Cathode ray tube deflection yoke arrangement

• US 5,077,533 A
• Filed: 09/28/1990
• Issued: 12/31/1991
• Est. Priority Date: 09/28/1990
• Status: Expired due to Fees

• Current Assignee: Syntronic Instruments, Inc.
• Original Assignee: Syntronic Instruments, Inc.
• Inventors: Klingelhofer, Fredric G.
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US07/590,156
• Time in Patent Office: 459 Days
• Field of Search: 335/210, 335/213, 313/426, 313/421, 313/428
• US Class Current: 335/213
• CPC Class Codes: H01J 29/76 Deflecting by magnetic fields only

Abstract

A deflection yoke for a cathode ray tube, including a first yoke portion and a second yoke portion engaged with opposite sides of the cathode ray tube neck. Each yoke portion includes a main winding for producing substantial first and associated higher harmonic magnetic fields in the neck and a correction winding for producing substantial third and higher harmonic fields. The correction winding is formed by running normally screen end transverse main winding turns longitudinally with the neck toward the cathode ray tube gun end in one yoke portion quadrant and returning them to the screen end transverse main winding in the other yoke portion quadrant.

Claims

1. A deflection arrangement for CRT comprising a source of deflection signals connected to a deflection yoke comprising a pair of windings engaged opposite one another on a neck portion of said CRT, each of said windings comprising:

a main winding comprising at least two spaced apart longitudinal sections engaged along the length of said neck, each having a plurality of turns for creating in conjunction with the other of the said pair of windings, a substantially first harmonic with associated higher harmonics magnetic field through said CRT neck, a gun end transverse section having a plurality of turns serially connecting the turns of said two longitudinal sections and a screen end transverse section having a plurality of turns serially connecting the turns of said two longitudinal sections; and

an additional winding for modifying third and higher harmonic nonuniformities of the magnetic field created in said CRT neck, said additional winding comprising a plurality of turns each connected in series with one turn of said main winding and extending from said screen end transverse section toward said gun end transverse section to a predetermined location on said CRT neck and extending from said predetermined location to said screen end transverse section such that no additional winding turn crosses itself.

2. In a deflection yoke for a cathode ray tube having a neck portion, a correction winding comprising:

a plurality of serially connected turns, each turn comprising a first longitudinal section for conveying current in a first direction along said neck, a first end section transverse to said neck serially connecting said first longitudinal section to a second longitudinal section, said second longitudinal section for conveying current in a second direction opposite to said first direction along said neck, and a correction section for connecting said first longitudinal section to said second longitudinal section,

said correction section comprising the serial connection of a first end portion transverse to said neck serially connecting said first longitudinal section to a third longitudinal section substantially parallel to said first longitudinal section for conveying current in said second direction along said neck, a second end portion transverse to said neck, serially connecting said third longitudinal section to a fourth longitudinal section substantially parallel to said second longitudinal section for conveying current in said first direction along said neck and a third end portion transverse to said neck, serially connecting said fourth longitudinal section to said second longitudinal section.

3. A coil for use in a deflection yoke for a cathode ray tube having a neck portion, said coil comprising:

a single conductor path series wound in a configuration having an inner surface in the shape of a surface of rotation about the longitudinal axis of said neck portion for engagement with said neck portion and including means for connection to an electrical signal source,

said coil configuration comprising;

a first longitudinal section of winding comprising n turns of said conduction path for conveying current in a first direction along said neck portion when energizing by said source,

a second longitudinal section of winding comprising n turns of said conduction path for conveying current in a second direction opposite to said first direction along said neck portion when energizing by said source,

a third longitudinal section of winding comprising m-turns located along said surface of rotation said first longitudinal section of winding and said second longitudinal section of winding for conveying current in said second direction along said neck portion when energizing by said source,

a fourth longitudinal section of winding comprising m-turns located along said surface of rotation between said third longitudinal section and said second longitudinal section for conveying current in said first direction along said neck portion when energized by said source,

a plurality of turns of said conduction path transverse to said neck portion for completing the series electrical connections of said first, said second, said third and said fourth longitudinal sections of said coil, and

said configuration being formed such that the total number of turns transverse to the neck between said third and said fourth longitudinal sections of winding is substantially less than 2n+2m.

4. The coil of claim 3 wherein said third longitudinal section of winding is located between said first longitudinal section and a center line equidistant along said surface of rotation from said first and said second longitudinal winding sections and said fourth longitudinal section of winding is located between said second longitudinal section and said center line.

5. A deflection yoke comprising a pair of windings for engagement with a neck portion of a cathode ray tube each of said windings comprising:

a main winding comprising a first plurality of turns of a single conduction path having a shape for engagement with said neck portion and comprising a first and second side of substantially equal length, a first substantially arcuate end electrically connecting the turns of one end of each of said sides and a second substantially arcuate end electrically connecting the turns of the other end of said sides; and

a second winding comprising a second plurality of turns of said single conduction path connected in electrical series with said first plurality of turns, said second plurality of turns running substantially parallel to the sides and first arcuate end of said main coil, and running substantially parallel to said second arcuate end for a first predetermined distance from said first side, said first predetermined distance being less than half of the arc length of said second arcuate end, then running longitudinally with said neck portion toward said first arcuate end for a second predetermined distance, running in a substantially arcuate shape transverse to said neck portion for a third predetermined distance, running longitudinally with said neck portion to said second arcuate end at said first predetermined distance from said second side and running parallel with said second arcuate end to said second side.