JP5859364B2

JP5859364B2 - Received light intensity calculation device and position detection device

Info

Publication number: JP5859364B2
Application number: JP2012081576A
Authority: JP
Inventors: エジソンゴメスカマルゴ
Original assignee: Asahi Kasei EMD Corp
Current assignee: Asahi Kasei Microdevices Corp
Priority date: 2012-03-30
Filing date: 2012-03-30
Publication date: 2016-02-10
Anticipated expiration: 2032-03-30
Also published as: JP2013210322A

Description

本発明は、人体の指・手・顔からの位置及び動きを検出するデバイスに関する。 The present invention relates to a device for detecting the position and movement of a human body from a finger, hand, or face.

人体の体温は３６度付近であり、このような体温を持つ人体の皮膚から放射される輻射が２〜３０μｍという広い範囲のスペクトラムの光を放出する。この光を検出することによって、人体の位置若しくは動きを検出することができる。 The body temperature of the human body is around 36 degrees, and the radiation radiated from the skin of the human body having such a body temperature emits light in a wide range of 2 to 30 μm. By detecting this light, the position or movement of the human body can be detected.

上記の２〜３０μｍの波長帯で動作するセンサとしては、焦電センサやサーモパイルに代表される熱型光センサが挙げられる。これらのセンサの高感度化を実現するために、受光部と光の入射窓部との間に中空領域を設ける必要があり、そのためセンサの小型化は制限されている。 Examples of the sensor that operates in the wavelength band of 2 to 30 μm include a pyroelectric sensor and a thermal optical sensor represented by a thermopile. In order to realize high sensitivity of these sensors, it is necessary to provide a hollow region between the light receiving part and the light incident window part, and thus downsizing of the sensor is limited.

サーモパイルや焦電センサの中空構造による制限を解決するため、フォトダイオードを用いた量子型（光起電力型）赤外線センサが期待されている。量子型赤外線センサは、多数キャリアが電子であるｎ型半導体と多数キャリアがホールであるｐ型半導体とが接合されて構成されるＰＮ接合又はｐ型半導体とｎ型半導体との間に真正半導体を有するＰＩＮ接合のフォトダイオード構造を有している。量子型赤外線センサでは、赤外線の光子によりＰＮ接合又はＰＩＮ接合に存在する空乏層内で発生した電子ホール対が価電子帯及び導電帯の電界傾斜に従って空間的に分離蓄積された結果、ｐ型半導体はプラス側に帯電し、ｎ型半導体はマイナス側に帯電して、その間に起電力が生ずる。この起電力は開放電圧と呼ばれ、非ＰＮ接合もしくはＰＩＮ接合部の抵抗より大きな外部抵抗（高入力インピーダンスの回路やアンプでもよい）を使用することにより電圧として読み出すことも、また量子型赤外線センサ外部で短絡することにより電流として読み出すことも可能である。 In order to solve the limitation due to the hollow structure of thermopile and pyroelectric sensor, a quantum type (photovoltaic type) infrared sensor using a photodiode is expected. A quantum infrared sensor is a PN junction formed by joining an n-type semiconductor whose majority carrier is an electron and a p-type semiconductor whose majority carrier is a hole, or a genuine semiconductor between a p-type semiconductor and an n-type semiconductor. It has a PIN junction photodiode structure. In a quantum infrared sensor, a pair of electron holes generated in a depletion layer existing in a PN junction or a PIN junction by infrared photons is spatially separated and accumulated according to the electric field gradient of a valence band and a conduction band. Is charged to the plus side, and the n-type semiconductor is charged to the minus side, and an electromotive force is generated therebetween. This electromotive force is called an open-circuit voltage, and can be read out as a voltage by using an external resistance (a circuit or amplifier having a high input impedance) that is larger than the resistance of the non-PN junction or PIN junction. It is also possible to read out as a current by short-circuiting outside.

このような量子型赤外線センサを室温で人感センサとして用いる場合に問題となるのが、人間が活動する環境温度と人間の体温との差が小いため、出力信号が小さく、また、環境から輻射される揺らいだ赤外線がセンサに検出され、ノイズとなるため、十分なＳ／Ｎ比を確保することが困難であるという点である。そのため、通常の量子型赤外線センサの場合、受光部を外界の温度に対して冷却することにより出力信号が大きくなり、Ｓ／Ｎ比が大きくなる。この量子型赤外線センサの代表的なものとして、ＩｎＳｂを半導体積層部として用いたセンサやＭＣＴ（ＭｅｒｃｕｒｙＣａｄｍｉｕｍＴｅｌｕｒｉｄｅ）などが挙げられる。 When such a quantum infrared sensor is used as a human sensor at room temperature, the difference between the environmental temperature at which a human is active and the human body temperature is small, so the output signal is small, and radiation from the environment is also a problem. Since the swaying infrared rays are detected by the sensor and become noise, it is difficult to ensure a sufficient S / N ratio. Therefore, in the case of a normal quantum infrared sensor, the output signal is increased by cooling the light receiving unit with respect to the external temperature, and the S / N ratio is increased. Typical examples of the quantum infrared sensor include a sensor using InSb as a semiconductor laminated portion, MCT (Mercury Cadmium Telluride), and the like.

上記化合物半導体を用いる量子型赤外線センサにおいては、特許文献１に示されるように、非冷却で小型化を行いながら、人感センサとしてのＳ／Ｎ比を向上させるために、平面状に半導体センサを配置し、各センサの出力電圧を多段直列接続して取り出す方式が提案されている。 In the quantum infrared sensor using the compound semiconductor, as shown in Patent Document 1, in order to improve the S / N ratio as a human sensor while reducing the size without cooling, the semiconductor sensor is planarly formed. Has been proposed, and the output voltage of each sensor is taken out in a multistage series connection.

上述の光センサの応用例として、被検出体から輻射された赤外線の受光強度の演算や、被検出体の動作や、センサまでの距離を演算する受光強度演算デバイスが期待されている。そのような受光強度演算デバイスを実現するためには、複数の光センサからの出力の差分値や加算値を用いる方法が考えられる。 As an application example of the above-described optical sensor, a received light intensity calculation device that calculates the received light intensity of infrared rays radiated from the detected object, the operation of the detected object, and the distance to the sensor is expected. In order to realize such a light reception intensity calculation device, a method using a difference value or an addition value of outputs from a plurality of optical sensors can be considered.

複数の出力からの出力の差分値を用いれば、被検出体から輻射された赤外線の受光強度や、被検出体の動作を検出することが可能であり、加算値を用いれば、人体の接近も検出できる。 By using the difference value of outputs from multiple outputs, it is possible to detect the received light intensity of infrared rays radiated from the detected object and the operation of the detected object. It can be detected.

図１０は、光センサからの出力から、出力の差分値や和を演算する従来の受光強度演算デバイスの構成を示す。図１０には、受光部ｄＡ〜ｄＤを含む光センサ部１０１０と、光センサ１０１０に接続され、電流／電圧（Ｉ−Ｖ）変換アンプ４ａ〜４ｄを含むＩ−Ｖ変換手段１０２０と、Ｉ−Ｖ変換手段１０２０に接続され、第１の減算回路５及び第２の減算回路６を含む差分演算手段１０３０と、Ｉ−Ｖ変換手段１０２０に接続され、Ｉ−Ｖ変換アンプ４ａ〜４ｄからの出力信号を加算する加算回路９からなる加算演算手段１０４０とを備えた従来の受光強度演算デバイス１０００が示されている。 FIG. 10 shows a configuration of a conventional received light intensity calculation device that calculates a difference value or a sum of outputs from an output from an optical sensor. 10 includes an optical sensor unit 1010 including light receiving units dA to dD, an IV conversion unit 1020 connected to the optical sensor 1010 and including current / voltage (IV) conversion amplifiers 4a to 4d, and I− The difference calculation means 1030 including the first subtraction circuit 5 and the second subtraction circuit 6 connected to the V conversion means 1020 and the output from the IV conversion amplifiers 4a to 4d connected to the IV conversion means 1020. A conventional received light intensity calculation device 1000 including an addition calculation means 1040 including an addition circuit 9 for adding signals is shown.

光センサ部１０１０において、受光部ｄＡ〜ｄＤの一端はそれぞれの接続端子３ａ１〜３ｄ１を介して各Ｉ−Ｖ変換アンプ４ａ〜４ｄの一方の入力端子に接続され、受光部ｄＡ〜ｄＤの他端はそれぞれの接続端子３ａ２〜３ｄ２を介して接地されている。Ｉ−Ｖ変換手段１０２０において、Ｉ−Ｖ変換アンプ４ａ〜４ｄの他方の入力端子は接地され、Ｉ−Ｖ変換アンプ４ａの出力端子は第１の減算手段５及び加算演算手段１０４０に接続され、Ｉ−Ｖ変換アンプ４ｂの出力端子は第２の減算手段６及び加算演算手段１０４０に接続され、Ｉ−Ｖ変換アンプ４ｃの出力端子は第１の減算手段５及び加算演算手段１０４０に接続され、Ｉ−Ｖ変換アンプ４ｄの出力端子は第２の減算手段６及び加算演算手段１０４０に接続されている。加算演算手段１０４０は加算回路９によって４つの信号（Ｉ−Ｖ変換アンプ４ａ〜４ｄの各出力）を加算する。 In the optical sensor unit 1010, one end of the light receiving units dA to dD is connected to one input terminal of each of the IV conversion amplifiers 4a to 4d via the respective connection terminals 3a1 to 3d1, and the other end of the light receiving units dA to dD. Are grounded via respective connection terminals 3a2 to 3d2. In the IV conversion means 1020, the other input terminals of the IV conversion amplifiers 4a to 4d are grounded, and the output terminal of the IV conversion amplifier 4a is connected to the first subtraction means 5 and the addition operation means 1040. The output terminal of the IV conversion amplifier 4b is connected to the second subtraction means 6 and the addition calculation means 1040, and the output terminal of the IV conversion amplifier 4c is connected to the first subtraction means 5 and the addition calculation means 1040. The output terminal of the IV conversion amplifier 4d is connected to the second subtracting means 6 and the addition calculating means 1040. The adding operation means 1040 adds four signals (outputs of the IV conversion amplifiers 4a to 4d) by the adding circuit 9.

光センサ部１０１０において、受光部ｄＡ〜ｄＤは、被検出体から輻射された光を入射し、入射した光の光強度に応じた電流をそれぞれの接続端子３ａ１〜３ｄ１を介して各Ｉ−Ｖ変換アンプ４ａ〜４ｄに出力する。Ｉ−Ｖ変換手段１０２０において、Ｉ−Ｖ変換アンプ４ａ〜４ｄは、それぞれ入力した電流を電圧に変換して差分演算手段１０３０及び加算演算手段１０４０にそれぞれ出力する。差分演算手段１０３０において、第１の減算回路５はＩ−Ｖ変換アンプ４ａ及び４ｃからのそれぞれの出力の差分を演算して減算信号を出力し、第２の減算回路６はＩ−Ｖ変換アンプ４ｂ及び４ｄからのそれぞれの出力の差分を演算して減算信号を出力する。加算演算手段１０４０は、４つの信号（Ｉ−Ｖ変換アンプ４ａ〜４ｄの各出力）の加算演算結果を出力する。 In the optical sensor unit 1010, the light receiving units dA to dD receive light radiated from the detection target, and currents corresponding to the light intensity of the incident light are applied to the IVs through the connection terminals 3a1 to 3d1. Output to the conversion amplifiers 4a to 4d. In the IV conversion means 1020, the IV conversion amplifiers 4a to 4d convert the input currents to voltages and output the voltages to the difference calculation means 1030 and the addition calculation means 1040, respectively. In the difference calculation means 1030, the first subtraction circuit 5 calculates the difference between the outputs from the IV conversion amplifiers 4a and 4c and outputs a subtraction signal, and the second subtraction circuit 6 is the IV conversion amplifier. The difference between the outputs from 4b and 4d is calculated and a subtraction signal is output. The addition calculation means 1040 outputs the addition calculation result of the four signals (outputs of the IV conversion amplifiers 4a to 4d).

