JP2001043815A - Color cathode ray tube device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To constitute a color cathode ray tube device capable of providing excellent beam spot with little distortion over the whole of a screen without causing a derivative problem, even if shortening of the whole length and flattening of the screen are advanced. SOLUTION: In this color cathode ray tube device, a convergence correction means 25 for relatively displacing a pair of side beams 18B, 18R in a direction away from center beam 18G in the surrounding for the center of a phosphor screen 15 in only a direction along a first shaft from a cathode of an electron gun up to a center of a deflection yoke 14 is provided. The deflection yoke 14 is formed so as to have a constitution in which first shaft direction deflection magnetic field mainly reduces ununiform magnetic field components degrading beam spot on the phosphor screen 15 and second shaft direction deflection magnetic field mainly corrects image distortion and convergence in the direction along the first shaft separating from the first shaft.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color cathode ray tube device such as a cathode ray tube for a TV and a cathode ray tube for a monitor, and particularly to a case where a flat screen or a reduced depth of a screen is used in a high definition TV or a high resolution monitor. The present invention relates to a color cathode ray tube device which has solved the problem of focus deterioration which is a problem.

[0002]

2. Description of the Related Art In general, a color cathode ray tube device has a vacuum envelope comprising a rectangular display panel, a funnel-shaped funnel connected to the panel, and a cylindrical neck connected to a small end of the funnel. With a container. On the inner surface of the panel, a phosphor screen having a three-color phosphor layer in the form of dots or stripes that emit blue, green, and red light is provided. In addition, a shadow mask having a large number of color-selecting electron beam passage holes formed on the opposing surface is disposed so as to be separated from and opposed to the phosphor screen. Also,
An electron gun that emits three electron beams (three electron beams) is provided in the neck. Further, a deflection yoke is mounted from the neck to the outside of the small diameter portion of the funnel. The three electron beams emitted from the electron gun are deflected by a deflection magnetic field generated by a deflection yoke, and the phosphor screen is horizontally scanned at a high frequency and vertically scanned at a low frequency via a shadow mask, thereby forming a color image. It is formed in a structure for displaying.

In such a color cathode ray tube device, three electron beams coincide with one point on the phosphor screen;
It is necessary to satisfy so-called convergence characteristics.
Regarding this convergence characteristic, in the early color cathode ray tube device, the convergence error was decomposed into a plurality of error patterns derived from the geometric structure of the three electron beams and the phosphor screen, and the convergence error mounted on the neck side of the deflection yoke. The convergence characteristic is satisfied by supplying a convergence correction current corresponding to each error pattern to the yoke. Therefore, in the early color cathode ray tube device (convergence yoke correction type color cathode ray tube device), it was necessary to supply a convergence correction current having a plurality of special waveforms from the drive device side in addition to the deflection current.

However, at present, an in-line self-convergence type color cathode ray tube device which does not require any convergence correction current has appeared, and has replaced the earlier convergence yoke correction type color cathode ray tube device. In this in-line self-convergence type color cathode ray tube device, an electron gun is arranged in a three-line arrangement of a center beam and a pair of side beams passing on the same horizontal plane.
With an in-line type that emits an electron beam, the horizontal deflection magnetic field generated by the deflection yoke is a pincushion type, and the vertical deflection magnetic field is a barrel type, these non-uniform horizontal and vertical deflection magnetic fields do not require special correction means, Satisfies convergence characteristics over the entire screen.

However, in this in-line self-convergence type color cathode ray tube device, the electron beam is inevitably distorted due to the non-uniform deflection magnetic field. Cause.

In recent years, color cathode ray tubes have been strongly demanded to have an improved resolution, a larger screen, a shorter overall length due to wide-angle deflection, and a flatter screen. An in-line self-convergence type color cathode ray tube device satisfying such a requirement requires more severe focusing performance, and therefore requires a strong asymmetric deflection magnetic field for concentrating three electron beams over the entire screen. Therefore, the beam spot around the screen is more strongly distorted. Furthermore, since the incident angle of the electron beam on the phosphor screen around the screen becomes smaller, the distortion of the beam spot is further promoted.

That is, as shown in FIG. 13, a PCM 1 (Purity Convergence Magnet) is arranged outside the neck, and this PCM 1 is adjusted so that the three electron beams 3 B, 3 G and 3 R are emitted from the center O of the phosphor screen 2. If they are matched, the path length of the three electron beams 3B, 3G, 3R becomes longer at the periphery P of the phosphor screen 2, so that the pair of side beams 3B, 3R becomes over-convergent as shown by the broken line.

To correct this, as shown in FIG. 14A, a horizontal deflection magnetic field 5 generated by a horizontal deflection coil 4H is used.
If H is made into a pincushion shape, three electron beams 3 when deflected to the right from the electron gun toward the phosphor screen
B, 3G, 3R receive the force FHB from the horizontal deflection magnetic field 5H,
FHG and FHR are in the relation of FHB>FHG> FHR, and a pair of side beams 3B and 3R are relatively formed.
In the direction away from the center beam 3G in the horizontal direction (H-axis direction), and acts in the under-convergence direction. Similarly, as shown in FIG. 14B, when the vertical deflection magnetic field 5V generated by the vertical deflection coil 4V is formed into a barrel shape, a pair of side beams 3 are generated from the vertical deflection magnetic field 5V.
The components FVB and FVR received by B and 3R are displaced in a direction away from each other in the horizontal direction, and act in the direction of under-convergence. By adjusting the degree of non-uniformity of the horizontal and vertical deflection magnetic fields 5H and 5V, FIG.
As shown by the solid line in FIG. 5, three electron beams 3B around the screen P
, 3G, 3R.

