JPH0547319A - Deflection yoke - Google Patents

Abstract

PURPOSE:To provide a good picture screen of less mis-convergence by disposing a pair of auxiliary vertical coils with respect to a pair of saddle type vertical coils. CONSTITUTION:Auxiliary vertical coils 4a, 4b are disposed at a window portion (having no main vertical coil wound therearound) in an intermediate portion, on the tube axial, between the picture-screen side opening end of a pair of saddle type vertical coils 1a, 1b constituting the deflection yoke and the electron gun side opening end. In these auxiliary vertical coils 4a, 4b for example, winding is effected over an angular range of 68 deg., 69 deg. at the picture screen side opening end and over an angular range of 86 deg. at the electron gun side opening end. The auxiliary vertical coils are mounted at a distance of approximately 8mm from the electron gun side opening end in the main vertical deflection field. Wiring of the auxiliary vertical coils is connected in series to the coils 1a, 1b. Namely, the coils 4a, 4b are connected in series to the coils 1a, 1b so that they may produce a magnetic flux in the same direction as in the main magnetic field produced by the coils 1a, 1b. This makes it possible to produce a correction field in the central field, thereby lessening the occurrence of mis- convergence.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection yoke to be combined with a cathode ray tube used in a television receiver or the like, and is a cathode ray tube misconverter having an electron gun for emitting a plurality of beams arranged in-line. A vertical deflection yoke for reducing the presence.

[0002]

2. Description of the Related Art A conventional deflection yoke comprises a saddle type horizontal deflection coil and a saddle type vertical deflection coil. However, reducing the misconvergence in the entire television screen is limited only by adjusting the winding distributions of the saddle-type horizontal deflection coil and the saddle-type vertical deflection coil, and the misconvergence as shown in FIG. 8 often remains. By adjusting the winding distribution of the saddle-type horizontal coil / saddle-type vertical coil, strong adjustments can be made to eliminate the amount of misalignment of the electron beam R and the electron beam B in the X direction in the central portion M of the screen. The misconvergence of the electron beam R of C and the electron beam B becomes large as shown in FIG.

On the contrary, if the adjustment is made so as to eliminate the deviation amount of the electron beam R in the peripheral portion C of the screen and the electron beam B in the X direction, the electron beam R and the electronic beam in the central portion M of the screen are adjusted. The misconvergence of Mumu B is as shown in FIG. That is, in the conventional technology, this relationship cannot be improved only by adjusting the winding distribution of the saddle type horizontal deflection coil and the saddle type vertical deflection coil.

This misconvergence amount is generally h
Since it is c2 × hm, in the conventional technique, a misconversion is performed.
It was general to realize the state shown in FIG. 8 in which the amount of presence is small.

The relationship between FIG. 8 and FIG. 9 will be described below by using a conventional saddle type vertical deflection coil distribution adjusting method.
FIG. 7 is a cross section S of the saddle type vertical coil in the Z-axis direction of the cathode ray tube.
And the magnetic field curve "BII term" for explaining the magnetic field distribution
Indicate. Further, FIG. 4 is a front view of a conventional saddle-type vertical deflection coil as seen from the cathode ray tube surface direction.

As is apparent from FIG. 7, in the saddle type vertical deflection coil, a pinned magnetic field is present outside the screen side opening end and the electron gun side opening end, but inside the coil (that is, the screen side opening end). And inside the opening end on the electron gun side), a barrel magnetic field is generated. In addition, due to the physical property of the barrel magnetic field (that is, the barrel magnetic field is generated at the place surrounding and pushing in the magnetic field), the place where the barrel magnetic field is strongest is between the screen side opening end and the electron gun side opening end. It is a department.

Further, the energy received by the electron beam is the sum e of all the deflection magnetic field energy at the passage point through which the electron passes.
From t, it is clear that the more the electron beam is deflected, the more energy it receives. That is, the electron beam receives a large barrel magnetic field amount from the electron gun side opening end toward the screen side opening end.

Also, the electron beams R and B of the actual CRT are used.
The surface of the television screen does not coincide with the surface of the television screen as shown in FIG. 10 (that is, the surface of the television screen is not the same as that of the surface of the television screen). The difference d between the surface where the electronic beams R and B intersect and the surface of the television screen becomes larger as it goes to the edge of the screen.

Further, a barrel magnetic field is required in order to converge the three beams arranged in line in the vertical direction of the screen (to match the electron beam R and the electron beam B). , The magnitude of d is proportional to this. That is, since the barrel magnetic field amount increases as the magnitude of d increases, it is necessary to increase the barrel magnetic field amount toward the screen edge.

Under such a geometric condition, when the saddle type vertical deflection coil having the above-mentioned physical properties is used to reduce the misconvergence on the cathode ray tube, the relation of et> d is generally established. Normally, the misconvergence shown in FIG. 9 is caused, but in reality, the saddle type vertical deflection coil is intentionally set as the barrel magnetic field as a whole as shown in FIG. 8 based on the relationship between hc and hm described above.

[0011]

However, the above-mentioned misconvergence is not a problem because the screen is a moving image when the television receiver is simply receiving a television broadcast. This is not a problem, but it has become a problem when used for still images (so-called displays) in recent years.

An object of the present invention is to provide a deflection yoke that solves these conventional problems.

[0013]

In order to solve the above-mentioned problems, the present invention is a window portion of a saddle type vertical deflection coil which constitutes a deflection yoke, and which is located between the screen side opening end and the electron gun side opening end. The auxiliary vertical coil is arranged in the section and is connected in series with the saddle type vertical deflection coil so as to generate a magnetic flux in the same direction as the main magnetic field.

