JPH01232645A - Color picture tube device - Google Patents

Abstract

PURPOSE:To enlarge the effectiveness of the inside dia. of a neck, make an electron lens in a great dia, and prevent generation of deflection abberation and coma abberation by supporting oppositely located cylindrical electrodes forming No.1 electron lens with a thin ceramic sheet furnished alongside the side of the cylindrical electrodes. CONSTITUTION:Oppositely situated cylindrical electrodes constituting No.1 electron lens, i.e. No.6 grid G6 and No,7 grid G7, are supported by two insulation supports with ceramic sheet CS joined to a metal sheet MS. This allows employment of a large dia. electron lens which makes good use of the inside dia. of the neck. Accordingly the difference in the beam focusing effect between the center and the sides can be decreased, and the coma aberration of the beam on two sides can better be controlled. Further the deflection angle due to the electrostatic deflection part can be lessened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a color picture tube device, and more particularly to a color picture tube device that converges and concentrates three electron beams arranged in-line.

(Prior Art) As shown in FIG. 10, a color picture tube (100) includes a face plate (102) having a screen surface (101) and a side wall (102') of this face plate through a funnel (103). A connected neck (104), an electron gun (105) housed in this neck, a deflection device (106) attached to the outer wall from the funnel to the neck, and a deflection device (106) installed opposite to the screen at a predetermined interval. a shadow mask (108) having a large number of apertures (107); a conductive film (109) uniformly applied to the inner wall of the funnel up to a part of the neck; and a conductive film (109) applied to the outside of the funnel. and an anode terminal (not shown) provided in a part of the funnel.

The screen is coated with a large number of red, green, and blue phosphors (110) in stripes, and three electron beams (BR), (R(]), and (BR) are shadow masks emitted from the electron gun. The selected phosphor is bombarded with light, causing it to emit light.

The electron gun has an electron beam generator GE for generating, accelerating, and controlling three parallel electron beams arranged in-line, and a main electron lens ML for converging and concentrating each of these beams on a screen. As a result, three electron beams are focused and concentrated at the center of the screen (111), and these three electron beams are deflected and scanned over the entire surface of the screen by the deflection device to form a raster.

The smaller the interval SD between the three electron beams at the center plane of deflection of the electron beam 11 deflected by this deflection device, the better the degree of concentration (convergence) of the three deflected electron beams. This has the advantage that less deflection power is required.

In order to improve the image performance of such a color picture tube, it is necessary to improve the performance of the electron gun and reduce the beam spot diameter on the screen.

An effective way to improve the performance of an electron gun is to improve the performance of the main electron lens section.

Generally, the main electron lens section is formed by coaxially disposing a plurality of electrodes each having an aperture and applying a predetermined potential to each electrode. There are several types of such electrostatic lenses depending on the electrode configuration, but basically they are formed by forming a large-diameter lens with a large electrode aperture diameter, or by elongating the orthogonal radiation between the electrodes to form a gradual lens. Lens performance can be improved by forming a long focal length lens by changing the potential.

However, since the electron gun of a color picture tube is generally enclosed within a neck, which is a thin glass cylinder, first, the aperture of the electrode, that is, the lens aperture, is physically controlled. Also, the distance between the electrodes is limited so that the focused electric field formed between the electrodes is not influenced by other undesired electric fields in the neck.

In particular, the shadow mask type color receiver 81/F? like 3
When a book's electron guns are integrated into a delta array or an inline array, the smaller the electron beam spacing (Sg) is, the easier it is to concentrate the three electron beams at one point near the entire surface of the screen, as described above. Since it has the advantage of low deflection power, the apertures in the electrodes have to be made even smaller in order to reduce the distance between the electron guns.

Therefore, a method was developed in which three electron lenses lined up on the same plane were completely overlapped to form one large electron lens, and this large-diameter electron lens was used to maximize the performance of the electron lens. No. 5591 (U.S. Patent No. 3
, 448,316), U.S. Patent No. 4,528,
476 specification, Japanese Patent Publication No. 47-43993, Japanese Patent Publication No. 4G-14502, U.S. Patent No. 3,011,0
No. 90 specification, U.S. Patent No. 2,861,208, U.S. Patent No. 2,726,348, Japanese Patent Application Laid-open No. 1983
This method has been proposed in Japanese Patent Application Laid-Open No. 62-217541, etc.

However, even if such a large-diameter electron lens is formed, as described above, since an electron lens generally has a cylindrical electrode enclosed within the neck, its outer diameter is limited by the inner diameter of the neck. This neck diameter is determined by standards in several sizes, and cannot be easily changed.

Generally, in the case of a color picture tube, the deflection of the electron beam is
This is often done using the magnetic field generated by a deflection yoke attached to the cone of the funnel, and when the neck diameter is increased,
The distance between the electron beam and the deflection yoke becomes longer, and the deflection power of the electron beam increases, which not only increases power consumption, which is not economically advantageous, but also increases the heat generated by the deflection yoke, which makes it technically difficult. Many problems arise.

Furthermore, in order to form a large-diameter electron beam as shown in FIGS. 11(a) and 11(b), it is necessary to apply different potentials to at least two cylindrical electrodes and to oppose them.

