JP2645071B2 - Color picture tube equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a color picture tube apparatus, and in particular, to a method in which three in-line arranged electron beams are formed into a large diameter common to these electron beams. The present invention relates to a color picture tube device having an electron gun focused and focused by an electron lens.

(Prior Art) FIG. 11 shows a horizontal cross section of a general color picture tube device.

In FIG. 1, a color picture tube device 1 includes a face plate 3 having a screen surface 2, and a neck 5 connected to a side surface 3 a of the face plate 3 via a funnel 4.
An electron gun 6 provided inside the neck 5; a deflecting device 7 mounted on the outer wall from the funnel 4 to the neck 5; and a shadow having a large number of apertures 8 provided at predetermined intervals to the screen surface 2. A mask 9, an internal conductive film 10 uniformly applied from the inner wall of the funnel 4 to a part of the neck 5, an external conductive film 11 applied to the outside of the funnel 4, and a part of the funnel 4. And an anode terminal (not shown).

The screen surface 2 is coated with a large number of red-emitting phosphors, green-emitting phosphors, and blue-emitting phosphors in stripes or dots, and the three electron beams BR, BG, and BB emitted from the electron gun 6 Each phosphor selected by the shadow mask 9 is bombarded and emits light.

The electron gun 6 has an electron beam forming unit GE for generating, accelerating and controlling three parallel electron beams BR, BG and BB in an in-line arrangement, and a main electron for focusing and concentrating these electron beams. It has a lens part ML. Then, the three electron beams BR, BG and BB are deflected and scanned over the entire screen by the deflecting device 7 to form a raster.

A method for focusing three electron beams is described in, for example, US Pat.
As shown in US Pat. No. 2,957,106, there is a technique for concentrating an electron beam emitted from a cathode in an inclined manner from the beginning, and as shown in U.S. Pat. Among the three electron beam passing openings provided, there is a technique of concentrating an electron beam by decentering openings on both sides of some electrodes slightly outside of the center axis of the electron gun. Has been adopted. The deflection device basically has a horizontal deflection coil for generating a horizontal deflection magnetic field for deflecting the electron beam in the horizontal direction and a vertical deflection coil for generating a vertical deflection magnetic field for deflecting the electron beam in the vertical direction. ing. In an actual color picture tube device, when the electron beam is deflected, the concentration of the three electron beam spots on the face plate is lost. Therefore, measures are taken to prevent this concentration loss. This is called a convergence-free system, in which the horizontal deflection magnetic field is made into a pincushion type and the vertical deflection magnetic field is made into a barrel type, so that three electron beams are concentrated in the entire self-concentrating magnetic field fluorescent screen. .

As described above, the quality of a color picture tube has been improved by the adoption of many development techniques, but new problems are being highlighted as the tube becomes larger and higher in quality.

That is, there is a problem of the spot diameter of the electron beam on the screen, a problem of distortion of the electron beam spot at the periphery of the screen when the electron beam is deflected, and a problem of convergence on the entire screen.

When the tube becomes large, the distance from the electron gun to the screen surface becomes longer, the electron optical magnification of the electron lens increases, the spot diameter on the screen becomes larger, and the resolution deteriorates. In order to reduce the spot diameter, the performance of an electron gun and an electron lens must be improved.

In general, the main electron lens portion is formed by a plurality of electrodes having openings arranged coaxially and applying a predetermined potential. There are several types of such electrostatic lenses depending on the electrode configuration. Basically, a large-diameter lens with a large electrode aperture is formed, or the distance between the electrodes is increased to achieve a gentle potential. The lens performance can be improved by forming the long focal length lens with the change.

However, the electron gun of a color picture tube is generally enclosed in a neck, which is a thin glass cylinder.
That is, the lens aperture is physically restricted. Also, the distance between the electrodes is limited so that the focused electric field formed between the electrodes is not affected by other unwanted electric fields in the neck.

In particular, when three electron guns are integrated in a delta arrangement or an inline arrangement as in a shadow mask type color picture tube, as described above, the smaller the electron beam interval (Sg), the more the three electron beams are screened. Since there is an advantage that it is easy to concentrate on one point near the entire surface and the deflection power is small, the opening of the electrode must be further reduced in order to reduce the interval between the electron guns.

