JPH0129018B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a deflection device for a color picture tube, and in particular to a deflection device for a color picture tube, in particular, the circuit impedance of each horizontal deflection coil is changed using magnetic flux emitted from the magnetic core of a deflection yoke. This configuration corrects the convergence shift by differentially changing the current flowing in the vertical deflection period and changing the aspect of the horizontal deflection magnetic field distribution over time, which effectively reduces the size and weight of the convergence. It is an object of the present invention to provide a deflection device for a color picture tube that can satisfactorily correct misalignment.

Generally, in a color picture tube used in a color television receiver, it is necessary for the electron beams individually emitted from three electron guns to converge and concentrate on a fluorescent surface.

For this reason, in the conventional three-electron gun in-line color picture tube, in order to obtain good concentration of the three electron beams on the fluorescent surface, the horizontal deflection magnetic field of the deflection yoke is changed to a strong pincushion shape (pincushion shape) or a vertical deflection shape. The magnetic field is made into a strong barrel shape (beer barrel shape),
Furthermore, the mechanical positional relationship between this magnetic field and the electron beam is changed. That is, the axis of the deflection magnetic field and the axis of the electron beam are aligned to obtain good convergence.

However, as the deflection angle of color picture tubes increases to around 90 degrees, it has become common practice to create a magnetic field distribution that sufficiently minimizes the pincushion distortion and beer barrel distortion of the upper and lower rasters. Fixing the neck side of the deflection yoke and adjusting the swing by swinging the screen side (front widening part) up and down and left and right to align the axis of the electron beam and the axis of the deflection magnetic field is not enough to correct the convergence shift. There were some cases where it was not possible to do it well.

Therefore, in order to eliminate this drawback, the present applicant first developed a pair of saddle-shaped horizontal deflection coils L _H1 and L _H2 and a toroidal-wound vertical deflection coil L _V that constitute a deflection yoke, as shown in FIG. Of these, reactors R ₁ and R ₂ whose impedance changes with the vertical deflection period are connected to each of the horizontal deflection coils L _H1 and L _H2 , and the circuit impedance of the horizontal deflection coils is differentially changed to create a horizontal deflection magnetic field. We have proposed a device that can obtain images with good convergence characteristics by changing the aspect of the distribution over time.

As the reactors R ₁ and R ₂ used in the above-mentioned apparatus, those having the configuration shown in FIG. 2 are generally used. In the figure, 1 and 2 are drum cores made of ferrite magnetic cores, and 3 is a permanent magnet that applies a DC magnetic bias to each magnetic core. Each drum-shaped core has a coil R _CH1 , which is connected to the horizontal deflection coil.
R _CH2 and the coil connected to the vertical deflection coil
R _CV1 and R _CV2 are wound. Coil R _CH1 ,
R _CH2 and the coil should be wound in opposite directions.
R _CV1 and R _CV2 are connected so that they wind in the same direction.

However, since the potential difference between the horizontal deflection coil and the vertical deflection coil is generally large, if the coil connected to the horizontal deflection coil and the coil connected to the vertical deflection coil are wound on the same drum, each Between coils, i.e. coils R _CH1 and R _CV1 , R _CH2
Since insulation treatment was required between the R _CV2 and the RCV2, a large drum-shaped core had to be used, making it difficult to downsize and making it difficult to obtain magnetic saturation characteristics.

Further, since the coils connected to the horizontal deflection coil and the vertical deflection coil are wound in the same groove, they are closely coupled to each other, which often causes undesirable phenomena in terms of circuit operation. In particular, due to rapid changes in current during the horizontal retrace period, high-frequency damped oscillations (generally called ringing) are superimposed on the deflection current at the beginning of the scanning period, causing the electron beam to undergo velocity modulation and Black and white vertical stripes tend to appear on the left side (at the beginning of scanning), resulting in a significant deterioration in image quality. For these measures, each coil R _CH1 and
If R _CV1 , R _CH2 , and R _CV2 are wound separately, the size of the reactor becomes large, which not only requires a large installation area but also increases production costs.

The present invention solves the above problems, and one embodiment thereof will be described below with reference to the drawings.

In summary, the present invention can be summarized by attaching a coil constituting a reactor close to the magnetic core of a deflection yoke, and operating the coil by receiving magnetic flux from the magnetic core of the deflection yoke that changes with the vertical deflection period. , the circuit impedance of each horizontal deflection coil can be changed without the windings of the coils R _CV1 and R _CV2 of the reactors R ₁ and R ₂ connected in series with the vertical deflection coil. This solves the conventional problem caused by the fact that the coils connected to the deflection coil and the vertical deflection coil are wound on the same drum-shaped core.