In this case, the problem is that it is necessary to insulate and support the two electrodes at a predetermined interval, and generally protrusions (SR) provided on the outside of the electrodes are implanted in glass supports (BG). In this way, the 11th section of the AA' cross section in FIG.
As shown in Figure (b), since the neck diameter is substantially reduced by the thickness of the glass rod, the outer diameter of one cylindrical electrode is further reduced. It is possible to increase the diameter of the electrode by reducing the thickness of the glass rod, but when implanting the protrusion (ST) of the electrode described above into the glass rod (BG), it is necessary to heat the glass (BG). When it softens, the actual origin (ST)
) will be buried.

If the thickness of the glass rod is made thinner, cracks will occur in the glass rod due to strain stress and other causes that occur when the glass rod cools and hardens, making it impossible to insulate and support the electrode with sufficient mechanical strength. The practical limit for reducing the thickness is approximately 3 mm.

Further, as is clear from FIG. 11(b), there is a gap of 0.5 to 2.0 mm between the inner wall of the neck gas and the glass rod. There are two reasons for this.

One is to prevent the neck glass from breaking due to heat shock if the neck glass and the electron gun come into contact when sealing the electron gun, and the other is to prevent the neck glass from breaking due to heat shock. This is to prevent the pressure resistance from worsening due to charge-up on the inner wall of the neck if they are in contact with each other.

Here, to explain in more detail by showing specific numerical values, the outer diameter of the neck glass in Fig. 11 is 36.5n++a,
It is a standard product with an inner diameter of 30.9 mm. The thickness of the glass rod is approximately 3. On+m, rl13.0mm The distance between the inner wall of the neck and the glass rod is at least 0.3+am, approximately 0.5 in the radial direction.
It is mm. The exposed length of the protrusion embedded in the glass rod is about 1.0 mm in the radial direction, and the thickness of the cylindrical electrode forming the large diameter lens is about 0.4 mm. Since the electrode is fixed with two glass rods, the effective inner diameter of the cylindrical electrode is about 21 mm, which is about 68 mm the inner diameter of the neck.
As a result, a large-diameter electron lens that fully utilizes the neck inner diameter has not been formed.

Thus, the insulating support of the glass rod effectively reduces the inside diameter of the neck. This is one of the major problems that hinders the improvement of the performance of the electron lens and significantly limits the improvement of the resolution of the picture tube.

In general, three parallel electron beams (BR
), (Bo), and (BB) pass through one common large-diameter electron lens LEL, when the central electron beam (Bq) is properly focused as shown in Fig. 12, the electron beams on both sides (BR), (Iln) is a screen (10
1) Above, three beam spots (SPR), (S
Pa) and (SPn) are greatly separated and the beams on both sides are distorted.

In order to match the convergence state of these three electron beams and reduce the coma aberration, there will be no practical problem if the distance Sg between the three beams is reduced to a certain extent with respect to the lens aperture of the electron lens LEL. Regarding the concentration state of the three beams on the screen, Sg must be made extremely small, making mechanical arrangement of the electron beam emitting section difficult.

Therefore, Japanese Patent Publication No. 49-5591 (U.S. Patent No. 3.
448,316) and U.S. Pat. No. 4,528,4
In the specification of No. 76, as shown in FIG.
The three electron beams incident on the electron beam are made to have an inclination angle O in advance, and the three electron beams pass through the center of the electron lens LEL at the same time so that the three beams are focused, and then diverge. The beams on both sides of the screen are deflected extremely strongly (φ°) in opposite directions so that the three beams are concentrated on the screen.

Therefore, there is a problem in that a large deflection aberration or coma aberration occurs in the beams on both sides.

Further, in Japanese Patent Publication No. 49-5591, this deflection is performed using an electrostatic deflection plate, but this case has the following drawbacks. That is, in a color picture tube, since the current of the electron beam is large, the diameter of the electron beam in the electron lens LEL is also quite large, and the three electron beams overlap in the electron lens. Thereafter, each electron beam is converged by an electron lens and an image is formed on a screen far away, but the position Qd where the electrostatic deflection plate is installed must be placed at a place where these three electron beams are completely separated.

For this reason, the electrostatic deflection plate has to be placed quite far from the electron lens, making the total length of the electron gun extremely long. Therefore, the distance from the electron lens to the screen, that is, the image point distance Q becomes longer, the electron optical magnification deteriorates (increases), and the beam spot diameter on the screen becomes worse. Furthermore, increasing the total length of the electron gun means increasing the total length of the color picture tube, which is extremely undesirable because it significantly impairs the economic efficiency of the color picture tube.

In U.S. Pat. No. 4,528,476, as shown in FIG. 14, three electron beams that pass through a first common electron lens L1 and separate from each other are refocused by a second common electron lens L2. However, this method also has the following problems.

That is, in general, when one electron beam B( ) is converged onto a predetermined screen by one electron lens L'EL, the beam emitted from the object point on the axis is focused on the image plane ( If we ignore 9spherical aberration, the three electron beams IIRr B(] + BB emitted from the same object point in this state will also be concentrated on the screen. , ignoring spherical aberration, the first
As can be clearly seen from FIG. 5, the object point position for focusing and the emission point on the axis for focusing must basically be at the same position.

