JP2008241518A - Current/voltage conversion circuit and automatic light controller using the same - Google Patents

Current/voltage conversion circuit and automatic light controller using the same Download PDF

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JP2008241518A
JP2008241518A JP2007083768A JP2007083768A JP2008241518A JP 2008241518 A JP2008241518 A JP 2008241518A JP 2007083768 A JP2007083768 A JP 2007083768A JP 2007083768 A JP2007083768 A JP 2007083768A JP 2008241518 A JP2008241518 A JP 2008241518A
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voltage
current
diode
conversion circuit
photocurrent
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JP2008241518A5 (en
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Nobutaka Amano
信孝 天野
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Seiko NPC Corp
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a current/voltage conversion circuit for converting a photocurrent into a voltage in a wide range of an illuminance, regardless of the output current range of a photoelectric converter and the ambient temperature. <P>SOLUTION: After the photocurrent Ip is generated by a photodiode 2 and converted into a voltage Vp by a diode 4, and a reference current Iref is generated by a variable current source 3 and converted into a voltage Vref by a diode 5, the difference signal between the voltages Vp, Vref is amplified by a differential amplifier 6. An output, corresponding to the lower illuminance, can be ensured by converting the photocurrent Ip into the voltage signal Vp having logarithmic characteristic. The voltage signal Vp having an error due to a temperature characteristic of the diode 4 can be outputted, without effects due to the ambient temperature by the differential amplifier 6 for amplifying the difference between the voltage signal Vp and the voltage signal Vref similarly having the error due to a temperature characteristic of the diode 5. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

本発明は光電変換器の光電流を電圧変換する電流電圧変換回路に関する。また、当該電流電圧変換回路を含む自動調光装置に関する。   The present invention relates to a current-voltage conversion circuit that converts a photocurrent of a photoelectric converter into a voltage. The present invention also relates to an automatic light control device including the current-voltage conversion circuit.

電流電圧変換回路は、フォトダイオード、フォトトランジスタ、およびフォトＩＣなどの光電変換器に接続されるとき、当該光電変換器に入射される光の照度に応じて生成される光電流を電圧に変換して出力する。
光電流を電圧に変換する従来の電流電圧変換回路として、特許文献１に示されるものが知られている。特許文献１の電流電圧変換回路は、抵抗によって電圧に変換されたフォトダイオードの光電流を演算増幅器の帰還抵抗に流すことで電圧信号に変換する。 When the current-voltage converter circuit is connected to a photoelectric converter such as a photodiode, phototransistor, or photo IC, it converts the photocurrent generated according to the illuminance of light incident on the photoelectric converter into a voltage. Output.
As a conventional current-voltage conversion circuit for converting a photocurrent into a voltage, one disclosed in Patent Document 1 is known. The current-voltage conversion circuit of Patent Document 1 converts a photocurrent of a photodiode, which has been converted into a voltage by a resistor, into a voltage signal by flowing it through a feedback resistor of an operational amplifier.

また、従来の電流電圧変換回路として、特許文献２に示されるものがある。特許文献２の電流電圧変換回路は、フォトトランジスタとダイオードとで直列回路を構成し、当該直列回路の両端に電圧を印加したときに、該ダイオードの両端電圧を出力する。
ダイオードの電流−電圧特性は図７に示されるように対数特性を有するため、当該電流電圧変換回路の出力電圧は該フォトトランジスタの光電流に対して対数特性をもつ。
特開平１１−２１１５６３号公報 特開２００５−２４１３０６号公報 Moreover, there exists a thing shown by patent document 2 as a conventional current-voltage conversion circuit. The current-voltage conversion circuit of Patent Document 2 forms a series circuit with a phototransistor and a diode, and outputs a voltage across the diode when a voltage is applied across the series circuit.
Since the current-voltage characteristic of the diode has a logarithmic characteristic as shown in FIG. 7, the output voltage of the current-voltage conversion circuit has a logarithmic characteristic with respect to the photocurrent of the phototransistor.
Japanese Patent Laid-Open No. 11-211153 JP-A-2005-241306

