JPH06229755A - Distance detector - Google Patents

Distance detector

Info

Publication number
JPH06229755A
JPH06229755A JP5015585A JP1558593A JPH06229755A JP H06229755 A JPH06229755 A JP H06229755A JP 5015585 A JP5015585 A JP 5015585A JP 1558593 A JP1558593 A JP 1558593A JP H06229755 A JPH06229755 A JP H06229755A
Authority
JP
Japan
Prior art keywords
light
light receiving
amount
distance
detected
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
Application number
JP5015585A
Other languages
Japanese (ja)
Inventor
Hiroyoshi Suzuki
尋善 鈴木
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Electric Corp
Original Assignee
Mitsubishi Electric Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Mitsubishi Electric Corp filed Critical Mitsubishi Electric Corp
Priority to JP5015585A priority Critical patent/JPH06229755A/en
Publication of JPH06229755A publication Critical patent/JPH06229755A/en
Pending legal-status Critical Current

Links

Abstract

PURPOSE:To detect the distance upto an object accurately regardless of the reflection characteristics of the object or the inclination of reflecting face. CONSTITUTION:A light beam is radiated from a light source 1 toward an object 3 and the light reflected thereon is received by PSDs 5R, 5L arranged on the focal planes of first and second optical focusing systems. A signal VXR (VXL) representative of a light receiving position and a signal VSR (VSL) representative of the quantity of received light of the PSD 5R(5L) are obtained through a position detecting section 6R (6L). Comparison circuits 104, 105 compare the ratio between the quantities of light received by the PSDs 5R and 5L with RDmin and RDmax. A comparison circuit 103 compares the total quantity of light received by the PSD 5R and 5L with RS. Operating formula is switched depending on the comparison results and light receiving positions XR and XL determined by the signals VXR and VXL are substituted in the operating formula thus operating the distance upto the object 3.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】この発明は、光源より測距対象に
向けてパルス状の光ビームを放射し、測距対象からの反
射光を受光し、この反射光の受光位置に基づいて測距対
象までの距離を演算する距離検出装置に関するものであ
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention emits a pulsed light beam from a light source toward a distance measuring object, receives reflected light from the distance measuring object, and measures the distance based on the light receiving position of the reflected light. The present invention relates to a distance detecting device that calculates a distance to an object.

【０００２】[0002]

【従来の技術】近年、自動車事故防止のために、車両に
障害物までの距離を検出する距離検出装置を設けて、車
両周辺を監視する方法が考えられている。障害物までの
距離検出方式としては、レーザレーダ方式やスレテオカ
メラ方式など、種々の方式が提案されている。この中で
も、従来よりカメラのオートフォーカス用として用いら
れているアクティブ光学式三角測距方式を採用すれば、
近距離の障害物検出に適した安価な距離検出装置を得る
ことができる。2. Description of the Related Art In recent years, in order to prevent an automobile accident, a method has been considered in which a vehicle is provided with a distance detecting device for detecting a distance to an obstacle to monitor the periphery of the vehicle. As a method of detecting the distance to an obstacle, various methods such as a laser radar method and a stereo camera method have been proposed. Among these, if you use the active optical triangulation method that has been used for autofocus of cameras,
It is possible to obtain an inexpensive distance detection device suitable for detecting an obstacle at a short distance.

【０００３】図１３は従来のアクティブ光学式三角測距
方式の距離検出装置の構成図である。同図において、１
は光源であり、一般に近赤外光を発光するＬＥＤが用い
られる。２は光源（以下、ＬＥＤと呼ぶ）１をパルス駆
動する光源駆動回路、３は距離を検出すべき測距対象、
４は集束レンズである。５は１次元光位置検出器であ
り、一般に両端に光電流を出力する２つのリード５１，
５１を持つ半導体光位置検出素子（以下、ＰＳＤと呼
ぶ）が用いられる。６は位置検出部で光源駆動回路２か
らの発光タイミングパルスＤＰとＰＳＤ５の２つの光電
流Ｉ１，Ｉ２を入力とし、位置信号Ｖｘを出力する。７
は減算回路で位置信号Ｖｘと一定値ＶCLを入力とする。
８は除算回路で減算回路７の出力と一定値ＶfBL を入力
とする。９は増幅回路で除算回路８の出力を入力とし距
離信号Ｄout を出力する。FIG. 13 is a block diagram of a conventional active optical triangulation distance detecting device. In the figure, 1
Is a light source, and an LED that emits near-infrared light is generally used. Reference numeral 2 is a light source drive circuit for pulse-driving a light source (hereinafter, referred to as LED) 1, 3 is a distance measurement target whose distance is to be detected,
4 is a focusing lens. Reference numeral 5 is a one-dimensional optical position detector, which generally has two leads 51, which output a photocurrent at both ends.
A semiconductor optical position detecting element (hereinafter referred to as PSD) having 51 is used. A position detector 6 receives the two light currents I1 and I2 of the light emission timing pulse DP and PSD5 from the light source drive circuit 2 and outputs a position signal Vx. 7
Is a subtraction circuit and receives the position signal Vx and a constant value VCL.
A division circuit 8 receives the output of the subtraction circuit 7 and a constant value VfBL. An amplification circuit 9 receives the output of the division circuit 8 and outputs a distance signal Dout.

【０００４】図１４に位置検出部６の構成を示す。同図
において、６１，６１はピークホールド（ＰＨ）回路
で、各々光電流Ｉ１，Ｉ２と発光タイミングパルスＤＰ
を入力とする。６２，６２は電流電圧（Ｉ／Ｖ）変換回
路でＰＨ回路６１，６１の出力を入力とする。６３は加
算回路でＩ／Ｖ変換回路６２，６２の出力を入力とす
る。６４は除算回路で、一方のＩ／Ｖ変換回路６２の出
力と加算回路６３の出力を入力とし、位置信号Ｖｘを出
力する。FIG. 14 shows the structure of the position detector 6. In the figure, reference numerals 61 and 61 denote peak hold (PH) circuits, which are respectively photocurrents I1 and I2 and a light emission timing pulse DP.
Is input. Reference numerals 62 and 62 denote current-voltage (I / V) conversion circuits which receive the outputs of the PH circuits 61 and 61 as inputs. Reference numeral 63 denotes an adder circuit which receives the outputs of the I / V conversion circuits 62, 62 as inputs. A division circuit 64 receives the output of one I / V conversion circuit 62 and the output of the addition circuit 63 and outputs a position signal Vx.

【０００５】次に、この距離検出装置の動作について説
明する。ＬＥＤ１は、光源駆動回路２の発光タイミング
パルスＤＰでパルス駆動され、前方に狭角の光ビームを
放射する。光ビーム放射方向に測距対象３が存在する
と、その照射領域Ｓからの拡散反射光は集束レンズ４に
より集束され、ＰＳＤ５上の点Ｐｄに入射される。入射
光はＰＳＤ５で光電変換され、光電流Ｉ１，Ｉ２がその
両端の電極のリード５１，５１より出力される。この
時、ＰＳＤ５上の入射光の受光位置Ｘは光電流Ｉ１，Ｉ
２およびＰＳＤ５の有効受光長ＬＳより、次式で与えら
れ、 Ｘ＝ＬＳ・Ｉ１／（Ｉ１＋Ｉ２） ・・・（１） 測距対象３までの距離Ｄは、三角測量の原理より、受光
位置Ｘ、集束レンズ４の焦点距離ｆ、集束レンズ４とＬ
ＥＤ１の光軸間距離で与えられる基線長ＢＬ、ＰＳＤ５
の原点から集束レンズ４の光軸までの距離ＣＬを用い
て、次式で得られる。 Ｄ＝ｆ・ＢＬ／（Ｘ−ＣＬ） ・・・（２）Next, the operation of this distance detecting device will be described. The LED 1 is pulse-driven by the light emission timing pulse DP of the light source drive circuit 2 and emits a narrow-angle light beam forward. When the distance measurement target 3 exists in the light beam emission direction, the diffuse reflection light from the irradiation area S is focused by the focusing lens 4 and is incident on the point Pd on the PSD 5. The incident light is photoelectrically converted by the PSD 5, and photocurrents I1 and I2 are output from the leads 51 and 51 of the electrodes at both ends thereof. At this time, the light receiving position X of the incident light on the PSD 5 is changed to the photocurrents I1, I
2 and the effective light receiving length LS of the PSD 5 are given by the following formula: X = LS · I1 / (I1 + I2) (1) The distance D to the distance measuring object 3 is the light receiving position X according to the principle of triangulation. , Focal length f of focusing lens 4, focusing lens 4 and L
Base line length BL, PSD5 given by distance between optical axes of ED1
Using the distance CL from the origin to the optical axis of the focusing lens 4, it is obtained by the following equation. D = f · BL / (X-CL) (2)

【０００６】ここで、位置検出部６は、ＰＨ回路６１，
６１で光電流Ｉ１，Ｉ２をＤＣカットした後、発光タイ
ミングパルスＤＰによりピークホールドして検波し、Ｉ
／Ｖ変換回路６２，６２で各々検波出力Ｉ１，Ｉ２をＩ
／Ｖ変換した後、加算回路６３で両出力を加算して（Ｉ
１＋Ｉ２）相当電圧を算出し、除算回路６４で一方の検
波出力Ｉ１を加算結果（Ｉ１＋Ｉ２）で除算して、
（１）式の位置Ｘに相当する電圧Ｖｘを位置信号として
出力する。Here, the position detector 6 includes a PH circuit 61,
At 61, the photocurrents I1 and I2 are DC-cut, and then the peak is held and detected by the light emission timing pulse DP.
The detection outputs I1 and I2 are input to I / V conversion circuits 62 and 62, respectively.
After V / V conversion, both outputs are added by the adder circuit 63 (I
1 + I2) equivalent voltage is calculated, and one detection output I1 is divided by a division circuit 64 by the addition result (I1 + I2),
The voltage Vx corresponding to the position X in the equation (1) is output as a position signal.

【０００７】位置信号Ｖｘは減算回路７へ与えられる。
減算回路７は、位置信号Ｖｘより距離ＣＬに相当するバ
イアス電圧ＶCLを減算し、（Ｘ−ＣＬ）に相当する減算
結果を除算回路８へ送る。除算回路８は、（２）式の分
子に相当する電圧ＶfBL を減算結果（Ｘ−ＣＬ）で除算
し、すなわち（２）式を演算して、距離Ｄに相当する電
圧ＶＤを出力する。この電圧ＶＤは、増幅回路９で検出
距離範囲において所定の電圧出力範囲となるようゲイン
Ｋがかけられて、距離信号Ｄout として出力される。The position signal Vx is given to the subtraction circuit 7.
The subtraction circuit 7 subtracts the bias voltage VCL corresponding to the distance CL from the position signal Vx, and sends the subtraction result corresponding to (X-CL) to the division circuit 8. The division circuit 8 divides the voltage VfBL corresponding to the numerator of the expression (2) by the subtraction result (X-CL), that is, calculates the expression (2), and outputs the voltage VD corresponding to the distance D. The voltage VD is multiplied by the gain K in the amplifier circuit 9 so as to have a predetermined voltage output range in the detection distance range, and is output as the distance signal Dout.

【０００８】[0008]

【発明が解決しようとする課題】しかしながら、このよ
うな従来の距離検出装置においては、測距対象３が自動
車のボディのように拡散反射面とみなせないような場合
には、距離を誤検出するといった問題があった。すなわ
ち、図１３において、測距対象３が完全拡散反射面でな
い場合、ＬＥＤ１から放射された光ビームの内、測距対
象３の照射領域Ｓで反射され集束レンズ４で集束されて
ＰＳＤ５に入力される反射光には、照射領域Ｓで乱反射
し点Ｐｄに入射される拡散反射光と、主光線が照射領域
Ｓの点ｍで鏡面反射し点Ｐｍに入射される鏡面反射光の
双方が存在する場合がある。このときの各入射点での光
量は測距対象３の拡散反射率に依存し、自動車のきれい
なボディ塗装面のような場合にはほゞ鏡面に近い反射特
性を示す。この鏡面反射によるＰＳＤ５上の入射点は測
距対象３の照射面の角度に依存するため、ＰＳＤ５上の
入射点（受光重心位置）Ｘより（２）式を用いて計算さ
れた距離信号Ｄout は実距離とは全く異なった値を示す
ことになる。特に、鏡面反射による入射点Ｐｍの位置
が、実距離を示す拡散反射による入射点Ｐｄより小なる
場合には、距離信号Ｄout は実距離よりも大きな値を示
すことになり、障害物検知の上では大変危険である。こ
のように、従来の距離検出装置においては、測距対象３
の反射特性や反射面の傾きにより距離を誤検出するとい
った問題があった。However, in such a conventional distance detecting device, the distance is erroneously detected when the distance measuring object 3 cannot be regarded as a diffuse reflection surface like a car body. There was such a problem. That is, in FIG. 13, when the distance measurement target 3 is not a perfect diffuse reflection surface, among the light beams emitted from the LED 1, it is reflected by the irradiation area S of the distance measurement target 3, is focused by the focusing lens 4, and is input to the PSD 5. There are both diffuse reflected light diffusely reflected in the irradiation area S and incident on the point Pd, and specular reflected light whose principal ray is specularly reflected at the point m in the irradiation area S and incident on the point Pm. There are cases. The amount of light at each incident point at this time depends on the diffuse reflectance of the object 3 to be measured, and exhibits a reflection characteristic close to a mirror surface in the case of a clean painted body surface of an automobile. Since the incident point on the PSD 5 due to this specular reflection depends on the angle of the irradiation surface of the object 3 to be measured, the distance signal Dout calculated from the incident point on the PSD 5 (light receiving center of gravity position) X using the formula (2) is It will show a completely different value from the actual distance. In particular, when the position of the incident point Pm due to the specular reflection is smaller than the incident point Pd due to the diffuse reflection indicating the actual distance, the distance signal Dout has a value larger than the actual distance, and the obstacle signal is detected. Then it is very dangerous. As described above, in the conventional distance detection device, the distance measurement target 3
However, there is a problem that the distance is erroneously detected due to the reflection characteristics of the above and the inclination of the reflection surface.

