US3588566A - Electromagnetic deflection yoke having bypassed winding turns - Google Patents

Electromagnetic deflection yoke having bypassed winding turns Download PDF

Info

Publication number
US3588566A
US3588566A US844318A US3588566DA US3588566A US 3588566 A US3588566 A US 3588566A US 844318 A US844318 A US 844318A US 3588566D A US3588566D A US 3588566DA US 3588566 A US3588566 A US 3588566A
Authority
US
United States
Prior art keywords
coil
coils
deflection
turns
winding
Prior art date
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
Application number
US844318A
Other languages
English (en)
Inventor
Robert Lloyd Barbin
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
RCA Licensing Corp
Original Assignee
RCA Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by RCA Corp filed Critical RCA Corp
Application granted granted Critical
Publication of US3588566A publication Critical patent/US3588566A/en
Assigned to RCA LICENSING CORPORATION, TWO INDEPENDENCE WAY, PRINCETON, NJ 08540, A CORP. OF DE reassignment RCA LICENSING CORPORATION, TWO INDEPENDENCE WAY, PRINCETON, NJ 08540, A CORP. OF DE ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: RCA CORPORATION, A CORP. OF DE
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • H01J29/72—Arrangements for deflecting ray or beam along one straight line or along two perpendicular straight lines
    • H01J29/76—Deflecting by magnetic fields only
    • H01J29/762—Deflecting by magnetic fields only using saddle coils or printed windings
    • 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

