JPS60216430A - Electron gun structure - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention relates] The present invention generally relates to an electron gun assembly used in a color image display device.

[Prior art]

When shadow-mask multi-beam color picture tubes were first used in color image displays, dynamic concentration correction circuits were used to ensure that the beam was focused at every point in the scanning raster on the display screen. Since then, self-focusing display systems have been developed, such as those described in U.S. Pat. No. 3,800,176, which eliminate the need for dynamic concentration correction circuits. In the system of the above-mentioned US patent, three in-line electron beams are deflected by a deflection magnetic field with inhomogeneities that produce negative horizontal axial aberrations and positive vertical axial aberrations such that substantial concentration is obtained at all rask points. pass through.

Although the beam spacing was kept below approximately 5.08 mm to simplify the concentration conditions, the beam positioning opening provided in the oblong element of the focusing electrode of the electron gun source for the scanned beam was reduced. There is a limit to the diameter of the hole. Since the effective diameter of the focusing lens for each beam is determined by the diameter of this aperture, if this aperture is small, a problem arises in which the beam spot is deformed due to spherical aberration associated with a small diameter lens.

However, later it became possible to widen the beam spacing and increase the aperture diameter of the focusing electrode, which reduced the problem of spot deformation but increased the problem of concentration.

For example, in the next improvement of the self-focusing display system described in Hamano et al.'s paper ``Mini Neck Color Video Tube'' published in the March/April 1980 issue of the Toshiba Review, the outside diameter of the neck was usually used. (2, ll city and 36.5f
l) A tube yoke assembly is used in which a relatively compact deflection yoke is attached to a color picture tube that is significantly smaller (g 2.5 mm). According to this paper, reducing the neck diameter saves horizontal deflection power and increases deflection sensitivity by 2.
0-30% improvement, but the dimensions of the neck area are sufficient for focusing performance and high voltage stability (i.e. reliability for discharge)
This will make it more difficult to obtain.

[Disclosure of the invention]

The electron gun assembly of the present invention is an electron gun assembly that generates three in-line electron beams, and includes a common asymmetric focusing lens for the beams (e.g., lens 18) disposed across the path of the beams. and the focusing lens has a maximum width dimension (e.g., f6) larger in a first direction (e.g., horizontal direction) than a maximum width dimension (e.g., f4) in a second direction (e.g., vertical direction) orthogonal to the first direction (e.g., horizontal direction). It is designed to show. The electron gun assembly of the present invention further forms each of the beams so that the cross section of each of the beams has a larger dimension in the first direction than a dimension in the second direction at the entrance of the focusing lens. means (for example, a recessed portion 68).

[Embodiments of the invention]

In the embodiment of the present invention, a normal tube having a neck outer diameter of 29.11ffff is used for the tube yoke structure. This results in a neck diameter of 22. ! The handling problems associated with the fragility of Mffi products are eliminated, both in tube manufacture and image display assembly, and the long evacuation time problems associated with evacuation of mini-neck J-tubes are also eliminated.

Using a 90° deflection angle, the S spacing is approximately 5.0811ff
The inner diameter of the horizontal deflection winding window at the beam exit end of the tube with a diameter of less than 29.1lffff is approximately 67.0 mm.
(i.e. Q per 1 degree of deflection angle, less than 76 fflff) and a compact deflection yoke of semi-troid type (i.e. vertical deflection winding is toroid type and horizontal deflection winding is saddle type) to perform self-concentrating 19V image display. . This compact 9
The stored energy requirement of the 0° yoke horizontal deflection winding is only 1.85 mJ at an anode voltage of 25 KV operation.

Using a 110° deflection angle, a tube with the same S spacing and neck diameter as above would have an inner diameter of approximately 81.5 at the beam exit end of the window.
111M (i.e. in this case also 0.76 per degree of deflection angle)
A self-concentrating 19V image display is performed by providing a compact semi-troid type yoke (less than 10cm). This compact 11
The stored energy requirement of the horizontal deflection winding of the 0° yoke is only 3.5 mJ at an anode voltage of 25 KV operation.

To appreciate the relative compactness of the yoke in the embodiment described above, it is important to note that the comparable internal diameter of a 90° deflection yoke used for a long time in the past with the wide S-spacing tubes described above is, for example, about 78.2πm; For example, the inner diameter of the 1100 deflection yoke used for a long time with the wide S-spacing tube is about 108.7 am (both inner diameters are
．． 76 MWI).

