| (19) |
 |
|
(11) |
EP 0 250 053 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
28.03.1990 Bulletin 1990/13 |
| (43) |
Date of publication A2: |
|
23.12.1987 Bulletin 1987/52 |
| (22) |
Date of filing: 16.06.1987 |
|
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| (84) |
Designated Contracting States: |
|
DE ES FR GB NL |
| (30) |
Priority: |
19.06.1986 US 876150
|
| (71) |
Applicant: North American Philips Corporation |
|
New York, N.Y. 10017 (US) |
|
| (72) |
Inventors: |
|
- Chung, Samuel Sunwhee
NL-5656 AA Eindhoven (NL)
- Rehkopf, Charles Henry
NL-5656 AA Eindhoven (NL)
- Reigel, Frankling George
NL-5656 AA Eindhoven (NL)
- Siefker, Donald Louis
NL-5656 AA Eindhoven (NL)
- Stowe, James Richard
NL-5656 AA Eindhoven (NL)
|
| (74) |
Representative: Koppen, Jan et al |
|
INTERNATIONAAL OCTROOIBUREAU B.V.,
Prof. Holstlaan 6
5656 AA Eindhoven
5656 AA Eindhoven (NL) |
|
| |
|
| (54) |
Aging process for cathode ray tubes |
(57) An improved aging process for a cathode ray tube in which the main focusing grid
(G3) is aged at a potential below that of the G2 grid, resulting in significantly
reduced incidence of dark center cathode. In a typical example of the process the
G3 grid is at a voltage of at least 100 volts, which voltage is at least 50 volts
less than the G2 grid voltage.