国際公開第２００５−２７２２８号パンフレットInternational Publication No. 2005-27228 Pamphlet

しかしながら、図１０に示される構成では、各受光部ｄＡ〜ｄＤからの出力を得るために、接続端子（パッド）が受光部の個数の２倍必要になり、装置が大型化してしまう。また、Ｉ−Ｖ変換アンプから見た信号源（受光部１個分）のインピーダンスが低いので、受光部の内部抵抗が小さい場合、Ｉ−Ｖ変換アンプの入力換算ノイズが増幅され、Ｉ−Ｖ変換アンプ出力のノイズレベルが高くなるという問題がある。 However, in the configuration shown in FIG. 10, in order to obtain outputs from each of the light receiving parts dA to dD, the number of connection terminals (pads) is twice as large as the number of light receiving parts, and the apparatus becomes large. Further, since the impedance of the signal source (one light receiving unit) viewed from the IV conversion amplifier is low, when the internal resistance of the light receiving unit is small, the input conversion noise of the IV conversion amplifier is amplified, and the IV There is a problem that the noise level of the output of the conversion amplifier becomes high.

また、図１０に示される回路においては、ノイズレベルを抑えつつ、複数の受光部からの出力の差分値及び加算値を求めるためには、スイッチング素子を使用する必要があるが、スイッチング素子を用いる場合、それを制御するための装置も必要となり、装置の大型化や消費電力の増大を招来してしまう。 Further, in the circuit shown in FIG. 10, in order to obtain the difference value and the added value of the outputs from the plurality of light receiving units while suppressing the noise level, it is necessary to use the switching element, but the switching element is used. In this case, a device for controlling it is also required, which leads to an increase in the size of the device and an increase in power consumption.

本発明は、これらの問題点に鑑みてなされたものであり、その目的は、接続端子の数を抑え、且つ、スイッチング素子を用いずに、各受光部からの出力の差分値及び加算値を同時に、且つ、高Ｓ／Ｎ比で演算することが可能な受光強度演算デバイスを提供するである。 The present invention has been made in view of these problems, and an object of the present invention is to suppress the number of connection terminals and to calculate the difference value and the addition value of outputs from each light receiving unit without using a switching element. At the same time, a received light intensity calculation device capable of calculating with a high S / N ratio is provided.

本発明の請求項１に記載の受光強度演算デバイスは、一端が第１の接続端子に接続された第１の受光部と、一端が第２の接続端子に接続された第２の受光部と、一端が第３の接続端子に接続された第３の受光部と、一端が第４の接続端子に接続された第４の受光部とを備えた光センサ部であって、前記第１の受光部ないし前記第４の受光部の他端は、共通の配線によって接続される、光センサ部と、スイッチング素子を介さずに前記第１の接続端子及び前記第３の接続端子と接続され、前記第１の受光部及び前記第３の受光部からの出力の差分を演算して第１の差分信号を出力する第１の差分演算部と、スイッチング素子を介さずに前記第２の接続端子及び前記第４の接続端子と接続され、前記第２の受光部及び前記第４の受光部からの出力の差分を演算して第２の差分信号を出力する第２の差分演算部と、スイッチング素子を介さずに前記第１の接続端子及び前記第２の接続端子と接続され、前記第１の受光部及び前記第２の受光部からの出力の差分を演算して第３の差分信号を出力する第３の差分演算部と、スイッチング素子を介さずに前記第３の接続端子及び前記第４の接続端子と接続され、前記第３の受光部及び前記第４の受光部からの出力の差分を演算して第４の差分信号を出力する第４の差分演算部と、前記第３の差分演算部及び前記第４の差分演算部に接続され、前記第３の差分信号及び前記第４の差分信号の和を演算して加算信号を出力する加算演算部とを備えることを特徴とする。 The received light intensity calculation device according to claim 1 of the present invention includes a first light receiving unit having one end connected to the first connection terminal, and a second light receiving unit having one end connected to the second connection terminal. , An optical sensor unit including a third light receiving unit having one end connected to the third connection terminal and a fourth light receiving unit having one end connected to the fourth connection terminal, The other end of the light receiving unit or the fourth light receiving unit is connected to the first sensor terminal and the third connector terminal without a switching element via the optical sensor unit connected by a common wiring, A first difference calculation unit that calculates a difference between outputs from the first light receiving unit and the third light receiving unit and outputs a first difference signal; and the second connection terminal without a switching element. And the output from the second light receiving unit and the fourth light receiving unit connected to the fourth connection terminal. A second difference calculation unit that calculates a difference and outputs a second difference signal; and the first light receiving unit that is connected to the first connection terminal and the second connection terminal without using a switching element. And a third difference calculation unit that calculates a difference between outputs from the second light receiving unit and outputs a third difference signal, and the third connection terminal and the fourth connection without using a switching element. A fourth difference calculation unit connected to a terminal and calculating a difference between outputs from the third light receiving unit and the fourth light receiving unit and outputting a fourth difference signal; and the third difference calculation unit. And an addition calculation unit connected to the fourth difference calculation unit and calculating a sum of the third difference signal and the fourth difference signal and outputting an addition signal.

本発明の請求項２に記載の受光強度演算デバイスは、本発明の請求項１に記載の受光強度演算デバイスであって、前記第１の受光部ないし前記第４の受光部はそれぞれ複数のフォトダイオードを含み、前記第１の受光部のカソードは、前記第２の受光部及び前記第４の受光部のアノードと、前記第３の受光部のカソードとに電気的に接続され、前記第１の受光部のアノードは、前記第１の接続端子及び第１の電流−電圧変換アンプを介して前記第１の差分演算部及び前記第３の差分演算部に接続され、前記第２の受光部のカソードは、前記第２の接続端子及び第２の電流−電圧変換アンプを介して前記第２の差分演算部及び前記第３の差分演算部に接続され、前記第３の受光部のアノードは、前記第３の接続端子及び第３の電流−電圧変換アンプを介して前記第１の差分演算部及び前記第４の差分演算部に接続され、前記第４の受光部のカソードは、前記第４の接続端子及び第４の電流−電圧変換アンプを介して前記第２の差分演算部及び前記第４の差分演算部に接続されることを特徴とする。 The light-receiving intensity calculation device according to claim 2 of the present invention is the light-receiving intensity calculation device according to claim 1 of the present invention, wherein each of the first light receiving unit to the fourth light receiving unit includes a plurality of photos. A cathode of the first light receiving unit is electrically connected to an anode of the second light receiving unit and the fourth light receiving unit, and a cathode of the third light receiving unit; The anode of the light receiving unit is connected to the first difference calculating unit and the third difference calculating unit via the first connection terminal and the first current-voltage conversion amplifier, and the second light receiving unit. Is connected to the second difference calculation unit and the third difference calculation unit via the second connection terminal and the second current-voltage conversion amplifier, and the anode of the third light receiving unit is , The third connection terminal and the third current-voltage conversion circuit. The cathode of the fourth light receiving unit is connected to the first difference calculation unit and the fourth difference calculation unit via the fourth connection terminal and the fourth current-voltage conversion amplifier. Connected to the second difference calculation unit and the fourth difference calculation unit.

本発明の請求項３に記載の受光強度演算デバイスは、本発明の請求項１又は２に記載の受光強度演算デバイスであって、前記第１の受光部ないし前記第４の受光部は、互いに直列接続された複数の受光素子を含むことを特徴とする。 The received light intensity calculation device according to claim 3 of the present invention is the received light intensity calculation device according to claim 1 or 2 of the present invention, wherein the first light receiving part to the fourth light receiving part are mutually connected. It includes a plurality of light receiving elements connected in series.

本発明の請求項４に記載の受光強度演算デバイスは、本発明の請求項１から３の何れか一項に記載の受光強度演算デバイスであって、前記第１の受光部ないし前記第４の受光部は、インジウムおよび／またはアンチモンを含み、かつ、ＰＮ接合またはＰＩＮ接合のフォトダイオード構造を有する半導体積層部を有することを特徴とする。 A light reception intensity calculation device according to a fourth aspect of the present invention is the light reception intensity calculation device according to any one of the first to third aspects of the present invention, wherein the first light receiving unit to the fourth light receiving unit are provided. The light receiving portion includes a semiconductor multilayer portion that includes indium and / or antimony and has a photodiode structure of a PN junction or a PIN junction.

本発明によれば、出力端子の数を抑え、且つ、スイッチング素子を用いずに、各受光部からの出力の差分値及び加算値を高Ｓ／Ｎ比で演算することが可能な受光強度演算デバイスを提供することが可能になる。 According to the present invention, the received light intensity calculation that can calculate the difference value and the added value of the output from each light receiving unit with a high S / N ratio without reducing the number of output terminals and using a switching element. It becomes possible to provide a device.

本発明に係る受光強度演算デバイス１００を示す図である。It is a figure which shows the light reception intensity | strength calculating device 100 which concerns on this invention. 本発明に係る受光強度演算デバイス１００の具体的な回路図を示す。A specific circuit diagram of the received light intensity calculation device 100 according to the present invention is shown. 本発明に係る光センサ部１１０の構成の一例を示す模式図である。It is a schematic diagram which shows an example of a structure of the optical sensor part 110 which concerns on this invention. 本発明に係る受光素子１の断面図である。It is sectional drawing of the light receiving element 1 which concerns on this invention. 多数の受光素子１を直列に接続して受光部とする場合の断面図を示す。Sectional drawing in case many light receiving elements 1 are connected in series and it is set as a light-receiving part is shown. 本発明に係る受光素子１の等価回路図を示す。The equivalent circuit schematic of the light receiving element 1 which concerns on this invention is shown. 受光素子１の個数ＮとＩ−Ｖ変換アンプの出力のノイズとの関係を示す図である。It is a figure which shows the relationship between the number N of the light receiving elements 1, and the noise of the output of IV conversion amplifier. 本発明に係る受光強度演算デバイス１００を用いた位置検出デバイスの実施例を示す図である。It is a figure which shows the Example of the position detection device using the light reception intensity | strength calculation device 100 which concerns on this invention. 実施例に係る位置検出デバイス３００の出力波形を示す図である。It is a figure which shows the output waveform of the position detection device 300 which concerns on an Example. 従来の受光強度演算デバイス１０００を示す図である。It is a figure which shows the conventional light reception intensity | strength calculating device 1000. FIG.

