JP3367125B2 - Deflection yoke - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection yoke provided with a saddle type horizontal deflection coil and a toroidal type vertical coil for use in an in-line type cathode ray tube. The present invention relates to a deflection yoke provided with a coma collector provided to improve the deflection sensitivity of the present invention. 2. Description of the Related Art FIG. 8 is a plan view of a deflection yoke provided with a conventional coma coil, and FIG. 9 is a side view of the deflection yoke.
Here, 1 is a saddle type horizontal deflection coil, 2 is a toroidal type vertical deflection coil, and 3 is an annular core. Reference numeral 4 denotes a top collector, 4a denotes a magnetic field emission section of the top collector 4, and 4b denotes a magnetic field collection section of the top collector 4. The function of the top collector 4 is to collect the leakage magnetic field of the toroidal type vertical deflection coil 2 by the magnetic field collection unit 4b, and to release the collected magnetic field by the magnetic field emission unit 4a located near the electron gun, thereby making the center electron of the cathode ray tube. In order to adjust the beam deflection sensitivity, the emitted magnetic field is a composite of a pin magnetic field, a barrel magnetic field, and a uniform magnetic field. The movement of the electron beam affected by the emitted magnetic field will be described below. FIG. 10 is a view of a screen of a cathode ray tube, and FIG. 11 is a view showing a deflection magnetic field acting on an electron beam.
11A shows a pin magnetic field, FIG. 11B shows a barrel magnetic field, and FIG.
(C) shows a uniform magnetic field. In FIG. 10, reference numeral 6 denotes emission lines of electron beams on both sides of the electron gun, and reference numeral 7 denotes emission lines of the center electron beam. That is, in the example shown in FIG. 10, the bright line 7 of the center electron beam is located inside the bright line 6 of the electron beam on both sides at the upper and lower ends of the screen. Indicates worse than sensitivity. This is generally called VCR narrow. Hereinafter, the cause of the VCR narrow will be described. If the deflection yoke is of the self-convergence type, the vertical deflection coil is generally constituted by a toroidal type vertical deflection coil for generating a barrel magnetic field. In the case of a barrel magnetic field, as shown in FIG. 11B, the density of the magnetic field lines applied to the center electron beam (G beam) is smaller than the density of the magnetic field lines applied to the electron beams (R beam, B beam) on both sides, and It can be seen that the influence of the magnetic field is smaller than the effect on the electron beams on both sides. Therefore, it is necessary to improve the deflection sensitivity of the center electron beam by some means. As a first method, there is a method in which the magnetic field near the electron gun is changed to a pin magnetic field, and one of the means is to use the top collector 4. As another second method, there is a method in which the toroidal type vertical deflection coil 2 is configured to increase only the magnetic field on the electron gun side. However, this method of increasing the magnetic field on the electron gun side causes the deflection center of the vertical deflection of the deflection yoke to shift toward the electron gun. That is, as shown in FIG. 12, the position C where the electron beam is deflected is shifted from the position D where the normal electron beam is deflected toward the electron gun. In this case, the deflected electron beam hits the inner glass of the cathode-ray tube, causing a problem that a shadow 8 appears on the screen of the cathode-ray tube called a neck shadow shown in FIG. Hereinafter, means for using the above-mentioned frame collector 4 will be described. FIG. 14A is a sectional view of the annular core 3, and FIG. 14B is a plan view of the annular core 3. First, the magnetic field generated by the toroidal vertical deflection coil 2 is divided into the following three magnetic fields shown in FIG. A magnetic field represented by reference numeral 9; this is a magnetic field diverged on the inner surface of the annular core 3 and mainly contributes to vertical deflection.
Hereinafter, this magnetic field is referred to as a main deflection magnetic field 9. The main deflection magnetic field 9 is adjusted so that the deflection yoke tends to have a barrel magnetic field due to convergence characteristics. Magnetic fields denoted by reference numerals 9a and 9b; annular core 3
A divergent leakage magnetic field before and after the end face, which also contributes to vertical deflection, but mainly contributes to determining the direction of the electron beam because it is at the end of the deflection magnetic field. This magnetic field also tends to be a barrel magnetic field for the deflection yoke. A magnetic field indicated by reference numeral 10 is an external leakage magnetic field radiated to the outer periphery of the annular core 3.
