JPS59154410A - Inputting circuit for range finder - Google Patents

Abstract

PURPOSE:To obtain a large number of information and reduce the scale of a photo-electric element outputting circuit by changing the photo-electric element freely and performing addition or subtraction by the element itself or a circuit element connected to it. CONSTITUTION:When a switch 1 is made off and a switch 3 is made on, photocurrent of photo-electric elements 5, 7 generated according to the intensity of incident light is converted to voltage by a feedback circuit 11 and an operational amplifier 9. If (a), (b) represent output voltage corresponding to output current of photo-electric elements 5, 7, signal voltage of (a+b) is outputted at the output end 9A of the amplifier 9. Conversely, when the switch 1 is made on and the switch 3 is made off, signal voltage of (b) corresponding only to photocurrent from the photo-electric element 7 is outputted at the output end 9A. As these signal voltage (a+b), (b) is outputted from the amplifier in time series, an arithmetic circuit 13 performs operation of (a+b)-b=a, aXb, a/b, a/(a+b) etc. and sends the information to a distance information processing circuit.

Description

【発明の詳細な説明】 本発明は、カメラ等の小型機器に於ける自動焦点合わせ
を行なう為の距離測定装置、特に被測定物体に光等のエ
ネルギーを投射して、その反射を基線距離を隔てて置か
れた複数の検知素子で受け、その各出力を演算処理する
ことにより物体迄の距離を測定する装置の入力回路に関
するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a distance measuring device for automatic focusing in small devices such as cameras, and in particular, to a distance measuring device that projects energy such as light onto an object to be measured and uses the reflected energy to calculate a baseline distance. The present invention relates to an input circuit of a device that measures the distance to an object by receiving signals from a plurality of spaced apart sensing elements and processing each output.

従来、可動部を廃止すべく複数の検知素子を設ける方式
は、投光部より測距対象に向けて光を照射し、その反射
光を投光部から所定の基線長−たけ離れて配置された受
光部により受光して測距を行なう光照射型の所謂光アク
ティブ型三角測距方式に於ても、又所謂能動型の三角測
距方式に於ても数多く提案され、また実用化もされてい
る。この方式は撮影操作以前に距離情報が判るという利
点を有する反面、例えば特開昭５６−２９１１０号公報
に見られる様に受光素子出方を処理する為に同数の増幅
器を含む入力回路を用いて各受光素子出力の比較演算等
を行なう様構成されている為に薗路規模が大きく、最近
の集積回路技術の進歩により実用化は可能となっている
が、構成が複雑、且つ高価なものとなる欠点がある。Conventionally, the method of providing multiple detection elements in order to eliminate movable parts is to emit light from a light projector toward the object to be measured, and the reflected light is placed at a distance of a predetermined baseline length from the light projector. Many proposals have been made for the so-called active triangulation method, which uses a light irradiation type to measure distance by receiving light using a light-receiving section, and many have been put into practical use. ing. This method has the advantage that distance information can be determined before the photographing operation, but on the other hand, as seen in Japanese Patent Application Laid-Open No. 56-29110, an input circuit containing the same number of amplifiers is used to process the output direction of the light receiving element. Since it is configured to perform comparison calculations of the outputs of each light receiving element, the scale of the circuit is large, and although recent advances in integrated circuit technology have made it possible to put it into practical use, the configuration is complex and expensive. There is a drawback.

一方、回路規模を縮小する為に実公昭５５−２４０１号
公報、実公昭５６−１１０５１号公報等に見られる様に
２つの受光素子の出力電流を相殺する様に２つの受光素
子を互いに逆向きの並列或いは直列に接続して、両受光
素子の出方差を得ることにより測距を行なう技術も提案
されている。しかしこの場合骨られる情報は差情報だけ
であって、差情報だけでは絶対距離情報を得ることは難
しく、サーボ機構の様な可動部の助けを必要とする欠点
があった。On the other hand, in order to reduce the circuit scale, as seen in Japanese Utility Model Publication No. 55-2401 and Japanese Utility Model Publication No. 56-11051, two light receiving elements are arranged in opposite directions so as to cancel out the output currents of the two light receiving elements. A technique has also been proposed in which distance measurement is performed by connecting two light receiving elements in parallel or in series and obtaining the difference in the output direction of both light receiving elements. However, in this case, the information that is needed is only the difference information, and it is difficult to obtain absolute distance information from only the difference information, which has the drawback of requiring the assistance of a movable part such as a servo mechanism.

