Patent Publication Number: US-2020282804-A1

Title: Fogging suppression apparatus and control method thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to and the benefit of Japanese Patent Application No. 2019-039743 filed on Mar. 5, 2019, the entire disclosure of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to techniques for suppressing window fogging. 
     Description of the Related Art 
     Air conditioning units mounted on vehicles are installed with defrosters that blow out warm air along windshields from below in order to suppress window fogging. However, there are cases in which fogging is not effectively suppressed due to the relationship between the outside temperature, the traveling state of the vehicle, and the temperature inside the vehicle cabin. Due to this, a fogging suppression function is proposed (see Japanese Patent Laid-Open No. 2010-36592) in which heaters for fogging suppression are installed in a window, and the heaters are energized and heated if the outside temperature is no higher than a predetermined temperature and the traveling speed is no lower than a predetermined vehicle speed. 
     However, the above-described fogging suppression function is not necessary if the outside temperature is no higher than the predetermined temperature and the traveling speed is no lower than the predetermined vehicle speed. Due to this, depending upon conditions, there can be cases in which the heaters are activated at unnecessary timings. 
     SUMMARY OF THE INVENTION 
     The present invention has been made in consideration of the aforementioned problems, and realizes techniques for appropriately controlling a fogging suppression function so that unnecessary heating is not performed. 
     In order to solve the aforementioned problems, the first aspect of the present invention provides a fogging suppression apparatus that suppresses fogging of a window of vehicle, comprising: an acquisition unit that acquires an external temperature of the vehicle; a heater that heats the window, the heater differing from an air conditioning apparatus including a blower provided in the vehicle; and a control unit that controls the heater so as to heat the window when the external temperature of the vehicle is lower than or equal to a predetermined temperature and there is a request for activation of the air conditioning apparatus. 
     In order to solve the aforementioned problems, the second aspect of the present invention provides a method of controlling a fogging suppression apparatus that suppresses fogging of a window of a vehicle, wherein the fogging suppression apparatus includes: an acquisition unit that acquires an external temperature of the vehicle; and a heater that heats the window, the heater differing from an air conditioning apparatus including a blower provided in the vehicle, and the control method comprises controlling the heater so as to heat the window when the external temperature of the vehicle is lower than or equal to a predetermined temperature and there is a request for activation of the air conditioning apparatus. 
     According to the present invention, the fogging suppression function can be controlled appropriately so that unnecessary heating is not performed. 
     Other features and advantages besides those discussed above shall be apparent to those skilled in the art from the description of an embodiment of the invention as follows. In the description, reference is made to accompanying drawings, which form a part thereof, and which illustrate an example of the invention. Such an example, however, is not exhaustive of the various embodiments of the invention, and therefore reference is made to the claims which follow the description for determining the scope of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a cross-sectional view illustrating a structure in the vicinity of a window, in which a fogging suppression apparatus according to the present embodiment is included. 
         FIG. 1B  is a schematic diagram corresponding to  FIG. 1A . 
         FIG. 2A  is a plan view illustrating the fogging suppression apparatus according to the present embodiment as seen from the outside of a vehicle through the window. 
         FIG. 2B  is a plan view illustrating the fogging suppression apparatus according to the present embodiment as seen from the inside of the vehicle. 
         FIG. 3  is a diagram illustrating functional blocks realizing fogging suppression control according to the present embodiment. 
         FIG. 4  is a timing chart describing the fogging suppression control according to the present embodiment. 
         FIG. 5  is a flowchart illustrating fogging suppression control processing according to the present embodiment. 
     
    
    
     DESCRIPTION OF THE EMBODIMENT 
     Hereinafter, an embodiment will be described in detail with reference to the attached drawings. Note that the following embodiment is not intended to limit the scope of the claimed invention, and limitation is not made to an invention that requires all combinations of features described in the embodiment. Two or more of the multiple features described in the embodiment may be combined as appropriate. Furthermore, the same reference numerals are given to the same or similar configurations, and redundant description thereof is omitted. 
     Description of Structure 
     First, constituent elements of a fogging suppression apparatus according to the present embodiment will be described with reference to  FIGS. 1A and 1B  and  FIGS. 2A and 2B . 
