JP3178024B2 - Cathode ray tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cathode ray tube.

[0002]

2. Description of the Related Art Conventionally, there is known a projector which concentrates respective images from three monochromatic cathode ray tubes corresponding to red, green and blue on a screen through a lens system, and enlarges and projects them to obtain a desired color image. Have been.

The cathode ray tube used in this projector is downsized by widening the deflection angle of the electron beam,
That is, development of a cathode ray tube having a reduced depth is being promoted. Normally, in a cathode ray tube, a getter material is scattered on the inner surface of the tube to maintain the degree of vacuum in the tube to extend the life.

In a cathode ray tube for a projector, for example, a getter container containing a getter material is arranged at the tip of an electron gun, and the getter material is scattered from the getter container and adhered to the inner surface of the tube. Such a getter device is usually called a gun top getter.

[0005]

In order to reduce the depth of the cathode ray tube, it has been considered to move the electron gun closer to the center of deflection of the electron beam. In such a case, in the above-mentioned gun top getter, the getter device is disposed in the deflection magnetic field, so that the power consumption of the electromagnetic deflection device increases. Inconveniences arise.

In order to solve such inconvenience, it is conceivable to arrange a getter device on the inner surface of the funnel, for example. However, if the depth of the cathode ray tube is reduced by widening the electron beam deflection angle, it is difficult to secure the getter scattering area. When the getter scatters, it cannot be scattered to the electron gun side because it causes discharge.
Also, getter scattering on the phosphor screen side causes luminance degradation,
Getter scattering on the electron gun side and the phosphor screen side must be minimized. Therefore, the getter scattering area is reduced by reducing the distance between the electron gun and the phosphor screen by widening the angle.

The above problem can occur not only in a cathode ray tube for a projector but also in an ordinary cathode ray tube having a wide deflection angle.

The present invention has been made in view of the above circumstances, and provides a cathode ray tube capable of sufficiently obtaining a getter-covered area without reducing the luminance of a phosphor screen.

[0009]

According to the present invention, a funnel 7 is provided.
This is a cathode ray tube 1 in which a getter device 9 is disposed on the inner surface. In this cathode ray tube, the getter device 9 includes the getter material 1
2 containing the getter material 11 and the getter material 12
The upper surface plate 13A that shields the upper opening of the getter container 11 and the side plates 13B and 13C that continuously shield the side surface of the getter container 11 Both sides of the shield member 13 except for the electron gun 5 side and the fluorescent screen 4 side are opened from the side plates 13B and 13C to the upper plate 13A so as to partially expose the upper surface of the getter material 12. Is done. The shielding angle on the fluorescent screen 4 side of the shield member 13 is set to be larger than the shielding angle on the electron gun 5 side.

The shielding angle on the electron gun 5 side of the getter device 9 can be set to 20 ° to 90 °, and the shielding angle on the fluorescent screen 4 side can be set to 90 ° to 180 °.

[0011]

[0012]

In the present invention, by arranging the getter device 9 on the inner surface of the funnel 7, even when the depth is reduced, the power consumption of the electromagnetic deflection device is reduced as compared with the cathode ray tube using the gun top getter. In addition, the deflection of the electron beam from the electron gun is properly performed.

The getter device 9 comprises a getter container 11 accommodating the getter material 12 and a shield member 13 for controlling the scattering of the getter material 12. The shield member 13 includes an upper plate 13A for shielding the upper opening of the getter container 11. ,
The so-called getter container 1 having side plates 13B and 13C for shielding the side surface of the getter container 11 continuously from this.
1, the fluorescent screen 4 and the electron gun 5 of the getter container 11 are completely shielded. Both sides except the electron gun 5 side and the fluorescent screen 4 side of the shield member 13 are opened from the side plates 13B, 13C to the upper plate 13A, and a part of the upper surface of the getter material 12 is exposed.
The getter material 12 scatters three-dimensionally in an upward direction and a lateral direction (lateral direction), and a getter film is formed over a wide area. Further, since the shielding angle θ _{2 of} the shield member 13 on the fluorescent screen 4 side is set to be larger than the shielding angle θ ₁ of the electron gun 5 side, even if the getter device 9 is arranged near the fluorescent screen 4 in the funnel 7. In addition, getter scattering to the fluorescent screen 4 side can be sufficiently suppressed.