However, when the horizontal and vertical deflection magnetic fields 5H and 5V are made non-uniform as described above, the three electron beams 3B, 3G and 3R act on the three electron beams 3B, 3G and 3R as indicated by arrows 6a and 6b in FIG. The electron beams 3 (3B, 3G, 3R) undergo a lens action that diverges in the horizontal direction and converges in the vertical direction (V-axis direction).

FIG. 16 is a diagram for explaining the action of the lens formed by the electron gun and the deflection magnetic field on the electron beam. The action in the vertical direction on the electron beam is shown above the tube axis (Z axis). Shows the horizontal action.
The broken line is the center of the phosphor screen 2 and the solid line is the trajectory of the electron beam 3 toward the periphery. DL is a lens formed by the deflection magnetic field, ML is a main lens for converging the electron beam 3 formed between the electrodes of the electron gun, and QL is formed between the electrodes near the main lens and dynamically fluctuates. This is an auxiliary lens that optimizes focusing conditions at each point on the phosphor screen 2 using a voltage. The auxiliary lens QL mainly has a function of compensating for the field curvature aberration due to the difference in path length of the electron beam 3 and the astigmatism due to the lens DL. It is illustrated as an astigmatism lens having an action of compensating the action of the lens DL around the screen 2.

In such a lens system, when the electron beam 3 travels toward the center of the phosphor screen 2, the lens DL and the auxiliary lens QL are not formed. A round object point is formed, connecting a round image point on the phosphor screen 2. But,
With respect to the electron beam 3 traveling toward the periphery of the phosphor screen 2, the lens DL located far away from the main lens ML in the direction of the phosphor screen 2 converges vertically and diverges in the horizontal direction. The astigmatism due to the lens DL is compensated by the auxiliary lens QL formed near the main lens ML. Therefore, these lenses D
The magnification of the combination lens combining L, QL and ML is
With respect to the magnification of the main lens ML alone, the beam spot on the phosphor screen 2 is reduced in the vertical direction to reduce the diameter in the vertical direction, and is increased in the horizontal direction to increase the phosphor screen 2.
Increase the horizontal diameter of the upper beam spot. As a result, an image point that is crushed in the horizontal direction on the phosphor screen 2 is connected to the round object point on the line 7.

In recent years, such problems have become non-negligible as screens have become flatter and higher in resolution. In particular, the radius of curvature of the panel approximated by a circle from the drop of the diagonal end to the neck side with respect to the center of the panel is at least twice the diagonal effective diameter of the phosphor screen, and the curvature of field caused by the phosphor screen forming a curved surface This problem has been one of the most important issues in focus characteristics since the realization of a color cathode ray tube device that changes the focus voltage so that focus conditions such as aberration and astigmatism due to the deflection magnetic field are optimized over the entire screen. It has become.

As means for solving the beam spot distortion due to the non-uniform deflection magnetic field, the following documents A, B, C and the like disclose the horizontal and vertical deflection magnetic fields, and use the horizontal and vertical ends generated by the homogenization. A technique is disclosed in which the overconvergence is corrected by convergence correction means arranged closer to the neck than the center of the deflection yoke.

Reference A: "A New High-Res
solution TrinitronColor Pi
cure for Display Applica
Tion "IEEE Trans. Consume
r Electron CE-26 pp466-47
1, 1980. Document B: “The SSC Deflection Y
oke for In-Line Color CRT
'S' Proc. Of the SID.
30/1, pp 29-32, 1989. Document C: “A New Picture Tube S
system withHomogeneous Spo
t Performance "Proc. of JP
N Display '89, pp458-461,1
989.

FIG. 17 shows the action of the lens on the electron beam by the uniform deflection magnetic field and the convergence correction means in these documents. The vertical action on the electron beam is shown above the tube axis, and the horizontal action is shown below the tube axis. The broken line is the center of the phosphor screen 2 and the solid line is the trajectory of the electron beam 3 toward the periphery. In this case, since the horizontal and vertical deflection magnetic fields are uniform magnetic fields, the lens DL is not formed by the deflection magnetic field of the conventional color cathode ray tube device shown in FIG.
Instead, a lens CL by the convergence correction means is formed, and the lens for the electron beam includes the main lens ML, the auxiliary lens QL, and the lens CL by the convergence correction means.

The lens CL depends on the structure of the convergence correction means (for example, in Document B, since a magnetic material that locally forms a uniform magnetic field is provided in a portion to which the convergence correction magnetic field is applied, the astigmatism effect is reduced. Disappears), but basically acts to generate astigmatism similar to that of the lens DL. However, this lens CL is formed between the cathode of the electron gun and the center of the deflection yoke, ideally near the auxiliary lens QL, and the distance from the auxiliary lens QL is much smaller than that of the conventional lens DL. . Therefore, there is almost no change in the magnification of the combination lens in which the lenses ML, QL, and CL are combined, and as a result, the collapse of the beam spot in the horizontal direction is improved, and the resolution and the like are improved.

The convergence correction means in the prior art is disclosed in Documents B and C as a convergence correction coil and a current supply means for supplying a parabolic correction current to the convergence correction coil which fluctuates in synchronization with horizontal and vertical deflections. It is composed of In particular, Document B discloses that a parabolic correction current is directly formed from a deflection current or a deflection voltage by using an electric circuit including a resistor and a capacitor on a deflection yoke. However, if the parabolic correction current is to be formed directly on the deflection yoke in this manner, a simple circuit as shown in the prior art will produce an ideal waveform which fluctuates symmetrically and quadratically. It is difficult to do so, and on the contrary, the design of the deflection yoke is burdensome. When the correction current is supplied from the drive circuit side, the load on the drive circuit side increases.

