JP2014133426A - Raindrop detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a raindrop detection device capable of performing simple processing to accurately determine whether a water-repellent treatment is applied to the outside surface of a windshield glass.SOLUTION: A rain sensor 3, including first raindrop detection means 20 for irradiating an inner surface of a window glass 1 with light and generating a first output x in accordance with reflective light reflected by the window glass 1, and a microcontroller 40 for detecting a raindrop amount attached to an outer surface of the glass 1 on the basis of the first output x, further includes: second raindrop detection means 30 for irradiating an inner surface of the window glass 1 with light and generating a second output y in accordance with reflective light reflected by a raindrop attached to the window glass 1; and a water-repellent glass determination part 43 capable of determining whether a water-repellent treatment is applied to the outside surface of the window glass 1 on the basis of comparison between the first output x and the second output y.

Description

  The present invention relates to a raindrop detection device that detects the amount of raindrops adhering to a window glass, and more particularly to a raindrop detection device that can determine whether or not a water repellent treatment has been performed on the outer surface of a window glass.

Conventionally, a light emitting element (for example, an LED) that projects light onto a detection region set on the inner surface of the window glass, a parallel light lens that changes the direction of light projected from the light emitting element in parallel, and a window A condensing lens that redirects and collects the light reflected from the outer boundary surface between the glass and the external space, and a light receiving element that outputs a detection signal corresponding to the amount of received reflected light collected by the condensing lens ( For example, a raindrop detection device including a photodiode) is known.
A vehicle having a wiper device that wipes raindrops by detecting the amount of raindrops adhering to the outer surface of the wind glass by such a raindrop detection device and automatically driving and controlling the wiper blade based on the detection result of the raindrop amount. It has been put into practical use.

  In this type of raindrop detection device, when no raindrop is attached to the detection area on the outer surface of the window glass, the projected light is totally reflected from the outer boundary surface between the window glass and the outer space and received by the light receiving element. . In addition, when raindrops are attached to the detection area on the outer surface of the wind glass, a part of the light projected to the part corresponding to the raindrops is transmitted to the outside through the raindrops attached to the window glass. Of the emitted light, only the reflected light of light that does not pass through the window glass and raindrops is received by the light receiving element. That is, in this raindrop detection apparatus, the detection signal increases as the amount of raindrops attached to the outer surface of the window glass decreases, and the detection signal decreases as the amount of raindrops attached to the outer surface of the window glass increases.

Usually, not only window glass but glass in general has high hydrophilicity, so that raindrops adhering to the outer surface of the window glass are formed into a flat shape due to gravity. A plurality of raindrops formed in a flat shape flow on the window glass to form a single flat raindrop in which a plurality of raindrops are aggregated, and finally have a uniform thickness along the surface direction of the windglass. In general vehicles, the water film on the surface of the wind glass is undulated by wind pressure or the like caused by the traveling wind, so the thickness of the water film is not uniform during traveling. Thus, when the thickness of the water film becomes non-uniform, the perspective image through the window glass is distorted, and there is a possibility that the forward visibility of the user may be reduced.
Therefore, in order to reduce the critical surface tension of the outer surface of the wind glass and repel raindrops adhering to the surface, a water repellent (surfactant) such as fluorine or silicon is applied to the outer surface of the window glass. Yes. With this water-repellent treatment, the shape of raindrops attached to the outer surface of the wind glass can be formed into a shape with a large contact angle with the outer surface of the window glass, a so-called oval shape with a small contact area. For example, the forward visibility of the user is ensured by splashing backward.

  The wiper control device disclosed in Patent Document 1 irradiates light on the inner surface of the wind glass and can generate an output corresponding to reflected light reflected by the wind glass, and adheres to the outer surface of the wind glass based on the output. A raindrop amount calculating means capable of detecting the raindrop amount, and a wiper control device for controlling the wiping speed and intermittent time of the wiper that wipes raindrops based on the detected raindrop amount. When the output returns to the direction in which the reflected light becomes strong again after the output has changed in the direction in which the light is weakened, water repellency detection means for determining whether the water repellency is high or not is determined by whether the return amount is larger than the set value. When the water repellency is high, the raindrop amount is calculated based on the raindrop detection output when the reflected light changes in the weakest direction. When the water repellency is low, all raindrop detection outputs are integrated to calculate the raindrop amount. There. In this wiper control device, excessive wiping operation is prevented when the water repellency is high by determining the presence or absence of the water repellency based on the tendency to increase or decrease the raindrop detection output.

Patent 4079000

In the wiper control device of Patent Document 1, when raindrops are dropped on the outer surface of a water-repellent window glass (hereinafter referred to as a water-repellent window glass), these raindrop groups are aggregated to form a very thin film. After that, it is considered that the light projected from the raindrop detection means is reflected also from the island-like raindrops under the assumption that the island-like raindrops are gathered through a bulge due to surface tension.
Therefore, in the case of the water-repellent window glass, the reflected light from the outer boundary surface of the island-shaped raindrop is added to the reflected light from the outer boundary surface of the water-repellent window glass. On the premise that the raindrop detection output increases and the raindrop detection output also recovers along with this, the determination condition for determining the water-repellent window glass is that the raindrop detection output once decreased due to the raindrop dropping returns to the increasing side again. .
However, in the wiper control device of Patent Document 1, since the correlation between the return amount of the raindrop detection output and the water repellency is set as a determination condition on the premise of the raindrop in the above state, the water repellent window glass and the water repellent treatment are used. There is a possibility that window glass (hereinafter referred to as non-water-repellent window glass) that has not been subjected to is not accurately distinguished.

