US3188534A - Convergence coil assembly - Google Patents

Description

2 Sheets-Sheet 1 Filed March 6, 1963 67 66 INVENTOR. I gizzcezzzJPaz/ ,1 TTORNEYS 2 Sheets-Sheet 2 Filed March 6, 1963 I NVEN TOR. noezz JPa z xiaa l 1 TTORNEYS United States Patent 3,188,534 CONVERGENSE COIL ASSEMBLY Vincent J. Patti, Norridge, Ill., assignor to Thompson Rargo Wooldridge, Inc., Cleveland, Ohio, a corporation of hi0 Filed Mar. 6, 1963, Ser. No. 263,304 Claims. (Cl. 317-200) The present invention relates to an improved electromagnetic convergence assembly for a cathode ray tube.

-The convergence assembly of the present invention is designed for operation with a color kinescope of the type employing a luminescent screen as part of a target electrode structure. Such screens include different phosphor areas which produce differently colored light when excited by electron beam components striking the target structure from different angles, the angle of impingement determining the particular color of the light produced by the phosphor-areas. I

For the satisfactory operation of such kinescopes, it is necessary to effect substantial convergence of the different electron beams at all points of the raster scanned by the beams at the target electrode structure.

One commonly used type of apparatus for controlling the convergence of a plurality of electron beams at a target electrode structure includes individual electromagnetic means located symmetrically about the axis of the tube neck and adjacent to the predefiection paths of the respective beams, and energized from the beam deflection circuit in a manner sutficient to effect the desired beam convergence. Typically, the individual convergence electromagnets are energized by waves which are available from both the vertical and horizontal deflection circuits which provide the scanning deflection of the beams.

Since the electron guns which produce the various electron beams in a color kinescope are symmetrically arranged about the peripheryof the tube neck, it is important that the magnetic circuits must be similarly aligned. The difiiculty arises because the neck diameters of various color kinescopes vary within substantial limits, on the order of one-quarter inch between extremes. There is a distinct mechanical problem presented, therefore, in employing a particularconvergence electromagnetic assembly with tubes of various sizes, since it is necessary that the magnetic circuits. retain their proper orientation with respect to the longiudinal axis of the kinescope while still retaining the symmetrical orientation of the magnetic structures about the tube neck.

In view of these requirements, the mechanical structure for housing the convergence electromagnets may be come quite complex and hence'expensive. Furthermore, such structures frequently"require considerable assembly time, particularly in thef'r'natter of securing external leads to the coils.

One of the objects of the present invention is to provide an improved convergence coil assembly which is usable with kinescopes having different neck diameters.

Still another object of the invention is to provide a convergence coil assembly for color kinescopes which is economical to manufacture and assemble.

A further object of the invention is to provide an improved type of housing for convergence coil assemblies making it considerably simpler to connect external'leads 'to the coils contained Within the housing.

A further object of the invention is to provide an improved type of housing for convergence coil assemblies, which housing has permeability adjusting means accessible from the outside of the housing to vary the reluctance of the magnetic circuits contained in the housing.

A further description of the present invention will be made in conjunction with the attached sheets of drawings which illustrate several embodiments of the invention.

. cable In the drawings:

FIGURE 1 is a view in elevation of an improved convergence coil assembly according to the present invention, illustrating the manner in which the assembly is placed about the neck of a cathode ray tube, a portion of the assembly being shown in completely assembled relation, another being shown with a portion of the housing removed to show the interior construction and a third portion of the assembly being shown completely devoid of magnetic components to illustrate the configuration of the housing section;

FIGURE 2 is a plan view of the assembly shown in FIGURE 1 looking upwardly into the structure;

FIGURE 3 is a view similar to FIGURE 1 but illustrating a somewhat modified form of the invention; and

FIGURE 4 is a fragmentary View of the tube engaging portion of the housing, on an enlarged scale, and also illustrating the coupling means by which the separate housings of the convergence coil assembly are interlocked.

As shown in the drawings:

In FIGURE 1, reference numeral 1%) indicates generally an assembled convergence coil assembly consisting of three identical housings 11, 12, and 13 disposed symmetrically about the longitudinal axis of the neck of a kinescope whose neck has been diagrammatically illus trated by means of the dashed lines 14.

Each of the housings 11, 12, and I3 is conveniently made from molded resinous materials such as polyethylene, polystyrene, or the like. Each of the housings is made in two sections 16 and 17 which mate along a line 18. The configuration of the section 17 is best illustrated in FIGURE 1 of the drawings, particularly in the lower left hand and lower right hand portions. As shown in that figure, the section 17 includes opposed wall portions 19 and 21 and a base for receiving a U-shaped magnetic core 23. A spring member 24 is bottomed on the wall 22 and urges the core 23 inwardly so that its pole faces 26 and 27 are snugly received in correspondingly shaped recesses '28 and 29 provided in the section 17. p

The legs of the core member 23 are provided with a plurality of coils on each leg, consisting of a vertical frequency exciter coil 31 and a horizontal frequency exciter coil 32 mounted on one leg, and a corresponding vertical frequency excitcr coil 33 and a horizontal frequency exciter coil 34 and mounted on the opposed leg. The corresponding vertical frequency exciter coils 31 and 33 and the horizontal frequency exciter coils 32 and 34 may be connected together. External connections from the coils are made by means of conductors 36,37, 38, and 39 which are connected to conductors 41, 42, 43, and 44 respectively. These last named conductors are part of a illustrated generally at reference numeral 46.

