JPS63210692A - Onboard water drop detector - Google Patents

Abstract

PURPOSE:To make malfunctioning hard to occur without blocking a driving field of view, by mounting light emitting and receiving elements direct at both ends of a light transmitting member separately mounted at least at a part of a body in such a manner as to be seen through from the front of a vehicle. CONSTITUTION:A light guide 51 using a light transmitting member is mounted on a door mirror 4 or the like in such a manner as to be seen through from the front of a vehicle. A light receiving element 53 such as photodiode is arranged direct at one end of the light guide 51 (above an upper corner of the door mirror 4) while a light emitting element 52 such as LED, at the other end thereof. This eliminates the need for mounting the apparatus on a front window and gets rid of a problem of handling during the mounting. This also removes possible damage to a driving field of view thereby making the apparatus free from a problem of law and appearance. A higher detection efficiency is achieved and malfunctioning hardly occurs.

Description

[Detailed description of the invention]

[Industrial Application Field 1] The present invention relates to a water droplet detection device installed in an automobile, which detects water droplets and automatically drives a wiper.
The present invention relates to a device that optically detects water droplets. K. Prior Art There is a conventional water droplet detection device of this kind as shown in FIG. 9, in which a part of the front window 2 of a vehicle 1 is used as a light-transmitting member for detection to form a detection part. 20, as shown in an enlarged view in FIG. 10, a part of the front window 2 is used as a detection part 20, and a triangular prism 21 is attached to the inner surface of the detection part 20, so that the front window 2, that is, the detection part A similar triangular prism 23 is provided at a position where the light beam from the light emitting element 22 is allowed to enter the light emitting element 20 at an angle less than the critical angle, and where the light beam is totally reflected multiple times at the contact surface with the atmosphere. Take out the light, light receiving element 2
4 measures the amount of light, and at this time the detection unit 20
When a water droplet adheres to the surface of the light emitting element 21, the light beam from the light emitting element 21 leaks from the surface to which the water droplet adheres, so that the amount of light received by the light receiving element 24 decreases. Based on the degree of this reduction, it is determined whether water droplets are attached or not, and the wiper is activated (started and stopped). [Problems to be Solved by the Invention K] However, the above-mentioned conventional device is attached directly to the front window 2, so for example, a water drop detection device must be installed before the front window 2 is attached to the automobile. This poses a handling problem in that a very large front window 2 must be handled in order to install the detection unit. ■ Adding this kind of thing to the front window 2 poses a safety problem as it may impair driving visibility. ■ There is a legal problem in that anything that can actually be installed on the front window 2 is subject to regulations. ■ It causes an appearance problem that spoils the beauty of the automobile itself, and furthermore, ■ All the light rays from the light emitting element 22 reach the light receiving element 24 as shown by the dotted arrow in FIG. 10. However, there were performance problems such as low detection efficiency, easy malfunction due to external light, and difficulty in detection.

[Means to solve the problem]

