JP3031921B2 - Manufacturing method of color image tube - Google Patents

Description

Description: Object of the Invention (Field of Industrial Application) The present invention relates to a method of manufacturing a color picture tube, and more particularly, to a color picture tube which forms a fluorescent screen so as to obtain good landing characteristics. And a method for producing the same.

(Prior Art) Generally, a color picture tube has an envelope composed of a panel (1) and a funnel (2) as shown in FIG.
The panel (1) faces the shadow mask (3) having a large number of through holes mounted inside the panel (1).
A fluorescent screen (4) is formed on the inner surface. The phosphor screen (4) is a striped or dot-shaped three-color phosphor layer that emits blue, green, and red light. Further, in order to improve the contrast of the screen, there is a so-called black stripe type or black matrix type in which a non-light emitting layer mainly containing carbon or the like is provided in a gap between the three color phosphor layers.

The image is displayed on the phosphor screen (1) by using three electron beams (6B), (6G), and (6R) emitted from the electron gun (5) in the deflection yoke (7) mounted outside the funnel (2). ) To deflect horizontally and vertically by the magnetic field
This is performed by scanning the phosphor screen (4). Therefore, in order to display an image with good color purity on the phosphor screen (4), as shown in FIG. 9, each electron passing through the through hole (8) is passed through the shadow mask (3). Phosphor layer (9B) corresponding to beam (6B), (6G), (6R),
It is necessary to correctly strike (9G) and (9R). In particular, the positions of the three-color phosphor layers (9B), (9G) and (9R) with respect to the through holes (8) of the shadow mask (3) are determined by the deflection angles of the electron beams (6B), (6G) and (6R). The apparent emission position (deflection center) changes according to, so that the electron beams (6B), (6G), and (6R) are correctly applied to the corresponding phosphor layers (9B), (9G), and (9R). In order to make the projection, the positions of the three-color phosphor layers (9B), (9G), and (9R) with respect to the through holes (8) of the shadow mask (3) at each point on the inner surface of the panel (1). Needs to be changed.

That is, as shown in FIG. 10 with respect to the center beam (6G) of three electron beams arranged in a row and emitted from the in-line type electron gun, the electron beam (6G) makes the magnetic field intensity of the deflection yoke (7) uniform. Then, the deflection magnetic field (11)
The light beam travels in a circular orbit inside the deflecting magnetic field (11), goes straight ahead, and strikes the phosphor layer (9G) through the through hole (8) of the shadow mask (3). Therefore, the apparent emission position of the electron beam (6G), that is, the position of the deflection center (F) where the extension of the linear trajectory intersects the tube axis (X axis) changes according to the deflection angle γ. In other words, when the deflection angle is γ with respect to the case where the deflection angle is zero, it has a γ-Δp characteristic that advances toward the Δp fluorescent screen (4).

On the other hand, conventionally, as shown in FIG. 11, a phosphor slurry containing a phosphor and a photosensitive resin as main components is applied to the inner surface of the panel, dried, and the film is exposed through a shadow mask. After the pattern corresponding to the through-hole of the shadow mask is printed, the phosphor layer of any one color is formed by developing and removing the unexposed portion. Then, each of the steps is repeated for the three-color phosphor layer. In particular, for a phosphor screen having a non-light emitting layer, a photosensitive resin is applied before forming the three-color phosphor layer,
After forming a pattern of the photosensitive resin corresponding to the through holes of the shadow mask at the position where the three-color phosphor layer is formed by a similar method, a non-light-emitting paint is applied. It is manufactured by peeling off with a pattern to form a non-light emitting layer having a void at a position where a three-color phosphor layer is formed.

In either case of the phosphor layer or the non-light emitting layer, the light for exposing the coating formed on the inner surface of the panel goes straight. Therefore, in the exposing step, as shown in FIG.
Exposure in which a correction lens (15) that approximates the trajectory of the light (14) radiated from the light source (13) to the trajectory of the electron beam is disposed between the panel (1) on which is mounted and the exposure light source (13). The device is used. Incidentally, (16) is a shutter for partially exposing the film, and (17) is an aperture for controlling the exposure area.

A spherical lens has been used as such a correction lens (15), but as the structure of the color picture tube becomes more complicated, the γ-Δp characteristic cannot be corrected with a simple lens, At present, an aspheric lens having a complicated surface shape is used.

