JPH0330118B2 - - Google Patents
Info
- Publication number
- JPH0330118B2 JPH0330118B2 JP59057007A JP5700784A JPH0330118B2 JP H0330118 B2 JPH0330118 B2 JP H0330118B2 JP 59057007 A JP59057007 A JP 59057007A JP 5700784 A JP5700784 A JP 5700784A JP H0330118 B2 JPH0330118 B2 JP H0330118B2
- Authority
- JP
- Japan
- Prior art keywords
- output
- amplification circuit
- circuit
- comparator
- logarithmic amplification
- 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.)
- Expired - Lifetime
Links
- 230000003321 amplification Effects 0.000 claims description 30
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 30
- 238000001514 detection method Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 3
- 230000007257 malfunction Effects 0.000 description 3
- 238000009792 diffusion process Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Length Measuring Devices By Optical Means (AREA)
- Geophysics And Detection Of Objects (AREA)
- Burglar Alarm Systems (AREA)
Description
【発明の詳細な説明】
（技術分野）
本発明は、産業機器用光電スイツチ、来客検知
などの民生用光電スイツチに関するものである。DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a photoelectric switch for industrial equipment and a photoelectric switch for consumer use such as visitor detection.
（背景技術）
従来、光電スイツチは第１図のように構成され
ていた。第１図において、１は位置検出素子で、
投光手段（図示せず）から所定間隔をもつて側方
に並設されたもので、被検知物体（図示せず）か
らの反射光を受光して出力電流I1，I2を出力し、
２個の受光回路２，３により信号電圧に増巾変換
される。４は第１の対数増巾回路、５は第２の対
数増巾回路で、それぞれ帰還ダイオード（図示せ
ず）の電圧−電流特性を利用して対数増巾特性を
得ており、受光回路２，３の出力を対数増巾し、
差動増巾回路６を介して第１の比較器７で基準電
圧と比較判別する。VR2はこの基準電圧を設定す
るための可変抵抗器である。８は第３の対数増巾
回路で、可変抵抗器VR1により設定される動作レ
ベルの基準電圧を発生するもので、第２の対数増
巾回路５の出力とともに第２の比較器９および第
３の比較器１０に入力する。第２の比較器９の出
力は、ノイズによる誤動作を防止するために用い
るもので、外部ノイズ又は受光回路３に発生する
内部ノイズにより誤動作しない受光信号が得られ
ているかどうかを判別するものである。第３の比
較器１０の出力は余裕表示するもので、正常動作
範囲に対して余裕があることを表示する。１１は
信号処理回路で、各比較器７，９，１０の出力を
入力し、信号処理を行なう。このものにあつて
は、領域反射型として使用する場合には、最低受
光レベル時の第２の対数増巾回路５の出力と第３
の対数増巾回路８の出力とを一致させるように可
変抵抗器VR1を固定とし、可変抵抗器VR2で距離
設定を行ない、又、拡散反射型として使用する場
合には、可変抵抗器VR1で距離設定を行なう。こ
のため、領域反射型と拡散反射型の切換えが容易
に行なえない。即ち、可変抵抗器と固定抵抗器と
の形状の違いおよび可変抵抗器の取付け位置の違
いによりプリント基板の変換を余儀なくされる。(Background Art) Conventionally, a photoelectric switch has been constructed as shown in FIG. In FIG. 1, 1 is a position detection element,
They are arranged side by side at a predetermined distance from the light projecting means (not shown), and receive the reflected light from the object to be detected (not shown) and output the output currents I 1 and I 2 . ,
The two light receiving circuits 2 and 3 amplify and convert the signal voltage into a signal voltage. 4 is a first logarithmic amplification circuit, and 5 is a second logarithmic amplification circuit, each of which obtains logarithmic amplification characteristics using the voltage-current characteristics of a feedback diode (not shown). , 3 is logarithmically amplified,
A first comparator 7 compares and discriminates the voltage with a reference voltage via a differential amplification circuit 6. VR 2 is a variable resistor for setting this reference voltage. Reference numeral 8 denotes a third logarithmic amplification circuit, which generates a reference voltage at the operating level set by the variable resistor VR1 , and outputs the output from the second logarithmic amplification circuit 5 as well as the second comparator 9 and the 3 is input to the comparator 10 of No. 3. The output of the second comparator 9 is used to prevent malfunctions due to noise, and is used to determine whether a light reception signal that does not malfunction due to external noise or internal noise generated in the light receiving circuit 3 is obtained. . The output of the third comparator 10 indicates a margin, indicating that there is a margin within the normal operating range. A signal processing circuit 11 receives the outputs of the comparators 7, 9, and 10 and performs signal processing. When this device is used as an area reflection type, the output of the second logarithmic amplification circuit 5 and the third logarithmic amplification circuit at the lowest received light level are
The variable resistor VR 1 is fixed so as to match the output of the logarithmic amplification circuit 8, and the distance is set with the variable resistor VR 2. Also, when used as a diffuse reflection type, the variable resistor VR Set the distance with 1 . For this reason, switching between the area reflection type and the diffuse reflection type cannot be easily performed. That is, the printed circuit board must be changed due to the difference in shape between the variable resistor and the fixed resistor and the difference in the mounting position of the variable resistor.
