200833165 九、發明說明： 【發明所屬之技術領域】 本發明大體而言係關於一種包含發光二極體之照明器 具，且更特定言之，係關於一種包含LED及一塗有一色彩 轉換層（諸如，一磷光層）之透明窗的照明器具。此外，本 發明係關於一種用於此等照明器具中之可再現可調節色彩 控制機構之方法。此外，本發明係關於包含經磷光體塗佈 之LED的發光裝置。 【先前技術】 所陳述之種類之裝置已為吾人所熟知。自從約十年前發 明了產生白光之經麟光體塗佈之發光二極體（pc_LED)以 來，其已被用於廣泛種類之應用。舉例而言，其被用作 LCD螢幕之背光單元中之光源、用作電子裝置中之指示 燈、用作數位視訊攝影機及具有成像功能之行動電話中之 辅助照明光源。此外，pC_LED被應用於汽車頭燈中及喷燈 中（用於地面手持、登山耳機或潛水目的）。此外，由於pc-led之效 率及輸 出功率 增加， 期望其 在通用 照明裝 置中之 滲透性顯著增長。 在大量上述pc-LED應用中，使用者可直接看到裝配於發 光裝置中之LED封裝。此等裝置為所謂之直接觀察型，與 LED封裝由射束播板或其他光學結構及元件阻擋直接觀察 的間接觀察型相反。當pc_LED封裝在發光裝置之功能關閉 狀悲下對於使用者可見時，其可由其特異淡黃色清楚地識 別。此色彩由塗覆於LED封裝内之磷光體之光學特徵產 125277.doc 200833165 生。相同色彩效應出現於一照明器具之功能關閉狀態下， 該照明器具包含作為光源之LED及一塗有色彩轉換層（諸 如，磷光體）之透明窗。 pc-LED及照明器具在其功能關閉狀態下之特異淡黃色外 觀在大量應用中為一干擾特徵。作為實例，可給出具有成 像功能及辅助照明光源的行動電話。行動電話市場之特徵 在於其電話式樣及類型的快速演進。除此等式樣之所有功 能特徵以外，許多人將此等式樣視為生活方式附屬品。因 此，映像及外觀為基本銷售點。在此情形下，許多電話製 造商之設計部門重複挑戰pc_LED辅助燈之清楚可見之淡黃 色光點。因此，明確需要pc_LED在其功能關閉狀態下之可 再現可調整色彩控制機構。 【發明内容】 本發明之一目標係提供一種所陳述之種類之發光裝置， 其中pc-LED封裝經控帝J以在發光裝置之功能關閉狀態下呈 現中性白色。用如請求項丨之根據本發明之發光裝置來達 成此目心 種包含一經鱗光體塗佈之發光二極體之發光 裝置，其特徵在於：該裝置包含控制構件，其用於在該發 光袭置之功此關閉狀態下將一殘餘電流提供至該經磷光體 塗佈之發光二極體，以實現該發光裝置在其功能關閉狀態 下之一中性白色外觀。 本么明提供一種發光裝置，其在該裝置之功能關閉狀態 下仍提i、非吊少量之光。然而，此量之光如此小而使得在 力月b關閉狀悲、下之裝置在幾乎所有實際情況下不可用於 125277.doc 200833165 其預期目的。由於在發光裝置之功能關閉狀態下流過pc_ LED之殘餘電流，由pc-LED產生之微量光比來自pc_LED之 、’二反射之環i兄光更免，此歸因於鱗光體之光學特徵經過遽 而變成淡黃色。因此，pc_LED將對人眼呈現為具有中性白 色。 在本發明之一實施例中，發光裝置包含用於在功能開啟 狀態下將一標稱電流提供至經磷光體塗佈之;LED的構件， 殘餘電流與標稱電流之比小於1 (Γ3，或較佳小於1 〇·5。 在本發明之另一實施例中，發光裝置進一步包含一用以 偵側環境照明度之感測器，其特徵在於··控制構件基於該 感測為之輸出在低於一預定環境照明度之情況下將該裝置 之功能關閉狀態下之殘餘電流設定為零。 本發明之另一態樣係提供一種包含一光學空腔之照明器 具，其包含至少一 LED及一透明窗，該透明窗具備一色彩 轉換層、覆蓋該光學空腔且使光能夠自該照明器具發射， 讜照明器具之特徵在於：該照明器具包含控制構件，其用 於在照明器具之功能關閉狀態下將一殘餘電流提供至該至 少一 LED，以實現色彩轉換層在該功能關閉狀態下之中性 白色外觀。 在一實施例中，該照明器具進一步包含一用以偵侧一環 境照明度之感測器，其特徵在於：提供控制構件以基於來 自該感測器之信號依賴於該環境照明度來調整該殘餘電 流。此情形係有利的，因為較高環境照明度需要較大殘餘 電流以便比經反射之環境光更亮。此外，在較低環境照明 125277.doc 200833165 度下，可減小殘餘電流，進而使該照明器具較為能量有 效。 在另一實施例中，根據本發明之照明器具中的控制構件 基於來自該感測器之該信號在低於一預定環境照明度的情 況下將該殘餘電流設定為零。又，此情形有益於節約能 量。 本發明之此等及其他態樣將自下文所述實施例顯而易見 並參考下文所述實施例予以闡明。 其他先前技術 專利申請案US2005/0148364描述一種具有一成像功能及 一辅助發光裝置的行動電話裝置。此輔助發光裝置被描述 包括紅色、綠色及藍色LED。此外，辅助發光裝置經設計 以基本上具有兩級照度位準：一低’’照射（shooting)"模式及 一高’’閃光”模式。在該低，，照射，，模式下，供應至RGB LED 之電流經控制以在低位準下用白點光照亮一物件使得可清 楚地確認該物件。此情形在無低位準照度的情況下不易於 識別物件的暗淡發光及/或黑暗環境中尤其實用。一旦已 確認物件及將獲取一影像，輔助發光裝置切換至高，，閃 光模式。在該’’閃光’’模式下，增加供應至RGB LED的電 流以便發射足夠的光使得可獲得一高品質圖片。通常，在 低π發射，，模式下供應至LED之電流為在，，閃光，，模式下供應 之電流的50%。 儘管自上文清楚，US2005/0148364描述一種包含LED的 發光裝置，其中至LED之電流可經控制以減少/增加LED之 125277.doc 200833165 光輸出，但清楚地預期該減少/增加設施可在該發光裝置 之功能開啟狀態下操作。此外，因為US2005/0148364未瞭 解pc-LED亦可用於發光裝置中，所以其未教示控制pc_ LED在其功能關閉狀態下之可見外觀。 【實施方式】 圖1展示一發光裝置1，其包含pc-LED 2、一控制器3， 及一電源電路4。該發光裝置1連接至一電源5，該電源5可 為一 AC電源或一諸如電池之DC電源。一使用者可操作指 令6-手動地或經由一使用者介面裝置（未圖示兴指示該控制 器3在發光裝置1之功能開啟狀態與其功能關閉狀態之間切 換。控制器又調整電源電路4而以與發光裝置丨之功能開啟 狀態或功能關閉狀態相符的位準將一電流提供至pc_LED 2。