HEATER DEVICE

A heater device includes a heat generating part that generates heat by energization, and a detection unit. The detection unit detects whether or not a distance between an object around the heat generating part and the heat generating part is equal to or less than a first detection distance with a first detection sensitivity, and whether or not the distance between the object around the heat generating part and the heat generating part is equal to or less than a second detection distance shorter than the first detection distance with a second detection sensitivity that is less sensitive than the first detection sensitivity.

TECHNICAL FIELD

The present disclosure relates to a heater device.

BACKGROUND

A device has a heat generating part that generates heat when energized, a plurality of electrodes for detecting a change in capacitance due to an object around the heat generating part, a proximity detection unit for detecting a proximity of the object based on a change in capacitance between the plurality of electrodes, and an energization control unit for controlling energization to the heat generating part based on the proximity of the object detected by the proximity detection unit.

SUMMARY

An object of the present disclosure is to enable more accurate detection of the proximity of the object around the heat generating part even if the capacitance between electrodes changes due to the external factor.

According to one aspect of the present disclosure, the heater device includes a heat generating part that generates heat by energization, and a detection unit. The detection unit detects whether or not a distance between an object around the heat generating part and the heat generating part is equal to or less than a first detection distance with a first detection sensitivity, and whether or not the distance between the object around the heat generating part and the heat generating part is equal to or less than a second detection distance shorter than the first detection distance with a second detection sensitivity that is less sensitive than the first detection sensitivity.

A reference numeral in parentheses attached to each component or the like indicates an example of correspondence between the component or the like and specific component or the like described in an embodiments below.

DETAILED DESCRIPTION

In an assumable example, a device has a heat generating part that generates heat when energized, a plurality of electrodes for detecting a change in capacitance due to an object around the heat generating part, a proximity detection unit for detecting a proximity of the object based on a change in capacitance between the plurality of electrodes, and an energization control unit for controlling energization to the heat generating part based on the proximity of the object detected by the proximity detection unit.

In the device, the capacitance between a plurality of electrodes changes depending on the energization of the heat generating part. According to a study, it was found that the capacitance between the plurality of electrodes also changes due to the heat shrinkage of each electrode due to the heat generation of the heat generating part. Further, according to the study, if the capacitance between the electrodes changes due to such an external factor, the proximity of the object may not be detected.

An object of the present disclosure is to enable more accurate detection of the proximity of the object around the heat generating part even if the capacitance between electrodes changes due to the external factor.

According to one aspect of the present disclosure, the heater device includes a heat generating part that generates heat by energization, and a detection unit. The detection unit detects whether or not a distance between an object around the heat generating part and the heat generating part is equal to or less than a first detection distance with a first detection sensitivity, and whether or not the distance between the object around the heat generating part and the heat generating part is equal to or less than a second detection distance shorter than the first detection distance with a second detection sensitivity that is less sensitive than the first detection sensitivity.

Therefore, even if the capacitance between the electrodes changes due to an external factor, the proximity of the object around the heat generating part can be detected more accurately.

Hereinafter, embodiments will be described with reference to the drawings. In the respective embodiments described herein, identical or equivalent parts are given identical reference numerals in the figures.

First Embodiment

A heater device of a first embodiment will be described with reference toFIGS. 1 to 8. As shown inFIG. 1, a heater device20is installed in an interior of a moving body such as a road traveling vehicle. The heater device20constitutes a part of the heating device for the interior. The heater device20is an electric heater that is supplied with a power from a power supply such as a battery and a generator mounted on the moving body to generate heat. The heater device20has a thin plate-shape. The heater device20generates heat when power is supplied. As shown inFIG. 2, the heater device20has a heat generating surface24athat radiates a radiant heat H primarily in a direction perpendicular to a surface of the heater device20to warm a target object positioned in the direction perpendicular to the surface. It can be called a plan heater.

A seat11on which an occupant12is seated is installed in the interior. The heater device20is installed in the interior to radiate the radiant heat H to feet of the occupant12. The heater device20can be used for quickly providing warmth to the occupant12immediately after activating other heater devices, for example. The heater device20is installed on a wall surface of the interior. The heater device20is arranged to face the occupant12who is in an assumed normal posture. The road traveling vehicle has a steering column13for supporting a steering column14. The heater device20is installed on a lower surface of the steering column14and a lower surface of an instrument panel cover15so as to face the occupant12.