One of the features of the present invention resides in the configuration of the housings by which external connections to the cable 46 may be made rapidly, conveniently, and inexpensively. For this purpose, the interior structure of the housings are provided with posts 47 and 48 disposed in the corners and a centrally disposed post 49 in the area of a slot 51 formed in the section 17 to accommodate the cable 46. Additional posts 52 and 53 are disposed intermediate the ends of the housing. The posts 47, 48, 49, 52, and 53 all extend the full thickness dimension of the two mating sections 16 and 17, that is, they are received snugly within suitable apertures formed in the section 16 and serve to lock the two sections together. Additional posts 54 and 56 of lesser height than the aforementioned posts are also provided to serve as wire guiding means within the housing as will be explained more fully in the succeeding description.

For convenience in assembly, the conductors constituting the cable 46 can all be cut to the same length and then portion 22 which provides a seat.

3, the bared ends can be tinned by dipping them in molten solder. Then, the conductors are slipped through the slot 51, and their lengths are adjusted by the manner in which they are led past the various posts and wall .structure within the section 17. For example, the conductor i2 which must havethe longest effective length to be con:

nected with the conductorSi of the coil 32 is passed di rectly around the core seat, and then between the post 52 and the inner wall of the housing 17. The clearance provided in this space is sufficiently small so that the conductor 42 is pinched and held against displacement by the close fit. Conductor 41 is to be secured to the lead 36 of coil 31 is provided with a more tortuous path to shorten the effective length. The conductor 41 first is trained about the centrally disposed post 49, then around the corner post47 and about a bafile 56 extending from the inner wall of the section 17 and terminating short of the core seat; Then, the conductor is pinched between the post 54 and the inner wall of the section 17. v

Similarly, the conductor 44 passes directly from the, slot 51 between a bafiie 5'8 and the wall 21 which forms a part of the seat structure for the magnetic core. The conductor then passes directly between the post 53 and the inner wall of the section 17 where is it pinched and held in proper alignment so that it may be connected to the conductorfifi extending frorn'the coil34.

The effective length of the conductor 43 is shortened by first training it about'the centrally disposed post 49 then about the corner post 43, between the baftle dd and the wall 21, and then betweenthe post55 and the inner wall of the housing 17. The conductor 43 is then at a level at which it can be conveniently connected to the lead 3% extending from the coil 33.

The housings 1 1, 12, and 13 are held together ininterlocking relationship about the neck 14 at the kinescope. For this purpose, each of the housings is provided at one end with bifurcated-portion 61 which is arranged to reproper alignment between the magnetic core and the longitudinal axis of the tube neck. The structure shown in FIGURE 3 differs in certain particulars from the structure or" FIGURES 1 and 2.

Where the elements are common between the two structures, however, the same reference numerals have been applied. The difference occurs in the type of magnetic 7 core which is employed.

In the form of the invention shown in FEGURE 3,.the magnetic core consists of two L-shaped pieces '72 and 73 upon which the coils 31, 32, 33, and 3d are mounted. The seat provided for the core structureis also difi'erent in that it includes a window 7 d for the purpose of providing access to an adjusting disc '76 composed of ferrite or other high permeability material, the disc 76 being urged against the abutting sides of the core legs 5'2 and 73 by. an undulating spring '77 which alsoserves to urge the magnetic core pole pieces 26 and 2.7 tightly against the recesses 28 and 2? in the housing. Rotation of the disc 76 is thereby effective to vary 2O a the reiuctance of the rnagnetic circuit. 7 v The manner of interlocking the housings 11, d2 and 13 is also modified from the 'form shown in FIGURES 1 iand'2. -In this'embodiment, the housings are interlocked by providing a set of coil springs '73 extending between angularly disposed lugs 79 on the exterior of the housings.

From the foregoing, it will be understood that the convergence tube assemblies of the present invention are of the kine-scope- I g *It should furtherbe evident that various modifications economical to manufacture andconsiderably simplify the problems of wiring. Furthermore, they are'readily adaptable for use with kinescope tubes having varying neck sizes without distorting the proper alignment which should exist between the coil assemblies and the longiudinal axis can 'bernade to the described embodiments without departing frorn theflscope of the present invention.)

ceive a foot portion 62 of an adjoining housing in sliding 1 V relation. 'The bifurcated portion dll also carries an abutment es which tends to hold the foot. portion 52 Within the bifurcated portiondl upon relative pivotal movement between the two. A C-shaped spring 64 acting between the foot portion 62 and the bifurcated portion 61 tends to keepthe housings in interlocked relationship. I Eachof the housings is provided with means accessible from the outside to vary the reluctance of the magnetic circuit existing between the magnetic coil structurecontained in each of the housings and internal pole pieces (not shown) Within the tube neck 14. The specific adjusting means shown in FIGURE 2 consist of a sleeve 66 which isheld in position by means of a bracket 67 secured to the back of the section 17. The sleeve 66 receives a ferromagnetic, member 68 in sliding relation therein and the position of the ferromagnetic member 68 thereby provides a means for controlling the magnetic characteristics of the coil assembly after it has been mounted onto I the tube neck.