在此項技術上中，存在適用於此目的之已知的許多電 路拓撲。實際上，主動地控制電源電路4對於本發明而言 並非為基本的。熟習此項技術者將易於瞭解··替代性，許 多被動電路拓撲係可預期的。 發光裝置1之功能關閉狀態被界定為所發射之光的量如 此小而使得裝置1在幾乎所有實際情況下不可用於其預期 功能目的之狀態。作為實例，意欲以標稱勒克司位準照亮 一物件或景物以便促進一任務（例如，讀書）之執行的發光 裝置1在其暗淡至一位準而使得其不再促進預期之任務時 被視為在功能關閉狀態下。通常，此功能關閉狀態已良好 達到超過可用於發光裝置之暗淡範圍。約3%至1〇〇%之暗 淡範圍通常用於發光應、用中。_，以低於標稱設計料 125277.doc -10- 200833165 之ο·ι%的輸出位準界定功能關閉狀態係安全的。 應認識到，在非常低之環境照明度下，人眼調節以便利 用仍存在的少量光。在此等條件下，可證明由發光裝置1 發射之微量之光在其功能關閉狀態下變成”功能性的”。換 言之’在此等情況下，裝置1將促進使用者進行其預期任 務。然而，亦認識到，人眼區分色彩之能力在此等暗淡環 境照明度下急劇降低，因為視覺系統自明視覺改變至暗視 覺。因此，pc-LED之干擾淡黃色外觀消失且發光裝置1可 在預汉％丨兄照明度以下被完全’’關閉"（亦即，無殘餘電 流）。因為LED展現光誘發電流，所以led自身可充當一用 以量測環境照明度之感測器。 圖2為由使用特定磷光體之pc_LEE)發射之光的光譜功率 分布200的圖表。該光譜功率分布2〇〇由兩個構成部分21〇 及220組成。弟一部分21〇為由LED晶片自身發射之”一次 光”。通常，具有在範圍430至480 nm中之峰值發射波長的 InGaN半導體用於此等應用中。第二部分22〇為由磷光體在 其已由’’ 一次光’’（之部分）激勵之後發射的"二次光，，。此等 應用中之眾所周知之磷光體為鈽摻雜之釔鋁石榴石 (YAG:Ce)。此外，在此項技術中存在已知的許多磷光體， 每一種具有其關於效率及演色性之特定優勢。由人眼感知 為白色的係組合之光譜200中之兩個部分21〇及22〇的組 合。色彩之此摻合被稱為加法混色。 圖2中亦展示磷光體之吸收光譜23〇(之部分）。顯然，此 吸收光譜230自（近）UV延伸至電磁波譜之可見部分，尤其 125277.doc 11 200833165 係藍色部分。磷光體之此吸收特徵使磷光體藉由優先濾出 環境光譜之藍色部分而在白光周圍環境下呈現淡黃色。在 ί哀境照明條件下的pc-LED之此淡黃色外觀在許多應用領域 中引起干擾。 應注意’目前狀態之pc-LED確實不再應用沈積於LED晶 片上、礙入於折射率匹配矽蓋中或分散該矽蓋上，或呈此 項技術中已知之任何其他配置的構光體粉末。.實情為，以 光接收關係將包含磷光體（或色彩轉換劑）之陶瓷片配置於 D曰a片之緊雄、附近。為達成本發明之目的，術語一 led”意欲包括此等新近描述之陶瓷片。 圖3展示包括數位攝影機32〇及輔助發光裝置31〇的行動 電話300。行動電話3〇〇包括一（彩色）螢幕（其可具有使用本 文所述之pc_LED的背光）及一鍵盤，兩者均未圖示。輔助 發光裝置310用作閃光燈以促進在多雲、黑暗或夜間條件 下拍攝照片及/或視訊圖片。 為了提供待拍攝照片之景物或物件之足夠照明，現代行 動電話300在辅助發光裝置3 10中裝備有至少一高功率pc-312 此 PC*"LED 3 12 之一實例為 philips LumiLeds hxeon F/wh。此等LED可持續非常高之峰值電流以賦能 所要之閃光功能。通常峰值電流在功能開啟狀態下（亦 即，S產生閃光時）為1〇〇〇 mA持續高達3〇〇 ^^的閃光週 期。在3·6 V之典型正向電壓下，在此功能開啟狀態下， '勺3.6 W功率被供應至LED。與由習知產生之約6勒 克司相比，單一 WΛ LED可因此在1 m距離處產生 125277.doc -12- 200833165 高達79勒克司。應注意，亦可以約35〇 mA或更低之電流以 連續模式驅動此等Zwxeon F/aA LED以產生景物或物件的 低位準照度。 根據本發明，以非常小之殘餘電流供給pc_LED 312以便 控制其視覺外觀在輔助發光裝置3 10之功能關閉狀態下為 中性白色。此殘餘電流可與9 μΑ—樣小，進而僅將約21 gW供應至pc_LED 3 12。在功能關閉狀態下之此功率消耗 將幾乎不影響電池壽命。更確切地，典型行動電話蓄電池 在3·6 V下具有約400至1〇〇〇 m Ah的容量。此均等於14至 3·6 Wh。因此，當通常連續使用2〇 來控制pc_LED 312 之視覺外觀為中性白色時，行動電話蓄電池具有7〇至1 8〇 千小時（khours)的容量。此容量遠遠超過行動電話自身之 適用經濟壽命。 圖4展示適用於室内照明目的之一向下式照燈^錄卜 1 ight)知明具400。§亥照明|§具4〇〇包含一光學空腔41 〇， 在该光學空腔410中裝配了至少一 LED 420。LED 420能夠 發射相對車父短波長之"一次光’’ 4 21。此外，照明器旦4 〇 〇包 含一覆蓋光學空腔410之透明窗430，由該（等）led 420產 生之光可牙過4透明囪4 3 0而透射。此外，窗4 3 〇 (例如）經 由絲網印刷、旋塗或此項技術中已知的任何其他適當塗佈 技術而具備一色彩轉換塗層或層440。該色彩轉換層44〇部 为地吸收一次光421且將其轉換成相對較長波長之"二次光，， 441。在塗覆適當色彩轉換材料（之混合）的情況下，人眼將 自照明器具400發射之組合的一次光及二次光感知為白 125277.doc -13- 200833165 光。此材料可能為磷光體或磷光體混合物（例如， CAS)或者其可能為有機色彩轉換劑（或混合物）， 諸如香豆素或喹琳染料。此種類之照明器具400被稱為 退端麟光（remote ph〇sphorescent)„ 或”遠端螢光（rem〇te fluorescent)'^ 明器具。 如同個別pc-LED，遠端螢光照明器具4〇〇在關閉時在環 境照明條件下不具有發白之夕卜觀。實情為，取決於色彩轉 換層440中之材料的吸收特徵，感知到遠端螢光照明器具 4〇〇具有截然不同的奶白（主要淡黃）色。將照明器具4〇〇2 奶白外觀轉換成中性白色外觀給自身帶來技術問題。