In both of the above-mentioned embodiments, a high level of focusing performance is ensured by inserting a focusing electrode assembly having the general shape disclosed in US Pat. In this shape, a part of the main focusing electrode at the beam exit end of the electron gun assembly is perpendicular to the long axis of the tube neck, and three circular holes are formed here through which each electron beam passes separately.

Adjacent portions of the main focusing electrode also extend longitudinally from the portion to form a common enclosure for the entire beam path. The surrounding walls of the main focusing electrode are juxtaposed to form a common focusing lens for the beam therebetween. The inner major axis of the common surrounding wall of the last focusing electrode is, for example, 17.65 mm, and the inner major axis of the common surrounding wall of the next focusing electrode at the last end is, for example, 1.
8.16ffffi.

If you make this size, it will be 29. The internal space of the neck portion with a diameter of ll+/1ffi is wider (compared to the above-mentioned "mini-neck"), and a focusing lens whose major axis is at least 3.5 times the center distance of the apertures is produced. The required concentration effect on the beam emitted from the electron gun assembly is controlled by the difference between the long spans.

In one example of an electron gun assembly embodying the present invention, the shape of the inner periphery of the common surrounding wall of the next last focusing electrode is, for example, a race track shape as described in the above-mentioned US patent application. In contrast, the inner periphery of the common surrounding wall of the last focusing electrode has a dumbbell shape, for example, as described in US Pat. No. 2,822,288. Furthermore, there is a lens asymmetry in the beam forming region of the electron gun assembly of the type that reduces the vertical dimension of each beam cross section at the entrance of the main focusing lens relative to its horizontal dimension. This asymmetry is introduced, for example, by cooperating a perpendicularly elongated rectangular opening with each circular hole in the first grid (G1) of the electron gun assembly.

By appropriately selecting the dimensions of the above-mentioned "racetrack-shaped" and "dumbbell-shaped" surrounding walls and the rectangular opening of Gl, the allowable shape of the light spot at the center and edge of the display raster is related to these elements. Obtained by optimal balance of astigmatism.

FIG. 1 is a plan view of a picture tube yoke structure of a color image display device equipped with an electron gun structure of the present invention.
Reference numeral 1 denotes a cylindrical neck portion 11N (accommodating an in-line electron gun assembly), a substantially rectangular screen portion housing a display surface (not shown due to the size of the drawing), and a funnel portion 11F (partially connected) connecting the two. (as shown).

A yoke mounting base 17 of the deflection yoke structure 13 surrounds the adjacent portion of the neck portion 11N and the funnel portion 11F.

The yoke structure 13 includes a vertical deflection winding 13V wound toroidally around a magnetic core 15 of magnetizable material surrounding a yoke mount 17 (of insulating material) and a horizontal deflection winding 13H not visible in FIG. However, as shown in the front view of the removed yoke structure 13 in FIG. .

The front end of the winding 13H is wound up and housed within the front edge 17F of the mounting base 17, and the rear end (not visible in FIGS. 1 and 2) is similarly housed within the rear edge 17R of the base 17. is housed in.

In FIG. 1, dimensional relationships suitable for one embodiment of the present invention are specified, and the compactness of the deflection yoke formed by one winding and 13 squares (the deflection angle given by the yoke) is 1. The front inner diameter corresponds to about 0,76 degrees per degree.
1”. As shown in FIG. 2, this inner diameter is measured at the front end of the active conductor of saddle winding 13H (ie, at the beam exit end of the window formed by the winding). color video tube 1
The outer diameter rOJ of the neck part 11N of 1 is the normal 29.1:L
It has become lllm. The electrostatic beam focusing lens 18 (indicated by a dotted line lens) formed between the electrodes of the electron gun assembly in the neck part 13 is located in the horizontal direction (that is, on the horizontal plane occupied by the three beam axes R, G, and B). ) across dimension rf
J is greater than or equal to 3.5 times the distance between adjacent beam axes "g" at the lens entrance (eg, approximately (9) 5.08 mm).

FIG. 3 is a partially sectional side view of one embodiment of an electron gun assembly according to the present invention suitable for the neck portion 11N of the color picture tube 11 of FIG. The electrodes of the electron gun assembly in FIG. 3 include three cathodes 21 (only one is visible in the side view of FIG. 3);
Control grid (Gl) 23, shielding grid CG2) 25
, a first accelerating and focusing electrode (G3) 27 and a second accelerating and focusing electrode (G4) 29. The mounts for these electron gun elements are provided by a pair of parallel glass columns 33a1331) between which each electrode is supported.

