JPH09147756A - Color cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent color shifts resulting from temperature rises so as to maintain high picture quality by providing arrangement such that the bending angle of each plate-shaped spring supporting a shadow mask structure against the interior wall of a panel is approximately zero when they are fitted to pins on the interior wall of the panel. SOLUTION: A shadow mask structure 1 comprises a shadow mask 2 whose end is welded to the mask welding bars 3a, 3b of a mask frame 3 bridged and fixed by U-shaped support arms 4a, 4b. The plate-shaped springs 6a to 6d of spring suspension mechanisms 5a to 5d which are welded to base plates 7a to 7d suspend the structure 1 from the interior wall of a panel on the inner surface of which a phosphor is formed. In this case, while the springs 6a, 6b secured to the bars 3a, 3b via the plates 7a, 7b have their respective ends fitted to the interior wall of the panel, they are arranged so that bending angle is approximately zero. Thus color shifts resulting from the relative movements of the mask 2 and the phosphor due to temperature rises are prevented, and high picture quality can be maintained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color cathode ray tube of a type in which color selection is performed by a shadow mask, and in particular, electron beam and fluorescence caused by the shadow mask moving due to thermal expansion due to electron beam bombardment. The present invention relates to a color cathode ray tube that eliminates displacement with the body.

[0002]

2. Description of the Related Art A color cathode ray tube widely used as a monitor tube of a television receiver or an information terminal is a so-called shadow mask type. This type of color cathode ray tube includes a panel having a phosphor formed on the inner surface thereof, a neck for accommodating an electron gun, and a vacuum envelope composed of a funnel connecting the panel and the neck, and is embedded in the inner wall of the panel. The pin has at least a shadow mask fixed to a mask frame suspended by a spring suspension mechanism.

In the shadow mask, three electron beams emitted from an electron gun housed in the neck are divided and divided into three phosphors of red, green, and blue, which are formed on the inner surface of the panel. It has a function of selectively controlling the path of each electron beam so as to collide. This shadow mask generally has a thin plate of iron or an iron-nickel alloy having a small coefficient of thermal expansion and has round, rectangular, or blind electron beam passage holes, and the electron of the shadow mask is formed on the inner surface of the panel. A mosaic of phosphors is formed by being divided as described above in a shape corresponding to the shape of the beam passage hole.

Then, a shadow mask having a round electron beam passage hole is used as a dot type shadow mask, a shadow mask having a rectangular electron beam passage hole is used as a slot type shadow mask, and a shadow mask having a blind electron beam passage hole is used. It is called a grill type shadow mask.
In general, the dot-type shadow mask and the slot-type shadow mask are often molded in a spherical shape, and the grill-type shadow mask is held by a frame-shaped or parallel pair mask frame in a cylindrical surface shape by applying tension to the grill. This tension-applied shadow mask is also called a stretched mask.

It is also known that a slot type shadow mask is held in a cylindrical surface shape by applying tension in the longitudinal direction of the grill, similarly to the grill type shadow mask.
The prior art relating to this type of color cathode ray tube is disclosed in, for example, Japanese Patent Laid-Open No. 62-133645.
JP-A-59-167936, JP-A-48-768
No. 57 publication and the like can be mentioned.

[0006]

In the shadow mask, the temperature rises due to the electron beam bombardment during the operation of the cathode ray tube, the shadow mask structure thermally expands, and the positional relationship between the electron beam passage holes and the phosphors. However, there is a problem that a predetermined color cannot be obtained. In recent years, there has been an increasing demand for high-definition display in cathode ray tubes, and as the precision of image display increases, the electron beam on the fluorescent screen due to the displacement of the electron beam passage hole due to the thermal expansion of the shadow mask structure The need to highly control landing misalignment is becoming more and more intense.

FIG. 6 is a schematic sectional view for explaining the structure of a color cathode ray tube to which the present invention is applied. 1 is a shadow mask structure, 2 is a shadow mask, 3 is a mask frame, and 5 is a mask frame.
Is a spring suspension mechanism, 11 is a panel, 12 is a funnel, 13 is a neck for accommodating an electron gun, 14 is an electron gun, 1
Reference numeral 5 is a deflection yoke, 16 is a phosphor screen formed with a plurality of phosphors (red, green, and blue), 18 is an internal magnetic shield, 19 is a pin embedded in the inner surface of the panel, and 20 is a reinforcing band.

