DE1639464A1 - Cathode ray tubes, in particular color television tubes - Google Patents

Description

187 Shimo-Takaido 1, Suginami-ku,
Tokyo, Japan

2) AKIO OHgosiii,

5-6 Akabane-kita 1, Kita-ku,
Tokyo, Japan

3) SEURI MIYAOKA,

22-405 fujisawa-jutaku 13,
Fujigaoka 1, Fujisawa-slii,
Kanagawa-ken, Japan

4) YOSHIHARU KATAGIRI,
c / o Sony Shirogane-ryo,

39 Saru-maehi, Shiba-Shirogane,
Minato-ku «Tokyo, Japan

Patent notice cathode ray tube , especially color television newsletters

The invention relates to a cathode ray tube, in particular a color picture tube, with a single electron beam system for emitting several electron beams, which, like e.g. Serve image.

The well-known color picture tubes are usually with three of each other independent electron beam systems for emitting each an electron beam, which is modulated by appropriate color signals and influenced by a grid system v / ground that they are on a collector or electron beam receiving be focused on the screen, which is a simple phosphorescent

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decorative or fluorescent luminescent screen or such May be fluorescent screen with a perforated electrode or a shadow mask arranged in front of it. Such color picture tubes, in which the three electron beam systems must be mutually aligned so that the emitted Electron beams converge on the electron beam receiving screen are disadvantageous in that they can be precisely aligned of the electron beam lysts and the maintenance of this ^ alignment is difficult and any deviation of them emitted electron beams causes deterioration in the image quality and the resolution of the color image. In addition, one requires working with three electron beam systems Color picture tube a lot of effort and can because of de3 space requirements for these systems can only be produced with a relatively large minimum size.

In order to avoid these disadvantages of the known color picture tubes with several electron beam systems, it is proposed ™, a color picture tube with only one electron beam system to use the designer with three cathodes or with just one Cathode generates three electron beams through a lens-like Go through the focussing system so that they are on the Converge electron beam receiving screen. In this proposed design, however, only one of the electron beams goes in the optical axis of the Fakussiersystemes through this, with the other two at a distance from the the optical axis & electron beams pass through the coma

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and are exposed to spherical alteration. For this reason and because of the associated deterioration of the color picture, color picture tubes have only one electron beam system has not found widespread use for emitting multiple electron beams.

In contrast, the invention is intended to use an electron beam system provided with only one, but with several Cathode ray tubes working with cathode rays are made possible, in which the stated disadvantages of hearing of this type are avoided and which is particularly suitable as a color picture tube for producing color images of high resolution and to be used with great luminosity. The tube should also be relatively small in size be easy to manufacture and be easily correctable with regard to the convergence of the rays.

Accordingly, the invention essentially consists in the fact that the focusing lens device has an optical center and is arranged so that it lies with the optical center substantially at the intersection of the rays and this avoids coma and spherical aberration. Here, the single electron beam system has a cathode device bum emitting electrons on which κ · Β · through a grid device formed by several electron beams converging in the optical center of an electron lens, which is common to all rays and the rays on the electron beam receiving screen to avoid

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Focused on coma and spherical aberration.

When the electron beams are emitted parallel to each other, the convergence of the beams becomes optical Center of the focusing lens device according to the invention achieved by an electrostatic auxiliary lens device, those between the grid system that forms the electron beams and the focusing lens device is arranged.

If still the one on the electron beam receiving screen focused beams are to converge on a common point of the receiving screen, according to another Feature of the invention those rays emanating from the focusing linden device Exiting in divergent directions, dewater by an electrostatic or magnetic deflector deflected, which is arranged between the focusing lens device and the receiving screen.

The invention is based on the in the drawing illustrated embodiments described in more detail «

In the drawing show:

Fig. 1 is the optical equivalent of one with three electron beam systems provided color picture cathode ray tube of known type;

Fig. 2 and 3 the optical equivalent of a tube, which in the manner already proposed with only one

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Electron beam system is provided for generating a plurality of electron beams;

Pig. 4 is the optical equivalent of another embodiment of a proposed tube with only one Electron beam system for generating multiple electron beams;

Pig. 5 is the optical equivalent of a cathode ray tube with a first embodiment of the electron beam system according to the invention;

! ig. 6 shows a representation corresponding to FIG. 5 with a second embodiment of the system according to FIG Invention;

Pig. Figures 7 and 8 show the optical equivalent of a cathode ray tube incorporating further embodiments of the invention;

Pig. 9 is a longitudinal section through one with the optical equivalent according to Pig. 5 provided cathode ray tube ;

Pig.10 an end view to Pig. 9;

Pig.11 is an enlarged view of details of a first and second grids of the Toei of the Pig embodiment. 9 electron beam system used;

Pig, 12 a section along the line II-II of Pig. 11;

Pig. 13 shows an axial section through a chromatron-like par picture tube according to the invention;

Pig. HA and 14-B show a side and an end view of one Magnetic deflector used to converge electron beams in a cathode ray tube can be used according to the invention.

