JPH01194236A - Exposing method for fluorescent screen of color picture tube - Google Patents

Abstract

PURPOSE:To correct the H/V difference of a deflection yoke even in the diagonal direction and also correct asymmetrical components by exposing a fluorescent screen to the light from a curved, thin and long light emitting part, which is situated a little apart from a thin and long opening in a photo-mask. CONSTITUTION:When a fluorescent screen 1 is to be baked a discharge arc light emitting part 11 having a radius of curvature R of a lamp is arranged an opening 10a in a photo-mask 10 so that the normal to the fluorescent screen at its center point passes the axes of the center point of the opening 10a and the light emitting part 11 and that the tangential drawn to the axis at this point of passage will be identical to the V-axis. When baking is made where the deflection angle in the H direction is omega, exposure is made by the light emitted at the point of origin for light emission where the normal to the fluorescent screen 1 at its center point intersects the axis of the discharge arc. Exposure where the deflection angle in the V direction is omega is made by the light emitted at the point X dislocated V in the V direction from the light emitting source, and the point X is dislocated H in the H direction from the point of origin O.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a color picture tube panel, and particularly to a method for manufacturing a color picture tube panel. It relates to a method of exposing a photosensitive fluorescent surface coated on the inner surface of a.

[Prior Art] Recent display devices are changing from conventional monochrome picture tubes to ones using color picture tubes. Since such display devices generally need to use high resolution, the picture tube uses three electron guns arranged in a triangular shape called a delta type, and displays three colors around the fluorescent screen. In order to concentrate the convergence of the two, we need a dynamic convergence circuit. High resolution requires a high degree of concentration of the three colors, and therefore, conventionally used color picture tube display devices have become expensive.

On the other hand, recent color picture tubes for televisions have slot-shaped holes in the shadow mask, striped fluorescent screens, and in-line picture tubes with electron guns lined up horizontally. It is being This type of picture tube has traditionally been required to produce special deflections, for example in combination with a deflection yoke that generates a strong binction field for horizontal deflections and a strong barrel field for vertical deflections. A dynamic convergence circuit can be made unnecessary. In such a picture tube, since the fluorescent screen is striped, mislanding in the longitudinal direction of the stripe (a mismatch between the center of the phosphor region and the center of the electron beam) can be ignored. Therefore, the design of the picture tube is also easy.

On the other hand, when such a picture tube is used in the field of display, the shadow mask of the slot holes is unsuitable for displaying characters on a fluorescent screen.

Therefore, it is necessary to use the conventionally used shadow mask with small round holes. However, the electron gun can be designed for high resolution with an in-line arrangement.

Almost the same type of deflection yoke can also be used. However, for the final quality of the electron beam, a special deflection magnetic field, that is, a magnetic field that cannot be called a uniform magnetic field, is used. teeth,
There is a difference between the two.

However, recent electron gun design technology has narrowed this difference to a level where there is no practical problem.

By the way, one of the difficult points in designing such a combination picture tube (hereinafter referred to as "dot-in-line tube") is the problem of landing error.

FIG. 5 shows a fluorescent screen 1 and three electron guns (or electron beams) BB arranged in an in-line arrangement.

GB, RB, and definitions of the horizontal axis (H axis) and vertical axis (V axis) are shown.

FIG. 6 is a graph in which the horizontal axis indicates the valve size (in inches) and the vertical axis indicates the horizontal/vertical deflection center difference of the deflection yoke. The upper part of the vertical axis indicates that the deflection center of the vertical coil is closer to the screen side than the deflection center of the horizontal coil.

The deflection deflection in this case shows the case where the design is made to optimize the misconvergence characteristics. The horizontal axis corresponds to a horizontal/vertical deflection center difference of 0 (hereinafter the expression "rH/V difference is 0"), and the printing of the fluorescent surface sometimes shows desirable characteristics. However, in reality, not only the landing state at the H-axis end and the V-axis end of the fluorescent screen, that is, the H/V difference, but also, for example, the characteristics in the diagonal axis direction are important factors.

Figure 7 shows an example of a mislanding situation for a 14-inch 90° deflection tube, when the deflection yoke is adjusted in the horizontal direction, that is, the phosphor dot and the corresponding beam are optimally adjusted in the H direction. It shows the landing characteristics when The direction of the arrow in the figure indicates the direction of deviation of the electron beam relative to the phosphor dot when looking through the phosphor screen with a microscope. That is, it means that the center of deflection in the ■ direction is located in front of the center of deflection in the H direction (on the fluorescent screen side).

FIG. 8 is an example in which an asymmetric component is added to the H/V difference component shown in FIG. 7, and shows an example of a pattern to be corrected in an embodiment of the present invention. That is, Figures 7 and 8
If the figure is carefully observed, it can be seen that a rightward landing error (necessary correction) occurs in the peripheral area in FIG. 8 compared to FIG. 7.