The shadow mask 2 is suspended by being mounted on the mask frame 3 by fitting a spring suspension mechanism 5 whose one end is fixed to the mask frame 3 to a pin 19. The reinforcing band 20 has a function of winding the panel 11 by applying tension to prevent implosion.

Bc is a center electron beam and Bs is two side electron beams. During operation of the color cathode ray tube, the electron beam scans the entire inner surface of the shadow mask 2 by the horizontal and vertical deflection magnetic fields generated by the deflection yoke. The scanning of the electron beam raises the temperature of the shadow mask 2 and causes thermal expansion. The tension-applied shadow mask structure is a system that absorbs elongation due to thermal expansion by relaxing tension.

Here, the spring structure of the spring suspension mechanism for suspending the shadow mask structure in the panel has a mounting angle between one end fixed to the mask frame and the other end suspended on the pin. FIG. 7 is an explanatory diagram of a spring suspension mechanism adopted in a conventional tension applying type shadow mask structure and its operation.

In the suspension system of (a), when the tension is relieved by the thermal expansion of the shadow mask and the mask frame 3 extends, the shadow mask structure is displaced in the directions of arrows A and B. Further, in the suspension method of (b), when the tension is relieved by the thermal expansion of the shadow mask and the mask frame 3 extends,
The shadow mask structure is displaced in the directions of arrows C and D.

That is, the stretched mask which is tensioned and stretched around the mask frame absorbs the thermal expansion by relaxing the tension of the shadow mask due to the thermal expansion. However, in the stretched mask, the relaxation of the tension acts to extend the mask frame constituting the shadow mask structure in the tension applying direction, and the spring of the spring suspension mechanism interposed between the mask frame and the pin includes a tube including this. In the XY plane perpendicular to the axis, if there is a mounting angle with respect to the X axis, the spring in the horizontal direction (X
The position of the shadow mask structure moves due to the lever effect of (direction), which causes color misregistration.

It is an object of the present invention to provide a high quality color cathode ray tube which prevents the occurrence of color misregistration due to the above-mentioned causes and prevents the position of the shadow mask structure from moving even when the temperature of the shadow mask rises. It is in.

[0014]

In order to achieve the above object, the first invention according to claim 1 is a panel having a phosphor formed on its inner surface, a neck for accommodating an electron gun, a panel and a neck. In a color cathode ray tube having a vacuum envelope consisting of a funnel connecting with and at least a shadow mask structure suspended via a spring suspension mechanism to a pin embedded in the inner wall of the panel, wherein the shadow mask structure is: A mask frame and a shadow mask whose edges are welded to the mask frame. The spring suspension mechanism has a plate spring, and one end is fixed to the mask frame and the other end is fitted to the pin. The plate-shaped spring is made to have almost no angle with the X-axis in the XY plane perpendicular to the tube axis including the plate-shaped spring, that is, Wherein the bending angle of the plate spring is arranged substantially zero.

According to a second aspect of the present invention, the spring suspension mechanism has a plate-shaped spring and a base plate supporting the plate-shaped spring, and the base plate fixes one end to the mask frame. The other end is swung in the peripheral direction of the mask frame.
Further, a third invention according to claim 3 is a stripe shape in which phosphors of each color forming the phosphor screen extend in a vertical direction, and the shadow mask is stretched by applying tension to the mask frame. An angle with the X-axis in the XY plane perpendicular to the tube axis including the plate-shaped spring in a state in which the plate-shaped spring that is stretched and that constitutes the spring suspension mechanism attached to the mask frame is fitted with the pin. So that the bending angle of the plate-shaped spring is substantially zero.