An example of this will be described below.

First, an example of the structure of the deflection device of the present invention will be explained with reference to FIGS. 3 to 6. In each figure,
The divided magnetic cores 4 and 4', around which the vertical deflection coils L _V are wound, are butted against each other at the dividing plane 5, and placed on top of a separator 6 made of an insulating material such as plastic, in which the horizontal deflection coils L _H1 and L _H2 are incorporated. Both magnetic cores 4, 4' are fixed by clamps 7.

A coil 10 forms a reactor, and is composed of a drum core 8 around which a coil connected to a horizontal deflection coil is wound, and a permanent magnet 9 for DC magnetic bias attached to the drum core 8. Four coils 10 are attached to magnetic cores 4, 4' using epoxy adhesive 11.
It is fixed at The drum core 8 has an open magnetic path.

Further, the separator 6 and the vertical deflection coil L _V are fixed with an adhesive 12 such as hot melt. A terminal portion 15 is provided at the rear (neck side) of the separator 6 to connect the lead wire 13 of each coil and the external lead wire 14. A connector 16 is provided at the tip of the external lead wire 14, and is easily connected to a terminal provided on a printed wiring board or the like.

Further, the neck side of the separator 6 has a structure having a plurality of tongue pieces 17, and this portion is tightened and fixed to the color picture tube using a band.

FIG. 7 is a diagram schematically showing the structure of the main parts of the present invention in the deflection device having the above structure, and FIG. 8 is a connection diagram of the main parts of the invention.

The coils 10 ₁₁ and 10 ₁₂ are connected so that their winding directions are opposite to each other, and the vertical deflection coil L _V
The reactor R ₁ ' is constructed in cooperation with the magnetic flux φ _V '.
Similarly, the coils 10 ₂₁ and 10 ₂₂ are connected so that their winding directions are opposite to each other, and cooperate with the magnetic flux φ _V ″ of the vertical deflection coil L _V to form a reactor R ₂ ′. That is, Coil 10 ₁₁ , 10 ₁₂ , 10 ₂₁ , 1
0 ₂₂ (drum core 8) generates a magnetic flux φ _{V ′, which will be described later, released outside the magnetic cores 4 and 4′ by forming a magnetic flux φ V inside} the magnetic cores 4 and 4′ by the vertical deflection coil _{L V.}
Specifically, the coils 10 ₁₁ , 10 ₁₂ are arranged on the magnetic core surface near the dividing surface 5 of the magnetic cores 4 and 4' so as to be located within the magnetic field where φ _V ″ exists. ,1
At 0 ₂₁ and 10 ₂₂ , magnetic cores 4,
A direct current magnetic bias φ _DC directed outward from the 4' side is applied. Further, an upper horizontal deflection coil L _H1 is connected in series to the coil 10 ₁₁ , and a lower horizontal deflection coil L _H2 is connected in series to the coil 10 ₂₁ .

As a result, as the vertical deflection current I _V changes over time, the magnitude and direction of the magnetic fluxes φ _V ′ and φ _V ″ change, which causes the inductance of the reactors R ₁ ′ and R ₂ ′ to change differentially. The horizontal deflection currents I _H1 and I _H2 flowing through the horizontal deflection coils L _{H1 and L H2 are} differentially changed. The convergence shift is corrected by changing the aspect of the horizontal deflection magnetic field distribution over time.

This specific operation will be explained below.

Next, an explanation will be given of the operation for correcting the case where the convergence deviation of the horizontal line is the convergence deviation of the normal cross, as shown in FIG. 9, as an example.

To correct this kind of shift, change the aspect of the horizontal deflection magnetic field distribution from the beginning (upper side of the screen) to the end (lower side of the screen) of vertical scanning, such as R, G, B.
All you have to do is change the vector of each beam so that the shift in convergence (correct cross) of the horizontal lines can be corrected, so as shown in Figure 10,
At the beginning of the horizontal scan (H direction) (left side of the screen), the vertical scan (V
All you have to do is change the direction from the beginning to the end. This change in the magnetic field distribution can be seen in the upper half of the horizontal deflection coil in Figure 8.
If the circuit impedance on the L _H1 side is Z _H1 and the circuit impedance of the lower half horizontal deflection coil L _H2 is Z _H2 , then the circuit impedance of each horizontal deflection coil is
Z _H1 and Z _H2 are as follows: At the top of the screen, Z _H1 < Z _H2 ...(1) At the center of the screen, Z _H1 = Z _H2 ...(2) At the bottom of the screen, Z _H1 > Z _H2 can be obtained by changing the relationship as shown in (3). For this purpose, the inductances of reactors R ₁ ′ and R ₂ ′ may be differentially changed by the vertical deflection current _IV .

