JP2002082044A - Device for detecting clinging matter and control device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for detecting clinging matter capable of determining with high sensitivity whether or not there is any clinging matter, such as raindrops on the detecting surface of an element. SOLUTION: Mounting of elements, such as a light emission means 10, an imaging lens 40, and a photocell portion 50, is adjusted according to a condition that no external light enters directly the photocell portion 50 and a condition that a condition for total reflection at the detecting surface 110 is either met or not met depending on whether or not there is clinging matter, and that totally reflected light is received by the photocell portion 50. The light emitted from the light emission means 10 enters the detecting surface 110 with an incidence angle θ0, and if there is no clinging matter, it is totally reflected by the detecting surface 110; if there is clinging matter, it is not totally reflected but escapes into the outside. The totally reflected light propagates into a contact medium layer 30 at a refraction angle θ3 and then enters the imaging lens 40 at an incidence angle θ4. The imaging lens 40 has a mounting angle of θ5 and an opening angle of θS and the light 213 is received by the photocell portion 50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an attached object detecting device for detecting the presence of an attached object on a detection surface, and a control content triggered by detection of the attached object by the attached object detecting device. The present invention relates to a control device using an attached matter detection device that changes the value.

[0002]

2. Description of the Related Art There are various systems which detect the presence or absence of a deposit and change the control content in response to the detection of the presence of a deposit. Considering raindrops as an example of the deposit, it is necessary for the window wiper control device of the windshield of the car to change the control content on an occasional basis when the weather changes and the rainfall starts. One of the important issues for improving the convenience of the window wiper control device is the development of a rain sensor for detecting whether or not it is raining. Hereinafter, a conventional rain sensor that detects raindrops on a windshield of a car as a deposit will be described as a conventional deposit detection device.

In the case of a generally used window wiper operated by a manual operation, the driver himself / herself recognizes that rain has started, and takes into consideration the running state of the vehicle and changes in the amount of raindrops attached to the windshield. It is necessary to manually switch the window wiper switch from off to on in order to ensure the necessary visibility through the windshield. In order to alleviate the trouble of manually switching the window wiper switch, a rain sensor is provided to detect the presence of deposits such as raindrops on the detection surface of the windshield of the vehicle, and to determine whether the window needs to be wiped. Has been determined.

As a conventional rain sensor, a reflected light detection type rain sensor or the like is known according to a method of detecting raindrops. FIG. 12 is a diagram simply illustrating the principle of raindrop detection by a reflected light detection type rain sensor according to the related art. In FIG. 12, reference numeral 1000 denotes an automobile windshield.
For convenience of explanation, the upper space of the windshield 1000 is the inside of the vehicle, that is, the space on the driver side, and the lower space is the outside world. 1010 is a light source, 1020 is a prism for introducing light from the light source into the windshield, 1030 is a prism for guiding reflected light from the windshield, 1040 is a lens, 1050 is a light receiving element, 1110
Is the detection surface. 1120 is a raindrop adhering on the detection surface. The light source 1010 irradiates a light beam having a spread capable of covering the entire detection surface, of which 1130 is a trajectory of light incident on a portion where raindrops are attached, and 1140 other than 1130 is a detection surface where no raindrops are attached. Represents the trajectory of the light incident on the light source.

In the reflected light detection type rain sensor, it is important to adjust the mounting angle of each element and the material (particularly, the refractive index of the material). To put it simply, the principle of raindrop detection is that light incident on the portion of the detection surface to which the raindrops are attached escapes to the outside world without satisfying the condition of total reflection at the outer interface of the windshield 1000, and the raindrop on the detection surface becomes The light that has entered the unattached portion is totally reflected at the outer interface of the windshield 1000 under the condition that the total reflection is satisfied, and the intensity difference of the reflected light is detected.

Therefore, the light source 1010 and the prism 102
In the case of 0, an angle and a material satisfying an incidence condition for irradiating light to enter the inside of the windshield 1000 are selected, and an angle of total reflection on a detection surface on an outer interface of the windshield 1000 is selected. Further, a change in the refractive index due to the attachment of raindrops satisfies the condition of total reflection on the detection surface 1110.
The light incident angle with respect to the detection surface is selected so as to switch the dissatisfaction.

The material and angle of the prism 1030 are also selected so as to satisfy the emission condition so that the reflected light can be emitted to the outside of the windshield 1000, that is, the total reflection condition is not satisfied. Lens 1040 and light receiving element 1050
The angle and distance are adjusted so that the light incident on the lens 1040 is focused on the sensor portion of the light receiving element 1050.

The elements 1010 to 1050 can be attached to places other than the windshield 1000, for example, on a hood or a roof.
Since the detection target is in the state of the windshield 1000, it is preferable that the detection target is attached to a wiper wiping unit which is a part of the windshield. In addition, it is preferable to be attached so as not to narrow the field of view of the driver. For example, it is preferable to attach to a windshield portion where a rearview mirror is originally attached and the view is blocked.

The operation of the above-mentioned conventional reflected light detecting type rain sensor will be briefly described. The light beam emitted from the light source 1010 is
00, and enters the entire detection surface 1110. Now, it is assumed that the raindrop 1120 has adhered to the detection surface 1110. Light 11 incident on the portion of the light incident on sensing surface 1110 to which raindrop 1120 is attached
30 is an outer interface of the windshield 1000,
The condition of total reflection is not satisfied due to the presence of raindrops having a refractive index n of about 1.3, and the light escapes to the outside world, and this light is
And is not detected. On the other hand, the detection surface 111
The light 1140 incident on the portion where the raindrops are not adhered among the light incident on 0 is satisfied by the presence of air having a refractive index n of 1 at the outer interface of the windshield 1000 and the total reflection condition is satisfied. reflect. The totally reflected light is the prism 1030 on the inner surface of the vehicle of the windshield 1000.
Exits into the vehicle without total reflection due to the presence of The emitted light is condensed by the lens 1040 on the light sensor portion on the light receiving element 1050.

As described above, the amount of light detected by the light receiving element 1050 decreases in the presence of the raindrop 1120, and decreases in the presence of the raindrop 112.
The larger the area where 0 covers the detection surface 1110, the smaller the amount of light received. By detecting this change in the amount of light, the presence of raindrops on the detection surface 1110 is detected. The above is the principle of raindrop detection by the conventional reflected light detection type rain sensor.

It should be noted that a rain sensor of the type described above is:
It is configured to output a raindrop detection signal when the above-described signal change is detected. The raindrop detection signal from the rain sensor is input to the control unit of the window wiper,
Control of a predetermined window wiper or the like is performed in response to the input of the raindrop detection signal.

[0012]

However, the conventional rain sensor has the following problems.

As seen from the above prior art, the detection probability of raindrops depends on the detection area, so that the detection surface 1110 is made as wide as possible in order to increase the detection probability of raindrops.
The change in the amount of reflected light is detected by receiving the reflected light from the light receiving element 1050 with one light receiving element 1050. For example, windshield 1
In order to secure the driver's view on the 000 above and to ensure the aesthetics of the car, a rain sensor was installed on a windshield near the rearview mirror and the detection surface was intended to be as wide as possible. .

