JP2000193590A - Device for detecting raindrop and dew condensation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable raindrops and dew condensation to be accurately detected without interfering with the field of view of a driver, by detecting totally reflected light in sheet glass inside and outside a vehicle due to first and second holograms provided for laminated glass by light receiving elements. SOLUTION: An light emitting element 5 and light receiving elements 61 and 62 are mounted on a laminated glass, and it is mounted as a wind shield. Detection light from the light emitting element 5 is partially diffracted by a hologram 31, totally reflected to travel in the laminated glass inside a vehicle, partially transmitted to be incident on a hologram 32, diffracted, and totally reflected to travel in the laminated glass outside the vehicle. When raindrops adheres to the laminated glass outside the vehicle, detection light is scattered to result in substantial reduction of detection light to be received by the light receiving element 62. When dew condensation occurs on the laminated glass inside the vehicle, detection light to be received by the light receiving element 61 is substantially reduced. By comparing the absolute amount of light reception of the light receiving element 62 with a reference value at the time of no rainfall and comparing the amount of light reception of the light receiving element 61 with a reference value at the time of no dew condensation, it is possible to detect raindrops and dew condensation each accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention automatically drives a wiper or the like by detecting that raindrops have adhered to a window glass of an automobile or the like, and automatically drives a defroster or the like by detecting dew condensation in a room. The present invention relates to a raindrop / condensation detection device for performing the above operation.

[0002]

2. Description of the Related Art Conventionally, a device for detecting raindrops has a light-emitting element and a light-receiving element arranged on the indoor side, and a light-emitting beam from the light-emitting element and a light-receiving field of view of the light-receiving element are located outside the room at a predetermined distance in front of glass. When raindrops are present in the sensing area, light from the light emitting element hits the raindrops and emits scattered light, and the scattered light is detected by the light receiving element to detect raindrops (Japanese Patent Application Laid-Open No. Hei 10-96891). Having a light-emitting element arranged toward the windshield and an element arranged toward the windshield and receiving light emitted from the light-emitting element and totally reflected inside the windshield, by raindrops on the windshield Apparatus for detecting the presence of raindrops based on a change in the amount of light received by a light-receiving element (Japanese Unexamined Patent Application Publication No.
No. 0-62336) and the like.

[0003] As a device for detecting raindrops and dew condensation,
Japanese Patent Application Laid-Open No. 9-257952, which combines a half mirror, a light guide plate, and a mirror, has been filed.

[0004]

However, the apparatus disclosed in Japanese Patent Application Laid-Open No. Hei 10-96891 always emits infrared light of the detection light in the forward direction. However, since the detection area is wide, energy is required for infrared radiation and detection. However, there is a problem because power consumption increases in a moving body such as a vehicle,
In particular, in the case of disposing the device in a vehicle interior, a green colored glass having a high heat shielding effect is often used in windshields of recent vehicles in order to suppress the flow of heat into the vehicle interior. At wavelengths longer than 3 μm, the transmittance is remarkably low at 10% or less, and the transmittance is low at 50% or less even in an infrared region shorter than that. This is particularly a concern, and the apparatus and the control system as a whole are very large. I have to be.

In the device disclosed in Japanese Patent Application Laid-Open No. H10-62336, the size of the entire detection device becomes large depending on the shape and installation state of the prism, so that the detection device is not only obstructive to a driver or the like, but also used for introduction and derivation. It is necessary to accurately attach the prism for use in a positional relationship with the light emitting element and the light receiving element.

The apparatus disclosed in Japanese Patent Application Laid-Open No. 9-257952 can also detect dew condensation in addition to raindrops, but requires a light guide plate, a half mirror, a mirror, and the like, and requires only a large-scale apparatus. However, the portion where the mirror is provided cannot be seen through, and is not preferable in terms of safety when used for a windshield or the like.

Further, since the conventional type is a device for detecting while transmitting and totally reflecting the interlayer film of the laminated glass,
When a shade band portion in which the intermediate film is colored is used, absorption of detection light is large, and detection is difficult.

The present invention has been made in view of the above points, does not require a light guide plate and a mirror, has no portion that cannot be seen through while the detection light is in progress, and uses a shade band portion. Therefore, it is an object of the present invention to provide a downsized and lightweight raindrop / condensation detection device which does not disturb a driver's view even if a light emitting element and a light receiving element are provided on a laminated glass in the vicinity thereof.