As a result of verifying the relationship between the raindrop detection output of the raindrop detection means and the water repellency, the present inventor has found that the water repellent window glass detects a smaller amount of raindrops than the non-water repellent window glass.
In other words, the period in which each raindrop is formed into an elliptical shape due to surface tension from the initial stage of attachment is extremely short, and the elliptical raindrops are likely to scatter backward due to traveling wind pressure or the like. The possibility of maintaining an island state on the water wind glass for a long time is extremely low. Therefore, when the dripped raindrop is close to the phenomenon actually occurring on the water-repellent window glass, it is assumed that the substantially elliptical sphere state is maintained from the time when it adheres to the water-repellent window glass until it splashes. Guessed.

In addition, in the raindrop detection means of Patent Document 1, the parallel light lens and the light receiving element are installed under an installation condition (for example, an inclination angle) that can detect the reflected light reflected from the planar outer boundary surface between the window glass and the external space. Therefore, it is theoretically not easy to detect the reflected light reflected from the spherical outer boundary surface between the elliptical spherical raindrop and the external space.
That is, it is difficult to detect the reflected light reflected from the raindrops attached to the water repellent window glass and the reflected light reflected from the raindrops attached to the non-water repellent window glass by the single specification raindrop detection means, Even if the reflected light is detected by the raindrop detection means, it is difficult to determine whether the detection output is due to the reflected light from the raindrops attached to the water repellent window glass or the non-water repellent window glass. It cannot be accurately controlled according to the presence or absence of water treatment.

  An object of the present invention is to provide a raindrop detection device capable of accurately determining whether or not a water repellent treatment is performed on the outer surface of a window glass by a simple process.

  According to a first aspect of the present invention, there is provided a raindrop detection apparatus that irradiates light on the inner surface of a window glass and generates a first output corresponding to reflected light reflected by the window glass, and based on the first output. And a control unit for detecting the amount of raindrops adhering to the outer surface of the window glass, in accordance with the reflected light reflected by the raindrops irradiating the inner surface of the window glass with light. Water-repellent glass determination capable of determining whether or not a water-repellent treatment is applied to the outer surface of the window glass based on a comparison between the second raindrop detecting means for generating the second output and the first output and the second output And a means.

  The raindrop detection apparatus according to claim 1 includes second raindrop detection means for irradiating light on the inner surface of the window glass and generating a second output corresponding to the reflected light reflected by the raindrop attached to the outer surface of the window glass. Therefore, it is possible to detect the reflected light from the raindrops attached to the outer surface of the window glass that has been subjected to the water repellent treatment by the second raindrop detection means.

  According to a second aspect of the present invention, in the first aspect of the invention, the water-repellent glass determination means calculates the first change amount of the first output during a predetermined period and the second change amount of the second output during the predetermined period. It is calculated, and when the second change amount is larger than the first change amount, it is determined that water repellent treatment is performed on the outer surface of the window glass.

  According to a third aspect of the present invention, in the first aspect of the invention, the water-repellent glass determining means includes a maximum value of the first output of the first raindrop detecting means and a minimum value of the second output of the second raindrop detecting means. Have a map set to have the same output value, and the second output value detected by the second raindrop detection means is larger than the first output value detected by the first raindrop detection means, It is characterized in that it is determined that the outer surface of the window glass has been subjected to water repellent treatment.

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, when the water repellent treatment is performed on the outer surface of the window glass, the control means performs the water repellent treatment on the outer surface of the window glass. It is characterized by controlling the wiper device so that the wiping ability is higher than when it is not applied.
The invention of claim 5 is characterized in that, in the invention of claim 4, the wiper device is configured such that at least one of a wiping speed and an intermittent period can be changed.

  According to invention of Claim 1, in order to detect the reflected light from the raindrop adhering to the outer surface of the window glass subjected to the water repellent treatment by the second raindrop detection means, the first output generated by the first raindrop detection means and Based on the comparison between the first output generated by the second raindrop detection means and the second output having a different output tendency, it is possible to reliably determine the presence or absence of the water-repellent treatment on the outer surface of the window glass when raindrops are present.

According to the invention of claim 2, since the presence or absence of the water-repellent treatment can be determined by comparing the first change amount of the first raindrop detection means and the second change amount of the second raindrop detection means, the configuration can be simplified and processed. Can be simplified.
According to the invention of claim 3, since it is possible to determine the presence or absence of the water-repellent treatment with a single detection value by the first and second raindrop detection means, the processing time can be shortened.

According to the invention of claim 4, the wiper device can be controlled in accordance with the amount of raindrops actually attached to the window glass regardless of the presence or absence of the water-repellent treatment of the window glass.
According to the invention of claim 5, the forward visibility of the user can be kept good irrespective of the presence or absence of the water-repellent treatment of the window glass.