However, the reflected light detecting rain sensor in the prior art has a problem in sensitivity. The conventional reflected light detection type rain sensor needs to detect a change in the amount of reflected light from the detection surface 1110 on the windshield 1000 with high sensitivity, but the change in the amount of reflected light caused by the attachment of raindrops on the windshield 1000 is high. The following reasons make it difficult to grasp the sensitivity.

The first consideration is to eliminate the influence of external light. The windshield 1000 is made of a transparent substrate such as glass, and is apt to receive natural light from the outside such as sunlight, artificial lighting such as street lights and neon signs, and external light such as headlights of oncoming vehicles. Light is windshield 1000, prism 1030, lens 104
0, the light is incident on the light receiving element 1050, and is easily received as optical noise. The amount of reflected light from the detection surface 1110 condensed by the lens 1040 determines the reference signal value, and only the amount of light that escapes from the portion of the detection surface 1110 where raindrops adhere to the outside determines the signal change. If the amount of external light relative to the signal change is relatively large, it is difficult to determine the presence or absence of a change in the detection signal from the light receiving element, resulting in a problem that the detection accuracy of raindrop adhesion is reduced.

The second consideration is that the incident angle of light from the light emitting means 1010 to the detection surface 1110, the transparent substrate, Is that the refractive index must be selected. This is mainly due to the angle of incidence of the outgoing light from the light emitting means 1010 to the detection surface 1110, the windshield 10
The material (refractive index) of 00 and the material (refractive index) of the attached matter are considerations.

A third consideration is that each element is arranged in consideration of the opening angle and the mounting angle of the lens 1040. The reflected light from the detection surface 1110 is
Lens 1 to collect light from the
Although 040 is used, the lens 1040 has an opening angle, and whether or not external light is picked up is affected by the opening angle. The aperture angle and the mounting angle of the lens 1040 must be selected so that external light is not picked up but only the reflected light from the detection surface 1110 is picked up. This mainly involves consideration of the angle of reflection of the reflected light from the detection surface 1110, the angle of emission from the windshield 1000, the material (refractive index) of the prism 1030, the opening angle of the lens 1040, the mounting angle of the lens, and the like.

The fourth consideration is that the windshield 10
The light loss of a transparent substrate such as 00 is reduced. Even if it is a transparent substrate, when light passes through it, a light loss is observed at a rate according to the characteristics of the material. If the light loss is large, there is a problem that the amount of reflected light to be received by the light receiving element 1050 is reduced.

Considering the above four considerations, it is necessary to be able to detect the change in the amount of reflected light caused by the attachment of raindrops with high sensitivity.

In view of the above problems, the present invention eliminates the influence of external light, and switches the satisfaction / dissatisfaction of the total reflection condition on the detection surface depending on the presence or absence of an attached matter with high sensitivity, thereby reducing the loss of light to be detected. An object of the present invention is to provide an attached object detection device which is small and can detect the presence or absence of attachment of raindrops or the like with high sensitivity and a control device using the attached object detection device.

[0021]

In order to solve the above-mentioned problems, the present invention relates to an apparatus for detecting an adhered substance, comprising the steps of: detecting an incident light emitted from a light emitting means and introduced into the transparent substrate; An outer surface is used as a detection surface, and reflected light from the detection surface is received by a light receiving unit via an optical imaging system, and a light detection signal detected by the light receiving unit is reflected on the detection surface by the attached matter in the light detection signal. An adhering matter detection device provided with an adhering matter detecting unit that detects a change in a light detection signal due to a change in conditions and detects the presence of the adhering matter, wherein external light from the outside enters from the transparent substrate. In order not to be directly received by the light receiving means, according to a refractive index of a substance existing from the outside to the light receiving means, an arrangement angle of the light emitting means, the transparent substrate, the imaging optical system, and the light receiving means Has been adjusted And butterflies.

According to the above configuration, the external light can be blocked so as not to directly enter the light receiving means, the optical noise caused by the external light can be reduced, and the detection accuracy of the presence or absence of the adhering substance can be improved. be able to.

In the above attached matter detection device, the refractive index of the medium on the outer surface side of the transparent substrate is defined as n _1, and the refractive index of the medium from the transparent substrate to the imaging optical system is defined as n _3. , the mounting angle of the imaging optical system and theta _5, if the opening angle with the said imaging optical system and a theta _S, so as to satisfy the equation (5), said light emitting means, said transparent substrate, said formation The arrangement angle of the image optical system and the light receiving means is adjusted.

[0024]

(Equation 5)

Next, the attached matter detection device of the present invention uses the outer surface of the transparent substrate, which reflects the incident light emitted from the light emitting means and introduced into the transparent substrate, as a detection surface, The reflected light is received by the light receiving means via the optical imaging system, and in the light detection signal detected by the light receiving means, a change in the light detection signal due to a change in the reflection condition on the detection surface due to the attached matter is detected. An adhering matter detecting device for detecting the presence of the adhering matter, wherein reflection of light emitted from the light emitting means on the detecting surface when the adhering material does not exist on the detecting surface. The light emitting means, the transparent substrate, so that light is received by the light receiving means,
The imaging optical system, the light receiving unit is disposed, and, when the adhering substance is present on the detection surface, light emitted from the light emitting unit due to a change in a reflection condition of the adhering object on the detection surface. The arrangement angle of the light emitting means, the transparent substrate, the imaging optical system, and the light receiving means is adjusted so that the light is not reflected on the detection surface.

According to the above configuration, the satisfaction / dissatisfaction of the total reflection condition on the detection surface due to the presence or absence of the attached matter is switched with high sensitivity, so that the presence or absence of the attached matter can be determined with high sensitivity.

In the above attached matter detection device, the refractive index of the medium on the outer surface side of the transparent substrate is defined as n _1, and the refractive index of the medium from the transparent substrate to the imaging optical system is defined as n _3. When the refractive index of the attached matter is n ₁ ′ and the angle of refraction into the transparent substrate is θ ₂ , the light emitting unit, the transparent substrate, and the image forming device satisfy Equation (6). Optical system,
The arrangement angle of the light receiving means is adjusted.

[0028]

(Equation 6)

It is preferable that the attached matter detection device is configured to satisfy the above (Equation 5) and (Equation 6) simultaneously.

Next, in the attached matter detection device of the present invention, the light emitting means, the transparent substrate, the imaging optical system,
In the adjustment of the arrangement angle of the light receiving unit, it is preferable that the arrangement angle is selected so that the path of the light emitted from the light emitting unit and reflected by the detection surface in the transparent substrate passes the shortest.

With the above configuration, light loss in a transparent substrate such as a windshield can be reduced, and a relative change in a light detection signal based on the presence or absence of light detection in the light receiving element can be kept large.

