JP2001250492A - Deflection yoke and cathode ray tube receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To strike a balance between a convergence correction and a coma aberration correction during a vertical deflection, and to improve an efficiency of deflection in a vertical deflection system. SOLUTION: A deflection yoke is connected in series to the vertical deflection coils Lv, and at the same time, the auxiliary coils L5 to L8 for a convergence correction are connected in series between the output terminals O, Q of the bridge. The deflection yoke is comprised of; a bridge circuit 19 having a current control systems 21, 22 composed of the diodes D1, D2 and resisters R1, R2 on one input terminal P side and the other input terminal S side of the bridge; a pair of cores, which are arranged in an opposing condition at a rear end of the deflection yoke in a direction of horizontal axis of the yoke; the first coil pair, which is made by winding the coils L31, L41 to a pair of cores; and the second coil pair, which is made by winding the coils L32, L42 to a pair of cores. The first coil pair is connected in series to one input terminal P side of the bridge circuit 19, and the second coil pair is comprised of the coma aberration correction coils that are connected in series to the other input terminal S side of the bridge circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode ray tube receiver used for a television receiver or a computer display, and more particularly to a deflection yoke used by being mounted on a cathode ray tube bulb.

[0002]

2. Description of the Related Art In a color cathode ray tube, three electron beams emitted from an electron gun, that is, R (red), G
A color image is assembled on a screen by deflecting the traveling directions of three electron beams for emitting phosphors of (green) and B (blue) colors up, down, left, and right. For deflection of the electron beam, a deflection yoke having a horizontal deflection coil and a vertical deflection coil is used. The deflection yoke is mounted on a portion called a cone from the neck of the cathode ray tube to the funnel.

In the deflection yoke, a horizontal deflection current is supplied to the horizontal deflection coil and a vertical deflection current is supplied to the vertical deflection coil on the trajectory of the three electron beams emitted from the electron gun, thereby forming a deflection magnetic field. The electron beam is vertically and horizontally deflected by the deflection magnetic field. Then, a desired color image is reproduced on the screen by converging the three electron beams on the phosphor screen through color selection electrodes (aperture grill, shadow mask, etc.).

Generally, in a color cathode ray tube having an in-line type electron gun in which an electron beam for emitting green phosphor is used as a center beam G, and electron beams for emitting red and blue phosphors are used as side beams R and B. By using the horizontal deflection magnetic field as a pincushion magnetic field and the vertical deflection magnetic field as a barrel magnetic field, convergence between the side beams R and B is realized without an external correction circuit.

However, since the deflection yoke used in this type of cathode ray tube employs an asymmetric magnetic field such as a pincushion magnetic field and a barrel magnetic field, the deflection sensitivity for the center beam G is smaller than the deflection sensitivity for the side beams R and B. So-called coma aberration occurs. Due to the influence of this coma, in the vertical direction of the screen, FIG.
As shown in FIG. 7, a convergence VCR (vertical center raster) occurs in which the scanning position of the center beam G is shifted inward from the scanning position of the side beams R and B.

Therefore, as means for correcting the VCR,
One having four coils (coma aberration correction coils) L51 to L54 as shown in FIG. 8 on the rear end side (neck side) of the deflection yoke is known. Of these, coil L51,
L52 is a pair of C arranged opposite each other in the yoke vertical axis direction.
The coils L53 and L54 are wound around cores (hereinafter referred to as C cores) 61A and 61B, and a pair of I-shaped (bar-shaped) cores (hereinafter referred to as I-cores) 62A arranged opposite to each other in the yoke horizontal axis direction. , 62B. The coils L55 and L56 are wound around both legs of the C core 61A, and the coils L57 and L58 are wound around both legs of the C core 61B. These four coils L55 to L58
Is to form a quadrupole magnetic field using the legs of the C cores 61A and 61B as magnetic poles, and to correct a bow-shaped misconvergence that appears symmetrically in the vertical direction of the screen by using the quadrupole magnetic field. In addition, in this specification, "core" means
It means a magnetic core made of a magnetic material such as iron.

