JPH0574369A - Picture tube - Google Patents

Abstract

PURPOSE:To remove the luster distortion by a deflection yolk, and allow a reduction in the consumed power of the deflection yolk and the wide angle deflection and shortening in depth of a picture tube. CONSTITUTION:In a picture tube in which electron beams 7B, 7G, 7R emitted from an electron gun 8 are deflected by the horizontal and vertical deflecting magnetic fields generated by a deflection yolk 10 to scan a stimulable phosphor screen 3, an electrode for generating a multipolar electric field such as a quadrupole electric field and an octalpole electric field, which consists of a first electrode 20a and a second electrode 20 to which a voltage lower than that applied to the first electrode 20a is applied is provided in emitting direction on the inside of an envelop between the phosphor screen 3 and the electron beam emitting end part of the electron gun.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a picture tube such as a color picture tube, and more particularly to a picture tube capable of reducing a deflection power and shortening a depth and capable of correcting a shape distortion of a raster.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 8, a color picture tube has an envelope including a panel 1 and a funnel-shaped funnel 2 integrally joined to the panel 1.
On the inner surface of 2, there is formed a phosphor screen 3 composed of a dot-shaped or striped three-color phosphor layer that emits blue, green, and red. A shadow mask 4 is formed inside the phosphor screen 3 so as to face the phosphor screen 3. Are arranged. This shadow mask 4 is located inside the large-diameter part of the funnel 2,
An internal magnetic shield 5 is attached to shield an external magnetic field such as geomagnetism. Also, inside the neck 6 of the funnel 2,
An electron gun 8 that emits three electron beams 7B, 7G, and 7R is arranged. Further, an inner conductive film 9 is formed by coating from the inner surface of the large-diameter portion of the funnel 2 to the inner surface of the neck 6 facing the electron beam emitting end of the electron gun 8. A deflection yoke 10 is mounted outside the boundary between the large-diameter portion of the funnel 2 and the neck 6.

In such a color picture tube, the three electron beams 7B, 7G, and 7R emitted from the electron gun 8 are deflected by the horizontal deflection magnetic field and the vertical deflection magnetic field generated by the deflection yoke 10, and the shadow mask 4 is deflected. A color image is displayed on the phosphor screen 3 by scanning the phosphor screen 3 horizontally and vertically via the phosphor screen 3. In this case, the electron gun
The three electron beams 7B, 7G, 7R emitted from
It is selected by the shadow mask 4 so as to enter the color phosphor layer.

In order to display a color image on the phosphor screen 3 as described above, 3 emitted from the electron gun 8 is used.
It is necessary to correctly concentrate the electron beams 7B, 7G, 7R over the entire area of the phosphor screen 3, and regarding the concentration of these 3 electron beams 7B, 7G, 7R, in particular, the phosphor screen 3
The three-color phosphor layer of the
Center beam 7G passing through 8 on the same horizontal plane and a pair of side beams 7B and 7R arranged in a row to form three electron beams 7
An in-line type electron gun that emits G, 7B, and 7R, and three electron beams 7G, 7B, which are arranged in a row and are emitted from this electron gun 8
Practical use of a self-convergence type color picture tube in which the horizontal deflection magnetic field generated by the deflection yoke 10 for deflecting 7R is a pincushion type and the vertical deflection magnetic field is a barrel type so that the three electron beams 7G, 7B and 7R are self-focused. Has been converted.
The color picture tube shown in FIG. 8 is an example of the self-convergence in-line color picture tube.

By the way, in order to improve the image quality of a color picture tube which displays an image by scanning the phosphor screen 3 with three electron beams 7B, 7G and 7R,
It is necessary to reduce the concentration deviation of the three electron beams 7B, 7G, 7R on the phosphor screen 3 and to reduce the shape distortion (raster distortion) of the raster. In the self-convergence in-line color picture tube, the horizontal deflection magnetic field generated by the deflection yoke 10 is pincushion type,
By making the vertical deflection magnetic field a barrel-shaped non-uniform magnetic field, three electron beams 7B arranged in a row passing through the same horizontal plane,
It is possible to concentrate 7G and 7R, but due to the non-uniform magnetic field, pin-cushion type distortion occurs on the top, bottom, left and right of the screen.

