JPH11258151A - Waterdrop detecting sensor - Google Patents
Waterdrop detecting sensorInfo
- Publication number
- JPH11258151A JPH11258151A JP5828598A JP5828598A JPH11258151A JP H11258151 A JPH11258151 A JP H11258151A JP 5828598 A JP5828598 A JP 5828598A JP 5828598 A JP5828598 A JP 5828598A JP H11258151 A JPH11258151 A JP H11258151A
- Authority
- JP
- Japan
- Prior art keywords
- light
- windshield
- detection
- light emitting
- detecting
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Investigating Or Analysing Materials By Optical Means (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、発光素子と受光素
子を用いて自動車用ウインドガラスなどの光透過性基板
に水滴が付着したことを検出する水滴検出センサに関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water drop detecting sensor for detecting that a water drop has adhered to a light transmitting substrate such as a window glass for an automobile using a light emitting element and a light receiving element.
【０００２】[0002]
【従来の技術】自動車のフロントガラスに雨滴が付着し
たことを検知して、ワイパーを自動的に動作させる試み
が従来から行なわれており、このような検知機能を備え
た基板として、図６に示す構造のものがある。2. Description of the Related Art Attempts to automatically operate a wiper by detecting that raindrops have adhered to a windshield of an automobile have been conventionally made. FIG. 6 shows a substrate having such a detection function. Some have the structure shown.
【０００３】即ち、ガラス板等の透明基板１００の表面
にプリズム１０１，１０２を貼着し、プリズム１０１を
介して光源１０３からの光を全反射する角度で透明基板
１００内に導入する。そして、水などの液体が透明基板
１００の表面に存在すると全反射が起こらないように入
射角度を設定しておくと、ガラス表面の全反射点におけ
る液体の有無により全反射の光量が変化するので、この
変化量を受光素子１０４などにより検知することによ
り、液体の存在を知ることができるというものである。That is, prisms 101 and 102 are adhered to the surface of a transparent substrate 100 such as a glass plate, and the light from the light source 103 is introduced into the transparent substrate 100 through the prism 101 at an angle that allows total reflection. If the incident angle is set so that total reflection does not occur when a liquid such as water is present on the surface of the transparent substrate 100, the amount of total reflection changes depending on the presence or absence of the liquid at the point of total reflection on the glass surface. By detecting the amount of change with the light receiving element 104 or the like, the presence of the liquid can be known.
【０００４】そして、特開昭６０−２１６２４５号公報
には、上記の検知方式のように、光源からの光をガラス
板面で全反射させ、これをプリズムを介して受光素子に
入射させていたのでは、検知感度が悪いので、ガラス面
に水滴が付着した時にのみ、当該水滴からの反射光を受
光素子に入射するようにプリズムの角度を設定した内容
が開示されている。Japanese Unexamined Patent Publication No. Sho 60-216245 discloses that light from a light source is totally reflected by a glass plate surface and incident on a light receiving element via a prism, as in the above-described detection method. However, since the detection sensitivity is poor, the content of setting the angle of the prism such that the reflected light from the water droplet enters the light receiving element only when the water droplet adheres to the glass surface is disclosed.
【０００５】また、特開昭６２−１６３９４９号公報に
は、２つの光源を用意し、一方の光源からの光束の検出
面における入射角を全反射の臨界角以上とし、他方の光
源からの光束の検出面における入射角を全反射の臨界角
以下とし、水以外の付着物との識別ができるようにした
構成が開示されている。In Japanese Patent Application Laid-Open No. 62-163949, two light sources are prepared, the angle of incidence of a light beam from one light source on a detection surface is made equal to or greater than the critical angle of total reflection, and the light beam from the other light source is emitted. A configuration is disclosed in which the angle of incidence on the detection surface is set to be equal to or less than the critical angle of total reflection so that it can be distinguished from attached matter other than water.
【０００６】更に、特開平８−２６１９７４号公報に
は、ガラス板の内部に櫛形の透明電極を配置し、ガラス
板表面に水滴が付着したことによって生じる櫛形の透明
電極間の静電容量の変化を検出し、これに応じて窓の開
閉やヒータの制御を行なうようにした構成が開示されて
いる。Further, Japanese Patent Application Laid-Open No. Hei 8-261974 discloses that a comb-shaped transparent electrode is arranged inside a glass plate, and a change in capacitance between the comb-shaped transparent electrodes caused by water droplets adhering to the surface of the glass plate. Is disclosed, and the opening and closing of the window and the control of the heater are performed in response to the detection.
【０００７】また、特表平６−５０９６５２号公報に
は、ウインドシールドの外側表面の水滴を検知し、水滴
に対応してウインドシールド用ワイパの動作を制御する
ために、ウインドシールドの内側表面に、プリズムなど
からなる感知ユニットを２つの粘着性の面を備えた中間
層で接着した構成が開示されている。Japanese Patent Application Laid-Open No. 6-509652 discloses a method for detecting water droplets on the outer surface of a windshield and controlling the operation of a windshield wiper in response to the water droplets. A configuration is disclosed in which a sensing unit including a prism and the like is bonded by an intermediate layer having two sticky surfaces.
