JPH07299295A - Clothes drying machine - Google Patents

Abstract

PURPOSE:To announce clogging of a filter of a clothes drying machine which dries clothes by circulating the hot air in a rotary drum rotationally driven by a motor and to improve detection accuracy without being affected by a change in cloth quantity and change in temp. CONSTITUTION:The hot air is circulated by a heat exchange type double winged fan 2 into the rotary drum 1 drying the clothes. The blasting route to the rotary drum 1 is provided with a PTC heater 3 and the filter. The rotary drum 1 and this heat exchange type double winged fan 2 are rotationally driven by the motor 5. The motor 5 and the PTC heater 3 are controlled by a control means 9. The current of the PTC heater is detected by a current detecting means 17 connected to this control means 9 and the cloth quantity in the rotary drum 1 is discriminated by a cloth quantity deciding means 20. The control means 9 detects the clogging of the filter by the output signal of a first temp. detecting means 6a disposed in the blasting route to the PTC heater 3 and the output signals of the current detecting means 17 and the cloth quantity deciding means 20 and announces the result by an announcing means 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clothes dryer which circulates warm air in a rotary drum which is driven by a motor to dry clothes.

[0002]

2. Description of the Related Art In recent years, household clothes dryers are provided with a filter for removing lint in a rotary drum for drying clothes. A clothes dryer that reports clogging has been proposed.

Conventionally, a clothes dryer of this type has been disclosed in Japanese Patent Laid-Open No. Sho 55.
It was configured as shown in Japanese Patent Publication No. 16631. That is, the current change of the positive temperature coefficient resistor (hereinafter referred to as PTC heater) is detected by the current transformer, and if the detected PTC heater current is smaller than the set value, clogging is notified.

[0004]

In such a conventional clothes dryer, the PTC heater current changes depending on the intake air temperature, the air volume, and the voltage, and the PTC due to the seasonal changes in summer and winter, the voltage change, and the cloth amount. Since the current change of the heater is much larger than the current change due to clogging, it is almost impossible to find a set value that can detect clogging by only the current change considering all the fluctuations. There is a problem that it is impossible to detect the clogging state.

The present invention solves the above conventional problems.
It is an object of the present invention to provide a clothes dryer capable of providing an optimal clogging notification corresponding to a temperature change, a cloth amount change, and a wind amount change.

[0006]

In order to achieve the above object, the present invention provides a rotating drum for drying clothes, an air blowing means for circulating warm air into the rotating drum, and an air blowing path into the rotating drum. A PTC heater provided in the fan, a filter provided in the air blowing path, a motor that rotationally drives the air blowing means or the rotary drum, control means that controls the motor and the PTC heater, and a air blowing path to the PTC heater. A first temperature detecting means provided on the rotating drum, a second temperature detecting means for detecting an exhaust temperature of the rotating drum, a current detecting means connected to the controlling means for detecting a current of the PTC heater, and the rotating drum. A cloth amount judging means for judging the cloth amount in the inside, and an informing means, and the control means,
The first problem solving means is to notify the clogging of the filter by the output signal of the first temperature detecting means and the output signals of the current detecting means and the cloth amount determining means.

A second problem solving means is that the cloth amount judging means of the first problem solving means judges the cloth amount based on the temperature change detected by the second temperature detecting means.

The cloth amount determining means of the first problem solving means is a third problem solving means in which the cloth amount is judged from the drying time from the start to the end of the drying operation.

As a fourth problem solving means, the control means of the first problem solving means does not give a clogging notification when the cloth amount judged by the cloth amount judging means is very small. There is.

Further, as a fifth problem solving means, the control means of the first problem solving means is adapted to give a clogging notification when the cloth amount judged by the cloth amount judging means is very large. There is.

Further, in order to achieve the above object, the present invention has a rotating drum for drying clothes, a blowing means for circulating warm air into the rotating drum, and a PTC provided in a blowing path into the rotating drum. A heater, a filter provided in the air blowing path, a motor for rotationally driving the air blowing means or the rotating drum, a rotation detecting means for detecting the number of rotations or a rotation cycle of the rotating drum, the motor, etc., and a rotation of the motor. Control means for controlling the number and the PTC heater, a first temperature detecting means provided in a blowing path to the PTC heater, a second temperature detecting means for detecting an exhaust temperature of the rotary drum, and the controlling means. Connected to the P
The controller includes a current detection unit that detects the current of the TC heater, a cloth amount determination unit that determines the amount of cloth in the rotary drum, and an informing unit, and the control unit outputs an output signal of the first temperature detection unit. A sixth problem solving means is that the clogging of the filter is notified by the current detection means and the output signal of the cloth amount determination means.