本発明の目的は情報量を増大したどしても情報処理回路
規模の増大を招くことのない距離測定装置用入力回路を
提供せんとするものである。An object of the present invention is to provide an input circuit for a distance measuring device that does not cause an increase in the scale of the information processing circuit even if the amount of information is increased.

以下未発’ＦＪについて図面を用いて詳細に説明する。The unreleased 'FJ will be explained in detail below using drawings.

第１図は本発明の一実施例の回路接続図にして、１は検
知素子としてのシリコン・フォト・ダイオード５に並列
接続されたスイッチ、３はダイオード５に直列接続され
たスインチ、７は信号変換回路としてのＭＯ３入力の演
算増幅器９の入力端に接続された検知素子としてのシリ
コン・フォト・ダイオードで、該ダイオード７のアノー
ドは増幅器９に動作電圧を与える基準電圧源Ｖ「に接続
される。１１は所定のインピーダンスを有するフィード
バック回路、１３は増幅器９の出力端に接続され、該出
力端からの出力信号を処理し、後述する如き各種情報を
記憶並びに出力する演算回路である。該演算回路１３の
出力は不図示の距離情報処理回路に供給され、距離情報
として不図示装置に出力される。−尚これら不図示の距
離情報処理回路並びに装置の詳細については理解を容易
とする為に省略する。FIG. 1 is a circuit connection diagram of an embodiment of the present invention, in which 1 is a switch connected in parallel to a silicon photodiode 5 as a sensing element, 3 is a switch connected in series to the diode 5, and 7 is a signal switch. A silicon photodiode as a sensing element is connected to the input end of an operational amplifier 9 with an MO3 input as a conversion circuit, and the anode of the diode 7 is connected to a reference voltage source V'' that provides an operating voltage to the amplifier 9. 11 is a feedback circuit having a predetermined impedance, and 13 is an arithmetic circuit that is connected to the output terminal of the amplifier 9, processes the output signal from the output terminal, and stores and outputs various information as described below. The output of the circuit 13 is supplied to a distance information processing circuit (not shown), and is output as distance information to a device (not shown).The details of these distance information processing circuits and devices (not shown) are omitted for ease of understanding. Omitted.

つぎに上記構成の動作について説明する。Next, the operation of the above configuration will be explained.

まずスイッチ１がオフとされ、スインチ３がオンとされ
ると、受光素子５，７は入射光の強さに応じた光電流を
発生し、該光電流はフィードパンク回路１１および演算
増幅器９によって電圧に変換される。ここで受光素子５
の出力電流に対応した出力電圧がａ、受光素子７の出力
電流に対応した出力電圧がｂであるとすると、増幅器９
の出力端９Ａには（ａ＋ｂ）の信号電圧が出力される。First, when the switch 1 is turned off and the switch 3 is turned on, the light receiving elements 5 and 7 generate a photocurrent according to the intensity of the incident light, and the photocurrent is passed through the feed puncture circuit 11 and the operational amplifier 9. converted to voltage. Here, the light receiving element 5
If the output voltage corresponding to the output current of the light receiving element 7 is a, and the output voltage corresponding to the output current of the light receiving element 7 is b, then the amplifier 9
A signal voltage of (a+b) is output to the output terminal 9A.

逆にスイッチｌがオンとされ、スイッチ３がオフとされ
ると、受光素子７からの光電流のみが信号変換回路を形
成するフィードバック回路１１および演算増幅器９によ
って電圧に変換され、増幅器９の出力端９Ａにはｂの信
号電圧が出力される。Conversely, when the switch 1 is turned on and the switch 3 is turned off, only the photocurrent from the light receiving element 7 is converted into voltage by the feedback circuit 11 and operational amplifier 9 forming a signal conversion circuit, and the output of the amplifier 9 is A signal voltage b is output to the end 9A.

