mask exactly matches the desired position of the hole in the black matrix film. The position of the slit opening is determined by adjusting the distance between the slit opening facing the slit and the mercury lamp axis of the light source, and the position of the light spot by the light rays that have actually passed through the shadow mask at the four corners of the panel is exactly black. The slits in the plane orthogonal to the light source axis were provided by adjusting the positions of the ends of the slit openings through which the light rays forming the light spots pass at the four corners so as to match the desired positions of the holes in the matrix film. By determining the curved shape of the shading plate, the slits share a considerable part of the correction lens action.

[0008]

With respect to the long arc mercury lamp, the light-shielding plate provided with the slit in the direction orthogonal to the axis of the mercury lamp is a light beam emitted from the long arc light emitting part and passing through the slit having a width shorter than the arc length. This is because the light-shielding plate and therefore the slit are naturally arranged on the side of the panel, which is the exposed object, with respect to the light source, because the light-shielding plate and therefore the slit are made to be close to the point light source. When the mercury lamp is viewed from a point in the plane orthogonal to the mercury lamp axis of the light source and passing through the slit, the position of the central axis of the mercury lamp, that is, the position of the central axis of the arc light emitting portion can be correctly seen from its original position. However, when the arc emission part (mercury lamp) is seen through the slit from a point in the plane including the mercury lamp center axis, if the point is directly in front of the slit (in this case, the point is orthogonal to the mercury lamp axis and the slit (In other words, it will be located in the plane that passes through.) In other words, if you look at the light emitting part through the slit from an oblique direction that makes an acute angle with the mercury lamp axis in the plane containing the mercury lamp, the light emitting part (more precisely, the mercury lamp tube The part with almost the same brightness as the surface) appears to float up to the surface of the slit. Utilizing the above, the present invention corrects the HV shift generated by the structure of the deflection yoke by defining the positional relationship between the light source (mercury lamp) and the slit. Actually, in the case of a horizontally long screen in which the horizontal deflection center of the deflection yoke is on the panel side, the mercury lamp of the exposure device is arranged parallel to the horizontal direction of the panel, and the light shielding plate is arranged on the panel side so that the slit is orthogonal to the mercury lamp axis. In the case of a vertically long screen with the vertical deflection center on the panel side, the mercury lamp of the exposure device is arranged parallel to the vertical direction of the panel, and the light shielding plate is arranged on the panel side so that the slit is orthogonal to the mercury lamp axis. To do. That is, the deflection center on the panel side (exposure center) is assigned to the slit, and the mercury lamp axis corresponds to the deflection center on the electron gun side (exposure center). In addition,
In this case, in practice, since the mercury lamp used as the light source is generally water-cooled and used in water, the HV shift amount of the deflection yoke is determined from the mercury lamp axis according to the present invention in consideration of the amount of floating due to the water depth. Make sure that the effective values of the distance to the slits match. By determining the positional relationship between the long arc mercury lamp and the light shielding plate slit opening according to the present invention, the thickness of the correction lens corresponding to the center of the panel and the thickness of the correction lens corresponding to the horizontal and vertical end positions of the panel are made the same. It is possible to reduce the correction amount by the lens.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a normal deflection yoke, the horizontal deflection center is on the panel side and the vertical deflection center is on the electron gun side. Therefore, as shown in FIG. 1, a mercury lamp is arranged parallel to the horizontal direction of the panel.

Actually, the present invention is convenient when mass-producing a product which has already been produced to some extent, by adding an exposure apparatus that is as simple as possible to cope with it. Fluorescent surface completed panel known to be usable (actually with only black matrix film formed and holes with holes for allowing the dots of the fluorescent material of a specific primary color to be seen from the outer surface of the panel) Then, according to the present invention, the exposure specifications are determined so that the correction lens curved surface is minimized. First, a light amount adjusting filter or lens is set at a predetermined position of the exposure device. At this time, instead of the correction lens, a flat glass plate having the same central thickness as the normal correction lens is used. In addition, the light source is covered with an appropriate slit (flat, the slit width is standard specifications, and the distance from the mercury lamp is adjustable). Here, the long arc mercury lamp of the light source is arranged such that its longitudinal direction is parallel to the horizontal direction of the panel and the slit is perpendicular to the axis of the mercury lamp, that is, parallel to the vertical direction of the panel. Next, the fluorescent surface completed panel is placed on this exposure apparatus, and the ends of vertical lines passing through the center of the panel (so-called 12 o'clock and 6 o'clock positions, at these positions, the mercury lamp light-emitting portion is orthogonal to it, As seen from the point on the plane passing through the slit), the light emitted from the mercury lamp passes through the hole of the shadow mask and is observed on the panel surface of the exposure apparatus, as shown in FIG. The distance between the light source and the panel is adjusted while observing with a microscope so that the holes of the black matrix at the corresponding positions of the completed panel match. Next, at the end of the horizontal line passing through the center of the panel (the so-called 9 o'clock and 3 o'clock positions), as shown in FIG. 3, the light emitted by the mercury lamp passes through the hole of the shadow mask and the panel on the exposure apparatus is exposed. Adjust the distance from the light source mercury lamp axis of the slit opening facing the center of the panel while observing with a microscope so that the light spot observed on the surface and the hole of the black matrix at the corresponding position of the completed panel match To do. At this time, as shown in FIG. 3, if the light spot appears outside the holes of the black matrix, the slit is brought closer to the mercury lamp (fixed at the position after the above adjustment), and conversely, if it appears inside, the slit is formed. Away from the mercury lamp. In this way, the angle at which the light rays enter the holes of the shadow mask at these positions is adjusted correctly. Further, as shown in FIG. 4, at the positions of the four corners of the panel, the light spots emitted by the mercury lamp pass through the holes of the shadow mask and are observed on the panel surface of the exposure apparatus, and the corresponding positions of the completed panel. Observe the position of the holes in the black matrix at. As shown in the figure, first, the difference between the positions A and B at the upper and lower corners of the right side of the panel in the horizontal direction is measured, and the average thereof is taken. As shown in FIG. The point at which it intersects, that is, the right end position of the slit is corrected. However, it is assumed that the slit has already passed through the corrected position as shown in FIG. 3 and is placed in parallel with the plane of the panel mounting table of the exposure apparatus. The same observations and measurements are made at the upper and lower left corners of the panel in the horizontal direction, and the left end position of the slit is similarly corrected.