Each cathode 21 is aligned with each aperture in each of the G1, G2, G3, and G4 electrodes so that electrons emitted from the cathode can pass through the apertures and reach the display surface of the picture tube. Electrons emitted from the cathode are connected to Gl and G held at different unidirectional potentials (e.g. O volts and +1100 volts, respectively).
Three electron beams are formed by each electrostatic beam forming lens set between opposing aperture areas of two electrodes 23, 25. This beam is first focused on the display surface by G3, G
The main electrostatic focusing lens (1 in FIG.
8). As an example, the G3 electrode is held at a potential (eg, +6500V) that is 26% of the potential applied to the G4 electrode (eg, +25KV).

The G3 electrode 27 consists of two cup-shaped elements 27a and 27b whose flanged open ends abut each other, and the front view of the front element 27a is shown in FIG. 4, and the cross-sectional view taken along the line CC' is shown in FIG. 8, a rear view of the rear element 27b is shown in FIG. 6, and a cross-sectional view thereof along line EE' is shown in FIG. 1O.

The two G4 electrodes consist of a cup-shaped element 29a and an electrostatic shielding cup 29b whose flanged open end and apertured closed end abut against each other. A rear view of the element 29a is shown in FIG. 5, and a cross-sectional view taken along the line DD' is shown in FIG.

Three openings 44 are formed in a portion 40 perpendicular to the axis that corresponds to the bottom of the concave portion at the closed front end of the G3 element 27a.

The peripheral wall 42 of the concave portion, which forms a common surrounding wall for the three beams emitted from each of the apertures 44, has semicircular sides on both sides and parallel straight lines between them. It looks like a "race truck" type. The maximum horizontal inner diameter of the surrounding wall of G3 lies on the plane of the beam axis, and is indicated by fl in FIG. Further, the maximum vertical inner diameter of the surrounding wall portion of G3 is determined by the interval between the parallel linear portions of the surrounding wall, and is represented by f in FIG. 4. This vertical inner diameter is equal to f2 at any beam position.

Three openings 54 are also formed in a portion 50 perpendicular to the axis that corresponds to the bottom of the recess at the closed rear end of the G4 element 29a.The recess forms a common surrounding wall for the three beams incident on the G4 electrode. The peripheral wall 52 has a parallel straight line shape at the center, but at both ends it has an extra semicircular shape with a diameter larger than the distance between the parallel walls at the center, forming a "dark bell" shape as shown in FIG. appear. Because of this shape, G at the axial position of the central hole
The vertical inner diameter f5 of the surrounding wall of No. 4 is smaller than that at the axial position of the openings on both sides. The maximum horizontal inner diameter of the surrounding wall of G4 is in the plane of the beam axis and is indicated by f3 in FIG. G again
The maximum vertical inner diameter of the enclosure wall 4 corresponds to the diameter of the semicircles at both ends, and is indicated by f4 in FIG.

Each of the G3.04 electrodes “Race Truck” and “Alin” (
12) The maximum outer width of the mold area is the same and f is shown in Figures 8 and 9.
6. The diameter of the opening 44.54 is also the same, and the 8th
It is indicated by α in the figure and FIG. The depths of the recesses of the G3 and G4 electrodes are also equal and are indicated by r in FIGS. 8 and 9. However, the depth of the hole in G3 is a□ in Figure 8.
) and that of 04 (ag in Figure 9) are not equal. d,
f,, f2, f3, f4, f5, f6, r, a, G2
For example, the value of is as follows. d=4. olIff, f
l: 18.1611N, f2=a, oochu, f3-1
7.65 MM, f4=7.2411! , f :6,8
6+11111, f6=22.22 txm, r=2
．． 92MMa□=o, G6 Tomo, G2:1.141111
! 10 The center spacing g between adjacent apertures of each focusing electrode is, for example, 5.08111M as described with respect to FIG. The axial lengths of the elements 27a and 29a are, for example, 1
2.451+! l! 1. ．． 3.05111111, and the 03.04 spacing of the structure in Figure 3 is, for example, 1.27ffll.
! It is.