Definitions

  • a deflection yoke for a color television picture tube is provided the coils of which have electrical taps which are connected such that a portion of the coil windings are bypassed to provide an effective turns distribution modification to control the electron beam misconvergence.
  • a color television receiver utilizing a color picture tube having three electron beams to excite different colored phosphors on the viewed portion of the picture tube it is necessary that the three beams be properly converged as they are deflected over the entire viewed portion in order to provide an acceptable picture having good resolution.
  • three electron beams are emitted from an electron gun structure having three electron guns disposed at the apices of an equilateral triangle and located in the neck portion of the picture tube. The electron beams are accelerated and converged to pass through small apertures in the mask after which the beams spread slightly to land upon and excite red, green and blue phosphor dots located on a phosphor screen in register with the mask apertures.
  • the three electron beams do not intersect the plane of the screen as a circular bundle as the beams are deflected over the screen. It is usual to converge the beams by applying convergence correction waveforms at the line scanning and field scanning rates to electromagnetic pole pieces located around the neck portion of the tube to dynamically vary the radial position of the beams. In this manner the beams tend to fomi a circular bundle everywhere on the screen.
  • the convergence of the beams is also affected by the electromagnetic fields produced by the deflection yoke, including the characteristics of astigmatism and coma.
  • Astigmatism may be isotropic or anisotropic. Isotropic astigmatism is a characteristic of the independent vertical and horizontal deflection coils and the effects of each set of coils is linearly combined in the corners of the screen. The misconvergence caused by astigmatism may be corrected by modifying the on-axis (vertical and horizontal) convergence correction waveforms described above. Anisotropic astigmatism occurs only during simultaneous deflection by both pairs of deflection coils andeffects the beam bundle in the corners of the screen. Expensive circuitry for producing complicated correction waveforms is required to correct the misconvergence due to the anisotropic astigmatism, therefore, the more practical approach is to design a deflection yoke having minimum anisotropic astigmatism.
  • Coma has the effect of distorting symmetry of a-hypothetical conical beam bundle about an axis perpendicular to the direction of deflection. Due to the orientation of the three electron guns of a typical delta gun color tube (either blue gun up or blue gun down) the misconvergence caused by coma in the vertical coils can be corrected by modification of the vertical rate dynamic convergence waveform. However, coma in the horizontal coil is not completely controllable by the radial convergence waveforms, resulting in the blue raster being narrower or wider than the red and green rasters. Thismay be corrected with dynamic blue lateral devices but is more readily corrected by changing the magnetic field distribution of the horizontal deflection coil.
  • the electromagnetic field of the yoke coils may be altered to reduce the adverse effects of coma and astigmatism.
  • the bulk of the active field-producing conductors disposed generally longitudinally of the tube may be shifted towards or away from the coil window to control the effects, including misconvergence, caused by coma and astigmatism.
  • the distortion of the beam bundle in the comers of the screen of a wide-angle picture tube is worse than in smaller deflection angle color picture tubes, and the design of a suitable deflection yoke is critical.
  • An object of this invention is to provide an improved deflection yoke for use with a color television picture tube for controlling the efiects of coma and astigmatism.
  • a deflection yoke for a color television picture tube.
  • the yoke comprises a pair of vertical and a pair of horizontal deflection coils, at least one pair of which has electrical taps formed in the windings and having the winding turns connected such that at least first and second portions of the windings adjacent the start and finish of the winding provide a path for deflection current waveforms applied thereto, and at least one portion of the winding turns located between the first and second portions is bypassed by the deflection current.
  • FIG. 1 is a side view of a saddle-type deflection coil utilized in the yoke embodying the invention
  • FIG. 2 is a top view of the deflection coil illustrated in FIG. 2;
  • FIG. 3 is a transverse cross-sectional view of the coil illustrated in FIG. 2 taken along the line 3-3 of FIG. 2;
  • FIG. 4 is a schematic diagram of coil of a deflection yoke according to the invention.
  • FIGS. l-3 illustrate a saddle-type coil used in a deflection yoke embodying the invention.
  • the yoke comprises a pair of vertical and a pair of horizontal coils, the coils of each pair suitably mounted on opposite sides of and around the neck and bell-shaped portion of a color television picture tube in a known manner. Either or both pairs of coils may be made according to the invention but for illustrative purposes structure of a single coil will be described.
  • Deflection coil 10 is a saddle-type coil having two groups of active field-producing conductors 11 joined by groups of front and rear conductors 13 and 14, respectively.
  • Conductor groups ll, 13 and 14 define a window area 12.
  • a wire S represents the start of the winding adjacent the window area 12 and a wire F represents the end of the winding, referred to as the finish," and located on the bottom portion of coil 10.
  • FIG. 4 illustrates schematically the interconnection of the portions of the coil 10 defined by the taps T and T, and start and finish turns S and F, respectively.
  • the winding portion S-T comprising the turns located from the window towards the central portion of the coil transverse cross section, is serially connected to a portion T -F comprising the turns located from a central portion of the coil spaced from tap T to the finish turns F located farthest from the window area.
  • a portion of the coil winding defined by the turns located between the tap wires T and T, in the central transverse cross section of the coil are bypassed and not connected to the field-producing turns.
  • the unused wire ends T and T,, are not connected to anything, or just one of them may be left connected to the other wire at its tap.
  • a source of deflection current waveforms, not shown, is applied to the start and finish turns S and F to energize the coil.
  • the saddle-type coil winding described may be wound on conventional coil-winding apparatus embodying the teaching of US. Pat. No. 2,448,672 granted to H.V. Knauf on Sept. 7, 1948.
  • the corner convergence may be controlled by providing a deflection coil having a higher turns density at the ends of a transverse cross section relative to the turns density at the central portion of the coil cross section.
  • no scanning current traverses the bypassed center portion of the winding, resulting in zero effective turns density in that area.
  • the average turns density of the center portion is reduced relative to the end turns, providing the desired magnetic field for best corner convergence.
  • deflection yoke used in combination with a 19-inch diagonal delta gun shadow mask color picture tube having a ll0 deflection angle utilized horizontal coils having a total of 47 turns of eight strands of wire, with taps at the 25th and 27th turns.
  • One advantage flowing from a deflection yoke having coils according to the invention is the ease of compensating for different coil-winding arbors.
  • An arbor may have to be replaced because of wear caused by the wire of many coils being passed over its surfaces.
  • the replacement arbor may not have the identical shape as the original and therefore the coils produced by it will have different characteristics.
  • the tapped portion of the coil may be moved towards or away from the window area, keeping the number of turns between the taps constant in accordance with the original design specification, to compensate for the variations in the arbor.
  • the effects astigmatism and comma may be controlled by moving the fixed-turn winding portion between the taps towards or away from .the window area; the impedance of the yoke remaining constant because the total number of turns remains constant. This is important in that the coil driving circuitry will not have to be changed as the taps are moved.
  • either a single strand of wire may be wound for forming the coil or multifilar strands may be utilized as the interconnection of the winding portions to bypass a central winding portion is simple, as illustrated in FIG. 4.
  • this method enables the coils to be produced more cheaply than the coils described in the aforementioned patent to Obert et al. because there are fewer interconnections to be made than in the prior art coils employing portions of the windings in a series-parallel arrangement.
  • An electromagnetic deflection yoke for a color television picture tube comprising:
  • An electromagnetic deflection yoke for a color television picture tube according to claim 1 wherein said coil wire comprises a plurality of strands of wire wound in a multifilar manner.
  • a deflection yoke for a shadow mask color television picture tube comprising:
  • each of said coils comprising convolutions of wire forming two groups of active side conductors disposed generally longitudinally of said picture tube for deflecting the electron beams of said picture tube and front and rear end groups of inactive conductors disposed generally transversely of said picture tube joining said side conductors, said side conductors and end conductors defining a window area; each of said horizontal coils having electrical taps formed therein and connected such that a first portion of said side conductors adjacent said window and a second portion of said side conductors farthest from said window are serially connected to each other and the remaining portion of said side conductors between said taps in the central portion of said side conductor groups is not electrically connected to said first and second portions.
  • said second coil portion being retained for providing support and displacement for said first and third coil portions.