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For a better understanding of the invention are based on the Fig. 1 to 4 first the design principles and features of "known triple electron beam systems and a single electron beam system with three electron beams "Be s ohr i just.

According to FIG. 1, there are three mutually independent electron beam systems or guns A ₁ , A ₂ and A, with three independent ones

P beam generating sources K ₁ , Kp and K ^ arranged for _{emitting three beams B 1} , B ₂ and B ^ each, which are focused on a phosphorescent electron beam receiving screen S by separate lens systems I ₁ , I ₂ and L ·. In such an arrangement, the three independent Elektronenstrah3s / stems A _1, Ap and A ,, need to be housed in the neck portion of the envelope, relatively much space and limit the extent to which the diameter of the neck portion could be reduced. But even if the

If the diameter of each electron beam system could be reduced so that the three beam systems could be accommodated in a neck part of an acceptable diameter, the outer parts of each beam must pass through parts of the respective lens system L ₁ , Lp and L ^ which are from the optical Axis have a considerable distance, whereby a spherical aberration is brought about with the result that each ray hits the screen S in a relatively large point, as in Pig. 1 is indicated on the right. A high resolution cannot be achieved here

^ 209817/011 3

the. Finally, "resulting in three El EKTR onens trahlsystemen difficulties with respect to their for _converging% of rays B _1, B ₂ and B, required on the screen S accurate alignment.

When training according to JPig. 2 is a single beam system A "of known type with equivalent beam generating sources K ₁ , Ko and K. * used, which are arranged at mutual distances d and _{emit three electron beams B 1} , B ₂ and B, parallel to one another. These beams go through the common main lens system L through and are deflected by this so that they converge on the screen S.

Both a color cathode ray tube having three electron beam systems (Fig. 1) as well as a tube with a simple beam system (Pig. 2), it is required that the three electron beams with an angle ^ © 'between the center beam B ₂ and each side beam B ₁ and B ~ converge in such a way that they cross or intersect at a shadow mask or gate arrangement arranged in front of the fluorescent screen and each impinge on parabots or stripes, which serve to generate different parblight rays.

With this requirement for the angle of convergence Δ θ in a simple electron beam system.

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It is essential that the rays B ^, B ₂ and B ^ have exactly the mutual distance d from one another when they pass through the main lens system L. The outer rays B ₁ and B therefore pass through parts of the main lens system or the main lens L, which are also at the distance d from the optical axis of the same, so that the points of incidence of the rays on the screen S both as a result of the coma and the spherical aberration, as shown on the right edge of the Mg · 2. The focussing of the beams is set in such a way that complete convergence is achieved on the screen S. As a result, the focusing effect transmitted to each beam is inevitably reduced, so that the beams are underfocused and their points of impact are enlarged, as can be seen from Mg. 2. If the focusing voltage is set so that the beam B ₂ results in a sharply focused image point on the screen S, the image points B-, B ₂ and B are scattered on the screen S, as shown in Fig. 3. Special measures must therefore be taken in order to combine the image points scattered in this way or to superimpose them. However, as can be seen from the illustration in Mg, 3 on the right, the image points B 1 and B 1 are still distorted by the coma.

When trying to meet the contradicting conditions for focusing and converging the three beams on the screen S, one could think of the three beams BJ, B ₂ and B- according to Mg. 4- from a single radiation source K in three different angular directions so broadcast that

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they have the distance d from one another at the point at which das.Hauptlinsensystem L is arranged. In this case, the two conditions explained can be fulfilled simultaneously and with only slight spherical aberration. The image points of the side rays B ₁ and B- are, however, as can be seen on the right in FIG to have.

It thus results that in cathode ray tubes of the known or proposed type with only one electron beam system and three electron beams, the focusing and converging conditions for the three beams are unsatisfactory are to be met, so that tubes of this type have so far not found any practical application.

