（実施形態１）
以下、本実施形態の方向検出装置１０を図１ないし図３に基づいて説明する。
(Embodiment 1)
Hereinafter, the direction detection apparatus 10 of this embodiment is demonstrated based on FIG. 1 thru | or FIG.
本実施形態の方向検出装置１０は、図１に示すように、焦電型の第１の受光素子１１ａと焦電型の第２の受光素子１１ｂとを並んで配置させた赤外線検出部１を有している。赤外線検出部１は、第１の受光素子１１ａと第２の受光素子１１ｂとが被検知体Ｈから受光した赤外線による温度変化に応じた波形の検知信号Ｓａ，Ｓｂを各別に出力する。方向検出装置１０は、赤外線検出部１から所定時間内に入力された検知信号Ｓａ，Ｓｂに基づき、被検知体Ｈの移動方向を判別する信号処理部２を有している。
As shown in FIG. 1, the direction detection device 10 of the present embodiment includes an infrared detection unit 1 in which a pyroelectric first light receiving element 11a and a pyroelectric second light receiving element 11b are arranged side by side. Have. The infrared detection unit 1 outputs detection signals Sa and Sb having waveforms corresponding to temperature changes caused by infrared rays received by the first light receiving element 11a and the second light receiving element 11b from the detection target H, respectively. The direction detection device 10 includes a signal processing unit 2 that determines the moving direction of the detection target H based on the detection signals Sa and Sb input from the infrared detection unit 1 within a predetermined time.
方向検出装置１０は、被検知体Ｈの移動方向が第１の受光素子１１ａ側から第２の受光素子１１ｂ側へ移動する第１の方向Ｄ１２か第２の受光素子１１ｂ側から第１の受光素子１１ａ側へ移動する第２の方向Ｄ２１かを判別し被検知体Ｈの移動方向を検出する。
The direction detecting device 10 receives the first light reception from the first light receiving element 11b side or the first direction D12 in which the moving direction of the detection object H moves from the first light receiving element 11a side to the second light receiving element 11b side. It is determined whether the second direction D21 moves to the element 11a side, and the moving direction of the detection target H is detected.
信号処理部２は、検知信号Ｓａ，Ｓｂの振幅が予め設定した入力開始閾値ＩＴを超えた検知信号Ｓａ，Ｓｂを記憶する（図２および図３を参照）。信号処理部２は、記憶させた検知信号Ｓａ，Ｓｂの振幅が予め設定した飽和判定閾値ＳＴ以下の場合、検知信号Ｓａ，Ｓｂの振幅が最大となる時刻をピーク時刻Ｔａ１，Ｔｂ１として記憶する（図２を参照）。また、信号処理部２は、記憶させた検知信号Ｓａ，Ｓｂの振幅が飽和判定閾値ＳＴを超える場合、入力開始閾値ＩＴと飽和判定閾値ＳＴとの間に予め設定した方向判断閾値ＤＴを超える時刻を閾値時刻Ｔａ２，Ｔｂ２として記憶する（図３を参照）。信号処理部２は、第１の受光素子１１ａおよび第２の受光素子１１ｂそれぞれのピーク時刻Ｔａ１，Ｔｂ１のうち、時間の早い順に第１の時刻ｔ１、第２の時刻ｔ２とする。あるいは、信号処理部２は、第１の受光素子１１ａおよび第２の受光素子１１ｂそれぞれの閾値時刻Ｔａ２，Ｔｂ２のうち、時間の早い順に第１の時刻ｔ１、第２の時刻ｔ２とする。
The signal processing unit 2 stores the detection signals Sa and Sb in which the amplitudes of the detection signals Sa and Sb exceed a preset input start threshold IT (see FIGS. 2 and 3). When the amplitudes of the stored detection signals Sa and Sb are equal to or smaller than the preset saturation determination threshold ST, the signal processing unit 2 stores the times when the amplitudes of the detection signals Sa and Sb are maximum as peak times Ta1 and Tb1 ( (See FIG. 2). Further, when the amplitude of the stored detection signals Sa and Sb exceeds the saturation determination threshold ST, the signal processing unit 2 exceeds the direction determination threshold DT set in advance between the input start threshold IT and the saturation determination threshold ST. Are stored as threshold times Ta2 and Tb2 (see FIG. 3). The signal processing unit 2 sets the first time t1 and the second time t2 in order from the earliest time among the peak times Ta1 and Tb1 of the first light receiving element 11a and the second light receiving element 11b. Alternatively, the signal processing unit 2 sets the first time t1 and the second time t2 in order from the earlier of the threshold times Ta2 and Tb2 of the first light receiving element 11a and the second light receiving element 11b.
信号処理部２は、第１の受光素子１１ａが検知する検知信号Ｓａに基づき第１の時刻ｔ１が特定され第２の受光素子１１ｂが検知する検知信号Ｓｂに基づき第２の時刻ｔ２が特定される場合、被検知体Ｈの移動方向を第１の方向Ｄ１２と判別する。信号処理部２は、図示しないが、第１の受光素子１１ａが検知する検知信号Ｓａに基づき第２の時刻ｔ２が特定され第２の受光素子１１ｂが検知する検知信号Ｓｂに基づき第１の時刻ｔ１が特定される場合、被検知体Ｈの移動方向を第２の方向Ｄ２１と判別する。
The signal processing unit 2 specifies the first time t1 based on the detection signal Sa detected by the first light receiving element 11a, and specifies the second time t2 based on the detection signal Sb detected by the second light receiving element 11b. In this case, the moving direction of the detection object H is determined as the first direction D12. Although not shown, the signal processing unit 2 specifies the second time t2 based on the detection signal Sa detected by the first light receiving element 11a and the first time based on the detection signal Sb detected by the second light receiving element 11b. When t1 is specified, the moving direction of the detection target H is determined as the second direction D21.
これにより本実施形態の方向検出装置１０は、焦電型の受光素子を用いて、より高い精度で被検知体Ｈの移動方向を検出することが可能となる。
Thereby, the direction detection device 10 of the present embodiment can detect the moving direction of the detection target H with higher accuracy by using the pyroelectric light receiving element.
より具体的には、本実施形態の方向検出装置１０は、第１の受光素子１１ａおよび第２の受光素子１１ｂに加え、被検知体Ｈが放射する赤外線を受光する焦電型の第３の受光素子１１ｃと、被検知体Ｈが放射する赤外線を受光する焦電型の第４の受光素子１１ｄとを備えている。赤外線検出部１は、第１の受光素子１１ａと、第１の受光素子１１ａと電気的に接続する第１の信号変換部１２ａとを備えている。赤外線検出部１は、第２の受光素子１１ｂと、第２の受光素子１１ｂと電気的に接続する第２の信号変換部１２ｂとを備えている。また、赤外線検出部１は、第３の受光素子１１ｃと、第３の受光素子１１ｃと電気的に接続する第３の信号変換部１２ｃとを備えている。さらに、赤外線検出部１は、第４の受光素子１１ｄと、第４の受光素子１１ｄと電気的に接続する第４の信号変換部１２ｄとを備えている。また、信号処理部２は、所定のプログラムを記憶させた記憶部２ａと、上記プログラムに基づいて、信号処理する判定部２ｂとを備えている。
More specifically, the direction detection device 10 of the present embodiment includes a pyroelectric third light receiving the infrared rays emitted from the detection target H in addition to the first light receiving element 11a and the second light receiving element 11b. A light receiving element 11c and a pyroelectric fourth light receiving element 11d that receives infrared rays emitted from the detection target H are provided. The infrared detection unit 1 includes a first light receiving element 11a and a first signal conversion unit 12a that is electrically connected to the first light receiving element 11a. The infrared detection unit 1 includes a second light receiving element 11b and a second signal conversion unit 12b that is electrically connected to the second light receiving element 11b. The infrared detection unit 1 includes a third light receiving element 11c and a third signal conversion unit 12c that is electrically connected to the third light receiving element 11c. Further, the infrared detection unit 1 includes a fourth light receiving element 11d and a fourth signal conversion unit 12d that is electrically connected to the fourth light receiving element 11d. The signal processing unit 2 includes a storage unit 2a that stores a predetermined program, and a determination unit 2b that performs signal processing based on the program.
本実施形態の方向検出装置１０は、第１の受光素子１１ａと第３の受光素子１１ｃとが配置される配置方向を、第１の受光素子１１ａと第２の受光素子１１ｂとが配置される配置方向と直交するようにしている。同様に、本実施形態の方向検出装置１０は、第２の受光素子１１ｂと第４の受光素子１１ｄとが配置される配置方向を、第１の受光素子１１ａと第２の受光素子１１ｂとが配置される配置方向と直交するようにしている。すなわち、赤外線検出部１は、第１の受光素子１１ａないし第４の受光素子１１ｄの４つの焦電型の受光素子を２×２の正方格子状に配置している。赤外線検出部１は、第１の受光素子１１ａないし第４の受光素子１１ｄにおける各検知領域の各中心間の間隔を、たとえば、５〜３０ｃｍとすることができる。
In the direction detection device 10 of this embodiment, the first light receiving element 11a and the second light receiving element 11b are arranged in the arrangement direction in which the first light receiving element 11a and the third light receiving element 11c are arranged. It is made to be orthogonal to the arrangement direction. Similarly, in the direction detection device 10 of the present embodiment, the first light receiving element 11a and the second light receiving element 11b are arranged in the arrangement direction in which the second light receiving element 11b and the fourth light receiving element 11d are arranged. It is made to be orthogonal to the arrangement direction to be arranged. That is, the infrared detecting unit 1 has four pyroelectric light receiving elements of the first light receiving element 11a to the fourth light receiving element 11d arranged in a 2 × 2 square lattice shape. The infrared detection unit 1 can set the distance between the centers of the detection regions in the first light receiving element 11a to the fourth light receiving element 11d to, for example, 5 to 30 cm.
