JPH0451421A - Exposuring device for color-picture tube - Google Patents

Abstract

PURPOSE:To easily enable formation of a black-matrix type phosphor screen by providing such constitution which comprises a correcting lens approximating the orbit of a light ray from a light source to the orbit of an electron beam, and a dioptric system for changing the orbit of a light ray projected on a photosensitive phosphor screen forming layer synchronizing with the movement of a shutter. CONSTITUTION:A correcting lens which approximates the orbit of a light ray emitted from a light source 20 to the orbit of an electron beam emitted from the electron gun of a color-picture tube is disposed. A dioptric system 33 moving in synchronization with a shutter 24 and rotating by a predetermined angle around the rotational center axis, which is a predetermined axis 32, and for refracting and changing the orbit of a light ray 21, which passes through an aperture 23 and radiates onto a photosensitive phosphor screen forming layer 31 is arranged on the side of the light source 20 against the aperture 23 of a shutter 24. When the dioptric system 33, is used, moving distance in the vertical axis direction can be approximately twice as large as the moving distance in the horizontal axis direction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) This invention relates to an exposure apparatus used for forming a phosphor screen of a color picture tube.

(Prior art) Generally, the collar receiver fl '+Q' has an envelope consisting of a panel (1) and a funnel (2), as shown in FIG. A phosphor screen (4) is provided on the inner surface of the panel (1), facing the shadow mask (3) in which a large number of electron beam passage holes are formed.
is formed. This phosphor screen (4) consists of a striped or dot-shaped three-color phosphor layer that emits blue, green, and red light. Also, this phosphor screen (4)
In order to improve the contrast of the image drawn on top, a non-luminescent layer made of carbon or other material is provided in the gaps between the three color phosphor layers, resulting in a so-called black stripe type or black matrix type. There is something.

The image is displayed on the phosphor screen (4) using three electron beams (6B) (6G) emitted from the electron gun (5).
(6R) is deflected horizontally and vertically 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 horizontally and vertically. .

Therefore, in order to display an image with good color purity on this phosphor screen (4), as shown in FIG.
8) Each electron beam (6B), (6G) passed through
, (6R) respectively correspond to three color phosphor layers (9B)
It is necessary to land correctly on , (9G), and (9R). Regarding this landing, the electron beam passage hole (8) of the shadow mask (3)
and three-color phosphor layer (9B), (9G), (9R)
The positional relationship with each electron beam is (8B), (6G)
, (fil?) The apparent upper injection position (deflection center) changes according to the deflection angle.

Therefore, each of the three color phosphor layers (9B), (9G),
3 electron beams (8B) corresponding to (9R),
In order for (GO) and (8R) to land correctly, the electron beam passing hole (8
) for three-color phosphor layers (9B), (9G),
It is necessary to change the position of (9R).

In other words, as shown in Fig. 5 for the center beam (6G) of three Ichiko beams arranged in a row emitted from an in-line electron gun, the electron beam (6G) is It moves in a circular orbit within the magnetic field (11) generated by the deflection yoke, and after exiting the magnetic field (11) of the deflection yoke, it moves straight and forms a shadow mask (3).
The electron beam passing hole (8) passes through the phosphor layer (9G).
Land on. Therefore, electron beam (6G)
The apparent upper injection position, that is, the position of the deflection center (P) where the extension of the linear trajectory intersects with the tube axis (X-axis) is the deflection angle γ.
It changes accordingly. −), the deflection angle is γ compared to the case of no deflection where the deflection angle is zero, the deflection center (F)
advances toward the phosphor screen (4) by Δp γ−Δ
There is a p characteristic.

On the other hand, conventionally, phosphor screens are manufactured by applying a phosphor slurry mainly composed of phosphor and photosensitive resin to the inner surface of a panel (1) and drying it as shown in FIG. 6(a).
3) is exposed through a shadow mask (3) to print a pattern corresponding to the electron beam passing hole (8) of the shadow mask (3), and then developed to remove the unexposed area. As shown in (b), a phosphor layer of any one color, for example, a blue phosphor layer (9B) is formed.

Then, each of these steps is repeated for other two-color phosphor layers.

Especially for phosphor screens with non-emissive layers.”
2. Prior to the formation of the three-color phosphor layer, a photosensitive resin is coated as shown in FIG. After forming a photosensitive resin pattern (15) corresponding to the holes, a non-luminescent paint is applied as shown in (b), and then this non-luminescent paint film (16) is applied to the underlying photosensitive layer. peeled off together with the pattern (15) of the synthetic resin,
As shown in (C), there are voids (
17), and then forming a three-color phosphor layer in the void (17) of the non-emissive layer (18) by a method for forming a distributed light layer. Manufactured by.