Therefore, a method is considered in which three electronic lenses arranged on the same plane are completely overlapped to form one large electronic lens, and the large-diameter electronic lens maximizes the performance of the electronic lens. FIG. 12 shows this optically. As shown in the figure, the core of the projected electron beam is small, but the result is still insufficient when viewed as a whole. That is, the beam interval is Sg3
When two parallel electron beams (BR), (BG), and (BB) pass through one common large-diameter electron lens LEL, the center electron beam (BG) is properly focused as shown in FIG. Electron beams (BR) and (BB) are in an over-focused state and an over-concentrated state, and have three beam spots (SPR) and (SP) on the screen (101) without large coma aberration.
G) and (SPB) are far apart and the beams on both sides are distorted.

In order to reduce the coma aberration by adjusting the focusing state of these three electron beams, there is no practical problem if the distance Sg between the three beams with respect to the lens diameter D of the electron lens LEL is reduced to some extent. Sg must be extremely small for the concentrated state of the three beams on the screen, and there is a limit in terms of the mechanical arrangement of the electron beam generator.

Therefore, Japanese Patent Publication No. Sho 49-5951 (U.S. Pat.
In US Pat. No. 4,528,476 and US Pat. No. 4,528,476, as shown in FIG. 13, three electron beams incident on the electron lens LEL are given a tilt angle θ in advance, and the three electron beams are simultaneously emitted from the electron lens LEL. The three beams are focused so as to pass through the central portion, and then the diverging beams are strongly intensified in the opposite direction by the second lens LEL2 (φ
Ii) The beam is deflected so that three beams are concentrated on the screen. As a result, the focusing and concentration of the three electron beams is improved. However, there remains a problem that large deflection aberration or coma aberration occurs in the beams on both sides.

As described above, it is difficult to use a large-diameter electron lens that works commonly for three electron beams, and it is not possible to maximize the performance of the large-diameter electron lens.

(Problems to be Solved by the Invention) As described above, in order to further improve the image performance of the color picture tube display device, the performance of the electron gun is reduced by using a large-diameter electron lens common to the three electron beams. Although it is effective to improve the beam spot diameter on the screen surface, it is effective to improve the performance of the large-diameter electron lens with the conventional technology, and further improve the image performance of the color picture tube device. Had the problem of being difficult. Therefore, in order to further improve the image performance of the color picture tube device, it is desirable to obtain a color picture tube device provided with an electron gun capable of sufficiently exhibiting the performance of a large-diameter electron lens.

The present invention has been made to solve the problems of the prior art, and is an electron gun capable of simultaneously and easily focusing and concentrating each electron beam by a large-diameter electron lens common to three beams. It is another object of the present invention to provide a color picture tube apparatus provided with an electron gun capable of sufficiently exhibiting the performance of the large-diameter electron lens.

[Effects of the Invention] (Means for Solving the Problems) That is, a color picture tube device of the present invention includes an in-line type electron gun unit, a deflection unit, and a screen unit, and deflects an electron beam emitted from the electron gun. In a color picture tube apparatus that deflects and scans vertically and horizontally by a unit, the electron gun unit generates, accelerates, and controls three electron beams, and a main electron that focuses and concentrates the electron beams. The main electron lens section has a large-diameter asymmetric electron lens that acts on three electron beams in common. The asymmetric electron lens has a horizontal aperture that acts on each of the three electron beams. The focusing force is weaker than the vertical focusing force, and the three electron beam axes incident on the asymmetric electron lens are parallel to each other, and the individual electron beams are more perpendicular than the horizontal direction. A color picture tube apparatus, characterized in that the beam diverges strongly direction.

The individual electron beams incident on the asymmetric electron lens are not meant to be beams that are divergent in the horizontal direction. This includes the case of a beam that is convergent in the horizontal direction.

The present invention also provides a color picture tube apparatus comprising an in-line type electron gun unit, a deflecting unit, and a screen unit, wherein a deflection unit scans an electron beam emitted from the electron gun in a vertical direction and a horizontal direction. The unit includes an electron beam forming unit that generates, accelerates, and controls three electron beams, and a main electron lens unit that focuses and concentrates the electron beams. The main electron lens unit includes three electron beams. It has a large-diameter asymmetric electron lens that acts in common. The asymmetric electron lens has a common cylindrical electron lens for three electron beams and a three-electron beam in the lens area of the cylindrical electron lens. It has a non-circular beam passage opening for common passage, and three electron beam axes incident on the asymmetric electron lens are parallel to each other on the electron beam forming portion side of the asymmetric electron lens. There is a color picture tube apparatus characterized by having a forming means for each of the electron beam is diverging beam strongly vertically than horizontally.

