Patent Publication Number: US-8117683-B2

Title: Toilet seat device and toilet seat apparatus having the same

Description:
TECHNICAL FIELD 
     The present invention relates to a toilet seat device having a heating function and a toilet apparatus having the same. 
     BACKGROUND ART 
     There has been a known toilet seat device having a heating function in order to prevent a user from unpleasant feeling when the user sits on a cold toilet seat (for example, see Patent Document 1).  FIG. 39  is a notched top plan view illustrating a part of a warm toilet seat according to Patent Document 1, and  FIG. 40  is a sectional view taken along the line J-J in  FIG. 39 . 
     As shown in  FIGS. 39 and 40 , a warm toilet seat  900  has an upper casing  926  and a lower casing  927  made from synthetic resins. The upper casing  926  and the lower casing  927  are joined to each other. Inside the upper casing  926  and the lower casing  927 , a radiation reflection plate  929 , a lamp heater  930 , a thermostat  931 , a thermal fuse  932 , and a thermistor  33  are provided. 
     The radiation reflection plate  929  is formed so as to coincide with a shape of the lower casing  927 . The lamp heater  930  is disposed on the radiation reflection plate  929 . Thermostat  931  and thermal fuse  932  are mounted on the radiation reflection plate  929  with a predetermined part of lamp heater  930  interposed therebetween. 
     As shown in  FIG. 40 , thermistor  933  is mounted on a place that is an inner side of the upper casing  926  and faces to the lamp heater  930 . 
     In this warm toilet seat  900 , an infrared sensor not shown in the drawings detects user&#39;s entry into a room. Accordingly, the lamp heater  930  is driven on the basis of a detection signal of the infrared sensor. Therefore, radiation energy from the lamp heater  930  is directly given to the upper casing  926  or indirectly given through the radiation reflection plate  929  to the upper casing  926 , and thus the upper casing  926  radiates heat. 
     According to the warm toilet seat 900 of Patent Document 1 with such a configuration, it is not necessary to constantly drive the lamp heater  930 , and thus it is possible to save energy. 
     In such a kind of warm toilet seat, which is another example, a seating section  2103  of a toilet seat  2102  having a cavity section  2101  formed therein is made from transparent polypropylene resin as shown in  FIG. 41 , whereby a radiated heat absorption layer  2104  is formed on a surface of the seating section  2103 , and a lamp heater  2105  is formed on the cavity section  2101 . The radiated heat from the lamp heater  2105  is transmitted through the seating section  2103  made from the transparent polypropylene resin, is converted to thermal energy in the radiated heat absorption layer  2104  on the surface thereof, and rise temperature of the seating section  2103 . The heat is generated in the radiated heat absorption layer  2104  that is used to be in contact with the hips, and thus it is possible to warm the hips in a short time as compared with a thermal conduction heating type that employs a code heater and the like in the toilet seat  2102 . In addition, a temperature control is performed by a thermostat  2106  that is disposed near the lamp heater  2105 , and the temperature control prevents danger caused by abnormal heating by using a thermal fuse  2107 . 
     Patent Document 1: Japanese Unexamined Patent Application Publication No. 2000-14598 
     Patent Document 2: Japanese Unexamined Patent Application Publication No. 2000-210230 
     DISCLOSURE OF THE INVENTION 
     Problems that the Invention is to Solve 
     In the warm toilet seat 900 according to Patent Document 1, temperature of the upper casing  926  is measured by thermistor  933  disposed on the inner side of the upper casing  926 , and drive of the lamp heater  930  is controlled by a control section not shown in the drawings. With such a configuration, it is possible to warm the upper casing  926  to a predetermined temperature. 
     However, there is generated a time delay until the temperature of the upper casing  926  reaches the predetermined temperature by radiation energy from the lamp heater  930 . 
     Accordingly, in a case where the drive of the lamp heater  930  is controlled on the basis of the measured temperature value obtained by thermistor  933 , it is difficult to accurately control the temperature of the upper casing  926 . 
     Therefore, for example, there is contrived a method of determining drive time of the lamp heater on the basis of room temperature and the measured temperature value of the seating section at the start time of applying current (see Patent Document 2). 
     In this case, relationship between the drive time of the lamp heater and an actual temperature of the seating section is previously calculated, the drive time of the lamp heater is controlled on the basis of the calculation result, and thus the temperature of the seating section can becomes close to the predetermined temperature (for example, user&#39;s set temperature). 
     However, in the warm toilet seat, there is a need to apply large current to the lamp heater in order that the lamp heater increases the temperature of the seating section in a short time. Because of this, overshoot is caused by temperature variance of the seating section. Hence, it is difficult to stabilize the temperature of the seating section at the set temperature in a short time. 
     In the known configuration as shown in  FIG. 41 , the lamp heater has good rapid heating performance because of good efficiency in electric power transformation and can rise temperature in a short time. However, since resistance of the lamp heater is low as much as 1/10 or less of rated electric power consumption when filament is in a cool down state (temperature of the filament is near room temperature of toilet), large inrush current flows at the beginning of applying current. As might be expected, the filament resistance reaches a rated resistance in a short time, and the inrush current is instantly suppressed. However, large current flows when current is applied to the toilet seat device and the other products (particularly, a heater) equipped in the toilet simultaneously. 
     Generally, since a house power wiring with respect to the toilet inside is not a large current wiring but a single power wiring, there are not usually provided a circuit breaker and an overcurrent breaker for dealing with the large current. In addition, generally, current is also applied to lighting apparatuses in the toilet from the same electric power wiring. For this reason, when current is applied to the lamp heater and heaters of the other products (for example, a hot water heater for heating washing water that washes a part of a human body) equipped in the toilet simultaneously, the circuit breaker is operated by overcurrent, and voltage drop is caused by resistance components of the house power wiring. Therefore, there have been problems of: supply voltage drop to a toilet seat device, other products equipped in toilet, and lighting in toilet; product performance deterioration of toilet seat device or other products equipped in toilet; and brightness down of indoor lighting. 
     It is an object of the invention to provide a toilet seat device capable of saving energy and accurately stabilizing the temperature of a seating section at a predetermined level in a short time, and a toilet apparatus having the same. In addition, it is an object of the invention to provide a toilet seat device that is convenient for use and can save more energy. 
     Means for Solving the Problem 
     In order to solve the known problems mentioned above, a toilet seat device according to the invention includes: a toilet seat section; a heating element for heating the toilet seat section; a human body sensing section for detecting a user; and a control section for controlling the heating element to be driven. When the human body sensing section detects a user, the control section drives the heating element during a first time period so as to increase temperature of the toilet seat section to first temperature along a first temperature gradient with first electric power, and then the control section drives the heating element during a second time period so as to increase temperature of the toilet seat section to second temperature, which is higher than the first temperature, along a second temperature gradient, which is lower than the first temperature gradient, with second electric power which is lower than the first electric power. 
     According to this toilet seat device, when the human body sensing section detects a user, the control section drives the heating element during a first time period so as to increase temperature of the toilet seat section to first temperature with first electric power. With such a configuration, the temperature of the toilet seat section increases along the first temperature gradient. 
     After the first electric power drives the heating element, the control section drives the heating element during a second time period so as to increase temperature of the toilet seat section to second temperature, which is higher than the first temperature, with second electric power that is lower than the first electric power. With such a configuration, the temperature of the toilet seat section increases along a second temperature gradient that is lower than the first temperature gradient. 
     When the temperature of the toilet seat section is measured and the heating element is driven on the basis of the measured temperature, there is generated delay time until the temperature of the heating element is transmitted to the toilet seat section. Therefore, it is difficult to accurately and rapidly control the temperature of the toilet seat section. Contrarily, according to the toilet device of the invention, the drive time of the heating element due to the first and second electric powers are previously set as the first and second time periods, respectively. Therefore, it is possible to accurately and rapidly control the temperature of the toilet seat section. 
     When the human body sensing section detects a user, the heating element is driven by the first and second electric powers. Therefore, when a user is not detected, it is not necessary to drive the heating element with the first and second electric powers that are necessary for rising the temperature of the toilet seat section. With such a configuration, electric power consumption is sufficiently reduced, and thus it is possible to save energy. 
     In addition, after the temperature of the toilet seat section is increased to the first temperature along the first temperature gradient, and then the temperature thereof is increased to the second temperature along the second temperature gradient that is lower than the first temperature gradient. With such a configuration, it is possible to reduce overshoot that is caused by temperature variance of the toilet seat section in the second temperature. Therefore, it is possible to easily stabilize the temperature of the toilet seat section at the second temperature. 
     In the toilet seat device according to the invention, when a human body is detected by human body sensing means in control means, electric power is supplied to the heating source for warming the toilet seat with a first duty ratio for constant time. Then, control operation is performed so that the toilet seat temperature reaches seatable temperature with a second duty ratio higher than the first duty ratio in a predetermined time. 
     With the configuration, it is possible to provide a toilet seat device that is convenient for use and can save more energy. 
     In the toilet seat device according to the invention, when a human body is detected by human body sensing means in the control means, electric power is supplied to the heating source for warming the toilet seat with a first duty ratio for constant time. Then, control operation is performed so that the toilet seat temperature reaches seatable temperature with a second duty ratio higher than the first duty ratio in a predetermined time. When seating of a human body is detected by the seating sensing means, control operation is performed on the heating source with a third duty ratio lower than the second duty ratio. 
     With the configuration, it is possible to provide a toilet seat device that is convenient for use and can save more energy. 
     In the toilet seat device according to the invention, when a human body is detected by human body sensing means in the control means, electric power is supplied to the heating source for warming the toilet seat with a plurality of duty ratios for constant time. Then, control operation is performed so that the toilet seat temperature reaches seatable temperature with a constant duty ratio higher than the plurality of duty ratios in a predetermined time. 
     With the configuration, it is possible to provide a toilet seat device that is convenient for use and can save more energy. 
     Advantage of the Invention 
     According to a toilet seat device and a toilet apparatus having the same of the invention, it is possible to save energy and accurately stabilize the temperature of a seating section at a predetermined level in a short time. 
     In addition, the toilet seat device according to the invention has a rapid heating function, and it is possible to provide a toilet seat device that is convenient for use and can save more energy. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exterior perspective view illustrating a toilet seat device and a toilet apparatus having the same according to an embodiment of the invention. 
         FIG. 2  is a schematic view illustrating an example of a remote control device in  FIG. 1 . 
         FIG. 3  is a schematic view illustrating a configuration of a toilet seat device according to an embodiment of the invention. 
         FIG. 4  is a diagram illustrating a detailed structure of the toilet seat section in  FIG. 1 . 
         FIG. 5  is a diagram illustrating a detailed structure of the toilet seat section in  FIG. 1 . 
         FIG. 6  is a diagram illustrating a detailed structure of the toilet seat section in  FIG. 1 . 
         FIG. 7  is a diagram illustrating a detailed structure of the toilet seat section in  FIG. 1 . 
         FIG. 8  is a diagram illustrating an example of heater control tables corresponding to predetermined toilet seat set temperatures (34° C., 36° C., and 38° C.). 
         FIG. 9  is a diagram illustrating an example of heater control tables corresponding to the predetermined toilet seat set temperatures (34° C., 36° C., and 38° C.). 
         FIG. 10  is a diagram illustrating an example of heater control tables corresponding to predetermined toilet seat set temperatures (34° C., 36° C., and 38° C.). 
         FIG. 11(   a ) is a waveform diagram illustrating current that flows in a lamp heater during 1200 W drive, and  FIG. 11(   b ) is a waveform diagram illustrating a current control signal given to a heater driving section from A duty ratio switching circuit during the 1200 W drive. 
         FIG. 12(   a ) is a waveform diagram illustrating current that flows in the lamp heater during 600 W drive, and  FIG. 12(   b ) is a waveform diagram illustrating a current control signal given to the heater driving section from the duty ratio switching circuit during the 600 W drive. 
         FIG. 13(   a ) is a waveform diagram illustrating current that flows in the lamp heater during a low electric power drive, and  FIG. 13(   b ) is a waveform diagram illustrating a current control signal given to the heater driving section from the duty ratio switching circuit during the low electric power drive. 
         FIG. 14  is a diagram illustrating a relationship between surface temperature of a seating section and surface temperature of the lamp heater at the time of a toilet seat temperature rise test. 
         FIG. 15  is a diagram illustrating a relationship between the surface temperature of the seating section and a temperature value measured by a thermistor at the time of a test for estimating the measured temperature value. 
         FIG. 16  is a diagram illustrating an exemplary drive of the lamp heater based on the heater control table in  FIG. 10  and variance of the surface temperature in the seating section ( FIG. 4 ). 
         FIG. 17  is a flowchart illustrating an operation of a control section in  FIG. 3 . 
         FIG. 18  is a flowchart illustrating an operation of the control section in  FIG. 3   
         FIG. 19  is a flowchart illustrating an operation of the control section in  FIG. 3   
         FIG. 20  is a flowchart illustrating an operation of the control section in  FIG. 3   
         FIG. 21  is a flowchart illustrating an operation of the control section in  FIG. 3   
         FIG. 22  is a flowchart illustrating an operation of the control section in  FIG. 3   
         FIG. 23  is a block diagram illustrating the toilet seat device according to Embodiment 2 of the invention. 
         FIG. 24  is a graph illustrating duty ratio of the heating source according to Embodiment 2 of the invention. 
         FIG. 25  is a block diagram illustrating the toilet seat device according to Embodiment 3 of the invention. 
         FIG. 26  is a graph illustrating variance of toilet seat temperature according to Embodiment 3 of the invention. 
         FIG. 27  is a block diagram illustrating the toilet seat device according to Embodiment 4 of the invention. 
         FIG. 28  is a block diagram illustrating the toilet seat device according to Embodiment 5 of the invention. 
         FIG. 29  is a graph illustrating duty ratio of the heating source according to Embodiment 5 of the invention. 
         FIG. 30  is a block diagram illustrating the toilet seat device according to Embodiment 6 of the invention. 
         FIG. 31  is a graph illustrating variance of the toilet seat temperature according to Embodiment 6 of the invention. 
         FIG. 32  is a block diagram illustrating the toilet seat device according to Embodiment 7 of the invention. 
         FIG. 33  is a block diagram illustrating the toilet seat device according to Embodiment 8 of the invention. 
         FIG. 34  is a graph illustrating duty ratio of the heating source according to Embodiment 8 of the invention. 
         FIG. 35  is a graph illustrating duty ratio of the heating source according to Embodiment 9 of the invention. 
         FIG. 36  is a block diagram illustrating the toilet seat device according to Embodiment 10 of the invention. 
         FIG. 37  is a graph illustrating variance of the toilet seat temperature according to Embodiment 10 of the invention. 
         FIG. 38  is a block diagram illustrating the toilet seat device according to Embodiment 11 of the invention. 
         FIG. 39  is a notched top plan view illustrating a part of a warm toilet seat according to Patent Document 1. 
         FIG. 40  is a sectional view taken along the line J-J in  FIG. 39 . 
