【０００１】
【発明の属する技術分野】
本発明は人体検知に測距センサを用いたトイレ装置に関する。
【０００２】
【従来の技術】
公知の如く測距センサは、図１に示すように、ＩＲＬＥＤから発光された赤外光は、投光レンズで収束され、前記光が人（被検出体）に当たり反射する。前記反射光が受光レンズによって収束され、前記反射光がＰＳＤ（半導体位置検出装置）上に集光される。そのＰＳＤ上の集光位置が図２に示すように、人の検出範囲に有れば人を検知させるものである。
【０００３】
前記ＰＳＤ上の反射光の位置は図３の等価回路の如く、前記ＰＳＤ上の反射光の位置をＸ＝（Ｉｂ／（Ｉａ＋Ｉｂ））×Ｌで求められる。
即ち、このＰＳＤ上の光の位置を求めることによって、相似である投光レンズから人（被検出体）迄の距離を三角測距の原理で求めるものである。
【０００４】
従来の誤検出を防止する測距センサの提案によれば、発光側レンズの周辺部に遮光板を配置することによって放射角を狭め発光部と測距対象物間の水滴や汚れ等の非検出物に赤外光が照射されることを防止して、三角測距原理に従って測距対象物が所定の位置に配置されたことを検出している。（例えば、特許文献１参照）
【０００５】
また従来の誤検出を防止するカメラの多点測距装置では、カメラの測距センサにおける複数のＩＲＬＥＤとＰＳＤを用いて誤測距を低減させる前記提案によれば、測距精度は高いが測距範囲の狭い第１の三角測距原理に従って測距対象物を検出する測距手段を構成する第１の投光手段と、測距精度は低いが測距範囲の広い第２の三角測距原理に従って測距対象物を検出する測距手段を構成する第２の投光手段からなる測距手段を構成して、第１の投光手段と第２の投光手段の測距結果に基づいて被写体距離を決定するものがある。（例えば、特許文献２参照）
【０００６】
【特許文献１】
特開２０００−３１０５０８号公報（第３−６項、第２図）
【０００７】
【特許文献２】
特開平７−２３９４３８号公報（第３−６項、第１図）
【０００８】
【発明が解決しようとする課題】
従来の測距センサの誤検知は、図４のＩＲＬＥＤの指向特性の例に示すように主光とは別の微小光量の散乱光（指向特性のすそ部）が起因している。
【０００９】
図５に示すように、主光は、発光部と測距対象物の間に位置する測距センサケース上の水滴や汚れ等に入射角が小さく当たるので、水滴や汚れ等で屈折しないで直進して透過する。
【００１０】
一方、ＩＲＬＥＤの微小光量の散乱光は、発光部と測距対象物の間に位置する測距センサケース上の水滴や汚れ等に入射角が大きく当たるので、水滴や汚れ等で屈折して更に反射してＰＳＤ上に散乱して集光する。
【００１１】
即ち、主光の延長上に被検出体が無い場合は、ＰＳＤ上に主光の反射光を受光しないので主光の影響を受けないが、微小光量の散乱光のみの影響を受けるので、発光部と測距対象物の間に位置する測距センサケース上の水滴や汚れ等によるＰＳＤ上の集光位置が、図６に示すように、ＰＳＤ上の人を検出する範囲内の場合に、前記水滴や汚れ等を御検知する問題があった。
【００１２】
更に、主光の延長上に被検出体が無い場合は、図７に示すように、検知範囲外の斜め遠点の被検出体に、微小光量の散乱光が当たると、その反射光がＰＳＤ上に散乱して集光されＰＳＤ上の集光位置が、図６に示すように、ＰＳＤ上の人を検出する範囲の場合は、誤検知する問題があった。
【００１３】
前述の従来例（１）の測距センサの提案によれば、発光側レンズの周辺部に遮光板を配置することによって放射角を狭め、発光部と測距対象物の間の水滴、汚れの非検出物に照射されることを防止している。
【００１４】
しかしながら、遮光板を配置することによって投光レンズの面積が小さくなるので、ＩＲＬＥＤの光量が減少する。それに伴いＰＳＤのＳ／Ｎ感度が低下して検知性能が低下するので、ＩＲＬＥＤの駆動電流を増加させて光量を増加させているが、駆動電流を増加させることにより、更にＩＲＬＥＤの光量の経年劣化が低下して検知距離性能が経年低下する問題があった。
【００１５】
又、光量を増加させることにより、斜め遠点の被検出体の誤検知が更に増加して信頼性が低下する問題があった。
【００１６】
前述の従来例（２）の測距センサの提案によれば、第一、又は、第二の測距手段の測距結果に基づいて被写体の距離を高精度に測定するものであるが、トイレ装置の人体センサの検知性能の要求は、人が所定の範囲内にいることのみを検知させるものであるので、第一と第二といった複雑な測定手段の構成と高精度な測定を要求しないので、過剰品質になり適さない。
【００１７】
本発明は、上述の不都合を解決し、発光部と測距対象物の間に位置する測距センサケース上の水滴や汚れ等による近点の被検出体を誤検知させない。更に、検知範囲外の斜め遠点の被検出体を誤検知させないトイレ装置の人体検知用の測距センサを単一のＩＲＬＥＤとＰＳＤのみで、提供することを目的とするものである。
【００１８】
【課題を解決するための手段】
【００１９】
