JPH04106787U - distance measuring device - Google Patents
distance measuring deviceInfo
- Publication number
- JPH04106787U JPH04106787U JP893991U JP893991U JPH04106787U JP H04106787 U JPH04106787 U JP H04106787U JP 893991 U JP893991 U JP 893991U JP 893991 U JP893991 U JP 893991U JP H04106787 U JPH04106787 U JP H04106787U
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- light
- receiving lens
- measuring device
- distance measuring
- photoelectric conversion
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- 238000006243 chemical reaction Methods 0.000 claims abstract description 10
- 238000011282 treatment Methods 0.000 claims abstract description 5
- 230000003287 optical effect Effects 0.000 claims description 11
- 230000000694 effects Effects 0.000 abstract description 4
- 239000011148 porous material Substances 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 7
- 239000000463 material Substances 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 101000582320 Homo sapiens Neurogenic differentiation factor 6 Proteins 0.000 description 1
- 102100030589 Neurogenic differentiation factor 6 Human genes 0.000 description 1
- 230000003667 anti-reflective effect Effects 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
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Abstract
(57)【要約】
【目的】 測距装置の受光側の光電変換素子へ有害光が
入光しないようにした。
【構成】 受光レンズと光電変換素子との間に受光レン
ズ側から光電変換素子側に徐々に孔径の小さくなる複数
枚の遮光板を配置し、遮光板の表面に反射防止処理を施
した。
【効果】 外部からの有害光を効果的に遮光することが
でき、かつ装置の小型化と受光効率の低下を解消でき
る。
(57) [Summary] [Purpose] To prevent harmful light from entering the photoelectric conversion element on the light receiving side of a distance measuring device. [Structure] A plurality of light-shielding plates whose pore diameters gradually become smaller from the light-receiving lens side to the photoelectric conversion element side are arranged between the light-receiving lens and the photoelectric conversion element, and anti-reflection treatment is applied to the surface of the light-shielding plate. [Effect] Harmful light from the outside can be effectively blocked, and the device can be miniaturized and a decrease in light receiving efficiency can be avoided.
Description
【0001】0001
この考案は光を送出し、その反射光を検出して対象物体までの距離を検出する 装置に関するもので、詳しくは反射光を受光する構造に関するものである。 This idea sends out light and detects the reflected light to determine the distance to the target object. The present invention relates to a device, and specifically relates to a structure for receiving reflected light.
【0002】0002
レーザ光などの光を対象物体に向けて送出し、その送出光がその対象物体で反 射されてくる反射光を凸レンズ又は凹面鏡などの光学手段で受光しレーザ光の送 出から受光までの遅延時間を検出して対象物体までの距離を測定する装置は公知 である。 Sends out light such as a laser beam toward a target object, and the transmitted light is reflected by the target object. The incoming reflected light is received by optical means such as a convex lens or concave mirror, and the laser beam is transmitted. Devices that measure the distance to a target object by detecting the delay time from light emission to light reception are well known. It is.
【0003】 図3はレーザダイオードを使用した従来の測距装置の例であり、1は送光鏡筒 、2はこの送光鏡筒1の底部に取り付けられたレーザダイオード、3はこのレー ザダイオード2が発するレーザ光を所定の角度θtに集束して、送出光Ltとす るための凸レンズからなる送光レンズであり、前記送光鏡筒1の開口端部に取り つけられている。なお前記送出角θtは対象物体の大きさとその距離を考慮して 決定される。0003 Figure 3 is an example of a conventional distance measuring device using a laser diode, and 1 is a light transmitting lens barrel. , 2 is a laser diode attached to the bottom of this light transmitting lens barrel 1, and 3 is a laser diode attached to the bottom of this light transmitting lens barrel 1. The laser light emitted by the diode 2 is focused at a predetermined angle θt to become the transmitted light Lt. This is a light transmitting lens consisting of a convex lens for transmitting light, and is attached to the open end of the light transmitting lens barrel 1. It's attached. Note that the delivery angle θt is determined by taking into account the size of the target object and its distance. It is determined.
【0004】 4は受光鏡筒で、その底部にはフォトダイオード5が取りつけられ、鏡筒の開 口端部には前記送出光Ltの対象物体からの反射光Lrを前記フォトダイオード 5に集光させるための凸レンズからなる受光レンズ6が取りつけられている。0004 4 is a light-receiving lens barrel, and a photodiode 5 is attached to the bottom of the lens barrel. At the end of the mouth, the reflected light Lr from the target object of the transmitted light Lt is connected to the photodiode. A light receiving lens 6 made of a convex lens is attached to condense light onto the light receiving lens 5 .