(Operation) In the present invention, 3 rays incident on the main electron lens of the electron gun are used.
The beam axes of the book electron beams are parallel to each other, and the individual electron beams are designed to diverge more strongly in the vertical direction than in the horizontal direction.

On the other hand, the main electron lens portion has a large-diameter asymmetric electron lens that acts on three electron beams in common, and this asymmetric electron lens has a horizontal focusing force acting on the electron beam that is higher than a vertical focusing force. Designed to be weak.

When the electron beam as specified above is incident on such a large-diameter asymmetric electron lens portion, the incident beam is subjected to the lens action of the large-diameter asymmetric electron lens, and the three electron beams projected on the screen are concentrated well. Each electron beam has a small diameter and no distortion. Moreover, since the three electron beams pass through the large-diameter lens, the merit of the large-diameter lens can be maximized.

In the present invention, the most preferable concentration and focusing characteristics are obtained when the individual electron beams incident on the main electron lens do not spread in the horizontal direction, that is, when they are substantially parallel.

For comparison with the present invention, those in which the individual electron beams incident on the main electron lens are substantially parallel in the horizontal direction and the vertical direction, and other conditions according to the present invention have poor focusing characteristics.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a cross section of the XZ plane of a part of the screen near the neck of the color picture tube apparatus embodying the present invention, and FIG. 2 shows a cross section of the YZ plane of only the electron gun. .

In FIG. 1 and FIG. 2, the electron gun section (100) arranged in the neck (5) includes a cathode (cathode) K, a first grid G1, a second grid G2, a third grid G3, Fourth grid G4, fifth grid G5, sixth grid G6, seventh grid G7
The electron gun (100) is fixed to a stem pin (113) below the neck.

The cathode K has a heater inside, and generates three electron beams BR, BG, and BB.

Each of the first grid G1 and the second grid G2 has three relatively small beam passage holes corresponding to the three cathodes K, and controls and accelerates an electron beam from the cathode K in this portion. It becomes the electron beam forming unit GE.
Next, the third grid G3, the fourth grid G4, the fifth grid
G5 also has three relatively large beam passage holes corresponding to the three cathodes K.

On the sixth grid G6 side of the fifth grid G5, four electrodes (20) in a direction perpendicular to the in-line arrangement direction (XZ plane),
(21), (22) and (23) are three beam passage holes (52
R), (52G), and (52B) are sandwiched therebetween, and the sixth grid G6 has three electrodes (24) and (25) on the fifth grid G5 side in parallel with the in-line arrangement direction. It is located above and below the beam passage holes (61R), (61G), and (61B).
Four electrodes on the fifth grid G5 side (20), (21), (2
2), (23) and two electrodes (24) on the sixth grid G6 side,
(25) are arranged so as to overlap each other, and when a voltage is applied between the fifth grid G5 and the sixth grid G6, the four electrode plates of the fifth grid G5 and the two electrode plates of the sixth grid G6 And a quadrupole lens is formed between them.

On the fifth grid G5 side of the sixth grid G6, three beam passing holes (61R), (61G) having the same size as the beam passing holes (52R), (52G), and (52B) of the fifth grid G5. ),
(61B), and a substantially cylindrical electrode provided with one large circular beam passage hole (62) on the seventh grid G7 side. And inside this cylindrical electrode,
In-line arrangement direction (X direction)
An electrode (60) having a track-field-shaped beam passage hole (63) having a long diameter is arranged at the center.

This beam passage hole (63) is located at a predetermined distance a from the end of the sixth grid G6 on the seventh grid side,
There is a relationship of a <D6 with respect to the diameter D6 of the large circular beam passage hole (62).

The seventh grid G7 partially overlaps the sixth grid G6, is a substantially cylindrical electrode including the sixth grid G6 that is a cylindrical electrode, and has a large circular beam passage hole (62) in the sixth grid G6. A substantially large-diameter cylindrical lens is formed.

A track field having a short diameter in the in-line arrangement direction (X direction) inside the cylindrical electrode of the seventh grid G7 and at a predetermined distance b from the end of the sixth grid toward the screen portion (2). An electrode (70) having a beam passage hole (73) in the shape is provided, and the cylindrical diameter of the seventh grid G7
B <D7 with respect to D7.