Here, a vertical deflection magnetic flux φ _V exists in the deflection device, and as a result, magnetic fluxes φ _{V ′} ,
φ _V ″ is emitted. The magnitude and direction of the emitted magnetic fluxes φ _V ′ and φ _V ″ change according to the vertical deflection magnetic flux φ _V . In the present invention, by utilizing this fact, the reactor
The purpose is to differentially change the inductance of the coils R ₁ ′ and R ₂ ′.

That is, at the beginning of vertical scanning (at the top of the screen), the vertical deflection magnetic flux φ _V and the emitted magnetic fluxes φ _V ′, φ _V ″ are both in the direction shown by the solid arrow, and the horizontal coil L in the upper half Coil 1 of reactor R ₁ ′ connected to _H1
For 0 ₁₁ and 10 ₁₂ , the emitted magnetic flux φ _V ′ and the DC magnetic bias φ _DC acting on them are in the same direction,
On the other hand, for the coils 10 ₂₁ and 10 ₂₂ of the reactor R ₂ ′ connected to the horizontal coil L _H2 in the lower half, the magnetic fluxes φ _V ″ and φ _DC are in opposite directions, and the magnetic flux of the reactor R ₁ ′ is smaller than that of the reactor R ₂ ′. The core is more easily saturated and the reactor
The inductance L _R1 ′ of R ₁ ′ becomes small.

In addition, at the end of the vertical scan (at the bottom of the screen), the direction of the vertical deflection magnetic flux φ _V is reversed, and the directions of the emitted magnetic fluxes φ _V ′ and φ _V ″ are also reversed, and the directions are the same as the dashed arrows. Therefore, the relationships between φ _V ′ and φ _DC and between φ _V ″ and φ _DC are all reversed, and the magnetic core of reactor R _{2 ′} is more easily saturated than that of reactor R ₁ ′. The inductance of the coil in the reactor R ₂ ′ compared to the coil
L _R2 ′ becomes small.

Figure 11 shows the time variation of the vertical deflection current _IV and the inductance of the reactors R ₁ ′ and R ₂ ′ as described above.
The relationship between L _R1 ′ and L _R2 ′ is shown. In the same figure, a is the reactor.
Changes in inductance L _R1 ′ of R ₁ ′, same figure b
indicates the state of change in the inductance L _R2 ′ of the reactor R ₂ ′. Figure c shows the vertical deflection current _IV flowing through the vertical deflection coil L _V.

Inductance of the above reactors R ₁ ′, R ₂ ′
The changes in the vertical deflection currents of L _R1 ′ and L _R2 ′ according to the time changes satisfy the above equations (1), (2), and (3).
As a result, the circuit impedance of the upper and lower horizontal deflection coils L _H1 and L _H2 changes differentially in the vertical deflection period, and the current flowing in the upper and lower horizontal deflection coils L _H1 and L _H2 changes differentially in the vertical deflection period. The horizontal deflection magnetic field distribution changes over time, and the convergence shift (positive cross) is corrected.

In addition, if the convergence shift is a reverse cross as shown in Figure 12, the relationships in equations (1) and (3) above may be reversed, which requires the reactors R ₁ ′,
Just reverse the magnetic bias of R ₂ ′. Also the first
As shown in Figure 3, if the shift in the convergence of the horizontal line when the screen is deflected halfway up or down from the center of the screen (positive cross) is larger than the shift when the screen is deflected further upward or downward, By changing the inductance of R ₁ ' to be maximum at about 3/4V of vertical deflection, and by changing the inductance of R ₂ ' to be maximum at about 1/4V of vertical deflection, It is obvious that the convergence shift can be corrected without further explanation.

Furthermore, even if the direction of convergence deviation is the same at each position in the vertical direction of the screen, as shown in Fig. 14, by providing a magnetic field distribution as shown in Fig. 15, the B and R side beams can be converged. The shift in convergence is corrected by moving in the direction in which the shift in convergence is corrected. This magnetic field distribution is
By changing the magnetic bias of reactors R ₁ ′ and R ₂ ′, the inductance L _R1 ′ of reactor R ₁ ′ becomes the inductance of reactor R ₂ ′ from the top to the bottom of the screen.
This can be obtained by making L _R2 ' larger than that and passing a larger current through the lower half horizontal deflection coil than the upper half horizontal deflection coil.