【０００８】[0008]
【発明が解決しようとする課題】従来の光学式検知機能
を備えた透明基板にあっては、ガラス中に全反射光を導
入するためにプリズムが必須要件であると共に、このプ
リズムをガラス面に密着させる必要があり、取付作業に
手間がかかる。特に、自動車のウインドシールドガラス
などは湾曲したデザインが多く採用されており、密着さ
せることが困難である。また、プリズムとガラス表面と
の界面での不要な反射をさけるために、屈折率をできる
だけ近づける必要がある（屈折率マッチング）。このた
めにマッチング層を設けることも考えられるが、工程が
増加し、コスト面で不利が生じる。In a conventional transparent substrate having an optical detection function, a prism is indispensable for introducing total reflection light into glass, and this prism is mounted on a glass surface. It is necessary to make them adhere to each other, and the installation work is troublesome. In particular, many windshield glasses and the like have a curved design, and it is difficult to bring them into close contact with each other. In addition, in order to avoid unnecessary reflection at the interface between the prism and the glass surface, it is necessary to make the refractive indexes as close as possible (refractive index matching). For this purpose, it is conceivable to provide a matching layer, but the number of steps is increased and disadvantages are caused in cost.
【０００９】一方、特開平８−２６１９７４号公報のよ
うに、電極間の電気抵抗の変化、電気容量の変化などを
検知して行う方式は、耐久性、感度の面で光学式に劣
り、特に自動車用のフロントガラスにあっては、運転者
あるいは同乗者の視認性に追随した信号であることが重
要であり、光学式のセンサが望ましい。On the other hand, a method of detecting a change in electric resistance between electrodes, a change in electric capacity, and the like as disclosed in Japanese Patent Application Laid-Open No. 8-261974 is inferior to an optical method in terms of durability and sensitivity. In a windshield for an automobile, it is important that the signal follows the visibility of a driver or a passenger, and an optical sensor is desirable.
【００１０】本発明は、従来の技術が有するこのような
問題点に鑑みてなされたものであり、その目的とすると
ころは、プリズムが不要で、且つ構造が簡単で、自動車
用ウインドガラスなどの光透過性基板に付着した水滴を
確実に検出することができる水滴検出センサを提供しよ
うとするものである。SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art. It is an object of the present invention to eliminate the need for a prism, to have a simple structure, and to provide a window glass for automobiles. An object of the present invention is to provide a water droplet detection sensor capable of reliably detecting a water droplet attached to a light transmitting substrate.
【００１１】[0011]
【課題を解決するための手段】上記課題を解決すべく請
求項１に係る発明は、検出用光の反射光量の変化で光透
過性基板に付着した水滴を検出する水滴検出センサであ
って、前記検出用光を前記光透過性基板に入射させる発
光手段と前記検出用光のうち前記光透過性基板内を全反
射した光を検出する受光手段を、前記光透過性基板に設
けたものである。According to a first aspect of the present invention, there is provided a water drop detection sensor for detecting a water drop attached to a light transmitting substrate by a change in a reflected light amount of detection light, A light-emitting unit that causes the detection light to enter the light-transmitting substrate and a light-receiving unit that detects light that is totally reflected inside the light-transmitting substrate among the detection light, provided on the light-transmitting substrate. is there.
【００１２】請求項２に係る発明は、請求項１記載の水
滴検出センサにおいて、前記発光手段と受光手段を基板
を介して前記光透過性基板に設けたものである。According to a second aspect of the present invention, in the water drop detecting sensor according to the first aspect, the light emitting means and the light receiving means are provided on the light transmitting substrate via a substrate.
【００１３】請求項３に係る発明は、請求項１又は請求
項２記載の水滴検出センサにおいて、前記発光手段の発
光面を検出用光が全反射する入射方向に向けると共に、
前記受光手段の受光面を全反射してくる検出用光の方向
に向けたものである。According to a third aspect of the present invention, in the water droplet detection sensor according to the first or second aspect, the light emitting surface of the light emitting means is directed in an incident direction in which the detection light is totally reflected.
The light receiving surface of the light receiving means is directed in the direction of the detection light totally reflected.
【００１４】[0014]
【発明の実施の形態】以下に本発明の実施の形態を添付
図面に基づいて説明する。ここで、図１は本発明に係る
水滴検出センサを装着した自動車前部の斜視図、図２は
本発明の第１の実施の形態に係る水滴検出センサの構成
説明図、図３は本発明に係る水滴検出センサをワイパ制
御に適用した構成図、図４は本発明の第２の実施の形態
に係る水滴検出センサの構成説明図、図５は本発明の第
３の実施の形態に係る水滴検出センサの構成説明図であ
る。Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 is a perspective view of a front portion of an automobile equipped with a water droplet detection sensor according to the present invention, FIG. 2 is a configuration explanatory diagram of the water droplet detection sensor according to the first embodiment of the present invention, and FIG. FIG. 4 is a configuration diagram illustrating a water droplet detection sensor according to a second embodiment of the present invention, and FIG. 5 is a configuration diagram illustrating a water droplet detection sensor according to a third embodiment of the present invention. FIG. 3 is a diagram illustrating the configuration of a water droplet detection sensor.
