JPH06223741A - Deflection yoke - Google Patents

Abstract

PURPOSE:To perform fine misconvergence correction. CONSTITUTION:A set of two vertical deflection coils 19a and 19b is connected in series, and variable terminals 20c and 20d of two variable resistors are connected to the central part of the deflection coils, that is, the connection of the vertical deflection coils 19a and 19b. Diodes 21a, 21b, 22a, and 22b are provided to let flow a vertical deflection current only in the direction A to one side variable resistor 20a, and to let flow the vertical deflection current only in the direction B to the other side variable resistor 20b. Consequently, the regulation can be carried out by the vertical resistor 20a at the upper half of an image plane where the vertical deflection current flows in the direction A, and the regulation can be carried out by the vertical resistor 20b at the lower half of the image plane where the vertical deflection current flows in the direction B. As a result, a fine correction of a misconvergence can be carried out by separating the upper half or the lower half of the image plane independently.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deflection yoke used in a television receiver or the like.

[0002]

2. Description of the Related Art At present, a vertical deflection coil of a deflection yoke for a display which requires a still image on a television screen is formed by connecting a pair of coils in series, and a damping resistor and a variable resistor are connected in parallel. Circuit is used.

FIG. 3 shows a vertical circuit of a conventional deflection yoke of this type. In the figure, 1a and 1b are vertical deflection coils, 2 is a damping resistor, and 3 is a variable resistor. The vertical deflection coil 1a and the vertical deflection coil 1b are connected in series,
A circuit in which a fixed resistor, a variable resistor, and a fixed resistor are connected in series in this order is connected in parallel to both ends thereof. Further, the movable terminal 3a of the variable resistor 3 is connected to the midpoint of the vertical deflection coils 1a and 1b.

FIG. 4 is an external view of the deflection yoke. In the figure, 4 is a ferrite core, 5 is a phosphor screen side opening, and 6 is an electron gun side small diameter part. The vertical deflection coils 1 a and 1 b are located inside the ferrite core 4.

FIG. 5 shows magnetic fields generated by the vertical deflection coils 1a and 1b. In the figure, 7 is a magnetic field line by the vertical deflection coil. 8 is a red electron beam, 9 is a green electron beam, and 10 is a blue electron beam.
Three electron guns are arranged in a horizontal row. The three electron beams are deflected by the downward force indicated by the arrow 11 due to the action of the magnetic field lines 7 generated by the vertical deflection coil 1a and the vertical deflection coil 1b.

FIG. 6 shows a CRT screen with the electron beam stationary. In the figure, 12 and 13 are red lines, and 14 and 15 are blue lines. As shown in the figure, at the top and bottom of the screen, red line 12,
For misconvergence in which 13 is outside the screen and blue lines 14 and 15 are inside the screen, adjustment is made as follows.

FIG. 7 is a diagram showing a state in which the magnetic field strengths of the vertical deflection coil 1a and the vertical deflection coil 1b are changed. Here, 16 is a magnetic flux when the magnetic field generated by the vertical deflection coil 1a is made stronger than the magnetic field generated by the vertical deflection coil 1b. When the movable terminal 3a of the variable resistor 3 in FIG. 3 is moved from the middle point to the right side, the current flowing through the vertical deflection coil 1a increases and the current flowing through the vertical deflection coil 1b decreases. Along with this, the magnetic flux 16 generated by the vertical deflection coils 1a increases and the magnetic flux 16 generated by the vertical deflection coils 1a and 1b decreases.

By increasing the magnetic flux 16 by the vertical deflection coil 1a in this way, the blue electron beam 10 emitted from the electron gun closest to the vertical deflection coil 1a has a stronger force 17 than before the adjustment of the variable resistor 3. Received, it is deflected downward. Also, the vertical deflection coil 1 with reduced magnetic flux
The red electron beam 8 closest to b is deflected downward with a weaker force 18 than before adjusting the variable resistor 3.

When the magnetic flux 16 by the vertical deflection coil 1a increases and the magnetic flux 16 by the vertical deflection coil 1b decreases,
On the screen, the correction is performed as shown by the arrow in FIG. That is, in the upper half C of the screen, the blue line 14 which has been deflected with a stronger force than before moves in the direction of the arrow 21, and conversely the red line which has been deflected with a weaker force than before. 12 moves in the direction of arrow 19. Similarly, in the lower half D of the screen, the blue line 15 that has been deflected with a stronger force than before moved in the direction of the arrow 22 and the red line 1 that has been deflected with a weaker force than before.
3 moves in the direction of arrow 20.

With the above operation, the red line 12 and the blue line 14 can be overlapped on the upper half C of the screen, and the red line 13 and the blue line 15 can be overlapped on the lower half D of the screen.

[0011]

As described above, in the conventional configuration, in the upper half and the lower half of the screen shown in FIG. 6, mis-convergence in which lines of the same color are outside or inside the screen is variable resistor 3. Can be adjusted by
There is a problem in that it is not possible to correct the misconvergence as shown in FIG. 8, that is, the misconvergence in which lines of different colors in the upper half and the lower half of the screen are outside or inside the screen.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a deflection yoke capable of finer misconvergence correction independently of the upper half of the screen or the lower half of the screen. .

[0013]

In order to achieve the above-mentioned object, the deflection yoke of the present invention is a series in which a variable resistor is connected in the middle of a diode which is connected in series to the vertical deflection coil in accordance with the energization direction. The circuits are connected in parallel, and a circuit having the same configuration as the series circuit including the diode and the variable resistor is connected in parallel with the vertical deflection coil in a direction opposite to that of the series circuit having the above configuration. It is configured by connecting the movable terminals of the individual variable resistors to the midpoint of the vertical deflection coil.