         FIG. 41  is a sectional view illustrating a main part of a known toilet seat device. 
     
    
    
     DESCRIPTION OF REFERENCE NUMERALS AND SIGNS 
     
         
         
           
               100 : TOILET SEAT DEVICE 
               210 : CONTROL UNIT 
               400 : TOILET SEAT SECTION 
               410 T: SEATING SECTION 
               411 : THERMISTOR 
               480 : LAMP HEATER 
               210 : CONTROL UNIT 
               220 : TEMPERATURE MEASUREMENT SECTION 
               290 : SEAT SENSOR 
               600 : ENTRY SENSOR 
               700 : TOILET BOWL 
               1000 : TOILET APPARATUS 
               2010 : TOILET SEAT 
               2011 : HEATING SOURCE 
               2012 : HUMAN BODY SENSING MEANS 
               2013 : CONTROL MEANS 
               2014 : ROOM TEMPERATURE DETECTING MEANS 
               2015 : TOILET SEAT TEMPERATURE DETECTING MEANS 
               3010 : TOILET SEAT 
               3011 : HEATING SOURCE 
               3012 : HUMAN BODY SENSING MEANS 
               3013 : SEATING SENSING MEANS 
               3014 : CONTROL MEANS 
               3015 : ROOM TEMPERATURE DETECTING MEANS 
               3016 : TOILET SEAT TEMPERATURE DETECTING MEANS 
               4010 : TOILET SEAT 
               4011 : HEATING SOURCE 
               4012 : HUMAN BODY SENSING MEANS 
               4013 : CONTROL MEANS 
               4014 : ROOM TEMPERATURE DETECTING MEANS 
               4015 : TOILET SEAT TEMPERATURE DETECTING MEANS 
           
         
       
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     (1) A toilet seat device according to a first aspect of the invention includes: a toilet seat section; a heating element for heating the toilet seat section; a human body sensing section for detecting a user; and a control section for controlling the heating element to be driven. When the human body sensing section detects a user, the control section drives the heating element during a first time period so as to increase temperature of the toilet-seat section to first temperature along a first temperature gradient with first electric power, and then the control section drives the heating element during a second time period so as to increase temperature of the toilet seat section to second temperature, which is higher than the first temperature, along a second temperature gradient, which is lower than the first temperature gradient, with second electric power which is lower than the first electric power. 
     According to this toilet seat device, when the human body sensing section detects a user, the control section drives the heating element during a first time period so as to increase temperature of the toilet seat section to first temperature with first electric power. With such a configuration, the temperature of the toilet seat section increases along the first temperature gradient. 
     After the first electric power drives the heating element, the control section drives the heating element during a second time period so as to increase temperature of the toilet seat section to second temperature, which is higher than the first temperature, with second electric power that is lower than the first electric power. With such a configuration, the temperature of the toilet seat section increases along a second temperature gradient that is lower than the first temperature gradient. 
     When the temperature of the toilet seat section is measured and the heating element is driven on the basis of the measured temperature, there is generated delay time until the temperature of the heating element is transmitted to the toilet seat section. Therefore, it is difficult to accurately and rapidly control the temperature of the toilet seat section. Meanwhile, according to the toilet device of the invention, the drive time of the heating element due to the first and second electric powers are previously set as the first and second time periods, respectively. Therefore, it is possible to accurately and rapidly control the temperature of the toilet seat section. 
     When the human body sensing section detects a user, the heating element is driven by the first and second electric powers. Therefore, when a user is not detected, it is not necessary to drive the heating element with the first and second electric powers that is necessary for rising the temperature of the toilet seat section. With such a configuration, electric power consumption is sufficiently reduced, and thus it is possible to save energy. 
     In addition, after the temperature of the toilet seat section is increased to the first temperature along the first temperature gradient, and then the temperature thereof is increased to the second temperature along the second temperature gradient that is lower than the first temperature gradient. With such a configuration, it is possible to reduce overshoot that is caused by temperature variance of the toilet seat section in the second temperature. Therefore, it is possible to easily stabilize the temperature of the toilet seat section at the second temperature. 
     In addition, the second temperature is set as temperature that makes a user feel comfortable, and thus a user can comfortably sit on the toilet seat section. 
     (2) In the configuration of the toilet seat device according to the first aspect of the invention, a toilet seat device according to a second aspect of the invention further includes: a toilet seat temperature measuring device for measuring the temperature of the toilet seat section, and a memory section for storing correspondence relationship between the first and second time periods and the temperature measured by the toilet seat temperature measuring device. When the human body sensing section detects a user, the control section reads out the corresponding first and second time periods from the memory section on the basis of the temperature measured by the toilet seat temperature measuring device, and the control section drives the heating element on the basis of the first and second time periods. 
     In this case, when the human body sensing section detects a user, the corresponding first and the second time periods are read from the memory section on the basis of the temperature measured by the toilet seat temperature measuring device. Then, the control section drives the heating element on the basis of the first and second time periods. 
     With such a configuration, it is possible to drive the heating element on the basis of the first and second time periods corresponding to the temperature around the toilet seat device. Accordingly, even when atmospheric temperature changes, it is possible to increase the temperature of the toilet seat section to the first and second temperatures. 
     In addition, when the human body sensing section detects a user, the heating element is not driven by the first and second electric powers. Accordingly, when the human body sensing section detects a user, the temperature measured by the toilet seat temperature measuring device is not changed and stabilized. Therefore, the heating element is driven on the basis of the first and second time periods, and thus it is possible to increase the temperature of the toilet seat section to the first and second temperatures. 
     (3) In the configuration of the toilet seat device according to the second aspect of the invention, a toilet seat device according to a third aspect of the invention is configured so that the control section drives the heating element with the second electric power when the temperature measured by the toilet seat temperature measuring device reaches a predetermined third temperature before the elapse of first time period. 
     In this case, when the temperature measured by the toilet seat temperature measuring device reaches the predetermined third temperature before the elapse of first time period, the control section drives the heating element with the second electric power. 
     Here, the third temperature is set as temperature measured by the toilet seat temperature measuring device at the time in which the temperature of the toilet seat section reaches the first temperature with the first electric power to the heating element to be driven. 
     With such a configuration, it is possible to prevent the toilet seat section from overheat so that the temperature thereof does not exceed the first temperature when the heating element is driven on the basis of the first time period. 
     (4) In the configuration of the toilet seat device according to any one of the first to third aspects of the invention, a toilet seat device according to a fourth aspect of the invention is configured so that the control section drives the heating element with the first electric power by applying alternating current throughout entire cycle periods, and the control section drives the heating element with the first electric power by applying alternating current throughout a predetermined number of half cycle periods. 
     In this case, the alternating current throughout the entire cycle periods or the predetermined number of half cycle periods is applied to the heating element when the heating element is driven by the first and second electric powers. Therefore, the current applied to the heating element varies like a sine curve. With such a configuration, the current applied to the heating element does not include harmonic components. Accordingly, occurrence of noise is sufficiently reduced. 
     (5) In the configuration of the toilet seat device according to the second or third aspect of the invention, a toilet seat device according to a fifth aspect of the invention is configured so that the control section drives the heating element with third electric power, which is lower than the first and second electric powers, so as to constantly maintain the temperature of the toilet seat section at the second temperature after the elapse of second time period. 
     In this case, the control section drives the heating element with third electric power, which is lower than the first and second electric powers, so as to constantly maintain the temperature of the toilet seat section at the second temperature, after the elapse of second time period. 
     In this manner, the temperature of the toilet section is constantly maintained at the second temperature, and thus a user can comfortably sit on the toilet seat section that is maintained at proper temperature. 
     In addition, the heating element is driven by the third electric power that is lower than the first and second electric powers, and thus it is possible to reduce electric power consumption and maintains the temperature of the toilet seat section at the second temperature. 
     (6) In the configuration of the toilet seat device according to the fifth aspect of the invention, a toilet seat device according to a sixth aspect of the invention is configured so that the control section drives the heating element with the third electric power when the temperature measured by the toilet seat temperature measuring device reaches a predetermined fourth temperature, before the elapse of second time period. 
     In this case, the control section drives the heating element with the third electric power when the temperature measured by the toilet seat temperature measuring device reaches a predetermined fourth temperature, before the elapse of second time period. 
     Here, the fourth temperature is set as temperature measured by the toilet seat temperature measuring device at the time in which the temperature of the toilet seat section reaches the second temperature with the second electric power to the heating element to be driven. 
     With such a configuration, it is possible to prevent the toilet seat section from overheat so that the temperature thereof does not exceed the second temperature when the heating element is driven on the basis of the second time period. 
     (7) In the configuration of the toilet seat device according to the fifth or sixth aspect of the invention, a toilet seat device according to a seventh aspect of the invention is configured so that the control section drives the heating element with the third electric power by applying alternating current throughout a predetermined number of quarter or less cycle periods. 
     In this case, since the current applied to the heating element is small when the heating element is driven by the third electric power, there is small effect from harmonic components that is caused by an alternating-current control. Accordingly, occurrence of noise caused by the current control is reduced. 
     (8) In the configuration of the toilet seat device according to any one of the first to seventh aspects of the invention, a toilet seat device according to an eighth aspect of the invention is configured so that the control section drives the heating element with electric power, which is lower than the first electric power, immediately before driving the heating element with the first electric power. 
     In this case, the control section drives the heating element with electric power, which is lower than the first electric power, immediately before driving the heating element with the first electric power, and thus it is possible to sufficiently prevent occurrence of large inrush current. 
     (9) In the configuration of the toilet seat device according to any one of the first to eighth aspect of the invention, a toilet seat device according to a ninth aspect of the invention further includes a seating sensing section for detecting user&#39;s seating state on the toilet seat section. When the seating sensing section detects user&#39;s seating on the toilet seat section, the control section drives the heating element so as to decrease the temperature of the toilet seat section. 
     In this case, the control section drives the heating element so as to decrease the temperature of the toilet seat section when the seating sensing section detects user&#39;s seating on the toilet seat section. Therefore, it is possible to prevent a user from suffering low temperature burn even when the user sits on the toilet seat section in a long time. 
     (10) In the configuration of the toilet seat device according to any one of the first to ninth aspects of the invention, a toilet seat device according to a tenth aspect of the invention is configured so that the second temperature is the temperature, which is previously set by a user, of the toilet seat section, and the control section drives the heating element so as to increase the temperature of the toilet seat section higher than the second temperature at the time of user&#39;s seating on the toilet seat section. 
     In this case, a user can previously set the temperature of the toilet seat to be comfortable temperature. Here, the heating element is driven so that the temperature of the toilet seat section becomes higher than the second temperature. In this manner, a user can feel like the substantially same temperature as the second temperature that is set by a user himself at the time of seating on the toilet seat section. 
     (11) In the configuration of the toilet seat device according to any one of the first to tenth aspects of the invention, a toilet seat device according to an eleventh aspect of the invention is configured so that the toilet seat section is made of aluminum. 
     In this case, the toilet seat section is made of aluminum that has higher thermal conductivity than resin. Therefore, heat applied to the toilet seat section by driving the heating element is sufficiently transmitted to the entire toilet seat section. 
     (12) In the configuration of the toilet seat device according to any one of the first to eleventh aspects of the invention, a toilet seat device according to a twelfth aspect of the invention is configured so that the heating element is a lamp heater. In this case the lamp heater can rapidly increase the toilet section by radiating energy. 
     (13) A toilet apparatus according to a thirteenth aspect of the invention includes a toilet bowl and the toilet seat device according to any one of the first to twelfth aspects of the invention. 
     In this toilet apparatus, the toilet seat device is mounted on the toilet bowl. In this toilet device, when the human body sensing section detects a user, the control section drives the heating element during a first time period so as to increase temperature of the toilet seat section to first temperature with first electric power. With such a configuration, the temperature of the toilet seat section increases along the first temperature gradient. 
     After the first electric power drives the heating element, the control section drives the heating element during a second time period so as to increase temperature of the toilet seat section to second temperature, which is higher than the first temperature, with second electric power that is lower than the first electric power. With such a configuration, the temperature of the toilet seat section increases along a second temperature gradient that is lower than the first temperature gradient. 
     When the temperature of the toilet seat section is measured and simultaneously the heating element is driven on the basis of the measured temperature, there is generated delay time until the temperature of the heating element is transmitted to the toilet seat section. Therefore, it is difficult to accurately and rapidly control the temperature of the toilet seat section. Contrarily, according to the toilet device of the invention, the drive time of the heating element due to the first and second electric powers are previously set as the first and second time periods, respectively. Therefore, it is possible to accurately and rapidly control the temperature of the toilet seat section. 
     When the human body sensing section detects a user, the heating element is driven by the first and second electric powers. Therefore, when a user is not detected, it is not necessary to drive the heating element with the first and second electric powers that is necessary for rising the temperature of the toilet seat section. With such a configuration, electric power consumption is sufficiently reduced, and thus it is possible to save energy. 
     In addition, after the temperature of the toilet seat section is increased to the first temperature along the first temperature gradient, and then the temperature thereof is increased to the second temperature along the second temperature gradient that is lower than the first temperature gradient. With such a configuration, it is possible to reduce overshoot that is caused by temperature variance of the toilet seat section in the second temperature. Therefore, it is possible to easily stabilize the temperature of the toilet seat section at the second temperature. 
     In addition, the second temperature is set as temperature that makes a user feel comfortable, and thus a user can comfortably sit on the toilet seat section. 
     (14) A fourteenth aspect of the invention includes: a heating source for warming the toilet seat; human body sensing means; and control means for controlling the heating source and the human body sensing means. When a human body is sensed, the control means performs a control operation so that the toilet seat temperature reaches seatable temperature in a predetermined time by employing a second duty ratio that is higher than the first duty ratio after electric power is supplied to the heating source with a first duty ratio for constant time, and thus it is possible to suppress large inrush current. Therefore, there is no problem that the circuit breaker is operated by overcurrent, or voltage drop is caused by resistance components of the house power wiring. Thus, there is no supply voltage drop to a toilet seat device, other products equipped in toilet, and lighting in toilet, no product performance deterioration of toilet seat device or other products equipped in toilet, and no brightness down of indoor lighting. As a result, it is possible to provide a toilet seat device that is convenient for use and can save more energy. 
     (15) According to the fourteenth aspect of the invention, a fifteenth aspect of the invention further includes a room temperature detecting means, and the predetermined time is determined in accordance with room temperature. Therefore, the temperature of the toilet seat reaches seatable temperature in a minimum time for necessary, and thus it is possible to provide a convenient toilet seat device. In addition, since current is not unnecessarily applied to the heating source, it is possible to achieve a toilet seat device that can save more energy. 
     (16) According to the fourteenth aspect of the invention, a sixteenth aspect of the invention further includes a toilet seat temperature detecting means for detecting toilet seat temperature, and the predetermined time is determined in accordance with the toilet seat temperature. Therefore, the temperature of the toilet seat reaches seatable temperature in a minimum time for necessary, and thus it is possible to provide a convenient toilet seat devices. In addition, since current is not unnecessarily applied to the heating source, it is possible to achieve a toilet seat device that can save more energy. 
