JP2000266664A - Clouding-detecting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a clouding-detecting apparatus which can surely detect a clouding state of window glasses beforehand. SOLUTION: The clouding-detecting apparatus has a thermally conductive member 11 of good thermal conduction properties embedded in a part of a window glass 36. A light is radiated toward the surface of the member from a light-emitting diode 22 and the light reflected at the surface of the thermally conductive member 11 is received by a photodiode 23. Since the thermally conductive member 11 has good thermal conduction properties, the temperature of the inner surface becomes almost equal to the temperature of the outside air. Therefore, the surface of the thermally conductive member 11 is turned cloudy earlier than the window glass 36 particularly when the outside air has a lower temperature than that of the inside. Moreover, the light is scattered when reflected at the surface, and consequently, the quantity of light received by the photodiode 23 is lessened in comparison with when the thermally conductive member is not cloudy. The clouding-detecting apparatus detects a clouding of the inner surface of the thermally conductive member 11 by the quantity of the received light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fogging detecting device, and more particularly to a fogging detecting device for detecting fogging of a window glass of a vehicle or the like.

[0002]

2. Description of the Related Art When a window glass of a vehicle or the like becomes cloudy due to a change in temperature or an increase in humidity, visibility deteriorates and hinders driving or the like. Therefore, a cloudy state of the window glass is detected and clouding of a defroster or a defogger is performed. It is required to remove the fogging by a removing device. To cope with this, one system of a fogging detection device for window glass is disclosed in Japanese Patent Application Laid-Open No. 1-132445. FIG. 11 is a diagram showing the fogging detection device of the conventional example.

In FIG. 1, a fogging detecting device 1 of the conventional example is shown.
Reference numeral 02 denotes a part of the interior surface of the window glass 100 in which a region where air by the defroster is difficult to reach and fogging easily occurs is provided by the support 108. In addition, the fogging detection device 102 transmits light generated by the light emitting diode D driven by the pulse oscillator 104 to the optical fiber 10.
5, and is projected on the window glass 100 almost vertically. The light transmitted through the window glass 100 is reflected by the reflection plate 10.
The reflected light is transmitted through the window glass 100 again to be incident on the other optical fiber 106. Since the light transmitted through the optical fiber 106 irradiates the phototransistor T at the end of the optical fiber 106, the phototransistor T is turned on. The microcomputer 200 determines the degree of fogging of the window glass 100 from the potential of the collector terminal of the phototransistor T.

When the temperature inside the vehicle is lower than the outside air temperature in the state where the defroster is operated, or when the moisture contained in the air inside the vehicle increases and becomes higher than the saturated water vapor, the window glass 100 is closed. Part A becomes cloudy. Therefore, the light projected on the window glass 100 is scattered in the portion A, and the amount of light received by the phototransistor T decreases. At this time, since the potential level of the collector terminal of the phototransistor T drops, the microcomputer 200 detects the fogging state of the portion A of the window glass 100.

[0005]

As described above, in the fogging detecting device 102 of the above-mentioned conventional example, a region where air is hard to reach by the defroster and fogging is likely to occur on a part of the inner surface of the window glass 100 is supported. Although it is provided by 108, there is a problem that the air does not always fog first depending on the installation location of the support body 108 because some air enters. Further, in a state where the defroster is not operated, since there is no temperature difference between the portion A of the window glass 100 and other portions, the portion A does not always become cloudy before the other portions. In order to prevent the fogging state of the window glass 100 before the fogging of the window glass 100 starts due to 102, there is a problem that the present apparatus 102 and a defrosting device such as a defroster must always be operated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide a fogging detection device capable of reliably detecting a fogging state of a window glass in advance.

[0007]

According to a first aspect of the present invention, there is provided a fogging detection device which is formed on a part of a window glass which blocks outside air from an internal space, and which is provided on an inner space side. A light reflecting member whose surface temperature is kept substantially equal to the outside air temperature, a light projecting means for projecting light onto the light reflecting member, and receiving reflected light reflected on an inner space side surface of the light reflecting member; Light receiving means for outputting an electric signal corresponding to the amount of reflected light.

According to a second aspect of the present invention, in the fogging detecting device according to the first aspect, the light reflecting member has one surface exposed to the outside air and the other surface exposed to the internal space. , Made of a metal having high thermal conductivity.