In both cases of forming the phosphor layer and the non-emissive layer, the light that exposes the phosphor slurry coating (13) formed on the inner surface of the panel and the photosensitive phosphor screen forming layer made of photosensitive resin travels in a straight line. , an exposure apparatus shown in FIG. 8 is used for about 2 U of exposure. This exposure device includes a light source (20) that emits light to be projected onto a photosensitive phosphor screen forming layer formed on the inner surface of the panel (1) through a shadow mask (3) attached to the panel (1). and its panel (
A correction lens (22) is arranged between the light source (20) and the light source (20) to approximate the trajectory of the light (21) emitted from the light source (20) to the trajectory of the electron beam emitted from the electron gun;
Further, an aperture (23) is formed between the correction lens (22) and the shadow mask (3) to project light emitted from the light source (20) onto a portion of the photosensitive phosphor screen forming layer. A partial exposure shutter (24) is disposed that moves when driven by a drive device (not shown) so that light passing through the opening (23) is projected onto the entire area of the photosensitive phosphor screen forming layer. There is.

A spherical lens was once used as the correction lens (22) disposed in such an exposure device, but as the structure of color picture tubes has become more complex, a simple lens has
It is no longer possible to correct the −Δp characteristic, and aspheric lenses with complicated surface shapes are now used.

The surface shape of this aspherical lens is expressed in an orthogonal coordinate system (X, Y, Z axes) with the origin at the center of the bottom surface of the lens, and the surface height X at any point is x = f (y, z)・・・・・・・・・・・・
... Represented by (1). Also, polar coordinates (r, θ)
Then, x=f (r, θ)...
...(2),=mu'shoulder 7 θ=tan'(y/z), and within the - shell, for example, equation (1) is expressed as a polynomial.

The design of the correction lens using such a formula is based on each coefficient a5. How the light emitted from the light source changes with respect to the amount of change in J is tracked over the entire phosphor screen, and the error with the electron beam incident position across the phosphor screen is less than a certain value (usually 10 microns). is designed to be. However, even with this design method, it is relatively easy to reduce errors at a limited number of points on the correction lens, but it is possible to reduce the error at any point on the correction lens surface by changing the coefficient a. ,,
Even if J is set, the coefficient a1. Generally acts to increase the error at the majority of other points J, so it is extremely difficult to design so that the error is less than the 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 in many cases the coefficient a8. Changes require judgment based on extensive experience.

Therefore, in color picture tubes with complex deflection magnetic fields, such as 110-degree deflection color picture tubes with large deflection angles and large color picture tubes, it takes a lot of time to design the correction lens, and it is difficult to achieve the desired γ-Δp characteristic. It cannot be used as a correction lens with

As another method of designing correction lenses,
No. 83 and Special Publication No. 49-22770 include No. 9
As shown in the figure, a method is shown in which the correction lens (22) is divided into a plurality of parts and the slope of the surface of each part is determined. Such a method allows the trajectory of light to be accurately approximated to the trajectory of the electron beam for each divided portion, making it possible to obtain a correction lens that fully satisfies the γ-Δp characteristics.

However, such a correction lens (22) has a step (26) at the boundary between the divided parts, so it is particularly difficult to use a black stripe type or black lens in which a non-emissive layer is provided between the three-color phosphor layers. For matrix-type phosphor screens, unevenness tends to occur on the phosphor screen due to unevenness in the amount of light caused by the steps (26).One way to solve this problem is to shake the correction lens (22) during exposure. There are methods of moving the phosphor screen and methods of shielding the stepped portion from light, but none of these methods can sufficiently reduce the unevenness of the phosphor screen.

(Problems to be Solved by the Invention) As described above, in the phosphor screen of a color picture tube, a pattern corresponding to the electron beam passing holes of the shadow mask is printed on the photosensitive phosphor screen forming layer formed on the inner surface of the panel. When attaching the beam, a correction lens is used to approximate the trajectory of the light emitted from the light source to the trajectory of the electron beam deflected by the magnetic field formed by the deflection yoke. However, the surface shape of this correction lens is complex and it is difficult to design it so that good landing can be obtained at all points on the phosphor screen, especially for wide deflection angle color picture tubes and large color picture tubes. For a color picture tube with a complex deflection magnetic field, the desired correction lens cannot be obtained.

As a result of various investigations into the causes, the inventor discovered that the major cause of difficulty in designing a correction lens is the difference between the γ-Δp characteristics of horizontal deflection and the γ-Δp characteristics of vertical deflection of electron beams. I found a headline.