以下、本実施形態の方向検出装置１０では、第１の受光素子１１ａと第２の受光素子１１ｂとの配置方向や、第３の受光素子１１ｃと第４の受光素子１１ｄとの配置方向を左右方向と称して説明することがある。また、本実施形態の方向検出装置１０では、第１の受光素子１１ａと第３の受光素子１１ｃとの配置方向や、第２の受光素子１１ｂと第４の受光素子１１ｄとの配置方向を上下方向と称して説明することがある。なお、本実施形態の方向検出装置１０では、第１の受光素子１１ａ側から第２の受光素子１１ｂ側へ向かう方向を第１の方向Ｄ１２と規定している。また、本実施形態の方向検出装置１０では、第２の受光素子１１ｂ側から第１の受光素子１１ａ側へ向かう方向を第２の方向Ｄ２１と規定している。同様に、本実施形態の方向検出装置１０では、第１の受光素子１１ａ側から第３の受光素子１１ｃ側へ向かう方向を第３の方向Ｄ１３と規定している。また、本実施形態の方向検出装置１０では、第３の受光素子１１ｃ側から第１の受光素子１１ａ側へ向かう方向を第４の方向Ｄ３１と規定している。
Hereinafter, in the direction detection device 10 of the present embodiment, the arrangement direction of the first light receiving element 11a and the second light receiving element 11b and the arrangement direction of the third light receiving element 11c and the fourth light receiving element 11d are changed to the left and right. Sometimes referred to as a direction. In the direction detection device 10 of the present embodiment, the arrangement direction of the first light receiving element 11a and the third light receiving element 11c and the arrangement direction of the second light receiving element 11b and the fourth light receiving element 11d are moved up and down. Sometimes referred to as a direction. In the direction detection device 10 of the present embodiment, the direction from the first light receiving element 11a side to the second light receiving element 11b side is defined as a first direction D12. In the direction detection device 10 of the present embodiment, the direction from the second light receiving element 11b side to the first light receiving element 11a side is defined as a second direction D21. Similarly, in the direction detection device 10 of the present embodiment, the direction from the first light receiving element 11a side to the third light receiving element 11c side is defined as a third direction D13. In the direction detection device 10 of the present embodiment, the direction from the third light receiving element 11c side to the first light receiving element 11a side is defined as a fourth direction D31.
本実施形態の方向検出装置１０では、人の手を被検知体Ｈとして、赤外線検出部１の第１の受光素子１１ａないし第４の受光素子１１ｄが、被検知体Ｈから放射される赤外線を受光する。第１の受光素子１１ａないし第４の受光素子１１ｄのそれぞれは、焦電効果によって赤外線を検知し、受光した赤外線による温度変化に応じた電流を出力するように構成している。なお、方向検出装置１０は、人の手を被検知体Ｈとして検知するものだけに限らず、赤外線を放出するものであれば被検知体Ｈとして検知することができる。
In the direction detection device 10 of the present embodiment, the first light receiving element 11a to the fourth light receiving element 11d of the infrared detecting unit 1 emit infrared rays emitted from the detected object H with a human hand as the detected object H. Receive light. Each of the first light receiving element 11a to the fourth light receiving element 11d is configured to detect an infrared ray by a pyroelectric effect and output a current corresponding to a temperature change caused by the received infrared ray. In addition, the direction detection apparatus 10 can detect not only what detects a human hand as the to-be-detected body H but also the to-be-detected body H as long as it emits infrared rays.
第１の受光素子１１ａないし第４の受光素子１１ｄは、図示していないが、たとえば、ＭＥＭＳ(Micro Electro Mechanical Systems)技術を利用して形成させた赤外線センサを用いることができる。赤外線センサは、ダイアフラム上に形成した下部電極と、下部電極におけるダイアフラムとは反対側に形成した焦電膜と、焦電膜における下部電極とは反対側に形成した上部電極とを備える構成とすることができる。赤外線センサは、たとえば、焦電膜の焦電効果により上部電極と下部電極との間に生じた電圧を、ＭＯＳトランジスタのゲート電圧として、ＭＯＳトランジスタのドレインとソースと間に流れる電流を制御して出力できるように構成すればよい。赤外線センサは、焦電膜の焦電材料として、たとえば、鉛系の酸化物強誘電体の一種であるチタン酸ジルコン酸鉛（ＰＺＴ）やチタン酸ランタン酸鉛（ＰＬＴ）などを利用することができる。また、赤外線センサは、下部電極の材料として、たとえば、Ｐｔを採用し、上部電極の材料として、ＮｉＣｒを用いることができる。赤外線センサは、下部電極の材料として、Ｐｔだけに限られず、Ａｕ、ＡｌやＣｕなどを用いてもよい。また、赤外線センサは、上部電極の材料として、ＮｉＣｒだけに限られず、Ｎｉや金黒などを用いてもよい。
Although the first light receiving element 11a to the fourth light receiving element 11d are not shown, for example, an infrared sensor formed by using MEMS (Micro Electro Mechanical Systems) technology can be used. The infrared sensor includes a lower electrode formed on the diaphragm, a pyroelectric film formed on the opposite side of the lower electrode from the diaphragm, and an upper electrode formed on the opposite side of the pyroelectric film from the lower electrode. be able to. For example, the infrared sensor controls the current flowing between the drain and source of the MOS transistor using the voltage generated between the upper electrode and the lower electrode due to the pyroelectric effect of the pyroelectric film as the gate voltage of the MOS transistor. What is necessary is just to comprise so that it can output. Infrared sensors may use, for example, lead zirconate titanate (PZT) or lead lanthanum titanate (PLT), which are one of lead-based oxide ferroelectrics, as the pyroelectric material of the pyroelectric film. it can. The infrared sensor can employ, for example, Pt as the material of the lower electrode, and NiCr as the material of the upper electrode. The infrared sensor is not limited to Pt as a material for the lower electrode, and Au, Al, Cu, or the like may be used. The infrared sensor is not limited to NiCr as a material for the upper electrode, and Ni, gold black, or the like may be used.
赤外線検出部１では、第１の信号変換部１２ａが第１の受光素子１１ａから出力される出力電流を電圧信号に変換する。第１の信号変換部１２ａは、出力電流を変換した電圧信号を増幅し検知信号Ｓａとして信号処理部２へ出力する。また、赤外線検出部１では、第２の信号変換部１２ｂが第２の受光素子１１ｂから出力される出力電流を電圧信号に変換する。第２の信号変換部１２ｂは、出力電流を変換した電圧信号を増幅し検知信号Ｓｂとして信号処理部２へ出力する。同様に、赤外線検出部１では、第３の信号変換部１２ｃが第３の受光素子１１ｃから出力される出力電流を電圧信号に変換する。第３の信号変換部１２ｃは、出力電流を変換した電圧信号を増幅し検知信号Ｓｃとして信号処理部２へ出力する。また、赤外線検出部１では、第４の信号変換部１２ｄが第４の受光素子１１ｄから出力される出力電流を電圧信号に変換する。第４の信号変換部１２ｃは、出力電流を変換した電圧信号を増幅し検知信号Ｓｄとして信号処理部２へ出力する。信号処理部２は、記憶部２ａに予め記憶させた上記プログラムに基づいて、所定時間内に入力された検知信号Ｓａ〜Ｓｄを信号処理して被検知体Ｈの移動方向を判別する。なお、信号処理部２は、信号処理部２の内部に設けた記憶部２ａの上記プログラムに基づいて信号処理するものだけに限られず、信号処理部２の外部に設けた記憶装置に記憶させたプログラムに基づいて信号処理を行うものでもよい。
In the infrared detector 1, the first signal converter 12 a converts the output current output from the first light receiving element 11 a into a voltage signal. The first signal converter 12a amplifies the voltage signal obtained by converting the output current, and outputs the amplified signal to the signal processor 2 as the detection signal Sa. In the infrared detection unit 1, the second signal conversion unit 12b converts the output current output from the second light receiving element 11b into a voltage signal. The second signal converter 12b amplifies the voltage signal obtained by converting the output current and outputs the amplified signal to the signal processor 2 as the detection signal Sb. Similarly, in the infrared detection unit 1, the third signal converter 12c converts the output current output from the third light receiving element 11c into a voltage signal. The third signal converter 12c amplifies the voltage signal obtained by converting the output current, and outputs the amplified signal to the signal processor 2 as the detection signal Sc. In the infrared detection unit 1, the fourth signal conversion unit 12d converts the output current output from the fourth light receiving element 11d into a voltage signal. The fourth signal converter 12c amplifies the voltage signal obtained by converting the output current and outputs the amplified signal to the signal processor 2 as the detection signal Sd. Based on the program stored in advance in the storage unit 2a, the signal processing unit 2 performs signal processing on the detection signals Sa to Sd input within a predetermined time to determine the moving direction of the detection target H. The signal processing unit 2 is not limited to the one that performs signal processing based on the program of the storage unit 2a provided inside the signal processing unit 2, but is stored in a storage device provided outside the signal processing unit 2. Signal processing may be performed based on a program.
方向検出装置１０は、信号処理部２により被検知体Ｈの移動方向を判別した結果の信号を、図示しないパーソナルコンピュータなどの外部機器へ出力することができる。外部機器では、入力された被検知体Ｈの移動方向を判別した結果の信号を、たとえば、キーボードの矢印キーで入力操作を行うのと同様に、外部機器への入力操作に利用することが可能となる。
The direction detection device 10 can output a signal obtained as a result of determining the moving direction of the detection target H by the signal processing unit 2 to an external device such as a personal computer (not shown). In the external device, the signal obtained as a result of determining the moving direction of the detected object H can be used for the input operation to the external device, for example, in the same manner as the input operation with the arrow keys of the keyboard. It becomes.
次に、本実施形態の方向検出装置１０の信号処理部２が被検知体Ｈの移動方向を判別する信号処理について説明する。
Next, signal processing in which the signal processing unit 2 of the direction detection device 10 according to the present embodiment determines the moving direction of the detection target H will be described.
