US 4,051,341 A · Microwave oven door screen

Abstract

A structure of a microwave oven door screen which facilitates the observation of the inside of a heating cavity and enhances the safety against the electromagnetic wave leakage and durability. A door screen of this type generally comprises a pair of transparent plates and an electromagnetic wave shielding material interposed therebetween. The present door screen uses a punched metal plate as the electromagnetic shielding material made of aluminum having a thickness of 0.1 to 0.35 mm, an aperture diameter of 1.2 mm or less and a ratio of the aperture diameter to a center-to-center distance of an aperture of 0.67 to 0.85, these parameters being chosen such that an aperture rate of more than 40% is assured and the electromagnetic wave leakage through the door screen is effectively prevented (to meet the Regulations of U.S. Department of Health, Education, and Welfare) and a strain due to continuous mechanical treatment of the punched metal plate is minimized.

Claims3

Dependent claims

A microwave oven comprising a main body having a heating cavity therein, a door mounted to said main body for closing a front opening of said heating cavity, a microwave generator for radiating microwave energy into said heating cavity, and a door screen mounted on said door, said door screen including a punched metal plate interposed between transparent plates, said punched metal plate having a thickness of 0.10 to 0.35 mm, an aperture diameter of not larger than 1.2 mm and a ratio of the aperture diameter to a center-to-center distance of the apertures of 0.67 to 0.85, an extended portion of said punched metal plate being coupled to a metal plate which electrically couples the heating cavity body to the door body.

Dependencies are inferred from the claim text.

Microwave oven door screen

Life of this patent

Microwave oven door screen

Life of this patent

Abstract

Claims3