Further, a fourth invention according to claim 4 is
The mask frame has a pair of welding bars for welding the shadow mask and a support arm that bridges the welding bars and is fixed in parallel. That is, the present invention is provided with a shadow mask suspended in the panel, which includes a vacuum envelope including a panel having a phosphor formed on an inner surface thereof, a neck accommodating an electron gun, and a funnel connecting the panel and the neck. In a color cathode ray tube having at least a structure, the shadow mask structure includes a mask frame and a shadow mask stretched around the mask frame, and the mask frame includes a pair of mask welding bars for welding the shadow mask. And a pair of support arms bridging the pair of mask welding bars and supporting the mask welding bars at regular intervals. One end of a spring is fixed to the mask frame and the other end is planted on the inner wall of the panel. A spring suspension mechanism fitted to the pin is attached.

The spring of the spring suspension mechanism is configured such that there is almost no bending angle of the spring (almost no mounting angle) while the other end of the spring is engaged with the pin. In addition, specifically, it is desirable that the mounting angle is within 5 degrees with the spring fitted to the pin.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION In the configuration of the first invention,
A plurality of phosphors (red, green, blue) are formed on the panel, and an electron gun for emitting a plurality of electron beams corresponding to the plurality of phosphors is housed in the neck. A vacuum envelope is formed by the panel, the neck and the funnel, and the shadow mask structure is suspended by a spring suspension mechanism on a pin embedded in the inner wall of the panel.

An edge of the shadow mask is welded to at least a pair of parallel mask frames to form a shadow mask structure. The plate-shaped spring that constitutes the spring suspension mechanism is such that the plate-shaped spring has one end fixed to the mask frame and the other end fitted to the pin, and the plate-shaped spring is an XY plane perpendicular to the tube axis including the plate-shaped spring. Is arranged so that there is almost no angle with the X-axis, and the displacement of the shadow mask structure in the horizontal direction of the screen by the plate-shaped spring is suppressed even if displacement occurs due to thermal expansion of the shadow mask. Is prevented from occurring.

In the structure of the second aspect of the present invention, the spring suspension mechanism is composed of a plate spring and a base plate supporting the plate spring, and
Fix the base plate to one end of the mask frame,
By arranging the other end so as to swing in the peripheral direction of the mask frame, even if displacement occurs due to thermal expansion of the shadow mask, positional movement of the shadow mask structure in the horizontal direction of the screen by the plate spring is suppressed. Therefore, the occurrence of color misregistration is prevented.

Further, in the configuration of the third invention,
The phosphors of the respective colors forming the phosphor screen are formed in stripes extending in the vertical direction, and the shadow mask is stretched by applying tension to the mask frame corresponding to the phosphors. By disposing the plate-shaped springs constituting the spring suspension mechanism attached to the mask frame so that the bending angle thereof is substantially 0, even if the shadow mask is displaced due to thermal expansion, the shadow mask formed by the plate-shaped springs is used. Since the position movement of the structure in the left-right direction of the screen is suppressed, the occurrence of color misregistration is prevented.

Further, in the configuration of the above-mentioned fourth invention,
In the shadow mask, tension is maintained by a support arm that bridges and fixes a pair of welding bars in parallel, and the bending angle of the plate spring of the spring suspension mechanism attached to the welding bars and the support arm is substantially zero. Even if the shadow mask is displaced due to the thermal expansion due to the arrangement, the movement of the shadow mask structure in the left-right direction of the screen is suppressed by the spring, so that the color shift is prevented.

In reality, it is desirable that the bending angle (mounting angle) be within 5 degrees. That is, the present invention is provided with a shadow mask suspended in the panel, which includes a vacuum envelope including a panel having a phosphor formed on an inner surface thereof, a neck accommodating an electron gun, and a funnel connecting the panel and the neck. In a color cathode ray tube having at least a structure, the shadow mask structure includes a mask frame and a shadow mask stretched around the mask frame, and the mask frame includes a pair of mask welding bars for welding the shadow mask. And a pair of support arms bridging the pair of mask welding bars and supporting the mask welding bars at regular intervals. One end of a spring is fixed to the mask frame and the other end is planted on the inner wall of the panel. A spring suspension mechanism fitted to the pin is attached.