It is a block diagram of the communication system of the motor vehicle based on Example 1 of this invention. It is the figure which looked at the vehicle body front from the vehicle interior. It is a control circuit diagram which shows the electrical structure which concerns on a wiper apparatus, a rain sensor, and a wiper switch. It is a perspective view of a rain sensor. It is a block diagram which shows the whole structure of a rain sensor. It is explanatory drawing which shows the raindrop detection principle of the wind glass which has not been subjected to water repellent treatment. It is explanatory drawing which shows the raindrop detection principle of the window glass in which the water repellent process was performed. It is a graph which shows the correlation with a raindrop adhesion rate and 1st output. It is a graph which shows the correlation with a raindrop adhesion rate and a 2nd output. It is a wiping speed map at the time of auto mode control. It is an intermittent time map at the time of auto mode control. It is a flowchart which shows the process sequence which concerns on a wiper control process. It is a block diagram which shows typically the whole structure of the rain sensor which concerns on Example 2. FIG. It is a 1st output map which shows the correlation with a raindrop adhesion rate and 1st output. It is a 2nd output map which shows the correlation with a raindrop adhesion rate and 2nd output. It is a flowchart which shows the process sequence which concerns on a wiper control process.

  Hereinafter, modes for carrying out the present invention will be described based on examples.

Hereinafter, Example 1 of the present invention will be described with reference to FIGS.
As shown in FIG. 1, in this embodiment, a front window glass (hereinafter referred to as a window glass) 1, a wiper blade (not shown) for wiping raindrops and dirt adhering to the outer surface of the window glass 1, a wiper motor 2 a, etc. As an example, a description will be given of a vehicle V including a wiper device 2 configured by the above, a rain sensor 3 (raindrop detection device), and the like.

First, a basic communication system of the automobile V will be briefly described.
As shown in FIG. 1, an automobile V includes a body control module (hereinafter referred to as BCM) 4, an engine control module (hereinafter referred to as ECM) 5, a brake control mechanism 6, and a head. A light control mechanism (Adaptive Front-Lighting System: AFS) 7 and the like are provided, and these control mechanisms 4 to 7 are connected to each other by a CAN (Controller Area Network) 8 so as to be able to transmit and receive each other.

As shown in FIG. 3, the BCM 4 is configured to be capable of comprehensive control of a plurality of devices such as the wiper device 2 (wiper motor 2 a) and the rain sensor 3, and includes a microcomputer (hereinafter referred to as a microcomputer) 9 and a first relay circuit 10. And a second relay circuit 11 and the like.
When the first relay circuit 10 is turned on and the second relay circuit 11 is turned off, the wiper motor 2a is driven at a low speed. When the first relay circuit 10 is turned off and the second relay circuit 11 is turned on, the wiper motor 2a is driven at a high speed. Is done.

  The microcomputer 9 is output from a CPU that performs control processing and arithmetic processing, a read-only memory (ROM) for storing various data such as various programs and control coefficients, each control mechanism 4 to 7 and a plurality of sensors. A memory (RAM) in which various data can be written, a power supply circuit, and the like (not shown). The microcomputer 9 converts a control signal from a wiper control unit 45 (to be described later) and transmits it to the wiper device 2.

The ECM 5 is configured to be able to control an engine ignition mechanism, a fuel injection device, an intake / exhaust system, a valve mechanism, start control, and the like based on a plurality of sensor outputs (all not shown).
The brake control mechanism 6 is configured to be able to control a mechanism (Antilock Brake System) that avoids a collision while applying a sudden brake and a mechanism (Dynamic Stability Control) that prevents understeer and oversteer during vehicle turning (any one) (Not shown).
The AFS 7 is configured such that the direction of a headlight (not shown) formed to be tiltable can be changed to a direction suitable for the traveling direction of the traveling vehicle V based on the steering angle and the vehicle speed.
The CAN 8 connects the control mechanisms 4 to 7 via the CAN bus 8a so that multiplex communication is possible, and performs bus access control by a multi-master method in which data is transmitted in units of frames (not shown). Communication signals output from the control mechanisms 4 to 7 and various sensors are stored in the data field of the frame and transmitted to the respective transmission destinations via the CAN bus 8a.

Next, the wiper device 2 will be described.
As shown in FIG. 3, the wiper device 2 includes a wiper blade, a wiper arm (not shown), a wiper motor 2a, an automatic stop switch 2b, etc., and each of them is manually operated by the user on the wiper switch 12 (see FIG. 2). The mode control is configured to be executable.
The auto stop switch 2b is a rotation maintaining circuit, and when the user turns off the wiper switch 12, if the wiper blade has not reached the lower reverse position (stop position), the current supply to the wiper motor 2a is continued. Then, the wiper blade is stopped at the stop position.

As shown in FIG. 2, the wiper switch 12 is provided on a side portion of the steering 13 and is configured to be movable in stages in the vertical direction. As shown in FIG. 3, the wiper switch 12 is manually operated to change the electrical connection to the OFF position 12a, the MIST position 12b, the AUTO position 12c, the LOW position 12d, and the HIGH position 12e. Each mode control can be switched.
The wiper switch 12 is set to the OFF position 12a by the user's off operation when it is not raining. When the wiper switch 12 is operated from the OFF position 12a to the MIST position 12b, after the wiper device 2 executes the mist mode control in which the window glass 1 is wiped only once, the wiper switch 12 is automatically operated by the biasing force of the compression spring. Is returned to the OFF position 12a.

