US3657675A - Convergence units for color television picture tubes - Google Patents
Convergence units for color television picture tubes Download PDFInfo
- Publication number
- US3657675A US3657675A US55387A US3657675DA US3657675A US 3657675 A US3657675 A US 3657675A US 55387 A US55387 A US 55387A US 3657675D A US3657675D A US 3657675DA US 3657675 A US3657675 A US 3657675A
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- United States
- Prior art keywords
- core
- convergence
- legs
- coil
- horizontal
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- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
- H01J29/46—Arrangements of electrodes and associated parts for generating or controlling the ray or beam, e.g. electron-optical arrangement
- H01J29/70—Arrangements for deflecting ray or beam
- H01J29/701—Systems for correcting deviation or convergence of a plurality of beams by means of magnetic fields at least
- H01J29/702—Convergence correction arrangements therefor
Definitions
- U-shaped cores are employed, each having a pair of legs and an intermediate portion extending between the legs.
- the intermediate portion may be either solid or formed with a gap.
- a reduced number of coils is employed on each core. In each case, there is only one vertical convergence coil, and either one or two horizontal coils.
- the vertical coil may be mounted on the intermediate portion, or on one of the legs.
- the horizontal coil or coils may be mounted on one or both legs.
- This invention relates to convergence units adapted to be mounted around the neck of a color television cathode ray picture tube.
- a picture tube has three electron guns in spaced relation to the axis of the tube.
- the beam of each gun is directed to illuminate phosphor dots of a certain color on the screen of the tube.
- the phosphor dots are usually arranged in arrays for each color.
- the electron beam from each gun passes through an aperture screen or shadow mask which as a single set of holes in the same geometric configuration as each array of dots. When the electron beam travels its intended course, it illuminates only those dots which produce the intended color.
- the electron beams from all three guns are aimed to converge upon the holes in the mask, and thereafter the beams diverge as they pass through the holes and arrive at the screen as three individual beams.
- the beams may be aimed to converge at the center of the mask, but problems arise when the beams are swept from side to side and up and down.
- the convergent point of the beams sweeps in an arc which moves it away from the mask at points other than the center of the mask.
- Convergence coil assemblies or units have been devised and are used to meet this problem.
- the beams must converge on the mask so that all three beams pass through the same hole in the mask at correct angles to strike the corresponding phosphor dots on the screen.
- These assemblies are known as dynamic convergence units because they correct any variations in the length from the deflection point to the apertured mask, as the beams are deflected from the center to the edges of the mask.
- Prior convergence units have generally utilized a plurality of U-shaped cores having legs with convergence coils mounted thereon. It has been the practice to mount one horizontal convergence coil and one vertical convergence coil on each leg, so that each core is equipped with two horizontal and two vertical convergence coils.
- the coils are energized with horizontal and vertical convergence signals developed by special circuits in the television set. These signals are effective to maintain the convergence of the three beams as they are deflected both horizontally and vertically from the center of the mask.
- One type of convergence unit utilizes three cores and three sets of coils thereon, spaced at equal angular intervals around the axis of the tube so as to be opposite the three electron beams.
- Another type of convergence unit utilizes only two cores with two sets of coils thereon, disposed at diametrically opposite points.
- One core and the coils thereon provide the convergence correction for one electron beam, generally the blue beam.
- the other core and the coils thereon provide the convergence correction for the other two beams, generally the red and green beams.
- One of the principal objects of the present invention is to provide a new and improved convergence unit in which the number of coils is greatly reduced, while preserving the ability of the unit to provide the necessary dynamic convergence corrections.
- each core of a triple core convergence unit may be provided with only one vertical convergence coil and either one or two horizontal convergence coils. These coils areenergized with the usual horizontal and vertical signals.
- One horizontal coil and one vertical convergence coil may be mounted on either the same leg or different legsof the U-shapedcore.
- the vertical coil may be mounted on the intermediate portion of the core, extending-between the two legs. In that case, it is preferred to provide a fully balanced construction by mounting interconnected horizontal coils on both legs.
- the core may be of the type in which the intermediate portion is interrupted by a gap. An adjustable permanent magnet is mounted across this gap to provide an initial biasing flux.
- the core may be of the solid type, without any such gap.
- one core may unit, with only one vertical coil, and either one or two interconnected horizontal coils.
- the other core of the double-core convergence unit has one vertical coil and two horizontal coils, mounted on the two legs.
- the vertical coil may be mounted on the intermediate portion, or on one leg.
