KR100403773B1 - The C-CRT Having the Magnet for Correcting - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color cathode ray tube having a correction magnet, and particularly to a reduction in BSN margin by optimizing the relationship between the inner thickness of the funnel and the magnetization amount of the magnet in a color cathode ray tube equipped with a pincushion correction magnet. The present invention relates to a color cathode ray tube having a correcting magnet for preventing the same.

Technical means of the present invention is a color cathode ray tube comprising a deflection yoke for deflecting the electron beam up, down, left and right, and a pincushion correction magnet attached to the deflection yoke, wherein the effective screen diagonal size of the color cathode ray tube is 14 to 16 inches. The thickness of the funnel from the portion where the funnel is sealed to the reference line of the yoke portion is 1.5 to 2.5 cm, and the magnetization amount of the pincushion correction magnet is 17 to 19 gauss.

According to the present invention, in the cathode ray tube using the pincushion correction magnet by forming the funnel according to the above criteria, the BSN margin (Beam Strike Neck Margin) on the inner wall of the funnel is prevented from being reduced, thereby realizing high image quality.

Description

C-CRT Having the Magnet for Correcting

The present invention relates to a color cathode ray tube having a correction magnet, and in particular, in a color cathode ray tube equipped with a correction magnet, it is possible to prevent the reduction of the BSN margin by optimizing the relationship between the inner thickness of the funnel and the magnetization amount of the magnet. It relates to a color cathode ray tube having a correcting magnet.

As shown in FIG. 1, a typical cathode ray tube includes a glass panel 1 having a substantially rectangular shape when viewed from the front, a funnel-shaped glass funnel 2 coupled to the panel 1, and the funnel 2. The cylindrical glass neck 3 provided in the edge part of which diameter is small is formed.

The neck 3 is filled with electron guns 4 arranged in a row on the same horizontal plane to scan the electron beams 5 of red (R), green (G), and blue (B), and the funnel 2 In the vicinity of the neck 3 side, a self-convergence deflection yoke 8 mainly using a non-uniform magnetic field is mounted to deflect the electron beam 5 to the front surface of the phosphor screen 7.

The deflection yoke 8 generates a pincushion-type horizontal deflection field and a barrel-type vertical deflection field, thereby generating three R, G, and B electron beams emitted from the electron gun 4 5) is deflected at a wide angle and landed on the phosphor screen 7 through the shadow mask 6, which is a color screening electrode, to display a color image.

Thus, as shown in Fig. 2 when the deflection yoke 5 mounted on the funnel 2 is viewed from the A-A 'side and from the side.

The deflection yoke 8 is basically a horizontal deflection coil 8-1 for deflecting the electron beam 5 in the horizontal direction and a vertical deflection coil 8-2 for deflecting the electron beam 5 in the vertical direction. And, mounted on the funnel (2) to fix the horizontal / vertical deflection coils (8-1) (8-2) and the ferrite core (8-4) at a predetermined position and perpendicular to the horizontal deflection coil (8-1). The magnetic force loss of the holder 8-3, which is insulated between the deflection coils 8-2, and the vertical deflection magnetic field generated on the vertical deflection coils 8-2, mounted on the holder 8-3, reduces magnetic force. It is composed of a ferrite core 8-4 used to increase the efficiency.

In addition, a convergence coil 8-5 is provided on the neck 3 side of the holder 8-3 to improve the coma aberration generated by the vertical barrel type magnetic field, and the neck 3 of the holder 8-3. Mechanically coupled to the funnel 2 by a ring band 8-6 provided at the side end, the upper and lower circumferential surfaces of the holder 8-3, that is, the openings of the deflection yoke 8, A magnet 8-7 is provided at the lower position to correct raster distortion (hereinafter referred to as "distortion") on the screen.

When the current having a frequency of 15.75 Hz or more is conducted to the horizontal deflection coil 8-1, the deflection yoke 8 configured as described above generates a pincushion type horizontal deflection magnetic field and deflects the electron beam 5 in the horizontal direction. When a current having a frequency of 60 Hz is normally conducted to the vertical deflection coil 8-2, a barrel-type vertical deflection magnetic field is generated to deflect the electron beam 5 in the vertical direction.

The horizontal deflection coil 8-1 is composed of a deflection coil on the left side and a deflection coil on the right side as shown in FIG. 3 (a), after connecting the left and right horizontal deflection coils 8-1 in parallel. Applying a sawtooth wave-shaped horizontal deflection current as shown in (b) of FIG. 3 forms a pincushion-like horizontal deflection magnetic field, which causes the electron beam 5 emitted from the electron gun 4 to deflect in the horizontal direction.