図１は、本発明に係る受光強度演算デバイス１００を示す。図１には、受光部ｄＡ〜ｄＤを含む光センサ部１１０と、光センサ１１０に接続され、Ｉ−Ｖ変換アンプ４ａ〜４ｄを含むＩ−Ｖ変換手段１２０と、Ｉ−Ｖ変換手段１２０に接続され、第１の減算回路５及び第２の減算回路６を含む差分演算手段１３０と、Ｉ−Ｖ変換手段１２０に接続され、第３の減算回路７、第４の減算回路８及び加算回路９を含む加算演算手段１４０とを備えた本発明に係る受光強度演算デバイス１００が示されている。 FIG. 1 shows a received light intensity calculation device 100 according to the present invention. 1 includes an optical sensor unit 110 including light receiving units dA to dD, an IV conversion unit 120 connected to the optical sensor 110 and including IV conversion amplifiers 4a to 4d, and an IV conversion unit 120. The third subtracting circuit 7, the fourth subtracting circuit 8, and the adding circuit connected to the difference calculating means 130 including the first subtracting circuit 5 and the second subtracting circuit 6 and the IV converting means 120. 9 shows a received light intensity calculation device 100 according to the present invention including an addition calculation means 140 including 9.

光センサ部１１０において、受光部ｄＡ〜ｄＤの一端はそれぞれの接続端子３ａ〜３ｄを介して各Ｉ−Ｖ変換アンプ４ａ〜４ｄの一方の入力端子に接続され、受光部ｄＡ〜ｄＤの他端は共通配線部２を介して互いに接続されている（場合によって定まった電圧を供給する電圧源に接続する）。Ｉ−Ｖ変換手段１２０において、Ｉ−Ｖ変換アンプ４ａ〜４ｄの他方の入力端子は接地され、Ｉ−Ｖ変換アンプ４ａの出力端子は第１の減算手段５及び第３の減算手段７に接続され、Ｉ−Ｖ変換アンプ４ｂの出力端子は第２の減算手段６及び第３の減算手段７に接続され、Ｉ−Ｖ変換アンプ４ｃの出力端子は第１の減算手段５及び第４の減算手段８に接続され、Ｉ−Ｖ変換アンプ４ｄの出力端子は第２の減算手段６及び第４の減算手段８に接続されている。加算演算手段１４０において、第３の減算手段７及び第４の減算手段８のそれぞれの出力端子は加算回路９に接続されている。 In the optical sensor unit 110, one ends of the light receiving units dA to dD are connected to one input terminal of each of the IV conversion amplifiers 4a to 4d via the connection terminals 3a to 3d, and the other ends of the light receiving units dA to dD. Are connected to each other via a common wiring section 2 (connected to a voltage source that supplies a voltage determined in some cases). In the IV conversion means 120, the other input terminals of the IV conversion amplifiers 4a to 4d are grounded, and the output terminal of the IV conversion amplifier 4a is connected to the first subtraction means 5 and the third subtraction means 7. The output terminal of the IV conversion amplifier 4b is connected to the second subtraction means 6 and the third subtraction means 7, and the output terminal of the IV conversion amplifier 4c is the first subtraction means 5 and the fourth subtraction. The output terminal of the IV conversion amplifier 4 d is connected to the second subtracting means 6 and the fourth subtracting means 8. In the addition operation unit 140, the output terminals of the third subtraction unit 7 and the fourth subtraction unit 8 are connected to the addition circuit 9.

差分演算手段１３０において、第１の減算回路５はＩ−Ｖ変換アンプ４ａ及び４ｃからのそれぞれの出力の差分を演算して第１の減算信号を出力し、第２の減算回路６はＩ−Ｖ変換アンプ４ｂ及び４ｄからのそれぞれの出力の差分を演算して第２の減算信号を出力する。加算演算手段１４０において、第３の減算回路７はＩ−Ｖ変換アンプ４ａ及び４ｂからのそれぞれの出力の差分を演算して第３の減算信号を出力し、第４の減算回路８はＩ−Ｖ変換アンプ４ｃ及び４ｄからのそれぞれの出力の差分を演算して第４の減算信号を出力し、加算回路９は第３の減算回路７及び第４の減算回路８からそれぞれ出力された第３の減算信号及び第４の減算信号の和を演算して加算信号を出力する。 In the difference calculation means 130, the first subtraction circuit 5 calculates the difference between the outputs from the IV conversion amplifiers 4a and 4c and outputs a first subtraction signal, and the second subtraction circuit 6 outputs the I−V. The difference between the outputs from the V conversion amplifiers 4b and 4d is calculated to output a second subtraction signal. In the addition operation means 140, the third subtraction circuit 7 calculates the difference between the outputs from the IV conversion amplifiers 4a and 4b and outputs a third subtraction signal, and the fourth subtraction circuit 8 outputs I− The difference between the outputs from the V conversion amplifiers 4c and 4d is calculated and a fourth subtraction signal is output, and the adder circuit 9 outputs the third subtraction circuit 7 and the fourth subtraction circuit 8 respectively. The sum of the subtracted signal and the fourth subtracted signal is calculated and an added signal is output.

図２は、図１に示される受光強度演算デバイス１００における、Ｉ−Ｖ変換手段１２０、差分演算部１３０及び加算演算部１４０のより具体的な回路図を示す。本発明に係る受光強度演算デバイス１００は、対角配置に設置された２つの受光部ｄＡ及びｄＣ、ｄＢ及びｄＤの２組それぞれにおける出力の差分信号と全受光部ｄＡ〜ｄＤの総和の信号とを同時に、出力することができるため、高速の信号処理の用途では適している。以下、受光強度演算デバイス１００における演算方法を説明する。ｉｐ_Aは接続端子３ａに接続された受光部ｄＡで生じる短絡光電流とし、ｉｐ_Bは接続端子３ｂに接続された受光部ｄＢで生じる短絡光電流とし、ｉｐ_Cは接続端子３ｃに接続された受光部ｄＣで生じる短絡光電流とし、ｉｐ_Dは接続端子３ｄに接続された受光部ｄＤで生じる短絡光電流とし、Ｉ−Ｖ変換アンプ４ａ〜４ｄの変換抵抗をＲｃとした場合、それぞれのＩ−Ｖ変換アンプ４ａ〜４ｄの出力信号Ｖ１〜Ｖ４は、以下の式（１）〜（４）のように示される。 FIG. 2 shows a more specific circuit diagram of the IV conversion means 120, the difference calculation unit 130, and the addition calculation unit 140 in the received light intensity calculation device 100 shown in FIG. The received light intensity calculation device 100 according to the present invention includes an output difference signal in each of two sets of two light receiving parts dA and dC, dB and dD installed in a diagonal arrangement, and a sum signal of all the light receiving parts dA to dD. Are suitable for high-speed signal processing. Hereinafter, a calculation method in the received light intensity calculation device 100 will be described. ip _A is a short-circuit photocurrent generated in the light-receiving unit dA connected to the connection terminal 3a, ip _B is a short-circuit photocurrent generated in the light-receiving unit dB connected to the connection terminal 3b, and ip _C is connected to the connection terminal 3c. When the short-circuit photocurrent generated in the light-receiving unit dC, ip _D is the short-circuit photocurrent generated in the light-receiving unit dD connected to the connection terminal 3d, and the conversion resistance of the IV conversion amplifiers 4a to 4d is Rc, each I The output signals V1 to V4 of the −V conversion amplifiers 4a to 4d are expressed by the following equations (1) to (4).

Ｖ１＝−Ｒｃ[３／４Ｉｐ_A−１／４(−Ｉｐ_B＋Ｉｐ_C−Ｉｐ_D)] （１）
Ｖ２＝−Ｒｃ[−３／４Ｉｐ_B−１／４(Ｉｐ_C−Ｉｐ_D＋Ｉｐ_A)] （２）
Ｖ３＝−Ｒｃ[３／４Ｉｐ_C−１／４(−Ｉｐ_D＋Ｉｐ_A−Ｉｐ_B)] （３）
Ｖ４＝−Ｒｃ[−３／４ｉｐ_D−１／４(Ｉｐ_A−Ｉｐ_B＋Ｉｐ_C)] （４） V1 = −Rc [3 / 4Ip _A −1/4 (−Ip _B + Ip _C −Ip _D )] (1)
V2 = −Rc [−3 / 4Ip _B −1/4 (Ip _C −Ip _D + Ip _A )] (2)
V3 = −Rc [3 / 4Ip _C −1/4 (−Ip _D + Ip _A −Ip _B )] (3)
V4 = −Rc [−3 / 4ip _D −1/4 (Ip _A −Ip _B + Ip _C )] (4)

更に、図２に示すように、これらの出力信号Ｖ１〜Ｖ４はＩ−Ｖ変換アンプ４ａ〜４ｄの出力端子に接続された差分演算手段１３０及び加算演算手段１４０に入力される。差分演算手段１３０においては、下記の式（５）、（６）による演算がなされることにより、第１の減算回路５及び第２の減算回路６から第１の減算信号ＶΔ１及び第２の減算信号ＶΔ２が出力される。ここで、ｋ１〜ｋ３は、Ｒｃ、第１ないし第４の減算回路５〜８及び加算回路９に利用されている抵抗器の抵抗値で決まる係数を表す。
ＶΔ１＝−ｋ１[Ｖ１−Ｖ３]
＝−ｋ１[３／４(Ｉｐ_C−Ｉｐ_A)−１／４(Ｉｐ_A−Ｉｐ_C)] （５）
＝ｋ１(Ｉｐ_A−Ｉｐ_C)
ＶΔ２＝−ｋ２[Ｖ２−Ｖ４]
＝−ｋ２[３／４(−Ｉｐ_D＋Ｉｐ_B)−１／４(−Ｉｐ_B＋Ｉｐ_D)]
＝ｋ２(Ｉｐ_D−Ｉｐ_B) （６） Further, as shown in FIG. 2, these output signals V1 to V4 are input to the difference calculation means 130 and the addition calculation means 140 connected to the output terminals of the IV conversion amplifiers 4a to 4d. In the difference calculation means 130, the first subtraction signal VΔ1 and the second subtraction are obtained from the first subtraction circuit 5 and the second subtraction circuit 6 by performing calculations according to the following equations (5) and (6). Signal VΔ2 is output. Here, k1 to k3 represent coefficients determined by Rc, the resistance values of the resistors used in the first to fourth subtraction circuits 5 to 8 and the addition circuit 9.
VΔ1 = −k1 [V1−V3]
= −k1 [3/4 (Ip _C −Ip _A ) −1/4 (Ip _A −Ip _C )] (5)
= K1 (Ip _A -Ip _C )
VΔ2 = −k2 [V2−V4]
= −k2 [3/4 (−Ip _D + Ip _B ) −1/4 (−Ip _B + Ip _D )]
= K2 (Ip _D -Ip _B ) (6)

加算演算手段１４０においては、第３の減算回路７及び第４の減算回路８から出力される第３の減算信号ＶΔ３＝（Ｖ１−Ｖ２)及び第４の減算信号ＶΔ４＝(Ｖ３−Ｖ４)を用いて、下記の式（７）による演算がなされることにより、加算回路９から加算信号ＶΣが出力される。
ＶΣ＝−ｋ３[（Ｖ１−Ｖ２)＋(Ｖ３−Ｖ４)]
＝ｋ３[Ｉｐ_A＋Ｉｐ_B＋Ｉｐ_C＋Ｉｐ_D] （７） In the addition operation means 140, the third subtraction signal VΔ3 = (V1−V2) and the fourth subtraction signal VΔ4 = (V3−V4) output from the third subtraction circuit 7 and the fourth subtraction circuit 8 are used. In addition, the addition signal VΣ is output from the adder circuit 9 by performing the calculation according to the following equation (7).
VΣ = −k3 [(V1−V2) + (V3−V4)]
= K3 [Ip _A + Ip _B + Ip _C + Ip _D ] (7)

以上により、式（５）〜式（７）から、受光部の数と接続端子の数が同じ光センサ部１１０を用いた小型の受光強度演算デバイス１００によって、スイッチング素子を用いずに、受光部ｄＡ〜ｄＤからの出力電流の差分信号及び加算信号を演算することが可能な受光強度演算デバイスが実現できることが理解される。 As described above, from the equations (5) to (7), the light receiving unit without using the switching element can be obtained by the small light receiving intensity calculation device 100 using the optical sensor unit 110 having the same number of light receiving units and the same number of connection terminals. It is understood that a received light intensity calculation device capable of calculating a difference signal and an addition signal of output currents from dA to dD can be realized.