【００１５】図１に示すように、水滴検出センサ１は、
自動車のウインドシールド２の室内側面であって外側面
を払拭するワイパ３の払拭領域に対向する部位に接着部
材４で取付けている。なお、ウインドシールド２には、
ＳｉＯ2を主成分とする５ｍｍ厚のソーダライムガラス
基板を用いている。As shown in FIG. 1, the water drop detection sensor 1
An adhesive member 4 is attached to a portion of the interior surface of the windshield 2 of the vehicle facing the wiping area of the wiper 3 for wiping the outer surface. The windshield 2 has
A 5 mm thick soda lime glass substrate mainly composed of SiO 2 is used.
【００１６】本発明の第１の実施の形態に係る水滴検出
センサ１は、図２に示すように、発光手段５と受光手段
６からなり、ウインドシールド２の室内側面で所定の間
隔を設け、発光手段５の発光面をウインドシールド２に
対向させると共に、接着部材４に埋設するようにして発
光手段５を固定し、同様に受光手段６の受光面をウイン
ドシールド２に対向させると共に、接着部材４に埋設す
るようにして受光手段６を固定している。The water drop detecting sensor 1 according to the first embodiment of the present invention comprises a light emitting means 5 and a light receiving means 6, as shown in FIG. The light emitting means 5 is fixed so that the light emitting surface of the light emitting means 5 faces the windshield 2 and is embedded in the adhesive member 4. Similarly, the light receiving surface of the light receiving means 6 faces the windshield 2 and 4, the light receiving means 6 is fixed.
【００１７】所定の間隔を設けて発光手段５と受光手段
６をウインドシールド２の室内側面に固定するのは、発
光手段５から受光手段６に至る光路長をなるべく短くし
て発光手段５から出射した検出用光の損失を所定レベル
に維持しつつ、所定の検出面積をウインドシールド２の
外側面に確保するためである。The reason why the light emitting means 5 and the light receiving means 6 are fixed to the indoor side surface of the windshield 2 at predetermined intervals is that the light path length from the light emitting means 5 to the light receiving means 6 is shortened as much as possible and the light is emitted from the light emitting means 5. This is because a predetermined detection area is secured on the outer surface of the windshield 2 while maintaining the loss of the detection light at a predetermined level.
【００１８】接着部材４としては、エポキシ接着部材や
紫外線硬化性のエポキシ接着部材など、ウインドシール
ド２の屈折率（１．４８）とほぼ等しい屈折率を有する
ものを選定している。また、発光手段５及び受光手段６
をシリコン系透明接着シートでウインドシールド２の室
内側面に固着させた後に、接着部材４に発光手段５及び
受光手段６を埋設するように固定することもできる。As the bonding member 4, a member having a refractive index substantially equal to the refractive index (1.48) of the windshield 2, such as an epoxy bonding member or an ultraviolet-curing epoxy bonding member, is selected. Light emitting means 5 and light receiving means 6
May be fixed to the indoor side surface of the windshield 2 with a silicon-based transparent adhesive sheet, and then the light emitting means 5 and the light receiving means 6 may be fixed to the adhesive member 4 so as to be embedded.
【００１９】また、発光手段５及び受光手段６をウイン
ドシールド２に固定するために盛った接着部材４を覆う
遮光部材７，８を設けている。遮光部材７，８は、接着
部材４を光学的に遮蔽するために樹脂や金属などで形成
され、一方の遮光部材７は発光手段５から不要な方向に
光が漏れるのを防ぐ役割を果たし、他方の遮光部材８は
外部光などが直接受光手段６に入るのを防ぐ役割を果た
す。従って、発光手段５から漏れる光がウインドシール
ド２の内部を伝播せずに、直接受光手段６に入ることは
ない。Further, light-shielding members 7 and 8 are provided to cover the adhesive member 4 which is provided to fix the light emitting means 5 and the light receiving means 6 to the windshield 2. The light shielding members 7 and 8 are formed of resin, metal, or the like to optically shield the adhesive member 4, and one of the light shielding members 7 plays a role of preventing light from leaking from the light emitting unit 5 in an unnecessary direction. The other light shielding member 8 has a role of preventing external light or the like from directly entering the light receiving unit 6. Therefore, the light leaking from the light emitting means 5 does not propagate into the windshield 2 and does not directly enter the light receiving means 6.
【００２０】また、遮光部材７，８の接着部材４との接
触面、即ち発光手段５及び受光手段６と対向する遮光部
材７，８の面に反射性能を持たせるとよい。また、遮光
部材７，８の接着部材４との接触面、即ち発光手段５及
び受光手段６と対向する遮光部材７，８の面を凹鏡面に
形成することもできる。It is preferable that the contact surfaces of the light shielding members 7 and 8 with the adhesive member 4, that is, the surfaces of the light shielding members 7 and 8 facing the light emitting means 5 and the light receiving means 6 have reflection performance. Further, the contact surfaces of the light shielding members 7 and 8 with the adhesive member 4, that is, the surfaces of the light shielding members 7 and 8 facing the light emitting unit 5 and the light receiving unit 6 may be formed as concave mirror surfaces.