【０００９】本発明はこのような課題を解決するために
なされたもので、その目的とするところは、測距対象の
反射特性や反射面の傾きに拘らず測距対象までの距離を
正確に検出することのできる距離検出装置を提供するこ
とにある。The present invention has been made to solve such a problem, and its object is to accurately measure the distance to the object to be measured regardless of the reflection characteristic of the object to be measured and the inclination of the reflecting surface. An object of the present invention is to provide a distance detecting device capable of detecting.

【００１０】[0010]

【課題を解決するための手段】このような目的を達成す
るために、その第１発明（請求項１に係る発明）は、光
源を挾みその光軸が光源の光軸とほゞ平行に配された第
１および第２の結像光学系と、この第１および第２の結
像光学系の結像面に配された第１および第２の光位置検
出器と、この第１および第２の光位置検出器における光
源の発光期間中の入射光の受光量を検出する第１および
第２の受光量検出手段と、第１および第２の光位置検出
器における光源の発光期間中の入射光の受光位置を検出
する第１および第２の受光位置検出手段と、第１および
第２の受光量検出手段の検出する受光量の比を所定の光
量比基準範囲と比較する光量比比較手段と、第１および
第２の受光量検出手段の検出する受光量の総和を求める
総受光量演算手段と、この総受光量演算手段の求めた受
光量の総和を所定の総受光量基準値と比較する光量和比
較手段と、複数の演算式を有し、光量和比較手段および
光量比比較手段での比較結果に応じて１つの演算式を選
択し、その選択した演算式を用い第１および第２の受光
位置検出手段の検出する受光位置の少なくとも一方から
測定対象までの距離を演算する距離演算手段とを備えた
ものである。また、その第２発明（請求項２に係る発
明）は、上記第１および第２の結像光学系と、上記第１
および第２の光位置検出器と、上記第１および第２の受
光量検出手段と、上記第１および第２の受光位置検出手
段と、上記光量比比較手段と、上記総受光量演算手段
と、この総受光量演算手段の求める受光量の総和が所定
の基準値となるように光源の発光量を制御する光量制御
手段と、この光量制御手段の制御量を所定の制御量基準
値と比較する制御量比較手段と、複数の演算式を有し、
制御量比較手段および光量比比較手段での比較結果に応
じて１つの演算式を選択し、その選択した演算式を用い
第１および第２の受光位置検出手段の検出する受光位置
の少なくとも一方から測定対象までの距離を演算する距
離演算手段とを備えたものである。また、その第３発明
（請求項３に係る発明）は、第１発明において、第１お
よび第２の受光位置検出手段の検出する受光位置に基づ
き入射光の光源方向を検出する方向検出手段と、この方
向検出手段により検出された検出方向と光源の放射角と
を比較し、検出方向が放射角の範囲外にある場合には測
距対象までの距離演算を棄却する手段とを備えたもので
ある。また、その第４発明（請求項４に係る発明）は、
第１発明において、第１および第２の受光量検出手段の
検出する受光量を所定の低光量基準値と比較する第１お
よび第２の低光量比較手段と、第１（第２）の受光位置
検出手段の検出する受光位置が第１（第２）の光位置検
出器のほゞ中心位置を示す場合に、第１（第２）の受光
量検出手段の検出する受光量が低光量基準値以下であっ
た場合、第１（第２）の受光位置検出手段の検出する受
光位置を用いての測距対象までの距離演算を棄却する手
段とを備えたものである。また、その第５発明（請求項
５に係る発明）は、第２発明において、光量制御手段の
制御量を所定の制御量上限値と比較する制御量上限値比
較手段と、第１（第２）の受光位置検出手段の検出する
受光位置が第１（第２）の光位置検出器のほゞ中心位置
を示す場合に、光量制御手段の制御量が制御量上限値以
上である場合、光量制御手段の制御量を制御量上限値に
クリップすると共に、第１（第２）の受光位置検出手段
の検出する受光位置を用いての測距対象までの距離演算
を棄却する手段とを備えたものである。In order to achieve such an object, the first invention (the invention according to claim 1) of the invention is such that the light source is sandwiched and its optical axis is substantially parallel to the optical axis of the light source. First and second image forming optical systems arranged, first and second optical position detectors arranged on the image forming planes of the first and second image forming optical systems, and the first and second optical position detectors. During the light emission period of the light source in the first and second optical position detectors, first and second received light amount detection means for detecting the amount of incident light received during the light emission period of the light source in the second optical position detector First and second light receiving position detecting means for detecting the light receiving position of the incident light, and a light amount ratio for comparing the ratio of the light receiving amounts detected by the first and second light receiving amount detecting means with a predetermined light amount ratio reference range. Comparing means and total received light amount calculation means for obtaining the sum of received light amounts detected by the first and second received light amount detecting means , A light quantity sum comparing means for comparing the sum of the light receiving quantity obtained by the total light receiving quantity calculating means with a predetermined total light receiving quantity reference value, and a plurality of arithmetic expressions, in the light quantity sum comparing means and the light quantity ratio comparing means. Distance calculating means for selecting one arithmetic expression according to the comparison result and calculating the distance from at least one of the light receiving positions detected by the first and second light receiving position detecting means to the measurement target using the selected arithmetic expression. It is equipped with and. A second invention (an invention according to claim 2) is the first and second imaging optical systems, and the first invention.
And a second light position detector, the first and second light receiving amount detecting means, the first and second light receiving position detecting means, the light amount ratio comparing means, and the total light receiving amount calculating means. , A light amount control means for controlling the light emitting amount of the light source so that the sum of the light receiving amounts calculated by the total light receiving amount calculating means becomes a predetermined reference value, and the control amount of the light amount controlling means is compared with a predetermined control amount reference value. Having a control amount comparison means and a plurality of arithmetic expressions,
One arithmetic expression is selected according to the comparison result by the control amount comparison means and the light quantity ratio comparison means, and at least one of the light receiving positions detected by the first and second light receiving position detection means is selected using the selected arithmetic expression. And a distance calculation means for calculating the distance to the measurement target. A third invention (the invention according to claim 3) of the first invention is the direction detecting means for detecting the light source direction of the incident light based on the light receiving positions detected by the first and second light receiving position detecting means in the first invention. A means for comparing the detection direction detected by the direction detection means with the radiation angle of the light source, and rejecting the distance calculation to the object to be measured when the detection direction is outside the radiation angle range. Is. The fourth invention (the invention according to claim 4) is
In the first invention, first and second low light amount comparing means for comparing the light receiving amounts detected by the first and second light receiving amount detecting means with a predetermined low light amount reference value, and first (second) light receiving When the light receiving position detected by the position detecting means indicates the approximate center position of the first (second) light position detector, the light receiving quantity detected by the first (second) light receiving quantity detecting means is a low light quantity reference. When it is less than or equal to the value, it is provided with a means for rejecting the distance calculation to the object for distance measurement using the light receiving position detected by the first (second) light receiving position detecting means. A fifth invention (an invention according to claim 5) is the second invention, which further comprises a control amount upper limit comparison means for comparing the control amount of the light amount control means with a predetermined control amount upper limit value, and a first (second invention). ), When the light receiving position detected by the light receiving position detecting means indicates the approximate center position of the first (second) light position detector, and the control amount of the light amount controlling means is equal to or more than the control amount upper limit value, the light amount The control amount of the control means is clipped to the control amount upper limit value, and means for rejecting the distance calculation to the object for distance measurement using the light receiving position detected by the first (second) light receiving position detecting means is provided. It is a thing.

【００１１】[0011]

【作用】したがって、その第１発明によれば、光量和比
較手段および光量比比較手段での比較結果に応じて１つ
の演算式が選択され、その選択された演算式を用い第１
および第２の受光位置検出手段の検出する受光位置の少
なくとも一方から、測定対象までの距離が演算される。
例えば、第１および第２の受光量検出手段の検出する受
光量の比が所定の光量比基準範囲外である場合には、受
光量の小さい光位置検出器における入射光の受光位置を
第１の演算式に代入して測距対象までの距離を演算し、
上記受光量の比が所定の光量比基準範囲内で第１および
第２の受光量検出手段の検出する受光量の総和が総受光
量基準値以上の場合には、第１の光位置検出器における
入射光の受光位置と第２の光位置検出器における入射光
の受光位置を第２の演算式に代入して測距対象までの距
離を演算し、上記受光量の比が所定の光量比基準範囲内
で上記受光量の総和が総受光量基準以下の場合には、第
１の光位置検出器における入射光の受光位置と第２の光
位置検出器における入射光の受光位置を第３の演算式に
代入して測距対象までの距離を演算する。また、その第
２発明によれば、光量制御手段により第１および第２の
受光量検出手段の検出する受光量の総和が所定の基準値
となるように光源の発光量が制御され、その制御量が制
御量比較手段により所定の制御量基準値と比較される。
そして、この制御量比較手段および光量比比較手段での
比較結果に応じて１つの演算式が選択され、その選択さ
れた演算式を用い第１および第２の受光位置検出手段の
検出する受光位置の少なくとも一方から、測定対象まで
の距離が演算される。また、その第３発明によれば、第
１および第２の受光位置検出手段の検出する受光位置に
基づき入射光の光源方向が検出され、この検出方向が光
源の放射角の範囲外にある場合には、測距対象までの距
離演算が棄却される。また、その第４発明によれば、第
１（第２）の光位置検出器における入射光の受光位置が
そのほゞ中心位置を示す場合に、その受光量が低光量基
準値以下であった場合には、第１（第２）の光位置検出
器における受光位置を用いての測距対象までの距離演算
が棄却される。また、その第５発明によれば、第１（第
２）の光位置検出器における入射光の受光位置がそのほ
ゞ中心位置を示し、かつ光量制御手段の制御量が制御量
上限値以上であれば、光量制御手段の制御量が制御量上
限値にクリップされると共に、第１（第２）の光位置検
出器における受光位置を用いての測距対象までの距離演
算が棄却される。Therefore, according to the first aspect of the invention, one arithmetic expression is selected according to the comparison result by the light quantity sum comparing means and the light quantity ratio comparing means, and the first arithmetic expression is used by using the selected arithmetic expression.
The distance from at least one of the light receiving positions detected by the second light receiving position detecting means to the measurement target is calculated.
For example, when the ratio of the received light amounts detected by the first and second received light amount detecting means is outside the predetermined light amount ratio reference range, the light receiving position of the incident light in the light position detector having the small received light amount is set to the first light receiving position. To calculate the distance to the object to be measured,
When the sum of the light receiving amounts detected by the first and second light receiving amount detecting means is equal to or more than the total light receiving amount reference value within the predetermined light amount ratio reference range, the first light position detector. The light receiving position of the incident light in and the light receiving position of the incident light in the second light position detector are substituted into the second arithmetic expression to calculate the distance to the object to be measured, and the ratio of the light receiving amount is a predetermined light amount ratio. When the sum of the received light amounts within the reference range is less than or equal to the total received light amount reference, the incident light receiving position of the first optical position detector and the incident light receiving position of the second optical position detector are set to the third light receiving position. The distance to the object to be measured is calculated by substituting into the calculation formula of. According to the second aspect of the invention, the light amount control unit controls the light emission amount of the light source so that the total of the light reception amounts detected by the first and second light reception amount detection units becomes a predetermined reference value, and the control thereof is performed. The amount is compared with a predetermined control amount reference value by the control amount comparison means.
Then, one arithmetic expression is selected in accordance with the comparison result by the control amount comparing means and the light quantity ratio comparing means, and the light receiving position detected by the first and second light receiving position detecting means using the selected arithmetic expression. From at least one of the above, the distance to the measurement target is calculated. According to the third aspect of the invention, the light source direction of the incident light is detected based on the light receiving positions detected by the first and second light receiving position detecting means, and the detection direction is outside the radiation angle range of the light source. , The distance calculation to the object of distance measurement is rejected. Further, according to the fourth aspect of the invention, when the light receiving position of the incident light in the first (second) optical position detector indicates its substantially central position, the light receiving amount is less than the low light amount reference value. In this case, the distance calculation to the object for distance measurement using the light receiving position in the first (second) optical position detector is rejected. Further, according to the fifth aspect of the invention, the light receiving position of the incident light in the first (second) optical position detector indicates its substantially central position, and the control amount of the light amount control means is equal to or more than the control amount upper limit value. If so, the control amount of the light amount control means is clipped to the control amount upper limit value, and the distance calculation to the object for distance measurement using the light receiving position in the first (second) optical position detector is rejected.

【００１２】[0012]

【実施例】以下、本発明を実施例に基づき詳細に説明す
る。EXAMPLES The present invention will now be described in detail based on examples.

【００１３】実施例１．図１はこの発明の一実施例を示
す構成図、図２はその光学系の片側に鏡面反射光が入射
した場合の受光状態を示す説明図、図３は図２に示した
受光状態におけるＰＳＤ上の検出位置の説明図、図４は
光学系の両側に鏡面反射光が入射した場合の受光状態を
示す説明図、図５は光学系の両側に拡散反射光のみが入
射した場合の受光状態を示す説明図、図６は距離演算の
フローチャートである。Embodiment 1. FIG. 1 is a configuration diagram showing an embodiment of the present invention, FIG. 2 is an explanatory diagram showing a light receiving state when specularly reflected light is incident on one side of the optical system, and FIG. 3 is a PSD in the light receiving state shown in FIG. FIG. 4 is an explanatory diagram of the above detection position, FIG. 4 is an explanatory diagram showing a light receiving state when specular reflected light is incident on both sides of the optical system, and FIG. 5 is a light receiving state when only diffuse reflected light is incident on both sides of the optical system. FIG. 6 is a flow chart of distance calculation.

【００１４】本実施例においては、光源１を挟みその光
源から基線長ＢＬ離れた位置に光源１の光軸と平行な光
軸を持つ一対の結像光学系（第１および第２の結像光学
系）を配しており、第１（第２）の結像光学系の集束レ
ンズを４Ｒ（４Ｌ）、集束レンズ４Ｒ（４Ｌ）の焦点面
におかれたＰＳＤを５Ｒ（５Ｌ）、そのリードを各々５
１Ｒ（５１Ｌ）で示している。In the present embodiment, a pair of image forming optical systems (first and second image forming systems) having an optical axis parallel to the optical axis of the light source 1 at a position which sandwiches the light source 1 and is away from the light source by the base line length BL. The focusing lens of the first (second) imaging optical system is 4R (4L), and the PSD placed on the focal plane of the focusing lens 4R (4L) is 5R (5L). 5 leads each
It is indicated by 1R (51L).

