JPH0461588A - Color picture tube device - Google Patents

Abstract

PURPOSE:To reduce mis-convergence deteriorating the performance of a color picture tube and to realize the color picture tube suitable for high precision by correcting an effect subjected to an electron beam locus with a force exerting among plural electron beams. CONSTITUTION:A 1st magnetic field correction means 30 is arranged to a position of an electron gun and a magnetic field H is generated as if N, S four pole lens magnets 32 were equivalently formed to four diagonal corners. Thus, electromagnetic coils 30 comprising a couple of loop coils 33, 34 are opposite to each other with a tube axis inbetween and the coil axis is arranged with a tilt by 45 deg. from an inline face. The magnetic field H by the coil 30 is formed reversely at a boundary near a center beam BG and when the electron beam quantity is much, the two electron beams BR, BB at both sides are deflected in a direction parted from the center beam BG to act like magnifying the interval of the three electronic beams in the deflection center face.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a color picture tube device.

(Prior Art) A general color picture tube device has an envelope consisting of a panel funnel and a neck. An electron gun is installed inside this neck, and a deflection yoke is attached to the outer wall from the neck to the funnel. A screen surface is formed on the inner surface of the panel, and a shadow mask having a large number of apertures is arranged at a predetermined interval from the screen surface. This shadow mask is supported by the panel side wall via a frame. Furthermore, an internal magnetic shield attached to the frame, an internal conductive film uniformly applied from the inner wall of the funnel to a part of the neck, an external conductive film applied to the outside of the funnel, and an internal conductive film applied to a part of the funnel. It is equipped with an anode terminal.

The screen surface is coated with a large number of red-emitting phosphors, green-emitting phosphors, and blue-emitting phosphors in the form of stripes or dots, and the three in-line electron beams emitted from the electron gun are deflected by the deflection yoke. It is deflected by a magnetic field and impacts the phosphor through a shadow mask, causing it to emit light and projecting an image.

The deflection yoke includes a horizontal deflection coil that generates a horizontal deflection magnetic field that deflects the electron beam in the horizontal direction.

and a vertical deflection coil for generating a vertical deflection magnetic field that deflects in the vertical direction.

Figure 7 shows three electron beams 13LBG emitted from the electron gun.
The relationship between BB, shadow mask 70, and screen 71 is shown. In the figure, three cathodes 72R172G, 72
Electron beams aR, BG, and BB emitted from B are arranged inline on the same plane, and each cross-over C
The light forms OR, COc, and COB, passes through a prefocus lens (not shown), etc., and is focused on the screen 71 by the main electron lens ML.

These beams are deflected by the deflection magnetic field produced by the deflection yoke, which is isometrically deflected by the deflection center plane 73.

In this deflection center plane 73, the three electron beams are separated by a distance Sg, so that each beam BR, B passes through one hole 74 of the shadow mask 70 arranged in front of the screen surface. are designed to impact the corresponding phosphors R, G, and B on the screen surface.

On the other hand, as shown in FIG. 8(a), the screen 71 has striped phosphors R, G, B and a black material BC distributed between these phosphors. The beam passing through the hole 74 of the mask appears on the screen surface with the spot shape of the hole 74 [3
Land with p, [3G, B[l. At this time, the phosphor of each electron beam? #If the impact position deviates from the normal phosphor position, the spot will go beyond the black material BC and impact other phosphors to emit light, resulting in a significant color shift, as shown in FIG. 8(b).

This is called mislanding, but as color picture tubes have become increasingly high-definition in recent years, the pitch of the holes in the mask 70 has become smaller, that is, the spacing between the phosphors has become smaller, making mislanding more likely to occur. The known causes of this mislanding are geomagnetism, thermal or mechanical fluctuations in the shadow mask, electron guns,
This is caused by electrical or thermal fluctuations in the deflection yoke, and many countermeasures have been taken to combat these factors.

However, the present inventors have discovered that there is a misconvergence component that cannot be countered by considering conventional factors alone, and through investigation, they have discovered that it is one of the important causes of mislanding.
Furthermore, it was discovered that there is a force acting between multiple electron beams. This phenomenon increases as color picture tubes become larger and have higher definition.

(Problems to be Solved by the Invention) An object of the present invention is to reduce misconvergence that degrades the performance of a color picture tube device, and to provide a color picture tube device suitable for high definition.