Japanese Patent Publication No. 57-35542 discloses a method of removing pincushion type distortion on the upper, lower, left and right sides of the screen by the magnetic field distribution of the deflection yoke. According to the method of this publication, it is possible to reduce the distortion, but it is difficult to completely remove it, and the deflection yoke actually manufactured must be a compromise design that minimizes the distortion. Even if it is designed optimally, it is still impossible to remove the high-order raster distortion 12 as shown in FIG.

For a color picture tube used in a general household image receiver, it is desirable that it has a high resolution over the entire screen, a short depth (distance from the phosphor screen to the electron gun), and low power consumption. Be done. However, since these characteristics include technically contradictory ones, it is difficult to solve all of them.

That is, in order to shorten the depth of the color picture tube, the maximum deflection angle of the deflection yoke should be increased (widened angle deflection). However, when the deflection angle is increased, the amount of current flowing through the deflection yoke increases. , The power consumption of the deflection yoke (deflection power) increases. In order to reduce the deflection power, it is sufficient to reduce the neck diameter and increase the deflection sensitivity.
If the neck diameter is made smaller, the aperture of the electron lens of the electron gun becomes smaller and the beam spot diameter on the phosphor screen becomes larger, resulting in deterioration of resolution.

The power consumption of the deflection yoke is mainly determined by the current flowing through the horizontal deflection coil. For example N
In case of TSC system, horizontal deflection frequency is 15.75kHz
And is significantly higher than the vertical deflection frequency of 60 Hz, and the power consumption increases as is apparent from the product of the square of the impedance LH (mH) of the horizontal deflection coil and the flowing current iH (A) LH.iH ^2. , Not just energy loss
This causes problems such as heat generation and burning of the deflection yoke.

On the other hand, the current TV system is EDT.
V (Extended Definition TV) (high definition TV) and H
DTV (High Definition TV) has been developed, but in these EDTV and HDTV, the horizontal deflection frequency is double the current frequency (33.75 kHz), and especially the aspect ratio of the screen is 9:16. A color picture tube has a larger horizontal deflection angle than a normal color picture tube. Further, some color picture tubes used for displays of computer terminals have a horizontal deflection frequency of 64 kHz or more, and in order to prevent the resulting heat generation and burning of the deflection yoke, the deflection coil is expensive. Litz wire will have to be used.

Therefore, with respect to EDTV, HDTV, etc., it is not possible to expect a reduction in the depth due to the wide-angle deflection, which is more than the current one, from the viewpoint of power consumption and heat generation of the deflection yoke.

[0012]

Generally, in a color picture tube which emits three electron beams, in order to display an image on the phosphor screen, the three electron beams emitted from the electron gun are spread over the entire area of the phosphor screen. Especially, it is necessary to concentrate the three electron beams emitted from the electron gun into three electron beams arranged in one row passing on the same 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. As an inhomogeneous single magnetic field, a self-convergence type in-line type color picture tube for self-focusing the three electron beams arranged in a row has been put to practical use. However, in this color picture tube, since the deflection magnetic field is a non-uniform magnetic field, pin-cushion type distortion is generated in the vertical and horizontal directions of the screen.

Conventionally, there is known a method of removing the pincushion type distortion generated in the vertical and horizontal directions of the screen of the self-convergence type in-line type color picture tube by the magnetic field distribution of the deflection yoke. According to this method, it is possible to reduce the distortion, but it is difficult to completely remove it, and the deflection yoke actually manufactured has to be a compromise design that minimizes the distortion. Even if it is designed optimally, there is a problem that high-order raster distortion remains on the screen.

Regarding the color picture tube, it is desired that the color picture tube used in a general household picture receiver has a short depth and low power consumption.
In a DTV or the like, the horizontal deflection frequency becomes high, and particularly in a color picture tube having an aspect ratio of 9:16, the horizontal deflection angle becomes larger than that in a normal color picture tube. Further, the deflection frequency of a color picture tube used for a display of a computer terminal tends to be high. Therefore, widening the deflection of such a color picture tube to shorten the depth not only significantly increases the deflection power, but also causes the deflection yoke to generate heat and burn out. Therefore, reducing the deflection power is also an important issue.

The present invention has been made in order to solve the above problems, and it is possible to reduce the power consumption of the picture tube, particularly the deflection power, and at the same time, if necessary, the raster distortion can be sufficiently reduced. The purpose is to configure.