The prominent main focusing lens formed between the elements 2'7a, 29a has equipotential lines of relatively low curvature in the region that extends continuously between the opposing recessed walls and intersects the beam path; It appears as a large single lens that intersects all of the book's electron beam paths. In contrast, (13) in conventional electron guns without recesses, a significant focusing effect is provided by strong equipotential lines with relatively high curvature concentrated in each unrecessed aperture region of the focusing electrode. Since the elements 27a, 29a of the illustrated embodiment have recesses, the relatively high curvature equipotential lines in the aperture region play little role in determining the quality of the focusing performance, but rather the recessed walls. Determined by the dimensions of the large lens involved.

This ensures that the level of undesirable spherical aberration effects is relatively independent of aperture diameter and is dominated primarily by the dimensions of the large lens formed by the recessed wall, resulting in a narrow beam even when limiting the aperture diameter. interval (for example, the above-mentioned 5.os+u
+) can be used.

Under these conditions, the diameter of the neck becomes the limiting factor in focusing performance, and using the aforementioned dimensions, good high voltage stability (even with worst glass tolerances) can be achieved within the neck of the above normal diameter (i.e. 29.11 s+s+). Very good focusing quality can be obtained with the external dimensions of the focusing electrode such that it is easily applied with an acceptable spacing to the inner wall of the envelope that is compatible with the . In contrast, the neck of the Hama et al. "mini-neck" tube described above does not accommodate focusing electrode structures of the dimensions described above.

On the converging side of the main electrostatic beam focusing lens 18 is a concave portion of the element having a racetrack shaped peripheral wall as described above. Such horizontal-to-vertical asymmetric shapes create astigmatism effects and
The vertical lines of the electron beam λ passing through the recesses of the three electrodes converge to a greater extent than the horizontal lines. If the concave portion of the G4 electrode existing alongside this is of the same race track shape, the divergent side of the main focusing lens 18 also exhibits an astigmatism effect in the compensation direction. This compensating effect is inadequately sized to prevent the presence of net astigmatism and may interfere with forming a light spot of the desired shape on the display surface.

One way to make the necessary additions to compensate for this astigmatism is to
As described in the above-mentioned U.S. Patent Application No. 201692, a pair of metal bands are used to form a slot in an opening in a plate perpendicular to the axis on the contact surface of the elements 29a and 29b, and this method Examples of dimensions of each part are given in the US patent application.

Another way to make the addition necessary to compensate for astigmatism is −(15
) As described in the above-mentioned US Patent Application No. 282,228, the shape of the concave portion of the G4 electrode is changed to a "dull shape". For this purpose, the reduction in the vertical dimension of its dumbbell-shaped central region is selected to substantially completely compensate for the astigmatism of the diverging part of the main focusing lens itself, or
Choose to replenish the compensation effect of 4 slots. Examples of the dimensions of each part obtained by this method are also described in that US application.

Here, G
Another method of astigmatism compensation is used which combines the compensation effect obtained by introducing a suitable asymmetry in the beam-forming lens formed by the L, G2 electrodes 23.25.

In order to understand the nature of this compensation effect, it is appropriate to consider the structure of the G1 electrode 23 as shown in the rear view in FIG. 7 and in cross-section in FIGS. 7a and 7b.

There are three openings 64 (diameter d) in the center of the G1 electrode 23.
Each opening communicates with a recess 66 on the back side and a recess 68 on the front side of the electrode 23. The shape of the circumferential wall of each concave portion 66 on the back surface is circular, and its diameter is large enough to receive the front end (16) of the cathode 21 (outline indicated by dotted lines in FIG. 7b) with an appropriate gap. Further, the peripheral wall of each of the front recesses 68 is in the shape of a rectangular slot whose vertical dimension (2) is much larger than its horizontal dimension.

The center distance g between adjacent openings 64 is 03 and G4 described above.
It is the same as that of the electrode. Examples of other dimensions of the 01 electrode 23 are as follows. d engineering = 0.615 myn,
k = 3.075Fffff, h = 0.711
txyn, V = 2.134 tnM, depth a3 of opening hole 64 = 0,102+1 [, slot 68) depth a
4=0.203, depth a5 of recessed part 66=0.45
7 mm. When assembled with the cathode 21 and the G2 electrode 25, the distance between the cathode 21 and the bottom of the recess 66 is, for example, 152M.
The interval between G1 and 02 is, for example, 0.178 h.