【００１５】光源１としては目に見えない近赤外光を使
用するのがよく、近赤外ＬＥＤや半導体レーザダイオー
ドを用いればよいが、比較的近距離の障害物検出に関し
ては近赤外ＬＥＤの使用がコスト上有利である。Invisible near-infrared light is preferably used as the light source 1, and a near-infrared LED or a semiconductor laser diode may be used, but a near-infrared LED is used for detecting an obstacle at a relatively short distance. Is advantageous in cost.

【００１６】また、基線長ＢＬは各結像光学系で別の値
をとってもよいし、結像光学系と光源１の光軸も必ずし
も平行である必要はないが、ここでは説明の単純化のた
め結像光学系の光軸は平行で基線長ＢＬは同一とした。The base length BL may take a different value in each image-forming optical system, and the optical axes of the image-forming optical system and the light source 1 do not necessarily have to be parallel to each other, but here the description is simplified. Therefore, the optical axes of the imaging optical system are parallel and the baseline length BL is the same.

【００１７】６Ｒは第１の位置検出部で、光源駆動回路
２からの発光タイミングパルスＤＰとＰＳＤ５Ｒの２つ
の光電流ＩＲ１，ＩＲ２を入力とし、位置信号ＶXRおよ
び受光量信号ＶSRを出力する。６Ｌは第２の位置検出部
で、光源駆動回路２からの発光タイミングパルスＤＰと
ＰＳＤ５Ｌの２つの光電流ＩＬ１，ＩＬ２を入力とし、
位置信号ＶXLおよび受光量信号ＶSLを出力する。位置検
出部６Ｒおよび６Ｌは、図１４に示した位置検出部６と
同様の構成とされている。Reference numeral 6R denotes a first position detector which receives the light emission timing pulse DP and the two photocurrents IR1 and IR2 of the PSD 5R from the light source drive circuit 2 and outputs a position signal VXR and a received light amount signal VSR. 6L is a second position detector, which receives two photocurrents IL1 and IL2 of the light emission timing pulse DP and PSD5L from the light source drive circuit 2,
The position signal VXL and the received light amount signal VSL are output. The position detectors 6R and 6L have the same configuration as the position detector 6 shown in FIG.

【００１８】１００は距離演算部で、１０１は各位置検
出部６Ｒ，６Ｌからの受光量信号ＶSR，ＶSLを入力とす
る加算回路、１０２は受光量信号ＶSRと加算回路１０１
の加算結果を入力とする除算回路、１０３は加算回路１
０１の加算結果と総受光量基準値ＲＳとを比較する光量
和比較回路、１０４は除算回路１０２の除算結果と光量
比最小基準値ＲＤmin とを比較する光量比比較回路、１
０５は除算回路１０２の除算結果と光量比最大基準値Ｒ
Ｄmax とを比較する光量比比較回路、１０６は位置検出
部６Ｒ，６Ｌの各位置信号ＶXR，ＶXLと光量和比較回路
１０３の比較結果Ｔｓと光量比比較回路１０４の比較結
果Ｄｍと光量比比較回路１０５の比較結果Ｄｐを入力と
する入力Ｉ／Ｆ、１０７はＣＰＵ、１０８はＲＯＭ、１
０９はＲＡＭ、１１０は距離信号Ｄout を出力する出力
Ｉ／Ｆである。Reference numeral 100 is a distance calculation unit, 101 is an adder circuit which receives the received light amount signals VSR and VSL from the respective position detection units 6R and 6L, and 102 is a received light amount signal VSR and an adder circuit 101.
A division circuit that receives the addition result of
A light quantity sum comparison circuit for comparing the addition result of 01 and the total received light quantity reference value RS, 104 is a light quantity ratio comparison circuit for comparing the division result of the division circuit 102 and the light quantity ratio minimum reference value RDmin, 1
Reference numeral 05 is the division result of the division circuit 102 and the maximum reference value R of the light quantity ratio.
A light quantity ratio comparison circuit for comparing Dmax, 106 is each position signal VXR, VXL of the position detection units 6R, 6L, a comparison result Ts of the light quantity sum comparison circuit 103, a comparison result Dm of the light quantity ratio comparison circuit 104, and a light quantity ratio comparison circuit. An input I / F which receives the comparison result Dp of 105, 107 is a CPU, 108 is a ROM, 1
Reference numeral 09 is a RAM, and 110 is an output I / F that outputs a distance signal Dout.

【００１９】なお、本実施例では、加算回路１０１、除
算回路１０２、比較回路１０３〜１０５を外部回路とし
て構成した場合を示したが、位置信号ＶXR，ＶXL、受光
量信号ＶSR，ＶSLを直接入力Ｉ／Ｆへ与えてＡ／Ｄ変換
し、これらの演算・比較処理をソフトウェアで行うよう
にしても良い。In this embodiment, the addition circuit 101, the division circuit 102, and the comparison circuits 103 to 105 are shown as external circuits. However, the position signals VXR and VXL and the received light amount signals VSR and VSL are directly input. You may make it perform A / D conversion given to I / F, and may perform these calculation / comparison processing by software.

【００２０】次に本実施例の動作について説明する。図
１において、ＬＥＤ１は光源駆動回路２の発光タイミン
グパルスＤＰでパルス駆動され、前方に狭角の光ビーム
を放射する。光ビーム放射方向に測距対象３が存在する
と、その照射領域Ｓからの反射光は集束レンズ４Ｒ，４
Ｌにより集束され、各々ＰＳＤ５Ｒ，５Ｌ上に集光す
る。これら入射光はＰＳＤ５Ｒ，５Ｌで各々光電変換さ
れ、光電流ＩＲ１，ＩＲ２がＰＳＤ５Ｒの両端のリード
５１Ｒより出力され、光電流ＩＬ１，ＩＬ２がＰＳＤ５
Ｌの両端のリード５１Ｌより出力される。Next, the operation of this embodiment will be described. In FIG. 1, the LED 1 is pulse-driven by the light emission timing pulse DP of the light source drive circuit 2 and emits a narrow-angle light beam forward. When the distance measurement target 3 exists in the light beam emission direction, the reflected light from the irradiation area S is focused by the focusing lenses 4R and 4R.
It is focused by L and focused on PSDs 5R and 5L, respectively. These incident lights are photoelectrically converted by PSDs 5R and 5L, photocurrents IR1 and IR2 are output from leads 51R at both ends of PSD5R, and photocurrents IL1 and IL2 are converted into PSD5.
It is output from the leads 51L at both ends of L.

【００２１】ここで、各位置検出部６Ｒ，６Ｌは、発光
タイミングパルスＤＰにより光電流を検波し、Ｉ／Ｖ変
換した後、加算回路で両出力を加算してＰＳＤの受光量
相当電圧を算出し、各々受光量信号ＶSR，ＶSLとして出
力する。また、これと共に、各位置検出部６Ｒ，６Ｌ
は、一方の検波出力を加算結果で除算して、ＰＳＤ５
Ｒ，５Ｌへの入射光の受光位置に相当する電圧を各々位
置信号ＶXR，ＶXLとして出力する。Here, each of the position detectors 6R and 6L detects the photocurrent by the light emission timing pulse DP, performs I / V conversion, and then adds both outputs by an adder circuit to calculate a voltage corresponding to the amount of light received by the PSD. Then, the received light amount signals VSR and VSL are output. Along with this, the position detection units 6R and 6L
Divides one detection output by the addition result,
Voltages corresponding to the light receiving positions of the incident light on R and 5L are output as position signals VXR and VXL, respectively.

【００２２】受光量信号ＶSR，ＶSLは、加算回路１０１
で加算され、ＰＳＤ５Ｒおよび５Ｌにおける入射光の総
受光量が計算される。この総受光量出力（ＶSR＋ＶSL）
は、比較回路１０３で総受光量基準値ＲＳと比較され、
（ＶSR＋ＶSL）＞ＲＳの場合に、比較結果ＴＳが「Ｈ
（Ｈｉｇｈ）」レベルとして出力される。The received light amount signals VSR and VSL are added to the adder circuit 101.
Is added to calculate the total amount of incident light received by the PSDs 5R and 5L. This total received light output (VSR + VSL)
Is compared with the total received light amount reference value RS in the comparison circuit 103,
When (VSR + VSL)> RS, the comparison result TS is "H".
(High) ”level.

【００２３】一方、除算回路１０２で、片側の受光量信
号ＶSRが総受光量出力（ＶSR＋ＶSL）で除算されて、光
量比ＲＤ（ＲＤ＝ＶSR／（ＶSR＋ＶSL））が計算され
る。この光量比ＲＤは、比較回路１０４で光量比最小基
準値ＲＤmin と比較され、ＲＤ＜ＲＤmin の場合に、比
較結果Ｄｍが「Ｈ」レベルとして出力される。また、光
量比ＲＤは、比較回路１０５で光量比最大基準値ＲＤma
x と比較され、ＲＤ＞ＲＤmax の場合に、比較結果Ｄｐ
が「Ｈ」レベルとして出力される。On the other hand, the division circuit 102 divides the received light amount signal VSR on one side by the total received light amount output (VSR + VSL) to calculate the light amount ratio RD (RD = VSR / (VSR + VSL)). The light amount ratio RD is compared with the light amount ratio minimum reference value RDmin in the comparison circuit 104, and when RD <RDmin, the comparison result Dm is output as the “H” level. In addition, the light amount ratio RD is determined by the comparison circuit 105 by the light amount ratio maximum reference value RDma.
x is compared, and if RD> RDmax, the comparison result Dp
Is output as "H" level.

【００２４】ＣＰＵ１０７は、ＲＯＭ１０８上のプログ
ラムに基づいて、入力Ｉ／Ｆ１０６を介して位置検出部
６Ｒ，６Ｌからの位置信号ＶXR，ＶXLを読み込んで、位
置信号ＸＲ，ＸＬに変換し、ＸＲ，ＸＬとあらかじめ記
憶されている光学系の定数を用い、同じく入力Ｉ／Ｆ１
０６を介して読み込んだ光量比比較結果Ｄｐ，Ｄｍおよ
び光量和比較結果ＴＳに応じて演算式を切り替えて、測
距対象３までの距離Ｄを演算し、出力Ｉ／Ｆ１０６を介
し距離信号Ｄout として出力する。ＲＡＭ１０９は演算
過程における一時的なデータ記憶に用いられる。The CPU 107 reads the position signals VXR, VXL from the position detectors 6R, 6L via the input I / F 106 based on the program on the ROM 108, converts them into position signals XR, XL, and XR, XL. Input the I / F1 using the optical system constants stored in advance
The calculation formula is switched according to the light quantity ratio comparison results Dp and Dm and the light quantity sum comparison result TS read via 06 to calculate the distance D to the distance measurement target 3 and output as the distance signal Dout via the output I / F 106. Output. The RAM 109 is used for temporary data storage in the calculation process.

【００２５】以下、測距対象３からの反射光のＰＳＤ５
Ｒ，５Ｌでの受光状態が異なる３つの場合の距離演算方
法について説明する。Hereinafter, the PSD 5 of the reflected light from the distance measuring object 3 will be described.
A distance calculation method in three cases where the light receiving states of R and 5L are different will be described.

【００２６】〔場合Ｉ：片側のＰＳＤにのみ鏡面反射光
が入射される場合〕図２のように、測距対象３が完全拡
散反射面でない場合、測距対象３のＬＥＤ１による光ビ
ームの照射領域Ｓにおいては、拡散反射と鏡面反射が混
在する。このうち、拡散反射光は集束レンズ４Ｒ，４Ｌ
により集束され、その入射光の受光位置を各々ＸｄＲ，
ＸｄＬとして、照射領域Ｓの像がＰＳＤ５Ｒ，５Ｌ上に
形成される。一方、照射領域Ｓで鏡面反射される反射光
は、照射領域Ｓ内の領域Ｓｍでの鏡面反射光のみが集束
レンズ４Ｒに対して図の如く反射角特性を満たすため、
集束レンズ４Ｒで集束され、その入射光の受光位置をＸ
mRとして、ＰＳＤ５Ｒ上にＬＥＤ１の像が形成される。
なお、図２では、ＬＥＤ１の鏡面像である仮想物点をＰ
ｉで示している。[Case I: When Specular Reflected Light Is Entered Only on One PSD] As shown in FIG. 2, when the distance measurement target 3 is not a perfect diffuse reflection surface, the LED 1 of the distance measurement target 3 emits a light beam. In the region S, diffuse reflection and specular reflection are mixed. Of these, diffuse reflected light is focused lenses 4R and 4L.
Are focused by XdR,
An image of the irradiation area S is formed on the PSDs 5R and 5L as XdL. On the other hand, as for the reflected light that is specularly reflected in the irradiation area S, only the specular reflection light in the area Sm in the irradiation area S satisfies the reflection angle characteristic with respect to the focusing lens 4R as shown in the figure.
The light is focused by the focusing lens 4R and the light receiving position of the incident light is set to X.
The image of LED1 is formed on PSD5R as mR.
Note that in FIG. 2, the virtual object point that is the mirror image of LED1 is indicated by P
It is indicated by i.