When the wiper switch 12 is operated from the OFF position 12a to the AUTO position 12c, the wiper device 2 is set to auto mode control that performs an intermittent wiping operation according to the amount of raindrops. An intermittent time setting section 12f (automatic volume) capable of manually setting the intermittent time of the intermittent wiping operation is provided at the tip end portion of the wiper switch 12. The intermittent time setting unit 12f is configured to be able to set the intermittent time by adjusting the amount of rotation of the wiper switch 12 around the axis.
When the wiper switch 12 is operated from the OFF position 12a to the LOW position 12d, the first relay circuit 10 is turned on and the second relay circuit 11 is turned off at the same time. Therefore, the wiper device 2 has a low speed with no stop time. The first continuous wiping mode control for performing the continuous wiping operation is set. When the wiper switch 12 is operated from the OFF position 12a to the HIGH position 12e, the first relay circuit 10 is turned off and the second relay circuit 11 is turned on at the same time. Therefore, the wiper device 2 is more effective than the first continuous wiping mode control. The second continuous wiping mode control that performs continuous wiping operation at high speed is set.

Next, the rain sensor 3 will be described.
As shown in FIGS. 1 to 7, the rain sensor 3 is detachably mounted at a position facing the raindrop detection region set in front of the room mirror 14 and at the upper end of the outer surface of the window glass 1. Therefore, by electrically connecting the rain sensor 3 and the BCM 4, the rain sensor 3 and the BCM 4 can be arbitrarily mounted on the vehicle V having different specifications such as the inclination angle of the window glass 1 and the vehicle body dimensions. It is also possible to attach the rain sensor 3 to the automobile V later.
The rain sensor 3 includes a first raindrop detection means 20, a second raindrop detection means 30, a microcomputer (hereinafter referred to as a microcomputer) 40 (control means), a substantially rectangular parallelepiped housing 3a that can accommodate these. I have.

As shown in FIG. 4, the first raindrop detection means 20 includes two sets of first raindrop detection units 21. Since the two sets of first raindrop detection units 21 have the same configuration, one of the first raindrop detection units 21 will be mainly described.
As shown in FIGS. 5 and 6, the first raindrop detection unit 21 includes a light projecting unit 22, a light projecting unit control unit 23 that controls the light projecting unit 22, a parallel light lens 24, and a condenser lens 25. A light receiving unit 26, and a light receiving unit control unit 27 for controlling the light receiving unit 26.

The light projecting unit 22 is formed by a light emitting element (for example, an LED), and is configured to be able to irradiate infrared rays α to a portion corresponding to the raindrop detection region on the inner surface of the window glass 1.
The light projecting unit control unit 23 is configured to be able to control the operation timing of the light projecting unit 22, the irradiation amount (intensity) of the infrared ray α, and the like based on a control signal from the microcomputer 40.
The parallel light lens 24 has a convex surface on the light projecting portion 22 side and a flat surface on the wind glass 1 side, and the traveling direction of the infrared ray α emitted from the light projecting portion 22 is changed from the diffusion direction to the parallel direction. It has changed.

The condensing lens 25 is formed such that the surface on the window glass 1 side is convex and the surface on the light receiving unit 26 side is flat. Since the infrared ray α reflected from the outer boundary surface of the wind glass 1 or the infrared ray α2 reflected from the outer boundary surface of the raindrop W1 travels in parallel, the condenser lens 25 receives the parallel infrared ray α or α2. The traveling direction of the infrared rays α or α2 is changed from the parallel direction to the converging direction so as to concentrate on the portion 26.
The light receiving unit 26 includes a light receiving element (for example, a photodiode), and is configured to detect infrared rays α and α2 reflected from the outer boundary surface of the window glass 1 and the outer boundary surface of the raindrop W1. The light receiving unit control unit 27 is configured to be able to control the light receiving sensitivity and the like of the light receiving unit 26 based on a control signal from the microcomputer 40, and outputs the infrared α or α2 detection signal detected by the light receiving unit 26 to the microcomputer 40. ing.

Next, the second raindrop detection means 30 will be described.
As shown in FIG. 4, the second raindrop detection means 30 includes two sets of second raindrop detection units 31. Since the two sets of second raindrop detection units 31 have the same configuration, one of the second raindrop detection units 31 will be mainly described.
As shown in FIGS. 5 and 7, the second raindrop detection unit 31 includes a light projecting unit 32, a light projecting unit control unit 33 that controls the light projecting unit 32, a parallel light lens 34, and a condenser lens 35. A light receiving unit 36, and a light receiving unit control unit 37 for controlling the light receiving unit 36.

The light projecting unit 32 is formed of a light emitting element (for example, an LED), and is configured to be able to irradiate infrared rays β to a portion corresponding to the raindrop detection region on the inner surface of the window glass 1.
The light projecting unit control unit 33 is configured to be able to control the operation timing of the light projecting unit 32, the irradiation amount (intensity) of infrared rays β, and the like based on a control signal from the microcomputer 40.
The parallel light lens 34 has a convex surface on the light projecting portion 32 side and a flat surface on the wind glass 1 side, and the traveling direction of the infrared rays β emitted from the light projecting portion 32 changes from the diffusion direction to the parallel direction. It has changed. When the raindrop W2 adheres to the outer surface of the wind glass 1, the parallel light lens 34 is totally reflected from the outer boundary surface between the raindrop W2 and the external space, so that the infrared rays β emitted from the light projecting unit 32 are reflected. The inclination angle and the like are set so that infrared rays β pass through the window glass 1 when no raindrop W2 is attached to the outer surface.