However, in U.S. Pat. No. 4,528,476, No. The beams are focused by the second electron lens L, 1 and 2, but the intersection point Oc with the axis of the three beams incident on the second electron lens L2 that causes the focusing action is the first electron lens L2. The intersection point (Oc) is located in L1 and is greatly different from the object point position for the focusing action. Therefore, it is easy to see that it is extremely difficult to perfectly match the focusing and concentration of each beam.

Also, U.S. Patent No. 3,011,090, U.S. Patent No. 2
．． No. 861,208, U.S. Patent No. 2,726,348, and Japanese Unexamined Patent Application Publication No. 1986-69, as shown in FIG. 16, a low electrode G4 having three holes is followed by a high electrode G having a common hole. , the electron beams on both sides are bent in the direction of one angle away from each other, which is aimed at concentrating the three electron beams on the screen surface.

Therefore, as shown in Fig. 17, the three parallel electron beams pass through the three individual focused electron beams Lc separately, and then immediately pass through the common large diverging electron lens LD, so that the overall While each beam is focused, the electron beams on both sides diverge away from each other.

In this state, the electron beams enter the single large common focusing electron lens LEL, and each beam receives a focusing action, and the electron beams on both sides receive a focusing action.

U.S. Patent No. 3,011,090, U.S. Patent No. 2.
861,208 and U.S. Patent No. 2,726,348, the focusing action is mainly performed by three individual focusing electron lenses Lc, and the common large-diameter electron lens LEL is mainly used to perform the focusing action. Against.

In Japanese Patent Application Laid-Open No. 53-69, the convergence effect is mainly performed by a common large-diameter electron lens LEL, so it is thought that the latter would improve the performance of the electron gun.

However, in Japanese Patent Application Laid-Open No. 53-69, if you try to take advantage of the performance of the large-diameter electron lens LEL to improve the focusing performance, the large-diameter electron lens LEL will become stronger, so three beams will be focused on the screen. In order to achieve concentration, the divergence angle α of the beams on both sides must be large. For this reason,
The diverging lens LD formed by the low electrode with three apertures and the high electrode with a common aperture must be strengthened, but at the same time, the first focusing electron lens. As a result, the beam becomes focused (over-focused) in front of the screen, and the beam diameter on the screen becomes large, making it impossible to fully utilize the performance of the large-diameter electron lens.

That is, as shown in FIG. 16, when a high potential electrode G5 with a common aperture is placed next to a low potential electrode G4 with three apertures, as is clear from the appearance of the equipotential lines, the boro diameter A converging lens Lc and a large-diameter diverging lens LD are formed as a pair, and since the function of this converging lens Lc is quite strong, it exhibits the lens performance of the next large-diameter lens LEL formed by G5lG6. The problem is that it cannot be done.

(Issues to be Solved by the Invention) An object of the present invention is to provide a color picture tube in which three electron beams are converged and concentrated near the screen. A problem that arises when trying to reduce the beam spot diameter on the screen by using Problems that limit the improvement of gun performance: Problems of deflection aberration or coma aberration that occur when performing focusing action, problems of increasing the length of the electron gun and eventually the color picture tube, and performing focusing and concentration at the same time. The problem is that it is difficult.

Another object of the present invention is to solve the problem of not being able to fully demonstrate the performance of large-diameter electron lenses, and to provide a color picture tube that has high resolution, high reliability, excellent economic efficiency, and is highly practical.

[Development of invention]

(Means for Solving the Problems) The present invention includes an electron gun section, a deflection section, and a screen section, and the deflection section deflects an in-line array of electron beams emitted from the electron gun section in vertical and horizontal directions. In a color picture tube device, the electron gun section generates three mutually parallel electron beams,
It is equipped with an electron beam forming section that accelerates and controls the electron beam, and a main electron lens section that converges and concentrates the electron beam. The first electron lens includes an electrostatic deflection section that deflects the beam away from the central electron beam, and a first electron lens section that has a common aperture that converges and concentrates the three electron beams that have passed through the electrostatic deflection section.
The opposing cylindrical electrode forming the electron lens is supported by a plurality of thin ceramic plates provided along the outer surface of the cylindrical electrode.

(Function) The bending strength of alumina ceramics is 30m+++
, width 30+a+a, thickness 1,0+am, about 1.
It is 5 kg or more.

With this level of strength, the electrode can be supported with sufficient mechanical strength.

In the conventional method of using a glass rod as the absolute support, the thickness of the glass rod was practically required to be 3 mm, so when supported by the two alumina ceramic plates mentioned above, the thickness of the glass rod was approximately 4.0 m1.
Il, it is easy to infer that the effective inner diameter is enlarged.

Furthermore, since there is no need for a protrusion to be implanted in the glass, the effective inner diameter is further enlarged.

In this way, by fixing and supporting the electrode with ceramics, it is possible to expand the effectiveness of the inner diameter of the neck, making it possible to encapsulate an electrode with a larger diameter inside the neck, thereby improving the performance of the electronic lens. can.

The incident angle α (divergence angle) of the electron beams on both sides entering the first electron lens, that is, the common large-diameter electron lens, is the first
Since the adjustment can be made completely independent of the focusing action of the electron lens, it is possible to easily satisfy the focusing and concentration of three electron beams at the same time. Furthermore, since the three beams can be concentrated on the screen by adjusting the incident angle α of the electron beams on both sides in the large-diameter electron lens, the electron gun does not become unnecessarily long.