In the assembled state shown in FIG. 3, the three circular holes 26 of the G2 electrode 25 are aligned one by one with the apertures 64 of the G1 electrode 23, and the slots 68 therebetween are aligned with each converging side of the G1-02 beam forming electrode. Introducing an asymmetry into. This moves the intersection of the vertical lines of each beam further along each beam path than the intersection of the horizontal lines, so that the cross-section of each beam entering the main focusing lens has a horizontal dimension larger than its vertical dimension. , the direction of the "pre-deformation" of the cross-sectional shape of this beam (17) is the direction that compensates for the light point deformation effect of the astigmatism of the main focusing lens.

One of the advantages of "pre-deforming" the beam before it enters the main focusing lens, as described above, is that it promotes equalization of focusing quality in the vertical and horizontal dimensions. The asymmetry of the main focusing lens is such that the vertical dimension of the lens region that intersects the beam path is significantly larger than the diameter of the focusing electrode aperture (which limited the size of the focusing lens in conventional electron guns discussed above), but the horizontal dimension of that region It is of a nature that it becomes smaller. Each beam's vertical lines therefore see a smaller lens than its horizontal lines see.

The "pre-deformation" described above limits the vertical divergence of each beam as it passes through the main focusing lens, so that the separation of the vertical boundaries of correctly centered beams passing through a small, low quality vertical lens is large and high quality. so that the separation of the horizontal boundaries of the beam passing through the horizontal lens is less than that of the horizontal lens.

Another advantage of adding "pre-deformation" to the beam entering the main focusing lens described above is that the main focus of the beam in response to the fringe magnetic field of the toroidal vertical winding 13V generated behind the yoke structure 13 (18) is The problem of vertical flare above and below the raster, which is associated with an unfavorable vertical shift of the point of incidence on the focusing lens, is eliminated or reduced. Although efforts are made to magnetically shield the beam from this fringe field, particularly in the low velocity regions of the beam path, as discussed below, subsequent regions of the path are not substantially shielded from the fringe field. The aforementioned limitations on the vertical spread of each beam as it passes through the main focusing lens reduce the likelihood that shifts in the point of incidence due to fringe fields will push boundaries out of the relatively aberration-free region of the lens.

Another advantage of adding "pre-deformation" to the beam entering the main focusing lens described above is to reduce the adverse effect of the main horizontal deflection magnetic field imparted by the saddle winding 13H to the light spot shape on either side of the raster. . To produce the necessary self-focusing effect in the yoke structure, the horizontal deflection field is strongly pincushion-shaped over a significant portion of the axial length of the beam deflection region. An unfortunate consequence of this inhomogeneity of the horizontal deflection field is that it tends to result in over-focusing of the vertical lines of each beam on both sides of the raster (19), but with the "pre-deformation" described above, The vertical dimension of each beam as it passes through the deflection region is sufficiently compressed to reduce overfocusing effects on either side of the raster to within acceptable limits.

Reference is made to US Pat. No. 4,234,814 to explain the "pre-deformation" of the beams mentioned above. In the construction of this patent, a horizontally elongated rectangular slot is provided on the back surface of each circular aperture in aligned communication with each circular aperture of the 02 electrode, thereby introducing an asymmetry in the diverging portion of each beam-forming lens.
The vertical dimension of each beam passing through the main focusing lens is compressed relative to its horizontal dimension. G of the above-mentioned electron gun method
It can be seen that the advantage of introducing the aforementioned asymmetry into the l electrode is an improvement in the depth of focus in the vertical direction. This obtained depth of focus is usually determined by adjusting the focusing voltage (applied to the G3 electrode 27) using a focusing voltage adjusting potentiometer provided in the display system.
By making minute changes over this range, horizontal focusing can be optimized without significantly disturbing vertical focusing.

(20) As mentioned above, it is desirable to shield the low-velocity region of each beam path from the backward fringe magnetic field of the deflection yoke. For this purpose, a cup-shaped magnetic shielding element 31 is fitted into the rear element 27b of the G3 electrode 27, and their closed ends are abutted and fixed as seen in the structure of FIG. Figure 6 and 1
As shown in FIG. 0, three in-line holes 28 having a circular peripheral wall are formed at the closed end of the cup-shaped element 27b, and are also fitted in place at the closed end of the magnetic shielding fitting element 31. Three in-line apertures 32 are similarly formed with circular peripheral walls that align and communicate with apertures 28 when installed.

