JPH0646547B2 - Deflection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a color image receiving device such as a color television receiver or a color cathode ray tube display device in which three electron guns are arranged in line and a field controller is not provided inside. It relates to a deflection device mounted on a tube.

<Prior Art> As is well known, in a deflection device which is mounted on a color picture tube having three electron guns in an in-line arrangement and deflects a beam generated by each electron gun, a horizontal deflection coil is used as a whole. As a pincushion-type deflection magnetic field and a vertical deflection coil as a barrel-type deflection magnetic field, and in addition to this, in the neck of the picture tube, the central beam and both Magnetic field control element (field controller) that combines a plurality of magnetic materials to match the side beam deflection sensitivity on the picture tube screen
By incorporating (hereinafter referred to as FC), the sensitivity of the three beams can be adjusted and theoretically the misconvergence can be made zero.

On the other hand, recently, for example, in order to obtain a high-definition and high-resolution screen, the horizontal scanning frequency is set to a high value between the usual 15.75 KHz and 64 KHz. When the horizontal scanning frequency is increased, F
Overcurrent is generated in C, the horizontal shift of the central beam becomes large, and other convergence characteristics are affected in various ways (misconvergence occurs). As a result, misconvergence occurs over the entire screen. It is extremely difficult to obtain a good screen characteristic with no noise. On the other hand, in the case of a picture tube having a small neck diameter, it is structurally difficult to incorporate FC in the neck portion, and the deflection device is attached to a color picture tube in which FC does not exist from the beginning. In this case, The beam sensitivity cannot be adjusted, resulting in misconvergence.

Conventionally, in order to eliminate such misconvergence and obtain good screen characteristics, a color picture tube without FC in the neck portion is used, and as shown in FIG. 6, caused by the absence of FC, On the vertical axis (Y-axis) of the screen, the central beam G has insufficient sensitivity to the left and right beams B and R, and the insufficient state is large in the upper and lower parts of the screen and small in the middle part. In order to eliminate such misconvergence, as shown in FIG. 7, an auxiliary magnetic field is generated for increasing (correcting) the sensitivity of the central beam G in series with the vertical deflection coil 31 of the deflection yoke. The coil 32 is connected, and the variable resistor 33 for adjusting the correction amount is connected in parallel to the auxiliary coil 32.

<Problems to be Solved by the Invention> However, in such a conventional configuration, the auxiliary magnetic field applied to the central beam G has the same amount (ratio) in the upper and lower parts and the middle part of the screen. As shown in FIG. 8, even if the misconvergence of the central beam G is eliminated in the upper and lower parts of the screen, the ratio of the misconvergence is smaller than that in the upper and lower parts, and the central beam G is in the middle part of the screen.
However, there was a problem that the beam R / B on both sides was overcorrected, and the misconvergence could not be resolved.

<Means for Solving Problems> The present invention has been made to solve the above problems.
A beam generated by the central electron gun of the electron guns, which is located on the rear side of the deflection yoke mounted on the color picture tube in which the three electron guns are arranged in a line in the horizontal direction and which has no field controller inside. A pair of auxiliary magnetic field generating means for applying an auxiliary magnetic field is provided in a direction orthogonal to the arrangement direction of the electron guns, and auxiliary coils forming the auxiliary magnetic field generating means have the same winding direction. A positive winding portion, a resistor and a parallel circuit of a second positive winding portion are connected in series to the first positive winding portion, and two diodes are connected in series to the second positive winding portion to polarize each other. They are connected in the reverse direction.

<Operation> An auxiliary coil constituting a pair of auxiliary magnetic field generating means for applying an auxiliary magnetic field to a beam generated by the central electron gun is composed of first and second positive winding parts having the same winding direction,
A resistor and a parallel circuit of a second positive winding portion are connected in series to the first positive winding portion, and two diodes are connected in series to the second positive winding portion with their polarities reversed. The amount of the auxiliary magnetic field generated by the auxiliary coil is
Depending on the value of the first positive winding portion and the resistance, or the amount of current flowing through the second positive winding portion which changes depending on whether the diode is conducting or not conducting, the central portion and the upper and lower portions of the screen are changed. As a result, the misconvergence in which the ratio of misconvergence is different between the central part and the upper and lower parts of the screen is eliminated over the entire screen.