[Structure of the invention]

(Means for Solving II!i!) The present invention includes a cathode, an electron gun section including an electron lens section for focusing a plurality of electron beams emitted from the cathode, a deflection section, and a screen section. In a color picture tube device in which a plurality of electron beams emitted from the electron gun section are deflected by a deflection section to scan a screen section, a plurality of electron beams emitted from the cathode are deflected by a deflection section before the electron beams emitted from the cathode reach the screen section. A color picture tube device is characterized in that it is equipped with beam modification means for modifying the influence of the electron beam trajectory due to forces acting between them.

(Function) The present inventors have discovered that one of the important causes of mislanding is the force acting between multiple electron beams. Only beam BR is emitted and the other two beams B
G and BB can be verified by looking at the difference in the landing of the beams that reach the screen surface when the radiation from the cathode is stopped (cutoff) and when the side beams BP and center beam 8G are emitted. Figure 9(a)
When the beam is landing correctly on the red phosphor R as shown in the figure, the center beam BG is further emitted as shown in the same figure (b), and the center beam 8G is adjusted so that it lands correctly on the green phosphor G. Then, the landing position of the beam BR moves toward the G phosphor side, causing a mislanding. Although the beam BG was adjusted so as to land at the correct position, in reality it is biased due to the beam passage hole. The amount of mislanding increases as the beam current increases. The fact that the landing position of the beam BR is biased toward the phosphor G side is due to the deflection center plane 73 shown in FIG.
, the distance Sg between the BG beam and the BR beam is the first
This means that Sg' has become smaller as shown in Figure 0. Here, FIG. 10 shows the deviation of the beam trajectory when a single beam Bi is emitted and when all beams BR1BG and BB are emitted.

This phenomenon is presumed to be due to the force acting between the electron beams.

In this case, the force acts as a force that pulls the beams together, so the beam trajectory becomes narrower than the designed value.

Therefore, the present invention corrects the mislanding by correcting the influence on the electron beam trajectory due to the force acting between the electron beams so that the beam spacing becomes narrower. As a result, even if a plurality of electron beams are emitted simultaneously, as shown in FIG. 8(a), for example, they will land correctly on the screen surface and no color shift will occur.

(Example) The present invention will be explained in detail below with reference to the drawings.

1 and 2 show one embodiment of the invention.

In FIG. 1, a color picture tube device 1 has a screen surface 2.
a neck 5 connected from this panel via a funnel 4, an electron gun 6 built into this neck, a deflection yoke 7 attached to this outer wall from the neck to the funnel, and the screen surface. a shadow mask 9 having a large number of apertures 8 facing each other at predetermined intervals; a frame 10 for holding the shadow mask; an internal magnetic shield 11 attached to the frame; It includes an internal conductive film 12 uniformly applied over a part of the neck, an external conductive film 13 applied to the outside of the funnel, and an anode terminal 14 provided in a part of the funnel. It also includes a drive device 15 that applies appropriate voltages to the electron gun 6 and anode terminal 14 and drives the deflection yoke 7.

The screen surface 2 is coated with a large number of red-emitting phosphors, green-emitting phosphors, and blue-emitting phosphors in the form of stripes or dots, and three electron beams aL emitted from the electron gun 6 are coated on the screen surface 2.
BG and all are selected by the shadow mask 9 and impact each phosphor, causing it to emit light. The electron gun 6 also includes an electron beam forming section GE for generating, controlling, and accelerating three parallel electron beams arranged in-line;
It has a main electron lens component for focusing and concentrating these electron beams. And three electron beams BR, B
An image is projected by deflecting and scanning G and 8B over the entire screen by a deflection yoke 7.

The deflection yoke 7 basically has a horizontal deflection coil for generating a horizontal deflection magnetic field that deflects 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.

FIG. 2 shows a cross-sectional view of the neck portion of the embodiment shown in FIG. 1 along the X-2 axis. In FIG. 2, the electron gun 6 disposed inside the neck 5 has three cathodes 20k.

20G, 20B, integrally formed first grid G1. 2nd grid G2, 3rd grid G1, 4th grid G4
and the insulating support 21 and fourth grid G that support these.
It consists of a convergence cup 22 and a valve spacer 23 attached to the tip of the electron gun 6, and the electron gun 6 is fixed to a stem pin 24 at the bottom of the neck.