[0014]

According to the present invention, since the auxiliary vertical coil is arranged in the saddle type vertical coil as described above, a magnetic field required in a desired range can be easily produced in addition to the main deflection magnetic field. As a result, the pattern of misconvergence generated due to the relationship of the pin magnetic field and barrel magnetic field is improved compared to the conventional deflection coil, and a good screen with less misconvergence can be realized, and it is sufficiently compatible with still images. It became possible.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of the deflection yoke of the present invention seen from the tube axis direction.

The saddle type vertical coils 1a and 1b constituting the deflection yoke according to the present invention have a window portion (the main vertical coil is not wound) in the tube axial direction intermediate portion between the screen side opening end and the electron gun side opening end. Auxiliary vertical coils 4a and 4b are arranged in a portion).

FIG. 2 is a front view of the auxiliary vertical coils 4a and 4b.
FIG. 5 is a sectional view of the deflection yoke according to the present invention in the tube axis direction. In the present embodiment, the auxiliary vertical coils 4a and 4b are 68 ° with respect to the vertical deflection axis Y-axis on the screen opening end side.
Winding is performed in the region of ~ 69 ° and 86 ° at the electron gun side opening end, and the vicinity of the electron gun side opening end of the main vertical deflection magnetic field is about 8 mm.
They are installed in separate positions. The wiring is connected in series with the saddle type vertical deflection coils 1a and 1b as shown in FIG.

As described above, by adding the auxiliary vertical deflection magnetic field set at the above angle to the main vertical deflection magnetic field, the "BII term" is as indicated by the broken line in FIG. That is, the portion to which the auxiliary vertical deflection coils 4a and 4b are added is
The barrel magnetic field becomes stronger, and accordingly, the other portions have a pin magnetic field tendency (that is, the barrel magnetic field becomes weaker). This is the sum of the energies received by the electron beam of all vertical deflection magnetic fields.
This is because the misconvergence of the electronic beam R and the electronic beam B in the peripheral portion C of the screen cannot be matched unless they are the same as when there is no auxiliary vertical coil.

Now, the "BII" of FIG. 7 at 20 inches.
", And the result of examining the relationship between the television screen of FIG.
Obtain the following Table 1.

[0020]

[Table 1]

This principle will be described below. The magnetic field generated by the auxiliary vertical coils 4a and 4b acts so that the electron beam R and the electron beam B are separated from each other in the direction of the lines of magnetic force 2 as shown in FIG. The forces 3a and 3b are shown in FIG.
Further, the range that acts on the beam is the central portion of the television screen. Therefore, it effectively acts on M of the misconvergence shown in FIG.

In the portion without the auxiliary vertical coil, as shown by forces 3a and 3b in FIG. 5, the direction of the magnetic force line 2 acts so that the electron beam R and the electron beam B attract each other. Also, the area that acts on the beam is the peripheral portion of the television screen. Therefore, the misconvergence C shown in FIG.
Effectively acts against.

[0023]

As described above, according to the present invention, in the deflection yoke including the saddle-type horizontal deflection coil and the saddle-type vertical deflection coil, the saddle-type vertical coil is provided between the opening end on the screen side and the opening end on the electron gun side. An auxiliary vertical coil is installed in the window portion of the section, and the auxiliary vertical coil is connected in series with the saddle type vertical deflection coil so as to generate a magnetic flux in the same direction as the main magnetic field produced by the saddle type vertical deflection coil, and By making the deflection current flow in the same direction as the vertical deflection coil, a correction magnetic field can be created in the central magnetic field, misconvergence can be reduced, and misconvergence can be made inconspicuous even on a still screen.

[Brief description of drawings]

FIG. 1 is a front view of a saddle type vertical deflection coil in which an auxiliary coil is added according to an embodiment of the present invention.

FIG. 2 is an explanatory view showing a vertical auxiliary coil in the same embodiment.

FIG. 3 is a perspective view showing a saddle type vertical deflection coil and an auxiliary vertical coil in the same embodiment.

FIG. 4 is a front view of a conventional saddle-type vertical deflection coil.

FIG. 5 is an explanatory view showing a cross section in the tube axis direction of the saddle type deflection coil of the embodiment, the direction of magnetic force lines generated from the coil, and the force received by the electron beam.

FIG. 6 is a connection diagram of a main deflection coil and an auxiliary deflection coil according to an embodiment.

FIG. 7 is a magnetic field characteristic curve diagram of the "BII" term of the deflection yoke.

FIG. 8 is an explanatory diagram showing misconvergence on a 20-inch television screen.

FIG. 9 is an explanatory diagram showing a state of misconvergence when the misconvergence at the center of the screen is improved.

FIG. 10 is an explanatory diagram showing a relationship between a surface of a television screen and an intersecting surface of an electron beam on a CRT.

[Explanation of symbols] 1a Saddle type vertical deflection coil 1b Saddle type vertical deflection coil 2 Magnetic field lines 3a force 3b force 4a Auxiliary vertical coil 4b Auxiliary vertical coil B Electron beam C Screen peripheral area R Electron beam

Claims (1)

[Claims] 1. A deflection yaw used for a cathode ray tube having an electron gun for emitting a plurality of beams arranged in-line and having a saddle type horizontal deflection coil and a saddle type vertical deflection coil.
In (4), an auxiliary vertical coil is installed in the window in the middle of the screen-side opening end of the saddle-type vertical coil and the electron gun-side opening end, and this auxiliary vertical coil is connected to the main magnetic field created by the saddle-type vertical deflection coil. A deflection yoke which is connected in series with a saddle type vertical deflection coil so as to generate magnetic flux in the same direction.