JP4337384B2 - lighting equipment - Google Patents

Description

【００１６】
評価実験で用いた評価器具のリストを表１に示す。表１に示す一般的な中角タイプのスポットライト8種で壁面および立体物を照射し、延べ18名の被験者に照射された状態の印象を評価させた。また同時に壁面上の照射パターンを測定し、その輝度特性を調べた。被験者は店舗分野の専門知識、視環境評価の専門知識を有する者、普段店舗を利用する者から選定した。立体物を照射した場合の評価は、壁面を照射した場合の評価ほど各スポットライト間に差異が無かったため、壁面照射パターンによって特性を捉えて、立体物を照射したときにどの特性が評価に有効かを見極めて、用途に応じた使い分けができるようにする必要がある。そこで基本となる壁面照射の場合を検討の対象とした。壁面照射の評価の被験者は照明技術の開発に携わる4名であった。
【００１７】
実験設備は図１３に示すとおりであり、高さ１．５ｍのスポットライト１０で1m先にある正面壁(白クロス、反射率70%)１１を照射して、ベース照明の有無で評価を行なった。ベース照明器具１２は天井１３（高さ２．７５ｍ）に配設され、昼白色４０Ｗ２灯用蛍光灯器具を用い、ベース照明による照度レベルは床上１．５ｍの器具正面壁面上鉛直面Ａが鉛直面照度３８０lx、床上0mの器具延長線上正面壁から2m地点水平面Ｂの水平面照度６８０lxである。
【００１８】
評価は壁面から5m離れた位置から表２に示す評価用紙によって7段階のSD評価をした。評価実験で用いた壁面照射パターンを評価するための評価用紙を表２に示す。
【００１９】
【表２】

【００２０】
特筆すべき評価結果を述べる。スポットライトの照射パターンがどのような要素によって評価されるのかを調べるため、評価実験の全シーンに対する主観評価の結果から評価項目ごとの相関係数を求めた結果、「エッジのはっきりさ」は、照射壁面全体の「はっきりさ」や「集中感」と相関が強く、照射エリアの「ムラが気にならない」は、照射エリアの「ムラの美しさ」、照射壁面全体の「美しさ、明るさ、精密さ」と相関が強い。そして、「好ましさ」は、照射エリアの「ムラの美しさ」、照射壁面全体の「美しさ、精密さ」、さらに照射エリアの「ムラが気にならない」、照射壁面全体の「明るさ、ハードさ」と相関が強いことが分かる。つまり照射エリアの均斉度、集中感や明るさ、エッジの処理が評価のポイントになると考えられた。
【００２１】
また、ベース照明の有る場合のシーンについて評価項目ごとの相関係数を求めると、照射部分の明るさがはっきりさや集中感と相関が高いことが分かった。周辺が明るいために、スポットライトの効果を強調するためにはその光の強さ（明るさ）を増すことが必要になる。
【００２２】
これらの相関からエッジのはっきりさと総合評価（好ましさ）は相関が低いと分かった。
【００２３】
次に、ベース照明の有無を考慮して各スポットライトの印象評価を比較してみる。
【００２４】
評価項目同士の相関を考慮して代表的な評価項目について、ベース照明の有る場合と無い場合の違いを示しながら評価結果を図１４（ａ）〜（ｆ）に示す。
【００２５】
図１４（ａ）に示す「エッジのはっきりさ」は、ベース照明の有る場合と無い場合で器具の評価傾向は類似している。ベース照明の有る場合と無い場合の評価値自体の変化は、直射光が要因となって照射エリアのエッジと判断する部分が変わっていることも影響していると考えられる。
【００２６】
図１４（ｂ）に示す照射エリアの「ムラが気にならない」の評価では、器具No．4、7、8は、ベース照明の有る場合に対して無い場合には良い方から悪い方へ大きく下がっている。これはベース照明が無い場合に直射光が問題になることが原因と考える。
【００２７】
図１４（ｃ）に示す照射壁面全体の「はっきりさ」の評価は、器具No．3、5、8ではベース照明の有る場合と無い場合の評価の差異は小さいが、器具No．1、2、4、6、7ではその差異が大きい。また、器具No．1、2はベース照明が無い場合の方が評価は高いが、器具No．4、6、7は、ベース照明が有る場合の方が評価は高い。これはダイクロイックミラー付きハロゲン電球であるかどうかが影響しているとも考えられる。
【００２８】
図１４（ｄ）に示す照射壁面全体の「集中感」の評価は、器具No．4、8ではベース照明の有る場合と無い場合の評価の差異が他に比べて大きい。器具No．4はベース照明の有る場合の方が評価は高く、器具No．8はベース照明の無い場合の方が評価は高い。これには照射壁面の中心照度の違いが考えられる。
【００２９】
図１４（ｅ）に示す照射壁面全体の「明るさ」の評価は、器具ごとの評価の差が、他の評価項目と比較して小さい。中でも最も評価が高いのは照度の均斉度が最も良い器具No・7で、中心照度は評価器具の中でも低い方である。照射壁面全体の「明るさ」が照度のみに依存していないと判断できる。
【００３０】
図１４（ｆ）に示す照射壁面全体の「好ましさ」の評価は、器具No．4、6、8ではベース照明の有る場合と無い場合の評価の差異が大きい。これらはベース照明の有る場合の評価はかなり良い評価であるのに対して、ベース照明の無い場合の評価はかなり悪くなっている。これにはベース照明の無い場合に際立つスポットライトからの直射光の輝度ムラなどの影響が考えられる。
【００３１】
壁面照射では、ベース照明の有る場合、エッジは周囲の明るさによってある程度不鮮明になることが前提となる。その上でエッジが明確にされることが評価の向上につながる。そして周囲の明るさがあるので、集中感すなわち照射部分の均斉度と明るさが要求される。ベース照明の無い場合、周囲は暗いのでスポットライトからの（配光制御されていない）直射光が問題になる。ベース照明の無い場合は周囲が暗いため、スポットライトに特に高照度は要求されず、輝度ムラ（均斉度）や照射パターン（エッジ）の美しさが重要になると考えられる。
【００３２】
なおスポットライトで壁面を照射してその照射パターンを見た場合、ランプからの直射光を除いて配光制御された部分では、照射エリアのエッジと判断できるのは中心照度（最大照度）に対して1／10程度の照度になる部分であった。
【００３３】
そして主観評価と輝度特性から、照射パターンに影響を与えるものは上記ポイントの（イ）、（ロ）であり、照射範囲の均斉度が高く、くっきりしていながら、輝度勾配が滑らかである方が好ましいと推測された。
【００３４】
また、このことは次に述べることからも示唆される。すなわち、上記主観評価の結果から「照射部分の均斉度に関してムラが気にならないこと」ｘと「好ましさ」ｙに強い相関（相関係数0 ．856 ）があることが分かった（図２参照）。直線は回帰直線を表し、ｙ＝０．７８１ｘ＋１．２４９であり、Ｒ² ＝０．７３２５であった。
【００３５】
よって、均斉度に注目しながら主観評価結果と照射パターンの輝度特性を考慮して、目標とすべき好ましい配光のスポットライトを考えた。ここで、上記ポイントの（イ）〜（ホ）は以下のようになる（図１参照）。「（イ）中心輝度５０」および「（ニ）エッジの広さ５３」は、用途
（目的）に合わせて決めることができる。中心輝度５０では輝度Ｌ₁ （＝Ｌ(ｒ_c )）は目標の明るさによって設定される。Ｌはある点での輝度である。エッジの広さ５３のエッジ位置５５では、∇² Ｇ^* log₁₀ Ｌ（ｒ）が０レベルと交差（正負の変化）することを満たすｒの位置として得られる。この位置は目標照射範囲によって設定する。ここでガウス関数Ｇにはエッジ検出の細かさを規定するパラメータσを要するが、今回の検討ではσは視角１度程度で適用した。溝江らの既往研究（滑らかな輝度変化に対するエッジ位置の知覚、信学技報（１９９５−１１））では、σ＝14（分）でエッジ検出がされており、エッジが１つに特定できればエッジ位置ははとんどσの値に依らないことを示している。
【００３６】
また、今回の検討からエッジ位置５５は平面を照射した際の中心輝度の1 ／10程度の輝度レベルとなる位置、すなわちエッジ位置５５での輝度Ｌ₂ （＝Ｌ（ｒ_e））はＬ₁ ：Ｌ₂ ＝１０:1程度である。