まず、本実施形態の方向検出装置１０では、第１の受光素子１１ａ、第２の受光素子１１ｂ、第３の受光素子１１ｃおよび第４の受光素子１１ｄそれぞれの各検知領域に、被検知体Ｈが進入した場合、赤外線検出部１から各別に検知信号Ｓａ〜Ｓｄが出力される。本実施形態の方向検出装置１０では、第１の受光素子１１ａの検知領域（図示していない）に被検知体Ｈが進入した場合、赤外線検出部１から検知信号Ｓａが出力される。方向検出装置１０は、第２の受光素子１１ｂの検知領域（図示していない）に被検知体Ｈが進入した場合、赤外線検出部１から検知信号Ｓｂが出力される。方向検出装置１０は、第３の受光素子１１ｃの検知領域（図示していない）に被検知体Ｈが進入した場合、赤外線検出部１から検知信号Ｓｃが出力される。方向検出装置１０は、第４の受光素子１１ｄの検知領域（図示していない）に被検知体Ｈが進入した場合、赤外線検出部１から検知信号Ｓｄが出力される。なお、赤外線検出部１の検知領域とは、第１の受光素子１１ａないし第４の受光素子１１ｄそれぞれの検知領域を合わせた総検知領域を意味する。
First, in the direction detection device 10 of the present embodiment, the detection target H is provided in each detection region of each of the first light receiving element 11a, the second light receiving element 11b, the third light receiving element 11c, and the fourth light receiving element 11d. , The detection signals Sa to Sd are output from the infrared detection unit 1 individually. In the direction detection device 10 of the present embodiment, the detection signal Sa is output from the infrared detection unit 1 when the detection target H enters the detection region (not shown) of the first light receiving element 11a. The direction detection device 10 outputs a detection signal Sb from the infrared detection unit 1 when the detection target H enters the detection region (not shown) of the second light receiving element 11b. The direction detection device 10 outputs a detection signal Sc from the infrared detection unit 1 when the detection target H enters the detection region (not shown) of the third light receiving element 11c. The direction detection device 10 outputs a detection signal Sd from the infrared detection unit 1 when the detection target H enters the detection region (not shown) of the fourth light receiving element 11d. In addition, the detection area of the infrared detection unit 1 means a total detection area including the detection areas of the first light receiving element 11a to the fourth light receiving element 11d.
方向検出装置１０は、たとえば、被検知体Ｈが赤外線検出部１を左側から右側に横切って移動する場合、図２に示す検知信号Ｓａを出力する。検知信号Ｓａは、被検知体Ｈが第１の受光素子１１ａに近づくにつれ、振幅が徐々に大きくなり検知信号Ｓａの振幅が最大となる正のピーク値Ｐａ１を超えて徐々に小さくなる。検知信号Ｓａは、たとえば、被検知体Ｈが第１の受光素子１１ａの検知領域を完全に覆った状態で、検知信号Ｓａの振幅が零となる。また、検知信号Ｓａは、被検知体Ｈが第１の受光素子１１ａを完全に覆った状態から離れるにつれて、振幅が徐々に小さくなり検知信号Ｓａの振幅が最小となる負のピーク値Ｐａ２を超えて徐々に大きくなる。
The direction detection device 10 outputs, for example, a detection signal Sa shown in FIG. 2 when the detected object H moves across the infrared detection unit 1 from the left side to the right side. As the detection object H approaches the first light receiving element 11a, the detection signal Sa gradually increases in amplitude and exceeds the positive peak value Pa1 at which the amplitude of the detection signal Sa is maximized. In the detection signal Sa, for example, the amplitude of the detection signal Sa becomes zero in a state where the detection target H completely covers the detection region of the first light receiving element 11a. In addition, the detection signal Sa exceeds the negative peak value Pa2 at which the amplitude gradually decreases and the amplitude of the detection signal Sa is minimized as the detection target H moves away from the state where the detection target H completely covers the first light receiving element 11a. Gradually grows.
次に、本実施形態の方向検出装置１０は、第１の受光素子１１ａと左右方向に並んで配置させた第２の受光素子１１ｂが、第１の受光素子１１ａを通った被検知体Ｈを検知し、図２に示す検知信号Ｓｂを出力する。検知信号Ｓｂは、被検知体Ｈが第２の受光素子１１ｂの左側から右側に横切って移動する場合、被検知体Ｈが第２の受光素子１１ｂに近づくにつれ、振幅が徐々に大きくなり検知信号Ｓｂの振幅が最大となる正のピーク値Ｐｂ１を超えて徐々に小さくなる。検知信号Ｓｂは、たとえば、被検知体Ｈが第２の受光素子１１ｂを完全に覆った状態で、検出信号Ｓｂの振幅が零となる。また、検知信号Ｓｂは、被検知体Ｈが第２の受光素子１１ｂを覆った状態から離れるにつれて、振幅が徐々に小さくなり検知信号Ｓｂの振幅が最小となる負のピーク値Ｐｂ２を超えて徐々に大きくなる。
Next, in the direction detection device 10 of the present embodiment, the second light receiving element 11b arranged side by side in the left-right direction with the first light receiving element 11a moves the detected object H that has passed through the first light receiving element 11a. It detects and outputs the detection signal Sb shown in FIG. When the detection target H moves from the left side to the right side of the second light receiving element 11b, the detection signal Sb has an amplitude that gradually increases as the detection target H approaches the second light reception element 11b. The positive peak value Pb1 at which the amplitude of Sb becomes maximum is gradually decreased. In the detection signal Sb, for example, the amplitude of the detection signal Sb becomes zero in a state where the detection target H completely covers the second light receiving element 11b. Further, the detection signal Sb gradually exceeds the negative peak value Pb2 at which the amplitude gradually decreases and the amplitude of the detection signal Sb is minimized as the detection target H moves away from the state of covering the second light receiving element 11b. Become bigger.
すなわち、方向検出装置１０では、被検知体Ｈが赤外線検出部１を左側から右側へ一定の速度で移動する場合、第１の受光素子１１ａと第２の受光素子１１ｂとが配置された間隔に比例する時間差をおいて略同一波形の検知信号Ｓａ，Ｓｂが出力される。また、方向検出装置１０は、被検知体Ｈが赤外線検出部１を左側から右側へ移動する場合、第１の受光素子１１ａと第３の受光素子１１ｃとは、ほぼ同時刻に略同一波形の検知信号Ｓａ，Ｓｃを出力する。同様に、本実施形態の方向検出装置１０では、被検知体Ｈが赤外線検出部１を左側から右側へ移動する場合、第２の受光素子１１ｂと第４の受光素子１１ｄとは、ほぼ同時刻に略同一波形の検知信号Ｓｂ，Ｓｄを出力する。
That is, in the direction detection device 10, when the detection target H moves the infrared detection unit 1 from the left side to the right side at a constant speed, the distance between the first light receiving element 11 a and the second light receiving element 11 b is set. Detection signals Sa and Sb having substantially the same waveform are output with a proportional time difference. Further, when the detection object H moves the infrared detection unit 1 from the left side to the right side, the direction detection device 10 causes the first light receiving element 11a and the third light receiving element 11c to have substantially the same waveform at substantially the same time. Detection signals Sa and Sc are output. Similarly, in the direction detection device 10 of the present embodiment, when the detection object H moves the infrared detection unit 1 from the left side to the right side, the second light receiving element 11b and the fourth light receiving element 11d are substantially at the same time. Output detection signals Sb and Sd having substantially the same waveform.
ところで、本実施形態の方向検出装置１０では、第１の受光素子１１ａ、第２の受光素子１１ｂ、第３の受光素子１１ｃおよび第４の受光素子１１ｄは、焦電型の受光素子を用いている。焦電型の受光素子は、温度変化を検知する特性を有する。
By the way, in the direction detection apparatus 10 of this embodiment, the 1st light receiving element 11a, the 2nd light receiving element 11b, the 3rd light receiving element 11c, and the 4th light receiving element 11d use a pyroelectric light receiving element. Yes. The pyroelectric light-receiving element has a characteristic of detecting a temperature change.
方向検出装置１０の赤外線検出部１では、第１の受光素子１１ａについてみると、被検知体Ｈが焦電型の第１の受光素子１１ａを横切った場合、被検知体Ｈが検知領域を覆うにつれ、たとえば、正のピーク値Ｐａ１を有する波形の第１のピークＳＰａ１を含んだ検知信号Ｓａを出力する。また、焦電型の第１の受光素子１１ａは、被検知体Ｈが検知領域から離れることで、正のピーク値Ｐ１を有する第１のピークＳＰａ１とは逆の極性のピーク値Ｐａ２を有する波形の第２のピークＳＰａ２を含んだ検知信号Ｓａを出力する（図２を参照）。
In the infrared detection unit 1 of the direction detection device 10, regarding the first light receiving element 11 a, when the detected object H crosses the pyroelectric first light receiving element 11 a, the detected object H covers the detection region. Accordingly, for example, the detection signal Sa including the first peak SPa1 having a waveform having the positive peak value Pa1 is output. Further, the pyroelectric first light receiving element 11a has a waveform having a peak value Pa2 having a polarity opposite to that of the first peak SPa1 having a positive peak value P1 when the detection target H is separated from the detection region. The detection signal Sa including the second peak SPa2 is output (see FIG. 2).
本実施形態の方向検出装置１０では、第１の受光素子１１ａは、背景に対して被検知体Ｈの温度が高ければ、赤外線検出部１が図２に示すＳ字形状の波形の検知信号Ｓａを出力する。図２に示す検知信号Ｓａでは、正のピーク値Ｐａ１を有する第１のピークＳＰａ１の波形は、背景に対して温度の高い被検知体Ｈが第１の受光素子１１ａの検知領域に侵入したことを示している。また、図２に示す検知信号Ｓａでは、負のピーク値Ｐａ２を有する第２のピークＳＰａ２の波形は、被検知体Ｈが第１の受光素子１１ａの検知領域から離れることに伴い焦電型の受光素子において不可避的に生ずるアンダーシュートの成分が含まれている。
In the direction detection device 10 of the present embodiment, the first light receiving element 11a is detected by the infrared detection unit 1 having the S-shaped waveform shown in FIG. Is output. In the detection signal Sa shown in FIG. 2, the waveform of the first peak SPa1 having the positive peak value Pa1 indicates that the detection object H having a higher temperature than the background has entered the detection region of the first light receiving element 11a. Is shown. Further, in the detection signal Sa shown in FIG. 2, the waveform of the second peak SPa2 having the negative peak value Pa2 is a pyroelectric type as the detected object H moves away from the detection region of the first light receiving element 11a. An undershoot component inevitably generated in the light receiving element is included.
なお、方向検出装置１０では、被検知体Ｈが背景に対して温度が低い冷体の場合、被検知体Ｈが背景に対して温度が高い温体の場合における検知信号Ｓａの波形と正負が逆転した形状となる。背景に対して温度の低い冷体となる被検知体Ｈとしては、たとえば、冷やした手や手を洗った直後の水が付着している手などが挙げられる。
In the direction detection device 10, when the detected object H is a cold body whose temperature is lower than the background, the waveform and positive / negative of the detection signal Sa when the detected object H is a warm body whose temperature is higher than the background. The shape is reversed. Examples of the detection target H that is a cold body having a low temperature with respect to the background include a cold hand and a hand to which water immediately after washing the hand is attached.