特許文献１の電流電圧変換回路は、光電流を抵抗で電圧変換しており、変換された電圧が光電流に対して比例関係をとることから、変換された電圧と入射光の照度も、図８に示されるように比例関係にある。そのため、検出する照度を１ルクス〜１０万ルクス程度の広範囲とした場合に、低照度の光を出力として得ることが困難になる。例えば、１０万ルクスの光に対して１Ｖの出力が得られるとき、１ルクスの光に対しては１０万分の１Ｖという値になってしまい、出力として得ることができない。
特許文献２の電流電圧変換回路は、図９に示されるように、出力信号が対数特性を有することで、低照度に対する分解能が高くなるため、検出する照度範囲を広く取った場合にも、低照度の光に対する出力を確保することができる。しかし、ダイオードの温度特性が考慮されていないため、周囲温度の影響によって出力電圧の値が変化してしまう。
また、従来の電流電圧変換回路は、接続される光電変換器の出力電流範囲に応じて出力信号の範囲も変化するため、出力電流範囲が異なる光電変換器を接続する場合には、その都度、その光電変換器の出力電流範囲に合わせて所望の範囲で出力電圧が得られるように、例えば基準電圧などの設定を変更しなければならなかった。 The current-voltage conversion circuit of Patent Document 1 converts a photocurrent into a voltage with a resistor, and the converted voltage has a proportional relationship with the photocurrent. Therefore, the converted voltage and the illuminance of incident light are also shown in FIG. As shown in FIG. For this reason, when the detected illuminance is in a wide range of about 1 lux to 100,000 lux, it is difficult to obtain light with low illuminance as an output. For example, when an output of 1V is obtained with respect to 100,000 lux light, the value becomes 1 / 100,000V with respect to 1 lux light and cannot be obtained as an output.
As shown in FIG. 9, since the output signal has a logarithmic characteristic, the current-voltage conversion circuit of Patent Document 2 has a high resolution with respect to low illuminance. Therefore, even when a wide illuminance range is detected. The output with respect to the light of illumination intensity can be ensured. However, since the temperature characteristics of the diode are not taken into consideration, the value of the output voltage changes due to the influence of the ambient temperature.
Moreover, since the range of an output signal also changes according to the output current range of the photoelectric converter to be connected in the conventional current-voltage conversion circuit, each time a photoelectric converter having a different output current range is connected, In order to obtain an output voltage in a desired range according to the output current range of the photoelectric converter, for example, the setting of the reference voltage or the like has to be changed.

本発明は上記の問題点に鑑み、光電変換器の出力電流範囲や周囲温度によらず、広範囲の照度に対して、光電流を電圧に変換することができる電流電圧変換回路を提供することを目的とする。
また、当該電流電圧変換回路および発光ダイオードを利用し、光電変換器の出力電流範囲によらず、簡単な設定で、周囲の照度に合わせた輝度の光を発する自動調光装置を提供することを目的とする。 In view of the above problems, the present invention provides a current-voltage conversion circuit capable of converting a photocurrent into a voltage with respect to a wide range of illuminance regardless of the output current range and ambient temperature of the photoelectric converter. Objective.
In addition, the present invention provides an automatic light control device that uses the current-voltage conversion circuit and the light-emitting diode and emits light having a luminance according to the ambient illuminance with a simple setting regardless of the output current range of the photoelectric converter. Objective.

上記の問題点を解決するため、本発明の電流電圧変換回路は、入射光の強度に応じた光電流を生成する光電変換器と、任意の値の基準電流を生成する可変電流源と、前記光電変換器に接続され、前記光電流を第１の電圧に変換する第１の素子と、前記可変電流源に接続され、前記基準電流を第２の電圧に変換する第２の素子と、前記第１の電圧および前記第２の電圧の差信号を増幅する差動増幅器と、を有することを特徴とする。   In order to solve the above problems, a current-voltage conversion circuit according to the present invention includes a photoelectric converter that generates a photocurrent according to the intensity of incident light, a variable current source that generates a reference current of an arbitrary value, A first element connected to a photoelectric converter for converting the photocurrent to a first voltage; a second element connected to the variable current source for converting the reference current to a second voltage; And a differential amplifier for amplifying a difference signal between the first voltage and the second voltage.