【００２１】このように遮光部材７，８の接着部材４と
の接触面に反射性能を持たせたり、接触面を凹鏡面に形
成することにより、発光手段５から後方に出射した光を
集めてウインドシールド２の方向へ進ませて検出用光と
して利用でき、更にウインドシールド２の内部を伝播し
てきたものの受光手段６に直接入射できなかった検出用
光を遮光部材８に反射させて受光手段６に入射させるこ
ともでき、光の有効利用が図れる。As described above, by making the contact surfaces of the light shielding members 7 and 8 with the adhesive member 4 reflective, or by making the contact surfaces concave concave surfaces, the light emitted backward from the light emitting means 5 is collected. The detection light which is allowed to travel in the direction of the windshield 2 and can be used as detection light, and which has propagated inside the windshield 2 but could not be directly incident on the light receiving means 6 is reflected by the light shielding member 8 to be received by the light receiving means 6. The light can be effectively used.
【００２２】発光手段５は、図３に示すように、発光ダ
イオード（ＬＥＤ）やレーザダイオード（ＬＤ）などの
発光素子１１と、発光素子１１から所定周波数で変調し
た光を出力させる駆動回路１２と、発光素子１１の出力
レベルをモニタするフォトダイオード（ＰＤ）などの受
光素子１３と、受光素子１３の出力信号から変調成分に
対応する信号を取り出し駆動回路１２にフィードバック
する検出回路１４などからなる。駆動回路１２では、検
出回路１４の出力信号が所望の出力レベルを維持するよ
うに発光素子１１に流す駆動電流を制御している。As shown in FIG. 3, the light emitting means 5 includes a light emitting element 11 such as a light emitting diode (LED) or a laser diode (LD), and a driving circuit 12 for outputting light modulated at a predetermined frequency from the light emitting element 11. A light receiving element 13 such as a photodiode (PD) that monitors the output level of the light emitting element 11, a detection circuit 14 that extracts a signal corresponding to a modulation component from an output signal of the light receiving element 13 and feeds it back to the drive circuit 12. The drive circuit 12 controls the drive current flowing through the light emitting element 11 so that the output signal of the detection circuit 14 maintains a desired output level.
【００２３】受光手段６は、図３に示すように、ＰＤな
どの受光素子１５と、受光素子１５の出力信号から発光
素子１１の駆動回路１２による変調成分に対応する信号
を取り出す検出回路１６と、検出回路１６の出力信号を
増幅する増幅回路１７とからなる。増幅回路１７の出力
信号は、ワイパ駆動部２０へ入力され、ワイパ制御に使
用される。As shown in FIG. 3, the light receiving means 6 includes a light receiving element 15 such as a PD and a detection circuit 16 for extracting a signal corresponding to a modulation component of the driving circuit 12 of the light emitting element 11 from an output signal of the light receiving element 15. And an amplification circuit 17 for amplifying the output signal of the detection circuit 16. The output signal of the amplifier circuit 17 is input to the wiper drive unit 20 and used for wiper control.
【００２４】なお、発光手段５を、発光素子１１のみ
で、又は発光素子１１とモニタ用の受光素子１３で構成
し、駆動回路１２や検出回路１４などを別の場所に配置
してもよい。また、受光手段６を、受光素子１５のみで
構成し、検出回路１６や増幅回路１７などを別の場所に
配置してもよい。The light emitting means 5 may be constituted by the light emitting element 11 alone or the light emitting element 11 and the light receiving element 13 for monitoring, and the drive circuit 12 and the detection circuit 14 may be arranged at another place. Further, the light receiving means 6 may be constituted only by the light receiving element 15 and the detection circuit 16 and the amplification circuit 17 may be arranged at another place.
【００２５】以上のように構成した水滴検出センサ１の
作用について説明する。発光手段５から出射した光は、
発光素子１１がＬＥＤの場合には、ほぼ四方八方に放射
され、発光素子１１がＬＤの場合には、ほぼ一方向に放
射される。これらの光は、接着部材４を通してウインド
シールド２の内部に入る。接着部材４として、ウインド
シールド２の屈折率とほぼ等しい屈折率のものを選定し
たので、発光手段５から出射した光は接着部材４とウイ
ンドシールド２との界面で屈折することなく直進する。The operation of the water droplet detection sensor 1 configured as described above will be described. The light emitted from the light emitting means 5 is
When the light emitting element 11 is an LED, the light is emitted in almost all directions, and when the light emitting element 11 is an LD, the light is emitted in almost one direction. These lights enter the windshield 2 through the adhesive member 4. Since the adhesive member 4 having a refractive index substantially equal to the refractive index of the windshield 2 is selected, the light emitted from the light emitting means 5 travels straight without being refracted at the interface between the adhesive member 4 and the windshield 2.
【００２６】そして、図２に示すように、ウインドシー
ルド２の内部に臨界角未満の入射角で入った光は、ウイ
ンドシールド２を通過して外部に抜ける。一方、ウイン
ドシールド２の内部に臨界角以上の入射角で入った光
は、ウインドシールド２の外側面と空気との界面及びウ
インドシールド２の室内側面と空気との界面を交互に全
反射しながらウインドシールド２の内部を伝播する。そ
して、ウインドシールド２の内部で全反射した光は、受
光手段６に入射する。Then, as shown in FIG. 2, light that enters the inside of the windshield 2 at an incident angle smaller than the critical angle passes through the windshield 2 and exits outside. On the other hand, light that enters the inside of the windshield 2 at an angle of incidence equal to or greater than the critical angle is alternately totally reflected at the interface between the outside surface of the windshield 2 and the air and the interface between the indoor side surface of the windshield 2 and the air. The light propagates inside the windshield 2. The light totally reflected inside the windshield 2 enters the light receiving means 6.