初段のＩ−Ｖ変換アンプ４ａ〜４ｄには低ノイズのアンプが適している。具体的には、入力のオフセット揺らぎを抑制するオートゼロアンプを利用すると良い。本発明では、初段のＩ−Ｖ変換アンプ４ａ〜４ｄで高いＳ／Ｎ比が実現できれば、後段の演算器５〜９ではオートゼロアンプを利用する必要はなく、一般的なＯＰアンプを利用してもよい。こうすることによって、小型の集積回路が実現できる。 Low noise amplifiers are suitable for the first-stage IV conversion amplifiers 4a to 4d. Specifically, an auto-zero amplifier that suppresses input offset fluctuations may be used. In the present invention, if a high S / N ratio can be realized by the first-stage IV conversion amplifiers 4a to 4d, it is not necessary to use the auto-zero amplifier in the subsequent arithmetic units 5 to 9, and a general OP amplifier is used. Also good. In this way, a small integrated circuit can be realized.

図３は、本発明に係る光センサ部１１０の構成の一例を示す模式図である。図３に示される光センサ部１１０は、基板１０上に、受光部ｄＡに配線層６０を介して接続された接続端子３ａと、受光部ｄＡに配線層６０を介して接続された接続端子３ａと、受光部ｄＢに配線層６０を介して接続された接続端子３ｂと、受光部ｄＣに配線層６０を介して接続された接続端子３ｃと、受光部ｄＤに配線層６０を介して接続された接続端子３ｄとを備える。受光部ｄＡ〜ｄＤの各々は、配線層６０からなる共通配線部２を介して互いに接続されている。受光部ｄＡ〜ｄＤは、接続端子３ａ〜３ｄを囲むようにＬ字型に構成されている。 FIG. 3 is a schematic diagram showing an example of the configuration of the optical sensor unit 110 according to the present invention. 3 includes a connection terminal 3a connected to the light receiving part dA via the wiring layer 60 on the substrate 10, and a connection terminal 3a connected to the light receiving part dA via the wiring layer 60. A connection terminal 3b connected to the light receiving part dB via the wiring layer 60, a connection terminal 3c connected to the light receiving part dC via the wiring layer 60, and a connection terminal 3c connected to the light receiving part dD via the wiring layer 60. Connecting terminal 3d. Each of the light receiving portions dA to dD is connected to each other via the common wiring portion 2 including the wiring layer 60. The light receiving portions dA to dD are configured in an L shape so as to surround the connection terminals 3a to 3d.

図３に示される光センサ部１１０では、受光部ｄＡ〜ｄＤが光センサ部１１０の周囲に配置され、接続端子３ａ〜３ｄが光センサ部１１０の中央に配置されている。従って、図３に示される光センサ部１１０では、受光部ｄＡ〜ｄＤがそれぞれ離れて配置されているため、光源の動きに対して、より高感度に検出を行うことができる。 In the optical sensor unit 110 shown in FIG. 3, the light receiving units dA to dD are arranged around the optical sensor unit 110, and the connection terminals 3 a to 3 d are arranged in the center of the optical sensor unit 110. Therefore, in the optical sensor unit 110 shown in FIG. 3, since the light receiving units dA to dD are arranged apart from each other, it is possible to detect the movement of the light source with higher sensitivity.

図４は、本発明に係る受光部ｄＡ〜ｄＤで用いられる受光素子１の構成の一例を示す断面図である。図３に示されるように、受光素子１は、基板１０と、基板１０上に形成された半導体積層部８０と、半導体積層部８０を覆うように基板１０及び半導体積層部８０上に形成された絶縁層５０と、絶縁層５０及び半導体積層部８０上に形成された配線層６０と、表面全体を覆う保護層７０と備える。半導体積層部８０は、基板１０上に、ｎ型ドーピングされたｎ型半導体層２０、ノンドープあるいはｐ型ドーピングされた光吸収層３０、バリア層３１、及びｐ型ドーピングされたとしてｐ型半導体層４０が順次積層されて構成されたＰＮ接合又はＰＩＮ接合のフォトダイオード構造部を含む。ｎ型半導体層２０上にはカソード（ｎ層電極）６１が形成されており、ｐ型半導体層４０上にはアノード（ｐ層電極）６２が形成されている。 FIG. 4 is a cross-sectional view showing an example of the configuration of the light receiving element 1 used in the light receiving portions dA to dD according to the present invention. As shown in FIG. 3, the light receiving element 1 is formed on the substrate 10, the semiconductor stacked unit 80 so as to cover the substrate 10, the semiconductor stacked unit 80 formed on the substrate 10, and the semiconductor stacked unit 80. An insulating layer 50, a wiring layer 60 formed on the insulating layer 50 and the semiconductor stacked portion 80, and a protective layer 70 covering the entire surface are provided. The semiconductor stacked unit 80 includes an n-type doped n-type semiconductor layer 20, a non-doped or p-type doped light absorbing layer 30, a barrier layer 31, and a p-type doped p-type semiconductor layer 40 on the substrate 10. Includes a photodiode structure part of a PN junction or a PIN junction configured by sequentially stacking layers. A cathode (n layer electrode) 61 is formed on the n-type semiconductor layer 20, and an anode (p layer electrode) 62 is formed on the p-type semiconductor layer 40.

被検出光としての赤外線が、基板１０上において半導体積層部８０が積層されている面と対抗する面から入射して（図４においては、基板１０から半導体積層部８０に向かう方向に光が進行する）、フォトダイオード構造部に入射すると、フォトダイオード構造部に存在する空乏層内で発生した電子ホール対が価電子帯と導電帯との電界傾斜に従って空間的に分離蓄積される。その結果、ｎ型半導体層２０はマイナス側に帯電し、ｐ型半導体層４０はプラス側に帯電することにより、その間に起電力が生ずる。この起電力は開放電圧と呼ばれ、高入力インピーダンスの信号処理回路（アンプなど）に接続した場合、電圧として読み出すことができ、また赤外線センサ外部で短絡して電流として読み出すことも可能である。 Infrared light as light to be detected is incident on a surface opposite to the surface on which the semiconductor multilayer portion 80 is laminated on the substrate 10 (in FIG. 4, light travels in a direction from the substrate 10 toward the semiconductor multilayer portion 80). When incident on the photodiode structure, electron hole pairs generated in the depletion layer existing in the photodiode structure are spatially separated and accumulated according to the electric field gradient between the valence band and the conduction band. As a result, the n-type semiconductor layer 20 is charged on the negative side and the p-type semiconductor layer 40 is charged on the positive side, thereby generating an electromotive force therebetween. This electromotive force is called an open-circuit voltage, and can be read as a voltage when connected to a signal processing circuit (such as an amplifier) having a high input impedance, or can be read as a current by short-circuiting outside the infrared sensor.

ｎ型半導体層２０は、高濃度のｎ型ドーピングを行うことで、バーシュタインモスシフトと呼ばれる効果により、ｎ型半導体層２０の赤外線吸収波長がより短波長側にシフトする。そのため、長波長の赤外線が吸収されなくなり、赤外線を効率よく透過させることができるようになる。 By performing high-concentration n-type doping, the n-type semiconductor layer 20 shifts the infrared absorption wavelength of the n-type semiconductor layer 20 to a shorter wavelength side due to an effect called a Barstein moss shift. Therefore, long-wavelength infrared rays are not absorbed, and infrared rays can be transmitted efficiently.

光吸収層３０は、赤外線を吸収して光電流Ｉｐを発生させるための光吸収層である。従って、ｎ型半導体層２０と光吸収層３０とが接する面積Ｓ１が赤外線の入射される受光面積となる。一般的に、受光素子１の光電流Ｉｐは、受光面積に比例して大きくなるため、ｎ型半導体層２０と光吸収層３０とが接する面積Ｓ１は大きい方が好ましい。また、光吸収層３０の体積が大きいほど吸収できる赤外線量は大きくなるので、光吸収層３０の体積は大きい方が好ましい。光吸収層３０の膜厚は、赤外線の吸収により発生した電子及び正孔のキャリアが拡散できる程度の膜厚に設定すると好ましい。 The light absorption layer 30 is a light absorption layer for absorbing infrared rays and generating a photocurrent Ip. Accordingly, the area S1 where the n-type semiconductor layer 20 and the light absorption layer 30 are in contact with each other is the light receiving area on which infrared rays are incident. Generally, since the photocurrent Ip of the light receiving element 1 increases in proportion to the light receiving area, it is preferable that the area S1 where the n-type semiconductor layer 20 and the light absorbing layer 30 are in contact with each other is large. Moreover, since the amount of infrared rays that can be absorbed increases as the volume of the light absorption layer 30 increases, the volume of the light absorption layer 30 is preferably larger. The film thickness of the light absorption layer 30 is preferably set to a film thickness that can diffuse electrons and holes generated by absorption of infrared rays.

一方、光吸収層３０で使用されるような、赤外線を吸収する半導体は、一般にバンドギャップの小さい半導体であり、このような半導体は、電子の移動度が正孔の移動度よりも非常に大きい。例えばＩｎＳｂの場合、電子の移動度が約８０，０００ｃｍ²／Ｖｓであるのに対して、正孔の移動度は数百ｃｍ²／Ｖｓである。従って、素子抵抗は電子の流れ易さによる影響が大きい。 On the other hand, a semiconductor that absorbs infrared rays as used in the light absorption layer 30 is generally a semiconductor having a small band gap, and such a semiconductor has an electron mobility much higher than a hole mobility. . For example, in the case of InSb, while the electron mobility is about 80,000cm ² / Vs, the mobility of holes is several hundred cm ² / Vs. Therefore, the element resistance is greatly influenced by the ease of electron flow.

光吸収層３０で赤外線吸収によって発生した電子は、ＰＮ又はＰＩＮ接合のフォトダイオード構造の部分で形成された電位差によって、光吸収層３０からｎ型半導体層２０側へと拡散し、光電流として取り出される。上述のように、バンドギャップの小さい半導体では正孔の移動度が非常に小さいことから、通常、ｎ型ドーピング層よりもｐ型ドーピング層の電気抵抗が高くなる。また、電気抵抗は、電流が流れる部分の面積に反比例する。従って、光吸収層３０とｐ型半導体層４０とが接する面積Ｓ３の大きさによって素子抵抗が決まり、素子抵抗が大きくなるためには面積Ｓ３が小さい方が好ましい。 Electrons generated by infrared absorption in the light absorption layer 30 are diffused from the light absorption layer 30 to the n-type semiconductor layer 20 side due to a potential difference formed in the photodiode structure portion of the PN or PIN junction, and taken out as a photocurrent. It is. As described above, since a hole mobility is very small in a semiconductor having a small band gap, the electric resistance of the p-type doping layer is usually higher than that of the n-type doping layer. Further, the electrical resistance is inversely proportional to the area of the portion where the current flows. Therefore, the element resistance is determined by the size of the area S3 where the light absorption layer 30 and the p-type semiconductor layer 40 are in contact, and the area S3 is preferably small in order to increase the element resistance.

