JPH1079232A - Cathod-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably shield over-scanned electron beams by providing an inner beam shielding mechanism on a supporting mechanism of a color selecting mechanism and specifying the angle formed between the reflecting surface and the loci of the electron beams. SOLUTION: An aperture grill 8 as a color selecting mechanism is supported by a supporting mechanism 13 comprising a pair of lateral frames 14a and a pair of longitudinal frames 15a. In the supporting mechanism 13, a shield member 20 for shielding electron beams 23, 24 over-scanned in the vertical direction is attached to the main surface 10 of the lateral frame 14a near welded joining parts 19 of the lateral frames 14a and the longitudinal frames 15a. This shield member 20 is constituted into an approximately U shape in the section, and the reflecting surfaces 21a, 21b, 21c are so formed that the angle θ formed between them and the loci of the electron beams may be in the range of 0 to 45 deg.. Therefore, the over-scanned electron beams 23, 24 are prevented from being radiated to a fluorescent surface 12, and a cathode-ray tube 1 in which color purity is prevented from being deteriorated is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode ray tube having an internal beam shielding mechanism for preventing color shift.

[0002]

2. Description of the Related Art A single-gun three-beam cathode ray tube has conventionally been proposed. In the cathode ray tube, in the case of a color system, an electron beam emitted from an electron gun passes through a color selection mechanism disposed inside a panel, is irradiated on a phosphor screen, and a predetermined phosphor is emitted. As a result, an image is projected.

The single-gun three-beam cathode ray tube 100
As shown in FIG. 4 and FIG. 5, a valve 103 composed of a funnel part 101 and a neck part 102, an electron gun (not shown) attached to an end of the neck part 102, and a funnel part 101 And an aperture grill 107 to be used. The funnel portion 101 has a face portion 105 serving as a screen on the main surface thereof, and a fluorescent surface 106 on which a phosphor made of red, green, and blue is printed is formed on the inner surface thereof. Further, the aperture grill 107 has a function as a color selection mechanism,
A striped opening is provided. The aperture grill 107 has a vertical frame 108 (108a, 108
b) and the horizontal frame 109 (109a, 109b). That is, the vertical frame 108 is attached to the pair of horizontal frames 109 by welding, and the aperture grill 1
Reference numeral 07 is attached by being stretched on an attachment surface constituted by the main surface of the horizontal frame 109.

The cathode ray tube 1 constructed as described above
At 00, when the power of the television receiver is turned on, the color signal output from the color signal input circuit is input to the electron gun, and the electron beam 104 is emitted to the fluorescent screen 106.
Then, the electron beam 104 emitted from the electron gun is deflected by the magnetic field of the deflection coil, and
7 and illuminates the phosphor screen 106, the phosphor emits light, and an image is displayed on the face portion 105.

[0005]

As shown in FIGS. 4 and 5, the cathode ray tube 100 constructed as described above has a so-called over-scan in which an electron beam is scanned in a vertical direction so as to be larger than a predetermined scanning area. In order to prevent irregular reflection of the scanned electron beam, a shielding plate 110 (110a,
110b, 110c, 110d) are provided. The shielding plate 110 is formed by small pieces having a rectangular shape, and is attached by welding so as to protrude toward respective opposing sides near a joint 111 where the vertical frame 108 and the horizontal frame 109 are joined by welding. I have. In the cathode ray tube 100 to which such a shielding plate 110 is attached, the overscanned electron beam 112 is usually applied to the vertical frame 1.
The light is reflected by the end face 113 of the light emitting device 08, and is thereafter shielded by the shielding plate 110. The electron beam 112 is directly reflected by the shielding plate 110 and is shielded. Therefore, the cathode ray tube 100 is prevented from irradiating the phosphor screen 106 with the electron beam 112, thereby preventing deterioration of color purity.