If the surface shape of this aspheric lens is represented by orthogonal coordinates (X, Y, Z axes) with the origin at the center of the bottom surface of the lens, the surface height x at an arbitrary point is x = f (y, z) (1) In polar coordinates (r, θ), In general, for example, equation (1) is a polynomial It is represented by

The design of the correction lens performed using such an equation is to track how the light emitted from the exposure light source changes with respect to the variation of each coefficient a _ij over the entire surface of the phosphor screen, It is designed so that the error from the incident position of the electron beam on the entire surface is less than a certain value (usually 10 microns).
However, with such a method, it is relatively easy to reduce the error at a limited few points of the correction lens, but the coefficient a is set so as to reduce the error at any point on the correction lens surface. _{Even if ij} is set, its coefficient a _ij is
In general, it works to increase the error at most of the other points, and it is extremely difficult to design so that all points on the phosphor screen have a desired error or less. Even with the use of high-performance, ultra-high-speed computers, not only does it take time to design, but in many cases, changing the coefficients a _ij requires a wealth of experience. Therefore, in a color picture tube having a complicated deflection magnetic field such as a 110 ° deflection color picture tube or a large color picture tube having a large deflection angle, it takes a lot of time to design a correction lens, and a correction lens having desired characteristics is required. Cannot be a lens.

As another design method of the correction lens, Japanese Patent Publication No. 47-40983
As shown in FIG. 13, JP-A-49-22770 discloses a method of dividing a correction lens (15) into a plurality of parts and determining the surface inclination of each part. .
According to such a method, the trajectory of light at the time of exposure can be accurately matched with the trajectory of the electron beam for each of the divided portions, and a correction lens satisfying the γ-Δp characteristic can be obtained. However, since such a correction lens (15) has a step (18) at the boundary between the divided portions, a black stripe type or a black matrix in which a non-light emitting layer is provided particularly in the gap between the three color phosphor layers is provided. Irregularity of the fluorescent screen is likely to occur with respect to the fluorescent screen of the mold due to the uneven light amount caused by the step (18). To solve this,
There are a method of swinging the correction lens (15) in an exposure manner and a method of shielding a step portion from light, but none of these methods can achieve a quality that sufficiently satisfies the unevenness of the phosphor screen.

(Problems to be Solved by the Invention) As described above, the manufacture of the fluorescent screen of the color picture tube involves forming a pattern corresponding to the through-holes of the shadow mask on the coating of the phosphor slurry or the photosensitive resin formed on the inner surface of the panel. When printing, a correction lens is used that approximates the trajectory of light emitted from the exposure light source to the trajectory of an electron beam deflected by a magnetic field formed by a deflection yoke. However, the surface shape of this correction lens is complicated, and it is difficult to design it so that good landings can be obtained at all points on the phosphor screen, especially for wide deflection angle color picture tubes and large color picture tubes. For the fluorescent screen of a color picture tube having a complicated deflection magnetic field, a desired correction lens has not been obtained.

As a result of various investigations of the cause, the inventor has found that a major cause that makes the design of the correction lens difficult is the difference between the γ-Δp characteristic of horizontal deflection and the γ-Δp characteristic of vertical deflection with respect to the electron beam. I found it.

That is, an arbitrary point P of the correction lens (15) shown in FIG.
Is not determined only by the point P, but is determined as a sum of inclinations from the central axis of the correction lens (15).
And, in general, on the Z axis and the Y axis, each of the landing characteristics is a curved surface that completely satisfies the respective landing characteristics.
Surface height x at an arbitrary point P, only if the case starting from y ₁ on the Y axis when starting with z ₁ on the Z axis is coincident, both y and z directions as to completely correct Becomes However, as shown in FIG. 15 (a), z ₁ on the Z axis
Is defined as x (0, z ₁ ), and the surface height of the point P is determined in the Y direction from z _1, and the surface height of the point P becomes x _z on the curve (19a). Become. On the other hand, as shown in (b), the surface height at y ₁ on the Y-axis and x (y _1, 0), the slide into determining the surface height of the point P in the Z direction from the y ₁ , Y surface height of the point P becomes x ₃ on the curve (19b), the Z axis
The correction in the direction does not always match the correction in the Y direction from the Y axis. Rather, they often do not match. this is,
It is based on the difference between the center of deflection when deflecting the electron beam in the horizontal direction and the center of deflection when deflecting in the vertical direction. It has been found that it is impossible to design a correction lens that corrects the landing error to a satisfactory degree.

Such a problem is not so serious in a color picture tube having a stripe-shaped fluorescent screen extending in the vertical direction such as a black stripe type and it is not necessary to consider vertical landing. However, this has a great effect on a color picture tube having a dot shape, particularly a wide deflection angle color picture tube or a large color picture tube.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to easily form a phosphor screen that cannot be corrected sufficiently with a conventional correction lens.