In the above-mentioned attached matter detection device, the light receiving means is a light receiving means having a light receiving element, and a light receiving surface of each light receiving element and the detection surface corresponding to each light receiving element are formed by an imaging optical system. It is preferable that the imaging optical system is an imaging system using an imaging lens having an aperture angle θ _S that satisfies the condition of the above (Equation 5).

According to the above configuration, it is possible to provide a light receiving element corresponding to the detection surface, provide an imaging optical system in which the detection surface corresponds to the light receiving element, and allow external light to directly enter the light receiving means in the imaging optical system. Can be cut off so that no
It is configured such that the dissatisfaction is switched with high sensitivity. In addition,
As the imaging lens, a rod lens array or a gradient index lens array can be used.

Further, in order to solve the above problems, a control device using the attached matter detection device of the present invention includes an attached matter detection device of the present invention used as the rain sensor, a window wiper driving means, and a window wiper control means. Wherein the window wiper control means receives an attached matter detection signal from the attached matter detection device, and changes the control content of the window wiper driving means based on the detection signal.

With the above configuration, it is possible to provide a window wiper device that can immediately and reliably detect the start of rainfall and start window wiper driving at an appropriate timing.

[0036]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of an attached matter detection device and a control device using the same according to the present invention.

(Embodiment 1) In Embodiment 1, each element and its mounting angle will be described by taking as an example a case where the attached matter detection device of the present invention is used as a rain sensor.

In order to determine with high sensitivity whether or not raindrops or the like have adhered to the attached matter detecting device of the present invention, the mounting angle of the light emitting means and the opening angle of the imaging lens must satisfy the following conditions. And the angle at which the imaging lens is mounted are adjusted.

The first condition is that, in order to eliminate the influence of external light which becomes noise, the mounting angle of the light emitting means, the aperture angle of the imaging lens, and the like so that the external light does not directly enter the light receiving element of the rain sensor. This is for selecting the mounting angle of the imaging lens. This is a condition for solving the first study problem in the section of the problem to be solved.

Here, the respective elements are arranged in consideration of the aperture angle and the mounting angle of the lens array, which are mentioned as the third study in the section to be solved.

The second condition is that the incident angle of light from the light emitting means to the detection surface and the refractive index of the transparent substrate are changed so as to switch between satisfaction and dissatisfaction of the total reflection condition on the detection surface depending on the presence or absence of the adhering matter. To choose. This is a condition for solving the second study problem described in the section of the problem to be solved.

As a third condition, in order to reduce the light loss of a transparent substrate such as a windshield, the mounting angle of the light emitting means and the aperture of the imaging lens are set so that the optical path in the transparent substrate is minimized. Selection of the angle and selection of the mounting angle of the imaging lens can be cited. This is a condition for solving the fourth study problem described in the section of the problem to be solved.

First, the first condition, that is, selection of the mounting angle of the light-emitting means, the aperture angle of the imaging lens, and the mounting angle of the imaging lens, in which external light does not directly enter the light receiving element of the rain sensor, will be described.

FIG. 1 is a diagram schematically showing the path of external light when external light enters from the external world and is received by a light receiving element in the attached matter detection device of the present invention. This is conceptually simply shown from a cross section of the kimono detecting device. The light path until the light refracted on the detection surface or the like after the incidence is received by the light receiving element, and the mounting angles and materials of the device elements are shown. FIG. 1 is a diagram intended to find a condition under which external light is not received by examining a critical condition under which external light is received, and does not show a configuration example. FIG. 2 schematically shows a configuration example of the attached matter detection device of the present invention.

In FIG. 1, three layers are described. The lower layer is the outside world, the middle layer is the vehicle windshield 100 as a transparent substrate, and the upper layer is the windshield 100.
The contact medium layer 30 is a prism that fills the space between the image forming lens 40 and the image forming lens 40 to contact the two. The space above the windshield 100 is the inside of the vehicle, that is, the space on the driver's side, and the space below is the outside world in front of the vehicle. The detection surface 110 is located in a certain area on the boundary surface between the windshield 100 and the outside world. In addition, 40 is an imaging lens,
50 is a light receiving element of the light receiving means.

Now, it is assumed that the refractive index of the outside world is n ₁ , the refractive index of the windshield 100 is n ₂ , and the refractive index of the contact medium layer 30 is n ₃ .

When external light is directly incident on the light receiving element 50
Following the path of the light once again, the incident angle θ from the outside world₁Inspection
The light enters the sensing surface 110 (this light is referred to as 201), and
Refracted at the boundary surface with the shield 100, and the refraction angle θ_TwoIn
Pass through the inner shield 100 (this light is
Do). Next, the light 202 is
Further refracted at the interface with the contact medium layer 30 and the refraction angle
θ_ThreeTravels through the contact medium layer at
Do). The light 203 enters the imaging lens 40 at an incident angle θ. _FourIncident on
I do. The mounting angle of the imaging lens is θ_FiveAnd here,
The imaging lens has an aperture angle θ_SAnd as described below.
The refractive index of the contact medium layer 30 is n_ThreeAnd the incident angle θ_FourIs constant
If the relationship is satisfied, the incident angle θ_FourLight 203 incident at
Bundled, angle θ_FivePasses through the imaging lens 40 (this light
Is 204), and the light is received by the light receiving element 50.

The examination of the condition that the external light does not directly enter the light receiving element of the rain sensor can be made by examining the case where the condition for the light to travel along the above-mentioned path is not satisfied.

First, the incident angle θ _{1 with} respect to the detection surface 110
The maximum possible angle is 90 °.

[0050]

(Equation 7)

Next, the relationship between the angles will be summarized.

The relationship between the light 201 and the light 202 on the detection surface 110, that is, the boundary surface between the outside world and the windshield 100 can be described as (Equation 8).

[0053]

(Equation 8)

Further, light 202 and light 203 at the interface between the windshield 100 and the contact medium layer 30
Can be described as (Equation 9).

[0055]

(Equation 9)

Also, from the light focusing relationship between the contact medium layer 30 and the imaging lens 40, the light 203 and the light 204
Can be described as (Equation 10).

[0057]

(Equation 10)

[0058] and if the external light is not directly incident on the light receiving element of the rain sensor are the case where the value of the left side in the equation (10) is less than theta _5, (8) through (1
0) can be expressed as (Equation 11).

[0059]

[Equation 11]

Here, the relationship between the incident angle θ ₄ to the imaging lens 40 and the aperture angle θ _S of the imaging lens 40 is as shown in (Equation 12).

[0061]

(Equation 12)

From (Equation 11) and (Equation 12), the condition that the external light does not directly enter the light receiving element of the rain sensor is (Equation 1).
It can be expressed as 3). Since the outside of the windshield 100 is air, its refractive index n ₁ is 1.

