JPH056374B2 - - Google Patents
Info
- Publication number
- JPH056374B2 JPH056374B2 JP58061244A JP6124483A JPH056374B2 JP H056374 B2 JPH056374 B2 JP H056374B2 JP 58061244 A JP58061244 A JP 58061244A JP 6124483 A JP6124483 A JP 6124483A JP H056374 B2 JPH056374 B2 JP H056374B2
- Authority
- JP
- Japan
- Prior art keywords
- light receiving
- light
- input device
- receiving circuit
- sensitivity
- 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
- 230000003287 optical effect Effects 0.000 claims description 24
- 230000035945 sensitivity Effects 0.000 claims description 13
- 230000007423 decrease Effects 0.000 description 3
- 230000005669 field effect Effects 0.000 description 2
- 239000000969 carrier Substances 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
- H03K17/51—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used
- H03K17/78—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used using opto-electronic devices, i.e. light-emitting and photoelectric devices electrically- or optically-coupled
Landscapes
- Electronic Switches (AREA)
Description
【発明の詳細な説明】
本発明は、バツクグラウンドとしての室光の影
響を低減することの可能な光信号入力装置に関す
るものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical signal input device that can reduce the influence of room light as a background.
光信号による入力装置としてはフオトダイオー
ド、フオトトランジスタが多く用いられており、
これらは通常発光源としての発光ダイオードと組
み合わされたユニツトとして使用され、光の条件
の安定した状況で用いられることが多い。この為
周囲の光の状態の変化はそれ程問題とはならな
い。 Photodiodes and phototransistors are often used as optical signal input devices.
These are usually used as a unit in combination with a light emitting diode as a light source, and are often used under stable light conditions. Therefore, changes in ambient light conditions do not pose much of a problem.
しかしながら、このようなユニツトとしての使
用の外、光信号による入力を行なう光入力端末と
しての使用では、最悪の条件では直射日光がこれ
らの光入力端末に入射し、このような状態でも光
信号の入力を検知する必要がある。 However, in addition to being used as such a unit, when used as an optical input terminal that inputs optical signals, under the worst conditions, direct sunlight enters these optical input terminals, and even under such conditions, the optical signal cannot be received. Need to detect input.
本発明は、光信号入力装置において、この装置
の置かれた光の状態を検知し、光の状態により光
信号の感度を調整し、室光、日光等の影響による
誤動作を低減することを目的とする。 An object of the present invention is to detect the light condition in which the device is placed in an optical signal input device, adjust the sensitivity of the optical signal according to the light condition, and reduce malfunctions caused by the influence of room light, sunlight, etc. shall be.
第１図に本発明の光信号入力装置の構成を示
す。本発明の光信号入力装置は大きく３の部分に
分けられる。同図１は基準の光量を検知する回路
であり、光入力装置に入射している光信号以外の
室光等を受光し、この光強度を検知する基準光受
光回路であり、２はその受光素子である。３はこ
の基準光受光回路からの信号により光入力信号の
受光感度を調整する感度調整回路である。この回
路により受光素子４の受けた光信号を検知する受
光回路５の感度を調整し光入力信号のバツクグラ
ウンドである室光の影響を相殺する。６は検知さ
れた出力信号である。 FIG. 1 shows the configuration of an optical signal input device of the present invention. The optical signal input device of the present invention can be roughly divided into three parts. 1 is a circuit for detecting the reference light intensity, and is a reference light receiving circuit that receives room light other than the optical signal entering the optical input device and detects the intensity of this light, and 2 is the reference light receiving circuit that detects the light intensity. It is element. Reference numeral 3 denotes a sensitivity adjustment circuit that adjusts the light reception sensitivity of the optical input signal using the signal from the reference light reception circuit. This circuit adjusts the sensitivity of the light receiving circuit 5 that detects the optical signal received by the light receiving element 4, thereby canceling out the influence of room light, which is the background of the optical input signal. 6 is the detected output signal.