上述の課題を解決するため本発明においては、単一のＰＳＤ（半導体位置検出装置）と、投光素子との位置関係において前記ＰＳＤの両端を設定される近点側出力及び遠点側出力が設定するとともに、前記近点側電流出力及び遠点側電流出力を電圧に変換するＩ−Ｖ変換手段と、前記Ｉ−Ｖ変換手段によって得られる前記近点側出力電圧及び前記遠点側出力電圧の電圧比で被検出体までの距離を演算する距離演算手段とを有する人体検知装置において、前記近点側出力電圧もしくは前記遠点側出力電圧が所定の電圧の場合、前記距離演算手段の出力を無効としている。
【００２０】
このように、近点側、遠点側それぞれの電圧判定手段を設け、前記距離演算手段で演算させるので、被検出体をＰＳＤ上の人体検知範囲内に検知しても、前記近点側出力電圧もしくは前記遠点側出力電圧が所定の電圧の場合には検知を無効とすることが可能となり、従来の電圧比の結果を距離演算手段のみで行う従来の測距センサよりも、著しく誤検知を低減できる。
【００２１】
更に、前記距離演算手段の出力を無効とする前記近点側出力電圧もしくは前記遠点側出力電圧の所定の電圧を所定電圧を予め人体を検出する距離に設定して、前記距離に対応した人体を検出する電圧範囲外にに設定することとしている。このように、前記近点側出力電圧もしくは前記遠点側出力電圧を人体が検知する電圧外に設定することで、確実に人体の判別が可能となり、誤検知を低減できる。
【００２２】
更に、前記人体を検知する電圧を予め人体と異なる反射率と検出する距離に設定して、前記反射率と距離に対応した人体を検出する電圧範囲に設定している。このように、前記近点側出力電圧もしくは前記遠点側出力電圧を人体の距離と反射率の変動まで設定することで、より確実に人体の判別が可能となり、誤検知を低減できる。
【００２３】
【実施の形態】
以下、図面に示す実施例に基づいて本発明を説明すると、図１は測距センサの構造の説明図、図８はＰＳＤの近側出力電圧−距離特性、図９はＰＳＤの遠側出力電圧−距離特性、図１０は測距判定を表すフローチャートである。
【００２４】
図１は本発明第１，２の実施例における測距センサの構造の説明図を示す。
ＰＳＤ８の近点側電極９と遠点側電極１０のそれぞれの電極から出力される電流を近点側、遠点側それぞれに電流を電圧に変換するＩ−Ｖ変換手段１１，１２と、前記Ｉ−Ｖ変換手段１１，１２によって電圧比で距離を演算する距離演算手段１３と、前記Ｉ−Ｖ変換手段１１，１２によって変換された近点側、遠点側の電圧を判定する電圧判定手段１４、１５を独立に設け、近点側もしくは遠点側それぞれの電圧が電圧判定手段１４，１５によって所定の電圧の場合、前記距離演算手段１３の出力を無効とするものである。
【００２５】
所定の電圧は、人体を検出する電圧外と設定するので、ここでは人体を検出する電圧を説明する。
【００２６】
人を検出する範囲１６の近側電圧判定手段１４の閾値である人体を検知する電圧３０を図８で説明する。近側出力電圧は、人（被検出体）５の距離が遠くなるほどＰＳＤ上の集光が遠点側へ遠ざかっていくので低下する特性となる。
又、ＩＲＬＥＤの赤外線と同一波長８７０ｎｍでの反射率が、９０％以上の高反射２６と１０％以下の低反射２５では、出力電圧は高反射２６＞低反射２５となる。
【００２７】
この特性を用いて、人を検出する範囲１６で、人を検出する電圧３０のＭＩＮ電圧３２は、低反射２５の人（被検出体）５が離れた時の電圧で設定する。
一方、人を検出する電圧３０のＭＡＸ電圧３１は、高反射２６の人（被検出体）５が近づいた時の電圧で設定する。
【００２８】
即ち、人（被検出体）５の反射率が変化しても人を検出する範囲で電圧３０が設定されているので、確実に人体の判別が可能となるので、近点側の誤検知を低減できる。
【００２９】
更に、検知位置２７で、人を検知する電圧３０のＭＩＮ電圧２９は、人（被検出体）５が低反射２５での電圧で設定する。
一方、検知位置２７で、人を検知する電圧３０のＭＡＸ電圧２８は２６人（被検出体）５が高反射の電圧で設定する。
即ち、人（被検出体）５の反射率が変化しても検知位置２７により電圧３０が設定されているので、より確実に人体の判別が可能となるので、近側の誤検知を低減できる。
【００３０】
同様に、人を検出する範囲１６の遠側電圧判定手段１５の閾値を図９で説明する。遠側出力電圧は、人（被検出体）５の距離が遠くなるほどＰＳＤ上の集光が遠点側へ近づいてくるので上昇する特性となる。
【００３１】
この特性を用いて、人を検出する範囲１６で、人を検出する電圧３０のＭＩＮ電圧３２は、低反射２５の人（被検出体）５が近づいた時の電圧で設定する。
一方、人を検出する電圧３０のＭＡＸ電圧３１は、高反射２６の人（被検出体）５が離れた時の電圧で設定する。
即ち、人（被検出体）５の反射率が変化しても人を検出する範囲で電圧が設定されているので、確実に人体の判別が可能となるので、遠点側の誤検知を低減できる。
【００３２】
更に、検知位置で、人を検知する電圧３０のＭＩＮ電圧２９は、人（被検出体）５が低反射２５での電圧で設定する。
一方、検知位置で、人を検出する電圧３０のＭＡＸ電圧２８は、人（被検出体）５が高反射２６での電圧で設定する。
【００３３】
即ち、人（被検出体）５の反射率が変化しても検知位置２７により電圧３０が設定されているので、より確実に人体の判別が可能となるので遠点の誤検知を低減できる。
【００３４】