Set to 0. The external leakage magnetic field 10 has no relation to the vertical deflection. In the conventional top collector 4, as shown in FIG. 15, the external leakage magnetic field 10 is collected by the magnetic field collection section 4b of the top collector 4, and is emitted by the magnetic field emission section 4a shown in FIG. However, since the conventional coma collector 4 uses the external leakage magnetic field 10 radiated in the outer peripheral direction of the vertical deflection coil, the magnetic field inside the vertical deflection coil is entirely reduced. As a result of vertical deflection, a strong barrel magnetic field is generated on the annular core 3, particularly on the electron gun side, as shown by the solid line in FIG. 5. Further, the magnetic field emitted from the magnetic field emission portion 4a of the top collector 4 is not necessarily limited to the pin magnetic field, but includes a uniform magnetic field. Therefore, the uniform magnetic field also contributes to the vertical deflection. The portion is added as it is near the electron gun, and the deflection center is shifted toward the electron gun. Then, the above-described neck shadow occurs, and there is a problem that the deflection angle cannot be widened. SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a deflection yoke capable of improving the deflection sensitivity of a center electron beam and widening the deflection angle without causing neck shadow. With the goal. According to the present invention, in order to solve the above-mentioned problems, a magnetic field pickup section of a coma collector is arranged to face an electron gun side end face of an annular core, and a magnetic field collection section is provided.
The tip of the collecting part is the inner surface of a toroidal vertical deflection coil.
And absorbs the magnetic field emitted from the end face of the annular core on the electron gun side, and utilizes the absorbed magnetic field to form a substantially cylindrical 4.
A pinned magnetic field is generated by a magnetic field emitting portion made of a single magnetic material. With the construction described above, the magnetic field leaking part absorbs the magnetic field leaking from the end face of the annular core, so that the deflection is not performed at this part, and the deflection center is moved to the center of the annular core. It can be shifted, and the deflection angle can be widened. Along with this, the barrel magnetic field also becomes stronger at the center of the annular core, but instead, a strong pinned magnetic field is generated at the magnetic field emitting portion using the above-described leakage magnetic field, and sufficient correction can be performed. FIG. 1 is a plan view of a deflection yoke according to an embodiment of the present invention as viewed from the electron gun side, and FIG. 2 is a side view of the deflection yoke. 1 is a saddle type horizontal deflection coil, 2 is a toroidal type vertical deflection coil, 3 is an annular core around which the toroidal type vertical deflection coil 2 is wound, and 11 is a coma collector. FIG.
FIG. 4 is a cross-sectional view for explaining a state of a magnetic field in the coma collector 11 of the deflection yoke. Next, the frame collector 11 will be described. Numeral 11a denotes a magnetic field emitting portion composed of four substantially cylindrical magnetic materials. The magnetic field emitting portion 11a is disposed in a straight line portion of the in-line type cathode ray tube in parallel with the electron gun, and the four magnetic materials are disposed to face each other. Numeral 11b denotes a magnetic field collecting portion of the top collector 11, which faces the electron gun side end surface of the annular core 3 so as to absorb a leakage magnetic field diverging from the electron gun side end surface of the annular core 3 as shown in FIG. Be placed. FIG. 3 is a perspective view of the above-described top collector 11, which shows a magnetic field until the top collector 11 absorbs a leakage magnetic field of the toroidal type vertical deflection coil 2 and emits the absorbed magnetic field at a portion near the electron gun. Are indicated by white arrows. As is apparent from FIG. 2, the magnetic field collection portion 11b of the top collector 11 is installed in parallel with the radial cross section of the toroidal type vertical deflection coil 2. That is, FIG.
Of the magnetic field emitted from the toroidal type vertical deflection coil 2 shown in FIG. 1 (hereinafter referred to as a leakage magnetic field 9a). Further, as shown in FIG. 14, since the magnetic field collecting portion 11b is provided in a direction perpendicular to the leakage magnetic field 9a, its absorption rate is 90% or more, so that it can be absorbed very efficiently. Although the leakage magnetic field 9a shown in FIG. 14 is a barrel magnetic field located on the electron gun side of the deflection yoke, the leakage magnetic field 9a is absorbed by the magnetic field collection section 11b in this embodiment, so that the deflection yoke electron gun side is removed. Can be weakened, and the magnetic field in the portion of the deflection yoke close to the electron gun is made into a pin magnetic field by the magnetic field emission portion 11a. [0024] As a result of the above, the premise form of frames collector 1
Due to the function of the magnetic field collection unit 11b, the deflection yoke can weaken the barrel component of the deflection magnetic field on the electron gun side and diverge the pin magnetic field in the portion of the cathode ray tube that most effectively affects the center electron beam. . The operation of the deflection magnetic field on the deflection yoke electron gun side will be described below. FIG. 5 is a graph of the magnetic field distribution of the vertical deflection component of the deflection yoke. The solid line shows the case where the conventional top collector shown in FIGS. 8 and 9 is used, and the dashed line shows the case where the top collector 11 according to the premise of the present invention is used. From this graph, it can be seen that when the conventional coma collector is used (solid line), the deflection yoke has the strongest magnetic field near the electron gun side end face of the annular core 3 (the portion where the leakage magnetic field 9a shown in FIG. 14 is applied). The fact that the magnetic field at this portion is a barrel magnetic field serves as the aforementioned VCR narrow. However, in the deflection yoke according to the present embodiment (the dashed line), by using the above-mentioned coma collector 11, a portion which is made to be a VCR narrow portion (a portion indicated by a symbol A).