     (17) According to the sixteenth aspect of the invention, a seventeenth aspect of the invention is configured so that the toilet seat temperature detecting means detects temperature in the toilet seat. Therefore, the temperature of the toilet seat reaches seatable temperature in a minimum time for necessary, it is possible to provide a convenient toilet seat device. In addition, since current is not unnecessarily applied to the heating source, it is possible to achieve a toilet seat device that can save more energy. 
     (18) According to any one of the fourteenth to the seventeenth aspects of the invention, a seventeenth aspect of the invention is configured so that electric power is supplied with duty ratio that maintains the toilet seat temperature at a set temperature, after the elapse of predetermined time. Therefore, since current is not unnecessarily applied to the heating source, it is possible to achieve a toilet seat device that can save more energy. 
     (19) A nineteenth aspect of the invention includes: a heating source for warming the toilet seat; seating sensing means; human body sensing means; and control means for controlling the heating source, the seating sensing means, and the human body sensing means. When a human body is sensed, the control means performs a control operation so that the toilet seat temperature reaches seatable temperature in a predetermined time by employing a second duty ratio that is higher than the first duty ratio, the electric power is applied with third duty ratio, which is lower than the second duty ratio after electric power is supplied to the heating source with a first duty ratio for constant time, and thus it is possible to suppress large inrush current directly after starting electric power supply. Therefore, there is no problem that the circuit breaker is operated by overcurrent, or voltage drop is caused by resistance components of the house power wiring. Thus, there is no supply voltage drop to a toilet seat device, other products equipped in toilet, and lighting in toilet, no product performance deterioration of toilet seat device or other products equipped in toilet, and no brightness down of indoor lighting. In addition, the toilet seat is covered by the human body when a human body is sitting on the toilet seat, so that heat retaining property increases and body temperature warms the toilet seat, and thus it is possible to minimize useless electric power by lowering duty ratio. As a result, it is possible to provide a toilet seat device that is convenient for use and can save more energy. 
     (20) According to the nineteenth aspect of the invention, a twentieth aspect of the invention further includes a room temperature detecting means, and the predetermined time is determined in accordance with room temperature. Therefore, the temperature of the toilet seat reaches seatable temperature in a minimum time for necessary, and thus it is possible to provide a convenient toilet seat device. In addition, since current is not unnecessarily applied to the heating source, it is possible to achieve a toilet seat device that can save more energy. 
     (21) According to the nineteenth aspect of the invention, a twenty first aspect of the invention further includes a toilet seat temperature detecting means for detecting toilet seat temperature, and the predetermined time is determined in accordance with the toilet seat temperature. Therefore, the temperature of the toilet seat reaches seatable temperature in a minimum time for necessary, and thus it is possible to provide a convenient toilet seat device. In addition, since current is not unnecessarily applied to the heating source, it is possible to achieve a toilet seat device that can save more energy. 
     (22) According to the twenty first aspect of the invention, a twenty second aspect of the invention is configured so that the toilet seat temperature detecting means detects temperature in the toilet seat. Therefore, the temperature of the toilet seat reaches seatable temperature in a minimum time for necessary, it is possible to provide a convenient toilet seat device. In addition, since current is not unnecessarily applied to the heating source, it is possible to achieve a toilet seat device that can save more energy. 
     (23) According to any one of the nineteenth to the twenty second aspects of the invention, a twenty third aspect of the invention is configured so that electric power is supplied with duty ratio that maintains the toilet seat temperature at a set temperature, after the elapse of predetermined time. Therefore, since current is not unnecessarily applied to the heating source, it is possible to achieve a toilet seat device that can save more energy. 
     (24) A twenty fourth aspect of the invention includes: a heating source for warming the toilet seat; human body sensing means; and control means for controlling the heating source and the human body sensing means. When a human body is detected by human body sensing means, the control means controls to supply electric power to the heating source for warming the toilet seat with a plurality of duty ratios for constant time. Then, the control means performs a control operation so that the toilet seat temperature reaches seatable temperature with a constant duty ratio higher than the plurality of duty ratios in a predetermined time, and thus it is possible to suppress large inrush current. Therefore, there is no problem that the circuit breaker is operated by overcurrent, or voltage drop is caused by resistance components of the house power wiring. Thus, there is no supply voltage drop to a toilet seat device, other products equipped in toilet, and lighting in toilet, no product performance deterioration of toilet seat device or other products equipped in toilet, and no brightness down of indoor lighting. As a result, it is possible to provide a toilet seat device that is convenient for use and can save more energy. 
     (25) According to the twenty fourth aspect of the invention, a twenty fifth aspect of the invention is configured so that the plurality of duty ratios stepwise increases. Therefore, the temperature of the toilet seat reaches seatable temperature in a minimum time for necessary, and thus it is possible to provide a convenient toilet seat device. In addition, since current is not unnecessarily applied to the heating source, it is possible to achieve a toilet seat device that can save more energy. 
     (26) According to the twenty fourth aspect of the invention, a twenty sixth aspect of the invention is configured so that the plurality of duty ratios continuously increase. Therefore, the temperature of the toilet seat reaches seatable temperature in a minimum time for necessary, and thus it is possible to provide a convenient toilet seat device. In addition, since current is not unnecessarily applied to the heating source, it is possible to achieve a toilet seat device that can save more energy. 
     (27) According to any one of the twenty fourth to twenty sixth aspects of the invention, a twenty seventh aspect of the invention further includes a room temperature detecting means, and the predetermined time is determined in accordance with room temperature. Therefore, the temperature of the toilet seat reaches seatable temperature in a minimum time for necessary, and thus it is possible to provide a convenient toilet seat device. In addition, since current is not unnecessarily applied to the heating source, it is possible to achieve a toilet seat device that can save more energy. 
     (28) According to any one of the twenty fourth to twenty sixth aspects of the invention, a twenty eighth aspect of the invention further includes a toilet seat temperature detecting means for detecting toilet seat temperature, and the predetermined time is determined in accordance with the toilet seat temperature. Therefore, the temperature of the toilet seat reaches seatable temperature in a minimum time for necessary, and thus it is possible to provide a convenient toilet seat device. In addition, since current is not unnecessarily applied to the heating source, it is possible to achieve a toilet seat device that can save more energy. 
     (29) According to the twenty eighth aspect of the invention, a twenty ninth aspect of the invention is configured so that the toilet seat temperature detecting means detects temperature in the toilet seat. Therefore, the temperature of the toilet seat reaches seatable temperature in a minimum time for necessary, it is possible to provide a convenient toilet seat device. In addition, since current is not unnecessarily applied to the heating source, it is possible to achieve a toilet seat device that can save more energy. 
     (30) According to any one of the twenty fourth to twenty ninth aspects of the invention, a thirtieth aspect of the invention is configured so that electric power is supplied with duty ratio for maintaining the toilet seat temperature at a set temperature, after the elapse of predetermined time. Therefore, since current is not unnecessarily applied to the heating source, it is possible to achieve a toilet seat device that can save more energy. 
     Hereinafter, a nozzle device according to an embodiment of the invention and a hygiene washing apparatus will be described with reference to drawings. 
     Embodiment 1 
     (1) Exterior View of Toilet Seat Device and Toilet Apparatus Having the Same 
       FIG. 1  is an exterior perspective view illustrating a toilet seat device and a toilet apparatus having the same according to an embodiment of the invention. As shown in  FIG. 1 , the toilet apparatus  1000  includes a toilet seat device  100  and a toilet bowl  700 , and the apparatus is provided in a toilet. 
     In the toilet apparatus  1000 , a toilet seat device  100  is mounted on the toilet bowl  700 . The toilet seat device  100  has a heating function, and is constituted of a main body section  200 , a remote control device  300 , a toilet seat section  400 , a cover section  500 , and an entry sensor  600 . 
     The toilet seat section  400  and cover section  500  is mounted on the main body section  200  so as to be freely openable. In addition, a washing water supply tool and a seat sensor  290  is provided in the main body section  200 , and the control section to be described later is built therein. 
     In the embodiment, a lamp heater is built in the toilet seat section  400 . Detailed description will be given later. 
     The washing water supply tool of the main body section  200  that is not shown in the drawings is connected to a water supply pipe, and the tool supplied washing water to the toilet bowl  700 . The seat sensor  290  is, for example, a reflection type infrared sensor. In this case, the seat sensor  290  senses that a user is on the toilet seat section  400  when detecting infrared rays reflected from a human body. 
     In addition, a notice LED  280  is provided on the upper face side of the main body section  200 . The notice LED  280  is turned on when temperature of the toilet seat section  400  reaches toilet seat set temperature to be described later. 
     A plurality of switches are provided on the remote control device  300 . The remote control device  300  is attached to, for example, a place where a user sitting on the toilet seat section  400  to be seated can manipulate. 
     The entry sensor  600  is attached to, for example, an entrance of toilet. The entry sensor  600  is, for example, a reflection type infrared sensor. In this case, the entry sensor  600  senses user&#39;s entry into the toilet room when detecting infrared rays reflected from a human body. 
     The control section of the main body section  200  controls a drive of the lamp heater to be described later that is built in the toilet seat section  400 , on the basis of signals received from the seat sensor  290 , the remote control device  300 , and the entry sensor  600 . 
     In addition, the control section of the main body section  200  also controls a washing water supply tool (which is not shown in the drawings), and a deodorizing device (which is not shown in the drawings) and warm air sending device (which is not shown in the drawings) that are disposed on the main body section  200 . 
     (2) Configuration of Remote Control Device 
       FIG. 2  is a schematic view illustrating an example of a remote control device  300  in  FIG. 1 . 
     As shown in  FIG. 2 , the remote control device  300  includes a warm switch  301 , a plurality of temperature adjustment switches  302 ,  303 , and  304  and a plurality of LEDs (a light emitting diode)  305 . 
     A user operates the warm switch  301  and the plurality of temperature adjustment switches  302 ,  303 , and  304  by pressing them. 
     Then, the remote control device  300  transmits a predetermined signal by wireless to the control section disposed on the main body section  200  of the toilet seat device  100  to be described later. The control section of the main body section  200  controls the drive of the lamp heater to be described later, by receiving the predetermined signal that is transmitted by wireless from the remote control device  300 . 
     When a user uses the heating function like winter season, the heating function of the toilet seat device  100  is turned on by previously pressing the warm switch  301 . In this state, the temperature of the toilet seat section  400  is set as low temperature (for example, 34° C.) when the temperature adjustment switch  302  is pressed, the temperature of the toilet seat section  400  is set as intermediate temperature (for example, 36° C.) when the temperature adjustment switch  303  is pressed, and the temperature of the toilet seat section  400  is set as high temperature (for example, 38° C.) when the temperature adjustment switch  304  is pressed. 
     In addition, when the user does not use the heating function like summer season, the heating function of the toilet seat device  100  is turned off by pressing the warm, switch  301 . 
     Hereinafter, the temperature of the toilet seat section  400  that is set by the temperature adjustment switches  302  to  304  is referred to as toilet seat set temperature. 
     The plurality of LEDs  305  are disposed corresponding to the warm switch  301  and the plurality of temperature adjustment switches  302 ,  303 , and  304 , respectively. The plurality of LEDs  305  is turned on by pressing the warm switch  301  and the plurality of temperature adjustment switches  302 ,  303 , and  304 . 
     (3) Configuration of Toilet Seat Device 
       FIG. 3  is a schematic view illustrating a configuration of a toilet seat device  100  according to an embodiment of the invention. As described above, the toilet seat device  100  includes the main body section  200 , the remote control device  300 , the toilet seat section  400 , and the entry sensor  600 . 
     As shown in  FIG. 3 , the main body section  200  includes a control section  210 , a temperature measurement section  220 , a heater driving section  230 , a notice LED  280 , and a seat sensor  290 . 
     In addition, the toilet seat section  400  includes a lamp heater  480  and a thermistor  411 . The lamp heater  480  includes a rear lamp heater  481  and a front lamp heater  482 . 
     The control section  210  is formed of, for example, micro computers. The control section  210  includes: a judgment section for judging user&#39;s entry, temperature of the toilet seat section  400 , and the like; a timer section having a timer function; a memory section for storing various information, and A duty ratio switching circuit for controlling an operation of the heater driving section  230 . 
     The temperature measurement section  220  of the main body section  200  is connected to thermistor  411  of the toilet seat section  400 . With such a configuration, the temperature measurement section  220  measures the temperature of the toilet seat section  400  on the basis of a signal outputted from thermistor  411 . Hereinafter, the temperature of the toilet seat section  400  measured by the temperature measurement section  220  via thermistor  411  is referred to as a measured temperature value. 
     In addition, the heater driving section  230  of the main body section  200  is connected to the lamp heater  480  of the toilet seat section  400 . With such a configuration, the heater driving section  230  drives the lamp heater  480 . 
     In the embodiment, the toilet seat device  100  operates as follows. 
     First, an operation of initial setting will be described. A user presses the warm switch  301  ( FIG. 2 ) of the remote control device  300 , and thereby a signal for turning on the heating function is transmitted to the control section  210  of the main body section  200 . With such a configuration, the control section  210  controls the heater driving section  230 , and thereby the lamp heater  480  is driven. With such a configuration, the temperature of the toilet seat section  400  is adjusted so as to be at, for example, 18° C. The temperature at that time is referred to as standby temperature. 
     Here, a user presses any one of the temperature adjustment switches  302 ,  303 , and  304  ( FIG. 2 ) of the remote control device  300 , and thereby the toilet seat set temperature is transmitted to the control section  210 . The control section  210  stores the toilet seat set temperature information received from the remote control device  300  in the memory section. 
     For example, when the temperature adjustment switch  302  is pressed by a user, the toilet seat set temperature is set as 34° C. and is stored in the memory section. In addition, when the temperature adjustment switch  303  is pressed by a user, the toilet seat set temperature is set as 36° C. and is stored in the memory section. Further, when the temperature adjustment switch  304  is pressed by a user, the toilet seat set temperature is set as 38° C. and is stored in the memory section. 
     When a user enters the toilet, the entry sensor  600  senses user&#39;s entry. With such a configuration, a signal representing the user&#39;s entry is transmitted to the control section  210 . 
     Next, an operation at the time of general use will be described. The judgment section of the control section  210  judges user&#39;s entry into a toilet on the basis of the signal from the entry sensor  600 . Accordingly, the judgment section selects a specified heater control pattern for driving the lamp heater  480  on the basis of the measured temperature value of the toilet seat section  400  and a heater control table to be described later that is stored in the memory section. 
     The duty ratio switching circuit controls the operation of the heater driving section  230  on the basis of the selected heater control pattern and time information that is obtained by the timer section. 
     With such a configuration, the lamp heater  480  is driven by the heater driving section  230 , and the temperature of the toilet seat section  400  is instantly increased to the toilet seat set temperature. 