これらの信号電圧（ａ＋ｂ）、ｂは時系列的に増幅器９
から出力されるので、演算回路１３は信号電圧（ａ＋ｂ
）或いはｂ、更には必要に応じて（ａ＋ｂ）’ｂ＝ａ、
（ａ＋ｂ）　−２ｂ＝ａ−ｂ、２ｂ−（ａ＋ｂ）＝ｂ−
ａ、ａＸｂ、ａ／ｂ。These signal voltages (a+b) and b are applied to the amplifier 9 in time series.
Since the arithmetic circuit 13 outputs the signal voltage (a+b
) or b, and if necessary, (a+b)'b=a,
(a+b) -2b=a-b, 2b-(a+b)=b-
a, aXb, a/b.

ａ／　（ａ＋　ｂ）、ｂ／　（ａ＋ｂ）等の演算を行な
い、距離情報処理回路（不図示）にそれら情報を送り、
該距離情報処理回路はこれら情報に応じた距離情報を出
力する。尚、第２図示の様にスイッチ８を受光素子７に
直列に接続し、スイッチ１゜３．８を適宜開閉すること
により増幅器９の出力端９Ａから信号電圧ａを単独に出
力させることができる。Performs calculations such as a/ (a + b), b/ (a + b), etc., and sends the information to a distance information processing circuit (not shown),
The distance information processing circuit outputs distance information according to these pieces of information. By connecting the switch 8 in series with the light-receiving element 7 as shown in the second diagram and opening and closing the switch 1°3.8 as appropriate, the signal voltage a can be output independently from the output terminal 9A of the amplifier 9. .

第１図における以上のような動作は原理的にはスイッチ
３のみ必要であってスイッチ１は不要である。しかし本
発明のように２受光素子を用いて測距を行なう装置にお
いては両受光素子５，７間の物理的隙間を可能な限り小
さくし、特性を等しく、かつ暗主がこの小さいものとす
る必要があるため通常は受光素子５，７を第３図（ａ）
のように１チップ−Ｌに形成する。このときスイッチ３
のみが存在して、そのスイッチ３がオフであったとして
も第３図（ｂ）のように光が受光素子５上に入射してい
るにも拘らず、受光素子７から受光素子５の出力電流の
数分の１程度の出力が現れる。これは受光素子５の出力
電流を環流するループかないために生じる漏れと考えら
れる。そこで第１図ではスイッチ１を付加しているもの
である。スイッチ１を４−ｊ加して受光素子５の出力を
スイッチを通して環流させると、第３図（Ｃ）の如くこ
の漏れ電流は生じなくなる。さらに図示しないが受光素
子５．７の陽極間の容量による影響も考えられる。In principle, the above-described operation in FIG. 1 requires only the switch 3, and the switch 1 is not necessary. However, in a device that measures distance using two light-receiving elements as in the present invention, the physical gap between both light-receiving elements 5 and 7 is made as small as possible so that the characteristics are equal and the dark main is small. Because it is necessary, the light receiving elements 5 and 7 are usually installed as shown in Fig. 3(a).
It is formed into 1 chip-L as shown in FIG. At this time switch 3
Even if the switch 3 is off and the light is incident on the light receiving element 5 as shown in FIG. 3(b), the output from the light receiving element 7 is still An output of about a fraction of the current appears. This is considered to be a leakage caused by the lack of a loop for circulating the output current of the light receiving element 5. Therefore, in FIG. 1, a switch 1 is added. If the switch 1 is added 4-j to circulate the output of the light receiving element 5 through the switch, this leakage current will no longer occur as shown in FIG. 3(C). Furthermore, although not shown, the influence of the capacitance between the anodes of the light receiving element 5.7 is also considered.

この時スイッチｌを設けると受光素子７の両端は増幅器
９の正負側入力に接続されているためイマジナリ−ショ
ー１・どなってＯ，（Ｖ）に安定し、受光素子５の両端
もスイッチ′１によって短絡されているためＯ（Ｖ）に
安定する。したがって容量の両端子間の電圧がほぼ一定
となるためこの受光素イの陽極間の容量は回路に影響を
与えず漏れ電流の発生は防止できる。従ってスイッチｌ
が設けられている。At this time, if a switch 1 is provided, both ends of the light receiving element 7 are connected to the positive and negative side inputs of the amplifier 9, so the imaginary show 1 becomes stable at O, (V), and both ends of the light receiving element 5 are also connected to the positive and negative side inputs of the amplifier 9. Since it is short-circuited by 1, it becomes stable at O(V). Therefore, since the voltage between both terminals of the capacitor is approximately constant, the capacitance between the anode of the light receiving element does not affect the circuit, and leakage current can be prevented from occurring. Therefore switch l
is provided.