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

FIG. 1 shows the neck portion of a color picture tube embodying the present invention. In FIG. 1, the electron gun section 0) disposed in the neck (104) has a cathode K, a first grid G, a second grid G2, a third grid G1, and a fourth grid G4.
, fifth grid Gg, Shizuoka deflector ED, sixth grid G6, seventh grid G7, insulating support BG and valve spacer (112) that support these, and the electron gun is connected to the stem pin (113) at the bottom of the neck. ).A YZ cross-sectional view and an X-Z cross-sectional view of this electron gun section are shown in FIGS. 2A and 2B, respectively.

Each of the cathodes has a heater (6R) inside.

Three cathodes KRy K with (6G), (6B)
It consists of O+ KB and three electron beams BRt B(]
+ [3(generates l.

In addition, the first grid G1 and the second grid G2 have three relatively small beam passing holes (7R), (7G), (7B) corresponding to the three cathodes KR+ Wo and KRk.
, (8R), (8G).

(8B), and this part controls and accelerates the electron beam from the cathode, forming a so-called electron beam forming part GE. Next, the third grid G3, the fourth grid G4. The fifth grid G, also has three cathodes KIt+ KO
There are three relatively large beam passing holes (9) corresponding to + and B.
R) to (14B). In addition, the electrostatic deflection section ED is
- four electrodes (20) perpendicular to the Z plane and parallel to the Y-Z plane;
(21), (22), and (23), and are arranged between each of the three beams and on both sides, and the two inside
The two electrodes (21) and (22) are at the same potential, and the two electrodes (20) and (23) on both sides are at the same potential at a higher voltage.

Furthermore, the sixth grid G6 has three beam passing holes (15R), (15G),
(15B), but the opposite side has one large aperture (16) through which the three beams pass in common, facing the seventh grid G7.

The seventh grid G7 is a cylindrical ffi pole with a large bloom (17) of the same diameter as the sixth grid G6.

The sixth grid G6 and the seventh grid G7 are fixed and supported by two insulating supports C8 in which a metal plate MS is bonded to a ceramic plate CS.

In addition, a cathode K is formed by another insulating support BG.

It is fixedly supported from the first grid G□ to the electrostatic deflection electrode.

In the above electrode configuration, for example, the cathode has about 15
Set the cutoff voltage to 0v, add a modulation signal to this,
The first grid G1 is connected to the ground potential, and the second grid G2
is approximately 500 to 1 V, and the third grid G3 is approximately 6 to 9 ■
, the fourth grid G4 is about 500-3KV, the fifth grid G5 is about 3-8V, the inner electrostatic deflection electrode is about 3-8K
V, the outer electrostatic deflection electrode is applied with a voltage 500-2 KV higher than that, the sixth grid G6 is applied with an anode voltage of about 3-8 V, and the seventh grid G7 is applied with an anode voltage of about 25-30 KV.

With such a potential configuration, the beams generated from each cathode K according to the modulation signal are connected to the cathode K,
The first grid G1 and the second grid G2 form a crossover CO as shown in Fig. 3, and the second grid G2 and the third grid
The light is slightly focused by the prefocus lens PL of the grid G, forming a virtual crossover vC○, and enters the third grid G while diverging. Each beam entering the third grid G3 is focused by the main electron lens section ML from the third grid G to the seventh grid G7, and the beams on both sides are focused and concentrated on the screen (101). .

The lens action of the main electron lens sections from the third grid G3 to the seventh grid G1 will be explained in more detail using the equivalent optical model shown in FIG.

The individual electron beams forming the virtual crossover vCO and entering the third grid G3 are transmitted to the third grid G3, the fourth grid G4, and so on. Each beam is slightly focused by each weak unipotential lens (second electron lens) formed by the fifth grid G5, and then only the beams on both sides are focused by a predetermined angle α without being subjected to the focusing action by the electrostatic deflection unit ED. It is deflected, and in this state the 6th grid G and the 7th grid
The light enters the common large-diameter electron lens LEL formed by the grid G7.

The common large-diameter electron lens LEL provides a main focusing effect on the individual beams and also provides a focusing effect on both beams by β.

In other words, if we ignore the second electron lens that provides a weak focusing effect for the sake of simplicity, for focusing, the beam emitted from the virtual crossover point vC○ on the axis is focused by the large-diameter electron lens LEL. A system has been established in which the image is formed on the screen surface by the electrostatic deflector ED.For concentration, if the beams on both sides deflected by the electrostatic deflector ED are extended in opposite directions and intersect with the axis, the same focusing system as mentioned above is established. In other words, a system is established in which the three beams emitted from this virtual exit point VP are concentrated on the screen surface by a large aperture lens, and one individual beam is focused. It can be seen that the focusing system of converging the three beams and the concentrating system of converging the three beams are established independently and at the same time.

Therefore, the three beams are properly focused and concentrated on the screen.

At this time, in reality, due to the spherical aberration of the large-diameter lens, the virtual exit point vP of the three beams for the focusing system is located at the point where the large-diameter lens is located before the virtual crossover point vCO of the focusing system. However, in the present invention, such operations can be easily performed without affecting the focusing system at all.

