JPH09259782A - Shadow mask holding structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lightweight shadow mask holding structure which can uniformly impress desired tensile force on the whole surface of a slot type shadow mask. SOLUTION: A shadow mask holding structure holds a shadow mask at a prescribed position by respectively stretching the long sides of a quadrangular shadow mask. In this case, it is composed of a quadrangular frame member 12b having the short sides and the long sides, a long side stretching member to respectively stretch the long sides of the shadow mask and a connecting member 12c to connect the long sides of the quadrangular frame member 12b to each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shadow mask holding structure, and more particularly, to a shadow mask which is arranged so as to face a fluorescent surface of a shadow mask type color cathode ray tube and which determines an arrival position of an electron beam. The present invention relates to a technique effectively applied to a shadow mask holding structure including a holding mask frame.

[0002]

2. Description of the Related Art The most widely used color cathode ray tube at present is a so-called shadow mask type color cathode ray tube, in which three electron beams emitted from an electron gun are applied to the inner surface of the panel (red). R, green (G), and blue (B) phosphors are allotted and collided with each other.

At this time, a shadow mask selectively controls the path of each electron beam, and generally has a round hole, a rectangular hole, or a blind-shaped electron beam passage hole.

Further, a phosphor having a shape corresponding to the shape of the electron beam passage hole is formed on the inner surface of the panel surface of the cathode ray tube where each electron beam having passed through the shadow mask is projected.

Depending on the shape of the electron beam passage hole provided in the shadow mask, one having a round hole may be a dot type shadow mask, one having a rectangular hole may be a slot type shadow mask, and one having a blind electron beam passage hole. I will call it a grill type shadow mask.

Generally, the dot type and slot type shadow masks are formed in a spherical shape, while the grill type shadow mask applies tension to the upper and lower sides of the shadow mask in order to hold the shadow mask in a cylindrical shape. Since it was necessary, it was formed into a cylindrical surface.

However, the slot-type shadow mask can be considered to have a structure in which bridges for connecting the grills are provided in places where the grills of the grill-type shadow mask are arranged in parallel.

On the other hand, as a demand for a cathode ray tube, a demand for high-definition display is increasing, and particularly in recent years,
A GUI (Graphical U) is added to the OS (operating system) of a personal computer (personal computer).
The demand for high-definition display is increasing more and more due to the adoption of an operating environment using the ser interface.

However, during the operation of the cathode ray tube, the temperature of the shadow mask rises due to the collision of the electron beam with the shadow mask, and the shadow mask thermally expands as the temperature rises.
It is known that since the electron beam passage hole is displaced, the landing position of the electron beam on the phosphor screen is displaced, which hinders high-definition display.

As one of means for reducing the thermal expansion, in the cathode ray tube of the dot type shadow mask and the slot type shadow mask, a method of forming the shadow mask by a metal having a small thermal expansion coefficient such as iron-nickel alloy is considered. Has been.

Further, in the cathode ray tube of the grill type shadow mask, the influence of thermal expansion is reduced by holding the shadow mask by applying tension to the mask frame.

FIG. 4 is a perspective view of a conventional shadow mask holding structure disclosed in Japanese Patent Publication No. 55-139743, and this shadow mask holding structure is particularly called an aperture grill.

The shadow mask holding structure shown in FIG. 4 includes a pair of long-side stretch members 10a and 10b and a pair of short-side support arm members 10c and 10d that hold the long-side stretch members 10a and 10b in opposition to each other. The shadow mask 11 is stretched over the mask frame 10 composed of.

At this time, the shadow mask 11 has a plate thickness of 0.
A large number of vertical slits having a predetermined shape were formed on a low carbon steel plate having a diameter of 02 to 0.3 mm by photolithography at predetermined intervals.

The shadow mask 1 thus formed
In order to apply a predetermined tension in the slit direction (longitudinal direction), the reference numeral 1 fixes the predetermined tension by fixing two laterally opposite sides to the long-side stretch members 10a and 10b of the mask frame 10, respectively. Was being applied.