According to a third aspect of the present invention, in the fogging detecting device according to the first aspect, the light reflecting member is constituted by a thermoelectric element, and the outside air temperature detecting means for detecting an outside air temperature; Control means for keeping the temperature detected by the temperature detecting means and the surface temperature of the light reflecting member on the side of the internal space at the same level.

In the fogging detecting device according to the first aspect of the present invention, the light reflecting member is formed on a part of the window glass that blocks the outside air and the inside space, and the surface temperature on the side of the inside space is kept substantially equal to the outside air temperature. The light is projected from the light projecting means, and the light receiving means receives the reflected light reflected on the surface on the internal space side of the light reflecting member, and converts the electric signal photoelectrically converted according to the amount of the reflected light. The fogging state of the surface of the light reflecting member on the side of the inner space is detected. In particular, in the fogging detection device according to claim 2, the light reflecting member is formed of a metal having high thermal conductivity, one surface of which is exposed to the outside air, and the other surface of which is exposed to the internal space. In the fogging detection device according to item 3, the light reflecting member is constituted by a thermoelectric element, and the outside air temperature detecting means for detecting the outside air temperature, and the temperature detected by the outside air temperature detecting means and the surface of the light reflecting member on the internal space side. Since the control means for keeping the temperature at the same level is used, the surface temperature on the inner surface side of the light reflecting member becomes the outside air temperature before the surface temperature on the inner space side of the window glass.

[0011] Therefore, especially when the outside air temperature is lower than the temperature of the internal space, the surface temperature of the light reflecting member on the internal space side decreases before the surface temperature of the window glass on the internal space side. Since the fogging occurs earlier, the fogging state of the window glass can be detected in advance.

When the fogging detecting device detects the fogging state of the surface on the side of the internal space of the light reflecting member, the fogging removing device is operated to detect the fogging state of the window glass before the fogging of the window glass starts. Since it can be prevented, the driver can always secure a sufficient view area. In addition, even when the apparatus is not operating, the fogging state of the window glass can be detected in advance and the fogging state of the window glass can be prevented. Electricity can be realized.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a first embodiment of a fogging detecting device according to the present invention; FIG. explain. Here, FIG. 1 is an exploded side view of the fogging detection device according to the first embodiment of the present invention, FIG. 2 is an external perspective view of the light guide plate, FIG. 3 is a plan view of the light guide plate, and FIG. FIG. 5, FIG. 5 is a sectional view taken along the line JJ of FIG. 3, FIG. 6 is a bottom view of the light guide plate, FIG. 7 is a view showing a state in which the fogging detection device according to the first embodiment is attached to window glass, FIG. Is a cross-sectional view of the fogging detection device according to the first embodiment attached to the window glass, FIG. 9 is a block diagram showing a control system applied to the fogging detection device according to the first embodiment, and FIG. It is sectional drawing of the fogging detection device of 2nd Embodiment attached.

A fogging detection device according to an embodiment of the present invention comprises:
This is a device that detects the fogging state of the window glass of a vehicle or the like in advance, and blows air such as warm air from an air conditioner through a control system composed of an electric circuit and blows the window glass (mainly windshield). It is connected to a defroster, such as a defroster that removes fogging by applying light, or a defogger, such as a defogger, that removes fogging of window glass by energizing heat rays embedded in window glass (mainly the rear window) to generate heat. .

[First Embodiment] A fogging detection device according to a first embodiment of the present invention will be described with reference to FIG. In the figure, the fogging detection device 20 of the present embodiment
A light guide plate 21, a silicon layer 35, a light emitting diode 22 corresponding to a light projecting unit, a photodiode 23 corresponding to a light receiving unit, a substrate 24, and a cover 2.
5 and a heat conductive member 11 corresponding to the light reflecting member.

Next, the light guide plate 21 will be described with reference to FIGS. The light guide plate 21 is a substantially convex member formed of a light transmitting material such as a resin that transmits light. Also,
As shown in FIG. 4, lenses 30A and 30B are respectively arranged on the both side walls of the protruding portion in an obliquely upward state. As shown in FIGS. 5 and 6, a space 28 is formed in the light guide plate 21 from the bottom surface to the center. Reference numerals 31A and 31B in FIG. 6 denote inclined surfaces on the space 28 side of the lenses 30A and 30B, respectively.