In this embodiment, a> b. FIG. 7 shows the electrodes (60) and (70).

On the outer periphery of the tip of the seventh grid G7, a valve spacer (11
2) is attached so that the inner wall of the funnel (4) is in contact with the conductive film (10) applied to the inner wall of the neck (5) so that the anode terminal provided on the funnel supplies an anode high voltage. Has become. At the tip of the seventh grid G7, a magnetic field correction element for the magnetic field generated by the deflection yoke can be provided. The cathode K, the first grid G1 to the seventh grid
The grid G7 is fixedly supported by the insulating support BG.

A deflection yoke (7) is attached from the neck (5) to the funnel (4).
It comprises a horizontal deflection coil and a vertical deflection coil for deflecting the electron beams BR, BG, BB horizontally and vertically. Further, a multipole magnet (51) for adjusting the trajectory of the beam is provided.

In the electron gun, a predetermined voltage is externally applied to all the electrodes except the seventh grid G7 through the stem pins (113).

In the above electrode configuration, for example, the cathode K is about 15
The cutoff voltage is 0 V, and the video signal is added to the cutoff voltage.
Grid G1 is at ground potential, second grid G2 is 500V-1k
V, 3rd grid G3 is 5-10kV, 4th grid G4 is 500-3k
V, the fifth grid G5 applies 5 to 10 kV, the sixth grid G6 applies slightly higher than the fifth grid G5, 5 to 10 kV, and the seventh grid G7 applies the anode high voltage of 25 to 35 kV.

With such a potential configuration, the beam generated from each cathode K according to the modulation signal is
K, 1st grid G1, 2nd grid G2
A crossover CO is formed as shown in FIG.
The focus is slightly focused by the prefocus lens PL by the third grid G3 to form a virtual crossover VCO,
It goes into the grid G3 while diverging. Each of the beams BR, BG, and BB entering the third grid G3 is focused on the main electron lens portion ML1 by the third grid G3 to the seventh grid G7, and the beams on both sides are concentrated on the screen (2). Focus and concentrate on FIGS. 3 and 4 are equivalent optical models corresponding to FIGS. 1 and 2, respectively.

The lens operation of the main electron lens section from the third grid G3 to the seventh grid G7 will be described in more detail using equivalent optical models shown in FIGS.

The individual electron beams that form the virtual crossover VCO and enter the third grid G3 are individually weak uni-potential lenses EL2 (the second ones) formed by the third grid G3, the fourth grid G4, and the fifth grid G5. Each is slightly focused by an electron lens.

Now, as described above, the fifth grid G5 has four electrodes (2) in a direction perpendicular to the in-line arrangement direction (xZ plane).
0) (21) (22) (23) are arranged, and the sixth grid G
6 has two electrodes (2
4) Since (25) is arranged, the fifth grid G5 and the sixth grid G5
When a voltage is applied between the grids G6, a quadrupole lens QEL is formed between these electrodes. Therefore, the electron beam incident here is subjected to the lens action and travels toward the large-diameter electron lens LEL so as to diverge more strongly in the vertical direction than in the horizontal direction. The intensity of the diverging force by the quadrupole lens QEL should be adjusted depending on the distortion and concentration of the electron beam projected on the screen.
The individual dimensions and relative spacing of (21), (22), (23), (24) and (25) are appropriately selected. In the present invention, the quadrupole lens QE
Most preferably, the quadrupole lens QEL is configured so that the electron beam emanating from L diverges vertically and becomes substantially parallel in the horizontal direction.

When the electron beam that has passed through such a quadrupole lens QEL enters the large-aperture lens LEL, it is subjected to the lens action of the large-aperture lens, and the electron beam finally projected on the screen shows good concentration and focusing characteristics. .

 This will be described in detail with reference to FIGS. 1 and 5.

The large-diameter electron lens unit LEL has a front-stage lens CL and a rear-stage lens DL, and can be viewed as one large-diameter electron lens LEL as a whole.