In such a configuration, the coil L5
1, L52 correction magnetic field (pin cushion magnetic field) φ7
1 and the correction magnetic field (barrel magnetic field) φ72 of the coils L53 and L54 make it possible to correct the convergence VCR shown in FIG. 7A.

That is, the correction magnetic field φ71 by the coils L51 and L52 acts more strongly on the center beam G, and the correction magnetic field φ72 by the coils L53 and L54 acts more strongly on the side beams R and B. Since these correction magnetic fields φ71 and φ72 both act in the barrel direction with respect to the upper and lower pincushion distortions, by adjusting the intensity balance of the correction magnetic fields φ71 and φ72, the balance with the upper and lower pincushion distortions is maintained. The convergence VCR can be corrected.

However, in such a configuration, for example,
When the VCR is corrected to the optimum state (zero) at the upper and lower ends of the screen, there is a problem that the VCR is excessively corrected in the middle part on the upper and lower sides of the screen (hereinafter simply referred to as the middle part of the screen). As a result, in the middle portion of the screen, as shown in FIG. 7B, the center beam G is deflected more than the side beams R and B (hereinafter referred to as an intermediate VC).
R). In addition, the upper and lower pincushion distortions in the middle portion of the screen tend to remain in the pincushion direction as shown in FIG. 7C as compared with the upper and lower ends of the screen, and the remaining pincushion distortion has also become a problem. In particular, such a problem has been remarkable with the recent flattening (flat face) of the screen.

To solve such a problem, a coil L
Control of the current flowing through 51 to L54 is performed. FIG. 9 is a coil connection diagram of a vertical deflection system including the correction coils L51 to L58. In FIG. 9, the coils L55 to L55 are provided for a pair of vertical deflection coils Lv and Lv.
A bridge circuit 63 including L58;
A series circuit 64 composed of L52 and coils L53 and L54;
Are connected in series with each other.

The bridge circuit 63 includes coils L55 to L58 connected in series with each other and two diodes D5 to D58.
1 and D52 and two resistors R51 and R52. The parallel circuit 65 includes coils L53 and L54 connected in series with each other, one resistor R53, and two diodes D53 and D54.

In such a circuit configuration, when a vertical deflection current (positive current) for deflecting the electron beam to the upper side of the screen flows through the pair of vertical deflection coils Lv, Lv, the voltage generated by the resistor R51 in the bridge circuit 63. The current flows through the coils L55 to L58 through the diode D51 only while the diode D51 is operating (turning on) due to the rise. On the other hand, the vertical deflection current continues to flow through the correction coils L51 and L52. In the parallel circuit 65, when the diode 53 is not operating, the vertical deflection current flows through the coils L53 and L54 as it is.
In the state in which the coil 3 operates, the current flowing through the coils L53 and L54 is controlled to be constant even if the vertical deflection current changes.

On the other hand, a pair of vertical deflection coils L
When a vertical deflection current (negative current) for deflecting the electron beam to the lower side of the screen flows in v and Lv, the diode D5 is generated in the bridge circuit 63 by a voltage increase due to the resistor R52.
Current flows through the diodes L52 to the coils L55 to L58 only while the device 2 is operating. At this time, since the direction of the current flowing through the coils L55 to L58 is the same as the above, the current waveform is parabolic. On the other hand, the vertical deflection current continues to flow through the coils L51 and L52. Also, in the parallel circuit 65, when the diode 54 is not operating, the vertical deflection current flows through the coils L53 and L54 as it is, but when the diode D54 is activated by the voltage rise by the resistor R53, the vertical deflection current is increased. Even if it changes, coils L53 and L54
Is controlled to be constant.