[0009]

SUMMARY OF THE INVENTION A raindrop / condensation detecting device according to the present invention is provided with a light emitting element and a light receiving element provided on a laminated glass for a vehicle in which two plate glasses are bonded by an intermediate film having a shade band portion partially colored. An element, a first hologram provided in a shade band portion on the mating surface side of the vehicle interior glass sheet, and a second hologram provided in a shade band portion on the mating surface side of the vehicle exterior glass sheet, and detecting light from the light emitting element. Two light beams are introduced, and one light beam is totally reflected in the interior glass by the first hologram.
The other light beam is totally reflected by the second hologram in the outside glass plate, and one light beam is received by the light receiving element to detect raindrops, and the other light beam is received to detect dew condensation. Features.

In the method of splitting into two light beams, a method of introducing detection light from one light-emitting element to a laminated glass and turning the detection light into two light beams by a hologram provided in the laminated glass is most effective without using a prism. Preferably, one light-emitting element may be branched by a half mirror, or two light-emitting elements may be used. In addition, when the detection light passes through the shaded band portion that is colored at the time of being introduced into the vehicle exterior glass plate, it is better to replace the intermediate film portion of the colored shade band portion with a non-colored intermediate film to reduce the amount of detection light. It is desirable because it can be suppressed. Further, when the detection light passes through the colored shade band portion when it is led out of the outside glass plate, it is better to replace the intermediate film portion of the colored shade band portion with a non-colored intermediate film to reduce the light amount of the detection light. This is desirable because reduction can be suppressed.

It is preferable that the detection light of the two light fluxes be guided to two light receiving elements provided on the laminated glass through two holograms for derivation without using a prism.
A prism may be used.

According to the present invention, the first hologram and the second hologram provided between two glass sheets totally reflect one of the detection lights of two light beams in the vehicle inner glass sheet and the other in the vehicle outer glass sheet. So that the light is emitted independently of the colored shade band portion of the intermediate film, so that the shade band portion does not disturb the driver's view.
A light receiving element or the like can be provided.

Further, an opaque plate such as a mirror is not required, and there is no hindrance between the light-emitting element and the light-receiving element, and projections such as a prism can be formed by using an introduction hologram and a derivation hologram. It does not need to be provided on the laminated glass.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The first hologram and the second hologram are reflection holograms, and are manufactured by irradiating a light-sensitive material such as a photopolymer with a total reflection surface of detection light of two light beams. Angle 2 in the direction of 41.8 ° -60.1 °
Laser light from different directions is radiated as divergent light and divergent light, divergent light and convergent light, or divergent light and parallel light from different surfaces through glass blocks, holograms, and the like to form interference fringes.

As the light emitting element, a light emitting diode emitting light of a single wavelength having a narrow wavelength range, an EL (electroluminescence) element, or the like can be suitably used. Can be used as well.

As the light receiving element, various small and lightweight light receiving elements such as a photodiode can be adopted.
One or two light emitting elements are provided on the laminated glass.

The detection light is introduced from the light emitting element to the laminated glass, as shown in Embodiments 2, 5 and 7, by providing the light emitting element 5 and the prism 7 on the laminated glass 1 or through the prism 7. As shown in the first embodiment, FIGS. 4 and 6, the hologram is introduced through the introduction holograms 3, 31, 32, and the like.

The holograms 3 and 32 in this case are transmission holograms. The holograms 3 and 32 are manufactured by first setting, for example, a vertical direction (0 ° incident angle) and an incident angle of 41.8 on one surface of a photosensitive material such as a photopolymer. A glass block from the same plane as laser light from two directions of ° to 60.1 ° as divergent light and divergent light, divergent light and convergent light or divergent light and parallel light;
Alternatively, irradiation is performed through a hologram or the like to form interference fringes.

When one light emitting element is used, it is necessary to split the detection light into two light beams. As a means for this, other than the known half mirror 8 shown in FIGS. 6 and 7, FIGS. As shown in Embodiment 1, the introduction hologram 3
1 and the introduction hologram 32, the diffraction efficiency of the introduction hologram 31 is set to approximately 50%, and the remaining light is incident on the introduction hologram 32. It preferably functions as a hologram, and furthermore, these holograms are preferable because they can also have a function of entering the detection light at an angle of total reflection in the glass.