That is, since there is a horizontally elongated beam passage opening (63) inside the cylindrical electrode of the sixth grid G6, the high-voltage electric field penetrating from the seventh grid is distorted by the beam passage opening (63) and becomes horizontal (X direction). Has a weak focusing force, vertical direction (Y
In the direction (1), a focusing lens CL at the front stage where a strong focusing force acts is formed. On the other hand, since there is a vertically elongated beam passage opening (73) inside the cylindrical electrode of the seventh grid G7, the low-voltage electric field penetrating from the sixth grid is distorted by the beam passage opening (73), and is horizontally (X direction). A divergent lens DL in the subsequent stage in which a strong diverging force acts in the vertical direction and a weak diverging force acts in the vertical direction (Y direction). In the large-diameter electron lens LEL as a whole, weak focusing in the horizontal direction (X direction) and strong focusing in the vertical direction (Y direction) work.

That is, a common large aperture asymmetric lens is formed. Here, the concentration and convergence characteristics in the embodiment will be described.

Since the axes of the three electron beams incident on the common large-aperture lens LEL are parallel to each other, the large-aperture lens LEL
Focuses well on the screen due to the weak focusing power in the horizontal direction.

This is in contrast to the case where the common large-aperture lens LEL has a strong horizontal focusing power as shown in FIG. 12, where three beams are over-focused on the screen.

 The focusing characteristics of the electron beam will be described.

The electron beam passing through the quadrupole lens QEL undergoes a slight focusing action in the horizontal direction and a diverging action in the vertical direction while passing therethrough. Then, the large-diameter lens LEL receives a focusing action while being weak in the horizontal direction, and further receives a strong focusing action in the vertical direction, so that the beam is well focused on the screen.

Each weak uni-potential lens EL2 (second electron lens) formed between G3, G4, and G5 shown in the present embodiment has a beam diameter of a beam incident on the large-diameter electron lens unit LEL and a main electron lens unit ML1. The purpose of the present invention is to adjust the overall convergence state. In the present invention, an asymmetric lens provided outside the lens area of the large-diameter electron lens can be provided in the lens EL2.

If the second electron lens EL2 having a weak focusing effect is ignored for the sake of simplicity, the beam emitted from the virtual crossover point VCO on the axis is shifted by each beam axis in the horizontal direction by the asymmetric lens QEL part. Are focused so that they are almost parallel to the virtual crossover point VC in the horizontal direction.
OH moves away from the cathode to infinity.

Therefore, the three parallel electron beams arranged in-line are concentrated on the screen by the large-diameter electron lens LEL, and each beam is focused on the screen. In other words, in the horizontal direction, the focal point on the image point side of the large-diameter electron lens is on the screen. However, in practice, the intensity of QEL and the intensity of LEL need to be adjusted due to the spherical aberration of the lens and the emittance of the beam emitted from the cathode. on the other hand,
In the vertical direction, it is diverged (or weakly focused) by the asymmetric lens QEL part, so the virtual crossover point in the vertical direction
The VCOV is located much closer to the screen side than the VCOH in the horizontal direction, and receives a strong focus by the large-diameter electron lens LEL, so that each beam is focused on the screen.

Therefore, the three electron beams arranged in-line are concentrated and each beam is focused round on the screen.

The detailed specifications of the above embodiment are as follows, for example.

Cathode spacing Sg = 4.92mm Opening diameter of each electrode G1φ, G2φ = 0.62mm G3φ, G4φ, G5φ, G6Bφ = 4.52mm G6Tφ = D6 = 25.0mm G7φ = D7 = 28.0mm Length of each electrode G3 = 6.2mm G4 = 2.0mm G5 = 35.4mm G6 = 30.0mm Electrodes (20) to (23) = 4mm Electrodes (24), (25) = 4mm Distance between each electrode G1 / G2 = 0.35 mm G2 / G3 = 1.2 mm G3 / G4, G4 / G5 = 0.6 mm a = 11.0 mm b = 6.0 mm In the above embodiment, a lens which obtains a strong diverging force in the horizontal direction at the rear stage of the large-diameter electron lens LEL. In this case, as shown in FIG. 6, the distance SD at the deflection center plane between the three electron beams which exits from the large-diameter electron lens and concentrates on the screen is simply concentrated (dotted line in the figure). Interval S
D 'is considerably smaller than that of D'. Therefore, it is possible to suppress the concentration error when the three beams are deflected over the entire screen and to reduce the deflection power, so that a high resolution and high quality color picture tube can be obtained. An apparatus can be provided.

