US3686527A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High-speed synthesized field focus coil
Assignee: Lockheed Martin Corp
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Filing: 1969-12-12
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Granted: 1972-08-22
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Expires: 1989-12-12
Abstract
Abstract A high speed magnetic focus lens develops a relatively large static magnetic force field which has radial symmetry and which varies along the axis of an electron beam and radially outwardly therefrom so as to focus off-axis electrons to the same focal point on a cathode ray tube screen, thereby producing a visible spot characterized by minimum distortion and aberration and therefor which is very small. The lens also develops a smaller dynamic field component which varies with beam deflection so as to maintain the beam in focus with minimum aberration, even though the beam is deflected through relatively large angles while moving over the screen. The static and dynamic elements of the lens are electrically isolated so as to minimize the time constant associated with dynamic focusing, thereby enabling the lens to focus a beam moving at high speed.
Inventors
- 👤 William D Gabor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:01
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/46; H01J29/58; H01J29/64; H01J29/66; H01F; H01F7/00; H01F7/06; H01F7/20
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
122 words
A magnetic focus lens system for focusing an electron beam generated in a cathode ray tube comprising A. a plurality of separate windings spaced closely along an axis and arranged to engage around the neck of said tube, B. means for supplying a d.c. current to said windings, the ampere turns of said windings being distributed along said axis so as to bring substantially all off-axis electrons to a single focal point on said screen, C. an additional winding wound coaxially with said windings, D. means for producing deflection signals for deflecting the electron beam, and E. means responsive to said deflection signals for applying a current signal to said additional winding which varies in accordance with the deflection of said beam.
Claim 2
Dependent Claim
122 words
A magnetic focus lens system for focusing an electron beam generated in a cathode ray tube comprising A. a plurality of separate windings spaced closely along an axis and arranged to engage around the neck of said tube, B. means for supplying a d.c. current to said windings, the ampere turns of said windings being distributed along said axis so as to bring substantially all off-axis electrons to a single focal point on said screen, C. an additional winding wound coaxially with said windings, D. means for producing deflection signals for deflecting the electron beam, and E. means responsive to said deflection signals for applying a current signal to said additional winding which varies in accordance with the deflection of said beam.
Claim 3
Dependent Claim
33 words
A magnetic focus lens system as defined in claim 1 and further including a bobbin A. for engaging over the neck of said tube, and B. having separate compartments for containing said windings.
Claim 4
Dependent Claim
56 words
beveled at an angle of approximately 45*- 135* measured from the radius of said sleeve, C. means for producing deflection signals for deflecting the electron beam, and D. means responsive to said deflection signals for varying the focal length of the lens so as to maintain the beam in focus as it moves across said surface.
Claim 5
Dependent Claim
56 words
beveled at an angle of approximately 45*- 135* measured from the radius of said sleeve, C. means for producing deflection signals for deflecting the electron beam, and D. means responsive to said deflection signals for varying the focal length of the lens so as to maintain the beam in focus as it moves across said surface.
Claim 6
Dependent Claim
28 words
means for applying a current signal to said winding which varies approximately as the square root of the distance which the beam is deflected from the beam axis.
Claim 7
Dependent Claim
28 words
means for applying a current signal to said winding which varies approximately as the square root of the distance which the beam is deflected from the beam axis.
Claim 8
Dependent Claim
43 words
A magnetic lens system as defined in claim 2 wherein A. said additional winding is situated in a compartment near the middle of said bobbin, and B. said windings progressively further away from said additional winding have progressively increasing numbers of winding turns.
Claim 9
Dependent Claim
27 words
A lens system as defined in claim 1 and further including a ferrite sleeve encircling said windings so as to confine the magnetic field within the tube.
Claim 10
Dependent Claim
28 words
A lens system as defined in claim 4 wherein the opposite ends of said sleeve are shaped to give the end field magnetic force lines generally parabolic curvature.
Claim 11
Dependent Claim
55 words
A lens system as defined in claim 1 and further including A. a pair of small trim windings situated adjacent the outer ones of said windings, and B. an adjustable current source connected to said trim windings for shaping the magnetic force lines of the ends of said lens to give them generally parabolic curvature.
Claim 12
Dependent Claim
68 words
A lens system as defined in claim 1 wherein said signal applying means comprises A. means for dynamically damping said windings, and B. control means connected to receive vertical and horizontal deflection signals, said control means including a signal shaping circuit which shapes the signal applied to said additional winding so that it has a generally parabolic waveform as the electron beam is deflected off the tube axis.
Claim 13
Dependent Claim
26 words
A lens system as defined in claim 1 wherein said windings comprise a plurality of separate current-carrying coiled ribbons arranged along the axiS of the beam.
Claim 14
Dependent Claim
28 words
A lens as defined in claim 8 and further including a sleeve of low magnetic permeability material encircling said ribbons for confining the focus field within the lens.
Claim 15
Dependent Claim
30 words
A lens as defined in claim 8 and further including a length of semi-conductive tape rolled up with each said ribbon so as to function as a shunt resistance therefor.
Claim 16
Dependent Claim
38 words
A lens as defined in claim 8 and further including discs of semi-conductive material mounted between and separating each of said ribbons and coupled to each of said ribbons so as to function as a shunt resistance therefor.