However, during the operation of the cathode ray tube, the shadow mask 11 thermally expands due to the heat generated when the electron beam collides with the shadow mask 11 as described above. Even at this time, the shadow mask 11 still has a predetermined value. The above tension must be applied.

Therefore, when the shadow mask 11 is fixed and attached to the mask frame 10, for example, as shown in FIG.
The shadow mask 11 is seam-welded to the long-side stretch members 10a and 10b while applying pressure so that the long-side stretch members 10a and 10b shown in FIG. The restoring force of 1 is applied to the shadow mask 11 with a tension of a predetermined value or more.

The above-described method cannot necessarily achieve high definition. For example, in the case of a dot type shadow mask and a slot type shadow mask, the hole diameter of the shadow mask is made small in order to improve the definition of the screen. In addition, it is necessary to narrow (decrease) the pitch between the holes.

However, since it is very difficult to form a hole having a small diameter in a shadow mask having a large plate thickness,
Although it is conceivable to reduce the plate thickness, this type of shadow mask needs to keep its shape spherical due to its own rigidity, and it is impossible to make it thinner than a predetermined value because of its rigidity, and it is naturally high. There was a limit to the definition.

On the other hand, in the cathode ray tube of the grill type shadow mask, it is necessary to provide a comb-shaped shadow mask over the entire display area. If the plate thickness is made thinner than a predetermined value, the shadow mask and the cathode ray tube itself are manufactured. Since there is a problem that the interdigital grilles are sometimes entangled with each other and the grill is deformed, it is difficult to reduce the thickness to a predetermined value or more.

[0021]

SUMMARY OF THE INVENTION As a result of studying the above prior art, the present inventor has found the following problems.

In order to increase the definition of a cathode ray tube using a conventional shadow mask, it is necessary to reduce the thickness of the shadow mask. As a technique for this, a slot type shadow mask is made spherical. Instead of holding
A method of applying tension to a pair of sides of the shadow mask like a grill shadow mask to keep the slot shadow mask cylindrical can be considered.

FIG. 6 is a view for explaining a procedure for stretching a slot type shadow mask on a conventional mask frame. In the conventional mask frame, short side members 10c and 10d are used.
And the long-side stretch members 10a and 10b were fixed by welding at the vessel point.

Therefore, as shown in FIG. 6B, when the long side stretch members 10a and 10b are compressed near the fixing points 15 and the long side stretch members 10a and 10b are compressed, as shown in FIG. )
As shown in FIG. 5, the central portion of the long-side stretch members 10a and 10b contracts the most, and the amount of displacement at both ends is small.

If the slot type shadow mask is welded in this state and the pressure is released, there is a problem that the mask frame is held in almost the same shape as when the pressure is applied, that is, the shadow mask is held in a distorted shape. .

Therefore, in addition to the pressurizing points shown in FIG. 6B, both ends of the long-side stretch members 10a and 10b are simultaneously pressed to maintain the shape of the long-side stretch members 10a and 10b. The method of welding the shadow mask was tried up to, but since both ends of the long-side stretch members 10a, 10b have a so-called cantilever structure with the fixed points 15 as supporting points, sufficient tension can be obtained. However, there is a problem that the shadow mask easily vibrates.

As another method, as shown in FIG. 5, both ends of the long-side stretch members 10a and 10b are connected to the short-side member 10.
It is conceivable to use a rectangular frame that is fixed to a supporting arm that is a c or 10d to stretch the shadow mask in a direction orthogonal to the horizontal scanning direction of the electron beam from the electron gun. Although the tension on the side is improved, there is a problem that the tension at the center is reduced.

It is an object of the present invention to provide a lightweight shadow mask holding structure capable of uniformly applying a desired tension to the entire surface of a slot type shadow mask.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0030]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

(1) A shadow mask holding structure for extending the long sides of a quadrilateral shadow mask to hold the shadow mask in a predetermined position, the frame being a quadrilateral frame having short sides and long sides. A member, a long side stretching member that stretches the long side of the shadow mask, and a connecting member that connects the long side stretching member and the long side of the quadrilateral frame member.

(2) At least three connecting members are provided on each of the long sides of the quadrilateral frame member.

