JPH10290898A - Clothes drier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decide the completion of the drying of materials to be dried despite of a simple constitution by judging the drying degree of the materials to be dried using the time change rate of a received light output by a control means and controlling the operation. SOLUTION: A light emitting means 11 is constituted of a light source such as a LED and a miniature lamp for irradiating visible rays or infrared rays to clothes in a drum 17. A light irradiated by the light emitting means 11 is reflected on the clothes 14, 15 in the drum 17 and received by a light receiving means 21. A detection signal of the light receiving means 21 is transmitted to a control board having a control means 12 attached thereto. As for a qualitative time change in the received light output in operating the clothes drier, the relative light receiving output becomes larger, as the drying is proceeded by continuing the operation, and when the drying is further proceeded, the evaporation amount becomes constant, and the constant rate period is passed, the change is gradually getting slowly, and when the drying is completed, it is saturated and shows no change. The drying completion time can be thus detected by just detecting the time when the time change is disappeared in the relative light receiving output.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drying detection system for measuring the moisture content of an object to be dried by utilizing the change in reflected light due to the amount of moisture contained in an object. It can be widely applied as a drying sensor and a cloth amount sensor.

[0002]

2. Description of the Related Art Conventionally, reflected light is attenuated by moisture in a substance to be dried, such as a phenomenon in which an infrared ray having a wavelength unique to each substance is absorbed by molecular vibration, a refractive index due to moisture attached to a fiber surface, and the like. A phenomenon due to a change in the scattering state is known. If this phenomenon is used, the amount of water in the object to be dried can be detected by projecting light onto the object to be dried and detecting a change in the reflected light.

[0003] Among these phenomena, in particular, a system using an infrared absorption phenomenon has already been put to practical use in measuring instruments such as a moisture meter and a spectroscopic analyzer. Since the degree of absorption of infrared rays changes in relation to the absolute amount of water contained in the object to be dried, the difference between the degree of absorption of the wavelength absorbed by water and the degree of absorption of the wavelength not absorbed is detected.

[0004]

The configuration put to practical use with these measuring instruments aims at detecting the absolute amount of moisture contained in the object to be dried by measuring only at a certain point in time. It is. In addition, since the principle of detection is primarily for stationary objects, if the target moves around, such as when detecting the moisture in clothes in a clothes dryer, corrections based on the facing angle and directivity of the clothes are required. Additional configuration and signal processing are required.

[0005] However, unlike the need to detect the absolute amount of moisture in an object to be detected only at a single point in time, when this method is applied to a clothes dryer or the like, it can be realized with a simple and inexpensive configuration. it can. In addition to being able to continuously observe the temporal change of the received light output from the state before operation to the end of drying, detecting the end of drying when there is no temporal change in the received light output, and the relative time at the start of operation This is because it is used for needs such as estimating the amount of cloth based on the received light output.

[0006]

In order to solve the above-mentioned problems, the present invention provides a light-emitting means for projecting light on an object to be dried, a light-receiving means for receiving light reflected from the object to be dried,
Control means for controlling the turning on and off of the light emitting means, calculating the light receiving output according to the amount of light received from the light receiving means, and controlling the operation of the clothes dryer; The operation control is performed by determining the degree of drying of the object to be dried or the amount of cloth based on the time change rate.

[0007]

According to the first aspect of the present invention, a light emitting means for projecting light on an object to be dried, a light receiving means for receiving light reflected from the object to be dried, Control of turning on and off, calculation of a light receiving output according to the amount of light received from the light receiving means, and control means for controlling the operation of the clothes dryer, wherein the control means controls a time change rate of the light receiving output. The operation control is performed by determining the degree of drying of the object to be dried.

According to a second aspect of the present invention, there is provided a light emitting means for projecting light on an object to be dried, a light receiving means for receiving light reflected from the object to be dried, and a control for turning on and off the light emitting means. And control means for controlling the operation of the clothes dryer, and calculating the light reception output according to the amount of light received from the light receiving means, and the control means controls the cloth amount of the object to be dried by the light reception output. The operation is controlled based on the determination.

According to a third aspect of the present invention, there is provided a light emitting means for projecting light on an object to be dried, a light receiving means for receiving light reflected from the object to be dried, and control of turning on and off the light emitting means. And control means for controlling the operation of the clothes dryer and calculating the light receiving output according to the amount of light received from the light receiving means, and determining the degree of drying of the object to be dried from the variance and average of the light receiving output. Operation control is performed based on the operation time determined by estimating the time required for drying and drying.