【００３７】
（ロ）「主照射部５１の広さ」については、均斉度が高く、広い方が好ましい。「（ハ）輝度勾配５２」については、ムラの観点から、エッジと類似した点ができないことが望ましい。すなわち、輝度勾配５２は滑らかであることが好ましく、∇² Ｇ^* log₁₀Ｌ（ｒ）＝０とならないことであり、輝度勾配５２が急勾配であるとエッジの雰囲気はシャープになる。「（ホ）直射光（漏れ光）５４の有無」については、周囲の明るさによって考慮する。すなわち、周囲が他の照明によってエッジ位置と同等の輝度レベルであればエッジ位置より外側は考慮する必要がなく、エッジ位置の輝度レベル以下であればよい。他の照明が無い場合は輝度勾配５２を考慮する。
【００３８】
以上を踏まえて好ましい照射面の輝度パターンをモデル化したのが図３である。７０はエッジレベル、７１は輝度パターンである。壁正面より反射率７０％完全拡散面に照射距離１ｍで照射した場合で検討した。輝度パターン７１は、中心から周囲へ向かう方向の輝度変化が滑らかな変化をする曲線（Ｓ字型関数）５８を有し、中心付近５９の均斉度を高くすることによって、エッジもはっきりすると考えられる。ここで中心付近の均斉度の指標として、中心からエッジの間を半分に分け、エッジと中心の輝度レベル差と、エッジと中間点（中心とエッジの中点）の輝度レベル差の比によって表現することを考えた。
【００３９】
その均斉度に関しては、中心からエッジまでの距離をｒ_eとしたとき、中心の輝度レベルをＬ（ｒ_c ） 、中心から距離ｒ_e／2 までの位置での輝度レベルをＬ（ｒ_e /2 ） 、エッジ位置の輝度レベルをＬ（ｒ_e ）とすると、log₁₀ ｛Ｌ (ｒ_e ／2)−Ｌ (ｒ_e )｝/log₁₀ ｛ Ｌ (ｒ_c ) −Ｌ (ｒ_e )｝で表すことができる。今回の検討から従来の器具ではlog₁₀ ｛Ｌ (ｒ_e ／2)−Ｌ (ｒ_e )｝/log₁₀ ｛ Ｌ (ｒ_c ) −Ｌ (ｒ_e )｝≦０．９であった。従来の器具の例として好ましさの評価が高かった器具を図１５に示す。図中、照射中心の輝度Ｌ₁＝Ｌ（ｒ_c）＝１１３０ｃｄ／ｍ²
、エッジ位置の輝度Ｌ₂＝Ｌ（ｒ_e）＝２１０ｃｄ／ｍ²、輝度中心とエッジの中点の輝度Ｌ₃＝Ｌ（ｒ_e/2）＝７００ｃｄ／ｍ²、したがって均斉度の評価指標log₁₀ （Ｌ₃−Ｌ₂）/log₁₀ （ Ｌ₁ −Ｌ₂）＝０．９である。
【００４０】
これらの器具は前述した主観評価に用いたものであり、以下のようにすれば均斉度が増し、より評価が高くなると考えられる。すなわち、log₁₀ ｛Ｌ (ｒ_e ／2)−Ｌ (ｒ_e )｝/log₁₀ ｛ Ｌ (ｒ_c ) −Ｌ (ｒ_e )｝＞０．９とすることで、従来以上の照射パターンが実現できるものと推測できる。また、log₁₀ ｛Ｌ (ｒ_e ／2)−Ｌ (ｒ_e )｝/log₁₀ ｛ Ｌ (ｒ_c ) −Ｌ (ｒ_e )｝≧0 ．９５とすることによって均斉度が高くエッジがはっきりして、より照射範囲の明確な好ましいものとなる。
【００４１】
また、主照射部５１については、均斉度が高い方が好ましい傾向にあるが、完全に均一であると照射した際に照射の中心部が暗く見える中落ちの現象が起きる。そこで図１０に示すように照射平面上で照射の中心から距離ｒ₁およびｒ₂離れた位置での輝度がL（r₁）およびL（ｒ₂）であり、r_c＜ｒ₁＜ｒ₂＜ｒ_e/2としたときに、log₁₀L（r₁）＞log₁₀L（r₂）を満たすこと（ここで、r_c＝0であり、r_eは照射平面上の照射の中心からエッジ位置までの距離とする。）で、この現象を緩和する。
【００４２】
さらに、エッジの外側は器具の効率面および見た目の好ましさからも余分な光を少なくしたい部分であるが、見た目の好ましさの点から滑らかなパターンとしておくことが必要である。そこで図１０に示すように照射平面上で照射の中心から距離ｒ₃およびr₄離れた位置での輝度がL（ｒ₃）およびL（r₄）であり、r_e＜ｒ₃＜r₄としたときに、log₁₀L（r₃）＞log₁₀L（r₄）を満たすこと（ここで、r_eは照射平面上の照射の中心からエッジ位置までの距離とする。）で、外側になるにつれて徐々に輝度を低くして、滑らかなパターンとなり、かつ器具として効率を高めることができる。
【００４３】
以上、この輝度パターンのモデルから目標配光パターンとしてもとめたものが図４である。ここでは照射輝度（中心輝度）1500cd／ｍ² 、1 ／2 ビーム角22度（ただし照射範囲を認識する1 ／10ビーム角は28度）程度とした。この配光は従来よりも主照射部が広く均斉度が高く、エッジ付近の明るさ変化は滑らかでありながらエッジはくっきりとした印象を与えるものとなった。直射光（エッジ外部の漏れ光）５４は周囲の明るさによっては無視できるものであるが、今回は滑らかな曲線で補完した。この配光で照射パターンをシミュレーションしたものを図５（ａ）に示す。Ａは認識されるエッジ、Ｂは配光の終点である。図５（ｂ）は比較として従来の器具の一例を示すものであり、図５（ａ）の方が光の有効性が推測できる。なおビーム角（１／２、１／１０）：前者の目標配光パターン〔ＳＰＯＴ−Ｒ１（２２．３°、２８．１°）〕、従来配光パターン〔ＳＰＯＴ ＮＯ．２（１７．１°、３７．４°）〕である。
【００４４】
【発明の実施の形態】
この発明の第１の実施の形態の照明器具を図６により説明する。すなわち、この照明器具は図６（ａ）に示すように天井８１に埋設されるダウンライト８２であり、照明器具反射鏡（板）８３の内面に照射範囲の均斉度が高くなるよう配光制御するための処理を施している。図６（ｂ）に示すように反射鏡８３は碗形であり、内面は図６（ｃ）、（ｄ）のように樋状の溝８４を放射状にすなわち中心部ほど溝幅が狭くなるように形成されている。これにより、図６（ｅ）に示すように反射鏡内面で反射した光８８が平面的に広がることで、全体の均斉度を高めることができる。８５はランプである。
【００４５】
図６に示す反射鏡を内蔵した照明器具の効果を図７により定量的に説明する。図７は、好ましさの主観評価値が既知の器具（データ）から均斉度と好ましさの関係モデル（図中の回帰直線）を求めたものである。横軸は均斉度の評価指標log₁₀ ｛Ｌ (ｒ_e ／2)−Ｌ (ｒ_e )｝/log₁₀ ｛ Ｌ (ｒ_c ) −Ｌ (ｒ_e )｝の式によって算出される値であり、縦軸は好ましさである。回帰直線は従来の反射鏡付きハロゲンランプの好ましさから均斉度と好ましさの関係をモデル化したもので、ｙ＝２８．１５２ｘ−２０．９６７であり、Ｒ²＝０．８９６８である。試作した新配光の反射鏡（図６に示すタイプ）と従来配光の反射鏡の均斉度を数値化し、このモデルに当てはめると新配光３５のパターンの好ましさが高くなることが推定できた。この関係モデルによれば、均斉度が0．9以上であれば好ましさは4（中庸）以上となることが分かる。また、目視評価によって従来配光３６よりも新配光３５が好ましいことも確認された。
【００４６】
さらに、図６のような形態の器具で請求項4および請求項5に該当する器具の効果を説明する。図１１は前述した評価実験で好ましさの評価が高かった（評価値は7段階中4．5）スポットライトの輝度分布図である。図１１において、図（ａ）は反射率７０％の白クロスの壁面１１に１ｍの距離に水平から２０度下向きに照射している状態を示す。図（ｂ）はスポットライトの外観であり、例えば器具名ＮＬ０２３５２ＷＺを使用し、ランプはダイクール電球（φ５０ｍｍ）、ビーム角（１／２光度）２３．４°、ランプ光束７７９lmである。ダイクロイックミラー付きハロゲン電球ＪＲ１２Ｖ５０Ｗを使用する。ベース照明は無しである。図（ｃ）は輝度分布を示し、撮影距離は奥壁から５．５ｍ（撮影デジタルカメラはＣａｎｏｎＥＯＳ・ＤＳＣ−３Ｃ）である。中心付近の最大照度の目安は３３００lxである。カラーで表示したものを白黒コピーで図示している。カラーでは輝度中心を有する黒い部分が赤、その外側が橙、その外側の白く見える部分が黄、その外側が緑と青、その外側が濃い青、その外側が図の縁にかけて紫である。輝度中心を有する部分の輝度がもっとも高くその部分から外側にかけて輝度が漸次低くなっている。