前記第１の素子は、アノードが前記光電変換器に接続されるとともにカソードが接地される第１のダイオードであり、前記第２の素子は、アノードが前記可変電流源に接続されるとともにカソードが接地される第２のダイオードであることを特徴としてもよい。   The first element is a first diode having an anode connected to the photoelectric converter and a cathode grounded, and the second element has an anode connected to the variable current source and a cathode The second diode may be grounded.

本発明に係る自動調光装置は、請求項１または請求項２に記載の電流電圧変換回路と、発光ダイオードと、前記電流電圧変換回路の出力に基づいて前記発光ダイオードに流れる電流を制御する発光ダイオード駆動回路と、を有することを特徴とする。   An automatic light control device according to the present invention includes a current-voltage conversion circuit according to claim 1 or 2, a light-emitting diode, and light emission for controlling a current flowing through the light-emitting diode based on an output of the current-voltage conversion circuit. And a diode driving circuit.

本発明によれば、光電変換器の出力電流範囲や周囲温度によらず、広範囲の照度に対して、光電流を電圧変換することができる。
また、当該電流電圧変換回路および発光ダイオードを利用し、光電変換器の出力電流範囲によらず、簡単な設定で、周囲の照度に合わせた輝度の光を発する自動調光装置を構成できる。 According to the present invention, the photocurrent can be converted into a voltage with respect to a wide range of illuminance regardless of the output current range of the photoelectric converter and the ambient temperature.
Further, by using the current-voltage conversion circuit and the light emitting diode, it is possible to configure an automatic light control device that emits light having a luminance according to ambient illuminance with a simple setting regardless of the output current range of the photoelectric converter.

以下、本発明に係る電流電圧変換回路を、図面に基づいて説明する。図１に、本発明に係る電流電圧変換回路の回路図を示す。本発明に係る電流電圧変換回路は、バイアス電圧源１、フォトダイオード２、可変電流源３、第１のダイオード４（以下、ダイオード４）、第２のダイオード５（以下、ダイオード５）、および、差動増幅器６を備える。   Hereinafter, a current-voltage conversion circuit according to the present invention will be described with reference to the drawings. FIG. 1 shows a circuit diagram of a current-voltage conversion circuit according to the present invention. A current-voltage conversion circuit according to the present invention includes a bias voltage source 1, a photodiode 2, a variable current source 3, a first diode 4 (hereinafter referred to as diode 4), a second diode 5 (hereinafter referred to as diode 5), and A differential amplifier 6 is provided.

バイアス電圧源１は、フォトダイオード２に逆方向バイアスをかける回路であり、フォトダイオード２のカソードに接続される。
フォトダイオード２は、入射光の照度に応じた光電流Ｉｐをダイオード４に供給する光電変換器であり、アノードがダイオード４に接続される。
可変電流源３は、基準電流Ｉｒｅｆをダイオード５に供給する回路であり、出力端がダイオード５に接続される。
ダイオード４は、フォトダイオード２による光電流Ｉｐを第１の電圧Ｖｐ（以下、電圧Ｖｐ）に変換する第１の素子であり、図７に示される電流‐電圧特性を有する。ダイオード４は、アノードがフォトダイオード２のアノードに接続され、カソードが接地される。
ダイオード５は可変電流源３による基準電流Ｉｒｅｆを第２の電圧Ｖｒｅｆ（以下、電圧Ｖｒｅｆ）に変換する第２の素子であり、ダイオード４と同様に、図７に示される電流‐電圧特性を有する。ダイオード５は、アノードが可変電流源３に接続され、カソードが接地される。
差動増幅器６は、電圧Ｖｐと電圧Ｖｒｅｆとの差信号を増幅する。差動増幅器６は、反転入力端がダイオード４のアノードに接続され、非反転入力端がダイオード５のアノードに接続される。 The bias voltage source 1 is a circuit that applies a reverse bias to the photodiode 2, and is connected to the cathode of the photodiode 2.
The photodiode 2 is a photoelectric converter that supplies a photocurrent Ip corresponding to the illuminance of incident light to the diode 4, and an anode is connected to the diode 4.
The variable current source 3 is a circuit that supplies a reference current Iref to the diode 5, and an output terminal is connected to the diode 5.
The diode 4 is a first element that converts the photocurrent Ip generated by the photodiode 2 into a first voltage Vp (hereinafter, voltage Vp), and has a current-voltage characteristic shown in FIG. The diode 4 has an anode connected to the anode of the photodiode 2 and a cathode grounded.
The diode 5 is a second element that converts the reference current Iref from the variable current source 3 into a second voltage Vref (hereinafter, voltage Vref), and has the current-voltage characteristic shown in FIG. . The diode 5 has an anode connected to the variable current source 3 and a cathode grounded.
The differential amplifier 6 amplifies a difference signal between the voltage Vp and the voltage Vref. The differential amplifier 6 has an inverting input terminal connected to the anode of the diode 4 and a non-inverting input terminal connected to the anode of the diode 5.