The condensing lens 35 is formed such that the surface on the window glass 1 side is convex and the surface on the light receiving portion 36 side is flat. Since all of the infrared rays β reflected from the outer boundary surface of the raindrop W2 travel in parallel, the condenser lens 35 parallels the traveling direction of the infrared β so that the parallel infrared β is concentrated on the light receiving unit 36. The direction is changed from the direction to the focusing direction.
The light receiving unit 36 is constituted by an image sensor (for example, CCD), and the infrared ray β reflected from the outer boundary surface of the raindrop W2 attached to the outer surface of the wind glass 1 that has been subjected to the water-repellent treatment by the water-repellent coating 15. The amount of reflected light can be detected. The light receiving unit control unit 37 is configured to be able to control the light receiving sensitivity and focus of the light receiving unit 36 based on a control signal from the microcomputer 40, and to the microcomputer 40 the reflected light amount detection signal of the infrared ray β detected by the light receiving unit 36. Output.

  Here, based on FIGS. 6-9, the raindrop detection principle of the 1st, 2nd raindrop detection means 20 and 30 is demonstrated easily. FIG. 6 shows an example in which raindrops W1 adhere to the wind glass 1 that has not been subjected to water repellent treatment, and FIG. 7 shows the windglass 1 in which the raindrops W2 have been subjected to water repellent treatment by the water repellent coating 15. An example attached to is shown.

As shown in FIG. 6, since the water repellent treatment is not performed on the outer surface of the window glass 1, the raindrop W1 is formed flat due to the influence of the hydrophilicity and gravity of the window glass 1.
The parallel light lens 24 has an inclination angle and the like so that the infrared ray α irradiated from the light projecting unit 22 is totally reflected from the planar outer boundary surface between the window glass 1 and the external space. In the portion where the raindrop W1 is not attached to the outer surface, the infrared ray α irradiated from the light projecting unit 22 is totally reflected from the outer boundary surface between the window glass 1 and the external space without passing through the window glass 1. Moreover, in the part which raindrop W1 dripped and the flat raindrop W1 has adhered to the outer surface of the wind glass 1, some infrared rays (alpha) 1 is the wind glass 1 and raindrop among the infrared rays (alpha) irradiated from the light projection part 22. Since the light passes through W1, the remaining infrared light α2 (α−α1) is reflected from the outer boundary surface between the raindrop W1 and the external space. Thereby, the 1st raindrop detection means 20 detects the reflected light quantity of infrared rays (alpha) or (alpha) 2 which is the reflected light from the outer surface of the window glass 1 or the raindrop W1.

As shown in FIG. 7, the outer surface of the window glass 1 is coated with a fluorine-based water repellent to form a water-repellent coat 15, so that the raindrop W2 has an oval shape with a large contact angle with the outer surface of the window glass 1. Formed.
The parallel light lens 34 has an inclination angle or the like so that the infrared ray β irradiated from the light projecting unit 32 is totally reflected from the spherical outer boundary surface between the raindrop W2 and the external space. In the portion where the raindrop W2 is not attached to the side surface, all the infrared rays β irradiated from the light projecting unit 32 are transmitted through the window glass 1 and the water-repellent coat 15, and thus no reflected light is generated. Further, in the portion where the raindrop W2 drops and the oval raindrop W2 adheres to the outer surface of the window glass 1 (water repellent coat 15), the infrared rays β transmitted through the window glass 1 are transmitted between the raindrop W2 and the external space. Total reflection from the outer interface. Thereby, the 2nd raindrop detection means 30 detects the reflected light quantity of the infrared rays (beta) which is the reflected light from the outer surface of the raindrop W2.

Next, the microcomputer 40 will be described.
The microcomputer 40 detects the amount of raindrops adhering to the outer surface of the window glass 1 based on the reflected light amounts of the infrared rays α, α2 and β detected by the first and second raindrop detection means 20 and 30 and the window glass 1. It is possible to determine whether or not the outer side surface has been subjected to water repellent treatment. The microcomputer 40 changes the operating characteristics of the wiper device 2 via the BCM 4.
As shown in FIG. 5, the microcomputer 40 includes a raindrop detection processing unit 41, a raindrop amount measurement unit 42, a water repellent glass determination unit 43 (water repellent glass determination unit), an auto wiper determination unit 44, and a wiper control unit 45. And is electrically connected to the light projecting unit control units 23 and 33 and the light receiving unit control units 27 and 37.

  In the raindrop detection processing unit 41, an average output is calculated for each reflected light output received by the two sets of light receiving units 26, and a value obtained by converting the average output to a negative value and adjusting the minimum value to zero is obtained. The first output x detected by the first raindrop detection means 20 is set, the average output is calculated for the output of each reflected light received by the two sets of light receiving sections 36, and this average output is calculated as the second raindrop detection means 30. Is set as the second output y detected.

  As shown in FIG. 8, the adhesion rate of the raindrops W1 to the wind glass 1 that has not been subjected to the water repellent treatment is proportional to the first output x, and as shown in FIG. The adhesion rate of the raindrops W2 to the applied window glass 1 is proportional to the second output y. Therefore, based on these correlations, the raindrop amount measuring unit 42 uses the first output x and the second output y set by the raindrop detection processing unit 41 as the first adhesion rate X (%) and the second adhesion. The ratio is converted to Y (%). In FIGS. 8 and 9, the first and second outputs x and x are less than a predetermined raindrop adhesion rate (for example, 1.0%) because of the detection accuracy of the first and second raindrop detection means 20 and 30. y is not output.