Below is now one designed according to the invention Single electron beam system with several electron beams described, which can be used in particular in color picture tubes, but also in any other cathode ray tube multiple electron beams are required.

In the embodiment of the invention shown in Fig. 5, the single electron beam system A is provided with three equivalent beam generating sources K ₁ , K ₂ and K ^, which are arranged on a straight line at distances d from one another in a plane which is substantially at right angles to axis

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of the jet system. These beam generating sources K., Ko and K ^ emit three electron beams B ₁ , B ₂ and B ^, which are refracted by means of a common auxiliary lens device L 'so that they converge or converge substantially in the optical center of a main lens device L. intersect there and emerge in diverging directions from the main lens device L. The outer rays B 1 and B 1, which initially diverge from the optical axis and the central ray B ₂ running in this axis, are then again directed towards the central _{ray B 2} by means of the convergence deflector i \ and]? ₂ deflected, which are arranged between the electron beam receiving screen S and the main lens envorr i rectification L at a distance from this and cause such a deflection of the beams that the beams B ₁ , B ₂ and B ^ on the screen S converge and overlap.

In this training, as on the right edge of the 3? Ig. is shown, very small beam or image points are formed, since all three beams B ₁ , Bp and B ^ pass through the center of the main lens envorr i rectification L and this prevents the image points from being distorted or blurred by coma and spherical aberration will. An image of high resolution is therefore produced. In addition, the dynamic convergence correction with respect to the three beams is advantageously facilitated by the arrangement of the deflectors P ₁ and F _2. The deflectors shown in FIG. 5 are electrostatic deflectors, but they can also according to the invention

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be formed by magnetic deflectors.

In the embodiment of the invention according to FIG. 6, the three beam generating sources K ₁ , K ₂ and K for the three electron beams B ₁ , B ₂ and B of the single electron beam system are arranged on a curved surface, the center of which is in the optical axis of the main lens L lies. The beam generation sources are at a straight distance d _Qi from one another and from the optical axis. In this embodiment, the auxiliary line L ¹ in FIG. 5 is omitted, since the beams B ₁ , B ₂ and 3 ~ due to the arrangement of the beam generating sources on the curved surface are anyway in the optical center of the halter lens L as in the embodiment according to FIG. 5 cut. In the area of the beam _{path of the outer beams B 1 and B ^ two deflectors F 1} and I ^- 2 are arranged at a distance 1 behind the main lens L, by means of which the beams B ₁ and B, which initially diverge behind the main lens, are deflected again to be converged which coincide with one another and with the central ray B ₂ on the screen S. Here, too, a clear image with a high resolution is formed in the embodiment according to FIG. 5.

As already mentioned, in the embodiments according to FIGS. 5 and 6, the beam generating sources K ₁ , K ₂ and K are arranged on a straight line at a distance d or d .. from one another. Instead, however, it is also possible to thin the radiation sources at the corners of an equilateral triangle Hviemc ^, with deflectors F ₁ and Fg for each of the three radiation

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'len or can be arranged for only two beams. Preferably however, the beam generating sources are arranged on a straight line, as shown, because in this case the Distance of the rays from the optical axis to a minimum reduced, the dynamic 'convergence correction facilitated and an asymmetrical convergence of the three pixels on the Umbrella can be avoided.

Furthermore, according to the embodiments of the invention Fig. 5 and 6 the design such that the three beams B ^, Bp and B, converge on screen S. Instead you can however, the deflectors 1- and Pp are also omitted, so that the three rays, after they have intersected in the optical center of the main lens, in diverging directions run up to the screen and on this at three different, spaced or at a certain distance from each other Hit points. With such a training as in Pig. 7 and 8, the three beam or Pixels on the fluorescent screen are also not affected by coma or spherical aberration, so that distortions or blurred pixels according to the known Pig statements. 2 to 4 are avoided. When the ray or When pixels are formed at a distance from one another on the screen S, the image signals become time differences transmitted; which correspond to the three pixels on the screen and modulate the three beams so that between the three generated on the phosphor screen by the three beams Images match is achieved.

