JP2000200560A - Color cathode ray tube with in-line type electron gun - Google Patents

Abstract

(57) [Problem] To provide a color cathode ray tube equipped with an in-line type electron gun capable of strongly shaping the shape of an incident electron beam of a latter-stage electrostatic quadrupole lens and obtaining good and uniform focus over the entire phosphor screen. I do. A phosphor screen, a shadow mask, a deflection yoke,
Equipped with an in-line type electron gun, etc.
Cathode 13, control electrode 14, accelerating electrode 15, multiple split focusing electrode 16
-21, an anode 22, a first focusing voltage is applied to the divided focusing electrodes 16 and 20, and a second focusing voltage is applied to the divided focusing electrodes 17, 19 and 21.
Adjacently arranged divided focusing electrodes to which the first focusing voltage is applied and divided focusing electrodes 16-17, 19-20, 20- to which the second focusing voltage is applied.
A pre-electrostatic quadrupole lens, a pre-electrostatic quadrupole lens, and a post-electrostatic quadrupole lens are formed in this order between 21 and three electrons are generated when the difference voltage between the first and second focusing voltages increases. The pre-electrostatic quadrupole lens and the pre-electrostatic quadrupole lens have the effect of increasing the horizontal divergence and the vertical focusing power on the beam. Strong focusing force in the direction,
The effect of increasing the vertical diverging force is shown.

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 having an in-line type electron gun, and more particularly, to a three-dimensional electron beam radiated from an in-line type electron gun to a phosphor screen to form a fluorescent tube. The present invention relates to a color cathode ray tube having an in-line type electron gun with good and uniform focus characteristics over the entire light plane.

[0002]

2. Description of the Related Art Conventionally, a color cathode ray tube equipped with an in-line type electron gun has a fluorescent surface formed on an inner surface of a face plate of a panel on which three electron beams are projected and a fluorescent surface arranged inside the panel portion. A shadow mask having a large number of electron beam passage holes arranged so as to face the light surface, a deflection yoke mounted on the outer periphery of the funnel portion and sequentially scanning and deflecting the projection positions of the three electron beams on the fluorescent surface; And an in-line type electron gun that is housed in the neck and generates three electron beams.

In this case, the in-line type electron gun has three cathodes for generating electron beams separately, a control electrode, an accelerating electrode, a focusing electrode composed of a plurality of divided focusing electrodes, an anode, A control electrode, an accelerating electrode, a plurality of divided focusing electrodes, an anode, and a shield cup are sequentially arranged on the fluorescent surface side of the three cathodes along the electron beam projection path.

FIG. 5 is a cross-sectional view showing an example of a configuration of a main part of a known in-line type electron gun, and is a vertical cross-sectional view of an axial center portion of the in-line type electron gun. This is disclosed in Japanese Unexamined Patent Publication No. Hei 4-43532.

In FIG. 5, reference numeral 41 denotes a center cathode;
Is a control electrode, 43 is an accelerating electrode, 44 is a first divided focusing electrode, 45 is a second divided focusing electrode, 46 is a third divided focusing electrode, 47 is a fourth divided focusing electrode, 48 is an anode, 49 is a shield cup, 50 is a plate-like electrode arranged inside the third divided focusing electrode 46; 51 is a pair of plate-like auxiliary electrodes that sandwich the center electron beam from the vertical direction and extend in the horizontal direction;
52 is a first internal electrode disposed in the fourth divided focusing electrode 47, and 53 is a second internal electrode disposed in the anode 48.

A center cathode 41 (actually, in an in-line type electron gun, there are two side cathodes for generating two side electron beams in addition to the center cathode 41 for generating a center electron beam. In FIG. 5, all components related to the two side electron beams are not shown.) On the fluorescent surface side, a plate-shaped control electrode 42, a plate-shaped acceleration electrode 43, and a tubular first electrode are provided. Split focusing electrode 44, cylindrical second split focusing electrode 45, cylindrical third split focusing electrode 4
6. A cylindrical fourth divided focusing electrode 47 and a cylindrical anode 48 are sequentially arranged at predetermined intervals, respectively.
A cylindrical shield cup 49 is joined and disposed on the fluorescent surface side.

A plate-shaped electrode 50 is provided inside the third divided focusing electrode 46 so as to face the fourth divided focusing electrode 47, and a surface of the fourth divided focusing electrode 47 facing the third divided focusing electrode 46. On the side, a pair of plate-like auxiliary electrodes 5 arranged in parallel in the horizontal direction so as to sandwich the center electron beam from the vertical direction
1 is provided. Further, a first internal electrode 52 is disposed in the fourth divided focusing electrode 47, and a first internal electrode 52 is disposed in the anode 48.
The second internal electrode 53 is disposed.

A fixed focusing voltage Vf1 is applied to the first divided focusing electrode 44 and the third divided focusing electrode 46, and the second divided focusing electrode 45 and the fourth divided focusing electrode 47 correspond to the amount of electron beam deflection. Dynamic voltage Vd1
Is applied.

In this case, the first divided focusing electrode 44, the second divided focusing electrode 45, and the third divided focusing electrode 46 constitute an electrostatic quadrupole lens for correcting field curvature (previous stage electrostatic quadrupole lens). The opposed surfaces of the third divided focusing electrode 46 and the fourth divided focusing electrode 47 constitute an astigmatism correcting electrostatic quadrupole lens (later stage electrostatic quadrupole lens).