フォトダイオード２に入射される光の照度と、電圧Ｖｐおよび電圧Ｖｒｅｆとの関係を表したグラフを図２に示す。ダイオード４およびダイオード５の温度特性により、電圧Ｖｐと電圧Ｖｒｅｆの値は、周囲温度の変化に伴ってともに破線で示すように増減する。
次に、照度の対数と出力電圧Ｖｏｕｔとの関係を図３に示す。両者の差信号を差動増幅器６によって増幅することで、周囲温度による増減値が打ち消され、差動増幅器６の出力信号Ｖｏｕｔは周囲温度に影響されない値となる。 FIG. 2 is a graph showing the relationship between the illuminance of light incident on the photodiode 2 and the voltage Vp and the voltage Vref. Due to the temperature characteristics of the diode 4 and the diode 5, the values of the voltage Vp and the voltage Vref both increase and decrease as indicated by the broken line as the ambient temperature changes.
Next, FIG. 3 shows the relationship between the logarithm of illuminance and the output voltage Vout. By amplifying the difference signal between the two by the differential amplifier 6, the increase / decrease value due to the ambient temperature is canceled out, and the output signal Vout of the differential amplifier 6 becomes a value not influenced by the ambient temperature.

以上のように、フォトダイオード２で生成される光電流Ｉｐは、ダイオード４によって対数特性を有する電圧信号Ｖｐに変換されることで、検出する照度範囲を広く取った場合でも、低照度の光に対する出力を確保することができる。
また、ダイオード４の温度特性によって値が変化する電圧Ｖｐは、同じくダイオード５の温度特性によって値が変化する電圧Ｖｒｅｆとの差信号を取ることにより、Ｖｐ、Ｖｒｅｆの温度特性を打ち消すことができるため、周囲温度によらない出力を得ることができる。
本実施例の電流電圧変換回路は、可変電流源３において基準電流Ｉｒｅｆを設定することで、フォトトランジスタ２の光電流Ｉｐの範囲に関わらず、分解能を確保し、温度特性によらない電流電圧変換を行うことができる。 As described above, the photocurrent Ip generated by the photodiode 2 is converted into a voltage signal Vp having a logarithmic characteristic by the diode 4, so that even when a wide illuminance range is detected, Output can be secured.
Further, the voltage Vp whose value changes depending on the temperature characteristics of the diode 4 can cancel the temperature characteristics of Vp and Vref by taking a difference signal from the voltage Vref whose value also changes depending on the temperature characteristics of the diode 5. An output independent of the ambient temperature can be obtained.
The current-voltage conversion circuit according to the present embodiment sets the reference current Iref in the variable current source 3, thereby ensuring the resolution regardless of the range of the photocurrent Ip of the phototransistor 2 and performing the current-voltage conversion independent of the temperature characteristics. It can be performed.

尚、本実施例では光電変換器にフォトダイオード２が用いられたが、例えばフォトトランジスタや、フォトＩＣなど、入射光強度に応じた光電流を生成する光電変換器が代わりに用いられてもよい。
また、第１の素子はダイオード４によって構成され、第２の素子はダイオード５によって構成されたが、ともに同様の対数特性を有する素子であればよい。 In the present embodiment, the photodiode 2 is used for the photoelectric converter, but a photoelectric converter that generates a photocurrent according to the intensity of incident light, such as a phototransistor or a photo IC, may be used instead. .
In addition, the first element is constituted by the diode 4 and the second element is constituted by the diode 5, but any element having the same logarithmic characteristic may be used.