【0005】 なお反射光Lrの受光角θrは前記送光角θtよりわずかに大き目となるよう フォトダイオード5の受光径と、受光レンズ6の焦点距離により決められる。[0005] Note that the light receiving angle θr of the reflected light Lr is set to be slightly larger than the light transmitting angle θt. It is determined by the light receiving diameter of the photodiode 5 and the focal length of the light receiving lens 6.
【0006】 7はコントローラで、前記レーザダイオード2をパルス駆動するためのパルス 発生器8と、前記フォトダイオード5の受光出力を増幅整形するためのパルス検 出器9及びこれら送出パルスと、受光パルス間の遅延時間から対象物までの距離 を演算する信号処理回路10よりなる。[0006] 7 is a controller which generates pulses for pulse-driving the laser diode 2; A generator 8 and a pulse detector for amplifying and shaping the received light output of the photodiode 5. Distance from the transmitter 9 and the delay time between these transmitted pulses and the received pulse to the target object It consists of a signal processing circuit 10 that calculates .
【0007】 11は表示装置で、上記により得られた距離情報を具体的な数字やグラフとし て表示するものである。[0007] 11 is a display device that displays the distance information obtained above in concrete numbers and graphs. It is displayed as follows.
【0008】 次に本装置の動作原理を図4で説明する。図4(a) は送光パルスの波形を示す もので、パルス中tw、周期tpでレーザダイオードを駆動している。[0008] Next, the operating principle of this device will be explained with reference to FIG. Figure 4(a) shows the waveform of the transmitted light pulse. The laser diode is driven with a pulse of tw and a period of tp.
【0009】 図4(b) は受光パルスの波形を示すもので、送光パルスより時間tだけ遅れて 受光される。この遅延時間tは対象物体までの往復距離に相当する時間差である から対象物体までの距離RとすればRは次式で求められる。[0009] Figure 4(b) shows the waveform of the received light pulse, which is delayed by time t from the transmitted light pulse. Light is received. This delay time t is a time difference corresponding to the round trip distance to the target object. Letting the distance R from to the target object be determined by the following equation.
【0010】0010
【数1】 ■■■■■■[Math 1] ■■■■■■
【0011】 ここで、cはレーザ光の伝播速度でc=3×108 m/sである。[0011] Here, c is the propagation speed of the laser beam and is c=3×10 8 m/s.
【0012】 ところで、受光角θrは前述の通り、通常送光角θtよりわずかに広く設定さ れ、これは受光レンズ6の焦点距離fと、フォトダイオード5の受光径Ds によ り決まる。即ち次式となる。By the way, as described above, the light receiving angle θr is normally set slightly wider than the light transmitting angle θt, and this is determined by the focal length f of the light receiving lens 6 and the light receiving diameter D s of the photodiode 5. That is, the following equation is obtained.
【0013】[0013]
【数2】 ■■■■■■[Math 2] ■■■■■■
【0014】 従って受光角θrの外側にある光はフォトダイオード5には到達しない訳であ るが、太陽光などの極めて輝度の大きい光源の場合は鏡筒内の内面反射によりフ ォトダイオード5に到達し、直流出力を生じ、ひどい場合には光電変換の飽和を 生じて測距不能となる場合がある。図5はこの状態を示した図で、受光角θrの 域外にある太陽Sからの光が受光鏡筒4の内面で反射されてフォトダイオード5 に到達している。[0014] Therefore, light outside the acceptance angle θr does not reach the photodiode 5. However, in the case of an extremely bright light source such as sunlight, the flame is caused by internal reflection inside the lens barrel. It reaches the photodiode 5, generates DC output, and in severe cases can cause saturation of photoelectric conversion. This may cause distance measurement to become impossible. Figure 5 is a diagram showing this state, where the acceptance angle θr is Light from the sun S outside the area is reflected by the inner surface of the light receiving lens barrel 4 and is transmitted to the photodiode 5. has been reached.