The known in-line type electron gun disclosed in Japanese Patent Application Laid-Open No. 4-43532 having the above-mentioned configuration operates as follows.

Thermions emitted from the center cathode 41 heated by a heater (not shown) are
Is attracted and accelerated toward the control electrode 42 by the positive voltage applied to the center electrode to form a center electron beam. Although not shown, both side electron beams are formed similarly to the center electron beam. The three electron beams pass through the corresponding electron beam openings in the control electrode 42 and then
After passing through the opening of the corresponding electron beam of the accelerating electrode 43, it is supplied to the first divided focusing electrode 44. At this time, 3
When the electron beam passes through the electron beam openings of the first divided focusing electrode 44, the second divided focusing electrode 45, and the third divided focusing electrode 46, the first divided focusing electrode 44 and the second divided focusing electrode By the electrostatic quadrupole lens for correcting the field curvature formed by the 45 and the third divided focusing electrode 46, the lens is slightly converged and the field curvature is corrected. Further, the three electron beams are supplied to the third divided focusing electrode 46 and the fourth divided focusing electrode 46.
When passing through each electron beam opening of the divided focusing electrode 47, a large astigmatism correcting electrostatic quadrupole lens formed between the third divided focusing electrode 46 and the fourth divided focusing electrode 47 is used. In addition to the focusing effect, the astigmatism is corrected. Thereafter, the three electron beams are applied to the anode 48,
It is accelerated by the shield cup 49 and projected from the in-line type electron gun toward the phosphor screen. Next, the three electron beams are scanned and deflected in a predetermined direction by the deflection yoke, pass through the electron beam passage holes of the shadow mask, and form a precisely focused projection spot on the fluorescent screen.

[0012]

In general, an in-line type electron gun used for a color cathode ray tube such as a television picture tube or a display tube has a good focus over the whole area on a phosphor screen and a high resolution. It is known that it is necessary to appropriately control the spot shape of the electron beam spot projected on the fluorescent screen in accordance with the magnitude of the electron beam deflection in order to obtain.

By the way, in such a general-purpose in-line type electron gun, an electron beam is affected by deflection aberration, or is incident on a subsequent-stage electrostatic quadrupole lens or the like in synchronization with the amount of deflection of the electron beam. Since the cross-sectional shape of the beam changes, it is difficult to achieve good and uniform focus over the entire area on the phosphor screen.

In order to overcome such difficulties, in the in-line type electron gun disclosed in Japanese Patent Application Laid-Open No. 4-43532, the opposing surface of the third divided focusing electrode 46 and the fourth divided focusing electrode 47 is described. An electrostatic quadrupole lens for correcting astigmatism (later stage electrostatic quadrupole lens) is formed on the optical axis, and an image is formed by the first divided focusing electrode 44, the second divided focusing electrode 45, and the third divided focusing electrode 46. An electrostatic quadrupole lens for surface curvature correction (previous stage electrostatic quadrupole lens) is formed.

The in-line type electron gun disclosed in Japanese Patent Application Laid-Open No. 4-43532 having the above-described configuration has an arrangement in which an electrostatic quadrupole lens for correcting astigmatism (later-stage electrostatic quadrupole lens) is provided. As the deflection amount of the beam increases, the cross-sectional shape of the three electron beams incident on the main focusing lens becomes longer. However, when the three electron beams pass through the deflection yoke, the deflection aberration in the deflection yoke is reduced. Since the cross-sectional shape of the electron beam becomes long horizontally due to the influence of the deflecting magnetic field, the spot shapes of the three electron beams when they reach the phosphor screen become closer to the periphery of the phosphor screen. It will be horizontally long.

For this reason, the in-line type electron gun disclosed in Japanese Patent Application Laid-Open No. 4-43532 has a field curvature in front of an electrostatic quadrupole lens for correcting astigmatism (later electrostatic quadrupole lens). Correction electrostatic quadrupole lens (previous stage electrostatic quadrupole lens)
The electrostatic quadrupole lens for correcting astigmatism and the electrostatic quadrupole lens for correcting field curvature cooperate to correct the influence of a deflection magnetic field having a deflection aberration in a deflection yoke, and to provide a fluorescent lamp. A good focus is achieved over the entire area of the fluorescent screen by preventing the formation of a horizontally elongated spot of the electron beam at the periphery of the light plane.

However, even in the in-line type electron gun disclosed in Japanese Patent Application Laid-Open No. 4-43532, it is possible to achieve better focus over the entire fluorescent surface as compared with the in-line type electron gun before that. However, considering that the demand for high-definition, high-resolution images has been increasing more and more recently, the in-line type electron gun disclosed in the above-mentioned JP-A-4-43532. Is still insufficient even in a good focus state, and it is necessary to achieve even better focus over the entire phosphor screen.

The present invention has been made in view of such a technical background, and an object of the present invention is to strongly shape the cross-sectional shape of an electron beam incident on a subsequent-stage electrostatic quadrupole lens so that the cross-sectional shape of the electron beam on the fluorescent surface is reduced. To provide a color cathode ray tube having an in-line type electron gun capable of achieving good and uniform focus over the entire region.