<Example> Hereinafter, an example of the deflecting device of the present invention will be described in detail with reference to the drawings. In FIG. 1, the deflection device 10 includes a core 11
A vertical deflection coil 12 wound toroidally around the outer periphery of the core 11, a paddle-shaped horizontal deflection coil 14 disposed on the inner surface of the core 11 via a coil bobbin 13, and a rear enlarged portion 13a of the coil bobbin 13. It is composed of a pair of fixed auxiliary magnetic field generating means 15 and 16, and three electron guns (B, G, R) of blue, green, and red are arranged in a line in a horizontal direction (in-line form), and FC is internally provided.
It is adhesively fixed on the color picture tube neck portion 17 where the (field controller) does not exist. Of these, the vertical deflection coil 12 generates a barrel-type vertical deflection magnetic field, and the horizontal deflection coil 14 generates a pincushion-type horizontal deflection magnetic field as in the conventional case. Auxiliary magnetic field generating means 15 arranged on the rear surface of the rear enlarged portion 13a of the coil bobbin 13,
16 is a substantially U-shaped core 18, 19 and a core 1
And an auxiliary coil 20 wound around 8 and 19,
Outside the picture tube neck portion 17, they are arranged to face each other in a direction orthogonal to the arrangement direction of the electron guns (B, G, R). Auxiliary coil 20 constituting auxiliary magnetic field generating means 15 and 16
As shown in FIG. 2, is composed of a first forward winding portion 20a and a second forward winding portion 20b, which have the same winding direction, and is wound around the cores 18 and 19 in a laminated manner. The auxiliary coils 20 (20a, 20b) are connected in series to the vertical deflection coil 12 connected to the vertical deflection circuit 21, as shown in FIG.
0a, 20b), like the vertical deflection coil 12, a sawtooth-shaped vertical deflection current flows. A resistor 22 is connected in parallel to the second positive winding portion 20b forming the auxiliary coil 20 through which the vertical deflection current flows, and the second positive winding portion 2 is connected.
0b is connected in series with two diodes 23, 24, such as a Zener diode and a Schottky diode, whose polarities are opposite to each other.
The second positive winding portion 20b, the diode 23,
A parallel circuit composed of 24 and a resistor 22 is connected in series. Further, the first and second positive winding portions 20a, 20b of the auxiliary coil 20 are arranged in parallel on the entire auxiliary coil 20.
A volume 25 for adjusting the amount of current flowing through is connected. In FIG. 3, reference numeral 26 is a volume for adjusting the amount of current flowing through the vertical deflection coil 12, which is connected in parallel to the vertical deflection coil 12 as necessary.

Next, the operation state of the deflecting device of the present invention will be described. The first and second positive winding portions 20a and 20b of the auxiliary coil 20 constituting the auxiliary magnetic field generating means 15 and 16 are connected in series to the vertical deflection coil 12, respectively. Like the vertical deflection coil 12, a vertical deflection current of a sawtooth wave flows through the second positive winding portions 20a and 20b. Accordingly, the core 18, 19 of the auxiliary magnetic field generating means 15 and 16, as shown in FIG. 4, the auxiliary magnetic field phi _A, is phi _B generated, the auxiliary magnetic field phi _A, phi _B is the neck 17 It concentrates on the green beam G generated by the electron gun (G) located in the center thereof, and as a result, the sensitivity of the green beam G is increased. Here, the amounts of the auxiliary magnetic fields φ _A and φ _B applied to the green beam G change according to the value of the vertical deflection current (sawtooth current) flowing in the auxiliary coil 20. In other words, above the center of the screen,
And in the upper part, the value of the vertical deflection current is close to the peak value,
The diode 23 becomes conductive, and the current passes through the first positive winding portion 20a and then the second positive winding portion 20b. Therefore, auxiliary magnetic fields (φ _A , φ _B ) corresponding to the number of turns of the first and second positive winding portions 20a and 20b are generated and added to the green beam G. On the other hand, in the middle part of the screen, the value of the vertical deflection current is close to the minimum value (0), the diode 23 becomes non-conductive, and the current passes through the first positive winding portion 20a and then the resistor 22 side. , The auxiliary magnetic fields (φ _A , φ _B ) corresponding to the number of turns of the first positive winding portion 20a are generated. That is, in the upper part of the screen, the amount of the auxiliary magnetic field generated is large corresponding to the number of turns of the first and second positive winding parts 20a and 20b, and in the middle part of the screen, only the first positive winding part 20a is turned. The amount of auxiliary magnetic field generated decreases in proportion to the number, and the sensitivity of the central green beam G is greatly increased at the upper part of the screen, and the sensitivity of the green beam G is slightly increased at the intermediate part of the screen compared to the upper part. Then, similarly below the central portion of the screen (in this case, the vertical deflection current becomes a negative component, the diode 24 becomes non-conductive at the middle portion of the screen, and the diode 24 becomes conductive at the lower portion of the screen). Next to),
A small amount of auxiliary magnetic field is generated in the middle portion (first positive winding portion 2
0a), and the amount of auxiliary magnetic field generated in the lower portion is large (first and second positive winding portions 20a, 20b).
(The amount of generation according to the number of turns of the green beam G), the sensitivity of the green beam G is narrowed in the middle part of the screen, and the sensitivity of the green beam G is significantly increased in the lower part of the screen. As a result, as shown in FIG. 5, the green beam G is largely corrected in the arrow direction at the upper and lower parts of the screen, and the green beam G is made at the middle part of the screen.
Is corrected in a small amount in the direction of the arrow to correct the misconvergence, and finally good convergence characteristics and screen characteristics in which the beams B, G, and R coincide with each other can be obtained over the entire screen. Where diode 2
By adjusting (changing) the value of the resistor 22 in the conducting state of the electrodes 3 and 24, the amount of current flowing through the second positive winding portion 20b can be finely adjusted. The amount of increase in the sensitivity of the green beam G in the lower part can be finely adjusted.