また、波長が５μｍ以上の赤外線を吸収できる半導体のバンドギャップは０．２５ｅＶ以下と小さい。このようなバンドギャップの小さな半導体（光吸収層３０の材料のバンドギャップが０．１〜０．２５ｅＶの半導体）では、ｐ型半導体層４０側に、電子による拡散電流を抑制するため、バンドギャップが光吸収層３０よりも大きなバリア層３１を形成すると、暗電流のような素子の漏れ電流が小さくなり、素子抵抗を大きくすることができるため好ましい。 The band gap of a semiconductor that can absorb infrared rays having a wavelength of 5 μm or more is as small as 0.25 eV or less. In such a semiconductor with a small band gap (a semiconductor having a band gap of 0.1 to 0.25 eV of the material of the light absorption layer 30), in order to suppress the diffusion current due to electrons on the p-type semiconductor layer 40 side, However, it is preferable to form a barrier layer 31 larger than the light absorption layer 30 because the leakage current of the element such as dark current is reduced and the element resistance can be increased.

バリア層３１は、光吸収層３０及びｐ型半導体層４０よりもバンドギャップが大きくなるように構成される。バリア層３１を構成する材料としては、例えば、ＡｌＩｎＳｂが挙げられる。このバリア層を設けることによって、受光部の抵抗は大きくなるため、Ｉ／Ｖ変換アンプで信号の増幅をすると、高いＳ／Ｎ比が実現できるので、望ましい。 The barrier layer 31 is configured to have a larger band gap than the light absorption layer 30 and the p-type semiconductor layer 40. Examples of the material constituting the barrier layer 31 include AlInSb. Providing this barrier layer increases the resistance of the light receiving section, and therefore, it is desirable to amplify a signal with an I / V conversion amplifier because a high S / N ratio can be realized.

絶縁層５０は、基板１０上及び半導体積層部８０上に形成され、基板１０及び半導体積層部８０の表面を絶縁及び保護する。配線層６０は、一層若しくは多層の金属等で構成され、光吸収層３０で生成された光起電力をカソード６１とアノード６２を介して取り出すための層であり、絶縁層５０上に形成されている。保護層７０の上部空間は、樹脂モールド（図示せず）されていてもよい。絶縁層５０及び保護層７０の材料としては、例えば樹脂、酸化シリコン、窒化シリコンなどが挙げられるが、絶縁性の材料であればいずれの材料であってもよい。 The insulating layer 50 is formed on the substrate 10 and the semiconductor stacked unit 80, and insulates and protects the surfaces of the substrate 10 and the semiconductor stacked unit 80. The wiring layer 60 is composed of a single layer or multiple layers of metal or the like, and is a layer for taking out the photovoltaic power generated in the light absorption layer 30 through the cathode 61 and the anode 62, and is formed on the insulating layer 50. Yes. The upper space of the protective layer 70 may be resin molded (not shown). Examples of the material of the insulating layer 50 and the protective layer 70 include resin, silicon oxide, and silicon nitride, but any material may be used as long as it is an insulating material.

単独の受光素子１を用いて受光部としてもよいし、複数の受光素子１を直列接続したものを受光部としてもよい。各受光部ｄＡ〜ｄＤが２つ以上の受光素子１で構成される場合において、光起電力を電流として読みだす場合は直列接続されていることが好ましい。電圧出力の場合、電圧を大きくするがあるため、同様に直列に接続すると良い。電流出力の場合、信号源の抵抗値及び電流値を高くするとＳ／Ｎ比が向上し、また、電圧出力の場合、信号源の抵抗値を低く、電圧値を大きくするとＳ／Ｎ比が向上する。受光部を何個に分割し、直列にするかは、ＰＮ接合の面積当たりの縦方向（基板表面に垂直方向）の抵抗値、アンプの電圧入力換算ノイズ及び製造上の制限（プロセスルールなど）を考慮して、最適なＳ／Ｎ比を実現するために最適化すると良い。無論、受光部の全体のサイズを大きくすればするほど、前記の方法で最適化されたＳ／Ｎ比が大きくなるので良い。しかし、画素数や各画素のサイズは、システムの光学系と合わせて最適化な形状に設計すると良い。 A single light receiving element 1 may be used as the light receiving unit, or a plurality of light receiving elements 1 connected in series may be used as the light receiving unit. In the case where each of the light receiving portions dA to dD is composed of two or more light receiving elements 1, it is preferable that they are connected in series when the photovoltaic power is read as a current. In the case of voltage output, the voltage may be increased. In the case of current output, the S / N ratio is improved by increasing the resistance value and current value of the signal source. In the case of voltage output, the S / N ratio is improved by decreasing the resistance value of the signal source and increasing the voltage value. To do. The number of light-receiving units divided into series is determined by the resistance value in the vertical direction (perpendicular to the substrate surface) per area of the PN junction, the voltage input conversion noise of the amplifier, and manufacturing restrictions (process rules, etc.) In consideration of the above, it is preferable to optimize in order to realize an optimum S / N ratio. Of course, the larger the overall size of the light receiving section, the larger the S / N ratio optimized by the above method. However, the number of pixels and the size of each pixel may be designed to be optimized in accordance with the optical system of the system.

図５は、多数の受光素子を直列に接続して受光部とする場合の断面図を示す。図５に示されるように、受光素子１同士はカソード６１又はアノード６２を介して配線層６０で直列接続され、共通配線部２は配線層６０を利用して形成される。このような構造を利用すると、製造プロセスの工程数が減るというメリットがある。 FIG. 5 shows a cross-sectional view when a large number of light receiving elements are connected in series to form a light receiving portion. As shown in FIG. 5, the light receiving elements 1 are connected in series by a wiring layer 60 via a cathode 61 or an anode 62, and the common wiring portion 2 is formed using the wiring layer 60. When such a structure is used, there is an advantage that the number of manufacturing process steps is reduced.

以下、光センサ部１１０を例にして受光強度演算の方法を説明する。図１〜３に示される光センサ部１１０においては、受光部ｄＡ及びｄＣの受光素子１のアノード６２は配線層６０を介してそれぞれ接続端子３ａ及び３ｃに接続され、受光部ｄＢ及びｄＤの受光素子１のカソード６１は配線層６０を介してそれぞれ接続端子３ｂ及び３ｄに接続されている。また、受光部ｄＡ及びｄＣの受光素子１のカソード６１は配線層６０を介して共通配線部２に接続され、受光部ｄＢ及びｄＤの受光素子１のカソード６２は配線層６０を介して共通配線部２に接続されている。従って、光センサ部１１０では、対角配置にあるパッド間の信号は、下記式（８）及び（９）で得ることができ、左右配置及び上下配置にあるパッド間の信号は、下記式（１０）及び（１１）で得ることができる。
ｉｐ_AC＝（ｉｐ_A−ｉｐ_C）／２（８）
ｉｐ_BD＝（ｉｐ_D−ｉｐ_B）／２（９）
ｉｐ_AD＝（ｉｐ_A＋ｉｐ_D）／２（１０）
ｉｐ_BC＝（−ｉｐ_B−ｉｐ_C）／２（１１） Hereinafter, a method of calculating the received light intensity will be described using the optical sensor unit 110 as an example. In the optical sensor unit 110 shown in FIGS. 1 to 3, the anodes 62 of the light receiving elements 1 of the light receiving units dA and dC are connected to the connection terminals 3 a and 3 c through the wiring layer 60, respectively, and light reception of the light receiving units dB and dD. The cathode 61 of the element 1 is connected to the connection terminals 3b and 3d through the wiring layer 60, respectively. The cathode 61 of the light receiving element 1 of the light receiving parts dA and dC is connected to the common wiring part 2 via the wiring layer 60, and the cathode 62 of the light receiving element 1 of the light receiving parts dB and dD is connected to the common wiring via the wiring layer 60. Connected to the unit 2. Therefore, in the optical sensor unit 110, signals between the pads in the diagonal arrangement can be obtained by the following formulas (8) and (9), and signals between the pads in the left and right arrangement and the vertical arrangement are represented by the following formulas ( 10) and (11).
ip _AC = (ip _A −ip _C ) / 2 (8)
ip _BD = (ip _D -ip _B ) / 2 (9)
ip _AD = (ip _A + ip _D ) / 2 (10)
ip _BC = (− ip _B −ip _C ) / 2 (11)

ここで、ｉｐ_ACは接続端子３ａと接続端子３ｃとの間から取り出せる短絡光電流を示し、ｉｐ_BDは接続端子３ｂと接続端子３ｄとの間から取り出せる短絡光電流を示し、ｉｐ_ADは接続端子３ａと接続端子３ｄとの間から取り出せる短絡光電流を示し、ｉｐ_BCは接続端子３ｂと接続端子３ｃとの間から取り出せる短絡光電流を示す。 Here, ip _AC indicates a short-circuit photocurrent that can be extracted from between the connection terminal 3a and the connection terminal 3c, ip _BD indicates a short-circuit photocurrent that can be extracted from between the connection terminal 3b and the connection terminal 3d, and ip _AD indicates a connection terminal. 3 represents a short-circuit photocurrent that can be extracted from between the connection terminal 3d and ip _BC represents a short-circuit photocurrent that can be extracted from between the connection terminal 3b and the connection terminal 3c.

例えば式（１）に示されるように、接続端子３ａと接続端子３ｃとの間で得られる出力電流ｉｐ_ACは、共通配線部２に受光部ｄＡ及びｄＣのカソード６１が接続され、接続端子３ａ及び３ｃに受光部ｄＡ及びｄＣのアノード６２が接続されているため、受光部ｄＡと受光部ｄＣとのそれぞれの出力電流の差分信号により得られる。また、例えば式（３）に示されるように、接続端子３ａと接続端子３ｄとの間で得られる出力電流ｉｐ_ADは、共通配線部２に受光部ｄＡのカソード６１及び受光部ｄＤのアノード６２が接続され、接続端子３ａ及び３ｄに受光部ｄＡのアノード６２及び受光部ｄＤのカソード６１がそれぞれ接続されているため、受光部ｄＡと受光部ｄＤとのそれぞれの出力電流の加算信号により得られる。 For example, as shown in Expression (1), the output current ip _AC obtained between the connection terminal 3a and the connection terminal 3c is connected to the cathode 61 of the light receiving parts dA and dC in the common wiring part 2 and connected to the connection terminal 3a. And 3c are connected to the anodes 62 of the light receiving portions dA and dC, and are obtained from the difference signals of the output currents of the light receiving portions dA and dC. For example, as shown in Expression (3), the output current ip _AD obtained between the connection terminal 3a and the connection terminal 3d is supplied to the common wiring portion 2 through the cathode 61 of the light receiving portion dA and the anode 62 of the light receiving portion dD. Are connected to the connection terminals 3a and 3d, respectively, and the anode 62 of the light receiving unit dA and the cathode 61 of the light receiving unit dD are connected to each other, so that the output currents of the light receiving units dA and dD are obtained by adding signals. .