In the structure of FIG. 3, the opening 28 is the opening 26 of the G2 electrode 25.
are aligned with but axially separated. The dimensions of this part of the structure are, for example, as follows. Diameter of opening 26 =
0,615 mm, depth of hole 26 = 'Q, 5Q8 mm, diameter of hole 28: 1,524 mm, depth of hole 28 = 0
．． 254 mm, diameter of the aperture 32 = 2.54 m, depth of the aperture 32 = 0.254 mm, axial spacing of the aligned apertures 26.28: 0,838 mm, center distance between each adjacent aperture (G
) ==5,081+11°Magnetic shielding fitting element 31
For example, the axial length of G3 elements 27b and 27a is, for example, 5.31ff and 13.335ff+11 and 12.45ffl, respectively.
! ! It is. The length of this shielding element is 1/ of the total length of the G3 electrode.
4 or less) to shield the beam path in the front focal region;
It represents an acceptable compromise between two competing desires to eliminate distortion of the magnetic field that disturbs the four corner concentrations. The shielding element 31 is made of, for example, a magnetizable material (for example, nickel 5
2% iron and 48% iron (nickel alloy).

The front element 29'D of the G4 electrode 29 has a plurality of contact springs z30 around its front periphery, which contact the conventional carbon coating on the inner surface of the picture tube and apply an anode potential (e.g. 25 KV) to the G4 electrode.
). Cup-shaped element 291)
The closed end of the lens has three in-line apertures (not shown) with center-to-center spacing, e.g. For example, a high permeability magnetic member for comatic aberration correction disclosed in US Pat. No. 3,772,554 is attached.

(22) Other electrodes (cathode, Gl, 02,
Application of the operating potential to G3) takes place from the base of the picture tube via a conventional conductor arrangement (not shown).

The main focusing lens formed between the G3 and G4 electrodes of the structure of FIG. 3 has a net focusing effect on the three beams passing through it, so that the beam either exits this lens with a tendency to concentrate or , 29a influence the strength of this concentration effect. That is, this concentration effect increases when the size ratio favors the width of the enclosure wall of 04, and decreases when the size ratio favors the width of the enclosure wall of G3. In the embodiments whose dimensions are illustrated above, a reduction in concentration is desired, and G3, G4
It was found that the appropriate ratio of the surrounding wall width was 715/695.

When using the display scheme of FIG. 1, other neck surrounding devices are typically used to optimize the concentration of the beam at the center of the raster. This device may be of the adjustable magnetic ring type as described in US Pat. No. 3,725,831 or of the sheath type as described in US Pat. No. 4,162,470, for example.

FIG. 13 shows the electric current (23) of FIG. 3 that can be used in the device of FIG.
) is a schematic diagram of the modification of the sub-gun structure. In this modification, a pair of auxiliary focusing electrodes 27'', two'' are provided between the shielding grid 25' and the main acceleration focusing electrodes W27', 29'.

The main focusing lens is formed between this final electrode, which in this case constitutes the G5, G6 electrodes. The auxiliary focusing electrode (G3 electrode 27'') through which the beam passes first is energized with the same potential as the G5 electrode 27' (e.g. +8KV), while the other auxiliary focusing electrode (G4 electrode 29'') is energized with the G6 electrode 27''. It is energized at the same level as 29' (for example, 25 KV). As in the embodiment of FIG. 3, each beam (emitted from each cathode 21' (from electrons).

To realize this second embodiment, the G5 and G6 electrodes 27
', 29' for example, the G3 and G4 electrodes 27 of the structure shown in FIG.
．． It has the same shape as 29, has the above-mentioned dimensional order of ``race track type'' and 1 diminutive type, and has the above-mentioned 5.08 mm on the bottom.
juxtapose enclosure walls with recessed apertures with center-to-center spacing of .

A "pre-deformation" of the beam of the type described above is also introduced by the asymmetry of each beam-forming lens. (24) For example, the Gl and G2 electrodes 23' and 25' are constructed in the form of the above-mentioned US Pat. No. 4,234,814, and a horizontal rectangular slot is provided on the back surface of the G1 electrode 23' to connect the
, G2 between three circular holes with a center spacing of 5.08ffll+. For example, the intervening auxiliary focusing lenses 27", 29" formed of cup-shaped elements having three twin-line circular holes with center spacing as described above are used to control the beam passing through the main focusing lens and the next deflection area. Pairs G3-G4 and G4 with the net effect of a symmetrical reduction in cross-sectional dimension
- Introduce G5 lens. Although this size reduction may be desirable to reduce the overfocusing effect of the horizontal deflection field on the spot shape on either side of the raster, the central spot is larger than in the simpler two-pronged focusing scheme of Figure 3. Become.