信号処理部２は、時刻を計時する計時部（図示していない）を備えている。計時部は、赤外線検出部１から出力される検知信号Ｓａ〜Ｓｄと対応させて、時刻を計時している。信号処理部２は、記憶部２ａに予め記憶させた上記プログラムを用いて、検知信号Ｓａの振幅が入力開始閾値ＩＴを超えて、最大となる時刻をピーク時刻Ｔａ１として特定する。信号処理部２は、記憶部２ａに予め記憶させた上記プログラムを用いて、検知信号Ｓｂの振幅が入力開始閾値ＩＴを超えて、最大となる時刻をピーク時刻Ｔｂ１として特定する。信号処理部２は、記憶部２ａに予め記憶させた上記プログラムを用いて、検知信号Ｓｃの振幅が入力開始閾値ＩＴを超えて、最大となる時刻をピーク時刻Ｔｃ１として特定する。信号処理部２は、記憶部２ａに予め記憶させた上記プログラムを用いて、検知信号Ｓｄの振幅が入力開始閾値ＩＴを超えて、最大となる時刻をピーク時刻Ｔｄ１として特定する。信号処理部２は、ピーク時刻Ｔａ１、ピーク時刻Ｔｂ１、ピーク時刻Ｔｃ１およびピーク時刻Ｔｄ１を記憶部２ａする。
The signal processing unit 2 includes a time measuring unit (not shown) that measures time. The timer unit measures the time in association with the detection signals Sa to Sd output from the infrared detector 1. The signal processing unit 2 specifies, as the peak time Ta1, the time when the amplitude of the detection signal Sa exceeds the input start threshold IT and becomes the maximum by using the program stored in advance in the storage unit 2a. The signal processing unit 2 specifies, as the peak time Tb1, the time when the amplitude of the detection signal Sb exceeds the input start threshold IT and becomes the maximum, using the program stored in advance in the storage unit 2a. The signal processing unit 2 specifies, as the peak time Tc1, the time when the amplitude of the detection signal Sc exceeds the input start threshold IT and becomes the maximum, using the program stored in advance in the storage unit 2a. The signal processing unit 2 specifies, as the peak time Td1, the time when the amplitude of the detection signal Sd exceeds the input start threshold value IT and becomes the maximum, using the program stored in the storage unit 2a in advance. The signal processing unit 2 stores the peak time Ta1, the peak time Tb1, the peak time Tc1, and the peak time Td1 in the storage unit 2a.
本実施形態の方向検出装置１０では、判別部２ｂは、たとえば、第１の受光素子１１ａと第２の受光素子１１ｂとにおいて、被検知体Ｈが左右方向に移動する場合、特定したピーク時刻Ｔａ１、Ｔｂ１を、時間の早い順に第１の時刻ｔ１、第２の時刻ｔ２とする（図２を参照）。信号処理部２は、第１の受光素子１１ａが検知する検知信号Ｓａに基づいて第１の時刻ｔ１が特定され第２の受光素子１１ｂが検知する検知信号Ｓｂに基づいて第２の時刻ｔ２が特定される場合、被検知体Ｈの移動方向が第１の方向Ｄ１２とする。信号処理部２は、第１の受光素子１１ａが検知する検知信号Ｓａに基づいて第２の時刻ｔ２が特定され第２の受光素子１１ｂが検知する検知信号Ｓｂに基づいて第１の時刻ｔ１が特定される場合、被検知体Ｈの移動方向が第２の方向Ｄ２１であると判別する。
In the direction detection device 10 of the present embodiment, the determination unit 2b determines the specified peak time Ta1 when, for example, the detected object H moves in the left-right direction in the first light receiving element 11a and the second light receiving element 11b. , Tb1 are set to a first time t1 and a second time t2 in order of increasing time (see FIG. 2). The signal processing unit 2 specifies the first time t1 based on the detection signal Sa detected by the first light receiving element 11a and determines the second time t2 based on the detection signal Sb detected by the second light receiving element 11b. When specified, the moving direction of the detection target H is the first direction D12. The signal processing unit 2 determines the second time t2 based on the detection signal Sa detected by the first light receiving element 11a, and determines the first time t1 based on the detection signal Sb detected by the second light receiving element 11b. When specified, it is determined that the moving direction of the detection target H is the second direction D21.
したがって、信号処理部２は、赤外線検出部１からの検知信号Ｓａ，Ｓｂに基づいて、被検知体Ｈの移動方向が、第１の受光素子１１ａおよび第２の受光素子１１ｂの配置方向に沿った第１の方向Ｄ１２か第２の方向Ｄ２１かを判別することが可能となる。
Therefore, in the signal processing unit 2, the moving direction of the detection target H is along the arrangement direction of the first light receiving element 11 a and the second light receiving element 11 b based on the detection signals Sa and Sb from the infrared detection unit 1. It is possible to determine whether the first direction D12 or the second direction D21.
なお、信号処理部２は、第３の受光素子１１ｃおよび第４の受光素子１１ｄからの検知信号Ｓｃ，Ｓｄを用いて、被検知体Ｈの移動方向を判別してもよい。また、信号処理部２は、検知信号Ｓａ，Ｓｂに加え、検知信号Ｓｃ，Ｓｄを用いて、被検知体Ｈの移動方向を判別してもよい。また、信号処理部２は、第１の受光素子１１ａおよび第３の受光素子１１ｃからの検知信号Ｓａ，Ｓｃを用いて、被検知体Ｈの移動方向が、第１の受光素子１１ａと第３の受光素子１１ｃとの配置方向に沿った上下方向のいずれかであるかを判別することができる。同様に、信号処理部２は、第２の受光素子１１ｂおよび第４の受光素子１１ｄからの検知信号Ｓｂ，Ｓｄを用いて、被検知体Ｈの移動方向が、第２の受光素子１１ｂと第４の受光素子１１ｄとの配置方向に沿った上下方向のいずれかであるかを判別することができる。
Note that the signal processing unit 2 may determine the moving direction of the detection target H by using the detection signals Sc and Sd from the third light receiving element 11c and the fourth light receiving element 11d. Further, the signal processing unit 2 may determine the moving direction of the detection target H using the detection signals Sc and Sd in addition to the detection signals Sa and Sb. The signal processing unit 2 uses the detection signals Sa and Sc from the first light receiving element 11a and the third light receiving element 11c so that the moving direction of the detection target H is the first light receiving element 11a and the third light receiving element 11c. It is possible to discriminate between the vertical direction along the arrangement direction of the light receiving element 11c. Similarly, the signal processing unit 2 uses the detection signals Sb and Sd from the second light receiving element 11b and the fourth light receiving element 11d so that the moving direction of the detection target H is the second light receiving element 11b and the second light receiving element 11b. It is possible to determine whether it is in the vertical direction along the arrangement direction with the four light receiving elements 11d.
本実施形態の方向検出装置１０は、たとえば、被検知体Ｈが赤外線検出部１の検知領域内を左から右へ移動した場合、検知信号Ｓａ，Ｓｃがほぼ同時刻に発生した後、検知信号Ｓｂ，Ｓｄがほぼ同時刻に発生する。本実施形態の方向検出装置１０は、たとえば、被検知体Ｈが赤外線検出部１の検知領域内を右から左へ移動した場合、検知信号Ｓｂ，Ｓｄがほぼ同時刻に発生した後、検知信号Ｓａ，Ｓｃがほぼ同時刻に発生する。また、本実施形態の方向検出装置１０は、たとえば、被検知体Ｈが赤外線検出部１の検知領域内を上から下へ移動した場合、検知信号Ｓａ，Ｓｂがほぼ同時刻に発生した後、検知信号Ｓｃ，Ｓｄがほぼ同時刻に発生する。本実施形態の方向検出装置１０は、たとえば、被検知体Ｈが赤外線検出部１の検知領域内を下から上へ移動した場合、検知信号Ｓｃ，Ｓｄがほぼ同時刻に発生した後、検知信号Ｓａ，Ｓｂがほぼ同時刻に発生する。
The direction detection device 10 of the present embodiment, for example, when the detection object H moves from the left to the right in the detection region of the infrared detection unit 1, the detection signals Sa and Sc are generated at substantially the same time, and then the detection signal Sb and Sd occur at approximately the same time. The direction detection device 10 according to the present embodiment detects, for example, the detection signal Sb and Sd generated at approximately the same time when the detection object H moves from the right to the left within the detection region of the infrared detection unit 1. Sa and Sc occur at approximately the same time. Further, the direction detection device 10 of the present embodiment, for example, when the detection object H moves from the top to the bottom within the detection region of the infrared detection unit 1, after the detection signals Sa and Sb are generated at substantially the same time, The detection signals Sc and Sd are generated at approximately the same time. The direction detection device 10 according to the present embodiment detects the detection signal Sc after the detection signals Sc and Sd are generated at substantially the same time, for example, when the detection target H moves from the bottom to the top in the detection region of the infrared detection unit 1. Sa and Sb occur at approximately the same time.
信号処理部２は、たとえば、検知信号Ｓａ〜Ｓｄのうち検知信号Ｓａのピーク時刻Ｔａ１と検知信号Ｓｂのピーク時刻Ｔｂ１のいずれが時間的に早いかの順に基づいて、被検知体Ｈの移動方向が第１の方向Ｄ１２であるか第２の方向Ｄ２１であるかを判別する。信号処理部２は、たとえば、検知信号Ｓａ〜Ｓｄのうち検知信号Ｓａのピーク時刻Ｔａ１と検知信号Ｓｄのピーク時刻Ｔｄ１のいずれが時間的に早いかの順に基づいて、被検知体Ｈの移動方向が第３の方向Ｄ１３であるか第４の方向Ｄ３１であるかを判別する。
For example, the signal processing unit 2 determines the moving direction of the detection target H based on which of the detection signals Sa to Sd the peak time Ta1 of the detection signal Sa and the peak time Tb1 of the detection signal Sb are earlier in time. Is the first direction D12 or the second direction D21. For example, the signal processing unit 2 determines the moving direction of the detection target H based on which of the detection signals Sa to Sd the peak time Ta1 of the detection signal Sa and the peak time Td1 of the detection signal Sd are earlier in time. Is the third direction D13 or the fourth direction D31.