FIG. 9 is a cross-sectional view schematically showing a conventionally used exposure apparatus. In this figure, a picture tube panel 2 whose inner surface is coated with photoresist or photosensitive phosphor is mounted on an exposure table 3, and between it and a lamp house 4, an optical path is formed that resembles the trajectory of the electron beam. Correction lens 5 for
and density filters 6 for determining the distribution of holes in the shadow mask, the distribution of illumination by the light source, and the distribution of dot sizes on the fluorescent screen are arranged at predetermined intervals.

FIG. 10 shows a straight-tube ultra-high pressure mercury lamp of IKW, for example, which is used in the lamp house 4 of FIG. 9.

The ultra-high pressure mercury lamp 7 includes cylindrical electrodes 8 at both ends and a glass tube 9 that generates a discharge arc inside.The outer wall of the glass tube 9 is covered with a lamp mask 10 having an opening 10a and functioning as a light mask. There is.

1IA is a plan view schematically showing the structure of the lamp house 4 in FIG. 9, and FIG. 11B is a line B-B in FIG. 11A.
FIG. The plan view of FIG. 11A is seen from the phosphor surface side to be exposed, and the lamp house 4 is provided with a circular window 12, and the light from the discharge arc 11 of the mercury lamp 7 passes through the lamp mask 10. is released through the opening 10a. The width W1 of the elongated opening 10a of the lamp mask 10 is, for example, about 1.8 mm, and the width W2 of the discharge arc 11 is, for example, 1.6 mm. Diameter W of lamp 7
3 is approximately 5 mm. In actual use, 2, 12
As shown in the figure, the normal line drawn to the center point of the fluorescent surface is the aperture 1.
The arrangement relationship is such that the central point of 0a passes through the central axis of the discharge arc.

In addition, as prior art documents for exposing the fluorescent surface of a color picture tube panel, there are
8231. There are Japanese Patent Application Laid-open No. 56-88230, etc.

[Problems to be Solved by the Invention] As shown in FIG. 11B, the lamp 7 is used with water cooling,
The fluorescent surface l is exposed through a glass window 12. but,
In this conventional method, although the H/V difference shown in FIG. 13, which is difficult to correct with a correction lens, is corrected, the asymmetric component is not corrected.

In view of these problems, it is an object of the present invention to provide an exposure method for the fluorescent surface of a color picture tube panel that can correct the H/V difference of the deflection yoke in the diagonal direction as well as correct the asymmetric component. . More specifically, the H/
It is an object of the present invention to provide an exposure method that can correct the V difference and also correct the asymmetric component, which has been difficult in the past.

C Means for Solving Problem] According to the present invention, in order to form a dot-shaped fluorescent screen on the inner surface of the face panel of a color picture tube, a photosensitive fluorescent surface coated on the inner surface of the face panel. In this method, the light emitting part, the aperture, and the phosphor surface are spaced apart from each other, and the normal line to the center point of the phosphor surface is The central point of the aperture of the light mask passes through the axis of the light emitting section, the longitudinal direction of the aperture of the light mask is in equilibrium with the horizontal axis of the phosphor surface, and the elongated light emitting section is curved and the axis of the light emitting section is A tangent line drawn to the axis of the light-emitting section at a point where the normal line drawn to the center point of the light-emitting part passes through the axis line of the light-emitting part is perpendicular to the longitudinal direction of the opening of the optical mask.

[Function] According to the present invention, since the elongated light emitting part that is slightly separated from the elongated opening of the optical mask is curved, the mislanding of the electron beam can be prevented by the H/V difference of the deflection yoke when exposing and printing the fluorescent surface. It is possible to correct not only the diagonal direction but also the asymmetric component.

Embodiment FIG. 1 schematically illustrates a method according to an embodiment of the invention. When printing a 14-inch fluorescent surface 1, the discharge arc light-emitting part 11 having a radius of curvature R of the balance wheel 7 and the opening 10a of the optical mask 10 are aligned as shown in this figure with respect to the H-axis and V-axis of the fluorescent surface. will be placed in That is, the normal line drawn to the center point of the fluorescent surface passes through the center point of the aperture 10a and the axis line of the light emitting part 11, and the tangent line drawn to the axis line at that passing point is V.
coincides with the axis.

Figures 2A, 2B, and 2C schematically illustrate the operation of the present invention. 2A shows an enlarged section along the H axis in FIG. 1, FIG. 2B shows an enlarged section along the V axis in FIG. An enlarged cross-section of a plane including the tube axis of the high-pressure mercury lamp 7 is shown.

Referring to these figures, when printing is performed at a deflection angle of ω in the H direction, the normal line set to the center point of the fluorescent surface 1 comes out from the emission origin O, where it intersects the central axis of the discharge arc. exposed by light. On the other hand, for exposure where the deflection angle in the ■ direction is ω, the light is emitted from a point marked X that is shifted by ΔV from the emission origin 0 in the V direction, and the X point is from the emission origin O to H It is shifted by ΔH in the direction. That is, the feature of the present invention is that the opening 10a of the lamp mask 10 is provided at a location slightly away from the light emitting section 11,
By utilizing the anisotropy in the geometrical relationship between the curved light emitting section 11 and the aperture 10a, it is possible to correct an asymmetrical component that could not be corrected with the conventional correction lens 5 and H/V difference correction. It can be done.