As a specific means for solving the many problems that occur in the conventional vehicle-mounted water droplet detection device described above, the present invention provides a method in which a light beam from a light-emitting element is incident on a light-transmitting member, and a contact surface between the transparent member and the atmosphere is provided. In an on-vehicle water drop detection device that detects water droplets adhering to a light-emitting element using a light-receiving element provided optically facing the light-emitting element, the light-transmitting member has a light-emitting element directly attached to one end thereof. By providing an on-vehicle water drop detection device, which is characterized in that a light receiving element is similarly attached to the other end, and the device is disposed on at least a part of the vehicle body that can be seen from the front of the vehicle. This is to solve the above-mentioned conventional problems. K Embodiment Next, the present invention will be described in detail based on an embodiment in which the present invention is attached to a door mirror shown in the drawings. 1 is a vehicle, and the front window 2 of this vehicle 1 is provided with a wiper device 3, which is driven according to the detection of water droplets.According to the present invention, a water droplet detection device 5 is installed. It is attached to the door mirror 4. This state is shown in FIG. 2, which shows the door mirror 4 viewed from the rear side. At this time, the water droplet detection device 5 is attached so as to follow the shape of the rear side of the door mirror 4, so as not to give a sense of discomfort to the viewer. FIG. 3 shows the structure of the water droplet detection device 5 in detail, and one surface side of the light guide 51 formed using a light-transmitting member such as resin has a shape corresponding to the attachment position to the door mirror 4. along one end, with an LFD at one end.
A light emitting element 52 such as a photodiode is directly disposed on the other end, and a light receiving element 53 such as a photodiode is similarly disposed directly on the other end. Light guide 5 formed in this way
1 transmits almost all of the light rays emitted from the light emitting element 52 to the light receiving element 53 under normal conditions.
At this time, when the water droplets R adhere to the surface of the light guide 51, that is, the surface in contact with the atmosphere, the light beam leaks from this adhering surface, and the output of the light receiving element 53 changes to the amount of water droplets R attached (
(number), the adhesion of water droplets R can be detected, and the wiper 3 is driven in accordance with this detection result. Next, a preferred embodiment of the water droplet detection device 5 of the present invention will be described. First of all, when performing detection at a position different from the front windshield 2, which is originally the object of detection, as in the present invention, it is necessary to approximate the detection conditions. As shown in FIG. 2, the device 5 is preferably provided on two sides at the upper corner of the door mirror 4. By providing the device 5 in this position, water droplets R from above while the car is stopped are also prevented from dropping from diagonally in front while driving. It is also possible to detect the windshield, and the conditions can be approximated to those of the front window 2 which is installed at an angle. Furthermore, by arranging the light receiving element 53 on the upper side at this time, the light receiving element 53 is mounted slightly downward and does not receive strong direct light such as sunlight. It is possible to prevent the so-called saturation phenomenon in which no change occurs in the output even when the light from the light emitting element 52 reaches a saturation value and some change occurs in the light beam from the light emitting element 52. Although the above embodiment has been described as an example in which the headlamp is attached to a door mirror, the present invention is not limited thereto, and may be applied to a headlamp shown on the front of the vehicle as shown in FIG. 4 or on the top of the vehicle as shown in FIG. It can be mounted freely on a bumper, etc. Although not shown, it can also be mounted on a fender mirror, and it can also be mounted in a place that does not obstruct the driver's view of the front window, such as on the outside of an interior mirror. There is no difference in action and effect. FIG. 6 shows an embodiment of the structure at the time of installation. For example, a recess may be provided in the case portion of the door mirror 4, and the water droplet detection device 5 may be fitted into the recess. As shown in FIG. 7, the case part itself of the door mirror 4 may be formed of a light-transmissive member, and a part thereof may serve as the water droplet detection device 5. FIG. 8 shows an embodiment of the light guide 51 of the water droplet detection device 5, in which the detection surface 51a of the light guide 51 is
By making the surface other than the detection surface 51b a mirror surface and non-light-transmitting surface 51b by, for example, vapor deposition of aluminum, it is possible to prevent a decrease in sensitivity due to dust, etc. that accumulates over time on surfaces other than the detection surface 51a, and to enable stable detection over a long period of time. This opaque surface 5
The treatment 1b is effective when provided on at least one surface. [Effects of the Invention] As explained above, by attaching the in-vehicle water drop detection device to at least a part of the vehicle body that can be seen from the front of the vehicle according to the present invention, By not installing this water droplet detection device, we solved production problems such as handling.
■ Eliminates safety problems that impair driving visibility caused by installing a water droplet detection device on the front window, ■ At the same time solves legal and aesthetic problems, and further improves the light guide mentioned above. By adopting a structure in which the light-emitting element and light-receiving element are directly attached without going through a triangular prism as in the conventional example, almost all of the light from the light-emitting element reaches the light-receiving element, increasing detection efficiency. This solves the problem of a low value of , which is likely to cause malfunctions, and has the excellent effect of increasing the practicality of the on-vehicle water droplet detection device due to the effects listed above.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an embodiment of the on-vehicle water droplet detection device according to the present invention, Fig. 2 is an enlarged perspective view of the main part of Fig. 1, and Fig. 3 is a ■A cross-sectional view taken along the line; Figure 4 is a front view of a vehicle in which this water drop detection device is installed;
6 is an exploded perspective view showing a structural embodiment of the present invention, FIG. 7 is a perspective view showing another embodiment, and FIG. 8 is an implementation of the present invention into a light guide. FIG. 9 is a perspective view showing an example, FIG. 9 is a perspective view showing a conventional example, and FIG. 10 is a sectional view showing essential parts of the same conventional example. 1...Vehicle 2...Front window 3...Wiper 4...
... Door mirror 5 ... Vehicle-mounted water drop detection device 51 ... Light guide 51a ... Detection surface 51b ... Non-transparent surface 52
...Light emitting element 53...Light receiving element 6...
... Headlight 7 ... Bumper patent applicant Honda Motor Co., Ltd. Stanley Electric Co., Ltd. N'g12 @6! I 7th W! A Figure 9