第２図には、フオトトランジスタを受光素子と
して使用した場合の、本発明の光入力装置の具体
的回路を示した。７が基準光受光回路である。８
がフオトトランジスターで、このベース領域に室
光９が当り、光電流１０（IJ）が流れている。１
１は負荷抵抗（RL）であり、これを流れる光電
流により出力信号１２のレベルが変動する。この
変動を１３の感度調整回路により検知し、次段の
受光回路１４のフオトトランジスタ１５のベース
−エミツタ間に挿入された電界効果トランジスタ
１６のゲート電位１７を設定し、ベース−エミツ
タ間の抵抗値（RBE）を変化させて、受光感度
を調整することができる。１８はベース−エミツ
ター間に直列に入られた抵抗（RK）であり、１
９は負荷抵抗、２０は検知信号２１を出力するイ
ンバータである。２２はHIGHレベル（VDD）、２
３はLOWレベル（VSS）である。 FIG. 2 shows a specific circuit of the optical input device of the present invention when a phototransistor is used as a light receiving element. 7 is a reference light receiving circuit. 8
is a phototransistor, the base region of which is illuminated by room light 9, and a photocurrent 10 (IJ) flows. 1
1 is a load resistor (RL), and the level of the output signal 12 fluctuates depending on the photocurrent flowing through it. This fluctuation is detected by the sensitivity adjustment circuit 13, and the gate potential 17 of the field effect transistor 16 inserted between the base and emitter of the phototransistor 15 of the next stage light receiving circuit 14 is set, and the resistance value between the base and emitter is set. (RBE) can be changed to adjust the light receiving sensitivity. 18 is a resistor (RK) inserted in series between the base and emitter, and 1
9 is a load resistor, and 20 is an inverter that outputs a detection signal 21. 22 is HIGH level (V DD ), 2
3 is the LOW level (V SS ).
１５のフオトトランジスタは、８のフオトトラ
ンジスタとは異なりベースに端子が設けられてお
り、ベース−エミツター間に抵抗（RBE）を挿入
しベース領域で発生したキヤリアをエミツターへ
逃してやることで光電流２４（IL）を減少させる
ことができ、よつてインバータ２０のゲート入力
レベル２５も抑えることができ、感度を低下させ
ることが可能である。 Phototransistor No. 15, unlike phototransistor No. 8, has a terminal at its base, and a resistor (R BE ) is inserted between the base and emitter to allow carriers generated in the base region to escape to the emitter, thereby increasing the photocurrent. 24 (I L ), and therefore the gate input level 25 of the inverter 20 can also be suppressed, making it possible to reduce the sensitivity.
第３図には、このフオトトランジスターのベー
ス−エミツタ間の抵抗値（RBE）をパラメータと
した照度(E)と光電流（IL）の関係を示した。図に
示したようにベース−エミツター間抵抗（RBE）
の減少とともに同一照度のもとで光電流ILは低下
する。したがつて室光の強度の増大に伴ないRBE
を小さくしてやれば、受光感度は低下し室光の影
響を除くことが可能となる。光の強度に対してフ
オトトランジスタ等の受光素子の感度はリニアで
はないので、受光素子４と受光素子２の実際の入
力の差が一定であつたとしても、感度補正をしな
い場合は周囲の光の強度により出力が変化してし
まう。そこで、基準光受光回路の出力に基づき受
光回路の感度を調整することにより、そのような
現象を防止することができる。第２図の回路例で
はこのベース−エミツター間の抵抗FBEの調整
を、電界効果トランジスターにおけるゲート電位
の変動によるソース−ドレイン間の抵抗値の変化
を利用したものである。 FIG. 3 shows the relationship between illuminance (E) and photocurrent ( IL ) using the base-emitter resistance value ( RBE ) of this phototransistor as a parameter. As shown in the figure, the base-emitter resistance (R BE )
As the photocurrent I L decreases under the same illuminance, the photocurrent I L decreases. Therefore, as the intensity of room light increases, R BE
By reducing the value, the light-receiving sensitivity decreases, making it possible to eliminate the influence of room light. Since the sensitivity of a photodetector such as a phototransistor is not linear with respect to the intensity of light, even if the difference between the actual inputs of photodetector 4 and photodetector 2 is constant, if sensitivity correction is not performed, ambient light The output changes depending on the strength of the Therefore, such a phenomenon can be prevented by adjusting the sensitivity of the light receiving circuit based on the output of the reference light receiving circuit. In the circuit example shown in FIG. 2, the base-emitter resistance FBE is adjusted by utilizing changes in the source-drain resistance value due to changes in the gate potential of the field effect transistor.
