Abstrict A reference temperature of the cooler is set which is required
to moderate an interior temperature of the refrigerator. During
a defrosting mode, if a door is opened, then a control part switches
on an air curtain fan if a temperature of a cooler is lower than
the reference temperature, or switches it off if it is not lower.
The control part switches off the air curtain fan when the door
is closed. Meanwhile, during the defrosting mode, if the door is
closed, then the control part switches on the air curtain fan if
the temperature of the cooler is lower than the reference temperature
in a heating state, or switches it off if it is not lower. The air
curtain fan is also switched off if it is not in a heating state.
Thus, the air curtain fan is driven depending on interior and exterior
conditions during a defrosting operation of the refrigerator. Thereby,
refrigerating efficiency as well as defrosting efficiency are increased.
Claims What is claimed is:
1. An air curtain fan driving device for a refrigerator comprising:
a door opening/closing detection part for detecting the opening
and closing of a door of the refrigerator;
a cooler temperature determination part for determining a temperature
of a cooler;
a heating part for outputting a control signal for driving a defrosting
heater;
a compressor driving part for outputting a control signal for driving
a compressor;
a cooling fan driving part for controlling a driving operation
of a cooling fan;
an air curtain fan driving part for controlling a driving operation
of an air curtain fan; and
a control part for driving the air curtain fan driving part by
comparing the temperature of the cooler with a reference temperature
of the cooler according to signals from the door opening/closing
detection part and the cooler temperature determination part.
2. An air curtain fan driving method for a refrigerator comprising:
(a) a step for setting a reference temperature of the cooler which
is required to moderate an interior temperature of the refrigerator;
(b) a step for detecting opening/closing of a door if in a defrosting
mode;
(c) a step for switching on the air curtain fan if the temperature
of the cooler is lower than the reference temperature, or switching
it off if the door is opened;
(d) a step for switching off the air curtain fan when the door
is closed;
(e) a step for checking whether it is in a heating state or not
when the door is closed in the defrosting mode;
(f) if in the heating state, a step for switching on the air curtain
fan if the temperature of the cooler is lower than the reference
temperature, or switching it off; and
(g) a step for switching off the air curtain fan if it is not in
the heating state. Description BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a refrigerator, and more particularly
to an air curtain fan driving device and a method for driving an
air curtain fan according to interior and exterior conditions during
a defrosting operation of a refrigerator.
2. Description of the Prior Art
Generally, the normal operation of the refrigerator is carried
out while the mode is appropriately changed into a cooling mode
for cooling the interior of the refrigerator or a defrosting mode
for defrosting frost formed on the cooler.
Viewing the refrigerant circulation cycle in a refrigerator, as
a gas refrigerant with high-temperature and high-pressure created
by a compressor passing through a condenser, the gas refrigerant
transmits its heat to the exterior and is converted into liquid
refrigerant. Thereafter, the liquid refrigerant, which still has
high pressure, passes through a dryer, so that foreign materials
and the water component in the liquid refrigerant are removed, and
the liquid refrigerant without the foreign materials and water moves
to the capillary tube. The liquid refrigerant moving through the
capillary tube expands in a liquid/gas-mixed state to easily evaporate,
thereby absorbing ambient heat in order for the refrigerant to return
to the original refrigerant condition. Accordingly, the refrigerant
is repeatedly circulated as a cooling air supply in the refrigerator.
Meanwhile, during the cooling operation of the refrigerator, frost
is formed on the cooler since the temperature in the refrigerator
changes by opening the door of the refrigerator. The amount of frost
is determined by the operating time of the compressor, external
temperature, the frequency in door opening of the refrigerator,
external humidity, and the time the door remains open. Frost formed
on the cooler causes a decrease in cooling efficiency.
Accordingly, a microprocessor of the refrigerator changes the mode
into the defrosting mode when more frost than the predetermined
amount is formed. The defrosting mode comprises a pre-cooling step,
a heating step, a compressor pausing step, and a cooling fan pausing
step. The pre-cooling step is for lowering the temperatures of the
refrigerating compartment and the freezing compartment of the refrigerator
before driving the heater. The heating step is to carry out the
defrosting operation. The compressor pausing step is for pausing
the compressor drive to prevent it from overheating. The cooling
fan pausing step is for pausing the cooling fan drive until the
cooler is cooled under the predetermined temperature.
During operation of the refrigerator, the interior temperature
of the refrigerator may rise due to an overload in the refrigerating
compartment of the refrigerator and if the exterior air flows in
the refrigerating compartment while the refrigerating compartment
door is opened. At this time, in order to restore the interior temperature
of the refrigerating compartment to its normal state, an air curtain
fan has been mounted in the refrigerating compartment in recent
years.