Another feature of the present invention resides in the I configuration of the tube engaging surfaces of the housings ll, 12, and 13 to accommodate necks of different diameter. This construction is best illustrated in FIGURE 4 of the drawings. As evident from that figure, the tube engaging portions of the housing are composed of compound radii including a centrally disposed section having a minimum radius R and the two adjoining portions extending outwardly from the central portion, each having a maximum radius R T he radius R is chosen to correspond to the smallest radius tub'e'which the convergence coil assembly will accommodate, and the maximum radius R is chosen to represent the longest radius. Tubes having radii intermediate the extremes will be engaged by the housing where the sections of diiierent radii merge as il lustrated in reference numeral '71 in the drawings. Thus,

regardless of the size of the tube neck, the housings will always engage the tube neck firmly while maintaining the I claim as my invention: o ll. An electromagnetic convergence assembly for a cathode ray tube comprising: v

a plurality of individual housings'disposed symmetrically about a central axis, 7 Y spring means connecting said housings together, each of said housings'hav'ing means for receiving a coil structure therein and posts therein'in close proximity to the inner walls of said housings, a coil seated in each of said housings, electrical leads eX- tending'into said housings and connected to the-coils, at least some of said posts'being spaced from said walls with a sufiiciently small clearance so that said 3 electrical leads passing therebetween are pinched between said posts and .said'inner'walls.

I 2. A n-electromagnetic convergence assembly for a cathode ray tube comprising;

a pluralityof individual'housings disposed symmetri-- cally about a-central axis,=- V spring means connecting said housings together, each of said housings having means for receiving a coil structure therein, and posts therein in close prox irnity to the innerwalls of said housings, a coil seated in each of said housings, electrical leads extending into said housings and connected to'the coils,

at least some of said posts being spaced from said walls with a sufficiently small clearance so that said electrical leads passing therebetween are pinched between said posts and said inner walls,.and permeability adjusting means accessible from outside said 5 thereof arranged to engage the neck of a cathode ray tube, said surface having diifering radii therealong, the shortest radius existing centrally of said surface, and the larger radii existing outwardly from the center of said surface.

4. In an electromagnetic convergence assembly, a coil structure comprising:

a housing, a

means in said housing defining a seat for a coil core,

a core disposed in said seat,

a plurality of coils disposed on said core,

posts within said housing spaced about the coil seat and in close proximity to the inner walls of said housing,

there being a sufiiciently small clearance between some of said posts and said inner walls so that an electrical conductor is pinched therebetween, said housing having .an arcuate tube engaging surface on the periphery thereof,

said surface having differing radii therealong,

the shortest radius existing centrally of said surface and the larger radii existing outwardly from the center of said surface.

structure comprising:

a housing,

means in said housing defining a seat for a coil core,

a core disposed in said seat,

.a plurality of coils disposed on said core, and a ferromagnetic disc in abutting relation to said core,

said housing having a Window therethrough permitting rotation of said disc from outside said housing,

said housing having an arcuate tube engaging surface on the periphery thereof,

said surface having differing radii therealong,

the shortest radius existing centrally of said surface and the larger radii existing outwardly from the center of said surface.

References Cited by the Examiner UNITED STATES PATENTS 2,766,393 40/56 Casey 3 l377 2,864,021 12/5 8 Lazzery 3 l7-20O 2,901,650 8/59 Barkow et al 31720O JOHN F. BURNS, Primary Examiner.

Claims (1)

1. AN ELECTROMAGNETIC CONVERGENCE ASSEMBLY FOR A CATHODE RAY TUBE COMPRISING: A PLURALITY OF INDIVIDUAL HOUSING DISPOSED SYMMERTICALLY ABOUT A CENTRAL AXIS, SPRING MEANS CONNECTING SAID HOUSING TOGETHER, EACH OF SAID HOUSINGS HAVING MEANS FOR RECEIVING A COIL STRUCTURE THEREIN AND POSTS THEREIN IN CLOSE PROXIMITY TO THE INNER WALLS OF SAID HOUSINGS, A COIL SEATED IN EACH OF SAID HOUSINGS, ELECTRICAL LEADS EXTENDING INTO SAID HOUSINGS AND CONNECTED TO THE COILS, AT LEAST SOME OF SAID POSTS BEING SPACED FROM SAID WALLS WITH A SUFFICIENTLY SMALL CLEARANCE SO THAT SAID ELECTRICAL LEADS PASSING THEREBETWEEN ARE PINCHED BETWEEN SAID POSTS AND SAID INNER WALLS.

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