[Configuration of the invention]

(Means for Solving the Problems) A coating of a photosensitive resin or a phosphor slurry is formed on the inner surface of the panel, and the coating is irradiated with light from a light source through a shadow mask. After baking a pattern corresponding to the above, in the method of manufacturing a color picture tube to form a phosphor screen on the inner surface of the panel by developing and forming a non-light emitting layer or a phosphor layer, the film formed on the inner surface of the panel Using a shutter for limiting the irradiation area of the light from the light source, when moving the light source in synchronization with the movement of the shutter, the pattern corresponding to the through-hole of the shadow mask obtained on the coating on the inner surface of the panel When the position is compared with the position of the pattern corresponding to the through-hole of the shadow mask when the fluorescent film is formed by fixing the light source, the shutter is positioned at the light source. When moving in the horizontal axis direction in a plane perpendicular to the optical axis of the, the position of the horizontal axis pattern and the position of the horizontal axis pattern when the fluorescent film is formed by fixing the light source and Controlling the movement of the light source in the optical axis direction and the movement in the horizontal axis direction so that the light source is substantially the same, and the shutter moves in the vertical axis direction in a plane orthogonal to the optical axis of the light source. In the optical axis direction of the light source such that the position of the pattern in the vertical axis direction and the position of the vertical axis direction pattern when the phosphor is formed by fixing the light source are substantially the same. By controlling the movement and the movement in the vertical axis direction, the light source is moved so as to coincide with the center of deflection of horizontal deflection based on the γ-Δp characteristic and the center of deflection in the vertical direction, respectively. Corresponds to mask holes Pattern is printed.

(Operation) According to the present invention, a shutter for limiting the light irradiation area with respect to the photosensitive resin or the phosphor slurry coating is used, and the movement of the light source that moves in synchronization with the movement of the shutter is controlled. In addition, it is possible to correct a landing error due to a difference in the deflection center position, and thereby to form a phosphor screen so as to obtain good landing characteristics over the entire phosphor.

Hereinafter, the present invention will be described based on embodiments with reference to the drawings.

As shown in FIGS. 2 and 3, the correction lens (20)
The center is the origin of the bottom surface of the (surface of the exposure light source side) in a rectangular coordinate with the central axis of the correction lens (20) and X-axis, an exposure light source (13) is a point x ₀ on the X axis (0, 0 ). Also, panel (1) an inner surface passing through the point x _i on the X-axis Y-
Assume a plane parallel to the Z plane. In this case, the light emitted from the exposure light source (13) is refracted by the correction lens (20) as shown by a broken line (21), and is transmitted through the aperture (17) of the shutter (16) and the shadow mask (3). through the holes reaching the panel (1) y ₁ on the inner surface '. And the shutter (1
The area (22) corresponding to the aperture (17) in 6) is exposed. Here, when the electron beam incident on y ₁ ′ is deflected so as to be incident on y ₁ by the vertical deflection magnetic field of the deflecting device, the deflection center is deflected so that the electron beam is incident on the same y ₁ . than deflection center, will have to allow the only panel (1) side x _4, in order to project light on y ₁ through same trajectory and electron beam, as shown by the solid line (23), an exposure light source (1
3) is the deflection direction (direction of y ₁ −y ₁ ′), that is, Y
So that the upper Z-Y plane passing through the x ₀ in the opposite direction may be moved by y ₂ and the shutter (16) which moves in the axial direction. That is, when gamma-Delta] p characteristic of the vertical deflection magnetic field of the gamma-gamma _1, when a Delta] p = x _4, the relationship is established as indicated by y = x ₄ · tanγ _1, a direction opposite to the moving direction of the shutter (16) an exposure light source (13) so that should be moved by y ₂ in.

Therefore, the movement of the exposure light source (13) can be performed as follows in order to obtain good landing characteristics over the entire phosphor screen.

For example Figure 14 of the straight line represented by Z = Z ₁ (Z-axis) is Δp = X ₅ γ-Δp characteristic in the Z-axis direction in the gamma-gamma ₂ in y = 0 when emphasizing landing characteristics of near, y = gamma-Delta] p characteristic of the Z-axis direction is a Delta] p = X ₆ in gamma-gamma ₃ in y _1, when x _5> x _{6, Δp} when the gamma = gamma _{1 is, Δp = x 4 - (x} 5 −x ₆ ), and the movement amount y of the exposure light source (13) at this time.
₄ becomes y ₄ = {x ₄ − (x ₅ −x ₆ )} tan γ ₁ .