In addition, regarding the focusing system, the beams on both sides pass through the edges of the electron lens with corners compared to the central beam, so they are subject to so-called coma aberration, but this is due to the size of the beam incident on the electron lens and the size of the electron lens. It varies depending on the strength of the beam and the beam spacing relative to the aperture of the electron lens.According to experiments by the inventors, the beam spacing is approximately 25% of the lens aperture.
If it is below, the coma aberration can be suppressed to a level that poses no problem in practice. Even if the beam has a beam spacing of 25% or more of the lens aperture, this is not the case if a coma aberration correcting means is provided.

The lens aperture here refers to the diameter of the electrodes in the case of a combination of cylindrical electrodes of the same diameter, and refers to the average diameter of the diameters of the electrodes in the case of the combination of cylindrical electrodes of different diameters.

Of course, even if the beam spacing is set to 25% or less of the lens aperture, there are manufacturing and performance issues such as cathode size, shadow mask hole pitch, phosphor stripe width, and beam landing margin. , the lower limit of the beam spacing is about 4.5 m+m.

Furthermore, the beams on both sides have a stronger binding effect than the central beam, but this is also of a level that poses no practical problem. However, it is preferable that the second electron lens focuses the central beam more strongly than the beams on both sides. This can easily be done by making the lens aperture (beam passing aperture diameter) of the second electron lens different between the center and both sides.

In addition, three openings (14R), (14G), (14B) on the sixth grid G6 side of the fifth grid G
and three openings (15R), (15G) on the fifth grid G5 side of the sixth grid G6.
(15B), the deflection electric field of the electrostatic deflection section ED located between the electrodes is connected to the large-diameter electron lens LEL (first
Another purpose is to shield the second electron lens from being affected.

Of course, if the potential required for deflection is as small as about 500 V or less, this shield can also be omitted.

The potential required for deflection can be adjusted by the angle required for deflection, the length of the electrostatic deflection section for performing deflection, and the potentials (electron beam speed) of the fifth grid G to sixth grid G6.

On the other hand, in a color picture tube, so-called focus P15I adjustment is performed by adjusting the strength of the electronic lens in order to adjust for manufacturing variations in various parts including the image receiving device.

At this time, the degree of concentration (convergence amount) of the three beams may vary greatly.

In other words, by changing the potential of the sixth grid G6, the strength of the large-diameter electron lens changes and focus adjustment can be performed, but at the same time, the degree of concentration changes greatly, and in reality, it is difficult to adjust the focus while changing the image. It becomes difficult.

If a weak second electron lens is placed before the large-diameter electron lens, which is independent for each of the three beams, the second
This is convenient because fine focus adjustment can be performed independently from the focusing system by changing the strength of the electronic lens.

If the focusing effect of the second electron lens is designed too strongly, the first
The performance of the large-diameter electronic lens, which is an electronic lens used in the 2000s, was no longer able to demonstrate its full potential. Since the spot diameter on the screen will not become small, it is better to design the second electron lens to have a weak convergence effect to the extent that focus adjustment is not hindered in practice.

Further, a preferable form of the second electron lens is a unipotential lens formed by the third grid G1, the fourth grid G, and the fifth grid G, as shown in this embodiment.

Firstly, the focus can be adjusted by adjusting the low potential of the fourth grid G4, so so-called dynamic focus adjustment can be easily performed.Secondly, since it is a unipotential lens, the fourth grid G4
Thirdly, the strength of the electron lens can be easily designed by changing the electrode length and electrode potential of the third grid G.
Since the potential of the fifth grid Gs can be made different from the potential of the fifth grid Gs, the potential of the third grid G can be kept at 6 to 8 KV to form a good virtual crossover, and the potential of the fifth grid G5 can be made different from the potential of the fifth grid Gs. The first −
There is an advantage that an extra focusing lens can be prevented from being formed between the second electron lens and the second electron lens.

Also, in focus adjustment, not varying the voltage of the third grid G: has the advantage that the cutoff state of the beam does not change.

Further, as a preferable form of each deflection electrode of the electrostatic deflection section, as shown in this embodiment, it is preferable that the electrode plates are arranged so that the distance between each electrode plate increases in the direction in which the beam travels.

This prevents the beam impact from occurring on the 'fd electrode plate, since each electron beam emitted from the virtual crossover continues toward the large-diameter electron lens while still diverging with a fairly large divergence angle. It is something. When the beam impacts the electrode, gas is emitted from the electrode, damaging the cathode, deteriorating the electron gun's withstand voltage, and melting the electrode, causing major problems. Therefore, the above structure can suppress the occurrence of such problems.

Here, we will explain in detail about the aperture of a large-diameter electron lens.Since the beams on both sides pass through the edges of the electron lens at an angle compared to the central beam, they are subject to some so-called coma aberration, which is caused by the electrostatic deflection section. The distance between the incident electron beams (Sg) and the deflection center (PD) of the electrostatic deflection section 1st
It changes depending on the distance fi (Q>) to the center (I-I) of the electron lens, the size of the beam incident on the electron lens, the strength of the electron lens, and the beam interval with respect to the aperture of the electron lens.

These relationships will be explained in detail using FIG. 4. FIG. 4 is a simplified version of the optical model in FIG. 3, and the symbols used in the figure are the same as in FIG. 3.