【００２７】ここで、空気とガラスとの界面で全反射が
始まるときの入射角、即ち臨界角を求めるには、スネル
の法則を用いて以下の計算を行う。スネルの法則の一般
式は、以下に示す数式（１）のようになる。但し、α及
びα0は、屈折率ｎの物質と屈折率ｎ0の物質との界面の
法線に対する角度である（α：入射角、α0：屈折
角）。Here, the following calculation is performed using Snell's law to determine the incident angle at which total reflection starts at the interface between air and glass, ie, the critical angle. The general expression of Snell's law is as shown in the following expression (1). Here, α and α 0 are angles with respect to the normal line of the interface between the substance having the refractive index n and the substance having the refractive index n 0 (α: incident angle, α 0 : refraction angle).
【００２８】 ｎ0・ｓｉｎα0＝ｎ・ｓｉｎα （１）N 0 · sin α 0 = n · sin α (1)
【００２９】ガラスの屈折率ｎをｎ＝１．４８とし、空
気の屈折率ｎ0をｎ0＝１とした場合、空気とガラスとの
界面であってガラス内部で全反射するための入射角αの
条件は、屈折角α0が、α0≧９０°となればよいので、
その時の入射角αは、数式（１）より、α≧４２．５°
となる。従って、入射角αが、臨界角（４２．５°）以
上であれば、ガラス媒質中での全反射が起こる。When the refractive index n of glass is n = 1.48 and the refractive index n 0 of air is n 0 = 1, the angle of incidence at the interface between air and glass and for total internal reflection inside the glass conditions of alpha is the angle of refraction alpha 0, since it if the alpha 0 ≧ 90 °,
The incident angle α at that time is given by α ≧ 42.5 ° from Expression (1).
Becomes Therefore, when the incident angle α is equal to or larger than the critical angle (42.5 °), total reflection occurs in the glass medium.
【００３０】一方、水がガラスに付着した場合でも、水
とガラスとの界面であってガラス内部で全反射するため
の入射角αの条件は、水の屈折率をｎ0＝１．３３とし
て、同様の計算を行うと、α≧６４．０°となる。従っ
て、入射角αが、臨界角（６４．０°）以上であれば、
ガラス媒質中での全反射が起こる。On the other hand, even when water adheres to the glass, the condition of the incident angle α for total reflection inside the glass at the interface between the water and the glass is such that the refractive index of the water is n 0 = 1.33. By performing the same calculation, α ≧ 64.0 ° is obtained. Therefore, if the incident angle α is equal to or greater than the critical angle (64.0 °),
Total reflection occurs in the glass medium.
【００３１】従って、入射角αが、４２．５°から６
４．０°の範囲（４２．５°≦α≦６４．０°）であれ
ば、水がガラスに付着してないときはガラス内部で全反
射し、水が付着すると全反射しなくなり、光はガラス内
部から水を介して外部に漏れることになる。Therefore, the angle of incidence α is 42.5 ° to 6 °.
In the range of 4.0 ° (42.5 ° ≦ α ≦ 64.0 °), when water does not adhere to the glass, it is totally reflected inside the glass. Will leak out of the glass via water.
【００３２】このような反射を起こさせるために、発光
手段５を固着する位置を調整して入射角αの条件（４
２．５°≦α≦６４．０°）を満たすように、発光手段
５から出射する光の入射角を設定した。また、受光手段
６に反射光が入る入射角も発光手段５の場合と対称の関
係になるので、反射光を漏れなく受光するように受光手
段６を固着する位置を調整した。In order to cause such reflection, the position where the light emitting means 5 is fixed is adjusted and the condition of the incident angle α (4
(2.5 ° ≦ α ≦ 64.0 °), the incident angle of light emitted from the light emitting means 5 was set. Further, since the incident angle at which the reflected light enters the light receiving means 6 is also symmetrical to that of the light emitting means 5, the position where the light receiving means 6 is fixed is adjusted so as to receive the reflected light without leakage.
【００３３】従って、ウインドシールド２の外側面又は
室内側面のいずれか又は両面に水滴Ｗが付着している場
合には、伝播途中の光は水滴Ｗを通してウインドシール
ド２の外部に抜けてしまい、受光手段６に到達する光量
が減少する。そこで、この光量の減少分を検出し演算処
理すれば、水滴Ｗの付着の程度が分かる。Therefore, if water droplets W adhere to either or both of the outer side surface and the indoor side surface of the windshield 2, the light that is being propagated passes through the water droplets W to the outside of the windshield 2 and is received. The amount of light reaching the means 6 decreases. Therefore, if the amount of decrease in the amount of light is detected and arithmetic processing is performed, the degree of adhesion of the water droplet W can be determined.