In one embodiment of the deflection device of the present invention, two Zener diodes or Schottky diodes are connected in series with the second positive winding portion of the auxiliary coil constituting the auxiliary magnetic field generating means so that their polarities are opposite to each other. Although the ones connected in series have been described, a silicon diode may be used. In the embodiment of the deflection apparatus of the present invention, the auxiliary coil is connected in series to the vertical deflection coil, and the vertical deflection current is passed through the auxiliary coil to generate the auxiliary magnetic field. May be configured so that an auxiliary current synchronized with the vertical deflection current is separately supplied to the auxiliary coil without being connected to the vertical deflection coil. Further, in the deflecting device of the present invention, the vertical deflection coil is configured to be wound toroidally with respect to the core. However, the vertical deflection coil may be configured to be wound in a square shape.

<Advantages of the Invention> The deflecting device of the present invention is as described above in detail, and the unique auxiliary magnetic field unrelated to the deflecting magnetic field generated by the deflecting coil is generated by the auxiliary magnetic field generating means and is positioned at the center. The lack of beam sensitivity caused by the electron gun can be increased by the required amount in the upper and lower parts of the screen and the middle part respectively, and the unbalanced sensitivity of the central beam at the upper and lower parts of the screen and the middle part can be eliminated. Thus, with a very simple configuration, it is possible to obtain good image quality characteristics without misconvergence over the entire screen while maintaining the best deflection characteristics. Further, the auxiliary coil constituting the auxiliary magnetic field generating means is composed of the first and second positive winding portions, and the portions (the upper and lower portions of the screen) where the amount of insufficient sensitivity of the central beam is large are the first and second. The positive winding part is used to generate the auxiliary magnetic field only in the first positive winding part in the part (the middle part of the screen) where the amount of sensitivity is small, and the total number of turns of the auxiliary coil should be reduced. As a result, it does not adversely affect other screen characteristics, and at low cost,
Misconvergence can be corrected. Further, according to the deflecting device of the present invention, a resistor is connected in parallel to the second positive winding portion, and the amount of current flowing in the second positive winding portion can be finely adjusted by changing the resistance value. With this, it is possible to finely adjust the misconvergence at the top and bottom of the screen. As described above, according to the deflecting device of the present invention, various effects are produced. In order to obtain a high-definition and high-resolution screen, the horizontal scanning frequency is set high, and the FC is internally provided. It will become more and more effective in the future as a deflection device for a picture tube that does not exist.

[Brief description of drawings]

FIG. 1 is a schematic rear view of the embodiment of the deflection apparatus of the present invention, and FIG. 2 is a sectional view of the auxiliary magnetic field generating means.
FIG. 3 is a connection diagram of an auxiliary coil which is also a part of the auxiliary magnetic field generating means, FIG. 4 is an explanatory view of the operation of the auxiliary magnetic field generating means, and FIG. 5 is a state in which three electron beams converge by the deflecting device of the present invention. FIG. 6 is an explanatory view of a state where the central beam caused by not providing FC in the neck portion of the picture tube is large at the upper and lower portions of the screen and small in the middle portion and is not converged, and FIG. FIG. 8 is a connection diagram of an auxiliary coil forming a part of the auxiliary magnetic field generating means, and FIG. 8 is an explanatory diagram of a state of overcorrection in the middle part of the screen of the central beam generated by the deflection device having the conventional auxiliary magnetic field generating means. is there. 10 ... Deflection device, 15, 16 ... Auxiliary magnetic field generating means, 20 ... Auxiliary coil, 20a ... 1st positive winding part, 20b ... 2nd positive winding part, 22 ... Resistance, 23, 24 ... Diode,

Claims (1)

[Claims] 1. A blue, green, and red electron guns are arranged in a row in a horizontal direction and are located on the rear side of a deflection yoke mounted on a color picture tube in which no field controller is provided inside. A pair of auxiliary magnetic field generating means for applying an auxiliary magnetic field to the beam generated by the central electron gun among the electron guns are provided orthogonally to the arrangement direction of the electron guns, and an auxiliary forming the auxiliary magnetic field generating means. The coil is composed of first and second positive winding parts having the same winding direction, a resistor and a parallel circuit of the second positive winding part are connected in series to the first positive winding part, and the second positive winding part is connected. 2. A deflection device in which two diodes are connected in series to the positive winding part of the device in a state where the polarities are opposite to each other.