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US 4,060,747 AGranted
Phototube having domed mesh with non-uniform apertures
AssigneeRCA Corporation
InventorRichard Dale Faulkner
Life of this patent
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Abstract
An electron discharge tube comprises a photocathode, a dynode, a mesh having openings of non-uniform sizes on the dynode, and an anode, all in an evacuated tube. The mesh comprises a plurality of spaced first elongated elements of electrically conducting material and a plurality of spaced second elongated elements of electrically conducting material, intersecting to form openings of non-uniform sizes.
Claims9
An electron discharge tube comprising an evacuated tube;
- a photocathode in said tube;
- a dynode having a covered input opening and an output opening in said tube;
- a dome-shaped radially symmetric mesh covering said input opening, said mesh having a plurality of spaced first elongated elements of electrically conducting material, and a plurality of spaced second elongated elements of electrically conducting material, said first elements and said second elements intersecting to form non-uniform apertures;
- said mesh further comprising a center and a periphery;
- said first elements being substantially radial elements;
- and said second elements being substantially circumferential elements;
- said apertures being progressively larger from the periphery to the center of said mesh whereby said central portion is more electron permeable than the peripheral portion.
4 more elements
An electron discharge tube comprising an evacuated tube having therein:
- a photocathode;
- a cup-shaped dynode and an anode;
- a dome-shaped mesh in contact with said dynode, said mesh comprising a plurality of spaced elongated elements of electrically-conducting material, said first elements and said second elements intersecting to form openings of non-uniform size;
- said mesh being radially symmetric wherein said first elements are radial elements and said second elements are circumferential elements;
- said mesh further comprising a central portion and a peripheral portion;
- said mesh further comprising an annular ring attached to said peripheral portion;
- said dynode having an approximately circular top opening;
- a circular flange around the periphery of said top opening;
- a side opening near the periphery of said top opening substantially perpendicular to said top opening;
- electron emissive material on the inside of said dynode;
- said top opening facing said photocathode;
- said dome-shaped mesh being on said top opening with said central portion being closer to said photocathode than said peripheral portion;
- said evacuated tube including a faceplate and a tubular body with a portion of the body having a circular cross-section;
- said photocathode being on said faceplate;
- and said dynode located in the portion of the tubular body having the central cross-section, the flange of the dynode being substantially parallel to the plane of the circular cross-section and having a diameter substantially the same as the diameter of the circular cross-section;
- whereby said central portion is more electron permeable than said peripheral portion.
13 more elements
Dependencies are inferred from the claim text.