Microwave oven

• US 5,270,510 A
• Filed: 07/16/1992
• Issued: 12/14/1993
• Est. Priority Date: 08/26/1991
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Aoki, Masayuki, Ohta, Nobuaki
• Primary Examiner(s): Reynolds, Bruce A.
• Assistant Examiner(s): HOANG, TU BA
• Application Number:
  US07/915,073
• Time in Patent Office: 516 Days
• Field of Search: 219/10.55 B, 219/10.55 F, 219/10.55 M, 219/10.55 E, 219/10.77, 219/10.55 R, 219/506, 424/DIG. 10, 424/16, 367/139, 99/325, 363/55, 336/180
• US Class Current: 219/706
• CPC Class Codes: H05B 6/66 Circuits

Abstract

A microwave oven includes a magnetron generating microwaves which are irradiated onto food for heating the same, a circuit substrate incorporating an electric circuit for driving and controlling the magnetron, circuit means for generating both an electrical alarming signal and a high-frequency electrical signal, and a sound producer producing an alarming sound regarding a heating operation when supplied with the alarming electrical signal and producing ultrasonic waves for the repelling of insects when supplied with the high-frequency electrical signal.

Claims

1. A microwave oven comprising;

a) a magnetron generating microwaves which are irradiated onto food for heating the same;

b) a circuit substrate incorporating an electric circuit for driving and controlling the magnetron, the electric circuit including a microcomputer;

c) circuit means for generating both an electrical alarming signal and a high-frequency electrical signal; and

d) a sound producer producing an alarming sound regarding a heating operation when supplied with the electrical alarming signal and producing ultrasonic waves for the repelling of insects when supplied with the high frequency electrical signal.

2. A microwave oven according to claim 1, further comprising control means for controlling the sound producer so that the high-frequency electrical signal is generated by the sound producer in a period of time other than a period of time of output of the electrical alarming signal.

3. A microwave oven according to claim 1, wherein the sound producer comprises a resonant cavity for the alarming sound and another resonant cavity for the ultrasonic waves, the cavities being separate from each other.

4. A microwave oven according to claim 1, further comprising time-base signal generating means for generating a time-base signal supplied to the microcomputer so that a clock function of the microcomputer is fulfilled, reset signal generating means for generating a reset signal so that the microcomputer is put into a reset-release state in association with power supply to the microcomputer, count means for counting pulses generated at predetermined intervals in the microcomputer, control means for starting a counting operation of the count means in response to the reset signal and interrupting the counting operation when a voltage level of the time-base signal is switched after generation of the reset signal, and selecting means for selecting a value of the frequency of the high-frequency electrical signal in accordance with a counted value of the count means.