本發 明藉由在照明器具400中併入控制構件3來提供一解決方 案，控制構件3用於在照明器具之功能關閉狀態下將殘餘 電流提供至該至少一LED，以實現色彩轉換層44〇在功能 關閉狀態下之中性白色外觀。因此，照明器具4〇〇中所產 生的一次光42丨及二次光441之混合比來自照明器具之經反 射之環境光更亮。 使照明器具400呈現中性白色所必需的提供至led 42〇之 殘餘電流I根據以下關係將通常取決於經塗佈之窗43〇的面 積a、取決於環境照明度E，且取決於照明器具中之[ED之 數目N ·· 1 = (1) 對於高達幾百勒克司的典型室内照明度Ε，係數_於範圍 〇·〇3 mA/cm2<c<3 mA/cm2 中。 125277.doc -14- 200833165 作為實例，考慮向下式照明器400，其具有一具有6 cm 之直徑（面積A=28 cm2)的經磷光體塗佈之（例如， YAG/CAS)窗 430，包含N=20 個 1W InGaN LED 420，且具 有50 lm/W之效率。此向下式照明器400通常產生1000 lm 之通Ϊ。在c=0.3 mA/cm2時，至每一個別LED 420之殘餘 電流為1=0.42 mA。或者，有可能將殘餘電流僅提供至存 在於照明器具400中的LED 420的一部分。舉例而言，在將 殘餘電流僅提供至存在之LED 420之一半的向下式照明器 實例中，意謂著電流位準將必須關於每一 ”有效"LED而設 定為1=0.84 mA。而非均勻地分配殘餘電流為另一替代方 式。例如，在以Iaver提供1〇個LED 420、以0.5xlaver提供5 個LED且以2xlaver提供5個LED的向下式照明器實例中，其 中平均殘餘電流Iaver=0.42 mA，產生了照明器具400之類似 外觀。 另一實例為包含一具有橫向尺寸113x3 cm2(面積A=3 40 cm2)之經磷光體塗佈之窗430的照明器具400，該經磷光體 塗佈之窗430安裝於距1W LED 420(N=40)某一距離處。此 照明器具適用於代替典型TL照明器具。又，典型室内環境 照明度（c=0.3 mA/cm2)關於每一 LED需要平均殘餘電流 I=2_7mA以使照明器具400呈現發白。 在本發明之一實施例中，照明器具400包含一用以偵側 環境照明度E的光感測器450。控制構件3基於感測器信號 根據照明度E來調整該（等）LED 420的殘餘電流。此情形係 有利的，因為較高環境照明度需要較大殘餘電流以便比經 125277.doc •15· 200833165 反射之環境光更亮。此外，在較低環境照明度下，可減小 殘餘電流，進而使該照明器具400較為能量有效。實際 上，可在低於預定環境照明度的情況下將殘餘電流設定為 零，因為人眼區分色彩之能力在此等暗淡環境照明度下由 於視覺系統自明視覺改變至暗視覺而急劇降低。 可將用於每一 LED 420之殘餘電流Ϊ對環境照明度E的依 賴性進一步闡明並表達為： 其中取決於色彩轉換層之特徵，c#通常在範圍i mA/lm<c#<100 mA/lmU=1〇 mA/lm對於yag/cas填光 體混合物及50 lm/W之整體照明器具400效率為典型的。 在一實施例中，照明器具400包含一，，存在感測器，，或能 夠自一外部”存在感測器”接收一信號。，，存在感測器，，在人 存在的情況下指示照明器具400。在人不存在的情況下（亦 即，具有零存在信號’’），關閉提供至照明器具4⑼中之 LED 420之殘餘電流以節約電力。 儘管已參考上文所述實施例闡明了本發明，但顯然其他 實加例可替代地用於達成相同目標。因此，本發明之範_ 不限於上文所述實施例，而是亦可應用於包含pc_LED之發 光裝置較佳在彼裝置之功能關閉狀態下具有中性白色外觀 的任何其他應用裝置，諸如，向下式照燈、汽車頭燈及日 間行車燈、數位視訊攝影機、噴燈等。此外，本發明可應 用於知明面板中以用於氣氛營造、導航、標諸、海報背光 125277.doc -16- 200833165 面板並用於LCD面板之LED為基礎之背光模組。 【圖式簡單說明】 圖1示意性地展示所陳述之種類之發光裝置。 圖2展示由使用特定磷光體之pc_LED發射之光的光譜功 率分布的圖表及彼磷光體之吸收光譜。 圖3展示包括數位攝影機及輔助發光裝置的行動電話。 圖4展示根據本發明之照明器具。 【主要元件符號說明】 1 發光裝置 2 pc-LED 3 控制器 4 電源電路 5 電源 6 使用者可操作指令 200 光譜功率分布 210 第一部分 220 第二部分 230 吸收光譜 300 行動電話 310 辅助發光裝置 312 Pc-LED 320 數位攝影機 400 照明器具 410 光學空腔 125277.doc -17- 200833165 420 LED 421 一次光 430 透明窗 440 色彩轉換層 441 二次光 450 感測器 ί 125277.doc - 18-200833165 IX. DESCRIPTION OF THE INVENTION: TECHNICAL FIELD OF THE INVENTION The present invention generally relates to a lighting fixture comprising a light emitting diode, and more particularly to an LED comprising a color conversion layer (such as , a phosphorescent layer) transparent window lighting fixture. Moreover, the present invention is directed to a method for reproducible adjustable color control mechanisms in such lighting fixtures. Furthermore, the present invention relates to a light-emitting device comprising a phosphor coated LED. [Prior Art] Devices of the type stated are well known. It has been used for a wide variety of applications since