The wall surface of the light guide plate 21 on the space 28 side is coated with a heat-insulating resin, and the temperature inside the vehicle is reduced to the space 2.
The inside of the space 28 is kept at the same temperature as the outside air temperature by being insulated so as not to be transmitted to the inside 8. A light-reflective material is applied to the upper surface of the side wall surface of the space 28, that is, the wall surface other than the inclined surface of the lenses 30A and 30B on the space 28 side (hereinafter referred to as the inner wall upper surface). Further, a small width and horizontally long ventilation hole 27 is formed in a part of the longitudinal side surface of the light guide plate 21. The ventilation port 27 is usually formed on the side to which the air from the defroster is blown, and restricts the amount of air flowing into the space 28.

Next, the silicon layer 35 is a member formed of silicon resin and having substantially the same shape as the bottom surface of the light guide plate 21, and is provided on the bottom surface of the light guide plate 21.

Next, the light emitting diode (LED) 22
For example, an infrared light emitting diode is a light emitting element that is driven to blink at a constant period by the drive circuit 49 shown in FIG. The light generated by the light emitting diode 22 is substantially perpendicularly incident on the center of one lens 30A. The photodiode 23 is a light receiving element that receives light transmitted through the other lens 30B from the space 28 side and performs photoelectric conversion. Note that a phototransistor may be used instead of the photodiode 23.

The light emitting diode 22 and the photodiode 23 are attached to both ends of a substrate 24, as shown in FIG. However, when the fogging detection device 20 is assembled, the light generated by the light emitting diode 22 is incident on one lens 30A, and the light transmitted through the other lens 30B is received by the photodiode 23. Attach to

Next, the cover 25 is a housing for covering the light guide plate 21, the light emitting diode 22, the photodiode 23 and the substrate 24, and is coupled to the light guide plate 21. In the cover 25, a ventilation port 26 having substantially the same shape as the ventilation port 27 of the light guide plate 21 is provided at the same position as the ventilation port 27 formed in the light guide plate 21 when the cover 25 is coupled to the light guide plate 21. Is formed to come.

Further, the heat conductive member 11 is a metal plate made of copper or the like having a high thermal conductivity embedded flush with a window glass 36 of a vehicle or the like, and each surface is exposed to the outside air or the space 28, respectively. Have been. Since the heat conductive member 11 has good heat conductivity, when the outside air temperature changes, the temperature of the heat conductive member 11 becomes approximately equal to the outside air temperature before the window glass 36.
In particular, when the outside air temperature is lower than the temperature of the space 28,
Since the temperature of the heat conductive member 11 is lowered before the window glass 36, the surface (hereinafter, referred to as an inner surface) 40 of the heat conductive member 11 on the space 28 side is fogged earlier.

When assembling the fogging detection device 20 using the components described above, the light-emitting diode 22 and the photodiode 23 are attached to the substrate 24 while
The cover 25 and the light guide plate 21 are combined so that the substrate 24 and the like are housed inside the cover 25, and the light guide plate 2
A silicon layer 35 is attached to the bottom surface of the substrate 1. Next, as shown in FIG. 7, the light guide plate 21 is attached to the window glass 36 such that the space 28 of the light guide plate 21 is located at a position corresponding to the heat conductive member 11 attached to the window glass 36.

Next, the operation of the fogging detecting device 20 will be described with reference to FIG. Fogging detection device 20 of the present embodiment
As described above, the heat conductive member 11 having good heat conductivity is embedded in a part of the window glass 36 as described above. In particular, when the outside air temperature decreases, the temperature of the heat conductive member 11 decreases before the window glass 36, so that the inner surface 40 foggs earlier. The light emitting diode 22 emits light to one lens 30A of the light guide plate 21 by being driven by the drive circuit 49, but regardless of whether the inner surface 40 of the heat conductive member 11 is clouded. The vehicle is always running when the vehicle's electrical system is running.

Light emitted from the light emitting diode 22 passes through the lens 30A and is totally reflected on the inner surface 40 of the heat conductive member 11, as shown in FIG. The light totally reflected on the inner surface 40 of the heat conductive member 11 is totally reflected on the upper surface of the inner wall of the light guide plate 21 and is again totally reflected on the inner surface 40 of the heat conductive member 11. In this way, the light of the light emitting diode 22 travels toward the photodiode 23 while reflecting the inner surface 40 of the heat conductive member 11 and the upper surface of the inner wall of the light guide plate 21, passes through the lens 30B, and is received by the photodiode 23. You. The photodiode 23 photoelectrically converts the received light into an electric signal indicating the amount of received light (the amount of received light).