     The fogging suppression apparatus  1  according to the present embodiment is installed in a vehicle, such as automobiles, railway vehicles, and airplanes. For example, automobiles include automobiles with internal combustion engines, hybrid automobiles, electric automobiles, etc. The fogging suppression apparatus  1  according to the present embodiment suppresses the fogging of a window  2 . A surroundings detection apparatus  10  that acquires information regarding an area around the self-vehicle is attached to the window  2 . For example, the surroundings detection apparatus  10  is attached to a windshield  2  of the vehicle, and is an image capturing apparatus such as a camera that photographs the area in front of the self-vehicle through a transparent window panel (window glass), or a Radar or LiDAR that detects obstacles around the self-vehicle. In the present embodiment, an example will be described in which the surroundings detection apparatus  10  is a camera monitoring the surroundings of the self-vehicle. In the present embodiment, a configuration in which the surroundings detection apparatus  10  is attached to the windshield  2  of the vehicle will be described as an example. However, the present invention is not limited to this, and is also applicable to configurations in which the surroundings detection apparatus  10  is attached to the rear window, a side window, or other parts. 
     The camera  10  according to the present embodiment includes an image capturing unit  13  that is composed of a lens unit  11  and a sensor unit  12 , and a camera main body unit  14  that performs image capturing processing using the image capturing unit  13  and performs image processing on image-captured data. The lens unit  11  forms, on the sensor unit  12 , an image of the area in front of the vehicle entering through the windshield  2 . The sensor unit  12  is constituted by an AD conversion circuit and a photoelectric conversion element such as a CMOS image sensor. The camera main body unit  14  generates image data by performing predetermined image processing on digital image signals output from the sensor unit  12 . 
     The fogging suppression apparatus  1  according to the present embodiment includes a heating apparatus  20  that suppresses or removes fogging of the windshield  2 , which transmits the optical image to be image-captured by the camera  10 , and a control apparatus  30  that controls the activation (energization) and the deactivation (de-energization) of the heating apparatus  20 . For example, the heating apparatus  20  is a heater that includes one or more heat generation elements that generate heat using the electric energy supplied during energization. The control apparatus  30  controls the energization of the heat generation elements. The heater has the shape of a rectangular sheet with small thickness but is not limited to this, and a defroster, a heating wire, etc., directly affixed to the window panel  2  may be used in place. 
     The camera  10  and the heater  20  according to the present embodiment are attached to a window panel surface (window glass surface)  2   a  of the windshield  2  that is located inside the vehicle cabin, in a state in which the camera  10  and the heater  20  are held by a bracket  3 . The camera  10  and the heater  20  are attached to the upper end of a portion of the window panel surface  2   a  at the boundary between the window panel surface  2   a  and the roof in the center in the vehicle width direction. The entirety of the camera  10  and the heater  20  inside the vehicle cabin is covered by a cover member  4 .  FIG. 1A  illustrates a state in which the cover member  4  is not attached. In a space portion  5  forward of the camera  10  in the bracket  3 , diffuse reflection prevention processing (finishing) is applied to the part extending forward from the camera  10  as a structure  8  for preventing a decrease in the surroundings-detecting accuracy of the camera  10 . For example, the diffuse reflection prevention processing is a shape in which groove portions extending in the vehicle width direction are arranged forward of the camera  10  in wave-like shapes, embossments, a coating, etc. 
     The bracket  3  includes a bracket main body portion  3   a  that holds the camera  10  and the heater  20 , and that is attached to the windshield  2 . The space portion  5  is formed forward of the camera  10  in the bracket main body portion  3   a . The fan-shaped space portion  5  spreads out radially from both sides of the image capturing unit  13  of the camera  10  forward along the windshield  2  and outward in the vehicle width direction. The space portion  5  is formed from left and right lateral wall portions  6 , a bottom surface portion  7 , and the window panel surface  2   a . The left and right lateral wall portions  6  extend radially and with left-right symmetry with the image capturing unit  13  of the camera  10  as the center. The left and right lateral wall portions  6  have a tapered shape such that the height of the left and right lateral wall portions  6  with respect to the window panel surface  2   a  decreases as the distance from the camera  10  increases. The bottom surface portion  7  includes a first bottom surface portion  7   a  that is connected to the left and right lateral wall portions  6 , and a rectangular second bottom surface portion  7   b  that is configured to be separable from the first bottom surface portion  7   a . The second bottom surface portion  7   b  is configured to be detachable from the first bottom surface portion  7   a . The camera  10  and the heater  20  can be attached to the second bottom surface portion  7   b , and the camera  10  and the heater  20  can be detached from the bracket  3  by detaching the second bottom surface portion  7   b  in a state in which the bracket  3  is attached to the windshield  2 . The camera  10  and the heater  20  are attached to the surface of the second bottom surface portion  7   b  facing the inside of the vehicle cabin. Further, the diffuse reflection prevention processing is applied to the surfaces of the first bottom surface portion  7   a  and the second bottom surface portion  7   b  facing the windshield  2  side. In such a manner, the camera  10  is arranged at a position adjacent to the bottom surface portion  7 , to which the diffuse reflection prevention processing is applied, and the heater  20  is arranged at the part at which the diffuse reflection prevention processing is applied. Due to this, the window panel surface  2   a  can be heated efficiently. 