[0016]

In a picture tube in which an electron beam emitted from an electron gun is deflected by a horizontal deflection magnetic field and a vertical deflection magnetic field generated by a deflection yoke to scan a phosphor screen, the phosphor screen and the electron are used. A multiplicity of first electrodes radially provided inside the envelope between the electron beam emitting end of the gun and a second electrode to which a voltage lower than the voltage applied to the first electrode is applied. A pole field generating electrode was provided.

The first electrode is provided inside the envelope between the phosphor screen and the electron beam emitting end of the electron gun so as to face in the horizontal direction, and the first electrode is provided so as to face in the vertical direction. A quadrupole electric field generating electrode composed of a second electrode to which a voltage lower than the voltage applied to the electrode was applied was provided.

Further, a first electrode is provided inside the envelope between the phosphor screen and the electron beam emitting end of the electron gun so as to face horizontally and vertically, and a first electrode is provided diagonally. An octopole electric field generating electrode composed of two electrodes was provided.

[0019]

As described above, a voltage lower than the voltage applied to the first electrode and the first electrode is applied inside the envelope between the phosphor screen and the electron beam emitting end of the electron gun. If an electrode that generates a multi-pole electric field such as a quadrupole electric field or an octupole electric field that is composed of a second electrode is provided, the first electrode and the second electrode are appropriately shaped and arranged so that the electron beam diverges It is possible to form an electric field that gives a focusing force.

As a result, the electron beam emitted from the electron gun and deflected by the deflection yoke is then converted into an electron beam only by the deflection yoke by the action of the multipole electric field formed by the first electrode and the second electrode. Raster distortion that occurs when deflected can be eliminated.

Further, by forming an electric field having a diverging force at least in the horizontal direction, it is possible to increase the deflection sensitivity in the horizontal direction by adding the diverging action of the multipole electric field to the deflection amount of the horizontal deflection magnetic field of the deflection yoke. As a result, the power consumption of the deflection yoke can be reduced, and the picture tube can be wide-angle deflected and the depth can be shortened.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described based on embodiments with reference to the drawings.

(Embodiment 1) FIG. 1 and FIG. 2 show a color picture tube which is one of the embodiments. This color picture tube has an envelope composed of a panel 1 and a funnel-shaped funnel 2 integrally joined to the panel 1, and the inner surface of the panel 1 has a dot-shaped or a blue-green-red-light-emitting type. A phosphor screen 3 composed of a stripe-shaped three-color phosphor layer is formed, and a shadow mask 4 is arranged inside the phosphor screen 3 so as to face the phosphor screen 3. This shadow mask
An internal magnetic shield 5 which is located inside the large-diameter portion of the funnel 2 and shields an external magnetic field such as the earth's magnetism is attached to 4. Further, in the neck 6 of the funnel 2, an electron gun 8 for emitting three electron beams 7B, 7G, 7R arranged in a line consisting of a center beam 7G and a pair of side beams 7G, 7R passing on the same horizontal plane is arranged. .. Further, from the inner surface of the large-diameter portion of the funnel 2 to the inner surface of the neck 6 facing the electron beam emitting end of the electron gun 8, an inner conductive film 20a forming a first electrode and an inner conductive film forming a second electrode, which will be described later, are formed. 20b and 20b are formed by coating so as to be electrically isolated from each other at a constant interval. Furthermore, a deflection yoke 10 is mounted outside the boundary between the large-diameter portion of the funnel 2 and the neck 6.

From the inner surface of the large diameter portion of the funnel 2 to the neck
6 Internal conductive films 20a, 20 formed by coating on the inner surface
Regarding b, the phosphor screen 3 side surrounding the inner magnetic shield 5 and the electron gun 8 side are entirely covered with the inner conductive film 20a constituting the first electrode, but the phosphor screen 3 side is covered. As shown in FIG. 3, an inner conductive film 20a forming the first electrode and an inner conductive film 20b forming the second electrode are applied in the radial direction with respect to the tube axis at the intermediate portion between the and the electron gun 8. Has been formed. Internal conductive film forming the first electrode
20a is opposed in the horizontal direction (X-axis direction), the internal conductive film 20b constituting the second electrode is opposed in the vertical direction (Y-axis direction), and these internal conductive films 20a, 20b are substantially diagonal. It is adjacent.