【００４７】
その輝度分布において照射中心から外側へ向かう距離とその位置での輝度を示したものが図１２である。これは、図１１に示す輝度分布図中、照射中心（黒く見える部分の中央Ａ（図示せず））とＡ′を結ぶ線における断面の輝度パターンである。図１２において、横軸は照射中心からの水平距離を画像上の画素数で表し、縦軸は輝度レベルを表している。照射中心（ｒ＝r_c＝0）の輝度は790cd／ｍ²、エッジ位置（r＝ｒ_e＝92．5）での輝度は70cd／ｍ²、照射中心とエッジ位置の中間（r＝r_e／2＝46．3）での輝度は440cd／m²となっている。一例としてｒ₁＝20、ｒ₂＝35、ｒ₃＝100、ｒ₄＝110 とするとL（r₁）＝720cd／m²、L（r₂）＝630cd／m²、L（r₃）＝50cd／m²、L（r₄）＝30cd／m²となっている。すなわち、請求項4に示す「r_c＜r₁＜r₂＜r_e／2としたとき、log ₁₀ L（r_l）＞log₁₀L（r₂）」であることを満たし、かつ請求項5に示す「r_e＜r₃＜r₄としたとき、log ₁₀ L（r₃）＞log₁₀L（r₄）」であることを満たしている。よって、このような特徴を有する請求項1または請求項2記載の器具がより好ましい器具となることが推測できる。
【００４８】
図８は図６に示す反射鏡を内蔵した各種照明器具を示し、図８（ａ）、（ｂ）、（ｃ）、（ｄ）は天井取り付け型、図８（ｅ）は灯具が可動し、照射方向が可変なユニバーサルダウンライトであり、図８（ｆ）は灯具を収納したり引き出せるようにしたものである。
【００４９】
この発明の第２の実施の形態の照明器具を図９により説明する。すなわち、この照明器具は、ランプ８５の近傍に小反射鏡８６を設け、小反射鏡８６の外側にこれらを含む大反射鏡８７を設けており、小反射鏡８６により中心部の光８９をより広げて大反射鏡８７の反射光９０とともに大小の反射鏡８６、８７で全体の均斉度を高めている。
【００５０】
各実施の形態によれば、従来と比べて構造が簡単で小型化でき、コストダウンを図れ、操作性を良好にでき、効率もよくできる。
【００５１】
【発明の効果】
請求項１記載の照明器具によれば、光源（ランプ）と反射板を組み合わせて配光制御を行なう従来のスポット照明に比べて、平面を照射したときに照射範囲のエッジがより明確になり、均斉度が高く、照射パターンに好ましさを感じさせることができる。
【００５２】
請求項２記載の照明器具によれば、請求項１記載の照明器具よりもさらに照射範囲のエッジが明確になり、均斉度が高く、照射パターンに好ましさを感じさせる。漏れ光を除く照射範囲について、レンズやカッタを用いることなく、それらを用いたスポットライトに近い光を得ることができる。
【００５３】
請求項３記載の照明器具によれば、周囲にある程度（エッジと同等レベル）の明るさがある場合に、光源（ランプ）と反射板を組み合わせて配光制御を行なう従来のスポット照明に比べて、照射範囲のエッジがより明確になり、均斉度が高く、照射パターンに好ましさを感じさせる。
【００５４】
請求項４記載の照明器具によれば、照射平面上で照射の中心付近の輝度について、中心に近づくにつれて徐々に高めることによって、照射した際に中心が暗く見える中落ちの現象を緩和する傾向となる。
【００５５】
請求項５記載の照明器具によれば、照射平面上でエッジ位置より外側の輝度について、より外側になるにつれて徐々に低くすることによって、滑らかなパターンであり、かつ器具として効率を高める傾向となる。
【図面の簡単な説明】
【図１】（ａ）は、この発明による設計目標を設定する指標となる照射面（壁面）の輝度パターンの説明図、（ｂ）は光の照射面の範囲の説明図である。
【図２】「照射部分のムラが気にならないこと」に対する「好ましさ」の関係を示す説明図である。
【図３】好ましい照射面の輝度パターンの説明図である。
【図４】目標配光パターンの説明図である。
【図５】（ａ）は目標配光の照射パターンのシミュレーション図、（ｂ）は従来例の照射パターンのシミュレーション図である。
【図６】第１の実施の形態を示し、（ａ）はダウンライトの設置状態の斜視図、（ｂ）は反射鏡の斜視囲および正面図、（ｃ）は反射鏡の正面図、（ｄ）はその部分拡大図、（ｅ）は光の反射を示す説明図である。
【図７】実際のスポットライトによる「照射パターン（壁面）の均斉度の評価指標」と「好ましさの推定値」の関係を示す説明図である。
【図８】この発明の実施の形態の各種照明器具である。
【図９】第２の実施の形態の光の反射を示す説明図である。
【図１０】請求項４および請求項５に関する機能付加をした配光の説明図である。
【図１１】評価実験においてスポットライトで照射した壁面の輝度分布を示す説明図である。
【図１２】評価実験でのスポットライトで照射した壁面の輝度′てターンを示す説明図である。
【図１３】評価実験の実験設備を示す説明図である。
【図１４】評価実験の結果を示す説明図である。
【図１５】評価実験の評価器具の照射パターンのモデルと均斉度評価の例を示す説明図である。
【符号の説明】
５０ 中心輝度
５１ 主照射部
５２ 輝度勾配
５３ エッジの広さ
５４ 直射光（漏れ光）
５５ エッジ位置
８５ ランプ
８３ 反射鏡
８６ 反射鏡
８７ 反射鏡[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a lighting fixture that performs spot light distribution control by combining a light source (lamp) and a reflector, and relates to a lighting fixture that clarifies an irradiation range (boundary portion), has high uniformity, and feels favorable. It is.
[0002]
[Prior art]
Conventionally, as spot lighting fixtures that keep the uniformity within the irradiation range high and clear the edge outside the range, spotlights that cut light with a condensing device such as a lens or a cutter are used. Are known.
[0003]
Furthermore, there is a spot lighting device that combines a lamp and a reflecting mirror (see Patent Document).
[0004]
[Patent Literature]
JP-A-6-275111
[0005]
[Problems to be solved by the invention]
However, these have a complicated structure and are likely to increase in size, leading to an increase in cost and poor operability. In addition, the use of a cutter is not efficient.
[0006]
