JPH0727736Y2 - In-line color picture tube image correction device - Google Patents

Description

The present invention relates to an image correction device for an in-line type color picture tube.

2. Description of the Related Art Generally, in a color picture tube used for a color television receiver, it is necessary that the electron beams individually emitted from the three electron guns are not only focused on the fluorescent screen but also focused (converged). .

Therefore, in the conventional three-electron gun in-line type color picture tube, in order to obtain a good concentration of the three electron beams on the fluorescent screen, the horizontal deflection magnetic field of the deflection yoke is set to a strong pink twitch type (pincushion type) or vertical deflection magnetic field. Is made into a strong barrel shape (beer barrel shape) to obtain good convergence.

However, in a 12-inch or 14-inch small tube having a deflection angle of a color picture tube of about 90 °, various misconvergence patterns appear when the upper and lower pincushion distortions are optimized. For example, as shown in FIG. 6, it is expected that misconvergence of a positive cross pattern having the same displacement amount will appear over the entire screen.

As a means for correcting this misconvergence, the present applicant has previously proposed that in Japanese Patent Application No. Sho 56-111650 "Color Picture Tube Deflection Device", it is wound around a magnetic core, connected in series with each horizontal deflection coil, and A biased coil (saturable reactor) is provided at a position where a magnetic flux emitted from the magnetic core of the deflection yoke and changing in the vertical deflection cycle acts.
We proposed a device that changes the circuit impedance of each horizontal deflection coil differentially in the vertical deflection cycle to change the aspect of the horizontal deflection magnetic field distribution with time. According to the apparatus having this configuration, the misconvergence of the above simple pattern can be corrected.

However, in reality, as shown in FIG. 7, a misconvergence of a positive cross pattern appears in which the shift amount is large in the central portion of the screen as indicated by A and is small in the upper and lower portions as indicated by B. When attempting to correct the misconvergence of such a pattern with the above device, the correction amount is the same in the central part and the upper and lower parts of the screen, so if the misconvergence in the upper and lower parts is corrected to zero, the center part of the screen is corrected. If the misconvergence remains without being completely corrected, and if it is corrected so that the central misconvergence becomes zero, the upper and lower parts will be overcorrected and the reverse cross misconvergence will appear, and the entire screen will be displayed. It was difficult to correct the misconvergence over the entire period.

Therefore, the present applicant has proposed Japanese Patent Application No. 58-234024 “Image correction device for in-line type color picture tube” in order to cope with the misconvergence of the pattern that is actually represented. In this device, a sawtooth wave current having a vertical deflection cycle is supplied to a saturable reactor provided at a position where a magnetic flux that is emitted from the magnetic core of the deflection yoke and that changes in the vertical deflection cycle acts, and the sawtooth wave current having the vertical deflection cycle is supplied to the saturable reactor. This configuration is provided with an auxiliary magnetic field forming coil that forms an auxiliary magnetic field in the same direction as the direction of the magnetic field emitted to the outside.

The feature of this device is that the added auxiliary magnetic field forming coil makes the operating range of the saturable reactor wider than in the prior art and utilizes the saturation region of the inductance, as shown in FIG. In FIG. 8, graph lines 1 and 2 show general characteristics of the inductance of a pair of left and right saturable reactors attached to the deflection yokes, respectively, and 3 is Japanese Patent Application No. 56-111650.
No. 58-234024 is the operating range of the device of Japanese Patent Application No. 58-234024. As a result, the relationship between the vertical deflection current and the misconvergence correction amount tends to be saturated as the vertical deflection current increases, as indicated by the graph line 5 in FIG. (Note that graph line 6
Shows the relationship between vertical deflection current and misconvergence correction amount in the device of Japanese Patent Application No. 56-111650. ) Graph line
The inclination angles of 5 and 6 represent the misconvergence correction amount. Therefore, according to this device, the amount of misconvergence correction is large in the central part of the screen and small in the upper part (same for the lower part). As a result, it is possible to satisfactorily correct the pattern misconvergence as shown in FIG. 7 in each part of the screen, that is, the entire screen.