（発明の目的）
本発明の目的とするところは、領域反射型とし
て使用する場合にも、拡散反射型として使用する
場合にも同一可変抵抗器で距離設定ができるよう
にすることにある。(Objective of the Invention) An object of the present invention is to enable distance setting with the same variable resistor both when used as an area reflection type and when used as a diffuse reflection type.
（発明の開示）
実施例
第２図において、１２は切換スイツチで、第２
の対数増巾回路５の出力と第３の対数増巾回路８
の出力とを差動増巾器６に切換可能に入力できる
ようにしたものである。Ｒは固定抵抗で、動作レ
ベルを設定するものであり、他は第１図と同様で
ある。(Disclosure of the Invention) Embodiment In FIG. 2, 12 is a changeover switch;
The output of the logarithmic amplification circuit 5 and the third logarithmic amplification circuit 8
The output of the amplifier 6 can be input to the differential amplifier 6 in a switchable manner. R is a fixed resistor that sets the operating level, and the rest is the same as in FIG.
動 作
切換スイツチ１２をａ側にした場合は拡散反射
型となり、ｂ側にした場合には領域反射型とな
る。領域反射型として使用する場合には、第１図
の従来例と同じであるため、動作説明は省略す
る。切換スイツチ１２をａ側にした場合には、受
光回路３、第２の対数増巾回路５、第２の比較器
９および第３の比較器１０を使用しない。又、位
置検出素子１の出力電流I1，I2は共に第３図のよ
うに受光回路２に入力する。このことにより位置
検出素子１の全受光電流が受光回路２に入力され
る。領域反射型として使用する場合は出力電流I1
とI2の比が重要であるが、拡散反射型として使用
する場合は受光量が重要となるため、受光量不足
による回路の誤動作防止のために位置検出素子１
に照射される全光量に対する光電流を扱う方がよ
い。この出力電流を受光回路２で電圧に変換す
る。受光回路２は、パルス光のみを通し直流光を
カツトして特定の周波数のみを通すバンドパスフ
イルタ回路を含んでいる。つぎに、受光回路２の
出力電圧を第１の対数増巾回路４で対数圧縮しか
つ増巾する。この出力電圧をV1とする。又、第
３の対数増巾回路８の出力電圧をV2とする。V2
が最低受光量、即ち、回路のノイズにより誤動作
しない受光量の最低値の入力時のV1の値と同じ
値になるように抵抗Ｒを決定する。差動増巾回路
６によつてV1とV2の差を増巾してその出力電圧
V3を第１の比較器７に入力する。可変抵抗器
VR2によつて決まる第１の比較器７の基準電圧を
Vrefとすると、V3とVrefの大小によつて第１の
比較器７の出力が決まる。同じ被検出物体である
と距離によつて受光量が決定される。V1は受光
量の関数であり、V2は一定であるためV3はV1の
関数であり、V3は距離の関数となる。したがつ
て、Vrefを可変することにより検出距離を調整
することができる。Operation When the changeover switch 12 is set to the a side, it becomes a diffuse reflection type, and when it is set to the b side, it becomes an area reflection type. When used as an area reflection type, the operation is the same as the conventional example shown in FIG. 1, so a description of the operation will be omitted. When the changeover switch 12 is set to the a side, the light receiving circuit 3, the second logarithmic amplification circuit 5, the second comparator 9, and the third comparator 10 are not used. Further, the output currents I 1 and I 2 of the position detection element 1 are both input to the light receiving circuit 2 as shown in FIG. As a result, the entire light-receiving current of the position detection element 1 is input to the light-receiving circuit 2. Output current I 1 when used as area reflective type
The ratio of
It is better to treat the photocurrent relative to the total amount of light irradiated on the This output current is converted into voltage by the light receiving circuit 2. The light receiving circuit 2 includes a bandpass filter circuit that passes only pulsed light, cuts out DC light, and passes only specific frequencies. Next, the output voltage of the light receiving circuit 2 is logarithmically compressed and amplified by a first logarithmic amplification circuit 4. Let this output voltage be V1 . Further, the output voltage of the third logarithmic amplification circuit 8 is assumed to be V2 . V2
The resistor R is determined so that the value is the same as the value of V1 at the time of inputting the minimum amount of light received, that is, the lowest value of the amount of received light that does not malfunction due to circuit noise. The difference between V 1 and V 2 is amplified by the differential amplification circuit 6 and its output voltage is
V 3 is input to the first comparator 7. variable resistor
Let the reference voltage of the first comparator 7 determined by VR 2 be
Vref, the output of the first comparator 7 is determined by the magnitude of V3 and Vref. For the same detected object, the amount of light received is determined by the distance. V 1 is a function of the amount of received light, and since V 2 is constant, V 3 is a function of V 1 , and V 3 is a function of distance. Therefore, the detection distance can be adjusted by varying Vref.