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In jig. 9 "to 12, a. Embodiment of a cathode ray tube is depicted with an optical equivalent to Fig. 5 corresponding electron beam system A. Here," forming the cathode K, the beam generation sources K _1, K ₂ and

Κ.,. Right behind the emitting surface of the cathode K is a 3

Arranged first control grid G ₁ , which, according to FIGS. 11 and 12, has three grid elements Gr- ^, G ₁₂ and CL. These three grid members are each with openings gi- | > S-io ^and ^ i ^ ^ver ~ see which are arranged on a straight line. Opposite the grid G ₁ is a second grid Gp with three openings ^g 21 '^ 22 ^and ^ ^S 23 ^at g ^{eor <irLe} "fc>& ie with the openings g .. ^, g ₁₂ and gr ^ of the first grid G ₁ The second grid can be cup-shaped and have a disk 1 in which the openings g ₂ -i> g ₂₂ and g ″ are arranged at a distance from one another on a diameter line II-II extends in the axial direction _{away from the grid G 1.} In this direction, the grid G _{2 is followed} to the rear by tubular grids or electrodes G 1, G, and G, - (Mg. 9).

The electrode G ~ has a central section 5 of larger diameter and two end sections 3, 4 of relatively small diameter and engages with its front end section 3 leaving a radial distance from the side wall 2 of the cup-shaped grid G ₂ . The electrode G. is provided with end portions 6 and 7 which have a larger diameter than the end portions 31 4 of the electrode G-2T, and has a central portion 8 of even larger

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Diameter on. Their arrangement is such that the rear end section 4 of the electrode G engages in the front end section with the formation of a radial gap. The electrode G ₁ - is provided with a middle section 11 of approximately the same diameter as the middle section 5 of the electrode 3 and with end sections 9 and 10 of a smaller diameter than the rear end section 7 of the electrode G. and engages with its front end section 9 again to form a radial gap in the end portion 7 of the electrode G ^ a. The electrodes G ^, G, and Gp- as well as the grids G ₁ , Qp and the cathode K are held together in the position explained by a carrier 12 made of insulating material. Furthermore, a getter chamber Gr is arranged around the rear end section 10 of the electrode 5.

To operate the electron beam system according to FIG. 9, _{voltages are applied to the grids G 1} and Gp and the electrodes G ^, G., G ₁ , for example zero to 400 Y on the grid G ₁ or the grids G _{11 forming it} , G ₁ ρ »G ₁ ^, zero to 500 Y on the grid Gp, 13 to 20 KV on the electrodes G-, and Gf- and zero to 400 V on the electrode G., the voltage of the cathode K is the reference voltage. The voltage distribution for the grids and electrodes G ₁ to G, - as well as their lengths and diameters are essentially the same as those of an indirectly heated electron beam system with a single electron beam, in which a first grid element and a second grid element each have a single opening

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is. With the given voltage distribution, an electron lens field is formed between the grid G ₂ and the front end section 3 of the electrode G, which is the auxiliary lens L ^{1 of} the Pig. corresponds, while at the same time one of the main lens L of the Pig. 5 corresponding electron lens field is formed by the electrodes G ^, G. and G ₁ - in the axial center of the electrode G.

_{So that the rays B 1} and B emerging from the electrode G ₁ - in diverging paths are used to converge again, the electron beam system naoh Kg. 9 is provided with a deflection device ϊ ¹ with mutually spaced shielding plates P and P ' which extend in the axial direction from the free end of the electrode G, -aus. The deflection device i ¹ furthermore has deflection plates Q and Q 'which are, for example, convexly bent or curved outwards and are attached opposite one another on the outer surfaces of the shielding plate P and P'. The shielding plates P and P ^! and the baffles Q and Q ¹ are arranged so that the beams B ₁ , B ₂ and B- pass between the plates P and Q, between the plates P and P ^1, and between the plates P ¹ and Q ^{1, respectively.} A voltage equal to the voltage applied to electrode Gj- is applied to plates P and P ¹ , while a voltage which is 200 to 300% lower than that of plates P by 200 to 300% is applied to plates Q and Q ' and P 'applied voltage. There are then generated between the plates P and Q and between the plates P 'and Q ¹ voltage differences, respectively

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the deflectors F ₁ and F ₂ "form and cause the respective deflection of the beams B ₁ and B- in the sense of FIG.

_{The rays B 1} , Bg and B emanating from the cathode K pass through the openings g _1. ,, g " ₁₂ and g ^ of the grid elements G ₁₁ , G ₁₂ and G ₁ -, and are modulated with three different signals, which are fed between the cathode K and the grid members G ₁₁ , G ₁₂ and G ₁ V. They then go through the auxiliary lens L * *, indicated by dash-dotted lines in FIG. 9, which is mainly formed by the grid Gp and the electrode Gz - and intersect in the middle of the main lens L, indicated by dash-dotted lines, which is mainly formed by the electrodes G ,, G. and G ₁ - The rays B ₁ , B ₂ and B- then run after leaving of the electrode G ^ respectively between the plates Q and P, between the plates P and P 'and between the plates P' and Q ^1. Since the plates P and P 'have the same potential, the beam B _{2 is} not deflected during the _{rays B 1} and B ~ emerging from the lens L with diverging paths be directed so that they converge in a point on the electron receiving screen.