- the construction of the present invention greatly reduces the cost and complexity of the dynamic convergence units. Nevertheless, it has been found that the convergence units are fully capable of providing the necessary convergence corrections.
- FIG. 1 is a diagrammatic sectional view of a triple-core convergence unit to be described as an illustrative embodiment of the present invention.
- FIGS. 2, 3 and 4 are fragmentary sections showing modified constructions.
- FIG. 5 is a diagrammatic section showing a double-core type of convergence unit, constituting another illustrative embodirnent of the present invention.
- FIGS. 6 and 7 are diagrammatic elevational views showing other modified constructions.
- FIG. 1 illustrates a triple-core type of dynamic convergence unit 10 adapted to be mounted around the neck 12 of a color television picture tube.
- the convergence unit or assembly 10 comprises three convergence devices 14, one for each of the electron beams, designated B, R and G for blue, red and green. It will be understood that suitable means are provided to mount the convergence devices 14 around the neck 12 of the picture tube, at substantially equal angular intervals. Those skilled in the art will be familiar with such mounting means, which are not illustrated in the diagrammatic representation of FIG. 1.
- Each device 14 comprises a U- shaped core 16 having a pair of legs 18 and an intermediate or connecting portion 20, extending between the outer ends of the legs.
- the core 16 is made of a suitable magnetic material, such as a ferrite material.
- pole pieces or shoes 22 are mounted against the inner ends of the legs 18. The pole pieces 22 are immediately adjacent to the neck 12 of the picture tube.
- the connecting portion 20 is interrupted by a gap 24. Tape or other thin non-magnetic material 26 may be mounted in the gap 24.
- An adjustable permanent magnet 28 is mounted on the connecting portion 20 so as to extend across the gap 24.
- the illustrated magnet is of the disc type, which may be rotated to change the initial or biasing magnetic flux in the core.
- each core 16 is provided with only one horizontal convergence coil 30, and only one vertical convergence coil 32. These coils are supplied with suitable horizontal and vertical convergence signals by the convergence circuits in the television receiver. It has been the prior practice to provide two horizontal and two vertical convergence coils on each core, one horizontal coil and one vertical coil having been mounted on each leg of the core. However, it has been found that one horizontal convergence coil and one vertical convergence coil may be eliminated, so
- the horizontal and vertical convergence coils 30 and 32 may be mounted on the same leg, or on different legs. In the construction of'FIG. l, the coils 30 and 32 are mounted on different legs. It will be understood that either coil may be mounted on either leg.
- FIGS-3 and 4 illustrate modified constructions in which the horizontal and vertical convergence coils 30 and 32 are mounted on thesame leg.
- the horizontal coil 30 is mounted within the hollow space 34 formed in the vertical coil 32.
- both of'the coils 30 and 32 may be positioned be the same as used for the three-core type of convergence near thepole pieces 22.
- FIG. 2 illustrates a modified construction utilizing a vertical convergence coil 32a which does not have such a hollow space. Vertical coils of either type may be employed as desired.
- FIG. 2 also utilizes a modified core 160 having a connecting portion 20a which is solid, rather than being formed with a gap. Either type of core may be employed as desired.
- FIG. 3 utilizes the same core 16 as in FIG. 1. However, the horizontal and vertical coils 30 and 32 are on the same leg of the core, rather than being on different legs. It will be understood that the coils 30 and 32 may be mounted on either leg.
- FIG. 4 The modified construction of FIG. 4 is the same as that shown in FIG. 3, except that the construction of FIG. 4 utilizes the solid core 16a, of the type shown in FIG. 2.
- FIG. 5 illustrates a convergence unit or assembly 40 which is of the type which utilizes only two convergence devices, mounted at diametrically opposite positions around the neck 12 of the color TV picture tube.
- One convergence device is the same as illustrated in FIG. 1 and is designated 14, as in FIG. 1. All of the components of the convergence device are also identified by the same reference characters.
- Convergence unit 40 of FIG. 5 utilizes a second convergence device 42 which is the same as the convergence device 14 except that the convergence device 42 has two horizontal convergence coils 30, one such coil being mounted on each leg 18 of the core 16.
- the convergence device 42 has two horizontal convergence coils 30, one such coil being mounted on each leg 18 of the core 16.
- one horizontal convergence coil is used to provide the correction for the red beam, while the other horizontal coil is employed to provide the correction for the green beam.
- the single vertical convergence coil 32 provides the vertical convergence correction for both beams. It will be understood that the vertical coil 32 may be mounted on either leg 18 of the core 16.