第４図は第１図示スイッチ１．３をＭＯＳ−Ｆ　Ｅ　Ｔ
　、（電界効果型トランジスタ）のアナログスイッチＬ
　Ａ　、　３　Ａ　ｆ、、用いて実現した例である。In Figure 4, the first illustrated switch 1.3 is a MOS-FET.
, (field effect transistor) analog switch L
This is an example realized using A, 3 A f,,.

第５図は第４図におけるスイッチｊＡ、３Ａをオン・オ
フするタイミングを示したものである。FIG. 5 shows the timing of turning on and off the switches jA and 3A in FIG. 4.

第４図において仮にスイッチＬＡ　、３Ａが同侍にオン
したとすると入力オフセット電圧のために過大な電流が
スイッチＩＡ、３Ａを介して流れＭＯＳ−ＡＭＰ９　（
演算増幅器９）の出力は飽和する。この様な不都合を無
くすため第４図示実施例に於ては第５図に示す一様に一
度スイッチＩＡ。In Fig. 4, if switches LA and 3A are simultaneously turned on, an excessive current flows through switches IA and 3A due to the input offset voltage, and MOS-AMP9 (
The output of operational amplifier 9) is saturated. In order to eliminate this inconvenience, in the embodiment shown in the fourth figure, the switches IA are uniformly connected once as shown in FIG.

３Ａともにオフの状態を経て所定の状態に・切り換える
ようにスイッチ制御回路１５がスイッチＩＡ３Ａのゲー
ト電圧切換用トランジスタ、１７　、１９のゲート電圧
を制御する様になっている。尚第４図で用いたＭｏ５−
ｔＥＴのスイッチＬＡ、３Ａの等価回路は第６図の様に
なっており、前述のような受光素子上の問題とは別にス
イッチＩＡ或いは３Ａにはドレイン−ソース間容量ＣＤ
ｓ、オン抵抗ＲＯＮおよびオフ抵抗ＲＯＦＦが存在する
ため受光素子を用いて変調された微小電流信号を取り出
すような用途ではＲＯＦＦおよびｃＤｓによる漏れ電流
を生じる。スイッチＬＡはこのＲＯＦＦおよびＣＤＳに
ついても有効で塾ってスイッチＩＡがオンすることによ
ってスイッチ３Ａの両端電圧はほぼ０（Ｖ）となるため
前述の場合と同様な理由により交流−直流両方において
漏れ電流が生じなくなる。The switch control circuit 15 controls the gate voltages of the gate voltage switching transistors 17 and 19 of the switch IA3A so that both IA3A go through an OFF state and then switch to a predetermined state. Furthermore, Mo5- used in Fig. 4
The equivalent circuit of the tET switches LA and 3A is as shown in Figure 6. Apart from the above-mentioned problem with the light receiving element, the switch IA or 3A has a drain-source capacitance CD.
s, on-resistance RON and off-resistance ROFF, leakage current due to ROFF and cDs occurs in applications where a modulated minute current signal is extracted using a light receiving element. The switch LA is also effective for this ROFF and CDS, and when the switch IA is turned on, the voltage across the switch 3A becomes almost 0 (V), so for the same reason as the above case, there is a leakage current in both AC and DC. will no longer occur.