【0015】 鏡筒4の内面はもちろん無光沢の黒色塗装或いは無反射材料で反射防止の処理 がなされているが、完全に光を吸収して無反射となる材料は現実には存在せず、 わずかの反射を生じる。受光角外の光源の輝度が低い場合にはこれによる内面反 射は無視できるが、太陽光などの極端に明るい光源の場合は、これによる反射光 も強いため、前記したような障害を生じる。[0015] The inner surface of the lens barrel 4 is coated with matte black paint or anti-reflective material. However, there is no material that completely absorbs light and does not reflect light. Causes slight reflection. If the brightness of the light source outside the acceptance angle is low, this will cause internal reflection. However, in the case of extremely bright light sources such as sunlight, the reflected light from this can be ignored. Since it is also strong, it causes the above-mentioned problems.
【0016】[0016]
これの対策として例えば実開昭59−41771号公報に記載されているよう に受光レンズの前にハニカム構造体を設置する方法や実開昭62−180784 号公報に記載のように同じく受光レンズの前に遮光板を設置する方法が提案され ている。図6はこれらを示す図であるが、現実に光を完全に吸収する材料が存在 しないため、遮光板内での内面反射により同様の障害を生じる。 As a countermeasure for this, for example, as described in Japanese Utility Model Application Publication No. 59-41771, A method of installing a honeycomb structure in front of a light receiving lens and Utility Model Application No. 62-180784 As described in the publication, a method of installing a light-shielding plate in front of the light-receiving lens was also proposed. ing. Figure 6 is a diagram showing these, but in reality there are materials that completely absorb light. Therefore, similar problems occur due to internal reflection within the light shielding plate.
【0017】 即ち、図6に於いて、受光角θrの域外のS1 の位置に太陽があった場合その 光は遮光板Gで1回反射され、受光レンズ6に向かう。又、太陽の位置がS2 の 場合は遮光板Gで2回反射された光が受光レンズ6に入射する。これを避けるた めには遮光板Gの奥行lを大きくするか、遮光板の数を増やしてピッチPを細か くする必要があるが、前者は装置の奥行寸法の増大をきたす事になるし、又、後 者は遮光板の板厚による有効受光量の減少を招き、測距能力を低下させてしまう 問題があった。That is, in FIG. 6, when the sun is at a position S 1 outside the light receiving angle θr, the light is reflected once by the light shielding plate G and heads toward the light receiving lens 6 . Further, when the sun position is S2 , the light reflected twice by the light shielding plate G enters the light receiving lens 6. In order to avoid this, it is necessary to increase the depth l of the light shielding plate G or increase the number of light shielding plates to make the pitch P finer, but the former will increase the depth dimension of the device, and However, the latter has a problem in that the effective amount of light received is reduced due to the thickness of the light-shielding plate, resulting in a decrease in distance measurement ability.
【0018】 この考案は上記のような問題点を解消するためになされたもので、鏡筒内の内 面反射を防止できると共に、装置全体を小型化した測距装置を得ることを目的と するものである。[0018] This idea was made to solve the problems mentioned above, and was designed to reduce the internal The aim is to obtain a distance measuring device that can prevent surface reflection and has a smaller overall size. It is something to do.
【0019】[0019]
この考案に係る測距装置は、光を対象物に向けて送出し、その対象物からの反 射光を受光して光の伝播遅延時間から対象物までの距離を求める測距装置におい て、受光レンズの有効外径と、その受光レンズの焦点の位置に設置される光電変 換素子の受光面外径を結んで形成される円錐又は多角錐状の入光範囲を任意の光 軸位置で、光軸を直角に切断して得られる形状に相当する穴を有し、表面に反射 防止処理を施した薄板状よりなる複数の遮光板を光軸と直角に設置したことを特 徴とする。 The distance measuring device according to this invention emits light toward an object and receives reflection from the object. In a distance measuring device that receives incoming light and calculates the distance to an object from the propagation delay time of the light. The effective outer diameter of the light-receiving lens and the photoelectric transformer installed at the focal point of the light-receiving lens are A conical or polygonal pyramidal light incident range formed by connecting the outer diameter of the light-receiving surface of the conversion element can be used to capture any light. At the axial position, there is a hole corresponding to the shape obtained by cutting the optical axis at right angles, and the reflection on the surface A special feature is that multiple light-shielding plates made of thin plates with anti-preventive treatment are installed perpendicular to the optical axis. be a sign.
【0020】[0020]
この考案においては、上記のように構成したことで、受光角の域外からの有害 光を遮光板に反射して光電変換素子から遠ざける方向へ導くことができる。 In this device, the configuration described above prevents harmful interference from outside the receiving angle. Light can be reflected by the light shielding plate and guided in a direction away from the photoelectric conversion element.