[0018]

As described above, the color cathode ray tube apparatus at present has an electron gun of an in-line type which emits three electron beams arranged in a line composed of a center beam and a pair of side beams passing on the same horizontal plane. The horizontal deflection magnetic field generated by the deflection yoke is a pincushion type, and the vertical deflection magnetic field is a barrel type. The inline self-convergence type color cathode ray tube device which deflects three electron beams arranged in a row by the horizontal and vertical deflection magnetic fields is widely used. Has been However, this in-line self-convergence type color cathode ray tube device has a problem that the beam spot is distorted due to the non-uniform deflecting magnetic field, and the resolution is degraded particularly around the screen.

Further, when the convergence correction means is used, there is a problem that a load on a current supply circuit for supplying a convergence correction current to the convergence correction coil and a disturbance of the convergence correction current waveform occur.

The present invention has been made to solve the above problems, and even if the total length is shortened or the screen is flattened, the distortion is reduced over the entire screen without causing a secondary problem. An object of the present invention is to configure a color cathode ray tube device capable of obtaining a good beam spot.

[0021]

(1) A rectangular panel having a first axis and a second axis intersecting with the tube axis and orthogonal to each other and having a phosphor screen provided on an inner surface thereof, which is connected to the panel. A funnel shaped like a funnel and a neck connected to the end of the small diameter part of the funnel. A vacuum envelope having a flatness of twice or more the effective diameter, and a three-electron beam arranged in the neck and arranged in a line composed of a center beam and a pair of side beams arranged in the first axis direction. An in-line electron gun having a cathode and a plurality of electrodes,
A deflection yoke that is mounted from the neck to the outside of the small diameter portion of the funnel and generates a deflection magnetic field that deflects the three electron beams in the first axis direction and the second axis direction; A convergence correction means for displacing a pair of side beams relatively in a direction away from the center beam relative to the center of the phosphor screen only in a direction along the first axis before reaching the center of the yoke; For the axial deflection magnetic field, the non-uniform magnetic field component that mainly degrades the beam spot on the phosphor screen is reduced, and for the second axial deflection magnetic field, the direction along the first axis that is mainly away from the first axis. The deflection yoke was designed to correct the image distortion and convergence.

(2) A rectangular panel having a first axis and a second axis intersecting with the tube axis and orthogonal to each other and having a phosphor screen provided on an inner surface thereof, a funnel-shaped funnel connected to the panel, and The radius of curvature of the panel consisting of a neck connected to the end of the small diameter portion of the funnel and having a circular approximation from the drop of the diagonal end to the neck side with respect to the center of the panel is at least twice the diagonal effective diameter of the phosphor screen. A vacuum envelope having flatness, a cathode, and a plurality of electrodes provided in the neck and emitting three electron beams arranged in a line composed of a center beam having a first axis direction as an arrangement axis and a pair of side beams. An in-line type electron gun having a deflection yoke that is mounted from the neck to the outside of the small diameter portion of the funnel and generates a deflection magnetic field that deflects the three electron beams in the first axis direction and the second axis direction. In a color cathode ray tube device, a pair of side beams are provided at least in a direction along at least a first axis or a second axis from a cathode of an electron gun to a center of a deflection yoke. Convergence correction means for displacing the convergence correction magnetic field in a direction away from the center beam, the convergence correction means comprising a coil for generating a convergence correction magnetic field and a current supply circuit for supplying a convergence correction current to the coil. An amplifier circuit for outputting a convergence correction current of the same waveform to the coil by an input voltage of at least the same waveform as the convergence correction magnetic field, the amplifier circuit is mounted on the color cathode ray tube device, and the first axis or the The non-directional deflection magnetic field degrades the beam spot on the phosphor screen. It was designed deflection yoke configured to reduce an magnetic field component.

(3) In the color cathode ray tube device of (2), a parabolic waveform voltage which fluctuates in synchronization with the deflection of the deflection yoke in the first axis direction or the second axis direction is applied to the electrode forming the main lens of the electron gun. The parabolic waveform voltage was diverted from the input voltage to the amplifier circuit section.

(4) In the color cathode ray tube device of (2), the input voltage to the amplifier circuit section is a voltage obtained by rounding off a high-frequency fluctuation component of the input voltage during a period in which no image is displayed.

(5) In the color cathode ray tube device of (2), a voltage forming circuit section for forming an input voltage to the amplifier circuit section from a deflection voltage or a deflection current of the deflection yoke in an electric circuit is provided. The unit was mounted on a color cathode ray tube device.

(6) In the color cathode ray tube apparatus of (2), a power supply section for operating the amplifier circuit section by processing the deflection voltage of the deflection yoke in an electric circuit is provided, and this power supply section is mounted on the color cathode ray tube apparatus. did.

(7) A rectangular panel having a first axis and a second axis intersecting the tube axis and orthogonal to each other and having a phosphor screen provided on the inner surface thereof, a funnel-shaped funnel connected to the panel, and The radius of curvature of the panel consisting of a neck connected to the end of the small diameter portion of the funnel and having a circular approximation from the drop of the diagonal end to the neck side with respect to the center of the panel is at least twice the diagonal effective diameter of the phosphor screen. A vacuum envelope having flatness, a cathode, and a plurality of electrodes provided in the neck and emitting three electron beams arranged in a line composed of a center beam having a first axis direction as an arrangement axis and a pair of side beams. An in-line type electron gun having a deflection yoke that is mounted from the neck to the outside of the small diameter portion of the funnel and generates a deflection magnetic field that deflects the three electron beams in the first axis direction and the second axis direction. In a color cathode ray tube device, a pair of side beams is provided at a position between the cathode of the electron gun and the center of the deflection yoke at least in a direction along the first axis or the second axis around the center of the phosphor screen. Convergence correction means for displacing in a direction away from the center beam is provided, and the convergence correction means is constituted by a coil for generating a convergence correction magnetic field and a current supply circuit for supplying a convergence correction current to the coil. The convergence correction effect is obtained by differentially shifting the convergence symmetry of the coil with respect to the second axis.