Further, the seventh problem solving means is that the cloth amount judging means of the sixth problem solving means judges the cloth amount from the load amount applied to the motor for driving the rotary drum.

[0013]

According to the first means for solving the above problems, the present invention provides:
The clogging of the filter can be detected by the intake air temperature of the PTC heater, the electric power applied to the PTC heater, and the amount of cloth in the rotating drum, and the clogging can be accurately detected and notified regardless of the change in the amount of cloth or the temperature change. That is, when the filter is clogged, the heat dissipation coefficient decreases due to a decrease in air flow due to the clogging, so the heat dissipation coefficient can be obtained from the input power and the intake air temperature. Furthermore, this heat dissipation coefficient is influenced by the amount of cloth in the rotating drum. Therefore, when the clogging is detected, the clogging of the filter can be accurately detected and notified by adding the data of the cloth amount.

Further, since the cloth amount can be accurately determined by the second means for solving the problem, the clogging detection accuracy can be improved.

Further, the progress of the clogging condition can be determined by the third problem solving means. Further, according to the fourth problem solving means, since the progress of the clogging state is small when the amount of cloth is very small, it is possible to reduce the time and effort for cleaning by the clogging notification.

Further, according to the fifth means for solving the problems, when the cloth amount is very large, the progress of the clogging state is large,
False detection of clogging notification can be reduced.

Further, by the sixth means for solving the problems, the blowing pressure of the blowing means can be made constant, and the clogging can be accurately detected and notified regardless of changes in the voltage, the cloth amount, and the temperature.

Further, since the seventh problem solving means can accurately determine the cloth amount, the clogging detection accuracy can be further improved.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

As shown in the figure, a rotary drum 1 is for accommodating and drying an article to be dried (clothes), and hot air is circulated in the rotary drum 1 by a heat exchange type double-blade fan (blowing means) 2. The heat exchange type double-blade fan 2 circulates warm air in the rotary drum 1 and at the same time takes in air from the outside to cool the fan and dehumidify the circulating air in the rotary drum 1. P
The TC heater (heating means) 3 is arranged in the air blowing path to the rotary drum 1, that is, in the circulating air intake, and heats the circulating air. The filter 4 is provided in the ventilation path of the heat exchange type double-blade fan 2, that is, in the air outlet of the rotary drum 1. When the filter 4 is clogged with lint, etc., the amount of air blown decreases, the heating power of the PTC heater 3 decreases, and the drying time becomes longer and the drying efficiency also decreases.

The motor 5 rotationally drives the rotary drum 1 and the heat exchanging double-sided fan 2. By controlling the number of revolutions of the motor 5, the speeds of the rotary drum 1 and the heat exchanging double-sided fan 2 can be controlled. , The amount of heat generated by the PTC heater 3 can be controlled, and the current can be controlled. First temperature detecting means 6a
Is for detecting the temperature of the intake air of the PTC heater 3. The second temperature detecting means 6b is provided on the exhaust side of the air in the rotary drum 1 and detects the exhaust temperature corresponding to the internal temperature of the rotary drum 1.

The rotation detecting means 7 detects the number of rotations of the rotary drum 1, and has magnets 2 to 6 on the rotary drum 1.
Individually attached, a magnetic sensor (not shown) is fixed to the main body to detect the number of rotations of the rotary drum 1. The control means 9 controls the rotation speed of the motor 5 and the PTC heater 3, and controls the rotation speed setting means 10 for setting the rotation speed of the rotary drum 1, the output of the rotation detection means 7 and the output of the rotation speed setting means 10. The rotation speed comparison means 11 for comparison and the bidirectional thyristor 1 connected in series to the motor 5 by the output of the rotation speed comparison means 11.
The conduction angle control means 13 for controlling the conduction angle of 2 and the motor 5
Low speed starting means 14 for lowering the set speed at the time of starting,
Temperature control means 15 for inputting the output of the second temperature detecting means 6b, clogging detection level setting means 16 for inputting the output of the first temperature detecting means 6a, output and current of the clogging detection level setting means 16 It comprises a clogging notification determination means 18 for comparing the output of the detection means 17.