According to the above-mentioned means (1) and (2), for example, a slot type shadow mask is used as the shadow mask, and the shadow mask is thinned to provide tension for holding the shadow mask in tension. Since the shadow mask holding structure can be made smaller and the rigidity of the shadow mask holding structure can be made smaller, the thickness of the shadow mask holding structure can be made thinner and the weight can be reduced. .

At this time, since the shadow mask has a bridge, adjacent grills are not entangled with each other.

Furthermore, since the connecting member connecting the long side stretch member for stretching the shadow mask and the long side of the quadrilateral frame member is connected at three or more points, the shadow mask is biased. Can be applied without tension.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings together with embodiments (examples) of the invention.

In all the drawings for describing the embodiments of the present invention, those having the same functions are denoted by the same reference numerals, and their repeated description will be omitted.

FIG. 1 is a view showing a schematic structure of a shadow mask holding structure of the present invention, in which 12a is a long side stretch member and 12 is a long side stretch member.
b is a quadrilateral frame member, 12c is a connecting member, 13 is a slot type shadow mask, 14 is a fixing bolt, 20 is an electron passage hole (slot), 21 is a grill part, 22 is a bridge part, and X, Y, Z Indicates the X axis, Y axis, and Z axis, respectively.

FIG. 7 is a perspective view showing a schematic structure of the shadow mask holding structure of the present invention shown in FIG.

Further, in FIG. 1, FIG. 1A is a front view of the shadow mask holding structure, and FIG. 1B is a side view of the shadow mask holding structure seen from the Y-axis direction.
1C is a side view when the shadow mask holding structure is viewed from the X-axis direction, and FIG. 1D is an assembly view of the mask frame.

In FIG. 1, the long-side stretch member 12a is made of stainless steel having an L cross section and has a radius of curvature of 800 mm.
It is.

The quadrilateral frame member 12b is made of 8 mm square stainless steel, and in the shadow mask holding structure of the present embodiment, there are four long sides in total at the Bessel point and both ends of the quadrilateral frame member 12b. A screw hole is provided for connecting the stretch member 12a.

The connecting member 12c is a member for connecting the long-side stretch member 12a and the quadrilateral frame member 12b, and the fixing bolts 14 are formed at both ends.

The shadow mask 13 is a well-known slot type shadow mask, which is made of mild steel with a thickness of 0.025 mm and the effective mask size is 280.
mm × 380 mm. The mask effective portion is the slot 20 having the bridge portion 22.

The slot 20 is a hole for guiding electrons to each phosphor of the phosphor screen 6 with the grill part 21 and the bridge part 22 as a frame.

The grill portion 21 extends linearly in the Y-axis direction in the figure, that is, in the horizontal scanning direction of the electron beam emitted from the electron gun, and they extend in the X-axis direction, that is, in the electron beam emitted from the electron gun. They are arranged at equal intervals in a direction perpendicular to the horizontal scanning direction.

The bridge portions 22 are arranged in parallel in the Y-axis direction in the figure at equal intervals, and are alternately arranged with the bridge portions 22 adjacent in the X-axis direction.

The horizontal pitch of the slots 20, that is, the pitch parallel to the horizontal scanning direction of the electron beam from the electron gun is 0.25 mm, and the vertical pitch is vertical to the horizontal scanning direction of the electron beam from the electron gun. The pitch in the direction of is 1.0 mm.

The width of the bridge portion 22 is 0.050 m.
m.

The square mass shown in the center circle is an enlargement of part of the slot shadow mask 13.

FIG. 2 is a diagram for explaining a procedure for stretching the slot type shadow mask on the mask frame according to the embodiment of the present invention, and in particular, FIG. 2 (a) illustrates a pressurizing point. 2B is a view for explaining the shadow mask holding structure after the shadow mask is stretched, FIG.
(C) is a view of the shadow mask holding structure seen from the Y-axis direction.

FIG. 3 is a sectional view showing a schematic structure of a color cathode ray tube using the shadow mask holding structure of the present embodiment, where 1 is a neck portion, 2 is a funnel, 3 is a panel, and 4 is a panel.
Is a cathode ray tube (bulb or tube), 5 is a face plate portion, 6 is a fluorescent screen, 7 is a shadow mask holding structure, 8 is an electron gun, 9 is an electron beam trajectory, 12 is a mask frame,
Reference numeral 13 indicates a shadow mask.