     Detailed description of the operation of control section  210 , the heater control pattern for driving the lamp heater  480 , and the heater control table will be given later. 
     (4) Details of Toilet Seat Section Structure 
     (4-a) Structure of Toilet Seat Section 
       FIGS. 4 to 7  are diagrams illustrating a detailed structure of the toilet seat section  400  in  FIG. 1 .  FIG. 4  is an exploded perspective view of the toilet seat section  400 .  FIG. 5  is a view of an upper toilet seat casing  410  as viewed from the lower side.  FIG. 6  is an enlarged sectional view of the upper toilet seat casing  410  taken along the line U-U in  FIG. 4 . 
     As shown in  FIG. 4 , the toilet seat section  400  includes the upper toilet seat casing  410  made of aluminum and a lower toilet seat casing  420  made of synthetic resin. 
     As shown in the portion drawn by the chain line, a part of upper face of the upper toilet seat casing  410  user&#39;s seating section  410 T. 
     As shown in  FIGS. 4 and 5 , two thermistors  411  are mounted on an area of the seating section  410 T in a lower face side of the upper toilet seat casing  410 . In addition, other two thermistors  412  are mounted on the other area. 
     In addition, only one thermistor  411  may be used as thermistor disposed on the area of the seating section  410 T. In addition, only one thermistor  412  may be used as thermistor disposed on the other area. 
     As shown in  FIG. 6 , the upper toilet seat casing  410  is manufactured by forming various layers on the upper and lower faces of aluminum layer  410   b  having excellent thermal conductivity. In addition, thermal conductivity of aluminum is about 237 W/n·K. 
     The lower face of the aluminum layer  410   b  is coated with black pigments including carbon and the like. With such a configuration, a radiation absorption layer  410   a  having a black color for efficiently absorbing radiation energy is formed on the lower face of the aluminum layer  410   b.    
     An alumite layer  410   c  and a surface coating layer  410   d  are sequentially formed on the upper face of the aluminum layer  410   b . By forming the alumite layer  410   c , corrosion resistance of the upper face of the aluminum layer  410   b  is improved. The surface coating layer  410   d  is formed by predetermined pigments and the like. 
     Thermistor  411  is mounted on the lower face of the aluminum layer  410   b  with the radiation absorption layer  410   a  interposed therebetween. Thermistor  411  detects temperature of the aluminum layer  410   b  via the radiation absorption layer  410   a.    
       FIG. 7  shows a view of the lower toilet seat casing  420  as viewed from the upper side. As shown in  FIGS. 4 and 7 , the radiation reflection plate  430  that is formed so as to follow the lower toilet seat casing  420  shape is mounted on the upper face side of the lower toilet seat casing  420 . The radiation reflection plate  430  is manufactured by making a surface of aluminum plate to be a mirror. 
     In addition, the lamp heater  480  is disposed on the upper face of the radiation reflection plate  430 . The lamp heater  480  is manufactured by connecting in series the rear lamp heater  481  with the front lamp heater  482  formed in a U shape. 
     In addition, on the upper face of the radiation reflection plate  430 , two thermostats  441  are mounted so as to be adjacent to predetermined places (two places) of the front lamp heater  482 , and two thermostats  442  are mounted so as to be adjacent to predetermined places (two places) of the rear lamp heater  481 . The all thermostats  441  and  442  are connected to the lamp heater  480  in series. 
     The upper toilet seat casing  410  in  FIG. 5  is conjugated with the lower toilet seat casing  420  in  FIG. 7  via seal material, and thus the toilet seat section  400  in  FIG. 1  is formed completely. With such a configuration, airtight space is formed in the upper toilet seat casing  410  and the lower toilet seat casing  420 . By using the seal material, water permeation into the upper toilet seat casing  410  and the lower toilet seat casing  420  is prevented. In this state, thermistors  411  mounted on the upper toilet seat casing  410  faces the front lamp heater  482 . 
     The rear lamp heater  481  and front lamp heater  482  is a halogen lamp heater formed of a glass tube, a filament, argon gas, and halogen gas. 
     In the rear lamp heater  481  and the front lamp heater  482 , the filament is disposed in the glass tube, and argon gas and halogen gas is sealed therein. 
     Rated electric powers of the rear lamp heater  481  and the front lamp heater  482  according to the embodiment are 500 W and 700 W, respectively. 
     (4-b) Drive of Lamp Heater 
     As described above, the rear lamp heater  481  and the front lamp heater  482  are connected to the heater driving section  230  in  FIG. 3 . When current is applied to the rear lamp heater  481  and the front lamp heater  482  by the heater driving section  230 , infrared rays are radiated from the lamp heaters. 
     The infrared rays radiated from the rear lamp heater  481  and the front lamp heater  482 , that is, radiation energy is directly incident on the lower face side of the upper toilet seat casing  410  or indirectly incident on upper toilet seat casing  410  by passing through the radiation reflection plate  430 . 
     As described above, the black-colored radiation absorption layer  410   a  ( FIG. 6 ) can efficiently absorb the radiation energy, and thus the radiation energy from the rear lamp heater  481  and the front lamp heater  482  is efficiently transmitted to the aluminum layer  410   b  ( FIG. 6 ). Accordingly, the aluminum layer  410   b  generates heat. 
     As described above, aluminum has high thermal conductivity, and thus the heat generated by the radiation energy is transmitted to the entire body of the upper toilet seat casing  410  in a short time. 
     (4-c) Function of Thermistors 
     In the upper toilet seat casing  410 , functions of thermistor  411  mounted on an area of the seating section  410 T and thermistor  412  mounted on the other area excluding the seating section  410 T will be described. 
     The seating section  410 T of the upper toilet seat casing  410  is disposed closer to the lamp heater  480  than the other parts. With such a configuration, heat is transmitted with relatively high responsiveness to the seating section  410 T of the upper toilet seat casing  410  at the time of driving the lamp heater  480 . 
     In addition, since the seating section  410 T is a part in contact with a human body in the upper toilet seat casing  410 , proper temperature management is needed. 
     Accordingly, thermistor  411  of the seating section  410 T is used for temperature adjustment at the time of driving the lamp heater  480 . 
     Meanwhile, thermistor  412  mounted on the other area excluding the seating section  410 T is used so as to prevent the upper toilet seat casing  410  from overheat when thermistor  411  is out of order. 
     (4-d) Function of Thermostats 
     In the lower toilet seat casing  420 , functions of two thermostats  441  mounted adjacent to the front lamp heater  482  and two thermostats  442  mounted adjacent to the rear lamp heater  481  will be described. 
     The two thermostats  441  of the front lamp heater  482  side are used in order to monitor temperature of the front lamp heater  482 . The two thermostats  441  are set so as to stop the current applied to the lamp heater  480  at, for example, 78° C. Accordingly, the two thermostats  441  have a function of a thermal fuse for stopping current at 78° C. 
     Meanwhile, the two thermostats  442  of the rear lamp heater  481  side are used in order to monitor environmental temperature around the rear lamp heater  481 . The two thermostats  442  are set so as to stop the current applied to the lamp heater  480  at, for example, 53° C. Accordingly, the two thermostats  442  serve as a thermal fuse for cutting off current at 53° C. 
     (5) Heater Control Table and Heater Control Pattern 
     Three heater control tables corresponding to three kinds of toilet seat set temperature (34° C., 36° C., and 38° C.) are stored in the control section  210  of the toilet seat device  100  according to the embodiment. 
       FIGS. 8 to 10  are diagrams illustrating examples of heater control tables corresponding to predetermined toilet seat set temperatures (34° C., 36° C., and 38° C.). The heater control tables as shown in  FIGS. 8 to 10  have a plurality of heater control patterns corresponding to measured temperature values of thermistor  411  ( FIG. 3 ) at the time of user&#39;s entry into a room, respectively. 
     A time schedule for driving the lamp heater  480  is set in the plurality of heater control patterns, respectively. In addition, a measured temperature value of thermistor  411  at the time of switching the electric power for driving the lamp heater  480  is set in each heater control pattern. Detailed description will be given later. 
     As described above, when the toilet seat set temperature is determined, the control section  210  selects one heater control table corresponding to the determined toilet seat set temperature. 
     In addition, when entry sensor  600  in  FIG. 3  senses user&#39;s entry, the control section  210  selects one heater control table among the heater control tables on the basis of the measured temperature value of thermistor  411 . With such a configuration, the lamp heater  480  is controlled to be driven on the basis of the selected heater control pattern. 
     For example, when the low toilet seat set temperature (34° C.) is set and the measured temperature value at the time of user&#39;s entry is 16° C. to 18° C., the control section  210  in  FIG. 3  performs 600 W drive to be described later for reducing inrush current for 0.2 seconds, on the basis of the heater control pattern corresponding to 16° C. to 18° C. in the heater control table in  FIG. 8 . 
     After that, the control section  210  performs 1200 W drive to be described later for 6 seconds, and continuously performs the 600 W drive to be described later for 2.1 seconds. 
     In the toilet seat device  100  according to the embodiment as described above, temperature of the toilet seat section  400  is adjusted at, for example, about 18° C. when the heating function is turned on. 
     In the heater control tables in  FIGS. 8 to 10 , there is assumed that the heating function is switched from OFF state into ON state. Accordingly, the heater control patterns corresponding to 0° C. to 16° C. are also set in the heater control tables in  FIGS. 8 to 10 . 
     That is, when a user turns on the heating function at room temperature 0° C., the control section  210  performs the 600 W drive for 16 seconds, for example, on the basis of the heater control pattern corresponding to 0° C. to 2° C. in the heater control table in  FIG. 8 . 
     (6) Drive of Lamp Heater 
     In the embodiment, a control operation of a drive of the lamp heater  480  is performed by changing the electric power for driving the lamp heater  480  mainly into three kinds. 
     For example, when temperature of the toilet seat section  400  is increased along a first temperature gradient, the heater driving section  230  in  FIG. 3  drives the lamp heater  480  with about electric power of 1200 W (1200 W drive). In addition, when temperature of the toilet seat section  400  is increased along a second temperature gradient slightly lower than the first temperature gradient, the heater driving section  230  drives the lamp heater  480  with about electric power of 600 W (600 W drive). Further, when temperature of the toilet seat section  400  is maintained at a constant level, the heater driving section  230  drives the lamp heater  480  with electric power of about 50 W (low electric power drive). The low electric power drive is defined to drive the lamp heater  480  with low electric power (for example, electric power in the range of 0 W to 50 W) that is sufficiently lower than the 1200 W drive and the 600 W drive. 
     A duty ratio switching circuit of the control section  210  performs a switching operation among the 1200 W drive, the 600 W drive and the low electric power drive by controlling current applied from the heater driving section  230  to the lamp heater  480 . 
     Alternating current is supplied from a power supply circuit not shown in the drawing to the heater driving section  230 . Accordingly, the heater driving section  230  makes the alternating current, which is supplied on the basis of a current control signal received from the duty ratio switching circuit, flow into the lamp heater  480 . 
     Each state where current is applied to the lamp heater  480  at the time of 1200 W drive, 600 W drive, and low electric power drive will be described with the current control signal of the duty ratio switching circuit. 
       FIG. 11(   a ) is a waveform diagram illustrating current that flows in the lamp heater  480  during the 1200 W drive, and  FIG. 11(   b ) is a waveform diagram illustrating the current control signal given to the heater driving section  230  from the duty ratio switching circuit during the 1200 W drive. 
     As shown in  FIG. 11(   b ), the current control signal at the time of the 1200 W drive is logic ‘1’ in any case. The heater driving section  230  makes the alternating current, which is supplied from the power supply circuit when the current control signal is logic ‘1’, flow in the lamp heater  480  (a thick-lined part in  FIG. 11(   a )). Accordingly, the alternating current flows in the lamp heater  480  in the range of entire cycle periods. As a result, the lamp heater  480  is driven by about electric power of 1200 W. 
       FIG. 12(   a ) is a waveform diagram illustrating current that flows in the lamp heater  480  during the 600 W drive, and  FIG. 12(   b ) is a waveform diagram illustrating the current control signal given to the heater driving section  230  from the duty ratio switching circuit during the 600 W drive. 
     As shown in  FIG. 12(   b ), the current control signal at the time of the 600 W drive is formed of pulses that has the same cycle as the alternating current supplied to the heater driving section  230 . Duty ratio of the pulses is set as 50%. 
     The heater driving section  230  makes the alternating current, which is supplied from the power supply circuit when the current control signal is logic ‘1’, flow in the lamp heater  480  (a thick-lined part in  FIG. 12(   a )). Accordingly, alternating current flows in the lamp heater  480  for half-cycle periods. As a result, the lamp heater  480  is driven by about electric power of 600 W. 
       FIG. 13(   a ) is a waveform diagram illustrating the current that flows in the lamp heater  480  during the low electric power drive, and  FIG. 13(   b ) is a waveform diagram illustrating the current control signal given to the heater driving section  230  from the duty ratio switching circuit during the low electric power drive. 
     As shown in  FIG. 13(   b ), the current control signal at the time of the 600 W drive is formed of pulses that has the same cycle as the alternating current supplied to the heater driving section  230 . Duty ratio of the pulses is set less than 50% (for example, about several %). 
     The heater driving section  230  makes the alternating current, which is supplied from the power supply circuit when the current control signal is logic ‘1’, flow in the lamp heater  480  (a thick-lined part in  FIG. 13(   a )). In each cycle, alternating current flows in the lamp heater  480  during period corresponding to the pulse width. As a result, the lamp heater  480  is driven by, for example, electric power of about 50 W. 
     When the temperature of the toilet seat section  400  is lowered by using the other methods or the heating function of the toilet seat device  100  is turned off, the duty ratio switching circuit does not send the current control signal to the heater driving section  230  (the current control signal is set as logic ‘0’). With such a configuration, the heater driving section  230  does not drive the lamp heater  480 . 
     Generally, when current supplied to electronics has harmonic components, noise occurs. In the embodiment as described above, when the 1200 W drive or the 600 W drive is performed on the lamp heater  480 , the current supplied to the lamp heater  480  varies along a sine curve, and thus it is possible to sufficiently reduce occurrence of noise even when current increases. 
     In addition, when the low electric power drive of the lamp heater  480  is performed, the current supplied to the lamp heater  480  has harmonic components, but the current is extremely small as compared with current of the 1200 W drive and the 600 W drive. Accordingly, it is possible to sufficiently reduce occurrence of noise. 
     In the embodiment as described above, the lamp heater  480  is driven with the electric powers having 1200 W, 600 W, and about 50 W, but the lamp heater  480  may be driven with electric power having different levels. 
     For example, when alternating current flows in the lamp heater  480  during half-cycle periods, a timing of the alternating current is set at intervals of a predetermined cycle such as two cycles or three cycles. With such a configuration, the lamp heater  480  can be driven by electric power having different level from 1200 W, 600 W, and, about 50 W while occurrence of noise is sufficiently prevented. 
     In the following description, duty ratio is defined as a ratio of time (which is a period of logic ‘1’ in the current control signal) in which the alternating current flows in the lamp heater  480  during one cycle of the alternating current. 