The rotation speed comparison means 11 compares the difference between the rotation speed of the rotary drum 1 detected by the rotation detection means 7 and the set rotation speed from the rotation speed setting means 10, and the conduction angle control means 13 causes the bidirectional thyristor. 12 to control the motor 5
Control the rotation speed of. Phase control can be considered as the simplest conduction time control method. In the case of an inverter, not only the conduction time but also the frequency is controlled. By doing so, stable rotation control of the motor 5 and the rotary drum 1 can be performed.

The output of the second temperature detecting means 6b for detecting the temperature of the circulating air in the rotary drum 1 is used as the temperature control means 1.
5 to the PTC by the output of the temperature control means 15.
Relay contacts 19 connected to the heaters 3a and 3b, respectively
a, 19b are controlled, PTC heaters 3a, 3b are turned on,
The temperature of the circulating air is controlled by off control. Furthermore, the first
The output of the clogging detection level setting means 16 for inputting the output of the temperature detection means 6a and the output of the current detection means 17 are input to the notification determination means 18, and the output of the cloth amount determination means 20 outputs the clogging detection level setting means. The setting of 16 can be changed, and the clogging of the filter 4 is notified by the notifying means 21.

The cloth amount judging means 20 judges the cloth amount from the output signal of the temperature control means 15. Operation setting means 22
Is connected to the control means 9 to operate and set a plurality of kinds of driving courses, and is inputted to the rotation speed setting means 10 so that the rotation speed of the rotary drum 1 can be set to the rotation speed according to the driving course. The temperature inside the rotary drum 1 is controlled according to the output of the second temperature detection means 6b by inputting to the temperature control means 15.

The current detecting means 17 is the current transformer 2
3 and the current-voltage conversion circuit 24, detects the input current of the PTC heater 3, and outputs the output from the current setting comparison means 2
Enter in 5. The current comparison setting means 25 compares the set current value of the PTC heater 3 with the output of the current detection means 17,
The output is input to the rotation speed setting means 10 to control the set rotation speed. Here, the set rotation speed set by the rotation speed setting means 10 is set so that the current of the PTC heater 3 does not exceed or fall below a predetermined current value.

The output of the current detection means 17 is also input to the clogging notification determination means 18 together with the output of the clogging detection level setting means 16 which calculates the clogging detection level by the output of the first temperature detection means 6a. The output of the clogging detection level setting means 16 and the output of the current detection means 17 are compared with each other while the rotation speed of the motor 5 is set constant, and the notifying means 21 notifies the clogging of the filter 4. . That is, by controlling the rotation of the heat exchange type double-blade fan 2, the blowing condition at the time of detecting clogging is set to be constant. When the amount of cloth is large, the pressure loss in the rotary drum 1 increases and it is easy to detect clogging. Therefore, the clogging detection level is changed by a signal from the cloth amount determination means 20.

The operation of the above structure will be described with reference to FIGS. 3 to 7. First, FIG. 3 shows the characteristics of the input power P of the PTC heater 3 and the intake air temperature T for showing the clogging detection method according to the present invention. In the figure, the input electric power P of the PTC heater 3 is the temperature difference ΔT between the Curie temperature Tq and the intake air temperature T.
Is represented by the product of the heat dissipation coefficient H, and P = H (Tq-T). When the filter 4 is clogged, the heat radiation coefficient H is lowered due to the decrease in the air volume due to the clogging, so that the Curie temperature Tq is constant, so the heat radiation coefficient H can be obtained from the input power P and the intake air temperature T, and the clogging is prevented. Can be estimated. A in FIG. 3 is PTC when there is little clothing
The relationship between the input current I of the heater 3 and the intake air temperature T is shown. A'shows characteristics when there is a lot of clothes and B shows characteristics when the filter is clogged. C indicates the clogging detection level of the input current I of the PTC heater 3 with respect to the intake air temperature T for determining clogging. The detection level Is can be set substantially linearly according to the intake air temperature T such that Is = K−kT. Here, K and k are constants.