Therefore, an object of the present invention is to realize an irradiation pattern that uniformly and clearly irradiates the irradiation range and makes the user feel favorable by performing light distribution control by combining a light source (lamp) and a reflector. It is possible to provide a simple lighting device that can solve the above-mentioned problems without using a lens or a cutter.
[0007]
[Means for Solving the Problems]
The lighting fixture according to claim 1 is a lighting fixture that performs spot light distribution control by combining a light source (lamp) and a reflector.
The S-shaped function has a smooth change in luminance from the irradiation center on the irradiation plane (the center point of the pattern that is point-symmetric at the brightest position when the front is irradiated) to the range that includes the leakage light beyond the edge. Yes, edge position r_e∇ except²G^*log_TenSatisfies that L (r) does not cross (change positive or negative) with the 0 level, and
log_Ten {L (r_e/ 2) -L (r_e)} / Log_Ten {L (r_c) −L (r_e)}> 0.9 (where G is a two-dimensional Gaussian function with σ (corresponding to the fineness of edge detection, set to a level capable of edge detection) as a parameter, ∇²G^*log_Ten L (r) is log_TenL (r) is convoluted with a Gaussian function G and differentiated twice, L (r) is the luminance at a distance r from the center of irradiation on the irradiation plane, L (r_c) Is the brightness of the irradiation center on the irradiation plane, L (r_e) Is the brightness of the edge position of the irradiated part on the irradiation plane, L (r_e/ 2) indicates the luminance at a position intermediate between the irradiation center on the irradiation plane and the edge position of the irradiated portion. ),.
[0008]
The edge here refers to the end of the irradiation range where light distribution is controlled (the part excluding leakage light), and the position where the luminance level is about 1/10 of the central luminance when the plane is irradiated, or ∇²G^*log_TenR (= r) where L (r) intersects with 0 level (changes between positive and negative)_e) Position.
[0009]
The lighting fixture according to claim 2 is the log according to claim 1, wherein_Ten {L (r_e/ 2) -L (r_e)} / Log_Ten {L (r_c) −L (r_e)}> 0.9 instead of log_Ten{L (r_e/ 2) -L (r_e)} / Log_Ten {L (r_c) -L (r_e)} ≧ 0. 95.
[0010]
The lighting fixture according to claim 3 is a lighting fixture that performs spot light distribution control by combining a light source (lamp) and a reflector.
The change in luminance from the irradiation center to the edge on the irradiation plane is a part of the smooth S-shaped function, and the edge position r_e∇ except²G^*log_TenSatisfy that L (r) does not cross the zero level, and
log_Ten {L (r_e/ 2) -L (r_e)} / Log_Ten {L (r_c) −L (r_e)}> 0.9 (where G is a two-dimensional Gaussian function with σ (corresponding to the fineness of edge detection, set to a level capable of edge detection) as a parameter, ∇²G^*log_TenL (r) is log_TenL (r) is convoluted with a Gaussian function G and differentiated twice, L (r) is the luminance at a distance r from the center of irradiation on the irradiation plane, L (r_c) Is the brightness of the irradiation center on the irradiation plane, L (r_e) Is the brightness of the edge position of the irradiated part on the irradiation plane, L (r_e/ 2) indicates the luminance at a position intermediate between the irradiation center on the irradiation plane and the edge position of the irradiated portion. ),
The brightness at a position outside the edge position when there is other illumination is not more than the brightness level of the edge position.