The spring of the spring suspension mechanism is configured such that the other end of the spring is fitted to the pin so that the spring has almost no bending angle (the mounting angle is almost zero). Thus, when the shadow mask structure of the stretched mask absorbs thermal expansion of the shadow mask by relaxation of tension when the shadow mask structure of the stretched mask is operating, the spring mechanism moves in the horizontal direction of the screen along with the extension in the tension applying direction. The lever effect is suppressed, and the positional deviation between the electron beam passage hole and the phosphor due to thermal expansion of the shadow mask is prevented.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view of a shadow mask structure for explaining an embodiment of a color cathode ray tube according to the present invention, in which 1 is a shadow mask structure, 2 is a shadow mask, 3 is a mask frame, 3a and 3b are mask welding bars ( Hereinafter, also referred to simply as a welding bar) 4a and 4b are support arms, 5a, 5b, 5c and 5d are spring suspension mechanisms,
6a, 6b, 6c and 6d are plate springs, 7a and 7
Reference numerals b, 7c and 7d are base plates.

In the figure, the shadow mask structure 1 is formed by welding and fixing both ends in the long side direction to a pair of welding bars 3a and 3b fixed by bridging with a pair of U-shaped support arms 4a and 4b. The pair of support arms 4a and 4b are configured to hold the pair of welding bars 3a and 3b in parallel at a predetermined interval and apply a predetermined tension to the shadow mask 2.

The panel of this color cathode ray tube is flat in one direction (vertical direction) and has a slight convex curve in the other direction (horizontal direction) orthogonal thereto, and the welding bar 3a,
3b is curved in a shape following the above-mentioned horizontal curvature. Therefore, the shadow mask 2 is the welding bar 3 described above.
It is welded and fixed so as to have a horizontal curve similar to the curves a and 3b.

During operation of the color cathode ray tube, the electron beam collides with the shadow mask 2 to generate heat. This heat tends to thermally expand the shadow mask 2, but in the stretched mask method in which tension is applied to the shadow mask 2, this thermal expansion is absorbed by relaxation of tension. in this way,
In the stretched mask method, the mask frame 3 extends in the tension applying direction by relaxing the tension of the shadow mask due to thermal expansion.

In this embodiment, the support arms 4a and 4b are bent to apply tension to the shadow mask 2.
When the electron beam collides with the shadow mask 2, the welding bar 3
It extends in a direction perpendicular to the extending direction of a and 3b. The spring suspension mechanisms 5a and 5b are attached via a base plate in a direction substantially orthogonal to the tube axis and substantially in parallel with each other, and the extension of the welding bars 3a and 3b in the direction perpendicular to the extending direction is a plate-like spring. 6a, 6b and the plate spring 6a,
Since there is almost no angle with the X axis in the XY plane perpendicular to the tube axis including 6b, the shadow mask structure is not moved in the horizontal direction.

FIG. 2 is a schematic view for explaining a spring suspension mechanism adopted in the shadow mask structure of this embodiment.
In the figure, the base plate 7a (7b) having one end welded to the welding bar 3a (3b) has the other end swung to the outside of the mask frame, and the plate-shaped spring 6a (6b) welded to the other end is The angle α with the X axis in the XY plane perpendicular to the tube axis including the plate spring is almost zero when fitted to the pin 19, that is, the plate spring is arranged so that its bending angle is substantially zero. There is.

FIG. 3 is an explanatory view of the spring suspension mechanism employed in the shadow mask structure of this embodiment and its operation. Even in the suspension method of (a), when the tension is relieved by the thermal expansion of the shadow mask and the mask frame 3 expands, the shadow mask structure also expands in the tension applying direction. However, since the plate springs 6a and 6b have almost no bending angle, the shadow mask and the phosphor are not displaced from each other.

Similarly, in the suspension system of (b), the positional displacement between the shadow mask and the phosphor does not occur. FIG. 4 is a sectional view of an essential part for explaining an example of a spring mechanism adopted in the shadow mask structure of the color cathode ray tube according to the present invention. In the same figure, the spring suspension mechanism 5a (5b) is welded and fixed to the base plate 7a (7b) whose one end is welded and fixed to the welding bar 3a (3b) on which the shadow mask 2 is stretched, and the end portion of this base plate 7a (7b). The plate-shaped spring 6a (6b) is attached to the welding bar 3a (3b) in parallel with the plate-shaped spring 6a (6b). Due to the thermal expansion of 3, the spring suspension mechanism 5a (5b) is displaced as shown by the phantom line in FIG. This displacement is in the tension application direction of the shadow mask 2, and a displacement component orthogonal to the tension application direction hardly occurs.