次に、本発明に係る電流電圧変換回路を利用した自動調光装置を、図４に基づいて説明する。図４の自動調光装置は、バイアス電圧源１、フォトダイオード２、可変電流源３、ダイオード４、ダイオード５、差動増幅器６、発光ダイオード駆動回路７、および、発光ダイオード８を備える。
バイアス電圧源１、フォトダイオード２、可変電流源３、ダイオード４、ダイオード５、および、差動増幅器６については、図１で示した構成と同様である。 Next, an automatic light control device using the current-voltage conversion circuit according to the present invention will be described with reference to FIG. 4 includes a bias voltage source 1, a photodiode 2, a variable current source 3, a diode 4, a diode 5, a differential amplifier 6, a light emitting diode drive circuit 7, and a light emitting diode 8.
The bias voltage source 1, the photodiode 2, the variable current source 3, the diode 4, the diode 5, and the differential amplifier 6 are the same as the configuration shown in FIG.

発光ダイオード駆動回路７は、差動増幅器６の出力信号Ｖｏｕｔに基づいて発光ダイオード８を駆動する回路であり、差動増幅器６の出力端と発光ダイオード８のアノードとカソードとに接続される。
差動増幅器６の出力信号Ｖｏｕｔと、発光ダイオード８を流れる電流ＩＬＥＤは、図５に示すように、比例関係をとる。よって、発光ダイオード８を流れる電流ＩＬＥＤは、図６に示されるように、フォトダイオード２の入射光照度の対数に対して線形に変化する。 The light emitting diode drive circuit 7 is a circuit that drives the light emitting diode 8 based on the output signal Vout of the differential amplifier 6, and is connected to the output terminal of the differential amplifier 6 and the anode and cathode of the light emitting diode 8.
As shown in FIG. 5, the output signal Vout of the differential amplifier 6 and the current ILED flowing through the light emitting diode 8 have a proportional relationship. Therefore, the current ILED flowing through the light emitting diode 8 changes linearly with respect to the logarithm of the incident light illuminance of the photodiode 2 as shown in FIG.

このように、本発明に係る自動調光装置は、フォトダイオード２の入射光の照度に基づいて発光ダイオード８の電流ＩＬＥＤが変化するため、周囲の照度に合わせて調光を行うことができる。
また、本発明に係る自動調光装置は、フォトダイオード２に代わって、フォトトランジスタや、フォトＩＣなど、入射光強度に応じた光電流を生成する光電変換器が接続されてもよい。いずれの光電変換器が接続された場合も、可変電流源３の基準電流Ｉｒｅｆを調整するだけで、光電変換器の出力電流範囲に対応して発光ダイオード８を調光することができる。 Thus, since the current ILED of the light emitting diode 8 changes based on the illuminance of the incident light of the photodiode 2, the automatic dimmer according to the present invention can perform dimming according to the ambient illuminance.
Further, in the automatic light control device according to the present invention, a photoelectric converter that generates a photocurrent according to the intensity of incident light, such as a phototransistor or a photo IC, may be connected instead of the photodiode 2. Regardless of which photoelectric converter is connected, the light emitting diode 8 can be dimmed by adjusting the reference current Iref of the variable current source 3 only by adjusting the output current range of the photoelectric converter.

本発明に係る電流電圧変換回路の回路図。The circuit diagram of the current voltage converter circuit concerning the present invention. フォトダイオード２の入射光照度と、電圧信号Ｖｐおよび電圧信号Ｖｒｅｆの関係を示す説明図。Explanatory drawing which shows the relationship between the incident light illumination intensity of the photodiode 2, and the voltage signal Vp and the voltage signal Vref. フォトダイオード２の入射光照度の対数と差動増幅器６の出力の関係を示す説明図。FIG. 3 is an explanatory diagram showing the relationship between the logarithm of incident light illuminance of a photodiode and the output of a differential amplifier. 本発明に係る自動調光装置のブロック図。The block diagram of the automatic light control apparatus which concerns on this invention. 差動増幅器６の出力と発光ダイオード８の電流の関係を示す説明図。FIG. 3 is an explanatory diagram showing the relationship between the output of the differential amplifier 6 and the current of the light emitting diode 8. フォトダイオード２の入射光照度の対数と発光ダイオード８の電流との関係を示す説明図。FIG. 3 is an explanatory diagram showing a relationship between a logarithm of incident light illuminance of a photodiode and a current of a light emitting diode. ダイオードの電流‐電圧特性を示す説明図。Explanatory drawing which shows the current-voltage characteristic of a diode. 従来例によって変換された出力電圧と照度との関係を示す説明図。Explanatory drawing which shows the relationship between the output voltage converted by the prior art example, and illumination intensity. 他の従来例の照度に対する出力電圧を示す説明図。Explanatory drawing which shows the output voltage with respect to the illumination intensity of another prior art example.

