Patent US4717853A successfully refreshed from Google Patents.
US4717853A
Expired / Lapsed
US
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Projection tube whose coolant contains an ethylene oligomer
Assignee: Hitachi Ltd
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Filing: 1986-03-06
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Granted: 1988-01-05
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Expires: 2006-03-06
Abstract
Abstract Disclosed is a projection tube containing a coolant comprising a liquid mixture of ethylene glycol and water filled in the space between a phosphor screen panel and a transparent face panel which is set up at a certain distance in front thereof, wherein the coolant is incorporated with 10 ppm to 20 wt. % of an ethylene oligomer. The present projection tube is an excellent product free from a decrease in transmittance due to the coloring of the coolant in operation at a high temperature.
Inventors
- 👤 Masayoshi Ezawa
- 👤 Hiroko Wakui
- 👤 Shigeru Wakana
- 👤 Toshikazu Morishita
- 👤 Akira Misumi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:51
CPC Classifications
H; H01; H01J; H01J9/00; H01J9/24; H01J9/28; H01J29/00; H01J29/006; H01J29/86; H01J29/89; H01J29/894
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
65 words
A projection tube containing a coolant comprising a liquid mixture of ethylene glycol and water filled in the space between a phosphor screen panel and a transparent face panel which is set up at a predetermined distance in front thereof, wherein the coolant is incorporated with 10 ppm to 20 wt. % of an ethylene oligomer having a degree of polmerization of 4 to 8.
Claim 2
Dependent Claim
65 words
A projection tube containing a coolant comprising a liquid mixture of ethylene glycol and water filled in the space between a phosphor screen panel and a transparent face panel which is set up at a predetermined distance in front thereof, wherein the coolant is incorporated with 10 ppm to 20 wt. % of an ethylene oligomer having a degree of polmerization of 4 to 8.
Claim 3
Dependent Claim
25 words
A projection tube as set forth in claim 1, wherein the ethlene oligomer is added in an amount of 500 ppm to 15 wt. %.
Claim 4
Dependent Claim
24 words
A projection tube as set forth in claim 1, wherein the ethylene oligomer is added in an amount of 1 to 5 wt. %.
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) | 1991-01-04 | 1991-07-06 | 1992-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-04 | 1995-07-06 | 1996-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-04 | 1999-07-06 | 2000-01-05 | $7700.00 | Window Closed / Lapsed |