Problems to be solved by the invention By the way, as shown in Fig. 7, the misconvergence pattern that appears on the screen of each assembled color picture tube has a large shift amount at the center of the screen and a small shift amount at the top and bottom of the screen. However, the amount of deviation differs, that is, varies depending on the individual color picture tube.

In the above device, it is difficult to variably adjust the correction amount of misconvergence because the current flowing through the auxiliary magnetic field forming coil cannot be adjusted. Therefore, it becomes practically difficult to optimally correct the misconvergence according to the amount of deviation of the convergence at that time, and the misconvergence correction function is insufficient.

An object of the present invention is to provide an image correction device for an in-line type color picture tube which solves the above problems.

Means for Solving the Problems The present invention provides a sawtooth wave current having a vertical deflection period in a saturable reactor provided at a position where a magnetic flux emitted from the magnetic core of a deflection yoke and changing in the vertical deflection period acts. And an auxiliary magnetic field forming coil that forms an auxiliary magnetic field in the same direction as the magnetic field emitted from the deflection yoke to the outside,
In addition, an adjusting member that can change the current flowing through the auxiliary magnetic field forming coil is provided.

Embodiment Next, an embodiment of the present invention will be described. In this embodiment, the image correction device is assembled to a part of the deflection yoke of the color picture tube.

FIG. 1 is a circuit diagram of the image correction apparatus, and FIGS. 2 and 3 show the mechanical structure thereof. In each drawing, L _H1 and L _H2 are a pair of saddle type horizontal deflection coils, and Lv is a toroidal winding vertical deflection coil, which constitutes the deflection yoke 10. 11- ₁ , 11- ₂ , 11- ₃ ,
11- ₄ controlled coils, 12- _1, 12- ₂ auxiliary magnetic field forming coil, 13 _1, 13 ₂ is a variable resistor forming a principal part of the present invention.
The controlled coil 11 ₁ and 11 ₂ are connected in series so winding directions thereof are opposite to each other, which horizontal deflection coil L
It is connected in series with _H1 . Another of the control coil 11 ₃ and 11 ₄
And are connected in series so that the winding directions are opposite to each other, and this is connected in series with the horizontal deflection coil L _H2 . Auxiliary magnetic field forming coils 12 _1, 12 ₂ Yes connected in parallel, the parallel connection circuit is connected to the vertical deflection coil Lv series. Variable resistor 13 _1, 13 ₂ are each auxiliary magnetic field forming coil _{12. 1} are connected in parallel to the _12-2, the coil 12
- ₁ varies the current flowing through the _12-2. The control coils 11- ₁ to
11- ₄ and the auxiliary magnetic field forming coils 12 _1, 12 _2, etc. are saturable reactor 14 _1, constitutes a _14-2.

As shown in FIGS. 2 and 3, a pair of core 15 ₁ vertical deflection coil Lv is wound, 15 ₂ are butted, plastics or the like horizontal deflection coil L _H1, L _H2 are incorporated It is fixed by a clamper 17 in a state of being assembled from above the separator 16 made of an insulating material. Furthermore, saturable reactor 14
- _1, 14 ₂ is mounted in the vicinity of the respective butting portions 18 _1, 18 _2.

Figure 4 shows taken out one of the saturable reactor 14 _1. The saturable reactor 14 _1, a drum-type core 19 shown in FIG. 5
- _1, 19 ₂ wrapping the control coil 11 ₁ formed by the mug the net wire, coil body _20-1 having 11 _2, 20-and _2, a permanent magnet 21 ₁ DC magnetic bias one but in the arrangement relationship shown in the drawing, is incorporated in the synthetic resin case _22-1, and the auxiliary magnetic field forming coil 12 ₁ is fitted fixed configuration on the outer periphery of the case _22-1. Saturable reactor 14 _1, as shown in FIG. 2, is attached to casing _22-1 integral with terminal board 23 is fixed to the cylindrical flange portion 24 of the separator 16.

As shown in FIG. 4, the auxiliary magnetic field forming coil 12 ₁ of the two ends of the lead wires 25, the terminal 26a of the terminal board 23 is connected to 26b, the control coil 11 _{1, 11-second} ends Lead wire 27 is a terminal
It is connected to 28a and 28b. Variable resistor 13 ₁ is attached to a position capable of adjusting operation from the outside on the terminal board 23, the lead wire 29 being drawn from this is coupled terminals 26a, to 26b.