That is, the surface height X at an arbitrary point P of the correction lens (22) shown in FIG. On-axis (Z-axis) and vertical axis (Y-axis)
As for the above, since each curve is a curve that completely satisfies each landing characteristic, the surface height (2) Only when the generated values match the generated values, complete correction will be made in both the Y-axis direction and the Z-axis direction. However, as shown in FIG. 11(a), the surface height x at 21 on the Z axis
(0, z) and the waist When determining the surface height of point P in the Y-axis direction from this zl, the surface height of point P is determined by the curve (28a
) becomes X2 above. On the other hand, as shown in (b), if the surface height at yl on the Y-axis is x(y, 0) and the surface height of point P■ is determined from this yl in the Z-axis direction, then The surface height of P is a curve (
28b) X3 above, from the Z axis to the Y axis direction] 1 correction and the correction from the Y axis to the Z axis direction do not necessarily match. In fact, there are many cases where they do not match.

This is based on the difference between the center of deflection when the electron beam is deflected in the horizontal direction and the center of deflection when it is deflected in the vertical direction. In this respect, it has been found that it is impossible to design a correction lens that satisfactorily corrects the landing error.

Such problems can be avoided in color picture tubes, such as black-striped color picture tubes, which have a phosphor screen consisting of a long striped phosphor layer at least in the vertical direction, and do not require consideration of vertical landing. Although this is not so much of a problem, it has a significant effect on color picture tubes with dot-shaped phosphor layers, especially wide deflection angle color picture tubes with a deflection angle of 110 degrees, and large color picture tubes.

This invention was made in view of the above problems, and
It is an object of the present invention to configure an exposure apparatus that can easily form a phosphor screen that cannot be sufficiently corrected with a conventional correction lens.

[Structure of the Invention] (Means for Solving the Problem) In an exposure device for a color picture tube used for forming a phosphor screen of a color picture tube, a photosensitive phosphor screen forming layer on the inner surface of the panel positioned at a predetermined position is provided. A light source that emits the light to be projected; a correction lens that approximates the trajectory of the light projected from the light source to the photosensitive phosphor screen forming layer to the trajectory of the electron beam emitted from the electron gun of the color picture tube; and the photosensitive material. A portion of the phosphor screen forming layer has an opening through which light emitted from the light source is projected;
In addition to a shutter that is moved by a driving device so that the apertures project light emitted from the light source onto the entire area of the photosensitive phosphor screen forming layer, there is also a shutter that moves and rotates in synchronization with the movement of the shutter. A refractive optical system was disposed that changes the trajectory of light that passes through the aperture of the shutter and is projected onto the photosensitive phosphor screen forming layer by only rotating.

(Function) As mentioned above, in addition to the correction lens that approximates the trajectory of the light projected from the light source onto the photosensitive phosphor screen forming layer to the trajectory of the electron beam emitted from the electron gun of the color picture tube, The light emitted from the light source is moved and rotated or only rotated in synchronization with the movement of a shutter having apertures for projecting light emitted from a light source onto a portion of the phosphor screen forming layer, and the photosensitive material passes through the apertures of the shutter. Placing a refractive optical system that changes the trajectory of light projected onto the phosphor screen forming layer makes it possible to design a correction lens, which previously had difficulty achieving both inclination and thickness at all points on the lens surface. It is possible to easily produce a color picture tube with good landing characteristics over the entire area of the phosphor screen.

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

FIG. 1 shows an exposure apparatus that is one embodiment of the present invention.

This exposure apparatus has a support base (30) that positions and supports the panel (1), and a light source (
20) are arranged. As this light source (20),
Typically, air-cooled or water-cooled ultra-high pressure mercury lamps are used. In this exposure apparatus, the light source (20
), a shadow mask (3 A correction lens (
22) is arranged between the correction lens (22) and the shadow mask (3), and directs the light (21) emitted from the light source (20) to a part of the photosensitive phosphor screen forming layer (31). An elongated slit-shaped aperture (23) is formed in the direction of the horizontal axis (Z-axis) for projection, and a driving device (not shown) causes the light passing through the aperture (23) to be directed to the photosensitive phosphor screen forming layer (3). ]) A partial exposure shutter (24) that moves in the vertical axis (Y-axis) direction is arranged so that the entire area of the image is projected.

Further, in this exposure apparatus, a predetermined axis (32) is moved and rotated in synchronization with the shutter (24) toward the light source (20) side with respect to the aperture (23) of the shutter (24). A refractive optical system (33) that refracts and changes the trajectory of the light (21) that passes through the aperture (23) and is projected onto the photosensitive phosphor screen forming layer (31) by rotating at a predetermined angle about a central axis. or are placed. This refractive optical system (33) is formed in a size that refracts all the light (21) passing through the aperture (23).

Figures 2(a) and (b) show an example of a 32-inch color picture tube with an aspect ratio of 16:9, a refractive index of approximately 1.5, a thickness of 8.0 mm, and maximum rotation in the vertical axis direction. A plate-shaped refractive optical system (3
3) shows the amount of movement of light on the inner surface of the panel (1) when the panel (24) is moved and rotated in synchronization with the movement of the shutter (24).