Next, the configuration of the heater device20will be described. As shown inFIGS. 3 and 4, the heater device20includes a first receiving electrode21, a second receiving electrode22, a transmitting electrode23, a heat generating part24, an insulation base member25, a cover member26, a detection unit28, and a control unit29. InFIG. 3, the cover member26is omitted. Further, inFIG. 3, for clarity of illustration, the first receiving electrode21is shown by line hatching and the second receiving electrode22is shown by point hatching. Further, the insulation base member25corresponds to an insulation substrate.

The insulation substrate25is composed of a plate-shaped member extending along an XY plane defined by an axis X and an axis Y. The insulation substrate25has a thickness in the direction of an axis Z in the XY plane. The insulation substrate25is formed in a substantially quadrangular thin plate shape. The insulation substrate25is made of a resin material having high insulating properties and withstanding high temperatures, for example, a polyimide film. The first receiving electrode21, the second receiving electrode22, the transmitting electrode23, and the heat generating part24are formed on the surface of the insulation substrate25on the occupant side.

The first receiving electrode21, the second receiving electrode22, the transmitting electrode23, and the heat generating part24are made of a thin copper film, and the heater device20is made thinner and has a lower heat capacity. Further, by reducing the heat capacity, the temperature of the heat generating part24can be rapidly raised by energization. Further, when the object comes into contact with a heat generating surface24a, the temperature of the contacted portion can be rapidly lowered. Further, the first receiving electrode21, the second receiving electrode22, and the transmitting electrode23are connected to the detection unit28.

The first receiving electrode21has a plurality of plate-shaped portions211formed so as to expand in the XY plane direction, and a connecting portion212connecting between the plate-shaped portions211. The plurality of plate-shaped portions211each have a rectangular shape, and the connecting portion212has a linear shape.

The second receiving electrode22has a plurality of plate-shaped portions221formed so as to expand in the XY plane direction, and a connecting portion222connecting between the plate-shaped portions221. Each plate-shaped portion221has a rectangular shape, and the connecting portion222has a linear shape. Further, each plate-shaped portion211of the first receiving electrode21has the same shape and area as each plate-shaped portion221of the second receiving electrode22.

The transmission electrode23has a main wire portion231and a plurality of branch-shaped portions232that branch off from the main wire portion231. The transmitting electrode23is arranged between the first receiving electrode21and the second receiving electrode22at a predetermined distance from the first receiving electrode21and the second receiving electrode22.

In the heater device20of the present embodiment, two branch-shaped portions232of the transmitting electrode23are arranged between the plate-shaped portions211of the first receiving electrodes21arranged side by side in the Y-axis direction. Further, one branch-shaped portion232of the transmitting electrode23is arranged between the plate-shaped portions221of the second receiving electrodes22arranged side by side in the Y-axis direction.

As a result, a distance in the Y-axis direction between the plate-shaped portion211of the first receiving electrode21and the branch-shaped portion232of the transmitting electrode23is shorter than a distance in the Y-axis direction between the plate-shaped portion221of the second receiving electrode22and the branch-shaped portion232of the transmitting electrode23.

Therefore, a capacitance formed between the transmitting electrode23and the first receiving electrode21becomes larger than a capacitance formed between the transmitting electrode23and the second receiving electrode22. That is, an electric line of force E1formed between the transmitting electrode23and the first receiving electrode21is larger than an electric line of force E2formed between the transmitting electrode23and the second receiving electrode22.

The detection unit28of the present embodiment amplifies a signal corresponding to a change in capacitance between the transmitting electrode23and the first receiving electrode21, and a signal corresponding to a change in capacitance between the transmitting electrode23and the second receiving electrode22by an amplifier. Further, the detection unit28detects whether or not the distance between the object around the heat generating part24and the heat generating part24is equal to or less than a first detection distance L1with a first detection sensitivity. Further, the detection unit28determines whether or not the distance between the object around the heat generating part24and the heat generating part24is equal to or less than a second detection distance L2with a second detection sensitivity lower than the first detection sensitivity.

The detection unit28outputs a signal indicating whether or not the distance between the object and the heat generating part24is equal to or less than the first detection distance L1and a signal indicating whether or not the distance between the object and the heat generating part24is equal to or greater than the second detection distance L2, to the control unit29.