According to a fourth aspect of the present invention, there is provided a light emitting means for projecting light on an object to be dried, a light receiving means for receiving light reflected from the object to be dried, and controlling turning on / off of the light emitting means. And control means for controlling the operation of the clothes dryer in accordance with the amount of light received from the light receiving means, and controlling the operation of the clothes dryer. And the operation control is performed.

According to a fifth aspect of the present invention, there is provided a light emitting means for projecting light on an object to be dried, a light receiving means for receiving light reflected from the object to be dried, and a temperature in a refrigerator of a clothes dryer. Temperature measuring means for measuring, and control of turning on and off the light emitting means,
A control means for calculating a light receiving output according to the amount of light received from the light receiving means and a temperature output by the temperature measuring means, and controlling an operation of the clothes dryer; and the controlling means controls the light receiving output and the temperature output. The operation control is performed based on the operation time determined by estimating the degree of drying of the object to be dried and the time required for the drying.

According to a sixth aspect of the present invention, there is provided a light emitting means for projecting light on an object to be dried, a light receiving means for receiving light reflected from the object to be dried, and a temperature in a refrigerator of a clothes dryer. Temperature measuring means for measuring, and control of turning on and off the light emitting means,
A control means for calculating a light receiving output according to the amount of light received from the light receiving means and a temperature output by the temperature measuring means, and controlling an operation of the clothes dryer; and the controlling means controls the light receiving output and the temperature output. The operation control is performed by judging the cloth amount of the object to be dried.

[0013] The invention according to claim 7 of the present invention is the invention according to claim 1.
In addition to the inventions described in the above items 6, the sub-sampling value, in which the maximum value of the light-receiving output in a certain time zone is set as a representative value in the certain time zone, is used as the light-receiving output to be operated by the control means, whereby more accurate The operation control is performed with high performance.

[0014] The invention according to claim 8 of the present invention is directed to claim 1.
In addition to the invention as described in 6 to 6, the accuracy of the light receiving output to be calculated by the control means is further improved by using a sub-sampling value that is the average value of the light receiving output in a certain time zone as a representative value in the certain time zone. The operation control is performed with high performance.

The ninth aspect of the present invention is the first aspect of the present invention.
In addition to the inventions described in (1) to (6), a more precise operation control is performed by using a light receiving output in a certain time width and a moving average value of a representative value as a light receiving output to be operated by the control means.

According to a tenth aspect of the present invention, in addition to the second to sixth aspects, a fuzzy inference is used for determining the operation time in the control means or calculating the cloth amount. The operation control is performed with high accuracy.

According to an eleventh aspect of the present invention, in addition to the first to sixth aspects, the operation of the control means is stopped and the clothes are stopped by the control means at the time when the received light output is sampled by the control means. Performing the sampling by
Alternatively, by performing sampling at a fixed time interval synchronized with the rotation speed of the drum, more accurate operation control is performed.

According to a twelfth aspect of the present invention, in addition to the first to sixth aspects, the light receiving output or the representative value in a certain time zone is used as the light receiving output to be operated by the control means. The operation control with higher accuracy is performed by using a value obtained by correcting a change in light receiving / emitting sensitivity such as a temperature characteristic of the light emitting unit and the light receiving unit by using the minimum value of the band.

According to a thirteenth aspect of the present invention, in addition to the first to sixth aspects, one or more temperature measuring means for measuring a temperature correlated with the temperature of the light emitting means or the light receiving means is provided. The light receiving output for which the control means performs an operation is
The operation control with higher accuracy is performed by using the value obtained by performing the temperature correction based on the temperature output measured by one or more temperature measuring means.

According to a fourteenth aspect of the present invention, in addition to the first to sixth aspects, the reflected light or the direct light other than the object to be dried, which is projected from the same light emitting means as the light receiving means, is emitted. Correction light receiving means for performing a corrected light receiving output according to the amount of received light is provided, and as a light receiving output to be operated by the control means, the corrected light receiving output corrects a change in light receiving and emitting sensitivity such as temperature characteristics of the light emitting means and the light receiving means. By using the calculated value,
The operation control is performed with higher accuracy.

According to a fifteenth aspect of the present invention, in addition to the first to fourteenth aspects, a condition for calculating a maximum value, an average value, a minimum value, or a moving average value is predetermined. The operation control with higher accuracy is performed by waiting at least one of the following conditions: a case where the condition is equal to or less than the upper limit value or a case where the condition exceeds a predetermined lower limit value.