Other saturable reactor 14 _2, said saturable reactor 14 ₁
Has the same structure as the drum-type core 19 _3, 19 ₄ the control coil 11 ₃ formed on the coil body _20-3 having 11 _4, 20
- a permanent magnet 21 ₂ DC magnetic bias and _4, the more the auxiliary magnetic field forming coil 12 _2.

The auxiliary magnetic field forming coils 12 _1, 12 ₂ in the winding direction, the core 15 _1, 15 ₂ field Hv 'emitted to the outside from, such that identical polarities of the auxiliary magnetic field Hc is generated and Hv " Has been set.

The permanent magnet 21 _1, 21 ₂ is a circular plate having a radial wide groove, is attached so as to be able to rotate by a manual operation from the outside, the DC bias magnetic field is variably adjusted by rotating It

The saturable reactor 14 ₁ of the above configuration, as shown in FIG. 3, in addition to the DC bias magnetic field H _DC by the magnetic field Hv 'and the permanent magnet 21 ₁ it is released in the vertical deflection period to the outside of the core, the auxiliary an auxiliary control field Hc acts by the vertical deflection current flowing through the magnetic field forming coil _12-1, Hv '+ the control coil 11 ₁ in accordance with a change in the control field of Hc, 11 ₂ across, i.e. terminal a~ a '
The inductance between (28a, 28b) changes. Similarly,
Other saturable reactor 14 _2, a magnetic field H that is released to the outside of the core
v "+ by controlling the magnetic field of the auxiliary magnetic field forming coil 12 ₂ by the auxiliary control field Hc, the control coil 11 _3, across the _11-4, i.e., the inductance between terminals B～b 'is changed.

As described above, basically, the above-mentioned device is based on the control magnetic fields Hv ′ + Hc and Hv ″ + Hc which change the circuit impedance of the horizontal deflection coils L _H1 and L _H2 with the vertical deflection period and the controlled coil.
Magnetic field by connexion generated in the horizontal deflection current flowing in the 11- ₁ ～11- ₄
The misconvergence of the pattern shown in FIG. 7 is corrected by changing it according to Hh.

Next, a means for dealing with variations in misconvergence for each color picture tube that is actually produced will be described.

To accommodate variations in the misconvergence, the above variable resistor _13-1, operates the _13-2.

Variable resistor _13-1, reducing the resistance of the _13-2, the auxiliary magnetic field forming coils 12 _1, the current flowing through the 12 ₂ is reduced, the auxiliary control field
Hc decreases. As a result, the operating range of the saturable reactor is narrowed by the operating range 4 (see FIG. 8), and the misconvergence correction amount characteristic becomes, for example, as shown by the graph line 7 in FIG. 9 and changes from the graph line 5.

As a result, for example, in the case where a pattern in which the deviation amount A of the convergence is reduced and the difference between the deviation amounts A and B is reduced as compared with FIG.
13 _1, by adjusting the direction in which the resistance value decreases to 13 _2,
Misconvergence is best corrected.

Thus, by adjusting the variable resistor 13 _1, 13 ₂ as appropriate in accordance with the Table Broken misconvergence situations on the screen, misconvergence is best corrected. That even after becomes such finished products by bonding fixing each point of the deflection yoke 10, the variable resistor 13 _1, 13 ₂ by so misconvergence can be corrected, when combined with any of the picture tube,
Variations in picture tubes can also be absorbed.

Further, it in actual manufacturing of the deflection yoke 10 is some variation in the vertical deflection coil Lv and horizontal deflection coil L _H1, L _H2 occurs, the variation in the above variable resistor _13-1, to adjust the _13-2 Can improve the quality of the deflection yoke.

Further, the apparatus described above, due to the use of variable resistors 13 _1, 13 ₂ the current flowing through the auxiliary magnetic field forming coil as means for variably adjusting the configuration is simple, it is inexpensive in cost.