Using the configuration of FIG. 13, the low velocity beam path region shielding effect described for the fitting element 31 is matched by forming the 03 electrode 27 from a high permeability material.

In order to increase the sensitivity of the deflection yoke of the method shown in Figure 1, the shape of the conical part of the deflection area of the funnel part 11F of the tube envelope is changed so that the effective conductor of the deflection winding 13H (25) of the compact yoke is in the neck shadow. It is desirable to select a beam path as close to the outermost beam path (towards the four corners of the raster) as possible while eliminating (impingement of the deflected beam against the inner surface of the funnel portion). Figure 11 shows one of the methods shown in Figure 1 using a 90' deflection angle.
The funnel shape selected to be suitable for the example is shown.

The formula representing this shape is as follows.

x=CO+01(Z)+02(Z2) 1003(Z3) 104(Z4)+05(Z5)+06(Z6)+07(Z
7) Here, X is the radius of the cone measured from the longitudinal axis A of the tube toward the outer surface of the envelope, and Z is 1.27 mm in front of the joining line between the neck part and the funnel part. Axis A at the point
It is the value expressed in units of distance measured from the plane 2 = 0 that intersects with the axis A in the direction of the display surface, in this case CQ = 15
．． 10490590, C1=-0,15822402
10, C2: 0.01162553080, C3
28,880522990 XIO', C4= -3,
877228960XIO, C5=7.249226
520 X10', C6=-6,'7238514
20X 1O-1C7:2.482776160X
10, and this value is valid for fin Z values between 9.35 and 52.0.

(26) Figure 12 shows a funnel shape selected to be suitable for one embodiment of the scheme of Figure 1 using a 110° deflection angle.

The formula representing this shape is as follows.

X=Co+C1(Z)+C2(Z2)+C3(Z3)+
04 (Z4) + 05 (Z"') where X is the radius of the cone measured from the longitudinal axis A to the outer surface of the envelope expressed in squares, and Z is 1.27 in front of the joining line between the neck and funnel parts. It is the distance measured in the direction of the display surface along the axis A from the plane 2 = 0 that intersects the axis A at the gate point, and in this case Co:
14.5840702, Ql=0.31253417
4, C2:0,0242187585, C3=-6,
99740898XlO-4, C4=1.64032
142 X 10-5, C5: 1.17802606
X 10-7, and this value is 1.53~50, Of
This is valid for the Z value of f.

For example, in the 1100 deflection angle 19 type embodiment of the method shown in FIG.
Envelope part 11F between y', winding 13 on the outer surface of IIN
The active conductors of H are brought into close abutment. 1st
In the funnel shape of Figure 2, the yoke (27) of length y-y' can be retracted by, for example, 5 to 6 degrees (for purity control) without impinging the beam on the corners of the envelope.

FIG. 14a shows the general form of the necessary non-uniformity function H2 of the horizontal deflection magnetic field required for the yoke of FIG.
It is shown in Here, the horizontal axis indicates the position along the longitudinal axis of the tube (the position of plane 2=0 in FIG. 12 is shown for reference), and the vertical axis indicates the degree of deviation from the uniform magnetic field. This 14th a
In the figure, the upward displacement (in the direction of arrow P) of the curve HH2 from the O axis indicates a "pincushion" non-uniformity of the magnetic field, and the downward displacement (
The displacement in the direction of arrow B) shows a "barrel-shaped" non-uniformity. The dotted curve HE(.) drawn with respect to the horizontal axis at the same position indicates the H6 function of the horizontal deflection magnetic field representing the relative magnetic field strength distribution along the tube axis. The positive waves of the curve I(E(2) The location of the strong pincushion field region mentioned above as the cause of the light spot shape problem is shown.

In Figure 14'b, the horizontal and vertical axes are the same as in Figure 14a.
4a shows the -(28) film shape of the necessary non-uniformity function H2 of the vertical deflection magnetic field to obtain a self-concentration result for the horizontal deflection magnetic field shown in FIG. 4a. The accompanying dotted curve ■Ho shows the H8 function of the vertical deflection magnetic field, and represents the relative magnetic field strength distribution along the tube axis. The left end of the curve VHo demonstrates the significant outflow of the vertical deflection field to the rear of the toroidal winding 13V, as discussed above regarding the benefits of "pre-deformation" of the beam.