By controlling the current flowing through each coil as described above, the correction magnetic field (quadrupole magnetic field) by the coils L55 to L58 is such that the scanning position of the electron beam is above and below the middle portion of the screen. Sometimes, the intensity of the magnetic field increases as the scanning position of the electron beam approaches the upper and lower ends of the screen. This makes it possible to correct a bow-shaped misconvergence that appears symmetrically in the vertical direction of the screen. In addition, the above four coils L55 to L55
The parabolic current necessary for image distortion correction and the like is supplied from the bridge circuit 63 by disposing (wrapping) 58 at an appropriate position other than the C cores 61A and 61B, for example, and having an image distortion correction function. can do.

On the other hand, since the intensity of the correction magnetic field φ71 by the coils L51 and L52 is proportional to the change in the vertical deflection current, it becomes stronger as the scanning position of the electron beam approaches the upper and lower ends of the screen. On the other hand, the intensity of the correction magnetic field φ72 by the coils L53 and L54 reaches a peak when the scanning position of the electron beam is in the middle part of the screen, and the scanning position of the electron beam is between the middle part of the screen and the upper and lower ends of the screen. Otherwise, the peak level is maintained at the above-mentioned peak level (constant level). As a result, the coil L53,
The correction magnetic field φ72 by the L54 acts more effectively on the electron beam, and the correction magnetic field φ71 by the coils L51 and L52 more effectively acts on the electron beam at the upper and lower ends of the screen. VC at upper and lower edges of screen while eliminating pincushion distortion left and right
R can be corrected to an optimal state.

[0016]

However, in the prior art, the convergence correction (or the image distortion correction) has been performed.
Since two resistors R51 and R52 are used for the bridge circuit 63 including the coils L55 to L58, and one resistor R53 is used for the parallel circuit 65 including the coils L53 and L54 for coma aberration correction, these resistors R51 are used. , R5
2, there is a problem that the deflection efficiency in the vertical deflection system is reduced due to power consumption by R53.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to achieve both vertical and horizontal convergence correction (or image distortion correction) and coma aberration correction. It is an object of the present invention to provide a deflection yoke capable of increasing deflection efficiency in a deflection system and a cathode ray tube receiver using the same.

[0018]

A deflection yoke according to the present invention is connected in series to a pair of vertical deflection coils, has an auxiliary coil connected in series between output ends of the bridge, and has a bridge. And a bridge circuit having a current control system using a diode and a resistance element on one input end side and the other input end side, respectively, and a rear end portion of the deflection yoke which is disposed to face the deflection yoke in the horizontal axis direction. A first coil pair formed by winding a coil around each of the pair of cores, and a second coil pair formed by winding a coil around each of the pair of cores; The coil pair is connected in series to one input end of the bridge circuit, and the second coil pair is provided with a coma aberration correction coil connected in series to the other input end of the bridge circuit. And it has a formation. Further, a cathode ray tube receiver according to the present invention uses the deflection yoke having the above configuration.

In the deflection yoke and the cathode ray tube receiver using the same, the auxiliary coil and the coma aberration correction coil are incorporated in a common bridge circuit, and the current flowing through each coil is controlled by a common current control system ( (Diode, resistance element), so that the resistance value in the vertical deflection system can be reduced compared to the case where convergence correction (or image distortion correction) and coma aberration correction are performed by separate circuits as in the past. Becomes

[0020]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic perspective view showing an overall image of a color cathode ray tube according to the present invention. In FIG. 1, a cathode ray tube bulb (cathode ray tube main body) 10 includes a panel section 11, a funnel section 12, and a neck section 13. On the inner surface of the panel section 11, a phosphor screen (not shown) in which red, blue, and green phosphors are arranged in a pattern is formed. on the other hand,
An electron gun 1 serving as an electron beam emission source is provided in the neck portion 13.
4 are furnished. Further, a deflection yoke (DY) 15 for deflecting the electron beam is mounted on a cone portion extending from the neck portion 13 to the funnel portion 12.