The heat generating part24is linear and is formed so as to meander on one surface of the insulation substrate25. The heat generating part24radiates radiant heat H that makes the occupant12feel warm by energizing by the control unit29. The heat generating part24is made of a material having a high thermal conductivity. For example, the heat generating part24may be made of copper, alloy of copper and tin (Cu—Sn), a metal such as silver, tin, stainless steel, nickel, and nichrome, or alloy including at least one of silver, tin, stainless steel, nickel or nichrome.

The cover member26protects the first receiving electrode21, the second receiving electrode22, the transmitting electrode23, and the heat generating part24. The cover member26is composed of a low thermal conductive member having a lower thermal conductivity than the first receiving electrode21, the second receiving electrode22, the transmitting electrode23, and the heat generating part24.

The control unit29is configured as a computer equipped with a CPU, a memory, an I/O, and the like, and the CPU executes various processes according to a program stored in the memory. The memory is a non-transitory tangible storage medium.

The heater device20of the present embodiment is configured as a mutual capacitive sensor. Next, an operation principle of the mutual capacitive sensor will be described with reference toFIGS. 5 and 6. Here, it will be described as the capacitive sensor having the transmitting electrode23and the first receiving electrode21.

A schematic diagram of the transmitting electrode23and the first receiving electrode21is illustrated on the left side inFIG. 5, and an equivalent circuit of the transmitting electrode23and the first receiving electrode21is illustrated on the right side inFIG. 5.

As shown on the left side inFIG. 5, the transmitting electrode23and the first receiving electrode21are adjacent to each other in the mutual capacitive sensor. An electric field is created between the transmitting electrode23and the first receiving electrode21when voltage is applied between the transmitting electrode23and the first receiving electrode21.

A capacitance C between the transmitting electrode23and the first receiving electrode21can be expressed as in Equation 1, where c is a permittivity between the transmitting electrode23and the first receiving electrode21, S is an area of one electrode, and d is a distance between the electrodes.

When a finger that is a part of a human body approaches as an object around the electrode, a part of the field line E is absorbed by the finger as shown on the left side inFIG. 6, and accordingly the electric field received by the first receiving electrode21decreases. As shown on the right side inFIG. 5, this situation can be regarded as same to a situation where a grounded object is inserted between the transmitting electrode23and the first receiving electrode21.

In this case, the capacitance C between the transmitting electrode23and the first receiving electrode21can be expressed as in Equation 2, where ΔS is an area of the grounded object overlapping the electrodes.

That is, the contiguity of the finger can be detected by determining the difference between the capacitance C expressed in the equation 1 and the capacitance C′ expressed in the equation 2.

As described above, the detection unit28detects whether or not the distance between the object around the heat generating part24and the heat generating part24is equal to or less than a first detection distance L1with a first detection sensitivity. Further, the detection unit28determines whether or not the distance between the object around the heat generating part24and the heat generating part24is equal to or less than a second detection distance L2with a second detection sensitivity lower than the first detection sensitivity.

FIG. 7shows a relationship of change C1in capacitance between the first receiving electrode21and the transmitting electrode23with respect to the distance L from the object in the heater device20of the present embodiment, and a relationship of change C2in capacitance between the second receiving electrode22and the transmitting electrode23with respect to the distance L from the object in the heater device20of the present embodiment.

As the distance L from the object becomes shorter, the changes C1and C2of each capacitance become larger. Further, the change C1in the capacitance between the first receiving electrode21and the transmitting electrode23is configured to be larger than the change C2in the capacitance between the second receiving electrode22and the transmitting electrode23.

Here, as shown by the dotted line inFIG. 7, the change C1in capacitance between the second receiving electrode22and the transmitting electrode23and the change C2in capacitance between the second receiving electrode22and the transmitting electrode23change depending on an external factor such as temperature in the operating temperature environment. Here, the operating temperature environment means, for example, an environment of −10° C. to 120° C.

In the heater device20of the present embodiment, a lower limit value of the change in capacitance C1between the first receiving electrode21and the transmitting electrode23is configured to be larger than an upper limit value of the change C2in capacitance between the second receiving electrode22and the transmitting electrode23.

Further, in the heater device20of the present embodiment, the lower limit value L1D of the first detection distance L1under the operating temperature environment is larger than the upper limit value L2U of the second detection distance L2under the operating temperature environment.

