JPH06203762A - Internal part beam shield plate - Google Patents

Abstract

PURPOSE:To shield an abnormal electron beam also in a frame corner part in a color selecting mechanism unit of a CRT. CONSTITUTION:Internal part beam shield plates 18 of rectangular shape are additionally provided to be opposed in a color selecting mechanism of a color cathode-ray tube. In these internal part beam shield plates, in each of both ends in opposed sides of the internal part beam shield plates 18 of rectangular shape, plate-shaped small pieces 18a, 18b, 18c, 18d, protruded respectively toward the opposed sides, are provided.

Description

Detailed Description of the Invention

[0001]

The present invention relates to an internal beam shield plate (Inne
r Beam Shield (IBS), especially cathode ray tube (C
The present invention relates to an internal beam shield plate capable of suppressing abnormal light emission at a panel corner portion of (RT).

[0002]

2. Description of the Related Art As shown in FIG. 3, a color selecting mechanism of a Trinitron color CRT is formed by seam-welding a color selecting mechanism 1 of an aperture grill (AG) to a frame A member 2 on a long side thereof to form a short side. The structure is such that it is stretched by the frame B member 3. A damper wire 4 whose end is fixed by a damper spring 5 is normally stretched on the panel side surface of the color selection mechanism 1 in order to prevent the vibration of the AG 1.
A frame support 6 for fixing and supporting the panel is attached to the frames A 2 and B 3. The color selection mechanism having such a structure, which is not shown in the drawings, has an inner magnetic shield (IMS) for preventing color shift due to the influence of an external magnetic field and an diffused reflection of an overscanned electron beam. Therefore, a rectangular internal beam shield plate (IBS) 10 as shown in FIGS. 3 and 4 is attached.

[0003]

FIG. 5 is a partial schematic cross-sectional view for explaining abnormal light emission by an electron beam emitted from an electron gun of a CRT. In FIG. 5, 12 is a normal electron beam trajectory (hereinafter referred to as normal 13 is an electron beam trajectory (hereinafter referred to as an abnormal electron beam) that causes an abnormality. That is, when the electron beam is largely scanned, the abnormal electron beam 13 that is overscanned toward the frame A member 2 hits the projecting end of the frame A member, and the beam reflected there is a phosphor screen on the back surface of the panel 8. 9 and incident light 9 causes abnormal light emission near the upper and lower sides of the screen. This phenomenon is often seen especially at the panel corners. The electron beam overscanned toward the frame B member is shielded by the rectangular IBS 10 attached to the frame B member 3, as shown in FIG. Therefore, there is no electron beam that is reflected by the frame B member and emits abnormally, and since the IBS 10 itself is sufficiently thin as it is made of a stainless steel thin plate, the amount of beam reflected at its tip is also negligible. .

In view of the above problems, the present invention considers CR.
An object of the present invention is to provide an internal beam shield plate capable of shielding an abnormal electron beam even at a frame corner portion of a T color selection mechanism.

[0005]

According to the present invention, there is provided a rectangular internal beam shield plate which is provided to face a color selection mechanism of a color cathode ray tube so as to face the color selection mechanism. The internal beam shield plate is characterized in that it has plate-like small pieces protruding toward the opposite side edges at both ends of each of the opposite side edges.

[0006]

According to the present invention, a plate projecting toward the opposite side edge of each of the opposite side edges of the conventional rectangular inner beam shield plate is, as shown in FIGS. 1 and 2, respectively. Since the small pieces 18a, 18b, 18c, and 18d are provided, it is possible to shield harmful reflection in the fluorescent screen direction of the overscanned corner electron beam at the corner described in FIG.

[0007]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 shows an internal beam shield plate (I
(BS) is a perspective view of a color selection mechanism provided with one embodiment,
FIG. 2 is a perspective view showing one of the pair of IBSs.
As shown in FIGS. 1 and 2, the IBS 18 of the present invention is shown in FIG.
At both ends of the conventional rectangular IBS 10 shown in FIG. 2, rectangular plate-like small pieces 18a, 18b, 1 protruding toward opposite sides are provided.
It has a U-shaped structure with 8c and 18d attached. The part of the IBS with respect to the central side of the U-shaped IBS (corresponding to the conventional IBS) is the short side frame of the color selection mechanism, that is, the frame B member
Is attached to.