Further, when the deflection yoke has a convergence-free magnetic field in the above embodiment, the beam distortion due to the deflection magnetic field is severe, so that the fifth grid is synchronized with the horizontal and vertical deflection.
If the voltage of G5 is made variable, the asymmetric lens QE
The lens power of L changes, so that the above-mentioned deflection distortion can be canceled out, or the deflection magnetic field is made a uniform magnetic field,
The beam distortion due to the deflection magnetic field can be eliminated, and the convergence can be performed by adjusting the mutual relationship between the video signal and the deflection current.

In the above embodiment, a bipotential cylindrical lens is used as a basic type as a common large-diameter asymmetric lens, and a horizontally long beam passage hole (48) is provided at the distance of the front stage a, and a vertically long beam passage hole (50) is provided at the distance of the rear stage b. , And by setting a> b, the horizontal divergence action by the rear stage is strengthened.
The present invention is not limited to this, and it is possible to form a common large-aperture asymmetric lens both when a = b and when a <b, and it is also possible to eliminate, for example, a horizontally long beam passage hole in the front part. Of course, the non-circular beam passage hole can be appropriately changed as long as it is a large aperture asymmetric lens having a stronger focusing power than the vertical or horizontal direction.

Needless to say, a unipotential lens, an extended electric field lens, or the like can be used in addition to the bipotential cylindrical lens.

In the above embodiment, the common large-aperture asymmetric lens LEL is used.
Asymmetric lens QE between the fifth grid G5 and the sixth grid G6 in order to make each of the three independent electron beams incident on the first grid substantially parallel in the horizontal section and a divergent system in the vertical parallel section.
Although L is provided, the present invention is not limited to this, and as described above, an asymmetric lens can be formed in the fourth grid G4, or an asymmetric lens can be formed in the electron beam forming unit so that the horizontal The cross section in the direction can be a substantially parallel beam.

 Another embodiment of the present invention will be described below.

FIG. 8 and FIG. 9 are X-Z corresponding to FIG. 1 and FIG.
A cross section and a YZ cross section are the same, and the same parts are indicated by the same numbers.

8 and 9, at the tip of the fifth grid G5, there are two electrode plates (53) and (54) above and below the three beam passage openings (52R) to (52B). Similarly, on the fifth grid side of the 51 grid G51, three beam passage openings (511
R)-Two electrode plates (511), (512) above and below (511B)
There are four electrode plates (513), (514), (515), and (516) in the vertical direction on the sixth grid G6 side of the 51st grid G51,
Similarly, on the 51st grid side of the 6th grid G6, 4 beam passing ports (61R) to (61G) are sandwiched in the vertical direction.
There are two electrode plates (612) (613) (614) (615) 7.

The sixth grid G6 and the seventh grid G7 include non-circular beam passage ports (63) and (73) based on a large-diameter cylindrical lens as in the case of the above embodiment.

When a high potential is gradually supplied to the fifth grid G5, the 51st grid G51, the sixth grid G6, and the seventh grid G7, between the facing electrode plates of the fifth grid G5 and the 51st grid G51,
A parallel flat lens FLv having a focusing action only in the vertical direction is formed (no force acts in the horizontal direction), and a focusing action only in the horizontal direction between the opposing electrode plates of the 51st grid G51 and the 6th grid G6. Is formed (no force acts in the vertical direction).

At this time, the lens FLH is focused more strongly than the lens FLV, whereby the beams from the electron beam forming unit are each focused strongly in the horizontal direction, become substantially parallel beams, and slightly focused in the vertical direction, As it is still diverging beam, it enters the common large aperture asymmetric lens part LEL,
As in the above-described embodiment, the three beams are focused and concentrated on the screen by the large-diameter lens unit.

In this embodiment, a dynamic correction circuit is externally provided so that the voltage supplied to the fifth grid G5 is parabolically varied in synchronization with the horizontal and vertical deflection currents H and V to the deflection yoke (7). (72) is connected.

Accordingly, when the horizontal deflection magnetic field generated by the deflection yoke is a strong pincushion magnetic field, as shown in FIG. 10, when the electron beam is deflected to the periphery of the screen, the pincushion magnetic field causes a strong overfocus in the vertical direction. Then, the convergence of the electron lens FLV becomes weak, and the electron lens FLV is brought into a state of insufficient convergence in the vertical cross-sectional direction.