Claim 17
Dependent Claim
80 words
A focus system for focusing an electron beam comprising A. a magnetic focus lens for producing a static magnetic field along the axis of the beam to focus the beam on a surface, B. means for producing deflection signals for deflecting the electron beam, and C. means responsive to said deflection signals for varying the focal length of the lens so as to maintain the beam in focus as it moves across said surface, said focal length varying means comprising
Claim 18
Dependent Claim
80 words
A focus system for focusing an electron beam comprising A. a magnetic focus lens for producing a static magnetic field along the axis of the beam to focus the beam on a surface, B. means for producing deflection signals for deflecting the electron beam, and C. means responsive to said deflection signals for varying the focal length of the lens so as to maintain the beam in focus as it moves across said surface, said focal length varying means comprising
Claim 19
Dependent Claim
88 words
A focus lens for focusing an electron beam on a surface comprising A. a plurality of magnetic field-producing elements spaced along the axis of the beam so as to generate a magnetic force field whose density varies along said axis and radially outwardly therefrom in a manner to focus off-axis electrons in the beam at a single focal point on said surface, B. a sleeve of low magnetic permeability material encircling said field-producing elements for confining the focus fields within the lens, said sleeve having its opposite ends
Claim 20
Dependent Claim
88 words
A focus lens for focusing an electron beam on a surface comprising A. a plurality of magnetic field-producing elements spaced along the axis of the beam so as to generate a magnetic force field whose density varies along said axis and radially outwardly therefrom in a manner to focus off-axis electrons in the beam at a single focal point on said surface, B. a sleeve of low magnetic permeability material encircling said field-producing elements for confining the focus fields within the lens, said sleeve having its opposite ends
Claim 21
Dependent Claim
15 words
A lens as defined in claim 13 wherein said sleeve has a barrel-shaped inside contour.
Claim 22
Dependent Claim
146 words
A magnetic focus lens system for focusing an electron beam generated in a cathode ray tube having a screen comprising A. a plurality of separate series-connected, coiled conductive ribbons spaced closely along an axis and arranged to engage around the neck of the tube, B. means for supplying a d.c. current to said ribbons, the dimensions of each said ribbon being selected so as to produce an ampere turns distribution along said axis so as to bring substantially all off-axis electrons to a single focal point on the tube screen, C. an additional conductive ribbon coiled coaxially with said other ribbons, said additional ribbon being situated midway along said axis and said ribbons progressively further away from said additional ribbon having progressively increasing dimensions, and D. means for applying a current signal to said additional ribbon which varies in accordance with the deflection of the beam.
Claim 23
Dependent Claim
146 words
A magnetic focus lens system for focusing an electron beam generated in a cathode ray tube having a screen comprising A. a plurality of separate series-connected, coiled conductive ribbons spaced closely along an axis and arranged to engage around the neck of the tube, B. means for supplying a d.c. current to said ribbons, the dimensions of each said ribbon being selected so as to produce an ampere turns distribution along said axis so as to bring substantially all off-axis electrons to a single focal point on the tube screen, C. an additional conductive ribbon coiled coaxially with said other ribbons, said additional ribbon being situated midway along said axis and said ribbons progressively further away from said additional ribbon having progressively increasing dimensions, and D. means for applying a current signal to said additional ribbon which varies in accordance with the deflection of the beam.
Claim 24
Dependent Claim
30 words
A lens system as defined in claim 15 and further including a length of semiconductive tape coiled up with each said ribbon so as to constitute a shunt resistance therefor.
Claim 25
Dependent Claim
28 words
A lens system as defined in claim 15 and further including a ferrite sleeve encircling said coiled ribbons so as to confine the magnetic field within the tube.
Claim 26
Dependent Claim
56 words
A lens system as defined in claim 15 and further including control means connected to receive vertical and horizontal deflection signals, said control means including a signal shaping circuit which shapes the signal applied to said additional ribbon so that it has a generally parabolic waveform as the electron beam is deflected off the tube axis.
Claim 27
Dependent Claim
39 words
A leNs system as defined in claim 15 and further including discs of semiconductive material mounted between and separating each of said ribbons and coupled to each of said ribbons so as to function as a shunt resistance therefor.
Claim 28
Dependent Claim
112 words
A magnetic focus lens system for focusing an electron beam generated in a cathode ray tube comprising A. a plurality of separate, toroidal, permanent magnet segments spaced closely along an axis arranged to engage around the neck of said tube, said magnets being arranged and distributed along said axis so as to bring substantially all off-axis electrons to a single focal point on said screen, B. a toroidal winding wound coaxially with said magnets. C. means for producing deflection signals for deflecting the electron beam, and D. means responsive to said deflection signals for applying a current signal to said toroidal winding which varies in accordance with the deflection of said beam.
Claim 29
Dependent Claim
112 words
A magnetic focus lens system for focusing an electron beam generated in a cathode ray tube comprising A. a plurality of separate, toroidal, permanent magnet segments spaced closely along an axis arranged to engage around the neck of said tube, said magnets being arranged and distributed along said axis so as to bring substantially all off-axis electrons to a single focal point on said screen, B. a toroidal winding wound coaxially with said magnets. C. means for producing deflection signals for deflecting the electron beam, and D. means responsive to said deflection signals for applying a current signal to said toroidal winding which varies in accordance with the deflection of said beam.
Claim 30
Dependent Claim
29 words
A lens system as defined in claim 20 and further including a ferrite sleeve encircling said magnets and winding so as to confine the magnetic field within the tube.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-22 | 1976-02-21 | 1976-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-22 | 1980-02-21 | 1980-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-22 | 1984-02-21 | 1984-08-22 | $7700.00 | Window Closed / Lapsed |