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Patent US3702950A successfully refreshed from Google Patents.
US3702950A
Expired / Lapsed
US
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Electrostatic focussing-type television picture tube utilizing a plurality of metal disks
Assignee: Panasonic Holdings Corp
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Filing: 1970-04-17
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Granted: 1972-11-14
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Expires: 1990-04-17
Abstract
Abstract An electrostatic focussing-type television picture tube wherein a plurality of ring-shaped metal plates are successively coaxially stacked to form an electrode assembly with the plates being separated, a relatively small space between adjacent plates. This electrode assembly is placed between a first accelerating electrode and a screen, whereby a periodic electric field is produced by the electrode assembly to thereby provide a lens effect of a main lens which is apparently a unitary system and which is moreover substantially free of aberration.
Inventors
- 👤 Hiroto Nakamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:19
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/46; H01J29/58; H01J29/62; H01J29/622; H01J29/624
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
154 words
In a picture tube including a periodic electric field-type lens system which comprises at least five metal disks having circular apertures and being axially aligned in sequential order from a first accelerating electrode and along an electron beam path between said first accelerating electrode and a fluorescent screen, the group of disks of odd order being at one potential and the group of disks of even order being at another potential so as to form a periodic electric field along said electron beam path, the improvement in that the apertures of the disks of each said group have the same diameter, the aperture radius r1 of said disks and the distance d between adjacent disks meet the condition 2r1 > OR = d, whereby said disks constitute a unitary main focusing lens system under said periodic electric field to cause electron beams passing through said first accelerating electrode to focus on said fluorescent screen.
Claim 2
Dependent Claim
154 words
In a picture tube including a periodic electric field-type lens system which comprises at least five metal disks having circular apertures and being axially aligned in sequential order from a first accelerating electrode and along an electron beam path between said first accelerating electrode and a fluorescent screen, the group of disks of odd order being at one potential and the group of disks of even order being at another potential so as to form a periodic electric field along said electron beam path, the improvement in that the apertures of the disks of each said group have the same diameter, the aperture radius r1 of said disks and the distance d between adjacent disks meet the condition 2r1 > OR = d, whereby said disks constitute a unitary main focusing lens system under said periodic electric field to cause electron beams passing through said first accelerating electrode to focus on said fluorescent screen.
Claim 3
Dependent Claim
37 words
A picture tube according to claim 1, wherein the outer radius r2 of said disks, the inner radius r1 of said disks and the distance d between adjacent disks meet the conditions r2-r1 > or = d.
Claim 4
Dependent Claim
20 words
A picture tube according to claim 1, wherein the thickness of each of said disks is less than 0.8 mm.
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) | 1975-11-14 | 1976-05-15 | 1976-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-14 | 1980-05-15 | 1980-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-14 | 1984-05-15 | 1984-11-14 | $7700.00 | Window Closed / Lapsed |