As described above, in the present invention, the getter scattering to the electron gun 5 side is prevented, the getter scattering to the fluorescent screen 4 side is sufficiently suppressed, and the getter scattering is performed on the inner surface of the funnel 7. That is, since the amount of the getter scattered on the fluorescent screen 4 side is reduced, the luminance does not deteriorate, and the main getter scatter is performed over a wide area of the inner surface of the funnel 7. Therefore, a reliable and long-life cathode ray tube can be provided.

[0015]

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a cathode ray tube (monochrome cathode ray tube) for a projector according to this embodiment. In the figure, reference numeral 1 denotes a cathode ray tube main body, and 2 denotes a liquid cooling device in which a cooling liquid disposed on the front surface of the panel 3 is sealed. Reference numeral 4 denotes a monochromatic phosphor screen formed on the inner surface of the panel 3, 10 denotes a metal back layer, and 5 denotes a phosphor screen.
Is an electron gun arranged opposite to.

In this embodiment, the elastic member 6 is provided by the electron gun 5.
And the getter device 9 is attached to the tip.
The getter device 9 is disposed just on the inner surface of the funnel 7. Here, since the elastic member 6 is formed of a metal material, the elastic member 6 is relayed via the ceramic member 8 at the intermediate portion.

As shown in FIGS. 2 and 3, the getter device 9 includes a getter container 11 having a ring shape in a plane circular shape, a getter material 12 accommodated in the getter container 11, and a getter material 12 from the getter container 11. And a shield member 13 for controlling scattering.

The shield member 13 shields the upper surface plate 13A for shielding most of the upper surface opening of the getter container 11 facing the getter material 12, and the side surface of the getter container 11 on the fluorescent screen 4 side and the electron gun 5 side, respectively. Side surfaces 13B and 13
C and a bottom plate 13D bent along a ring-shaped central hole of the getter container 11. Therefore, the upper surface plate 13A has a portion connected to the side surface plate 13B on the phosphor screen side and a portion connected to the side plate 13C on the electron gun side has an arc shape along the outer periphery of the getter container 11, and the upper surface plate 13B Both sides 13 on which side plate is not formed
a and 13b are formed in a linear shape. Therefore, the getter container 11 is partially covered with the upper plate 13 of the shield member.
A is exposed outside from both sides 13a and 13b of A, that is, a part of the upper surface of the getter material 12 is exposed outside from both sides 13a and 13b. As shown in the figure, the upper surface plate 13A of the shield member 13 and the side surface of the getter container 11 are separated from each other at a predetermined interval. In addition, the portion shielded by the shield member 13 on the fluorescent screen side and the electron gun side also has a side plate 13B of the shield member 13 on the back side facing the funnel.
A gap is formed between 13C and the getter container 11.

Here, the shielding angle θ ₂ shielded by the side plate 13B on the fluorescent screen 4 side is equal to the side plate 13C on the electron gun 5 side.
It is set to be larger than the shielding angle θ _1, which is shielded by. The shielding angle θ ₁ is determined by the neck diameter of the tube, the distance between the electron gun 5 and the getter device 9, and the like. The shielding angle θ ₂ is determined by the electron beam deflection angle, the inch size of the cathode ray tube, and the like. The shielding angle theta ₁ is for example _{20 ° ~90 ° (θ 1/} 2 = 1
0 to 45 °), the shielding angle theta ₂ is for example 90 ° to 180 °
It can be set to _{(θ 2/2 = 45 °} ~90 °). In this example, the beam deflection angle is 90 °,
The shielding angle theta ₁ to 50 °, are set shielding angle theta ₂ to 180 °.

