JP2004070298A - Image projector and image projecting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image projector for projecting an image onto a screen in which safety is enhanced for a human body or the like intruding into the projection range without complicating the the arrangement. <P>SOLUTION: A monitoring region is defined on the outside of the projecting region 3 of a screen 2, a detection wave, e.g. infrared ray, is emitted from a detection wave source 1c of the image projector 1, and reflection wave from the monitoring region is detected by a reflection wave detecting means 1d, e.g. a CCD sensor. A human body or an obstacle intruding into a monitoring space surrounded by a detection wave 4 between the body section of the image projector 1 and the screen 2 is monitored and when intrusion is detected, intensity of an irradiating light directed toward the projecting region 3 is reduced or the irradiating light is interrupted depending on the situation or extent of intrusion. <P>COPYRIGHT: (C)2004,JPO

Description

【０１０４】
次ステップＳ４では、赤外線照射部１２０Ａ〜１２０Ｄから各監視領域４６Ａ〜４６Ｄに向けてそれぞれ投射される赤外光の通過範囲（角錐台状の検出範囲）への障害物の通過確認試験を行う。つまり、オペレータは、赤外光によって包囲された上記検出範囲に障害物を出し入れして、監視領域４６Ａ〜４６Ｄに関する撮像手段１００の検出画像データに基いて検出信号レベルの低下又は上昇が検出されるか否かを確認することでテストする。
【０１０５】
図１１の時刻ｔ３では赤外光で包囲される監視空間内に障害物の侵入が開始された状況を示しており、このことが検知されると、ＡＰＲが作動してレーザパワーが急激に低下して、時間Ｔ１（＜Ｔ２）以内でパワーがゼロとなる。つまり、障害物がレーザ光の投射範囲に入るまでに要する侵入時間Ｔ２よりも短い時間でレーザ出力がクラス１以下のレベルまで低減される。
【０１０６】
この試験方法には種々の形態が挙げられるが、例えば、各監視領域について検出範囲の外側から、人の手指や光沢のある黒色定規等の物体を出し入れして、上記検出信号レベルの低下等をチェックする。
【０１０７】
侵入検出及び危険防止制御部１１０は、この通過試験において、障害物が上記検出範囲に侵入したときは警報音を出すように制御を行う（図示しない警報装置に対して出力信号が送出される。）。これによってオペレータは正常に障害の検出が行われたことを聴覚で確認できる。また、侵入検出及び危険防止制御部１１０は、必要に応じて、図示しない表示装置に対して、障害物に該当する部分を赤色等で区別して表示させることもできる（障害物が検出されない監視領域については、その検出画像を、例えば、白色で表示する。）。そして、侵入検出及び危険防止制御部１１０はこのときのデータをメモリに記憶しておくこともできる。
【０１０８】
このような試験は、監視領域４６Ａ〜４６Ｄについて行う（但し、障害物の侵入や通過を想定する必要性のないことが事前に明らかな場合には、該当する監視領域は当然に試験対象から除外される。）。
【０１０９】
尚、この試験期間中、投影レンズ３２から投影領域４２への投影は不要であるから、侵入検出及び危険防止制御部１１０は、レギュレータ５４を駆動して電源装置５２から光源部１２に給電される電力を非常に低いレベルに低下させるか、又は電源装置５２から光源部１２への給電を停止させることが望ましい。
【０１１０】
通過試験が完了すると次ステップＳ５に進み、上記した一連の調整作業が終了する。尚、Ｓ２乃至Ｓ４の順序や回数等は適宜に変更可能である。
【０１１１】
上記調整及び確認が終了したら、オペレータは図示しない操作入力手段（操作スイッチ等）を使って、侵入検出及び危険防止制御部１１０に対してその旨を指示する。
【０１１２】
上記通過試験の間、電源装置５２から光源部１２への給電を停止したり、あるいは非常に少ない電力供給状態とするときは、侵入者が、投影レンズ３２と投射領域４２を結んだ範囲に入っても障害はないので、オペレータが上記調整終了の指示を出した場合に、侵入検出及び危険防止制御部１１０は給電装置１３０から赤外線照射手段１２０への給電を停止させることができる。
【０１１３】
他方、侵入者が上記検出範囲に侵入することに対して警告を発するため、電源装置５２から光源部１２への給電状態に係わりなく、電源スイッチ１４０がオン状態である限り、侵入検出及び危険防止制御部１１０が給電装置１３０から赤外線照射手段１２０への給電を継続させることで、上記警報を常に出力可能な状態にしておくこともできる。
【０１１４】
最終ステップＳ６では、通常監視状態に設定される。
【０１１５】
例えば、図示しない映像ソース機器からの映像信号ＶＩＤＥＯが映像信号処理部６２に入力されて、プロジェクタ装置の投影動作が開始すると、ドライバ回路６４は空間変調光生成部１６に映像信号ＶＩＤＥＯに応じた駆動信号を出力し、全体制御部６６がスキャナ制御部６８を介してスキャナ３４を制御する。
【０１１６】
侵入検出及び危険防止制御部１１０には、全体制御部６６から通常の投影動作が開始したことを示す情報が送られ、上記検出範囲に相当する領域（以下、「侵入禁止領域」という。）に人や障害物等が侵入したか否かを常時検出する。
【０１１７】
この検出方法については、上記ステップＳ４で説明した方法と同様であるが、侵入者の保護のためには、侵入検出及び危険防止制御部１１０によって侵入禁止領域内に侵入者等を検出したときに、下記の手段を講じることが好ましい。
【０１１８】
・投影レンズ３２からスクリーン４０に向かう照射光のレベルが侵入者の肉眼に障害を与えない程度のレベルになるまで低下するように、レギュレータ５４を制御して電源装置５２から光源部１２に供給される電力を低下させること。
【０１１９】
・状況次第では、電源装置５２から光源部１２に供給される電力を遮断すること。
【０１２０】
それらの結果、投影レンズ３２からスクリーン４０に向かう照射光が暗くなるか又は皆無となる。また、このとき、侵入検出及び危険防止制御部１１０は警告音又は警報メッセージ等を出力することができる。
【０１２１】
侵入検出及び危険防止制御部１１０による危険防止処理については、侵入禁止領域に侵入物が侵入するときの状態に応じて異なる。
【０１２２】
例えば、各監視領域４６Ａ〜４６Ｄに係るＷ値を１０ｃｍとして、侵入速度が２ｍ／ｓ（メートル毎秒）の場合に、線状侵入物の侵入時間は０．０５秒であり、また、侵入速度がその半分（１ｍ／ｓ）の場合には、線状の侵入物の侵入時間は０．１０秒である。人間の場合にはその幅が線状物体より広いから、侵入時間が０．０５〜０．１秒よりの数倍〜１０数倍程度長くなる。
【０１２３】
また、各赤外線照射部と各監視領域を繋いてできる面（侵入禁止領域の境界）に沿って人間が移動しているときは、侵入禁止領域に入り続けた状態になる。各監視領域の長手方向における長さを２ｍと仮定した場合、侵入速度が２ｍ／ｓのときには、約１秒間侵入禁止領域に侵入していることになる。
【０１２４】
他方、撮像手段１００により撮像された画像データにはノイズの混入が避けられず、侵入者が瞬間的にかつ部分的に侵入禁止領域に侵入したとの誤判断が下される可能性がある（このような場合は過敏な判断処理を行う必要がない。）。
【０１２５】
そこで、侵入継続時間と侵入領域の大きさとの乗算結果に応じて段階的な防止処理を行うことが好ましい。
【０１２６】
ここにいう「侵入継続時間」とは、侵入禁止領域への侵入状態が継続している時間を意味する。また、「侵入領域の大きさ」とは、撮像手段１００で検出した各監視領域４６Ａ〜４６Ｄに係る反射光レベルが所定の基準範囲を逸脱している合においてその部分の面積（例えば、閾値以下のデータをもつ画素数に相当する。）等をいう。
【０１２７】
下記表２は、継続侵入時間と侵入領域の大きさ（侵入部分の面積等）との積によって規定される「侵入状態指示値」と、これに応じて侵入検出及び危険防止制御部１１０により行われる処理内容を例示したものである。
【０１２８】
【表２】

【０１２９】
本例では、侵入状態指示値に応じた４段階（光源部に係るパワー低減や給電停止）の処理が行われ、侵入検出及び危険防止制御部１１０は、レギュレータ５４を介して電源装置５２の電力レベルを変化させて光源部１２の出力を調整して、侵入禁止領域への侵入者の眼等に悪影響を及ぼさないように防止する。尚、侵入状況に応じた、侵入検出及び危険防止制御部１１０の処理については、上記の例に限定されず、種々の処理方法が可能であり、例えば、侵入継続時間だけで判断する方法又は侵入領域の大きさ（侵入面積）だけで判断する方法、あるいは、さらに別の要因を考慮して判断する方法等が挙げられる。
【０１３０】
上記の処理によって、人間が侵入禁止領域に侵入した場合に、人体への障害を及ぼさないように防止することができ、特に、事情が分からない幼児等が侵入禁止領域に入り込んだ場合でも充分な安全対策が講じられる。
【０１３１】
次に、上記構成の変形態様について説明する。
【０１３２】
赤外線照射手段１２０を構成する各赤外線照射部１２０Ａ〜１２０Ｄについて、それらの傾動角（チルト角度）の調整を自動化することが好ましく、モータ等の駆動源及びチルト機構を各赤外線照射部に設けることでそれらの姿勢制御によって照射方向制御を行うことができる。
【０１３３】
また、上記形態においては、図１０に示すステップＳ５の調整終了後に通常監視処理に移行する例を述べたが、既に調整作業が終了した状態のプロジェクタ装置を使用するときは、電源スイッチ１４０をオン状態にしたときに、直ちにステップＳ６の通常監視状態から開始することもできる。その場合、例えば、ステップＳ５において調整作業が完了したことを示すためのフラグ（調整終了フラグ）を用意し、これを所定値（例えば、「１」）に設定して、侵入検出及び危険防止制御部１１０のメモリ内に記憶させておけば良い。
【０１３４】
ステップＳ６の通常監視状態においては、各赤外線照射部１２０Ａ〜１２０Ｄからスクリーン４０の各監視領域４６Ａ〜４６Ｄに赤外線を連続的に照射するものとしたが、これに限らず、侵入禁止領域への侵入者の検出が可能な時間間隔をもって赤外線照射を行っても良い（例えば、監視領域４６への赤外線照射を数ミリ秒間隔で断続的に行うこともできる。）。
【０１３５】
また、上記形態では、監視領域４６Ａ〜４６Ｄの全てについて赤外線照射手段１２０から赤外線を照射する場合について述べたが、例えば、領域４６Ａの位置が高く、普通人の身長範囲を考えると侵入の可能性がない場合には、あえて該領域の赤外線照射を行う必要はない。
【０１３６】
上記の説明では、スクリーン上の投射領域４２の外側に位置する監視領域４６を設け、侵入禁止領域への侵入について監視するシステムを想定したが、該監視領域の外側にさらに別の監視領域を設定し、監視空間の多重化（２重化、３重化等）によって監視体制を強化することが可能であり、以下ではそのような実施態様について説明する。
【０１３７】
図１４はプロジェクションシステムの構成例を示した構成図であり、基本的な要素については図９と同様であり（よって、機能的に同じ要素には既に付した符号を用いて重複説明を回避する。）、相違点だけを箇条書きで下記に示す。
【０１３８】
・監視領域については２重とされ、内側の領域（第１監視空間又は第１監視ゾーン）を第１警報処理部７０が担当し、外側の領域（第２監視空間又は第２監視ゾーン）を第２警報処理部８０が担当すること及び各監視空間への侵入についてそれぞれ検出するとともに、侵入の状態や状況に応じて警報処理を行うこと。
【０１３９】
・第１警報処理部７０が第１検出手段７２と第１警報手段７４を有しており、第１検出手段７２によって人体等の侵入が検出されると、第１警報手段７４が警報を出力し、レーザ光の強度を変化させる（低下又はゼロ）こと。
【０１４０】
・第２警報処理部８０が第２検出手段８２と第２警報手段８４を有しており、第２検出手段８２によって人体等の侵入が検出されると、第２警報手段８４が警報を出力すること。
【０１４１】
図１５は、プロジェクタ装置の本体部１Ｂとスクリーン４０との位置関係を示す概略図であり、（Ａ）図は投影光の状態を示す斜視図、（Ｂ）図は投影方向に直交する方向（側方）からみた場合の断面図である。
【０１４２】
本体部１Ｂの光投射部３０からスクリーン４０に投影される映像は、光投射部３０のスキャナ３４により走査が行われ、スクリーン上の投影領域４２に投影される。
【０１４３】
光投射部３０から投影領域４２に投影される光（映像光）の通過領域４２Ｓを、以下では「映像光通過空間領域」と呼ぶことにする。
【０１４４】
また、上記第１監視空間（又はゾーン）については、下記の領域から構成されるものとする。
【０１４５】
・「第１監視領域」＝投影領域４２の外周に位置する監視領域（前記した監視領域４６と同様であり、図にはその幅を誇張して示す。）
・「第１空間監視領域」＝上記映像光通過空間領域４２Ｓの外側（外周）に位置する空間領域（光投射部３０から出力される映像光の周囲に位置する空間領域４６Ｓ）。
【０１４６】
同様に、上記第２監視空間（又はゾーン）については、下記の領域から構成されるものとする。
【０１４７】
・「第２監視領域」＝第１監視領域４６の外周又は第１監視領域４６を含む外部領域９０（（Ａ）図に破線で示す領域）
・「第２空間監視領域」＝第１空間監視領域４６Ｓの外周又は第１空間監視領域４６Ｓを含む空間領域９０Ｓ（（Ｂ）図参照）。
【０１４８】
第１警報処理部７０において（図１４参照）、第１検出手段７２は第１空間監視領域４６Ｓへの人体や物体の侵入、あるいは、これらが継続的に存在することを検出する。そして、第１警報手段７４は、第１検出手段７２からの検出情報に基いて警報を出力するとともに、光源部１２への電力供給について制御する。
【０１４９】
また、第２警報処理部８０において、第２検出手段８２は、第２空間監視領域９０Ｓへの人体又は物体の侵入、あるいはこれらが継続的に存在することを検出する。そして、第２警報手段８４は、第２検出手段８２からの検出情報に基いて警報を出力する。
【０１５０】
図１６は警報処理の一例を示したフローチャート図であり、下記ステップに従って処理が行われる。
【０１５１】
（Ｓ１１）正常投影動作
（Ｓ１２）第２検出手段による侵入検出
（Ｓ１３）第２警報手段による警報処理
（Ｓ１４）第１検出手段による侵入検出
（Ｓ１５）第１警報手段による警報処理。
【０１５２】
先ず、ステップＳ１１では、図１４の電源装置５２からの規定電圧をもって光源部１２が駆動され、映像信号ＶＩＤＥＯに応じて空間変調光生成部１６で変調された映像光が光投射部３０からスクリーン４０上の投影領域４２に投影される。
【０１５３】
そして、ステップＳ１２に進み、第２検出手段８２によって第２空間監視領域９０Ｓに人体等が侵入したか否かについて検出される。つまり、人体等の侵入や存在が検出された場合に、ステップＳ１３に進み、第２警報手段８４によって警報処理が行われる。該警報処理としては、例えば、「危険ですから投影領域から離れて下さい」といった内容の音声メッセージを出力する（視聴者が投影領域４２を注視していない状態でも該メッセージを耳で聞けるので、視聴者は事前に危険を察知することができる。）。これにより侵入者に回避行動が促される。尚、この音声メッセージに加えて、又は音声メッセージとは別に、第２警報手段８４から全体制御部６６に第２警報信号を出力することにより、全体制御部６６が映像信号処理部６２において映像信号ＶＩＤＥＯに警告メッセージ信号や警告図形信号を重畳させた上でドライバ回路６４に出力し、空間変調光生成部１６を経由して、投影領域４２に映像表示を行っても良い（これにより、視聴者が投影領域４２上の警告表示や上記音声メッセージにより、事前に危険を察知することができる。）。
【０１５４】
このような警報にも係わらず、侵入等が継続された場合には、次ステップＳ１４において、第１検出手段７２によって、第１空間監視領域４６Ｓへの侵入が検出される。つまり、人体等の侵入又は該領域４６Ｓにおける人体等の存在を検出すると、ステップＳ１５に進んで第１警報手段７４が第１警報処理を行う。例えば、第１警報手段７４は、レギュレータ５４を介して電源装置５２の出力電圧を遮断状態にして、光源部１２からレーザビームを出射させない状態にする。これにより、視聴者の眼が保護される。好ましくは、「危険ですから装置を停止します。」といった内容の音声メッセージを出力する（プロジェクタ装置の停止理由が視聴者に理解される。）。