the invention of a light-emitting diode (pc_LED) coated with a white light for about ten years ago. For example, it is used as a light source in a backlight unit of an LCD screen, as an indicator light in an electronic device, as an auxiliary illumination source in a digital video camera and a mobile phone having an imaging function. In addition, the pC_LED is used in automotive headlights and blowtorches (for ground handling, mountaineering headphones or diving purposes). In addition, due to the increased efficiency and output power of pc-led, it is expected that its permeability in general-purpose lighting devices will increase significantly. In a large number of the above-mentioned pc-LED applications, the user can directly see the LED package mounted in the light-emitting device. These devices are of the so-called direct view type, as opposed to indirect viewing types in which the LED package is blocked by a beam deck or other optical structures and components. When the pc_LED package is visible to the user when the function of the illumination device is turned off, it can be clearly identified by its specific light yellow color. This color is produced by the optical characteristics of the phosphor coated in the LED package. The same color effect occurs in a functionally closed state of a lighting fixture comprising an LED as a light source and a transparent window coated with a color conversion layer (e.g., phosphor). The specific yellowish appearance of pc-LEDs and lighting fixtures in their closed state is an interference feature in a large number of applications. As an example, a mobile phone having an imaging function and an auxiliary illumination source can be given. The mobile phone market is characterized by the rapid evolution of its phone style and type. In addition to all the functional features of these styles, many consider these styles as lifestyle accessories. Therefore, the image and appearance are basic points of sale. In this case, the design department of many telephone manufacturers repeatedly challenged the clearly visible yellowish spots of the pc_LED auxiliary light. Therefore, it is expressly required that the pc_LED can reproduce an adjustable color control mechanism in its function-off state. SUMMARY OF THE INVENTION One object of the present invention is to provide a light-emitting device of the kind stated, wherein the pc-LED package is controlled to be neutral white in the functionally closed state of the illumination device. A light-emitting device comprising a scale-coated light-emitting diode according to the light-emitting device of the present invention is claimed, characterized in that the device comprises a