The method of determining the γ-Δp characteristic depends on which part of the phosphor screen the landing characteristic is important, but in any case, the moving amount y _m of the exposure light source (13) and the Δ of the γ-Δp characteristic
Assuming that p is x _s , y _m = x _s · tanγ ₁ .

According to the method of exposing by moving the exposure light source (13) in the direction opposite to the direction of movement of the shutter (16), the correction lens (20) whose surface height of the correction lens is determined only on the Z axis is used. ) Can be used to form a phosphor screen with a small landing error. That is, Y over the entire phosphor screen
The landing in the axial direction can be almost zero. However, as for the landing displacement in the Z-axis direction, the correction lens (20) shown in FIG.
As shown in (b) and (c), respectively, the A-section and the CC section parallel to the Z-axis, on the z-axis,
While the surface height decreases as going from the lens center to the periphery, the surface height increases in the portion deviating from the Z axis as going toward the periphery. Therefore, the Y axis shown in FIG. 5A and the lines (24a) to (24a) parallel to the Y axis are shown.
The landing error in e) is the same as in (b),
As shown in (25e), the value increases as the coordinate value of z increases.

If the exposure light source is moved in the X direction in synchronization with the movement of the shutter in the Y direction, the arrow (2) in FIG.
The movement of the pattern corresponding to the exposure point, that is, the through hole of the shadow mask, occurs in the direction indicated by 6). This arrow (26)
Represents the relative movement amount. If the exposure light source is moved in the Y direction in the opposite direction in synchronization with the movement of the shutter in the Y direction, the movement of the exposure point indicated by the arrow (27) in FIG. Therefore, the exposure light source is set to X-axis and Y-axis.
When it is moved in the axial direction, and the amount of movement in the X-axis direction and the amount of movement in the Y-axis direction are coordinated, the exposure light source is fixed to form a phosphor screen as shown by an arrow (28) in FIG. The exposure error in this case can be corrected so that the landing error shown in FIG. 5B is only in the Z-axis direction.

The directions of arrows (26) to (28) shown in FIG.
When the shutter and the exposure light source are moved in the opposite directions, the directions are reversed. Further, the magnitude of the landing error indicated by the arrow (28) in FIG. 6C can be adjusted to a desired magnitude by adjusting the amount of movement of the exposure light source.

FIG. 1 shows an exposure apparatus for performing the above-described exposure method. The exposure apparatus has a support (30) for positioning and supporting the panel (1), and an exposure light source (1) is provided below the support (30).
3) is installed. As the exposure light source (13),
Usually, a water-cooled or air-cooled ultra-high pressure mercury lamp is used, but in addition, a laser beam or a device that emits a laser beam through a light conductor such as an optical fiber can also be used.
Further, a shutter (16) having a long opening (17) in the axial direction (horizontal direction) is formed at a lower portion of the shutter (16) in proximity to the support table (30). And this shutter (1
A correction lens (20) is provided between 6) and the exposure light source (13).

The shutter (16) has a rack (31) for moving it in the Y direction (vertical direction), and the exposure light source (13) has a tilt with respect to the Y axis so as to move it in the XY direction. Racks (32) are attached, and the pinions (34) and (35) meshing with the racks (31) and (32) are driven by the drive motor (32) via the belts (36) and (37). By rotating, the shutter (16) and the exposure light source (13) are synchronized and moved in the direction perpendicular to the longitudinal direction of the long aperture (17) of the shutter (16) in the direction opposite to and inclined on the XY plane. It has a structure to make it.

As a moving mechanism of such an exposure light source (13),
As shown in the figure, an exposure light source (13) is connected to a crank mechanism (38) driven by a drive motor, and the exposure light source (13) is moved along a guide groove (39) inclined with respect to the Y axis. It may be configured so as to make it. In this case, an effective correction can be obtained by changing the shape of the guide groove (39).

By the way, using such an exposure apparatus, for example, a phosphor slurry film (4) formed on the inner surface of the panel (1) is formed.
When the coating such as 0) is exposed through the shadow mask (3), the exposure area of the phosphor slurry coating (40) moves with the movement of the shutter (16). The position of the exposure light source (13) can be changed so that the deflection center of the horizontal deflection and the deflection center of the vertical deflection based on the characteristics coincide with each other. Therefore, it is possible to form a three-color phosphor layer at a required position on the inner surface of the panel (1) to form a color picture tube having a phosphor screen with good landing characteristics.