The introduction hologram 31 in this case is a reflection type hologram. The hologram 31 is provided with a light-sensitive material such as a photopolymer so that the incident angle is, for example, 41.8 ° to 61.8 in the vertical direction (incident angle 0 °).
Laser light from two directions of 0.1 ° is divergent light and divergent light, divergent light and convergent light, or divergent light and parallel light.
Irradiating with a glass block, a hologram or the like interposed to form interference fringes,
Is a transmission type hologram. The transmission type hologram is manufactured by, for example, setting the vertical direction (incident angle 0 °) and the incident angle on one surface of a photosensitive material such as a photopolymer to 41.8 ° to 60.1 °.
Interfering fringes are formed by irradiating laser light from two directions in the direction of ° as divergent light and divergent light, divergent light and convergent light, or divergent light and parallel light from the same surface through a glass block, hologram, etc. I do.

When there are two light-emitting elements, there is only a prism for introduction or an introduction hologram for diffracting vertical light to an angle of total reflection in the glass, and an optical element for branching into two light beams. Is unnecessary.

Further, the detection light may be introduced and derived using the end face of the laminated glass. As shown in the third embodiment, a light receiving element may be provided near the end face and the detection light may be derived from the end face. Alternatively, both the light emitting element and the light receiving element may be provided near the end face of the laminated glass, and the detection light may be introduced and led out using the end face. In this case, it is necessary to provide folding holograms for folding the detection light of the two light beams by changing the optical path.

As the light receiving element, various small and lightweight light receiving elements such as a photodiode can be adopted.
Usually, two are provided on the laminated glass, but when two light emitting elements are provided, one can be provided. That is, two light emitting elements are used, and detection light for raindrop detection and dew condensation detection are alternately switched by a timer or the like, introduced into the laminated glass, and detected by the detection circuit in conjunction with the light emitting element to detect raindrops and dew condensation. The light-emitting element and the light-receiving element may be replaced with each other in the configurations described in Example 1 and Example 3 described later.

Derivation of the detection light to the light receiving element may be performed using a hologram for derivation or a prism, and the hologram for derivation may be manufactured in the same manner as the hologram for introduction.

As for the hologram photosensitive material, a 25 μm-thick photopolymer such as OmniD
Ex-352 (manufactured by DuPont) is preferably used, but any material may be used as long as it has a film coated with a photosensitive material.

When the raindrop adheres to the plate glass, the light is scattered at the raindrop portion and the amount of detection light incident on the light receiving element is reduced. It is possible to use a normal detection circuit to which a differentiating circuit or the like which can detect a change in the detection light, if necessary, may be used, such as a comparison circuit for performing a comparison.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings.

FIGS. 1 to 3 show Embodiments 1 to 3, respectively.
It is principal part sectional drawing of the windshield in FIG.

Embodiment 1 As shown in FIG. 1, this is an example in which the laminated glass 1 is used as a vehicle windshield and one light-emitting element is used, and detection light is introduced and derived by using an introduction hologram and a derivation hologram.

Here, an AlGaAs-based near-infrared light emitting diode was used as the light-emitting element, and a germanium-based detector was used as the detector. The hologram for introduction, the hologram for total reflection, and the hologram for derivation were manufactured as follows.

First, a 25 μm-thick photopolymer was applied to a resin film, for example, OmniDex.
-352 (manufactured by DuPont) Optics combining a laser oscillator, a beam splitter, a convex lens, a mirror, etc., which oscillates 647 nm light (not shown) by masking the area other than the 5 mm x 4 mm area of one side (left side) of a 5 mm x 14 mm photosensitive material. The laser beam is split into two by the device, and the reproduction angle of one light is 0 ° and the reproduction angle of the other light is 41.8 °
Divergent light at an incident angle of 21.4 ° by using a glass block so that the angle becomes between 6 ° and 60.1 °.
A parallel light beam of 1.4 ° is applied to different surfaces of the light-sensitive material at a reduced exposure amount to form an interference fringe having a diffraction efficiency of approximately 50% in an area of 5 mm × 4 mm on the left side of the light-sensitive material. 31.

Next, the left and right 5 mm × 4 mm areas are masked, and the laser light is split into two parts by an optical device (not shown) that combines a laser oscillator that oscillates light of 647 nm, a beam splitter, a convex lens, a mirror, and the like. And 60.7 ° parallel light using a glass block so that the reproduction angle of one light is 50.0 ° and the reproduction angle of the other light is 50.0 °.
Irradiation of 0.7 ° parallel light to different surfaces of the photosensitive material respectively forms interference fringes in a central 5 mm × 6 mm area,
This is a first hologram 21 for total reflection.

Next, the other area is masked in a 5 mm × 4 mm area on the right side, and 647 (not shown) is masked.
The laser beam is split into two by an optical device that combines a laser oscillator that oscillates light of nm, a beam splitter, a convex lens, a mirror, and the like.
And a convergent light having an incident angle of 21.4 ° using a glass block so that the reproduction angle of the other light is between 41.8 ° and 60.1 °. Parallel light is applied to different surfaces of the light-sensitive material to form interference fringes in an area of 5 mm × 4 mm to form a hologram 41 for derivation.