[0019]

In order to achieve the above object, a color cathode ray tube provided with an in-line type electron gun according to the present invention comprises a phosphor screen, a shadow mask, a deflection yoke, and an in-line type electron gun. The in-line type electron gun has three cathodes, a control electrode, an accelerating electrode, a plurality of divided focusing electrodes, and an anode, and is fixed to two of the plurality of divided focusing electrodes. The first focusing voltage is applied to the three divided focusing electrodes in accordance with the amount of electron beam deflection, and the second focusing voltage is applied, and the divided focusing electrode to which the first focusing voltage is applied and the second focusing voltage are applied. Between the split focusing electrodes,
A front electrostatic quadrupole lens, a front electrostatic quadrupole lens, and a rear electrostatic quadrupole lens are sequentially formed, and a front electrostatic quadrupole lens and a front electrostatic quadrupole for three electron beams are formed. Means are provided for reversing the focusing and diverging action of the polar lens and the same action of the subsequent electrostatic quadrupole lens.

According to the above-mentioned means, when the difference voltage between the first focusing voltage and the second focusing voltage in the in-line type electron gun increases, the latter-stage electrostatic quadrupole lens can react with three electron beams. While it has the effect of increasing the horizontal (or vertical) focusing power and the vertical (or horizontal) divergence, the front electrostatic quadrupole lens and the preceding electrostatic quadrupole lens Has the effect of increasing the horizontal (or vertical) diverging force and the vertical (or horizontal) focusing power, contrary to the above-described operation of the subsequent electrostatic quadrupole lens. The cross-sectional shape of the electron beam incident on the electrostatic quadrupole lens can be strongly shaped by the two front electrostatic quadrupole lenses and the front electrostatic quadrupole lens, and the color cathode ray tube Good and uniform focus over the entire phosphor screen There can be achieved.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In one embodiment of the present invention, a color cathode ray tube provided with an in-line type electron gun has at least a fluorescent surface formed on the inner face of a face plate of a panel and a fluorescent surface inside the panel. A shadow mask disposed opposite to the surface, a deflection yoke mounted on the outer periphery of the funnel portion, and an in-line type electron gun housed in the neck portion, the in-line type electron gun has three cathodes, a control electrode and , An accelerating electrode, a plurality of divided focusing electrodes, and an anode, a first focusing voltage of a constant voltage applied to two of the plurality of divided focusing electrodes, and a constant voltage applied to the three divided focusing electrodes. And a second focusing voltage obtained by applying a dynamic voltage corresponding to the amount of electron beam deflection, and a divided focusing electrode and a second focusing voltage applied adjacent to each other and having a first focusing voltage applied thereto. A pre-electrostatic quadrupole lens, a pre-electrostatic quadrupole lens, and a post-electrostatic quadrupole lens are formed between the split focusing electrodes in order from the cathode side, and a first focusing voltage and a second focusing voltage are formed. When the difference voltage increases, the pre-electrostatic quadrupole lens and the pre-electrostatic quadrupole lens increase the focusing power in either the horizontal direction or the vertical direction with respect to the three electron beams. And increase the diverging force in the other direction,
The post-stage electrostatic quadrupole lens strengthens the diverging force in one direction,
In addition, the focusing force in the other direction is increased.

In another embodiment of the present invention, a color cathode-ray tube provided with an in-line type electron gun is configured such that one of the plurality of divided focusing electrodes to which a first focusing voltage is applied is connected to the cathode side divided focusing electrode. An electrode and an anode-side split focusing electrode are divided into two, a second focusing voltage is applied to the cathode-side split focusing electrode, a first focusing voltage is applied to the anode-side split focusing electrode, and the cathode-side split focusing electrode and the anode-side split focusing electrode are applied. An electrostatic quadrupole lens for field curvature correction is formed between the divided focusing electrodes, and when a difference voltage between the first focusing voltage and the second focusing voltage increases, the electrostatic quadrupole lens for field curvature correction is formed. The polar lens enhances the focusing power of the three electron beams in both the horizontal and vertical directions.

According to these embodiments of the present invention, among the plurality of divided focusing electrodes in the in-line type electron gun,
One divided focusing electrode to which the first focusing voltage is applied is divided into two into a cathode-side divided focusing electrode and an anode-side divided focusing electrode, and a second focusing voltage is applied to the cathode-side divided focusing electrode. A pre-electrostatic quadrupole lens, a pre-electrostatic quadrupole lens, and a post-electrostatic quadrupole lens are provided between the adjacent divided focusing electrodes to which the first focusing voltage is applied and the divided focusing electrodes to which the second focusing voltage is applied. Is to be formed respectively,
When the difference voltage between the first focusing voltage and the second focusing voltage supplied to the in-line type electron gun increases, the subsequent electrostatic quadrupole lens horizontally (or vertically) shifts the three electron beams. Direction) and the divergent force in the vertical (or horizontal) direction, while the front electrostatic quadrupole lens and the front electrostatic quadrupole lens Contrary to the action of the electrostatic quadrupole lens, the diverging force in the horizontal direction (or the vertical direction) and the focusing force in the vertical direction (or the horizontal direction) are increased for three electron beams. The three electrodes that are incident on the subsequent electrostatic quadrupole lens without being limited by the length of the divided focusing electrodes that form the front electrostatic quadrupole lens or the previous electrostatic quadrupole lens. Cross-sectional shape of the electron beam of the pre-electrostatic quadrupole lens and It is possible to strongly shaped by people, it is possible to achieve a good and uniform focus over the entire area on the fluorescent screen of the color cathode ray tube.

