Electric heating – Microwave heating – With control system
Reexamination Certificate
2001-12-07
2004-12-28
Van, Quang T. (Department: 3742)
Electric heating
Microwave heating
With control system
C219S702000, C338S035000
Reexamination Certificate
active
06835920
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of Korean Application No. 200147535, filed Aug. 7, 2001 in the Korean Industrial Property Office, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to microwave ovens, and more particularly, to a microwave oven with a humidity detector that has a simple construction and is inexpensively fabricated.
2. Description of the Prior Art
In general, microwave ovens are apparatuses that cook food using microwaves. In a conventional microwave oven, the intensity of microwaves and the cooking time are determined according to a state of food to be cooked. The material, shape and the kind of the food placed in the cooking chamber of the microwave oven determines the absorption of the microwaves and the amount of energy required. As such, the microwave oven detects and assesses the state of the food being cooked using a variety of sensors. Based upon the assessed state, the microwave oven and care out a cooking operation.
As shown in
FIG. 9
, a conventional microwave oven comprises a body
1
, the interior of which is partitioned into a cooking cavity
2
and a machine room
3
. A door
4
is hinged to the body
1
so as to close the cooking cavity
2
. The microwave oven also has a control panel
5
, which is installed at the front wall of the body
1
and is provided with a variety of control buttons. A humidity sensor
6
is installed in the body
1
to sense the operational conditions of the food in the cooking cavity
2
.
The cooking cavity
2
has an opening in front, and has a turntable cooking tray
2
a
rotatably mounted on a bottom of the cooking cavity
2
. An air inlet
7
a
is formed at a front portion of a sidewall
7
of the cooking cavity
2
so as to allow the cooking cavity
2
to communicate with the machine room
3
. Air flows from the machine room
3
into the cooking cavity
2
through the air inlet
7
a
. An air outlet
8
a
is formed at a rear portion of the opposite sidewall
8
of the cooking cavity
2
so as to discharge the air from the cooking cavity
2
to the atmosphere exterior to the microwave oven.
A magnetron
3
a
, a cooling fan
3
b
, an air guide duct
3
c
, and other similar devices (not shown) are installed within the machine room
3
. The magnetron
3
a
generates the high-frequency electromagnetic waves, while the cooling fan
3
b
sucks atmospheric air into the machine room
3
to cool the elements
3
a
,
3
b
installed within the machine room
3
. The air guide duct
3
c
guides the air inside the machine room
3
to the air inlet
7
a
and into the coking cavity
2
. The cooling fan
3
b
is installed between the magnetron
3
a
and a rear wall of the machine room
3
. In order to allow the atmospheric air to flow into the machine room
3
, a predetermined area of the rear wall of the machine room
3
is perforated to form a plurality of air suction holes
3
d.
The humidity sensor
6
is installed on a sidewall
8
of the cooking cavity
2
at a position adjacent to an air outlet
8
a
. Thus, the humidity sensor
6
is located. In an air discharging passage leading from the cooking cavity
2
. The humidity sensor
6
thus senses the humidity of the exhaust air discharged from the cooking cavity
2
through the air outlet
8
a
and that is defined by a surface of the humidity sensor
6
. The humidity sensor
6
is connected to a circuit board (not shown) installed in the control panel
5
, and outputs a signal to the circuit board.
When turning on the microwave oven containing food on the cooking tray
2
a
, the high frequency electromagnetic waves are radiated from the magnetron
3
a
into the cooking cavity
2
and the food is cooked using the generated electromagnetic waves.
During such an operation of the microwave oven the cooling fan
3
b
is rotated to form a suction force to suck the atmospheric air into the machine room
3
through the air suction holes
3
d
as to cool the elements installed in the room
3
. The air is, thereafter guided to the air inlet
7
a
by the air guide duct
3
c
and introduced into the cooking cavity
2
through the air inlet
7
a
. The air inside the cooking cavity
2
is exhausted along with vapor (moisture) generated from the food, which is exhausted in the form of humidity to the atmosphere through the air outlet
8
a
as shown by the arrows of FIG.
9
. Therefore, it is possible to remove odor and vapor generated from food during the operation of the oven. When the exhaust air from the cooking cavity
2
to the atmosphere, it comes into contact with and is turned by the humidity sensor
6
. The humidity sensor
6
senses the humidity of the exhaust air, and outputs a signal to the circuit board of the control panel
5
. The circuit board of the control panel
5
controls the operation of the magnetron
3
a
, the cooking tray
2
a
and the cooling fan
3
b
in response to the signal from the humidity sensor
6
, thus automatically cooks the food on the tray
2
a.
The conventional microwave oven shown in
FIG. 9
uses the humidity sensor
6
to detect the cooking state of the food. The conventional microwave oven detects the moisture formed from the food in the form of humidity, and controls the cooking operation according to the detected moisture.
The conventional humidity sensor
6
is a porous humidity sensor made of a semiconductor ceramic of MgCrO
4
—TiO
2
. The conventional semiconductor ceramic humidity sensor
6
has a characteristic in that its value of resistance is varied according to the amount of moisture that infiltrates into the pores/holes of the semiconductor ceramic humidity sensor
6
.
However, the conventional semiconductor ceramic humidity sensor
6
is disadvantageous in that its fabrication cost is high. In addition, when remainders exist in the holes, the detection performance deteriorates and the overall life span of the sensor
6
is shortened.
SUMMARY OF THE INVENTION
Accordingly, to solve the above and other problems, an object of the present invention is to provide a microwave oven with a humidity detector that has a simple construction and is inexpensively fabricated.
Additional objects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
In order to accomplish the above and other objects, a microwave oven according to an embodiment of the invention includes a magnetron to generate microwaves, a cooking chamber to contain food to be cooked using the generated microwaves, a humidity detector to detect humidity formed as the food is being cooked, the humidity detector being provided at an outlet of the cooking chamber to receive air containing moisture from the cooking chamber and including first and second electrodes formed on a board and spaced apart from each other at a predetermined interval to form a gap therebetween into which the air is received, and a control unit to control the cooking operation of the microwave oven according to an output of the humidity detector.
REFERENCES:
patent: 4015230 (1977-03-01), Nitta et al.
patent: 4080564 (1978-03-01), Nitta et al.
patent: 4422129 (1983-12-01), Briant et al.
patent: 4501147 (1985-02-01), Niwa
patent: 4520341 (1985-05-01), Miyoshi et al.
patent: 4677415 (1987-06-01), Howng
patent: 4707244 (1987-11-01), Harman et al.
patent: 5837886 (1998-11-01), Nakahara et al.
Samsung Electronics Co. LTD
Staas & Halsey , LLP
Van Quang T.
LandOfFree
Microwave oven does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Microwave oven, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Microwave oven will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3301084