[0063]

(Equation 13)

The boundary conditions shown in (Equation 13) are shown with specific numerical values. Examples of the material of the contact medium layer 30 include silicone, glass, and polycarbonate, and the respective refractive indexes n ₃ are 1.41, 1.51, and 1.59, respectively.
It is. Table 1 shows the relationship between the opening angle θ _S of the imaging lens 40 and the mounting angle θ ₅ of the imaging lens 40 using n ₃ as a parameter.

[0065]

[Table 1]

The condition that the external light does not directly enter the light receiving element of the rain sensor is the minimum allowable value when the imaging lens 40 having the opening angle θS of the angle shown in the left column in Table 1 is selected. Image forming lens 40 mounting angle θ ₅
Are shown in the three right columns for each material of the contact medium layer 30.

As the optical axis of the imaging lens 40 is closer to the direction perpendicular to the windshield, external light is more likely to be taken in. If the mounting angle is smaller than the numerical value shown in Table 1 as an example, the external light will not be directly received.

As described above, as a conclusion of the first condition, (Table 1)
If the mounting angle theta ₅ greater than the value shown in, the external light is not directly incident on the light receiving element of the rain sensor.

Next, the angle of incidence of light from the light emitting means to the detection surface, the transparent substrate, and the second condition, that is, whether the total reflection condition on the detection surface is satisfied or not satisfied depending on the presence or absence of an adhered substance are switched. The selection of the refractive index will be described.

FIG. 2 shows a path of light reflected from the light emitting means and incident on the detection surface in the attached matter detection device of the present invention. The mounting angle and material are indicated.

The three layers in FIG. 2, the outer layer, the windshield 100, and the contact medium layer 30 are the same as those in FIG. The same element numbers and materials (refractive indexes) of the respective elements can be used for the elements shown in FIG.

Reference numeral 10 denotes a light emitting means. From the light emitting means 10
Once again following the path of the emitted light,
The emitted light is incident angle θ₀To enter the detection surface 110 (this
Light is assumed to be 211) when there is no adhering matter on the detection surface 110.
If the windshield 100
(This light is referred to as 212). This angle of reflection
Is a convenient way to divert some of the results of the study under the first condition.
The angle of light traveling inside the upper windshield 100 is θ_Two
Divert. The light 212 is connected to the windshield 100
Further refracted at the interface with the tact medium layer 30, the refraction angle θ
_ThreeTo travel through the contact medium layer (this light is denoted by 213).
). The light 213 is incident on the imaging lens 40 at an incident angle θ._FourIncident on
You. The mounting angle of the imaging lens 40 is θ_FiveAnd here
And the imaging lens 40 has an aperture angle θ_SWith contours
The index of refraction of the_ThreeAnd the incident angle θ _FourHave a certain relationship
If satisfied, the incident angle θ_FourThe light 213 incident at is focused.
Angle θ_FivePasses through the imaging lens 40 (this light is
14), and is received by the light receiving element 50.

First, when there is no attached matter, the detection surface 110
If the total reflection condition is satisfied in (1), (Equation 14) must be satisfied.

[0074]

[Equation 14]

Now, since the windshield 100 has no deposits, that is, it is in contact with the outside air, its refractive index n ₁ is 1, and the refractive index n ₂ of the glass windshield 100 is 1.51. , 41.47 ° <θ ₂ .

Next, when there is an attached matter, the detection surface 110
In order for the total reflection condition to be unsatisfactory, (Equation 15) must be satisfied. The refractive index of the deposit is n ₁ ′.

[0077]

(Equation 15)

Now, assuming that the windshield 100 has raindrops as deposits, that is, is in contact with the raindrops,
The refractive index n ₁ ′ is 1.33, and if the refractive index n ₂ of the windshield is 1.51, θ ₂ <61.74 °.

From the above, the condition for satisfying or not satisfying the total reflection condition on the detection surface depending on the presence or absence of the adhered substance is (Equation 1).
It can be summarized as in 6).

[0080]

(Equation 16)

A specific numerical value given by (Equation 16) is as shown in (Equation 17).

[0082]

[Equation 17]

Next, the relationship between the light 212 and the light 213 at the boundary surface between the windshield 100 and the contact medium layer 30 is obtained by modifying the above-mentioned (Equation 9) under the first condition as (Equation 18). Can be described.

[0084]

(Equation 18)

The boundary conditions shown in (Equation 18) are shown with specific numerical values. Examples of the material of the contact medium layer 30 include silicone, glass, and polycarbonate, and the respective refractive indexes n ₃ are 1.41, 1.51, and 1.59, respectively.
Therefore, Table 2 shows the relationship between the reflection angle θ _{2 on the} detection surface 110 and the incident angle θ ₃ on the contact medium layer 30 using n ₃ as a parameter.

[0086]

[Table 2]

Table 3 shows a numerical example of (Equation 12) showing the relationship between the opening angle θ _S of the imaging lens 40 and the incident angle θ ₄ of the light 213 using n ₃ as a parameter. is there.

[0088]

[Table 3]

Now, θ_TwoThe range of (Equation 16), (Equation 1)
7), θ_TwoAnd θ_ThreeShows the relationship (Table
2), θ_ThreeAnd θ_FourAnd θ_Five(Equation 10), the opening angle
θ_SAnd θ _Four(Table 3), the opening angle θ_SAnd θ_Fiveof
The relationship, n_Three(Table 4)
It is.

[0090]

[Table 4]

As described above, the conclusion of the second condition is that if the mounting angle θ ₅ of the imaging lens 40 is within the range shown in (Table 4) (excluding the boundary value), the raindrop adhering matter is detected on the detection surface 110. When there is no light, the light emitted from the light emitting means 10 is received by the light receiving element 50, and when there is a raindrop deposit, it is not received.

Next, a range that simultaneously satisfies both the first condition and the second condition discussed above will be discussed.

A numerical example of the first condition shown in (Table 1)
FIG. 3 shows a result of plotting numerical examples of the second condition shown in (Table 4) on the same graph.

FIG. 3A is a graph when the contact medium layer 30 is made of silicone (refractive index n ₃ = 1.41). 301 is a boundary under the first condition, 302 is a boundary under the second condition, the first condition is satisfied in a range where θ ₅ is larger than 301, and the second condition is a range in which θ ₅ is smaller than 302. Is satisfied. In other words, a range that satisfies the first condition and the second condition at the same time is a range hatched by oblique lines. Generally, the opening angle θ _S needs to be 18 ° or less. That is, when the contact medium layer 30 is made of silicone, the imaging lens 40 having an opening angle θ _S of 18 ° or less is used.
Using the well, and it suffices to adjust the mounting angle theta ₅ of the imaging lens according to the selected aperture angle theta _S.

Next, FIG. 3B shows the contact medium layer 30.
Is glass (refractive index n_Three= 1.51) graph
It is. Similarly, 303 is a boundary based on the first condition.
304 is a boundary based on the second condition, and the first condition
The range that satisfies the second condition and the second condition at the same time is indicated by hatching
It becomes the range which did. Approximate opening angle θ_SMust be less than 15 °
It is necessary. That is, the contact medium layer 30 is made of silicone.
, The opening angle θ _SImaging lens 4 having an angle of 15 ° or less
0, and the selected aperture angle θ_SDepending on
Image lens mounting angle θ_FiveShould be adjusted
You.