[0006] However, the cathode ray tube 100 to which such a shielding plate 110 is attached is mounted on the electron beam 11.
When the electron beam 114 overscanned further than 2 is emitted from the electron gun, the electron beam 114 reflected on the end face 113 of the vertical frame 108 as shown in FIG.
Means that the electron beam 114 is irradiated on the phosphor screen 106 without hitting the shielding plate 110. Therefore, in the cathode ray tube 100, mislanding occurred, and deterioration of color purity could not be prevented.

Accordingly, an object of the present invention is to provide a cathode ray tube capable of steadily shielding an electron beam reflected by a support mechanism of a color selection mechanism or the like.

[0008]

In order to solve the above-mentioned problems, a cathode ray tube according to the present invention has a color selection mechanism for transmitting an electron beam emitted from an electron gun and a support for supporting the color selection mechanism. A mechanism, and an internal beam shielding mechanism attached to the upper and lower side edges of the supporting mechanism so as to face each other, wherein the internal beam shielding mechanism forms an angle between a trajectory of the electron beam and a reflection surface of the internal beam shielding mechanism. Is 0 to 4
The angle is 5 degrees.

In the cathode ray tube configured as described above, even when the overscanned electron beam is emitted from the electron gun, the internal beam shielding mechanism causes the trajectory of the electron beam and the reflection surface of the internal beam shielding mechanism to change. The electron beam is steadily shielded because the angle is formed between 0 and 45 degrees.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a cathode ray tube according to the present invention will be described in detail with reference to the drawings. The cathode ray tube is applied to, for example, a color cathode ray tube.

As shown in FIGS. 1 and 2, the cathode ray tube 1 has a tubular neck portion 2, a funnel portion 3 formed by projecting from the neck portion 2, and a face portion 4 serving as a screen surface. A valve 6 comprising a panel portion 5 to be formed, and an electron gun 7 provided at an end of the neck portion 2
And an aperture grille 8 which is a color selection mechanism attached inside the valve 5.

The bulb 6 is formed in the shape of a flask as a whole, and is made of glass having excellent X-ray blocking properties so that the bulb 6 does not turn brown even with the collision of an electron beam due to high voltage acceleration. The face portion 4 is formed in a rectangular shape and forms a screen surface. The skirt portion 1 provided on the periphery of the face portion 4 is provided on the panel portion 5.
1 is provided, and the end face of the funnel portion 3 is welded after the aperture grill 8 is attached inside the panel portion 5. In addition, a fluorescent screen 12 is formed on the back surface of the face portion 4. The phosphor screen 12 has stripes of red, green, and blue phosphors printed thereon.

An electron gun 7 arranged on the neck 2
Has a single electron gun structure in which electron beams corresponding to red, green and blue emitted from three in-line cathodes intersect at the center of one main lens. The electron beams dispersed in three directions are refracted by the electrostatic polarizing plate and converge on the phosphor screen 12.

The aperture grille 8 performs color selection by transmitting electron beams corresponding to red, green, and blue emitted from the electron gun 7 so as to irradiate only the phosphors of the corresponding emission colors. It is. The aperture grill 8 has a rectangular shape substantially the same as the face portion 4 and is made of a mild steel plate having a thickness of about 0.1 mm, and a plurality of stripe-shaped slits are formed on a main surface thereof. Have been. That is, the aperture grill 8 performs color selection by transmitting an electron beam through a plurality of rows of striped slits. The aperture grill 8 is supported by the support mechanism 13. The support mechanism 13 includes a pair of horizontal frames 14 (14a, 14b) and a pair of vertical frames 15 (15a, 15b). These frames 14 and 15 are formed of a metal material such as stainless steel. The cross-sectional shape of the horizontal frame 14 is substantially L-shaped, and a side edge of the aperture grill 8 in the long side direction is welded to one end surface thereof. The vertical frame 15 is welded to connect the horizontal frame 14 to one main surface 10 of the horizontal frame 14.