Effect of the Invention As described above, the image correction apparatus for an in-line type color picture tube of the present invention includes a pair of horizontal deflection coils and a pair of vertical deflection coils forming a deflection yoke, and horizontal deflection by the pair of horizontal deflection coils. The magnetic field is pink twitch type, and the vertical deflection magnetic field by the pair of vertical deflection coils is barrel type, and the dynamic concentration of three electron beams from three electron guns arranged inline is automatically adjusted by the horizontal vertical deflection magnetic field. The present invention is applied to a self-convergence type color picture tube as described in (1) and (2) in which a horizontal deflection current flowing through the pair of horizontal deflection coils of the deflection yoke is changed differentially between a vertical deflection cycle and a horizontal deflection current. Therefore, a saturable reactor is used that corrects the deviation of the horizontal line convergence by changing the distribution mode of the horizontal deflection magnetic field with time. In the image correction apparatus described above, a sawtooth wave current having a vertical deflection period is supplied to the saturable reactor provided at a position where a magnetic flux emitted from the magnetic core of the deflection yoke and changing in the vertical deflection period acts. A configuration in which an auxiliary magnetic field forming coil that forms an auxiliary magnetic field in the same direction as the direction of the magnetic field emitted from the deflection yoke to the outside is provided, and an adjusting member that can change the current flowing in the auxiliary magnetic field forming coil is provided. Therefore, it has the following features.

Since the correction amount of I misconvergence can be varied, it is possible to absorb the variation relating to the misconvergence of the picture tube, and thus it is possible to best correct the misconvergence that actually appears.

II It is possible to absorb variations in the horizontal deflection coil and vertical deflection coil of the deflection yoke.

III It can be constructed easily and inexpensively.

[Brief description of drawings]

1 and 2 are a circuit diagram and a perspective view, respectively, of an embodiment of the image correction apparatus of the present invention, and FIG. 3 is a sectional view taken along a horizontal plane including line III-III in FIG. FIG. 4 is a perspective view showing the saturable reactor taken out from FIG. 2, and FIG. 5 is a perspective view showing the permanent magnet and the coil body incorporated in the saturable reactor in correspondence with each other. FIG. 7 is a diagram showing a misconvergence pattern, FIG. 8 is a diagram showing the relationship between the vertical deflection magnetic field and the inductance of the coil of the saturable reactor, and FIG. 9 is a diagram showing the misconvergence correction amount. 7 ...... present invention apparatus according misconvergence correction amount of the graph line, 10 ...... deflection yoke, 11 ₁ ～11- ₄ ...... controlled coils, 12- _1, 12- ₂ ...... correction magnetic field forming coils, 13- ₁ , 13, ₂ …
... variable resistance, 14- _1, 14- ₂ ...... saturable reactor, 15 _1, 15
- ₂ ...... core, 19- _1, 19- _2, 19- _3, 19- ₄ ...... core, 20- _1,
20- _2, 20- _3, 20- ₄ ...... coil body 21 _1, 21 ₂ ...... permanent magnet, 23 ...... terminal plate.

Claims (1)

[Scope of utility model registration request] 1. A pair of horizontal deflection coils and a pair of vertical deflection coils forming a deflection yoke, wherein a horizontal deflection magnetic field generated by the pair of horizontal deflection coils is pink twitch type, and a vertical deflection magnetic field generated by the pair of vertical deflection coils is vertical. It is applied to a self-convergence type color picture tube in which the deflection magnetic field has a barrel shape and the dynamic concentration of three electron beams from three electron guns arranged inline is automatically performed by the horizontal and vertical deflection magnetic fields. By changing the horizontal deflection current flowing in the pair of horizontal deflection coils of the deflection yoke differentially between the vertical deflection cycle and the horizontal deflection current, the distribution mode of the horizontal deflection magnetic field is changed with time. In an image correction device using a saturable reactor that corrects the deviation of convergence of horizontal lines, the magnetic flux of the deflection yoke is emitted to the outside. The sawtooth wave current of the vertical deflection period is supplied to the saturable reactor provided at the position where the magnetic flux changing in the vertical deflection period acts, and the direction of the magnetic field emitted to the outside from the deflection yoke is the same. An image correction device for an in-line type color picture tube, comprising an auxiliary magnetic field forming coil for forming an auxiliary magnetic field, and an adjusting member capable of varying a current flowing through the auxiliary magnetic field forming coil.