     In the embodiment, the control section  210  supplies current to the lamp heater  480  when the current control signal is logic ‘1’ and stops the current supply to the lamp heater  480  when the current control signal is logic ‘0’. However, the control section  210  may stop the current supply to the lamp heater  480  when the current control signal is logic ‘1’ and may supply the current to the lamp heater  480  when the current control signal is logic ‘0’. 
     (7) Method of Making Heater Control Table 
     (7-a) Inrush Current 
     In the toilet seat device  100  according to the embodiment, large current flows in the lamp heater  480  when the temperature of the toilet seat section  400  instantly increases. In this case, comparatively large inrush current occurs in the lamp heater  480 . 
     When the large inrush current occurs, a circuit breaker is operated by overcurrent, and voltage drop occurs in the electric power wiring to which the toilet seat device  100  is connected. 
     Accordingly, when making the heater control table, it is preferred that the plurality of heater control patterns be set so as to sufficiently reduce the inrush current. 
     In examples of  FIGS. 8 to 10 , when the 1200 W drive is performed on the lamp heater  480 , the heater control pattern is set so as to perform the 600 W drive just before the 1200 W drive. In  FIGS. 8 to 10 , the 600 W drive before the 1200 W drive is represented by 600 W drive for reducing inrush current. 
     (7-b) Overshoot 
     As described above, large current flows in the lamp heater  480  in order to instantly increase the temperature of the toilet seat section  400  by using the lamp heater  480 . Accordingly, overshoot occurs in temperature variance of the toilet seat section  400 . Hence, it is difficult to stabilize the temperature of the toilet seat section  400  at the toilet seat set temperature in a short time. 
     In the embodiment, when making the heater control table, the plurality of heater control patterns are set so as to sufficiently reduce the overshoot in the temperature variance of the toilet seat section  400 . 
     In the examples of the heater control table in  FIGS. 8 to 10 , in order to prevent the toilet seat section  400  from the overshoot in the temperature variance, the drive of the lamp heater  480  is set so as to be controlled by two steps when temperature of the toilet seat section  400  increases. 
     (7-c) Limit Temperature 
     In the toilet seat device  100  having a heating function, it is preferred to make a user not to feel that the seating section  410 T is cold. Hereinafter, the minimum temperature of the seating section  410 T that makes a user not to feel cold is referred to as limit temperature. 
     Accordingly, when a user enters a toilet room and sits on the seating section  410 T, it is preferred that at least the temperature of the seating section  410 T should have been higher than the limit temperature. 
     Therefore, when making the heater control table, the plurality of heater control patterns are set so as to sufficiently decrease the time while surface temperature of the seating section  410 T at the time of user&#39;s entry is increased to the limit temperature. In addition, the limit temperature was about 29° C. as the result of the experiment performed by the applicant. 
     In the examples of the heater control tables in  FIGS. 8 to 10 , since the temperature of the toilet seat section  400  is instantly increased to the limit temperature, the lamp heater  480  is set to perform the 1200 W drive when the measurement temperature at the time of user&#39;s entry is less than the limit temperature. 
     (7-d) Seating Section and Sensory Temperature 
     Temperature (sensory temperature) that a user feels at the time of sitting on the seating section  410 T is different from actual surface temperature of the seating section  410 T. 
     Generally, the sensory temperature felt when a human body comes in contact with a specified object varies in accordance with thermal conductivity of the object, thermal capacity difference between the human body and the object, and the like. 
     Accordingly, there is a case where difference occurs between the actual surface temperature of the seating section  410 T and the sensory temperature felt by a user sitting on the seating section  410 T. 
     In the embodiment, the seating section  410 T is made of aluminum that is excellent in thermal conductivity. 
     With such a configuration, for example, when the temperature of the seating section  410 T is lower than body temperature of a user, the body temperature of a user is transmitted to the seating section  410 T in a short time. Therefore, the sensory temperature of a user becomes lower than the actual temperature of the seating section  410 T. 
     Accordingly, when making the heater control table, the plurality of heater control patterns are set so that the sensory temperature at the time of user&#39;s seating is as close as possible to the toilet seat set temperature. 
     (7-e) Relationship Between Temperature of Lamp Heater and Surface Temperature of Seating Section 
     When temperature of the toilet seat section  400  increases, there is a large temperature difference between the surface temperature (temperature of a glass tube) of the lamp heater  480  and the actual surface temperature of the seating section  410 T. 
     Accordingly, in order to increase the surface temperature of the seating section  410 T to the toilet seat set temperature and stably maintain the temperature, it takes a predetermined time from the drive start time of the lamp heater  480 . 
     Therefore, the applicant performed the following test (a toilet seat temperature rise test) with respect to the time from when the drive of the lamp heater  480  starts until when the surface temperature of the seating section  410 T is stabilized at the toilet seat set temperature. 
     When room temperature of the toilet is about 25° C., the toilet seat set temperature was set by about 40° C. In this state, the lamp heater  480  was driven. Then, the time until when the surface temperature of the seating section  410 T is stabilized at about 40° C. was measured. As a result, the relationship shown in  FIG. 14  was obtained. 
       FIG. 14  is a diagram illustrating the relationship between the surface temperature of the seating section  410 T and the surface temperature of the lamp heater  480  at the time of the toilet seat temperature rise test. In  FIG. 14 , a vertical axis represents temperature, and a horizontal axis represents time. In addition, a thick solid line represents the surface temperature of the lamp heater  480  and a thick dotted line represents the surface temperature of the seating section  410 T. 
     As shown in  FIG. 14 , the lamp heater  480  is driven, and thus the surface temperature of the lamp heater  480  reaches 100° C. in about 10 seconds. Then, the surface temperature of the lamp heater  480  is constantly maintained at about 100° C. 
     Meanwhile, as the surface temperature of the lamp heater  480  varies, the surface temperature of the seating section  410 T slightly increases and reaches about 40° C. in about 10 seconds. Then, the surface temperature of the seating section  410 T is constantly maintained at about 45° C. 
     In this manner, for example, the difference between the surface temperature of the seating section  410 T and the toilet seat set temperature increases as time passes, and the difference is maintained at a substantially constant level after about 10 seconds. 
     That is, when the temperature is controlled in a shorter time than 10 seconds, it is difficult to control the current that flows in the lamp heater  480  in consideration of difference between the surface temperature of the lamp heater  480  and the surface temperature of the seating section  410 T. 
     Accordingly, when making the heater control tables, the plurality of heater control patterns are set in consideration of the electric power used in the drive of the lamp heater  480  and necessary time to stabilize temperature of the seating section  410 T at the toilet seat set temperature due to the electric power. 
     (7-f) Relationship Between Temperature Value Measured by Thermistor and Surface Temperature of Seating Section 
     When temperature of the toilet seat section  400  increases, temperature difference occurs between temperature value measured by thermistor  411  and actual surface temperature of the seating section  410 T in  FIG. 3 . 
     Therefore, the applicant performed the following test (a test for estimating the measured temperature value) with respect to relationship between the temperature value measured by thermistor  411  and the actual surface temperature of the seating section  410 T, when temperature of the toilet seat section  400  increases. 
     When room temperature of the toilet is 21° C., the toilet seat set temperature was set by about 38° C. In this state, the lamp heater  480  was driven during a predetermined time. Then, the time until when the measured temperature value and the surface temperature of the seating section  410 T had been stabilized at about 38° C. was measured. As a result, the relationship shown in  FIG. 15  was obtained. 
       FIG. 15  is a diagram illustrating the relationship between the surface temperature of the seating section  410 T and the temperature value measured by thermistor  411  at the time of the test for estimating the measured temperature value. In  FIG. 15 , a vertical axis represents temperature, and a horizontal axis represents time. In addition, a thick solid line represents the temperature value measured by thermistor  411  and a thick dotted line represents the surface temperature of the seating section  410 T. 
     As shown in  FIG. 15 , when the lamp heater  480  is driven and temperature of the toilet seat section  400  increases, the temperature difference occurs between the measured temperature value and the surface temperature of the seating section  410 T. 
     In an example in  FIG. 15 , after about 4 seconds from the drive start time of the lamp heater  480 , there is a temperature difference of about 2.5° C. between the measured temperature value and the surface temperature of the seating section  410 T. 
     In addition, not shown in the drawings, but when the test for estimating the measured temperature value was performed by using the other state, there was a temperature difference of about 6° C. as the maximum value between the measured temperature value and the surface temperature of the seating section  410 T. 
     That is, when temperature of the toilet seat section  400  increases, it is difficult to accurately control the drive of the lamp heater  480  on the basis of the temperature value measured by thermistor  411 . 
     Accordingly, when making the heater control tables, the plurality of heater control patterns are set in consideration of the electric power used in the drive of the lamp heater  480  and necessary time to stabilize temperature of the seating section  410 T at the toilet seat set temperature due to the electric power. 
     In addition, the heater control pattern may have the measured temperature value at the time of switching electric power for driving the lamp heater  480 . In this case, by performing a pre-test or a simulation, the relationship between the measured temperature value and the surface temperature of the seating section  410 T is examined. Then, the measured temperature value at the time of switching electric power is set. 
     In this manner, when the heater control pattern has information relating to the drive time of the lamp heater  480  and information relating to the measured temperature value, it is possible to more accurately control the drive the lamp heater  480  on the basis of the information. 
     In the examples in  FIGS. 8 to 10 , the measured temperature value (conversion temperature) at the time of switching from the 1200 W drive to the 600 W drive is set in addition to the time schedule relating to the drive of the lamp heater  480 . The conversion temperature corresponds to the limit temperature on the surface of the seating section  410 T. 
     In this case, the control section  210  performs the 1200 W drive on the lamp heater  480  in accordance with the time schedule when the measured temperature value is in the range of 16° C. to 28° C. at the time of user&#39;s entry, and the control section  210  judges whether the measured temperature value reaches the conversion temperature or not. 
     Accordingly, when the measured temperature value reaches the conversion temperature, the operation of switching from 1200 W drive to the 600 W drive is performed without regard to the time schedule. 
     In addition, in the examples of the heater control tables in  FIGS. 8 to 10 , the measured temperature value (target temperature) at the time of switching from the 600 W drive to the low electric power drive is set. The target temperature corresponds to the surface temperature of the seating section  410 T in a state of stopping the temperature rise and waiting user&#39;s seating. 
     In this case, the control section  210  performs the 600 W drive on the lamp heater  480  in accordance with the time schedule, and the control section  210  judges whether the measured temperature value reaches the target temperature or not. 
     Accordingly, when the measured temperature value reaches the target temperature, the operation of switching from 600 W drive to the low electric power drive is performed without regard to the time schedule. Therefore, the surface temperature of the seating section  410 T is maintained at a constant level. 
     (7-g) Prevention of Low Temperature Burn at the Time of Seating 
     When a human body keeps in contact with a heating source having slightly higher temperature than body temperature for a long time, there is a case where the contact portion of the human body suffers a low temperature burn. In the embodiment, when the toilet seat set temperature is higher than user&#39;s body temperature and a user keeps sitting on the toilet seat for a long time, there is a case where the user suffers a low temperature burn. 
     Accordingly, when making the heater control tables, it is preferred that the plurality of heater control patterns are set so as to gradually decrease the temperature of the seating section  410 T as time passes after user&#39;s seating. 
     In the heater control patterns of the heater control tables in  FIGS. 8 to 10 , time schedule after user seating is omitted. However, it is practically preferred that time schedule of the electric power for driving the lamp heater  480  is set so as to gradually decrease the surface temperature of the seating section  410 T after user&#39;s seating. 
     (8) Exemplary Drive of Lamp Heater Based on Heater Control Table 
       FIG. 16  is a diagram illustrating an exemplary drive of the lamp heater  480  based on the heater control table in  FIG. 10  and variance of the surface temperature in the seating section  410 T ( FIG. 4 ). 
       FIG. 16  shows a graph illustrating relationship between time and the surface temperature of the seating section  410 T and a graph illustrating relationship between time and duty ratio at the time of driving the lamp heater  480 . Horizontal axes of the two graphs are a common time axis. 
     In the example, there is assumed that a user previously turns on the heating function and sets high toilet seat set temperature (38° C.). 
     As described above, when room temperature is lower than the standby temperature of 18° C. like winter season, the control section  210  ( FIG. 3 ) adjusts the temperature of the toilet seat section  400  to 18° C. In this manner, during the standby period D 1  until the entry sensor  600  senses user&#39;s entry, the control section  210  performs the low electric power drive on the lamp heater  480  so as to maintain the surface temperature of the seating section  410 T at 18° C. 
     When the entry sensor  600  senses user&#39;s entry at time t 1 , the control section  210  performs the 600 W drive on the lamp heater  480  on the basis of the heater control table in  FIG. 10  during an inrush current reduction period D 2 . In addition, the 600 W drive is performed in order to sufficiently reduce the inrush current. In this case, the surface temperature of the seating section  410 T increases along slightly gentle second temperature gradient. 
     Then, the control section  210  starts the 1200 W drive of the lamp heater  480  at time t 2  after the elapse of inrush current reduction period D 2  and continuously performs the 1200 W drive on the lamp heater  480  during a first temperature rise period D 3 . In this case, the surface temperature of the seating section  410 T increases along the above-mentioned first temperature gradient. 
     Here, the surface temperature of the seating section  410 T rapidly increases. The 1200 W drive is performed on the lamp heater  480  until the surface temperature of the seating section  410 T reaches the limit temperature. In the graph illustrating the surface temperature of the seating section  410 T in  FIG. 16 , the limit temperature that is about 29° C. is represented by a chain line. While the 1200 W drive is performed on the lamp heater  480 , the temperature value measured at the time when the surface temperature of the seating section  410 T reaches the limit temperature is defined as a conversion temperature in  FIG. 10 . 
     Time t 3  when the surface temperature of the seating section  410 T reaches the limit temperature is defined as a shortest time selected between the time of 1200 W drive determined by the heater control tables and the time when the measured temperature value reaches the conversion temperature determined by the heater control tables. 
     In this manner, the surface temperature of the seating section  410 T is rapidly increased to the limit temperature by the 1200 W drive, in the first temperature rise period D 3 . With such a configuration, a user can comfortably sit on the toilet seat section  400  without cold feeling of the seating section  410 T, even when the above-mentioned notice LED  280  ( FIG. 1 ) is not turned on. 
     As described above, when the surface temperature of the seating section  410 T rapidly increases, overshoot occurs in temperature variance. However, in the embodiment, the 1200 W drive of the lamp heater  480  is switched into the 600 W drive thereof when the surface temperature of the seating section  410 T reaches the limit temperature. Accordingly, even when overshoot occurs in surface temperature variance of the seating section  410 T, the surface temperature does not exceed the toilet seat set temperature. As a result, a user does not feel hot temperature of the seating section  410 T when a user sits thereon. 