Figure 4 (a) and (b) show the deflection center (PD) of electrostatic deflection.
The distance between the center (H) of the main lens and
The case where Qn<Qb is shown for l and Ilb. The strength of the lens is determined by the object point distance OP and image point distance MOQ (a)
(b) has the same strength.

As is clear from this figure, the shorter Ω is, the closer the position where the beams on both sides pass through the main lens is to the axis of the lens < (
ra<rb), which means that it is less susceptible to comatic aberration and spherical aberration.Also, the shorter Q is, the smaller the electrostatic deflection angle (α8 x Qb), so the beam distortion due to electrostatic deflection is smaller. Recognize. Furthermore, the smaller the beam spacing sg, the more α
Although it can be seen that the beam spacing becomes smaller, even if the beam spacing is made smaller, manufacturing and performance factors such as the size of the cathode, the pitch of the holes in the shadow mask, the width of the phosphor strips, the beam landing margin, etc. Due to this problem, the lower limit of the beam spacing is about 4.5 mm.

Therefore, in order for the beams on both sides to pass as close to the central axis of the main lens as possible, the distance Q must be small, but if the electrostatic deflection section is located at a distance of about 80% or less of the lens aperture, the main・The electric field distribution that forms the lens will be distorted, resulting in deterioration of lens performance.

Therefore, in order to pass the beams on both sides as close to the center axis of the main lens as possible, it is necessary to make the lens aperture as large as possible.

Therefore, in the case of this embodiment, the neck glass has an outer diameter of 36.5 mm, as shown in FIG. 5, which shows the cross section of FIG.
, inner diameter: 30.9III11 standard, insulating support, length approximately 30.0mm, Ill approximately 3.0m++
+, thickness approximately 1, thickness 0.4 on a 0mm ceramic plate
It is made by joining stainless steel plates of mm. The distance between the ceramic and the inner wall of the neck glass is approximately 0.5 mm in the radial direction.
It's Toshide. Since the thickness of the cylindrical electrode of the sixth grid (G,,) is approximately 0.4 mm, the effective inner diameter of the cylindrical electrode is approximately 2 mm.
It becomes 6.3n+m.

This occupies approximately 85% of the inner diameter of the neck.

When a conventional insulating support is used, the effective diameter is about 21 mm, so by implementing the present invention, the effective diameter can be increased by about 17%.

Here, the performance of a large-diameter electron lens embodying the present invention and a large-diameter electron lens with other configurations will be compared.

When the opening hole diameter of the low potential side electrode and the opening diameter 0H of the high potential electrode are (1) DL=Du=φ26.3a+m■D1.
=φ28.0+am [)o=φ1.9.011111
In the case of 1 (DL, > Dll) ■D = φ19. Oam
[If 1u=φ28.011111 (DI, <DH)) DL=φ21. Omm DH:φ21. Omm(O
L=DH), the radius R for each electron lens
Find the focal length f2 of the beam incident on the position in the direction, R
Fig. 6 shows f2 normalized to be the same in a region where f2 is small.

In Figure 6, the horizontal axis is the radius R and the vertical axis is LEL f, X,
The first curve (31) is Q) DL = Do = φ26
, in the case of a 3mm electronic lens.

The second curve (32) is ■D1. =φ28. O+nm [
), =:φ19゜0LIII! 1, the third curve (33) is (3D+-=φ1!], Omm
In the case of an electron lens with DH=φ28.0m11, the fourth curve (34) is @) OL=OH=φ21.
This is the case where Omm(D[,=D+d.

As is clear from Figure 6, the smallest difference between f8 in the region where R is small and f2 in the region where R is large is ■o.
This is the case when = Dll = φ26.3 mm.

Therefore, in the case of the electron lens (3), the difference between the focusing power for the central electron beam and the focusing power for the electron beams on both sides is the smallest, and the strength of the overfocusing force for the beams on both sides is also the smallest.

Therefore, by adopting an electron lens with Q) DL = Do = φ26.3 mm, the difference in focusing power between the three electron beams is the smallest, so the coma aberration is also small, and the incident angle α required for focusing is the smallest. It has the extremely large effect of being small in size.

Now, regarding the issue of withstand voltage, the withstand voltage of ceramics is generally about V/mm, and in particular, about 1 to 2 KV/ml+ in the case of alumina ceramics.

According to experiments conducted by the present inventors, as shown in Figure 7, the distance between the high pressure side and the low pressure side of gold (ns) bonded to ceramics;
If the LP is separated by 15 mm or more, and the gap between the ceramic and the electrode is about 0.2 mm or more, the voltage will be about 25 KV.
It has been confirmed that it has a withstand voltage of

Although various methods for joining ceramics and metals are known, the following two methods are used in the present invention.

■ Bonding with ceramic adhesive Apply ceramic adhesive to the alumina ceramic and stainless steel plates, then pre-dry at 110°C for about 30 minutes, then sinter at about 150° for about 30 minutes to join them. . Adhesive strength is 85kgf/cd (vertical tensile strength)
Even at a beer strength of 90'', the bond can be so strong that the ceramic substrate will break first.

■ Bonding using active metal method First, an active metal layer is formed on the surface of the stainless steel plate.