According to the above-mentioned invention, by having such a configuration, it is possible to know the value of the water content of the garment moving at any time with high accuracy and with a simple configuration.

[0023]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory diagram showing a configuration in which the drying detection system for a clothes dryer according to the present embodiment is incorporated in a clothes dryer. This clothes dryer uses a drum-type warm air blowing system. Reference numeral 11 denotes a light-emitting unit configured by a light source such as an LED or a miniature bulb that emits visible light or infrared light (hereinafter, simply referred to as light) to clothing in the drum. The light emitted by the light emitting means 11 is the clothes 14 and 15 in the drum 17.
And is received by the light receiving means 21. The detection signal of the light receiving means 21 is transmitted to a control board on which the control means 12 is mounted.

Reference numeral 20 denotes a front door for putting in clothes, 18
Is a baffle for blowing hot air into the drum 17 and is usually provided at a plurality of locations. Reference numeral 19 denotes a rotating shaft for supporting rotation of the drum 17, and reference numeral 13 denotes a cooling fan for heat exchange.

Although FIG. 1 shows the mounting position of the light emitting means 11 and the light receiving means 21 in the case where the light emitting means 11 and the light receiving means 21 are mounted inside the lid, it is not particularly limited. 12 or a method of attaching the light emitting means 11 and the light receiving means 21 separately from each other.

FIG. 2 shows a qualitative relationship between the drying rate of the clothes and the output when the reflected light is received by the light receiving element. In FIG.
The horizontal axis represents the drying rate, and the vertical axis represents the relative light receiving output V when the light receiving element 21 receives the reflected light. As shown in FIG. 2, a right-up relationship is established, in which the reflected light quantity increases as the dry clothes have a higher drying rate. In addition, since the slope of the graph shown in FIG. 2 varies depending on factors such as the material and color of the clothing, the degree of surface treatment, and the method of knitting the fiber, the vertical axis does not represent the absolute light output but rather the value for each clothing. It is shown as a relative value by a method such as normalization.

FIG. 3 shows a qualitative time-dependent change of the received light output when the apparatus is actually operated by the clothes dryer shown in FIG.
In FIG. 3, the horizontal axis represents the operation elapsed time T, and the vertical axis represents the relative light receiving output V when the light receiving element 21 receives the reflected light.
Is shown. In the case of actual driving, the clothing is rotated by the drum and the reflection distance is deviated, so that a signal whose light reception output fluctuates is obtained. In FIG. 3, however, the signal processing such as the average value processing is performed to perform smoothing. As a result, it shows a qualitative tendency.

As shown in FIG. 3, as the operation is continued and the drying proceeds, the relative light receiving output V increases. After the drying proceeds and the evaporation rate becomes constant, the relative light output V gradually decreases. Finally, when the drying is completed, it is saturated and there is no change. Therefore, the end of drying can be detected by detecting the point in time at which there is no change in the relative light receiving output V with time. In addition, by determining the degree of decrease in the time change rate dV / dT of the relative light receiving output, it is possible to determine other than the end of drying.

As described above, a clothes dryer as in the present embodiment does not need to adopt a complicated structure including a plurality of wavelength light receiving and emitting means in order to detect an absolute moisture content in a conventional moisture meter or the like. If the needs are narrowed down to the detection of the end of drying, the detection can be performed with a simple configuration using only the light receiving means 21 of one wavelength. In this method, the structure is simple, the number of parts is reduced, and the effect of commercial cost reduction is great.
The effect for practical use in general consumer products is great.

FIG. 4 shows the distance of the reflected light from clothing having a constant drying rate.
Shows the release characteristics. In FIG. 4, the horizontal axis represents the distance between the clothing and the light receiving element.
The vertical axis indicates the relative light receiving output V. In FIG.
Distance D = d₁ In the case of V = V₁ Is output.
Distance D = d_Two In the case of V = V_Two Is output
And approaching this distance D = d₀ In the case of V = V ₀
Is output. The relative light output
The distance characteristic of the force V is generally inversely proportional to the square of the distance D.
Attenuate.

5 and 6 based on the distance characteristics in FIG.
Next, a description will be given of an embodiment in the case of detecting the cloth amount and estimating the initial drying rate. FIG. 5 is a histogram in the case of ranking by relative light receiving output V. 5 is a histogram when the amount of cloth is small, and 52 and 53 are histograms when the amount of cloth is medium and large, respectively. The larger the amount of cloth, the more frequently the clothing is reflected at a short distance to the sensor to obtain a large relative light receiving output, and the smaller the amount of cloth, the less frequently the clothing is reflected at a light receiving element at a short distance.