FIG. 3C shows a case where the contact medium layer is a polycarbonate.
In the case of bonate (refractive index n_Three= 1.59) graph
It is. Similarly, 305 is a boundary based on the first condition.
306 is a boundary based on the second condition, and the first condition
The range that satisfies the second condition and the second condition at the same time is indicated by hatching
It becomes the range which did. Approximate opening angle θ_SMust be less than 14 °
It is necessary. That is, the contact medium layer 30 is made of silicone.
, The opening angle θ _SIs less than 14 °
0, and the selected aperture angle θ_SDepending on
Image lens mounting angle θ_FiveShould be adjusted
You.

As described above, the structure of the attached matter detection device of the present invention is based on the above examination, and the light emitted from the light emitting means when the attached matter is not present on the sensing surface is reflected by the light receiving means by the light receiving means. The light emitting means, the transparent substrate, the imaging optical system, and the light receiving means are arranged so that light can be received, and the external light from the outer surface of the transparent substrate does not enter the transparent substrate and is directly received by the light receiving means. The arrangement angles of the light emitting means, the transparent substrate, the imaging optical system, and the light receiving means are adjusted according to the refractive index of the substance existing from the outside to the light receiving means.

Next, as a third condition, in order to reduce the light loss of a transparent substrate such as a windshield, the light emitting means 10 is set so that the optical path in the transparent substrate becomes the shortest.
The selection of the mounting angle of the imaging lens 40, the selection of the opening angle θ _S of the imaging lens 40, and the selection of the mounting angle θ ₅ of the imaging lens 40 will be described.

As is apparent from FIG. 3, in order to make the path of the light 211 and the light 212 passing through the windshield 100 the shortest, the incident angle θ ₀ and the reflection angle θ ₂ are adjusted to be as small as possible. That would be good. The fact that θ ₂ is small means that the contact medium layer 30
Means that the refraction angle θ ₃ is as small as possible,
This means that the incident angle θ ₄ to the imaging lens 40 is made as large as possible, and eventually the mounting angle θ _{5 of the} imaging lens 40
Is adjusted to be as small as possible.

That is, FIGS. 3 (a) to 3 (c)
In the figure, the selected aperture angle θ _SImaging lens with
40 and its mounting angle θ_FiveSo that
In other words, in the range indicated by hatching,
Mounting angle near 301, 303, 305 indicating the boundary of the case
What is necessary is just to select the degree θ5. Most actual implementation
In doing so, the variation in the refractive index of the material,
It is preferable to consider margins that take into account mounting errors, etc.
Good.

As described above, the mounting angle θ of the imaging lens 40 is
By adjusting ₅ , the path passing through the windshield 100 is shortened, and light loss occurring in the windshield 100 can be reduced as much as possible.

(Embodiment 2) Embodiment 2 shows an example of the structure of an apparatus in which the attached matter detection apparatus of the present invention is used as a rain sensor. It should be noted that the adjustment of the mounting angle of each element is adjusted within the same range as that described in the first embodiment, and detailed description thereof will be omitted.

In the second embodiment, each element is formed in an array, and FIG. 4A shows only one of the sets in a cross-sectional shape. A plurality of sets of each element of FIG. 4A are provided in a direction perpendicular to the paper surface.

In FIG. 4A, reference numeral 100 denotes a vehicle windshield as a transparent substrate. Embodiment 1
Similarly to the above, the upper space of the windshield 100 was set to the inside of the vehicle, that is, the space on the driver side, and the lower space was set to the outside world.
Reference numeral 110 denotes a surface for detecting an adhering substance.
0 on the surface.

10a is a light source section as a light emitting means, 20 is a prism for introducing light from the light source into the windshield, 30 is a prism for guiding reflected light from inside the windshield, 40a is an imaging lens, 50a Denotes a light receiving element portion (charge coupled element) as light receiving means.

Incidentally, the incident angle θ of the irradiation light from the light source section 10
₀ , the reflection angle θ _{2 on} the detection surface 110, the opening angle θ _S of the imaging lens 40, and the mounting angle θ ₅ thereof, as described in the first embodiment. It is adjusted according to the parameters such as the refractive index of. Note that θ ₂ = 47 ° is set as an example.

In the second embodiment, the light source section 10a has a small light source such as a plurality of LEDs at one end or both ends, such as one end, and emits uniform light. The light source unit 10a is, for example, provided with a plurality of minute light sources at an end and taken out from a linearly provided opening. Several are taken out. The light receiving element unit 50a has a light receiving element, and a plurality of light receiving elements are arranged so as to correspond to parallel and parallel linear lights of the light source unit 10a. That is, the light source unit 10a
Light receiving means for individually detecting a plurality of straight light beams emitted from the light source. The imaging lens 40a is an imaging lens array constituting a plurality of imaging systems, and includes a light source unit 10a
Is formed on the light receiving element of the corresponding light receiving element unit 50a.

That is, a plurality of sets of the attached matter detection device including the light source unit, the imaging lens, and the light receiving means, which are attached so as to satisfy the conditions described in the first embodiment, are configured in parallel. , Detecting the presence or absence of a deposit on the corresponding detection surface on the detection surface 110.

Each component is mounted so as to satisfy the conditions described in the first embodiment, and the material is selected.
When the deposit is not attached on the detection surface 110 of the windshield 100, the irradiation light is totally reflected on the detection surface 110, and the reflected light is transmitted through the prism 30 attached to the surface of the windshield 100. 100
The light exits to the outside and is formed by the imaging lens 40a.
An image is formed on the light receiving surface of the corresponding light receiving element to obtain a light detection signal. On the other hand, when raindrops as attachments adhere to the detection surface, the condition for total reflection on the detection surface 110 is not satisfied, and irradiation light escapes to the outside world, and the light receiving surface of the corresponding light receiving element of the light receiving element unit 50a No image is formed thereon, and no light detection signal is detected.

Further, each element shown in FIG. 4 will be described in detail. FIG. 5A shows an end face of the light source unit 10a.
(B) shows a state where the opening 14 can be seen from the front. The light source unit 10a is provided with, for example, a plurality of minute light sources at an end and takes out the light from an opening 14 provided in a linear shape. Plural 15 are taken out.
In FIG. 5A, 11 is an LED as a minute light source,
12 is a light guide, 13 is a light shielding cover, 14 is LE
An opening 15 for extracting D light is a minute light beam emitted from the LED 11. The LED 11 is provided at one end or both ends at the left and right in FIG. 5B, and is configured to repeat reflection on the inner surface of the cover 13 and to lead to each part of the opening 14. Further, the LEDs may be arranged at regular intervals on the surface of the glass light guide facing the opening 14.

The light extracted from the opening 14 shown in FIG. 5B has directivity and is not scattered, but travels as straight light.
It is incident on zero.