[0028]

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

FIG. 1 shows a color cathode ray tube device as one embodiment thereof. This color cathode ray tube apparatus has a rectangular panel 10 having a horizontal axis (H axis, first axis) and a vertical axis (V axis, second axis) which intersects the tube axis (Z axis) and is orthogonal to each other. The funnel 11 has a funnel shape connected to the panel 10 and a cylindrical neck 12 connected to a small end of the funnel 11, and a circle is approximated from a drop toward the neck 12 at a diagonal end with respect to the center of the panel 10. A vacuum envelope having a flatness in which the radius of curvature of the panel 10 is at least twice the diagonal effective diameter of the phosphor screen described below is provided. A deflection yoke 14 is mounted from the funnel 11 side of the neck 12 to the small diameter portion 13 of the funnel 11. Panel 10 above
Is provided with a phosphor screen 15 having a three-color phosphor layer of a dot shape or a stripe shape (in the illustrated example, a stripe shape) which emits blue, green and red light. Further, a shadow mask 17 in which a large number of color-selecting electron beam passage holes 16 are formed at a predetermined arrangement pitch is arranged on the opposing surface so as to be separated from and opposed to the phosphor screen 15. In the neck 12, a center beam 18G and a pair of side beams 18B, 1B passing on the same horizontal plane are provided.
8R, three electron beams 18B, 18G,
An electron gun 19 for emitting 18R is provided. Further, P is added to the outside of the neck 12 at the rear of the deflection yoke 14.
A CM (purity convergence magnet) (not shown) is mounted.

The electron gun 19 has three cathodes arranged in a row in the horizontal direction, three heaters for heating these cathodes, and a plurality of electrodes arranged in the direction from the cathode to the phosphor screen 15. The plurality of electrodes allows at least one row of three electron beams 18 to be emitted from the cathode.
A main lens for converging B, 18G, and 18R and an auxiliary lens for diverging in the vertical direction and converging in the horizontal direction by applying a voltage that fluctuates in synchronization with the deflection of the deflection yoke 14 are formed.

The deflection yoke 14 is a horizontal deflection coil for generating a horizontal deflection magnetic field for horizontally deflecting the three electron beams 18B, 18G, 18R emitted from the electron gun 19.
And a vertical deflection coil for generating a vertical deflection magnetic field that deflects vertically. As shown in FIG. 2, a horizontal deflection magnetic field 22H generated by the horizontal deflection coils 21a and 21b is provided.
Generates a substantially uniform magnetic field. When the horizontal deflection magnetic field is equalized in this way, compared to the conventional pincushion-type horizontal deflection magnetic field, the vertical deflection magnetic field acting in the direction that prevents the vertical deflection of the electron beam toward the diagonal end of the phosphor screen is reduced. The components decrease, and the upper and lower ends of the screen 24 are distorted in a pincushion shape as shown in FIG. Therefore, in order to correct such pincushion-type image distortion, the deflection yoke 14 is provided with a distortion correction unit (not shown) including a set of NS magnets, and the distortion correction unit is strengthened. On the other hand, the vertical deflection magnetic field generated by the vertical deflection coil is formed into a barrel shape, and the barrel shape is rather strengthened, and the overconvergence at the upper and lower ends of the screen 24 due to the enhancement of the distortion correction means is calculated by the barrel type vertical deflection magnetic field. The compensation is made by under-convergence caused by a magnetic field.

That is, the deflection system in this embodiment corrects the pincushion image distortion while satisfying the convergence at the upper and lower ends of the screen 24.

Further, in the color cathode ray tube device of this embodiment, the three electron beams 18B, 18G, 18R are provided between the cathode of the electron gun 19 and the center of the deflection yoke 14.
Moves toward the horizontal periphery of the phosphor screen 15,
A pair of side beams 18B and 18R is applied to the center beam 18G in the arrangement direction of the three electron beams 18B, 18G and 18R.
There is provided a convergence correction means (not shown) made of magnetic or electrical means which operates so as to move away from (under convergence).

As described above, the horizontal deflection coils 21a, 21a
Assuming that the horizontal deflection magnetic field 22H generated by b is a uniform magnetic field,
As shown in FIG. 2, forces FHB, FH received by the three electron beams 18B, 18G, 18R from the horizontal deflection magnetic field 22H.
G and FHR become equal. In the conventional color cathode ray tube device, over-convergence occurs at the left and right ends of the phosphor screen as indicated by broken lines in FIG. 15, but in this embodiment, since convergence correction means is provided, FIG. As shown in (1), forces FSB and FSR from the convergence correcting means 25 act on the pair of side beams 18B and 18R at the left and right ends P of the phosphor screen 15, thereby compensating for the overconvergence caused by the uniform horizontal deflection magnetic field. And the three electron beams 18B, 18G and 18R can be matched. However, the phosphor screen 15
At the center O, the convergence correction means 25 does not operate, and the three electron beams 18B, 18G, and 18R remain coincident. In addition, 26 is PCM.

Therefore, when the color cathode ray tube device is configured as described above, the horizontal deflection of the horizontal deflection magnetic field 22H at the left and right ends of the phosphor screen 15 is reduced by the uniformity of the horizontal deflection magnetic field 22H, as in the prior art. Resolution is improved.

On the other hand, since the vertical deflection magnetic field remains non-uniform (rather, the barrel shape is strengthened), it is considered that the same effect as in the prior art cannot be expected at the upper and lower ends of the phosphor screen 15. But the electron beam 18B
, 18G, 18R, the angle of incidence on the phosphor screen 15 is taken into consideration, so that the incident angle becomes shallow around the phosphor screen 15, so that the beam spot is distorted into a shape extending in the radiation direction. Therefore, at the left and right ends of the phosphor screen 15, the influence of the non-uniform deflection magnetic field on the beam spot and the effect of the incident angle are in a direction that reinforce each other, and the distortion of the beam spot is increased. The effects tend to compensate each other. Therefore, the distortion of the beam spot is reduced, and the beam spots 28B, 28G, 28R are located at the upper and lower ends of the screen 24 as shown in FIG.
Has almost no distortion. Rather, the vertical deflection tends to be slightly collapsed due to the enhancement of the distortion correcting means having the lens action opposite to that of the barrel-type vertical deflection magnetic field.