That is, if the form of the output histogram is determined, the cloth amount can be determined. Histogram 51
As an example of a signal processing method for discriminating to 53, there is a method of calculating a variance value. Histogram 5 when the amount of cloth is large
At 1, the variance value increases, and the variance value decreases in the histogram when the cloth amount is small. Therefore, the control means 12
By calculating the variance value of the sensor output values sampled in the above, it is possible to determine the amount of cloth.

Next, FIG. 6 shows a histogram when the amount of clothes is the same and the drying rate is different. In FIG. 6, reference numeral 61 denotes a histogram of clothes that are dry, 62 denotes a histogram of clothes that are wet to some extent, and 63 denotes a histogram of clothes that include more moisture. If the amount of clothing is the same,
The histogram shows a distribution of almost the same shape.

However, as shown in FIG. 2, since the reflected light is attenuated due to the inclusion of moisture, the histogram becomes lower as the drying rate becomes lower. Therefore, if the shapes of the histograms 61 to 63 are determined, the amount of water in the clothing can be determined. As an example of a signal processing method for determining the histograms 61 to 63, there is a method of calculating an area of the histogram or an average value obtained by dividing the area by the total frequency.

In other words, the average value increases in dry clothing having a high drying rate, and the average value increases in wet clothing having a low drying rate. Therefore, if the variance of the sampled light output value is calculated by the control means 12, the level of the drying rate of the clothes can be determined.

As described above with reference to FIGS. 5 and 6, the variance value of the histogram has a correlation with the amount of cloth, and the average value has a correlation with the level of the drying rate of the clothes. Therefore, by using these two calculated values, it is possible to determine the amount of the cloth and the level of the drying rate. Generally, in a clothes dryer, if the amount of cloth and the drying rate before operation are the same, the time required for drying to progress to a certain drying rate and the time required for drying to be completed are almost the same. .

Therefore, the required time is measured experimentally in advance by using the same clothes dryer for several combinations of the cloth amount and the drying rate, and the variance value and average value of the histogram of the sensor output are used as input values to determine the required time. By preparing a table as an output value, it is possible to predict and determine a required time until a constant drying rate or a required time until the end of drying at an early stage of operation.

By incorporating this method into the control means 12,
Controls such as changing the number of rotations of the drum or turning off the hot air heater after a predetermined time to the drying rate,
It is possible to control the operation of the clothes dryer such that the operation is stopped at the required time for finishing the operation drying.

Further, fuzzy inference is known as a means for improving the accuracy of a control method for calculating an output value from a plurality of input values. Therefore, according to the user's usage as in the present embodiment, application to a clothes dryer or the like in which drying is performed with a combination of various amounts of clothes and an initial drying rate requires two inputs of a variance value and an average value. It is very effective to use fuzzy inference as an arithmetic means for calculating one output of the required time.

Next, FIG. 7 shows a method of using the magnitude of the time rise rate of the internal temperature as a method of determining the amount of clothes and the initial drying rate of clothing. The rate of increase in the temperature in the refrigerator has a correlation with both the cloth weight and the initial drying rate. In FIG. 7, the horizontal axis represents the rate of increase, the left vertical axis represents the amount of cloth when the drying rate is constant, and the right horizontal axis represents the level of the initial drying rate when the cloth amount is constant. Is shown.

As shown in FIG. 7, when the amount of cloth is constant, the lower the initial drying rate, the lower the rate of increase in the internal temperature, and the higher the initial dry rate, the higher the rate of increase in the internal temperature. Further, under a condition where the drying rate is constant, the increasing rate is small as the cloth amount is large, and the increasing rate is large as the cloth amount is small.

As described above, since the rise rate of the internal temperature has a correlation with the cloth amount and the initial drying rate, the temperature rise rate can be used as substitute information for the average value of the histogram correlated with the initial drying rate. Therefore, if a table is created in which the variance value and the rate of increase are input and the required time is output,
Can control the operation of the clothes dryer. In addition, if a table is created in which the temperature rise rate is used as substitute information for the variance value of the histogram correlated with the cloth amount, the average rise rate is input, and the required time is output, the operation of the clothes dryer is performed. Can control.

Finally, a method particularly effective in a clothes dryer or the like will be described as a pre-processing of the received light output when determining the cloth amount and the initial drying rate described above. In the clothes dryer, when the clothes reflected light is measured while stirring the clothes with the drum, the output fluctuates depending on the distance between the light receiving means 21 and the clothes, as described in the distance characteristic of FIG.