【００３４】本発明では、入射角αの条件（４２．５°
≦α≦６４．０°）を満たす範囲で入射する光を全て利
用するため、ウインドシールド２の面に付着する水滴Ｗ
を離散的な光の反射点ではなく、多数の反射点の集合で
ある面に付着する水滴Ｗを検出するので、離散的な反射
点に付着する水滴Ｗを検出する場合に比べ、ウインドシ
ールド２の面に付着する水滴Ｗの検出確度が向上する。In the present invention, the condition of the incident angle α (42.5 °
≦ α ≦ 64.0 °), the water droplet W adhering to the surface of the windshield 2 is used in order to use all the light incident within the range satisfying the condition
Is detected not on discrete reflection points of light but on a surface that is a set of a large number of reflection points. The detection accuracy of the water droplet W attached to the surface is improved.
【００３５】そして、図３に示すように、水滴検出セン
サ１は、水滴Ｗの付着量に相当する出力信号を、ワイパ
駆動部２０へ入力する。すると、ワイパ駆動部２０で
は、検出された水滴Ｗの付着量が設定値以上の場合に
は、水滴Ｗの付着量に応じた間隔でワイパ３を作動さ
せ、一方検出された水滴Ｗの付着量が設定値未満になっ
た場合には、ワイパ３の作動を停止させる。Then, as shown in FIG. 3, the water droplet detection sensor 1 inputs an output signal corresponding to the amount of the water droplet W attached to the wiper driving unit 20. Then, the wiper driving unit 20 activates the wiper 3 at intervals corresponding to the amount of the attached water droplet W when the detected amount of the attached water droplet W is equal to or greater than the set value. Is less than the set value, the operation of the wiper 3 is stopped.
【００３６】図４に示すように、本発明の第２の実施の
形態に係る水滴検出センサ２１は、発光手段５と、受光
手段６と、透明基板２２を備え、発光手段５と受光手段
６を所定の間隔を設けて透明基板２２の一面側に固着し
てなる。発光手段５と受光手段６は、ともに接着部材４
に埋設するようにして透明基板２２に固定されている。
ここで、発光手段５と受光手段６を固着して水滴検出
センサ２１を構成する基板としては、ガラス基板などの
透明基板２２に限らず、透明ではないガラス基板や樹脂
基板などの光透過性基板であればよい。As shown in FIG. 4, a water drop detecting sensor 21 according to a second embodiment of the present invention includes a light emitting unit 5, a light receiving unit 6, and a transparent substrate 22, and the light emitting unit 5, the light receiving unit 6 Are fixed to one surface of the transparent substrate 22 at a predetermined interval. The light emitting means 5 and the light receiving means 6 are both bonded members 4
And is fixed to the transparent substrate 22 so as to be embedded therein.
Here, the substrate forming the water droplet detection sensor 21 by fixing the light emitting means 5 and the light receiving means 6 is not limited to the transparent substrate 22 such as a glass substrate, but may be a light transmitting substrate such as a non-transparent glass substrate or a resin substrate. Should be fine.
【００３７】また、発光手段５及び受光手段６を透明基
板２２に固定するために盛った接着部材６を覆う遮光部
材７，８を設けたり、遮光部材７，８と接着部材４との
接触面に反射性能を持たせたり、或は遮光部材７，８と
接着部材４との接触面を凹鏡面に形成するのは、本発明
の第１の実施の形態に係る水滴検出センサ１と同様であ
る。In order to fix the light emitting means 5 and the light receiving means 6 to the transparent substrate 22, light shielding members 7 and 8 for covering the adhesive members 6 are provided, and a contact surface between the light shielding members 7 and 8 and the adhesive member 4 is provided. Is provided with a reflective performance, or the contact surface between the light shielding members 7, 8 and the adhesive member 4 is formed as a concave mirror surface, similarly to the water droplet detection sensor 1 according to the first embodiment of the present invention. is there.
【００３８】そして、水滴検出センサ２１は、透明基板
２２の他面側を接着部材４でウインドシールド２の室内
側面に固着することによりウインドシールド２に固定さ
れる。なお、透明基板２２には、ウインドシールド２と
同じＳｉＯ2を主成分とするソーダライムガラス基板を
用いている。また、発光手段５や受光手段６などを固着
した透明基板２２をウインドシールド２の室内側面へ接
着する方法としては、接着部材４の他に、シリコン系透
明接着シートを用いて固定してもよい。The water drop detection sensor 21 is fixed to the windshield 2 by fixing the other surface of the transparent substrate 22 to the indoor side surface of the windshield 2 with the adhesive member 4. As the transparent substrate 22, a soda-lime glass substrate mainly composed of SiO 2 as in the windshield 2 is used. In addition, as a method of bonding the transparent substrate 22 to which the light emitting means 5 and the light receiving means 6 are fixed to the indoor side surface of the windshield 2, in addition to the bonding member 4, a silicon-based transparent bonding sheet may be used. .
【００３９】このように、予め透明基板２２に発光手段
５と受光手段６を所定の間隔を設けて固着し水滴検出セ
ンサ２１を構成するので、ウインドシールド２の室内側
面へ発光手段５と受光手段６を別個に所定の間隔を設け
て固着するのに比べて、ウインドシールド２の室内側面
への水滴検出センサ２１の取付けが容易になり、作業性
が向上する。なお、その他の作用効果は、本発明の第１
の実施の形態に係る水滴検出センサ１と同様である。As described above, the light emitting means 5 and the light receiving means 6 are fixed to the transparent substrate 22 in advance with a predetermined distance therebetween to constitute the water droplet detecting sensor 21. As compared with the case where the fixing members 6 are separately provided at predetermined intervals, the attachment of the water droplet detection sensor 21 to the indoor side surface of the windshield 2 is facilitated, and the workability is improved. Note that the other operation and effects are the same as those of the first embodiment of the present invention.