第７図は受光素子５，７を逆並列に接続した例で、スイ
ッチ３Ａをオン、スイッチＩＡをオフとすることにより
、増幅器９の出力端９Ａから信号電圧（ｂ−ａ）が、ま
たスイッチＩＡをオン、スイッチ３Ａをオフす８二とに
より信号電圧すが直接得られ、さらに信号電圧ｆｂ−（
ｂ−ａ））により信号電圧ａを、信号電圧（２ｂ−（ｂ
　−ａ））により信号電圧（ａ＋ｂ）を算出できる例で
ある。FIG. 7 shows an example in which the light receiving elements 5 and 7 are connected in antiparallel. By turning on the switch 3A and turning off the switch IA, the signal voltage (b-a) is applied from the output terminal 9A of the amplifier 9 to the switch By turning on IA and turning off switch 3A, the signal voltage is directly obtained, and the signal voltage fb-(
b-a)), the signal voltage a is changed to the signal voltage (2b-(b
-a)) This is an example in which the signal voltage (a+b) can be calculated.

該実施例のその他の構成および動作は第４図示のそれと
同様であるので省く。The rest of the configuration and operation of this embodiment are the same as those shown in FIG. 4, and will therefore be omitted.

第８図は２つの受光素子５，７を逆直列に接続した例で
、該実施例ではスイッチ３Ａをオン、スイッチＩＡをオ
フすることにより信号電圧ａが、またスイッチＩＡをオ
ン、スイッチ３Ａをオフすることにより信号電圧−ｂが
得られる。FIG. 8 shows an example in which two light-receiving elements 5 and 7 are connected in anti-series. In this embodiment, by turning on the switch 3A and turning off the switch IA, the signal voltage a becomes By turning off, signal voltage -b is obtained.

尚受光素子５，７を第８図において順直列に接続するこ
とにより信号電圧ａまたはｂを得ることができる。By connecting the light receiving elements 5 and 7 in series as shown in FIG. 8, the signal voltage a or b can be obtained.

第９図は第４図示受光素子５，７と同様な多数の受光素
子２５〜３３の夫々に第４図示スイッチ３Ａに相当する
直列スイッチ５５〜６３と第１図示スイッチ１Ａに相当
する並列スイッチ３５〜４３を付加した例で、該実施例
によれば任意の受光素子の単独出力および任意の受光素
子の任意の個数の組合わせの和出力を得ることができる
。尚第４図示スイッチ制御回路１５と同様なスイッチ制
御回路１５ａの出力端１５Ａ〜１５Ｊからのスイッチン
グ用出力信号の出力タイミングは増幅器９から得る信号
電圧に応じて変えるだけであり、また以上の説明からこ
の出力タイミングの詳細については容易に知り得るもの
と思われるのでここでは省略する。また他の回路素子の
説明についても各素子に第４図示素子と同一符号を付し
てその説明を省略する。FIG. 9 shows a series switch 55 to 63 corresponding to the fourth illustrated switch 3A and a parallel switch 35 corresponding to the first illustrated switch 1A to each of a large number of light receiving elements 25 to 33 similar to the fourth illustrated light receiving elements 5 and 7. .about.43 is added, and according to this embodiment, it is possible to obtain the individual output of any light receiving element and the sum output of any combination of any number of light receiving elements. Note that the output timing of the switching output signals from the output terminals 15A to 15J of the switch control circuit 15a similar to the switch control circuit 15 shown in the fourth figure is only changed according to the signal voltage obtained from the amplifier 9, and from the above explanation. The details of this output timing are likely to be easily known, so they will be omitted here. Also, regarding the description of other circuit elements, each element will be given the same reference numeral as the fourth illustrated element, and the description thereof will be omitted.

第１０図は受光素子を３個とし、その内１つを逆方向に
接続した例で、該実施例ではスイッチ制御回路１５ｂに
よって第４図示スイッチ制御。FIG. 10 shows an example in which there are three light receiving elements, one of which is connected in the opposite direction, and in this embodiment, the switch shown in the fourth figure is controlled by the switch control circuit 15b.

３Ａと同様なスインチア１．７３をオン、スインチア５
．７７をオフにすると、信号電圧（−ｂ）が得られ、ま
たスインチア５．７３をオン、スイッチ７１．７７をオ
フとすると信号電圧（ａ−ｂ）が得られ、スイッチ７１
．７７をオン、スイッチ７５．７３をオフとすると信号
電圧（Ｃ−ｂ）が得られ、スイッチ７５．７７をオン、
スイッチ７１．７３をオフとすると信号電圧（ａ＋Ｃ−
ｂ）が得られる。Turn on Sinchia 1.73 similar to 3A, Sinchia 5
．． When switch 77 is turned off, a signal voltage (-b) is obtained, and when switch 71.73 is turned on and switch 71.77 is turned off, a signal voltage (a-b) is obtained.
．． When 77 is turned on and switch 75.73 is turned off, a signal voltage (C-b) is obtained, and switch 75.77 is turned on and switch 75.73 is turned off.
When switches 71 and 73 are turned off, the signal voltage (a+C-
b) is obtained.