A temperature control method for refrigerator is disclosed, in
U.S. Pat. No. 5,263,332 granted to Mr. Park on Nov. 23, 1993, for
reducing the cooling time by stabilizing the temperature fluctuation
occurring when the refrigerator door is opened. The patent includes
a step for controlling a compressor and a fan for a normal operation
in order to maintain interior temperature of a refrigerator at a
temperature preset by a user (called "normal operation step").
In a door-opening control step, if opening of a door of the refrigerator
is detected, the fan is turned off, and a time period during the
opening of a door of the refrigerator is calculated until closing
of the door is detected. Thereafter, if the closing of the door
is detected, a temperature-resetting step restarts the normal operation
step after automatically resetting the preset temperature based
on the calculated time period. A reset temperature operation step
determines whether the temperature is reset during the normal operation
step. If the temperature is reset, the compressor and the fan are
driven for a cooling operation until the temperature reaches reset
temperature. Thereafter, the reset temperature operation step restarts
the normal operation step. The patent of Mr. Park enhances food
preservation and the efficiency of the refrigerator since the interior
temperature influenced by exterior air when a door of the refrigerator
has been opened is rapidly stabilized after the closing of the door.
Hereinafter, a conventional air curtain fan driving device will
be described in detail with reference to FIG. 1. FIG. 1 is a view
for showing a conventional air curtain fan driving device. The conventional
air curtain fan driving device 10 includes an air curtain fan 100,
a temperature detector 102, a compressor 104, a compressor driver
106, a cooling fan 108, a cooling fan driver 110, an air curtain
fan driver 112, and a controller 114.
The temperature detector 102 detects an interior temperature T1
of the refrigerator under the control of the controller 114. The
detection of the interior temperature T1 of the refrigerator is
applied to the controller 114. The compressor 104 converts normal
gas refrigerant into gas refrigerant of high temperature and high
pressure. The compressor driver 106 controls the driving of the
compressor 104. The cooling fan 108 blows cool air into the refrigerating
compartment. The cooling air is provided from the evaporator (not
shown). The cooling fan driver 110 controls the driving of the cooling
fan 108. The controller 114 controls the operations of the temperature
102, compressor driver 106, cooling fan driver 110, and air curtain
fan driver 112. The controller 114 causes normal cooling operations
to be performed since the controller 114 drives the compressor 104
and cooling fan 108 by the compressor driver 106 and cooling fan
driver 110 respectively. The controller 114 determines whether the
interior temperature T1 of the refrigerating compartment detected
by the temperature detector 102 is normal.
Hereinafter, operations of the conventional air curtain fan driving
device will be described in detail.
FIG. 2 is a flow chart for explaining operations of the conventional
air curtain fan driving device of FIG. 1.
When electric power is applied, the controller 114 drives the compressor
104 and cooling fan 108 by means of the compressor driver 106 and
cooling fan driver 110 respectively, so that normal cooling operations
are performed (step S201). The temperature detector 102 detects
an interior temperature T1 of the refrigerator under the control
of the controller 114 (step S202). The detected interior temperature
T1 is transmitted to the controller 114. The controller 114 determines
whether the detected interior temperature T1 is a normal temperature
by the temperature detector 102 (step S203). If the detected interior
temperature T1 is below or over the normal temperature as a result
of the determination of the step S203, the compressor driver 106
drives the compressor 104 under the
control of the controller 114 (step S204). Thereafter, the cooling
fan driver 108 and the air curtain fan driver 112 drive the cooling
fan 108 and the air curtain fan 100 under the control of the controller
114 respectively (step S205). In step 206, the controller 114 determines
again whether the detected interior temperature T1 by the temperature
detector 102 is the normal temperature. If the detected interior
temperature T1 is below or over the normal temperature as a result
of the determination of the step S206, the step S204 is restarted.
In the meantime, if the detected interior temperature T1 is determined
as the normal temperature, the controller 114 enables the normal
cooling operations to be performed (S207).
With the conventional method mentioned above, the air curtain fan
is driven when the door of the refrigerator is opened regardless
of the interior condition of the refrigerator, i.e., regardless
of whether the operating mode is the cooling one or the defrosting
one.
The air curtain fan is driven even in the defrosting mode when
the door of the refrigerator is opened. That is to say, in the heating
step of the defrosting mode, the temperature of the cooler can be
higher than the required temperature in the normal cooling operation.