図１０は本発明第１，２の実施例における測距判定を表すフローチャートを示すもので、ＩＲＬＥＤ投光後に、先ずＳ１０１にて距離を演算する。次にＳ１０２にて距離演算結果が人を検出する範囲内か判断する。Ｓ１０２にて肯定で有ればＳ１０３に進み、否定で有ればＳ１０６に進み人体と検知しない結果を出力する。
【００３５】
次にＳ１０３にて遠点側の電圧が所定の電圧外（人体を検知する電圧）か判断する。Ｓ１０３にて肯定で有ればＳ１０４に進み、否定で有ればＳ１０５に進み人体と検知しない結果を出力する。
【００３６】
次にＳ１０４にて近点側の電圧が所定の電圧外（人体を検出する電圧）か判断する。Ｓ１０４にて肯定で有ればＳ１０５に進み人体と検知する結果を出力し、否定で有ればＳ１０５に進み人体と検知しない結果を出力する。
【００３７】
本発明は上述の実施例に限定されること無く種手の変形が可能であり、例えばトイレ装置として、温水洗浄乾燥便座のほか大便器や小便器や換気扇や照明やパネルヒータやエアコンで人体を検知させるものであっても良い。
【００３８】
【発明の効果】
本発明は以上のように、ＰＳＤの両端を設定される近点側出力及び遠点側出力が設定するとともに、前記近点側電流出力及び遠点側電流出力を電圧に変換するＩ−Ｖ変換手段と、前記Ｉ−Ｖ変換手段によって得られる前記近点側出力電圧及び前記遠点側出力電圧の電圧比で被検出体までの距離を演算する距離演算手段とを有する人体検知装置において、前記近点側出力電圧もしくは前記遠点側出力電圧が所定の電圧の場合、前記距離演算手段の出力を無効とすることができるので、従来の測距センサでは距離演算手段から、出力電圧の大小にかかわらず電圧比のみの結果しか得られないので、近側の発光部と測距対象物の間に位置する測距センサケース上の水滴や汚れ等の誤検知、遠点側の誤検知を防止できなかったが、本発明はこの誤検知を著しく低減できる。更に簡単な構成で安価に達成可能となる。
【図面の簡単な説明】
【図１】測距センサの構造の説明図
【図２】人体検出時の測距センサ内のＰＳＤ上の受光位置の説明図
【図３】人体検出時の測距センサ内のＰＳＤの等価回路
【図４】ＩＲＬＥＤの指向特性の説明図
【図５】測距センサの表面の水滴による迷光が反射する説明図
【図６】ＰＳＤ上の迷光の反射の説明図
【図７】ＰＳＤ上の迷光の反射の説明図
【図８】ＰＳＤの近側出力電圧−距離特性
【図９】ＰＳＤの遠側出力電圧−距離特性
【図１０】本発明第１の実施例における測距判定を表すフローチャート
【符号の説明】
１： 測距センサ
２： ＩＲＬＥＤ
３： 投光レンズ
４： 主光
５： 人（被検出体）
６： 反射光
７： 受光レンズ
８： ＰＳＤ（半導体位置検出装置）
９： 近点側電極
１０： 遠点側電極
１１： 近点側Ｉ−Ｖ変換手段
１２： 遠点側Ｉ−Ｖ変換手段
１３： 距離演算手段
１４： 近点側電圧判定手段
１５： 遠点側電圧判定手段
１６： 人を検出する範囲
１７： 電流源Ｉｏ
１８： 遠点側電極に発生する電流Ｉａ
１９： 近点側電極に発生する電流Ｉｂ
２０： 迷光の散乱光
２１： 被検出体
２２： 迷光の反射光
２３： 水滴、汚れ
２４： 遮光壁
２５： 低反射
２６： 高反射
２７： 検知位置
２８： 検知位置でのＭＡＸ電圧
２９： 検知位置でのＭＩＮ電圧
３０： 人体を検知する電圧
３１： 人を検出する範囲でのＭＡＸ電圧
３２： 人を検出する範囲でのＭＩＮ電圧
３３： 所定の電圧[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a toilet device using a distance measuring sensor for detecting a human body.
[0002]
[Prior art]
As is well known, in a distance measuring sensor, as shown in FIG. 1, infrared light emitted from an IRLED is converged by a light projecting lens, and the light hits a person (object to be detected) and is reflected. The reflected light is converged by a light receiving lens, and the reflected light is collected on a PSD (semiconductor position detecting device). As shown in FIG. 2, a person is detected if the light condensing position on the PSD is within the detection range of the person.
[0003]
The position of the reflected light on the PSD is obtained by X = (Ib / (Ia + Ib)) × L, as in the equivalent circuit of FIG.