control member for the illumination In the off state, a residual current is supplied to the phosphor coated light-emitting diode to achieve a neutral white appearance of the light-emitting device in its functionally closed state. The present invention provides a light-emitting device that still raises a small amount of light while the device is in a functionally closed state. However, this amount of light is so small that the device under the stagnation of the force month b is not available for use in almost all practical situations. 125277.doc 200833165 Its intended purpose. Due to the residual current flowing through the pc_LED in the function-closed state of the illuminating device, the trace light generated by the pc-LED is more free than the di-resonant ring from the pc_LED, which is attributed to the optical characteristics of the scale. It turns pale yellow after smashing. Therefore, the pc_LED will appear neutral to the human eye. In an embodiment of the invention, the illuminating device comprises means for supplying a nominal current to the phosphor coated in the functionally open state; the LED component has a ratio of residual current to nominal current of less than 1 (Γ3, Or, preferably, less than 1 〇·5. In another embodiment of the present invention, the illuminating device further includes a sensor for detecting ambient illuminance, wherein the control member outputs the sensor based on the sensing The residual current in the functionally closed state of the device is set to zero below a predetermined ambient illumination. Another aspect of the invention provides a lighting fixture comprising an optical cavity comprising at least one LED And a transparent window having a color conversion layer covering the optical cavity and enabling light to be emitted from the lighting fixture, wherein the lighting fixture is characterized in that the lighting fixture comprises a control member for use in the lighting fixture A residual current is supplied to the at least one LED in a functionally closed state to achieve a neutral white appearance of the color conversion layer in the functionally closed state. In an embodiment, the illumination The invention further includes a sensor for detecting an ambient illumination, wherein the control means is provided to adjust the residual current based on the ambient illumination according to a signal from the sensor. This situation is advantageous. Because higher ambient illumination requires a larger residual current to be brighter than the reflected ambient light. In addition, at lower ambient illumination 125277.doc 200833165 degrees, the residual current can be reduced, thereby making the lighting fixture