Microwave oven with humidity sensor

• US 6,774,347 B2
• Filed: 12/07/2001
• Issued: 08/10/2004
• Est. Priority Date: 12/07/2001
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, So-Hyun, Lee, Won-Woo, Oh, Keun-Seuk, Shon, Jong-Chull
• Primary Examiner(s): Van, Quang T.
• Application Number:
  US10/005,222
• Publication Number:
  US 20030106892A1
• Time in Patent Office: 977 Days
• Field of Search: 219/707, 219/705, 219/703, 219/716, 219/704, 219/715, 219/718, 219/719, 219/757, 993/25, 73/10.7, 73/10.2
• US Class Current: 219/707
• CPC Class Codes: H05B 6/642 Cooling of the microwave components and related air circulation systems H05B6/6473 takes precedence
• CPC Class Codes: H05B 6/6458 using humidity or vapor sensors

Abstract

A microwave oven includes a humidity sensor, a main-outlet and a sub-outlet formed at opposite sidewalls of a cooking cavity such that the cooking cavity communicates with the atmosphere through the main-outlet and the sub-outlet. The sub-outlet is installed in a machine room adjacent an air inlet side of a cooling fan. The humidity sensor is installed in the machine room at a position adjacent to the sub-outlet and senses the humidity of air inside the cooking cavity by sensing the humidity of a part of the air discharged from the cooking cavity through the sub-outlet. The surface of the humidity sensor is less likely to be easily contaminated by the air exhausted from the cooking cavity, moisture deposited on the surface of the humidity sensor 60 is quickly evaporated so that the humidity sensor performs its desired operation even when the microwave oven sequentially performs several cooking processes.

Claims

1. A microwave oven to cook food comprising:

a body including a cooking cavity and a machine room;

a heating element installed in the machine room and which cooks the food in the cooking cavity;

a cooling fan installed in the machine room and which sucks atmospheric air through an air inlet side of said cooling fan into the machine room and into the cooking cavity while cooling said heating element installed in the machine room;

an air outlet unit to discharge air from the cooking cavity; and

a humidity sensor to sense operational conditions of the food in the cooking cavity,

wherein

said air outlet unit includes;

a main-outlet formed at a sidewall of the cooking cavity to allow the cooking cavity to communicate with the atmosphere outside of said body, and

a sub-outlet formed at another sidewall of the cooking cavity to allow the cooking cavity to communicate with the air inlet side of said cooling fan; and

said humidity sensor includes a contact surface arranged to both sense a humidity of the air discharged from the cooking cavity through the sub-outlet and to contact the atmospheric air sucked into the machine room so as to prevent said humidity sensor from being overheated and/or contaminated by the air discharged from the cooking cavity.

2. The microwave oven according to claim 1, further comprising an air guide disposed in the machine room to guide the air discharged from the sub-outlet to the air inlet side of said cooling fan;

and

said humidity sensor is arranged on a rear surface of said air guide so as to be positioned adjacent to the sub-outlet.

3. The microwave oven according to claim 2, wherein the machine room is provided with an air suction hole at a rear wall through which the atmospheric air is sucked into the machine room;

and

said humidity sensor is arranged adjacent to the air suction hole such that moisture deposited on said humidity sensor is removed from said humidity sensor by the atmospheric air sucked into the machine room through the air suction hole.

4. The microwave oven according to claim 1, wherein

the machine room further comprises an air suction hole at a rear wall through which the atmospheric air is sucked into the machine room;

and

said humidity sensor is arranged adjacent to the air suction hole such that moisture deposited on said humidity sensor is removed from said humidity sensor by the atmospheric air sucked into the machine room through the air suction hole.

5. The microwave oven of claim 1, wherein the contact surface is disposed such that a rate of moisture deposited by the air discharged through the sub-outlet is less than a rate of moisture removed by the atmospheric air sucked into the machine room.

6. The microwave oven of claim 1, wherein, when the cooking of the food is completed, the contact surface returns to an initial state which existed prior to cooking the food due to a removal of moisture on the contact surface by the atmospheric air sucked into the machine room.

7. A microwave oven to cook food, comprising:

a body including a cooking cavity and a machine room;

a heating element disposed in the machine room and which heats the food in the cooking cavity;

a cooling fan installed in the machine room and which sucks atmospheric air through an air inlet side of said cooling fan into the machine room and into the cooking cavity while cooling said heating element installed in the machine room;

an air outlet unit to discharge air from the cooking cavity; and

a humidity sensor to sense operational conditions of the food being cooked in the cooking cavity,

wherein;

said air outlet unit includes

a main-outlet formed at a sidewall of the cooking cavity and which allows air in the cooking cavity to communicate with the atmospheric air exterior to said body, and

a sub-outlet formed at another sidewall of the cooking cavity and which allows air in the cooking cavity to communicate with the air inlet side of said cooling fan,

a ratio of an area of the sub-outlet to a sum of the areas of the main-outlet and the sub-outlet is roughly between 10 and 25%, and

said humidity sensor is arranged to sense a humidity of the air discharged from the cooking cavity through the sub-outlet at a contact surface and to contact at the contact surface the atmospheric air sucked into the machine room.