That is, by calculating the position of the light on the PSD, the similar distance from the light projecting lens to the person (object to be detected) is obtained by the principle of triangulation.
[0004]
According to the conventional proposal of a distance measuring sensor that prevents erroneous detection, the radiation angle is narrowed by arranging a light shielding plate around the light emitting side lens to prevent detection of water droplets and dirt etc. between the light emitting part and the object to be measured. Irradiation of the object with infrared light is prevented, and it is detected that the object to be measured is located at a predetermined position in accordance with the principle of triangulation. (For example, see Patent Document 1)
[0005]
Further, in the conventional multi-point distance measuring device for a camera which prevents erroneous detection, according to the above-mentioned proposal of reducing erroneous distance measurement by using a plurality of IRLEDs and PSDs in a camera distance measurement sensor, the distance measurement accuracy is high, but the distance measurement accuracy is high. A first light projecting means which constitutes a distance measuring means for detecting an object to be measured in accordance with a first triangulation principle having a narrow distance range, and a second triangle measuring means having a low distance measurement accuracy but a wide distance measurement range A distance measuring means comprising a second light projecting means constituting a distance measuring means for detecting an object to be measured in accordance with the principle is constructed, and based on a distance measurement result of the first light projecting means and the second light projecting means. To determine the subject distance. (For example, see Patent Document 2)
[0006]
[Patent Document 1]
JP-A-2000-310508 (Section 3-6, FIG. 2)
[0007]
[Patent Document 2]
JP-A-7-239438 (Section 3-6, FIG. 1)
[0008]
[Problems to be solved by the invention]
The erroneous detection of the conventional distance measuring sensor is caused by scattered light (a skirt of the directional characteristic) having a small amount of light different from the main light as shown in the example of the directional characteristic of the IRLED in FIG.