The inner conductive film 20a forming the first electrode is the first anode terminal provided on the large diameter portion of the funnel 2 surrounding the inner magnetic shield 5 as shown in FIG.
It is electrically connected to 21a, and the voltage V1 supplied to this first anode terminal 21a is applied. It should be noted that this voltage is applied to the final accelerating electrode 22 of the electron gun 8 and is a valve spacer press-contacted to the internal conductive film 20a formed by coating on the inner surface of the neck 6.
It is supplied to the final accelerating electrode 22 via 23. The internal conductive film 20b forming the second electrode is electrically connected to the second anode terminal 21b provided on the large-diameter portion of the funnel 2 on which the internal conductive film 20b is formed by coating. A voltage V2 which is slightly lower than the voltage supplied to the first anode terminal 21a supplied to the two anode terminals 21b is applied.

The voltage V1 supplied to the first anode terminal 21a is attached to the shadow mask 4 and the shadow mask 4 via a connector (not shown) attached to the shadow mask 4 and in pressure contact with the internal conductive film 20a. It is applied to the phosphor screen 3 via the internal magnetic shield 5 and the support 24 (a mask holder attached to the shadow mask and a stud pin fixed to the panel) that supports the shadow mask 4.

By the way, as described above, on the inner surface of the funnel 2, the first electrode and the second electrode made of the internal conductive films 20a and 20b are formed.
An electrode is provided and a voltage V1 is applied to the first electrode of the second electrode
When a voltage V2, which is slightly lower than the voltage V1 applied to its first electrode, is applied to the electrodes, these first and second electrodes have a three-electron beam 7 with a quadrupole lens 26 therebetween.
A quadrupole electric field that exerts a divergent force FH in the horizontal direction and a focusing force FV in the vertical direction with respect to B, 7G, and 7R is generated.

As a result, in this color picture tube, the electron gun
The three electron beams 7B, 7G, and 7R emitted from 8 are subjected to the deflection action of θH in the horizontal direction by the horizontal deflection magnetic field of the deflection yoke 10 as shown in FIG. The three electron beams 7B, 7G, and 7R are subjected to the deflection effect of ψ H due to the divergence action in the horizontal direction, and in the horizontal direction, due to the horizontal deflection magnetic field of the deflection yoke 10 and the divergence action in the horizontal direction of the quadrupole lens 26, θH It is deflected by + ψH. On the other hand, in the vertical direction, due to the vertical deflection magnetic field of the deflection yoke 10, FIG.
As shown in FIG. 7, the deflection action of θV is performed, and then the vertical focusing action of the quadrupole lens 26 causes the deflection action of ψV. The focusing action of the quadrupole lens 26 is due to the deflection yoke 10
Since the three electron beams 7B, 7G, and 7R have a negative action on the deflection by the vertical deflection magnetic field of, the vertical deflection magnetic field of the deflection yoke 10 and the vertical focusing action of the quadrupole lens 26 in the vertical direction. Causes a deflection of θV − ψV.

Therefore, as shown in FIG. 4, the raster drawn on the phosphor screen 3 is perpendicular to the raster 27a when only the deflection yoke is operated without the quadrupole lens being operated. A raster 27b that contracts and extends horizontally is formed.

The ability to extend in the horizontal direction in this way means that the deflection yoke 10 can be used when the horizontal deflection frequency increases or when wide-angle deflection is performed, or when the horizontal deflection frequency is increased and wide-angle deflection is performed at the same time. Even if the amount of deflection due to is suppressed, it means that the quadrupole lens facilitates the deflection and the desired deflection can be obtained.
It is shown that the horizontal deflection current of the deflection yoke 10 can be suppressed to be small.

On the other hand, with respect to vertical deflection, the deflection sensitivity is lowered as described above, but since the vertical deflection frequency is generally much lower than the horizontal deflection frequency,
Even if the vertical deflection current is increased to increase the deflection sensitivity, the heat generation and the vertical deflection current only slightly increase, and there is almost no problem.

Therefore, when the color picture tube is constructed as described above, the power consumption of the deflection yoke can be reduced, the heat generation of the deflection yoke 10 can be suppressed, and the coil can be formed by an expensive litz wire conventionally used as a heat generation countermeasure. There is no need to form.

(Embodiment 2) The entire structure of the color picture tube of Embodiment 2 is almost the same as that of the color picture tube shown in FIGS. 1 and 2, except for the internal conductive film formed on the inner surface of the funnel. Therefore, the description thereof will be omitted.