ところで、焦電型の受光素子は、被検知体Ｈの温度が背景に対して高すぎるなど、被検知体Ｈと背景との温度差が大きすぎる場合、受光素子の出力が飽和し検知信号Ｓａ〜Ｓｄからピーク時刻Ｔａ１〜Ｔｄ１を検出することが難しい場合がある。
By the way, in the pyroelectric light-receiving element, when the temperature difference between the detected object H and the background is too large, such as the temperature of the detected object H is too high, the output of the light-receiving element is saturated and the detection signal Sa. It may be difficult to detect peak times Ta1 to Td1 from ~ Sd.
本実施形態の方向検出装置１０では、記憶させた検知信号Ｓａの振幅が飽和判定閾値ＳＴを超える場合、入力開始閾値ＩＴと飽和判定閾値ＳＴとの間に予め設定した方向判断閾値ＤＴを超える時刻を閾値時刻Ｔａ２として記憶させている。また、方向検出装置１０では、記憶させた検知信号Ｓｂの振幅が飽和判定閾値ＳＴを超える場合、入力開始閾値ＩＴと飽和判定閾値ＳＴとの間に予め設定した方向判断閾値ＤＴを検知信号Ｓｂの振幅が超える時刻を閾値時刻Ｔｂ２として記憶させている。方向検出装置１０は、検知信号Ｓａ，Ｓｂのいずれかが飽和判定閾値ＳＴを超える場合、閾値時刻Ｔａ１，Ｔｂ１を記憶する。
In the direction detection device 10 of the present embodiment, when the amplitude of the stored detection signal Sa exceeds the saturation determination threshold ST, the time when the direction determination threshold DT preset between the input start threshold IT and the saturation determination threshold ST is exceeded. Is stored as the threshold time Ta2. Further, in the direction detection device 10, when the amplitude of the stored detection signal Sb exceeds the saturation determination threshold ST, the direction determination threshold DT set in advance between the input start threshold IT and the saturation determination threshold ST is set in the detection signal Sb. The time when the amplitude exceeds is stored as the threshold time Tb2. The direction detection device 10 stores threshold times Ta1 and Tb1 when any of the detection signals Sa and Sb exceeds the saturation determination threshold ST.
本実施形態の方向検出装置１０では、判別部２ｂは、たとえば、第１の受光素子１１ａと第２の受光素子１１ｂとにおいて、被検知体Ｈが左右方向に移動する場合、特定した閾値時刻Ｔａ２、Ｔｂ２を、時間の早い順に第１の時刻ｔ１、第２の時刻ｔ２とする（図３を参照）。
In the direction detection device 10 of the present embodiment, the determination unit 2b determines, for example, the specified threshold time Ta2 when the detected object H moves in the left-right direction in the first light receiving element 11a and the second light receiving element 11b. , Tb2 are set to a first time t1 and a second time t2 in order of increasing time (see FIG. 3).
信号処理部２は、第１の受光素子１１ａが検知する検知信号Ｓａに基づいて第１の時刻ｔ１が特定され第２の受光素子１１ｂが検知する検知信号Ｓｂに基づいて第２の時刻ｔ２が特定される場合、被検知体Ｈの移動方向が第１の方向Ｄ１２であると判別する。信号処理部２は、第１の受光素子１１ａが検知する検知信号Ｓａに基づいて第２の時刻ｔ２が特定され第２の受光素子１１ｂが検知する検知信号Ｓｂに基づいて第１の時刻ｔ１が特定される場合、被検知体Ｈの移動方向が第２の方向Ｄ２１であると判別する。
The signal processing unit 2 specifies the first time t1 based on the detection signal Sa detected by the first light receiving element 11a and determines the second time t2 based on the detection signal Sb detected by the second light receiving element 11b. When specified, it is determined that the moving direction of the detection target H is the first direction D12. The signal processing unit 2 determines the second time t2 based on the detection signal Sa detected by the first light receiving element 11a, and determines the first time t1 based on the detection signal Sb detected by the second light receiving element 11b. When specified, it is determined that the moving direction of the detection target H is the second direction D21.
同様に、方向検出装置１０は、記憶させた検知信号Ｓｃの振幅が飽和判定閾値ＳＴを超える場合、入力開始閾値ＩＴと飽和判定閾値ＳＴとの間に予め設定した方向判断閾値ＤＴを超える時刻を閾値時刻Ｔｃ２として記憶する。また、方向検出装置１０は、記憶させた検知信号Ｓｄの振幅が飽和判定閾値ＳＴを超える場合、入力開始閾値ＩＴと飽和判定閾値ＳＴとの間に予め設定した方向判断閾値ＤＴを超える時刻を閾値時刻Ｔｄ２として記憶する。
Similarly, when the amplitude of the stored detection signal Sc exceeds the saturation determination threshold ST, the direction detection device 10 sets a time that exceeds a preset direction determination threshold DT between the input start threshold IT and the saturation determination threshold ST. Stored as threshold time Tc2. Further, when the amplitude of the stored detection signal Sd exceeds the saturation determination threshold ST, the direction detection device 10 sets a time that exceeds a predetermined direction determination threshold DT between the input start threshold IT and the saturation determination threshold ST as a threshold. Store as time Td2.
すなわち、本実施形態の方向検出装置１０では、各検知信号Ｓａ〜Ｓｄの第１のピークに対して、飽和判定閾値ＳＴを設定し、検知信号Ｓａ〜Ｓｄの振幅が飽和判定閾値ＳＴを超えるか否かで焦電型の受光素子の出力の飽和の有無を判別している。信号処理部２は、記憶部２ａに予め記憶させた上記プログラムに基づいて、第１のピークにおいて、検知信号Ｓａ〜Ｓｄの振幅が正のピーク値Ｐ１にまで増大した後、零点に達する時刻（以下、ゼロクロス時刻ともいう）を経過後にピーク時刻Ｔａ１〜Ｔｄ１や閾値時刻Ｔａ２〜Ｔｄ２を特定する。
That is, in the direction detection device 10 of the present embodiment, the saturation determination threshold value ST is set for the first peak of each of the detection signals Sa to Sd, and whether the amplitude of the detection signals Sa to Sd exceeds the saturation determination threshold value ST. The presence or absence of saturation of the output of the pyroelectric light-receiving element is determined based on whether or not. Based on the program stored in advance in the storage unit 2a, the signal processing unit 2 increases the amplitude of the detection signals Sa to Sd to the positive peak value P1 at the first peak and then reaches the zero point ( Hereinafter, the peak times Ta1 to Td1 and the threshold times Ta2 to Td2 are specified after elapse of time).
方向検出装置１０は、各検知信号Ｓａ〜Ｓｄがゼロクロス時刻で、記憶している検知信号Ｓａ〜Ｓｄの振幅の最大値の時刻をピーク時刻Ｔａ１〜Ｔｄ１、あるいは閾値時刻Ｔａ２〜Ｔｄ２として記憶すればよい。
If the direction detection device 10 stores each of the detection signals Sa to Sd at the zero cross time and stores the time of the maximum amplitude of the stored detection signals Sa to Sd as the peak times Ta1 to Td1 or the threshold times Ta2 to Td2. Good.
ところで、方向検出装置１０は、第１の受光素子１１ａや第２の受光素子１１ｂが製造ばらつきなどに伴うセンサ特性の違いなどにより、零点を検出する振幅の基準値が各検知信号Ｓａ〜Ｓｄごとに異なる場合がある。方向検出装置１０は、各検知信号Ｓａ〜Ｓｄ同士の振幅の基準値がずれている場合、被検知体Ｈの移動方向を精度よく検出することが難しくなる。また、方向検出装置１０では、零点がずれた検知信号Ｓａ〜Ｓｄでは、入力開始閾値ＩＴ、飽和判定閾値ＳＴや方向判断閾値ＤＴを設定することが難しくなる。
By the way, in the direction detection device 10, the reference value of the amplitude for detecting the zero point is determined for each of the detection signals Sa to Sd due to differences in sensor characteristics caused by manufacturing variations of the first light receiving element 11a and the second light receiving element 11b. May be different. When the reference value of the amplitude between the detection signals Sa to Sd is deviated, it is difficult for the direction detection device 10 to accurately detect the moving direction of the detection target H. Further, in the direction detection device 10, it is difficult to set the input start threshold IT, the saturation determination threshold ST, and the direction determination threshold DT with the detection signals Sa to Sd whose zeros are shifted.
以下、検知信号Ｓａ〜Ｓｄの値を補正することを説明する。
Hereinafter, correcting the values of the detection signals Sa to Sd will be described.
本実施形態の方向検出装置１０では、信号処理部２が所定の時間間隔ごとに各検知信号Ｓａ〜Ｓｄの振幅値をそれぞれ抽出するサンプリングを行う。方向検出装置１０は、検知信号Ｓａ〜Ｓｄの振幅値の測定を開始する測定開始時刻Ｓから所定のオフセット計測期間ＯＭの間、検知信号Ｓａの振幅値をサンプリングしている。方向検出装置１０は、抽出した検知信号Ｓａの振幅値が所定の回数Ｎ（たとえば、１０回）連続して、予め設定したオフセット閾値ＯＴの範囲内において検出した場合、所定の回数Ｎの振幅値の平均値をオフセット量として設定して補正している。
In the direction detection device 10 of the present embodiment, the signal processing unit 2 performs sampling for extracting the amplitude values of the detection signals Sa to Sd at predetermined time intervals. The direction detection device 10 samples the amplitude value of the detection signal Sa during a predetermined offset measurement period OM from the measurement start time S at which the measurement of the amplitude values of the detection signals Sa to Sd is started. When the direction detection device 10 detects the amplitude value of the extracted detection signal Sa for a predetermined number N (for example, 10 times) continuously within the preset offset threshold value OT, the direction detection device 10 determines the amplitude value for the predetermined number N. The average value is set as the offset amount and corrected.
方向検出装置１０は、検知信号Ｓａから設定したオフセット量の値を除去することで、オフセット補正を行うことが可能となる。方向検出装置１０は、逐次自動的にオフセット補正を行うよう構成すればよい。本実施形態の方向検出装置１０は、オフセット量が補正された検知信号Ｓａを用いて被検知体Ｈの移動方向の検出を行うことで、より高い精度で被検知体Ｈの移動方向を検出することが可能となる。
The direction detection device 10 can perform offset correction by removing the set offset amount value from the detection signal Sa. The direction detection device 10 may be configured to automatically and sequentially perform offset correction. The direction detection device 10 of the present embodiment detects the moving direction of the detected object H with higher accuracy by detecting the moving direction of the detected object H using the detection signal Sa with the offset amount corrected. It becomes possible.