When the three electron beams emitted from the electron gun 4, ie, the red, green, and blue beams, pass through the region of the horizontal deflection magnetic field, the force received by the electron beam according to Fleming's left hand law is the inner surface of the horizontal deflection coil 8-1. Deflected in the horizontal direction in inverse proportion to the cube of the distance between the electron beam 5 and the electron beam 5.

The distortion is corrected by the magnets 8-7 attached to the upper and lower openings of the holder 8-3 so that the electron beam 5 emitted from the electron gun 4 is deflected upward. In order to make -Bx magnetic field, the upper magnet (8-7) is magnetized so that the N pole is located on the right side and the S pole is on the left side.

The magnet 8-7 installed in this way forms a magnetic force line in a pincushion type magnetic force line by forming a -Bx magnetic field as shown in FIG. 4, and when the deflection upwards as shown in FIG. , B) is the center portion (12 o'clock; G) is moved a little further upward by the greater magnetic force, depending on the position of the deflection, has a different amount of movement according to the position of each RGB electron beam The raster shape may have linearity on the screen.

However, when the pincushion correction magnet is installed as described above, the deflection angle of the electron beam is widened by the magnetic force of the magnet, and as a result, the distance between the trajectory of the electron beam and the inner side of the funnel is closer, the BSN margin (Beam Strike Neck) to the inner side of the funnel. There is a problem that the margin is reduced.

Accordingly, an object of the present invention is to provide a color cathode ray tube having a correction magnet that prevents reduction of BSN margin (Beam Strike Neck Margin) by optimizing the relationship between the inner thickness of the funnel and the magnetization amount of the magnet.

1 is a view showing the structure of a typical cathode ray tube,

2a to b is a detailed assembly view of the deflection yoke of the cathode ray tube according to the prior art,

3A to 3B are a deflection circuit diagram of a horizontal deflection coil of a deflection yoke of the prior art;

FIG. 4 is a diagram illustrating an arrangement of magnets and a distribution of magnetic force lines in FIG. 2;

FIG. 5 is a diagram illustrating a motion of an electron beam by the magnet magnetic force line of FIG. 2;

FIG. 6 is a diagram showing a reduction of BSN margin in a color cathode ray tube equipped with a pincushion correction magnet. FIG.

*** Explanation of symbols for the main parts of the drawing ***

10: deflection yoke 11: horizontal deflection coil

12: vertical deflection coil 16: magnet

The technical means of the present invention for achieving this object is a panel having a phosphor screen on the inner surface, a funnel connected to the panel, an electron gun mounted to the neck portion of the funnel and emitting an electron beam toward the phosphor screen, the funnel In a color cathode ray tube comprising a deflection yoke mounted on the yoke of the deflection yoke and deflecting the electron beam up, down, left and right, and a pincushion correction magnet attached to the deflection yoke, the effective screen diagonal size of the color cathode ray tube is 14 to 19 inches. The funnel thickness from the portion where the funnel is sealed to the reference line of the yoke portion is 1.5 to 2.5 cm, and the magnetization amount of the pincushion correction magnet is 17 to 20 gauss.

Hereinafter, the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 6 shows the reduction of the BSN margin in a color cathode ray tube equipped with a pincushion correction magnet. As shown, the deflected electron beam at the deflection start point (Reference Line, RL) is widened by the pincushion correction magnet, and the widenized electron beam hits the inner wall of the funnel, thereby causing a BSN margin (Beam Strike Neck) to the inner wall of the funnel. Margin) is reduced.

Therefore, in order to prevent the reduction of the BSN margin (Beam Strike Neck Margin), the thickness of the inner wall of the funnel hit by the electron beam should be reduced. However, the degree of widening angle of the electron beam is determined by the magnetization amount of the pincushion correction magnet, and the magnetization amount depends on the diagonal size of the cathode ray tube effective screen. Therefore, the thickness of the funnel is determined by the diagonal size of the cathode ray tube effective screen and the magnetization of the magnet.

The present invention defines the thickness and the main dimensions of the funnel in the state in which the magnetization amount of the pincushion correction magnet for the diagonal size of the effective screen is set.