【００２７】図３はこの場合の各ＰＳＤ５Ｒ，５Ｌ上で
の入射光の強度分布を模式的に示したものである。ここ
で、拡散反射光による照射領域Ｓの像は、照射領域Ｓで
の拡散反射光のうち集束レンズ４Ｒ，４Ｌを臨む光のみ
が入射し、また物点である照射領域Ｓも大きいため、入
射光分布はブロードとなる。これに対し、鏡面反射光に
よる像は、領域ＳｍでのＬＥＤ１の反射光が全て集束レ
ンズ４Ｒに入射し、物点ＰであるＬＥＤ１も小さいた
め、入射光分布は鋭いピークを持つ。このように、ＰＳ
Ｄ５Ｒ上では受光位置と強度分布が異なる拡散反射と鏡
面反射による２つの像が重畳するが、その受光位置（受
光重心位置）ＸＲはＸＲ＝ＸmRと、ほゞ鏡面反射光の受
光位置に一致する。また、鏡面反射光が入射されるＰＳ
Ｄ５Ｒ側の受光量信号ＶSRはＰＳＤ５Ｌ側の受光量信号
ＶSLと比較し、ＶSR＞＞ＶSLとなるため、光量比ＲＤは
１に近い値となる。逆に、鏡面反射光がＰＳＤ５Ｌ側に
入射した場合は、ＶSL＞＞ＶSRとなるため、光量比ＲＤ
は０に近い値となる。したがって、比較回路１０４，１
０５による光量比比較により、ＰＳＤ５Ｒ，５Ｌの片側
のみに鏡面反射光が入射した場合を分離できると共に、
鏡面反射光が入射した側を特定できる。FIG. 3 schematically shows the intensity distribution of incident light on each PSD 5R, 5L in this case. Here, in the image of the irradiation area S formed by the diffuse reflection light, only the light that faces the focusing lenses 4R and 4L out of the diffuse reflection light in the irradiation area S is incident, and the irradiation area S that is the object point is also large. The light distribution becomes broad. On the other hand, in the image formed by the specularly reflected light, all the reflected light of the LED 1 in the area Sm is incident on the focusing lens 4R and the LED P1 which is the object point P is also small, so that the incident light distribution has a sharp peak. In this way, PS
On D5R, two images due to diffuse reflection and specular reflection, which have different intensity distributions from the light receiving position, are superimposed, but the light receiving position (light receiving center of gravity position) XR is XR = XmR, which is almost the same as the light receiving position of specular reflected light. . In addition, PS on which specular reflection light is incident
The received light amount signal VSR on the D5R side is compared with the received light amount signal VSL on the PSD5L side, and VSR >> VSL, so the light amount ratio RD becomes a value close to 1. On the contrary, when the specular reflection light is incident on the PSD 5L side, VSL >> VSR, and therefore the light quantity ratio RD
Is a value close to 0. Therefore, the comparison circuits 104 and 1
By comparing the light quantity ratios according to 05, it is possible to separate the case where the specular reflection light is incident only on one side of the PSD 5R, 5L, and
The side on which the specularly reflected light is incident can be specified.

【００２８】鏡面反射による測距対象３までの距離は仮
想物点Ｐｉまでの約１／２として算出し得るが、ＰＳＤ
５Ｒ側の位置のみでは算出不可能である。The distance to the object 3 to be measured by specular reflection can be calculated as about 1/2 of the virtual object point Pi.
It cannot be calculated only from the position on the 5R side.

【００２９】この場合、測距対象３まで距離Ｄは、上記
光量比比較によりＰＳＤ５Ｌ側の位置信号ＶXLを選定
し、拡散反射による受光位置ＸＬ（＝ＸｄＬ）を用い
て、従来と同様の演算式（第１の演算式）、 Ｄ＝ｆ・ＢＬ／（ＸＬ−ＣＬ） ・・・（３） で算出する。In this case, for the distance D to the object 3 to be measured, the position signal VXL on the PSD 5L side is selected by the above light quantity ratio comparison, and the light receiving position XL (= XdL) by diffuse reflection is used to calculate the same formula as the conventional one. (First calculation formula), D = f · BL / (XL-CL) (3)

【００３０】逆に、ＰＳＤ５Ｌ側のみに鏡面反射光が入
射している場合には、測距対象３までの距離Ｄは、ＰＳ
Ｄ５Ｒの拡散反射による受光位置ＸＲを用いて、上述と
同様に、従来と同様の演算式（第１の演算式）、 Ｄ＝ｆ・ＢＬ／（ＸＲ−ＣＬ） ・・・（４） で算出する。On the contrary, when the specular reflection light is incident only on the PSD 5L side, the distance D to the object 3 to be measured is PS.
Using the light receiving position XR by the diffuse reflection of D5R, similar to the above, the following formula (first formula), D = fBL / (XR-CL) (4) is calculated. To do.

【００３１】〔場合II：両側のＰＳＤに鏡面反射光が入
射される場合〕図４のように、測距対象３が完全拡散反
射面でなく、また反射面の傾きが小さい場合には、ＬＥ
Ｄ１の照射領域Ｓ内の各領域ＳmR，ＳmLで生じた鏡面反
射によるＬＥＤ１の像が、その入射光の受光位置を各々
ＸmR，ＸmLとして、ＰＳＤ５Ｒ，５Ｌ上に形成される。
この場合、ＰＳＤ５Ｒ，５Ｌの受光量はほゞ同程度とな
り、光量比ＲＤは約０．５を中心に分布するため、光量
比比較により、〔場合Ｉ〕との区別が可能である。測距
対象３までの距離Ｄは、ＸＲ＝ＸmR、ＸＬ＝ＸmLとし
て、 Ｄ＝ＢＬ・｛（ＸＲ−ＸＬ）2 ／４＋ｆ2 ｝1/2 ／
〔（ＸＲ＋ＸＬ−２ＣＬ）・ｃｏｓ｛ｔａｎ（ＸＲ−Ｘ
Ｌ）-1／２ｆ｝〕 ・・・（５） で与えられるが、近似的に、下記（６）式（第２の演算
式）で算出してもよい。 Ｄ＝ｆ・ＢＬ／（ＸＲ＋ＸＬ−２ＣＬ） ・・・（６）[Case II: When Specular Reflected Light is Entered on PSDs on Both Sides] As shown in FIG. 4, when the distance measurement target 3 is not a perfect diffuse reflection surface and the inclination of the reflection surface is small, LE is used.
Images of the LED 1 due to specular reflection generated in the respective areas SmR, SmL in the irradiation area S of D1 are formed on the PSDs 5R, 5L with the light receiving positions of the incident light as XmR, XmL, respectively.
In this case, the light receiving amounts of the PSDs 5R and 5L are approximately the same, and the light amount ratio RD is distributed around about 0.5. Therefore, it is possible to distinguish from [case I] by comparing the light amount ratios. Distance D to the distance measuring object 3, XR = XMR, as XL = XmL, D = BL · {(XR-XL) 2/4 + f 2} 1/2 /
[(XR + XL-2CL) / cos {tan (XR-X
L) −1 / 2f}] (5), but may be approximately calculated by the following equation (6) (second arithmetic equation). D = f · BL / (XR + XL-2CL) (6)

【００３２】〔場合III ：両側のＰＳＤに拡散反射光の
みが入射する場合〕図５のように、測距対象３がほゞ拡
散反射面とみなし得る場合には、測距対象３の傾きの如
何に拘らず、照射領域Ｓの像が、その入射光の受光位置
を各々ＸｄＲ，ＸｄＬとして、ＰＳＤ５Ｒ，５Ｌに形成
される。この場合のＰＳＤ５Ｒ，５Ｌの光量比は図４の
場合とほゞ同様となるが、図４の場合に比べＰＳＤ５Ｒ
と５Ｌとの総受光量は極めて小となるため、比較回路１
０３の光量和比較により、〔場合II〕との区別が可能で
ある。測距対象３までの距離Ｄは、ＸＲ＝ＸｄＲ，ＸＬ
＝ＸｄＬとして、下記（７）式（第３の演算式）で算出
する。 Ｄ＝２ｆ・ＢＬ／（ＸＲ＋ＸＬ−２ＣＬ） ・・・
（７）[Case III: Case where Only Diffuse Reflected Lights Enter PSDs on Both Sides] As shown in FIG. 5, when the distance measuring object 3 can be regarded as a diffuse reflection surface, the inclination of the distance measuring object 3 is reduced. Regardless of the image, an image of the irradiation region S is formed on the PSDs 5R and 5L with the light receiving positions of the incident light being set to XdR and XdL, respectively. The light amount ratio of PSD5R, 5L in this case is almost the same as that of the case of FIG. 4, but PSD5R is larger than that of the case of FIG.
And the total amount of light received by 5L are extremely small, the comparison circuit 1
It is possible to distinguish from [Case II] by comparing the sum of light amounts of 03. The distance D to the object 3 is XR = XdR, XL
= XdL, and calculated by the following expression (7) (third arithmetic expression). D = 2f · BL / (XR + XL-2CL) ...
(7)

【００３３】図６は距離演算のフローチャートであり、
ＣＰＵ１０７は、まず、ステップ２００でＰＳＤ５Ｒ側
の位置信号ＶXRを入力Ｉ／Ｆ１０６を介して読み込み、
ステップ２０１で受光位置ＸＲに変換演算し、同様にス
テップ２０２でＰＳＤ５Ｌ側の位置信号ＶXLを読み込
み、ステップ２０３で受光位置ＸＬに変換演算する。FIG. 6 is a flow chart of the distance calculation,
First, in step 200, the CPU 107 reads the position signal VXR on the PSD5R side via the input I / F 106,
In step 201, the light receiving position XR is converted and calculated, similarly, in step 202, the position signal VXL on the PSD 5L side is read, and in step 203, the light receiving position XL is converted and calculated.

【００３４】次に、ステップ２０４で光量比比較結果Ｄ
ｍが「Ｈ」レベルであるか否かを判定し、「Ｈ」レベル
の場合はＰＳＤ５Ｌ側にのみ鏡面反射光が入射している
ものと判断して（場合Ｉ）、ステップ２０５で距離Ｄを
（４）式により算出する。ステップ２０４でＤｍが
「Ｌ」レベルの場合は、ステップ２０６で光量比比較結
果Ｄｐが「Ｈ」レベルであるか否か判定し、「Ｈ」レベ
ルの場合はＰＳＤ５Ｒ側にのみ鏡面反射光が入射してい
るものと判断して（場合Ｉ）、ステップ２０７で距離Ｄ
を（３）式により算出する。Next, at step 204, the light quantity ratio comparison result D
It is determined whether or not m is at the “H” level, and when it is at the “H” level, it is determined that specular reflected light is incident only on the PSD 5L side (case I), and the distance D is determined in step 205. It is calculated by the equation (4). If Dm is "L" level in step 204, it is determined in step 206 whether or not the light quantity ratio comparison result Dp is "H" level. If it is "H" level, specular reflection light is incident only on the PSD5R side. (Case I), the distance D is determined in step 207.
Is calculated by the equation (3).

【００３５】ステップ２０６でＤｐが「Ｌ」レベルの場
合は、次に、ステップ２０８で光量和比較結果ＴＳが
「Ｈ」レベルであるか否かを判定し、「Ｈ」レベルの場
合はＰＳＤ５Ｒ，５Ｌの両方へ強面反射光が入射してい
るものと判断して（場合II）、ステップ２０９で距離Ｄ
を（６）式（あるいは（５）式）により算出する。If Dp is "L" level in step 206, it is then determined in step 208 whether the light quantity sum comparison result TS is "H" level. If it is "H" level, PSD5R, It is judged that the strong surface reflected light is incident on both 5 L (case II), and the distance D is determined in step 209.
Is calculated by equation (6) (or equation (5)).

【００３６】ステップ２０８でＴＳが「Ｌ」レベルの場
合は、ＰＳＤ５Ｒ，５Ｌの両方へ拡散反射光のみが入射
しているものと判断して（場合III ）、ステップ２１０
で距離Ｄを（７）式により算出する。If TS is at "L" level in step 208, it is determined that only diffuse reflection light is incident on both PSDs 5R and 5L (case III), and step 210.
Then, the distance D is calculated by the equation (7).

【００３７】そして、ステップ２１１において、算出さ
れた測距対象３までの距離Ｄを出力Ｉ／Ｆ１１０を介
し、距離信号Ｄout として出力する。Then, in step 211, the calculated distance D to the distance measuring object 3 is output as a distance signal Dout via the output I / F 110.

【００３８】以上説明したように、本実施例によれば、
ＰＳＤ５Ｒ，５Ｌの受光状態で演算式を切り替えること
により、測距対象３が自動車のボディのように拡散反射
面でない場合でも、測距対象３までの距離を正確に検出
できる。As described above, according to this embodiment,
By switching the arithmetic expressions in the light receiving states of the PSDs 5R and 5L, the distance to the distance measuring object 3 can be accurately detected even when the distance measuring object 3 is not a diffuse reflection surface like a car body.

【００３９】実施例２．図７はこの発明の他の実施例の
構成図であり、１１１は加算回路１０１の出力と所定の
基準値ＲＣＳとを比較積分する比較積分回路、１１２は
比較積分回路１１１の出力（制御量ＣＳ）と所定の制御
量基準値ＲＳ’とを比較する制御量比較回路、１１３は
比較積分回路１１１の出力をクリップするクリップ回路
であり、クリップ回路１１３の出力は光源駆動回路２へ
与えられる。また、実施例１と異なり、光量比比較回路
１０４，１０５には片側の位置検出部６Ｒの受光量信号
ＶSRが直接与えられる。Example 2. FIG. 7 is a block diagram of another embodiment of the present invention. 111 is a comparison and integration circuit for comparing and integrating the output of the addition circuit 101 and a predetermined reference value RCS, and 112 is the output of the comparison and integration circuit 111 (control amount CS ) Is compared with a predetermined control amount reference value RS ', and 113 is a clipping circuit for clipping the output of the comparison and integration circuit 111. The output of the clipping circuit 113 is given to the light source drive circuit 2. Further, unlike the first embodiment, the light amount ratio comparison circuits 104 and 105 are directly supplied with the received light amount signal VSR of the position detection unit 6R on one side.