第１１図は多数の受光素子を用い、その内の受光素子７
９，８３，８７．８９を図示の様に逆方向に接続し、常
時用いる受光素子７９，８１゜８９．９３に対するスイ
ッチを省いた例であって、第９図波ひに第１０図示実施
例の応用例である。第１１図において受光素子７９〜９
３は第４図示受光素子５，７と同様な受光素子であり、
スイッチ９５〜１０９は第４図示スインチＩＡ、３Ａと
同様なＭＯＳ−ＦＥＴで形成されたスイッチであり、′
スイッチ制御回路１５ｃは第４図示素子・ソチ制御回路
１５と同様な機能を有する、前記スイ、千群９５−１０
８のスイッチングのタイミングを帛ｊ御するスイッチ制
御回路である。、尚第４図示の素子と同一機能を有する
素子については同一符号を付してその説明を省略する。In FIG. 11, a large number of light receiving elements are used, of which light receiving element 7 is used.
9, 83, 87, and 89 are connected in the opposite direction as shown in the figure, and a switch for the constantly used light receiving elements 79, 81, and 89.93 is omitted. This is an application example of In FIG. 11, the light receiving elements 79 to 9
3 is a light receiving element similar to the light receiving elements 5 and 7 shown in the fourth figure;
Switches 95 to 109 are switches formed with MOS-FETs similar to the switches IA and 3A shown in the fourth figure;
The switch control circuit 15c has the same function as the fourth illustrated element/Sochi control circuit 15.
This is a switch control circuit that controls the switching timing of No. 8. Elements having the same functions as the elements shown in FIG. 4 are designated by the same reference numerals and their explanations will be omitted.

第１２図は第４図示受光素子と同様な受光素子ｌｉｔ、
　１１３の一端をＭＯＳ−ＡＭＰ９の入力端ではなく、
接地点に接続した例で、前述の第４図の実施例よりも受
光素子１１１からの漏れ電流の点において不利になるも
のの、何らかの理由により受光素子１−１１．１１３の
一端がＭｏｓ−ＡＭＰ９の入力端と接続できない場合に
有効となる例である。FIG. 12 shows a light receiving element lit similar to the light receiving element shown in FIG.
One end of 113 is not the input end of MOS-AMP9,
Although this example is connected to the ground point and is disadvantageous in terms of leakage current from the light receiving element 111 than the embodiment shown in FIG. 4, for some reason one end of the light receiving element 1-11. This example is effective when the input terminal cannot be connected.

第１３図は第９図示実施例と同様な多数の受光素子を用
いた例であって、受光素子を複数の群、すなわち１１５
と１１７からなる第１群、１１９の第２群、１２１．１
２３．１２５からなる第３群にまとめ、これら群に対し
て１組の並列・直列スイッチ１２７〜１３７を設け、第
９図示スイッチ制御回路１５ａと同様なスイッチ制御回
路１５ｄからの出力により各スイッチ１２８〜１３７を
適宜切り換えて増幅器９より所望の信号電圧を得る様に
した例である。該構成を採用することにより必要なスイ
ッチの数を減少させ、またスイッチ制御回路１５ｄも簡
単となる。FIG. 13 shows an example using a large number of light receiving elements similar to the embodiment shown in FIG.
and the first group consisting of 117, the second group of 119, 121.1
23 and 125, and one set of parallel/series switches 127 to 137 is provided for these groups, and each switch 128 is controlled by an output from a switch control circuit 15d similar to the switch control circuit 15a shown in the ninth figure. This is an example in which a desired signal voltage is obtained from the amplifier 9 by appropriately switching the signals .about.137. By adopting this configuration, the number of necessary switches can be reduced, and the switch control circuit 15d can also be simplified.