The hologram 31 for introduction, the total reflection hologram 21, and the hologram 41 for derivation are recorded on the photosensitive material thus obtained, and thereafter, a normal developing process is performed.

Further, a photopolymer having a thickness of 25 μm is applied to a resin film, for example, OmniDe.
An x-352 (manufactured by DuPont) 5 mm × 19 mm photosensitive material was masked except for an area of 5 mm × 4 mm on one side (left side), and a laser oscillator (not shown) for oscillating 647 nm light, a beam splitter, a convex lens, a mirror, and the like were combined. Laser light is split into two by an optical device,
The reproduction angle of one light is 0 ° and the reproduction angle of the other light is 41.8.
Divergent light at an incident angle of 6.2 ° using a glass block so that the angle is between 4 ° and 60.1 °.
Irradiation of 3.8 ° parallel divergent light is performed on one and the same surface of the photosensitive material to form interference fringes, thereby forming a transmission-type introduction hologram 32.

Next, the left and right 5 mm × 4 mm
Area is masked, and the laser light is split into two by an optical device combining a laser oscillator (not shown) that oscillates light of 647 nm, a beam splitter, a convex lens, a mirror, and the like, and the reproduction angle of one light is 50.0 °. Using a glass block, for example, parallel light of 60.7 °, so that the reproduction angle of the other light becomes an angle of 50.0 °,
A parallel light beam of 0.7 ° is applied to different surfaces of the light-sensitive material to form interference fringes in a central area of 5 mm × 11 mm to form a second hologram 22 for total reflection.

Next, the other area is masked in a 5 mm × 4 mm area on the right side thereof, and 647 (not shown) is masked.
The laser beam is split into two by an optical device that combines a laser oscillator that oscillates light of nm, a beam splitter, a convex lens, a mirror, and the like.
And a convergent light having an incident angle of 6.2 ° using a glass block so that the reproduction angle of the other light is between 41.8 ° and 60.1 °. Irradiate parallel light to one and the same surface of the light-sensitive material, respectively, 5 mm x 4 mm
An interference fringe is formed in the area of the hologram 42 for derivation.

The hologram 32 for introduction, the total reflection hologram 22, and the hologram 42 for derivation are recorded on the photosensitive material thus obtained, and thereafter, a normal developing process is performed.

Next, the above-mentioned first hologram sheet is placed on the side of the mating surface of the vehicle interior glass sheet 11 with the vehicle exterior glass sheet 12.
The above-mentioned second hologram sheet is stuck on the mating surface side of the above, and a normal laminating process is performed with an intermediate film 13 such as polyvinyl butyral having a shade band portion (hatched portion in the figure) colored, and then bonded and laminated. Get. It should be noted that the intermediate film of the portion where the detection light from the light emitting element is introduced and the portion where the detection light is led out to the light receiving element are replaced with an uncolored intermediate film.

The light-emitting element 5, light-receiving element 61, and light-receiving element 62 are mounted on the laminated glass, and are mounted on the front opening of the automobile as a windshield.

Although not shown, a lead wire from a power supply is connected to the light emitting element 5, and a detection circuit is connected to the output side of the light receiving elements 61 and 62.

In the raindrop / condensation detecting device thus obtained, when the detection light from the light emitting element 5 is introduced into the laminated glass, a part thereof is diffracted by the introduction hologram 31 and becomes one of the detection lights as the inside of the vehicle. The light travels while being totally reflected in the glass sheet, and a part that is not diffracted passes through and enters the introduction hologram 32, is diffracted by this hologram and becomes the other detection light, and travels while being totally reflected in the vehicle outside glass sheet.

The detection light traveling in the vehicle exterior glass sheet is totally reflected between the vehicle exterior surface of the vehicle exterior glass plate and the hologram 22 for total reflection when it is not raining, and is received by the light receiving element 62 and is received by the vehicle interior glass. The detection light traveling in the glass sheet is totally reflected between the glass plate inside the vehicle and the hologram 21 for total reflection when there is no dew condensation in the vehicle, and the light receiving element 61
Received.

In this case, since the light does not pass through the colored portion of the intermediate film, almost all light is received with only a slight attenuation of light in the laminated glass. When the raindrops adhere to the vehicle exterior surface of the vehicle exterior glazing, part or all of the detection light traveling in the vehicle exterior glazing is incident on the raindrops and is scattered by the raindrops. Almost 0
Or drastically decrease.