[0024]

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

FIG. 1 is a sectional view showing a schematic structure of an embodiment of a color cathode ray tube according to the present invention.

In FIG. 1, 1 is a panel portion, 1F is a face plate, 2 is a neck portion, 3 is a funnel portion, 4 is a fluorescent surface, 5 is a shadow mask, 6 is an internal magnetic shield,
7 is a deflection yoke, 8 is a purity adjustment magnet, 9 is a center beam static convergence adjustment magnet, 10 is a side beam static convergence adjustment magnet, 11 is an in-line type electron gun, 12
Is an electron beam.

The vacuum envelope (glass bulb) constituting the color cathode ray tube comprises a panel section 1 having a substantially rectangular face plate 1F and an in-line type electron gun 11
And a substantially funnel-shaped funnel 3 connecting the panel 1 and the neck 2 to each other. A fluorescent surface 4 is formed on the inner surface of the panel 1 face plate 1F, and a shadow mask 5 having a number of electron beam passage holes (not shown) is fixedly disposed inside the panel 1 so as to face the fluorescent surface 4. ing. An internal magnetic shield 6 is arranged inside a portion of the funnel 3 near the panel 1, and a deflection yoke 7 is mounted on an outer periphery of a portion of the funnel 3 near the neck 2. Outside the neck portion 2, a purity adjusting magnet 8, a center beam static convergence adjusting magnet 9, and a side beam static convergence adjusting magnet 10 are arranged side by side. The three electron beams 12 (only one is shown in FIG. 1) emitted from the in-line type electron gun 11 are deflected and scanned in the deflection yoke 7 in the horizontal and vertical directions, respectively. The light impinges on the fluorescent screen 4 through the electron beam passage hole.

In this case, the image display operation of the color cathode ray tube of the present embodiment is almost the same as the image display operation of this type of known color cathode ray tube, and such operation is well known in the art. Therefore, the description of the image display operation in the color cathode ray tube of the present embodiment will be omitted.

Next, FIG. 2 is a sectional view showing a main part of a first embodiment of an in-line type electron gun 11 used in the color cathode ray tube shown in FIG. FIG. 4 shows a cross-sectional view of a vertical plane along the center.

In FIG. 2, 13 is a center cathode, 14
Is a control electrode (first electrode), 15 is an acceleration electrode (second electrode), 16 is a first divided focusing electrode (3-1 electrode), 17
Represents a second divided focusing electrode (third second electrode), 18 represents a third divided focusing electrode (fourth electrode), and 19 represents a fourth divided focusing electrode (fifth electrode).
-1 electrode), 20 is the fifth divided focusing electrode (the 5-2 electrode), 21 is the sixth divided focusing electrode (the 5-3 electrode), 22
Is an anode, 23 is a shield cup, 24 is a first horizontal plate-shaped auxiliary electrode, 25 is a first vertical plate-shaped auxiliary electrode, 26 is a second vertical plate-shaped auxiliary electrode, 27 is a second horizontal plate-shaped auxiliary electrode, 28 is The third vertical plate-like auxiliary electrode 29 is a third horizontal plate-like auxiliary electrode,
0 is a first internal electrode, and 31 is a second internal electrode.

The center cathode 13 (actually, in the in-line type electron gun of this embodiment, in addition to the center cathode 13 for generating the center electron beam, two side cathodes for generating two side electron beams However, in FIG. 2, all components related to the two side electron beams are not shown.) On the electron beam projecting side (fluorescent surface side), a plate-like control electrode is provided. 14, a plate-shaped acceleration electrode 15, a cylindrical first divided and focused electrode 16, a cylindrical second divided and focused electrode 17, a plate-shaped third divided and focused electrode 18, a cylindrical fourth divided and focused electrode 19, a tube A fifth cylindrical focusing electrode 20, a fifth cylindrical focusing electrode 21, and a cylindrical anode 22 are sequentially arranged at predetermined intervals, and a cylindrical shield is provided on the fluorescent surface side of the cylindrical anode 22. The cup 23 is joined and arranged.

On the side of the first divided focusing electrode 16 facing the second divided focusing electrode 17, a first horizontal plate-shaped auxiliary electrode 24 sandwiching the center electron beam from the vertical direction and extending in parallel with the horizontal direction. A first vertical plate-shaped auxiliary electrode 25 extending in parallel with the center electron beam from the horizontal direction and extending in the vertical direction is provided on the side of the second divided focusing electrode 17 facing the first divided focusing electrode 16. Is provided. On the side of the fourth divided focusing electrode 19 facing the fifth divided focusing electrode 20,
A second vertical plate-shaped auxiliary electrode 26 extending in parallel with the center electron beam from the horizontal direction and extending in the vertical direction is provided, and a center of the fifth divided focusing electrode 20 facing the fourth divided focusing electrode 19 is provided at the center. A second horizontal plate-like auxiliary electrode 27 is provided which sandwiches the electron beam from the vertical direction and extends in parallel with the horizontal direction. On the side of the fifth divided focusing electrode 20 facing the sixth divided focusing electrode 21, there is provided a third vertical plate-like auxiliary electrode 28 which sandwiches the center electron beam from the horizontal direction and extends in parallel with the vertical direction. A third horizontal plate-shaped auxiliary electrode 29 is provided on the side of the six-division focusing electrode 21 facing the fifth divisional focusing electrode 20 so as to sandwich the center electron beam from the vertical direction and extend parallel to the horizontal direction.