[0011]
The edge here refers to the end of the irradiation range where light distribution is controlled (the part excluding leakage light), and the position where the luminance level is about 1/10 of the central luminance when the plane is irradiated, or ∇²G^*log_TenR (= r) where L (r) intersects with 0 level (changes between positive and negative)_e) Position. The brightness level at the edge position is equal to or lower than the brightness at the edge position, and the brightness at the position outside the edge position is equal to or lower than the brightness level at the edge position. Including.
[0012]
According to a fourth aspect of the present invention, there is provided the lighting apparatus according to the first or second aspect, wherein the distance r from the center of irradiation is on the irradiation plane.₁And r₂The luminance at a distant position is L (r₁) And L (r₂) And r_c<R_l<R₂<R_eWhen set to / 2,
log_Ten L (r_l) ＞ log_TenL (r₂)
(However, r_c= 0 and r_eIs the distance from the center of irradiation on the irradiation plane to the edge position. ).
[0013]
The lighting apparatus according to claim 5 is the distance r from the center of irradiation on the irradiation plane according to claim 1 or 2._ThreeAnd r_FourThe brightness at a remote location is L (r_Three) And L (r_Four) And r_e<R_Three<R_FourLog_TenL (r_Three) ＞ log_TenL (r_Four)
(However, r_eIs the distance from the center of irradiation on the irradiation plane to the edge position).
[0014]
The above means will be described. Due to the nature of the spotlight, the outline of the irradiation pattern (diameter size, prominence) and pattern unevenness are important characteristics. Therefore, subjective evaluation and luminance characteristics of various general spotlights were examined, and preferable light distribution was studied. As a result of the examination, the points for evaluating (designing) the spotlight were estimated as follows (see FIG. 1). That is, (b) the central luminance (luminous intensity) 50, (b) the width of the main irradiation unit 51, (c) the luminance gradient 52, and (d) the width of the edge (55) (the width and beam angle of the irradiation unit). 53, (e) presence / absence of direct light (leakage light) 54.
Here, an outline of an evaluation experiment for deriving factors affecting the evaluation of the spotlight is shown.
[0015]
[Table 1]

[0016]
Table 1 shows a list of evaluation instruments used in the evaluation experiment. Wall surfaces and three-dimensional objects were irradiated with 8 types of general medium-angle spotlights shown in Table 1, and a total of 18 subjects were evaluated for the impression of irradiation. At the same time, the irradiation pattern on the wall surface was measured and the luminance characteristics were examined. The subjects were selected from those who have expertise in the store field, expertise in visual environment evaluation, and those who usually use the store. Since there was no difference between spotlights in the evaluation when illuminating a solid object, there was no difference between the spotlights as in the evaluation when illuminating the wall surface. Therefore, it is necessary to be able to use it properly according to the purpose. Therefore, the basic case of wall surface irradiation was considered. Four subjects were involved in the development of lighting technology.
[0017]
The experimental equipment is as shown in FIG. 13. The spotlight 10 with a height of 1.5 m irradiates the front wall (white cross, reflectance 70%) 11 1 m ahead, and evaluates with or without base illumination. It was. The base lighting fixture 12 is disposed on the ceiling 13 (height 2.75 m), and uses a fluorescent lamp fixture for daylight white 40W. The illuminance level by the base lighting is vertical on the vertical surface A on the fixture front wall surface 1.5 m above the floor The surface illuminance is 380 lx, and the horizontal plane illuminance 680 lx of the horizontal plane B 2 m from the front wall on the instrument extension line of 0 m above the floor.
[0018]
The evaluation was performed in 7 stages using the evaluation sheet shown in Table 2 from a position 5 m away from the wall surface. Table 2 shows an evaluation sheet for evaluating the wall surface irradiation pattern used in the evaluation experiment.
[0019]
[Table 2]

[0020]
Describe the results of special evaluation. As a result of obtaining the correlation coefficient for each evaluation item from the result of subjective evaluation for all scenes of the evaluation experiment in order to investigate what factors the spotlight irradiation pattern is evaluated, `` edge clarity '' There is a strong correlation with “clearness” and “concentration” of the entire irradiated wall, and “irregularity of unevenness” in the irradiated area means “beauty of unevenness” in the irradiated area and “beauty and brightness” of the entire irradiated wall. "Precision" is strongly correlated. “Preference” refers to “Beauty of unevenness” in the irradiation area, “Beauty and precision” of the entire irradiation wall, “I do not care about unevenness” in the irradiation area, “Brightness” of the entire irradiation wall It can be seen that there is a strong correlation with “hardness”. In other words, the uniformity of the irradiated area, concentration, brightness, and edge processing were considered to be the evaluation points.
[0021]
In addition, when the correlation coefficient for each evaluation item was obtained for a scene with base illumination, it was found that the brightness of the irradiated part had a high correlation with clarity and concentration. Since the surroundings are bright, it is necessary to increase the intensity (brightness) of the light in order to emphasize the effect of the spotlight.
[0022]
From these correlations, it was found that the edge clarity and overall evaluation (preference) were low.
[0023]
Next, the impression evaluation of each spotlight is compared in consideration of the presence or absence of base illumination.
[0024]
14A to 14F show the evaluation results of representative evaluation items in consideration of the correlation between the evaluation items, while showing the difference between the case with and without the base illumination.
[0025]
The “edge definition” shown in FIG. 14A is similar in the evaluation tendency of the instrument with and without the base illumination. It can be considered that the change in the evaluation value itself with and without the base illumination is also due to the fact that the part that is determined as the edge of the irradiation area is changed due to direct light.
[0026]
In the evaluation of “I don't care about unevenness” in the irradiation area shown in FIG. 4, 7, and 8 are greatly lowered from the better to the worse when there is no base illumination. This is considered to be caused by direct light becoming a problem when there is no base illumination.
[0027]
The evaluation of the “clarity” of the entire irradiated wall surface shown in FIG. In 3, 5, and 8, the difference in evaluation with and without base lighting is small. The difference is large in 1, 2, 4, 6, and 7. Instrument No. 1 and 2 are more highly evaluated when there is no base lighting. 4, 6, and 7 have higher ratings when the base lighting is used. This is thought to be influenced by whether or not it is a halogen bulb with a dichroic mirror.
[0028]
The evaluation of “concentration” of the entire irradiated wall surface shown in FIG. In 4 and 8, the difference in evaluation with and without base lighting is greater than others. Instrument No. No. 4 has a higher evaluation when base lighting is used. 8 is higher in the case of no base lighting. This may be due to the difference in the center illuminance of the irradiated wall.
[0029]
In the evaluation of “brightness” of the entire irradiated wall surface shown in FIG. 14 (e), the difference in evaluation for each instrument is small compared to other evaluation items. Among them, the highest evaluation is appliance No. 7, which has the best illuminance uniformity, and the central illuminance is the lowest of the evaluation appliances. It can be determined that the “brightness” of the entire irradiated wall surface does not depend only on the illuminance.