The projecting length L of the plate-like small pieces 18a-18d
1 is substantially the same as the shield length L2 of the IBS 18 along the frame B member 3. In addition, plate-like small pieces 18a to 18d
The protrusion width W1 is about 1/2 of L2. This IB
As the material of S18, a stainless steel plate such as SUS403 is used as in the conventional case, and punching is performed by a press or the like.

By disposing the color selection mechanism provided with the IBS of the present invention shown in FIG. 1 on the back side of a predetermined CRT panel, the abnormal electron beam is effectively shielded especially at the corner portion where the abnormal light emission has been generated conventionally. I was able to.

In this embodiment, a rectangular plate-like small piece is attached to the conventional rectangular IBS, but it is not limited to the rectangular shape.
Other shapes are possible.

[0012]

As described above, according to the present invention, since the overscanned electron beam can be effectively shielded at the corner portion of the color selection mechanism of the CRT, abnormal light emission can be suppressed. .

Although the present invention is intended to prevent electron beam reflection at the frame A member of the color selection mechanism,
It is also effective for the electron beam reflection on the structure arranged on the panel side of the BS arrangement position.

[Brief description of drawings]

FIG. 1 is a perspective view of a color selection mechanism provided with an embodiment of an internal beam shield plate (IBS) according to the present invention.

FIG. 2 is a perspective view showing one of a pair of IBSs according to the present invention shown in FIG.

FIG. 3 is a perspective view of a conventional color selecting mechanism provided with an IBS.

FIG. 4 is a perspective view showing one of the pair of conventional IBSs shown in FIG.

FIG. 5 is a partial schematic diagram for explaining abnormal light emission by an electron beam emitted from an electron gun of a CRT.

[Explanation of symbols]

1 color selection mechanism (aperture grill: AG) 2 frame A member 3 frame B member 4 damper wire 5 damper spring 6 frame support 8 panel 9 phosphor screen 10 and 18 internal beam shield 12 normal electron beam orbit (normal electron Beam) 13 Electron beam trajectories that cause abnormal light emission (abnormal electron beam) 18a, 18b, 18c, 18d Plate-like small pieces

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[Procedure amendment]

[Submission date] September 14, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

[0003]

FIG. 5 is a partial schematic cross-sectional view for explaining abnormal light emission by an electron beam emitted from an electron gun of a CRT. In FIG. 5, 12 is a normal electron beam trajectory (hereinafter referred to as normal 13 is an electron beam trajectory (hereinafter referred to as an abnormal electron beam) that causes an abnormality. That is, when the electron beam is largely scanned, the abnormal electron beam 13 that is overscanned toward the frame A member 2 hits the projecting end of the frame A member, and the beam reflected there is a phosphor screen on the back surface of the panel 8. 9 and incident light 9 causes abnormal light emission near the upper and lower sides of the screen. This phenomenon is often seen especially at the panel corners. The electron beam overscanned toward the frame B member is shielded by the rectangular IBS 10 attached to the frame B member 3, as shown in FIG. Therefore, there is no electron beam that is reflected by the frame B member and emits abnormally, and the IBS 10 itself is sufficiently thin as it is made of a thin steel plate. Therefore, the amount of beam reflected at the tip end is also small and can be ignored. .

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

The projecting length L of the plate-like small pieces 18a-18d
1 is substantially the same as the shield length L2 of the IBS 18 along the frame B member 3. In addition, plate-like small pieces 18a to 18d
The protrusion width W1 is about 1/2 of L2. This IB
As the material of S18, a low carbon steel plate such as SPCC material or SIS material is used as in the conventional case, and punching is performed by pressing or the like.

Claims (3)

[Claims] 1. A rectangular internal beam shield plate, which is provided so as to face a color selection mechanism of a color cathode ray tube so as to face each end of each of opposite sides of the rectangular internal beam shield plate. An internal beam shield plate comprising plate-like small pieces projecting toward the sides. 2. The plate-like small piece has a rectangular shape having a protruding length as a long side length, and the long side and the short side have substantially the short side length and the short side length of the rectangular inner beam shield plate, respectively. The internal beam shield plate according to claim 1, wherein each of the short side lengths is approximately equal to ½ of the short side length. 3. The U-shape, and the portion corresponding to the central side of the U-shape is attached to the short side frame of the color selection mechanism. Internal beam shield.