上記の通り、光センサ部１１０では、受光部ｄＡと受光部ｄＣのエリアに入射する輻射に関する差分信号（式（８））、及び受光部ｄＢと受光部ｄＤのエリアに入射する輻射に関する差分信号（式（９））を得ることができる。また、パッドの数が少なく、基板１０の利用効率が高いため、望ましい場合がある。 As described above, in the optical sensor unit 110, the difference signal (Equation (8)) regarding the radiation incident on the areas of the light receiving unit dA and the light receiving unit dC, and the difference signal regarding the radiation incident on the areas of the light receiving unit dB and the light receiving unit dD. (Expression (9)) can be obtained. Moreover, since the number of pads is small and the utilization efficiency of the substrate 10 is high, it may be desirable.

ここで、図１、２に示される光センサ部１１０においては、４つの受光部ｄＡ〜ｄＤを使用した場合を例に説明したが、４つの受光部に限らず、複数個の受光部を使用することができる。この場合、得られる出力信号は、各受光部の接続方法及び信号取り出しに選択したパッドによって異なる。例えば、任意の２つの受光部の差分の信号を取り出すには、両方の受光部のカソード６１若しくは両方の受光部のアノード６２を共通配線部２に接続する必要がある。 Here, in the optical sensor unit 110 shown in FIGS. 1 and 2, the case where four light receiving units dA to dD are used has been described as an example, but not limited to four light receiving units, a plurality of light receiving units are used. can do. In this case, the output signal obtained differs depending on the connection method of each light receiving unit and the pad selected for signal extraction. For example, in order to extract a difference signal between any two light receiving units, it is necessary to connect the cathode 61 of both light receiving units or the anode 62 of both light receiving units to the common wiring unit 2.

また、式（８）〜（１１）においては、各受光部ｄＡ〜ｄＤの内部抵抗が全く同じである場合の出力信号を示したが、必要に応じて、各受光部の内部抵抗が互いに異なってもよい。例えば、受光部ｄＡ及び受光部ｄＣの内部抵抗をそれぞれｒ_A及びｒ_Cとすると、この場合、ｉｐ_AC’は式（１２）で表される。 Further, in the equations (8) to (11), the output signals when the internal resistances of the light receiving portions dA to dD are exactly the same are shown. However, the internal resistances of the light receiving portions are different from each other as necessary. May be. For example, assuming that the internal resistances of the light receiving part dA and the light receiving part dC are r _A and r _C , ip _AC ′ in this case is expressed by Expression (12).

ｉｐ_AC’＝ｉｐ_Aｒ_A／（ｒ_A＋ｒ_C）−ｉｐ_Cｒ_C／（ｒ_A＋ｒ_C）（１２）
各受光部ｄＡ〜ｄＤの短絡光電流は、各受光部ｄＡ〜ｄＤに入射する赤外線の強度に応じて発生する。このようにして得られた短絡光電流は、受光部同士の電気的接続によって生じた演算結果であり、その結果自身を増幅することで、それぞれの独立の受光部の出力信号を個別に増幅してから、後段の演算器で演算（差分や加算）をするよりも、高いＳ／Ｎ比が実現できる。この高いＳ／Ｎ比を持った差分信号の更なる演算によって、微弱の輻射光源の位置・移動を高いＳ／Ｎ比で実現できる。 ip _AC '= ip _A r _A / (r _A + r _C ) −ip _C r _C / (r _A + r _C ) (12)
The short-circuit photocurrents of the light receiving portions dA to dD are generated according to the intensity of infrared rays incident on the light receiving portions dA to dD. The short-circuit photocurrent obtained in this way is the calculation result generated by the electrical connection between the light receiving parts, and by amplifying the result itself, the output signal of each independent light receiving part is amplified individually. After that, a higher S / N ratio can be realized than when the calculation (difference or addition) is performed by a subsequent arithmetic unit. By further calculation of the differential signal having a high S / N ratio, the position and movement of the weak radiation light source can be realized with a high S / N ratio.

製造の簡易さの観点から、基板１０が半絶縁材料（例えば、ＧａＡｓ）もしくは絶縁材料（例えば、サファイア）からなる基板であると好ましいが、基板１０の材料としては、ｎ型半導体層２０を含む半導体積層部８０を形成することが可能なものであれば特に制限されず、例えばシリコンやＧａＡｓやサファイアからなる基板でもよい。半絶縁材料や絶縁材料からなる基板を用いることにより、半導体積層部８０と基板１０とを電気的に絶縁するための工程が不要となるため、製造工程が簡易なものとなる。赤外線センサとしての効率を上げる観点からは、入射される赤外線に対して吸収が生じにくい材料が好ましい。プロセスを容易にする観点からは、絶縁基板を用いることが好ましい。また、半導体積層部８０がＩｎＳｂを含む組成の場合、上記観点に加え、半導体積層部８０の品質を高める観点からＧａＡｓからなる絶縁基板を用いることがより好ましい。 From the viewpoint of ease of manufacture, the substrate 10 is preferably a substrate made of a semi-insulating material (for example, GaAs) or an insulating material (for example, sapphire), but the material of the substrate 10 includes an n-type semiconductor layer 20. There is no particular limitation as long as the semiconductor stacked portion 80 can be formed, and for example, a substrate made of silicon, GaAs, or sapphire may be used. By using a substrate made of a semi-insulating material or an insulating material, a process for electrically insulating the semiconductor stacked portion 80 and the substrate 10 is not required, so that the manufacturing process is simplified. From the viewpoint of increasing the efficiency as an infrared sensor, a material that hardly absorbs incident infrared light is preferable. From the viewpoint of facilitating the process, it is preferable to use an insulating substrate. Moreover, when the semiconductor laminated part 80 is a composition containing InSb, it is more preferable to use an insulating substrate made of GaAs from the viewpoint of improving the quality of the semiconductor laminated part 80 in addition to the above viewpoint.

図６は、受光素子１の等価回路を示す。図６に示されるように、単一の受光素子１毎に内部抵抗ｒ₀を有している。従って、受光部ｄＡ〜ｄＤに多数の受光素子１を設けることにより、受光部ｄＡ〜ｄＤ全体の抵抗を拡大することができ、信号取り出しが容易になる。また、多数の受光素子１を直列に接続すると、１画素となる受光部ｄの抵抗ｒは受光素子の数に比例する。例えば、Ｎ個の受光素子１を直列に接続した場合、１画素の抵抗ｒは式（１３）で表される。
ｒ＝Ｎ×ｒ₀ （１３） FIG. 6 shows an equivalent circuit of the light receiving element 1. As shown in FIG. 6, each single light receiving element 1 has an internal resistance r ₀ . Therefore, by providing a large number of light receiving elements 1 in the light receiving portions dA to dD, the resistance of the entire light receiving portions dA to dD can be increased, and signal extraction becomes easy. Further, when a large number of light receiving elements 1 are connected in series, the resistance r of the light receiving part d that is one pixel is proportional to the number of light receiving elements. For example, when N light receiving elements 1 are connected in series, the resistance r of one pixel is expressed by Expression (13).
r = N × r ₀ (13)

さらに、ｋをＢｏｌｔｚｍａｎ係数とし、Ｔをセンサ温度とすると、光センサ部１１０からのノイズＩ_noiseは式（１４）で表される。
Ｉ_noise＝[４ｋＴ／（Ｎ×ｒ₀）]^1/2 （１４） Furthermore, when k is a Boltzman coefficient and T is a sensor temperature, noise I _noise from the optical sensor unit 110 is expressed by Expression (14).
I _noise = [4 kT / (N × r ₀ )] ^1/2 (14)

ｎ型半導体層２０及びｐ型半導体層４０で構成されるＰＮ接合又はＰＩＮ接合のフォトダイオード構造を含む半導体積層部８０の材料としては、ＩｎＳｂ系材料、ＩｎＧａＳｂ系材料、ＩｎＡｌＳｂ系材料、ＩｎＡｓＳｂ系材料、又はＩｎ、Ｓｂ、Ｇａ若しくはＡｌを含む材料を使用することができるが、用途に応じて、デバイスの検知波長帯を変える必要がある。ＩｎＳｂ系材料で構成された受光素子の場合、１〜７μｍの波長を検知することができる。ＩｎＧａＳｂ又はＩｎＡｌＳｂ系材料で構成された受光素子の場合、１〜５μｍの波長帯に絞ることができる。また、ＩｎＡｓＳｂ系材料で構成された受光素子の場合、１〜１２μｍの波長帯を検知することができる。同様の波長を検知するには、ＨｇやＣｄを用いたＭＣＴを用いたフォトダイオード構造も研究されているが、本発明では一般用途に幅広く普及するため、環境負荷軽減の観点から、ｎ層２０、π層３０及びｐ層４０で構成されるフォトダイオード構造部がＩｎ、Ｓｂ、Ｇａ、又はＡｌを含む材料で構成されることが好ましい。 As a material of the semiconductor stacked portion 80 including a PN junction or PIN junction photodiode structure composed of the n-type semiconductor layer 20 and the p-type semiconductor layer 40, an InSb-based material, an InGaSb-based material, an InAlSb-based material, and an InAsSb-based material are used. Alternatively, a material containing In, Sb, Ga, or Al can be used, but the detection wavelength band of the device needs to be changed depending on the application. In the case of a light receiving element made of an InSb-based material, a wavelength of 1 to 7 μm can be detected. In the case of a light receiving element composed of InGaSb or InAlSb-based material, it can be narrowed down to a wavelength band of 1 to 5 μm. In the case of a light receiving element made of an InAsSb-based material, a wavelength band of 1 to 12 μm can be detected. In order to detect the same wavelength, a photodiode structure using MCT using Hg or Cd has been studied. However, in the present invention, it is widely used for general purposes. The photodiode structure portion constituted by the π layer 30 and the p layer 40 is preferably made of a material containing In, Sb, Ga, or Al.

上記の材料から選択することによって、単一の受光素子１の内部抵抗ｒ₀が変化する。これは主に、光を吸収し、起電力を発生する光吸収層３０のバンドギャップによって、室温での真性キャリア数が変わるためである。具体的には、バンド材料のバンドギャップが小さいほど、真性キャリア数が増え、受光素子１の内部抵抗ｒ₀が低下する。 By selecting from the above materials, the internal resistance r ₀ of the single light receiving element 1 changes. This is mainly because the number of intrinsic carriers at room temperature varies depending on the band gap of the light absorption layer 30 that absorbs light and generates electromotive force. Specifically, the smaller the band gap of the band material, the greater the number of intrinsic carriers, and the lower the internal resistance r ₀ of the light receiving element 1.

特に、長波長の赤外線を検知するためは、ＩｎＳｂのような狭いバンドギャップを有する受光素子１を用いて受光部ｄＡ〜ｄＤを構成することが好ましい。狭いバンドギャップの受光素子１を用いて受光部ｄＡ〜ｄＤを構成する場合、デバイスは周囲の温度揺らぎに敏感になるため、内部抵抗ｒ₀は周囲の温度揺らぎによって大きく変動する。この問題を改善するために、本発明においては、受光部ｄＡ〜ｄＤの内部抵抗ｒ₀の変動の影響を受けにくい短絡出力電流を電子回路で処理するため、著しくその効果が表れる。 In particular, in order to detect long-wavelength infrared light, it is preferable to configure the light receiving portions dA to dD using the light receiving element 1 having a narrow band gap such as InSb. When the light receiving elements dA to dD are configured using the light receiving element 1 having a narrow band gap, the device becomes sensitive to ambient temperature fluctuations, and thus the internal resistance r ₀ varies greatly due to ambient temperature fluctuations. In order to improve this problem, in the present invention, the short circuit output current that is not easily affected by the fluctuation of the internal resistance r ₀ of the light receiving portions dA to dD is processed by the electronic circuit, so that the effect is remarkably exhibited.