  Here, the first adhesion rate X of the first raindrop detecting means 20 converted from the first output x is set to 0% when there is no raindrop adhering to the wind glass 1, and is applied to the entire surface of the wind glass 1. When raindrops adhere, the deposition rate is set to 100%. Further, the second adhesion rate Y of the second raindrop detecting means 30 converted from the second output y is set to 0% when there is no raindrop adhering to the window glass 1 and is elliptical on the entire surface of the window glass 1. When spherical raindrops adhere, the deposition rate is set to 100%.

  The raindrop amount measuring unit 42 measures the amount of raindrops adhering to the window glass 1 based on the reduction width of the average output of the respective reflected lights received by the two sets of light receiving units 26 of the first raindrop detecting means 20. The raindrop amount measured based on the output value of the first raindrop detection means 20 corresponds to the raindrop amount detected by the rain sensor 3. In this embodiment, it is determined that there are raindrops due to rain when the first adhesion rate X is 2% or more in consideration of external factors and the like.

The water repellent glass determination unit 43 uses the first change amount dX of the first adhesion rate X in a predetermined time (for example, 0.1 to 1 sec) and the second change amount dY of the second adhesion rate Y in the same predetermined time. Each is calculated, and when the second change amount dY is larger than the first change amount dX, it is determined that the outer surface of the window glass 1 has been subjected to water repellent treatment.
That is, in the case of the wind glass 1 that has not been subjected to the water repellent treatment, since the flat raindrop W1 (see FIG. 6) is formed on the outer surface of the windglass 1, the first output x is increased as the raindrop W1 increases. Although the outer boundary surface of the raindrop W1 does not have a spherical shape that can be received by the second raindrop detection means 30, the increase amount of the second output y is smaller than the increase amount of the first output x.
In the case of the wind glass 1 that has been subjected to water repellent treatment, since the elliptical raindrop W2 (see FIG. 7) is formed on the outer surface of the windglass 1, the second output y increases as the raindrop W2 increases. Since the outer boundary surface of W2 is not a plane that can be received by the first raindrop detection means 20, the increase amount of the first output x is smaller than the increase amount of the second output y.

The auto wiper determination unit 44 determines whether or not the auto mode control is selected based on a manual switching operation of the wiper switch 12 (see FIGS. 2 and 3) by the user.
The wiper control unit 45 changes the operation characteristics of the wiper device 2 based on the basic function of controlling the wiper device 2 according to the mode control selected by the user and the raindrop amount measured by the raindrop amount measurement unit 42 in the auto mode control. It has a wiper characteristic change function.

As shown in FIGS. 10 and 11, the wiper control unit 45 includes a wiping speed map M1 and an intermittent time map M2 used when the auto mode control is selected.
As shown in FIG. 10, the wiping speed map M <b> 1 sets a correlation between the raindrop amount measured by the raindrop amount measuring unit 42 and the wiping speed of the wiper device 2. In the case of the wind glass 1 that has not been subjected to the water repellent treatment, the wiping speed of the wiper device 2 is controlled according to the wiping speed characteristic V1 that increases according to the raindrop amount up to the raindrop amount L1 and is constant at or above the raindrop amount L1. . In the case of the wind glass 1 that has been subjected to water repellent treatment, the wiping speed of the wiper device 2 increases according to the raindrop amount up to the raindrop amount L2 that is smaller than the raindrop amount L1, and is the same as the wiping speed characteristic V1 above the raindrop amount L2. It is controlled by the wiping speed characteristic V2 that makes the speed constant.

  As shown in FIG. 11, the intermittent time map M <b> 2 sets a correlation between the raindrop amount measured by the raindrop amount measuring unit 42 and the intermittent time of the wiper device 2. In the case of the wind glass 1 that has not been subjected to water repellent treatment, the intermittent time of the wiper device 2 is controlled by the intermittent time characteristic T1 that decreases according to the raindrop amount up to the raindrop amount L1 and becomes zero when the raindrop amount L1 or more. Is done. In the case of the wind glass 1 that has been subjected to water repellent treatment, the intermittent time of the wiper device 2 decreases according to the amount of raindrop to a raindrop amount L2 that is smaller than the raindrop amount L1, and becomes zero when the raindrop amount L2 or more. It is controlled by the intermittent time characteristic T2. As described above, in the wiping speed map M1 and the intermittent time map M2, the characteristics V2 and T2 of the wind glass 1 subjected to the water repellent treatment are compared to the characteristics V1 and T1 of the window glass 1 not subjected to the water repellent treatment. Is also set to increase the wiping ability.

Next, the wiper control process will be described based on the flowchart of FIG. Si (i = 1, 2,...) Indicates a step for each process.
First, it is determined whether or not the ignition of the automobile V is on (S1). If the ignition is not on, S1 is repeated.
When the ignition is in the on state, the process proceeds to S2, and it is determined whether or not the wiper switch 12 is in the on state other than the off operation. If the wiper switch 12 is not in the ON state, S2 is repeated.

When the wiper switch 12 is in the on state, the process proceeds to S3, and it is determined whether or not the auto mode control is set. When the auto mode control is not set, the process proceeds to S15, the mode control other than the auto mode control such as the first continuous wiping mode control set by the user is executed, and the process returns. When the auto mode control is set, the process proceeds to S4, and it is determined based on the detection result of the rain sensor 3 whether or not raindrops due to rain have been detected. If no raindrop is detected (first adhesion rate X <2%), S4 is repeated.
If raindrops are detected (2% ≦ first adhesion rate X), the process proceeds to S5 to calculate the first and second change amounts dX and dY.