In the present invention, the lens performance is improved by arranging a common large-diameter electron lens for three independent electron beams in the main electron lens portion. In order to simultaneously satisfy the beam focusing and concentration, the common large-aperture electron lens is an asymmetric lens having a weaker focusing power than the horizontal or vertical direction, and three independent electron beams incident on the common large-aperture asymmetric electron lens are The common large-aperture asymmetric electron lens is capable of forming, for example, three independent electron beams emitted from an electron beam forming unit. Three electron beams are commonly transmitted to a common cylindrical electron lens and at least one of the cathode side and the screen side in the lens area of the cylindrical electron lens. A non-circular beam passage hole is formed, and an asymmetric electron lens independent of three electron beams is arranged on the cathode side outside the lens area of the cylindrical electron lens. By converging the electron beam in the horizontal direction more strongly than in the vertical direction, a beam substantially parallel to the horizontal direction is created.

More specifically, in the lens area of the cylindrical electron lens, the non-circular beam passage hole arranged on the cathode side has a substantially longer horizontal direction than the vertical direction, and the non-circular beam passage hole arranged on the screen side has The beam passage hole is substantially shorter in the horizontal direction than in the vertical direction.

Further, an asymmetric electron lens independent of the three electron beams disposed outside the cylindrical electron lens region and arranged on the cathode side can change the strength of the electron lens according to the amount of deflection by the deflection unit. Means may be provided.

[Effects of the Invention] As described above, according to the color picture tube device of the present invention, the performance of the common large-aperture electron lens can be sufficiently exhibited,
With this common large-diameter electron lens, three parallel electron beams generated from the cathode can be focused on the screen surface in an optimum focusing state and an optimum focusing state, respectively.

Therefore, a very small beam spot can be realized on the screen surface, and a color picture tube device with improved image performance can be obtained.

[Brief description of the drawings]

FIG. 1 shows a main part X- of a color picture tube apparatus embodying the present invention.
FIG. 2 is a sectional view taken along the line YZ of the color picture tube apparatus embodying the present invention, and FIGS. 3 and 4 are optical equivalent views corresponding to FIGS. 1 and 2. FIG. 5 and FIG.
FIG. 7 is a view for explaining a large-diameter electron lens of the present invention, FIG. 7 is a view showing electrodes for forming a large-diameter asymmetric lens of the present invention, and FIG. 8 and FIG. FIG. 10 is a diagram showing the electron beam shape of the present invention and a conventional example, FIG. 11 is a schematic cross-sectional view of a general color picture tube device, FIG. 12 and FIG. Is an explanatory diagram of a conventional technique. 1 ... Color picture tube apparatus figure 100 ... Electron gun unit 7 ... Deflecting device 2 ... Screen GE ... Electron beam forming unit ML1 ... Main electron lens unit QEL ... Asymmetric lens LEL ... Common large-diameter lens

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-53-69 (JP, A) JP-A-61-188838 (JP, A) JP-A-61-250933 (JP, A)

Claims (2)

(57) [Claims] 1. A color picture tube device comprising an in-line type electron gun unit, a deflecting unit, and a screen unit, wherein a deflection unit scans an electron beam emitted from the electron gun in a vertical direction and a horizontal direction. The gun unit generates, accelerates, and controls three electron beams, and an electron beam forming unit.
A main electron lens unit for converging and concentrating the electron beam; the main electron lens unit includes a large-diameter asymmetric electron lens acting commonly on three electron beams; The horizontal focusing force acting on each of the electron beams is weaker than the vertical focusing force, and the three electron beam axes incident on the asymmetric electron lens are parallel to each other, and the individual electron beams are A color picture tube device characterized by a beam that diverges more strongly in the vertical direction. 2. A color picture tube apparatus comprising an in-line type electron gun section, a deflecting section, and a screen section, wherein the electron beam emitted from the electron gun is deflected and scanned in a vertical direction and a horizontal direction by a deflecting section. The gun unit generates, accelerates, and controls three electron beams, and an electron beam forming unit.
A main electron lens section for converging and concentrating the electron beam; the main electron lens section has a large-diameter asymmetric electron lens that acts commonly on three electron beams; A cylindrical electron lens common to the electron beam and a non-circular beam passage opening in the lens area of the cylindrical electron lens for passing three electron beams in common; On the forming part side, there are provided beam forming means in which three electron beam axes incident on the asymmetric electron lens are parallel to each other, and each electron beam becomes a beam which diverges more strongly in the vertical direction than in the horizontal direction. A color picture tube device characterized by the above-mentioned.