Built-in leakage radiation detecting device for a microwave oven

Claim 2

In a microwave oven of the type having a box-like oven liner and an access door defining an oven cooking cavity, and microwave radiation seal means between the door and oven liner, a leakage radiation detecting device comprising: sensor means partially projecting into the space formed between the access door and the oven frame external to the seal means, the sensor means being sensitive to and arranged so as to communicate with the magnetic field of the microwave leakage radiation; transmission line means, resonant to the operating microwave frequency, coupled with the sensor means and located coaxially within a waveguide communicating with the leakage radiation; and indicator means coupled with and responsive to the output of the resonant transmission means to become activated; whereby, in the presence of radiation above a predetermined level leaking from the oven cavity past the seal means, a voltage induced in the sensor means will be amplified in the resonant transmission line means sufficiently to activate the indicator means to provide an indicium of the presence of such leakage radiation.

Claim 3

The device of claim 1 wherein the sensor means is arranged so as to communicate with the electric field of the microwave leakage radiation and is sensitive thereto such that a voltage will be generated in the sensor means to be amplified in the resonant transmission line means.

Claim 4

In a microwave oven having a metallic box-like oven liner and a metallic access door hingedly attached to the oven at the bottom thereof forming an oven cooking cavity, a front frame surrounding the oven liner, means for supplying microwave energy to the oven cavity, a conductive radiation seal gasket attached to the inner surface of the door and positioned to contact the liner flange around the entire periphery thereof when the door is closed, and a continuous channel-like space defined by the inner surface of the door and the front frame external to the seal gasket, a leakage radiation detecting device comprising: a sensor partially projecting into the channel-like space and sensitive to and arranged so as to communicate with the magnetic field of the microwave leakage radiation; a transmission line, resonant to the operating microwave frequency, operatively coupled with the sensor and located coaxially within and isolated from a waveguide communicating with the channel-like space and thereby, the leakage radiation; and an indicator coupled with and responsive to the output of the resonant transmission line to become activated.

Claim 5

In a microwave oven having a metallic box-like oven liner and a metallic access door hingedly attached to the oven at the bottom thereof forming an oven cooking cavity, a front frame surrounding the oven liner, means for supplying microwave energy to the oven cavity, a conductive radiation seal gasket attached to the inner surface of the door and positioned to contact the liner flange around the entire periphery thereof when the door is closed, and a continuous channel-like space defined by the inner surface of the door and the front frame external to the seal gasket, a leakage radiation detecting device comprising: a sensor partially projecting into the channel-like space and sensitive to and arranged so as to communicate with the magnetic field of the microwave leakage radiation; a transmission line, resonant to the operating microwave frequency, operatively coupled with the sensor and located coaxially within and isolated from a waveguide communicating with the channel-like space and thereby, the leakage radiation; and an indicator coupled with and responsive to the output of the resonant transmission line to become activated.

Claim 6

The device of claim 3 wherein the sensor is arranged so as to communicate with and is sensitive to the electric field of the microwave leakage radiation.

Claim 7

In a microwave oven haviNg a metallic box-like oven liner and a metallic access door hingedly attached to the oven at the bottom thereof forming an oven cooking cavity, a front frame surrounding the oven liner, means for supplying microwave energy to the oven cavity, a metallic radiation seal gasket attached to the inner surface of the door and positioned to contact the liner flange around the entire periphery thereof when the door is closed, and a continuous channel defined by the inner surface of the door and the front frame external to the seal gasket, a leakage radiation detecting device located within the door comprising: an inductive pickup loop partially projecting into the channel and arranged so as to communicate with the magnetic field of the microwave leakage radiation; a conductive transmission line resonant to a quarter wavelength of the operating microwave frequency, operatively coupled with the pickup loop and located coaxially within and isolated from a cylindrical waveguide and communicating with the channel and thereby the leakage radiation; and a neon lamp having one of its terminals coupled with and responsive to the output of the resonant transmission line to become activated, and the other terminal connected with a common ground and thereby with the pickup loop to complete the circuit.

Claim 8

In a microwave oven haviNg a metallic box-like oven liner and a metallic access door hingedly attached to the oven at the bottom thereof forming an oven cooking cavity, a front frame surrounding the oven liner, means for supplying microwave energy to the oven cavity, a metallic radiation seal gasket attached to the inner surface of the door and positioned to contact the liner flange around the entire periphery thereof when the door is closed, and a continuous channel defined by the inner surface of the door and the front frame external to the seal gasket, a leakage radiation detecting device located within the door comprising: an inductive pickup loop partially projecting into the channel and arranged so as to communicate with the magnetic field of the microwave leakage radiation; a conductive transmission line resonant to a quarter wavelength of the operating microwave frequency, operatively coupled with the pickup loop and located coaxially within and isolated from a cylindrical waveguide and communicating with the channel and thereby the leakage radiation; and a neon lamp having one of its terminals coupled with and responsive to the output of the resonant transmission line to become activated, and the other terminal connected with a common ground and thereby with the pickup loop to complete the circuit.