【０１５５】
尚、第１警報手段７４がレギュレータ５４を介して、電源装置５２の出力を下げて、安全なレベルまでレーザ光の強度を低下させることにより、視聴者の眼が保護されるようにしても良い。その際、「目に危険ですから暗くします。」といった内容の音声メッセージを出力することにより、投影光の低下理由を視聴者が理解できるように配慮することが好ましい。
【０１５６】
また、第１警報手段７４が動作したとき、第１警報信号を全体制御部６６に出力し、全体制御部６６は必要に応じて、映像信号ＶＩＤＥＯを出力する外部装置に対して映像信号ＶＩＤＥＯの出力停止を要求し、プロジェクタ装置による投影を停止させることができる。
【０１５７】
第１警報手段７４が動作した後におけるプロジェクタ装置の再起動については、オペレータの操作によりレギュレータ５４をリセットすることで行うことができる。コンピュータ機器等の外部装置からの映像信号ＶＩＤＥＯの出力再開については、オペレータによってプロジェクタ装置が再起動されたときに全体制御部６６が外部装置に対して映像信号を要求する。
【０１５８】
上記形態によれば、第２空間監視領域９０Ｓへの侵入が検出され、さらに第１空間監視領域４６Ｓへの侵入が検出されたときに、レーザ光を遮断し又はその光強度を低下させることにより、１段階の侵入検出に比べてプロジェクタ装置の稼働率を低下させずに安全対策を講じることができる。そして、第１空間監視領域４６Ｓへの侵入前に、第２空間監視領域９０Ｓに人体が侵入したことを検出して、事前警告を行えるので、侵入禁止領域に人体が誤って入り込まないよう未然に防止できる。
【０１５９】
好ましくは、第２警報手段８４が動作した時点から、所定時間以内に第１検出手段７２が第１空間監視領域４６Ｓへの侵入を検出した場合に、第１警報手段７４によって上記警報処理を行う。それにより、第１検出手段７２の誤検出や誤動作、あるいは第１空間監視領域４６Ｓの検出に係るノイズ成分の影響を低減させ、第１警報手段７４が頻繁に動作してプロジェクタ装置の利用度が低下するといった不具合を防止できる。
【０１６０】
上記した第２警報処理部８０の実施形態について、その第２検出手段８２には下記に示す形態が挙げられる。
【０１６１】
（Ｉ）人体の発する放射エネルギーを検出する焦電センサ（警備装置等において人体の侵入を検出するために使用されている。）を用いる形態
（ＩＩ）サーモグラフィ装置等に使用される熱感知センサを用いる形態。
【０１６２】
上記（Ｉ）については、例えば、下記の形態が挙げられる。
【０１６３】
（Ｉ−１）１つの焦電センサを用いた形態（図１７参照）
（Ｉ−２）複数の焦電センサを組み合わせた形態（図１８参照）。
【０１６４】
先ず、上記（Ｉ−１）では、例えば、図１７に示すように、焦電センサの設置方法として、スクリーン４０を含む第２監視領域９０のほぼ全体を包囲する領域（図に太線の円形枠で示す。）への指向特性をもった１個の焦電センサを光投射部３０の近傍に設けることができる。尚、誤動作やノイズ等に起因して、第２警報手段８４の頻繁な動作が起きないようにするためには、焦電センサが所定時間以上継続して人体等を検出したときに（例えば、継続時間の判定用閾値を２秒間程度とする。）、第２警報手段８４を動作させれば良い。
【０１６５】
第１検出手段７２については前記したように撮像素子（ＣＣＤセンサ等）を用いることができるが、これを第２検出手段８２と共用させた形態も勿論可能であり、その場合には、１個の焦電センサで、第１空間監視領域４６Ｓへの侵入状態をも検出できる（該焦電センサが第１及び第２検出手段の役目を果たす。）。さらには、該焦電センサを用いて、映像光通過空間領域４２Ｓに人体が侵入することも検出可能である。
【０１６６】
上記（Ｉ−２）では、例えば、比較的指向性の狭い焦電センサを複数個用いることができる。図１８に示す複数の円形枠は各焦電センサによる検出領域を表しており、図の下方にはそれらの指向性分布について概略的に示している。本例では、７個の焦電センサを用いて、それぞれ第２空間監視領域９０Ｓの下部、右側部、左側部を指向させるために、光投射部３０の近傍に配置している。尚、第２空間監視領域９０Ｓの上部に人間が接近することはありえないので、当該部分を指向する焦電センサを設ける必要はないものとしている。
【０１６７】
第２空間監視領域９０Ｓの下部を担当する焦電センサについて、図には指向性の強度分布例を３つの波形で示しているが、指向性としてそれほど厳密な条件が要求される訳ではないので、第１空間監視領域４６Ｓの外部、あるいは当該領域４６Ｓを含む範囲を指向していれば良い。
【０１６８】
この場合も、誤動作やノイズ等による、第２警報手段８４の頻繁な動作を回避するためには、各焦電センサが所定時間以上に亘って継続して人体を検出したときに第２警報手段８４を動作させるように構成すれば良い。
【０１６９】
また、２個の焦電センサを組み合わせて用いること、例えば、２個の焦電センサを並べて１組にし、それらの検出信号の差を演算すると、差の符号（±）に応じて人体の移動方向を検出することができる。このような焦電センサ対を用いて、第２空間監視領域９０Ｓの下部、右側部、左側部を指向させて配置して、差動型焦電センサとして用いることにより、第２空間監視領域９０Ｓに侵入してくる人体を検出できる。
【０１７０】
次に、上記形態（ＩＩ）について説明すると、熱感知センサを用いることにより、人体の温度（体温）を検出して温度に応じた表示や制御等を行うことができる。例えば、熱感知センサによって検出された温度が、人の体温範囲（３４〜４０度）内であるとき、人体が第２空間監視領域９０Ｓにいることが判断されて、第２警報手段８４が動作する。尚、熱感知センサの検出領域については、焦電センサの場合と同様に規定することができる。また、第１検出手段７２との共用も可能であり、１個の熱感知センサを光投射部３０の近傍に設け、第１検出手段７２として第１空間監視領域４６Ｓにいる人体を検出したり、さらには映像光通過空間領域４２Ｓにいる人体の検出にも使用できる。
【０１７１】
この他、複数の熱感知センサを光投射部３０の近傍に設けることにより、第２空間監視領域９０Ｓを中心に人体の存在を検出することができる。
【０１７２】
次に、上記第１検出手段７２について下記の構成形態を説明する。
【０１７３】
（ｉ）超音波センサを用いた形態（図１９参照）
（ｉｉ）光センサを用いた形態（図２０参照）。
【０１７４】
先ず、形態（ｉ）では、図１９に円形枠で示すように、第１監視領域４６及び第１空間監視領域４６Ｓを検出領域として包含し、第２監視領域９０および第２空間監視領域９０Ｓを検出領域として含まない超音波センサを複数個（例えば、４個程度）用いる（各超音波センサを光投射部３０の近傍に設ける。）。超音波センサは送受信部を備えており、圧電素子に電圧を印加することにより超音波を発生し、超音波を受信すると受信した超音波の振幅に応じた電気信号を出力する。人体等の侵入がない状態では光投射部３０とスクリーン４０との間に超音波を遮るものはないので、この場合には、超音波センサから超音波が出力されてスクリーン４０の第１監視領域４６を含むスクリーン４０に向かって進み、スクリーン４０上で反射された反射波が超音波センサに受信される。超音波センサと第１監視領域４６との間や、第１空間監視領域４６Ｓに超音波を遮る物体や人体が存在する場合には、反射波のレベルが低くなるか又は反射波が検出されないことにより判断される。
【０１７５】
上記形態（ｉｉ）では、例えば、図２０に黒色太線の矩形枠で示すように、スクリーン４０の第１監視領域４６に沿って、複数の光センサや、ライン状センサ（１次元ＣＣＤ）等の受光素子群を配置し、他方、プロジェクタ装置本体部の前面には、光投射部３０の周囲から第１監視領域４６に向かって光源部１２からの照射光よりも充分レベルの低い光や赤外光等を出力する発光素子群（ＬＥＤ等）を設ける。これにより、該発光素子群と上記受光素子群との間に形成される光路を遮る物体や人体を検出することができる。あるいは、第１監視領域４６に赤外光の発光素子群を配置して、それらが出射する光線をプロジェクタ装置本体部の光学センサで検出するといった構成形態が挙げられる。
【０１７６】
これらの形態以外にも、焦電センサや熱感知センサ等を使用したり、第２検出手段８２と共用するといった、各種の実施形態が可能であることは勿論である。
【０１７７】
尚、上記の説明では、第１監視領域４６が投影領域４２の外周のスクリーン４０内に規定された例を示したが、投影領域４２の外部に位置していれば、スクリーン４０の内部に位置しなくても良い。また、第２監視領域９０をスクリーン４０の外部に位置する例を上述したが、第２監視領域９０を第１監視領域４６とともにスクリーン４０内に位置させることもできる。
【０１７８】
上記した構成により、例えば、下記に示す利点が得られる。
【０１７９】
・レーザ光の投射領域に人体や障害物が侵入するまでの間に、レーザ光を瞬時に遮断し又は減光することができるので、安全性が高い。
【０１８０】
・人体や障害物の侵入検知に用いられる検出波（赤外光や赤外線）については、視聴者に視認されず、従って、スクリーン上の投影画像に影響を及ぼして画質を低下させるといった不都合がない。また、検出波自体の影響による人体への危険もない。
【０１８１】
【発明の効果】
以上に記載したところから明らかなように、請求項１や請求項１５に係る発明によれば、人体に対する安全性を保証するとともに、監視空間内への侵入検出を簡易に実現することが可能である。
【０１８２】
請求項２に係る発明によれば、装置の小型化に適している。
【０１８３】
請求項３や請求項１６に係る発明によれば、検出精度を充分に確保するとともに、投射画像への影響がない。
【０１８４】
請求項４や請求項１７に係る発明によれば、画像検出を確実に行うことができるとともに、スクリーン周縁の全範囲を監視する方法に比較して、監視領域の幅を必要最小限度で設定することができ、検知処理が簡単で迅速である。
【０１８５】
請求項５に係る発明によれば、照射光を規制して人体への影響を抑え、充分な安全対策を講じることができる。
【０１８６】
請求項６に係る発明によれば、光変調手段を備えた画像投射装置への適用において、安全性や信頼性の向上に有効である。
【０１８７】
請求項７や請求項９に係る発明によれば、出射光の遮光や変調停止により迅速な処理が可能である。
【０１８８】
請求項８に係る発明によれば、光源への供給電力を制御することにより、光強度を確実に規制することができる。
【０１８９】
請求項１０に係る発明によれば、侵入状態の度合いに応じて詳細な光出力レベルの制御が可能であり、また、誤検出防止等に有効である。
【０１９０】
請求項１１に係る発明によれば、侵入検知処理が容易であり、複雑な画像処理等を必要としない。
【０１９１】
請求項１２に係る発明によれば、安全性が確認されるまで照射光の強度が抑制されるので、高い安全性を保証することができる。
【０１９２】
請求項１３、請求項１４、請求項１８に係る発明によれば、多重の監視体制によって、安全対策の強化に有効である。
【図面の簡単な説明】
【図１】本発明に係る画像投射装置の基本構成例を示す概略図である。
【図２】スクリーン上における各投射領域、監視領域を例示した説明図である。
【図３】スクリーン周縁に照射される検出波の強度分布について説明するための図である。
【図４】画像投射装置における安全対策について説明するためのフローチャート図である。
【図５】画像投射装置の構成例について説明するための図であり、プロジェクタ装置とスクリーン部との配置例を示す図である。
【図６】図５に示すプロジェクタ装置の正面図である。
【図７】（Ａ）〜（Ｄ）に赤外線照射手段の一例を図解した図である。
【図８】（Ａ）、（Ｂ）に赤外線照射手段の照射例を示す図である。
【図９】プロジェクションシステムの構成例を示す図である。
【図１０】侵入検出及び危険防止制御部の処理例を示すフローチャート図である。
【図１１】レーザ光のパワーレベルについて時間経過の一例を示したグラフ図である。
【図１２】赤外線強度と距離との関係を例示したグラフ図である。
【図１３】検出波の投射範囲と監視領域との設定方法について、（Ａ）〜（Ｃ）に従って説明するための図である。
【図１４】プロジェクションシステムの構成について別例を示した図である。
【図１５】図１４に示すプロジェクタ装置とスクリーンとの位置関係を示した図である。
【図１６】図１４のプロジェクタ装置における警報動作を例示したフローチャート図である。
【図１７】第２監視空間への侵入検出について、第２検出手段の検出領域を例示した説明図である。
【図１８】第２検出手段について他の検出領域を例示した説明図である。
【図１９】第１監視空間への侵入検出について、第１検出手段として超音波センサを用いた場合の検出領域を例示した説明図である。
【図２０】第１検出手段の別例を示した説明図である。
【符号の説明】
１…画像投射装置、１ａ…光源、１ｂ…投射部、１ｃ…検出波源、１ｄ…反射波検出手段、２…スクリーン、３…投射領域、６…監視領域、４０…スクリーン、７２…第１検出手段、７４…第１警報手段、８２…第２検出手段、８４…第２警報手段[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a technique for sufficiently taking safety measures in an image projection device and an image projection method configured using a high-intensity light source.
[0002]
[Prior art]
As an image display device capable of displaying a large screen, a projection type projector device is known, and an observer can see an image projected by projecting light from a light source onto a screen.
[0003]
Hitherto, a high-brightness projection tube has been used as a light source of the projector device. However, red (R), green (G) is used for the purpose of improving brightness and color reproducibility, and facilitating modulation by a video signal. And a projection system using a blue (B) laser light source.
[0004]
When laser light is used, it is important to ensure its safety. For example, it is necessary to take sufficient measures when a viewer inadvertently enters a laser light projection area. In other words, it has been pointed out that there is a danger when the laser light directly enters the eyes. As a safety measure, it is detected that a person or the like has entered the laser light projection area, and the projection of the laser light is shut off. Various devices having functions have been proposed (for example, see Patent Documents 1 to 3).
[0005]
[Patent Document 1]
JP-A-4-111585
[Patent Document 2]
Japanese Patent Publication No. Hei 11-501419
[Patent Document 3]
JP 2001-249399 A
[0006]
[Problems to be solved by the invention]
By the way, in the conventional apparatus, there are problems associated with taking safety measures, for example, a problem that the configuration of the apparatus is complicated or that the size of the apparatus is hindered.
[0007]