     In a state in which the bracket  3  is attached to the windshield  2 , a slit-shaped gap  2   b  that extends in the vehicle width direction is formed between the window panel surface  2   a  and a front end portion  7   c  of the first bottom surface portion  7   a  that is located farthest from the camera  10 . Further, a gap  2   c  is also formed between the window panel surface  2   a  and a front end portion  4   a  of the cover member  4 . The inside of the space portion  5  and the outside of the space portion  5  (the inside of the vehicle cabin) are placed in communication with one another through the predetermined gaps  2   b  and  2   c , and the space portion  5  can be ventilated through the gaps  2   b  and  2   c  by the air inside the vehicle cabin, such as conditioned air generated by an air conditioning apparatus  40 , being blown by a blower of the air conditioning apparatus  40 . 
     In the present embodiment, fogging suppression control using the heater  20  is performed, in consideration of a case in which the fogging of the window panel surface  2   a  inside the space portion  5  cannot be suppressed by only the ventilation through the gaps  2   b ,  2   c  between the window panel surface  2   a . The heater  20  heats an area of the window panel surface  2   a  in the space portion  5  that overlaps with the visual field range of the camera  10 . By adopting such a configuration, the fogging of the windshield  2  overlapping with the visual field range of the camera  10  can be reduced, and a decrease in surroundings-detecting performance caused by a decrease in image quality, etc., can be prevented. 
     Next, functional blocks for realizing the fogging suppression control according to the present embodiment will be described with reference to  FIG. 3 . 
     The fogging suppression control according to the present embodiment is realized by hardware such as the heating apparatus  20 , the control apparatus  30 , an outside temperature sensor  51 , an inside temperature sensor  52 , the air conditioning apparatus  40 , etc., and a software program used by the control apparatus  30  to execute the fogging suppression control. 
     The control apparatus  30  includes a memory  32  that stores the program for the fogging suppression control, an arithmetic processing unit (CPU)  31  that reads out and executes the program stored in the memory  32 , an interface circuit  33  that exchanges data with the other pieces of hardware, etc. 
     The outside temperature sensor  51  detects information regarding the temperature outside the vehicle, and outputs the detection result to the control apparatus  30 . If the vehicle has an internal combustion engine, for example, the temperature outside the vehicle is the intake air temperature of the engine. The inside temperature sensor  52  detects information regarding the temperature inside the vehicle, and outputs the detection result to the control apparatus  30 . The air conditioning apparatus  40  detects information regarding the operation state of the air conditioning apparatus  40  that is in accordance with user operations (including remote operations performed using a remote controller, etc.), and outputs the detection results to the control apparatus  30 . For example, the operation state of the air conditioning apparatus  40  includes information regarding the on or off of the air conditioner (A/C), information regarding the defroster, information regarding the switching between fresh air and recirculation, and information regarding settings such as the temperature, the humidity, the wind amount, and the wind direction. Note that the control apparatus  30  may perform an estimation calculation using the above-described detection results to acquire information regarding the detection results. Furthermore, the control apparatus  30  may be configured so as to be built into the camera main body unit  14  of the camera  10  or may be configured so that the control apparatus  30  is separate from the camera  10  and connected to the camera  10  using a harness, etc. 
     Next, fogging suppression control processing according to the present embodiment will be described with reference to  FIGS. 4 and 5 . 
     First, the fogging suppression control processing according to the present embodiment will be described with reference to the timing chart in  FIG. 4 . 
     In the fogging suppression control according to the present embodiment, the control apparatus  30  switches the heater  20  on and off in accordance with a predetermined condition. The predetermined condition is a condition under which it can be expected that fogging of the window panel surface  2   a  in the space portion  5  forward of the camera will occur. If the predetermined condition is fulfilled, fogging suppression control for suppressing or removing fogging is performed by turning the heater  20  on. 