Therefore, the lower limit value of the first detection distance under the operating temperature environment is not smaller than the upper limit value of the second detection distance under the operating temperature environment, and the proximity of the object is detected with high accuracy.

Next, a processing of the control unit29will be described with reference to the flowchart ofFIG. 8. This processing starts as soon as the heater device20is turned on. When the power of the heater device20is turned on, the control unit29energizes the heat generating part24. As a result, the heat generating part24generates heat. Further, the detection unit28applies a predetermined voltage to the heat generation part24.

First, the control unit29determines in S100whether or not the distance between the object around the heat generating part24and the heat generating part24is equal to or less than the first detection distance L1. Specifically, it is determined whether or not the distance between the object and the heat generating unit24is equal to or less than the first detection distance L1based on an output signal of the detection unit28.

Here, when it is determined in S100that the distance between the object around the heat generating part24and the heat generating part24is not equal to or less than the first detection distance L1, the control unit29determines in S104whether or not the distance between the object and the heat generating part24is equal to or less than the second detection distance L2. Specifically, it is determined whether or not the distance between the object and the heat generating part24is equal to or less than the second detection distance L2based on the output signal of the detection unit28. Then, when it is determined that the distance between the object and the heat generating part24is not equal to or less than the second detection distance L2, the control unit29ends this process. Therefore, the energization of the heat generating part24is continued.

Further, when it is determined in S100that the distance between the object and the heat generating part24is equal to or less than the first detection distance L1, in S102, the control unit29lowers the heater temperature of the heat generating part24to the first temperature. As a result, the temperature of the heat generating part24is lowered.

Next, the control unit29determines in S104whether or not the distance between the object and the heat generating part24is equal to or less than the second detection distance L2. Specifically, it is determined whether or not the distance between the object and the heat generating part24is equal to or less than the second detection distance L2based on the output signal of the detection unit28.

Here, when the distance between the object and the heat generating part24is equal to or less than the second detection distance L2, the control unit29stops the energization of the heat generating part24and stops the operation of the heat generating part24in S106. As a result, the temperature of the heat generating part24is further lowered, and the thermal discomfort to the occupant can be reduced.

As described above, the heater device20of the present embodiment includes the heat generating part24that generates heat when energized. Further, the detection unit28detects whether or not the distance between the object and the heat generating part24is equal to or less than the first detection distance L1with the first detection sensitivity, and whether or not the distance between the object and the heat generating part24is equal to or less than the second detection distance L2being shorter than the first detection distance L1with the second detection sensitivity which is lower than the first detection sensitivity.

Therefore, even if the capacitance between the electrodes changes due to an external factor, the proximity of the object around the heat generating part can be detected more accurately.

Further, when the detection unit28detects that the distance between the object around the heat generating part24and the heat generating part24is equal to or less than the first detection distance L1, the heater device20has a first temperature lowering portion (S102) that sets the heater temperature of the heat generating part24to a first temperature. Further, when the detection unit28detects that the distance between the object around the heat generating part24and the heat generating part24is equal to or less than the second detection distance L2, the heater device20has a second temperature lowering portion (S106) that stops energization of the heat generating part24. Therefore, the thermal discomfort to the occupant can be reduced.

Further, the lower limit value L1D of the first detection distance L1under the operating temperature environment is larger than the upper limit value L2U of the second detection distance L2under the operating temperature environment. Therefore, the lower limit value L1D of the first detection distance L1under the operating temperature environment is not smaller than the upper limit value L2U of the second detection distance L2under the operating temperature environment, and the proximity of the object can be detected accurately.

Further, the heater device20includes the receiving electrodes21and22and the transmitting electrodes23. Then, the detection unit28detects whether or not the distance between the object and the heat generating part24is equal to or less than the first detection distance L1based on the change in capacitance between the receiving electrodes21and22and the transmitting electrode23. Further, the detection unit28detects whether or not the distance between the object around the heat generating part24and the heat generating part24is equal to or less than the second detection distance L2based on the change in capacitance between the receiving electrodes21and22and the transmitting electrode23.

In this way, the distance between the object and the heat generating part24can be detected based on the change in capacitance between the receiving electrodes21and22and the transmitting electrode23.