more energy efficient. In another embodiment, the control member in the lighting fixture according to the present invention sets the residual current to zero based on the signal from the sensor below a predetermined ambient illumination level. Again, this situation This and other aspects of the present invention will be apparent from the embodiments described hereinafter and will be clarified with reference to the embodiments described below. Other prior art patent application US 2005/0148364 describes an imaging function and an auxiliary. A mobile telephone device of a lighting device. This auxiliary lighting device is described as including red, green and blue LEDs. The illuminating device is designed to have substantially two levels of illumination: a low 'shooting" mode and a high 'flash' mode. In this low, illumination, mode, supply to the RGB LED The current is controlled to illuminate an object with white point illumination at a low level so that the object can be clearly identified. This situation is not particularly identifiable in the absence of low illuminance and is particularly useful in dark lighting and/or dark environments. Once the object has been confirmed and an image will be acquired, the auxiliary lighting device switches to the high, flash mode. In the 'flash' mode, the current supplied to the RGB LED is increased to emit enough light to obtain a high quality picture. Typically, in low π emission, the current supplied to the LED in the mode is 50% of the current supplied in the ,, flash, mode. Although clear from the above, US 2005/0148364 describes a lighting device comprising an LED in which the current to the LED can be controlled to reduce/increase the 125277.doc 200833165 light output of the LED, but it is clearly contemplated that the reduction/increasing facility can be The function of the illuminating device is operated in an open state. Furthermore, since US 2005/0148364 does not understand that the pc-LED can also be used in a lighting device, it does not teach the visible appearance of the control pc_LED in its functionally closed state. [Embodiment] FIG. 1 shows a light-emitting device 1 comprising a pc-LED 2, a controller 3, and a power supply circuit 4. The lighting device 1 is connected to a power source 5, which may be an AC power source or a DC power source such as a battery. A user operable command 6 - manually or via a user interface device (not shown to switch between the function on state of the light emitting device 1 and its function off state. The controller adjusts the power circuit 4 again A current is supplied to the pc_LED 2 at a level corresponding to the function on state or the function off state