     In the fogging suppression control according to the present embodiment, the control apparatus  30  intermittently activates the heater  20  if the control apparatus  30  determines that the predetermined condition is fulfilled. The basic cycle of the intermittent activation of the heater  20  (referred to hereinafter as “heater control”) by the control apparatus  30  includes: outputting a drive signal to the heater  20 , and turning on the heater  20  and continuing the heating for a first period D 1 ; following the elapse of the first period D 1 , stopping the output of the drive signal, and turning off the heater  20  and stopping the heating for a second period D 2 ; following the elapse of the second period D 2 , outputting the drive signal once again, and turning on the heater  20  for a third period D 3 ; and following this, repeating the second period D 2  and the third period D 3  until a termination condition is fulfilled. Here, the first period D 1 , the second period D 2 , and the third period D 3  can be changed in accordance with the predetermined condition. However, the first period D 1  is set to be longer than or equal to the second period D 2 , and the second period D 2  is set to be longer than the third period D 3  (D 1 ≥D 2 &gt;D 3 ). 
     In  FIG. 4 , the control apparatus  30  turns on a flag functioning as a trigger for starting the activation of the heater  20  if the control apparatus  30  determines that the predetermined condition is fulfilled, or that is, if the control apparatus  30  determines that the outside temperature Tout has become lower than or equal to a predetermined threshold TO and that a request for activation of the air conditioning apparatus  40  has been made through a user operation. Then, the control apparatus  30  keeps the flag on until the predetermined condition becomes unfulfilled, and continues the heater control while the flag is on. Accordingly, the window panel surface  2   a  in the space portion  5  forward of the camera is heated and fogging is suppressed or removed. Note that a configuration may be adopted in which, in place of a flag that is kept on once the condition is fulfilled and until the condition becomes unfulfilled, an on signal is output as a trigger signal for a short period of time when the condition is fulfilled and when the condition becomes unfulfilled. 
     Following this, the control apparatus  30  resets the flag to off and stops the heater control (stops the output of the drive signal) if the control apparatus  30  determines that the predetermined condition has become unfulfilled, or that is, if the control apparatus  30  determines that the outside temperature Tout has exceeded the predetermined threshold TO and/or that a request to stop the air conditioning apparatus  40  has been made through a user operation. 
     Overheating of the window panel surface  2   a  in the space portion  5  forward of the camera can be prevented by intermittently activating the heater  20  after the predetermined condition is fulfilled so that the window panel surface  2   a  is heated for the first period D 1  and then the heating of the window panel surface  2   a  is stopped for the second period D 2  in the manner described above. Furthermore, the load exerted on the power source such as the battery can be reduced by refraining from continuously activating the heater  20 , and power consumption can be reduced by only using the battery from time to time. 
     Also, after the heater  20  is turned on and heating is performed for the first period D 1 , the heater  20  is turned off and heating is stopped for the second period D 2 , and then the heater  20  is turned on and heating is performed for the third period D 3 . If the air conditioning apparatus  40  is started in a situation in which the outside temperature Tout is low, the possibility is high that there is some room for adjustment in the state of the air inside the vehicle cabin. By activating the heater  20  in such a situation, unnecessary activation of the heater  20  can be suppressed and the fogging of the window panel surface  2   a  in the space portion  5  forward of the camera can be effectively reduced. 
     Furthermore, in the fogging suppression control according to the present embodiment, the control apparatus  30  is capable of changing the first period D 1  in accordance with the outside temperature Tout, and sets the first period D 1  longer for a lower outside temperature Tout. By adopting such a configuration, the initial heating period is extended when the outside temperature Tout is low, and thus, the temperature of the window panel surface  2   a  can be rapidly increased. 
     Furthermore, the control apparatus  30  is capable of changing the second period D 2  in accordance with the outside temperature Tout, and sets the second period D 2  (&gt;D 3 ) shorter for a lower outside temperature Tout. By adopting such a configuration, the interval between the initial heating period and the second heating period is reduced when the outside temperature Tout is low, and thus, a decrease in the temperature of the window panel surface  2   a  can be suppressed. 