Next, it is determined whether or not the second change amount dY is larger than the first change amount dX (S6).
When the second change amount dY is larger than the first change amount dX, it is determined that the outer surface of the window glass 1 has been subjected to water repellent treatment (S8), and the wiping speed characteristic V2 (S9) and the intermittent time characteristic T2 (S10). ) And the process proceeds to S11. In S11, after the auto mode control is executed based on the wiping speed characteristic and the intermittent time characteristic determined in the preceding step, the process returns.
When the second change amount dY is equal to or less than the first change amount dX, it is determined that the water repellency treatment is not performed on the outer surface of the window glass 1 (S12), and the wiping speed characteristic V1 (S13) is slower than the wiping speed characteristic V2. The intermittent time characteristic T1 (S14) longer than the intermittent time characteristic T2 is determined, and the process proceeds to S11.

Next, operations and effects of the rain sensor 3 according to the first embodiment will be described.
According to the rain sensor 3, the first raindrop detection means 20 is generated in order to detect the reflected light from the raindrops attached to the outer surface of the window glass 1 subjected to the water repellent treatment by the second raindrop detection means 30. Reliably determining the presence or absence of water-repellent treatment on the outer surface of the window glass 1 based on a comparison between the first output x and the first output generated by the second raindrop detection means 30 and the second output y having a different output tendency. Can do.

The water-repellent glass determination unit 43 calculates a first change amount dX of the first output x in a predetermined period and a second change amount dY of the second output y in the predetermined period, and the second change amount dY is a first change. When the amount is greater than the amount dX, it is determined that the outer surface of the window glass 1 has been subjected to water repellent treatment.
As a result, the presence or absence of water repellent treatment can be determined by comparing the first change amount dX of the first raindrop detection means 20 and the second change amount dY of the second raindrop detection means 30, thereby simplifying the configuration and simplifying the processing. Can be achieved.

  When the water repellent treatment is performed on the outer surface of the wind glass 1, the microcomputer 40 outputs a signal indicating that the water repellent treatment is performed, so that the wiping ability is higher than when the water repellent treatment is not performed on the outer surface of the wind glass 1. Since the wiper device 2 is controlled to be higher, the wiper device 2 can be controlled in accordance with the amount of raindrops actually attached to the window glass 1 regardless of whether or not the water repellent treatment is performed on the window glass 1.

  Since the wiper device 2 is configured so that the wiping speed and the intermittent period can be changed, the forward visibility of the user can be kept good regardless of the presence or absence of the water repellent treatment of the window glass 1.

Next, the rain sensor 3A according to the second embodiment will be described with reference to FIGS. The same main components as those in the first embodiment are denoted by the same reference numerals, description thereof is omitted, and only different components are described.
In the first embodiment, the presence or absence of the water repellent treatment is determined by comparing the first change amount dX of the first adhesion rate X and the second change amount dY of the second adhesion rate Y. The presence or absence of water repellent treatment is determined by comparing the first output x of the detection means 20 and the second output ya converted from the second output y of the second raindrop detection means 30.

As shown in FIG. 13, the microcomputer 40A includes a raindrop detection processing unit 41, a raindrop amount measurement unit 42, a water repellent glass determination unit 43A, an auto wiper determination unit 44, and a wiper control unit 45. Has been.
The water repellent glass determination unit 43A stores a first output map and a second output map in advance (see FIGS. 14 and 15).

  As shown in FIG. 14, in the first output map, an output characteristic A1 of the window glass 1 that has not been subjected to the water repellent treatment and an output characteristic A2 of the window glass 1 that has been subjected to the water repellent treatment are set. ing. The output characteristic A1 and the output characteristic A2 having a smaller increasing tendency than the output characteristic A1 are obtained from the correlation between the first output x and the amount of raindrops according to the presence or absence of the water repellent treatment based on experiments.

As shown in FIG. 15, in the second output map, an output characteristic B1 of the window glass 1 that has not been subjected to the water repellent treatment and an output characteristic B2 of the window glass 1 that has been subjected to the water repellent treatment are set. ing. The second output ya is obtained by converting the second output y so that the minimum value of the second output y when there is no raindrop matches the minimum value of the first output x when there is no raindrop. Here, the first output x detected by the first raindrop detection means 20 is set by calculating an average output for each reflected light output received by the light receiving unit 26 and converting the average output to negative. Therefore, the minimum value of the first output x is the maximum value of the output of the first raindrop detection means 20.
The output characteristic B1 and the output characteristic B2 having a larger increasing tendency than the output characteristic B1 are obtained from the correlation between the second output ya and the amount of raindrops according to the presence or absence of the water repellent treatment based on experiments.

  The water repellent glass determination unit 43A compares the first output x and the second output ya at a predetermined time point. When the second output ya is larger than the first output x, the water repellent treatment is performed on the outer surface of the window glass 1. Is determined to have been applied. That is, in the case of the wind glass 1 subjected to the water repellent treatment, the output characteristic B2 becomes a large value as the raindrop W2 (see FIG. 7) increases, but the value of the output characteristic A2 is larger than the value of the output characteristic B2. Therefore, the second output ya is larger than the first output x.

Next, the wiper control process will be described based on the flowchart of FIG. Only steps different from the flowchart of the first embodiment will be described.
If raindrops are detected in S4, the first and second outputs x and ya are detected (S25), and the process proceeds to S26 to determine whether or not the second output ya is greater than the first output x. To do.
If the second output ya is greater than the first output x, it is determined that the outer surface of the window glass 1 has been subjected to water repellent treatment (S8). If the second output ya is less than or equal to the first output x, the wind glass 1 It is determined that the outer surface is not subjected to water repellent treatment (S12).