When the cloth amount judging means 20 judges that the cloth amount is large, the clogging detection level is lowered like Is' to make it difficult to detect the clogging.

FIG. 4 is a diagram showing an embodiment of the operation of the cloth amount judging means 20 according to the present invention, and shows the exhaust temperature change of the rotary drum 1 detected by the second temperature detecting means 6b. Q is when the amount of cloth is small, and when the time t1 until the temperature reaches the limit temperature Tl and the heater 3 is turned off is large, the amount of cloth is Q '.
It will be shorter than. The heater 3 is turned on at time t2, and the heater 3 is turned off again at time t3. When the amount of cloth is small, the ON / OFF cycle of the heater 3 also becomes short, so that the amount of cloth can be determined by this temperature change.

When the amount of cloth is small, the second temperature detecting means 6b for detecting the exhaust temperature of the rotary drum 1 and P
The temperature difference from the first temperature detecting means 6a for detecting the intake air temperature of the TC heater 3 becomes large, and the opposite occurs when the amount of cloth is large. Therefore, if the temperature difference is detected, the amount of cloth can be determined more accurately. You can

Next, the operation will be described in detail with reference to FIG. 5. The operation starts in step 30, is initialized by the operation setting means 22 in step 31, and is soft-started in step 32. That is, the low speed start-up means 14 sets the rotation speed of the rotation speed setting means 10 to the low speed rotation speed and starts.

Then, in step 33, the set rotation speed is set to a rotation speed lower than the normal rotation speed to detect clogging.
In step 34, the second temperature detecting means 6b detects the exhaust temperature (internal temperature), and in step 35, if the exhaust temperature is below the limit temperature Tl, the heater 3 is energized, and in step 36 the current detecting means 17 causes the PTC heater. 3 current is detected, and the rotation speed setting means 10 is supplied via the current comparison setting means 25.
Is input to step 37, the set rotation speed is calculated, and the rotation speed of the motor 5 is controlled at step 38 based on the set rotation speed.

If the exhaust temperature is higher than the limit temperature Tl, the heater 3 is turned off in step 39, the time t1 for reaching the temperature adjustment is measured in step 40, and the cloth amount is determined in step 41. In step 42, it is determined that the drying operation is completed, and in step 43, the clogging detection level Is is calculated based on the temperature measured in the clogging detection subroutine and the cloth amount determined in step 41. In step 44, the current I measured in the clogging detection subroutine and the clogging detection level Is
The clogging of the filter 4 is determined by comparing with, and in step 45, an output signal is sent to the notification means 21 to notify the clogging.

This clogging detection operation will be described with reference to FIG. 6. In step 50, the clogging detection subroutine is started, and in step 51, the rotation speed of the rotary drum 1 is controlled to a value lower than the normal rotation speed. After delaying for a fixed time (for example, 3 minutes) in step 52, first in step 53
The temperature detecting means 6a detects the temperature of the circulating air.
Next, in step 54, the current detection means 17 causes the PT
The current I of the C heater 3 is detected, the detected temperature and the current I are stored in step 55, the process proceeds to step 56, and the process returns to step 33 in FIG.

FIG. 7 shows a flowchart of another embodiment of the present invention. In step 60, it is determined that the drying is completed. After the drying is detected, the drying time Th is calculated in step 62, and the amount of cloth is determined from the drying time Th in step 62. If the drying time is long, it is judged that the amount of cloth is large. In step 63, when the drying time is very short, that is, when the drying time Th is shorter than the set time Tmin, the operation is ended without notifying the clogging. If the drying time Th is longer than the set time Tmax in step 64, the clogging notification flag is turned on in step 65. In step 66, the clogging detection level Is is obtained from the temperature and the cloth amount determination level obtained in the clogging detection subroutine, and if it is determined that the filter 4 is clogged, the clogging flag is set in step 68 and step 69 is executed. Through step 45, a clogging notification is given.