符号の説明Explanation of symbols

１ バイアス電圧源
２ フォトダイオード
３ 可変電流源
４、５ ダイオード
６ 差動増幅器
７ 発光ダイオード駆動回路
８ 発光ダイオード DESCRIPTION OF SYMBOLS 1 Bias voltage source 2 Photodiode 3 Variable current source 4, 5 Diode 6 Differential amplifier 7 Light emitting diode drive circuit 8 Light emitting diode

Claims (3)

光電変換器への入射光の照度に応じた光電流を電圧に変換する電流電圧変換回路であって、
前記光電流を生成する前記光電変換器と、
任意の基準電流を生成する可変電流源と、
前記光電変換器に接続され、前記光電流を第１の電圧に変換する第１の素子と、
前記可変電流源に接続され、前記基準電流を第２の電圧に変換する第２の素子と、
前記第１の電圧および第２の電圧の差信号を増幅する差動増幅器と、
を有すること
を特徴とする電流電圧変換回路。 A current-voltage conversion circuit that converts a photocurrent according to the illuminance of incident light to the photoelectric converter into a voltage,
The photoelectric converter for generating the photocurrent;
A variable current source that generates an arbitrary reference current;
A first element connected to the photoelectric converter and converting the photocurrent into a first voltage;
A second element connected to the variable current source and converting the reference current into a second voltage;
A differential amplifier for amplifying a difference signal between the first voltage and the second voltage;
A current-voltage conversion circuit comprising: 前記第１の素子は、アノードが前記光電変換器に接続されるとともにカソードが接地される第１のダイオードであり、
前記第２の素子は、アノードが前記可変電流源に接続されるとともにカソードが接地される第２のダイオードである
ことを特徴とする請求項１に記載の電流電圧変換回路。 The first element is a first diode having an anode connected to the photoelectric converter and a cathode grounded;
2. The current-voltage conversion circuit according to claim 1, wherein the second element is a second diode having an anode connected to the variable current source and a cathode grounded. 請求項１または請求項２に記載の電流電圧変換回路と、
発光ダイオードと、
前記電流電圧変換回路の出力に基づいて前記発光ダイオードに流れる電流を制御する発光ダイオード駆動回路と、を有することを
特徴とする自動調光装置。 The current-voltage conversion circuit according to claim 1 or 2,
A light emitting diode;
An automatic light control device comprising: a light emitting diode driving circuit that controls a current flowing through the light emitting diode based on an output of the current-voltage conversion circuit.
JP2007083768A 2007-03-28 2007-03-28 Current/voltage conversion circuit and automatic light controller using the same Withdrawn JP2008241518A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
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Application Number Priority Date Filing Date Title
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010004026A (en) * 2008-05-22 2010-01-07 Semiconductor Energy Lab Co Ltd Photoelectric conversion device, and electronic apparatus provided with the photoelectric conversion device
WO2024082599A1 (en) * 2022-10-21 2024-04-25 武汉市聚芯微电子有限责任公司 Proximity detection circuit and proximity sensor

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5030576A (en) * 1973-04-12 1975-03-26
JP2004233569A (en) * 2003-01-29 2004-08-19 New Japan Radio Co Ltd Led driving circuit

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5030576A (en) * 1973-04-12 1975-03-26
JP2004233569A (en) * 2003-01-29 2004-08-19 New Japan Radio Co Ltd Led driving circuit

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010004026A (en) * 2008-05-22 2010-01-07 Semiconductor Energy Lab Co Ltd Photoelectric conversion device, and electronic apparatus provided with the photoelectric conversion device
JP2014017522A (en) * 2008-05-22 2014-01-30 Semiconductor Energy Lab Co Ltd Electronic apparatus
WO2024082599A1 (en) * 2022-10-21 2024-04-25 武汉市聚芯微电子有限责任公司 Proximity detection circuit and proximity sensor

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