| US 7,548,026 B2 | ||
| Magnetron | ||
| Nagisa Kuwahara, Tochigi (Japan); Masayuki Aiga, Tochigi (Japan); and Takeshi Ishii, Tochigi (Japan) | ||
| Assigned to Panasonic Corporation, Osaka (Japan) | ||
| Filed on Jan. 10, 2005, as Appl. No. 11/31,340. | ||
| Claims priority of application No. P. 2004-004201 (JP), filed on Jan. 09, 2004. | ||
| Prior Publication US 2005/0167426 A1, Aug. 04, 2005 | ||
| Int. Cl. H01J 25/50 (2006.01) | ||
| U.S. Cl. 315—39.51 [315/39.67; 315/39.69] | 2 Claims |
| 1. A magnetron comprising:
an anode assembly having an approximately cylindrical anode tube body, an even number of plate shaped vanes fixedly mounted
to an inner circumference of the anode tube body and radially arranged from the inner circumference of the anode tube body
to a central axis, and large and small strap rings for electrically connecting the plate shaped vanes to each other; and
a cathode assembly inserted on the central axis of the anode assembly,
wherein an end portion of each plate shaped vane positioned on the central axis of the anode tube body is formed in a step
shape whose thickness in a range of a predetermined length L from the end thereof is smaller than other portion, and
wherein the step shape, when viewed in the direction of the central axis, creates a reduced thickness in the innermost portion
of each plate shaped vane,
wherein, when a plate thickness of the base substrate of the plate shaped vanes is t0, the thickness of the end portion which is thinned in a step shape is t1, a distance between ends of adjacent plate shaped vanes is w, and the number of the plate shaped vanes is N, and
wherein N, L, t0 and t1 satisfy the following equations:
w/(t1+w)≤0.5
L≧{(t0−t1)/2}÷tan (180/N).
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