- the cores of FIG. 5 may be formed with or without the gap 24.
- the horizontal and vertical convergence coils 30 and 32 may be mounted on the same leg, or on different legs. Either coil may be mounted on either leg. 1
- FIG. 6 illustrates another modified convergence device 114 having a U-shaped core 116 which is the same as the core 16a in FIG. 2.
- the core 116 has a pair of legs 118 and a solid intermediate or connecting portion 120. It will be understood that the intermediate portion 120 may be provided with a gap, if desired.
- the convergence device 114 is provided with two horizontal convergence coils 130, and a single vertical convergence coil 132.
- the horizontal coils 130 are symmetrically mounted on the legs 118, while the vertical coil 132 is mounted on the intermediate portion 120 of the core 116.
- This arrangement provides a balanced construction which is highly adventageous.
- the convergence device 114 of FIG. 6 can readily be used as a direct replacement for existing types of convergence devices, without any change in the electronic circuits for developing the horizontal and vertical direction signals.
- the convergence device 114 of FIG. 6 has the further advantage that it can be used in either a triple core unit, similar to that of FIG. 1 or a double core unit, of the type illustrated in FIG. 5.
- the horizontal convergence coils 130 are normally interconnected to receive the same horizontal correction signal. This is also true when the convergence device 114 is used as the blue beam convergence device for a double core unit, of the type shown in FIG. 5.
- the horizontal convergence coils 130 are connected to different circuits, to receive the horizontal correction signals for the red and green beams.
- FIG. 7 illustrates still another modified convergence device 214, which is the same as the device of FIG. 6, except that the core 116 of FIG. 6 is replace by a modified core 216 having generally radial legs 218 and an intermediate portion 220 of increased length.
- the core 216 is basically U-shaped and is generally in the form of a triangle.
- the horizontal and vertical convergence coils and 132 are the same as before.
- the horizontal coils 130 are mounted on both legs 218, while the vertical coil 132 is mounted on the intermediate portion 220, to provide a balanced construction.
- the intermediate portion 220 may be formed with a gap, if desired.
- the convergence device 214 of FIG. 7 has all of the advantages of a symmetrical or balanced construction as discussed in connection with FIG. 6.
- the present invention makes it possible to reduce the number of coils employed in the convergence unit.
- the cost and complexity of the convergence unit are greatly reduced.
- the convergence units of the present invention are fully capable of providing the necessary dynamic convergence corrections.
- a convergence unit construction comprising a horseshoe-type core having a single magnetic circuit including a pair of legs and an intermediate connecting portion extending between said legs at one end thereof,
- said core having a single magnetic axis extending along said legs and said intermediate connecting portion
- a horseshoe-type core having a single magnetic circuit including a pair of legs and an intermediate connecting portion extending between said legs at one end thereof,
- said vertical convergence coil being substantially larger than said horizontal convergence coil.
- said horizontal coil and said vertical coil are mounted around different legs of said core.
- said second core having a pair of such legs and an intermediate portion extending between said legs
- first and second such horizontal convergence coils mounted around different legs of said second core
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Abstract
Description
Claims (14)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US5538770A | 1970-07-16 | 1970-07-16 |
Publications (1)
Publication Number | Publication Date |
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US3657675A true US3657675A (en) | 1972-04-18 |
Family
ID=21997470
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US55387A Expired - Lifetime US3657675A (en) | 1970-07-16 | 1970-07-16 | Convergence units for color television picture tubes |
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US (1) | US3657675A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3774132A (en) * | 1972-06-16 | 1973-11-20 | Warwick Electronics Inc | Dynamic convergence system |