図３では、Ｌ字型の形状を有する受光部ｄＡ〜ｄＤが示されているが、チップサイズや、接続端子のサイズによって、他の形状でもよい。これらの形状は各受光部ｄＡ〜ｄＤを構成する多数の受光素子１を互いに直列に接続することにより設計が可能となる。そのため、受光部ｄＡ〜ｄＤを多数の受光素子１で構成することが望ましい。また、各受光部ｄＡ〜ｄＤＡ〜ｄＤを多数の受光素子１で構成すると、受光部ｄＡ〜ｄＤの各々の全体の抵抗を増大することができ、信号取り出しが容易になるという観点からも好ましい。 In FIG. 3, the light receiving portions dA to dD having an L-shape are shown, but other shapes may be used depending on the chip size and the size of the connection terminal. These shapes can be designed by connecting a large number of light receiving elements 1 constituting the light receiving portions dA to dD in series with each other. For this reason, it is desirable that the light receiving portions dA to dD include a large number of light receiving elements 1. Further, if each of the light receiving portions dA to dDA to dD is constituted by a large number of light receiving elements 1, it is preferable from the viewpoint that the overall resistance of each of the light receiving portions dA to dD can be increased and signal extraction becomes easy.

本発明において、Ｉ−Ｖ変換アンプ４ａ〜４ｄは受光部ｄＡ〜ｄＤの短絡電流を増幅するための手段であり、一般的にはＴｒａｎｓｉｍｐｅｄａｎｃｅ−Ａｍｐと呼ばれる。システム全体のノイズは光センサ部１１０のみではなく、Ｉ−Ｖ変換アンプ４ａ〜４ｄのノイズも考慮しなければならない。一般的なＩ−Ｖ変換アンプは信号源（ここでは受光部ｄ）の内部抵抗Ｎ×ｒ₀が小さいほど、アンプの出力に現れるノイズが増える（式１４を参照）。 In the present invention, the IV conversion amplifiers 4a to 4d are means for amplifying a short-circuit current of the light receiving portions dA to dD, and are generally referred to as Transimpedance-Amp. As for the noise of the entire system, not only the optical sensor unit 110 but also the noises of the IV conversion amplifiers 4a to 4d must be considered. In a general IV conversion amplifier, the noise that appears at the output of the amplifier increases as the internal resistance N × r ₀ of the signal source (in this case, the light receiving unit d) decreases (see Equation 14).

図７は、３７９ΩのＩｎＳｂ系の受光素子１をＮ個直列に接続した場合の受光素子１の個数Ｎとアンプの出力のノイズとの関係を示す（同様に、センサのみのノイズ（熱雑音）も表示してある）。図７に示されるように、個数Ｎが少ないほど、センサのノイズよりもアンプからのノイズが著しくなる。そのため、高Ｓ／Ｎ比を実現するために、受光部ｄＡ〜ｄＤの設計の際、アンプに接続する信号源の内部抵抗（ここではＮ×ｒ₀）を考慮しなければならない。 FIG. 7 shows the relationship between the number N of light receiving elements 1 and the noise of the output of the amplifier when N 379Ω InSb light receiving elements 1 are connected in series (similarly, noise (thermal noise) of only the sensor). Is also displayed). As shown in FIG. 7, as the number N is smaller, the noise from the amplifier becomes more significant than the noise of the sensor. Therefore, in order to realize a high S / N ratio, the internal resistance (N × r _{0 in this case} ) of the signal source connected to the amplifier must be considered when designing the light receiving portions dA to dD.

本発明は、特に受光強度演算デバイス１００を小型化にした場合、効果が著しくなる。基板１０の寸法の具体的なサイズとしては、４ｍｍ²以下、２ｍｍ²以下が望ましく、更に望ましいのは０．５ｍｍ²以下、０．２ｍｍ²以下である。基板１０のサイズが小さいほど、製造効率が高まるだけではなく、受光強度演算デバイス１００のパッケージや実装された周囲の不均一な温度変化による受光強度演算デバイス１００の出力信号への影響が小さくなるので、基板１０のサイズは小さい方が好ましい。 The present invention is particularly effective when the light receiving intensity calculation device 100 is downsized. The specific size of the substrate 10 is preferably 4 mm ² or less and 2 mm ² or less, more preferably 0.5 mm ² or less and 0.2 mm ² or less. As the size of the substrate 10 is smaller, not only the manufacturing efficiency is increased, but also the influence on the output signal of the received light intensity calculation device 100 due to the nonuniform temperature change in the package of the received light intensity calculation device 100 and the surrounding area is reduced. The substrate 10 is preferably smaller in size.

また、小型なデバイスを実現するためには、受光部ｄＡ〜ｄＤを小さくする必要があるため、受光素子１の数にも限りがある。そこで、本実施形態では、小さい受光部ｄＡ〜ｄＤからの出力信号を高Ｓ／Ｎ比で増幅できるように、受光部ｄＡ〜ｄＤの出力信号を受光部１個ずつではなく、直列接続された２つずつの受光部の信号を増幅すると好ましい。 Further, in order to realize a small device, it is necessary to reduce the light receiving portions dA to dD, and therefore the number of light receiving elements 1 is limited. Therefore, in this embodiment, the output signals of the light receiving parts dA to dD are connected in series instead of one by one so that the output signals from the small light receiving parts dA to dD can be amplified with a high S / N ratio. It is preferable to amplify the signals of the two light receiving parts.

光源（人体の手・指・顔）の接近・位置・移動の検出は、二つの受光部の差分処理を行うことによって、高感度、且つ、高Ｓ／Ｎ比の信号処理を実現できる。受光部が小さいほど、同一基板上にそれぞれの受光部が近い位置に配置されているため、周囲の温度の揺らぎが生じても、同時に両方の受光部の温度が揺らぐこととなるので、温度差（及び出力信号の揺らぎ）が生じない。一方、デバイスが小さいほど、周囲の熱揺らぎの影響が小さくなるが、各受光部の抵抗は小さくなるため、その信号処理は困難となる。そこで、本発明を実施することによって、受光部内に入射した光の強度が演算されアンプに出力されるため、高Ｓ／Ｎ比の演算・信号処理が実現できる。 The detection of the approach, position, and movement of the light source (human hand / finger / face) can be realized by performing a differential process between the two light receiving units to achieve a signal process with high sensitivity and a high S / N ratio. The smaller the light receiving part, the closer each light receiving part is located on the same substrate, so even if the ambient temperature fluctuates, the temperature of both light receiving parts will fluctuate at the same time. (And fluctuation of the output signal) does not occur. On the other hand, the smaller the device is, the smaller the influence of the surrounding thermal fluctuation is, but the resistance of each light receiving unit is small, so that the signal processing becomes difficult. Therefore, by implementing the present invention, the intensity of the light incident on the light receiving unit is calculated and output to the amplifier, so that calculation / signal processing with a high S / N ratio can be realized.

なお、図４には、基板１０上に、ｎ型半導体層２０、光吸収層３０、ｐ型半導体層４０の順に積層した層構造を有する受光素子１を示したが、ｐ型半導体層４０、光吸収層３０、ｎ型半導体層２０の順に積層した構造としてもよい。その場合、ｐ型半導体層４０と光吸収層３０との間にバリア層３１が形成されることとなる。また、図４には、ＰＩＮ接合の半導体積層部８０を有する受光素子１を示したが、ＰＮ接合のフォトダイオード構造として構成してもよい。さらに、上記説明では、例示として、基板１０の裏面から光が入射するものとしたが、本発明では基板１０において半導体積層部８０が積層されている面側から光が入射するように構成してもよい。 4 shows the light receiving element 1 having a layer structure in which the n-type semiconductor layer 20, the light absorption layer 30, and the p-type semiconductor layer 40 are stacked in this order on the substrate 10, but the p-type semiconductor layer 40, The light absorption layer 30 and the n-type semiconductor layer 20 may be stacked in this order. In that case, the barrier layer 31 is formed between the p-type semiconductor layer 40 and the light absorption layer 30. 4 shows the light receiving element 1 having the PIN junction semiconductor stacked portion 80, it may be configured as a PN junction photodiode structure. Furthermore, in the above description, light is assumed to be incident from the back surface of the substrate 10 as an example. However, in the present invention, the light is incident from the side of the substrate 10 on which the semiconductor laminated portion 80 is laminated. Also good.

図８は、本発明に係る受光強度演算デバイス１００を使用した位置検出デバイス３００の実施例を示す。図８は、本発明に係る受光強度演算デバイス１００を使用した位置検出デバイス３００の断面図である。図８には、受光強度演算デバイス１００と、基板１０の裏面に設置され、受光強度演算デバイス１００に入射する光の波長を制限する光学フィルター３０１と、受光強度演算デバイス１００の受光部の視野を制御する視野角制限体３０２と、受光強度演算デバイス１００及び光学フィルター３０１をモールディングする樹脂モールド３０４とを供えた位置検出デバイス３００が示されている。図８に示される受光強度演算デバイス１００は、受光部ｄＡ及びｄＣの他にさらに受光部ｄＢ及びｄＤを備えているが、説明を簡略化するため、特に言及がない限り、受光部ｄＡ及びｄＣを使用した場合を例に説明する。 FIG. 8 shows an embodiment of a position detection device 300 using the received light intensity calculation device 100 according to the present invention. FIG. 8 is a cross-sectional view of a position detection device 300 using the received light intensity calculation device 100 according to the present invention. In FIG. 8, the received light intensity calculation device 100, the optical filter 301 that is installed on the back surface of the substrate 10 and restricts the wavelength of light incident on the received light intensity calculation device 100, and the light receiving field of the received light intensity calculation device 100 are shown. A position detection device 300 including a viewing angle limiter 302 to be controlled and a resin mold 304 for molding the received light intensity calculation device 100 and the optical filter 301 is shown. The light receiving intensity calculation device 100 shown in FIG. 8 further includes light receiving portions dB and dD in addition to the light receiving portions dA and dC. However, to simplify the description, unless otherwise noted, the light receiving portions dA and dC. The case where is used will be described as an example.

光源３０３から輻射された赤外線は、位置検出デバイス３００に入射する際に、視野角制限体３０２によって入射角が制限されながら位置検出デバイス３００の光学フィルター３０１を介して基板１０の裏面から入射し、受光部ｄＡ及びｄＣに入射する。この視野角制限体３０２によって、光源３０３の位置によって各受光部ｄＡ及びｄＣに入射する光の強度が異なるようになるため、その差分を演算することによって、光源３０３の位置が検出することができる。図８で示すような光源３０３の位置の場合、受光部ｄＡに入射する光束が受光部ｄＣに入射する光束より大きいため、ｉｐ_Aはｉｐ_Cより大きくなる。このことを利用して、ｉｐ_Aとｉｐ_Cの差分を求めることにより、光源３０３が視野角内のどの位置に存在するかの一次元的な位置検出をすることができる。また、受光強度演算デバイス１００が受光部ｄＡ及びｄＣの他にさらに受光部を備える場合は、それらを用いることにより二次元的な位置検出も可能になる。さらに、受光部の出力の和を求めることにより受光部ｄＡ及びｄＣと光源３０３との距離も検出することができるため、３次元的な位置検出も可能になる。 When the infrared ray radiated from the light source 303 is incident on the position detection device 300, the incident angle is limited by the viewing angle limiter 302 and is incident from the back surface of the substrate 10 through the optical filter 301 of the position detection device 300. It enters the light receiving parts dA and dC. Since the intensity of light incident on the light receiving portions dA and dC varies depending on the position of the light source 303 by the viewing angle limiting body 302, the position of the light source 303 can be detected by calculating the difference. . In the case of the position of the light source 303 as shown in FIG. 8, since the light beam incident on the light receiving unit dA is larger than the light beam incident on the light receiving unit dC, ip _A is larger than ip _C. By utilizing this fact, the difference between ip _A and ip _C is obtained, so that it is possible to detect the one-dimensional position where the light source 303 exists within the viewing angle. In addition, when the received light intensity calculation device 100 further includes a light receiving unit in addition to the light receiving units dA and dC, two-dimensional position detection can be performed by using them. Furthermore, since the distance between the light receiving portions dA and dC and the light source 303 can be detected by calculating the sum of the outputs of the light receiving portions, three-dimensional position detection is also possible.