The color cathode ray tube having the above-described structure is provided in the panel section 1.
1 Along with various accessories necessary for reproducing a color image (or a black-and-white image) on a phosphor screen on the inner surface, it is incorporated in a casing (not shown) so that a cathode ray tube receiver such as a television receiver or a computer display can be obtained. Is configured.

FIGS. 2A and 2B illustrate the structure of a deflection yoke to which the present invention is applied. FIG. 2A is a rear view and FIG. 2B is a side view. 2, the deflection yoke 15 includes a pair of horizontal deflection coils (not shown) and a pair of vertical deflection coils (not shown), and a DY core 16 is mounted so as to cover these deflection coils.

A pair of C-shaped cores (hereinafter, referred to as a "y-axis") in the direction of the yoke vertical axis (Y-axis) is provided at the rear end of the deflection yoke 15 (the portion located on the neck portion 13 side of the cathode ray tube bulb 10).
17A and 17B (referred to as C cores) are arranged in an opposed state. A coil L1 is wound around an intermediate portion of one (upper) C core 17A, and a coil L2 is wound around an intermediate portion of the other (lower) C core 17B.

At the rear end of the deflection yoke 15, a pair of I-shaped (bar-shaped) cores (hereinafter, referred to as I-cores) 18A and 18B are arranged in opposition to each other in the direction of the horizontal axis (X-axis) of the yoke. ing. One I-core 18A has a coil L3
Is wound, and the coil L4 is also wound around the other I core 18B. Further, coils L5 and L6 are wound around both legs of one C core 17A, and coils L7 and L8 are wound around both legs of the other C core 17B.

Of these eight coils L1 to L8, coils L1 to L4 are mainly for correcting coma (VCR), and coils L5 to L8 are auxiliary coils for mainly correcting convergence. . Among them, the coil L3 wound around the I-cores 18A and 18B
L4 is, as shown in FIG. 3, two coils L31, L32, and L2 wound by bifilar winding (double winding).
41 and L42. The auxiliary coil is used for correcting image distortion, for example, in addition to the convergence correction, depending on the arrangement form.

FIG. 4 shows a coil connection diagram of a vertical deflection system including the eight coils L1 to L8. In FIG. 4, the coils L5 to L8, L31, L32 and L41, L42 are applied to the pair of vertical deflection coils Lv, Lv.
And a series circuit 20 including the coils L1 and L2 are connected in series.

In the bridge circuit 19, coils L5, L6, L7 and L8 are connected in series between the output terminals O and Q. The polarity of the diode D1 is inverted between the input terminal P and the output terminal O of the bridge circuit 19 and between the other input terminal S and the output terminal O of the bridge circuit 19, respectively.
D2 is connected.

On the other hand, between the input terminal P and the output terminal Q of the bridge circuit 19, a resistor R1, a coil L31 and a coil L41 are connected.
Are connected in series, and a resistor R2, a coil L32, and a coil L are connected between the other input terminal S and the output terminal Q of the bridge circuit 19.
42 are connected in series. Of these, diode D
1 and the resistor R1 constitute a current control system 21 on one input terminal P side of the bridge circuit 19, and include a diode D2 and a resistor R2.
Constitutes a current control system 22 on the other input end S side of the bridge circuit 19. Further, the coil L31 and the coil L
Reference numeral 41 denotes a first coil pair in the present invention, and the coils L32 and L42 form a second coil pair in the present invention.

Here, the pair of vertical deflection coils Lv,
When a vertical deflection current (positive current) Iv for deflecting the electron beam to the upper side of the screen flows to Lv, in the bridge circuit 19, when the diode D1 is not operating, the vertical deflection current Iv is directly applied to the coils L31 and L41. Flows.
The diode D rises due to the voltage rise due to the resistor R1.
In the state where 1 operates, the current flows through the diodes L1, L6, L7, L8 through the diode D1, and the current flowing through the coils L31, L41 is controlled to be constant.
Meanwhile, the vertical deflection current Iv continues to flow through the coils L32 and L42 and the coils L1 and L2.