     Subsequently, the control section  210  starts the 600 W drive of the lamp heater  480  at the time t 3  after the elapse of first temperature rise period D 3  and continuously performs the 600 W drive on the lamp heater  480  during a second temperature rise period D 4 . In this case, the surface temperature of the seating section  410 T increases along the above-mentioned second temperature gradient. 
     The 600 W drive is performed on the lamp heater  480  until the surface temperature of the seating section  410 T reaches slightly higher temperature (40° C.) than the toilet seat set temperature. While the 600 W drive is performed on the lamp heater  480 , the temperature value measured at the time when the surface temperature of the seating section  410 T reaches the temperature slightly higher than the toilet seat set temperature is defined as a target temperature in  FIG. 10 . 
     Time t 4  when the surface temperature of the seating section  410 T reaches the temperature slightly higher than the toilet seat set temperature is defined as a shortest time selected between the time of 600 W drive determined by the heater control tables and the time when the measured temperature value reaches the target temperature determined by the heater control tables. 
     The second temperature gradient is lower than the first temperature gradient. Accordingly, occurrence of larger overshoot is prevented in the surface temperature variance of the seating section  410 T. 
     The control section  210  starts the low electric power drive of the lamp heater  480  at the time t 4  after the elapse of second temperature rise period D 4  and continuously performs the low electric power drive on the lamp heater  480  during a first maintenance period D 5 . As a result, the surface temperature of the seating section  410 T is constantly maintained at slightly higher temperature than the toilet seat set temperature. 
     In the example, the surface temperature of the seating section  410 T increases to the slightly higher temperature than the toilet seat set temperature that is set by a user, and the temperature is maintained until the time of user&#39;s seating. Accordingly, the user can feel the substantially same sensory temperature as the toilet seat set temperature that is previously set by the user himself at the time of seating. 
     When the seat sensor  290  senses user&#39;s seating on the toilet seat section  400  at time t 5 , the control section  210  decreases the duty ratio of the low electric power drive, and the control section  210  continuously performs the low electric power drive on the lamp heater  480  so that the surface temperature of the seating section  410 T decreases to the toilet seat set temperature during the first seating period D 6 . In the example, the first seating period D 6  is set as about two minutes. 
     The control section  210  further decreases the duty ratio of the low electric power drive at the time t 6  after the elapse of first seating period D 6 , and the control section  210  continuously performs the low electric power drive on the lamp heater  480  so that the surface temperature of the seating section  410 T decreases to slightly lower temperature (36° C.) than the toilet seat set temperature during a second seating period D 7 . In the example, the second seating period D 7  is set as about two minutes. 
     The control section  210  more further decreases the duty ratio of the low electric power drive at the time t 7  after the elapse of second seating period D 7 , and the control section  210  continuously performs the low electric power drive on the lamp heater  480  so that the surface temperature of the seating section  410 T is constantly maintained at the slightly lower temperature (36° C.) than the toilet seat set temperature during a second maintenance period D 8 . In the following description, the surface temperature of the seating section  410 T constantly maintained during the second maintenance period D 8 , that is, the temperature slightly lower than the toilet seat set temperature is referred to as a maintenance temperature. 
     In the example, after a user sits on the toilet seat section  400 , the control section  210  gradually decreases the surface temperature of the seating section  410 T. As a result, the user is prevented from suffering the low temperature burn. 
     When the seat sensor  290  senses user&#39;s leaving from the toilet seat section  400  at time t 8 , the control section  210  stops the drive of the lamp heater  480  during a stop period D 9 . Therefore, the surface temperature of the seating section  410 T decreases. 
     The control section  210  restarts the low electric power drive of the lamp heater  480  at time t 9  when the surface temperature of the seating section  410 T reaches 18° C., and maintains the low electric power drive of the lamp heater  480  during a standby period D 10  so as to constantly maintain the surface temperature of the seating section  410 T at 18° C. 
     In the second temperature rise period D 4 , the control section  210  performs the 600 W drive on the lamp heater  480 , but the control section  210  may gradually decrease the electric power for driving the lamp heater  480  along a parabola (see the thick dotted line part in the graph illustrating duty ratio). 
     In this case, as shown in the thick dotted line part in the graph illustrating the surface temperature of the seating section  410 T, the temperature gradient gradually becomes lower as the surface temperature of the seating section  410 T becomes closer to slightly higher temperature than the toilet seat set temperature. 
     When the temperature gradient gradually becomes gentle as described above, it is possible to sufficiently reduce overshoot caused by temperature variance of the seating section  410 T. 
     In the example, the surface temperature of the seating section  410 T is gradually decreased by adjusting the electric power for driving the lamp heater  480  after user&#39;s seating on the toilet seat section  400 , but the drive of the lamp heater  480  may be stopped at the time of user&#39;s seating on the toilet seat section  400 . In this case, the user is prevented from suffering the low temperature burn. 
     In addition, the surface temperature of the seating section  410 T is increased to the slightly higher temperature than the toilet seat set temperature, but the surface temperature of the seating section  410 T may be increased to the toilet seat set temperature. 
     (9) Operation of Control Section 
       FIGS. 17 to 22  are flowcharts illustrating an operation of the control section  210  in  FIG. 3 . Hereinafter, the operation of the control section  210  will be described with reference to the drawings. 
     First, the control section  210  performs the low electric power drive on the lamp heater  480  so that the surface temperature of the seating section  410 T reaches 18° C. (step S 101 ). Then, the control section  210  judges whether a user enters the toilet room or not by using the entry sensor  600  (step S 102 ). 
     When the user does not enter the toilet room, the control section  210  acquires the measured temperature value (step S 201 ), and judges whether the measured temperature value is not less than the standby temperature or not (step S 202 ). 
     When the measured temperature value is not less than the standby temperature, the control section  210  stops the low electric power drive of the lamp heater  480  (step S 203 ), and repeats the operations in the steps S 201  to S 203 . In addition, when the measured temperature value is less than the standby temperature, the control section  210  performs the step S 101  again. 
     The operations ( FIG. 17 ) of the steps S 101 , S 102 , and S 201  to S 203  correspond to the operations of the control section  210  during the standby periods D 1  and D 10  mentioned above. 
     In the step S 102 , when the user enters the toilet room, the control section  210  acquires the measured temperature value (step S 103 ), and selects one heater control pattern from the heater control tables stored in the memory section on the basis of the measured temperature value (step S 104 ). 
     Then, the control section  210  judges whether information relating to the 1200 W drive of the lamp heater  480  exists in the selected heater control pattern or not (step S 105 ). In addition, when the information relating to the 1200 W drive of the lamp heater  480  does not exist, the control section  210  judges whether information relating to the 600 W drive of the lamp heater  480  exists or not (step S 211 ). 
     In the step S 105 , when the information relating to the 1200 W drive of the lamp heater  480  exists, the control section  210  turns on a timer in a timer section included in the control section  210  (step S 111 ), and performs the 600 W drive on the lamp heater  480  in order to reduce inrush current (step S 112 ). Here, the control section  210  judges whether the time set on the basis of the selected heater control table elapses or not (step S 113 ). 
     The operations ( FIG. 18 ) of the steps S 111  to S 113  correspond to the operations of the control section  210  during the inrush current reduction period D 2  mentioned above. 
     In the step S 211 , the control section  210  performs an operation of a step S 121  to be described later when the information relating to the 600 W drive of the lamp heater  480  exists, and performs an operation of a step S 131  to be described later when the information relating to the 600 W drive of the lamp heater  480  does not exist. 
     In the step S 113 , when the set time elapses, the control section  210  resets the timer and turns on the timer again (step S 114 ), and the control section performs the 1200 W drive on the lamp heater  480  (step S 115 ). Here, the control section  210  judges whether the time set on the basis of the selected heater control table elapses or not (step S 116 ). 
     When the set time does not elapse, the control section  210  acquires the measured temperature value (step S 221 ), and judges whether the measured temperature value is not less than the conversion temperature or not (step S 222 ). 
     When the measured temperature value is less than the conversion temperature, the control section  210  repeats the operation of the step S 116 . 
     The operations ( FIG. 18 ) of the steps S 114  to S 116 , S 221 , and S 222  correspond to the operations of the control section  210  during the first temperature rise period D 3  mentioned above. 
     When the set time elapses in the step S 116  or the measured temperature value is not less than the conversion temperature in the step S 222 , the control section  210  resets the timer and turns on the timer again (step S 121 ), and the control section performs the 600 W drive on the lamp heater  480  (step S 122 ). Here, the control section  210  judges whether the time set on the basis of the selected heater control table elapses or not (step S 123 ). 
     When the set time does not elapse, the control section  210  acquires the measured temperature value (step S 231 ), and judges whether the measured temperature value is not less than the target temperature or not (step S 232 ). 
     When the measured temperature value is less than the target temperature, the control section  210  repeats the operation of the step S 123 . 
     The operations ( FIG. 19 ) of the steps S 121  to S 123 , S 231 , and S 232  correspond to the operations of the control section  210  during the second temperature rise period D 4  mentioned above. 
     When the set time elapses in the step S 123  or the measured temperature value is not less than the target temperature in the step S 232 , the control section  210  resets the timer, and judges whether a user sits on the toilet seat section  400  by using the seat sensor  290  (step S 131 ). 
     When the user does not sit, the control section  210  performs the low electric power drive on the lamp heater  480  (step S 241 ). Then, the control section  210  acquires the measured temperature value (step S 242 ), and judges whether the measured temperature value is not less than the target temperature or not (step S 243 ). 
     When the measured temperature value is not less than the target temperature, the control section  210  stops the low electric power drive of the lamp heater  480  (step S 244 ), and repeats the operation of the step S 243 . In addition, the control section  210  repeats the operation of the step S 131  when the measured temperature value is less than the target temperature. 
     The operations ( FIG. 20 ) of the steps S 131 , and S 241  to S 244  correspond to the operations of the control section  210  during the first maintenance period D 5  mentioned above. 
     When the user sits in the step S 131 , the control section  210  judges whether the user leaves the toilet seat section  400  or not by using the seat sensor  290  (step S 141 ). 
     Then, when the user leaves toilet seat section  400 , the control section  210  turns on the timer (step S 250   a ), and judges again whether the user sits on the toilet seat section  400  by using the seat sensor  290  (step S 250   b ). 
     When the user does not sit, the control section  210  judges whether 30 seconds elapse or not (step S 250   c ). When 30 seconds do not elapse, the control section  210  repeats the operation of the step S 250   b . Meanwhile, when 30 seconds elapse, the control section  210  stops the drive of the lamp heater  480  (step S 251 ), performs the operation of the step S 101 . 
     When the user sits on the toilet seat section  400  in the step S 250   b , the control section  210  performs the operation of the step S 241 . 
     In this manner, the control section  210  performs the operations of the steps S 250   a  to S 250   c , and thus a user can sits on the toilet seat section  400  again without a sense of incongruity even when the user instantly stands up from the toilet seat section  400 . 
     When the other user immediately sits on the seat after a first user leaves the toilet seat section  400 , the other user can sit on the toilet seat section  400  of which temperature is increased. 
     Meanwhile, when a user does not leave the toilet seat section  400  in the step S 141 , the control section  210  turns on the timer again (the step S 142 ), and performs the low electric power drive on the lamp heater  480  (step S 143 ). Here, the control section  210  judges whether two minutes elapse or not by using the timer (step S 144 ). 
     When the two minutes do not elapse, the control section  210  acquires the measured temperature value (step S 261 ), and judges whether the measured temperature value is not less than the toilet seat set temperature or not (step S 262 ). 
     When the measured temperature value is not less than the toilet seat set temperature, the control section  210  stops the low electric power drive of the lamp heater  480  (step S 263 ), and repeats the operation of the step S 262 . When the measured temperature value is less than the toilet seat set temperature, the control section  210  repeats the operation of the step S 144 . 
     The operations ( FIG. 21 ) of the steps S 141  to S 144  and S 261  to S 263  correspond to the operations of the control section  210  during the first seating period D 6  mentioned above. 
     When two minutes elapse in the step S 144 , the control section  210  judges whether a user leaves the toilet seat section  400  by using the seat sensor  290  (step  3151 ). 
     Then, when a user leaves the toilet seat section  400 , the control section  210  stops the drive of the lamp heater  480  (step S 271 ), and performs the operation of the step S 101 . 
     Then, when a user leaves the toilet seat section  400 , the control section  210  turns on the timer (step S 270   a ), and judges again whether the user sits on the toilet seat section  400  by using the seat sensor  290  (step S 270   b ). 
     When a user does not sit, the control section  210  judges whether 30 seconds elapse or not by using the timer (step S 270   c ). When 30 seconds do not elapse, the control section  210  repeats the operation of the step S 270   b . Meanwhile, when 30 seconds elapse, the control section  210  stops the drive of the lamp heater  480  (step S 251 ), and performs the operation of the step S 101 . 
     In addition, When the user sits on the toilet seat section  400  in the step S 270   b , the control section  210  performs the operation of the step S 241 . 
     In this manner, the control section  210  performs the operations of the steps S 270   a  to S 270   c , and thus a user can sits on the toilet seat section  400  again without a sense of incongruity even when the user instantly stands up from the toilet seat section  400 . 
     When the other user immediately sits on the seat after a first user leaves the toilet seat section  400 , the other user can sit on the toilet seat section  400  of which temperature is increased. 
     Meanwhile, when a user does not leave the toilet seat section  400  in the step S 151 , the control section  210  performs the low electric power drive on the lamp heater  480  (step S 152 ). Then, the control section  210  acquires the measured temperature value (step S 153 ), and judges whether the measured temperature value is not less than the maintenance temperature or not (step S 154 ). 
     When the measured temperature value is not less than the maintenance temperature, the control section  210  stops the low electric power drive of the lamp heater  480  (step S 155 ), and repeats the operation of the step S 154 . When the measured temperature value is less than the maintenance temperature, the control section  210  repeats the operation of the step S 151 . 
     The operations ( FIG. 22 ) of the steps S 151  to S 155  correspond to the operations of the control section  210  during the second seating period D 7  and the second maintenance period D 8  mentioned above. 
     In addition, operations that are the same as the steps S 142  to S 144  and S 261  to S 263  may be inserted between the step S 151  and the step S 152 . 
     The operations ( FIGS. 17 ,  21 , and  22 ) of the steps S 101 , S 102 , S 201  to S 203 , S 251 , and S 271  correspond to the operations of the control section  210  during the stop period D 9  mentioned above. 
     (10) Advantages 
     As described above, in the toilet seat device  100  according to the embodiment, it is not necessary to constantly maintain the temperature of the toilet seat section  400  at the toilet seat set temperature. Accordingly, in the standby periods D 1  and D 10  ( FIG. 16 ) while a user does not enter the toilet, it is possible to sufficiently decrease the current for driving the lamp heater  480 . 
     With such a configuration, even when the heating function of the toilet seat device  100  is turned on, the electric power consumption is sufficiently reduced. As a result, it is possible to save energy. 
