EP0268329A1
Expired / Lapsed
EP
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Microwave oven
Assignee: Whirlpool Italia SRL
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Filing: 1987-11-09
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Granted: —
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Expires: 2007-11-09
Abstract
Abstract A microwave oven comprising a generator (7) for radiating energy, fan means (6) for producing an air flow in the oven cavity, humidity sensor means (8) for sensing the humidity in the oven cavity and control means (11) for controlling the supply of energy in dependence on the sensed humidity. The defrosting process is controlled only by the sensed change in humidity. Preferably the control means (11) detects a minimum humidity and interrupt the defrosting process when after said minimum is reached, the difference between said minimum humidity and the detected reaches a predetermined value.
Inventors
- 👤 Franciscus Kokkeler
- 👤 Mario Fioroli
- 👤 Per Olov Gustav Risman
- 👤 Liliana Vigano
- 👤 Mats Gunnar Idebro
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 17:26
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/64; H05B6/6408; H05B6/6411; H05B6/6447; H05B6/6458
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
88 words
A microwave oven comprising an oven cavity in which an article to be heated is placed, a microwave generator for radiating microwave energy into said cavity for heating said article, fan means for producing an air flow in said cavity, humidity sensor means for sensing a change in humidity of the air in said cavity and control means for controlling the supply of energy to the article in dependence on the sensed humidity, characterized in that a defrosting mode is controlled only by the sensed change in humidity.
Claim 2
Dependent Claim
88 words
A microwave oven comprising an oven cavity in which an article to be heated is placed, a microwave generator for radiating microwave energy into said cavity for heating said article, fan means for producing an air flow in said cavity, humidity sensor means for sensing a change in humidity of the air in said cavity and control means for controlling the supply of energy to the article in dependence on the sensed humidity, characterized in that a defrosting mode is controlled only by the sensed change in humidity.
Claim 3
Dependent Claim
49 words
A microwave oven as claimed in Claim 1, characterized in that said control means is arranged to detect a minimum humidity value, said defrosting being interrupted when, after said minimum value is reached, the difference between said minimum humidity value and the detected humdity value reaches a predetermined value.
Claim 4
Dependent Claim
38 words
A microwave oven as claimed in Claim 1, characterized in that the change in humidity corresponds to a humdity gradient and interruption of the defrosting mode is effected when the control means detect a predetermined positive humidity gradient.
Claim 5
Dependent Claim
86 words
A microwave oven as claimed in Claim 2, characterized in that the oven cavity has an inlet aperture in connection with the envirnmental air and an outlet aperture connected to an inlet of a channel, an outlet of which channel opens into the environment, said fan means being positioned inside the channel for producing said air flow from the environment into the oven cavity towards the channel and back to the environment, and said humidity sensor means being positioned inside the channel downstream the oven cavity.
Claim 6
Dependent Claim
55 words
A microwave oven as claimed in Claim 4, characterized in that said control means is operable to effect defrosting in cycles, each cycle having at least two periods, a first period in which both the generator and the fan are operating, and a second period in which both the generator and the fan are inoperative.&
Claim 7
Dependent Claim
43 words
A microwave oven as claimed in Claim 5, characterized in that said control means is operable to lengthen the first period of next cycles dependent on the detected humidity value with respect to the predetermined difference value after a predetermined number of cycles.
Claim 8
Dependent Claim
41 words
A microwave oven as claimed in Claim 6, characterized in that said control means is operable to start defrosting with a first cycle in which the first period has a predetermined duration dependent on a minimum quantity of a critical article.
Claim 9
Dependent Claim
68 words
A microwave oven as claimed in Claim 2 or 3, characterized in that a channel is provided outside the oven cavity, both ends of the channel open into said oven cavity, said fan means being positioned inside the channel for producing said air flow to circulate in a closed loop, and said humdity sensor means being positioned in the air flow inside the channel downstream the oven cavity.
Claim 10
Dependent Claim
75 words
A microwave oven as claimed in Claim 8, characterized in that a branch-channel is provided, having one end opening into the channel, and the other end opening into the environment, and in that at a junction of said channels there is provided a valve which can be switched between two positions, i.e. one position in which the air circulates in a closed loop and another position in which the air is blown into the environment.
References Cited (Backward Citations)
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