[0009]
As shown in FIG. 5, the main light impinges on water droplets and dirt on the distance measuring sensor case located between the light emitting portion and the object to be measured at a small incident angle. And transmitted.
[0010]
On the other hand, the small amount of scattered light of the IRLED impinges on water drops and dirt on the distance measuring sensor case located between the light emitting part and the object to be measured at a large incident angle, and is refracted by the water drops and dirt and further refracted. The light is reflected, scattered on the PSD, and collected.
[0011]
That is, when there is no object to be detected on the extension of the main light, the reflected light of the main light is not received on the PSD and thus is not affected by the main light. When the light condensing position on the PSD due to water droplets or dirt on the distance measuring sensor case located between the unit and the object to be measured is within the range for detecting a person on the PSD as shown in FIG. There was a problem of detecting the water droplets and dirt.
[0012]
Further, when the object to be detected is not on the extension of the main light, as shown in FIG. 7, when a small amount of scattered light hits the object at an obliquely distant point outside the detection range, the reflected light becomes PSD. As shown in FIG. 6, when the light is scattered upward and condensed, and the light condensing position on the PSD is in a range for detecting a person on the PSD, there is a problem of erroneous detection.
[0013]
According to the proposal of the distance measuring sensor of the above-described conventional example (1), the radiation angle is narrowed by disposing a light-shielding plate around the light-emitting side lens, and water droplets and dirt between the light-emitting portion and the object to be measured are reduced. Irradiation to non-detected objects is prevented.
[0014]
However, since the area of the light projecting lens is reduced by disposing the light shielding plate, the light amount of the IRLED is reduced. As a result, the S / N sensitivity of the PSD is reduced and the detection performance is reduced. Therefore, the driving current of the IRLED is increased to increase the light amount. However, by increasing the driving current, the aging of the light amount of the IRLED is further reduced. And the detection distance performance deteriorates over time.
[0015]
In addition, there is a problem in that, by increasing the amount of light, erroneous detection of an object at an obliquely distant point is further increased and reliability is reduced.
[0016]
According to the proposal of the distance measuring sensor of the conventional example (2) described above, the distance to the subject is measured with high accuracy based on the distance measurement result of the first or second distance measuring means. Since the requirement of the detection performance of the human body sensor of the apparatus is to detect only that the person is within the predetermined range, the configuration of the complicated measuring means such as the first and second and the high accuracy measurement are not required. It is unsuitable because of excessive quality.
[0017]
The present invention solves the above-described inconvenience, and does not erroneously detect an object at a near point due to water droplets, dirt, or the like on a distance measuring sensor case located between a light emitting unit and a distance measuring object. Still another object of the present invention is to provide a distance measuring sensor for detecting a human body of a toilet device that does not erroneously detect an object at an obliquely distant point outside the detection range, using only a single IRLED and a PSD.
[0018]
[Means for Solving the Problems]
[0019]
In order to solve the above-described problems, in the present invention, a near point output and a far point output whose both ends of the PSD are set in a positional relationship between a single PSD (semiconductor position detecting device) and a light projecting element are provided. An IV converter for setting and converting the near-point current output and the far-point current output into a voltage; and the near-point output voltage and the far-point output voltage obtained by the IV converter. And a distance calculating means for calculating the distance to the object to be detected at a voltage ratio of: the output of the distance calculating means when the near point output voltage or the far point output voltage is a predetermined voltage. Is invalidated.
[0020]
As described above, the near-point and far-point voltage determination means are provided, and the distance calculation means calculates the voltage. Therefore, even if the object to be detected is detected within the human body detection range on the PSD, the near-point output is obtained. If the voltage or the far-point output voltage is a predetermined voltage, the detection can be invalidated, and the result of the conventional voltage ratio is significantly erroneously detected as compared with the conventional distance measuring sensor which performs only the distance calculation means. Can be reduced.