In other words, in a device in which the safety of the human body is important, a safety mechanism for that purpose is indispensable.However, the addition of this mechanism complicates the projection optical system and the like, or causes a significant increase in the cost of the device. If it occurs, there is a possibility that it may hinder its spread. In addition, the operation delay of the safety mechanism is not allowed, and promptness is required for intrusion detection.
[0008]
Accordingly, the present invention provides an image projection apparatus having a function of projecting and displaying an image on a screen, improving safety when a human body or the like enters a projection range of irradiation light, and, for that purpose, has a complicated configuration. It is an object of the present invention to avoid the occurrence of such problems.
[0009]
[Means for Solving the Problems]
The image projection device according to the present invention, in order to solve the above-described problem, a detection wave source provided on the surface or screen facing the screen in the device main body, and from the detection wave source to the outside of the projection area on the screen. And a reflected wave detecting means for detecting a reflected wave reflected by the monitoring area after the detection wave is emitted to a monitoring area located at a distance, wherein a detection level of the reflected wave detecting means is set to a predetermined threshold or a reference range. Based on the result of comparison with the above, it is configured to detect intrusion into the monitoring space surrounded by the detection wave.
[0010]
Further, the image projection method according to the present invention, with respect to the projection area on the screen located at a distance from the image projection device, while defining a monitoring area located outside the outside, and with respect to the monitoring area A detection wave is emitted from a detection wave source provided on a front surface of the image projection apparatus, and detection of a reflected wave from the monitoring area is performed to detect intrusion into a monitoring space surrounded by the detection wave, and to a projection area. The light radiated toward it is blocked or the intensity of the light is reduced depending on the state of penetration.
[0011]
Therefore, according to these inventions, the detection wave source facing the screen is provided, and the intrusion into the monitoring space is detected with a simple configuration by detecting the reflected wave emitted from the detection wave source and reflected by the monitoring area. can do. Then, when intrusion into the monitoring space is detected, it is possible to prevent the human body from being exposed to danger by blocking the irradiation light to the projection area or reducing the light intensity.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
An object of the present invention is to guarantee safety in an image projection apparatus by immediately blocking light or reducing light intensity when an obstacle enters a projection area of irradiation light (laser light or the like). I do.
[0013]
FIG. 1 schematically illustrates a basic configuration example of an image projection apparatus according to the present invention, and illustrates an example of an apparatus using a laser light source (eg, a laser projector apparatus).
[0014]
The image projection apparatus 1 includes a light source 1a for displaying an image by projecting onto a projection area 3 on a screen 2 located at a fixed distance from the apparatus main body, and a projection section 1b including a projection lens. For example, a configuration is known which includes a laser light source (a laser light source for each color of RGB) and a light modulator (modulation means), and has a function of projecting an image on the screen 2 using laser light. The optical modulator includes a modulator and an optical system for modulating each of the RGB laser beams according to an image signal. The laser beam is modulated according to the image signal. For example, a galvanomirror constituting an optical scanning unit is provided. Scanning (sweep) is performed by the above-described method. In addition, the light modulator includes a projection optical system including an objective lens for projecting each color laser beam on the screen 2, and each color laser beam swept by the optical scanning unit is transmitted through the projection optical system. The screen 2 is irradiated. The application of the present invention is not limited to a projector device that modulates illumination light with a video signal and projects it on a screen, but can be applied to projector devices having various configurations.
[0015]
In addition, as the light source 1a, a configuration using a discharge lamp, a light emitting tube, or the like having high light intensity or luminance can be cited. In particular, in the configuration using a laser light source, as compared with the case using a projection tube or the like. It has excellent characteristics in terms of brightness and color reproducibility, and it is easy to modulate a video signal. However, when the laser light source is used as described above, it is necessary to take safety measures against the intrusion of the human body or the like into the irradiation light passage area from the projection unit 1b toward the projection area 3 on the screen (for example, , Blocking laser light or reducing light intensity, etc.).
[0016]
In FIG. 1, a rectangular frame “LA” indicated by a solid line on the screen 2 indicates an outer frame of the laser light projection region 3, and an image is projected and displayed in the region.
[0017]
In the image projection device 1, for example, even if the viewer inadvertently enters the irradiation range of the laser beam toward the projection region 3, it does not harm the human body (eg, prevent the laser beam from directly entering the eyes). For detecting intrusion into a set area (monitoring space) using a detected wave and detecting a reflected wave of the detected wave. Then, when it is detected that a person or the like has entered the area, the irradiation light to the projection area 3 is blocked or the intensity of the irradiation light is sufficiently reduced (so as not to affect the human eyes. To prevent.).
[0018]
The intrusion detection means using the detection wave includes a detection wave source 1c and a reflected wave detection means 1d.
[0019]
The detection wave source 1c is provided on the front surface or the screen facing the screen 2 in the apparatus main body. For example, a safe light source such as a light emitting diode (LED) is used as an infrared light source or an infrared light source. (Even if infrared light enters the viewer's eyes, there is no safety problem.)
[0020]
A detection wave emitted from the detection wave source 1c (see a two-dot chain line 4 in FIG. 1) is emitted toward the screen 2. In FIG. 1, a rectangular frame IR indicated by a broken line on the screen 2 indicates a projection area of a detection wave. In this example, it is a quadrangular area located outside the laser light projection area 3 and slightly larger than the area. Note that the reason why the size (angle of view) of the detection wave projection area (rectangular frame IR) is set larger than that of the laser light projection area 3 is that a viewer or the like enters the projection area 3 before the viewer enters the projection area 3. This is because of the need to detect that.