In the embodiment according to FIGS. 9 to 12 it is necessary that the signals _{are fed separately to the three grating elements G 11} , G ₁₂ , G ₁ ,, of the first grating G ₁ , since the three radiation sources K ₁ , K ₂ and K, are arranged on a single cathode K. In order for this to be achieved, the three right

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angular grid members G--, ^, G ₁₂ and G ₁ ^, in each of which the openings gij ι g ₁₂ ^uia ^ S ₁ * are arranged, provided with connecting pins 13 extending therefrom for receiving the signals for the independent modulation of the electron beams.

So that the mutual position of the openings gj-]> g ₁₂ ^{un (} * S-] 3 of the grid members G ₁ ^, G ₁₂ and G ₁ ^ precisely determined and with openings gp-i »S ₂₂ and S ₂ - * ^des second grid G ₂ are brought to coincide concentrically at a certain distance D (Mg. 12), _{two ceramic insulating pieces 14 are arranged between the grids G 1} and G _? according to FIGS. 11 and 12, each having a thickness corresponding to the distance D. Each of these insulating pieces 14 is provided over an entire surface with an electrically conductive cover layer 15, which can be formed on the corresponding surface, for example by metallizing the same, and three electrically conductive layers M ₁ , M ₂ and M ~ are arranged, each of which can be seen extend over the width of the opposite surface of each insulating piece 14 and have a uniform longitudinal spacing from one another The insulating strips 14 are attached to the pane 1 of the second grid G ₂ in a symmetrical position to the line II-II on which the openings ungen g _{? 1} , gpo and 5ρ · ζ are arranged. They are attached to the pane of the second grid with their conductive layers 13, for example by hard annealing. The grid members G ₁₁ , G ₁₂ and G ₁ ^ bridge the distance between the insulating pieces 14 and are, for example, also by brazing on the conductive layers

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M ₁ , Mp and M ~ of the insulating pieces "attached.

In Mg. 13, a single electron beam system A according to the invention is shown as an example in its application "to a chromatron-like color picture tube. The beam system has three electrically separated cathodes JL, K" and Kg, each of which is red, green and "blue" Color signals are supplied. The three cathodes are arranged in such a way that their electron-emitting surfaces lie _{on a straight line and in alignment with openings gjn »g 1G} and g _{1B of} a plate-shaped grid G _{1, which are likewise arranged.} A cup-shaped grating Gp is arranged just behind the grating G ₁ , the pane of which faces the grating G ₁ and is provided with three openings gp _R , g ₂ ß "U-TiCl gp-g, each of which is aligned with the openings gio» g _1G. and GIP. As lie in the previously described embodiment, the electron beam system with electrodes G ,, G, and GF is provided, which are also arranged ao as to form the dot-dash lines electron lenses L ¹ and L.

To the grid G ₁ and G ₂ and to the electrodes G ,, G, and G ₁ - of the radiation system A v / ground voltages applied on the basis of the cathode voltages corresponding to the voltages indicated in connection with Fig. 9. The from. The rays B ^, B ^ and B- ^ emanating from the cathodes Kp, K "and Kg pass through the openings g _1R » g _1G and g _{1B of} the first grid (L and then through the openings SnR ' ^g ? G ^and " ^e 2B sr? ± · '":. ■ :. Sitters / J ₉ ^ spwie then through the Elel-t ^ 3: ien lens L ^f

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through which the rays are deflected so that they see in the optical center of the main lens L intersect. The rays B _R and B ^ emerge from the main lens L in diverging directions, but are then deflected in a converging manner by a deflection device P, which corresponds to the deflectors ^ ₁ and P ₂ according to FIGS. 9 and 5 and again consists of shielding plates P and P ' and baffles Q and Q '. The beams Bq, B "and Bg deflected in a converging manner by this deflection device strike a parachute screen S after they have passed through a perforated electrode or shadow mask Gp which is arranged in front of the parachute screen S and to which a medium-high voltage V ™ is applied. The color screen S is provided with groups of red, green and blue phosphorescent stripes Sp, S "and SD, which are arranged in succession on a front plate Pp. _{Voltages Vp and V Q are} applied to the shielding plates and deflecting plates P and Q as well as P 'and Q' of the deflecting device P, these voltages being chosen so that the three beams B ", B _& and B ^ intersect at the point where the shadow mask Gp is arranged, and c th so only £ · corresponding strip EL, S "and S _B arrive. In this pail, the beams B _D , B «and B-, since they converge at the shadow mask Gp, are focused on the para screen S.