In the in-line type electron gun shown in FIG. 2, the first, second, and third horizontal plate-shaped auxiliary electrodes 24, 2
Reference numerals 7 and 29 show the configuration in which the center electron beam is sandwiched in the horizontal direction. However, actually, both side electron beams are extended so as to be sandwiched in the horizontal direction.
In addition, the first, second, and third vertical plate-like auxiliary electrodes 25, 26,
Although reference numeral 28 is shown as sandwiching the center electron beam from the vertical direction, another vertical plate-like auxiliary electrode (not shown) is arranged so that both side electron beams are similarly sandwiched from the vertical direction. Have been.

Further, the first divided focusing electrode 21 has the first
An internal electrode 30 is arranged, and a second internal electrode 31 is arranged inside the anode 22.

In this case, a first focusing voltage Vf1 consisting of a constant voltage V1 is applied to the first divided focusing electrode 16 and the fifth divided focusing electrode 20, respectively.
A second focusing voltage Vf2, which is a sum of a constant voltage V2 and a dynamic voltage Vd that changes according to the amount of electron beam deflection, is applied to the fourth divided focusing electrode 19 and the sixth divided focusing electrode 21.

FIG. 4 is a characteristic diagram showing the states of the first focusing voltage and the second focusing voltage supplied to the in-line type electron guns of the first embodiment and a second embodiment described later.

In FIG. 4, the vertical axis represents the voltage expressed in V, and the horizontal axis represents the electron beam deflection amount, that is, the electron beam scanning position on the fluorescent screen.

As shown in FIG. 4, the first focusing voltage Vf
1 is a constant voltage value irrespective of the amount of electron beam deflection, whereas the second focusing voltage Vf2 is a constant voltage of the electron beam deflection amount (electron beam scanning position on the fluorescent screen).
Is a voltage value on which a dynamic voltage that changes in accordance with the above is superimposed.

The in-line type electron gun of the first embodiment having the above configuration operates as follows.

When the center cathode 13 is heated by a heater (not shown), thermoelectrons are emitted from the electron emission surface of the center cathode 13 and these thermoelectrons are emitted from the accelerating electrode 1.
After being attracted to the control electrode 14 side by the positive voltage applied to 5, the electron beam is accelerated to form a center electron beam.
Although not shown, both side electron beams are formed similarly to the center electron beam. The three electron beams pass through the corresponding electron beam openings of the control electrode 14, then pass through the corresponding electron beam openings of the acceleration electrode 15, and are projected toward the first split focusing electrode 16. You. At this time, when the three electron beams pass through the respective electron beam openings of the first divided focusing electrode 16 and the second divided focusing electrode 17, the first divided focusing electrode 16 and the second divided focusing electrode 17
And a diverging effect in the horizontal direction and a focusing effect in the vertical direction by the pre-electrostatic quadrupole lens formed between them. Next, the three electron beams pass through the electron beam aperture of the third divided focusing electrode 18 and are projected in the direction of the fourth divided focusing electrode 19.
When passing through each electron beam opening of the split focusing electrode 20, the front electrostatic quadrupole lens formed between the fourth split focusing electrode 19 and the fifth split focusing electrode 20 causes Similar to the action received by the quadrupole lens, the diverging action is given in the horizontal direction and the focusing action is given in the vertical direction.
The light is projected on the divided focusing electrode 21. Subsequently, the three electron beams are applied to the fifth divided focusing electrode 20 and the sixth divided focusing electrode 21.
When passing through the respective electron beam apertures, the front electrostatic quadrupole lens and the rear electrostatic quadrupole lens formed between the fifth divided focusing electrode 20 and the sixth divided focusing electrode 21 It has the opposite effect to that performed by the pre-electrostatic quadrupole lens, that is, a strong focusing effect in the horizontal direction and a strong diverging effect in the vertical direction. After that, the three electron beams
The light passes through the electron beam aperture of the sixth divided focusing electrode 21, is accelerated by the high voltage applied to the anode 22 and the shield cup 23, and is projected from the opening of the shield cup 23 toward the fluorescent surface.

As described above, in the in-line type electron gun of the first embodiment, in the latter-stage electrostatic quadrupole lens, a strong focusing action is applied to three electron beams in the horizontal direction, and a strong diverging action is provided in the vertical direction. Prior to the addition, the three electron beams incident on the subsequent electrostatic quadrupole lens are horizontally moved by two lenses, the front electrostatic quadrupole lens and the front electrostatic quadrupole lens. And the electron beam is focused in the vertical direction to shape the cross-sectional shape of the electron beam. Therefore, the entire length of the first divided focusing electrode 16 and the second divided focusing electrode 17 or the fourth divided focusing electrode Without significantly increasing the total length of the electrode 19 and the fifth divided focusing electrode 20,
A strong electron beam shaping function can be provided, and good and uniform focus characteristics can be obtained over the entire fluorescent surface of the color cathode ray tube.

FIG. 3 is a cross-sectional view showing a main part of a second embodiment of the in-line type electron gun used in the color cathode ray tube shown in FIG. FIG. 3 shows a cross-sectional view of a vertical plane along the line A.