【００４０】この実施例においては、比較積分回路１１
１において、加算回路１０１で計算されたＰＳＤ５Ｒと
５Ｌとの総受光量相当電圧（ＶSR＋ＶSL）が基準値ＲCS
となるように光源駆動回路２への制御量ＣＳが決定さ
れ、ＰＳＤ５Ｒと５Ｌとの総受光量が常に一定となるよ
うＬＥＤ１の発光量がフィードバック制御される。制御
量ＣＳは、制御量比較回路１１２において制御量基準値
ＲＳ’と比較され、ＣＳ＜ＲＳ’なる場合に比較結果Ｔ
Ｓが「Ｈ」レベルとして出力される。In this embodiment, the comparison and integration circuit 11
1, the total received light amount equivalent voltage (VSR + VSL) of PSD5R and 5L calculated by the adder circuit 101 is the reference value RCS.
The control amount CS to the light source drive circuit 2 is determined so that the light emission amount of the LED 1 is feedback-controlled so that the total light reception amount of the PSDs 5R and 5L is always constant. The control amount CS is compared with the control amount reference value RS ′ in the control amount comparison circuit 112, and when CS <RS ′, the comparison result T
S is output as "H" level.

【００４１】測距対象３の鏡面反射光がＰＳＤ５Ｒ，５
Ｌの少なくとも一方に入射する場合、すなわち実施例１
に示す〔場合Ｉ〕および〔場合II〕においては、ＰＳＤ
５Ｒおよび５Ｌへの入射光量は前述した如く拡散反射光
のみが入射する〔場合III 〕の入射光量に比較して相当
大となるため、制御量ＣＳは小となり、制御量比較回路
１１２の比較結果ＴＳは「Ｈ」レベルとなる。すなわ
ち、実施例１と同様、比較結果ＴＳにより〔場合Ｉ〕お
よび〔場合II〕と〔場合III 〕とを分離できる。また、
ＰＳＤ５Ｒ，５Ｌ間の受光光量比ＲＤは、ＲＤ＝ＶSR／
ＲCSとなるため、〔場合Ｉ〕における鏡面反射光が入射
される側のＰＳＤの特定は、ＰＳＤ５Ｒ側の受光量信号
ＶSRのみを光量比比較回路１０４，１０５で比較するこ
とにより可能となる。測距対象３までの距離Ｄは、実施
例１と同様、図６に示されるフローチャートを実行して
算出する。The specular reflection light of the distance measuring object 3 is PSD5R, 5
When incident on at least one of L, that is, Example 1
In [case I] and [case II] shown in FIG.
The amount of light incident on 5R and 5L is considerably larger than that of [case III] in which only diffuse reflected light is incident as described above, so the control amount CS is small and the comparison result of the control amount comparison circuit 112 is small. TS becomes "H" level. That is, as in Example 1, [case I] and [case II] and [case III] can be separated based on the comparison result TS. Also,
The received light amount ratio RD between the PSDs 5R and 5L is RD = VSR /
Since it becomes RCS, the PSD on the side where the specular reflected light is incident in [case I] can be specified by comparing only the received light amount signal VSR on the PSD 5R side with the light amount ratio comparison circuits 104 and 105. The distance D to the distance measurement target 3 is calculated by executing the flowchart shown in FIG. 6 as in the first embodiment.

【００４２】この実施例においても、実施例１と同様の
効果が期待できるとともに、ＰＳＤ５Ｒと５Ｌとの総受
光量が常に一定に保持されるため、ＰＳＤ５Ｒ，５Ｌに
おける受光位置演算のＳ／Ｎ比が向上し、距離演算精度
が高められるという利点がある。Also in this embodiment, the same effect as that of the first embodiment can be expected, and since the total amount of light received by the PSDs 5R and 5L is always kept constant, the S / N ratio of the light receiving position calculation in the PSDs 5R, 5L is calculated. And the accuracy of the distance calculation is improved.

【００４３】実施例３．図８および図９は総受光量基準
値ＲＳを検出距離Ｄに応じて可変するようにした場合の
実施例の説明図であり、図８は距離Ｄに対する基準値Ｒ
Ｓを示すグラフ、図９はこの実施例の距離演算のフロー
チャートである。Example 3. 8 and 9 are explanatory views of an embodiment in which the total received light amount reference value RS is changed according to the detection distance D, and FIG. 8 is a reference value R with respect to the distance D.
FIG. 9 is a graph showing S, and FIG. 9 is a flowchart of the distance calculation of this embodiment.

【００４４】この場合、図９において、ステップ２２０
で距離検出結果ＤＮＥＷをＲＡＭ１０９から読み出し、
ステップ２２１で図８に示す距離Ｄ−ＲＳ値のマップを
ＲＯＭ１０８より読み出して、ステップ２２２で距離Ｄ
ＮＥＷに相当するＲＳ値ＲＳＳをマップより算出する。
そして、ステップ２２３で、出力Ｉ／Ｆ１１０を介し、
ＲＳＳに相当する電圧を総受光量基準値ＲＳとして比較
回路１０３の反転入力に与える。この後、図６と同様の
ステップ２０４〜２１０を実行し、測距対象３までの距
離Ｄを計算し、ステップ２１１で出力Ｉ／Ｆ１１０から
距離信号Ｄoutを出力する。そして、ステップ２２４で
演算距離Ｄを距離検出結果ＤＮＥＷとしてＲＡＭ１０９
に格納する。In this case, step 220 in FIG.
To read the distance detection result NEW from the RAM 109,
In step 221, the map of the distance D-RS value shown in FIG. 8 is read from the ROM 108, and in step 222 the distance D-RS value is read.
The RS value RSS corresponding to NEW is calculated from the map.
Then, in step 223, via the output I / F 110,
A voltage corresponding to RSS is applied to the inverting input of the comparison circuit 103 as the total received light amount reference value RS. Thereafter, steps 204 to 210 similar to those in FIG. 6 are executed to calculate the distance D to the distance measurement target 3, and in step 211, the output I / F 110 outputs the distance signal Dout. Then, in step 224, the calculation distance D is set as the distance detection result DNEW in the RAM 109.
To store.

【００４５】なお、ステップ２２４でＤＮＥＷは演算距
離Ｄとこれより前の数回の検出距離を移動平均して求め
ても良い。ＰＳＤ５Ｒ，５Ｌの受光量は、ＬＥＤ１の放
射角が狭い場合、ほゞ測距対象３までの距離Ｄの２乗に
反比例するため、距離Ｄに対する基準値ＲＳも同等の曲
線を用いるのが有利である。In step 224, the DNEW may be calculated by moving the average of the calculated distance D and the detected distances several times before this. When the emission angle of the LED 1 is narrow, the amount of light received by the PSDs 5R and 5L is almost inversely proportional to the square of the distance D to the distance measurement target 3. Therefore, it is advantageous to use an equivalent curve for the reference value RS for the distance D. is there.

【００４６】なお、上述においては、図１において総受
光量基準値ＲＳを可変する場合を示したが、図７におい
て制御量基準値ＲＳ’を検出距離Ｄに応じて可変するよ
うにしてもよい。この場合、距離Ｄ−ＲＳ’値のマップ
は上記と逆にＲＳ’値が距離の２乗にほゞ比例した曲線
となる。また、マップより算出した新しい制御量基準値
ＲＳ’は、出力Ｉ／Ｆ１１０を介して比較回路１１２の
非反転入力へ与える。In the above description, the case where the total received light amount reference value RS is changed is shown in FIG. 1, but the control amount reference value RS ′ may be changed according to the detection distance D in FIG. . In this case, the map of the distance D-RS 'value becomes a curve in which the RS' value is almost proportional to the square of the distance, contrary to the above. Further, the new control amount reference value RS ′ calculated from the map is given to the non-inverting input of the comparison circuit 112 via the output I / F 110.

【００４７】この実施例によれば、距離変化での受光量
変動や制御量変動によらず、測距対象３の反射状態のみ
を抽出することができるため、測距対象３までの距離を
より正確に検出できる。According to this embodiment, only the reflection state of the object 3 to be measured can be extracted regardless of the variation in the amount of received light and the variation in the amount of control due to the change in the distance. Can be accurately detected.

【００４８】実施例４．図１０および図１１は、入射光
の光源方向を検出し、その検出方向をＬＥＤ１の放射角
と比較することにより、測距対象からの反射光か否かを
判断するようにした実施例の説明図である。図１０はＬ
ＥＤ１の放射角範囲外からの光の結像光学系への入射状
態を示す説明図、図１１はこの実施例の距離演算のフロ
ーチャートである。図１０において、３１はＬＥＤ１の
放射光軸からの角度θがＬＥＤ１の放射角θmax より大
なる位置にある放射光源であり、この光源３１の像が、
その入射光の受光位置を各々ＸＲ，ＸＬとして、ＰＳＤ
５Ｒ，５Ｌ上に形成された場合を示している。Example 4. 10 and 11 describe an embodiment in which the light source direction of incident light is detected and the detected direction is compared with the emission angle of the LED 1 to determine whether or not the light is reflected light from a distance measurement target. It is a figure. Figure 10 is L
FIG. 11 is an explanatory view showing a state of incidence of light from outside the radiation angle range of the ED1 on the image forming optical system, and FIG. 11 is a flowchart of distance calculation of this embodiment. In FIG. 10, reference numeral 31 denotes a radiation light source at a position where the angle θ from the radiation optical axis of the LED 1 is larger than the radiation angle θ max of the LED 1, and the image of the light source 31 is
The light receiving position of the incident light is set to XR and XL, respectively, and PSD
The case where it is formed on 5R and 5L is shown.

【００４９】この場合、図１１において、図６と同様の
ステップ２００〜２０３の実行後、ステップ２３０でＰ
ＳＤ５Ｒ，５Ｌにおける受光位置ＸＲ，ＸＬより入射光
の光源方向θを、 θ＝ｔａｎ-1｛（ＸＲ−ＸＬ）／２ｆ｝ ・・・（８） で算出し、ステップ２３１でその検出方向θがＬＥＤ１
の放射角θmax 内であるか否かを判定し、θ≧θmax の
場合には測距対象からの反射光ではないと判断して、ス
テップ２３２で距離Ｄとして測距対象が検出距離範囲に
無いことを示す値ＤＭＡＸを格納し、ステップ２１１で
ＤＭＡＸに相当する距離信号Ｄout を出力する。ステッ
プ２３１でθ＜θmax である場合には、図６と同様のス
テップ２０４〜２１０で通常の距離演算を行い、ステッ
プ２１１で距離信号Ｄout を出力する。In this case, in FIG. 11, after steps 200 to 203 similar to those in FIG.
From the light receiving positions XR and XL in SD5R and 5L, the light source direction θ of the incident light is calculated by θ = tan −1 {(XR−XL) / 2f} (8), and the detection direction θ is determined in step 231. LED1
Is within the radiation angle θmax. If θ ≧ θmax, it is determined that the light is not reflected light from the distance measurement target, and the distance measurement target is not within the detection distance range as the distance D in step 232. The value DMAX indicating that is stored and the distance signal Dout corresponding to DMAX is output in step 211. If θ <θmax in step 231, normal distance calculation is performed in steps 204 to 210 similar to FIG. 6, and the distance signal Dout is output in step 211.

【００５０】この実施例によれば、ＬＥＤ１の発光期間
中にＰＳＤ５Ｒ，５Ｌに測距対象外の他の光源からの光
が入射しても、測距対象からの反射光と区別でき、誤測
距を防止できるという利点がある。According to this embodiment, even if light from another light source other than the object to be measured is incident on the PSDs 5R and 5L during the light emission period of the LED 1, it can be distinguished from the reflected light from the object to be measured, and the erroneous measurement is performed. There is an advantage that distance can be prevented.

【００５１】実施例５．図１２はＰＳＤの受光量を所定
の低光量基準値と比較する手段を設けた他の実施例を示
す距離演算のフローチャートである。この場合、ステッ
プ２４０でＲＣＵＴとＬＣＵＴフラグをリセットし、ス
テップ２００でＰＳＤ５Ｒ側の位置信号ＶXRを読み込
み、ステップ２０１で位置ＸＲを算出する。そして、ス
テップ２４１で、位置ＸＲがＰＳＤ５Ｒの有効受光長Ｌ
Ｓの中央近傍にあるか否かを判定する。中央近傍にある
と判定した場合には、ステップ２４２でＰＳＤ５Ｒ側の
受光量信号ＶSRを入力Ｉ／Ｆ１０６を介して読み込み、
ステップ２４３で受光量ＳＲを低光量基準値Ｓmin と比
較して、受光量ＳＲが低光量基準値Ｓmin より小なる場
合にはＲＣＵＴフラグを１とする。Example 5. FIG. 12 is a flow chart of distance calculation showing another embodiment in which a means for comparing the received light amount of the PSD with a predetermined low light amount reference value is provided. In this case, the RCUT and LCUT flags are reset in step 240, the position signal VXR on the PSD5R side is read in step 200, and the position XR is calculated in step 201. Then, in step 241, the position XR is the effective light receiving length L of the PSD 5R.
It is determined whether or not it is near the center of S. If it is determined that it is near the center, the light receiving amount signal VSR on the PSD 5R side is read in via the input I / F 106 in step 242,
In step 243, the received light amount SR is compared with the low light amount reference value Smin, and if the received light amount SR is smaller than the low light amount reference value Smin, the RCUT flag is set to 1.

【００５２】続いて、ステップ２０２でＰＳＤ５Ｌ側の
位置信号ＶXLを読み込み、ステップ２０３で位置ＸＬを
算出する。そして、ステップ２４５で、ステップ２４１
と同様に位置ＸＬがＰＳＤ５Ｌの受光長ＬＳの中央近傍
にあるか否かを判定する。中央近傍にあると判定した場
合には、ステップ２４６〜２４８でＰＳＤ５Ｒ側と同様
な処置を行い、受光量ＳＬが低光量基準値Ｓmin より小
なる場合にはＬＣＵＴフラグを１とする。Then, in step 202, the position signal VXL on the PSD 5L side is read, and in step 203 the position XL is calculated. Then, in step 245, step 241
Similarly, it is determined whether or not the position XL is near the center of the light receiving length LS of the PSD 5L. If it is determined that it is in the vicinity of the center, the same procedure as on the PSD5R side is performed in steps 246 to 248, and if the received light amount SL is smaller than the low light amount reference value Smin, the LCUT flag is set to 1.