On the other hand, a pair of vertical deflection coils L
When a vertical deflection current (negative current) Iv for deflecting the electron beam to the lower side of the screen flows in v and Lv, in the bridge circuit 19, when the diode D2 is not operating, the vertical deflection current Iv is directly applied to the coil L32. , L42. Then, in a state where the diode D2 is operated due to the voltage rise by the resistor R2, a current flows through the coils L5, L6, L7, L8 through the diode D2, and a current flowing through the coils L32, L42 is controlled to be constant. Meanwhile, the coils L31, L41 and the coils L1,
The vertical deflection current Iv continues to flow through L2.

Incidentally, the direction of the current flowing through the coils L5 to L8 is always controlled by the diodes D1 and D2 regardless of the direction (positive / negative) of the vertical deflection current Iv. Therefore, the waveform of the current flowing through the coils L5 to L8 is parabolic.

From the above, the pair of I-cores 18
A, L31, L32, L4 wound around 18B
1, L42 (see FIG. 3) changes as shown in FIG. That is, the vertical deflection period is 1 V
, The current flowing through the coils L31 and L41 changes as shown by the solid line in the figure, and the current flowing through the coils L32 and L42 changes as shown by the broken line in the figure. Therefore, the current flowing through the coil L3 wound around one I-core 18A is
Since it is the sum of the currents flowing through the coils L31 and L32, it changes as shown by the dashed line in the figure. Similarly, the current flowing through the coil L4 wound around the other I-core 18B is the sum of the currents flowing through the coils L41 and L42, and thus changes as indicated by the one-dot chain line in the figure.

By controlling the current flowing through each coil in this way, the correction magnetic field (quadrupole magnetic field) by the coils L5 to L8 is such that the scanning position of the electron beam is above and below the screen middle part. Sometimes, the intensity of the magnetic field increases as the scanning position of the electron beam approaches the upper and lower ends of the screen. This makes it possible to correct the bow-shaped misconvergence that appears symmetrically in the vertical direction of the screen as in the conventional case.

On the other hand, the current flowing through the coils L1 and L2 increases in proportion to the vertical deflection current Iv, while the current flowing through the coils L1 and L2 increases.
3, the increasing tendency of the current flowing through L4 is weakened by the operation of the diodes D1 and D2, respectively. Therefore, when the current flowing through the coils L1 and L2 is compared with the current flowing through the coils L3 and L4, when the scanning position of the electron beam is between the upper and lower intermediate parts of the screen, the coils L1 and L2
Although the same current flows through the coils L3 and L4, when the scanning position of the electron beam is between the middle of the screen and the upper and lower ends, a smaller current flows through the coils L3 and L4 than the current flowing through the coils L1 and L2.

At this time, the intensity of the correction magnetic field φ1 by the coils L1 and L2 and the intensity of the correction magnetic field φ2 by the coils L3 and L4 are proportional to the magnitude of the current flowing through each coil. As a result, the coil L
3, the correction magnetic field φ2 by L4 more effectively acts on the electron beam, and the correction magnetic field φ1 by the coils L1, L2 more effectively acts on the electron beam at the upper and lower ends of the screen. It becomes possible to correct the VCR to the optimum state at the upper and lower ends of the screen while eliminating the excessive correction of the VCR and the remaining upper and lower pincushion distortions.

By adopting such a circuit configuration, it is possible to provide a correction function equivalent to that of a conventional correction circuit and reduce the number of resistors (elements) conventionally required from three to two. . As a result, the resistance value in the vertical deflection system can be reduced, so that the power consumption during vertical deflection can be reduced and the deflection efficiency can be increased.

Further, as for the number of elements constituting the correction circuit, one resistor and two diodes can be eliminated as compared with the conventional one (see FIG. 9), so that the correction circuit is simplified and the price is reduced. At the same time.