Since the magnetic field of the VCR is absorbed, the VCR narrow can be made relatively small, and the magnetic field is reduced to a portion near the deflection yoke electron gun (reference B).
(Part indicated by), there is no movement of the deflection center and no occurrence of neck shadow. The magnetic field emission part 11 of the top collector 11
Since a is divided into four pieces, the area of the emission surface can be reduced, and therefore, the direction of the electron beam can be simply determined, and the effect can be exerted on the vertical deflection without any effect. You can. FIG. 6 shows the first embodiment. FIG.
In the figure, reference numeral 12 denotes a top collector, and 12a denotes a magnetic field emission portion of the top collector 12 composed of four substantially cylindrical magnetic bodies, and has substantially the same configuration as that of the premise . 12
b is a magnetic field collection part of the top collector 12. A part of the magnetic field collection part 12b faces the electron gun side end face of the annular core 3, but a tip part 12c of the magnetic field collection part 12b is bent in a direction parallel to the tube axis of the cathode ray tube, and the toroidal vertical deflection coil 2b is bent. Is inserted into the wound annular core 3. That is, a part of the main deflection magnetic field 9 is absorbed. In this embodiment, a part of the main deflection magnetic field 9 is absorbed, so that the deflection is not performed in this part. Therefore, with this configuration, it is possible to move the deflection center to the front surface of the deflection yoke. FIG. 7 is a perspective view of the top collector 13 of the deflection yoke according to the reference example of the present invention. Numeral 13a denotes a magnetic field emission portion having substantially the same structure as that of the previous embodiment, and has substantially the same structure as that of the previous embodiment. The magnetic field collection portion of the top collector 13 includes a central portion 13b and both end portions 13c and 13d. Both ends 13c and 13d are toroidal type vertical deflection coils 2 wound vertically on an annular core 3 shown in FIG.
Somewhat away from the annular core 3 to avoid copper wire bundles. Since there is no copper wire bundle in the center, the central part 1 of the magnetic field collection part
3 b is cut and raised so as to approach the annular core 3. With this configuration, it is possible to more efficiently absorb the leakage magnetic field 9a diverging from the electron gun side end surface of the annular core 3. As described above, according to the present invention, the magnetic field collecting portion of the top collector is arranged to face the electron gun side end face of the annular core, and the tip of the magnetic field collecting portion is of a toroidal type.
Position it on the inner surface of the vertical deflection coil or
The pick-up part has a center part and both ends, and this center part is used as an annular core.
By approaching and absorbing the magnetic field emitted from the end face of the ring core on the electron gun side, the deflection sensitivity to the center electron beam can be improved more efficiently without the deflection center coming to the electron gun side. Moreover, the neck shadow can be eliminated, and the deflection angle can be made wider.

[Drawings BRIEF DESCRIPTION] [Figure 1] frame collector used in the deflection yoke of the side view [FIG 3] the premise embodiment of the deflection yoke of plan view Figure 2 the assumption embodiment of the deflection yoke in the premise of the invention perspective view of FIG. 4 is a graph 6 shows a sectional view Figure 5 the distribution of the vertical deflection magnetic field of the same assumptions form the deflection yoke for explaining a state of the magnetic field in the frame collector of the deflection yoke of the same assumptions form FIG. 7 is a sectional view of a deflection yoke in the first embodiment of the present invention. FIG. 7 is a perspective view of a coma collector used in the deflection yoke in the reference example of the present invention. FIG. 8 is a plan view of a conventional deflection yoke. FIG. 10 is a view of a cathode ray tube. FIG. 11 is an explanatory view showing a deflection magnetic field acting on an electron beam. FIG. 12 is an explanatory view for explaining occurrence of neck shadow. FIG. 13 is a neck. The shadow FIG. 14 is an explanatory diagram showing a magnetic field diverging from a toroidal type vertical deflection coil. FIG. 15 is an explanatory diagram illustrating the function of a magnetic field collection unit of a conventional coma collector. Type horizontal deflection coil 2 Toroidal type vertical deflection coil 3 Annular core 11 Coma collector 11a Magnetic field emission unit 11b Magnetic field collection unit

Claims (1)

(57) [Claim 1] A saddle-type horizontal deflection coil and a toroidal vertical deflection coil wound around an annular core, wherein the linear portion of the cathode ray tube is made of four magnetic materials. A frame in which a magnetic field emission part is arranged in parallel with the electron gun and a magnetic field pickup part is arranged facing the electron gun side end face of the annular core so as to absorb a leakage magnetic field diverging from the electron gun side end face of the annular core. A deflection yoke having a collector;
The tip of the pick-up part is the inner surface of the toroidal vertical deflection coil.
A deflection yoke, wherein