Patent DE867771C successfully refreshed from Google Patents.
US4376272A
Expired / Lapsed
US
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Magnetic field generators for use in electromagnetic focusing type cathode ray tubes
Assignee: Hitachi Ltd
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Filing: 1981-11-09
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Granted: 1983-03-08
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Expires: 2001-11-09
Abstract
Abstract In a magnetic field generator mounted about a neck of a cathode ray tube for focusing an electron beam and made up of a permanent magnet, a magnetic field adjusting mechanism for adjusting field intensity produced by the permanent magnet and a magnetic member adapted to compensate for a temperature characteristic of the permanent magnet, the temperature characteristic compensating member is located at a position not affected by magnetic flux adjusted by the magnetic field adjusting mechanism.
Inventors
- 👤 Kuniharu Osakabe
- 👤 Isao Yoshimi
- 👤 Soichi Sakurai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:39
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/46; H01J29/58; H01J29/64; H01J29/68
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
101 words
In a magnetic field generator for use in an electromagnetic focusing type cathode ray tube of the type wherein the magnetic field generator is disposed on the outside of said cathode ray tube for focusing an electron beam in the tube and composed of a permanent magnet, a magnetic field adjusting mechanism for adjusting field intensity produced by said permanent magnet, and a magnetic member adapted to compensate for a temperature characteristic of said permanent magnet the improvement wherein said temperature characteristic compensating member is located at a position not affected by magnetic flux adjusted by said magnetic field adjusting mechanism.
Claim 2
Dependent Claim
101 words
In a magnetic field generator for use in an electromagnetic focusing type cathode ray tube of the type wherein the magnetic field generator is disposed on the outside of said cathode ray tube for focusing an electron beam in the tube and composed of a permanent magnet, a magnetic field adjusting mechanism for adjusting field intensity produced by said permanent magnet, and a magnetic member adapted to compensate for a temperature characteristic of said permanent magnet the improvement wherein said temperature characteristic compensating member is located at a position not affected by magnetic flux adjusted by said magnetic field adjusting mechanism.
Claim 3
Dependent Claim
59 words
The magnetic field generator according to claim 1 wherein said permanent magnet comprises an annular permanent magnet magnetized in an axial direction of said cathode ray tube, said magnetic field adjusting mechanism is provided on an outer periphery of said permanent magnet, and said temperature characteristic compensating magnetic member is provided on an inner periphery of said permanent magnet.
Claim 4
Dependent Claim
43 words
The magnetic field generator according to claim 2 wherein said magnetic field adjusting mechanism comprises a magnetic yoke plate on one side surface of said annular permanent magnet and a magnetic adjusting piece threaded on an outer periphery of said magnetic yoke plate.
Claim 5
Dependent Claim
43 words
The magnetic field generator according to claim 2 wherein said magnetic field adjusting mechanism comprises a magnetic yoke plate on one side surface of said annular permanent magnet and a magnetic adjusting piece threaded on an inner periphery of said magnetic yoke plate.
Claim 6
Dependent Claim
51 words
The magnetic field generator according to claim 1 wherein said permanent magnet comprises an annular permanent magnet magnetized in a direction perpendicular to an axis of said cathode ray tube and said magnetic field adjusting mechanism comprises a cup shaped ferromagnetic member threaded on an outer periphery of said permanent magnet.
Claim 7
Dependent Claim
57 words
The magnetic field generator according to claim 1 wherein said permanent magnet comprises an annular permanent magnet magnetized in a direction perpendicular to an axis of said magnetic field adjusting mechanism comprises a hollow annular magnetic yoke surrounding said annular permanent magnet and a magnetic cylindrical adjusting member threaded to an inner periphery of said magnetic yoke.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-03-07 | 1986-09-06 | 1987-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-03-07 | 1990-09-06 | 1991-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-03-07 | 1994-09-06 | 1995-03-08 | $7700.00 | Window Closed / Lapsed |