As shown in FIG. 2, the support mechanism 13 to which the aperture grille 8 is welded and attached is substantially equivalent to one main surface 10 of the horizontal frame 14 and one main surface of the vertical frame 15 as shown in FIG. A rectangular plate-shaped support 16 for supporting the support mechanism 13 is welded to the center. One end of a spring 17 is hooked to the support 16, and the other end is hooked and attached to a hook 18 provided inside the panel 5.

The support mechanism 13 shields the main surface 10 of the horizontal frame 14 near the welded portion 19 between the horizontal frame 14 and the vertical frame 15 from an overscanned electron beam. A shielding member 20 is attached. As shown in FIG. 2, the shielding member 20 has a substantially U-shaped cross section, and is formed by bending a metal plate such as stainless steel. Then, the shielding member 20 is welded with its opening sides facing each other inward. The shielding member 20 attached to the horizontal frame 14 has a reflective surface 21
(21a, 21b, 21c), and these reflecting surfaces 21 are perpendicular to the vertical frame 15. That is, the reflection surface 21a is formed on the inner surface of the bulb 6, the reflection surface 21b is formed on the back surface of the reflection surface 21a, and the reflection surface 21c is the surface on the opposite side of the reflection surface 21b. . The shielding member 20 may be attached not only partially to the main surface 10 of the horizontal frame 14 near the joint 19 but also to the entire main surface 10 of the horizontal frame 14. In this case, the electron beam overscanned by the shielding member 20 can be further shielded.

When the electron beam 22 is normally emitted from the electron gun 7, the cathode ray tube 1 in which such a shielding member 20 is attached to the support mechanism 13 is provided with a predetermined fluorescent light on the fluorescent screen 12 through the aperture grill 8. Irradiated on body, face part 4
A predetermined image is projected on the screen. When the overscanning is performed and the shielding member 20 is not provided, the electron beam 23 that is supposed to be irradiated on the horizontal frame 14 is applied to the shielding member 20.
The electron beam 23 can be prevented from going in the direction of the aperture grill 8 by being radiated and reflected on the reflection surface 21c. Further, the electron beam 24 that is overscanned and applied to the vertical frame 15 is applied to the reflection surface 21a and reflected, whereby the electron beam 24 can be prevented from going in the direction of the aperture grill 8. That is, according to the cathode ray tube 1, the overscanned electron beams 23 and 24 are prevented from being irradiated to the fluorescent screen 12 via the aperture grill 8 by the shielding member 20, so that the deterioration of color purity is prevented. Can be prevented.

The cathode ray tube 30 according to the second embodiment has
For example, as shown in FIG. 3, the shielding member 31 is formed in a sawtooth shape. The same members as those of the cathode ray tube 1 according to the first embodiment are denoted by the same reference numerals, and the details are omitted.

The shielding member 31 is formed by the shielding member 20 described above.
Similarly to the above, the horizontal frame 1 is provided in order to shield the electron beam that has been overscanned in the vertical direction, and is near the welded joint 19 between the horizontal frame 14 and the vertical frame 15.
4 and is attached to the main surface 10 by welding. As shown in FIG. 3, the shielding member 31 is formed in a sawtooth shape, and is formed by bending a metal plate such as stainless steel. The shielding members 31 are attached to the vertically opposed horizontal frames 14 so as to face each other. The shielding member 31 attached to the horizontal frame 14 has a reflective surface 32 (32a, 32b, 32c, 32d, 32).
e). Further, the reflection surfaces 32a, 32c,
32 e is perpendicular to the vertical frame 15, and the reflection surfaces 32 b and 32 d are inclined with respect to the vertical frame 15. The shielding member 31 may be attached not only partially to the main surface 10 of the horizontal frame 14 near the joint portion 19 but also to the entire main surface 10 of the horizontal frame 14. In this case, the electron beam overscanned by the shielding member 31 can be further shielded.