In FIG. 3, reference numeral 20 (1) denotes a cathode-side fifth divided focusing electrode, and 20 (2) denotes an anode-side fifth divided focusing electrode.
2 is a fourth vertical plate-shaped auxiliary electrode, 33 is a fourth horizontal plate-shaped auxiliary electrode, 34 is a fifth horizontal plate-shaped auxiliary electrode, 35 is a fifth vertical plate-shaped auxiliary electrode, 36 is a sixth horizontal plate-shaped auxiliary electrode, Reference numeral 37 denotes a sixth vertical plate-like auxiliary electrode, and the same components as those shown in FIG. 2 are denoted by the same reference numerals.

A plate-like control electrode 14 and a plate-like control electrode 14 are provided on the electron beam projection side (fluorescent surface side) of the center cathode 13 (actually, the arrangement of the two side cathodes is omitted). The accelerating electrode 15, the cylindrical first divided focusing electrode 16, the cylindrical second divided focusing electrode 17, the plate-shaped third divided focusing electrode 18, the cylindrical fourth divided focused electrode 19, and the cylindrical cathode side Five-divided focusing electrode 20 (1), cylindrical anode-side fifth divided focusing electrode 20
(2), cylindrical sixth divided focusing electrode 21, cylindrical anode 22
Are sequentially arranged at predetermined intervals, and a cylindrical shield cup 23 is joined to the fluorescent surface side of the cylindrical anode 22.

On the side of the first divided focusing electrode 16 facing the second divided focusing electrode 17, a fourth vertical plate-like auxiliary electrode 32 sandwiching the center electron beam from the horizontal direction and extending in parallel in the vertical direction. On the side of the second divided focusing electrode 17 facing the first divided focusing electrode 16, a fourth horizontal plate-shaped auxiliary electrode 33 sandwiching the center electron beam from the vertical direction and extending parallel to the horizontal direction is provided. Is provided. On the side of the fourth divided focusing electrode 19 facing the cathode-side fifth divided focusing electrode 20 (1), the center electron beam is sandwiched from the vertical direction,
A fifth horizontal plate-like auxiliary electrode 34 extending in parallel with the horizontal direction is provided, and the center electron beam is horizontally applied to a surface of the cathode-side fifth divided focusing electrode 20 (1) facing the fourth divided focusing electrode 19. A fifth vertical plate-like auxiliary electrode 35 extending in parallel with the vertical direction and sandwiched from the direction is provided. Anode-side fifth divided focusing electrode 20 of cathode-side fifth divided focusing electrode 20 (1)
On the side opposite to (2), a sixth horizontal plate-shaped auxiliary electrode 36 that sandwiches the center electron beam from the vertical direction and extends in parallel with the horizontal direction is provided.
A sixth vertical plate-like auxiliary electrode 37 extending in parallel with the center electron beam from the horizontal direction and extending in the vertical direction is provided on the side of the surface (2) facing the cathode-side fifth divided focusing electrode 20 (1). ing.

In the in-line type electron gun shown in FIG. 3, the fourth, fifth, and sixth horizontal plate-shaped auxiliary electrodes 33, 3
Reference numerals 4 and 36 are shown as sandwiching the center electron beam from the horizontal direction. Actually, both side electron beams are extended so as to sandwich the center electron beam from the horizontal direction.
In addition, the fourth, fifth, and sixth vertical plate-shaped auxiliary electrodes 32, 35,
Reference numeral 37 denotes a configuration in which the center electron beam is sandwiched from the vertical direction. However, another vertical plate-like auxiliary electrode (not shown) is arranged so that both side electron beams are also sandwiched in the vertical direction. Have been.

Further, the first divided focusing electrode 21 has the first
An internal electrode 30 is provided, and a second internal electrode 31 is provided in the anode 22. These components are the same as those in the first embodiment.

In this case, the first divided focusing electrode 16, the fourth divided focusing electrode 19, and the anode-side fifth divided focusing electrode 20 (2) are respectively supplied to the fixed first focusing voltage Vf shown in FIG.
1 is applied to the second divided focusing electrode 17, the cathode-side fifth divided focusing electrode 20 (1), and the sixth divided focusing electrode 21, respectively, and the varying second focusing voltage Vf 2 shown in FIG. ing.

The operation of the in-line type electron gun according to the second embodiment having the above-described configuration is as follows.

The thermoelectrons emitted from the center cathode 13 are attracted and accelerated toward the control electrode 14 by a positive voltage applied to the accelerating electrode 15 to form a center electron beam. In addition, both side electron beams are formed similarly to the center electron beam. The three electron beams are applied to the control electrode 1
4 and then pass through the corresponding electron beam aperture of the acceleration electrode 15 and are projected toward the first split focusing electrode 16. Next, the three electron beams are applied to the first divided focusing electrode 16 and the second divided focusing electrode 1.
7, when passing through the respective electron beam apertures, the front electrostatic quadrupole lens formed between the first divided focusing electrode 16 and the second divided focusing electrode 17 causes a horizontal diverging effect. And is subject to a vertical focusing action. Next, the three electron beams pass through the electron beam aperture of the third divided focusing electrode 18 and are projected in the direction of the fourth divided focusing electrode 19. Focusing electrode 2
When passing through each electron beam aperture of 0 (1), the former electrostatic quadrupole lens formed between the fourth divided focusing electrode 19 and the cathode-side fifth divided focusing electrode 20 (1) Similar to the action received by the front electrostatic quadrupole lens, it undergoes a horizontal divergence action and a vertical focusing action. Subsequently, the three electron beams are applied to the fifth split focusing electrode 2 on the cathode side.
0 (1) and the anode-side fifth split focusing electrode 20 (1) and the anode-side fifth split focusing electrode 20 (2) when passing through the respective electron beam openings of the anode-side fifth split focusing electrode 20 (2). ), The action opposite to that performed by the front electrostatic quadrupole lens or the preceding electrostatic quadrupole lens, that is, strong horizontal focusing action. And a strong vertical divergence. Next, when the three electron beams pass through the electron beam openings of the anode-side fifth split focusing electrode 20 (2) and the sixth split focusing electrode 21, the anode-side fifth split focusing electrode 20 (2). A strong focusing action in both the horizontal direction and the vertical direction is received by the electrostatic quadrupole lens for correcting the curvature of field formed between the lens and the sixth divided focusing electrode 21. After that, the three electron beams
After passing through the electron beam aperture of the split focusing electrode 21, the anode 2
2 and is accelerated by the high voltage applied to the shield cup 23, and is projected from the opening of the shield cup 23 toward the fluorescent screen.