For scanning the three beams horizontally and vertically at the same time with respect to the Parbso screen as in known ones Picture tubes are known horizontal and vertical deflection means in the form of the bracket D arranged.

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If the color picture tube after I ¹ Ig. 13 red, green and blue color image _{signals are fed between the cathodes K R} , K “and Kg and the grid G · ^, then the three beams B _R , Bg and B ^ experience a brightness modulation, whereby a colored image is generated on the larbr screen .

In the embodiments according to Mg. 9 and 13 ", the convergence deflection device ¥ is of an electrostatic type. Instead, magnetic deflection devices I" can also be used, as shown in Mg. HA and 14B. Such a magnetic deflection device i ¹¹ has a magnetic screen member or an intercepting screen 16 in the form of a tube of rectangular cross-section, which is arranged in the axial direction behind the electrode G, not shown in Fig. 1.4A, in such a way that the central beam Bp Mg. 9 or B "after Mg. 13 can pass through it. On one side 16a (lower in Mg. 14A and 14B) of the screen 16, two magnetic plates 17a and 17b are arranged opposite one another at such a distance from one another that the beam B. or Bp can pass between them. On the other side 16b of the screen, two magnetic plates 18a and 18b are attached in the same way, between which the third beam B 1 and 33 _B can pass. The ends of the plates 17a, 17b and 18a, 18b facing the screen 16 are, as can be seen in particular from Mg Panels preferred

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are bent outwards away from each other and extend along the inner wall surface of the neck part of the tubular piston N, which is indicated by the dash-dotted line in Fig. HB is indicated. The outer ends 20a and 20b of the Plates 18a and 18b are bent outwards in the same way and, like the ends 19a and 19b, form magnetic poles. On the outside of the tube piston F are electromagnets 21 and 22 are arranged opposite one another, each with the windings 2j5 surrounding the magnetic cores 25 and 26 and 24 are provided. The magnetic core 25 has magnetic poles 25a and 25b which are opposite to the magnetic poles 19a and 19b, while the magnetic core 26 is provided with magnetic poles 26a and 26b opposite to the magnetic poles 20a and 20b.

In the arrangement described, the three beams B ₁ , Bo and B-, after they have intersected in the optical center of the main lens envor direction L and emerged from the electrode Gp., Each between the magnetic plates 17a, 17b, through the screen 16 and between the opposing magnetic plates 18a, 18b. The beam Bp is not deflected here because it is shielded from the external magnetic field by the intercepting screen 16. The beams B-, and B ~, on the other hand, are deflected by the magnetic flux between the magnetic plates 17a and 17b and between the plates 18a, 18b, which is caused by the steady convergence current flow through the electromagnets 21, and 22, so that the three beams B ₁ , Bp and B ^ in the desired V / eise either in the image point of the receiving screen or at the front of the

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sem arranged shadow mask converge. The through the Static convergence currents flowing through electromagnets 21 and 22 can also be superimposed by dynamic convergence currents, so that in this pail a special dynamic Convergence is not required.

Because the sides 16a and 16b of the interception screen 16 facing inner ends of the magnetic plates 17a, 17b and 18a, 18b bent converging inwards according to FIG. HB are, the beams are guided very close to one another or along the intercepting screen 16, so that it is possible a disturbance of the magnetic field along the path of the rays B. and B ~ by the magnetic flux from the magnetic plates 17a, 17b, 18a, 18b to the magnetic interception screen 16 effective to avoid. This also avoids distortion of the pixels on the receiving screen. When the distance between the opposing magnetic plates equal to a, the length of the bent part of each of these plates equals c, the distance between the free edges of the converging inner ends equals b and the small side of the rectangle of the Interception screen 16 is equal to d, the best results are achieved when

b / a = 0.625; | _a = c / a = 0.325

and the angle between the inner bent ends is about 30 ° to 60 °. If the magnetic interception screen 16

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facing inner ends of the magnetic plates are not bent _t so the magnetic field is not distributed uniformly, because the magnetic flux in the beam path of the beams B ^ and B _7, under the influence of the magnetic flux of the magnetic plates 17a, 17b and 18a, 18b to the Abfangsobirm 16 is curved. The distortion caused by such an uneven magnetic field becomes particularly great if the distance between the adjacent beams is reduced so that the beams come close to the side surfaces of the magnetic interception screen 16. However, such distortion can be effectively avoided if the magnetic plates are bent as described.