Further, the insulation substrate25on which the heat generating part24, the receiving electrodes21,22and the transmitting electrode23are formed is provided, and the heat generating part24, the receiving electrodes21,22and the transmitting electrode23are formed on the same surface of the insulation substrate25. Therefore, the structure can be simplified and the manufacturing cost can be reduced.

Further, the receiving electrodes21and22have a first receiving electrode21and a second receiving electrode22respectively. The detection unit28detects whether or not the distance between the object around the heat generating part24and the heat generating part24is equal to or less than the first detection distance L1based on the change in capacitance between the first receiving electrode21and the transmitting electrode23. Then, the detection unit28detects whether or not the distance between the object around the heat generating part24and the heat generating part24is equal to or less than the second detection distance L2based on the change in capacitance between the second receiving electrode22and the transmitting electrode23.

According to this configuration, since the transmitting electrode23also serves as the transmitting electrode of the first receiving electrode21and the transmitting electrode of the second receiving electrode22, wiring can be greatly simplified.

Further, the heat generating part24is formed so as to meander, and the first receiving electrode21, the second receiving electrode22, and the transmitting electrode23are arranged side by side between the heat generating parts24.

Therefore, since the first receiving electrode21, the second receiving electrode22, and the transmitting electrode23are arranged alongside the heat generating part24, the distance between the object around the heat generating part24and the heat generating part24can be detected accurately.

Further, the capacitance formed between the transmitting electrode23and the first receiving electrode21becomes larger than the capacitance formed between the transmitting electrode23and the second receiving electrode22. The first detection sensitivity is higher than the second detection sensitivity.

In this way, the capacitance formed between the transmitting electrode23and the first receiving electrode21is made larger than the capacitance formed between the transmitting electrode23and the second receiving electrode22. Therefore, the first detection sensitivity can be made higher than the second detection sensitivity.

In the present embodiment, when the distance between the object and the heat generating part24is equal to or less than the second detection distance L2, the control unit29stops the operation of the heat generating part24in S106. On the other hand, when the distance between the object and the heat generating part24is equal to or less than the second detection distance L2, the control unit29may lower the temperature of the heat generating part24to a second temperature lower than the first temperature in S106.

Second Embodiment

A heater device20according to a second embodiment will be described with reference toFIGS. 9 to 10. The heater device20of the first embodiment has the first receiving electrode21, the second receiving electrode22, and the transmitting electrode23as electrodes. On the other hand, the heater device20of the present embodiment has the first receiving electrode21, the second receiving electrode22, a first transmitting electrode23a, and a second transmitting electrode23bas electrodes.

The detection unit28detects whether or not the distance between the object around the heat generating part24and the heat generating part24is equal to or less than the first detection distance L1based on the change in capacitance between the first receiving electrode21and the first transmitting electrode23a. Then, the detection unit28detects whether or not the distance between the object around the heat generating part24and the heat generating part24is equal to or less than the second detection distance L2based on the change in capacitance between the second receiving electrode22and the second transmitting electrode23b.

As described above, the detection unit28detects whether or not the distance between the object around the heat generating part24and the heat generating part24is equal to or less than the first detection distance L1based on the change in capacitance between the first receiving electrode21and the first transmitting electrode23a. Then, the detection unit28detects whether or not the distance between the object around the heat generating part24and the heat generating part24is equal to or less than the second detection distance L2based on the change in capacitance between the second receiving electrode22and the second transmitting electrode23b.

The present embodiment can achieve the effects and advantages, which are obtained from the structure common to the first embodiment.

Third Embodiment

A heater device according to a third embodiment is described with reference toFIG. 11. In the heater device20of the present embodiment, a heat radiating plate27is formed on the same surface as the surface on which the first receiving electrode21, the second receiving electrode22, the transmitting electrode23, and the heat generating part24are formed on the insulation substrate25. The heat radiating plate27is made of the same thin copper film as the first receiving electrode21, the second receiving electrode22, the transmitting electrode23, and the heat generating part24. The heat radiating plate27can promote heat dissipation from the heat generating part24.

The present embodiment can achieve the effects and advantages, which are obtained from the structure common to the first embodiment.