The internal conductive film formed on the inner surface of the funnel of this color picture tube is formed by coating from the inner surface of the funnel-shaped funnel having a large diameter to the inner surface of the neck, and is attached to the shadow masker so as to have a large diameter of the funnel. The phosphor screen side and the electron gun side surrounding the inner magnetic shield located inside of the are covered with the inner conductive film forming the first electrode, but the phosphor screen side and the electron gun side are covered. As shown in FIG. 5, the intermediate part between the inner conductive film 20a and the inner conductive film 20b forming the first electrode and the second conductive film are electrically insulated from each other in the radial direction with respect to the tube axis. Is formed by coating. Internal conductive film 20 that constitutes the second electrode
b is formed by coating so as to face in a substantially diagonal direction (D-axis direction), and the internal conductive film 20a forming the first electrode faces in the horizontal and vertical directions so as to surround the internal conductive film 20b. Is formed by coating.

Internal conductive film 20a forming the first electrode
Is electrically connected to a first anode terminal (not shown) provided on the large-diameter portion of the funnel, and a voltage V1 supplied to the first anode terminal is applied. The internal conductive film 20b forming the second electrode is electrically connected to a second anode terminal (not shown) provided on the large-diameter portion of the funnel 2 on which the internal conductive film 20b is formed by coating. A voltage V2 which is slightly lower than the voltage supplied to the first anode terminal 21a supplied to the second anode terminal 21b is applied.

The voltage V1 supplied to the first anode terminal is passed through a valve spacer 23 which is attached to the final accelerating electrode 22 of the electron gun 8 and press-contacts the internal conductive film 20a formed by coating on the inner surface of the neck 6. Are supplied to the final acceleration electrode 22.
The voltage V1 supplied to the first anode terminal 21a is applied to the shadow mask through a connector which is attached to the shadow mask and is in pressure contact with the internal conductive film 20a, the internal magnetic shield attached to the shadow mask, and the shadow. It is applied to the phosphor screen via a support or the like that supports the mask.

By the way, as described above, the first electrode and the second electrode composed of the internal conductive films 20a and 20b are provided on the inner surface of the funnel 2, the voltage V1 is applied to the first electrode, and the first electrode is applied to the second electrode. When a voltage V2 slightly lower than the voltage V1 applied to the electrodes is applied, these first and second electrodes are
An octopole electric field shown in FIG. 6 is generated between them to form an octopole lens. The arrow 29 shown in FIG. 6 indicates the direction of the force F acting on the electron beam in the direction opposite to the direction of the octupole electric field, and this octupole lens has horizontal and vertical directions. Has a diverging force for the electron beam and has a focusing force in the diagonal direction.

Therefore, in this color picture tube, as shown in FIG. 1, the three electron beams 7 emitted from the electron gun 8 are emitted.
In the horizontal direction, B, 7G, and 7R are subjected to a deflection action of θH by the horizontal deflection magnetic field of the deflection yoke 10, and then a deflection action of ψH due to the horizontal divergence action of the octupole lens. , 7G, 7R are deflected in the horizontal direction by θH + φH due to the horizontal deflection magnetic field of the deflection yoke 10 and the horizontal divergence action of the octupole lens. Similarly, in the vertical direction, as shown in FIG. 2, the vertical deflection magnetic field of the deflection yoke 10 causes a deflection action of θ V, and then the octupole lens has a vertical divergence action. On the other hand, in the diagonal direction, the deflection yoke 10 is subjected to the deflection action of the horizontal and vertical deflection magnetic fields, and then subjected to the diagonal focusing action of the octupole lens. This focusing action is a negative action with respect to the deflection action of the deflection yoke 10.

Therefore, in the color picture tube having the above-mentioned structure, only the deflection magnetic field generated by the deflection yoke is used.
When the electron beams 7B, 7G, and 7R are deflected, for example, as shown in FIG. 7, even if the deflection yoke has a high-order raster distortion 12, if the octupole lens is combined with this deflection yoke, a broken line 30
The distortion can be removed, as shown in.

Further, since the octupole lens 28 has a divergence function in the horizontal and vertical directions, respectively, even if the deflection amount by the deflection yoke is suppressed, the deflection is promoted by the octupole lens to obtain a desired deflection. Therefore, the power consumption of the deflection yoke can be reduced.