If the air curtain fan is operated in this case, then air of a higher
temperature passing through the cooler flows into the refrigerating
compartment and the freezing compartment, which causes a decrease
in cooling efficiency.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an air curtain
fan driving device for a refrigerator for driving an air curtain
fan according to interior and exterior conditions during a defrosting
operation of a refrigerator.
It is another object of the present invention to provide an air
curtain fan driving method for a refrigerator for driving an air
curtain fan according to interior and exterior conditions during
a defrosting operation of a refrigerator.
In order to achieve the above objects, the air curtain fan driving
device of the present invention includes a door opening/closing
detection part, a cooler temperature determining part, a heating
part, a compressor driving part, a cooling fan driving part, an
air curtain fan driving part, and a control part.
The door opening/closing detection part detects the opening and
closing of a door of the refrigerator. The cooler temperature determination
part determines temperature of a cooler. The heating part outputs
a control signal for driving a defrosting heater. The compressor
driving part outputs a control signal for driving a compressor.
The cooling fan driving part controls driving operation of a cooling
fan. The air curtain fan driving part controls a driving operation
of an air curtain fan. The control part is for driving the air curtain
fan driving part by comparing a temperature of the cooler with a
reference temperature of the cooler according to signals from the
door opening/closing detection part and the cooler temperature determination
part.
In order to achieve the above objects, an air curtain fan driving
method according to the present invention includes
(a) a step for setting a reference temperature of the cooler which
is required to moderate an interior temperature of the refrigerator;
(b) a step for detecting opening/closing of a door if in a defrosting
mode;
(c) a step for switching on the air curtain fan if the temperature
of the cooler is lower than the reference temperature, or switching
it off if the door is opened;
(d) a step for switching off the air curtain fan when the door
is closed;
(e) a step for checking whether it is in a heating state or not
when the door is closed in the defrosting mode;
(f) if in the heating state, a step for switching on the air curtain
fan if the temperature of the cooler is lower than the reference
temperature, or switching it off; and
(g) a step for switching off the air curtain fan if it is not in
the heating state.
In the air curtain fan driving method of the present invention,
if opening of the door in the defrosting mode is detected, then
the air curtain fan is driven only when the temperature of cooler
is lower than the reference temperature, or when the air curtain
fan is not driven.
Therefore, when the temperature of the cooler is increased over
a predetermined temperature by operation of the defrosting heater,
the air curtain fan is not driven even though the door is opened,
whereby air of higher temperature via the cooler does not flow into
the refrigerating compartment.
Furthermore, if the closing of the door in the defrosting mode
is detected, then the air curtain fan is driven when the temperature
of the cooler is lower than the reference temperature in heating
by the defrosting heater. Since driving of the air curtain fan in
heating by the defrosting heater takes the coldness of the cooler
more quickly, the defrosting operation is more quickly carried out.
Therefore, efficiency of the defrosting operation is increased.
Moreover, when the temperature of the cooler is higher than the
reference temperature in heating by the defrosting heater, the air
curtain fan is not driven, which prevents increase in the temperature
of the refrigerating compartment.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and features of the present invention can
be understood through the following embodiment by reference to the
accompanying drawing, in which:
FIG. 1 is a block diagram for showing a conventional air curtain
fan driving device for a refrigerator;
FIG. 2 is a flow chart for explaining operations of the conventional
air curtain fan driving device of FIG. 1;
FIG. 3 is a block diagram for showing an air curtain fan driving
device for a refrigerator according to an embodiment of the present
invention; and
FIG. 4 is a flow chart for explaining operations of the air curtain
fan driving device for a refrigerator according to the embodiment
of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, the air curtain fan driving device according to an
embodiment of the present invention will be described in detail
with reference to the accompanying drawings. FIG. 3 is a block diagram
for showing an air curtain fan driving device 30 for a refrigerator
according to an embodiment of the present invention.
The device 30 includes a cooler temperature-determining part 302,
a door opening/closing detection part 304, a memory 306, a heating
part 308, a compressor driving part 310, a cooling fan driving part
312, an air curtain fan driving part 314, a defrosting heater 316,
a compressor 318, a cooling fan 320, an air curtain fan 322, and
a control part 300.
The cooler temperature determination part 302 determines a temperature
of a cooler.
The door opening/closing detection part 304 detects whether the
door of the refrigerator is opened or closed by a predetermined
switching circuit.
In the memory 306 a reference temperature is set which is required
to moderate the interior temperature of the refrigerator.
The control part 300 controls the signals inputted from the respective
parts depending on the interior program and controls the general
operation of the refrigerator by outputting predetermined signals.