【００５３】次に、ステップ２０４，２０６，２０８で
〔場合Ｉ〕から〔場合III 〕の受光状態の識別を行い、
各場合に応じた距離演算式で測距対象３までの距離Ｄを
計算する。この際、ＲＣＵＴあるいはＬＣＵＴフラグが
１の場合は、各々ＸＲ，ＸＬを用いた距離演算を実行せ
ず、ステップ２４９，２５１，２５４のＹＥＳに応じ、
ステップ２５０で距離Ｄとして測距対象物が検出距離範
囲に無いことを示す値ＤＭＡＸを格納する。Next, in steps 204, 206 and 208, the light receiving states from [case I] to [case III] are identified,
The distance D to the distance measurement target 3 is calculated by the distance calculation formula according to each case. At this time, if the RCUT or LCUT flag is 1, the distance calculation using XR and XL is not executed, respectively, and in response to YES in steps 249, 251, 254,
In step 250, a value DMAX indicating that the object to be measured is not within the detection distance range is stored as the distance D.

【００５４】例えば、ステップ２０８でＴＳが「Ｌ」レ
ベル、すなわちＰＳＤ５Ｒ，５Ｌへの入射光量が小さく
ＰＳＤ５Ｒ，５Ｌ間の光量比も小さい場合、ステップ２
５２でＲＣＵＴ，ＬＣＵＴが共に０であるか否かを判定
し、共に０の場合は通常の演算式（７）により距離Ｄを
算出する。共に０でない場合は、ステップ２５３でまず
ＬＣＵＴフラグを判定し、ＬＣＵＴが０ならばＰＳＤ５
Ｌ側の位置ＸＬを用いた演算式（３）で距離Ｄを算出
し、ＬＣＵＴが１ならば演算式（３）での距離演算を棄
却する。そして、ステップ２５４でＲＣＵＴフラグを判
定し、ＲＣＵＴが０ならばＰＳＤ５Ｒ側の位置ＸＲを用
いた演算式（４）で距離Ｄを算出する。ＲＣＵＴが１な
らば、演算式（４）での距離演算を棄却し、ステップ２
５０で距離ＤとしてＤＭＡＸを格納し、ステップ２１１
で距離信号Ｄout として出力する。For example, if TS is at the "L" level in step 208, that is, if the amount of light incident on PSDs 5R, 5L is small and the ratio of the amount of light between PSDs 5R, 5L is also small, step 2
At 52, it is determined whether RCUT and LCUT are both 0, and when both are 0, the distance D is calculated by the normal arithmetic expression (7). If both are not 0, the LCUT flag is first determined in step 253, and if LCUT is 0, PSD5 is set.
The distance D is calculated by the arithmetic expression (3) using the position XL on the L side, and if the LCUT is 1, the distance calculation by the arithmetic expression (3) is rejected. Then, in step 254, the RCUT flag is determined, and if RCUT is 0, the distance D is calculated by the arithmetic expression (4) using the position XR on the PSD 5R side. If RCUT is 1, the distance calculation in formula (4) is rejected, and step 2
Store DMAX as distance D at 50, step 211
Is output as a distance signal Dout.

【００５５】例えば、ＬＥＤ１の発光期間中に背景光の
近赤外成分が変動した場合、ＰＳＤ５Ｒ（５Ｌ）には、
受光長全体にわたりわずかな変動光が入射される。この
時、ＰＳＤ５Ｒ（５Ｌ）は光の重心位置を検出するため
位置ＸＲ（ＸＬ）はＰＳＤ５Ｒ（５Ｌ）の受光長ＬＳの
ほゞ中心位置を示し、光量ＳＲ（ＳＬ）はＳmin より小
となり、フラグＲＣＵＴ（ＬＣＵＴ）が１となって位置
信号ＸＲ（ＸＬ）を棄却することにより、この背景変動
光による誤測距を防止できるという利点がある。For example, when the near-infrared component of the background light fluctuates during the light emission period of the LED 1, the PSD 5R (5L) is
A small amount of fluctuating light is incident over the entire light receiving length. At this time, the PSD 5R (5L) detects the center of gravity of the light, so the position XR (XL) indicates the approximate center position of the light-receiving length LS of the PSD 5R (5L), and the light amount SR (SL) becomes smaller than Smin, and the flag Since RCUT (LCUT) becomes 1 and the position signal XR (XL) is rejected, there is an advantage that erroneous distance measurement due to this background fluctuation light can be prevented.

【００５６】実施例６．実施例５においてはＰＳＤの受
光量を低光量基準値と比較する例を示したが、光量制御
手段１１１の出力を所定の制御量上限値と比較するよう
にしても同様の処理が可能である。すなわち、ＰＳＤ５
Ｒ，５Ｌにおける受光位置ＸＲ，ＸＬが各々その受光長
ＬＳの中央近傍であるか否かを判定後、いずれかが中央
近傍にあると判定した場合、光量制御手段１１１の制御
量ＣＳを所定の制御量上限値ＣＳmax と比較し、ＣＳ≧
ＣＳmax ならば、制御量ＣＳをクリップ回路１１３によ
り制御量上限値ＣＳmax にクリップすると共に、その側
の位置信号による距離演算を棄却する。Example 6. In the fifth embodiment, an example in which the light receiving amount of the PSD is compared with the low light amount reference value is shown, but the same processing can be performed by comparing the output of the light amount control means 111 with a predetermined control amount upper limit value. . That is, PSD5
After determining whether or not the light receiving positions XR and XL in R and 5L are near the center of the light receiving length LS, when it is determined that either is near the center, the control amount CS of the light amount control means 111 is set to a predetermined value. Compared with the control amount upper limit value CSmax, CS ≧
If CSmax, the control amount CS is clipped to the control amount upper limit value CSmax by the clipping circuit 113, and the distance calculation based on the position signal on that side is rejected.

【００５７】この実施例においては、実施例５と同様の
効果が得られると共に、ＬＥＤ１の発光強度を制御する
制御量ＣＳが上限値ＣＳmax にクリップされるため、Ｌ
ＥＤ１の過度の発熱を抑制し、その劣化を防止できると
いう利点もある。In this embodiment, the same effect as that of the fifth embodiment can be obtained, and the control amount CS for controlling the light emission intensity of the LED 1 is clipped to the upper limit value CSmax.
There is also an advantage that excessive heat generation of the ED1 can be suppressed and its deterioration can be prevented.

【００５８】なお、各実施例においては、一次元位置検
出器としてＰＳＤを用いた場合を示したが、ＣＣＤやフ
ォトダイオードアレイ等の他の一次元位置検出器を使用
できることは言うまでもない。Although the PSD is used as the one-dimensional position detector in each embodiment, it goes without saying that another one-dimensional position detector such as a CCD or a photodiode array can be used.

【００５９】[0059]

【発明の効果】以上説明したことから明らかなように本
発明によれば、その第１発明によると、光量和比較手段
および光量比比較手段での比較結果に応じて１つの演算
式が選択され、その選択された演算式を用い第１および
第２の受光位置検出手段の検出する受光位置の少なくと
も一方から、測定対象までの距離が演算されるものとな
り、比較結果に応ずる演算式を適当に定めることによ
り、測距対象の反射特性や反射面の傾きに拘らず測距対
象までの距離を正確に検出することができるようにな
る。また、その第２発明によると、制御量比較手段およ
び光量比比較手段での比較結果に応じて１つの演算式が
選択され、その選択された演算式を用い第１および第２
の受光位置検出手段の検出する受光位置の少なくとも一
方から、測定対象までの距離が演算されるものとなり、
比較結果に応ずる演算式を適当に定めることにより、第
１発明と同様に、測距対象の反射特性や反射面の傾きに
拘らず測距対象までの距離を正確に検出することができ
るようになる。また、その第３発明によると、第１およ
び第２の受光位置検出手段の検出する受光位置に基づき
入射光の光源方向が検出され、この検出方向が光源の放
射角の範囲外にある場合には測距対象までの距離演算が
棄却されるものとなり、測距対象からの反射光と他の光
源からの光とを区別でき、誤測距を防止できるようにな
る。また、その第４発明によると、第１（第２）の光位
置検出器における入射光の受光位置がそのほゞ中心位置
を示す場合に、その受光量が低光量基準値以下であった
場合には、第１（第２）の光位置検出器における受光位
置を用いての測距対象までの距離演算が棄却されるもの
となり、変動背景光等による誤測距を防止できるように
なる。また、その第５発明によると、第１（第２）の光
位置検出器における入射光の受光位置がそのほゞ中心位
置を示し、かつ光量制御手段の制御量が制御上限値以上
であれば、光量制御手段の制御量が制御量上限値にクリ
ップされると共に、第１（第２）の光位置検出器におけ
る受光位置を用いての測距対象までの距離演算が棄却さ
れるものとなり、第４発明と同様に、変動背景光等によ
る誤測距を防止できるようになる。As is apparent from the above description, according to the present invention, according to the first invention, one arithmetic expression is selected according to the comparison result by the light quantity sum comparing means and the light quantity ratio comparing means. , The distance from at least one of the light receiving positions detected by the first and second light receiving position detecting means to the measurement target is calculated using the selected calculation formula, and the calculation formula corresponding to the comparison result is appropriately selected. By setting the distance, the distance to the distance measurement target can be accurately detected regardless of the reflection characteristic of the distance measurement target and the inclination of the reflection surface. According to the second aspect of the invention, one arithmetic expression is selected according to the comparison result by the control amount comparison means and the light amount ratio comparison means, and the first and second arithmetic expressions are used.
The distance from at least one of the light receiving positions detected by the light receiving position detecting means to the measurement target is calculated,
By appropriately setting the arithmetic expression according to the comparison result, the distance to the distance measuring object can be accurately detected regardless of the reflection characteristic of the distance measuring object or the inclination of the reflecting surface, as in the first invention. Become. According to the third aspect of the invention, the light source direction of the incident light is detected based on the light receiving positions detected by the first and second light receiving position detecting means, and this detection direction is outside the radiation angle range of the light source. Since the distance calculation to the object to be measured is rejected, the reflected light from the object to be measured can be distinguished from the light from other light sources, and erroneous distance measurement can be prevented. According to the fourth aspect of the invention, when the light receiving position of the incident light in the first (second) optical position detector indicates its almost center position, and the light receiving amount is equal to or lower than the low light amount reference value. Therefore, the distance calculation to the object for distance measurement using the light receiving position in the first (second) optical position detector is rejected, and erroneous distance measurement due to fluctuating background light or the like can be prevented. Further, according to the fifth aspect of the invention, if the light receiving position of the incident light in the first (second) optical position detector indicates its almost center position and the control amount of the light amount control means is equal to or more than the control upper limit value. The control amount of the light amount control means is clipped to the control amount upper limit value, and the distance calculation to the object for distance measurement using the light receiving position in the first (second) optical position detector is rejected. Similar to the fourth invention, it becomes possible to prevent erroneous distance measurement due to fluctuating background light or the like.

【図面の簡単な説明】[Brief description of drawings]

【図１】本発明の実施例１を示す構成図である。FIG. 1 is a configuration diagram showing a first embodiment of the present invention.

【図２】光学系の片側に鏡面反射光が入射した場合の受
光状態を示す説明図である。FIG. 2 is an explanatory diagram showing a light receiving state when specular reflected light is incident on one side of the optical system.

【図３】図２に示した受光状態におけるＰＳＤ上の検出
位置の説明図である。FIG. 3 is an explanatory diagram of detection positions on a PSD in the light receiving state shown in FIG.

【図４】光学系の両側に鏡面反射光が入射した場合の受
光状態を示す説明図である。FIG. 4 is an explanatory diagram showing a light receiving state when specular reflected light is incident on both sides of the optical system.

【図５】光学系の両側に拡散反射光のみが入射した場合
の受光状態を示す説明図である。FIG. 5 is an explanatory diagram showing a light receiving state when only diffuse reflected light is incident on both sides of the optical system.

【図６】実施例１における距離演算のフローチャートで
ある。FIG. 6 is a flowchart of distance calculation in the first embodiment.

【図７】本発明の実施例２を示す構成図である。FIG. 7 is a configuration diagram showing a second embodiment of the present invention.

【図８】本発明の実施例３における距離に対する基準値
のグラフを示す図である。FIG. 8 is a diagram showing a graph of a reference value with respect to a distance in Example 3 of the present invention.

【図９】実施例３における距離演算のフローチャートで
ある。FIG. 9 is a flowchart of distance calculation in the third embodiment.

【図１０】本発明の実施例４における外部光源からの光
の結像光学系への入射状態を示す説明図である。FIG. 10 is an explanatory diagram showing how light from an external light source is incident on an image forming optical system according to a fourth embodiment of the present invention.

【図１１】実施例４における距離演算のフローチャート
である。FIG. 11 is a flowchart of distance calculation in the fourth embodiment.

【図１２】本発明の実施例５における距離演算のフロー
チャートである。FIG. 12 is a flowchart of distance calculation according to the fifth embodiment of the present invention.

【図１３】従来のアクティブ光学式三角測距方式の距離
検出装置の構成図である。FIG. 13 is a block diagram of a conventional active optical triangulation distance detection device.

【図１４】図１３に示した距離検出装置における位置検
出部のブロック図である。14 is a block diagram of a position detection unit in the distance detection device shown in FIG.