Further, when the color cathode ray tube device is configured as described above, basically, the convergence correction in the vertical axis direction becomes unnecessary. In this embodiment, the correction by the convergence correction means 25 is performed only in the horizontal axis direction, and the correction means in the vertical axis direction is omitted.

In the above embodiment, the convergence correcting means which acts on the under convergence at the left and right ends of the phosphor screen has been described. On the contrary, the convergence correcting means acts on the convergence at the center of the phosphor screen. It may be a thing. In other words, the convergence correction means only needs to change the side beam in a direction away from the center beam when the three electron beams relatively move toward the center of the phosphor screen and toward the left and right ends.

The horizontal deflection magnetic field is not limited to a uniform magnetic field, but may be a weak pincushion or barrel type by changing the correction amount of the convergence correction means. If the horizontal deflection magnetic field is non-uniform, for example, if the horizontal deflection magnetic field is barrel-shaped, the magnification of the combination lens at the left and right ends of the phosphor screen is increased in the vertical direction, reduced in the horizontal direction, and collapsed in the vertical direction. Beam spot, and the above-described distortion of the beam spot due to the incident angle can be compensated.

Hereinafter, the main parts of the embodiment of the present invention will be described with reference to examples.

[0041]

FIG. 6 shows a deflection yoke provided with convergence correction means and the like. The deflection yoke 14 has a pair of upper and lower horizontal deflection coils 21a and 21b, a pair of left and right vertical deflection coils 30a and 30b, and a magnetic core 31. On the neck side (rear side) of the deflection yoke 14,
A pair of coma-free coils 34a, 34b in which coils (not shown) are wound around U-shaped magnetic cores 33a, 33b are arranged. Also, a distortion correcting means comprising a pair of upper and lower NS magnets 35a and 35b is arranged on the deflection yoke 14 on the phosphor screen side.

Further, in this embodiment, coils 36a and 36b (convergence correction coils) of convergence correction means are wound around magnetic cores 33a and 33b of the pair of coma free coils 34a and 34b. The convergence correction coils 36a and 36b are connected to the magnetic cores 34a and 3b.
The four magnetic poles formed at the tip of 4b are wound so that the polarities are inverted in adjacent quadrants, and have a function of over-converging or under-converging a pair of side beams by a quadrupole magnetic field generated by energization. It has become.

FIG. 7 shows a convergence correction current supply circuit for supplying a current to the coil of the convergence correction means. This convergence correction current supply circuit 37
The convergence correction coil is operated by an electrically configured current output circuit unit. The current output circuit section 37 includes an amplifier 38 and a feedback resistor 39, and has a parabolic waveform voltage 40 that varies with the horizontal deflection frequency.
, The DC power supplies 41a and 41b, and the ground 42 are all mounted on the color cathode ray tube device. In the case of a high-definition TV or a high-resolution monitor, a focus voltage that fluctuates in synchronization with the deflection of the electron beam is used as the parabolic waveform voltage 40, so that the focus voltage can be diverted. In this current output circuit section 37, a convergence correction coil 36 (36a, 36b) is connected in series with a feedback resistor 39 between the amplifier 38 and the earth 42, and the convergence correction coil 36 side of the feedback resistor 39 is connected to the amplifier amplifier. It has returned to 38. Accordingly, when the parabolic waveform voltage 40 is input to the amplifier 38, the amplifier 38 operates so as to eliminate the difference between the voltage and the feedback voltage. As a result, the convergence correction coil 36 has the same waveform as the parabolic waveform voltage 40. Operate to supply current.

Therefore, such a current output circuit section operates only to convert and output a current of the same shape by input of a parabolic waveform voltage, so that the drive circuit side outputs the parabolic waveform voltage 40. It is only necessary to divert and supply the existing focus voltage that fluctuates in synchronization with the deflection of the electron beam, and to supply DC power supplies 41a and 41b that can be used together with the existing DC power supply as a power source. Also,
Compared with a conventional example in which a parabolic waveform current is formed directly on a deflection yoke, a parabolic waveform current that is close to ideal can be obtained without imposing any electric load on the voltage of the deflection system.

The amplifying amplifier 38 is usually composed of a transistor or the like. However, recently, various OP amplifiers which can withstand high frequency and high power are commercially available. And cost can be reduced.

In such a current output circuit section, the sharp portion of the parabolic waveform voltage 40 may be cut by using a diode or the like as an energy suppressing means and then input to the amplifier 38. Since the sharp portion of the parabolic waveform voltage 40 is a portion that fluctuates at a high frequency, the energy consumption of the amplifier 38 increases when the current waveform follows the voltage waveform. Therefore, if the sharp portion of the parabolic waveform voltage 40 is cut and smooth as described above, the waveform voltage is input, whereby power consumption can be suppressed and the amplifier 38 can be configured at low cost. Note that the sharp portion of the parabola waveform voltage 40 is a horizontal retrace period that is not displayed on the screen, and thus has no effect on the screen.

If a DC voltage is superimposed on the parabolic waveform voltage 40 and input, the convergence of the pair of side beams in the horizontal direction can be adjusted over the entire screen, which is convenient for the user.