FIG. 3 shows the direction of movement of the light irradiation point according to an embodiment of the present invention, and includes an asymmetrical correction that is not included in the conventional correction shown in FIG.

The correction pattern in Figure 3 is an explanation of the common correction components when printing phosphor dots for three types of phosphors, red, green, and red, on one picture tube panel. . In other words, three electron beams B in an inline arrangement
This was an explanation of common correction components for each of B, GB, and RB. Specifically, these are the tendencies that occur when the vertical component of the earth's magnetism is applied to the picture tube, and are corrections for mislanding errors that occur in the same way for the three beams. For example, +ΔH in FIG. 2C, which corresponds to the error component in the H direction in FIG. 3, is an electron beam landing error component that occurs in picture tubes used at high latitudes in the Northern Hemisphere. Conversely, for picture tubes used in the southern hemisphere, the curvature of the light emitting section 11 may be selected so that the direction of curvature is in the opposite direction (the center of the radius of curvature is on the -H side).

In yet another embodiment, the printing for both side beams (e.g., green in the center and blue and red on both sides) sometimes reverses the direction of each center of curvature and prints for the center beam (for example, green in the center and blue and red on both sides).
Green) baking can sometimes be done using conventional straight pipe. FIG. 4 shows an example of a correction pattern in such a case. The advantage of this correction pattern is that it can adjust for landing errors between both side beams and the corresponding dots. The groups of three points drawn on the phosphor surface in FIG. 4 represent printing corrections for blue, green, and red.

In the above embodiments, a dot-in-line tube was used as an example, but it goes without saying that the present invention can also be applied to printing a striped fluorescent surface.

[Effects of the Invention] Traditionally, one of the biggest drawbacks of dot-in-line type tubes is that the horizontal/vertical deflection center difference of the deflection yoke and its asymmetric component cannot be avoided in order to minimize misconvergence. However, the landing characteristics were sacrificed. However, according to the present invention, it is possible to provide a method for exposing a fluorescent surface that can correct not only the horizontal/vertical deflection center difference but also the asymmetric component.

[Brief explanation of the drawing]

FIG. 1 is a diagram schematically showing the geometrical relationship between a fluorescent surface, an aperture, and a light emitting part in a method according to an embodiment of the present invention. FIG. 2A is a sectional view of the main part along the H axis in FIG. 1. FIG. 2B is a sectional view of the main part along the V axis of FIG. 1. FIG. 2C is a sectional view of the main part taken along a plane parallel to the fluorescent surface and including the axis of the light emitting section. FIG. 3 is a diagram showing a correction effect on a fluorescent screen according to an embodiment of the present invention. FIG. 4 is a diagram showing the correction effect according to another embodiment. FIG. 5 is a diagram showing the fluorescent screen and the definition of horizontal and vertical deflection directions. FIG. 6 is a graph showing the relationship between the horizontal/vertical deflection center difference and the picture tube size. FIG. 7 is a diagram showing the landing characteristics of a 14-inch 90° deflection tube. FIG. 8 is a diagram showing necessary correction for landing including an asymmetrical component. FIG. 9 is a sectional view schematically showing a conventional exposure apparatus. FIG. 10 is a perspective view showing an ultra-high pressure mercury lamp and a light mask. FIG. 11A is a plan view showing the structure of the lamp house. FIG. 11B is a cross-sectional view taken along line B--B in FIG. 11A. Figure 12 shows a light source using a conventional straight tube lamp. FIG. 3 is a diagram showing the aperture of the optical mask and its geometrical relationship with the fluorescent surface. FIG. 13 is a diagram showing the effect of conventional H/V difference correction. In the figure, 1 is a fluorescent surface, 2 is a picture tube panel, 3 is an exposure stage, 4 is a lamp house, 5 is a correction lens, 7 is an ultra-high pressure mercury lamp, 10 is a light mask, 10a is an aperture, 11 is a discharge arc, R indicates the radius of curvature of the arc. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] In order to form a dot-like fluorescent screen on the inner surface of the face panel of a color picture tube, a photosensitive fluorescent surface coated on the inner surface of the face panel is passed through the elongated light emitting part of the light mask. A method of exposing with light passed through an elongated aperture, wherein the light emitting part, the aperture, and the fluorescent surface are spaced apart from each other, and the normal line erected to the center point of the fluorescent surface is the center point of the aperture. and passing through the axis of the light emitting section, the longitudinal direction of the opening being parallel to the horizontal axis of the fluorescent surface, and the elongated light emitting section being curved so that the normal line passes through the axis. A method for exposing a fluorescent surface of a color picture tube, characterized in that a tangent line drawn to the axis at a point is perpendicular to the longitudinal direction of the aperture.