  As described above, the water repellent glass determination unit 43A has the same minimum value of the first output x corresponding to the maximum value of the output of the first raindrop detection means 20 and the minimum value of the second output y of the second raindrop detection means 30. The second output ya corresponding to the output detected by the second raindrop detection means 30 corresponds to the output of the first raindrop detection means 20, having first and second output maps set so as to be output values. When the output is larger than the first output x, it is determined that the outer surface of the window glass 1 has been subjected to water repellent treatment, so that the water repellent treatment is performed with a single detection value by the first and second raindrop detection means 20 and 30. Therefore, the processing time can be shortened.

Next, a modification in which the above embodiment is partially changed will be described.
1) In the above embodiment, the example in which the presence or absence of the water repellent treatment is determined by comparing the first change amount dX of the first adhesion rate X and the second change amount dY of the second adhesion rate Y has been described. The presence / absence of water repellent treatment may be determined by comparing the amount of change dx of the first output x of the first raindrop detecting means with the amount of change dy of the second output y of the second raindrop detecting means.

2) In the above-described embodiment, the example in which the light projecting unit and the light projecting unit control unit of the first and second raindrop detecting means are provided independently, but the light projecting unit of the first and second raindrop detecting means is provided. The light unit may be shared and the light projecting unit control unit of the first and second raindrop detection means may be shared. It is also possible to share only one of the light projecting unit and the light projecting unit control unit of the first and second raindrop detecting means.

3) In the above embodiment, an example in which the amount of reflected light from a raindrop is detected using a CCD as the second raindrop detection means has been described, but a raindrop may be detected directly using image processing.
Further, any detection means can be applied as long as it is a detection means that detects raindrops through the window glass.

4) In the above-described embodiment, the example in which the presence / absence of the water-repellent treatment of the window glass is determined based on the comparison between the first output of the first raindrop detection unit and the second output of the second raindrop detection unit. The auto washer may be controlled by comparing the outputs of the first and second raindrop detection means.
The first raindrop detection means does not react very much to the dust adhering to the window glass. However, since the second raindrop detection means reacts to the dust adhering to the window glass, the second raindrop detection means has a predetermined output or more and the first raindrop. When there is almost no output from the detection means, it is possible to judge that the window glass is dirty and to automatically inject the window washer.

5] In the above embodiment, in the auto mode control, the example in which the wiping speed and the intermittent time of the wiper device are changed based on the presence / absence of the water repellent treatment has been described. The control mode may be changed for a mechanism related to the wiper device such as the operation start time.
When changing the operation start time of the wiper device, the raindrop detection standard is lowered (for example, 2% ≦ first adhesion rate) when the water repellent treatment is performed compared to when the water repellent treatment is not performed. Can be wiped away.

6) In addition, those skilled in the art can implement the present invention in various forms added with various modifications without departing from the spirit of the present invention, and the present invention includes such modifications. is there.

  The present invention relates to a raindrop detection device capable of determining whether or not a water glass repellent treatment has been performed on the outer surface of the window glass, from raindrops attached to the outer surface of the window glass that has been subjected to the water repellent treatment by the second raindrop detection means. By detecting the reflected light, it is possible to accurately determine whether or not the water repellent treatment is applied to the outer surface of the Indian glass with a simple process.

DESCRIPTION OF SYMBOLS 1 Window glass 2 Wiper apparatus 3, 3A Rain sensor 20 1st raindrop detection means 30 2nd raindrop detection means 40, 40A Microcomputer 43, 43A Water-repellent glass determination part x 1st output y, ya 2nd output dX 1st change amount dY First change amount

Claims (5)

First raindrop detecting means for irradiating light on the inner surface of the window glass and generating a first output corresponding to the reflected light reflected by the window glass; and the amount of raindrops adhering to the outer surface of the window glass based on the first output In a raindrop detection device comprising a control means for detecting
Second raindrop detection means for irradiating the inner surface of the window glass with light and generating a second output corresponding to the reflected light reflected by the raindrops attached to the outer surface of the window glass;
A raindrop detection device comprising: a water repellent glass determining means capable of determining whether or not a water repellent treatment is applied to an outer surface of the window glass based on a comparison between the first output and the second output .   The water repellent glass determination means calculates a first change amount of the first output during a predetermined period and a second change amount of the second output during the predetermined period, and the second change amount is the first change amount. The raindrop detection device according to claim 1, wherein when it is larger, the water repellent treatment is determined on the outer surface of the window glass. The water repellent glass determining means has a map set so that the maximum value of the first output of the first raindrop detecting means and the minimum value of the second output of the second raindrop detecting means are the same output value. And
When the second output value detected by the second raindrop detection means is larger than the first output value detected by the first raindrop detection means, it is determined that the water repellent treatment has been performed on the outer surface of the window glass. The raindrop detection apparatus according to claim 1.   The control means controls the wiper device so that the wiping ability is higher when the water repellent treatment is performed on the outer surface of the window glass than when the water repellent treatment is not performed on the outer surface of the window glass. The raindrop detection device according to any one of claims 1 to 3, wherein   The raindrop detection device according to claim 4, wherein the wiper device is configured to be capable of changing at least one of a wiping speed and an intermittent period.