EP0053841A2
Expired / Lapsed
EP
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Microwave oven having controllable frequency microwave power source
Assignee: Panasonic Holdings Corp
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Filing: 1981-12-09
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Granted: —
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Expires: 2001-12-09
Abstract
Abstract A microwave oven comprising a heating cavity (11), a controllable frequency microwave power source (10), a detector (12) for detecting the intensity of electric field in the cavity and control means (13, 23) for setting the microwave power source at the frequency as determined by the intensity of electric field. The frequency at which the loaded cavity is energized is selected by the control means to store high power in the cavity. The cavity has the dimensions for generating only the TE mφp mode at the frequency of the microwave power source being limited to 915 ± 13 MHz, where 0 is the mode index in the direction of height of the cavity.
Inventors
- 👤 Tomotaka Nobue
- 👤 Shigeru Kusunoki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 15:43
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/64; H05B6/6435; H05B6/6447; H05B6/70; H05B6/705
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
100 words
A microwave oven comprising; a cavity (11) for receiving a load to be heated, said cavity having dimensions for generating a limited electromagnetic mode within a predetermined frequency bandwidth; a controllable frequency microwave power source (10) for providing power to said cavity, the operating frequency of said microwave power source being controllable within said predetermined frequency bandwidth; detector means (12) for providing a detector signal indicative of the resonant frequency of said cavity when the cavity is loaded and energized; and control means (13, 23) for controlling the operating frequency of said microwave power source according to said detector signal.
Claim 2
Dependent Claim
100 words
A microwave oven comprising; a cavity (11) for receiving a load to be heated, said cavity having dimensions for generating a limited electromagnetic mode within a predetermined frequency bandwidth; a controllable frequency microwave power source (10) for providing power to said cavity, the operating frequency of said microwave power source being controllable within said predetermined frequency bandwidth; detector means (12) for providing a detector signal indicative of the resonant frequency of said cavity when the cavity is loaded and energized; and control means (13, 23) for controlling the operating frequency of said microwave power source according to said detector signal.
Claim 3
Dependent Claim
94 words
A microwave oven as claimed in claim 1 wherein the operating frequency of said controllable frequency microwave power source (10) is limited to 915 ± 13 MHz being one of the ISM band, and said cavity (11) has the dimensions for generating only the TE d mode, where m is the mode index in the direction of width of said cavity, φ is the mode index in the direction of height of said cavity and p is the mode index in the direction of depth of said cavity, m and p being positive integers.
Claim 4
Dependent Claim
41 words
A microwave oven as claimed in claim 1 or claim 2, wherein said control means (13, 23) includes a voltage ramp generator (19) coupled to said microwave power source (10) for controlling the power source frequency within the predetermined frequency bandwidth.
Claim 5
Dependent Claim
58 words
A microwave oven as claimed in claim 1 or claim 2, wherein said detector means (12) includes first means for coupling to the electric field which generates in said cavity (11) when the loaded cavity is energized and second means for generating a DC voltage corresponding to the intensity of said electric field to provide the detector signal.
Claim 6
Dependent Claim
81 words
A microwave oven as claimed in claim 1 or claim 2, wherein said detector means (12) includes first means for coupling to the electric field which generates in said cavity (11) when the loaded cavity is energized, second means for generating a DC voltage corresponding to the intensity of said electric field, and an indicator (17), arranged in a control panel (18) of said microwave oven, for providing the detector signal, said indicator emitting light in proportion to said DC voltage.
Claim 7
Dependent Claim
26 words
A microwave oven as claimed in claim 4, wherein said first means is a pole antenna (14), and said second means is a crystal diode (15).
Claim 8
Dependent Claim
37 words
A microwave oven as claimed in claim 5, wherein said first means is a pole antenna (14), said second means is a crystal diode (15), and said indicator is a level meter (17) with light emitting diodes.
Claim 9
Dependent Claim
55 words
A microwave oven as claimed in claim 5, wherein said control means (13) includes a control part (20) arranged in said control panel (18) of said microwave oven for controlling a voltage ramp generator (19) coupled to said controllable frequency microwave power source (10) to control the power source frequency within the predetermined frequency bandwidth.
Claim 10
Dependent Claim
26 words
A microwave oven as claimed in claim 1 or claim 2, wherein said controllable frequency microwave power source (10) is a solid state variable frequency source.
References Cited (Backward Citations)
No citation records indexed.
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