When the electron beam 22 is normally emitted from the electron gun 7, the cathode ray tube 30 in which such a shielding member 31 is attached to the support mechanism 13 is provided with a predetermined fluorescent light on the fluorescent screen 12 through the aperture grill 8. The body is irradiated, and a predetermined image is projected on the face portion 4. When the overscanning is performed and the shielding member 31 is not provided, the electron beam 23 supposed to irradiate the horizontal frame 14 is applied to the shielding member 2.
By irradiating and reflecting on the 0 reflection surface 32a,
It is possible to prevent the electron beam 23 from going in the direction of the aperture grill 8. Further, the electron beam 24 that is overscanned and irradiates the vertical frame 15 is
The electron beam 24 can be prevented from going in the direction of the aperture grill 8 by being irradiated and reflected on the reflection surface 32e. That is, according to the cathode ray tube 30,
The overscanned electron beams 23 and 24 are transmitted through the aperture grill 8 by the shielding member 31 to the fluorescent screen 12.
Is prevented from being irradiated, so that deterioration of color purity can be prevented.

The reflection surfaces 2 of the shielding members 20, 31
1 and 32, the angle θ between the trajectory of the electron beam and the trajectory of the electron beam is 0 to 45 degrees. This is because, when θ is larger than 45 degrees, the electron beam is reflected by the reflection surface 21 in the direction of the aperture grille 8, that is, in the image portion where an image is drawn, and the color purity is deteriorated. Because it becomes. Therefore, the shape of the shielding member is not limited to the shielding members 20 and 31 as long as the shielding member has a reflecting surface having an angle θ with the trajectory of the electron beam of 0 to 45 degrees. is there.

The above-mentioned cathode ray tubes 1 and 30 are reflected by, for example, the reflecting surfaces 21c and 32e of the shielding members 20 and 31 and further reflected by the other reflecting surfaces 21b and 32d. May be irradiated with an electron beam. However, since such an electron beam has already been reflected twice by the reflection surfaces 21 and 32 and has been deteriorated, it does not affect the deterioration of the color purity.

[0023]

According to the cathode ray tube according to the present invention, even when an overscanned electron beam is emitted from an electron gun, the internal beam shielding mechanism makes the trajectory of the electron beam and the reflection surface of the internal beam shielding mechanism correspond to each other. Angle between 0 degree and 4
Since the electron beam is provided at 5 degrees, the electron beam is steadily shielded, and the deterioration of color purity can be prevented.

[Brief description of the drawings]

FIG. 1 is a side view of a cathode ray tube according to the present invention.

FIG. 2 is a cross-sectional view of a main part of a cathode ray tube for explaining a relationship between a reflection surface of a shielding member and a trajectory of an electron beam.

FIG. 3 is a cross-sectional view of a main part of a cathode ray tube for explaining a relationship between a reflection surface of a shielding member and a trajectory of an electron beam in a second embodiment.

FIG. 4 is an overall perspective view of a conventional aperture grill.

FIG. 5 is a sectional view of a main part of the cathode ray tube.

[Explanation of symbols]

1 cathode ray tube, 2 neck, 3 funnel, 4
Face part, 5 panel part, 6 valve, 7 electron gun,
Reference Signs List 8 aperture grille, 10 main surface, 11 skirt portion, 12 fluorescent screen, 13 support mechanism, 14 horizontal frame, 15 vertical frame, 16 support, 17 spring, 18 hooking portion, 19 joining portion, 20 shielding member, 2
1 reflective surface,

Claims (3)

[Claims] 1. A color selection mechanism for transmitting an electron beam emitted from an electron gun, a support mechanism for supporting the color selection mechanism, and an interior provided opposite to upper and lower side edges of the support mechanism so as to face each other. A cathode ray tube, comprising: a beam shielding mechanism; wherein the internal beam shielding mechanism has an angle between a trajectory of the electron beam and a reflection surface of the internal beam shielding mechanism of 0 to 45 degrees. 2. The cathode ray tube according to claim 1, wherein said internal beam shielding mechanism is formed in a substantially U-shape. 3. The cathode ray tube according to claim 1, wherein said internal beam shielding mechanism is formed in a saw-tooth shape.