なお、本実施形態の方向検出装置１０は、ゆっくりと手を動かすなど被検知体Ｈがゆっくりと移動する場合、検知した検知信号Ｓａにおける振幅の変化量も小さく、検知信号Ｓａ〜Ｓｄのオフセット補正を行うことが難しい場合がある。
Note that the direction detection device 10 of the present embodiment has a small amplitude change amount in the detected detection signal Sa when the detected object H moves slowly, such as slowly moving the hand, and offset correction of the detection signals Sa to Sd. It may be difficult to do.
方向検出装置１０は、予め設定したオフセット閾値ＯＴの範囲以下において、被検知体Ｈから検知信号Ｓａの振幅が緩やかに変化する場合、第１の受光素子１１ａが赤外線を受光しているにも関わらず、オフセット補正が行われる恐れがある。方向検出装置１０は、検知信号Ｓａの振幅が緩やかに変化する場合であっても、誤ってオフセット補正が行われることを抑制するため、所定の時間間隔ごとに各検知信号Ｓａ〜Ｓｄの振幅を抽出するサンプリングの回数を適宜に間引いてもよい。方向検出装置１０は、たとえば、サンプリングの抽出回数を５回に１回間引けばよい。
In the direction detection device 10, when the amplitude of the detection signal Sa gradually changes from the detection target H within the range of the preset offset threshold value OT, the first light receiving element 11 a receives infrared rays. In some cases, offset correction may be performed. The direction detection device 10 sets the amplitudes of the detection signals Sa to Sd at predetermined time intervals in order to suppress erroneous offset correction even when the amplitude of the detection signal Sa changes slowly. The number of samplings to be extracted may be thinned out as appropriate. For example, the direction detection device 10 may thin out the number of sampling extractions once in five.
また、方向検出装置１０は、たとえば、図４に示すように、検知信号Ｓａの測定開始時刻Ｓからオフセット計測期間ＯＭの間における検知信号Ｓａの振幅の最大値と最小値との幅を比較してオフセット補正を行ってもよい。方向検出装置１０は、所定の回数Ｎ（たとえば、１０回）内における検知信号Ｓａの振幅の最大値と最小値とが予め設定したオフセット閾値ＯＴの範囲内の場合、所定の回数Ｎの振幅値の平均値をオフセット量として設定して補正することができる。方向検出装置１０は、検知信号Ｓａから設定したオフセット量の値を除去することで、オフセット補正を行うことが可能となる（図４のＡで示す破線の矢印を参照）。
Further, for example, as illustrated in FIG. 4, the direction detection device 10 compares the width between the maximum value and the minimum value of the amplitude of the detection signal Sa between the measurement start time S of the detection signal Sa and the offset measurement period OM. Offset correction may be performed. The direction detection device 10 determines the amplitude value of the predetermined number N when the maximum value and the minimum value of the amplitude of the detection signal Sa within the predetermined number N (for example, 10 times) are within the preset offset threshold value OT. Can be corrected by setting the average value as an offset amount. The direction detection device 10 can perform offset correction by removing the value of the offset amount set from the detection signal Sa (see the broken line arrow indicated by A in FIG. 4).
本実施形態の方向検出装置１０は、方向検出装置１０が被検知体Ｈの移動方向を検出中において、逐次繰り返して各検知信号Ｓａ〜Ｓｄに対しオフセット補正を行っている。言い換えれば、本実施形態の方向検出装置１０は、赤外線検出部１から出力される各検知信号Ｓａ〜Ｓｄの振幅方向のずれが小さくなるようにオフセット補正を行っている。方向検出装置１０は、逐次繰返してオフセット補正を行うことにより、方向検出装置１０に経時変化が生じても、より高い精度で被検知体の移動方向を検出することができる。
The direction detection device 10 according to the present embodiment performs offset correction on the detection signals Sa to Sd repeatedly and repeatedly while the direction detection device 10 is detecting the moving direction of the detection target H. In other words, the direction detection device 10 of the present embodiment performs offset correction so that deviations in the amplitude direction of the detection signals Sa to Sd output from the infrared detection unit 1 are reduced. The direction detection device 10 can detect the moving direction of the detected object with higher accuracy even if the direction detection device 10 changes with time by performing offset correction repeatedly and sequentially.
ところで、本実施形態の方向検知装置１０では、被検知体Ｈが赤外線検出部１の４つ全ての受光素子１１ａ〜１１ｄの検知領域を停止することなく横切る第１の動作と、被検知体Ｈが検知領域に進入して検知領域に停止した後、検知領域から離れる第２の動作とを検出することもできる。第１の動作は、たとえば、赤外線検出部１上を水平方向に横切る被検知体Ｈの移動方向の動作と見做すことができる。方向検知装置１０は、被検知体Ｈが赤外線検出部１の検知領域を停止することなく横切る被検知体Ｈの移動によって、外部機器の操作内容における選択動作などに利用することができる。また、第２の動作は、たとえば、第１の受光素子１１ａから第４の受光素子１１ｄが並んで配置された赤外線検出部１の水平面に対して垂直方向に近づいたり遠ざかったりする被検知体Ｈの移動方向の動作と見做すことができる。方向検知装置１０は、被検知体Ｈが赤外線検出部１に対し垂直方向に近づき一旦停止した後に遠ざかる被検知体Ｈの移動によって、外部機器の操作内容における入力動作などに利用することができる。
By the way, in the direction detection apparatus 10 of this embodiment, the to-be-detected body H and 1st operation | movement which the to-be-detected body H crosses without stopping the detection area | region of all the four light receiving elements 11a-11d of the infrared rays detection part 1 After entering the detection area and stopping in the detection area, it is also possible to detect the second movement away from the detection area. The first operation can be regarded as, for example, an operation in the moving direction of the detection target H that crosses the infrared detection unit 1 in the horizontal direction. The direction detection device 10 can be used for a selection operation in the operation content of an external device by the movement of the detection target H that the detection target H crosses without stopping the detection region of the infrared detection unit 1. Further, the second operation is performed by, for example, the detection target H that approaches or moves away from the horizontal plane of the infrared detection unit 1 in which the first light receiving element 11a to the fourth light receiving element 11d are arranged side by side. This can be considered as movement in the direction of movement. The direction detection device 10 can be used for an input operation or the like in the operation content of the external device by the movement of the detection target H that is moved away from the detection target H after approaching the infrared detection unit 1 in the vertical direction and once stopped.
本実施形態の方向検知装置１０では、信号処理部２が被検知体Ｈの第１の動作で生ずる被検知体Ｈの移動方向を判別するに先立って、信号処理部２が被検知体Ｈの第２の動作で生ずる被検知体Ｈの移動方向を判別することができる。
In the direction detection device 10 of the present embodiment, the signal processing unit 2 detects the moving direction of the detected object H that occurs in the first operation of the detected object H before the signal processing unit 2 detects the moving direction of the detected object H. The moving direction of the detection target H generated by the second operation can be determined.
以下、本実施形態の方向検出装置１０における第２の動作について、より詳細に説明する。
Hereinafter, the second operation in the direction detection device 10 of the present embodiment will be described in more detail.
信号処理部２は、所定時間内に入力された４つの検知信号Ｓａ〜Ｓｄの平均をとった平均検知信号ＡＳにおける波形に基づいて、被検知体Ｈの移動方向を検出する信号処理を行う。
The signal processing unit 2 performs signal processing for detecting the moving direction of the detection target H based on the waveform of the average detection signal AS obtained by averaging the four detection signals Sa to Sd input within a predetermined time.
まず、本実施形態の方向検出装置１０は、信号処理部２が赤外線検出部１から出力される各検知信号Ｓａ〜Ｓｄの平均をとった平均検知信号ＡＳを生成する（図５を参照）。信号処理部２は、平均検知信号ＡＳの波形が４つの検知信号Ｓａ〜Ｓｄの発生時刻を時間軸上において略一致させた状態で、各検知信号Ｓａ〜Ｓｄの振幅の平均値をとって平均検知信号ＡＳを生成している。
First, in the direction detection device 10 of the present embodiment, the signal processing unit 2 generates an average detection signal AS that is an average of the detection signals Sa to Sd output from the infrared detection unit 1 (see FIG. 5). The signal processing unit 2 takes the average value of the amplitudes of the detection signals Sa to Sd in the state where the waveform of the average detection signal AS substantially matches the generation time of the four detection signals Sa to Sd on the time axis. A detection signal AS is generated.
平均検知信号ＡＳは、被検知体Ｈが赤外線検出部１の検知領域に進入した場合、平均検知信号ＡＳの振幅が正のピーク値Ｐ１を有する波形の第１のピークＳＰ１が形成された後、負のピーク値Ｐ２を有する波形の第２のピークＳＰ２が形成される。平均検知信号ＡＳは、第１のピークＳＰ１と第２のピークＳＰ２の波形を備えた略Ｓ字形状となっている。
When the detected object H enters the detection region of the infrared detection unit 1, the average detection signal AS is formed after the first peak SP1 having a waveform in which the amplitude of the average detection signal AS has a positive peak value P1 is formed. A second peak SP2 having a waveform having a negative peak value P2 is formed. The average detection signal AS has a substantially S shape with waveforms of the first peak SP1 and the second peak SP2.
なお、本実施形態の方向検出装置１０では、第１のピークＳＰ１において、平均検知信号ＡＳの振幅が入力開始閾値ＩＴを超えて、再び入力開始閾値ＩＴに戻ってくるまでの時間を平均検知信号ＡＳにおける第１のピーク幅Ｘと規定している。また、本実施形態の方向検出装置１０では、平均検知信号ＡＳの第１のピークＳＰ１のピーク値Ｐ１と第２のピークＳＰ２のピーク値Ｐ２と比率を波形比Ｙと規定している。
In the direction detection device 10 of the present embodiment, the average detection signal is the time until the amplitude of the average detection signal AS exceeds the input start threshold IT and returns to the input start threshold IT again at the first peak SP1. This is defined as the first peak width X in AS. In the direction detection device 10 of the present embodiment, the ratio of the peak value P1 of the first peak SP1 to the peak value P2 of the second peak SP2 of the average detection signal AS is defined as the waveform ratio Y.