     Furthermore, the control apparatus  30  executes the heater control, in which the control apparatus  30 , after turning on the heater  20  and performing heating for the first period D 1 , turns off the heater  20  and stops the heating for the second period D 2  before turning on the heater  20  and performing heating for the third period D 3  and then repeating the second period D 2  and the third period D 3  until the termination condition is fulfilled. By adopting such a configuration, even if the outside temperature Tout is low, the window temperature can be maintained by performing heating for the third period D 3 , which is shorter than the first period D 1 , because the window temperature is already increased once heating is performed for the first period D 1 . Also, by setting the third period D 3  shorter than the first period D 1 , overheating of the window panel surface  2   a  can be prevented. 
     Furthermore, the control apparatus  30  is capable of changing the third period D 3  in accordance with the outside temperature Tout, and sets the third period D 3  (&lt;D 2 ) longer for a lower outside temperature Tout. By adopting such a configuration, the temperature of the window panel surface  2   a  can be kept within a predetermined temperature range by extending the third period D 3  when the outside temperature Tout is low. 
     Furthermore, the diffuse reflection prevention processing is provided in the photographing direction of the camera  10  and on the bottom surface portion  7  intersecting with the window  2 , and the front end portion  7   c  positioned away from the camera  10  is arranged close to the window  2 . Due to the diffuse reflection prevention processing being positioned close to the window  2  at a side distant from the camera  10  in such a manner, the space portion  5 , which is the visual field range (photographing area) of the camera  10 , is separated from the air inside the vehicle cabin by the diffuse reflection prevention processing. The change in temperature of the photographing area of the camera  10 , which is separated from the air inside the vehicle cabin, is delayed with respect to the change in temperature of the air inside the vehicle cabin. Due to this, the fogging of the photographing area of the camera  10  can be reduced and a decrease in surroundings-detecting performance can be prevented by performing heating based on the predetermined condition. 
     Furthermore, by the diffuse reflection prevention processing being covered by the cover member  4 , the delay with respect to the change in temperature inside the vehicle cabin increases to a further extent. Due to this, the fogging of the photographing area of the camera  10  can be reduced and a decrease in surroundings-detecting performance can be prevented by performing heating based on the predetermined condition. 
     Next, the operation procedures in the fogging suppression control processing according to the present embodiment will be described with reference to the flowchart in  FIG. 5 . 
     Note that the processing in  FIG. 5  is realized by the CPU  31  of the control apparatus  30  executing the program relating to the fogging suppression control processing stored in the memory  32  and controlling the constituent elements of the fogging suppression apparatus  1 . 
     In step S 51 , the CPU  31  receives a detection result of the outside temperature sensor  51  and acquires the outside temperature Tout. 
     In step S 52 , the CPU  31  determines whether or not the outside temperature Tout acquired in step S 51  has decreased to lower than or equal to the predetermined threshold TO. The CPU  31  proceeds to step S 53  if determining that the outside temperature Tout has decreased to lower than or equal to the predetermined threshold TO, and returns to step S 51  and repeats the acquisition and determination regarding the outside temperature Tout if determining that the outside temperature Tout is not lower than or equal to the predetermined threshold TO. 
     In step S 53 , the CPU  31  determines whether or not a request for activation of the air conditioning apparatus  40  was made by a user operation. The CPU  31  proceeds to step S 54  if determining that a request of activation was made, and returns to step S 51  and repeats the acquisition and determination regarding the outside temperature Tout and the determination regarding the request of activation of the air conditioning apparatus  40  if determining that a request for activation is not made. 
     In step S 54 , the CPU  31  executes the heater control, in which the heater  20  is intermittently activated. 
     In step S 55 , the CPU  31  determines whether or not to terminate the heater control. The CPU  31  terminates processing if determining to terminate the heater control, and returns to step S 54  and continues the heater control if determining not to terminate the heater control. The CPU  31  terminates the heater control if determining that the outside temperature Tout has exceeded the predetermined threshold TO and/or that a request to stop the air conditioning apparatus  40  has been made by a user operation, or if a state in which such a determination is made continues for a predetermined amount of time or longer. 
     The invention is not limited to the foregoing embodiment, and various variations/changes are possible within the spirit of the invention. 
     Additionally, in the present invention, a computer program corresponding to the fogging suppression control according to the above-described embodiment or a storage medium storing the computer program may be supplied to a computer mounted on a vehicle, and the computer may load and execute program codes stored in the storage medium. 
     Summary of Embodiment 
     First Aspect 
     A fogging suppression apparatus  1  that suppresses fogging of a window  2  of a vehicle, including: 
     an acquisition unit  51  that acquires an external temperature Tout of the vehicle; 
     a heater  20  that heats the window  2 , the heater  20  differing from an air conditioning apparatus  40  including a blower provided in the vehicle; and 
     a control unit  30  that controls the heater  20  so as to heat the window  2  when the external temperature Tout of the vehicle is lower than or equal to a predetermined temperature TO and there is a request for activation of the air conditioning apparatus  40 . 