As described above, in the in-line type electron gun of the second embodiment, in the latter-stage electrostatic quadrupole lens, a strong horizontal focusing action and a strong vertical diverging action are applied to the three electron beams in the horizontal direction. Prior to addition, the three electron beams incident on the subsequent electrostatic quadrupole lens are diverged in the horizontal direction by two lenses, the front electrostatic quadrupole lens and the front electrostatic quadrupole lens. The electron beam cross-sectional shape is shaped by applying an action and a focusing action in the vertical direction, and further, an electrostatic quadrupole lens for field curvature correction is used to convert the three electron beams. Since the focusing action is applied in both the horizontal and vertical directions, the first
As in the embodiment, a strong electron beam can be obtained without significantly increasing the total length of the first divided focusing electrode 16 and the second divided focusing electrode 17 or the entire length of the fourth divided focusing electrode 19 and the fifth divided focusing electrode 20. In addition to providing a shaping function, the electron beam spot diameter can be reduced, and good and uniform focus characteristics can be obtained over the entire fluorescent screen of the color cathode ray tube.

In the first and second embodiments, the latter-stage electrostatic quadrupole lens applies a strong horizontal focusing effect and a strong vertical diverging effect to the three electron beams. On the other hand, an example in which the pre-electrostatic quadrupole lens and the pre-electrostatic quadrupole lens apply a diverging effect in the horizontal direction and a focusing effect in the vertical direction to the three electron beams. Although described above, the focusing and diverging directions by these electrostatic quadrupole lenses in the present invention are not limited to the above-described example. A strong diverging effect in the direction and a strong focusing effect in the vertical direction, while the front electrostatic quadrupole lens and the front electrostatic quadrupole lens focus the three electron beams in the horizontal direction. Add a divergent effect in the vertical direction It may be.

[0053]

As described above, according to the present invention, the in-line type electron gun is provided with at least three of the front electrostatic quadrupole lens, the front electrostatic quadrupole lens, and the rear electrostatic quadrupole lens. A lens is formed, and when the voltage difference between the first focusing voltage and the second focusing voltage supplied to the in-line type electron gun increases, the three electron beams in the subsequent electrostatic quadrupole lens are
The effect of increasing the focusing force in either the horizontal or vertical direction and the diverging force in the other direction, and the divergence in one direction in the pre-electrostatic quadrupole lens and the pre-electrostatic quadrupole lens Because the force and the effect of strengthening the focusing force in the other direction are used together, the length is limited to the length of the split focusing electrode that forms the front electrostatic quadrupole lens or the previous electrostatic quadrupole lens. Instead, the cross-sectional shape of the three electron beams incident on the rear electrostatic quadrupole lens can be strongly shaped by both the front electrostatic quadrupole lens and the front electrostatic quadrupole lens. Thus, there is an effect that good and uniform focus can be achieved in the entire area on the fluorescent screen of the color cathode ray tube.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a schematic configuration of an embodiment of a color cathode ray tube according to the present invention.

FIG. 2 is a sectional view showing a configuration of a main part of a first embodiment of an in-line type electron gun used in the color cathode ray tube shown in FIG.

FIG. 3 is a sectional view showing a configuration of a main part of a second embodiment of the in-line type electron gun used in the color cathode ray tube shown in FIG.

FIG. 4 is a characteristic diagram showing states of a first focusing voltage and a second focusing voltage supplied to the in-line type electron guns of the first embodiment and the second embodiment.

FIG. 5 is a cross-sectional view showing an example of a main configuration of a color cathode ray tube having a known in-line type electron gun.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Panel part 1F Face plate 2 Neck part 3 Funnel part 4 Fluorescent surface 5 Shadow mask 6 Internal magnetic shield 7 Deflection yoke 8 Purity adjustment magnet 9 Center beam static convergence adjustment magnet 10 Side beam static convergence adjustment magnet 11 In-line type electronic Gun 12 Electron beam 13 Center cathode 14 Control electrode 15 Acceleration electrode 16 First divided focusing electrode 17 Second divided focusing electrode 18 Third divided focusing electrode 19 Fourth divided focusing electrode 20 Fifth divided focusing electrode 21 Sixth divided focusing electrode 22 Anode 23 Shield cup 24 First horizontal plate-shaped auxiliary electrode 25 First vertical plate-shaped auxiliary electrode 26 Second vertical plate-shaped auxiliary electrode 27 Second horizontal plate-shaped auxiliary electrode 28 Third vertical plate-shaped auxiliary electrode 29 Third horizontal plate-shaped Auxiliary electrode 30 First Partial electrode 31 Second internal electrode 32 Fourth vertical plate-shaped auxiliary electrode 33 Fourth horizontal plate-shaped auxiliary electrode 34 Fifth horizontal plate-shaped auxiliary electrode 35 Fifth vertical plate-shaped auxiliary electrode 36 Sixth horizontal plate-shaped auxiliary electrode 37 Sixth Vertical plate-shaped auxiliary electrode