The size of raindrops adhering to the windshield 100 was examined below. However, the size of the raindrops that adhere to the windshield 100 varies depending on the size of the raindrops that have rained and the state of the raindrops on the windshield 100. However, specific numerical values were used as a guide. Generally, the diameter of raindrops called drizzle in the air is about 0.1 to 0.2 mm, and the diameter of raindrops called small rain in the air is 0.2 mm.
The diameter of raindrops, which are called large rain, is about 2 to 4 mm, and the diameter of raindrops of particularly heavy rain such as showers is about 4 to 6 mm in air. The size of these raindrops when they adhere to the windshield 100 varies depending on whether the glass surface is hydrophilic or water-repellent. Assuming that the glass surface is water-repellent, the raindrops have a surface size substantially the same as the size in air. Adheres to Here, as the smallest raindrop to be detected, the average size of small rain, for example, 0.5 mm
If a raindrop having a diameter is selected, the area of the minute region corresponding to one raindrop is about 0.2 mm ² . To further increase the sensitivity, the minimum size of the small rain as the smallest rain drop to be detected, by selecting the raindrops 0.2mm diameter, the area of the small region corresponding to the raindrop grain is about 0.03 mm ² is there.

As described above, L as the minute light source of the light source section 10a is
Sectional area of the light guided through the cell guide 12 from per single ED11 is preferably about 0.2 mm ² or less, more preferably about 0.03 mm ² or less. Further, the area of the minute area on the detection surface 110 is also this area.

Next, the imaging lens 40a will be described in detail. FIG. 6 is a diagram schematically illustrating an example of the imaging lens 40a. As the imaging lens 40a, a gradient index lens array can be used. The example shown in FIG. 6 is an SLA which is a kind of a gradient index lens array of the same magnification imaging system.
FIG. 2 is a simple configuration diagram of ^(R) (Selfoc Lense Array). 4
1 is a rod lens as a micro lens, 42 black resin,
43 is an FRP plate. The rod lens 41 has a rod shape, and its lens surface is visible in FIG. FIG. 4 shows a side cross section of only one rod lens 41. If this SLA is used, it is possible to bend an incident light beam and form an image of an erect and equal magnification at a predetermined position. That is, the reflected light obtained from one minute area on the detection surface 110 can be imaged on one light receiving element as it is.

In the above example, the rod lenses 41 are arranged in a straight line. However, the arrangement of the minute rays to be extracted from the light source unit 10a and the lens arrangement according to the arrangement of each light receiving element of the light receiving element unit 50a described later. I do. The example in FIG. 6 corresponds to L in FIG.
This is an SLA corresponding to the example of the light source unit 10a in which the openings ED are arranged linearly in the ED.

Although the above description is an example of the same-magnification imaging system, each light-receiving element light-receiving surface, which is a light-receiving element of the light-receiving element portion 50a, and the detection surface 110 form an image-forming optical system. It is important that

Next, the light receiving element 50a will be described in detail. FIG. 7 is a diagram schematically illustrating an example of the light receiving element unit 50a. The example of FIG. 7 is an example in which each light receiving element of each light receiving element section 50 is linearly arranged. Reference numeral 51 denotes each light receiving element, which conceptually shows a light receiving surface. In addition, a capacitor, a transistor circuit, a sense amplifier circuit, and the like inside the light receiving element 51 are not shown, and the figure shows that the light receiving surface of the light receiving element 51 is linearly arranged. The light receiving surface of each light receiving element 51 is arranged so as to correspond to the arrangement of the opening 14 of the light source unit 10a and the arrangement of each lens of the imaging lens 40a, and the detection surface 110 is formed via the imaging lens 40a.
And the distance and angle are adjusted so that the reflected light from the lens forms an image.

Note that the effective area of the light receiving surface of the light receiving element 51 can be adjusted according to the area of the adhered substance to be detected.
According to the examination of the area of the minute region, if the imaging lens 40a is a unit-magnification imaging system, it is preferably about 0.2 mm ² or less,
More preferably, it is about 0.03 mm ² or less. However, a light receiving element having a light receiving surface effective area different from the above range can be used.

Next, the operation of the attached matter detection device shown in FIG. 4A and the principle of the attached matter detection will be described in detail.

FIGS. 4 (b) and 4 (c) show two light trajectories when a raindrop as a deposit is attached to a part of the detection surface 110 and when it does not. I have.
120 is a raindrop adhering to the detection surface 110, 130 is a trajectory of light incident on a minute area to which the raindrop is admitted, 140
Is a trajectory of light incident on a minute area to which no raindrop is attached.

From the light source unit 10a to the windshield 100
A plurality of lights guided inside are incident on the detection surface 110.
As shown in FIG. 4C, the detection surface 11 where no raindrop 120 exists.
As described above, the light that has entered the minute area on the surface 0 satisfies the condition of total reflection on the surface of the detection surface 110, and the windshield 10
Reflects within 0. The reflected light is prism 30, imaging lens 4
Oa is received by the light receiving element unit 50a. At this time, since the light is received on the entire light receiving surface of the light receiving element 51, the signal value detected by one corresponding light receiving element 51 is sufficiently large.

On the other hand, as shown in FIG. 4C, the light incident on the minute area on the detection surface 110 where the raindrops 120 exist does not satisfy the condition of total reflection on the surface of the detection surface 110.
As shown by the locus of 140, the light passes through the windshield 100 and is emitted to the outside world. That is, the light receiving element 51 of the light receiving element section 50a corresponding to the minute area of the detection surface 110 to which the raindrop 120 has adhered hardly receives light, and the signal value to be detected is sufficiently small.

FIG. 8 shows the structure of each light receiving element section 50a.
FIG. 4 is a diagram showing an example of a light detection signal from a certain light receiving element 51. In the example of FIG. 8, light detection signals obtained from the eight light receiving elements 51a to 51h are shown. 51a-d, 51g
To h, the values of the light detection signals obtained from the six light receiving elements are relatively sufficiently large.
The values of the light detection signals obtained from e and f are relatively sufficiently small. That is, when raindrops exist in a minute area on the detection surface 110 where the light receiving element 51f receives light, and the incident light has escaped to the outside as shown by the light trajectory 140 in FIG. 4, no light is received, and the light detection signal level decreases. Can be estimated. As shown in FIG. 8, since the light detection signal from each light receiving element 51 clearly appears digitally as "high" or "low", the presence or absence of the adhering matter on the detection surface 110 can be reliably detected. That is, the presence / absence of the assumed deposit on the detection surface 110 can be detected with high sensitivity.

It is to be noted that an appropriate threshold value is provided for the light detection signal by making use of the fact that the light detection signal from each light receiving element 51 clearly appears digitally as "high" or "low". Further, it is also possible to convert the light detection signal from each light receiving element 51 into a digital signal based on the magnitude of the difference value lowered from the reference light detection signal level.