This is the same as the water droplet detection sensor 1 according to the embodiment.
【００４０】また、図５に示すように、本発明の第３の
実施の形態に係る水滴検出センサ３１は、発光手段５の
発光面５ａを検出用光が全反射する入射方向に向ける共
に、受光手段６の受光面６ａを全反射してくる検出用光
の方向に向けてウインドシールド２の室内側面又は透明
基板２２に固着して構成するものである。なお、図５
は、ウインドシールド２の室内側面に直接発光手段５と
受光手段６を固着した場合を示している。As shown in FIG. 5, the water drop detecting sensor 31 according to the third embodiment of the present invention directs the light emitting surface 5a of the light emitting means 5 in the incident direction in which the detection light is totally reflected. The light receiving surface 6a of the light receiving means 6 is fixed to the inner side surface of the windshield 2 or the transparent substrate 22 in the direction of the detection light totally reflected. FIG.
5 shows a case where the light emitting means 5 and the light receiving means 6 are directly fixed to the indoor side surface of the windshield 2.
【００４１】特に、発光素子１１がＬＥＤの場合には、
出射した光がほぼ四方八方に放射されるので、発光面５
ａを検出用光が全反射する入射方向に向けると発光面５
ａから出射した光の検出用光として作用する割合が高め
られ、光の有効利用が図れる。 また、受光面６ａを全
反射してくる検出用光の方向に向けておけば、確実に検
出用光を捉えることができる。なお、その他の作用効果
は、本発明の第１の実施の形態に係る水滴検出センサ１
と同様である。In particular, when the light emitting element 11 is an LED,
Since the emitted light is emitted in almost all directions, the light emitting surface 5
When a is directed to the incident direction where the detection light is totally reflected, the light emitting surface 5
The ratio of the light emitted from a acting as detection light is increased, and the light can be effectively used. In addition, by directing the light receiving surface 6a in the direction of the detection light totally reflected, the detection light can be reliably captured. Note that the other functions and effects are the same as those of the water droplet detection sensor 1 according to the first embodiment of the present invention.
Is the same as
【００４２】なお、本発明に係る水滴検出センサ１，２
１，３１は、水滴Ｗに限らず、屈折率の既知な液体や粒
状体など光透過性基板に付着するものであれば検出対象
となる。The water drop detection sensors 1 and 2 according to the present invention
Reference numerals 1 and 31 are not limited to the water droplets W, but may be detection targets as long as they adhere to the light-transmitting substrate, such as a liquid or a granular material having a known refractive index.
【００４３】また、水滴検出センサ１，２１，３１を固
着する光透過性基板としては、自動車用ウインドシール
ド２の他に、自動車のリアウインドやドアーミラーなど
のガラス基板、鉄道、船舶や航空機などのウインドガラ
ス、建造物のウインドガラス、洗面台などのミラー、道
路に設置されるカーブミラーなど、光を通すガラスや樹
脂などであれば適用できる。As the light-transmitting substrate to which the water droplet detection sensors 1, 21, 31 are fixed, in addition to the windshield 2 for automobiles, glass substrates such as rear windows and door mirrors of automobiles, railways, ships and aircrafts, etc. It can be applied to any glass or resin that can transmit light, such as a window glass, a building window glass, a mirror such as a wash basin, and a curved mirror installed on a road.
【００４４】そして、水滴検出センサ１，２１，３１の
水滴検出信号は、自動車のウインドシールド２に設置す
るワイパ３の他に、リアウインドやドアーミラーなど設
置するワイパの制御信号、また自動車のリアウインド、
ドアーミラーや洗面台ミラーなどに設置する曇止め用熱
線の起動信号として使用することができる。The water drop detection signals from the water drop detection sensors 1, 21 and 31 are used to control the wiper 3 installed on the windshield 2 of the automobile, the control signal of the wiper installed on the rear window or the door mirror, and the rear of the automobile. Wind,
It can be used as a start signal for a fogging hot wire installed on a door mirror or a sink mirror.
【００４５】[0045]
【発明の効果】以上説明したように請求項１に係る発明
によれば、プリズムが不要且つ構造が簡単になる。ま
た、離散的な反射点に付着した水滴を検出するのではな
く、ある範囲内の入射角で光透過性基板に入射して光透
過性基板内を全反射する光を有効に利用し、反射点の集
合である面に付着する水滴を検出するので、水滴の検出
確度が向上する。As described above, according to the first aspect of the present invention, no prism is required and the structure is simplified. Also, instead of detecting water droplets attached to discrete reflection points, the light incident on the light-transmitting substrate at an incident angle within a certain range and totally reflected inside the light-transmitting substrate is effectively used for reflection. Since the water droplet attached to the surface which is a set of points is detected, the detection accuracy of the water droplet is improved.
【００４６】請求項２に係る発明によれば、光透過性基
板に発光手段と受光手段を別個に所定の間隔を設けて直
接固定するのに比べて、光透過性基板への水滴検出セン
サの取付けが容易になり、作業性が向上する。According to the second aspect of the present invention, the light-emitting means and the light-receiving means are separately fixed to the light-transmitting substrate at predetermined intervals and directly fixed to the light-transmitting substrate. Installation is easy and workability is improved.