Each of the cathodes has a heater inside, and an electron beam BF? , B generates 8B.

Furthermore, the first grid G1 and the second grid G2 have three relatively small beam passing holes corresponding to the three cathodes, and the third grid G on the second grid G2 side has a larger diameter than the second grid G2. It has three beam passing holes, and the part from the cathode to the third grid G3 controls and accelerates the electron beam from the cathode.

This becomes a so-called electron beam forming section GE.

Next, three relatively large beam passing holes are formed on the fourth grid G4 side of the third grid G and on the third grid G3 side of the fourth grid G4, and the main electron lens part is heated by the penetrating voltage of these parts. The three electron beams are focused and focused on the screen.

The electron beam emitted from the electron gun section 6 is deflected in horizontal and vertical directions by a deflection magnetic field generated by a deflection yoke 7, and is scanned over the entire surface of the screen section.

Further, in this embodiment, a first magnetic field correcting means 30 and a second magnetic field correcting means 31 are provided on the outer periphery of the neck as magnetic field correcting means for correcting the trajectories of the three electron beams.

The second magnetic field correction means 31 includes at least two bipolar magnets,
It consists of a combination of two quadrupole magnets and two six-pole magnets, and is a general type that corrects errors in landing and convergence (concentration of three electron beams) caused by variations in electron beam trajectory and color picture tube dimensions. It is.

In this embodiment, mislanding and misconvergence caused by forces moving between a plurality of beams are corrected by a 5-beam correction means, that is, a first magnetic field correction means 30. This first magnetic field correction means 30 is arranged at the position of the electron gun 6 as shown in FIG. 2, and forms an isometric N, S quadrupole lens at the four diagonal corners as shown in FIG. A magnetic field H is generated that forms a magnet 32. For this reason, as shown in FIG.

Electromagnetic coil 30 consisting of a pair of loop-shaped coils 33 and 34
The coil shaft is in-line (
Place it at a 45 degree angle from the X axis. This electromagnetic coil 30
As shown in Figure 3, a magnetic field H is formed in opposite directions around the central beam BG.
The electron beams Bg and B13 of the book are deflected in a direction away from the central beam BG as shown by the arrow, and the distance between the three electron beams in the deflection center plane is expanded.

According to experiments conducted by the present inventors, the phenomenon described in FIGS. 9(a) and 9(b) occurs to a large extent when each electron beam current is large, and especially when the center electron beam BG current pattern is large. It becomes a problem.

When the amount of each electron beam is small, this phenomenon is negligible, and even when the amount of electron beams on both sides is large (and the amount of electron beam in the center is small), the landing movement is small.

As described above, this phenomenon is caused by the mutual force between the electron beams generated from the cathode before they reach the shadow mask, and the beam spacing Sg on the deflection center plane is changed isometrically as shown in Figure 1O. ' and /JS are smaller. In other words, this is a phenomenon in which the beams appear as if they are attracting each other.

Therefore, according to this embodiment, four
By widening the beam spacing Sg', which has been reduced isometrically by the its coil 30 for generating the polar magnetic field, the landing as shown in Fig. 8(b) can be made to land correctly as shown in Fig. 8 CB>. It becomes like this. The current flowing through this electromagnetic coil varies depending on the transfer of the video signal applied to the central cathode 20G. That is, the transfer amount of the video signal applied to the cathode from the drive circuit 15 is detected, and the beam correction circuit 1G sends a current corresponding to this beam amount to the electromagnetic coil 30 to drive the electromagnetic coil, thereby creating the magnetic field shown in FIG. Generate H. To adjust the magnetic field, use a high magnetic permeability material for the electrodes of the electron gun, or install a magnetic field adjustment piece to locally strengthen or block the magnetic field, so that it operates optimally for the beam. I can do it.

5 and 6 show other embodiments of the invention.

In this embodiment, 4
To make the pole magnet 32, a U-shaped core 35 as shown in FIG.
and an electromagnetic coil 37 consisting of a coil 36 wound around the electromagnetic coil 37.
Prepare a pair and attach them to the neck of the envelope. The current flowing through the coil 36 is changed depending on the amount of each electron beam. In this embodiment, an abnormal phenomenon in which beams appear to be attracting each other is further corrected.