     The applicant performed an experiment of electric power consumption (the electric power consumption for driving the lamp heater  480 ) in the toilet seat device that constantly maintains the surface temperature of the seating section  410 T at the toilet seat set temperature, where the amount of electric power consumption was about 125 W/h. On the contrary, the amount of the electric power consumption (the electric power consumption for driving the lamp heater  480 ) in the toilet seat device  100  according to the embodiment is decreased to about 42 W/h. 
     The control section  210  of the toilet seat device  100  performs the 1200 W drive on the lamp heater  480  thereby increasing the surface temperature of the seating section  410 T to the limit temperature in a short time. Then, the control section  210  performs the 600 W drive on the lamp heater  480  thereby increasing the surface temperature of the seating section  410 T along the temperature gradient slightly lower than that at the time of the 1200 W drive. 
     With such a configuration, the overshoot caused by temperature variance of the seating section  410 T is sufficiently reduced. As a result, the surface temperature of the seating section  410 T accurately increases in a short time, and stabilizes at the toilet seat set temperature. 
     (11) Other Exemplary Configuration 
     In the embodiment, the lamp heater  480  is used in order to increase the surface temperature of the seating section  410 T, but a heater having a electric heating coil may be used instead of the lamp heater  480  if the heater can instantly increase the surface temperature of the seating section  410 T. 
     The lamp heater  480  is driven with 1200 W, 600 W, and the electric power that is sufficiently lower than those of 1200 W drive and 600 W drive, but the electric power for driving the lamp heater  480  is not limited to them. The electric power for driving the lamp heater  480  may be set in accordance with the rated electric powers. 
     (12) Correspondence Relationship between Components of Claims and Embodiment 
     In the toilet seat device  100  and toilet apparatus  1000  according to the embodiment as described above, the toilet seat section  400  corresponds to the toilet seat section, the lamp heater  480  corresponds to the heating element, the entry sensor  600  corresponds to the a human body sensing section, the control section  210  and the heater driving section  230  correspond to the control section, the surface temperature of the seating section  410 T corresponds to the temperature of the toilet seat section, the limit temperature (29° C.) corresponds to the first temperature, the electric power of 1200 W corresponds to the first electric power, duration of the 1200 W drive set as a motor control pattern corresponds to the first time period, the toilet seat set temperature (34° C., 36° C. and 38° C.) corresponds to the second temperature, the electric power of 600 W corresponds to the second electric power, and duration of the 600 W drive set as the motor control pattern corresponds to the second time period. 
     Thermistor  411  and the temperature measurement section  220  corresponds to the toilet seat temperature measuring device, the heater control tables and the heater control patterns correspond to the temperature measured by the toilet seat temperature measuring device and the correspondence relationship between first and second time periods, the memory section included in the control section  210  corresponds to the memory section, the conversion temperature corresponds to the third temperature, the low electric power in the range of 0 to 50 W corresponds to the third electric power, the target temperature corresponds to the fourth temperature, and the seat sensor  290  corresponds to the seating sensing section. 
     Embodiment 2 
       FIG. 23  is a block diagram illustrating the toilet seat device according to Embodiment 2 of the invention.  FIG. 24  is a graph illustrating duty ratio of the heating source according to Embodiment 2 of the invention. 
     As shown in  FIG. 23 , there is provided: a heating source  2011  for warming the toilet seat  2010 ; human body sensing means  2012  for sensing a human body; and control means  2013  for controlling the heating source and the human body sensing means. 
     Hereinafter, operations and functions of the toilet seat device configured as described above will be described. 
     The heating source  2011  is built in the toilet seat  2010 , and warms the toilet seat  2010  by using the heating source  2011 . Human body sensing means  2012  detects whether a user is in the toilet or not, and outputs user&#39;s existence in the toilet as a signal to the control means  2013 . The control means  2013  includes micro computers and peripheral circuits, and controls electric power supply to the heating source  2011  on the basis of the output signal of the human body sensing means  2012 . 
     As shown in  FIG. 24 , when the human body sensing means  2012  senses a human body, the control means  2013  allows electric power to be supplied to the heating source  2011  that warms the toilet seat  2010  for constant time with a first duty ratio. After the constant time, control means  2013  controls the electric power supply operation so that temperature of the toilet seat  2010  reaches seatable temperature with a second duty ratio higher than the first duty ratio in a predetermined time. After the predetermined time elapses from the start time of applying current to the heating source  2011 , the electric power supply operation is performed with the duty ratio for maintaining temperature of the toilet seat  2010  at the set temperature. In addition, the seatable temperature is defined as the minimum temperature at which a user does not feel unpleasant when the user sits on the toilet seat  2010 . 
     Generally, it can be considered that current is applied to the heating source  2011  with the second duty ratio from the start time of applying the current, in order that temperature of the toilet seat  2010  reaches the seatable temperature as soon as possible. However, as described in the above-mentioned problems, resistance of the heating source  2011  is as very small as 1/10 the resistance at the time of rated electric power consumption when the heating source  2011  is cooled down (temperature corresponding to room temperature in the toilet), and thus large inrush current flows in the initial time period of applying current. In addition, when another product (particularly, the product having a heater formed therein) is used at the same time in the toilet, it is considered that larger current flows. Generally, since a house power wiring with respect to the toilet inside is not a large current wiring but a single power wiring, there are not usually provided a circuit breaker and an overcurrent breaker for dealing with the large current. In addition, generally, current is also applied to lighting apparatuses in the toilet from the same electric power wiring. For this reason, when current is applied to the heating source  2011  and heaters of the other products (for example, a hot water heater for heating washing water that washes a part of a human body) equipped in the toilet simultaneously, the circuit breaker is operated by overcurrent, and voltage drop is caused by resistance components of the house power wiring. Therefore, there are cases of: supply voltage drop to a toilet seat device, other products equipped in toilet, and lighting in toilet; product performance deterioration of toilet seat device or other products equipped in toilet; and brightness down of indoor lighting. 
     Generally, the resistance of the heating source  2011  reaches a rated resistance in a short time, and the inrush current is immediately suppressed. Thus, electric power is supplied to the heating source  2011  with the first duty ratio at the start time of applying current, and then the control operation is performed with the second duty ratio that is higher than the first duty ratio, thereby suppressing large inrush current. Therefore, there is no problem that the circuit breaker is operated by overcurrent, or voltage drop is caused by resistance components of the house power wiring. Thus, there is no supply voltage drop to a toilet seat device, other products equipped in toilet, and lighting in toilet, no product performance deterioration of toilet seat device or other products equipped in toilet, and no brightness down of indoor lighting. As a result, it is possible to provide a toilet seat device that is convenient for use and can save more energy. 
     In addition, since current is not unnecessarily applied to the heating source by switching to the minimum electric power that is necessary to maintain the toilet seat temperature at the seatable temperature, it is possible to achieve a toilet seat device that can save more energy. 
     Embodiment 3 
       FIG. 25  is a block diagram illustrating the toilet seat device according to Embodiment 3 of the invention. 
     As shown in  FIG. 25 , there is provided room temperature detecting means  2014  for detecting room temperature, and the control means  2013  determines a predetermined time for applying current to the heating source  2011  in accordance with the room temperature detected by the room temperature detecting means  2014 . 
       FIG. 26  is a graph illustrating variance of toilet seat temperature according to Embodiment 3 of the invention. 
     As shown in  FIG. 26 , since there is a difference in temperature of the toilet seat  2010  at the time immediately before a human body is sensed and current is applied to the heating source  2011 , in cases where the room temperature is high and low. Therefore, the time periods corresponding to the cases are also different until temperature of the toilet seat  2010  reaches the seatable temperature after current is applied to the heating source  2011 . For example, when the room temperature is low, the temperature of the toilet seat  2010  is also low, and speed of a rise in the temperature of the toilet seat  2010  is also low. Therefore, it is necessary to apply current to the heating source  2011  in a long time when the temperature of the toilet seat  2010  reaches the seatable temperature. However, when current is applied to the heating source  2011  in the same time period in the case of high room temperature, the temperature of the toilet seat  2010  exceeds the seatable temperature. Conversely, when the room temperature is high, the temperature of the toilet seat  2010  is also high, and speed of a rise in the temperature of the toilet seat  2010  is also high. Therefore, it is possible to apply current to the heating source  2011  in a short time when the temperature of the toilet seat  2010  reaches the seatable temperature. However, when current is applied to the heating source  2011  in the same time period in the case of low room temperature, the temperature of the toilet seat  2010  does not reach the seatable temperature. 
     Accordingly, the control means  2013  determines a predetermined time for applying current to the heating source  2011  in accordance with room temperature. Therefore, the temperature of the toilet seat  2010  reaches seatable temperature in a minimum time for necessary, and thus it is possible to provide a convenient toilet seat device. In addition, since current is not unnecessarily applied to the heating source  2011 , it is possible to achieve a toilet seat device that can save more energy. 
     Embodiment 4 
       FIG. 27  is a block diagram illustrating the toilet seat device according to Embodiment 4 of the invention. 
     As shown in  FIG. 27 , the toilet seat  2010  includes toilet seat temperature detecting means  2015  for detecting the temperature of the toilet seat  2010 , and the control means  2013  determines a predetermined time for applying current to the heating source  2011  in accordance with the toilet seat temperature detected by the toilet seat temperature detecting means  2015 . 
     Generally, when the heating source  2011  warms the toilet seat  2010  once, a certain time period is needed until the temperature of the toilet seat  2010  decreases in a case where a user stops supply of electric power to the heating source  2011  after use. In practical use, there are various time intervals whenever the toilet seat device is used in accordance with an installation environment, a time zone, and the like. For example, in the morning time zone of a family having four members, the toilet seat device is continuously used in the same time zone in order to go to school or work. In addition, when a toilet seat device is installed in public facilities and the like where people frequently come and go, the toilet seat device is continuously used. In these cases, since the time interval whenever the toilet seat device is used is very short, applying current to the heating source  2011  starts in a state where the temperature of the toilet seat  2010  is sufficiently high. Even in this case, current is unnecessarily applied when the predetermined time for applying current to the heating source  2011  is set as the same time, electric power is uselessly consumed. 
     Accordingly, the control means  2013  determines a predetermined time for applying current to the heating source  2011  in accordance with temperature of the toilet seat  2010 . Therefore, the temperature of the toilet seat  2010  reaches seatable temperature in a minimum time for necessary, and thus it is possible to provide a convenient toilet seat device. In addition, since current is not unnecessarily applied to the heating source  2011 , it is possible to achieve a toilet seat device that can save more energy. 
     In the embodiment, the toilet seat temperature detecting means  2015  is installed in the toilet seat, but the invention is not limited to this, and it is possible to obtain the same advantage when the means is located at a position such as the surface section of the toilet seat having high correlationship with the surface temperature of the toilet seat. 
     Embodiment 5 
       FIG. 28  is a block diagram illustrating the toilet seat device according to Embodiment 5 of the invention.  FIG. 29  is a graph illustrating duty ratio of the heating source  3011  according to Embodiment 5 of the invention. 
     As shown in  FIG. 28 , there are provided a heating source  3011  for warming the toilet seat  3010 , human body sensing means  3012  for sensing a human body, and control means  3014  for controlling the seating sensing means  3013  that detects user&#39;s seating. 
     Hereinafter, operations and functions of the toilet seat device configured as described above will be described. 
     The heating source  3011  is built in the toilet seat  3010 , and warms the toilet seat  3010  by using the heating source  3011 . Human body sensing means  3012  detects whether a user is in the toilet or not, and outputs user&#39;s existence in the toilet as a signal to the control means  3014 . The seating sensing means  3013  detects whether the user sits on the toilet seat device or not, and outputs user&#39;s seating/no-seating state as a signal to the control means  3014 . The control means  3014  includes micro computers and peripheral circuits, and controls electric power supply to the heating source  3011  on the basis of the output signals of the human body sensing means  3012  and the seating sensing means  3013 . 
     As shown in  FIG. 29 , when the human body sensing means  3012  senses a human body, the control means  3014  allows electric power to supply to the heating source  3011  that warms the toilet seat  3010  for constant time with a first duty ratio. After the constant time, control means  3014  controls the electric power supply operation so that temperature of the toilet seat  3010  reaches seatable temperature with a second duty ratio higher than the first duty ratio in a predetermined time. In addition, when the seating sensing means  3013  senses a human body&#39;s seating on the toilet seat  3010 , the control means  3014  controls the duty ratio of the heating source  3011  as a third duty ratio lower than the second duty ratio. After the predetermined time elapses from the start time of applying current to the heating source  3011 , the electric power supply operation is performed with the duty ratio for maintaining temperature of the toilet seat  3010  at the set temperature. In addition, the seatable temperature is defined as the minimum temperature at which a user can not feel unpleasant when the user sits on the toilet seat  3010 . 
     Generally, it can be considered that current is applied to the heating source  3011  with the second duty ratio from the start time of applying the current, in order that temperature of the toilet seat  3010  reaches the seatable temperature as soon as possible. However, as described in the above-mentioned problems, resistance of the heating source  3011  is as very small as 1/10 the resistance at the time of rated electric power consumption when the heating source  3011  is cooled down (temperature corresponding to room temperature in the toilet), and thus large inrush current flows in the initial time period of applying current. In addition, when another product (particularly, the product having a heater formed therein) is used at the same time in the toilet, it is considered that larger current flows. Generally, since a house power wiring with respect to the toilet inside is not a large current wiring but a single power wiring, there are not usually provided a circuit breaker and an overcurrent breaker for dealing with the large current. In addition, generally, current is also applied to lighting apparatuses in the toilet from the same electric power wiring. For this reason, when current is applied to the heating source  3011  and heaters of the other products (for example, a hot water heater for heating washing water that washes a part of a human body) equipped in the toilet simultaneously, the circuit breaker is operated by overcurrent, and voltage drop is caused by resistance components of the house power wiring. Therefore, there are cases of: supply voltage drop to a toilet seat device, other products equipped in toilet, and lighting in toilet; product performance deterioration of toilet seat device or other products equipped in toilet; and brightness down of indoor lighting. 
     Generally, the resistance of the heating source  3011  reaches a rated resistance in a short time, and the inrush current is immediately suppressed. Thus, electric power is supplied to the heating source  3011  with the first duty ratio at the start time of applying current, and then the control operation is performed with the second duty ratio that is higher than the first duty ratio, thereby suppressing large inrush current. Therefore, there is no problem that the circuit breaker is operated by overcurrent, or voltage drop is caused by resistance components of the house power wiring. Thus, there is no supply voltage drop to a toilet seat device, other products equipped in toilet, and lighting in toilet, no product performance deterioration of toilet seat device or other products equipped in toilet, and no brightness down of indoor lighting. As a result, it is possible to provide a toilet seat device that is convenient for use and can save more energy. 
     In addition, the surface states of the toilet seat  3010  of the time when a human body sits on the toilet seat  3010  and a human body does not sit thereon are different, and thus there is a difference in temperature of the toilet seat  3010 . In addition, the toilet seat  3010  is covered by the human body when a human body is sitting on the toilet seat  3010 , so that heat retaining property increases and body temperature warms the toilet seat, and thus the surface temperature of the toilet seat  3010  is warm as compared with the time when a human body does not sit thereon. 