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Shinichi Kato 3300 Hayano, Mobara-shi, Chiba Electronic Device Division, Hitachi, Ltd. (72) Inventor Koichi Miyagawa 3300, Hayano, Mobara-shi, Chiba Electronic Device Business, Hitachi, Ltd. Internal F-term (reference) 5C041 AA03 AA12 AA14 AB07 AC26 AC35 AD02 AD03 AE01

Claims (3)

[Claims] At least a fluorescent surface formed on an inner surface of a face plate of a panel portion, a shadow mask disposed inside the panel portion to face the fluorescent surface, a deflection yoke mounted on an outer periphery of a funnel portion, and a neck. An in-line type electron gun housed in the unit, the in-line type electron gun has three cathodes, a control electrode, an acceleration electrode, a plurality of divided focusing electrodes, and an anode, A first focusing voltage of a constant voltage is applied to two of the divided focusing electrodes, and a second focusing voltage obtained by adding a dynamic voltage corresponding to the amount of electron beam deflection to the fixed voltage is applied to the three divided focusing electrodes. In the color cathode ray tube provided with the in-line type electron gun, the divided focusing electrode applied with the first focusing voltage and the divided focusing electrode applied with the second focusing voltage are arranged adjacent to each other. A front electrostatic quadrupole lens, a front electrostatic quadrupole lens, and a rear electrostatic quadrupole lens are formed in order from the cathode side, and the difference voltage between the first focusing voltage and the second focusing voltage increases. When doing, for three electron beams,
The pre-electrostatic quadrupole lens and the pre-electrostatic quadrupole lens increase the converging force in one of the horizontal direction and the vertical direction, and increase the diverging force in the other direction. A color cathode ray tube comprising an in-line type electron gun, wherein the electrostatic quadrupole lens increases the diverging force in the one direction and the focusing force in the other direction. 2. The split focusing electrode according to claim 1, wherein the plurality of split focusing electrodes divide the one split focusing electrode to which the first focusing voltage is applied into a cathode split split focusing electrode and an anode split split focusing electrode. A second focusing voltage is applied to the anode-side split focusing electrode, and the first focusing voltage is applied to the anode-side split focusing electrode. A quadrupole lens is formed, and when the difference voltage between the first focusing voltage and the second focusing voltage increases, the electrostatic quadrupole lens for field curvature correction applies the three electron beams to the three electron beams. 2. The color cathode ray tube having an in-line type electron gun according to claim 1, wherein the focusing force in both the horizontal direction and the vertical direction is increased. 3. A fluorescent screen formed at least on an inner surface of a face plate of a panel portion, a shadow mask disposed inside the panel portion so as to face the fluorescent surface, a deflection yoke mounted on an outer periphery of a funnel portion, and a neck. A cathode ray tube including an in-line type electron gun housed in the unit, wherein the in-line type electron gun includes three cathodes, a control electrode, an acceleration electrode, a focusing electrode, and an anode; Comprises: a third electrode disposed adjacent to the acceleration electrode;
A fourth electrode disposed adjacent to the electrode; and a fifth electrode disposed adjacent to the fourth electrode, wherein the third electrode has a plurality of electrodes disposed adjacent to each other. , An electrode to which a first focusing voltage is applied, and an electrode to which a second focusing voltage is applied, wherein the fifth electrode has a plurality of electrodes arranged adjacent to each other, and An electrode to which a first focusing voltage is applied and an electrode to which a second focusing voltage is applied, wherein the second focusing voltage changes to a constant voltage according to the amount of deflection of the electron beam. A voltage is superimposed, and the plurality of third electrodes are a first electrostatic quadrupole between an electrode to which the first focusing voltage is applied and an electrode to which the second focusing voltage is applied. Forming a lens, wherein the plurality of fifth electrodes are connected to the electrode to which the first focusing voltage is applied; A second electrostatic quadrupole lens and a third electrostatic quadrupole lens are formed between the electrodes to which the focusing voltage is applied, and wherein the second electrostatic quadrupole lens is The third electrostatic quadrupole lens is disposed between a second electrostatic quadrupole lens and a third electrostatic quadrupole lens, and the third electrostatic quadrupole lens is arranged between the first focusing voltage and the second electrostatic quadrupole lens. As the potential difference from the focusing voltage increases, the force for converging the electron beam in one direction and the force for diverging the electron beam in another direction perpendicular to the one direction are increased, and the first electrostatic quadrupole is increased. The lens and the second electrostatic quadrupole lens are characterized in that, as the potential difference increases, a force for diverging the electron beam in the one direction and a force for converging the electron beam in the other direction are increased. Color cathode ray tube with in-line type electron gun.