FIGS. 8 (a) (b) and 9 show a cloth amount determination method utilizing phase control. FIGS. 8 (a) (b) show the AC power supply voltage V and the case of phase control. Shows the motor current IM,
The conduction time ton (conduction angle) of the bidirectional thyristor 12 is controlled to control the current IM of the motor 5 to control the rotation speed. FIG. 9 shows the relationship between the cloth amount (load amount) of dry clothes and the conduction angle (conduction time ton) when the number of revolutions is constant,
F50 shows the case where the power supply frequency is 50 Hz, and F60 shows the case where the power supply frequency is 60 Hz. The conduction angle changes with the load amount (cloth amount) applied to the motor 5, so that the rotation speed is kept constant and conduction with the power supply frequency occurs. The amount of cloth is determined from the corner.

As described above, according to this embodiment, after the rotation speed of the rotary drum 1 is set to a constant value lower than the normal rotation speed at the time of starting the operation, the first temperature detection is performed before the rotation speed is increased to the normal rotation speed. Since the clogging of the filter 4 is detected by the output signal of the means 6a, the output signal of the current detecting means 17 and the cloth amount judging means 20, the filter amount is not affected by the cloth amount change, temperature change or voltage change. Clogging can be notified, and clogging detection accuracy can be improved.

In the above embodiment, the output signal of the first temperature detecting means 6a, the current detecting means 17 and the cloth amount determining means 2 are controlled while the rotating speed of the rotary drum 1 is controlled to a constant value.
Although the clogging of the filter 4 is detected by the output signal of 0, even if the rotation speed of the rotary drum 1 is not controlled to a constant rotation speed, it is affected by the change of the cloth amount, the temperature change, and the voltage change. Needless to say, it is possible to detect the clogging of the filter.

[0040]

As is apparent from the above embodiments, according to the present invention, a rotating drum for drying clothes, an air blowing means for circulating warm air into the rotating drum, and an air blowing path into the rotating drum. The PTC heater provided on the fan, the filter provided on the air blowing path, the motor for rotating the air blowing means or the rotary drum, and the rotation speed or rotation period of the rotary drum, the motor, or the like. Rotation detecting means for detecting, control means for controlling the rotation speed of the motor or the PTC heater, first temperature detecting means provided in a ventilation path to the PTC heater, and the rotating drum. Second temperature detecting means for detecting the exhaust temperature of the PTC heater, and current detecting means connected to the control means for detecting the current of the PTC heater.
The rotary drum comprises a cloth amount judging means for judging the cloth amount in the rotary drum and an informing means, and the control means sets the rotation speed of the motor to a constant value lower than the normal rotation speed, and the temperature detecting means. Since the clogging of the filter is notified by the output signal of the PTC heater, the output signal of the current detecting means, and the cloth amount determining means, the intake temperature of the PTC heater and the PTC heater are detected.
The clogging of the filter can be detected by the power applied to the machine and the amount of cloth determined by the temperature change in the rotating drum.
The clogging can be accurately detected and notified regardless of changes in the amount of cloth, changes in voltage, and changes in temperature.

Further, since the cloth amount discriminating means discriminates the cloth amount based on the temperature change detected by the second temperature detecting means, the cloth amount discriminating means is unlikely to be affected by the voltage change or the temperature change and the detection accuracy can be improved. You can

Further, since the cloth amount judging means judges the cloth amount from the drying time from the start to the end of the drying operation, the progress of clogging can be judged, and when the drying time is very short, If the clogging is not notified and the drying time is very long, the clogging is notified to more accurately estimate the clogging state.

Further, the control means does not notify the clogging when the cloth amount judged by the cloth amount judging means is very small. Therefore, when the cloth amount is very small, the progress of the clogging state occurs. Since there are few, it is possible to reduce the time and effort required for cleaning due to the clogging notification.

Further, the control means notifies the clogging when the cloth amount judged by the cloth amount judging means is very large. Therefore, when the cloth amount is very large, the progress of the clogging state is advanced. Since it is large, it is possible to reduce false detection of clogging notification.