（発明の効果）
上述のように本発明は、第２の対数増巾回路の
出力と第３の対数増巾回路の出力とを差動増巾回
路に切換可能に入力するようにし、第１の比較器
の基準電圧を調整して領域反射型および拡散反射
型の距離設定を同一可変抵抗器でできる如くした
から、領域反射型として使用する場合にも拡散反
射型として使用する場合にも同一可変抵抗器で距
離設定ができ、部品交換が不必要になるという効
果を奏するものである。(Effects of the Invention) As described above, the present invention allows the output of the second logarithmic amplification circuit and the output of the third logarithmic amplification circuit to be inputted to the differential amplification circuit in a switchable manner; By adjusting the reference voltage of the comparator, the distance setting for area reflection type and diffuse reflection type can be done with the same variable resistor, so it is the same whether it is used as area reflection type or diffuse reflection type. The distance can be set using a variable resistor, and there is no need to replace parts.
第１図は従来の光電スイツチのブロツク回路
図、第２図は本発明の一実施例のブロツク回路
図、第３図は同上の拡散反討型として使用する場
合の等価的ブロツク回路図である。
２……受光回路、３……受光回路、４……第１
の対数増巾回路、５……第２の対数増巾回路、６
……差動増巾回路、７……第１の比較器、８……
第３の対数増巾回路、９……第２の比較器、１０
……第３の比較器、１２……切換スイツチ、VR2
……可変抵抗器。
Fig. 1 is a block circuit diagram of a conventional photoelectric switch, Fig. 2 is a block circuit diagram of an embodiment of the present invention, and Fig. 3 is an equivalent block circuit diagram when used as a diffusion type switch. . 2... Light receiving circuit, 3... Light receiving circuit, 4... First
a logarithmic amplification circuit, 5... a second logarithmic amplification circuit, 6
... Differential amplifier circuit, 7 ... First comparator, 8 ...
Third logarithmic amplification circuit, 9...Second comparator, 10
...Third comparator, 12...Selector switch, VR 2
...variable resistor.
Claims (1)
の受光回路と、前記受光回路出力を対数増巾する
第１および第２の対数増巾回路と、前記第１およ
び第２の対数増巾回路の出力を差動増巾した出力
を基準電圧と比較判別する第１の比較器と、動作
レベルを設定する基準電圧を発生する第３の対数
増巾回路と、前記第３の対数増巾回路の出力と第
２の対数増巾回路の出力とを比較判別する第２お
よび第３の比較器を具備した光電スイツチにおい
て、第２の対数増巾回路の出力と第３の対数増巾
回路の出力とを差動増巾回路に切換可能に入力す
るようにし、第１の比較器の基準電圧を調整して
領域反射型および拡散反射型の距離設定を同一可
変抵抗器でできる如くして成ることを特徴とする
光電スイツチ。1. Two light receiving circuits that detect changes in the amount of light received by the object to be detected, first and second logarithmic amplification circuits that logarithmically amplify the output of the light receiving circuit, and the first and second logarithmic amplification circuits. a first comparator that differentially amplifies the output of the output and compares and discriminates the output with a reference voltage; a third logarithmic amplification circuit that generates a reference voltage that sets an operating level; and the third logarithmic amplification circuit. In the photoelectric switch equipped with second and third comparators for comparing and determining the output of the second logarithm amplification circuit and the output of the second logarithm amplification circuit, the output of the second logarithm amplification circuit and the output of the third logarithm amplification circuit are The output is switchably input to a differential amplification circuit, and the reference voltage of the first comparator is adjusted so that distance setting for area reflection type and diffuse reflection type can be performed using the same variable resistor. A photoelectric switch characterized by:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59057007A JPS60200105A (en) | 1984-03-24 | 1984-03-24 | Photoelectric switch |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59057007A JPS60200105A (en) | 1984-03-24 | 1984-03-24 | Photoelectric switch |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60200105A JPS60200105A (en) | 1985-10-09 |
| JPH0330118B2 true JPH0330118B2 (en) | 1991-04-26 |
Family
ID=13043396
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59057007A Granted JPS60200105A (en) | 1984-03-24 | 1984-03-24 | Photoelectric switch |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60200105A (en) |
-
1984
- 1984-03-24 JP JP59057007A patent/JPS60200105A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60200105A (en) | 1985-10-09 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EXPY | Cancellation because of completion of term |