Fourth Embodiment

The heater device20according to a fourth embodiment will be described with reference toFIG. 12. In the heater device20of the first embodiment, as shown inFIG. 3, the distance in the Y direction between the plate-shaped portion211of the first receiving electrode21and the branch-shaped portion232of the transmitting electrode23is the second is shorter than the distance in the Y direction between the plate-shaped portion221of the second receiving electrode22and the branch-shaped portion232of the transmitting electrode23. Therefore, a capacitance formed between the transmitting electrode23and the first receiving electrode21becomes larger than a capacitance formed between the transmitting electrode23and the second receiving electrode22.

On the other hand, in the heater device20of the present embodiment, the area of the plate-shaped portion211of the first receiving electrode21is larger than the area of the plate-shaped portion221of the second receiving electrode22. Therefore, a capacitance formed between the transmitting electrode23and the first receiving electrode21becomes larger than a capacitance formed between the transmitting electrode23and the second receiving electrode22.

The capacitance formed between the transmitting electrode23and the first receiving electrode21becomes larger than the capacitance formed between the transmitting electrode23and the second receiving electrode22. The first detection sensitivity is higher than the second detection sensitivity.

The present embodiment can achieve the effects and advantages, which are obtained from the structure common to the first embodiment.

Other Embodiments

(1) In the above embodiment, the heater device arranged in the vehicle interior of the moving body has been described, but it can be applied to various devices arranged outside the vehicle interior of the moving body.

(2) In the first embodiment, the distance in the Y direction between the plate-shaped portion211of the first receiving electrode21and the branch-shaped portion232of the transmitting electrode23is set to be shorter than the distance in the Y direction between the plate-shaped portion221of the second receiving electrode22and the branch-shaped portion232of the transmitting electrode23. Therefore, the capacitance formed between the transmitting electrode23and the first receiving electrode21becomes larger than the capacitance formed between the transmitting electrode23and the second receiving electrode22.

On the other hand, the capacitance formed between the transmitting electrode23and the first receiving electrode21can be considered to be larger than the capacitance formed between the transmitting electrode23and the second receiving electrode22by making a gain of the amplifier of the detection unit28. In this way, the distance between the object around the heat generating part24and the heat generating part24may be detected with different detection sensitivities.

(3) In each of the above embodiments, the control unit29controls the temperature of the heat generating part24according to the output signal of the detection unit28. On the other hand, the control unit29does not control the temperature of the heat generating part24according to the output signal of the detection unit28, the control unit29can be configured as a device that outputs the output signal of the detection unit28.

(4) In each of the above embodiments, one heat generating surface24ais formed on one insulation substrate25, but as shown inFIG. 13, it is also possible to disperse and form a plurality of heat generating surfaces24aon one insulation substrate25. That is, the heater device has a plurality of heat generating surfaces24athat radiate radiant heat by the heat generated by the heat generating part24, and the plurality of heat generating surfaces24acan be dispersedly arranged on the insulation substrate25.

The present disclosure is not limited to the above-described embodiments, and can be appropriately modified. The embodiments described above are not independent of each other, and can be appropriately combined except when the combination is obviously impossible. The constituent element(s) of each of the above embodiments is/are not necessarily essential unless it is specifically stated that the constituent element(s) is/are essential in the above embodiment, or unless the constituent element(s) is/are obviously essential in principle. Furthermore, in each of the above embodiments, in the case where the number of the constituent element(s), the value, the amount, the range, and/or the like is specified, the present disclosure is not necessarily limited to the number of the constituent element(s), the value, the amount, and/or the like specified in the embodiment unless the number of the constituent element(s), the value, the amount, and/or the like is indicated as indispensable or is obviously indispensable in view of the principle of the present disclosure. Furthermore, a material, a shape, a positional relationship, or the like, if specified in the above-described example embodiments, is not necessarily limited to the specific material, shape, positional relationship, or the like unless it is specifically stated that the material, shape, positional relationship, or the like is necessarily the specific material, shape, positional relationship, or the like, or unless the material, shape, positional relationship, or the like is obviously necessary to be the specific material, shape, positional relationship, or the like in principle.

According to the first aspect shown in part or all of the above embodiments, the heater device includes a heat generating part that generates heat when energized. The detection unit detects whether or not a distance between a object around the heat generating part and the heat generating part is equal to or less than a first detection distance with a first detection sensitivity, and whether or not the distance between the object around the heat generating part and the heat generating part is equal to or less than a second detection distance shorter than the first detection distance with a second detection sensitivity that is less sensitive than the first detection sensitivity.