In FIG. 3, the neck portion 1 is arranged at a position facing the phosphor screen 6, and the funnel 2 is a portion extending from the neck portion 1 to the panel 3 and is irradiated from the electron gun 8 by a deflection yoke (not shown). This is a space for performing scanning (deflection) for sequentially irradiating each pixel of the phosphor screen 6 with the electron beam.

The panel 3 is a front portion of the cathode ray tube 4,
A phosphor screen 6 is formed on the inner surface of the face plate portion 5 of the panel 3.

The face plate portion 5 is a display portion of the cathode ray tube 4, and the fluorescent surface 6 is a surface coated with an object that emits light of a predetermined wavelength by the electron beam emitted from the electron gun.

The electron gun 8 is a well-known electron gun that emits three electron beams of red (R), green (G), and blue (B), and the trajectory 9 of the electron beam is emitted from the electron gun 8. It is a locus when the electron beam is guided in the X-axis direction (direction parallel to the horizontal scanning of the electron beam) by a deflection yoke (not shown).

Next, the shadow mask holding structure according to the embodiment of the present invention will be described with reference to FIGS. 1 and 7.
As shown in FIG. 1B, of the quadrilateral frame member 12b serving as the pedestal of the mask frame 12, a member parallel to the X axis, that is, a member parallel to the horizontal scanning direction of the electron beam from the electron gun and a long side frame The tension member 12a is fixed to the frame member 12b by a connecting member 12c.

The fixed positions at this time are, for example, as shown in FIG. 1, the apexes corresponding to both ends of the long-side stretch member 12a and the quadrilateral frame member 12b, and 2 corresponding to the Bessel point. There are a total of four points, and the tension of the shadow mask 13 is held by the connecting members 12c installed at these four points.

As shown in FIG. 1D, the mask frame according to the present embodiment has a long side of the quadrilateral frame member 12b and a screw hole portion provided in the long side tension member 12a. The fixing bolts 14 of the connecting member 12c are attached to the long side stretching member 12a and the connecting member 12c, and the quadrangular frame member 12b and the connecting member 12c are fixed to the long side stretching member 12a and the quadrilateral, respectively. The frame member 12b is fixed via the connecting member 12c.

Further, the shadow mask 13 has long-side stretch members 12 attached to both sides of the quadrilateral frame member 12b.
It is stretched and arranged by a.

At this time, in the shadow mask 13, for example, as shown in FIG. 2A, the portion where the connecting member 12c is attached is pressed inward of the quadrilateral frame member 12b, and in this state, the shadow mask 13 is pressed. Is welded to the long-side stretch member 12a, and the pressure is released after the welding.

After the pressure is released, as shown in FIG. 2 (b), a force acting on the long-side stretch member 12a indicated by the dotted line to return to the original position works, and this force acts on the shadow mask 13. It is applied as a tension pulled in the Y-axis direction.

At this time, in the shadow mask holding structure of the present embodiment, the connecting members 12c are installed at both ends of the long-side stretch member 12a and at a total of four Bessel points. , Uniform tension is applied and sufficient tension is obtained.

FIG. 3 shows a cathode ray tube using the above-described shadow mask holding structure. Red (R), green (G), and blue (B) electron guns (not shown) are integrally formed. The electron gun 8 emits an electron beam for developing each color.

Further, a fluorescent screen 6 is arranged so as to face the electron gun 8, and the fluorescent screen 6 is provided with regions of pixels arranged in a matrix.

The electron gun 8 and the fluorescent screen 6 described above are enclosed by the neck portion 1, the funnel 2 and the panel 3 which are envelopes made of glass, and in particular, the fluorescent screen 6 is covered on the inner wall surface of the panel 3. It has been worn.

Here, the panel 3 serves as a display portion of the cathode ray tube, and an observer can confirm the color development of the phosphor screen 6 through the panel 3.