第１４図は受光素子として公知の半導体装置検出器（Ｐ
ＳＤと略称する）１３９を用いた例で、ＭＯＳ−ＦＥＴ
のスイッチ１４１．１４３の夫々を適宜オン争オフとす
ると２個の検出端子（電極）　１３９ａ１３８ｂから和
の信号電圧（ａ＋　ｂ）が得られ、スイッ９−１４１を
オフ、スイッチ１４３をオンとすると信号電圧すのみを
得ることができる。Figure 14 shows a well-known semiconductor device detector (P
This is an example using 139 (abbreviated as SD), MOS-FET
When switches 141 and 143 are turned on and off as appropriate, a sum signal voltage (a + b) is obtained from the two detection terminals (electrodes) 139a and 138b, and when switches 9 to 141 are turned off and switch 143 is turned on, the signal is Only the voltage can be obtained.

尚Ｐ　Ｓ　Ｄ　１３９の一方の検出端子１３９ｂとＭＯ
Ｓ−ＡＭＰ９の反転入力端子（−）間等に直列にスイッ
チ手段を入れてＰ　Ｓ　Ｄ　１３９からの信号を完全に
断つ構成も可能であることは言うまでもない。また検出
器の２個の電極の相互及び／或いは各電極間に直列にス
イッチ手段を接続しても同様な効果が得られることは言
うまでもない。Note that one detection terminal 139b of PSD 139 and MO
Needless to say, it is also possible to completely cut off the signal from the PSD 139 by inserting a switch means in series between the inverting input terminal (-) of the S-AMP 9, etc. It goes without saying that the same effect can be obtained by connecting the switch means in series between the two electrodes of the detector and/or between each electrode.

また更に以上の説明では演−算増幅器９としては入力手
段がＭＯＳ−ＦＥＴのＭＯＳ−ＡＭＰが好ましいものと
して説明したが受光素子に入射する信号光が偏重されて
いる場合には入力バイアス電流の存在する通常の演算増
幅器でも良、いことは言うもでもない。Further, in the above explanation, it is assumed that a MOS-AMP in which the input means is a MOS-FET is preferably used as the operational amplifier 9, but if the signal light incident on the light receiving element is biased, an input bias current exists. There is nothing wrong with using a normal operational amplifier.

以上のように本発明では複数の受光素子を有する距離測
定装置において受光素子を任意に切り換え１．かつ素子
自体あるいはそれに接続された回路素子により加算ある
いは減算を行□なわせる分散処理的手法を取り入れたの
で、多数の情報が得られ、また同時に受光素子用信号変
換回路９及び演算回路１３等の受光素子出力処理回路の
規模を縮小することができるものである。As described above, in the present invention, in a distance measuring device having a plurality of light receiving elements, the light receiving elements can be arbitrarily switched.1. In addition, a distributed processing method is adopted in which addition or subtraction is performed by the element itself or the circuit elements connected to it, so a large amount of information can be obtained, and at the same time, the signal conversion circuit 9 for the light receiving element, the arithmetic circuit 13, etc. The scale of the light receiving element output processing circuit can be reduced.

更には信号変換回路を一本化し得たので、全ての信号が
同一の変換回路で処理され、電流から電圧への変換定数
およびその周波数特性、さらにはオフセット電圧等の諸
条件が等しい信号が得られ、精度の高い信号乃至は距離
情報が得られるものである。Furthermore, since we were able to integrate the signal conversion circuit into one, all signals are processed by the same conversion circuit, and signals with the same conditions such as the current-to-voltage conversion constant, its frequency characteristics, and offset voltage can be obtained. It is possible to obtain highly accurate signals or distance information.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は距離測定装置に適用した本発明の一実施例の回
路接続図。 第２図は本発明の他の実施例の回路接続図、第３図（ａ
）は第１図示実施例における受光集子の具体的構成図、 第３図（ｂ）　、　（Ｃ）は第１図示実施例に関連する
動作説明図、 第４図は本発明の第三実施例の回路接続図、第５図は第
４図示実施例の動作説明図、第６図は第４図示スインチ
の等価回路図、第７図乃至第１４図は本発明の他の実施
例の回路接続図である。 図において、ｌ　、　３．−−−−スイ・ンチ、５　、
７−−−−受光素子、９−一一一演算増幅器、１．３−
−−一演算回路である。 出願人　　キャノン株式会社 必 ○ １兜 第　７　図 ｖｒ 第　６　暖 ／／FIG. 1 is a circuit connection diagram of an embodiment of the present invention applied to a distance measuring device. FIG. 2 is a circuit connection diagram of another embodiment of the present invention, and FIG.
) is a specific configuration diagram of the light receiving collector in the first illustrated embodiment, FIGS. 3(b) and (C) are operation explanatory diagrams related to the first illustrated embodiment, and FIG. 4 is a third embodiment of the present invention. 5 is an explanatory diagram of the operation of the fourth embodiment, FIG. 6 is an equivalent circuit diagram of the spinch shown in the fourth embodiment, and FIGS. 7 to 14 are circuits of other embodiments of the present invention. It is a connection diagram. In the figure, l, 3. -----Sui Nchi, 5,
7-----Photodetector, 9-11 operational amplifier, 1.3-
--One arithmetic circuit. Applicant: Canon Co., Ltd.