[0030]
The evaluation of “preferability” of the entire irradiated wall surface shown in FIG. For 4, 6, and 8, the difference in evaluation with and without base lighting is large. In these cases, the evaluation in the presence of the base lighting is quite good, whereas the evaluation in the absence of the base lighting is considerably worse. This may be affected by brightness unevenness of direct light from a spotlight that stands out when there is no base illumination.
[0031]
In the case of wall illumination, it is assumed that the edge becomes unclear to some extent due to ambient brightness when there is base illumination. In addition, clarifying the edges leads to improvement in evaluation. Since there is ambient brightness, a sense of concentration, that is, uniformity and brightness of the irradiated part is required. In the absence of base illumination, the surroundings are dark and direct light from the spotlight (not light distribution controlled) becomes a problem. In the absence of base illumination, the surroundings are dark, so that the spotlight does not require particularly high illuminance, and it is considered that brightness unevenness (homogeneity) and the beauty of the irradiation pattern (edge) are important.
[0032]
In addition, when illuminating the wall surface with a spotlight and looking at the irradiation pattern, it is possible to determine that the edge of the irradiation area is the center illuminance (maximum illuminance) in the part where the light distribution is controlled except for direct light from the lamp. It was a part where the illuminance was about 1/10.
[0033]
And from subjective evaluation and luminance characteristics, the ones that affect the irradiation pattern are (b) and (b) of the above points. The uniformity of the irradiation range is high and the luminance gradient is smoother while being clear. It was speculated that it was preferable.
[0034]
This is also suggested from the following. That is, from the result of the above subjective evaluation, it was found that there is a strong correlation (correlation coefficient 0.856) between “not worrying about unevenness with respect to the uniformity of the irradiated portion” x and “preference” y (FIG. 2). reference). The straight line represents a regression line, y = 0.81 1x + 1.249, R²= 0.7325.
[0035]
Therefore, a spotlight with a preferable light distribution to be targeted was considered in consideration of the subjective evaluation results and the luminance characteristics of the irradiation pattern while paying attention to the uniformity. Here, (a) to (e) of the above points are as follows (see FIG. 1). “(A) Center luminance 50” and “(D) Edge size 53”
It can be decided according to (purpose). At center brightness 50, brightness L₁(= L (r_c)) Is set according to the target brightness. L is the luminance at a certain point. At the edge position 55 of the edge width 53, the wrinkle²G^*log_Ten It is obtained as a position of r that satisfies that L (r) crosses (changes between positive and negative) with the 0 level. This position is set according to the target irradiation range. Here, the Gaussian function G requires a parameter σ that defines the fineness of edge detection. In this study, σ is applied at a viewing angle of about 1 degree. In Mizoe et al.'S previous research (perception of edge position for smooth luminance change, IEICE Technical Report (1995-11)), edge detection is performed at σ = 14 (minutes), and if one edge can be specified, the edge is detected. The position is almost independent of the value of σ.
[0036]
Further, from this examination, the edge position 55 is a position where the brightness level is about 1/10 of the center brightness when the plane is irradiated, that is, the brightness L at the edge position 55.₂(= L (r_e)) L₁: L₂= About 10: 1.
[0037]
(B) About "the width of the main irradiation part 51", a high degree of uniformity is preferable. Regarding “(c) luminance gradient 52”, it is desirable that a point similar to an edge cannot be formed from the viewpoint of unevenness. That is, the brightness gradient 52 is preferably smooth,²G^*log_TenThis means that L (r) = 0 is not satisfied, and if the luminance gradient 52 is steep, the atmosphere of the edge becomes sharp. "(E) Presence / absence of direct light (leakage light) 54" is considered according to the brightness of the surroundings. In other words, if the surrounding area has a luminance level equivalent to that of the edge position due to other illumination, it is not necessary to consider the area outside the edge position, and it may be equal to or lower than the luminance level of the edge position. When there is no other illumination, the luminance gradient 52 is considered.
[0038]
FIG. 3 shows a model of a preferable luminance pattern of the irradiated surface based on the above. 70 is an edge level, and 71 is a luminance pattern. Examination was performed in the case where the complete diffusion surface with a reflectance of 70% was irradiated from the front of the wall at an irradiation distance of 1 m. The luminance pattern 71 has a curve (S-shaped function) 58 in which the luminance change in the direction from the center toward the periphery changes smoothly, and it is considered that the edge becomes clear by increasing the uniformity in the vicinity of the center 59. . Here, as an index of the degree of uniformity near the center, the distance between the center and the edge is divided in half, and expressed by the ratio of the brightness level difference between the edge and the center and the brightness level difference between the edge and the middle point (center and the middle point of the edge) Thought to do.
[0039]
For the uniformity, the distance from the center to the edge is r_e, The central luminance level is L (r_c), Distance r from center_eThe luminance level at positions up to / 2 is set to L (r_e/ 2), the brightness level of the edge position is set to L (r_e) And log_Ten {L (r_e/ 2) -L (r_e)} / Log_Ten {L (r_c) −L (r_e)}. From this study, with conventional instruments, log_Ten {L (r_e/ 2) -L (r_e)} / Log_Ten {L (r_c) −L (r_e)} ≦ 0.9. As an example of a conventional instrument, an instrument having a high evaluation of preference is shown in FIG. In the figure, luminance L at the center of irradiation₁= L (r_c) = 1130 cd / m²
, Brightness L of edge position₂= L (r_e) = 210 cd / m², Luminance L at the midpoint of the luminance center and edge_Three= L (r_e/ 2) = 700cd / m²Therefore, the evaluation index of uniformity log_Ten (L_Three-L₂) / Log_Ten (L₁ -L₂) = 0.9.
[0040]
These instruments are used for the subjective evaluation described above, and it is considered that the uniformity is increased and the evaluation is further increased as follows. Ie log_Ten {L (r_e/ 2) -L (r_e)} / Log_Ten {L (r_c) −L (r_e)}> 0.9, it can be estimated that an irradiation pattern more than conventional can be realized. Log_Ten {L (r_e/ 2) -L (r_e)} / Log_Ten {L (r_c) −L (r_e)} ≧ 0. By setting it to 95, the degree of uniformity is high, the edge is clear, and the irradiation range is clear and preferable.
[0041]
Further, with respect to the main irradiation part 51, it is preferable that the degree of uniformity is high. However, when the irradiation is completely uniform, a phenomenon that the center part of the irradiation appears dark is generated. Therefore, as shown in FIG. 10, the distance r from the center of irradiation on the irradiation plane.₁And r₂The brightness at a remote location is L (r₁) And L (r₂) And r_c<R₁<R₂<R_e/ 2 when log_TenL (r₁) ＞ log_TenL (r₂) (Where r_c= 0 and r_eIs the distance from the center of irradiation on the irradiation plane to the edge position. ) To alleviate this phenomenon.