【００４７】請求項３に係る発明によれば、発光面を検
出用光が全反射する入射方向に向けると、発光面から出
射した光の検出用光として作用する割合が高められ、光
の有効利用が図れる。また、受光面を全反射してくる検
出用光の方向に向けておけば、確実に検出用光を捉える
ことができる。According to the third aspect of the present invention, when the light emitting surface is directed in the incident direction in which the detection light is totally reflected, the ratio of the light emitted from the light emitting surface acting as the detection light is increased, so that the light can be effectively used. Can be used. In addition, by directing the light receiving surface in the direction of the detection light totally reflected, the detection light can be reliably captured.
【図１】本発明に係る水滴検出センサを装着した自動車
前部の斜視図FIG. 1 is a perspective view of a front part of a vehicle equipped with a water droplet detection sensor according to the present invention.
【図２】本発明の第１の実施の形態に係る水滴検出セン
サの構成説明図FIG. 2 is a configuration explanatory view of a water droplet detection sensor according to the first embodiment of the present invention.
【図３】本発明に係る水滴検出センサをワイパ制御に適
用した構成図FIG. 3 is a configuration diagram in which a water droplet detection sensor according to the present invention is applied to wiper control.
【図４】本発明の第２の実施の形態に係る水滴検出セン
サの構成説明図FIG. 4 is a configuration explanatory view of a water droplet detection sensor according to a second embodiment of the present invention.
【図５】本発明の第３の実施の形態に係る水滴検出セン
サの構成説明図FIG. 5 is a configuration explanatory view of a water droplet detection sensor according to a third embodiment of the present invention.
【図６】従来の水滴検出センサの構成図FIG. 6 is a configuration diagram of a conventional water droplet detection sensor.
１，２１，３１…水滴検出センサ、２…ウインドシール
ド（光透過性基板）、３…ワイパ、４…接着部材、５…
発光手段、５ａ…発光面、６…受光手段、６ａ…受光
面、７，８…遮光部材、２２…透明基板（基板）、Ｗ…
水滴。1, 21, 31: water drop detection sensor, 2: windshield (light transmitting substrate), 3: wiper, 4: adhesive member, 5:
Light emitting means, 5a: Light emitting surface, 6: Light receiving means, 6a: Light receiving surface, 7, 8: Light shielding member, 22: Transparent substrate (substrate), W ...
Water drops.
Claims (3)
板に付着した水滴を検出する水滴検出センサであって、
前記検出用光を前記光透過性基板に入射させる発光手段
と前記検出用光のうち前記光透過性基板内を全反射した
光を検出する受光手段を、前記光透過性基板に設けたこ
とを特徴とする水滴検出センサ。1. A water droplet detection sensor for detecting a water droplet attached to a light-transmitting substrate by a change in the amount of reflected light of the detection light,
A light-emitting unit that causes the detection light to enter the light-transmitting substrate; and a light-receiving unit that detects light that is totally reflected inside the light-transmitting substrate among the detection light, provided on the light-transmitting substrate. Characteristic water drop detection sensor.
前記光透過性基板に設けた請求項１記載の水滴検出セン
サ。2. The water drop detection sensor according to claim 1, wherein the light emitting means and the light receiving means are provided on the light transmitting substrate via a substrate.
射する入射方向に向けると共に、前記受光手段の受光面
を全反射してくる検出用光の方向に向けた請求項１又は
請求項２記載の水滴検出センサ。3. The light-emitting device according to claim 1, wherein the light-emitting surface of the light-emitting device is directed in an incident direction in which the detection light is totally reflected, and the light-receiving surface of the light-receiving device is directed in a direction of the detection light totally reflected. Item 3. A water drop detection sensor according to Item 2.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5828598A JPH11258151A (en) | 1998-03-10 | 1998-03-10 | Waterdrop detecting sensor |
| EP99301803A EP0941900A3 (en) | 1998-03-10 | 1999-03-10 | Water detection sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5828598A JPH11258151A (en) | 1998-03-10 | 1998-03-10 | Waterdrop detecting sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH11258151A true JPH11258151A (en) | 1999-09-24 |
Family
ID=13079938
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5828598A Pending JPH11258151A (en) | 1998-03-10 | 1998-03-10 | Waterdrop detecting sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH11258151A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100396736B1 (en) * | 1999-12-09 | 2003-09-02 | 가부시키가이샤 고이토 세이사꾸쇼 | Evaluation device for a moisture in a vehicle lamp |
| JP2020533589A (en) * | 2017-09-11 | 2020-11-19 | ピルキントン グループ リミテッド | Sensors and glazing with built-in sensors |
-
1998
- 1998-03-10 JP JP5828598A patent/JPH11258151A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100396736B1 (en) * | 1999-12-09 | 2003-09-02 | 가부시키가이샤 고이토 세이사꾸쇼 | Evaluation device for a moisture in a vehicle lamp |
| JP2020533589A (en) * | 2017-09-11 | 2020-11-19 | ピルキントン グループ リミテッド | Sensors and glazing with built-in sensors |
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