The electromagnets 21 and 22 can also be permanent magnets replaces v / earth.

The foregoing is the application of the invention to color picture tubes in which a single electron beam system is used to deliver three electron beams generate that with the usual red, green and blue color signals experience a brightness modulation. However, the electron beam system of the invention can be applied to others Cathode ray tubes are used with multiple beams pointing to a common point or several separate points an electron beam receiving screen.

The invention is not limited to the described embodiments

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forms that can be changed in some ways can without departing from the scope of the invention characterized in the claims.

Claims;

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Claims (1)

Claims 1 , J Cathode ray tube with a single electron beam system for generating several electron beams and —a receiving screen for the electron beams, "in which the electron beams intersect at a point in the tube between the beam generating source and the receiving screen and one for all in the beam path Rays common lens device for focusing the rays is arranged on the receiving screen, characterized in that the lOkussier-Lens device (It) has an o ^ feiaeiies center and is arranged so that it is with the optical center essentially at the intersection of the rays (B ^ , Bg »B ,; Β *., B„, B _R ) and here-uroh-coma -and spherical aberration are avoided. 2, tube according to claim 1, characterized in that the focusing lens device (L) has a plurality of electrodes (G ,, Gr., Gr ₁ -) applied to different electrical voltages, which create an electron lens field for focusing the rays (B ₁ , B ^, B '; B _B , B ^, B _R ) ". 3. Tube according to claim 1 or 2, wherein the rays of of the radiation generating source essentially parallel to one another are emitted, characterized in that between the radiation generation source (K ^, Kg »K ^; Kg, K ^ t K ^) and the The focusing lens device (L) is an auxiliary lens device 209817/0113 (L ¹ ) is arranged, which brings about a convergence of the rays and their sons in the optical center of the focusing lens device. 4. Tube according to claim 3, characterized in that the auxiliary lens device (L ¹ ) has a plurality of electrodes or grids (G ₁ , G ₂ , G,) applied to different electrical voltages, which have an electron lens field for converging the rays passing through it ( B ₁ , B ₂ , B ~; Β- ™, B ~, Bo) form in the optical center of the focusing lens device (L). 5. Tube according to claim 1 or 2 with a plurality of individual radiation generation sources each serving to generate a beam, characterized in that the radiation generation sources (K ₁ , K ₂ , K ~) are arranged on a carrier which at the same time enables the beams (B ₁ , B ₂ , B,) and their cutting in the optical center of the focusing lens device (L) brings about (Mg. 6 and 8). 6. Tube according to one of the preceding claims, characterized in that the electron beam system (A) between the focusing lens device (L) and the receiving screen (S) is provided with a deflection device (F, F ') which those beams (B ₁ , B ,; B ^, B _R ), which emerge from the focusing lens device (L) in directions diverging from the optical axis of the same, deflects all rays (B ₁ , B ₂ , B ^; B _B , B _ß , B _R ) on a common point on the screen (S) converge, 209817/0113 BATH ORIGINAL 7. The tube of claim 6, wherein the electron receiving screen through a phosphorescent screen and a "before." this arranged shadow mask is formed, characterized in that the Folmssier Linsenvorriehtung (L) all Rays (B ₁ ,, B _n , Β _π ) focused on the screen and the Ab lS U- xt Steering device (i ¹ , "I") brings about such a convergence of the rays that all rays converge on a common point of the shadow mask (Gp). 8. Tube according to claim 6 or 7, characterized in that the deflection device (]?) Is provided with spaced apart deflection plates (P, Q, P ¹ , Q ¹ ) of different electrical potential, which are on both sides of the beam path of each diverging beam (B _{1 f} B ~; Bo, Bp) are arranged and deflect these rays electrostatically. 