As described above, the parabolic waveform voltage 40 having the horizontal deflection frequency can be formed on the deflection yoke from the horizontal deflection voltage or the horizontal deflection current without inputting the parabolic waveform voltage 40 from the outside. FIG. 8 shows the parabolic waveform voltage forming circuit. The parabolic waveform voltage forming circuit 43 is connected to a ground 42 via a capacitor 44 and a shunt resistor 45 on the minus side of the horizontal deflection coils 21a and 21b.
Having a circuit connected thereto. When such a circuit is provided, the sawtooth-shaped horizontal deflection current flowing through the horizontal deflection circuit is shunted to the capacitor 44 via the shunt resistor 45 to accumulate the electric charge.
The parabolic waveform voltage 40 at the horizontal deflection frequency can be extracted from the side.

Even if the parabolic waveform voltage 40 is formed in this manner, since the power related to the above-mentioned voltage → current is supplied from an external DC power source, the deflection power is directly changed as in the prior art in which the parabolic waveform current is formed. And the problem of disturbing the waveform of the formed parabolic waveform current does not occur.

Further, by providing resistors 46 and 47 for detecting a sawtooth voltage on the minus side of the horizontal deflection coils 21a and 21b to divide the sawtooth horizontal deflection current flowing through the horizontal deflection circuit, a sawtooth voltage waveform is obtained. A sawtooth voltage waveform 49 is formed by inverting the voltage waveform 48 and the sawtooth voltage waveform 49. The sawtooth voltage waveform is formed by appropriately dividing the above voltage waveforms 48 and 49 by the variable resistor 50. The convergence correction amount can be adjusted differentially on the left and right sides of the screen by the variable resistor 50 by inputting to the amplification amplifier 38 of the current output circuit unit.

Similarly, by making the shunt resistor 45 a variable resistor, the peak of the parabolic waveform voltage can be adjusted, and the entire convergence correction amount can be adjusted.

As shown in FIG. 9, the AC component of the pulsed horizontal deflection voltage is taken out from the minus side of the horizontal deflection coils 21a and 21b via the capacitor 52,
3a, 53b, and diodes 54a, 54b and capacitors 55a, 55b connected in series to the resistors 53a, 53b, respectively, to add the plus or minus part of the AC component of the horizontal deflection voltage to the amplification amplifier 38 of the current output circuit. By supplying the power as the DC power supplies 41a and 41b, the power supply unit 56 can be provided on the deflection yoke without the need for supply from an external DC power supply.

In this case, since the power related to the above-mentioned voltage → current is supplied from the power supply of the deflection system, the power related to the formation of the parabolic waveform current is forced to the deflection power, but the parabolic waveform current is not disturbed.

Accordingly, the convergence correction coil is operated by such a convergence correction current supply circuit, and the convergence sense can be matched over the entire screen by weakening the pincushion shape of the horizontal deflection magnetic field of the deflection yoke. The distortion of the beam spot can be improved over the entire surface of the phosphor screen.

However, in this case, if the pincushion shape of the horizontal deflection magnetic field is weakened, the vertical component of the horizontal deflection magnetic field acting in a direction that impedes the vertical deflection of the electron beam toward the diagonal end of the phosphor screen decreases. 3, a pincushion-shaped distortion occurs at the upper and lower ends of the screen 24 shown in FIG. Therefore, in this embodiment, it is necessary to strengthen the pair of NS magnets 35a and 35b shown in FIG. 6 and to strengthen the barrel shape of the vertical deflection magnetic field. When the pair of NS magnets is strengthened in this way, the convergence of the side beams at the upper and lower ends of the phosphor screen acts on the over-conversion. Further, if the barrel shape of the vertical deflection magnetic field is strengthened, it acts on under-convergence. Therefore, by strengthening the barrel shape of the NS magnet and the vertical deflection magnetic field as described above, it is possible to correct the pincushion distortion at the upper and lower ends of the screen while satisfying the convergence.

Therefore, with the above configuration, the convergence can be corrected basically only in the horizontal direction, and the configuration of the convergence correction means can be simplified.

As a specific example, the convergence correction is performed on an inline self-convergence type color cathode ray tube device using a panel having an effective diagonal diameter of 46 cm and a curvature approximately three times the diagonal effective diameter and having a maximum deflection angle of 100 °. By means, the convergence was corrected to about 8 mm under convergence at the left and right ends with respect to the center of the phosphor screen, and the pincushion shape of the horizontal deflection magnetic field was reduced correspondingly. As a result, the horizontal diameter / vertical diameter of the beam spot at the left and right ends of the phosphor screen could be improved from the conventional 0.35 to 0.55.

At the same time, the dynamically fluctuating voltage required for the conventional 600 V at the left and right ends of the phosphor screen is 37
It could be set to 0V. This is because the astigmatism is also reduced by the above-described beam spot distortion improving effect.
Further, by increasing the convergence correction amount, the distortion of the beam spot can be further corrected in the longitudinal direction. Further, the voltage that dynamically fluctuates can be finally reduced to a value necessary for correcting the defocus due to the curvature of field.

In the above embodiment, the convergence correction coil is wound around the magnetic core of the coma-free coil. Therefore, unnecessary components can be eliminated, and the convergence correction means can be made compact.

As for the convergence correcting means, as shown in FIG.
Are the magnetic cores, and four convergence correction coils 36 a to 36
d may be wound to generate a quadrupole magnetic field.
In this case, the number of the magnetic cores of the convergence correction coils 36a to 36d may be four, but in consideration of the degree of freedom of the distribution of the coma-free coil to be combined and wound, about eight protrusions 58 are provided as shown. It is desirable. Specifically, the cross-sectional area of the projection 58 is set to 5 mm × 5 mm, and the convergence correction coils 36a to 36d are wound around the projection 58, so that the trajectory is corrected as compared with the case where the projection 58 is wound around a magnetic core made of a silicon steel plate. Sensitivity can be improved.