As a method for improving this, by setting a certain time and performing subsampling for extracting the maximum value within the time, the clothing can use only the light receiving output reflected at the nearest light receiving element. Can be calculated.

As another improvement method, a light reception output corresponding to a light reception output reflected at an average distance in which clothes move within a certain time range by setting a certain time and replacing the average value within that time. Can be calculated using

Further, as a peculiar phenomenon in the clothes dryer, when the clothes are agitated by the drum, it may take a long time for the clothes on the back side of the drum to appear on the front side. In the method of the present invention, the clothes on the back side where the light of the light emitting means does not reach cannot be directly detected, and means for waiting until appearing on the front side or estimating with the clothes on the front side is necessary. As a method for realizing this, if a calculation is performed using a moving average value in a predetermined time zone, the determination can be made using a representative value indicating the average degree of dryness of the clothes in the entire warehouse.

Also, when attaching to a clothes dryer,
The light receiving output changes due to fluctuation factors such as the temperature characteristics and temporal changes of the light receiving and emitting elements, and the use environment such as scratches and dirt on the window material covering the light receiving and emitting elements. As a method of correcting the fluctuation factor, there is a method of correcting the minimum value in a certain time. The minimum value for a certain period of time is a light receiving output corresponding to an offset when light from the light emitting means does not hit the clothing. Therefore, this minimum value is usually constant, and changes under the influence of only the fluctuation factors. Therefore, these fluctuation factors can be corrected by a method such as normalization using the minimum value.

As a means for precisely correcting the temperature characteristic among the fluctuation factors, a temperature sensor or the like for measuring the temperature of the light receiving / emitting means is added, and the temperature characteristic is corrected based on the temperature information. be able to.

As another correction method, if a light receiving means for correction having a configuration in which reflected light from clothing does not enter is provided,
Since the fluctuation factors other than the reflected light are affected in the same manner as the light receiving means for detection, the fluctuation means can be corrected by a method such as normalizing the light receiving output of the light receiving means for correction.

Although the present embodiment has been described as being applied to a drum-type rotary dryer, the present invention can also be applied to a dryer installed in a bathtub or a hanger-type hanging dryer. It is something.

The wavelengths used for the light emitting means 11 and the light receiving means 21 do not need to be particularly limited.
A large number of light emitting elements and light receiving elements having a light receiving sensitivity near 900 nm have been put to practical use in remote controls of various home electric appliances such as televisions and videos, and can be used at very low cost due to the mass production effect. Therefore, if a light receiving element near 900 nm is used as the reference light, the commercial effect is increased.

In this embodiment, the mounting position is the lower position outside the drum. However, the mounting position is not limited to this position. Since the influence of disturbance can be considered, it is also effective to avoid such a place and mount the drum facing the center axis direction of the drum. In particular, if the optical path of the light is set at a position perpendicular to the axis of the drum, the clothing falls to the lower part of the drum due to the weight of the clothing, so that the clothing can be irradiated with light at a high frequency.

[0054]

According to the present invention, the water content of a moving object can be reliably detected, and the value can be immediately followed up. Thus, the end of drying of the clothes dryer can be accurately determined.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of a clothes dryer of the present invention.

FIG. 2 is a diagram showing a relationship between a clothes drying rate and a relative light receiving output of the clothes dryer.

FIG. 3 is a diagram illustrating an example of a relative light receiving output in a drying operation process of the clothes dryer.

FIG. 4 is a diagram showing characteristics of a relative light receiving output with respect to a distance from the light emitting / receiving element surface to clothing.

FIG. 5 is a diagram showing a histogram of a sensor output with respect to a cloth amount of the clothes dryer.

FIG. 6 is a diagram showing a histogram of a sensor output at each drying rate of the clothes dryer.

FIG. 7 is a diagram showing an initial rise rate of the internal temperature at each drying rate of the clothes dryer.