図８に示される位置検出デバイス３００では、視野角制限体３０２として穴の開いた板を用いた場合を図示したが、光学レンズを利用又は組み合わせてもよい。視野角制限体３０２の直径φ及びその開口部の厚みｔに基づいて、デバイスの光学特性が決定される。検出対象となる光源３０３としては、受光強度演算デバイス１００の受光素子の感度波長内の赤外線を発する物質であれば特に制限されない。 In the position detection device 300 shown in FIG. 8, the case where a plate with a hole is used as the viewing angle restricting body 302 is illustrated, but an optical lens may be used or combined. The optical characteristics of the device are determined based on the diameter φ of the viewing angle limiter 302 and the thickness t of the opening. The light source 303 to be detected is not particularly limited as long as it is a substance that emits infrared rays within the sensitivity wavelength of the light receiving element of the received light intensity calculation device 100.

光学フィルター３０１は、一部の波長範囲のみ検知したい場合には、基板１０と視野角制限体６０２との間に必要に応じて設けることができる。光学フィルター３０１の一例としては、Ｓｉ基板上に異なった屈折率の２種類の材料を多層に積層することによって得られる波長選択効果の干渉フィルターが挙げられる。このような光学フィルター３０１であれば、大気に対して屈折率が高い（ｎ＝３以上）ため、入射光は光学フィルター３０１の表面に対してほぼ垂直となり、受光部ｄＡ及びｄＣまで進行する。 The optical filter 301 can be provided between the substrate 10 and the viewing angle limiter 602 as necessary when only a partial wavelength range is desired to be detected. An example of the optical filter 301 is an interference filter having a wavelength selection effect obtained by laminating two types of materials having different refractive indexes on a Si substrate. In such an optical filter 301, since the refractive index is high with respect to the atmosphere (n = 3 or more), the incident light is substantially perpendicular to the surface of the optical filter 301 and travels to the light receiving portions dA and dC.

図８に示される位置検出デバイス３００では、視野角制限体３０２／光学フィルター３０１／基板１０という構造を示したが、パッケージの構造の制限に応じて、光学フィルター３０１／視野角制限体３０２／基板１０という構造でもよい。または、蓋／視野角制限体３０２／光学フィルター３０１／基板１０でもよい。但し、ここで言う「蓋」とは、光源３０３が放射する光の波長に対して十分な透過率を持つことが望ましい。また、この蓋の形状によって、光の屈折効果を利用して、視野角を広げたり、狭めたりさせてもよい。この場合、各用途に応じて適した形状を利用すると良い。 In the position detection device 300 shown in FIG. 8, the structure of the viewing angle limiter 302 / the optical filter 301 / the substrate 10 is shown, but the optical filter 301 / the viewing angle limiter 302 / the substrate depending on the limitation of the package structure. The structure of 10 may be sufficient. Alternatively, lid / viewing angle limiter 302 / optical filter 301 / substrate 10 may be used. However, the “lid” mentioned here preferably has a sufficient transmittance with respect to the wavelength of light emitted from the light source 303. Further, depending on the shape of the lid, the viewing angle may be widened or narrowed by utilizing the light refraction effect. In this case, a shape suitable for each application may be used.

図８で示したような位置検出デバイス３００を作製し、直径１５ｍｍの光源をセンサ表面から２０ｍｍの距離に設定した。位置検出デバイス３００で使用される受光強度演算デバイス１００において、基板１０は０．４５ｍｍ角のＧａＡｓ基板を使用し、２４個のＩｎＳｂのフォトダイオードからなる受光素子１を直列接続した各受光部２ａ〜２ｄを使用し、図３で示されるようなレイアウトとした。視野角制限体３０２の開口部の厚みｔを０．５ｍｍとし、穴の直径φを０．５ｍｍとした。 A position detection device 300 as shown in FIG. 8 was manufactured, and a light source having a diameter of 15 mm was set at a distance of 20 mm from the sensor surface. In the received light intensity calculation device 100 used in the position detection device 300, the substrate 10 uses a 0.45 mm square GaAs substrate, and the light receiving portions 2a to 2 are connected in series with the light receiving elements 1 made of 24 InSb photodiodes. The layout as shown in FIG. 3 was used using 2d. The thickness t of the opening of the viewing angle limiter 302 was 0.5 mm, and the diameter φ of the hole was 0.5 mm.

上記のようにして作製された位置検出デバイス３００に対して光源３０３を移動させた場合における、光源３０３の位置（開口部の中心軸を０ｍｍとする）に対するｉｐ_Aとｉｐ_Cの差分の関係、及びｉｐ_A〜ｉｐ_Dの総和の関係を図９に示す。図９に示される差分の波形から、光源３０３の位置と、ｉｐ_Aとｉｐ_Cとの差分とが相関を持つことが理解できる。この相関を用いることにより、光源３０３が視野角内のどの位置に存在するかを検出することが可能になる。また、図９に示される差分の波形から、ノイズが少なく高Ｓ／Ｎが得られることも理解される。 When the light source 303 is moved with respect to the position detection device 300 manufactured as described above, the relationship between the difference between ip _A and ip _C with respect to the position of the light source 303 (the central axis of the opening is 0 mm), FIG. 9 shows the relationship of the sum of ip _{A to} ip _D. From the waveform of the difference shown in FIG. 9, it can be understood that the position of the light source 303 and the difference between ip _A and ip _C have a correlation. By using this correlation, it is possible to detect where the light source 303 exists within the viewing angle. It can also be understood from the difference waveform shown in FIG. 9 that there is little noise and a high S / N can be obtained.

また、図９に示されるｉｐ_A〜ｉｐ_Dの総和の信号から、光源３０３が位置検出デバイス３００に接近しているかどうかが判別できる。この判別の結果から、差分の信号がゼロの場合でも、光源３０３が位置検出デバイス３００に接近しているかどうか（若しくは、光源３０３が位置検出デバイス３００の視野範囲に入っているかどうか）が分かるため、多くの用途では有効である。 Further, it is possible to determine whether or not the light source 303 is approaching the position detection device 300 from the signal of the sum of ip _A to ip _D shown in FIG. As a result of this determination, even when the difference signal is zero, it is possible to know whether the light source 303 is close to the position detection device 300 (or whether the light source 303 is within the field of view of the position detection device 300). It is effective in many applications.

１受光素子
ｄＡ〜ｄＤ受光部
２共通配線部
３ａ〜３ｄ、３ａ１〜３ｄ１、３ａ２〜３ｄ２接続端子
４ａ〜４ｄＩ−Ｖ変換アンプ
５〜８減算回路
９加算回路
１０基板
２０ｎ型半導体層
３０光吸収層
４０ｐ型半導体層
５０絶縁層
６０配線層
６１カソード（ｎ層電極）
６２アノード（ｐ層電極）
７０保護層
８０半導体積層部
１００、１０００受光強度演算デバイス
１１０、１０１０光センサ部
１２０、１０２０Ｉ−Ｖ変換手段
１３０、１０３０差分演算手段
１４０、１０４０加算演算手段
３００位置検出デバイス
３０１光学フィルター
３０２視野角制限体
３０３光源
３０４樹脂モールド DESCRIPTION OF SYMBOLS 1 Light receiving element dA-dD Light receiving part 2 Common wiring part 3a-3d, 3a1-3d1, 3a2-3d2 Connection terminal 4a-4d IV conversion amplifier 5-8 Subtraction circuit 9 Addition circuit 10 Substrate 20 N-type semiconductor layer 30 Light Absorption layer 40 P-type semiconductor layer 50 Insulating layer 60 Wiring layer 61 Cathode (n layer electrode)
62 Anode (p-layer electrode)
DESCRIPTION OF SYMBOLS 70 Protective layer 80 Semiconductor laminated part 100, 1000 Light reception intensity | strength calculation device 110, 1010 Photosensor part 120, 1020 IV conversion means 130, 1030 Difference calculation means 140, 1040 Addition calculation means 300 Position detection device 301 Optical filter 302 Viewing angle Restrictor 303 Light source 304 Resin mold

Claims

A first light-receiving unit having one end connected to the first connection terminal, a second light-receiving unit having one end connected to the second connection terminal, and a third light-receiving unit having one end connected to the third connection terminal An optical sensor unit comprising a light receiving unit and a fourth light receiving unit having one end connected to a fourth connection terminal, wherein the other ends of the first light receiving unit to the fourth light receiving unit are common. The optical sensor connected by the wiring of
A first difference signal is calculated by calculating a difference between outputs from the first light receiving unit and the third light receiving unit, connected to the first connection terminal and the third connection terminal without using a switching element. A first difference calculation unit that outputs
A second differential signal is calculated by calculating a difference between outputs from the second light receiving unit and the fourth light receiving unit, connected to the second connection terminal and the fourth connection terminal without using a switching element. A second difference calculation unit that outputs
A third difference signal is calculated by calculating a difference between outputs from the first light receiving unit and the second light receiving unit, connected to the first connection terminal and the second connection terminal without using a switching element. A third difference calculation unit that outputs
A fourth differential signal is calculated by calculating a difference between outputs from the third light receiving unit and the fourth light receiving unit, connected to the third connection terminal and the fourth connection terminal without passing through a switching element. A fourth difference calculation unit that outputs
An addition calculation unit connected to the third difference calculation unit and the fourth difference calculation unit, and calculating a sum of the third difference signal and the fourth difference signal and outputting an addition signal. Received light intensity calculation device.

Each of the first light receiving unit to the fourth light receiving unit includes a plurality of photodiodes,
The cathode of the first light receiving unit is electrically connected to the anode of the second light receiving unit and the fourth light receiving unit, and the cathode of the third light receiving unit,
The anode of the first light receiving unit is connected to the first difference calculation unit and the third difference calculation unit via the first connection terminal and a first current-voltage conversion amplifier,
The cathode of the second light receiving unit is connected to the second difference calculation unit and the third difference calculation unit via the second connection terminal and a second current-voltage conversion amplifier,
The anode of the third light receiving unit is connected to the first difference calculation unit and the fourth difference calculation unit via the third connection terminal and a third current-voltage conversion amplifier,
The cathode of the fourth light receiving unit is connected to the second difference calculation unit and the fourth difference calculation unit via the fourth connection terminal and a fourth current-voltage conversion amplifier. The received light intensity calculation device according to claim 1.

The received light intensity calculation device according to claim 1, wherein the first light receiving unit to the fourth light receiving unit include a plurality of light receiving elements connected in series to each other.

2. The first light receiving portion to the fourth light receiving portion each include a semiconductor stacked portion that includes indium and / or antimony and has a photodiode structure of a PN junction or a PIN junction. The received light intensity calculation device according to claim 1.