[0042]
Furthermore, the outside of the edge is a portion where it is desired to reduce excessive light from the viewpoint of the efficiency of the instrument and the preference of appearance, but it is necessary to make a smooth pattern from the viewpoint of appearance preference. Therefore, as shown in FIG. 10, the distance r from the center of irradiation on the irradiation plane._ThreeAnd r_FourThe brightness at a distant position is L (r_Three) And L (r_Four) And r_e<R_Three<R_FourAnd log_TenL (r_Three) ＞ log_TenL (r_Four) (Where r_eIs the distance from the center of irradiation on the irradiation plane to the edge position. ), The luminance is gradually lowered toward the outside, resulting in a smooth pattern and increasing the efficiency of the instrument.
[0043]
FIG. 4 shows the target light distribution pattern obtained from the luminance pattern model. Here, irradiation brightness (center brightness) 1500cd / m²1/2 beam angle was set to 22 degrees (however, 1/10 beam angle for recognizing the irradiation range was 28 degrees). This light distribution has a wider main irradiation part and higher uniformity than before, and the brightness change near the edge is smooth, but the edge gives a clear impression. The direct light (leakage light outside the edge) 54 is negligible depending on the brightness of the surroundings, but this time it was supplemented with a smooth curve. A simulation of the irradiation pattern with this light distribution is shown in FIG. A is the recognized edge, and B is the end point of the light distribution. FIG. 5B shows an example of a conventional instrument as a comparison, and the effectiveness of light can be estimated in FIG. 5A. Beam angle (1/2, 1/10): former target light distribution pattern [SPOT-R1 (22.3 °, 28.1 °)], conventional light distribution pattern [SPOT NO. 2 (17.1 °, 37.4 °)].
[0044]
DETAILED DESCRIPTION OF THE INVENTION
The lighting fixture of 1st Embodiment of this invention is demonstrated with reference to FIG. That is, this lighting fixture is a downlight 82 embedded in the ceiling 81 as shown in FIG. 6A, and the light distribution control is performed so that the uniformity of the irradiation range is increased on the inner surface of the lighting fixture reflector (plate) 83. Processing to do. As shown in FIG. 6B, the reflecting mirror 83 has a bowl shape, and the inner surface is radially formed with the bowl-shaped grooves 84 as shown in FIGS. 6C and 6D, that is, the groove width becomes narrower toward the center. Is formed. Thereby, as shown in FIG.6 (e), the light 88 reflected by the reflecting mirror inner surface spreads planarly, and can improve the whole uniformity. Reference numeral 85 denotes a lamp.
[0045]
The effect of the lighting fixture incorporating the reflecting mirror shown in FIG. 6 will be quantitatively described with reference to FIG. FIG. 7 shows a relationship model (regression line in the figure) between uniformity and preference from an instrument (data) whose preference evaluation value of preference is known. Horizontal axis is evaluation index of uniformity_Ten {L (r_e/ 2) -L (r_e)} / Log_Ten {L (r_c) −L (r_e)}, And the vertical axis represents the preference. The regression line models the relationship between the uniformity and the preference from the preference of the conventional halogen lamp with a reflector, and y = 28.152x-20.967.²= 0.8968. It is estimated that the degree of preference of the pattern of the new light distribution 35 will be higher when the uniformity of the prototype of the newly distributed light distribution mirror (type shown in FIG. 6) and the conventional light distribution reflector are quantified and applied to this model. did it. According to this relational model, it is understood that the preference is 4 (medium) or more when the uniformity is 0.9 or more. It was also confirmed by visual evaluation that the new light distribution 35 is preferable to the conventional light distribution 36.
[0046]
Furthermore, the effect of the appliance corresponding to claim 4 and claim 5 will be described using the appliance of the form shown in FIG. FIG. 11 is a spotlight luminance distribution chart showing a high evaluation of preference in the evaluation experiment described above (evaluation value is 4.5 out of 7 levels). In FIG. 11, FIG. 11A shows a state in which a wall surface 11 of a white cloth having a reflectance of 70% is irradiated at a distance of 1 m downward from the horizontal by 20 degrees. FIG. 2B shows the appearance of a spotlight, for example, using an instrument name NL02352WZ. The lamp has a Dycool bulb (φ50 mm), a beam angle (1/2 luminous intensity) of 23.4 °, and a lamp luminous flux of 779 lm. Use a halogen bulb JR12V50W with a dichroic mirror. There is no base lighting. FIG. 7C shows the luminance distribution, and the shooting distance is 5.5 m from the back wall (the shooting digital camera is Canon EOS / DSC-3C). The standard of maximum illuminance near the center is 3300 lx. The color display is shown in black and white copy. In color, the black part having the luminance center is red, the outside is orange, the part that appears white on the outside is yellow, the outside is green and blue, the outside is dark blue, and the outside is purple over the edge of the figure. The portion having the luminance center has the highest luminance, and the luminance gradually decreases from that portion to the outside.
[0047]
FIG. 12 shows the distance from the irradiation center to the outside and the luminance at that position in the luminance distribution. This is a luminance pattern of a cross section along a line connecting the irradiation center (center A (not shown) of a black portion) and A ′ in the luminance distribution diagram shown in FIG. In FIG. 12, the horizontal axis represents the horizontal distance from the irradiation center in terms of the number of pixels on the image, and the vertical axis represents the luminance level. Irradiation center (r = r_c= 0) brightness is 790cd / m², Edge position (r = r_e= 92.5), brightness is 70cd / m², Between irradiation center and edge position (r = r_e/ 2 = 46.3), the brightness is 440cd / m²It has become. As an example, r₁= 20, r₂= 35, r_Three= 100, r_Four= 110, L (r₁) = 720cd / m², L (r₂) = 630cd / m², L (r_Three) = 50cd / m², L (r_Four) = 30cd / m²It has become. That is, “r” shown in claim 4_c<R₁<R₂<R_eWhen set to / 2, log_Ten L (r_l) ＞ log_TenL (r₂) ”And as shown in claim 5“ r_e<R_Three<R_FourLog_Ten L (r_Three) ＞ log_TenL (r_Four) ”. Therefore, it can be presumed that the device according to claim 1 or 2 having such characteristics is a more preferable device.
[0048]
8 shows various lighting fixtures incorporating the reflecting mirror shown in FIG. 6, FIGS. 8 (a), (b), (c) and (d) are ceiling-mounted types, and FIG. The universal downlight has a variable irradiation direction, and FIG. 8 (f) is configured such that the lamp can be accommodated and pulled out.
[0049]
A lighting apparatus according to a second embodiment of the present invention will be described with reference to FIG. That is, in this lighting fixture, a small reflecting mirror 86 is provided in the vicinity of the lamp 85, and a large reflecting mirror 87 including these is provided outside the small reflecting mirror 86. The overall uniformity is enhanced by the large and small reflecting mirrors 86 and 87 together with the reflected light 90 of the large reflecting mirror 87.