As described above, the attached matter detection device shown in the second embodiment is an example, and the attached matter detection device of the present invention is not limited to the above specific example of the device configuration, and the technical features of the present invention can be applied. It goes without saying that other device configurations are possible based on the idea and can be used for applications other than raindrop detection.

(Embodiment 3) Embodiment 3 is an embodiment of a control device using the attached matter detection device of the present invention.
1 shows an example of a device configuration of a window wiper control device using an attached matter detection device as a rain sensor.

FIG. 9 is an example of a block diagram of a window wiper control device using the attached matter detection device as a rain sensor. 700 is a functional block of a rain sensor which is the attached matter detection device of the present invention shown in the first embodiment;
Reference numeral 10 denotes a window wiper control unit, 720 denotes a window wiper driving unit, and 730 denotes a window wiper, which are connected as shown. FIG. 10 is a flowchart illustrating an example of a processing operation flow of the window wiper control device according to the third embodiment.

As described in the first embodiment, the rain sensor 700 is one in which the mounting angle and material of each element are selected, detects raindrops due to rainfall, and outputs a light detection signal from each light receiving element. It is. Embodiment 2
It is also possible to use a configuration having a plurality of sets of the attached matter detection device including a light source, an imaging lens, and a light receiving element.

The window wiper control means 710 receives a light detection signal from each light receiving element of the rain sensor 700 as an input, and if the light detection signal includes a light detection signal of “low”, raindrops are placed on the windshield. There is, that is,
This is to estimate that rain has started and output a wiper control signal to the window wiper driving means 720.

The window wiper driving means 720 receives the control signal from the window wiper control means 710 and controls the driving of the window wiper 730.

The window wiper 730 is driven by a driving force given by the window wiper driving means 720, and has a stopped state and a driven state. The driving state may have a plurality of states such as a short or long intermittent driving pitch. In the driving state, a predetermined surface of the windshield is cleaned.

The flow of the processing operation of the window wiper control device will be described with reference to the flowchart of FIG.

When the window wiper control device is operating (step S801: Y), the window wiper control means 710 inputs a light detection signal from each light receiving element of the rain sensor 700 and monitors the light detection signal level (step S801). Step S802). Window wiper control means 7
10 checks whether the light detection signal includes a level lower than a predetermined level or a "low" signal as a digital value (step S803).

If the light detection signal does not include a level lower than the predetermined level or a "low" signal as a digital value (step S803: N), the window wiper control means 710 determines that rain has not started or rain has not occurred. Is completed, and outputs a window wiper control signal for stopping the window wiper 730 (step S804). Window wiper driving means 720
Receives the control signal from the window wiper control unit 710, and maintains the window wiper 730 in a stopped state (step S805). After step S805, control is continued by looping back to step S801 (return to step S801).

It is assumed that rainfall has started and raindrops have adhered to the detection surface of the windshield. If the light detection signal includes a level lower than a predetermined level or a “low” signal as a digital value (step S803: Y), the window wiper control unit 710 determines that rain has started or is raining. (Step S806) A window wiper control signal for driving the window wiper 730 is output in order to clean raindrops attached to the windshield (Step S807). The window wiper driving unit 720 receives the control signal from the window wiper control unit 710, and sets the window wiper 730 to the driving state (step S808). After step S808, control is continued by looping back to step S801 (return to step S801).

When the flow of the above-mentioned processing cooperates and transits without delay, when the rain starts, the drive of the window wiper 730 is started immediately and surely.
The drive of the window wiper 730 is appropriately terminated.

FIG. 11 is a diagram simply showing an example of a mounting configuration of a window wiper control device using the attached matter detection device of the present invention as a rain sensor. As shown in FIG. 11, a rain sensor 700, which is an attached matter detection device, is attached to a windshield portion 910 on the rear surface of a rearview mirror 900 of a car. Thus, the rearview mirror 9
By attaching to the windshield part 910 on the back of 00, the driving view of the driver is not unnecessarily obstructed,
In addition, the detection surface can be secured on the windshield. Although not shown, the window wiper control means 710 and the window wiper drive means 720 are assumed to be stored in the cabin as vehicle components near the window wiper 730.

As described above, the control device using the attached matter detection device shown in the third embodiment is an example, and the attached matter detection device of the present invention is not limited to the above specific example of the device configuration. It is needless to say that other device configurations are possible based on the technical idea of the present invention and can be used for applications other than the window wiper control device.

[0139]

According to the attached matter detecting device of the present invention, it is possible to block the external light so as not to directly enter the light receiving means, and it is possible to reduce the optical noise caused by the external light. In addition, the detection accuracy of the presence or absence of the attached matter can be improved.

Further, according to the attached matter detection device of the present invention,
Since the configuration is such that the satisfaction / dissatisfaction of the total reflection condition on the detection surface depending on the presence / absence of the attached matter is switched with high sensitivity, the presence / absence of the attached matter can be determined with high sensitivity.

Further, according to the attached matter detection device of the present invention,
Of the paths of the light emitted from the light source until the light is received by the light receiving means, the path that passes through a windshield or the like where there is light loss can be selected so as to be shorter. The loss is small, the light detection signal can be increased, and the presence / absence of a deposit can be determined with high sensitivity.

[Brief description of the drawings]

FIG. 1 is a diagram schematically illustrating the path of external light incident from the external world in an attached matter detection device of the present invention.

FIG. 2 is a view showing a light path from the light emitting means to the detection surface to the reflected light incident on the light receiving element, and the mounting angles and materials of the device elements in the attached matter detection device of the present invention.

FIG. 3 shows a numerical example of the first condition shown in (Table 1),
The figure which shows the result which plotted the numerical example of the 2nd condition shown in (Table 4) on the same graph.

FIG. 4 is a diagram showing an example of a device configuration when the attached matter detection device of the present invention is used as a rain sensor.

FIG. 5 is a diagram schematically showing an example of a light source arrangement of the light source unit 10a.

FIG. 6 is a diagram schematically illustrating an example of an imaging lens 40a.

FIG. 7 is a diagram schematically illustrating an example of each light receiving element unit 50a.

FIG. 8 shows each light receiving element 5 constituting each light receiving element section 50a.
FIG. 4 is a diagram showing an example of a light detection signal from the first light source

FIG. 9 is a block diagram of a window wiper control device using the attached matter detection device as a rain sensor.

FIG. 10 is a flowchart illustrating an example of a processing operation flow of the window wiper control device according to the second embodiment.

FIG. 11 is a diagram simply showing an example of a mounting configuration of a window wiper control device using the attached matter detection device of the present invention as a rain sensor.

FIG. 12 is a diagram simply illustrating the principle of raindrop detection by a conventional reflected light detection type rain sensor.