【符号の説明】[Explanation of symbols]

１ 光源（ＬＥＤ） ２ 光源駆動回路 ３ 測距対象 ４Ｒ，４Ｌ 集束レンズ ５Ｒ，５Ｌ １次元光位置検出器（ＰＳＤ） ６Ｒ，６Ｌ 位置検出部 １００ 距離演算部 １０１ 加算回路 １０２ 除算回路 １０３ 光量和比較回路 １０４，１０５ 光量比比較回路 １０６ 入力Ｉ／Ｆ １０７ ＣＰＵ １０８ ＲＯＭ １０９ ＲＡＭ １１０ 出力Ｉ／Ｆ １１１ 比較積分回路 １１２ 制御量比較回路 １１３ クリップ回路 1 Light source (LED) 2 Light source drive circuit 3 Distance measurement object 4R, 4L Focusing lens 5R, 5L One-dimensional optical position detector (PSD) 6R, 6L Position detection section 100 Distance calculation section 101 Addition circuit 102 Division circuit 103 Light quantity sum comparison Circuits 104 and 105 Light ratio comparison circuit 106 Input I / F 107 CPU 108 ROM 109 RAM 110 Output I / F 111 Comparison integration circuit 112 Control amount comparison circuit 113 Clip circuit

─────────────────────────────────────────────────────
─────────────────────────────────────────────────── ───

【手続補正書】[Procedure amendment]

【提出日】平成５年９月２７日[Submission date] September 27, 1993

【手続補正１】[Procedure Amendment 1]

【補正対象書類名】明細書[Document name to be amended] Statement

【補正対象項目名】請求項４[Name of item to be corrected] Claim 4

【補正方法】変更[Correction method] Change

【補正内容】[Correction content]

【手続補正２】[Procedure Amendment 2]

【補正対象書類名】明細書[Document name to be amended] Statement

【補正対象項目名】請求項５[Name of item to be corrected] Claim 5

【補正方法】変更[Correction method] Change

【補正内容】[Correction content]

【手続補正３】[Procedure 3]

【補正対象書類名】明細書[Document name to be amended] Statement

【補正対象項目名】００１０[Correction target item name] 0010

【補正方法】変更[Correction method] Change

【補正内容】[Correction content]

【００１０】[0010]

【課題を解決するための手段】このような目的を達成す
るために、その第１発明（請求項１に係る発明）は、光
源を挾みその光軸が光源の光軸とほゞ平行に配された第
１および第２の結像光学系と、この第１および第２の結
像光学系の結像面に配された第１および第２の光位置検
出器と、この第１および第２の光位置検出器における光
源の発光期間中の入射光の受光量を検出する第１および
第２の受光量検出手段と、第１および第２の光位置検出
器における光源の発光期間中の入射光の受光位置を検出
する第１および第２の受光位置検出手段と、第１および
第２の受光量検出手段の検出する受光量の比を所定の光
量比基準範囲と比較する光量比比較手段と、第１および
第２の受光量検出手段の検出する受光量の総和を求める
総受光量演算手段と、この総受光量演算手段の求めた受
光量の総和を所定の総受光量基準値と比較する光量和比
較手段と、複数の演算式を有し、光量和比較手段および
光量比比較手段での比較結果に応じて１つの演算式を選
択し、その選択した演算式を用い第１および第２の受光
位置検出手段の検出する受光位置の少なくとも一方から
測定対象までの距離を演算する距離演算手段とを備えた
ものである。また、その第２発明（請求項２に係る発
明）は、上記第１および第２の結像光学系と、上記第１
および第２の光位置検出器と、上記第１および第２の受
光量検出手段と、上記第１および第２の受光位置検出手
段と、上記光量比比較手段と、上記総受光量演算手段
と、この総受光量演算手段の求める受光量の総和が所定
の基準値となるように光源の発光量を制御する光量制御
手段と、この光量制御手段の制御量を所定の制御量基準
値と比較する制御量比較手段と、複数の演算式を有し、
制御量比較手段および光量比比較手段での比較結果に応
じて１つの演算式を選択し、その選択した演算式を用い
第１および第２の受光位置検出手段の検出する受光位置
の少なくとも一方から測定対象までの距離を演算する距
離演算手段とを備えたものである。また、その第３発明
（請求項３に係る発明）は、第１発明において、第１お
よび第２の受光位置検出手段の検出する受光位置に基づ
き入射光の光源方向を検出する方向検出手段と、この方
向検出手段により検出された検出方向と光源の放射角と
を比較し、検出方向が放射角の範囲外にある場合には測
距対象までの距離演算を棄却する手段とを備えたもので
ある。また、その第４発明（請求項４に係る発明）は、
第１発明において、第１および第２の受光量検出手段の
検出する受光量を所定の低光量基準値と比較する第１お
よび第２の低光量比較手段と、第１（第２）の受光位置
検出手段の検出する受光位置が第１（第２）の光位置検
出器の受光範囲のほゞ中心位置を示す場合に、第１（第
２）の受光量検出手段の検出する受光量が低光量基準値
以下であった場合、第１（第２）の受光位置検出手段の
検出する受光位置を用いての測距対象までの距離演算を
棄却する手段とを備えたものである。また、その第５発
明（請求項５に係る発明）は、第２発明において、光量
制御手段の制御量を所定の制御量上限値と比較する制御
量上限値比較手段と、第１（第２）の受光位置検出手段
の検出する受光位置が第１（第２）の光位置検出器の受
光範囲のほゞ中心位置を示す場合に、光量制御手段の制
御量が制御量上限値以上である場合、光量制御手段の制
御量を制御量上限値にクリップすると共に、第１（第
２）の受光位置検出手段の検出する受光位置を用いての
測距対象までの距離演算を棄却する手段とを備えたもの
である。In order to achieve such an object, the first invention (the invention according to claim 1) of the invention is such that the light source is sandwiched and its optical axis is substantially parallel to the optical axis of the light source. First and second image forming optical systems arranged, first and second optical position detectors arranged on the image forming planes of the first and second image forming optical systems, and the first and second optical position detectors. During the light emission period of the light source in the first and second optical position detectors, first and second received light amount detection means for detecting the amount of incident light received during the light emission period of the light source in the second optical position detector First and second light receiving position detecting means for detecting the light receiving position of the incident light, and a light amount ratio for comparing the ratio of the light receiving amounts detected by the first and second light receiving amount detecting means with a predetermined light amount ratio reference range. Comparing means and total received light amount calculation means for obtaining the sum of received light amounts detected by the first and second received light amount detecting means , A light quantity sum comparing means for comparing the sum of the light receiving quantity obtained by the total light receiving quantity calculating means with a predetermined total light receiving quantity reference value, and a plurality of arithmetic expressions, in the light quantity sum comparing means and the light quantity ratio comparing means. Distance calculating means for selecting one arithmetic expression according to the comparison result and calculating the distance from at least one of the light receiving positions detected by the first and second light receiving position detecting means to the measurement target using the selected arithmetic expression. It is equipped with and. A second invention (an invention according to claim 2) is the first and second imaging optical systems, and the first invention.
And a second light position detector, the first and second light receiving amount detecting means, the first and second light receiving position detecting means, the light amount ratio comparing means, and the total light receiving amount calculating means. , A light amount control means for controlling the light emitting amount of the light source so that the sum of the light receiving amounts calculated by the total light receiving amount calculating means becomes a predetermined reference value, and the control amount of the light amount controlling means is compared with a predetermined control amount reference value. Having a control amount comparison means and a plurality of arithmetic expressions,
One arithmetic expression is selected according to the comparison result by the control amount comparison means and the light quantity ratio comparison means, and at least one of the light receiving positions detected by the first and second light receiving position detection means is selected using the selected arithmetic expression. And a distance calculation means for calculating the distance to the measurement target. A third invention (the invention according to claim 3) of the first invention is the direction detecting means for detecting the light source direction of the incident light based on the light receiving positions detected by the first and second light receiving position detecting means in the first invention. A means for comparing the detection direction detected by the direction detection means with the radiation angle of the light source, and rejecting the distance calculation to the object to be measured when the detection direction is outside the radiation angle range. Is. The fourth invention (the invention according to claim 4) is
In the first invention, first and second low light amount comparing means for comparing the light receiving amounts detected by the first and second light receiving amount detecting means with a predetermined low light amount reference value, and first (second) light receiving When the light receiving position detected by the position detecting means indicates the center position of the light receiving range of the first (second) optical position detector, the light receiving amount detected by the first (second) light receiving amount detecting means is When it is less than or equal to the low light amount reference value, it is provided with a means for rejecting the distance calculation to the object for distance measurement using the light receiving position detected by the first (second) light receiving position detecting means. A fifth invention (an invention according to claim 5) is the second invention, which further comprises a control amount upper limit comparison means for comparing the control amount of the light amount control means with a predetermined control amount upper limit value, and a first (second invention). receiving the optical position detector of the detection receiving position first (second) light-receiving position detecting means)
In the case of indicating the almost center position of the light range, when the control amount of the light amount control means is equal to or more than the control amount upper limit value, the control amount of the light amount control means is clipped to the control amount upper limit value, and the first (second) And means for rejecting the distance calculation to the object for distance measurement using the light receiving position detected by the light receiving position detecting means.

【手続補正４】[Procedure amendment 4]

【補正対象書類名】明細書[Document name to be amended] Statement

【補正対象項目名】００１１[Correction target item name] 0011

【補正方法】変更[Correction method] Change

【補正内容】[Correction content]

【００１１】[0011]

【作用】したがって、その第１発明によれば、光量和比
較手段および光量比比較手段での比較結果に応じて１つ
の演算式が選択され、その選択された演算式を用い第１
および第２の受光位置検出手段の検出する受光位置の少
なくとも一方から、測定対象までの距離が演算される。
例えば、第１および第２の受光量検出手段の検出する受
光量の比が所定の光量比基準範囲外である場合には、受
光量の小さい光位置検出器における入射光の受光位置を
第１の演算式に代入して測距対象までの距離を演算し、
上記受光量の比が所定の光量比基準範囲内で第１および
第２の受光量検出手段の検出する受光量の総和が総受光
量基準値以上の場合には、第１の光位置検出器における
入射光の受光位置と第２の光位置検出器における入射光
の受光位置を第２の演算式に代入して測距対象までの距
離を演算し、上記受光量の比が所定の光量比基準範囲内
で上記受光量の総和が総受光量基準以下の場合には、第
１の光位置検出器における入射光の受光位置と第２の光
位置検出器における入射光の受光位置を第３の演算式に
代入して測距対象までの距離を演算する。また、その第
２発明によれば、光量制御手段により第１および第２の
受光量検出手段の検出する受光量の総和が所定の基準値
となるように光源の発光量が制御され、その制御量が制
御量比較手段により所定の制御量基準値と比較される。
そして、この制御量比較手段および光量比比較手段での
比較結果に応じて１つの演算式が選択され、その選択さ
れた演算式を用い第１および第２の受光位置検出手段の
検出する受光位置の少なくとも一方から、測定対象まで
の距離が演算される。また、その第３発明によれば、第
１および第２の受光位置検出手段の検出する受光位置に
基づき入射光の光源方向が検出され、この検出方向が光
源の放射角の範囲外にある場合には、測距対象までの距
離演算が棄却される。また、その第４発明によれば、第
１（第２）の光位置検出器における入射光の受光位置が
その受光範囲のほゞ中心位置を示す場合に、その受光量
が低光量基準値以下であった場合には、第１（第２）の
光位置検出器における受光位置を用いての測距対象まで
の距離演算が棄却される。また、その第５発明によれ
ば、第１（第２）の光位置検出器における入射光の受光
位置がその受光範囲のほゞ中心位置を示し、かつ光量制
御手段の制御量が制御量上限値以上であれば、光量制御
手段の制御量が制御量上限値にクリップされると共に、
第１（第２）の光位置検出器における受光位置を用いて
の測距対象までの距離演算が棄却される。Therefore, according to the first aspect of the invention, one arithmetic expression is selected according to the comparison result by the light quantity sum comparing means and the light quantity ratio comparing means, and the first arithmetic expression is used by using the selected arithmetic expression.
The distance from at least one of the light receiving positions detected by the second light receiving position detecting means to the measurement target is calculated.
For example, when the ratio of the received light amounts detected by the first and second received light amount detecting means is outside the predetermined light amount ratio reference range, the light receiving position of the incident light in the light position detector having the small received light amount is set to the first light receiving position. To calculate the distance to the object to be measured,
When the sum of the light receiving amounts detected by the first and second light receiving amount detecting means is equal to or more than the total light receiving amount reference value within the predetermined light amount ratio reference range, the first light position detector. The light receiving position of the incident light in and the light receiving position of the incident light in the second light position detector are substituted into the second arithmetic expression to calculate the distance to the object to be measured, and the ratio of the light receiving amount is a predetermined light amount ratio. When the sum of the received light amounts within the reference range is less than or equal to the total received light amount reference, the incident light receiving position of the first optical position detector and the incident light receiving position of the second optical position detector are set to the third light receiving position. The distance to the object to be measured is calculated by substituting into the calculation formula of. According to the second aspect of the invention, the light amount control unit controls the light emission amount of the light source so that the total of the light reception amounts detected by the first and second light reception amount detection units becomes a predetermined reference value, and the control thereof is performed. The amount is compared with a predetermined control amount reference value by the control amount comparison means.
Then, one arithmetic expression is selected in accordance with the comparison result by the control amount comparing means and the light quantity ratio comparing means, and the light receiving position detected by the first and second light receiving position detecting means using the selected arithmetic expression. From at least one of the above, the distance to the measurement target is calculated. According to the third aspect of the invention, the light source direction of the incident light is detected based on the light receiving positions detected by the first and second light receiving position detecting means, and the detection direction is outside the radiation angle range of the light source. , The distance calculation to the object of distance measurement is rejected. According to the fourth aspect of the invention, when the light receiving position of the incident light in the first (second) optical position detector indicates the approximate center position of the light receiving range , the light receiving amount is equal to or lower than the low light amount reference value. In this case, the distance calculation to the object for distance measurement using the light receiving position in the first (second) optical position detector is rejected. Further, according to the fifth aspect of the invention, the light receiving position of the incident light in the first (second) optical position detector indicates the approximate center position of the light receiving range , and the control amount of the light amount control means is the control amount upper limit. If it is equal to or more than the value, the control amount of the light amount control means is clipped to the control amount upper limit value,
The distance calculation to the object for distance measurement using the light receiving position in the first (second) optical position detector is rejected.

