EP0214816A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Cathode ray tubes
Assignee: Sony Corp
•
Filing: 1986-08-28
•
Granted: —
•
Expires: 2006-08-28
Abstract
Abstract In a cathode ray tube provided with a limiting aperture (LA) in an electron gun, the axial potential between the limiting aperture (LA) and an electrode (SG) arranged at the rear stage of the limiting aperture (LA) is lower than a potential of the limiting aperture (LA) by several tens of volts, so that secondary electrons generated from the limiting aperture (LA) are hindered from reaching a fluorescent screen (1) or a target screen of the cathode ray tube.
Inventors
- 👤 Takehiro C/O Patent Division Kakizaki
- 👤 Koumei C/O Patent Division Kusuda
- 👤 Koichi C/O Patent Division Furui
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 12:44
CPC Classifications
H; H01; H01J; H01J29/00; H01J29/46; H01J29/48; H01J29/488; H01J3/00; H01J3/02; H01J3/029
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
54 words
A cathode ray tube including an electron gun with a limiting aperture (LA); characterized in that: an axial potential between said limiting aperture (LA) and an electrode (SG; G3) arranged at the rear stage of said limiting aperture (LA) is lower than the potential of said limiting aperture (LA) by several tens of volts.
Claim 2
Dependent Claim
54 words
A cathode ray tube including an electron gun with a limiting aperture (LA); characterized in that: an axial potential between said limiting aperture (LA) and an electrode (SG; G3) arranged at the rear stage of said limiting aperture (LA) is lower than the potential of said limiting aperture (LA) by several tens of volts.
Claim 3
Dependent Claim
30 words
A cathode ray tube according to claim 1 wherein said electrode (SG) arranged at the rear stage of said limiting aperture (LA) is a disc-like secondary electron control electrode (SG).
Claim 4
Dependent Claim
22 words
A cathode ray tube according to claim 1 and claim 2 wherein said several tens of volts are at least 50 V.
Claim 5
Dependent Claim
30 words
A cathode ray tube according to claim 1 wherein said electrode (SG) arranged at the rear stage of said limiting aperture (LA) is a cylindrical secondary electron control electrode (SG).
Claim 6
Dependent Claim
27 words
A cathode ray tube according to claim 1 wherein said electrode (G3) arranged at the rear stage of said limiting aperture (LA) is a grid electrode (G3).
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.