Further, the coils L31, L32, L41,
By making the coil wire diameter of L42 thinner or increasing the number of coil turns, the coils themselves have a resistance component, and the resistance component constitutes a resistance element necessary for operating the diodes D1 and D2. As a result, FIG.
As shown in (1), it is possible to further simplify the correction circuit and reduce the cost by completely eliminating the resistance element.

In the above embodiment, the coil L
3 and L4 are constituted by coils L31, L32 and L41, L42 wound by bifilar, respectively, but coils L31, 32 and L41, L42 may be wound on common I-cores 18A, 18B, respectively. It is not necessarily limited to bifilar winding.

In the above embodiment, the coil L
1, L2 and directions of coils L3, L4
Although the case where the directions of the correction magnetic field φ2 are set to be the same has been described as an example, the present invention is also applicable to the case where the directions of the two magnetic fields are different (opposite). In that case, as the configuration of the bridge circuit 19, coil pairs L31, 41 and L32, L42 are connected in series to the diodes D1 and D2, respectively.

[0042]

As described above, according to the present invention, the auxiliary coil and the coma aberration correction coil are incorporated in a common bridge circuit, and the current flowing through each coil is controlled by a common current control system (diode, resistance element). ), So that the resistance value in the vertical deflection system is reduced as compared with the case where convergence correction (or image distortion correction) and coma correction are performed by individual circuits as in the conventional case. Can be. This makes it possible to reduce power consumption during vertical deflection and increase deflection efficiency.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing an overall image of a color cathode ray tube according to the present invention.

FIG. 2 is a diagram illustrating a structure of a deflection yoke to which the present invention is applied.

FIG. 3 is a diagram showing a winding configuration of a coil according to the embodiment of the present invention.

FIG. 4 is a coil connection diagram of a vertical deflection system according to the embodiment of the present invention.

FIG. 5 is a diagram showing a change in a current flowing through a coil in a vertical deflection cycle.

FIG. 6 is a diagram illustrating an application example of the present invention.

FIG. 7 is a diagram illustrating a state in which coma aberration and image distortion occur.

FIG. 8 is a diagram showing a winding form of a conventional coil.

FIG. 9 is a coil connection diagram of a conventional vertical deflection system.

[Explanation of symbols]

10: cathode ray tube bulb, 15: deflection yoke, 17A, 1
7B ... C core, 18A, 18B ... I core, 19 ... Bridge circuit, 20 ... Series circuit, 21,22 ... Current control system, L
v: vertical deflection coil, D1, D2: diode, Iv ...
Vertical deflection current, L1 to L4: coil (for coma aberration correction), L5 to L8: coil (for convergence correction), R1, R2: resistance

Claims (3)

[Claims] 1. A pair of vertical deflection coils are connected in series, an auxiliary coil is connected in series between output ends of a bridge, and one input end and the other input end of the bridge are connected. A bridge circuit having a current control system using a diode and a resistance element; a pair of cores disposed at a rear end of the deflection yoke so as to face each other in the horizontal axis direction of the deflection yoke; And a second coil pair formed by winding a coil around each of the pair of cores, and the first coil pair is connected to one input of the bridge circuit. A deflection coil having a coma aberration correction coil connected in series to one end of the bridge circuit and the second coil pair connected in series to the other input end of the bridge circuit. Click. 2. The deflection yoke according to claim 1, wherein the coma aberration correction coil has a resistance component, and the resistance component constitutes the resistance element. 3. A pair of vertical deflection coils are connected in series, an auxiliary coil is connected in series between output ends of the bridge, and one input terminal side and the other input terminal side of the bridge. A bridge circuit having a current control system using a diode and a resistance element; a pair of cores disposed at a rear end of the deflection yoke so as to face each other in the horizontal axis direction of the deflection yoke; And a second coil pair formed by winding a coil around each of the pair of cores, and the first coil pair is connected to one input of the bridge circuit. A deflection yoke having a coma aberration correction coil connected in series to one end of the bridge circuit and the second coil pair connected in series to the other input end of the bridge circuit; Cathode-ray tube receiver and features.