When the refractive optical system (33) is arranged, as shown in (a), compared to the case where this refractive optical system is not arranged, the diagonal section moves 130 μm in the Y-axis direction on the vertical axis. Then, it moves 340 μm, and the difference is 210 μm,
As shown in (b), in the horizontal axis direction, it is almost zero on both the vertical and horizontal axes, but on the diagonal, it is 100 μm.
Moving. In other words, when the refractive optical system (33) is used, the amount of movement in the vertical axis direction can be approximately twice as large as the amount of movement in the horizontal axis direction.

Therefore, by arranging the refractive optical system (33) as described above and moving and rotating it in synchronization with the movement of the shutter (24), it is possible to correct the difference in the deflection centers in the horizontal and vertical axes. (22) Design problems can be solved and a desired phosphor screen can be formed.

In the above example, a plate-shaped refractive optical system made of glass with a refractive index of about 1.5 and a thickness of 8.0 mm was used as an example of the refractive optical system, but the action of this refractive optical system is as follows. Since the refractive index does not change much even if the refractive index is different, it may be formed of other glass having a different refractive index, quartz, plastic, or the like.

Further, the rotation angle of this refractive optical system can be determined experimentally, but it can also be determined using a computer. Furthermore, the rotation angle of this refractive optical system may be changed in proportion to the position of the shutter, but may be a certain function of the position.
For example, it can also be determined using a polynomial determined by .

In addition, in the above embodiment, the refractive optical system was moved and rotated in synchronization with the movement of the shutter, but this refractive optical system is used to illuminate the entire area of the photosensitive phosphor screen forming layer on the inner surface of the panel with the light projected from the light source. It may be formed to a size that allows the lens to refract, and only rotate in synchronization with the movement of the shutter.

[Effects of the Invention] In addition to a correction lens that approximates the trajectory of light projected from a light source to the photosensitive phosphor screen forming layer to the trajectory of the electron beam emitted from the electron gun of a color picture tube, the photosensitive phosphor screen The light emitted from the light source is projected onto a portion of the forming layer by moving and rotating or only rotating in synchronization with the movement of a shutter having an aperture that projects light emitted from a light source, and the photosensitive fluorescent light passes through the aperture of the shutter. Conventionally, when a refractive optical system is arranged to change the trajectory of light projected onto the body screen forming layer,
By improving the exposure equipment that made it difficult to balance the slope and thickness of the lens surface at all points on the surface of the correction lens, we were able to create the required striped three-color phosphor layer or its three-color phosphor layer. Easily produce black stripe type phosphor screens with non-emissive layers in the gaps, dot-shaped three-color phosphor layers, or Bramma matrix-type phosphor screens with non-emissive layers in the gaps between the three-color phosphor layers. can be formed into

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are detailed explanatory diagrams of this invention.
The figure shows the main part configuration of an exposure device for a color picture tube, which is one embodiment of the system. Fig. 3 shows the structure of a color picture tube, and Fig. 4 shows the three-color phosphor layer of the phosphor screen and the electron beam passage hole of the shadow mask. Figure 5 is a diagram to explain the influence of the deflection magnetic field on the electron beam, Figures 6 (a) and (b)
Figures 7(a) to 7(c) each illustrate a method for forming a three-color phosphor layer of a color picture tube phosphor screen, and FIGS. FIG. 8 is a diagram showing the configuration of a conventional color picture tube exposure device, and FIGS. 9(a) and (b) are a plan view and a cross-section of the configuration of a correction lens divided into multiple parts, respectively. 10 are diagrams for explaining the conventional correction lens design method, and FIG. 11 (a
) and (b) are a diagram showing the surface shape of the z-p cross section and a diagram showing the surface shape of the yp cross section of the conventional correction lens shown in FIG. 10, respectively. ]...Panel, 20...Light source, 21...
Light, 22... Correction lens, 23... Aperture, 24... Nyatter 31... Phosphor screen forming layer, 32... Rotation center axis, 33... Refractive optical system, 2] Fig. Figure Figure

Claims (1)

[Scope of Claims] A light source that emits light to be projected onto a photosensitive phosphor screen forming layer on the inner surface of the panel positioned at a predetermined position, and a trajectory of light projected from this light source onto the photosensitive phosphor screen forming layer. a correction lens disposed above to approximate the trajectory of this light to the trajectory of an electron beam emitted from an electron gun of a color picture tube; a shutter that has an aperture for projecting light and is moved by a driving device so that the aperture projects the light emitted from the light source over the entire area of the photosensitive phosphor screen-forming layer; and a shutter that is synchronized with the movement of the shutter. and a refractive optical system that moves and rotates or only rotates to change the trajectory of light that passes through the aperture of the shutter and is projected onto the photosensitive phosphor screen forming layer. Exposure device for color picture tubes.