[0021]
The reflected wave detecting means 1d is provided for detecting a reflected wave of the detected wave from the screen. That is, after the detection wave is emitted to a predetermined area (see the monitoring area 6 in FIG. 2) located outside the projection area 3 from the detection wave source 1c, the reflected wave reflected by the area is detected. For example, when infrared light or infrared light is used as the detection wave, an image pickup device (CCD type, CMOS type image sensor, or the like) may be used as the reflected wave sensor.
[0022]
Note that the detection wave source 1c and the reflected wave detection means 1d are arranged around a projection unit 1b provided on a surface facing the screen 2 (the front surface of the apparatus main body). As shown in this example, if the reflected wave detecting means 1d is located near the projection unit 1b and the detection wave source 1c is arranged so as to surround them, it is advantageous for miniaturization and downsizing of the device. . Further, by providing the reflected wave detecting means 1d at a location close to the projection unit 1b, it is possible to reduce the probability of occurrence of erroneous detection or the like (for example, the reflected wave detecting means 1d is too far from the projection unit 1b). In such a case, detection irrelevant to the projection is performed, and when the intrusion detection responds to this, there is a possibility that the safety mechanism may be activated unnecessarily.) In addition, by using a method such as modulating the detection wave, the detection accuracy can be increased or erroneous detection can be prevented.
[0023]
FIG. 2 illustrates the relationship between the projection area 3 of the laser beam, the projection area 5 of the detection wave (indicated by a broken line), and the monitoring area 6 on the screen 2.
[0024]
The monitoring area 6 is set at a position substantially corresponding to the projection area 5, but the width of the monitoring area 6 is narrower than the projection area 5. In this example, the monitoring area 6 is composed of four areas 6A to 6D having a predetermined width corresponding to the respective sides of the rectangular frame (quadrilateral). However, the present invention is not limited to this. Implementation in various forms using regions is possible.
[0025]
2, the area 6A is the left side of the quadrilateral, the area 6B is the upper side of the quadrilateral, the area 6C is the right side of the quadrilateral, and the area 6D is the lower side of the quadrilateral. Each part is constituted. Each of the constituent regions is monitored based on the acquired data relating to the range (detection range) detected by the reflected wave detecting means 1d, corresponding to each of the regions. For example, in a case where an infrared light or infrared reflected wave sensor, an image sensor, or the like is used, intrusion monitoring is performed by processing using pixel data forming a detection image of each component region.
[0026]
Regarding the distance from the outer frame LA of the projection area 3 to the monitoring area 6 (see “W” in FIG. 3), the invasion speed assumed from the motion of the human body and the intrusion of the human body and obstacles are detected. It is determined based on the relationship with the time required until the laser light is cut off or dimmed (that is, if this distance is too short, the laser light cutoff or dimming after intrusion detection will not be in time. There is a risk that the distance (interval) needs to be set appropriately.)
[0027]
The monitoring area 6 has, for example, the following forms.
[0028]
(A) A mode in which the screen is set to a high reflectance range
(B) A mode in which a reflective member (a retroreflective sheet or the like) is provided in a range where the reflectance of the peripheral portion of the screen is low.
[0029]
In the mode (a), image projection is performed in a state where the projection area 3 is located in a range having a high reflectance in the screen 2, and usually, a range slightly smaller than its maximum size (the size of a white background portion) is set. In consideration of this, the positions of the regions 6A to 6D are set on the outer periphery of the projection region 3. That is, while the range having a high reflectance on the screen 2 can be used as it is, the presence of the monitoring area 6 affects the image size of the projection area 3 and the display range is slightly narrowed.
[0030]
Therefore, in the embodiment (b), a retroreflective sheet or the like is attached to the peripheral portion of the screen (a black background portion or the like), and this portion is used as a monitoring area, so that an image can be displayed on the entire screen.
[0031]
The size and position of the monitoring area 6 are set to be larger than those of the projection area 3 based on the measured value of the distance from the image projection apparatus 1 to the screen 2 and the F value of the projection lens. In that case, instead of irradiating the irradiation light with high light intensity to the projection area 3 immediately, first irradiate the irradiation light with sufficient brightness for the eyes to the projection area 3 and observe the angle of view. Then, it is preferable to set the size and the position of the monitoring area 6.
[0032]
FIG. 3 schematically shows the intensity distribution of the detection wave. With respect to a graph curve 7 showing the intensity distribution, the intensity of the detection wave is shown in the direction indicated by the arrow L, and the direction orthogonal to this is the screen. 2 shows the position.
[0033]
The detection wave is emitted from the outer shape of the projection area 3 to a position spaced apart by “W” from the outer shape of the projection area 3, and a predetermined wave is set in a range slightly wider than the width of the monitoring area 6 (width of 6A to 6D). It shows a substantially constant intensity equal to or higher than the level, and has a distribution in which the intensity gradually decreases toward the inside or outside of the screen 2 from the range. In other words, if the width of the monitoring area 6 is too large compared to the width of the projection area 5, the foot of the detected wave having a low intensity will fall on the monitoring area 6, so that the intensity becomes unstable or necessary for detection. Problems such as insufficient S / N (signal to noise) ratio occur. Therefore, the width of the monitoring area 6 is within a substantially constant level range (in the projection area 5 of the detection wave, when the intensity of the detection wave is equal to or higher than a predetermined level, when viewed from the direction facing the screen 2). It is preferable to set so as to fall within the flat area.
[0034]
Next, the monitoring process will be described.
[0035]
The principle of monitoring each area 6A to 6D of the monitoring area 6 by the reflected wave detecting means 1d and performing a judgment process relating to intrusion detection is as follows.
[0036]
Each component area of the monitoring area is monitored, for example, as an image detected by the reflected wave detecting means 1d. As an example, the size of a certain monitoring area 6B corresponds to the image size of “2 pixels in width × 600 pixels in length = 1200 pixels in total” in the corresponding detection image, and each pixel data has a predetermined floor. It indicates the intensity of the reflected wave according to the tone expression. That is, the detection wave is applied to the projection area 5 on the screen 2 and reflected by the screen, and the intensity of the reflected wave is recognized as data of each pixel constituting the detection image of the monitoring area. For example, when the intensity of the reflected wave from the screen 2 is detected with an accuracy of 256 gradations, a reference range of the reflected wave intensity based on the pixel data is set in advance, and the actual reflected wave intensity is set in this reference range. It is possible to judge intrusion detection by examining whether or not it is inside. If the reference range is provisionally set to 70 to 120, the data is shown when the actual reflected wave intensity is less than the reference range (0 to 69) or exceeds the reference range (121 to 255). It is recognized that the detected wave is blocked at the pixel or, conversely, too bright.
[0037]
Of the 1200 pixels related to the monitoring area, for a predetermined number of pixels (for example, 6 pixels) or more, it is determined from the comparison result with the reference range that the reflected wave intensity is not allowed, and the intensity decrease or intensity increase When it is recognized, it is determined that a human body or an obstacle has entered. Note that a change in the detected value of the reflected wave intensity based on each pixel data is caused by the detection wave being interrupted by the intrusion of a human body or an obstacle or by directly reflecting the detection wave. The detection level of the reflected wave detection means 1d is compared with a predetermined threshold value or reference range, and based on the comparison result, intrusion into the monitoring space surrounded by the detection wave can be detected. The “detection” includes not only the presence or absence of a human body or an object, but also detection of the size or the moving direction.
[0038]
As described above, it is effective to detect not a whole detected image but a part of an image corresponding to a monitoring area by level comparison, and does not require complicated and time-consuming image processing.
[0039]
When such a monitoring system detects intrusion of a person or the like, a safety mechanism operates. That is, the reflected wave detecting means 1d detects a reflected wave from the screen 2 with respect to the monitoring area 6 (6A to 6D). The reflected wave detecting means 1d measures the intensity of the reflected wave from the screen 2 based on each pixel data in the monitoring area 6, and for example, when the detected wave intensity reflected by the intrusion of a human body or an obstacle has no such intrusion. It is detected that the intensity is different from the intensity of the reflected wave from the screen or the reflecting member (such as a retroreflective sheet). Then, when an abnormality including a decrease or increase in intensity is detected in any of the monitoring regions, the irradiation light (laser light or the like) is cut off or dimmed. Regarding the mechanism, for example, the following configuration forms can be given.
[0040]
A mode in which the light emitted from the light source 1a is blocked by a blocking mechanism such as a mechanical shutter.
Drive control of the light modulation means, for example, a form in which the drive of the light modulation element is turned off (dark state)
A form in which the power supply to the light source 1a is stopped or the supplied power is reduced
-Combinations of the above forms.
[0041]
FIG. 4 is a flowchart for explaining an example of a safety measure regarding the image projection apparatus 1. According to the present algorithm, until the safety of the laser beam projection is confirmed, it is sufficiently safe for human eyes. By performing projection with a laser beam having a high intensity, it is possible to prevent an accident when a person accidentally enters the projection range of the laser beam.
[0042]
The processing steps are as follows.
[0043]
(S1) Switch on the device and start operation
(S2) Irradiate laser light with sufficient intensity for eyes
(S3) The setting state of the safety mechanism is confirmed, and if resetting is required, proceed to (S4). If there is no problem with the setting, proceed to (S5).
(S4) After performing various adjustments and confirmation processing, return to (S3).
(S5) After the safety of the device is confirmed by the user or the administrator of the device, the switch is turned on to activate the safety mechanism.
(S6) Irradiate laser light with specified brightness. In this state, when the intrusion of a human body or an obstacle is detected as described above, the laser beam is cut off or the intensity of the laser beam is reduced to a safe level as in (S2) due to dimming. .
[0044]
The items of adjustment and confirmation in (S4) are, for example, as follows.
[0045]
・ Automatic adjustment and confirmation of projection distance
・ Setting of monitoring area based on projection distance and angle of view
・ Irradiation of detection wave to screen and automatic adjustment of detection wave output and irradiation position according to distance
-Check the reflected wave intensity from the screen and change the screen settings as necessary.
[0046]
As in this example, the intensity of the irradiation light is reduced to a level that is not dangerous to the human body until it is confirmed that no intrusion into the surveillance space surrounded by the detection wave, in particular, no human body has been detected. After the image projection is performed and the safety is sufficiently confirmed, it is desirable to perform control to increase the intensity of the irradiation light to a specified level. After confirming that no human body or obstacle enters the monitoring space in the image projection device 1, the user (operator of the device) confirms that no human body or obstacle enters the projection area 3 just in case. After confirming that the projection power of the irradiation light is increased for the first time by turning on a dedicated switch, it is possible to further enhance the safety.
[0047]
Note that the above (S2) to (S4) can be performed manually or automatically, but automation is preferable from the viewpoint of user convenience. Also, the previous adjustment and setting state are stored in a storage unit in the apparatus together with the conditions at that time (projection angle of view, projection distance, etc.), and when the apparatus is started next time, the previous storage information is obtained from the current state. It is preferable to collate with. For example, when the collation result is permitted (that is, when there is not much difference from the previous state), the process proceeds from (S2) to (S5). And configure the settings again from the beginning.
[0048]
Next, an example of a projector device having functions of intrusion detection and danger prevention will be described with reference to FIGS. It should be noted that, when a human enters the area where the projection light beam (laser light) passes, it is detected to prevent the light beam from being incident on the human eye or to reduce the intensity of the light beam to such an extent that there is no danger. Is applicable.
[0049]
FIG. 5 is a perspective view showing a projector device main body and a screen. The projector device includes the device main body 1A and an image pickup unit 100 such as a CCD image sensor mounted thereon (the reflection unit). This corresponds to the wave detecting means 1d.)
[0050]
A screen 40 is arranged in front of the projector device, and a projection area 42 of an image is defined on the surface thereof, and a rectangular monitoring area 46 is defined in a peripheral area 44 of the area. I have. In this example, the monitoring area 46 is composed of monitoring areas 46A to 46D corresponding to the respective sides of the quadrilateral.
[0051]
FIG. 6 is a front view of the apparatus main body 1A, and shows the projection lens 32, the imaging means 100, and the infrared irradiation means 120 (120A to 120D).
[0052]
A projection lens 32 is positioned at the center of the front surface of the apparatus body 1A, and an image is projected from the projection lens 32 onto a projection area 42 on a screen 40 (the projection lens 32 can adjust the focal length).
[0053]
An infrared irradiating means 120 is located on the peripheral edge of the front surface of the apparatus main body 1A, and has four infrared irradiating sections 120A to 120D for irradiating infrared rays in this example. That is, these infrared irradiators irradiate each of the monitoring areas 46A to 46D constituting the monitoring area 46 with infrared light having a predetermined wavelength (for example, λ = 880 nm).