9. Tube according to claim 6 or 7, characterized in that the deflection device (Ij) with devices (16, 17a, 17b, 18a, 18b, 21, 22) for generating a magnetic field transversely to the beam path of each diverging beam (B ,, , B _R ) and is provided for magnetic deflection of the beam. 10. Tube according to claim 8 or 9, with three sources of radiation generation for generating one beam at a time, characterized in that the one beam ene r ζ eugungs que lie (K ~) as central radiation source in the optical axis of the lOkussier- 209817/0113 ORIGINAL BATHROOM Lens device (L) and the "two other radiation sources (Kn, K _R )" on both sides of the first radiation generation source at the same distance from the same on a straight line diametrically through the optical axis are arranged in such a way that only those of these two others Beam generating sources (ICg, K _R ) emitted rays (Bg, B _R ) run on diverging paths as they emerge from the focusing lens device. 11. Tube according to claim 10, characterized in that the deflection device (F) has two inner deflection plates (P, P ') of the same electrical potential, which are located on both sides of the optical axis for the passage between them from the central radiation source (K " ) emitted and through the focusing line device (L) passed beam (B ") are arranged within and at a distance from two outer deflection plates (Q, Q ¹ ), between which and the W jeweilc inner baffle pass the beams (B ^, B _R) of the other two beam generation sources (Kn, K ") and for electrostatically deflecting the two beams on the optical axis to a by the electric potential of the inner deflection plates (P, P ' ) have different electrical potentials. 12. Tube according to claim 9 and 10, characterized in that that the gate directions for generating the magnetic field from a central magnetic interception screen (16) are tubular 0 9 8 17/0113 _aAD Design for the passage of the from the central radiation source (Kq.) Emitted and through the focusing lens device (L) passed through beam (B ") as well as from two arranged on both sides of the middle initial screen Pairs of magnetic plates (17a, 171 »» 18a, 18b), their plates (17a, 17b or 18a, 18b) for the passage of the Rays (IL ,, B ") of the other two sources of radiation (K-g, Κ-,) are arranged at a distance from each other and its to generate the magnetic field to be used to deflect these two beams onto the optical axis between the Plates of each plate pair is assigned a magnet (21 or 22) » 13. Ilöhre according to claim 12, characterized in that the magnetic plates of each plate pair (I7a, 17b or 18a, 18b) are bent converging towards one another at their inner ends facing the central interception screen (16), so that a "distortion of the respective beam (B ,,, B ") by non-uniformity of the magnetic field reduces v / ill. 14. Ilöhre according to one of claims 4 to 13 »in which the Gtrahlerzagngsquelle is formed by an electron-emitting cathode device, characterized in that the grids (G ₁ , G ₂ ) two in close succession behind the cathode device (K; Kg, ^K (#r) arranged and with ^ congruent openings Cg ₁₁ , g ₁₂ , g ₁₃ ; g _g1 »g ₂₂ » S ₂ ^) ^for BAD ORJGINAi. 209817/0113 each ray (IL, Bp. B-; B ", B", B ^) are provided "around the To direct beams parallel to each other, 15 «Tube according to claim 14», characterized in that the second sitter (G ₂ ) is designed in the form of a simple ^{disc (1) containing the openings (gp- |> S? 2 un <} * ^ 23 ^, behind which the the focusing lens device (L) forming electrodes (G. *, G, and G ₁ -) successively with P tubular shape and different electrical potential to form the one used to focus the rays (B- ^, B ~, B ") Electron lens field are arranged and at their peripheral edge to form a device for the son of the rays in the optical center of the focussing -Lisen-in front- : ichtung (L) is connected to a cylindrical side wall (2) facing the same, which is opposite to the electrical Potential of the next electrode (G,) has a different electrical potential in order to generate the auxiliary electron k field for converging the mutually parallel rays to form. 16. Tube according to claim 14 »characterized in that the cathode device is formed by a single cathode (K) with an electron-emitting surface and the first grid (G>,) arranged behind the cathode with several, each one of the beams (B ^, B «, B _R ) corresponding and an opening (g -, - ρ g ₁₂ » S ^) ^{having lattice members (G -} -J 1 »^ ₁ P * ^& i3 ^ is provided, which at a small distance opposite 209817/0113 BAD ORIGtNAL of the electron-emitting surface and behind which a simple disc (1) of the second grid (G ₂ ) with the openings (g ₂ -j, go? »& 23 ^ ¹ ^ ¹¹ * ^he interposition of spacer and insulating members (14 ), which are attached to the grid members of the first grid and to the pane of the second grid, a certain distance (D) s between the grids and the covering position of the openings arranged in the two grids (g ₁₁ , g ₁₂ , g ₁₅ ? G ₂₁ , g ₂₂ , g ₂ ^). The patent attorney BATH 20b817 / 0113 ... 3i blank page