【0021】[0021]
以下、この考案の一実施例を図面について説明する。図1において、6は受光 レンズ、DL はその有効外径、Xは光軸を示す。5は前記受光レンズ6の焦点位 置に設置されたフォトダイオードで、DS はその受光面外径を表す。An embodiment of this invention will be described below with reference to the drawings. In FIG. 1, 6 is a light receiving lens, D L is its effective outer diameter, and X is an optical axis. 5 is a photodiode installed at the focal point of the light receiving lens 6, and D S represents the outer diameter of its light receiving surface.
【0022】 G1 〜G5 は表面に黒色塗装などの反射防止処理を施した薄い板材より成る遮 光板で、フォトダイオード5の受光板DS と、レンズ6の有効径DL を結んで形 成される円錐状の入光範囲を、任意の光軸位置で、光軸を直角に切断して得られ る円形の穴があけられている。即ち、受光レンズ6に近い遮光板G1 はレンズ有 効径DL に近い大きい穴を持ち、フォトダイオード5に近い遮光板G5 はDS に 近い小さい穴を有することになる。G 1 to G 5 are light shielding plates made of thin plates whose surfaces have been subjected to antireflection treatment such as black coating, and are formed by connecting the light receiving plate D S of the photodiode 5 and the effective diameter D L of the lens 6. A circular hole is made by cutting the conical light incident range at a right angle to the optical axis at an arbitrary optical axis position. That is, the light-shielding plate G 1 near the light-receiving lens 6 has a large hole close to the lens effective diameter D L , and the light-shielding plate G 5 near the photodiode 5 has a small hole close to D S.
【0023】 これらの遮光板G1 〜G5 を図1に示すように光軸と垂直に設置する。この装 置に於いて、今、仮に受光角θrの域外に太陽Sがあったとするとレンズ6を透 過した太陽光は遮光板G5 とG4 の間で反射を繰り返すことになり、遮光板は前 述の通り黒色塗装などの反射防止処理により、反射を極力少なくするようにして あるので反射の都度、その光は減衰される。又、この図から理解される通り、そ の反射光はフォトダイオード5から遠ざかる方向に向かうので太陽光などの強烈 な光であっても実用上、問題のないレベルにできる。These light shielding plates G 1 to G 5 are installed perpendicular to the optical axis as shown in FIG. In this device, if the sun S is now outside the range of the acceptance angle θr, the sunlight transmitted through the lens 6 will be repeatedly reflected between the light shielding plates G5 and G4 , and the light shielding plate will be As you can see, anti-reflection treatments such as black coating are used to minimize reflections, so each time the light is reflected, the light is attenuated. Further, as can be understood from this figure, the reflected light is directed away from the photodiode 5, so even intense light such as sunlight can be reduced to a level that poses no problem for practical use.
【0024】 図2はこの遮光板を示す配列状態の斜視図である。[0024] FIG. 2 is a perspective view of this light shielding plate in an arranged state.
【0025】 なお、上記実施例では遮光板G1 〜G5 にあけた穴を円としたが、これはフォ トダイオード5の受光部が円形である場合の例であり、例えば受光部が矩形の場 合は遮光板の穴形状を矩形としてもよい。又、太陽光などのように受光角外の有 害光源の位置が常に装置の上部にある場合は遮光板は光軸より下の部分のみとし 、光軸より上部の遮光板を省いてもさしつかえない。In the above embodiment, the holes drilled in the light shielding plates G 1 to G 5 are circular, but this is an example in which the light receiving portion of the photodiode 5 is circular. For example, the light receiving portion may be rectangular. In this case, the hole shape of the light shielding plate may be rectangular. Also, if the harmful light source outside the receiving angle, such as sunlight, is always located at the top of the device, the light shielding plate should only be placed below the optical axis, and the light shielding plate above the optical axis may be omitted. .
【0026】 さらに実施例では遮光板の数を5枚としこれらを等間隔としたが、これに限定 されるものではなく、遮光板の板厚が薄く出来るのであれば、枚数を増やした方 が効果的であるのは当然であり、間隔も域外有害光が入射し易いフォトダイオー ド5近くを密とし、レンズ軸を疎にしてもよい。[0026] Furthermore, in the example, the number of light shielding plates was five and they were spaced equally apart, but this is not limiting. If the thickness of the light-shielding plate can be made thinner, it is better to increase the number of light-shielding plates. It is natural that this is effective, and the spacing is also limited to avoid the photodiode, where harmful outside light is likely to enter. It is also possible to make the area near the dot 5 dense and the lens axis sparse.