FIG. 5 is a cross-sectional view of an essential part for explaining another example of the spring mechanism adopted in the shadow mask structure of the color cathode ray tube according to the present invention. Also in the figure, the spring suspension mechanism 5a (5b) has a base plate 7a (7b) whose one end is welded and fixed to the welding bar 3a (3b) on which the shadow mask 2 is stretched, and the end portion of the base plate 7a (7b). It is composed of a fixed plate spring 6a (6b), and the base plate 7a (7b) has a bending portion 71 in the middle thereof.

The plate spring 6 is formed by the welding bar 3a.
It is attached in parallel with (3b), and is configured so that there is almost no attachment angle described above. In this structure, the spring suspension mechanism 5a (5
b) is displaced as shown by an imaginary line in FIG. This displacement is in the tension application direction of the shadow mask 2, and is absorbed by the elastic force of the spring 6a (6b). Also at this time, a displacement component orthogonal to the tension application direction hardly occurs.

The displacement of the spring suspension mechanism in FIGS. 4 and 5 is relatively illustrated. In each of the above-mentioned examples, the spring 6 is bent by bending the base plate 7 to the fitting position of the spring 6 and the pin.
However, the spring may be formed into a shape including the base plate without using the base plate.

In the above, the case where the display of the color cathode-ray tube suddenly became bright from a dark state was explained, but if the electron beam continues to hit the shadow mask, the shadow mask 2 causes the welding bar 3a (3b) to the supporting arm 4a. The heat is transferred to (4b), and the shadow mask structure 1
The whole thermally expands. At this time, if the bending angle of the plate-shaped spring of the spring suspension mechanism is almost in the state of being engaged with the pin, the color shift caused by the spring suspension mechanism due to the thermal expansion does not occur.

The present invention not only relates to a stretched mask to which tension is applied, and also in a stretched mask, not only a spring suspension mechanism in the direction of tension application, but also a side pair that functions as a welding bar of a mask frame. The same applies to a spring suspension mechanism attached to a pair of orthogonal sides. The specific dimensions and configuration of the shadow mask structure shown in FIG. 1 will be described below.

The shadow mask structure 1 of FIG. 1 has a plane shape of 300 m in the vertical direction (vertical direction).
m, the size in the left-right direction (horizontal direction) is 400 mm, and the shadow mask 2 has a rectangular electron beam passage hole (slot) with a width of 0.075 mm and a length of 0.9 mm on a 0.025 mm thick iron plate. Vertical pitch 1.0m
m, horizontal pitch 0.3 mm, vertical 280 m
m, 380 mm in the horizontal direction.

That is, in this shadow mask 2, a grill having a width of 0.225 mm and a length of 280 mm has a thickness of 0.0.
The bridges are connected to each other by 25 mm, width 0.1 mm, and pitch 1.0 mm, and are shifted by half pitch between adjacent grills, and the bridges are arranged at the same position in every other horizontal direction. A pair of mask welding bars 3a, 3b
Is formed of 13 chrome steel and has a cross-sectional thickness of 3.
The frame is composed of an L-shaped member having a length of 5 mm and a side length of 8 mm, and the pair of welding bars 3a and 3b are supported in parallel by U-shaped support arms 4a and 4b made of the same material.

The shape and structure of the spring suspension mechanism and the arrangement position of the spring suspension mechanism in the mask frame are not limited to those shown in the above embodiment, and various modifications can be made within the technical scope of the present invention.

[0041]

As described above, according to the present invention,
Applying tension by making the plate-shaped spring bending angle of the spring suspension mechanism that supports the shadow mask structure, which is the color selection electrode, on the panel inner wall almost zero when fitted to the pin erected on the panel inner wall. When the shadow mask thus stretched is thermally expanded by the collision of the electron beam and expanded in the tension applying direction, the positional relationship between the electron beam passage hole of the shadow mask and the phosphor does not deviate.