Claims (5)

【特許請求の範囲】[Claims] （１）複数の検知素子を用いて対象物迄の距離を測定す
る装置における検知素子出力電流を電圧に変換する入力
回路において、前記複数の検知素子を弔−の信号変換回
路に接続し、該変換回路出力に演算回路を接続し、かつ
前記複数の検知素子の少なくとも１つに直列に第１スイ
ンチ手段を接続し、該スイッチ手段の開閉により前記演
算回路より各検知素子出力の単独及び／或いは組合わせ
出力を得ることを特徴とする入力回路。(1) In an input circuit that converts a sensing element output current into voltage in a device that measures the distance to an object using a plurality of sensing elements, the plurality of sensing elements are connected to a signal conversion circuit, and the An arithmetic circuit is connected to the output of the conversion circuit, and a first switch means is connected in series to at least one of the plurality of sensing elements, and the output of each sensing element is independently and/or An input circuit characterized by obtaining a combinational output. （２）前記組合わせ出力は前記複数検知素子出力の和で
あることを特徴とする特許請求の範囲第（１）項記載の
入力回路。(2) The input circuit according to claim (1), wherein the combined output is a sum of the outputs of the plurality of sensing elements. （３）前記組合わせ出力は前記複数検知素子出力の差で
あることを特徴とする特許請求の範囲第（１）項記載の
入力回路。(3) The input circuit according to claim (1), wherein the combined output is a difference between the outputs of the plurality of sensing elements. （４）前記第１スインチ手段が接続された検知素子に並
列に第２のスイッチ手段を接続し、前記第１スイッチ手
段が閉じている時は前記第２スインチ手段を開き、前記
第１スイッチ手段が開いている時は前記第２スイツチｆ
段を閉じる様にしたことを特徴とする特許請求の範囲第
（１）項記載の入力回路。(4) A second switch means is connected in parallel to the detection element to which the first switch means is connected, and when the first switch means is closed, the second switch means is opened, and the first switch means is opened. is open, the second switch f
The input circuit according to claim 1, characterized in that the stages are closed. （５）半導体装置検出器を用いて対象物迄の距離を検出
する装置における前記検出器の共通電極以外の複数の電
極からの出力電流を電圧に変換する入力回路にお−いて
、前記検出器を単一の信号変換回路に接続し、該変換回
路出力に演算回路を接続し、かつ前記検出器の複数電極
の相互及び／或１７）は各電極間に直列にスイッチ手段
を接続し、該スイッチ手段の開閉により前記演算回路よ
り各電極出力の単独及び／或いは組合わせ出力を得るこ
とを特徴とする入力回路。(5) In an input circuit that converts output current from a plurality of electrodes other than a common electrode of the detector into a voltage in a device that detects a distance to an object using a semiconductor device detector, the detector is connected to a single signal conversion circuit, an arithmetic circuit is connected to the output of the conversion circuit, and a switch means is connected in series between the plurality of electrodes of the detector and/or each electrode, and An input circuit characterized in that an individual and/or combined output of each electrode is obtained from the arithmetic circuit by opening and closing a switch means.