US3831122A (en) * | 1972-09-13 | 1974-08-20 | Blaupunkt Werke Gmbh | Blue lateral correction system for color television tubes |
US3849697A (en) * | 1972-06-16 | 1974-11-19 | Warwick Electronics Inc | Method and apparatus for static and dynamic convergence |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2864021A (en) * | 1955-09-01 | 1958-12-09 | Rca Corp | Color kinescope adjunct |
US3002120A (en) * | 1954-08-02 | 1961-09-26 | Rca Corp | Beam convergence apparatus for tri-color kinescope |
US3325675A (en) * | 1964-08-05 | 1967-06-13 | Paramount Pictures Corp | Three in-line gun magnetic convergence system |
-
1970
- 1970-07-16 US US55387A patent/US3657675A/en not_active Expired - Lifetime
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3002120A (en) * | 1954-08-02 | 1961-09-26 | Rca Corp | Beam convergence apparatus for tri-color kinescope |
US2864021A (en) * | 1955-09-01 | 1958-12-09 | Rca Corp | Color kinescope adjunct |
US3325675A (en) * | 1964-08-05 | 1967-06-13 | Paramount Pictures Corp | Three in-line gun magnetic convergence system |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3774132A (en) * | 1972-06-16 | 1973-11-20 | Warwick Electronics Inc | Dynamic convergence system |
US3849697A (en) * | 1972-06-16 | 1974-11-19 | Warwick Electronics Inc | Method and apparatus for static and dynamic convergence |
US3831122A (en) * | 1972-09-13 | 1974-08-20 | Blaupunkt Werke Gmbh | Blue lateral correction system for color television tubes |
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AS | Assignment |
Owner name: TORONTO-DOMINION BANK, THE,STATELESS Free format text: SECURITY INTEREST;ASSIGNOR:TRACOR, INC., (SEE RECORD FOR REMAINING GRANTORS);REEL/FRAME:004829/0701 Effective date: 19871216 Owner name: TORONTO-DOMINION BANK, THE Free format text: SECURITY INTEREST;ASSIGNOR:TRACOR, INC., (SEE RECORD FOR REMAINING GRANTORS);REEL/FRAME:004829/0701 Effective date: 19871216 |
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Owner name: TORONTO-DOMINION BANK, THE Free format text: SECURITY INTEREST;ASSIGNORS:TRACOR, INC.;LITTLEFUSE, INC.;TRACOR AEROSPACE, INC.;AND OTHERS;REEL/FRAME:005234/0127 Effective date: 19880801 Owner name: BANK OF AMERICA NATIONAL TRUST AND SAVING ASSOCIAT Free format text: SECURITY INTEREST;ASSIGNOR:TORONTO DOMINION BANK, THE,;REEL/FRAME:005284/0163 Effective date: 19880801 Owner name: BANK OF AMERICA NATIONAL TRUST AND SAVINGS ASSOCIA Free format text: SECURITY INTEREST;ASSIGNORS:TORONTO-DOMINION BANK;TRACOR, INC.;REEL/FRAME:005224/0276 Effective date: 19880801 Owner name: BANK OF AMERICA NATIONAL TRUST AND SAVINGS ASSOCIA Free format text: SECURITY INTEREST;ASSIGNOR:TRACOR, INC.;REEL/FRAME:005217/0247 Effective date: 19880801 Owner name: BANK OF AMERICA NATIONAL TRUST AND SAVINGS ASSOCIA Free format text: SECURITY INTEREST;ASSIGNOR:TRACOR INC.;REEL/FRAME:005217/0224 Effective date: 19880801 Owner name: BANK OF AMERICA AS AGENT Free format text: SECURITY INTEREST;ASSIGNOR:TORONTO-DOMINION BANK, THE;REEL/FRAME:005197/0122 Effective date: 19880801 |
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Owner name: TRACOR, INC. Free format text: RELEASED BY SECURED PARTY;ASSIGNOR:BANK OF AMERICA NATIONAL TRUST AND SAVINGS ASSOCIATION AS COLLATERAL AGENT;REEL/FRAME:005957/0562 Effective date: 19911220 Owner name: TRACOR, INC. Free format text: RELEASED BY SECURED PARTY;ASSIGNOR:BANK OF AMERICA NATIONAL TRUST AND SAVINGS ASSOCIATION AS COLLATERAL AGENT;REEL/FRAME:005957/0542 Effective date: 19911227 Owner name: TRACOR, INC. A DE CORPORATION, TEXAS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:OTC TRACOR, INC., A DE CORPORATION;REEL/FRAME:005955/0348 Effective date: 19911220 Owner name: OTC TRACOR, INC. Free format text: CHANGE OF NAME;ASSIGNOR:TRACOR INC., A CORPORATION OF DE;REEL/FRAME:005955/0323 Effective date: 19911122 Owner name: CONTINENTAL BANK N.A. Free format text: SECURITY INTEREST;ASSIGNOR:TRACOR, INC.;REEL/FRAME:005953/0965 Effective date: 19911227 |
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Owner name: BANKERS TRUST COMPANY, NEW YORK Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:TRACOR, INC.;REEL/FRAME:006674/0551 Effective date: 19930825 |
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Owner name: TRACOR, INC., TEXAS Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:CONTINENTAL BANK N.A.;REEL/FRAME:006683/0046 Effective date: 19930825 |