本実施形態の方向検出装置１０では、被検知体Ｈの移動方向における第１の動作と第２の動作とを、平均検知信号ＡＳにおける第１のピーク幅Ｘの値と波形比Ｙの値との相関関係から次の関係式により判別することが可能となる。
In the direction detection device 10 of the present embodiment, the first operation and the second operation in the moving direction of the detection target H are performed by using the value of the first peak width X and the value of the waveform ratio Y in the average detection signal AS. It is possible to discriminate by the following relational expression from the correlation.
すなわち、式（１）は、波形比Ｙの値と第１のピーク幅Ｘの値とが反比例の関係となっている。
That is, in the equation (1), the value of the waveform ratio Y and the value of the first peak width X are in an inversely proportional relationship.
本実施形態の方向検出装置１０では、波形比Ｙの値よりもａ／Ｘ＋ｂの値が小さい領域に第１の動作となる値が収まる。また、本実施形態の方向検出装置１０では、波形比Ｙの値がａ／Ｘ＋ｂの値以上の領域に第２の動作となる値が収まる。すなわち、本実施形態の方向検出装置１０では、信号処理部２は、波形比Ｙの値と第１のピーク幅Ｘの値との相関関係から第１の動作と第２の動作とを判別することができる。
In the direction detection device 10 according to the present embodiment, the value for the first operation is within a region where the value of a / X + b is smaller than the value of the waveform ratio Y. Further, in the direction detection device 10 of the present embodiment, the value for the second operation falls within the region where the value of the waveform ratio Y is greater than or equal to the value of a / X + b. That is, in the direction detection device 10 of the present embodiment, the signal processing unit 2 determines the first operation and the second operation from the correlation between the value of the waveform ratio Y and the value of the first peak width X. be able to.
なお、本実施形態の方向検出装置１０は、平均検知信号ＡＳに基づいて、赤外線検出部１の検知領域を停止することなく被検知体Ｈが横切る第１の動作と、被検知体Ｈが赤外線検出部１の検知領域に進入して検知領域に停止した後、検知領域から離れる第２の動作とを判別する。方向検出装置１０は、第１の動作であると判定した後に、各検知信号Ｓａ〜Ｓｄに基づいて被検知体Ｈの移動方向を判別している。
In addition, the direction detection apparatus 10 of this embodiment is based on the average detection signal AS, the 1st operation | movement which the to-be-detected body H crosses without stopping the detection area | region of the infrared detection part 1, and the to-be-detected body H is infrared rays. After entering the detection area of the detection unit 1 and stopping in the detection area, the second operation of moving away from the detection area is discriminated. The direction detection device 10 determines the moving direction of the detection target H based on the detection signals Sa to Sd after determining the first operation.
被検知体Ｈが第１の動作を行った場合の平均検知信号ＡＳと、被検知体Ｈが第２の動作を行った場合の平均検知信号ＡＳとは、図示していないが、非検知体Ｈの移動に伴う時間的な差があるため、第１のピークＳＰ１の波形と第２のピークＳＰ２の波形の形状が異なる。被検知体Ｈが第１の動作を行った場合に生成される平均検知信号ＡＳは、被検知体Ｈが第２の動作を行った場合に生成される平均検知信号ＡＳと比較して、第１のピーク幅Ｘの時間間隔が短い傾向にある。また、被検知体Ｈが第１の動作を行った場合に生成される平均検知信号ＡＳは、被検知体Ｈが第２の動作を行った場合に生成される平均検知信号ＡＳと比較して、正のピーク値Ｐ１と負のピーク値Ｐ２との波形比Ｙが小さい傾向にある。
The average detection signal AS when the detection target H performs the first operation and the average detection signal AS when the detection target H performs the second operation are not shown, but are not detected. Since there is a temporal difference associated with the movement of H, the waveform of the first peak SP1 and the waveform of the second peak SP2 are different. The average detection signal AS generated when the detection target H performs the first operation is compared with the average detection signal AS generated when the detection target H performs the second operation. The time interval of the peak width X of 1 tends to be short. The average detection signal AS generated when the detection target H performs the first operation is compared with the average detection signal AS generated when the detection target H performs the second operation. The waveform ratio Y between the positive peak value P1 and the negative peak value P2 tends to be small.
本実施形態の方向検出装置１０は、より具体的には、焦電型の第１の受光素子１１ａと焦電型の第２の受光素子１１ｂと焦電型の第３の受光素子１１ｃと焦電型の第４の受光素子１１ｄとを正方格子状に配置させた赤外線検出部１を有している。赤外線検出部１は、第１の受光素子１１ａ、第２の受光素子１１ｂ、第３の受光素子１１ｃおよび第４の受光素子１１ｄが被検知体Ｈから受光した赤外線による温度変化に応じた波形の検知信号Ｓａ〜Ｓｄを各別に出力する。方向検出装置１０は、赤外線検出部１から入力された検知信号Ｓａ〜Ｓｄに基づき、被検知体Ｈの移動方向が、上記正方格子の各辺に沿った上下方向または左右方向であることを判別し、被検知体Ｈの移動方向を検出する信号処理部２を有している。
More specifically, the direction detection device 10 of the present embodiment includes a pyroelectric first light receiving element 11a, a pyroelectric second light receiving element 11b, a pyroelectric third light receiving element 11c, and a pyroelectric type light receiving element 11c. It has the infrared detection part 1 which has arrange | positioned the electric type 4th light receiving element 11d in the square-lattice form. The infrared detection unit 1 has a waveform corresponding to a temperature change due to infrared rays received from the detection target H by the first light receiving element 11a, the second light receiving element 11b, the third light receiving element 11c, and the fourth light receiving element 11d. The detection signals Sa to Sd are output separately. The direction detection device 10 determines based on the detection signals Sa to Sd input from the infrared detection unit 1 that the moving direction of the detection target H is the vertical direction or the horizontal direction along each side of the square lattice. The signal processing unit 2 detects the moving direction of the detection target H.
信号処理部２は、被検知体Ｈの移動方向が、上記正方格子のいずれかの辺に沿った方向であることを判別するのに先立って、被検知体Ｈの動きが、第１の動作であるか判別する。信号処理部２は、被検知体Ｈの移動方向が、上記正方格子のいずれかの辺に沿った方向であることを判別するのに先立って、被検知体Ｈの動きが、第２の動作であるかを判別する。
Prior to determining that the moving direction of the detection target H is a direction along any side of the square lattice, the signal processing unit 2 determines that the movement of the detection target H is the first operation. Is determined. Prior to determining that the moving direction of the detection target H is a direction along any side of the square lattice, the signal processing unit 2 determines that the movement of the detection target H is the second operation. Is determined.
また、信号処理部２は、第１の動作あるいは第２の動作を判別するため、各検知信号Ｓａ〜Ｓｄの平均をとった平均検知信号ＡＳを生成する。平均検知信号ＡＳは、被検知体Ｈが赤外線検出部１の検知領域に進入した後に一旦停止する場合、第１のピーク値Ｐ１を有する第１のピークＳＰ１と、第１のピークＳＰ１に連続し第１のピークＳＰ１と正負の極性が反対で第２のピーク値Ｐ２を有する第２のピークＳＰ２とを含む波形をしている。平均検知信号ＡＳは、平均検知信号ＡＳの振幅が予め設定した入力開始閾値ＩＴを超えて、再び入力開始閾値ＩＴに戻ってくるまでの第１のピークＳＰ１の時間間隔である第１のピーク幅Ｘの値と、第１のピーク値Ｐ１と第２のピーク値Ｐ２との比率である波形比Ｙの値とで式（１）の反比例の関係にある。
In addition, the signal processing unit 2 generates an average detection signal AS that is an average of the detection signals Sa to Sd in order to determine the first operation or the second operation. The average detection signal AS is continuous to the first peak SP1 having the first peak value P1 and the first peak SP1 when the detected object H temporarily stops after entering the detection region of the infrared detection unit 1. The waveform includes a first peak SP1 and a second peak SP2 having opposite polarity and having a second peak value P2. The average detection signal AS is a first peak width that is a time interval of the first peak SP1 until the amplitude of the average detection signal AS exceeds the preset input start threshold IT and returns to the input start threshold IT again. The value of X and the value of the waveform ratio Y, which is the ratio of the first peak value P1 and the second peak value P2, are in an inversely proportional relationship of equation (1).
信号処理部２は、平均検知信号ＡＳが式（１）で表される反比例曲線よりも小さい領域にある場合、被検知体Ｈの動きが、赤外線検出部１の検知領域を停止することなく横切る第１の動作であると判別する。信号処理部２は、平均検知信号ＡＳが式（１）の反比例曲線以上の領域にある場合、被検知体Ｈの動きが、赤外線検出部１の検知領域に進入して検知領域に一旦停止する第２の動作であると判別する。
When the average detection signal AS is in a region smaller than the inverse proportional curve represented by the expression (1), the signal processing unit 2 crosses the movement of the detection target H without stopping the detection region of the infrared detection unit 1. It is determined that the operation is the first operation. When the average detection signal AS is in a region that is equal to or greater than the inverse proportional curve of the expression (1), the signal processing unit 2 enters the detection region of the infrared detection unit 1 and temporarily stops in the detection region. It is determined that the operation is the second operation.
これにより、本実施形態の方向検出装置１０では、たとえば、赤外線検出部１と水平方向に沿った被検知体Ｈの移動方向を検出することに加え、赤外線検出部１と垂直方向に沿った被検知体Ｈの移動方向を検出することが可能となる。
Thereby, in the direction detection device 10 of the present embodiment, for example, in addition to detecting the moving direction of the detection target H along the infrared detection unit 1 and the horizontal direction, the detection target along the infrared detection unit 1 and the vertical direction. It becomes possible to detect the moving direction of the detection body H.
さらに、本実施形態の方向検出装置１０は、第２の動作の後、次の処理を行うこともできる。
Furthermore, the direction detection apparatus 10 of the present embodiment can also perform the following process after the second operation.