[Explanation of symbols]

10, 10a Light source section 11 LED 12 Cell guide 20, 30 Prism 40 Imaging lens 40a Imaging lens 50, 50a Light receiving element section 51 Light receiving element 100 Wind shield 110 Detecting surface 120 Raindrop 130 Incident on minute area where raindrop is attached Trajectory of light 140 Trajectory of light incident on a minute area to which no raindrop is attached 700 Rain sensor 710 Window wiper control means 720 Window wiper driving means 730 Window wiper 900 Rearview mirror 910 Windshield part on the rear surface of rearview mirror

Continued on the front page (72) Inventor Hideki Imanishi 3-5-1, Doshumachi, Chuo-ku, Osaka-shi, Osaka Inside Nippon Sheet Glass Co., Ltd. (72) Inventor ▲ Yoshinobu Harunobu 3 Doshomachi, Chuo-ku, Osaka-shi, Osaka 5-11-11 Nippon Sheet Glass Co., Ltd. (72) Inventor Masahide Wakisaka 3-5-1-11 Doshomachi, Chuo-ku, Osaka City, Osaka Prefecture Nippon Sheet Glass Co., Ltd. (72) Inventor Kenmi Tokuda Chuo-ku, Osaka City, Osaka 3-5-11, Doshomachi Nippon Sheet Glass Co., Ltd. F-term (reference) 2G059 AA05 BB02 CC11 EE02 GG02 JJ11 JJ12 KK01 3D025 AA01 AB01 AD01 AD09 AG42

Claims (10)

[Claims] An external surface of the transparent substrate on which incident light emitted from light emitting means and introduced into the transparent substrate is reflected is used as a detection surface, and reflected light from the detection surface passes through an optical imaging system. Detecting the presence of the adhering object by detecting a change in a light detection signal due to a change in a reflection condition of the adhering object on the detection surface in the light detection signal received by the light receiving unit and detected by the light receiving unit. An adhering substance detection device provided with adhering substance detecting means, wherein the external light is present from the outside to the light receiving means so that external light from the outside enters from the transparent substrate and is not directly received by the light receiving means. An attachment detection device, wherein an arrangement angle of the light emitting means, the transparent substrate, the imaging optical system, and the light receiving means is adjusted according to a refractive index of a substance. 2. The method according to claim 1, wherein the refractive index of the medium on the outer surface side of the transparent substrate is n ₁ , the refractive index of the medium from the transparent substrate to the imaging optical system is n ₃ , Assuming that the mounting angle is θ ₅ and the aperture angle of the imaging optical system is θ _S , the light emitting unit, the transparent substrate, the imaging optical system, and the light receiving unit satisfy Equation (1). The attached matter detection device according to claim 1, wherein an arrangement angle of the object is adjusted. (Equation 1) 3. An outer surface of the transparent substrate, on which the incident light emitted from the light emitting means and introduced into the transparent substrate is reflected, is used as a detection surface, and the reflected light from the detection surface is transmitted through an optical imaging system. A detecting means for detecting the presence of the deposit by detecting a change in a light detection signal due to a change in a reflection condition on the detection surface due to the deposit in the light detection signal received by the light receiving means and detected by the light receiving means; An adhering matter detection device provided with a kimono detecting means, wherein when there is no adhering matter on the detecting surface, reflected light of the light emitted from the light emitting means on the detecting surface is received by a light receiving means. The light emitting means, the transparent substrate, the imaging optical system, the light receiving means is arranged, and,
The light emitting unit and the transparent unit are arranged such that, when the attachment is present on the detection surface, light emitted from the light emitting unit is not reflected on the detection surface due to a change in a reflection condition on the detection surface due to the attachment. An attachment detection device, wherein the arrangement angles of the conductive substrate, the imaging optical system, and the light receiving unit are adjusted. 4. The refractive index of the medium on the outer surface side of the transparent substrate is defined as n ₁ , the refractive index of the medium from the transparent substrate to the imaging optical system is defined as n _3, and the refractive index of the attached matter is defined as n _3. To n ₁ '
When the angle of refraction into the transparent substrate is θ ₂ , the arrangement angles of the light emitting unit, the transparent substrate, the imaging optical system, and the light receiving unit are adjusted so as to satisfy (Equation 2). The attached matter detection device according to claim 3, wherein: (Equation 2) 5. An outer surface of the transparent substrate, on which light emitted from the light emitting means and introduced into the transparent substrate is incident and reflected, is used as a detection surface, and the reflected light from the detection surface forms an optical imaging system. Detecting a change in a light detection signal due to a change in a reflection condition on the detection surface due to the adhering matter in a light detection signal received by the light receiving means and detected by the light receiving means to detect the presence of the attached matter An adhering matter detection device provided with an adhering material detecting means, wherein, when there is no adhering matter on the detecting surface, reflected light of the light emitted from the light emitting means on the detecting surface is received by a light receiving means. The light emitting means, the transparent substrate, the imaging optical system, the light receiving means is arranged, and,
The light emitting unit and the transparent unit are arranged such that, when the attachment is present on the detection surface, light emitted from the light emitting unit is not reflected on the detection surface due to a change in a reflection condition on the detection surface due to the attachment. The arrangement angle of the transparent substrate, the imaging optical system, and the light receiving unit is adjusted, and further, external light from the outer surface of the transparent substrate is incident from the transparent substrate and is not directly received by the light receiving unit. According to the refractive index of a substance existing from the outside to the light receiving means, the light emitting means, the transparent substrate, the imaging optical system,
An attached matter detection device, wherein an arrangement angle of the light receiving means is adjusted. 6. The medium on the outer surface side of the transparent substrate is n ₁
The medium from the transparent substrate to the imaging optical system is n ₃ , the refractive index of the attached matter is n ₁ ′, the refraction angle into the transparent substrate is θ ₂ , Assuming that the mounting angle of the system is θ ₅ and the aperture angle of the imaging optical system is θ _S , the light emitting means, the transparent substrate, 6. The attached matter detection device according to claim 5, wherein an arrangement angle of the imaging optical system and the light receiving unit is adjusted. (Equation 3) (Equation 4) 7. In the adjustment of the arrangement angle of the light emitting means, the transparent substrate, the imaging optical system, and the light receiving means, the transparency through which reflected light of the light emitted from the light emitting means on the detection surface passes. The attached matter detection device according to any one of claims 1 to 6, wherein the arrangement angle is selected such that a path in the substrate is minimized. 8. The light receiving means is a light receiving means having a light receiving element, wherein the light receiving surface of each light receiving element and the detection surface corresponding to each light receiving element are arranged so as to form an imaging optical system. The imaging optical system is an imaging system using an imaging lens having an aperture angle θ _S that satisfies the condition of the above (Equation 1).
An adhering matter detection device according to any one of the above. 9. The attached matter detection device according to claim 8, wherein the imaging lens is a rod lens array or a gradient index lens array. 10. The rain sensor according to claim 1, wherein the object to be detected is raindrops, said detection surface is provided on a windshield of an automobile, and said rain sensor is configured to detect the presence of raindrops adhering to said windshield. A window wiper driving unit; and a window wiper control unit, wherein the window wiper control unit receives a detection signal of an adhesion object from the adhesion object detection device, and based on the detection signal. A window wiper device that changes the control content of a window wiper driving unit.