     According to the first aspect, because there is a high possibility that there is some room for adjustment in the state of interior air when the air conditioning apparatus is started in a situation in which the outside temperature is low, activating the heater in such a situation enables effective reduction of fogging of the window while suppressing unnecessary activation of the heater. 
     Second Aspect 
     In the first aspect, the control unit  30  heats the window  2  for a first period D 1  using the heater  20 , and then stops the heating of the window  2  for a second period D 2 . 
     According to the second aspect, overheating of the window can be prevented by activating the heater intermittently. 
     Third Aspect 
     In the second aspect, the first period D 1  can be changed based on the external temperature Tout, and 
     the control unit  30  sets the first period D 1  longer for a lower external temperature Tout. 
     According to the third aspect, the initial heating period is extended when the outside temperature is low, and thus, the temperature of the window can be rapidly increased. 
     Fourth Aspect 
     In the second or third aspect, the second period D 2  can be changed based on the external temperature Tout, and the control unit  30  sets the second period D 2  shorter for a lower external temperature Tout. 
     According to the fourth aspect, the interval between the initial heating period and the second heating period is reduced when the outside temperature is low, and thus, a decrease in the temperature of the window can be suppressed. 
     Fifth Aspect 
     In any of the second to fourth aspects, after heating the window  2  for the first period D 1  using the heater  20 , the control unit  30  stops the heating of the window  2  for the second period D 2 , and then heats the window  2  for a third period D 3  that is shorter than the first period D 1 . 
     According to the fifth aspect, even if the outside temperature is low, the window temperature can be maintained by performing heating for the third period, which is shorter than the first period, because the window temperature is already increased once heating is performed for the first period. Further, by setting the third period shorter than the first period, overheating of the window can be prevented. 
     Sixth Aspect 
     In the fifth aspect, the third period D 3  can be changed based on the external temperature Tout, and 
     the control unit  30  sets the third period D 3  longer for a lower external temperature Tout. 
     According to the sixth aspect, the temperature of the window can be kept within a predetermined temperature range by extending the third period when the outside temperature is low. 
     Seventh Aspect 
     In any of the first to sixth aspects, the heater  20  includes a heater that generates heat using electric energy. 
     According to the seventh aspect, the load exerted on the power source can be reduced by reducing the activation timings of the heater. 
     Eighth Aspect 
     In any of the first to seventh aspects, the vehicle includes a surroundings detection apparatus  10  that performs detection with respect to the surroundings of the vehicle, and 
     the heater  20  heats an area that is a detection area of the surroundings detection apparatus  10  and that overlaps with the window  2 . 
     According to the eighth aspect, a visual field range of the surroundings detection apparatus can be heated using the heater, and thus, the fogging of the detection area can be reduced and a decrease in surroundings-detecting performance can be prevented. 
     Ninth Aspect 
     In the eighth aspect, the surroundings detection apparatus  10  is arranged adjacent to a structure  8  for preventing a decrease in surroundings-detecting accuracy, and 
     the heater  20  is supported by a member  7  including the structure  8 . 
     According to the ninth aspect, the window can be heated effectively because the heater is installed in the structure for preventing a decrease in detecting accuracy, which is arranged adjacent to the surroundings detection apparatus. 
     Tenth Aspect 
     A method of controlling a fogging suppression apparatus  1  that suppresses fogging of a window  2  of a vehicle, wherein 
     the fogging suppression apparatus  1  includes: 
     an acquisition unit  51  that acquires an external temperature Tout of the vehicle; and 
     a heater  20  that heats the window  2 , the heater  20  differing from air conditioning apparatus  40  including a blower provided in the vehicle, and 
     the control method includes 
     controlling (step S 54 ) the heater  20  so as to heat the window  2  if the external temperature Tout of the vehicle is lower than or equal to a predetermined temperature TO (YES in step S 52 ) and there was a request for activation of the air conditioning apparatus  40  (YES in step S 53 ). 
     According to the tenth aspect, because there is a high possibility that there is some room for adjustment in the state of interior air when the air conditioning apparatus is started in a situation in which the outside temperature is low, activating the heater in such a situation enables effective reduction of fogging of the window while suppressing unnecessary activation of the heater.