Further, a rotating drum for drying clothes, an air blowing means for circulating warm air into the rotating drum, a PTC heater provided in an air blowing path into the rotating drum, and a filter provided in the air blowing path. A motor for rotationally driving the blower unit or the rotary drum; a rotation detection unit for detecting the rotational speed or rotational period of the rotary drum, the motor or the like; and a control unit for controlling the rotational speed of the motor and the PTC heater. , A first temperature detecting means provided in a blowing path to the PTC heater, a second temperature detecting means for detecting an exhaust temperature of the rotary drum, and a current of the PTC heater connected to the control means. An electric current detection unit, a cloth amount determination unit that determines the amount of cloth in the rotary drum, and an informing unit are provided, and the control unit outputs the output of the first temperature detection unit. Since the clogging of the filter is notified by the output signal of the signal, the current detection means and the cloth amount determination means, the rotating drum or the motor rotation speed is set to a constant value lower than the normal rotation speed at the time of starting the operation. After that, before the operation to increase to the normal rotation speed, the cloth amount can be determined by the cloth amount determination means by the conduction time of the motor current,
It is possible to improve the clogging detection accuracy by starting with the PTC heater current lowered, and the power breaker does not shut off due to the inrush current of the PTC heater. You can

Further, since the cloth amount judging means judges the cloth amount from the load amount applied to the motor for driving the rotary drum, the cloth amount can be accurately judged, so that the clogging detection accuracy can be further improved.

[Brief description of drawings]

FIG. 1 is a block diagram of a clothes dryer according to an embodiment of the present invention.

FIG. 2 is a sectional view of the clothes dryer.

FIG. 3 is a characteristic diagram showing changes over time of circulating temperature and current of the clothes dryer.

FIG. 4 is a characteristic diagram showing changes in exhaust temperature of a rotary drum of the clothes dryer.

FIG. 5 is an operation flowchart of the clothes dryer.

FIG. 6 is a flowchart for detecting filter clogging of the clothes dryer.

FIG. 7 is a flow chart of a filter clogging notification of a clothes dryer according to another embodiment of the present invention.

FIG. 8 is a diagram showing a relationship between a power supply voltage and a motor current during phase control of the clothes dryer.

FIG. 9 is a characteristic diagram showing the relationship between the cloth amount and the motor current conduction angle of the clothes dryer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 rotating drum 2 heat exchange type double-blade fan (blowing means) 3 PTC heater (heating means) 4 filter 5 motor 6a first temperature detecting means 6b second temperature detecting means 9 control means 17 current detecting means 20 cloth amount judging means 21 Notification means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shoji Akira 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (7)

[Claims] 1. A rotating drum for drying clothes, a blowing unit for circulating warm air into the rotating drum, a heating unit provided in a blowing route into the rotating drum, and a filter provided in the blowing route. A motor for rotationally driving the blower means or the rotary drum; a control means for controlling the motor and the heating means; a first temperature detection means provided in a blower path to the heating means; Second temperature detection means for detecting exhaust temperature, current detection means connected to the control means for detecting current of the heating means, cloth amount determination means for determining the amount of cloth in the rotary drum, and notification means And a control means for notifying clogging of the filter by an output signal of the first temperature detection means, an output signal of the current detection means and an output signal of the cloth amount determination means. Kind dryer. 2. The clothes dryer according to claim 1, wherein the cloth amount judging means judges the cloth amount based on a temperature change detected by the second temperature detecting means. 3. The cloth amount judging means judges the cloth amount from the drying time from the start to the end of the drying operation.
The described clothes dryer. 4. The clothes dryer according to claim 1, wherein the control means does not notify the clogging when the cloth amount judged by the cloth amount judging means is very small. 5. The clothes dryer according to claim 1, wherein the control means gives a clogging notification when the cloth amount judged by the cloth amount judging means is very large. 6. A rotating drum for drying clothes, a blowing unit for circulating warm air into the rotating drum, a heating unit provided in a blowing route into the rotating drum, and a filter provided in the blowing route. A motor for rotationally driving the blower means or the rotary drum; a rotation detection means for detecting the rotation speed or rotation cycle of the rotary drum, the motor or the like; and a control means for controlling the rotation speed of the motor and the heating means. A first temperature detecting means provided in a blowing path to the heating means, a second temperature detecting means for detecting an exhaust temperature of the rotary drum, and a current of the heating means connected to the control means. An electric current detection unit, a cloth amount determination unit that determines the amount of cloth in the rotary drum, and an informing unit are provided, and the control unit includes an output signal of the first temperature detection unit and the current detection unit. A clothes dryer which notifies the clogging of the filter by means of an output signal of the cloth amount judging means. 7. The clothes dryer according to claim 6, wherein the cloth amount judging means judges the cloth amount from a load amount applied to a motor for driving the rotary drum.