As shown in FIG. 9, the fogging detection device 20 of this embodiment includes an amplifying circuit 50, a rectifying circuit 51, and a judging circuit 5.
2 and a control system having a controller 53 are connected to a defroster and a defogger. Hereinafter, the operation of the control system after the light received by the photodiode 23 is photoelectrically converted will be described with reference to FIG.

The electric signal photoelectrically converted by the photodiode 23 is amplified by the amplifier circuit 50, and is amplified by the rectifier circuit 51.
And supplied to the decision circuit 52. Judgment circuit 52
Compares the potential of the obtained electric signal with a preset reference value to determine whether the inner surface 40 of the heat conductive member 11 is clouded. When the determination circuit 52 determines that the inner surface 40 of the heat conductive member 11 is clouded, it supplies a signal having, for example, an “H” level potential to the controller 53 to drive the defroster or the defogger.

Normally, the potential level of the electric signal photoelectrically converted by the photodiode 23 changes according to the amount of received light, and when a large amount of light is irradiated on the photodiode 23, an electric signal having a relatively high potential is output. . For this reason, when the inner surface 40 of the heat conductive member 11 is not cloudy, the light generated from the light emitting diode 22 is totally reflected on the inner surface 40 of the heat conductive member 11, so that a light having a relatively high light amount is obtained. Is irradiated on the photodiode 23. At this time, the potential level of the electric signal output from the photodiode 23 is relatively high, and since the potential level of the electric signal is higher than the reference value, the determination circuit 52 determines that the inner surface 40 of the heat conductive member 11 is cloudy. It is determined that there is no
For example, a signal having an “H” level potential is supplied.

On the other hand, when the inner surface 40 of the heat conductive member 11 is fogged, the light generated from the light emitting diode 22 is scattered on the inner surface 40 of the heat conductive member 11, so that the amount of light received by the photodiode 23 is Decrease. At this time, the potential level of the electric signal output from the photodiode 23 becomes relatively low, and when the potential level of the electric signal is equal to or lower than the reference value, the determination circuit 52 determines that the inner surface 40 of the heat conductive member 11 is cloudy. Controller 53
, For example, a signal having an “L” level potential is supplied.
Therefore, the controller 53 drives the defroster or the defogger.

As described above, according to the fogging detecting device 20 of the present embodiment, the heat conductive member 11 having good heat conductivity is provided on a part of the window glass 36.
In particular, when the outside air temperature decreases, the temperature lowers before the window glass 36 and the inner surface 40 foggs, so that the fogging state of the window glass 36 can be detected in advance. At this time, by operating a fogging removal device such as a defroster or a defogger, the fogging state of the window glass 36 is prevented beforehand, so that the driver can always secure a sufficient visibility area.

Further, even if the defogging apparatus is not operating, the defogging state of the window glass 36 can be detected in advance, so that there is no need to uselessly operate the defogging apparatus and power saving can be realized. .

[Second Embodiment] Next, a fogging detecting device according to a second embodiment of the present invention will be described with reference to FIG. In the figure, the same reference numerals are given to the same parts as those in the first embodiment (FIG. 8), and the description is omitted.
In FIG. 10, the fogging detection device of the present embodiment is a light guide plate 2 used in the fogging detection device 20 of the first embodiment.
1. In addition to the silicon layer 35, the light emitting diode 22, the photodiode 23, the substrate 24, and the cover 25, an outside air temperature sensor (not shown) corresponding to an outside air temperature detecting means;
The thermoelectric element 13 is provided.

First, the outside air temperature sensor is, for example, a thermistor that detects the outside air temperature. next,
The thermoelectric element 13 is, for example, a Peltier element, and is formed on a surface of a window glass 36 on which light generated from the light emitting diode 22 is reflected. The thermoelectric element 13 is
Driven by a drive circuit (not shown) controlled by a microcomputer (not shown) corresponding to the control means so that the temperature of the inner surface becomes substantially equal to the outside air temperature detected by the outside air temperature sensor. Is done.

As described above, according to the fogging detection device of the present embodiment, the thermoelectric element 13 is installed on a part of the surface of the window glass 36, and the temperature of the inner surface thereof is made substantially equal to the outside air temperature. As a result, the temperature of the internal surface of the thermoelectric element 13 decreases and foggs before the window glass 36 particularly when the outside air temperature decreases, and therefore, similarly to the fogging detection device 20 of the first embodiment, the window glass 36 Cloudiness can be detected in advance. Also in the present embodiment, when the fogging state of the internal surface of the thermoelectric element 13 is detected, the fogging state of the window glass 36 is prevented by operating a fogging removing device such as a defroster or a defogger. Therefore, the driver can always secure a sufficient view area.