On the other hand, as shown in FIG. 4 and FIG. 5, the elastic member 6 supporting the getter device has a support part in a cross shape, and is spot-welded to the getter container 11 at a predetermined position 21 of the cross shape. Is spot-welded with the bottom plate 13D of the shield member 13 at another predetermined position 22 of the cross shape. Also, the getter device 9 for the elastic member 6
At a plurality of positions, for example, each of three crosses
Bent ends 23a, 23b, 23
c is brought into contact with the inner surface of the funnel. That is, the getter device 9 is supported by the bent ends 23a, 23b, and 23c away from the inner surface of the funnel.

According to the above configuration, the getter device 9 is arranged on the inner surface of the funnel 7 so that the beam deflection angle can be widened and the depth of the cathode ray tube can be reduced. The power consumption of the electromagnetic deflecting device can be reduced as compared with a tube, and the electron beam from the electron gun can be properly deflected without being disturbed by the getter device.

The getter device 9 has a getter container 11 containing a getter material 12 and a shield member 13 integrally, and the shield angle 13 of the shield member 13 on the fluorescent screen 4 side.
₂ is set larger than the shielding angle θ ₁ on the electron gun 5 side,
Both sides 13a, 13b are opened and a part of the upper surface of the getter material 12 is shielded by the shield member 13, and thus both sides 13a, 13b.
b, the getter material 12 scatters three-dimensionally and widely in the upward and lateral directions (lateral direction), and further prevents the getter material from scattering toward the electron gun 5. In addition, getter scattering on the fluorescent screen 4 side can be reduced, and getter scattering can be performed over a wide area of the inner surface of the funnel 7. Therefore, it is possible to avoid the luminance deterioration of the fluorescent screen 4 and to increase the getter scattering area.

The getter device 9 is supported by the elastic member 6 and has bent ends 23a, 23b, 23c of the support portion.
Is disposed at a predetermined distance from the inner surface of the funnel 6, so that when the getter material 12 is scattered by high frequency heating from the outside, the getter container 11 and the shield member 13
Does not affect the funnel glass, thereby avoiding inconveniences such as cracks in the funnel glass.

Therefore, it is possible to provide a reliable and long-life wide deflection angle type cathode ray tube for a projector.

Although the getter device 9 is supported by the elastic member 6 extending from the electron gun 5 in the above example, the getter device 9 is directly connected to the funnel 7 via a member that is directly separated from the inner surface of the funnel. It can also be configured to be installed on the inner surface. Alternatively, the getter device 9 may be attached to an anode button (not shown) for supplying a high pressure embedded in the funnel 7.

In the above example, the cathode ray tube for a projector has been described. However, the getter device 9 according to the present invention can be applied to other ordinary cathode ray tubes.

[0029]

According to the present invention, the getter scattering area can be widened while avoiding the luminance degradation of the phosphor screen.
A highly reliable and long-life cathode ray tube can be obtained. Therefore, the present invention can be suitably applied to, for example, a cathode ray tube for a three-tube projector.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an example of a cathode ray tube according to the present invention.

FIG. 2 is an enlarged sectional view of a getter device according to the present invention.

FIG. 3 is an enlarged plan view of the getter device according to the present invention.

FIG. 4 is a plan view of a getter device according to the present invention.

FIG. 5 is a rear view of the getter device according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 cathode ray tube main body 2 liquid cooling device 3 panel 4 phosphor screen 5 electron gun 6 elastic member 7 funnel 9 getter device 11 getter container 12 getter material 13 shield member

Claims (2)

(57) [Claims] 1. A cathode ray tube having a getter device disposed on an inner surface of a funnel, wherein the getter device includes a getter container containing a getter material and a shield member for controlling scattering of the getter material. An upper surface plate that shields an upper surface opening of the getter container, and a side plate that continuously shields a side surface of the getter container, and both sides except the electron gun side and the fluorescent surface side of the shield member are provided. ,
The shield is opened from the side plate to the top plate, the upper surface of the getter material is partially exposed, and the shield angle of the shield member on the fluorescent screen side is set to be larger than the shield angle on the electron gun side. CRT. 2. A shielding angle on the electron gun side of the getter device is 20 ° to 90 °, and a shielding angle on the phosphor screen side is 9 °.
2. The method according to claim 1, wherein the angle is between 0 [deg.] And 180 [deg.].
A cathode ray tube as described.