Therefore, according to the present invention, it is possible to provide a color cathode ray tube which does not cause a color shift due to a temperature rise during operation and always displays a high purity color image.

[Brief description of the drawings]

FIG. 1 is a perspective view of a shadow mask structure for explaining an embodiment of a color cathode ray tube according to the present invention.

FIG. 2 is a schematic view illustrating an example of a spring suspension mechanism adopted in a shadow mask structure of a color cathode ray tube according to the present invention.

FIG. 3 is an explanatory diagram of a spring suspension mechanism adopted in the shadow mask structure of the present embodiment and its operation.

FIG. 4 is a sectional view of an essential part for explaining an example of a spring mechanism adopted in a shadow mask structure of a color cathode ray tube according to the present invention.

FIG. 5 is a sectional view of an essential part for explaining another example of the spring mechanism adopted in the shadow mask structure of the color cathode ray tube according to the present invention.

FIG. 6 is a schematic sectional view illustrating the structure of a color cathode ray tube to which the present invention is applied.

FIG. 7 is an explanatory diagram of a spring suspension mechanism adopted in a conventional shadow mask structure and its operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shadow mask structure 2 Shadow mask 3 Mask frame 3a, 3b Mask welding bar 4a, 4b Support arm 5a, 5b, 5c, 5d Spring suspension mechanism 6a, 6b, 6c, 6d Plate spring 7a, 7b, 7c, 7d Base plate. 71 Base Plate Refraction Part 11 Panel 12 Funnel 13 Neck 14 Electron Gun 15 Deflection Yoke 16 Plural Fluorescent Substances 18 Internal Magnetic Shield 19 Pins 20 Reinforcing Band.

Front page continuation (72) Inventor Akio Nakamura 3300 Hayano, Mobara-shi, Chiba Electronic Devices Division, Hitachi, Ltd. (72) Inventor Hiroshi Kawasaki 3681 Hayano, Mobara-shi, Chiba Hitachi Device Engineering Co., Ltd. (72) Inventor Yuichi Kijima 3300 Hayano, Mobara-shi, Chiba Hitachi, Ltd. Electronic Device Division

Claims (4)

[Claims] 1. A pin which is embedded in an inner wall of the panel, comprising a vacuum envelope including a panel having a phosphor formed on an inner surface thereof, a neck for accommodating an electron gun, and a funnel connecting the panel and the neck. In a color cathode ray tube having at least a shadow mask structure suspended via a spring suspension mechanism, the shadow mask structure includes a mask frame and a shadow mask having an edge welded to the mask frame, and the spring suspension mechanism is A plate spring having one end fixed to the mask frame and the other end fitted to the pin, and a long side of the plate spring is an X axis in an XY plane perpendicular to a tube axis including the spring. Has almost no angle, that is, the bending angle of the plate spring is approximately 0.
A color cathode ray tube characterized by being arranged as follows. 2. A pin which is embedded in an inner wall of the panel, comprising a vacuum envelope including a panel having a phosphor formed on an inner surface thereof, a neck for accommodating an electron gun, and a funnel connecting the panel and the neck. In a color cathode ray tube having at least a shadow mask structure suspended via a spring suspension mechanism, the spring suspension mechanism has a plate spring and a base plate supporting the plate spring, and the base plate has one end on a mask frame. Fixed,
A color cathode ray tube, wherein the other end is swung in the peripheral direction of the mask frame. 3. The phosphor according to claim 1, wherein the phosphors of each color forming the phosphor screen have a stripe shape extending in a vertical direction, and the shadow mask is stretched by applying tension to the mask frame. In addition, with the spring on the long side that constitutes the spring suspension mechanism attached to the mask frame fitted with the pin, the angle with the X axis in the XY plane perpendicular to the tube axis including the plate spring. A color cathode-ray tube characterized in that the plate-shaped spring is arranged so that the bending angle thereof is substantially zero. 4. The color cathode ray tube according to claim 3, wherein the mask frame has a pair of welding bars for welding the shadow mask, and a supporting arm that bridges the welding bars and is fixed in parallel. .