The heating part 308 outputs a control signal for driving a defrosting
heater 316 depending on the control signal from the control part
300.
The compressor driving part 310 outputs a control signal for driving
a compressor 318 depending on the control signal from the control
part 300.
The cooling fan driving part 310 controls the driving operation
of the cooling fan 314.
The air curtain fan driving part 310 controls the driving operation
of the air curtain fan 322.
Hereinafter, the air curtain fan driving method according to the
embodiment of the present invention will be described in detail
with reference to FIG. 4. FIG. 4 is a flow chart for explaining
the air curtain fan driving method of a refrigerator according to
the embodiment of the present invention.
When the refrigerator is powered on, the normal operation of the
refrigerator is carried out by the control part 300 while the mode
is appropriately changed into a cooling mode or a defrosting mode
(step S401). In the cooling mode, the compressor 318 cools the interior
of the refrigerator. In the defrosting mode the defrosting heater
316 defrosts frost formed on the cooler. Furthermore, if the door
of the refrigerator is opened, then the control part 300 drives
the air curtain fan 322, and if the door of the refrigerator is
closed, then the control part 300 stops the air curtain fan 322.
Thus, the refrigerator maintains the temperature of the refrigerating
compartment at from -1.degree. C. to 5.degree. C. and the temperature
of the freezing compartment at -25.degree. C.
A reference temperature Tr which is required to moderate the interior
temperature of the refrigerator is set by a predetermined method
to be stored in the memory 306. For example, the reference temperature
Tr can be set by the manufacturer when the refrigerator is manufactured
or set by the user when the user sets the interior temperature of
the refrigerator by any desired temperature.
In step S402, the control part 300 checks whether the mode is in
the defrosting mode during the normal operation of the refrigerator.
If in the defrosting mode, in step S403, the control part 300 receives
the opening signal from the door opening/closing detection part
304 when the door is opened.
In step S404, the control part 300 compares the temperature of
the cooler with the reference temperature when the door is opened.
The control part 300 switches on the air curtain fan 322 if the
temperature of the cooler is lower than the reference temperature
Tr (step S405). If the control part 300 receives the closing signal
from door opening/closing detection part 304, then the control part
300 switches off the air curtain fan 322 (step S407).
In step S403, if the door is closed in the defrosting mode, then
the control part 300 checks whether it is in a heating state or
not.
In step S411, if it is in the heating state, then the control part
300 compares the temperature of the cooler with the reference temperature
(step S411).
In step S412, if the temperature of the cooler isn't lower than
the reference temperature, then the control part 300 switches off
the air curtain fan (step S407). In step S412, if the temperature
of the cooler is lower than the reference temperature, then the
control part 300 switches on the air curtain fan (step S413), and
performs step S412 and step S413 repeatedly. That is, the control
part 300 switches on the air curtain fan if the temperature of the
cooler is lower than the reference temperature during the heating
state. Meanwhile, the control part 300 switches off the air curtain
fan if the temperature of the cooler isn't lower than the reference
temperature or if the heating state is closed.
If the air curtain fan is switched off, the refrigerator returns
to its normal operation (step S410).
In the air curtain fan driving method of the present invention,
if opening of the door in the defrosting mode is detected, then
the air curtain fan is driven only when the temperature of the cooler
is lower than the reference temperature, or the air curtain fan
is not driven.
Therefore, when the temperature of the cooler is increased over
a predetermined temperature by the operation of the defrosting heater,
the air curtain fan is not driven even though the door is opened,
whereby air of a higher temperature via the cooler does not flow
into the refrigerating compartment.
Furthermore, if closing of the door in the defrosting mode is detected,
then the air curtain fan is driven when the temperature of the cooler
is lower than the reference temperature through heating by the defrosting
heater. Since driving of the air curtain fan in heating by the defrosting
heater takes the coldness of the cooler more quickly, the defrosting
operation is carried out more quickly. Therefore, efficiency of
the defrosting operation is increased. Moreover, when the temperature
of cooler is high than the reference temperature in heating by the
defrosting heater, the air curtain fan is not driven, which prevents
an increase in the temperature of the refrigerating compartment.
It is understood that various other modifications will be apparent
to, and can be readily made by those skilled in the art without
departing from the scope and spirit of this invention. Accordingly,
it is not intended that the scope of the claims appended thereto
be limited to the descriptions set forth herein, but rather that
the claims be constructed to encompass all the features of the patentable
novelty that reside in the present invention, including all the
features that would be treated as equivalent thereof by those skilled
in the art to which this pertains. |