8. The microwave oven according to claim 7, wherein:

a ratio of an area of the main-outlet to the sum of the areas is roughly between 70 and 75%, and

the ratio of the area of the sub-outlet to the sum of the areas is roughly between 20 and 25%.

9. A microwave oven to cook food, comprising:

a cooking cavity to hold the food to be cooked and including an inlet through which air enters said cooking cavity, and first and second outlets through which air is exhausted from said cooking cavity;

a machine room into which air is exhausted through the second outlet and from which the air is introduced into said cooking cavity through the inlet;

a heating element disposed in said machine room and which heats the food in said cooking cavity;

a cooling fan installed in said machine room and which sucks atmospheric air exterior to said machine room into said machine room and into said cooking cavity through the inlet while cooling said heating element in said machine room; and

a humidity sensor disposed adjacent to the second outlet to sense operational conditions of the food being cooked by sensing a humidity of the air discharged through the second outlet,

wherein;

the inlet and the second outlet comprise holes through which air passes, and

a piercing ratio of the sum of the areas of the holes of the second outlet to an area of the second outlet is 2% or more greater than a piercing ratio of the sum of the areas of the holes of the inlet to an area of the inlet.

10. The microwave oven of claim 9, wherein the piercing ratio of the second outlet is 5% or more greater than the piercing ratio of the inlet.

11. The microwave oven of claim 9, wherein a ratio of the area of the second outlet to a sum of the areas of the first and second outlets is roughly between 10 and 25%.

12. The microwave oven of claim 11, wherein a ratio of an area of the first outlet to the sum of the areas is roughly between 70 and 75%.

13. The microwave oven of claim 9, wherein said humidity sensor comprises a contact surface which contacts both the air exhausted through the second outlet and the atmospheric air sucked into said machine room.

14. The microwave oven of claim 13, wherein the contact surface is disposed such that a rate of moisture deposited by the air exhausted through the second outlet is less than a rate of moisture removed by the atmospheric air sucked into said machine room.

15. The microwave oven of claim 13, wherein the contact surface is roughly parallel to an airflow direction of the air exhausted through the second outlet so as to not substantially affect the airflow direction.

16. The microwave oven of claim 13, wherein the contact surface is roughly perpendicular to an airflow direction of the atmospheric air sucked into said machine room such that a portion of the contact surface is in the airflow of the atmospheric air.

17. The microwave oven of claim 16, wherein the contact surface is roughly parallel to an airflow direction of the air exhausted through the second outlet so as to not substantially affect the airflow direction.

18. The microwave oven of claim 17, wherein the first and second outlets are disposed on a top half of first and second sidewalls of said cooking cavity.

19. The microwave oven of claim 18, wherein the inlet is disposed on the second sidewall farther from said cooling fan than the second outlet.

20. The microwave oven according to claim 9, wherein:

said machine room further comprises an atmospheric inlet through which the atmospheric air is sucked into said machine room and an air guide to guide the air exhausted through the second outlet to an area between the atmospheric inlet and said cooling fan; and

said humidity sensor is arranged on a rear surface of the air guide so as to be positioned adjacent to the second outlet.

21. The microwave oven according to claim 9, wherein

said machine room further comprises an air suction hole at a rear wall to suck the atmospheric air into said machine room;

and

said humidity sensor is arranged adjacent to the air suction hole such that moisture deposited on said humidity sensor is removed from said humidity sensor by the atmospheric air sucked into said machine room through the air suction hole.

22. A microwave oven to cook food, comprising:

a body including a cooking cavity and a machine room;

a heating element installed in the machine room and which cooks food in the cooking cavity;

a cooling fan installed in the machine room and which sucks atmospheric air through an air inlet side of said cooling fan into the machine room and into the cooking cavity while cooling said heating element installed in the machine room;

an air outlet unit to discharge air from the cooking cavity; and

a humidity sensor to sense operation conditions of the food in the cooking cavity,

wherein;

said air outlet unit includes

a main-outlet formed at a sidewall of the cooking cavity to allow the cooking cavity to communicate with the atmospheric air outside of said body, and

a sub-outlet formed at another sidewall of the cooking cavity to allow the cooking cavity to communicate with the air inlet side of said cooling fan, and

said humidity sensor includes a contact surface arranged to sense a humidity of the air discharged from the cooking cavity through the sub-outlet and to contact air received through the main-outlet so as to prevent said humidity sensor from being overheated and/or contaminated by the air discharged from the cooking cavity.

23. The microwave oven of claim 22, wherein the air discharged through the sub-outlet flows in a first direction before reaching the contact surface, and the contact surface is disposed in a plane parallel to the first direction.

24. The microwave oven of claim 23, wherein the atmospheric air sucked into the machine room flows in a second direction other than the first direction so as to contact the contact surface as the air discharged through the sub-outlet flows across the contact surface.

25. The microwave oven of claim 22, wherein humidity sensor is arranged such that the air discharged through the sub-outlet flows in a first direction and flows around the humidity sensor.

26. The microwave oven of claim 25, wherein the atmospheric air sucked into the machine room flows in a second direction other than the first direction so as to contact the contact surface as the air discharged through the sub-outlet contacts the contact surface.

27. The microwave oven of claim 25, wherein the humidity sensor comprises a round-type humidity sensor.