本実施形態の方向検出装置１０は、第２の動作を行う被検知体Ｈを検出した場合、被検知体Ｈが赤外検出部１の検知領域に進入して一旦停止した後、被検知体Ｈが離れることに伴い検知領域から離れる際に、被検知体Ｈが赤外線検出部１の検知領域に進入する際の信号と正負が逆の極性を備え被検知体Ｈの進入時と同じ波形形状の信号（以下、逆温度特性信号ともいう）が検出されることがある。方向検出装置１０では、逆特性信号を検出することにより、第２の動作後の被検知体Ｈの移動方向の検出に誤検出を生ずる恐れがある。
When the direction detection apparatus 10 of the present embodiment detects the detection target H that performs the second operation, the detection target H enters the detection region of the infrared detection unit 1 and stops temporarily, and then the detection target H When H moves away from the detection area, the signal when the detected object H enters the detection area of the infrared detection unit 1 has a polarity opposite to that of the signal when the detected object H enters, and the same waveform shape as when the detected object H enters. May be detected (hereinafter also referred to as an inverse temperature characteristic signal). In the direction detection device 10, by detecting the reverse characteristic signal, there is a risk of erroneous detection in the detection of the moving direction of the detection target H after the second operation.
本実施形態の方向検出装置１０では、被検知体Ｈが第２の動作を行う場合、第２の動作に伴って入力される平均検知信号ＡＳに続いて入力される逆温度特性信号を一度だけ無視する。
In the direction detection device 10 of the present embodiment, when the detection target H performs the second operation, the reverse temperature characteristic signal input after the average detection signal AS input along with the second operation is only once. ignore.
また、本実施形態の方向検出装置１０は、赤外線検出部１が検出する被検出体Ｈの温度特性によっては逆温度特性信号が検出されない場合もある。そのため、本実施形態の方向検出装置１０では、信号処理部２が第２の動作を判別した後、第１の動作を検出する場合は、検出された平均検知信号ＡＳを無視することなく利用すればよい。
Moreover, the direction detection apparatus 10 of this embodiment may not detect a reverse temperature characteristic signal depending on the temperature characteristic of the detection target H detected by the infrared detection unit 1. Therefore, in the direction detection device 10 of the present embodiment, when the signal processing unit 2 determines the second operation and then detects the first operation, the detected average detection signal AS is used without being ignored. That's fine.
なお、本実施形態の方向検出装置１０では、第１の動作と第２の動作とを判別した後、引き続いて、新たに被検知体Ｈの移動方向を検出する場合がある。
In the direction detection device 10 of the present embodiment, after the first operation and the second operation are discriminated, there is a case where the movement direction of the detection target H is newly detected subsequently.
本実施形態の方向検出装置１０では、第２の動作の後、新たに被検知体Ｈの移動方向を検出する場合、次の処理を行うこともできる。
In the direction detection device 10 of the present embodiment, when the movement direction of the detection target H is newly detected after the second operation, the following processing can be performed.
本実施形態の方向検出装置１０では、信号処理部２は、第２の動作の平均検知信号ＡＳを検出した後、逆温度特性信号が入力開始閾値ＩＴを超えてから新たに被検知体Ｈの移動に伴う平均検知信号ＡＳが入力されると、被検知体Ｈの移動方向を正常に検出することができる。
In the direction detection device 10 of the present embodiment, the signal processing unit 2 detects the average detection signal AS of the second operation and then newly detects the detected object H after the reverse temperature characteristic signal exceeds the input start threshold IT. When the average detection signal AS accompanying the movement is input, the moving direction of the detection target H can be normally detected.
しかしながら、方向検出装置１０の信号処理部２は、第２の動作の平均検知信号ＡＳを検出した後、逆温度特性信号が入力開始閾値ＩＴを超える前に次の新たな被検知体Ｈの移動にともなう平均検知信号ＡＳが入力されると、被検知体Ｈの移動方向を正常に検出することができない恐れがある。
However, after detecting the average detection signal AS of the second operation, the signal processing unit 2 of the direction detection device 10 moves the next new detection target H before the reverse temperature characteristic signal exceeds the input start threshold IT. When the average detection signal AS is input, there is a possibility that the moving direction of the detection target H cannot be detected normally.
そのため、本実施形態の方向検出装置１０では、信号処理部２は、次に入力される被検知体Ｈの平均検知信号ＡＳの変化率（傾き）が一定値以上になったら、新たな平均検知信号ＡＳの入力が開始されたと見做し、被検知体Ｈの移動方向の検出を行う。
Therefore, in the direction detection device 10 of the present embodiment, the signal processing unit 2 performs a new average detection when the rate of change (slope) of the average detection signal AS of the next detection target H that is input next becomes a certain value or more. Assuming that the input of the signal AS is started, the moving direction of the detection target H is detected.
方向検出装置１０の信号処理部２は、たとえば、第２の動作の平均検知信号ＡＳを検出した後、入力開始閾値ＩＴを超える逆温度特性信号の波形の傾きが、所定の傾き以上になる場合、被検知体Ｈの移動方向を新たに検出する。
For example, when the signal processing unit 2 of the direction detection device 10 detects the average detection signal AS of the second operation, the slope of the waveform of the inverse temperature characteristic signal exceeding the input start threshold IT becomes a predetermined slope or more. Then, the moving direction of the detection object H is newly detected.
これにより本実施形態の方向検出装置１０は、平均検知信号ＡＳの値の絶対値によらず新たな平均検知信号ＡＳの入力を検知することが可能となる。
Thereby, the direction detection device 10 of the present embodiment can detect the input of a new average detection signal AS regardless of the absolute value of the average detection signal AS.
なお、信号処理部２は、入力開始閾値ＩＴを超える平均検知信号ＡＳの傾きが、所定の傾き未満の場合、平均検知信号ＡＳの次の波形が入力開始閾値ＩＴを超えるまで待機状態とすればよい。
Note that if the slope of the average detection signal AS exceeding the input start threshold IT is less than a predetermined slope, the signal processing unit 2 is in a standby state until the next waveform of the average detection signal AS exceeds the input start threshold IT. Good.
また、本実施形態の方向検出装置１０の信号処理部２は、第２の動作の後、平均検知信号ＡＳを検出した後、所定の一定時間の間、新たな平均検知信号ＡＳを無視するものでもよい。これにより方向検出装置１０は、逆温度特性信号を検知することにともなう、被検知体Ｈの移動方向を検出する際の誤検知を抑制することが可能となる。
In addition, the signal processing unit 2 of the direction detection device 10 of the present embodiment ignores the new average detection signal AS for a predetermined time after detecting the average detection signal AS after the second operation. But you can. As a result, the direction detection device 10 can suppress erroneous detection when detecting the moving direction of the detection target H that accompanies detection of the reverse temperature characteristic signal.
（実施形態２）
本実施形態の方向検出装置１０は、実施形態１の方向判断閾値ＤＴを超える時刻を閾値時刻Ｔａ２，Ｔｂ２とする代わりに、線形補完することによりデータ補完した値を閾値時刻Ｔａ２，Ｔｂ２とする点が相違する。なお、実施形態１と同様の構成には、同一の符号を付して説明は省略する。
(Embodiment 2)
The direction detection device 10 of the present embodiment uses the values complemented by linear interpolation as threshold times Ta2 and Tb2 instead of threshold times Ta2 and Tb2 when the time exceeding the direction determination threshold DT of the first embodiment is used. Is different. In addition, the same code | symbol is attached | subjected to the structure similar to Embodiment 1, and description is abbreviate | omitted.
本実施形態の方向検出装置１０では、図６に示すように、信号処理部２は、記憶させた検知信号Ｓａの振幅が方向判断閾値ＤＴを超える前の時刻ｔ２１における、検知信号Ｓａの振幅が方向判断閾値ＤＴよりも小さい第１振幅値ｄ２１を検出する。信号処理部２は、記憶させた検知信号Ｓａの振幅が方向判断閾値ＤＴを超えた後の時刻ｔ２２における、検知信号Ｓａの振幅が方向判断閾値ＤＴよりも大きい第２振幅値ｄ２２を検出する。信号処理部２は、第１振幅値ｄ２１と、第２振幅値ｄ２２との間を線形補完することによりデータ補完した値が、方向判断閾値ＤＴとなる時刻を閾値時刻Ｔａ２としている。なお、図６では、説明を分かり易くするため検知信号Ｓａの一部だけを抜粋して図示している。
In the direction detection device 10 according to the present embodiment, as illustrated in FIG. 6, the signal processing unit 2 determines that the amplitude of the detection signal Sa at time t21 before the stored amplitude of the detection signal Sa exceeds the direction determination threshold value DT. A first amplitude value d21 smaller than the direction determination threshold value DT is detected. The signal processing unit 2 detects a second amplitude value d22 in which the amplitude of the detection signal Sa is larger than the direction determination threshold value DT at time t22 after the stored amplitude of the detection signal Sa exceeds the direction determination threshold value DT. The signal processing unit 2 sets a time at which a value obtained by data complementation by linearly complementing between the first amplitude value d21 and the second amplitude value d22 becomes the direction determination threshold value DT as a threshold time Ta2. In FIG. 6, only a part of the detection signal Sa is extracted and illustrated for easy understanding.
実施形態１の方向検出装置１０では、赤外線検出部１が所定の時間間隔ごとに検知信号Ｓａの振幅を抽出する場合、抽出するサンプリングの時間間隔の大きさによって、被検知体Ｈの移動方向を判断する時刻が他の検知信号Ｓｂ〜Ｓｄが検出されている時刻と重なる恐れがある。方向検出装置１０は、各検知信号Ｓａ〜Ｓｄにおけるサンプリングの時刻が重なれば、精度よく被検知体Ｈの移動方向を検出することが難しくなる恐れがある。
In the direction detection device 10 according to the first embodiment, when the infrared detection unit 1 extracts the amplitude of the detection signal Sa at every predetermined time interval, the moving direction of the detection target H is determined depending on the size of the sampling time interval to be extracted. There is a possibility that the time to judge overlaps with the time when the other detection signals Sb to Sd are detected. The direction detection device 10 may have difficulty in accurately detecting the moving direction of the detection target H if the sampling times in the detection signals Sa to Sd overlap.
本実施形態の方向検出装置１０は、たとえば、検知信号Ｓａ〜Ｓｄの振幅が方向判断閾値ＤＴを超える前後の時刻における２点間でデータ補完処理を行うことにより、より高い精度で被検知体Ｈの移動方向を検出することが可能となる。
The direction detection device 10 according to the present embodiment performs, for example, data complement processing between two points before and after the amplitudes of the detection signals Sa to Sd exceed the direction determination threshold value DT, so that the detection target H is detected with higher accuracy. Can be detected.