When dew condensation occurs on the vehicle interior glass sheet, a part or all of the detection light traveling through the vehicle interior glass sheet is incident on water droplets and is scattered by the water droplets. Decrease dramatically.

In a detection circuit (not shown), raindrops can be accurately detected by comparing the absolute value of the amount of light received by the light receiving element 62 with an amount corresponding to a normal amount without rain as a reference value. Similarly, by comparing the amount of light received by the light receiving element 61 with a reference value in a normal state where no dew condensation occurs, dew condensation can be accurately detected.

Embodiment 2 As shown in FIG. 2, a laminated glass 1 is used as a windshield for a vehicle, two light-emitting elements 51 and 52 are provided, and detection light is introduced and extracted through prisms 7 and 7. In this case, the first hologram 21 and the second hologram 22 are manufactured as long as they have the same optical characteristics as the first total reflection hologram and the second total reflection hologram in the first embodiment. Good.

Embodiment 3 As shown in FIG. 3, the laminated glass 1 is used as a vehicle windshield and one light emitting element 5 is provided. The light emitting element 5 is provided near the end face of the laminated glass and detected by the half mirror 8. The light is split into two light beams, and the detection light is extracted to the light receiving elements 61 and 62 by the derivation holograms 41 and 42. The first hologram 21 and the second hologram 22 are manufactured in the first embodiment. Like the first total reflection hologram and the second total reflection hologram, the derivation holograms 41 and 42 may be formed in the same manner as the derivation hologram 42 in the first embodiment.

[0049]

According to the present invention, the raindrop is detected by using the shade band portion to detect the raindrop by using only the outer glass sheet and using only the outer glass sheet to detect the raindrop. This is to detect the dew condensation as it travels, so that it does not disturb the driver's field of view. Moreover, the hologram is used so that the two light beams do not cross each other, so that the laminated glass is kept transparent. Thus, raindrops and dew can be accurately detected, and the size of the apparatus can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part of a windshield according to a first embodiment.

FIG. 2 is a sectional view of a main part of a windshield in a second embodiment.

FIG. 3 is a sectional view of a main part of a windshield in a third embodiment.

FIG. 4 is a sectional view of a main part showing one embodiment of introduction of detection light.

FIG. 5 is a cross-sectional view of a main part showing one embodiment of introduction of detection light.

FIG. 6 is a sectional view of a main part showing one embodiment of introduction of detection light.

FIG. 7 is a cross-sectional view of a principal part showing one embodiment of introduction of detection light.

[Description of Signs] 1 Laminated glass 2 Hologram for total reflection 3, 31, 32 Hologram for introduction 41, 42, 43, 44 Hologram for derivation 5, 51, 52 Light emitting element 61, 62 Light receiving element 7 Prism 8 Half mirror

Continuation of the front page F term (reference) 2G059 AA05 BB04 BB08 BB20 CC11 EE02 EE09 GG02 GG03 HH01 JJ12 JJ30 KK03 KK10 LL01 MM05 3D025 AA01 AB01 AC01 AC05 AC21 AD02 AG42 AG68

Claims (5)

[Claims] 1. A light-emitting element and a light-receiving element provided on a laminated glass for a vehicle, which are bonded by an intermediate film having a shade band portion in which two glass sheets are partially colored, and a shade band portion on a laminated surface side of a vehicle-inside glass sheet. The first provided
And a second hologram provided in a shade band portion on the mating surface side of the vehicle exterior glass sheet, and two detection light beams from the light emitting element are introduced, and one of the light beams is supplied to the vehicle interior glass sheet by the first hologram. The inside is totally reflected, and the other light beam is totally reflected inside the outer glass plate by the second hologram. One light beam is received by the light receiving element to detect raindrops, and the other light beam is received to detect condensation. A raindrop / condensation detection device characterized in that: 2. The raindrop / condensation detection according to claim 1, wherein detection light is introduced from one light emitting element to the laminated glass, and the detection light is made into two light beams by a branch sheet provided on the same surface as the hologram. apparatus. 3. The raindrop / condensation detecting device according to claim 2, wherein the branch sheet is a hologram. 4. The raindrop / condensation detection device according to claim 1, wherein two light beams of detection light are introduced into the laminated glass from the two light emitting elements. 5. The raindrop according to claim 1, wherein the colored intermediate film portion of the detection light introducing part and / or the deriving part is replaced with a non-colored intermediate film.・ Condensation detector.