800 ~ while pressing this on the alumina ceramics
Heat bonding at 900°C. In this case as well, 1okKf/a+
It has a vertical tensile strength of more than f, and the 90-pil strength is such that ceramics break first (approximately 5kf/2.5mm
2.5mm) or more. in this way,
By using a metal piece bonded with a ceramic plate with sufficient strength, it becomes possible to firmly insulate and support the electrodes of an electron gun.

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

Neck outer diameter φ36.5+am Neck inner diameter φ30. Omm Beam spacing = 4.92mm Aperture diameter of each electrode G, φ, G2φ = 0.62φ G3φ, G, φ, G, φ = 4.52 G6φ = 26.3 G7φ = 26.3 Length of each electrode G, Q =6.2n+m 04Q =2.0mm G, Q =18.71! I16 Deflection electrode=10.0mm GGQ=27.0m11 G7Q=50.0III11 Spacing between each electrode G1/G2=0.3511II11 G2/G,=1.2mna G,/G4. G4/G, = 0.60aayaGG/G
,=1.0 KV I Each electrode potential G,=OV a, 4600~800V G, valve 8.0KV G4#1.3KV G, cape 4.5KV G, :4.5KV G, Dou 25. OKV Center deflection electrode plate #4.5 V Both sides deflection electrode plate valve 5. OKV At this time, the three beams are concentrated on the screen, and the diameter of each beam spot becomes very small.

Incidentally, according to experiments conducted by the present inventors, the spot size on the screen is 1/2 to 1/4 of an optimally designed electron gun when all the beam passing holes in the main electron lens section are 4.52 mm. was measured.

As is clear from the above explanation, according to the present invention, the length of the electrode necessary for a large-diameter electron lens to fully exhibit its lens performance, that is, from the virtual crossover point or the virtual emission point to the lens Once the distance to the reference plane I is determined, an electrostatic deflection section is provided in between to deflect the beams on both sides outward by a predetermined angle, so that the electron gun does not become longer than necessary.

In addition, the electrostatic deflection section can be placed in a portion where the diameter of the beam that diverges from the virtual crossover point is relatively small, or the electrostatic deflection plates can be arranged so that the intervals between the electrostatic deflection plates are sequentially waved. Therefore, there is no problem of electron beam impact on the electrostatic deflection section.

Furthermore, Japanese Patent Publication No. 49-5591 and U.S. Patent No. 4.5
As in No. 28,476, the cathode K on both sides must be tilted and arranged in advance so that the electron beam enters the center of the large-diameter electron lens at a predetermined angle. There's no need to, or
It is necessary to create a complex structure in which the beams from three cathodes arranged in parallel are deflected by a predetermined angle in a very short area from the first grid G1 to the third grid G, which also poses problems in manufacturing. Nor.

Furthermore, as mentioned above, an electron lens in which a converging lens and a diverging lens are integrated is not used to deflect the beams on both sides of the three parallel beams outward at a predetermined angle.
This does not impair the performance of the large-diameter electron lens, and has the extremely large effect of allowing the focusing system and focusing system to be adjusted independently.

Furthermore, as explained in the above embodiment, when the second electron lens is a weak unipotential lens, it has advantages such as easy focus adjustment and the ability to use a high-quality virtual crossover. In the electron lens No. 1, a cylindrical electrode of the same diameter is fixedly supported using alumina ceramics, making it possible to form a large-diameter lens that makes full use of the inner diameter of the neck, reducing the divergence angle for concentration, and This has the advantage that seven coma aberrations and differences in focusing effects are also reduced.

FIG. 8 shows another embodiment of the present invention.

FIG. 8 is a diagram corresponding to FIG. 2, and the same parts are designated by the same numbers.

In FIG. 8, the electron gun includes a cathode K, a first grid G1, a second grid G2, a third grid G1, a fourth grid G4, a fifth grid G5, an electrostatic deflection section ED, and a fifth grid G5, as in the previous embodiment. 6th grid G, 7th grid G
7, and the difference from the previous embodiment is that a resistor IR and alumina ceramic are used to fix and support the seventh grid G1 and the sixth grid G.

The resistor IR has a ruthenium oxide-based high-resistance material patterned on a thin alumina ceramic substrate, and an insulating layer made of glass is provided thereon.

A plurality of terminals provided on the resistor are bonded to the alumina ceramic substrate in the same manner as in the previous embodiment, and are electrically connected to the pattern of the high resistance material.

One end of this resistor is connected to the seventh grid G7, and one of its intermediate terminals is connected to the sixth grid G, . . . to fix and support the seventh grid G7 and the sixth grid. The other intermediate electrodes are a sixth grid G6 electrostatic deflection electrode, a fifth grid G9 . It is connected to the third grid G3, and the other end is led out of the tube through a stem pin and connected to ground potential or a low voltage source. In this structure, the width of the resistor is 6
mm, the lens aperture is smaller than in the case of the above embodiment, and the performance of the large-diameter lens is slightly degraded, but the anode high voltage Eb applied to the seventh grid G7 is reduced by this resistor. As shown in Figure 9, the resistance is divided to supply a predetermined potential to each grid, so in order to operate the main electron lens section, the anode high voltage E is required.
The only electric potential other than b is the potential of the fourth grid G4, and the economical efficiency including the picture tube device is greatly improved.