[0014]

With this structure, the misconvergence can be corrected independently of the upper half of the television screen or the lower half of the screen.

[0015]

An embodiment of the present invention will be described below with reference to the drawings. First, referring to FIG. 1, 19a and 19b
Is a vertical deflection coil, 20a and 20b are variable resistors, 2
1a and 21b and 22a and 22b are diodes, and arrows A and B indicate the directions of vertical deflection currents. The vertical deflection coils 19a and 19b are the vertical deflection coils 1 shown in FIG.
It has the same configuration as a and 1b.

In this structure, when a deflection current is passed in the direction of arrow A, the upper half C of the screen is scanned on the screen,
When a deflection current is passed in the direction of arrow B, the lower half D of the screen is scanned.

When the deflection current flows in the direction of arrow A, the diode 21a and the diode 21b act to cause a current to flow in the variable resistor 20a, and the vertical deflection coils 19a and 19b.
And a current flows through the variable resistor 20a.

When the movable terminal 20c of the variable resistor 20a is moved from the center to the right, the current flowing through the vertical deflection coil 19a increases and the current flowing through the vertical deflection coil 19b decreases. Along with this, the magnetic flux generated in the vertical deflection coil 19a increases and the magnetic flux of the vertical deflection coil 19b decreases. Due to the decrease in the magnetic flux of the vertical deflection coil 19b, the red electron beam 8 is deflected downward than before adjustment and the blue electron beam 10 is deflected above before adjustment.

FIG. 2 shows the screen of a cathode ray tube. In the drawing, the operation of the upper half C of the screen is the movement of the electron beam due to the magnetic field when the deflection current is passed in the direction of arrow A, and the red line 23 above it. Moves in the downward direction 25 and the blue line 24 in the lower direction moves in the upward direction 26, and the red line 23 and the blue line 24 can be overlapped with each other in the upper half C of the screen.

On the other hand, when the deflection current flows in the direction of arrow B, the current flows through the variable resistor 20b by the action of the diodes 22a and 22b. That is, the current is shunted to the vertical deflection coils 19a and 19b and the variable resistor 20b, and a current flows in the direction opposite to the arrow A. Therefore, the magnetic poles shown in FIG. 5 are reversed and operate in the opposite magnetic field. Variable resistor 20
When the movable terminal 20d of b is moved from the midpoint to the left, the current flowing through the vertical deflection coil 19a decreases and the current flowing through the vertical deflection coil 19b increases. Therefore, the magnetic flux generated in the vertical deflection coil 19a decreases and the magnetic flux generated in the vertical deflection coil 19b increases. Vertical deflection coil 19
Due to the increase in the magnetic flux of b, the red electron beam 8 is deflected downward and the blue electron beam 10 is deflected upward as compared with before adjustment. In FIG. 2, the red line 23 on the lower half D of the screen moves downward 28 and the blue line 24 moves upward 27, so that the red line 23 and the blue line 24 can be overlapped on the lower half D of the screen.

In this way, the upper half C of the screen or the lower half D of the screen can be scanned depending on the direction in which the deflection current flows. When the deflection current is flowing in the direction of arrow A, the magnetic field of the vertical deflection coil 19a and the vertical deflection coil 19b can be adjusted by the variable resistor 20a to correct the misdivergence of the half C on the screen, and the deflection current is further changed to the arrow B When flowing in the direction, the variable resistor 20b can adjust the inverted magnetic fields of the vertical deflection coil 19a and the vertical deflection coil 19b to correct the misvergence of the lower half D of the screen.

[0022]

As described above, according to the present invention, in the screen of a television or the like, the upper half of the screen can be adjusted by one variable resistor, and the lower half of the screen can be adjusted. Since it can be adjusted by the other variable resistor,
The upper half of the screen or the lower half of the screen can be independently corrected for finer misconvergence, and a deflection yoke with reduced misconvergence can be provided.

[Brief description of drawings]

FIG. 1 is a wiring diagram of a deflection yoke according to an embodiment of the present invention.

FIG. 2 is a screen view of a CRT using a deflection yoke in the same embodiment.

FIG. 3 is a wiring diagram of a conventional deflection yoke.

FIG. 4 is an external perspective view of a conventional deflection yoke.

FIG. 5 is a diagram showing a magnetic field generated by a vertical deflection coil of a conventional deflection yoke.

FIG. 6 is a screen view of a cathode ray tube using a conventional deflection yoke.

FIG. 7 is a diagram showing a magnetic field generated by a vertical deflection coil of a conventional deflection yoke.

FIG. 8 is a screen view of a CRT using a conventional deflection yoke.

[Explanation of symbols]

 19a, 19b Vertical deflection coil 20a, 20b Variable resistor 20c, 20d Movable terminal 21a, 21b, 22a, 22b Diode 23 Red line 24 Blue line

Claims (1)

[Claims] 1. A first series circuit in which a variable resistor is provided in the middle of two diodes, which are connected in series in the energization direction, and a second series circuit configured in the same manner as the first series circuit. A circuit and a third series circuit formed by connecting a pair of vertical deflection coils in series, the first series circuit is connected in parallel to the third series circuit, and the second series circuit is , A variable resistor of the first series circuit and the second series circuit, the diode being connected in parallel to the third series circuit so that the diode is in a direction opposite to the direction of the diode of the first series circuit. 2. The deflection yoke, wherein both movable terminals are connected between the pair of vertical deflection coils.