For example, based on the shape of FIG. 12 and suggested by the curve of FIG. 14b, the main deflection effect of the method of FIG. It occurs in the area of gain.

Therefore, it can be seen that the lack of neck diameter reduction relied upon in the "mini-neck" approach is less important in achieving deflection efficiency. On the other hand, since there is no reduction in this diameter, focusing lens diameters not possible with the "mini-neck" method can be easily obtained, ensuring high focusing quality consistent with high voltage stability performance.

In FIG. 12, planes C and C' perpendicular to the axis represent the positions of the front and rear ends of the magnetic core 15 in the 110° deflection type 19 embodiment of the method shown in FIG. 1, respectively. As shown in the figure, the axial distance (29) between the front and rear ends of the effective conductor of the horizontal winding 13H (:5'-y') is determined from the axial distance (c-c') between the front and rear ends of the magnetic core 15. It is significantly larger (for example, 1.4 times), and there is more than 1/2 of the extra conducting wire length (for example, 62.5%) behind the magnetic core 15. Each plane 4 distances CC-y), (y-
y') and (y'-C') are, for example, about 7.62 gates, 50I8 drunkenness, and 12.7 fights, respectively.

The feature of significantly extending the effective conductor of the horizontal winding behind the magnetic core is the storage energy of the system (i.e., 1/2
HLH2) to help reduce the demand for the horizontal deflection center and move the horizontal deflection center rearward to make it substantially flush with the vertical deflection center. This restriction on the backward travel of the four water windings arises from consideration of the neck clearance under the required yoke retraction conditions and its effect on sufficient beam concentration at the four raster corners. The relative position and axial distance ratio between the winding 13H and the magnetic core 15 in FIG. It shows possible compromises. As can be seen by comparing the curves HE (.) and ■Ho in Figures 14a and 14b, the relative positions of the winding 13H and the magnetic core 15 in Figure 12 are equal to each intensity distribution amount (30) several times. It is desirable to substantially coincide with the axial inner device of the peak.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a combination of a picture tube and yoke equipped with an electron gun structure of the present invention, FIG. 2 is a front view of the yoke structure of the device shown in FIG. 1, and FIG. 3 is an image of the device shown in FIG. A partial cross-sectional side view of one embodiment of the electron gun assembly according to the present invention used in the neck portion of a tube, and FIGS. 4, 5, 6, and 7 show end faces of each element of the electron gun assembly of FIG. 3. Figure 7a is a cross-sectional view of the electron gun element in Figure 7 along line AA', Figure 7b is a cross-sectional view of the electron gun element in Figure 7 along line B-B', and Figure 8 is a cross-sectional view of the electron gun element in Figure 7 along line BB'. Fourth
9 is a cross-sectional view of the electron gun element in FIG. 5 along line D-D', and FIG. 10 is a cross-sectional view of the electron gun element in FIG. Sectional view along line E-E', first
Figure 1 is a diagram showing the picture tube funnel shape using a 90' deflection angle, Figure 12 is a diagram showing the picture tube funnel shape using a 110° deflection angle, and Figure 13 is a modification of the electron gun assembly in Figure 3. 14a and 1411) are the second
31 is a diagram illustrating a desirable non-uniformity function related to one embodiment of the yoke structure shown in FIG. 18... Focusing lens, 68... Concave portion, f4...
Maximum vertical inner diameter of surrounding wall of G4 (maximum across dimension in second direction), f6... Maximum outer width of G3, G4 (first
direction). Patent Applicant R Ciney Corporation Agent
Person Tetsu Shimizu 2 people (32) 13 Figure 15 Figure 7 Appetizer Figure 78 Figure 1 - 1) Continuation of X9 Figure 1 O Figure 1st page Priority claim [Phase] January 29, 2019 Japan [phase] United States (U.S.
S) 0 Inventor William Henry Amebacola Sen [Ltd.] 343734 7235 Giz Avenue, Pennsauken, New Jersey, United States

Claims (1)

[Claims] (1) An electron gun assembly for generating three in-line electron beams, comprising an element for setting a common asymmetrical focusing lens for the beams disposed across the path of the beams, the focusing lens being the cross-section of each of the beams at the entrance of the focusing lens exhibits a maximum width dimension in one direction that is greater than a maximum width dimension in a second direction perpendicular to the direction; an electron gun assembly, comprising means for forming each of the beams so that the dimension in the first direction is larger than the size of the beam in the first direction;