[0054]
7A and 7B illustrate one of the infrared irradiation units (120A). FIG. 7A is a front view, FIG. 7B is a side view showing one light emitting element, FIG. FIG. D) is an explanatory diagram of the infrared irradiation angle.
[0055]
Each of the infrared irradiators 120A to 120D has the same configuration, and as shown in FIG. 1A, a plurality of light emitting elements (for example, 11 light emitting diodes emitting infrared light) are arranged along the longitudinal direction. ) Are arranged in two stages in a direction perpendicular to the longitudinal direction (vertical direction in the figure).
[0056]
Each light emitting diode is provided with a correction lens “LNS” on the front surface thereof, as shown in FIG. In this example, as shown in FIG. 7C, the divergence angle (elevation angle) with respect to the optical axis direction in the vertical plane including the optical axis of the correction lens is 2 °, and (D) As shown in the figure, the divergence angle with respect to the optical axis direction in the horizontal plane is set to 34 °, and the infrared light is irradiated toward the monitoring area (for example, 46A) corresponding to each of the infrared irradiation units. .
[0057]
It is not necessary that the number of light emitting elements used in each infrared irradiating unit is the same. For example, the number of light emitting elements is located on the shorter side of the quadrilateral compared to the infrared irradiating units 120A and 120C located on the longer side of the quadrilateral. The number of elements used in the infrared irradiation units 120B and 120D may be small.
[0058]
In addition, a tilt mechanism is provided for each infrared irradiation unit so that the irradiation angle toward the screen 40 can be adjusted manually or automatically. That is, since the projection distance from the main body 1A to the screen 40 and the positional relationship between the two are not always fixed, the irradiation direction and range of the infrared irradiation units 120A to 120D are adjusted, and the focal length of the projection lens 32 is adjusted. It is preferable to be configured so as to be able to adjust the like. Since the projector device is often used in various situations, for example, when the projection distance is 3 m and the projection lens 32 and the projection area 42 of the screen 40 are in a horizontal positional relationship, or when the projection distance is 5 m, There are various situations, such as when the projection image is projected upward from the projection lens 32 to the projection area 42 (the direction and the focal length of the projection lens 32 can be adjusted, and the infrared irradiation sections 120A to 120D can be adjusted). It is preferable that tilting (tilting) be possible so that the tilt angle of each infrared irradiation unit can be adjusted according to zooming or the like of the projection lens 32.)
[0059]
For example, it can be adjusted manually or automatically according to the projection distance as shown by an upward arrow “U” or a downward arrow “D” in FIG. 7C.
[0060]
FIG. 8 is a diagram for explaining an irradiation direction and an irradiation width of the infrared irradiation unit, and shows a state viewed from a side orthogonal to a vertical plane, using the infrared irradiation unit 120A as an example.
[0061]
The vertical and horizontal divergence angles and infrared irradiation width can be adjusted and set according to the distance between the main body 1A and the screen 40. For example, as shown in FIG. 7A, the light path (infrared light) from the infrared irradiation unit 120A is made almost parallel light and the optical path is set to be irradiated to the monitoring area 46A, or as shown in FIG. And an optical path setting in which the irradiation light beams from the infrared irradiation unit 120A approach and cross each other, and then travel away from each other.
[0062]
The intensity distribution of the infrared rays radiated to the peripheral area 44 of the screen by each infrared irradiating unit is as described in FIG. That is, the graph curve 7 in FIG. 3 represents the intensity of infrared rays, and the monitoring area 46 is located within the range on the screen 40 corresponding to the range of the intensity peak (flat portion). For example, the value of the distance “W” is 10 cm, and the width of each of the monitoring areas 46A to 46D may be the same, or the widths may be individually changed as needed.
[0063]
The imaging unit 100 captures an image of the screen 40 including the monitoring area 46. A filter that transmits only the infrared component during normal operation of the projector device is provided on the front surface of the imaging unit 100, and the filter reflects light from the area including the monitoring area 46. The detected infrared ray is detected (however, it is necessary to remove the filter in the adjustment step described later).
[0064]
The infrared image (detected image by the infrared light transmitted through the filter) detected by the imaging unit 100 is subjected to signal processing by the intrusion detection and danger prevention control unit 110 described later.
[0065]
FIG. 9 is a block diagram illustrating a configuration example of the projection system. The light modulation unit 10, the light adjustment unit 20, the light projection unit 30, the screen 40, the power supply system 50, the signal processing unit 60, the imaging unit 100, intrusion detection and danger A prevention control unit 110, an infrared irradiation unit 120, and a power supply device 130 are provided.
[0066]
The power supply device 130 supplies power to the infrared irradiation units 120A to 120D, and can change the power supplied to each infrared irradiation unit in response to a command from the intrusion detection and danger prevention control unit 110. Thereby, it is possible to adjust and set the output level of the light emitting element group constituting each infrared irradiation unit. The intrusion detection and danger prevention control unit 110 constitutes an intrusion detection unit, and is configured using, for example, a computer (including a memory and a display device), a dedicated circuit, and the like.
[0067]
The light modulation unit 10 includes a light source unit 12, an illumination light generation unit 14, and a spatially modulated light generation unit 16.
[0068]
The light source unit 12 includes a green laser diode LD (G), a blue laser diode LD (B), and a red laser diode LD (R). Out of the laser beam.
[0069]
The power supply system 50 includes a power supply device 52 that outputs a voltage and a current for driving a laser to the light source unit 12 and a regulator 54, and the output level of the power supply device 52 can be adjusted by the regulator 54. (As for the output adjustment, the current and the like output from the power supply device 52 to the light source unit 12 in response to the command of the intrusion detection and danger prevention control unit 110 range from zero to the maximum allowable value. Can be adjusted arbitrarily.)
[0070]
The illumination light generation unit 14 is provided to receive the laser beams of each color of RGB emitted from the light source unit 12 and generate parallel illumination light, respectively, and includes a green illumination optical unit LG (G) and a blue illumination optical unit. LG (B) and a red illumination optical unit LG (R).
[0071]
The spatially modulated light generating section 16 includes a light modulating means, and in this example, a one-dimensional light modulating element called a grating light valve (GLV: Grating Light Valve) is used. The element is configured using a phase diffraction grating capable of electrically controlling light on / off (used for digital image display).
[0072]
A GLV (G) for green, a GLV (B) for blue, and a GLV (R) for red are provided for each color light from the illumination light generation unit 14, and the spatial modulation light generation unit 16 further includes a combiner " MX ”. A drive signal for modulation corresponding to the video signal (VIDEO) processed by the signal processing unit 60 is supplied to the GLV of each color from the driver circuit 64, and the light from the illumination light generation unit 14 is supplied to the GLV according to the video signal VIDEO. Is modulated and output.
[0073]
The combiner “MX” is a unit (image combining unit) that combines the lights of the respective GLVs, and the output light is emitted to the light adjustment unit 20 at the subsequent stage.
[0074]
The light adjustment unit 20 includes an offner relay optical system 22 and a diffuser optical system 24, and adjusts image light from the spatially modulated light generation unit 16.
[0075]
The light projection unit 30 located downstream of the light adjustment unit 20 includes a projection lens 32 and a scanner 34, and constitutes a means for projecting an image on a screen. A projection screen 40 is disposed in front of the light projection unit 30, and an image corresponding to the video signal VIDEO is projected on the screen 40 by a scanner 34 having a deflection unit such as a galvanometer mirror. In this example, the scanner 34 is disposed at the subsequent stage of the projection lens 32. However, the embodiment can be implemented in various forms such as a form in which the positional relationship between the two is reversed (a form in which enlarged projection is performed after scanning). It is possible.
[0076]
The signal processing unit 60 includes a video signal processing unit 62, a driver circuit 64, an overall control unit 66, and a scanner control unit 68.
[0077]
The video signal processing unit 62 receives a video signal VIDEO from a video source device (such as a computer or a recording / reproducing device) (not shown) and controls each GLV of the spatially modulated light generation unit 16 via a driver circuit 64 to illuminate the video signal. Signal processing is performed to generate a signal that modulates light (laser light). Then, the driver circuit 64 receives the output signal of the video signal processing unit 62, sends a drive signal to each color GLV, and drives each element.
[0078]
The scanner control section 68 is provided for controlling the rotation of the scanner 34, and is under the control of the overall control section 66. The overall control unit 66 issues a command to the scanner control unit 68 in accordance with, for example, a signal from the driver circuit 64, and controls overall video signal processing and projection control.
[0079]
FIG. 10 is a flowchart illustrating an example of processing in the intrusion detection and danger prevention control unit 110. Processing steps S1 to S6 are as follows.
[0080]
(S1) Device startup
(S2) Class 1 light irradiation and position adjustment
(S3) Class 3R level adjustment
(S4) Passage confirmation test
(S5) Adjustment end
(S6) Normal monitoring state setting.
[0081]
Note that (S1) to (S5) relate to the initial adjustment, and (S6) is set when the apparatus is started up and used after the initial adjustment. Further, (S2) and (S3) both show steps related to the adjustment of the irradiation of the laser beam. At the “class 1” irradiation level of (S2), the intensity is reduced to a level that is sufficiently safe for the eyes. The irradiation level of “Class 3R” in (S3) is the intensity used in normal operation of the projector device (see “JIS C6802” for the laser safety standard).
[0082]
Next, S1 to S6 will be described with reference to FIG. Note that FIG. 11 illustrates the process of the temporal change by taking the time on the horizontal axis and the irradiation level of the laser beam on the vertical axis. The meaning of each of the times t1 to t4 and the times T1 and T2 is as follows. It is as follows.
[0083]
-"T1" = time when the power switch of the device is turned on
-"T2" = at the start of the rise from class 1 to class 3R
-"T3" = the point at which a human body or obstacle begins to enter the monitored space
・ "T4" = Start of climb to class 3R
"T1" = APR operation time
-"T2" = time of entry of the human body or obstacle into the monitored space (T2> T1)
“APR” (Auto Power Reduction) in the figure means a safety mechanism that reduces the level of laser power when an intrusion of a human body or the like is detected, “ON” indicates an operation state of the mechanism, and “OFF” indicates an operation state of the mechanism. Means that the laser beam is cut off.
[0084]
First, in step S1, at time t1, the operator operates the power switch 140 (see FIG. 9) of the projector device to turn on the switch, and the start of the projector device is instructed. Thus, power is supplied to each unit of the projector device. In a state where the video signal VIDEO is not supplied to the video signal processing unit 62, only illumination is performed in a state where there is no video (however, in this state, light from the projection lens 32 always projects the projection area 42 correctly). Note that this is not the case.)
[0085]
In the next step S2, the irradiation level (power) of the laser beam increases to class 1. That is, at time t1, when a signal indicating that the power switch 140 is turned on is input to the intrusion detection and danger prevention control unit 110, power control is performed on the light source unit 12 to have class 1 power. A laser beam is applied. Then, position adjustment on the screen is performed.
[0086]
Immediately after the apparatus main body 1A of the projector apparatus and the screen 40 are installed, it is said that the infrared rays radiated from the infrared irradiating sections 120A to 120D toward the monitoring areas 46A to 46D correctly irradiate a predetermined position. Not exclusively.
[0087]
Therefore, in addition to adjusting the directivity and the projection distance of each infrared irradiation unit, the focal length of the projection lens 32 is adjusted by means or automatically as necessary. For example, the direction of the apparatus main body 1A, the focal length of the projection lens 32, and the like are adjusted so that light from the projection lens 32 is irradiated to a range corresponding to the projection area 42 in the screen 40. Then, after the position of the projection area 42 on the screen 40 is determined, the irradiation range from each of the infrared irradiation units 120A to 120D onto the screen and each of the monitoring areas 46A to 46D have a corresponding positional relationship. Perform position adjustment.
[0088]
The adjustment of the projection distance, the display position, the image size, etc., the alignment between the infrared irradiation range and the monitoring area, and the like are performed by using the imaging unit 100 to project the projection light from the projection lens 32 onto The reflected light of the light emitted from the light emitting diode constituting the infrared irradiating unit is imaged as the reflected light, and the imaged signal is input to the intrusion detection and danger prevention control unit 110 and can be confirmed on the image display by performing the signal processing here. (In the adjustment of the projection area 42 and the like, the infrared transmission filter (visible light cut filter) provided in the imaging unit 100 is not mounted).