Claims (14)

[Claims] (1) Vehicle-mounted water droplet detection by making light from a light-emitting element enter a light-transmitting member and detecting water droplets adhering to the light-transmitting member with a light-receiving element provided so as to optically face the light-emitting element. In the device, the light-transmitting member has a light-emitting element directly attached to one end, a light-receiving element similarly attached to the other end, and at least a part of the vehicle body that can be seen from the front of the vehicle. An in-vehicle water drop detection device characterized in that: (2) The vehicle-mounted water droplet detection device according to claim (1), wherein the light-transmitting member is disposed on at least a portion of the vehicle body that can be seen from the top surface of the vehicle. (3) The vehicle-mounted water droplet according to claim (1) and/or claim (2), wherein the light-transmitting member is disposed on a protruding portion from the general surface of the vehicle body. Detection device. (4) Claim (1) and/or Claim (2) characterized in that the light-transmissive member is disposed on parts that are retrofitted to the vehicle body, such as door mirrors, fender mirrors, bumpers, etc. ) Vehicle-mounted water droplet detection device described in section 2. (5) Claim (1) and/or the light transmitting member is arranged near the front window.
Or an in-vehicle water droplet detection device according to claim (2). (6) The vehicle-mounted water droplet detection device according to claim (1) and/or claim (2), wherein the light-transmitting member has a shape extending substantially in the vertical direction. (7) The vehicle-mounted water droplet detection device according to claim (1) and/or claim (2), wherein the light-transmitting member has a curved portion. (8) Claim (1) and/or Claim (2) and/or Claim (8) The light-transmitting member has the light-receiving element attached to its upper end.
The in-vehicle water droplet detection device described in section 6). (9) The vehicle-mounted water droplet detection device according to claim (3), wherein the light-transmitting member is disposed along the shape of the protrusion. (10) The vehicle-mounted water droplet detection device according to claim (9), wherein the protruding portion is a rear view mirror of the vehicle. (11) The vehicle-mounted water droplet detection device according to claim (10), wherein the light-transmitting member is disposed so as to follow the shape of an upper corner portion of the rear view mirror. (12) Claim (10) and/or Claim (11), characterized in that the light-transmitting member is housed in a recess provided in a case portion of the rearview mirror. Automotive water drop detection device. (13) Claim (10) and/or wherein the light-transmitting member is a case portion of the rear view mirror.
Alternatively, an in-vehicle water droplet detection device according to claim (11). (14) The light-transmitting member has an opaque surface formed on at least one surface other than the water droplet adhering surface, as set forth in claim (1) and/or claim (2). Automotive water drop detection device.