Such convergence correction means can increase the sensitivity of convergence correction by increasing the cross-sectional area of the magnetic core. However, with an inexpensive silicon steel plate, the larger the cross-sectional area, the higher the horizontal deflection that fluctuates at higher frequencies. An adverse effect such as heat generated by a magnetic field or an induced magnetic field occurs. Therefore, it is effective to use a high-resistance material such as ferrite as described above.

Further, the convergence correction means is provided in FIG.
As shown in FIG. 1, it is composed of four convergence correction coils 36a to 36d curved in an arc shape, and these four convergence correction coils 36a to 36d are a vacuum between the main lens of the electron gun and the center of the deflection yoke. It may be arranged so as to surround the envelope. In such convergence correction means, the convergence correction sensitivity can be improved by increasing the magnetic path length L. However, if it is too close to the phosphor screen, the beam spot distortion, which is a conventional problem, cannot be improved. On the other hand, if the electron beam is too close to the cathode, the trajectory of the electron beam passing through the main lens may be changed, and the beam spot may be deteriorated due to the spherical aberration of the lens. Therefore, ideally, the neck around which the deflection yoke is mounted is good.

Further, the convergence correction means includes:
The convergence correction coils 36a and 36b are not limited to those generating a quadrupole magnetic field, but are provided on the right and left sides of a ring-shaped core 60 disposed on the neck side of the deflection yoke, as shown in FIG. The convergence correction coils 36a and 36b may be connected to the horizontal deflection coils 21a and 21b via the circuit shown in FIG. In this circuit, variable load coils 63a and 63b connected to horizontal deflection coils 21a and 21b are wound around a saturable core 62 magnetically biased by magnets 61a and 61b so as to compensate for a magnetic field. The convergence correction coils 36a and 36b are connected in parallel with the coils 63a and 63b.

In such convergence correction means,
When the horizontal deflection current flows, one of the load variable coils 63a and 63b increases due to magnetic saturation, and the other load decreases. As a result, at the left end of the phosphor screen, one of the magnetic fields of the convergence correction coils 36a and 36b becomes larger than the other magnetic field, and at the right end, the magnetic field operates differentially so that the magnitude of the magnetic field is reversed. Therefore, the convergence correction means is constructed such that the differentially generated magnetic fields of the convergence correction coils 36a and 36b act strongly on the side beam which is always deflected in a direction to assist horizontal deflection, or The convergence of the pair of side beams can be corrected by using a structure that strongly acts on the side beam opposite to the side that is always deflected in the direction that prevents deflection.

[0065]

As described above, when the convergence correction means is provided between the cathode of the electron gun of the in-line self-convergence type color cathode ray tube used for a high-definition TV and a high-resolution monitor and the center of the deflection yoke, The distortion of the beam spot can be eliminated over the entire screen to make a substantially perfect circle. In addition, by separating the convergence correction current into a pressurization / current conversion portion and a correction voltage generation portion, an ideal correction current waveform can be obtained, and power consumption can be separated from deflection power.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a color cathode ray tube device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a horizontal deflection magnetic field generated by a deflection yoke of the color cathode ray tube device.

FIG. 3 is a diagram showing image distortion generated when the horizontal deflection magnetic field of the deflection yoke is weakened.

FIG. 4 is a diagram for explaining a method of adjusting the three electron beam compatibility at the center and right and left ends of the phosphor screen of the color cathode ray tube device.

FIG. 5 is a diagram showing a shape of a beam spot of the color cathode ray tube device.

FIG. 6 is a diagram illustrating a configuration of a deflection yoke provided with a convergence correction unit and the like according to the first embodiment of the present invention.

FIG. 7 is a diagram illustrating a configuration of a current supply circuit that supplies a current to a convergence correction coil of the convergence correction unit of the first embodiment.

FIG. 8 is a diagram illustrating a configuration of a parabolic waveform voltage forming circuit that supplies a parabolic waveform voltage to the current supply circuit according to the first embodiment.

FIG. 9 is a diagram illustrating a configuration of a power supply unit that supplies a DC voltage to the current supply circuit according to the first embodiment.

FIG. 10 is a diagram showing a different configuration of a convergence correction coil provided in the deflection yoke.

FIG. 11 is a diagram showing a further different configuration of the convergence correction coil.

FIG. 12A is a view showing another configuration of a convergence correction coil provided in the deflection yoke,
FIG. 12B is a diagram showing a circuit configuration for supplying a current to the convergence correction coil.

FIG. 13 is a view for explaining convergence of three electron beams at the center and the corner of a phosphor screen of a conventional color cathode ray tube device.

FIG. 14 (a) is a view showing a horizontal deflection magnetic field generated by a deflection yoke of a conventional color cathode ray tube device, and FIG.
(B) is a diagram showing a vertical deflection magnetic field.

FIG. 15 is a diagram for explaining a force exerted on an electron beam by a deflection magnetic field of a conventional color cathode ray tube device.

FIG. 16 is a view for explaining a lens effect that a deflection magnetic field of a conventional color cathode ray tube device exerts on an electron beam.