[0089]
In addition, it is necessary to ensure sufficient security for the infrared emission power.
[0090]
FIG. 12 is a graph illustrating the relationship between the power of an infrared LED and the distance.
[0091]
The MPE (Maximum Permissible Exposure) in the cornea for direct eye exposure specified in “JIS C6802” is a wavelength λ = 880 nm and an irradiation time t = 3 × 10 ^-4 0.733 mW / cm for seconds (0.3 ms) ² In this example, too, the design is made to satisfy this criterion. For example, when the screen size is 80 inches and the projection distance is 2.35 m, the power of the infrared light in the monitoring area 46 is about 0.15 mW / cm. ² And the infrared irradiation width in the monitoring area 46 is 5 cm. As another example, when the screen size is 180 inches and the projection distance is 6.53 m, the power of the infrared light in the monitoring area 46 is about 0.054 mW / cm. ² And the infrared irradiation width in the monitoring area 46 is 5 cm.
[0092]
FIG. 13 is a diagram for explaining the adjustment and confirmation processing of the positional relationship between the projection regions by the infrared irradiation units 120A to 120D and the monitoring regions 46A to 46D. In this example, after the position adjustment to the projection area 42 projected from the projection lens 32 is completed, the imaging result of the imaging unit 100 stored in the memory of the intrusion detection and danger prevention control unit 110 is displayed on a display device (not shown). The case where the irradiation state from the infrared irradiation units 120A to 120D to the monitoring areas 46A to 46D is confirmed is illustrated.
[0093]
(A) shows the initial state immediately after the projection area 42 is set, and the projection ranges 46a to 46d (shown by broken lines) of the infrared irradiation units 120A to 120D are projected around the projection area 42. Numerical values indicate that they are separated from the outer edge of the area 42 by a distance d1 = 30 cm, a distance d2 = 20 cm, a distance d3 = 20 cm, and a distance d4 = 40 cm.
[0094]
The image pickup means 100 picks up an image of the reflection of the light emitted from the infrared irradiators 120A to 120D applied to the screen 40 through an infrared transmission filter. For example, the monitoring area width is set to 5 cm, and the width direction corresponds to data for 6 pixels, and the length of each area 46A and 46C in the longitudinal direction of the monitoring area 46 shown in the drawing is data for 200 pixels. The length of the areas 46B and 46D corresponds to data of 114 pixels. Each pixel data is represented, for example, as data of 256 gradations.
[0095]
The intrusion detection and danger prevention control unit 110 performs signal processing on the imaging data input from the imaging unit 100, binarizes the pixel data related to the projection ranges 46a to 46d with a threshold value, for example, 50, and converts the pixel data into 50 or more pixel data. Is distinguished as a logical value “1” and pixel data less than 49 as a logical value “0”, and the projection area 42 and the projection ranges 46 a to 46 d are displayed on the display screen. At this time, the distance between the projection area 42 and the projection units 46a to 46d is calculated and displayed as distances d1 to d4.
[0096]
In this example, the W value is set to 10 cm. Therefore, the tilt angles of the infrared irradiation units 120A to 120D are adjusted so that the distances d1 to d4 are all about 10 cm.
[0097]
(B) shows that the light from the infrared irradiators 120A and 120C is adjusted so as to be projected onto the areas 46A and 46C separated by 10 cm from the upper and lower peripheral edges of the projection area 42. FIG. 4C shows that the light from the infrared irradiators 120B and 120D is adjusted so as to be projected onto the regions 46B and 46D separated from the left and right peripheral edges of the projection region 42 by 10 cm.
[0098]
The value of W = 10 cm is merely an example, and it is needless to say that it is necessary to appropriately set the position of the infrared light or the projection range of the infrared light and the monitoring area according to the change in the angle of view due to zooming.
[0099]
(C) After the position adjustment is performed automatically or manually in the state shown in the figure, when the confirmation is completed, the process proceeds to the next step S3, and proceeds to the laser power adjustment process in the class 3R. At this time, an infrared transmission filter is mounted on the imaging means 100.
[0100]
By increasing the power supplied from the power supply device 52 to the light source unit 12, the laser power of class 1 at time t2 is increased to class 3R. At time t2, it is necessary to set the APR to operate so as to enable the function of the safety mechanism.
[0101]
The reflected light (infrared light) related to each of the monitoring areas 46A to 46D is received by the imaging unit 100. The intrusion detection and danger prevention control unit 110 acquires the detection level of the reflected light imaged by the imaging unit 100 from the pixel data, and compares the level with a reference range to determine whether the level is within an allowable range. For example, when each pixel data is represented by 256 gradations, the data is binarized by comparison with a threshold value. Pixel data that is equal to or greater than the threshold value corresponds to a logical value “1”, and pixel data that is less than the threshold value is identified as corresponding to a logical value “0”, and the monitoring areas 46A to 46D are properly irradiated with infrared light. It is necessary to make sure that
[0102]
According to the experiment, the detection levels of the image pickup device (CCD type image sensor) with respect to various reflecting surfaces were as shown in Table 1 below. The above threshold value is preferably determined according to the material used for the screen 40. For example, if the material of the screen 40 is set to about 55 when the material is a white mat screen, white paper, etc. It is possible to distinguish from one of the subjects, Japanese skin.
[0103]
[Table 1]

[0104]
In the next step S4, a test is performed to check the passage of an obstacle into the passing range (a truncated pyramid-shaped detection range) of infrared light projected from the infrared irradiation units 120A to 120D toward the monitoring areas 46A to 46D. That is, the operator moves an obstacle into and out of the detection range surrounded by the infrared light, and a decrease or an increase in the detection signal level is detected based on the detection image data of the imaging unit 100 regarding the monitoring areas 46A to 46D. Test by checking whether or not.
[0105]
At time t3 in FIG. 11, a situation is shown in which an obstacle has begun to enter the monitoring space surrounded by the infrared light. When this is detected, the APR is activated and the laser power sharply decreases. Then, the power becomes zero within the time T1 (<T2). That is, the laser output is reduced to a class 1 or lower level in a time shorter than the intrusion time T2 required for the obstacle to enter the laser beam projection range.
[0106]
This test method may take various forms.For example, for each monitoring area, an object such as a human finger or a glossy black ruler may be taken in and out from the outside of the detection range to reduce the detection signal level and the like. To check.
[0107]
In the pass test, the intrusion detection and danger prevention control unit 110 performs control so as to emit an alarm sound when an obstacle enters the detection range (an output signal is sent to an alarm device (not shown)). ). As a result, the operator can visually confirm that the failure has been normally detected. Further, the intrusion detection and danger prevention control unit 110 can also display a portion corresponding to an obstacle in a display device (not shown) in red or the like as necessary (a monitoring area where no obstacle is detected). Is displayed in white, for example). Then, the intrusion detection and danger prevention control unit 110 can store the data at this time in a memory.
[0108]
Such a test is performed on the monitoring areas 46A to 46D (however, if it is clear in advance that there is no need to assume the entry or passage of an obstacle, the corresponding monitoring area is naturally excluded from the test target. Is done.)
[0109]
During the test period, since the projection from the projection lens 32 to the projection area 42 is unnecessary, the intrusion detection and danger prevention control unit 110 drives the regulator 54 to supply power from the power supply device 52 to the light source unit 12. It is desirable to reduce the power to a very low level or stop the power supply from the power supply device 52 to the light source unit 12.
[0110]
When the passing test is completed, the process proceeds to the next step S5, and the above-described series of adjustment work ends. The order and the number of steps S2 to S4 can be changed as appropriate.
[0111]
When the adjustment and confirmation are completed, the operator uses an operation input unit (such as an operation switch) (not shown) to instruct the intrusion detection and danger prevention control unit 110 to that effect.
[0112]
During the passage test, when the power supply from the power supply device 52 to the light source unit 12 is stopped or the power supply state is set to a very small amount, the intruder enters the range between the projection lens 32 and the projection area 42. Even if there is no obstacle, the intrusion detection and danger prevention control unit 110 can stop the power supply from the power supply device 130 to the infrared irradiation means 120 when the operator issues an instruction to end the adjustment.
[0113]
On the other hand, to issue a warning that an intruder has entered the detection range, regardless of the power supply state from the power supply device 52 to the light source unit 12, as long as the power switch 140 is on, detection of intrusion and prevention of danger. By causing the control unit 110 to continue supplying power from the power supply device 130 to the infrared irradiation unit 120, the alarm can be always output.
[0114]
In the final step S6, the normal monitoring state is set.
[0115]
For example, when the video signal VIDEO from a video source device (not shown) is input to the video signal processing unit 62 and the projection operation of the projector device starts, the driver circuit 64 causes the spatial modulation light generation unit 16 to drive the spatial modulation light generation unit 16 according to the video signal VIDEO. A signal is output, and the overall control unit 66 controls the scanner 34 via the scanner control unit 68.
[0116]
Information indicating that the normal projection operation has been started is sent from the overall control unit 66 to the intrusion detection and danger prevention control unit 110, and the intrusion detection and danger prevention control unit 110 sends the information to an area corresponding to the detection range (hereinafter, referred to as an “intrusion prohibition area”). It constantly detects whether a person or an obstacle has entered.
[0117]
This detection method is the same as the method described in step S4. However, in order to protect an intruder, when the intrusion detection and danger prevention control unit 110 detects an intruder or the like in an intrusion prohibited area, It is preferable to take the following measures.
[0118]
The regulator 54 is controlled to be supplied from the power supply device 52 to the light source unit 12 so that the level of the irradiation light from the projection lens 32 toward the screen 40 is reduced to a level that does not impair the naked eye of the intruder. To reduce power consumption.
[0119]
In some situations, shut off the power supplied from the power supply 52 to the light source 12.
[0120]
As a result, the illuminating light from the projection lens 32 toward the screen 40 is darkened or completely absent. At this time, the intrusion detection and danger prevention control unit 110 can output a warning sound or a warning message.
[0121]
The danger prevention processing performed by the intrusion detection and danger prevention control unit 110 differs depending on the state when an intruder enters the intrusion prohibited area.
[0122]
For example, assuming that the W value relating to each of the monitoring areas 46A to 46D is 10 cm and the penetration speed is 2 m / s (meters per second), the penetration time of the linear intruder is 0.05 second, and the penetration speed is In the case of half (1 m / s), the penetration time of a linear intruder is 0.10 seconds. In the case of a human, the width is wider than that of a linear object, so that the penetration time is several times to ten and several times longer than 0.05 to 0.1 seconds.
[0123]
Further, when a person is moving along a surface (boundary of the intrusion prohibition area) formed by connecting each infrared irradiation unit and each monitoring area, the state is kept in the intrusion prohibition area. Assuming that the length of each monitoring area in the longitudinal direction is 2 m, when the intrusion speed is 2 m / s, the intruder enters the intrusion prohibition area for about 1 second.
[0124]
On the other hand, noise is unavoidable in the image data captured by the image capturing means 100, and there is a possibility that an erroneous determination that an intruder has instantaneously and partially entered the intrusion prohibited area may be made ( In such a case, there is no need to perform sensitive judgment processing.)
[0125]
Therefore, it is preferable to perform stepwise prevention processing according to the result of multiplication of the intrusion duration and the size of the intrusion area.
[0126]
The “intrusion continuation time” here refers to a time during which the intrusion state into the intrusion prohibited area continues. In addition, the “size of the intrusion area” refers to the area of the portion (for example, the threshold value or less) when the reflected light level of each of the monitoring areas 46A to 46D detected by the imaging unit 100 deviates from a predetermined reference range. , Etc.).
[0127]
Table 2 below shows the “intrusion state indication value” defined by the product of the continuous intrusion time and the size of the intrusion area (such as the area of the intrusion part), and the intrusion detection and danger prevention control unit 110 performs the intrusion state instruction value accordingly. This is an example of the processing contents to be performed.
[0128]
[Table 2]

[0129]
In this example, four stages of processing (power reduction and power supply stop related to the light source unit) according to the intrusion state instruction value are performed, and the intrusion detection and danger prevention control unit 110 controls the power of the power supply device 52 via the regulator 54. The output of the light source unit 12 is adjusted by changing the level to prevent an intruder's eyes or the like from entering the forbidden area from being adversely affected. The processing of the intrusion detection and danger prevention control unit 110 according to the intrusion situation is not limited to the above example, and various processing methods are possible. There is a method of making a determination based only on the size of the region (invasion area), or a method of making a determination by further considering other factors.