Further, according to the second viewpoint, when the detection unit detects that the distance between the object around the heat generating part and the heat generating part is equal to or less than the first detection distance, the heater device20has a first temperature lowering portion that sets the heater temperature of the heat generating part to a first temperature. Further, when the detection unit detects that the distance between the object around the heat generating part and the heat generating part is equal to or less than the second detection distance, the heater device has a second temperature lowering portion that sets the heater temperature of the heat generating part to a second temperature lower than the first temperature. Therefore, the thermal discomfort to the occupant can be reduced.

Further, according to the third viewpoint, when the detection unit detects that the distance between the object around the heat generating part and the heat generating part is equal to or less than the second detection distance, the second temperature lowering portion stops the energization to the heat generating part. Therefore, the thermal discomfort to the occupant can be reduced.

Further, according to the fourth viewpoint, the lower limit value of the first detection distance under the operating temperature environment is larger than the upper limit value of the second detection distance under the operating temperature environment.

Therefore, the lower limit value of the first detection distance under the operating temperature environment is not smaller than the upper limit value of the second detection distance under the operating temperature environment, and the proximity of the object can be detected accurately.

Further, according to the fifth aspect, the heater device includes the receiving electrode and the transmitting electrode. The detection part detects whether or not the distance between the object around the heat generating part and the heat generating part is equal to or less than the first detection distance based on the change in capacitance between the first receiving electrode and the transmitting electrode. Then, the detection unit detects whether or not the distance between the object around the heat generating part and the heat generating part is equal to or less than the second detection distance based on the change in capacitance between the second receiving electrode and the transmitting electrode.

As described above, the detection unit detects whether or not the distance between the object around the heat generating part and the heat generating part is equal to or less than the first detection distance based on the change in capacitance between the receiving electrode and the transmitting electrode. Further, it is possible to detect whether or not the distance between the object around the heat generating part and the heat generating part is equal to or less than the second detection distance based on the change in the capacitance between the receiving electrode and the transmitting electrode.

Further, according to the sixth aspect, the heater device includes the substrate on which the heat generating part, the receiving electrode, and the transmitting electrode are formed. The heat generating part, the receiving electrode, and the transmitting electrode are formed on the same surface of the substrate. Therefore, the structure can be simplified and the manufacturing cost can be reduced.

Further, according to the seventh aspect, the receiving electrode has the first receiving electrode and the second receiving electrode. The detection unit detects whether or not the distance between the object around the heat generating part and the heat generating part is equal to or less than the first detection distance based on the change in capacitance between the first receiving electrode and the transmitting electrode. Then, the detection unit detects whether or not the distance between the object around the heat generating part and the heat generating part is equal to or less than the second detection distance based on the change in capacitance between the second receiving electrode and the transmitting electrode.

According to this configuration, since the transmitting electrode also serves as the transmitting electrode of the first receiving electrode and the transmitting electrode of the second receiving electrode, wiring can be greatly simplified.

Further, according to the eighth viewpoint, the heat generating part is formed so as to meander, and the first receiving electrode, the second receiving electrode, and the transmitting electrode are arranged side by side between the heat generating parts.

Therefore, since the first receiving electrode, the second receiving electrode, and the transmitting electrode are arranged alongside the heat generating part, the distance between the object around the heat generating part and the heat generating part can be detected accurately.

Further, according to the ninth aspect, the capacitance formed between the transmitting electrode and the first receiving electrode is larger than the capacitance formed between the transmitting electrode and the second receiving electrode. As a result, the first detection sensitivity is higher than the second detection sensitivity.

In this way, the capacitance formed between the transmitting electrode and the first receiving electrode is made larger than the capacitance formed between the transmitting electrode and the second receiving electrode. Therefore, the first detection sensitivity can be made higher than the second detection sensitivity.

Further, according to the tenth viewpoint, it has a plurality of heat generating surfaces that radiate radiant heat by the heat generated by the heat generating part, and the plurality of heat generating surfaces are dispersedly arranged on the substrate.

As described above, the heater device has a plurality of heat generating surfaces that radiate radiant heat by the heat generated by the heat generating part, and the plurality of heat generating surfaces can be dispersedly arranged on the substrate.

The process of S102corresponds to the first temperature lowering portion, and the process of S106corresponds to the second temperature lowering portion.