TABLE 1

Effective screen diagonal size Neck Φ [± 0.5 mm] RL Φ [± 5mm] N / S-R / L [± 0.5 mm] Funnel thickness from N / S to R / L [cm] Magnet magnetization [gauss] Min Max Min Max 14-16 〃 29.1 56 43 1.5 2.5 17 19 17-19 yen 29.1 56 43 1.5 2.5 18 20 20 ~ 21 yen 29.1 56 43 2.5 3.5 22 24 25〃 29.1 66 35 4.0 5.0 26 28 29〃 29.1 66 35 4.0 5.0 30 32 32〃 37.5 68 34 4.0 5.0 33 35

The values in Table 1 are determined by experiments, in which R / L is a reference line which is the starting point of deflection, and N / S is a neck seal where the neck and the funnel are sealed, and the neck Negative φ is the diameter of the neck portion, RLφ represents the diameter of the reference line, and the neck portions φ, RLφ, N / S to R / L allow errors of ± 0.5 mm, ± 5 mm and ± 0.5 mm, respectively.

As described above, if the thickness of the funnel is changed according to the diagonal size of the effective screen, the beam beam impacting the inner surface of the funnel is reduced when using the same magnetizing magnet as in the prior art, thereby reducing the BSN margin (Beam Strike Neck Margin) on the inner wall of the funnel. Can be prevented, and high definition can be realized.

As described above, in the cathode ray tube using a pincushion correction magnet by forming a funnel according to the above criteria, the effect of realizing high image quality is prevented by preventing BSN margin (Beam Strike Neck Margin) on the inner wall of the funnel from being reduced. have.

Claims (5)

A panel having a phosphor screen on the inner surface, a funnel connected to the panel, an electron gun mounted on the neck of the funnel to emit an electron beam toward the phosphor screen, and mounted on the yoke of the funnel to deflect the electron beam up, down, left, and right In a color cathode ray tube comprising a deflection yoke and a correction magnet attached to the deflection yoke, When the effective screen diagonal size of the color cathode ray tube is 14 to 19 inches, the funnel thickness from the portion where the funnel is sealed to the reference line of the yoke portion is 1.5 to 2.5 cm, and the magnetization amount of the pincushion correction magnet is 17 to 20 gauss. A color cathode ray tube having a magnet for correction, characterized in that it is (gauss). A panel having a phosphor screen on the inner surface, a funnel connected to the panel, an electron gun mounted on the neck of the funnel to emit an electron beam toward the phosphor screen, and mounted on the yoke of the funnel to deflect the electron beam up, down, left, and right In the color cathode ray tube comprising a deflection yoke and a pincushion correction magnet attached to the deflection yoke, When the effective screen diagonal size of the color cathode ray tube is 20 to 21 inches, the funnel thickness from the portion where the funnel is sealed to the reference line of the yoke portion is 2.5 to 3.5 cm, and the magnetization of the pincushion correction magnet is 22 to 24 gauss. A color cathode ray tube having a magnet for correction, characterized in that it is (gauss). A panel having a phosphor screen on the inner surface, a funnel connected to the panel, an electron gun mounted on the neck of the funnel to emit an electron beam toward the phosphor screen, and mounted on the yoke of the funnel to deflect the electron beam up, down, left, and right In the color cathode ray tube comprising a deflection yoke and a pincushion correction magnet attached to the deflection yoke, When the effective screen diagonal size of the color cathode ray tube is 25 inches, the funnel thickness from the portion where the funnel is sealed to the reference line of the yoke portion is 4.0 to 5.0 cm, and the magnetization of the pincushion correction magnet is 26 to 28 gauss (gauss). ) Is a color cathode ray tube. A panel having a phosphor screen on the inner surface, a funnel connected to the panel, an electron gun mounted on the neck of the funnel to emit an electron beam toward the phosphor screen, and mounted on the yoke of the funnel to deflect the electron beam up, down, left, and right In the color cathode ray tube comprising a deflection yoke and a pincushion correction magnet attached to the deflection yoke, When the effective screen diagonal size of the color cathode ray tube is 29 inches, the funnel thickness from the portion where the funnel is sealed to the reference line of the yoke portion is 4.0 to 5.0 cm, and the magnetization amount of the pincushion correction magnet is 30 to 32 gauss (gauss). ) Is a color cathode ray tube. A panel having a phosphor screen on the inner surface, a funnel connected to the panel, an electron gun mounted on the neck of the funnel to emit an electron beam toward the phosphor screen, and mounted on the yoke of the funnel to deflect the electron beam up, down, left, and right In the color cathode ray tube comprising a deflection yoke and a pincushion correction magnet attached to the deflection yoke, When the effective screen diagonal size of the color cathode ray tube is 32 inches, the thickness of the funnel from the portion where the funnel is sealed to the reference line of the yoke portion is 4.0 to 5.0 cm, and the magnetization of the pincushion correction magnet is 33 to 55 gauss (gauss). ) Is a color cathode ray tube.