According to the method of the present invention described with reference to the drawings, the panel and the shadow mask are used at least when there is a prototype product which is satisfactory in terms of performance. This is done prior to the design and manufacture of a new highly accurate correction lens that is easy to make.Because it is performed using the actual product, it is possible to anticipate the effects of unavoidable errors associated with the manufacturing work, which is a great value. There is. At present, correction lenses, including those of the micropolyhedron type, are designed by computer simulation using the ray tracing method. The gist of the present invention is to divide a part of the correction action of the conventional correction lens into the slit, but since the procedure itself of the method is extremely simple, as a part of a new color cathode ray tube design prior to the design of the correction lens. The position of the light source mercury lamp in the exposure light source and the distance from the mercury lamp axis to each part of the slit on the light shielding plate, including the shape of the slit (light shielding plate), can all be determined by computer software.

[0012]

As described above, according to the present invention, a part of the correction work in the direction of the exposure light beam, which has been conventionally performed by the correction lens, can be shared by the slit, and the thickness of the correction lens is substantially equal. As described above, since the curved surface of the correction lens can be loosened, the correction lens for the exposure apparatus can be easily manufactured, and the precision is improved, and the color purity of the dot type color cathode ray tube is excellent and the unevenness of brightness and darkness is small. Can be easily manufactured.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the arrangement direction of a shaft of a mercury lamp for a light source of an exposure apparatus according to the present invention.

FIG. 2 is a diagram illustrating a method of determining a position of a mercury lamp for a light source of an exposure apparatus according to the present invention with respect to an exposure target panel surface.

FIG. 3 is a diagram illustrating a method of determining a position of the slit opening by adjusting a distance from a light source mercury lamp axis of a slit opening facing the center of the panel.

FIG. 4 adjusts the positions of the ends of the slit openings through which light rays forming light spots at the four corners of the panel are adjusted to determine the curved shape of the light shielding plate provided with slits in the plane orthogonal to the light source axis. It is a figure explaining a method.

5 is a diagram showing a curved shape of a slit in a plane orthogonal to the light source axis, which is determined by the method described in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Panel, 2 ... Long arc mercury lamp, 3 ... Light spot, 4 ... Hole of black matrix film, 5 ... Light-shielding plate provided with slits, 6 ... Cross section of mercury lamp.

Claims (2)

[Claims] 1. When a fluorescent surface for a color cathode ray tube, in which dots each consisting of a phosphor of three primary colors are repeatedly arranged in a predetermined order on the back surface of a panel, is formed by a photolithography technique, the light is emitted from a fixed long arc mercury lamp. The horizontal direction of the deflection yoke used in combination with the target color cathode ray tube in the manufacturing method of the color cathode ray tube which is used as an exposure light source by passing a When the deflection center is separated on the panel side and the vertical deflection center is separated on the electron gun side, the mercury lamp axis of the exposure light source is arranged parallel to the horizontal direction of the panel, and the direction of the light source slit is arranged parallel to the vertical direction of the panel. When the horizontal deflection center of the deflection yoke is separated from the electron gun side and the vertical deflection center is separated into the panel side, the mercury lamp axis of the exposure light source is parallel to the vertical direction of the panel. The color cathode ray tube manufacturing method which is characterized in that to arrange the direction of the light source slits parallel to the horizontal direction of the panel. 2. A conventional correction lens of an exposure apparatus is replaced with a flat glass plate having a thickness equal to the thickness of the central portion of the lens, and first, when the horizontal deflection center is on the panel side, the panel passes through the panel center. At both ends of the vertical line, when the center of vertical deflection is on the panel side, at the both ends of the horizontal line that passes through the center of the panel, the size and position of the light spot actually caused by the light beam that has passed through the shadow mask will be accurate. Adjust the light source position so that it matches the desired size and position of the hole of the, and then, when the horizontal deflection center is on the panel side, at the both ends of the horizontal line passing through the panel center, the vertical deflection center is When located on the panel side, at both ends of a vertical line passing through the center of the panel, the position of the light spot by the light rays that have actually passed through the shadow mask matches exactly the desired position of the holes in the black matrix film. Adjust the distance from the light source mercury lamp axis of the slit opening facing the center of the channel to determine the above-mentioned opening position.Furthermore, at the four corners of the panel, the position of the light spot by the light beam that actually passed through the shadow mask is accurate. In order to match the desired positions of the holes in the black matrix film, the end positions of the slit openings through which the light rays forming the light spots pass through are adjusted to adjust the slits in the plane orthogonal to the light source axis. The method of manufacturing a color cathode ray tube according to claim 1, wherein the curved shape of the light shielding plate provided is determined.