In Figure 16A, the magnetic bias of the reactor R ₁ ′ is reduced, and the overall inductance L _R1 ′ is shifted in a larger direction (in the direction of arrow A) than before adjustment, L _R1MAX ″−L _R2MIN ′＞L _R1MAX ′−L _R2MIN ′ L _R10 ″−L _R20 ′＞L _R10 ′−L _R20 ′ L _R1MIN ″−L _R2MAX ′＞L _R1MIN ′−L _R2MAX ′.

Figure B shows that by increasing the magnetic bias of reactor R ₂ ′, the overall inductance L _R2 ′ is shifted in the direction smaller than before adjustment (in the direction of arrow B), L _R1MAX ′−L _R2MIN ″＞L _R1MAX ′ −L _R2MIN ′ L _R10 ′−L _R20 ＞L _R10 ′−L _R20 ′ L _R1MIN ′−L _R2MAX ″＞L _R1MIN ′−L _R2MAX ′.

In Figure C, the magnetic biases of both reactors R ₁ ′ and R ₂ ′ are adjusted, and L _R1MAX −L _R2MIN ＞L _R1MAX ′−L _R2MIN ′ L _R10 −L _R20 ＞L _R10 ′−L _R20 ′ L The following relationship is obtained: _R1MIN −L _R2MAX >L _R1MIN ′−L _R2MAX ′.

No matter which method is used, the horizontal deflection magnetic field distribution shown in FIG. 15 is obtained, and the convergence shift shown in FIG. 14 is corrected.

Further, FIG. 17 shows a convergence shift state when the direction of shift is opposite to that in FIG. 14. To correct this convergence shift,
The inductance L _R1 ′ of the reactor R ₁ ′ from the top to the bottom of the screen (from the beginning to the end of vertical scanning) may be made smaller than the inductance L _R2 ′ of the reactor R ₂ ′. Specifically, by changing the magnetic bias and adjusting by decreasing or increasing the inductance in the opposite direction to the cases of A, B, and C in Figure 16, the same concept as in the case of correction in Figure 14 is used. , the convergence shift can be corrected. Note that the magnetic bias can be changed by adjusting the mounting position of the permanent magnet piece 9 by changing the distance from the magnetic core 8.

The method for correcting the typical convergence deviations shown in Figures 9, 12 to 14, and 17 has been described above. Even if they are combined, correction is possible by appropriately adjusting the magnetic bias.

Further, in the above embodiment, a permanent magnet is used as a means for applying a magnetic bias, but the present invention is not limited to this. For example, it is also possible to wind an auxiliary winding around each drum core 8 and apply a magnetic bias using a direct current. be. Furthermore, when this auxiliary winding is used, it is possible to correct a more complicated convergence shift by adding a current whose magnitude changes over time to the auxiliary winding. By making the circuit impedances of the upper and lower horizontal deflection coils different in this way, even when the state of convergence shift is symmetrical in the vertical direction of the screen, the shift can be favorably corrected.

As described above, the color picture tube deflection device according to the present invention is comprised of a pair of saddle-shaped horizontal deflection coils and a pair of toroidal-wound vertical deflection coils, in which the deflection device for a color picture tube is composed of a pair of saddle-shaped horizontal deflection coils and a pair of toroidal-wound vertical deflection coils. A connected coil to which a magnetic bias is applied is installed at a position where a magnetic flux emitted from the magnetic core of the deflection yoke to the outside and which changes with the vertical deflection period acts, and the circuit impedance of each horizontal deflection coil is differentiated with the vertical deflection period. Since the configuration is configured to correct the convergence shift by changing the aspect of the horizontal deflection magnetic field distribution over time, it has various features described below.

Conventionally, it has been difficult to obtain good convergence characteristics and upper and lower raster distortions at the same time in deflection devices. The convergence shift can be corrected by differential current, and a deflection device can be realized that can obtain an image with the best convergence characteristics and vertical raster distortion in accordance with the characteristics of the picture tube.

By effectively utilizing the magnetic flux emitted from the magnetic core of the deflection yoke, which was wasted in the past, there is no need for a coil or electric power to be connected to the vertical deflection coil to control reactor impedance, resulting in a simple structure. Furthermore, the degree of freedom in design can be greatly improved. Furthermore, by omitting the above-mentioned coil, it is possible to significantly reduce problems in circuit operation, especially ringing of the horizontal deflection current, caused by the horizontal coil and the vertical coil being wound in the same groove. Furthermore, since there is no need for insulation treatment between the coils, it is possible to significantly reduce the size and improve reliability.