FIG. 17 is a diagram for explaining a lens effect exerted on an electron beam by a convergence correction means of a conventional color cathode ray tube device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Panel 11 ... Funnel 12 ... Neck 13 ... Small diameter part 14 ... Deflection yoke 15 ... Phosphor screen 18B, 18R ... A pair of side beam 18G ... Center beam 19 ... Electron gun 25 ... Convergence correction means 36a, 36b, 36c, 36d: convergence correction coil 37: current output circuit 43: parabolic waveform voltage forming circuit 56: power supply

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroaki Ibuki 1-9-2 Harara-cho, Fukaya-shi, Saitama Prefecture Inside the Toshiba Fukaya Plant (72) Inventor Hideo Mori 1-9-1-2 Harara-cho, Fukaya-shi, Saitama No. F-term in Toshiba Fukaya Plant (reference) 5C042 AA07 FF05 FF06 HH02 HH03 HH12 5C060 BA02 BA07 BC01 BE02 BE07 CA04 CF03 CF06 CG03 CG04 HA02 HA03 HA07 HA14 HB01 HB16 JA00

Claims (7)

[Claims] 1. A rectangular panel having a first axis and a second axis intersecting with a tube axis and orthogonal to each other and having a phosphor screen provided on an inner surface thereof, a funnel-shaped funnel connected to the panel, and a funnel-shaped funnel connected to the panel. A radius of curvature of the panel, which is formed of a neck connected to the end of the small diameter portion of the funnel and is approximated by a circle from the drop of the diagonal end to the neck side with respect to the center of the panel, is 2 times the diagonal effective diameter of the phosphor screen. A vacuum envelope having a flatness that is at least twice that of the vacuum envelope;
An in-line type electron gun having a cathode and a plurality of electrodes for emitting three electron beams arranged in a line composed of a center beam and a pair of side beams having an axial axis as an arrangement axis, and from the neck to the outside of the small diameter portion of the funnel. And a deflection yoke mounted on the electron gun to generate a deflection magnetic field for deflecting the three electron beams in the first axis direction and the second axis direction. A convergence correcting means for displacing the pair of side beams relatively in a direction away from the center beam relative to the center of the phosphor screen only in a direction along the first axis; As for the axial deflection magnetic field, a non-uniform magnetic field component that mainly deteriorates the beam spot on the phosphor screen is used. The deflection yoke is designed to reduce the deflection magnetic field in the second axis direction and to correct image distortion and convergence in a direction along the first axis away from the first axis. Color cathode ray tube device. 2. A rectangular panel having a first axis and a second axis intersecting the tube axis and orthogonal to each other and having a phosphor screen provided on an inner surface thereof, a funnel-shaped funnel connected to the panel, and a funnel-shaped funnel connected to the panel. A radius of curvature of the panel, which is formed of a neck connected to the end of the small diameter portion of the funnel and is approximated by a circle from the drop of the diagonal end to the neck side with respect to the center of the panel, is 2 times the diagonal effective diameter of the phosphor screen. A vacuum envelope having a flatness that is twice or more, and provided in the neck,
An in-line type electron gun having a cathode and a plurality of electrodes for emitting three electron beams arranged in a line composed of a center beam and a pair of side beams having an axial axis as an arrangement axis, and from the neck to the outside of the small diameter portion of the funnel. And a deflection yoke mounted on the electron gun to generate a deflection magnetic field for deflecting the three electron beams in the first axis direction and the second axis direction. Convergence correction means for displacing the pair of side beams relatively away from the center beam in a direction at least in a direction along the first axis or the second axis around the center of the phosphor screen. A convergence correction means for generating a convergence correction magnetic field and a convergence A current supply circuit for supplying a convergence correction current, the current supply circuit having an amplifier circuit section that outputs a convergence correction current having the same waveform to the coil by an input voltage having the same waveform as at least the convergence correction magnetic field. The deflection yoke has a configuration in which an amplification circuit section is mounted on a color cathode ray tube device, and wherein the deflection magnetic field in the first axis direction or the second axis direction reduces an asymmetric magnetic field component that degrades a beam spot on the phosphor screen. A color cathode ray tube device characterized by being designed. 3. A parabolic waveform voltage, which fluctuates in synchronization with the deflection of the deflection yoke in the first axis direction or the second axis direction, is applied to an electrode forming a main lens of the electron gun, and the input voltage to the amplifier circuit is reduced. 3. The color cathode ray tube device according to claim 2, wherein the voltage is obtained by diverting the parabolic waveform voltage. 4. The color cathode ray tube device according to claim 2, wherein the input voltage to the amplifier circuit is a voltage obtained by rounding off a high-frequency fluctuation component of the input voltage during a period during which no image is displayed. 5. A voltage forming circuit section for forming an input voltage to an amplifier circuit section from a deflection voltage or a deflection current of a deflection yoke in an electric circuit is provided, and the voltage forming circuit section is mounted on a color cathode ray tube device. 3. The method according to claim 2, wherein
The color cathode ray tube device as described in the above. 6. A power supply unit for operating a deflection circuit unit by processing a deflection voltage of a deflection yoke in an electric circuit, and the power supply unit is mounted on a color cathode ray tube device. 2. The color cathode ray tube device according to 2. 7. A rectangular panel having a first axis and a second axis intersecting the tube axis and orthogonal to each other and having a phosphor screen provided on an inner surface thereof, a funnel-shaped funnel connected to the panel, and a funnel-shaped funnel connected to the panel. A radius of curvature of the panel, which is formed of a neck connected to the end of the small diameter portion of the funnel and is approximated by a circle from the drop of the diagonal end to the neck side with respect to the center of the panel, is 2 times the diagonal effective diameter of the phosphor screen. A vacuum envelope having a flatness that is at least twice that of the vacuum envelope;
An in-line type electron gun having a cathode and a plurality of electrodes for emitting three electron beams arranged in a line composed of a center beam and a pair of side beams having an axial axis as an arrangement axis, and from the neck to the outside of the small diameter portion of the funnel. And a deflection yoke mounted on the electron gun to generate a deflection magnetic field for deflecting the three electron beams in the first axis direction and the second axis direction. Convergence correction means for displacing the pair of side beams relatively away from the center beam in a direction at least in a direction along the first axis or the second axis around the center of the phosphor screen. A convergence correction means for generating a convergence correction magnetic field, and a convergence correction means A current supply circuit for supplying a convergence correction current, wherein the coil of the convergence correction means obtains a convergence correction action by differentially shifting the convergence symmetry with respect to the second axis. apparatus.