以上述べてきたように、本発明の構成により、
光信号入力装置の置かれた光の状態を基準光受光
装置で検知し、この信号により光信号の受光回路
の感度を調整することにより、周囲の光による出
力の変動を抑えることが可能となり、高精度の光
入力装置を提供することができる。 As described above, with the configuration of the present invention,
By detecting the state of the light where the optical signal input device is placed with the reference light receiving device and adjusting the sensitivity of the optical signal receiving circuit using this signal, it is possible to suppress fluctuations in the output due to surrounding light. A highly accurate optical input device can be provided.
第１図は、本発明の光入力装置の構成を示すブ
ロツクダイヤグラムである。第２図は、本発明の
光入力装置の具体的回路例である。第３図は、フ
オトトランジスタにおけるベース−エミツタ間抵
抗をパラメータとした照度対光電流特性である。
FIG. 1 is a block diagram showing the configuration of an optical input device of the present invention. FIG. 2 shows a specific circuit example of the optical input device of the present invention. FIG. 3 shows illuminance vs. photocurrent characteristics using the base-emitter resistance of the phototransistor as a parameter.
Claims (1)
続された入力抵抗とを有し、前記受光素子で受光
された検出すべき光を検出する受光回路を備えた
光入力装置において、 前記光入力装置の周囲の光を検出する第２の受
光素子を有する基準光受光回路と、前記基準光受
光回路の出力に基づき前記受光回路の前記入力抵
抗を変化させる感度調整手段とを設け、前記受光
回路は前記入力抵抗の変化に基づき出力を調整さ
れる構成であることを特徴とする光入力装置。[Claims] 1. A light receiving circuit comprising a first light receiving element and an input resistor connected to the first light receiving element, and detecting light to be detected received by the light receiving element. The optical input device includes a reference light receiving circuit having a second light receiving element that detects light surrounding the optical input device, and a sensitivity adjustment that changes the input resistance of the light receiving circuit based on the output of the reference light receiving circuit. An optical input device comprising: means for adjusting the output of the light receiving circuit based on a change in the input resistance.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6124483A JPS59186421A (en) | 1983-04-07 | 1983-04-07 | Optical input device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6124483A JPS59186421A (en) | 1983-04-07 | 1983-04-07 | Optical input device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59186421A JPS59186421A (en) | 1984-10-23 |
| JPH056374B2 true JPH056374B2 (en) | 1993-01-26 |
Family
ID=13165623
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6124483A Granted JPS59186421A (en) | 1983-04-07 | 1983-04-07 | Optical input device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59186421A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4336669C1 (en) * | 1993-10-27 | 1994-12-15 | Ziegler Horst | Input field |
| JP2010141526A (en) * | 2008-12-10 | 2010-06-24 | Sanyo Electric Co Ltd | Light receiving circuit |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5211972A (en) * | 1975-07-18 | 1977-01-29 | Suginami Sokki Seisakusho:Kk | Light controlling method in the light receiving unit |
-
1983
- 1983-04-07 JP JP6124483A patent/JPS59186421A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5211972A (en) * | 1975-07-18 | 1977-01-29 | Suginami Sokki Seisakusho:Kk | Light controlling method in the light receiving unit |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59186421A (en) | 1984-10-23 |
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