JPH03226945A - Deflection yoke attaching method - Google Patents

Abstract

PURPOSE:To lower the magnification ratio and improve focusing properties by installing a deflection yoke and a focusing magnet in the way that the inclining plane of the conical deflection yoke and the inclining plane of the reversely conical focusing magnet contact each other. CONSTITUTION:A deflection yoke 4 is so formed as to have a conical inclining plane 6 in the outside plane of a rare end of a cylindrical project 5. A focusing magnet is so formed as to have a reversely conical inclining plane 8 which is able to joint with the conical inclining plane 6 of the deflection yoke 4 face to face without a gap. The conical inclining plane 6 of the deflection yoke 4 and the conical inclining plane 8 of the focusing magnet 7 are thus jointed each other face to face without a gap. Consequently, the focusing magnet 7 moves forward to the fluorescent plane of a CRT so that low magnification ratio is achieved and at the same time axial shearing of the focusing magnet 7 is prevented and focusing properties of a projection-type television are improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a CRT which is a projection tube for a projection television.
In, an electromagnetic focusing type C having a focusing magnet
This article relates to a method of attaching a deflection yoke of an RT.

[Prior Art] A conventional method for attaching a deflection yoke is shown in FIG. In the figure, the deflection yoke 10 is a cylindrical protrusion 11 having a cylindrical inner surface with approximately the same diameter as the outer diameter of the neck portion 2 of the CRTI.
It was attached to the neck part 2 of the CRT by tightening it with a band 9 made of aluminum or the like. Further, a focus magnet 12 was attached to a position closer to the electron gun of the CRTI in the same manner as the deflection yoke 10 by tightening the front and rear parts with aluminum bands 9. The reason why the focus magnet 12 is fastened by the band 9 at the front and back as described above is to prevent misalignment of the center axis of the focus magnet 12 and the center axis of the CRT. In this way, conventionally,
The deflection yoke 10 and the focus magnet 12 were attached completely separately.

[Problems to be Solved by the Invention] Therefore, in the case of the conventional mounting method described above, there are two mounting parts, the deflection yoke 10 and the focus magnet 12, in front of the focus magnet 12, that is, on the tube surface side of the CRTl. Focus magnet 12
had to be installed in a position set back from the tube side. - In the case of an electromagnetic focusing type CRT for boat fishing, as shown in Figure 5,
When the distance between the RT phosphor screen 3 and the electron beam crossover point is constant, the focus magnet 12 that focuses the electron beam moves toward the phosphor screen 3 side, that is, in the direction where the magnification becomes lower (b/a). Since focus characteristics can be improved by moving the lens in the direction where Therefore, it is possible to move the focus magnet 12 forward by removing the attachment part 13 of the focus magnet 12 on the deflection yoke 10 side, but if it is attached only on the rear side, the weight of the focus magnet 12 will cause the focus magnet 12 to move forward as shown in FIG. The beam spot is mounted at an angle with respect to the central axis of the CRT, causing axis misalignment, which adversely affects the shape of the beam spot.

Therefore, an object of the present invention is to reduce the magnification ratio by removing the attachment portion 13 on the deflection yoke side of the focus magnet 12, and to prevent axis deviation due to the removal of the attachment portion 13 on the deflection yoke side. By doing so, it is attempted to improve the focus characteristics without deteriorating the beam spot shape.

[Means for Solving the Problems] Therefore, in order to achieve the above-mentioned object, the present invention provides a projection television that creates a color image by superimposing images of a plurality of monochrome CRTs on the outside of the neck portion of the monochrome CRT. In the method for attaching the deflection yoke, the deflection yoke has a cylindrical protrusion having a cylindrical inner surface having a diameter approximately the same as the outer diameter of the neck of the single-color CRT, and a conically inclined outer surface of the end thereof. The focus magnet, which has a surface and is disposed on the outside of the neck portion so as to face the deflection yoke, has an inverted conical inclined surface that comes into contact with the conical inclined surface of the deflection yoke, and has an inverted conical inclined surface that contacts the conical inclined surface of the deflection yoke. The conical inclined surface of the focus magnet is attached with the inverted conical inclined surface of the focus magnet in contact with each other.

[Function] By adopting the present invention, it becomes possible to reduce the magnification ratio without complicating the structure at all and without causing axis deviation, etc., and improves the focusing characteristics of the projection television. becomes possible.

"Example" Next, an example of the present invention will be described with reference to FIGS. 1 to 3.

Fig. 1 is a partial cross-sectional view of the deflection yoke used in the present invention, Fig. 2 is a schematic cross-sectional view of the focus magnet used in the present invention, and Fig. 3 is a state showing the method of attaching the deflection yoke of the present invention. It is a diagram.

Conventionally, as shown in FIG. 6, in order to attach the deflection yoke 1o, the outer surface of the rear end of the cylindrical protrusion 1■, which has a cylindrical inner surface with approximately the same diameter as the outer diameter of the neck portion 2 of the CRTI, was formed into a cylindrical shape. It may have remained in the same shape, or it may have been slightly stepped to prevent the band 9 from slipping. The deflection yoke 4 of the present invention shown in FIG. 1 has a conical inclined surface 6 formed on the outer surface of the rear end of the cylindrical protrusion 5 . Further, the focus magnet 7 of the present invention shown in FIG. 2 forms an inverted conical inclined surface 8 that faces the conical inclined surface 6 of the deflection yoke 4 and can be brought into contact with the conical inclined surface 6 without any gap. As shown in FIG. By attaching the surface 6 and the conical inclined surface 8 of the focus magnet 7 against each other without any gap, the focus magnet 7 can be moved forward toward the phosphor screen of the CRT. It also makes it possible to prevent axis misalignment.

[Effects of the Invention] By employing the present invention, the structure is completely complicated. It becomes possible to reduce the magnification factor without causing any axis deviation or the like, and it becomes possible to improve the focus characteristics of the projection television.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view of a deflection yoke used in the present invention;
FIG. 2 is a schematic sectional view of a focus magnet used in the present invention, FIG. 3 is a state diagram showing the deflection yoke attachment method of the present invention, and FIG. 4 is a state diagram showing a conventional deflection yoke attachment method. 1--CRT, 2-CRT neck, 3-m-phosphor screen, 4, 10-deflection yoke, 5°11--cylindrical protrusion, 6-conical inclined surface , 7, 12... Focus magnet h, 8-... Inverted conical inclined surface, 9...
·band.

Claims (1)

[Claims] The monochrome CRT of a projection television that creates a color image by superimposing images of a plurality of monochrome CRTs.
In the method for attaching a deflection yoke disposed outside the neck of the monochromatic CRT, the deflection yoke has a cylindrical protrusion having a cylindrical inner surface having approximately the same diameter as the outer diameter of the neck of the single-color CRT. The focus magnet has a conical inclined surface and is disposed on the outside of the neck so as to face the deflection yoke. A method for attaching a deflection yoke, characterized in that the deflection yoke is attached in a state where the conical inclined surface of the yoke and the inverted conical inclined surface of the focus magnet are in contact with each other.