Seat heater

#This application is a 371 application of PCT/JP2010/006795 having an international filing date of Nov. 19, 2010, which claims priority to JP2009-282513 filed Dec. 14, 2009, the entire contents of which are incorporated herein by reference.

#The present invention relates to a heater embedded in a seat such as, for example, an automotive seat to heat the seat.

#In a conventional seat heater, a planar heater includes an electric heating wire disposed on a base material over an entire surface thereof so as to wind therethrough at predetermined intervals. The planar heater is interposed between a skin and a main pad of both a seat cushion and a seat back of the seat. When the electric heating wire is energized, the heater generates heat to make a seat occupant warm and comfortable even in a cold season (see, for example, Patent Document 1).

#FIG. 1 is a schematic view showing a construction of a seat heater according to a first embodiment of the present invention.

#FIG. 2 is a perspective view of an automotive seat having the seat heater of FIG. 1 embedded therein.

#FIG. 3 is a schematic view showing a fluctuation control executed by a controller shown in FIG. 1.

#The seat heater according to the present invention includes: a first heat generator embedded in a seat; a second heat generator embedded in the seat at a location different from the first heat generator; and a controller operable to execute a fluctuation control in which a first set temperature of the first heat generator and a second set temperature of the second heat generator are increased or decreased in each of a plurality of predetermined time periods; wherein the controller sets the first set temperature to be higher than the second set temperature in one of the time periods and sets the second set temperature to be higher than the first set temperature in another of the time periods.

#In this invention, for example, the first heat generator is placed so as to be brought into contact with seat-occupant's sites that are effective in terms of a sensible temperature, and the controller sets the first set temperature and the second set temperature in a manner as described above. Accordingly, a set temperature of the heater can be dropped as a whole without dropping the sensible temperature of the seat occupant, thus resulting in a reduction in electric power consumption and making it possible to provide a seat heater capable of achieving energy saving while keeping comfort.

#The first heat generator and the second heat generator are placed at different locations of the seat depending on properties of seat-occupant's sites. By way of example, the first heat generator is placed so as to be brought into contact with at least one of thighs, a central portion of a hip, a central portion of a waist, a central portion of a back, and shoulders of the seat occupant. In general, a human body includes sites that are quick to sense warmth and show a high heating effect in response to heat supply and also includes sites that are slow to sense warmth and accordingly insensitive to warmth, but can enhance comfort when heated. By making use of the properties of the sites of the human body and bringing the first heat generator and the second heat generator into contact with those sites of the human body that are effective in body sense, more efficient heating can be conducted.