[Explanation of symbols]

 Reference Signs List 11 light emitting means 21 light receiving means 12 control means 14 clothing 17 drum

Claims (15)

[Claims] A light emitting means for projecting light on an object to be dried;
Light receiving means for receiving the reflected light from the object to be dried, control means for turning on and off the light emitting means, calculation of a light receiving output according to the amount of light received from the light receiving means, and operation control of the clothes dryer. A clothes dryer in which the control means determines the degree of drying of the object to be dried based on a time change rate of the light receiving output and performs operation control. 2. A light emitting means for projecting light on an object to be dried,
Light-receiving means for receiving reflected light from the object to be dried; control means for turning on and off the light-emitting means; calculating light-receiving output according to the amount of light received from the light-receiving means; and controlling the operation of the clothes dryer. A clothes dryer for controlling the operation by determining the cloth amount of the object to be dried based on the output of the received light by the control means. 3. A light emitting means for projecting light on an object to be dried,
Light-receiving means for receiving reflected light from the object to be dried; control means for turning on and off the light-emitting means; calculating light-receiving output according to the amount of light received from the light-receiving means; and controlling the operation of the clothes dryer. A clothes dryer for performing operation control based on an operation time determined from a variance value and an average value of the light reception output. 4. A light emitting means for projecting light on an object to be dried,
Light-receiving means for receiving reflected light from the object to be dried; control means for turning on and off the light-emitting means; calculating light-receiving output according to the amount of light received from the light-receiving means; and controlling the operation of the clothes dryer. A clothes dryer for determining the amount of cloth of the object to be dried from the variance value and the average value of the received light output and performing operation control. 5. A light emitting means for projecting light on an object to be dried,
A light receiving unit for receiving the reflected light from the object to be dried; a temperature measuring unit for measuring a temperature inside the refrigerator of the clothes dryer; a control of turning on / off the light emitting unit; a light receiving according to a light receiving amount from the light emitting unit Control means for calculating the output and the temperature output by the temperature measuring means and controlling the operation of the clothes dryer, and performing operation control based on the operation time determined from the received light output and the temperature output by the control means. Clothes dryer. 6. A light emitting means for projecting light on an object to be dried,
A light receiving unit for receiving the reflected light from the object to be dried; a temperature measuring unit for measuring a temperature inside the refrigerator of the clothes dryer; a control of turning on / off the light emitting unit; a light receiving according to a light receiving amount from the light emitting unit Control means for calculating the output and the temperature output by the temperature measuring means and controlling the operation of the clothes dryer, and determining the cloth amount of the object to be dried from the received light output and the temperature output by the control means. Clothes dryer that controls operation. 7. A light receiving output for performing an arithmetic operation by the control means,
The clothes dryer according to any one of claims 1 to 6, wherein a sub-sampling value is used in which a maximum value of the light receiving output in a certain time zone is a representative value in the certain time zone. 8. A light receiving output for performing an operation in the control means,
The clothes dryer according to any one of claims 1 to 6, wherein a sub-sampling value is used in which an average value of the light reception output in a certain time zone is a representative value in the certain time zone. 9. A light receiving output for which a calculation is performed by the control means,
The clothes dryer according to any one of claims 1 to 6, wherein a light receiving output and a moving average value of a representative value in a certain time width are used. 10. The method according to claim 2, wherein the control means uses fuzzy inference to determine the operation time or to calculate the amount of cloth.
The clothes dryer according to any one of claims 1 to 6. 11. The sampling of the received light output to the control means may be performed by stopping the operation by the control means and stopping the clothes to perform the sampling, or sampling at a fixed time interval synchronized with the rotation speed of the drum. The clothes dryer according to any one of claims 1 to 6, wherein the drying is performed. 12. A light receiving output or a representative value in a certain time zone as a light receiving output to be operated by the control means, and a change in light receiving and emitting sensitivity such as a temperature characteristic of the light emitting means and the light receiving means depending on the minimum value in the certain time zone. The clothes dryer according to any one of claims 1 to 6, wherein a value obtained by correcting the above is used. 13. One or more temperature measuring means for measuring a temperature having a correlation with the temperature of the light emitting means or the light receiving means, and a light receiving output to be operated by the control means is provided by the one or more temperature measuring means. The clothes dryer according to any one of claims 1 to 6, wherein a temperature corrected value is used based on the measured temperature output. 14. A light receiving means for correction which outputs a corrected light reception according to an amount of reflected light or direct light received by an object other than the object to be dried, which is projected from the same light emitting means as the light receiving means. The clothes dryer according to any one of claims 1 to 6, wherein a value obtained by correcting a change in light receiving and emitting sensitivity, such as a temperature characteristic of the light emitting unit and the light receiving unit, by the corrected received light output is used as the received light output for performing the above. 15. A condition for calculating a maximum value, an average value, a minimum value, or a moving average value, wherein at least one of a condition that is equal to or less than a predetermined upper limit value or a case that exceeds a predetermined lower limit value. The clothes dryer according to any one of claims 1 to 14, which satisfies the following.