[0130]
With the above processing, when a human enters the intrusion prohibited area, it is possible to prevent the human body from being hindered. In particular, even when a child or the like who does not know the circumstances enters the intrusion prohibited area, it is sufficient. Safety measures are taken.
[0131]
Next, a modification of the above configuration will be described.
[0132]
It is preferable that the adjustment of the tilt angle (tilt angle) of each of the infrared irradiators 120A to 120D constituting the infrared irradiator 120 is automated, and a drive source such as a motor and a tilt mechanism are provided in each of the infrared irradiators. Irradiation direction control can be performed by these attitude controls.
[0133]
Further, in the above embodiment, the example has been described in which the process shifts to the normal monitoring process after the adjustment in step S5 shown in FIG. 10 is completed. However, when using the projector device in which the adjustment work has already been completed, the power switch 140 is turned on. When the state is set, it is also possible to immediately start from the normal monitoring state in step S6. In this case, for example, a flag (adjustment end flag) for indicating that the adjustment work has been completed in step S5 is prepared, and set to a predetermined value (for example, “1”) to perform intrusion detection and danger prevention control. What is necessary is just to store it in the memory of the part 110.
[0134]
In the normal monitoring state of step S6, each of the infrared irradiation units 120A to 120D continuously irradiates infrared rays to each of the monitoring areas 46A to 46D of the screen 40. However, the present invention is not limited to this. Irradiation may be performed at time intervals at which a person can be detected (for example, infrared irradiation to the monitoring area 46 may be performed intermittently at intervals of several milliseconds).
[0135]
Further, in the above-described embodiment, the case where infrared rays are radiated from the infrared irradiating means 120 to all of the monitoring areas 46A to 46D has been described. However, for example, the position of the area 46A is high, and the possibility of intrusion is considered in consideration of the height range of an ordinary person. When there is no infrared ray, there is no need to irradiate the area with infrared rays.
[0136]
In the above description, a monitoring area 46 is provided outside the projection area 42 on the screen, and a system for monitoring entry into the intrusion prohibited area is assumed. However, another monitoring area is set outside the monitoring area. However, it is possible to strengthen the monitoring system by multiplexing (duplicate, triple, etc.) the monitoring space, and such an embodiment will be described below.
[0137]
FIG. 14 is a configuration diagram showing a configuration example of a projection system. Basic elements are the same as those in FIG. 9 (therefore, redundant description is avoided by using the same reference numerals for functionally the same elements). )), Only the differences are listed below.
[0138]
The monitoring area is doubled, the first alarm processing unit 70 is in charge of the inner area (the first monitoring space or the first monitoring zone), and the outer area (the second monitoring space or the second monitoring zone). The second alarm processing unit 80 is responsible for detecting each intrusion into each monitoring space, and performing an alarm process according to the intrusion state and situation.
[0139]
The first alarm processing unit 70 has a first detection unit 72 and a first alarm unit 74, and when the first detection unit 72 detects intrusion of a human body or the like, the first alarm unit 74 outputs an alarm. And change (decrease or zero) the intensity of the laser beam.
[0140]
The second alarm processing unit 80 includes a second detection unit 82 and a second alarm unit 84. When the second detection unit 82 detects an intrusion of a human body or the like, the second alarm unit 84 outputs an alarm. To do.
[0141]
FIGS. 15A and 15B are schematic diagrams showing the positional relationship between the main body 1B of the projector device and the screen 40. FIG. 15A is a perspective view showing the state of projection light, and FIG. 2 is a cross-sectional view when viewed from the side.
[0142]
The image projected from the light projection unit 30 of the main unit 1B onto the screen 40 is scanned by the scanner 34 of the light projection unit 30 and projected on the projection area 42 on the screen.
[0143]
The passage area 42S of the light (image light) projected from the light projection unit 30 to the projection area 42 is hereinafter referred to as an “image light passage space area”.
[0144]
Further, the first monitoring space (or zone) includes the following areas.
[0145]
“First monitoring area” = a monitoring area located on the outer periphery of the projection area 42 (similar to the above-described monitoring area 46, and its width is exaggerated in the figure).
“First space monitoring area” = a space area located outside (outer periphery) of the image light passing space area 42S (a space area 46S located around the image light output from the light projection unit 30).
[0146]
Similarly, the second monitoring space (or zone) includes the following areas.
[0147]
"2nd monitoring area" = the outer periphery of the 1st monitoring area 46 or the external area 90 including the 1st monitoring area 46 (the area shown by the broken line in FIG. 7A).
"Second space monitoring area" = the outer periphery of the first space monitoring area 46S or the space area 90S including the first space monitoring area 46S (see FIG. (B)).
[0148]
In the first alarm processing unit 70 (see FIG. 14), the first detection means 72 detects the intrusion of a human body or an object into the first space monitoring area 46S, or the continuous presence thereof. Then, the first alarm unit 74 outputs an alarm based on the detection information from the first detection unit 72 and controls the power supply to the light source unit 12.
[0149]
Further, in the second alarm processing unit 80, the second detection unit 82 detects that a human body or an object has entered the second space monitoring area 90S, or that these are continuously present. Then, the second alarm unit 84 outputs an alarm based on the detection information from the second detection unit 82.
[0150]
FIG. 16 is a flowchart illustrating an example of the warning process, and the process is performed according to the following steps.
[0151]
(S11) Normal projection operation
(S12) Intrusion detection by the second detection means
(S13) Alarm processing by the second alarm unit
(S14) Intrusion detection by first detection means
(S15) Warning processing by the first warning means.
[0152]
First, in step S11, the light source unit 12 is driven by the specified voltage from the power supply device 52 in FIG. 14, and the image light modulated by the spatially modulated light generation unit 16 in accordance with the image signal VIDEO is transmitted from the light projection unit 30 to the screen 40. The image is projected on the upper projection area 42.
[0153]
Then, the process proceeds to step S12, where the second detection means 82 detects whether a human body or the like has entered the second space monitoring area 90S. That is, when intrusion or presence of a human body or the like is detected, the process proceeds to step S13, and the second alarm unit 84 performs an alarm process. As the alarm processing, for example, a voice message having a content such as "Please move away from the projection area because it is dangerous" is output (since the message can be heard by the ear even when the viewer is not watching the projection area 42, Can detect danger in advance.). This encourages the intruder to evade. By outputting a second alarm signal from the second alarm means 84 to the overall control unit 66 in addition to or separately from the audio message, the overall control unit 66 causes the video signal processing unit 62 to output a video signal. A warning message signal or a warning figure signal may be superimposed on the VIDEO and output to the driver circuit 64, and the image may be displayed on the projection area 42 via the spatially modulated light generation unit 16 (this allows the viewer The danger can be detected in advance by the warning display on the projection area 42 and the voice message.)
[0154]
If the intrusion or the like is continued despite such a warning, in the next step S14, the intrusion into the first space monitoring area 46S is detected by the first detection means 72. That is, when detecting the intrusion of a human body or the like or the presence of the human body or the like in the area 46S, the process proceeds to step S15, and the first alarm means 74 performs the first alarm process. For example, the first alarming unit 74 shuts off the output voltage of the power supply device 52 via the regulator 54 so that the laser beam is not emitted from the light source unit 12. This protects the viewer's eyes. Preferably, a voice message such as "Stop the device because it is dangerous" is output (a viewer understands the reason for stopping the projector device).
[0155]
The first alarm means 74 may reduce the output of the power supply device 52 via the regulator 54 to reduce the intensity of the laser beam to a safe level, thereby protecting the eyes of the viewer. . At this time, it is preferable to output a voice message such as "Dangerous to the eyes and darken it" so that the viewer can understand the reason for the decrease in the projection light.
[0156]
Further, when the first alarm means 74 operates, the first alarm signal is output to the overall control unit 66, and the overall control unit 66 outputs the video signal VIDEO to an external device that outputs the video signal VIDEO as necessary. It is possible to request the output stop and stop the projection by the projector device.
[0157]
Restarting of the projector device after the first alarm means 74 operates can be performed by resetting the regulator 54 by an operator's operation. For restarting the output of the video signal VIDEO from an external device such as a computer device, the overall control unit 66 requests a video signal from the external device when the operator restarts the projector device.
[0158]
According to the above embodiment, when the intrusion into the second space monitoring area 90S is detected and the intrusion into the first space monitoring area 46S is detected, the laser light is cut off or the light intensity is reduced. First, safety measures can be taken without lowering the operation rate of the projector device as compared with one-stage intrusion detection. Then, before entering the first space monitoring area 46S, it is possible to detect that a human body has entered the second space monitoring area 90S and to give a warning in advance, so that the human body is prevented from accidentally entering the intrusion prohibited area. Can be prevented.
[0159]
Preferably, when the first detection means 72 detects intrusion into the first space monitoring area 46S within a predetermined time from the time when the second alarm means 84 operates, the above-mentioned alarm processing is performed by the first alarm means 74. . Thereby, the erroneous detection or malfunction of the first detection means 72 or the influence of noise components related to the detection of the first space monitoring area 46S is reduced, and the first alarm means 74 operates frequently to reduce the usage of the projector device. Problems such as lowering can be prevented.
[0160]
Regarding the above-described embodiment of the second alarm processing section 80, the second detection means 82 may have the following forms.
[0161]
(I) A form using a pyroelectric sensor for detecting radiant energy emitted from a human body (used for detecting intrusion of a human body in a security device or the like).
(II) A form using a heat sensing sensor used in a thermographic device or the like.
[0162]
The above (I) includes, for example, the following forms.
[0163]
(I-1) Form using one pyroelectric sensor (see FIG. 17)
(I-2) An embodiment in which a plurality of pyroelectric sensors are combined (see FIG. 18).
[0164]
First, in the above (I-1), as shown in FIG. 17, for example, as shown in FIG. 17, as a method of installing the pyroelectric sensor, an area surrounding substantially the entire second monitoring area 90 including the screen 40 (a thick circular frame in the figure) One pyroelectric sensor having a directional characteristic can be provided in the vicinity of the light projection unit 30. In order to prevent the frequent operation of the second alarm means 84 from occurring due to malfunction, noise, or the like, when the pyroelectric sensor continuously detects a human body or the like for a predetermined time or longer (for example, The threshold value for determining the duration is about 2 seconds.), And the second alarm means 84 may be operated.
[0165]
As described above, an image sensor (CCD sensor or the like) can be used as the first detecting means 72, but a form in which this is shared with the second detecting means 82 is of course also possible. Can detect the state of intrusion into the first space monitoring area 46S (the pyroelectric sensor serves as first and second detection means). Further, it is possible to detect that a human body enters the image light passing space area 42S by using the pyroelectric sensor.
[0166]
In the above (I-2), for example, a plurality of pyroelectric sensors having relatively narrow directivity can be used. A plurality of circular frames shown in FIG. 18 represent detection areas by the respective pyroelectric sensors, and their directivity distributions are schematically shown below the figure. In this example, seven pyroelectric sensors are used and arranged near the light projection unit 30 so as to direct the lower part, the right part, and the left part of the second space monitoring area 90S, respectively. Since a person cannot approach the upper part of the second space monitoring area 90S, it is not necessary to provide a pyroelectric sensor pointing at the part.
[0167]
For the pyroelectric sensor in charge of the lower part of the second space monitoring area 90S, an example of the intensity distribution of directivity is shown by three waveforms in the figure, but not so strict conditions are required for directivity. It is only necessary that the point is directed to the outside of the first space monitoring area 46S or a range including the area 46S.
[0168]
Also in this case, in order to avoid frequent operation of the second alarm means 84 due to malfunction or noise, the second alarm means is used when each pyroelectric sensor continuously detects a human body for more than a predetermined time. 84 may be configured to operate.
[0169]
Further, when two pyroelectric sensors are used in combination, for example, two pyroelectric sensors are arranged side by side to calculate a difference between their detection signals, the movement of the human body is determined according to the sign (±) of the difference. The direction can be detected. By using such a pyroelectric sensor pair, the lower, right and left sides of the second space monitoring area 90S are oriented so as to be oriented and used as a differential pyroelectric sensor. Can detect a human body that invades the sea.