In addition, since the potential of each grid is supplied through the resistor, it is extremely reliable because it does not cause a discharge to occur in the tube, and even if it does discharge, the discharge current is kept small. .

There is a big advantage.

In the above embodiments, a weak unipotential lens is used as the second electron lens, but the present invention is not limited to this, and a pipotential lens is used as the first electron lens. However, the present invention is not limited to this, and an extended electric field lens or the like may also be used.

Furthermore, it is also possible to appropriately design a system in which distortion of the beam spot diameter at the periphery of the screen is corrected by making the electron beam particularly asymmetrical at the center.

〔Effect of the invention〕

According to the present invention, it is possible to realize a color picture tube with good three-electron beam concentration characteristics and a small electron beam diameter.

In other words, since the focusing system that focuses the electron beam and the focusing system that focuses the three electron beams are independent, the three electron beams can be focused on the screen while maximizing the performance of the large aperture lens. The diameter of the electron beam on the screen becomes extremely small, resulting in a color picture tube device with clear images.

Furthermore, since the electrostatic deflection section is arranged in front of the first electron lens section (common large diameter electron lens), the total length of the electron gun does not become long.

Since the electrostatic deflection section is placed in a low-potential part in front of the common large-diameter electron lens, the deflection sensitivity is extremely high, and a predetermined deflection angle can be obtained with a small potential difference. can also be made very short, ensuring reliability in terms of voltage resistance and preventing the overall length of the electron gun from increasing, which has a large economical effect.

In addition, the electrostatic deflection section can be placed in the part where the beam diameter of each electron beam is small without increasing the total length of the electron gun.
The reliability of the color picture tube can be ensured without the problem of beam impact on the electrodes.

Furthermore, since three parallel electron beams are used, there is no need for complicated electrode structures such as tilting the cathode in advance or deflecting the beam in an extremely narrow area from the first grid to the third grid. Therefore, it is easy to manufacture and has great industrial value.

Next, if a second electron lens is placed in front of the common large-diameter electron lens, the focus can be adjusted completely independently of the focusing system, which facilitates the adjustment of the color picture tube and is highly practical.

By making the second electron lens a unipotential lens, it is possible to provide more leeway in the design of the electron gun, it is easier to adjust the focus independent of the focusing system, it is easier to make dynamic focus, and it has good quality and lossover. can be used, a smaller spot diameter can be achieved, and the image quality of the color picture tube can be further improved.

The first electron lens has electrodes fixed with alumina ceramic.
By supporting the electron beam and adopting a large-diameter electron lens that makes full use of the inner diameter of the neck, it is possible to further reduce the difference in focusing between the central electron beam and the electron beams on both sides, and also to better control coma aberration between the beams on both sides. So 3 on the screen
The two spot diameters and shapes can be matched almost identically. Furthermore, the deflection angle by the electrostatic deflection section required for concentration can also be made smaller.

[Brief Description of the Drawings] Fig. 1 is a partially enlarged view of a color picture tube embodying the present invention;
2 is a sectional view of FIG. 1, FIGS. 3 and 4 are optical equivalent model diagrams for explaining the present invention, and FIG. 5 is a sectional view of FIG.
AA' cross-sectional view of Figure (a), No. 6 is a diagram explaining the focusing power of the lens of the first electron lens section of the present invention, FIG. 7 is a diagram explaining the details of the present invention, No. 8 9 and 9 are views showing other embodiments of the present invention, FIGS. 10 and 11 are schematic sectional views of a color picture tube device of the prior art, and FIGS.
FIG. 7 is an optical equivalent model diagram for explaining the prior art. 100... Color picture tube 101... Screen surface 104... Neck 105... Electron gun section GE... Electron beam forming section ML... Main electron lens section ED... Electrostatic deflection section LE
L...Common large-diameter electronic lens C8...Alumina ceramic fixed, support agent Patent attorney Nori Chika Ken Yudo To Takehana Kikuo Shun Nko
(b) Figure 4 Figure 5 (/1 (2) (,3) (4) DL = DHCl > Ds Dt, < DH
Dt-=Dda MS CB 104s Figure N 50

Claims (2)

[Claims] (1) Equipped with an electron gun section, a deflection section, and a screen section,
In a color picture tube device in which an in-line array of electron beams emitted from the electron gun section is deflected in vertical and horizontal directions by the deflection section, the electron gun section generates and accelerates three mutually parallel electron beams. , an electron beam forming section for controlling the electron beam, and a main electron lens section for converging and concentrating the electron beam, and the main electron lens section is configured to control the electron beams on both sides of the three electron beams emitted from the electron beam forming section. an electrostatic deflection section that deflects the electron beam away from the central electron beam, and a first electron lens section that has a common aperture that converges and concentrates the three electron beams that have passed through the electrostatic deflection section;
A color picture tube device characterized in that opposing cylindrical electrodes forming an electron lens are supported by a plurality of thin ceramic plates provided along the outer surface of the cylindrical electrode. (2) In the color picture tube device according to claim 1, a second electron lens section is provided between the electron beam forming section and the electrostatic deflection section, and has an aperture corresponding to each of the three electron beams. 1. A color picture tube device characterized in that the electron beam focusing power of the second electron lens is weaker than the electron beam focusing power of the first electron lens.