A deflection yoke (not shown) is arranged between the neck portion 1 and the funnel 2, and as described above,
The deflection yoke is configured to perform scanning (deflection) for sequentially irradiating each pixel on the fluorescent screen 6 with each electron beam from the electron gun 8.

Further, in the portion on the panel 3 side in the envelope, in order to guide each scanned electron beam from each electron gun constituting the electron gun 8 to each corresponding phosphor, The shaped shadow mask holding structure 7 is arranged so as to face the phosphor screen 6.

At this time, the shadow mask holding structure 7
As described above, since the quadrilateral frame member 12b is acted on the two long-side stretch members 12a via the connecting member 12c in the direction of separating from each other, the shadow mask 1
A uniform and sufficient tension is applied to 3 in the direction orthogonal to the horizontal scanning direction of the electron beam, that is, in the direction perpendicular to the paper surface.

Therefore, the vibration of the shadow mask 13 can be prevented.

As described above, according to the shadow mask holding structure of the present embodiment, the long side stretch member 12a to which the shadow mask 13 is welded is attached to the long side stretch member 12a.
The quadrilateral frame member 1 via the connecting members 12c arranged at a total of four positions of both ends of a and Bessel points as other arbitrary points.
By fixing the long side of 2b, a force acts in the direction of separating the two long side stretching members 12a from each other, so that the shadow mask 13 welded to the long side stretching member 12a is horizontally scanned with the electron beam. A uniform and sufficient tension is applied in the direction orthogonal to the direction, that is, in the direction perpendicular to the paper surface.

Therefore, the vibration of the shadow mask 13 can be prevented.

As described above, the invention made by the present inventor is:
Although specifically described based on the embodiments of the present invention, the present invention is not limited to the embodiments of the present invention, and it is needless to say that various modifications can be made without departing from the gist of the present invention. .

[0075]

The effects obtained by typical ones of the inventions disclosed in the present application will be briefly described as follows.

A desired tension can be uniformly applied to the entire surface of the slot type shadow mask, and the weight can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a shadow mask holding structure according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining a procedure when the slot type shadow mask is stretched over the mask frame according to the embodiment of the present invention.

FIG. 3 is a sectional view showing a schematic configuration of a color cathode ray tube using the shadow mask holding structure according to the present embodiment.

FIG. 4 is a perspective view showing a schematic configuration of a conventional shadow mask holding structure.

FIG. 5 is a perspective view of a rectangular frame shadow mask holding structure in which both ends of long sides are fixed to support arms of short sides.

FIG. 6 is a diagram for explaining a procedure for stretching a slot-type shadow mask on a conventional mask frame.

FIG. 7 is a perspective view showing a schematic configuration of the shadow mask holding structure of the present invention shown in FIG.

[Explanation of symbols]

1 ... Neck part, 2 ... Funnel, 3 ... Panel, 4 ... Cathode ray tube, 5 ... Face plate part, 6 ... Phosphor screen, 7 ... Shadow mask holding structure, 8 ... Electron gun, 9 ... Electron beam trajectory, 11 ... Shadow mask, 12 ... Mask frame, 1
2a ... Long-side stretch member, 12b ... Quadrilateral frame member, 12c
... Connecting member, 13 ... Slot type shadow mask, 14 ...
Fixing bolt, 20 ... Electron passage hole (slot), 21 ...
Grill part, 22 ... Bridge part.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideo Tanabe, 3300 Hayano, Mobara-shi, Chiba Electronic device division, Hitachi, Ltd. (72) Inventor, Akio Nakamura 3300, Hayano, Mobara-shi, Chiba Hitachi, Ltd. Electronic device Within the business unit

Claims (2)

[Claims] 1. A shadow mask holding structure for extending long sides of a quadrilateral shadow mask to hold the shadow mask in a predetermined position, the quadrilateral frame member having short sides and long sides. And a long-side stretch member that stretches the long sides of the shadow mask, and a connecting member that connects the long-side stretch member and the long sides of the quadrangular frame member. And a shadow mask holding structure. 2. The shadow mask holding structure according to claim 1, wherein at least three connecting members are provided on each of the long sides of the quadrilateral frame member.