[0021]
Further, a predetermined voltage of the near-point side output voltage or the far-point side output voltage that invalidates the output of the distance calculation means is set to a predetermined voltage as a distance for detecting a human body in advance, and a human body corresponding to the distance is set. Is set outside the voltage range for detection. In this way, by setting the near point output voltage or the far point output voltage outside the voltage detected by the human body, it is possible to reliably determine the human body and reduce erroneous detection.
[0022]
Further, the voltage for detecting the human body is set in advance to a distance different from that of the human body for detecting the reflectance, and the voltage is set to a voltage range for detecting the human body corresponding to the reflectance and the distance. In this way, by setting the near point output voltage or the far point output voltage up to the change in the distance and the reflectance of the human body, the human body can be more reliably determined, and erroneous detection can be reduced.
[0023]
Embodiment
Hereinafter, the present invention will be described based on an embodiment shown in the drawings. FIG. 1 is an explanatory diagram of the structure of a distance measuring sensor, FIG. 8 is a near output voltage-distance characteristic of a PSD, and FIG. 9 is a far output voltage of a PSD. FIG. 10 is a flowchart showing distance measurement determination.
[0024]
FIG. 1 is an explanatory view of the structure of a distance measuring sensor according to the first and second embodiments of the present invention.
IV conversion means 11 and 12 for converting currents output from the near-point side electrode 9 and far-point side electrode 10 of the PSD 8 into voltages on the near-point side and the far-point side, respectively; Distance calculating means 13 for calculating a distance by a voltage ratio by means of -V converting means 11 and 12; voltage determining means 14 for determining near-point and far-point side voltages converted by said IV converting means 11 and 12; , 15 are provided independently, and when the voltages on the near point side or the far point side are predetermined voltages by the voltage determination means 14, 15, the output of the distance calculation means 13 is invalidated.
[0025]
Since the predetermined voltage is set outside the voltage for detecting the human body, the voltage for detecting the human body will be described here.
[0026]
The voltage 30 for detecting a human body, which is the threshold value of the near-side voltage determining means 14 in the range 16 for detecting a human, will be described with reference to FIG. The near-side output voltage has such a characteristic that as the distance of the person (detected object) 5 increases, the light condensing on the PSD moves away to the far point side, so that the near-side output voltage decreases.
Further, when the reflectance at the same wavelength 870 nm as that of the infrared light of the IRLED is high reflection 26 of 90% or more and low reflection 25 of 10% or less, the output voltage is high reflection 26> low reflection 25.
[0027]
Using this characteristic, in the range 16 for detecting a person, the MIN voltage 32 of the voltage 30 for detecting a person is set at a voltage when the person (detected body) 5 with a low reflection 25 is separated.
On the other hand, the MAX voltage 31 of the voltage 30 for detecting a person is set at a voltage when the person (detected body) 5 having the high reflection 26 approaches.
[0028]
In other words, since the voltage 30 is set within the range for detecting a person even if the reflectance of the person (detected body) 5 changes, the human body can be reliably determined. Can be reduced.
[0029]
Further, the MIN voltage 29 of the voltage 30 for detecting a person at the detection position 27 is set by the voltage at the low reflection 25 of the person (detected body) 5.
On the other hand, the MAX voltage 28 of the voltage 30 for detecting a person at the detection position 27 is set to a voltage that is highly reflected by 26 persons (the object to be detected) 5.
That is, even if the reflectance of the person (detected body) 5 changes, the voltage 30 is set by the detection position 27, so that the human body can be more reliably determined, and erroneous detection on the near side can be reduced. .
[0030]
Similarly, the threshold of the far-side voltage determination means 15 in the range 16 for detecting a person will be described with reference to FIG. The far-side output voltage has such a characteristic that, as the distance of the person (detected object) 5 increases, the condensed light on the PSD approaches the far point side.
[0031]
Using this characteristic, in the range 16 for detecting a person, the MIN voltage 32 of the voltage 30 for detecting a person is set at the voltage when the person (detected body) 5 with low reflection 25 approaches.
On the other hand, the MAX voltage 31 of the voltage 30 for detecting a person is set at the voltage when the person (detected body) 5 with high reflection 26 is separated.