【0027】[0027]
以上のようにこの考案によれば、受光レンズと光電変換素子の間に受光レンズ 側から光電変換素子側に孔径の小さくなる複数枚からなる遮光板を設けるように したので、有害光の効果的な遮光ができるとともに、従来装置のように装置全体 が大型化することもなく、又、受光効果を低下させることもない。 As described above, according to this invention, the light receiving lens is placed between the light receiving lens and the photoelectric conversion element. A light shielding plate consisting of multiple sheets with smaller pore diameters is installed from the side to the photoelectric conversion element side. As a result, harmful light can be effectively blocked, and the entire device can be does not increase in size and does not reduce the light receiving effect.
【提出日】平成3年8月30日[Submission date] August 30, 1991
【手続補正1】[Procedural amendment 1]
【補正対象書類名】明細書[Name of document to be amended] Specification
【補正対象項目名】0008[Correction target item name] 0008
【補正方法】変更[Correction method] Change
【0008】 次に本装置の動作原理を図4で説明する。図4(a)は送光パルスの波形を示 すもので、パルス巾tw、周期tpでレーザダイオードを駆動している。Next, the operating principle of this device will be explained with reference to FIG. FIG. 4(a) shows the waveform of a light transmission pulse, which drives a laser diode with a pulse width tw and a period tp.
【図1】この考案の一実施例による測距装置における受
光鏡筒の要部の構成図である。FIG. 1 is a configuration diagram of a main part of a light receiving lens barrel in a distance measuring device according to an embodiment of the present invention.
【図2】本考案による遮光板の斜視図である。FIG. 2 is a perspective view of a light shielding plate according to the present invention.
【図3】従来の測距装置全体の構成図である。FIG. 3 is an overall configuration diagram of a conventional distance measuring device.
【図4】送光パルスと受光パルスを示す波形図である。FIG. 4 is a waveform diagram showing a light transmission pulse and a light reception pulse.
【図5】従来の受光鏡筒の構成図である。FIG. 5 is a configuration diagram of a conventional light receiving lens barrel.
【図6】従来の受光鏡筒の他の例の構成図である。FIG. 6 is a configuration diagram of another example of a conventional light receiving lens barrel.
1 送光鏡筒 2 レーザダイオード 3 送光レンズ 4 受光鏡筒 5 フォトダイオード(光電変換素子) 6 受光レンズ G1 〜G5 遮光板 X 受光レンズ6の光軸1 Light transmitting lens barrel 2 Laser diode 3 Light transmitting lens 4 Light receiving lens barrel 5 Photodiode (photoelectric conversion element) 6 Light receiving lens G1 to G5 Light shielding plate X Optical axis of light receiving lens 6
Claims (1)
からの反射光を受光して光の伝播遅延時間から対象物ま
での距離を求める測距装置において、受光レンズの有効
外径と、その受光レンズの焦点の位置に設置される光電
変換素子の受光面外径を結んで形成される円錐又は多角
錐状の入光範囲を任意の光軸位置で、かつ光軸と直角に
切断して得られる形状に相当する穴を有し、表面に反射
防止処理を施した薄板状よりなる複数の遮光板を光軸と
直角に設置したことを特徴とする測距装置。Claim 1: In a distance measuring device that transmits light toward an object, receives reflected light from the object, and calculates the distance to the object from the propagation delay time of the light, the effective outer diameter of the light receiving lens is and the outer diameter of the light-receiving surface of the photoelectric conversion element installed at the focal point of the light-receiving lens. A distance measuring device characterized in that a plurality of light shielding plates made of thin plates having holes corresponding to the shape obtained by cutting and whose surfaces are subjected to anti-reflection treatment are installed perpendicular to an optical axis.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP893991U JPH04106787U (en) | 1991-02-26 | 1991-02-26 | distance measuring device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP893991U JPH04106787U (en) | 1991-02-26 | 1991-02-26 | distance measuring device |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH04106787U true JPH04106787U (en) | 1992-09-14 |
Family
ID=31899684
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP893991U Pending JPH04106787U (en) | 1991-02-26 | 1991-02-26 | distance measuring device |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH04106787U (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2012068120A (en) * | 2010-09-24 | 2012-04-05 | Denso Wave Inc | Laser radar device |
-
1991
- 1991-02-26 JP JP893991U patent/JPH04106787U/en active Pending
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2012068120A (en) * | 2010-09-24 | 2012-04-05 | Denso Wave Inc | Laser radar device |
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