[0050]
According to each embodiment, the structure is simpler and smaller than before, the cost can be reduced, the operability can be improved, and the efficiency can be improved.
[0051]
【The invention's effect】
According to the lighting apparatus of claim 1, the edge of the irradiation range becomes clearer when the plane is irradiated, compared to the conventional spot illumination that performs light distribution control by combining a light source (lamp) and a reflector. The degree of uniformity is high, and it is possible to make the irradiation pattern feel favorable.
[0052]
According to the lighting fixture of Claim 2, the edge of an irradiation range becomes clearer than the lighting fixture of Claim 1, and the degree of uniformity is high, and it makes the irradiation pattern feel favorable. With respect to the irradiation range excluding leakage light, light close to a spotlight using them can be obtained without using a lens or a cutter.
[0053]
According to the lighting apparatus of claim 3, when there is a certain level of brightness (equivalent to the edge) in the surroundings, as compared with the conventional spot lighting that performs light distribution control by combining a light source (lamp) and a reflector. The edge of the irradiation range becomes clearer, the degree of uniformity is high, and the irradiation pattern feels favorable.
[0054]
According to the luminaire of claim 4, the brightness near the center of irradiation on the irradiation plane is gradually increased as the distance from the center is approached, thereby reducing the phenomenon that the center appears dark when irradiated. Become.
[0055]
According to the luminaire of claim 5, the brightness outside the edge position on the irradiation plane is gradually lowered as it goes further outside, so that it is a smooth pattern and tends to increase efficiency as a fixture. .
[Brief description of the drawings]
FIG. 1A is an explanatory diagram of a luminance pattern of an irradiation surface (wall surface) serving as an index for setting a design target according to the present invention, and FIG. 1B is an explanatory diagram of a range of a light irradiation surface.
FIG. 2 is an explanatory diagram showing a relationship of “preference” with respect to “not worrying about unevenness of an irradiated portion”;
FIG. 3 is an explanatory diagram of a luminance pattern of a preferable irradiation surface.
FIG. 4 is an explanatory diagram of a target light distribution pattern.
5A is a simulation diagram of an irradiation pattern of a target light distribution, and FIG. 5B is a simulation diagram of an irradiation pattern of a conventional example.
6A is a perspective view of a downlight installation state, FIG. 6B is a perspective view and a front view of a reflecting mirror, FIG. 6C is a front view of the reflecting mirror; d) is a partially enlarged view thereof, and (e) is an explanatory view showing reflection of light.
FIG. 7 is an explanatory diagram showing a relationship between “an evaluation index of uniformity of an irradiation pattern (wall surface)” and “estimated value of preference” by an actual spotlight.
FIG. 8 shows various lighting fixtures according to the embodiment of the present invention.
FIG. 9 is an explanatory diagram showing light reflection according to the second embodiment;
FIG. 10 is an explanatory diagram of light distribution to which functions related to claims 4 and 5 are added.
FIG. 11 is an explanatory diagram showing a luminance distribution of a wall surface irradiated with a spotlight in an evaluation experiment.
FIG. 12 is an explanatory diagram showing the turn of the brightness of the wall surface irradiated with the spotlight in the evaluation experiment.
FIG. 13 is an explanatory diagram showing experimental equipment for an evaluation experiment.
FIG. 14 is an explanatory diagram showing the results of an evaluation experiment.
FIG. 15 is an explanatory diagram showing an example of an irradiation pattern model and uniformity evaluation of an evaluation tool for an evaluation experiment.
[Explanation of symbols]
50 center brightness
51 Main irradiation unit
52 brightness gradient
53 Edge width
54 Direct light (leakage light)
55 Edge position
85 lamp
83 Reflector
86 Reflector
87 Reflector

Claims (5)

In a lighting fixture that performs spot light distribution control by combining a light source and a reflector,
A smooth S-shaped function is a change in luminance from the irradiation center to a range including the leakage light beyond the edge of the irradiation plane, ∇ except in positions r _e of the edge _{^{2 G * log 10 L (r}} ) is 0 Satisfy not crossing the level, and
log ₁₀ {L (r _e / 2) −L (r _e )} / log ₁₀ {L (r _c ) −L (r _e )}> 0.9 (where G is σ (edge detection ² G ^* log ₁₀ L (r) is a convolution of the Gaussian function G into log ₁₀ L (r) twice. Differentiated, L (r) is the luminance at a position r away from the center of irradiation on the irradiation plane, L (r _c ) is the luminance of the irradiation center on the irradiation plane, and L (r _e ) is on the irradiation plane. The brightness of the edge position of the irradiated portion of L, and R (r _e / 2) represents the brightness at the middle position between the irradiation center on the irradiation plane and the edge position of the irradiated portion). Instead of the expression log ₁₀ {L (r _e / 2) −L (r _e )} / log ₁₀ {L (r _c ) −L (r _e )}> 0.9, the expression is log ₁₀ {L (r _e / 2) −L (r _e )) / log ₁₀ {L (r _c ) −L (r _e )} ≧ 0. 95. A luminaire according to claim 1 which is 95. In a lighting fixture that performs spot light distribution control by combining a light source and a reflector,
Is part of a smooth S-shaped function change in brightness from the irradiation center of the irradiation plane to edge, that ∇ except in positions r _e of the edge _{^{2 G * log 10 L (r}} ) does not intersect the zero level And satisfy
log ₁₀ {L (r _e / 2) −L (r _e )} / log ₁₀ {L (r _c ) −L (r _e )}> 0.9 (where G is σ (edge detection ² G ^* log ₁₀ L (r) is a convolution of the Gaussian function G into log ₁₀ L (r) twice. Differentiated, L (r) is the luminance at a position r away from the center of irradiation on the irradiation plane, L (r _c ) is the luminance of the irradiation center on the irradiation plane, and L (r _e ) is on the irradiation plane. The brightness of the edge position of the irradiated portion of L, L (r _e / 2) represents the brightness at the middle position between the irradiation center on the irradiation plane and the edge position of the irradiated portion).
The luminaire characterized in that the luminance at a position outside the edge position when there is other illumination is equal to or lower than the luminance level of the edge position. Luminances at positions r ₁ and r ₂ away from the center of irradiation on the irradiation plane are L (r ₁ ) and L (r ₂ ), and r _c <r _l <r ₂ <r _e / 2. When
log ₁₀ L (r _l )> log ₁₀ L (r ₂ )
It is (provided that at r _c = 0, r _e is the distance from the center of the irradiation on the irradiation plane to edge position.), According to claim 1 or claim 2 luminaire according. When the luminances at positions r ₃ and r ₄ away from the center of irradiation on the irradiation plane are L (r ₃ ) and L (r ₄ ), and r _e <r ₃ <r ₄ ,
log ₁₀ L (r ₃ )> log ₁₀ L (r ₄ )
It is (although, r _e is the distance from the center of the irradiation on the irradiation plane to edge position.), According to claim 1 or claim 2 luminaire according.

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