Microwave oven with circuit cooling system and magnetic shield system

• US 4,868,362 A
• Filed: 02/13/1989
• Issued: 09/19/1989
• Est. Priority Date: 03/14/1979
• Status: Expired due to Fees

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Takeuji, Koichi
• Primary Examiner(s): Leung, Philip H.
• Application Number:
  US07/312,412
• Time in Patent Office: 218 Days
• Field of Search: 219/10.55 R, 219/10.55 B, 219/10.55 D, 174/35 R, 174/35 MS, 174/15.1, 174/16.1, 174/16.3, 361/383, 361/384, 361/424, 361/394, 361/395, 336/84 R, 336/84 C, 336/84 M
• US Class Current: 219/757
• CPC Class Codes: H05B 6/6402 Aspects relating to the microwave cavity
• CPC Class Codes: H05B 6/642 Cooling of the microwave components and related air circulation systems H05B6/6473 takes precedence
• CPC Class Codes: H05B 6/666 Safety circuits emergency protective circuits in general H02H

Abstract

A microwave oven comprises a cooling system and a magnetic shield system applied to a plurality of circuit elements. The cooling system comprises a compartment through which air can pass. The compartment is formed by at least one printed circuit board carrying a plurality of circuit elements and a supporting member for supporting the printed circuit board. The circuit elements are cooled by the flow of the air. In addition, the circuit elements are magnetically shielded from a magnetic field generation device such as a magnetic card reader/writer and a high voltage transformer by a shield member. It is possible that the circuit elements are protected from very large quantities of heat emitted by the high voltage transformer. The magnetic card reader/writer may be provided for reading/cooking program information from a magnetic card and writing the same on it. The microwave oven should be controlled according to the cooking program information for cooking purposes.

Claims

1. A microwave oven which comprises:

a housing;

a door attached to the front portion of said housing;

a control panel disposed on said front portion of said housing adjacent to said door;

a circuit structure disposed behind said control panel, wherein said circuit structure comprises;

a C-shaped supporting member having upper and lower front portion plates secured to a rear portion of said control panel, at top portion plate and a bottom portion plate extending perpendicularly from said control panel, and a rear portion plate connecting said top and bottom portion plates opposite from said front portion plates, wherein said top and bottom portion plates each include top and bottom openings therein, respectively;

first and second printed circuit boards secured to first and second side portions of said C-shaped supporting members respectively, so as to form a compartment having said top and bottom openings, each of said first and second printed circuit boards having circuit elements disposed thereon so as to face into said compartment; and

a high voltage transformer disposed behind said rear portion plate of said C-shaped supporting member, wherein said top and bottom openings in said C-shaped supporting member provide for air flow through said compartment so as to cool said circuit elements, said C-shaped supporting member reinforces the construction strength of said printed circuit boards, and said rear portion plate of said C-shaped supporting member shields said circuit elements from heat generated by said voltage transformer and from the magnetic field generated by said voltage transformer.

2. The microwave oven as defined in claim 1, wherein said C-shaped supporting member comprises a metallic plate.

3. The microwave oven as defined in claim 2, wherein said control panel comprises a keyboard and a display secured to a control panel support plate.

4. The microwave oven as defined in claim 3, wherein said control panel further comprises a card inlet for receiving cooking program information cards.