Further, according to such a method, it is necessary to carry out a compromise design in which the surface height at an arbitrary point of the correction lens coincides with the value obtained on the Z-axis and the value obtained on the Y-axis as in the related art. However, in the case of the above embodiment, the surface height of the correction lens need only be determined from the Z axis, and the design of the correction lens becomes easy.

In the above embodiment, the case where the shutter is moved in the Y-axis direction and the exposure light source is moved on the YX plane has been described. However, the movement of the shutter and the exposure light source is performed by moving the shutter in the Z-axis direction and exposing the exposure light source. May be moved in the ZX plane.

The correction lens to be used is not only a lens that can express the surface shape by a single mathematical expression such as x = f (y, z), but also one that can be expressed by a plurality of mathematical expressions, or is divided into a plurality of blocks. A correction lens having a step on the surface can also be used.

As for the γ-Δp characteristic, when the trajectory of light does not intersect the x-axis, an intersection angle when projected on the YX plane or the ZX plane may be used.

〔The invention's effect〕

According to the present invention, it is possible to form a color picture tube having good landing characteristics over the entire phosphor screen.

[Brief description of the drawings]

1 to 7 are explanatory views of an embodiment of the present invention. FIG. 1 is a view showing a configuration of an exposure apparatus used for forming a fluorescent screen according to one embodiment, and FIG. FIG. 3 is a perspective view for explaining the principle, FIG.
FIGS. 4 (a) to 4 (c) are diagrams for explaining the surface shape of the correction lens, and FIGS. 5 (a) and (b) are diagrams for explaining a landing error of the correction lens, respectively, and FIG. FIGS. 9A to 9C are diagrams for explaining movement of an exposure point and correction of a landing error when an exposure light source is moved in synchronization with movement of a shutter, respectively.
FIG. 7 is a diagram showing a main part configuration of a different exposure apparatus, FIGS. 8 to 15 are explanatory views of the prior art, FIG. 8 is a configuration diagram of a color picture tube, and FIG. 3 for phosphor layer
FIG. 10 is a diagram for explaining landing of an electron beam, FIG. 10 is a diagram for explaining movement of a deflection center by a deflection magnetic field,
FIG. 11 is a block diagram for explaining a method of manufacturing a phosphor screen, FIG. 12 is a diagram showing a configuration of a conventional exposure apparatus, and FIGS. 13 (a) and 13 (b) each show a correction divided into a plurality of portions. FIG. 14 is a plan view and a cross-sectional view of the lens, FIG. 14 is a view for explaining a method of designing the correction lens, and FIGS. 15 (a) and (b) are zP cross-sectional views of the correction lens shown in FIG. 3A and 3B are a diagram showing a surface shape of a cross section and a diagram showing a surface shape of a yP cross section. 1 Panel, 3 Shadow mask 13 Exposure light source, 16 Shutter 20 Correction lens, 33 Drive motor 40 Phosphor slurry coating

Claims (1)

(57) [Claims] 1. A coating of a photosensitive resin or a phosphor slurry is formed on the inner surface of a panel, and the coating is irradiated with light from a light source through a shadow mask. After baking, a method for manufacturing a color picture tube for forming a phosphor screen on the inner surface of the panel by forming a non-light emitting layer or a phosphor layer by developing, wherein the coating film formed on the inner surface of the panel is exposed to light from the light source. Using a shutter to limit the light irradiation area, when moving the light source in synchronization with the movement of the shutter, the position of the pattern corresponding to the through-hole of the shadow mask obtained on the coating on the inner surface of the panel, The shutter is perpendicular to the optical axis of the light source when compared with the position of the pattern corresponding to the through hole of the shadow mask when the fluorescent film is formed by fixing the light source. When moving in the horizontal axis direction on the plane, the position of the horizontal axis pattern is substantially the same as the position of the horizontal axis pattern when the light source is fixed and the phosphor film is formed. Controlling the movement of the light source in the optical axis direction and the movement in the horizontal axis direction so that the shutter moves in the vertical axis direction in a plane perpendicular to the optical axis of the light source. The movement of the light source in the optical axis direction and the vertical movement of the light source so that the position of the pattern in the direction and the position of the vertical axis direction pattern when the fluorescent film is formed by fixing the light source are substantially the same. By controlling the movement, the light source is moved so as to coincide with the deflection center of the horizontal deflection and the deflection center in the vertical direction based on the γ-Δp characteristic, and the film corresponds to the through-hole of the shadow mask. Baking pattern Method for manufacturing a color picture tube, wherein the kick.