The operation will be explained below with reference to FIG.

The current of each electron beam BR, BG, BB is IR, IG,
When Ill, the current i□ flowing through the electromagnetic coil 371 on the right side, that is, the electron beam BR side, is proportional to IG, I3, and the current 12 flowing through the electromagnetic coil 37□ on the left side, that is, the electron beam aB side, is It increases in proportion to G and IR.

Therefore, when IG is thick as shown in Fig. 6(a), a large current 11.12 flows through both electromagnetic coils 371.37□, and the generated magnetic field H pulls the beams BR and BB on both sides strongly outward for correction. do.

Next, when IB is large as shown in FIG. 6(b), a large current 11 flows through the electromagnetic coil 371, and the beam 131?
and F3G are pulled in the direction away from the beam DB to correct it.

On the other hand, when IR is large, a large current j2 flows through the electromagnetic coil 372 as shown in FIG. 6(c), and the beam FIB,
Correction is made by pulling BG away from beam BR.

The phenomenon in which the electron beams appear to be pulled together is that the landing state of the beams on the screen changes depending on whether the current is low or high, and the convergence state of the three beams also changes. This example can solve this problem.

In the embodiment described above, the beam correction magnetic field generator is disposed around the outer periphery of the pi-potential type electron gun whose main lens hole is formed by the grid G3.64, and forms a correction magnetic field near the third grid G3. However, according to the present invention,
The present invention is not limited to the pi-potential type electron gun as in this embodiment, but can be similarly applied to various other types of electron guns. It can also be applied to electron guns.

Further, according to the present invention, the beam correction magnetic field generating means is not limited to the four-pole magnet of the embodiment described above, but can be magnetic or electrostatic as long as it corrects the fluctuation in the beam spacing due to the magnitude of the beam current. For example, it is possible to apply means for adjusting the beam interval by changing the trajectory of the electron beam by changing the electron lens of the electron gun.

〔Effect of the invention〕

According to the present invention, it is possible to improve mislanding and misconvergence caused by forces acting between multiple beams, and in particular, it is possible to improve the quality of images of color picture tube devices having high-definition screens. .

[Brief explanation of the drawing]

1 is a sectional view of a color picture tube device according to an embodiment of the present invention, FIG. 2 is a sectional view illustrating the neck portion of the embodiment shown in FIG. 1, and FIG. 3 is a sectional view of the embodiment shown in FIG. 1. A schematic diagram illustrating the operation, FIG. 4 is a scale diagram of the beam modifying magnetic field generator used in the embodiment of FIG. 1, FIG. 5 is a perspective view showing the beam modifying magnetic field generator of another embodiment, and FIG. A schematic diagram for explaining the operation of another embodiment, FIG. 7 is a schematic diagram for explaining the deflection trajectory of the electron beam, FIGS. 8 and 9 are schematic diagrams for explaining the beam landing of the conventional device, and FIG. 10 is a schematic diagram for explaining the electron beam trajectory. FIG. 6...Cathode, 8...Screen, 20R120G
, 20B... cathode, BR, BG, BB... electron beam, 30... first magnetic field correction means (beam correction means). Agent Patent Attorney Norihiro Ogo Continuation of page 1 @ Inventor 0 shots 0 shots 0 shots 1-9-2 Hara-cho, Fukaya-shi, Saitama Prefecture, Saitama, Lounge Pipe Factory Toshiba Corporation Toshiba Corporation Fukaya Bu Co., Ltd. Toshiba Fukaya Bu Co., Ltd. Toshiba Fukaya Bu Co., Ltd. Toshiba Fukaya Bu Co., Ltd.

Claims (2)

[Claims] (1) An electron gun section comprising a cathode and an electron lens section for focusing a plurality of electron beams emitted from the cathode, a deflection section, and a screen section, and a plurality of electrons emitted from the electron gun section. In a color picture tube device in which a beam is deflected by a deflection section to scan a screen section, the electron beam emitted from the cathode is deflected by a force acting between a plurality of electron beams before reaching the screen section. 1. A color picture tube device comprising a beam correction means for correcting the influence of the beam. (2) The beam correction means is placed on the electron gun side of the deflection section.
2. The color picture tube device according to claim 1, wherein the color picture tube device is a polar lens.