     In the control means  3014 , when the seating sensing means  3013  senses user&#39;s seating, electric power is supplied to the heating source  3011  with the third duty ratio lower than the second duty ratio, thereby suppressing useless electric power. Therefore, it is possible to provide a toilet seat device that is convenient for use and can save more energy. 
     Embodiment 6 
       FIG. 30  is a block diagram illustrating the toilet seat device according to Embodiment 6 of the invention.  FIG. 31  is a graph illustrating variance of the toilet seat temperature according to Embodiment 6 of the invention. 
     As shown in  FIG. 30 , there is provided room temperature detecting means  3015  for detecting room temperature, and the control means  3014  determines a predetermined time for applying current to the heating source  3011  in accordance with the room temperature detected by the room temperature detecting means  3015 . 
     As shown in  FIG. 31 , since there is a difference in temperature of the toilet seat  3010  at the time immediately before a human body is sensed and current is applied to the heating source  3011 , in cases where the room temperature is high and low. Therefore, the time periods corresponding to the cases are also different until temperature of the toilet seat  3010  reaches the seatable temperature after current is applied to the heating source  3011 . For example, when the room temperature is low, the temperature of the toilet seat  3010  is also low, and speed of a rise in the temperature of the toilet seat  3010  is also low. Therefore, it is necessary to apply current to the heating source  3011  in a long time when the temperature of the toilet seat  3010  reaches the seatable temperature. However, when current is applied to the heating source  3011  in the same time period in the case of high room temperature, the temperature of the toilet seat  3010  exceeds the seatable temperature. Conversely, when the room temperature is high, the temperature of the toilet seat  3010  is also high, and speed of a rise in the temperature of the toilet seat  3010  is also high. Therefore, it is possible to apply current to the heating source  3011  in a short time when the temperature of the toilet seat  3010  reaches the seatable temperature. However, when current is applied to the heating source  3011  in the same time period in the case of low room temperature, the temperature of the toilet seat  3010  does not reach the seatable temperature. 
     Accordingly, the control means  3014  determines a predetermined time for applying current to the heating source  3011  in accordance with room temperature. Therefore, the temperature of the toilet seat  3010  reaches seatable temperature in a minimum time for necessary, and thus it is possible to provide a convenient toilet seat device. In addition, since current is not unnecessarily applied to the heating source  3011 , it is possible to achieve a toilet seat device that can save more energy. 
     Embodiment 7 
       FIG. 32  is a block diagram illustrating the toilet seat device according to Embodiment 7 of the invention. 
     As shown in  FIG. 32 , there is provided toilet seat temperature detecting means  3016  for detecting the temperature of the toilet seat  3010 , and the control means  3014  determines a predetermined time for applying current to the heating source  3011  in accordance with the toilet seat temperature detected by the toilet seat temperature detecting means  3016 . 
     Generally, when the heating source  3011  warms the toilet seat  3010  once, a certain time period is needed until the temperature of the toilet seat  3010  decreases in a case where a user stops supply of electric power to the heating source  3011  after use. In practical use, there are various time intervals whenever the toilet seat device is used in accordance with an installation environment, a time zone, and the like. For example, in the morning time zone of a family having four members, the toilet seat device is continuously used in the same time zone in order to go to school or work. In addition, when a toilet seat device is installed in public facilities and the like where people frequently come and go, the toilet seat device is continuously used. In these cases, since the time interval whenever the toilet seat device is used is very short, applying current to the heating source  3011  starts in a state where the temperature of the toilet seat  3010  is sufficiently high. Even in this case, current is unnecessarily applied when the predetermined time for applying current to the heating source  3011  is set as the same time, electric power is uselessly consumed. 
     Accordingly, the control means  3014  determines a predetermined time for applying current to the heating source  3011  in accordance with temperature of the toilet seat  3010 . Therefore, the temperature of the toilet seat  3010  reaches seatable temperature in a minimum time for necessary, and thus it is possible to provide a convenient toilet seat device. In addition, since current is not unnecessarily applied to the heating source  3011 , it is possible to achieve a toilet seat device that can save more energy. 
     In the embodiment, the toilet seat temperature detecting means  3016  is installed in the toilet seat, but the invention is not limited to this, and it is possible to obtain the same advantage when the means is located at a position such as the surface section of the toilet seat having high correlationship with the surface temperature of the toilet seat. 
     Embodiment 8 
       FIG. 33  is a block diagram illustrating the toilet seat device according to Embodiment 8 of the invention.  FIG. 34  is a graph illustrating duty ratio of the heating source according to Embodiment 8 of the invention. 
     As shown in  FIG. 33 , there is provided: a heating source  4011  for warming the toilet seat  4010 ; human body sensing means  4012  for sensing a human body; and control means  4013  for controlling the heating source and the human body sensing means. 
     Hereinafter, operations and functions of the toilet seat device configured as described above will be described. 
     The heating source  4011  is built in the toilet seat  4010 , and warms the toilet seat  4010  by using the heating source  4011 . Human body sensing means  4012  detects whether a user is in the toilet or not, and outputs user&#39;s existence in the toilet as a signal to the control means  4013 . The control means  4013  includes micro computers and peripheral circuits, and controls electric power supply to the heating source  4011  on the basis of the output signal of the human body sensing means  4012 . 
     As shown in  FIG. 34 , when the human body sensing means  4012  senses a human body, the control means  4013  stepwise increases the electric power for supplying to the heating source  4011 , which warms the toilet seat  4010 , by using a plurality of duty ratios, and allows the electric power to be supplied for constant time. After the constant time, the control means  4013  controls the electric power supply operation so that temperature of the toilet seat  4010  reaches seatable temperature with a constant duty ratio higher than the plurality of duty ratios in a predetermined time. After the predetermined time elapses from the start time of applying current to the heating source  4011 , the electric power supply operation is performed with the duty ratio for maintaining temperature of the toilet seat  4010  at the set temperature. In addition, the seatable temperature is defined as the minimum temperature at which a user can not feel unpleasant when the user sits on the toilet seat  4010 . 
     Generally, it can be considered that current is applied to the heating source  4011  with the constant duty ratio from the start time of applying the current, in order that temperature of the toilet seat  4010  reaches the seatable temperature as soon as possible. However, as described in the above-mentioned problems, resistance of the heating source  4011  is as very small as 1/10 the resistance at the time of rated electric power consumption when the heating source  4011  is cooled down (temperature corresponding to room temperature in the toilet), and thus large inrush current flows in the initial time period of applying current. In addition, when another product (particularly, the product having a heater formed therein) is used at the same time in the toilet, it is considered that larger current flows. Generally, since a house power wiring with respect to the toilet inside is not a large current wiring but a single power wiring, there are not usually provided a circuit breaker and an overcurrent breaker for dealing with the large current. In addition, generally, current is also applied to lighting apparatuses in the toilet from the same electric power wiring. For this reason, when current is applied to the heating source  4011  and heaters of the other products (for example, a hot water heater for heating washing water that washes a part of a human body) equipped in the toilet simultaneously, the circuit breaker is operated by overcurrent, and voltage drop is caused by resistance components of the house power wiring. Therefore, there are cases of; supply voltage drop to a toilet seat device, other products equipped in toilet, and lighting in toilet; product performance deterioration of toilet seat device or other products equipped in toilet; and brightness down of indoor lighting. 
     Generally, the resistance of the heating source  4011  reaches a rated resistance in a short time, and the inrush current is immediately suppressed. Thus, electric power is supplied to the heating source  4011  with the plurality of duty ratios at the start time of applying current, and then the control operation is performed with the constant duty ratio that is higher than plurality of duty ratios, thereby suppressing large inrush current. Therefore, there is no problem that the circuit breaker is operated by overcurrent, or voltage drop is caused by resistance components of the house power wiring. Thus, there is no supply voltage drop to a toilet seat device, other products equipped in toilet, and lighting in toilet, no product performance deterioration of toilet seat device or other products equipped in toilet, and no brightness down of indoor lighting. As a result, it is possible to provide a toilet seat device that is convenient for use and can save more energy. 
     In addition, since current is not unnecessarily applied to the heating source by switching to a retentive duty ratio of the minimum electric power that is necessary to maintain the toilet seat temperature at the seatable temperature, it is possible to achieve a toilet seat device that can save more energy. 
     In the embodiment, the control operation is performed so that current is applied while the plurality of duty ratios are stepwise increased, but the invention is not limited to this. Accordingly, it is also possible to suddenly decrease the duty ratio in the process of an increase of the duty ratio or to extend the time period during applying current with the constant duty ratio. By performing the control operation mentioned above, it is possible to prevent the toilet seat from overheat. 
     Embodiment 9 
       FIG. 35  is a graph illustrating duty ratio of the heating source  4011  according to Embodiment 9 of the invention. 
     The embodiment is different from Embodiment 8 in view point of the following description. As shown in FIG.  35 , when the human body sensing means  4012  senses a human body, the control means  4013  continuously increases duty ratio of the electric power for supplying to the heating source  4011  that warms the toilet seat  4010 , and simultaneously allows the electric power to be supplied for constant time. After the constant time, the control means  4013  controls the electric power supply operation so that temperature of the toilet seat  4010  reaches seatable temperature with a constant duty ratio higher than the continuously increased duty ratio in a predetermined time. 
     As described above, resistance of the heating source  4011  is as very small as 1/10 the resistance at the time of rated electric power consumption when the heating source  4011  is cooled down (temperature corresponding to room temperature in the toilet), and thus large inrush current flows in the initial time period of applying current. However, the own temperature of the heating source  4011  is increased by heat generation of the heating source  4011  when current is applied to the heating source  4011 . The resistance of the heating source  4011  gradually increases, thereby suppressing inrush current in accordance with resistance variance of the heating source  4011 . 
     Accordingly, when the human body sensing means  4012  senses a human body, the control means  4013  continuously increases duty ratio of the electric power for supplying to the heating source  4011  that warms the toilet seat  4010 . Therefore, the temperature of the toilet seat  4010  reaches seatable temperature in a minimum time for necessary, and thus it is possible to provide a convenient toilet seat device. In addition, since current is not unnecessarily applied to the heating source  4011 , it is possible to achieve a toilet seat device that can save more energy. 
     Embodiment 10 
       FIG. 36  is a block diagram illustrating the toilet seat device according to Embodiment 10 of the invention.  FIG. 37  is a graph illustrating variance of the toilet seat temperature according to Embodiment 10 of the invention. 
     As shown in  FIG. 36 , there is provided room temperature detecting means  4014  for detecting room temperature, and the control means  4013  determines a predetermined time for applying current to the heating source  4011  in accordance with the room temperature detected by the room temperature detecting means  4015 . 
     As shown in  FIG. 37 , since there is a difference in temperature of the toilet seat  4010  at the time immediately before a human body is sensed and current is applied to the heating source  4011 , in cases where the room temperature is high and low. Therefore, the time periods corresponding to the cases are also different until temperature of the toilet seat  4010  reaches the seatable temperature after current is applied to the heating source  4011 . For example, when the room temperature is low, the temperature of the toilet seat  4010  is also low, and speed of a rise in the temperature of the toilet seat  4010  is also low. Therefore, it is necessary to apply current to the heating source  4011  in a long time when the temperature of the toilet seat  4010  reaches the seatable temperature. However, when current is applied to the heating source  4011  in the same time period in the case of high room temperature, the temperature of the toilet seat  4010  exceeds the seatable temperature. Conversely, when the room temperature is high, the temperature of the toilet seat  4010  is also high, and speed of a rise in the temperature of the toilet seat  4010  is also high. Therefore, it is possible to apply current to the heating source  4011  in a short time when the temperature of the toilet seat  4010  reaches the seatable temperature. However, when current is applied to the heating source  4011  in the same time period in the case of low room temperature, the temperature of the toilet seat  4010  does not reach the seatable temperature. 
     Accordingly, the control means  4013  determines a predetermined time for applying current to the heating source  4011  in accordance with room temperature. Therefore, the temperature of the toilet seat  4010  reaches seatable temperature in a minimum time for necessary, and thus it is possible to provide a convenient toilet seat device. In addition, since current is not unnecessarily applied to the heating source  4011 , it is possible to achieve a toilet seat device that can save more energy. 
     Embodiment 11 
       FIG. 38  is a block diagram illustrating the toilet seat device according to Embodiment 11 of the invention. 
     As shown in  FIG. 38 , there is provided toilet seat temperature detecting means  4015  for detecting the temperature of the toilet seat  4010 , and the control means  4013  determines a predetermined time for applying current to the heating source  4011  in accordance with the toilet seat temperature detected by the toilet seat temperature detecting means  4015 . 
     Generally, when the heating source  4011  warms the toilet seat  4010  once, a certain time period is needed until the temperature of the toilet seat  4010  decreases in a case where a user stops supply of electric power to the heating source  4011  after use. In practical use, there are various time intervals whenever the toilet seat device is used in accordance with an installation environment, a time zone, and the like. For example, in the morning time zone of a family having four members, the toilet seat device is continuously used in the same time zone in order to go to school or work. In addition, when a toilet seat device is installed in public facilities and the like where people frequently come and go, the toilet seat device is continuously used. In these cases, since the time interval whenever the toilet seat device is used is very short, applying current to the heating source  4011  starts in a state where the temperature of the toilet seat  4010  is sufficiently high. Even in this case, current is unnecessarily applied when the predetermined time for applying current to the heating source  4011  is set as the same time, electric power is uselessly consumed. 
     Accordingly, the control means  4013  determines a predetermined time for applying current to the heating source  4011  in accordance with temperature of the toilet seat  4010 . Therefore, the temperature of the toilet seat  4010  reaches seatable temperature in a minimum time for necessary, and thus it is possible to provide a convenient toilet seat device. In addition, since current is not unnecessarily applied to the heating source  4011 , it is possible to achieve a toilet seat device that can save more energy. 
     In the embodiment, the toilet seat temperature detecting means  4015  is installed in the toilet seat, but the invention is not limited to this, and it is possible to obtain the same advantage when the means is located at a position such as the surface section of the toilet seat having high correlationship with the surface temperature of the toilet seat. 
     The invention has been described in detail with reference to specific embodiments, but, as might be expected, it is possible to add various modification and amendment without departing from spirit and gist of the invention. This application claims the benefit of priority under Japanese Patent Application No. 2005-189419 filed on Jun. 29, 2005, Japanese Patent Application No. 2005-189420 filed on Jun. 29, 2005, Japanese Patent Application No. 2005-189421 filed on June 2005, and Japanese Patent Application No. 2005-240311 filed on Aug. 22, 2005, which are hereby incorporated by reference in its entirety. 
     Industrial Applicability 
     The invention is useful as a heating device that is in contact with a human body. In addition, the invention can be used for applications such as other heating apparatuses since it is possible to control a heating source capable of saving more energy.