In Japanese Patent Laid-Open No. 52-79776, Japanese Patent Laid-Open No. 52-79764, etc., a structure similar to that of the color picture tube of the above-mentioned embodiment is formed, and an internal conductive film and a shadow masker are formed. A color picture tube is disclosed which has a different potential than the phosphor screen. However, in this known color picture tube, the electron beam is focused in front of the phosphor screen to correct the raster, which is different from the color picture tubes of the above-described embodiments.

In Japanese Patent Laid-Open No. 2-195623, an electrostatic lens is formed inside the funnel to increase the incident angle of an electron beam incident on a shadow mask or a phosphor screen, thereby preventing mislanding. A color picture tube for miniaturization is disclosed. However, the electrostatic lens formed inside the funnel of this color picture tube is
A cylindrical lens such as a unipotential type lens or a bipotential type lens, and in principle, a multipole lens generating a multipole electric field such as a quadrupole lens generating a quadrupole electric field or an octupole lens generating an octupole electric field is used. This is different from the color picture tube of the embodiment to be formed.

That is, in the multipole lens of the color picture tube of each of the above embodiments, the first electrode and the second electrode are arranged in the direction orthogonal to the traveling direction of the electron beam, and the electron beam is formed by these first and second electrodes. Is to form an electric field perpendicular to the traveling direction of, and by increasing the length of the electrode,
A strong electron lens can be easily formed. The electron lens action has a diverging action or a focusing action in a desired direction. On the other hand, in a cylindrical lens, electrodes are arranged along the traveling direction of an electron beam, and an electron lens is formed between the electrodes. The lens action is only a focusing action as a whole, The lens itself is also weak.

A multipole lens that generates a multipole electric field, such as a quadrupole lens or an octupole lens, gives a slight potential difference to the first and second electrodes forming the multipole lens so that the divergence power and the focusing power are increased. can get. This means that when an electrode is actually formed on the inner surface of the funnel, if a large potential difference causes discharge, a multipole lens is more advantageous than when forming another lens such as a cylindrical lens. Shows.

In each of the above embodiments, the internal conductive film forming the first electrode and the internal conductive film forming the second electrode are insulated by the exposed glass surface (inner surface of the funnel).
In order to ensure the insulation between the electrode and the second electrode, it is effective to suppress electrical discharge by applying frit glass, ceramics, insulating heat-resistant organic material, or other insulating inorganic oxide between both internal conductive films. ..

Further, in each of the above embodiments, the internal conductive film forming the first electrode and the internal conductive film forming the second electrode are
The required voltage is applied from each separate anode terminal, but the voltage is applied to each internal conductive film so that it is supplied from one anode terminal having two insulated terminals. May be. In addition, a resistor may be arranged so that the voltage supplied to one anode terminal is divided and supplied to the internal conductive film to which a low voltage is applied.

In each of the above embodiments, a voltage is applied to the internal conductive film forming the first electrode and the internal conductive film forming the second electrode through the anode terminal provided on the funnel. However, the voltage can be applied to each electrode from the electron gun side through the stem.

Further, in each of the above-mentioned embodiments, only the internal conductive film forming the first electrode is extended to the phosphor screen side and the electron gun side. Both the internal conductive film forming the two electrodes may be extended to at least one of the phosphor screen side and the electron gun side. Further, raster distortion, convergence, etc. can be corrected by appropriately changing the shape of both internal conductive films.

Furthermore, in each of the above-mentioned embodiments, the internal conductive film forming the first electrode and the internal conductive film forming the second electrode are formed on the inner surface of the funnel, but the first and second electrodes are Not limited to the internal conductive film formed on the inner surface of the funnel, it may be separately formed, for example, by a metal plate and disposed inside the funnel. Also, one of the electrodes is formed by a metal plate or the like and the other electrode is formed. May be formed of an internal conductive film. It is also possible to use the internal magnetic shield as an electrode.

In each of the above embodiments, the case where the quadrupole lens and the octupole lens are formed has been described.
The present invention is not limited to the quadrupole lens and the octupole lens, and it is optional to use a multipole lens such as a ten-pole lens and a sixteen-pole lens that generate a multipole electric field necessary for a desired correction. Further, the shape of the electrodes forming the multipole lens is not limited to those shown in each of the above embodiments.

Although each of the above embodiments has been described with respect to a color picture tube having a shadow mask, the present invention is applicable to other color picture tubes and also to a monochrome picture tube. is there.