[0170]
Next, the mode (II) will be described. By using a heat sensor, the temperature (body temperature) of a human body can be detected, and display and control can be performed according to the temperature. For example, when the temperature detected by the heat sensor is within the human body temperature range (34 to 40 degrees), it is determined that the human body is in the second space monitoring area 90S, and the second alarm means 84 operates. I do. The detection area of the heat sensor can be defined in the same manner as the pyroelectric sensor. In addition, the heat detecting sensor 72 can be shared with the first detecting means 72. One heat sensing sensor is provided in the vicinity of the light projecting unit 30 to detect a human body in the first space monitoring area 46S as the first detecting means 72. Further, it can be used for detecting a human body in the image light passing space area 42S.
[0171]
In addition, by providing a plurality of heat sensing sensors near the light projection unit 30, the presence of a human body can be detected around the second space monitoring area 90S.
[0172]
Next, the following configuration of the first detecting means 72 will be described.
[0173]
(I) Form using ultrasonic sensor (see FIG. 19)
(Ii) Embodiment using an optical sensor (see FIG. 20).
[0174]
First, in the form (i), as shown by a circular frame in FIG. 19, the first monitoring region 46 and the first space monitoring region 46S are included as detection regions, and the second monitoring region 90 and the second space monitoring region 90S are included. A plurality (for example, about four) of ultrasonic sensors which are not included in the detection area are used (each ultrasonic sensor is provided near the light projection unit 30). The ultrasonic sensor includes a transmission / reception unit, generates an ultrasonic wave by applying a voltage to the piezoelectric element, and outputs an electric signal according to the amplitude of the received ultrasonic wave when the ultrasonic wave is received. In a state where there is no intrusion of a human body or the like, there is nothing that blocks the ultrasonic wave between the light projecting unit 30 and the screen 40. In this case, the ultrasonic wave is output from the ultrasonic sensor and the first monitoring area of the screen 40 is Proceeding toward the screen 40 including 46, the reflected wave reflected on the screen 40 is received by the ultrasonic sensor. When there is an object or a human body that blocks the ultrasonic wave between the ultrasonic sensor and the first monitoring area 46 or in the first space monitoring area 46S, the level of the reflected wave is reduced or the reflected wave is not detected. Is determined by
[0175]
In the above mode (ii), for example, as shown by a rectangular frame of a thick black line in FIG. 20, a plurality of optical sensors, linear sensors (one-dimensional CCD), and the like are arranged along the first monitoring area 46 of the screen 40. On the other hand, a light receiving element group is arranged. On the other hand, on the front surface of the projector device main body, light or infrared light having a level sufficiently lower than the irradiation light from the light source unit 12 toward the first monitoring area 46 from around the light projection unit 30. A light-emitting element group (eg, an LED) that outputs light or the like is provided. Thereby, an object or a human body that blocks an optical path formed between the light emitting element group and the light receiving element group can be detected. Alternatively, there is a configuration in which a group of infrared light emitting elements is arranged in the first monitoring area 46, and a light beam emitted from the group is detected by an optical sensor of the projector device main body.
[0176]
In addition to these modes, it is needless to say that various embodiments such as using a pyroelectric sensor or a heat sensing sensor, or sharing with the second detecting means 82 are possible.
[0177]
In the above description, an example in which the first monitoring area 46 is defined in the screen 40 on the outer periphery of the projection area 42 has been described, but if the first monitoring area 46 is located outside the projection area 42, the first monitoring area 46 may be located inside the screen 40. You don't have to. Although the example in which the second monitoring area 90 is located outside the screen 40 has been described above, the second monitoring area 90 may be located in the screen 40 together with the first monitoring area 46.
[0178]
With the above configuration, for example, the following advantages can be obtained.
[0179]
・ Because the laser light can be instantaneously cut off or dimmed before a human body or an obstacle enters the laser light projection area, the safety is high.
[0180]
A detection wave (infrared light or infrared light) used for detecting intrusion of a human body or an obstacle is not visually recognized by a viewer, and therefore, there is no inconvenience such as affecting a projected image on a screen and deteriorating image quality. . Further, there is no danger to the human body due to the influence of the detection wave itself.
[0181]
【The invention's effect】
As is apparent from the above description, according to the first and the fifteenth aspects of the present invention, it is possible to guarantee the safety of the human body and easily detect the intrusion into the monitoring space. is there.
[0182]
According to the invention according to claim 2, it is suitable for downsizing of the device.
[0183]
According to the invention according to claims 3 and 16, the detection accuracy is sufficiently ensured, and there is no influence on the projection image.
[0184]
According to the invention according to claims 4 and 17, image detection can be performed reliably, and the width of the monitoring area is set to the minimum necessary as compared with the method of monitoring the entire range of the screen periphery. And the detection process is simple and quick.
[0185]
According to the fifth aspect of the invention, it is possible to control the irradiation light to suppress the influence on the human body and to take a sufficient safety measure.
[0186]
According to the invention according to claim 6, when applied to an image projection apparatus provided with a light modulating means, it is effective to improve safety and reliability.
[0187]
According to the seventh and ninth aspects of the present invention, quick processing can be performed by blocking outgoing light and stopping modulation.
[0188]
According to the invention of claim 8, by controlling the power supplied to the light source, the light intensity can be reliably regulated.
[0189]
According to the tenth aspect, it is possible to control the light output level in detail according to the degree of the intrusion state, and it is effective for preventing erroneous detection.
[0190]
According to the eleventh aspect, the intrusion detection processing is easy and does not require complicated image processing or the like.
[0191]
According to the twelfth aspect, since the intensity of the irradiation light is suppressed until the safety is confirmed, high security can be guaranteed.
[0192]
According to the thirteenth, fourteenth, and eighteenth aspects of the present invention, a multiple monitoring system is effective in strengthening safety measures.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating a basic configuration example of an image projection apparatus according to the present invention.
FIG. 2 is an explanatory view exemplifying each projection area and monitoring area on a screen.
FIG. 3 is a diagram for describing an intensity distribution of a detection wave applied to the periphery of a screen.
FIG. 4 is a flowchart for explaining safety measures in the image projection apparatus.
FIG. 5 is a diagram for describing a configuration example of an image projection device, and is a diagram illustrating an example of arrangement of a projector device and a screen unit.
FIG. 6 is a front view of the projector device shown in FIG.
FIGS. 7A to 7D are diagrams illustrating an example of an infrared irradiation unit.
FIGS. 8A and 8B are diagrams showing an example of irradiation by infrared irradiation means.
FIG. 9 is a diagram illustrating a configuration example of a projection system.
FIG. 10 is a flowchart illustrating a processing example of an intrusion detection and danger prevention control unit.
FIG. 11 is a graph showing an example of a lapse of time with respect to a power level of a laser beam.
FIG. 12 is a graph illustrating the relationship between infrared intensity and distance.
FIG. 13 is a diagram for explaining a method of setting a projection range and a monitoring area of a detection wave according to (A) to (C).
FIG. 14 is a diagram showing another example of the configuration of the projection system.
15 is a diagram showing a positional relationship between the projector device shown in FIG. 14 and a screen.
FIG. 16 is a flowchart illustrating an alarm operation in the projector device of FIG. 14;
FIG. 17 is an explanatory diagram exemplifying a detection area of a second detection unit in detecting intrusion into a second monitoring space.
FIG. 18 is an explanatory view exemplifying another detection area in the second detection means.
FIG. 19 is an explanatory diagram exemplifying a detection area when an ultrasonic sensor is used as the first detection means for detecting intrusion into the first monitoring space.
FIG. 20 is an explanatory diagram showing another example of the first detection means.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Image projection apparatus, 1a ... Light source, 1b ... Projection part, 1c ... Detection wave source, 1d ... Reflection wave detection means, 2 ... Screen, 3 ... Projection area, 6 ... Monitoring area, 40 ... Screen, 72 ... First detection Means 74 first alarm means 82 second detection means 84 second alarm means

Claims (18)

A light source and a projection unit for performing image display by projection to a projection area on a screen, and an image projection apparatus having a safety mechanism against intrusion of irradiation light from the projection unit toward the projection area into a passage area,
A detection wave source provided on the surface or screen facing the screen in the apparatus main body,
After a detection wave is emitted from the detection wave source to a monitoring region located outside the projection region, the detection wave includes reflected wave detection means for detecting a reflected wave reflected by the monitoring region,
An image projection apparatus for detecting intrusion into a monitoring space surrounded by the detection wave based on a result of comparing a detection level of the reflected wave detection means with a threshold or a reference range. The image projection device according to claim 1,
An image projection apparatus, wherein the detection wave source or the reflected wave detection means is disposed around the projection unit provided on a surface facing the screen. The image projection device according to claim 1,
An image projection apparatus, wherein the detection wave is infrared light or infrared light. The image projection device according to claim 3,
The reflected wave detection means is configured using an image sensor, and the monitoring area is monitored based on image data detected by the image sensor, and the width of the monitoring area is projected on a screen by the detection wave source. An image projecting device characterized in that the image projecting device is narrower than a region to be projected. The image projection device according to claim 1,
An image projection apparatus, wherein when an intrusion into the monitoring space is detected, irradiation light from the light source to the projection area is blocked or the intensity of the irradiation light is reduced. The image projection device according to claim 1,
Light modulation means for modulating the light emitted from the light source according to a video signal,
Light projection means for projecting the light modulated by the light modulation means to a projection area on the screen,
Intrusion detection means for detecting intrusion into the monitoring space,
When the intrusion into the monitoring space is detected by the intrusion detection means, the irradiation light from the light source to the projection area is blocked or the intensity of the irradiation light is reduced depending on the state of the intrusion. Characteristic image projection device. The image projection device according to claim 6,
When the intrusion detecting means detects intrusion into the monitoring space, the light emitted from the light source is blocked. The image projection device according to claim 6,
An image projection apparatus, wherein when the intrusion into the monitoring space is detected by the intrusion detection means, the power supplied to the light source is reduced or set to zero. The image projection device according to claim 6,
An image projection apparatus, wherein when the intrusion into the monitoring space is detected by the intrusion detection means, the driving of the light modulation means is stopped. The image projection device according to claim 8,
An image projection device, wherein the power supplied to the light source is controlled in accordance with the duration of intrusion into the monitoring space or the area of the intruding portion. The image projection device according to claim 1,
The reflected wave detection means measures the intensity of the reflected wave from the screen by each pixel data related to the monitoring area, and the intensity of the detected wave reflected when entering the monitoring space, and the case where there is no intrusion. An image projection apparatus, comprising: comparing an intensity of reflection from the monitoring area; and detecting an intrusion when the two are different from each other. The image projection device according to claim 1,
Until it is confirmed that intrusion into the surveillance space is not detected, the intensity of the irradiation light is reduced to a level that is safe for the human body and an image is projected, and after the confirmation, the intensity of the irradiation light is regulated. An image projection device characterized by rising to a level. The image projection device according to claim 1,
First detection means for detecting intrusion of the monitoring space as the reflected wave detection means;
Second detection means for detecting intrusion into the surveillance space including the outside area of the surveillance space;
First alarm means for performing an alarm process when an intrusion is detected by the first detection means;
An image projection apparatus comprising: a second alarm unit that performs an alarm process when an intrusion is detected by the second detection unit. The image projection device according to claim 13,
When the intrusion is detected by the first detection means, the irradiation light from the light source to the projection area is blocked or the intensity of the irradiation light is reduced to a level that is not dangerous to a human body. Image projection device. For a projection area on a screen located at a distance from the image projection apparatus, a monitoring area located outside the projection area is defined, and a detection wave source provided on the front of the image projection apparatus with respect to the monitoring area Detecting intrusion into the surveillance space surrounded by the detection wave by emitting a detection wave from, and detecting a reflected wave from the monitoring area,
An image projection method, wherein the light emitted toward the projection area is blocked or the intensity of the light is reduced according to the state of intrusion. The image projection method according to claim 15, wherein infrared light or infrared light is used as the detection wave. 17. The image projection method according to claim 16, wherein the monitoring area having a width smaller than an area projected on a screen by the detection wave source is monitored based on image data detected by an image sensor. Image projection method. 16. The image projection method according to claim 15, wherein the first monitoring space includes a region where a detection wave passes from the front surface of the monitoring region and the image projection device to the monitoring region, and a second monitoring space further provided outside the monitoring region. Stipulates,
An image projection method comprising: detecting intrusion into each monitoring space; and performing an alarm process according to a state of the intrusion.

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