Further, similarly to the fogging detecting device of the first embodiment, the fogging state of the window glass 36 can be detected in advance even when the fogging removing device is not operating. Need not be operated, and power saving can be realized.

Although the lenses 30A and 30B of the first and second embodiments are formed integrally with the light guide plate 21, they may be formed separately and attached to the light guide plate 21. good.

[0037]

As described above, according to the fogging detection device of the present invention, the surface temperature of the internal space is formed at a part of the window glass that blocks the outside air and the internal space, and the surface temperature on the internal space side is kept substantially equal to the external air temperature. Light is projected from the light projecting means to the dropped light reflecting member, and the light receiving means receives the reflected light reflected on the surface of the light reflecting member on the internal space side, and performs photoelectric conversion according to the amount of the reflected light. The fogging state on the inner space side surface of the light reflecting member is detected by using the obtained electric signal. In particular, the light reflecting member is formed of a metal having high thermal conductivity, one surface of which is exposed to the outside air and the other surface of which is exposed to the internal space, and an outside air temperature detecting means for detecting the outside air temperature. Because it is configured by a thermoelectric element controlled by a control unit that keeps the detected outside air temperature and the surface temperature of the light reflecting member on the inner space side at the same level, the surface temperature on the inner surface side of the light reflecting member is The outside air temperature can be set earlier than the surface temperature on the inner space side of the window glass.

For this reason, especially when the outside air temperature is lower than the temperature of the internal space, the surface temperature of the light reflecting member on the internal space side is reduced before the surface temperature of the window glass on the internal space side, and the window glass is reduced. Since the fogging occurs earlier than before, the fogging state of the window glass can be reliably detected in advance.

When the fogging detecting device detects a fogging state on the surface of the light reflecting member on the inner space side, the fogging removing device is operated to detect the fogging state of the window glass before the fogging of the window glass starts. Since it can be prevented, the driver can always secure a sufficient view area. In addition, even when the apparatus is not operating, the fogging state of the window glass can be detected in advance and the fogging state of the window glass can be prevented. Electricity can be realized.

[Brief description of the drawings]

FIG. 1 is an exploded side view of a fogging detection device according to a first embodiment of the present invention.

FIG. 2 is an external perspective view of a light guide plate.

FIG. 3 is a plan view of a light guide plate.

FIG. 4 is a front view of a light guide plate.

FIG. 5 is a sectional view taken along line JJ of FIG. 3;

FIG. 6 is a bottom view of the light guide plate.

FIG. 7 is a diagram showing a state in which the fogging detection device according to the first embodiment is attached to a window glass.

FIG. 8 is a cross-sectional view of the fogging detection device according to the first embodiment attached to a window glass.

FIG. 9 is a block diagram illustrating a control system applied to the fogging detection device according to the first embodiment.

FIG. 10 is a cross-sectional view of the fogging detection device according to the second embodiment attached to a window glass.

FIG. 11 is a diagram illustrating a conventional example of a fogging detection device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 heat conductive member 13 thermoelectric element 20 fogging detector 21 light guide plate 22 light emitting diode 23 photodiode 24 substrate 25 cover 26, 27 ventilation port 28 space 30A, 30B lens 35 silicon layer 36 window glass 48 control system 49 drive circuit 50 amplification Circuit 51 Rectifier circuit 52 Judgment circuit 53 Controller

Claims (3)

[Claims] 1. A light reflecting member formed on a part of a window glass that blocks outside air and an internal space, and has a surface temperature on the side of the internal space kept substantially equal to the outside air temperature, and emits light to the light reflecting member. Light projection means, and light receiving means for receiving reflected light reflected on the inner space side surface of the light reflecting member and outputting an electric signal corresponding to the amount of the reflected light, Detection device. 2. The light reflecting member is formed of a metal having a high thermal conductivity, one surface of which is exposed to the outside air and the other surface of which is exposed to an internal space. Fogging detection device. 3. The light reflecting member is constituted by a thermoelectric element, an outside air temperature detecting means for detecting an outside air temperature, a temperature detected by the outside air temperature detecting means, a surface temperature on an inner space side of the light reflecting member, and 2. A fogging detection device according to claim 1, further comprising control means for keeping the same.