[0052]

The first electrode and a voltage lower than the voltage applied to the first electrode are applied inside the envelope between the phosphor screen and the electron beam emitting end of the electron gun. When an electrode for forming a multi-pole electric field such as a quadrupole electric field or an octapole electric field composed of two electrodes is provided, by arranging the first electrode and the second electrode in appropriate shapes and arrangements, divergence and focusing of the electron beam can be achieved. It is possible to create the required electric field that acts.

Therefore, by configuring the picture tube as described above, the electron beam emitted from the electron gun is deflected by the deflection yoke, and then the multipole electric field generated by the first electrode and the second electrode is generated. Due to the action, the raster distortion generated when the electron beam is deflected only by the deflection yoke can be removed by the multipole electric field formed by the first electrode and the second electrode.

By forming an electric field having a diverging action at least in the horizontal direction, the diverging action of the multipole electric field is added to the deflection amount of the horizontal deflection magnetic field of the deflection yoke,
The deflection sensitivity in the horizontal direction can be increased, whereby the power consumption of the deflection yoke can be reduced, and the wide-angle deflection and depth of the picture tube can be shortened.

[Brief description of drawings]

FIG. 1 is a front view showing a cross section of the configuration of a color picture tube according to a first embodiment of the present invention.

FIG. 2 is a side view showing the configuration of the same color picture tube in section.

FIG. 3 is a sectional view taken along line III-III of the color picture tube shown in FIG.

FIG. 4 is a raster diagram for explaining the operation of a quadrupole lens formed by the first and second electrodes.

FIG. 5 is a cross-sectional view showing the main configuration of a color picture tube of Embodiment 2 of the present invention.

FIG. 6 is a view for explaining the action of an octupole lens formed by the first and second electrodes.

FIG. 7 is a raster diagram for explaining the operation of the octupole lens formed by the first and second electrodes.

FIG. 8 is a plan view showing a cross section of the configuration of a conventional color picture tube.

FIG. 9 is a diagram showing raster distortion of a conventional color picture tube.

[Explanation of symbols]

 1 ... Panel 2 ... Funnel 3 ... Phosphor screen 6 ... Neck 7G ... Center beams 7B, 7R ... Pair of side beams 8 ... Electron gun 10 ... Deflection yoke 20a ... First electrode 20b ... Second electrode 21a ... First anode terminal 21b ... Second anode terminal 26 ... Quadrupole lens

Claims (3)

[Claims] 1. A phosphor screen formed on an inner surface of a panel of an envelope including a panel and a funnel, an electron gun arranged in a neck of the funnel, and an electron gun mounted on an outer side of the funnel. A deflection yoke that generates a horizontal deflection magnetic field that horizontally deflects the emitted electron beam and a vertical deflection magnetic field that vertically deflects the emitted electron beam, and the outer portion between the phosphor screen and the electron beam emission end of the electron gun. A multipole electric field generating electrode including a first electrode radially provided inside the envelope and a second electrode to which a voltage higher than a voltage applied to the first electrode is applied. A picture tube that does. 2. A phosphor screen formed on an inner surface of a panel of an envelope composed of a panel and a funnel, an electron gun arranged in a neck of the funnel, and an electron gun mounted on an outer side of the funnel, A deflection yoke that generates a horizontal deflection magnetic field that horizontally deflects the emitted electron beam and a vertical deflection magnetic field that vertically deflects the emitted electron beam, and the outer portion between the phosphor screen and the electron beam emission end of the electron gun. A quadrupole element including a first electrode provided inside the envelope in a horizontal direction and a second electrode provided in a vertical direction opposite to the first electrode and applied with a voltage lower than a voltage applied to the first electrode. A picture tube comprising an electric field generating electrode. 3. A phosphor screen formed on an inner surface of a panel of an envelope including a panel and a funnel, an electron gun disposed inside a neck of the funnel, and an electron gun mounted outside the funnel, A deflection yoke that generates a horizontal deflection magnetic field that horizontally deflects the emitted electron beam and a vertical deflection magnetic field that vertically deflects the emitted electron beam, and the outer portion between the phosphor screen and the electron beam emission end of the electron gun. From a first electrode provided inside the envelope in a horizontal and vertical direction and a second electrode provided in a diagonal direction opposite to each other and to which a voltage lower than a voltage applied to the first electrode is applied. And an octopole electric field generating electrode.