Further, there is no need to use a vertical raster distortion correction circuit or a correction magnet, there is no loss of color purity due to vibration adjustment, and it is possible to eliminate adverse effects on characteristics caused by varying the scanning frequency.

In addition, since the coils connected in series to each horizontal deflection coil are configured to each have an adjustable magnetic bias applied to them, it is possible to avoid deviations due to unbalanced convergence on the screen due to variations in the color picture tube or deflection yoke. This also makes it possible to correct image quality during mass production.

Furthermore, since the magnetic core of the coil connected in series with the horizontal deflection coil is an open magnetic path, the influence of changes in μ of the magnetic core on the inductance is reduced, and the characteristics with respect to temperature are also stable.

Taken together, there is no need to install a correction circuit to improve image quality, reducing the number of parts, installation space, and installation and wiring man-hours, which speeds up design.
It is possible to reduce production costs, significantly improve image quality, save power, reduce size and weight, and improve reliability.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram of the main parts of an example of a conventional deflection device, Fig. 2 is a perspective view showing the structure of the reactor in Fig. 1, and Fig. 3 is a deflection yoke magnetic core used in an embodiment of the present invention. FIG. 4 is a perspective view of a vertical deflection coil used in an embodiment of the present invention, FIG. 5 is a diagram showing an embodiment of a deflection device according to the present invention, and FIG. 7 is a diagram schematically showing the structure of the main part of the present invention, FIG. 8 is a circuit diagram of the main part of the invention, and FIG. 9 is a diagram showing the deviation of the convergence of a normal cross. , Fig. 10 is a diagram showing changes in the aspect of the horizontal deflection magnetic field distribution to correct this convergence shift, and Fig. 11 a, b, and c are diagrams showing the changes in the horizontal deflection magnetic field distribution for correcting this convergence shift.
Figure 12 shows the inductance characteristics of R ₁ ' and R ₂ ', the waveform of the vertical deflection current, Figure 12 shows the convergence shift of the reverse cross, Figure 13 shows another convergence shift, Figure 14 The figure shows a convergence shift where the direction of the convergence shift is the same at each position in the vertical direction of the screen, and Figure 15 shows the change in the aspect of the horizontal deflection magnetic field distribution to correct the convergence shift in Figure 14. Figures 16A, B, and C are diagrams showing various characteristic examples of the reactor for obtaining the horizontal deflection magnetic field distribution shown in Figure 15, respectively, and Figure 17 is a diagram showing a convergence shift opposite to that shown in Figure 14. It is. L _H1 , L _H2 ...Horizontal deflection coil, L _V ...Vertical deflection coil, R ₁ ', R2'...Reactor, ₄ , 4'...Magnetic core of deflection yoke, 5...Dividing surface, 6... ...Separator, 7...Clamp, 8...Drum core, 9...
Permanent magnet for magnetic bias, 10...Coil forming reactor, 10 ₁₁ , 10 ₁₂ , 10 ₂₁ , 10 ₂₂
... Coil, 11, 12 ... Adhesive, 13, 14
... Lead wire, 15 ... Terminal section, 16 ... Connector, 17 ... Tongue piece, φ _V ... Vertical deflection magnetic flux, φ _V ′,
φ _V ″...Emission magnetic flux, φ _DC ...Direct current magnetic bias.

Claims (1)

[Claims] In a color picture tube deflection device comprising a pair of saddle-shaped horizontal deflection coils and a pair of toroidal-wound vertical deflection coils, the deflection device is connected in series to each horizontal deflection coil and is provided with a magnetic bias. The coils are installed at positions where the magnetic flux emitted from the magnetic core of the deflection yoke to the outside and changes with the vertical deflection period acts, and the circuit impedance of each horizontal deflection coil is differentially changed with the vertical deflection period to produce horizontal deflection. A deflection device for a color picture tube characterized in that it is configured to change the aspect of magnetic field distribution over time to correct a convergence shift. 2. The color picture tube deflection device according to claim 1, wherein each of the horizontal deflection coils connected in series is provided with an adjustable magnetic bias. 3. The deflection device for a color picture tube according to claim 1, wherein the coils connected in series to each of the horizontal deflection coils have a magnetic core forming an open magnetic path.