US3906281A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color cathode ray tube having gas for conduction of heat from shadow mask
Assignee: Mitsubishi Electric Corp
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Filing: 1973-04-27
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Granted: 1975-09-16
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Expires: 1993-04-27
Abstract
Abstract A shadow mask color cathode-ray tube and a process for the preparation thereof. In a color cathode-ray tube having a shadow mask, an electron beam having an energy of about 26 KV. and 1.0 mA. is directly received by the shadow mask. A part of the energy is converted to thermal energy, resulting in the thermal expansion of said shadow mask to cause undesirable phenomenon. According to the present invention, an inert gas is filled in said cathode-ray tube whereby the thermal radiation of said shadow mask is improved to reduce the deviation of said beam that causes color breakup.
Inventors
- 👤 Koji Nakamura
- 👤 Hisao Nakahishi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:16
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/94
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
178 words
An improved shadow mask color cathode-ray tube comprising: an air-tight tube comprising a panel and a funnel having a neck part and a funnel part wherein the funnel part is sealed to said panel to form an air-tight enclosure, a fluorescent screen having numerous three color fluorescent dots arranged in a pattern and disposed within said tube adjacent to said panel, three electron guns disposed within said tube for emitting three electron beams having an energy of about 26 KV and 1.0 mA which strike said fluorescent dots causing them to fluoresce where struck, a shadow mask containing numerous openings corresponding to the pattern of the three color fluorescent dots disposed within said tube adjacent said fluorescent screen between said fluorescent screen and said electron guns, a gas having a low specific heat disposed in said tube at a partial pressure in the range of 10 2 to 10 7 Torr., for distributing to the walls of said tube the heat caused by said electron beams striking said shadow mask thereby preventing thermal deformation of said shadow mask.
Claim 2
Dependent Claim
178 words
An improved shadow mask color cathode-ray tube comprising: an air-tight tube comprising a panel and a funnel having a neck part and a funnel part wherein the funnel part is sealed to said panel to form an air-tight enclosure, a fluorescent screen having numerous three color fluorescent dots arranged in a pattern and disposed within said tube adjacent to said panel, three electron guns disposed within said tube for emitting three electron beams having an energy of about 26 KV and 1.0 mA which strike said fluorescent dots causing them to fluoresce where struck, a shadow mask containing numerous openings corresponding to the pattern of the three color fluorescent dots disposed within said tube adjacent said fluorescent screen between said fluorescent screen and said electron guns, a gas having a low specific heat disposed in said tube at a partial pressure in the range of 10 2 to 10 7 Torr., for distributing to the walls of said tube the heat caused by said electron beams striking said shadow mask thereby preventing thermal deformation of said shadow mask.
Claim 3
Dependent Claim
35 words
The shadow mask color cathode-ray tube according to claim 1, wherein said sealed gas is selected from the group consisting of the gases of Group O which comprise helium, neon, argon, krypton, xenon, and radon.
Claim 4
Dependent Claim
26 words
The shadow mask color cathode-ray tube according to claim 1, wherein said sealed gas is selected from the group consisting of hydrogen, nitrogen and hydrocarbon gas.
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) | 1978-09-15 | 1979-03-17 | 1979-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-15 | 1983-03-17 | 1983-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-15 | 1987-03-17 | 1987-09-16 | $7700.00 | Window Closed / Lapsed |