【手続補正５】[Procedure Amendment 5]

【補正対象書類名】明細書[Document name to be amended] Statement

【補正対象項目名】００５９[Correction target item name] 0059

【補正方法】変更[Correction method] Change

【補正内容】[Correction content]

【００５９】[0059]

【発明の効果】以上説明したことから明らかなように本
発明によれば、その第１発明によると、光量和比較手段
および光量比比較手段での比較結果に応じて１つの演算
式が選択され、その選択された演算式を用い第１および
第２の受光位置検出手段の検出する受光位置の少なくと
も一方から、測定対象までの距離が演算されるものとな
り、比較結果に応ずる演算式を適当に定めることによ
り、測距対象の反射特性や反射面の傾きに拘らず測距対
象までの距離を正確に検出することができるようにな
る。また、その第２発明によると、制御量比較手段およ
び光量比比較手段での比較結果に応じて１つの演算式が
選択され、その選択された演算式を用い第１および第２
の受光位置検出手段の検出する受光位置の少なくとも一
方から、測定対象までの距離が演算されるものとなり、
比較結果に応ずる演算式を適当に定めることにより、第
１発明と同様に、測距対象の反射特性や反射面の傾きに
拘らず測距対象までの距離を正確に検出することができ
るようになる。また、その第３発明によると、第１およ
び第２の受光位置検出手段の検出する受光位置に基づき
入射光の光源方向が検出され、この検出方向が光源の放
射角の範囲外にある場合には測距対象までの距離演算が
棄却されるものとなり、測距対象からの反射光と他の光
源からの光とを区別でき、誤測距を防止できるようにな
る。また、その第４発明によると、第１（第２）の光位
置検出器における入射光の受光位置がその受光範囲のほ
ゞ中心位置を示す場合に、その受光量が低光量基準値以
下であった場合には、第１（第２）の光位置検出器にお
ける受光位置を用いての測距対象までの距離演算が棄却
されるものとなり、変動背景光等による誤測距を防止で
きるようになる。また、その第５発明によると、第１
（第２）の光位置検出器における入射光の受光位置がそ
の受光範囲のほゞ中心位置を示し、かつ光量制御手段の
制御量が制御上限値以上であれば、光量制御手段の制御
量が制御量上限値にクリップされると共に、第１（第
２）の光位置検出器における受光位置を用いての測距対
象までの距離演算が棄却されるものとなり、第４発明と
同様に、変動背景光等による誤測距を防止できるように
なる。As is apparent from the above description, according to the present invention, according to the first invention, one arithmetic expression is selected according to the comparison result by the light quantity sum comparing means and the light quantity ratio comparing means. , The distance from at least one of the light receiving positions detected by the first and second light receiving position detecting means to the measurement target is calculated using the selected calculation formula, and the calculation formula corresponding to the comparison result is appropriately selected. By setting the distance, the distance to the distance measurement target can be accurately detected regardless of the reflection characteristic of the distance measurement target and the inclination of the reflection surface. According to the second aspect of the invention, one arithmetic expression is selected according to the comparison result by the control amount comparison means and the light amount ratio comparison means, and the first and second arithmetic expressions are used.
The distance from at least one of the light receiving positions detected by the light receiving position detecting means to the measurement target is calculated,
By appropriately setting the arithmetic expression according to the comparison result, the distance to the distance measuring object can be accurately detected regardless of the reflection characteristic of the distance measuring object or the inclination of the reflecting surface, as in the first invention. Become. According to the third aspect of the invention, the light source direction of the incident light is detected based on the light receiving positions detected by the first and second light receiving position detecting means, and this detection direction is outside the radiation angle range of the light source. Since the distance calculation to the object to be measured is rejected, the reflected light from the object to be measured can be distinguished from the light from other light sources, and erroneous distance measurement can be prevented. According to the fourth aspect of the invention, when the light receiving position of the incident light in the first (second) optical position detector indicates the almost center position of the light receiving range , the light receiving amount is below the low light amount reference value. In that case, the distance calculation to the object for distance measurement using the light receiving position in the first (second) optical position detector is rejected, and erroneous distance measurement due to fluctuating background light or the like can be prevented. become. According to the fifth invention, the first
If the light receiving position of the incident light in the (second) light position detector indicates the almost center position of the light receiving range and the control amount of the light amount control means is equal to or more than the control upper limit value, the control amount of the light amount control means is While being clipped to the control amount upper limit value, the distance calculation to the object for distance measurement using the light receiving position in the first (second) optical position detector will be rejected, and the fluctuation will occur as in the fourth invention. It becomes possible to prevent erroneous distance measurement due to background light or the like.

Claims (5)

【特許請求の範囲】[Claims] 【請求項１】 光源より測距対象に向けてパルス状の光
ビームを放射し、測距対象からの反射光を受光し、この
反射光の受光位置に基づいて測距対象までの距離を演算
する距離検出装置において、 前記光源を挾みその光軸が前記光源の光軸とほゞ平行に
配された第１および第２の結像光学系と、 この第１および第２の結像光学系の結像面に配された第
１および第２の光位置検出器と、 この第１および第２の光位置検出器における前記光源の
発光期間中の入射光の受光量を検出する第１および第２
の受光量検出手段と、 前記第１および第２の光位置検出器における前記光源の
発光期間中の入射光の受光位置を検出する第１および第
２の受光位置検出手段と、 前記第１および第２の受光量検出手段の検出する受光量
の比を所定の光量比基準範囲と比較する光量比比較手段
と、 前記第１および第２の受光量検出手段の検出する受光量
の総和を求める総受光量演算手段と、 この総受光量演算手段の求めた受光量の総和を所定の総
受光量基準値と比較する光量和比較手段と、 複数の演算式を有し、前記光量和比較手段および前記光
量比比較手段での比較結果に応じて１つの演算式を選択
し、その選択した演算式を用い前記第１および第２の受
光位置検出手段の検出する受光位置の少なくとも一方か
ら測定対象までの距離を演算する距離演算手段とを備え
たことを特徴とする距離検出装置。1. A light source emits a pulsed light beam toward a distance measurement target, receives reflected light from the distance measurement target, and calculates a distance to the distance measurement target based on the light receiving position of the reflected light. In the distance detecting device, the first and second image forming optical systems are provided, the first and second image forming optical systems sandwiching the light source and arranged so that their optical axes are substantially parallel to the optical axis of the light source. First and second optical position detectors arranged on an image plane of the system, and first detecting the amount of incident light received during the light emission period of the light source in the first and second optical position detectors. And the second
Light receiving amount detecting means, first and second light receiving position detecting means for detecting light receiving positions of incident light during the light emitting period of the light source in the first and second light position detectors, and the first and second A light amount ratio comparing means for comparing the ratio of the light receiving amounts detected by the second light receiving amount detecting means with a predetermined light amount ratio reference range, and a total of the light receiving amounts detected by the first and second light receiving amount detecting means are obtained. Total light receiving amount calculation means, light amount sum comparing means for comparing the sum of the light receiving amounts obtained by the total light receiving amount calculation device with a predetermined total light receiving amount reference value, and a plurality of calculation expressions, the light amount sum comparing means And one arithmetic expression is selected according to the comparison result in the light quantity ratio comparing means, and the selected arithmetic expression is used to measure from at least one of the light receiving positions detected by the first and second light receiving position detecting means. Distance calculator to calculate the distance to Distance detecting apparatus characterized by comprising and. 【請求項２】 光源より測距対象に向けてパルス状の光
ビームを放射し、測距対象からの反射光を受光し、この
反射光の受光位置に基づいて測距対象までの距離を演算
する距離検出装置において、 前記光源を挾みその光軸が前記光源の光軸とほゞ平行に
配された第１および第２の結像光学系と、 この第１および第２の結像光学系の結像面に配された第
１および第２の光位置検出器と、 この第１および第２の光位置検出器における前記光源の
発光期間中の入射光の受光量を検出する第１および第２
の受光量検出手段と、 前記第１および第２の光位置検出器における前記光源の
発光期間中の入射光の受光位置を検出する第１および第
２の受光位置検出手段と、 前記第１および第２の受光量検出手段の検出する受光量
の比を所定の光量比基準範囲と比較する光量比比較手段
と、 前記第１および第２の受光量検出手段の検出する受光量
の総和を求める総受光量演算手段と、 この総受光量演算手段の求める受光量の総和が所定の基
準値となるように前記光源の発光量を制御する光量制御
手段と、 この光量制御手段の制御量を所定の制御量基準値と比較
する制御量比較手段と、 複数の演算式を有し、前記制御量比較手段および前記光
量比比較手段での比較結果に応じて１つの演算式を選択
し、その選択した演算式を用い前記第１および第２の受
光位置検出手段の検出する受光位置の少なくとも一方か
ら測定対象までの距離を演算する距離演算手段とを備え
たことを特徴とする距離検出装置。2. A pulsed light beam is emitted from a light source toward a distance measurement target, the reflected light from the distance measurement target is received, and the distance to the distance measurement target is calculated based on the light receiving position of this reflected light. In the distance detecting device, the first and second image forming optical systems are provided, the first and second image forming optical systems sandwiching the light source and arranged so that their optical axes are substantially parallel to the optical axis of the light source. First and second optical position detectors arranged on an image plane of the system, and first detecting the amount of incident light received during the light emission period of the light source in the first and second optical position detectors. And the second
Light receiving amount detecting means, first and second light receiving position detecting means for detecting light receiving positions of incident light during the light emitting period of the light source in the first and second light position detectors, and the first and second A light amount ratio comparing means for comparing the ratio of the light receiving amounts detected by the second light receiving amount detecting means with a predetermined light amount ratio reference range, and a total of the light receiving amounts detected by the first and second light receiving amount detecting means are obtained. Total light receiving amount calculation means, light amount control means for controlling the light emitting amount of the light source so that the sum of the light receiving amounts calculated by the total light receiving amount calculation means becomes a predetermined reference value, and the control amount of the light amount control means is predetermined. Control amount comparison means for comparing with the control amount reference value of 1. and a plurality of arithmetic expressions, and one arithmetic expression is selected according to the comparison result by the control amount comparison means and the light amount ratio comparison means, and the selection thereof The first and second receiving Distance detecting apparatus characterized by comprising a distance calculating means for calculating a distance from at least one of the light receiving position to the measurement target to be detected of the position detecting means. 【請求項３】 請求項１において、 第１および第２の受光位置検出手段の検出する受光位置
に基づき入射光の光源方向を検出する方向検出手段と、 この方向検出手段により検出された検出方向と光源の放
射角とを比較し、検出方向が放射角の範囲外にある場合
には測距対象までの距離演算を棄却する手段とを備えた
ことを特徴とする距離検出装置。3. The direction detecting means for detecting the light source direction of the incident light based on the light receiving positions detected by the first and second light receiving position detecting means, and the detection direction detected by the direction detecting means. And a radiation angle of the light source, and when the detection direction is out of the radiation angle range, means for rejecting the distance calculation to the object for distance measurement is provided. 【請求項４】 請求項１において、 第１および第２の受光量検出手段の検出する受光量を所
定の低光量基準値と比較する第１および第２の低光量比
較手段と、 第１（第２）の受光位置検出手段の検出する受光位置が
第１（第２）の光位置検出器のほゞ中心位置を示す場合
に、第１（第２）の受光量検出手段の検出する受光量が
低光量基準値以下であった場合、第１（第２）の受光位
置検出手段の検出する受光位置を用いての測距対象まで
の距離演算を棄却する手段とを備えたことを特徴とする
距離検出装置。4. The first and second low light amount comparing means for comparing the light receiving amounts detected by the first and second light receiving amount detecting means with a predetermined low light amount reference value, and the first ( (2) When the light receiving position detected by the light receiving position detecting means indicates the approximate center position of the first (second) light position detector, the light receiving detected by the first (second) light receiving amount detecting means When the amount is less than or equal to the low light amount reference value, a unit for rejecting the distance calculation to the object for distance measurement using the light receiving position detected by the first (second) light receiving position detecting unit is provided. Distance detection device. 【請求項５】 請求項２において、 光量制御手段の制御量を所定の制御量上限値と比較する
制御量上限値比較手段と、 第１（第２）の受光位置検出手段の検出する受光位置が
第１（第２）の光位置検出器のほゞ中心位置を示す場合
に、光量制御手段の制御量が前記制御量上限値以上であ
る場合、光量制御手段の制御量を前記制御量上限値にク
リップすると共に、第１（第２）の受光位置検出手段の
検出する受光位置を用いての測距対象までの距離演算を
棄却する手段とを備えたことを特徴とする距離検出装
置。5. The control amount upper limit comparing means for comparing the control amount of the light amount control means with a predetermined control amount upper limit value, and the light receiving position detected by the first (second) light receiving position detecting means. Is approximately the center position of the first (second) optical position detector, and the control amount of the light amount control means is equal to or more than the control amount upper limit value, the control amount of the light amount control means is set to the control amount upper limit. A distance detection device, which is provided with a unit for clipping the value to a value and for rejecting a distance calculation to the object for distance measurement using the light receiving position detected by the first (second) light receiving position detecting unit.
JP5015585A 1993-02-02 1993-02-02 Distance detector Pending JPH06229755A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP5015585A JPH06229755A (en) 1993-02-02 1993-02-02 Distance detector

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP5015585A JPH06229755A (en) 1993-02-02 1993-02-02 Distance detector

Publications (1)

Publication Number Publication Date
JPH06229755A true JPH06229755A (en) 1994-08-19

Family

ID=11892811

Family Applications (1)

Application Number Title Priority Date Filing Date
JP5015585A Pending JPH06229755A (en) 1993-02-02 1993-02-02 Distance detector

Country Status (1)

Country Link
JP (1) JPH06229755A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011505612A (en) * 2007-10-25 2011-02-24 アーデーツエー・オートモテイブ・デイスタンス・コントロール・システムズ・ゲゼルシヤフト・ミツト・ベシユレンクテル・ハフツング Adaptive calculation method of threshold for recognizing vehicle light by camera system
KR101358102B1 (en) * 2012-05-14 2014-02-05 주식회사 아이디로 Apparatus for detecting drive distance of vehicles and method for detecting thereof
US8735825B2 (en) 2011-04-08 2014-05-27 Seiko Epson Corporation Optical position detection device

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011505612A (en) * 2007-10-25 2011-02-24 アーデーツエー・オートモテイブ・デイスタンス・コントロール・システムズ・ゲゼルシヤフト・ミツト・ベシユレンクテル・ハフツング Adaptive calculation method of threshold for recognizing vehicle light by camera system
US8735825B2 (en) 2011-04-08 2014-05-27 Seiko Epson Corporation Optical position detection device
KR101358102B1 (en) * 2012-05-14 2014-02-05 주식회사 아이디로 Apparatus for detecting drive distance of vehicles and method for detecting thereof

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