Landscapes

  • Video Image Reproduction Devices For Color Tv Systems (AREA)
  • Details Of Television Scanning (AREA)
  • Formation Of Various Coating Films On Cathode Ray Tubes And Lamps (AREA)
US844318A 1969-07-24 1969-07-24 Electromagnetic deflection yoke having bypassed winding turns Expired - Lifetime US3588566A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US84431869A 1969-07-24 1969-07-24

Publications (1)

Publication Number Publication Date
US3588566A true US3588566A (en) 1971-06-28

Family

ID=25292378

Family Applications (1)

Application Number Title Priority Date Filing Date
US844318A Expired - Lifetime US3588566A (en) 1969-07-24 1969-07-24 Electromagnetic deflection yoke having bypassed winding turns

Country Status (10)

Country Link
US (1) US3588566A (xx)
JP (2) JPS5323657B1 (xx)
AT (1) AT301634B (xx)
BE (1) BE753769A (xx)
DE (1) DE2036890B2 (xx)
ES (1) ES381808A1 (xx)
FR (1) FR2055232A5 (xx)
GB (1) GB1281329A (xx)
NL (1) NL7010916A (xx)
SE (1) SE362732B (xx)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2852509A1 (de) * 1977-12-07 1979-06-13 Videon Sa Ablenkspule fuer eine farbfernsehbildroehre
US6734614B1 (en) * 1998-12-07 2004-05-11 Koninklijke Philips Electronics N.V. Saddle-shaped deflection coil and winding method

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2852509A1 (de) * 1977-12-07 1979-06-13 Videon Sa Ablenkspule fuer eine farbfernsehbildroehre
US6734614B1 (en) * 1998-12-07 2004-05-11 Koninklijke Philips Electronics N.V. Saddle-shaped deflection coil and winding method

Also Published As

Publication number Publication date
NL7010916A (xx) 1971-01-26
DE2036890A1 (de) 1971-02-04
JPS57154749A (en) 1982-09-24
BE753769A (fr) 1970-12-31
AT301634B (de) 1972-09-11
SE362732B (xx) 1973-12-17
ES381808A1 (es) 1972-11-16
FR2055232A5 (xx) 1971-05-07
DE2036890B2 (de) 1976-04-22
GB1281329A (en) 1972-07-12
JPS5323657B1 (xx) 1978-07-15

Similar Documents

Publication Publication Date Title
CA1124304A (en) Deflection yoke with a magnet for reducing sensitivity of convergence to yoke position
US5506469A (en) Display tube with deflection unit comprising field deflection coils of the semi-saddle type
US4689525A (en) Color cathode ray tube device
US4041428A (en) Deflection yoke for use with in-line cathode ray tubes
US4524340A (en) Device for displaying television pictures
US4882521A (en) Deflection yoke for a color cathode ray tube
JPH0542776B2 (xx)
US5418422A (en) Combination of display tube and deflection unit comprising line deflection coils of the semi-saddle type with a gun-sided extension
US3721930A (en) Deflection yoke for use with in-line electron guns
EP0589064B1 (en) Deflection device for use in a color cathode-ray tube
US4755714A (en) Electromagnetic deflection unit for a television picture display tube
US4866336A (en) Display device including a combination of a display tube and a deflection unit
US3588566A (en) Electromagnetic deflection yoke having bypassed winding turns
JPS59134530A (ja) テレビジヨン画像表示装置
US4881015A (en) Color cathode-ray apparatus having an improved deflection unit
EP0102396A1 (en) Flat cathode ray tubes
EP0569079B1 (en) Combination of display tube and deflection unit comprising line deflection coils of the semi-saddle type with a gun-sided extension
US3668580A (en) Toroidal deflection yoke having asymmetrical windings
JP2656591B2 (ja) 偏向装置及びそれを構成する偏向ヨーク
JP3215132B2 (ja) インライン型カラー受像管装置
JP3378301B2 (ja) 陰極線管装置
JP2703138B2 (ja) 偏向ヨーク
JPH1021850A (ja) 偏向ヨーク装置
KR20050080310A (ko) 페라이트 코어 및 이를 포함한 편향요크
JPH087790A (ja) カラー受像管装置

Legal Events

Date Code Title Description
AS Assignment

Owner name: RCA LICENSING CORPORATION, TWO INDEPENDENCE WAY, P

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:RCA CORPORATION, A CORP. OF DE;REEL/FRAME:004993/0131

Effective date: 19871208