That is, even if the reflectance of the person (detected body) 5 changes, the voltage is set within the range for detecting the person, so that the human body can be reliably discriminated, and erroneous detection on the far point side is reduced. it can.
[0032]
Further, the MIN voltage 29 of the voltage 30 for detecting a person at the detection position is set by the voltage at the low reflection 25 of the person (detected body) 5.
On the other hand, the MAX voltage 28 of the voltage 30 for detecting the person at the detection position is set by the voltage of the person (detected body) 5 at the high reflection 26.
[0033]
That is, even if the reflectance of the person (detected body) 5 changes, the voltage 30 is set by the detection position 27, so that the human body can be more reliably determined, and erroneous detection of a far point can be reduced.
[0034]
FIG. 10 is a flowchart showing the distance measurement determination in the first and second embodiments of the present invention. After the IRLED projection, first, the distance is calculated in S101. Next, in S102, it is determined whether or not the result of the distance calculation is within the range for detecting a person. If affirmative in S102, the process proceeds to S103, and if negative, the process proceeds to S106 to output a result not detected as a human body.
[0035]
Next, in S103, it is determined whether the voltage on the far point side is outside a predetermined voltage (voltage for detecting a human body). If affirmative in S103, the process proceeds to S104, and if negative, the process proceeds to S105 to output a result not detected as a human body.
[0036]
Next, in S104, it is determined whether the voltage on the near point side is outside a predetermined voltage (voltage for detecting a human body). If affirmative in S104, the process proceeds to S105 to output a result of detection as a human body, and if negative, the process proceeds to S105 and outputs a result not detected as a human body.
[0037]
The present invention is not limited to the above embodiment, and can be modified in various ways.For example, as a toilet device, a human body with a toilet, a urinal, a ventilation fan, lighting, a panel heater, and an air conditioner as well as a hot water washing and drying toilet seat. The detection may be performed.
[0038]
【The invention's effect】
As described above, according to the present invention, the near-point output and the far-point output in which both ends of the PSD are set are set, and the I-V conversion for converting the near-point current output and the far-point current output into a voltage is performed. Means, and a human body detection device having a distance calculation means for calculating a distance to a detection target by a voltage ratio of the near point output voltage and the far point output voltage obtained by the IV conversion means, When the near-point output voltage or the far-point output voltage is a predetermined voltage, the output of the distance calculating means can be invalidated. Regardless, only a voltage ratio result is obtained, preventing erroneous detection of water droplets and dirt on the distance measurement sensor case located between the near-side light emitting unit and the object to be measured, and erroneous detection on the far point side. Although this was not possible, the present invention Significantly be reduced. Further, it can be achieved at a low cost with a simple configuration.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a structure of a distance measuring sensor. FIG. 2 is an explanatory diagram of a light receiving position on a PSD in the distance measuring sensor when detecting a human body. FIG. 3 is an equivalent circuit of a PSD in the distance measuring sensor when detecting a human body. FIG. 4 is an explanatory view of a directional characteristic of an IRLED. FIG. 5 is an explanatory view of reflecting stray light due to water droplets on the surface of a distance measuring sensor. FIG. 6 is an explanatory view of reflecting stray light on a PSD. FIG. FIG. 8 is a near-side output voltage-distance characteristic of a PSD. FIG. 9 is a far-side output voltage-distance characteristic of a PSD. FIG. 10 is a flowchart showing distance measurement determination in the first embodiment of the present invention. Explanation of code]
1: Distance measuring sensor 2: IRLED
3: Floodlight lens 4: Main light 5: Person (detected object)
6: reflected light 7: light receiving lens 8: PSD (semiconductor position detecting device)
9: near point side electrode 10: far point side electrode 11: near point side IV conversion means 12: far point side IV conversion means 13: distance calculation means 14: near point side voltage determination means 15: far point side Voltage determining means 16: Range 17 for detecting a person: Current source Io
18: Current Ia generated in far-side electrode
19: Current Ib generated at the near-point side electrode
20: Stray light scattered light 21: Detected body 22: Stray light reflected light 23: Water drop, dirt 24: Light shielding wall 25: Low reflection 26: High reflection 27: Detection position 28: MAX voltage at the detection position 29: Detection position MIN voltage 30: voltage for detecting a human body 31: MAX voltage in a range for detecting a person 32: MIN voltage 33 in a range for detecting a person 33: predetermined voltage