of the illumination device. In the art, there are many known circuit topologies suitable for this purpose. In fact, actively The control power supply circuit 4 is not essential to the present invention. Those skilled in the art will readily appreciate that alternative passive circuit topologies are contemplated. The functional shutdown state of the illumination device 1 is defined as the emitted light. The amount is so small that the device 1 is not available for its intended functional purpose in almost all practical situations. As an example, it is intended to illuminate an object or scene with a nominal lux position to facilitate a task (eg, reading). The illuminating device 1 that is executed is considered to be in a functionally closed state when it is dimmed to a level such that it no longer promotes the intended task. Generally, the off state of this function is well above the dim range that can be used for the illuminating device. The dim range of about 3% to 1% is usually used for illuminating and in use. _, below the nominal design material 125277.doc -10- 200833165 The output level of ο·ι% defines the function off state is safe. It should be recognized that under very low ambient illumination, the human eye adjusts to take advantage of the small amount of light still present. Under these conditions It can be demonstrated that the trace amount of light emitted by the illumination device 1 becomes "functional" in its functionally closed state. In other words, in this case, the device 1 will facilitate the user to perform his intended task. However, it is also recognized that The ability of the human eye to distinguish colors is drastically reduced under such dim ambient illumination, because the visual system changes from a clear vision to a dark vision. Therefore, the interference pale yellow appearance of the pc-LED disappears and the illumination device 1 can be illuminated in advance. Below the degree is completely ''closed') (ie, no residual current). Because the LED exhibits light-induced current, the LED itself acts as a sensor for measuring ambient illumination. 2 is a graph of the spectral power distribution 200 of light emitted by pc_LEE) using a particular phosphor. The spectral power distribution 2〇〇 consists of two constituent parts 21A and 220. Part of the 21st is the "primary light" emitted by the LED chip itself. In general, InGaN semiconductors having peak emission wavelengths in the range of 430 to 480 nm are used in such applications. The second portion 22 is a "secondary light emitted by the phosphor after it has been excited by the 'primary light'. A well-known phosphor in these applications is yttrium doped yttrium aluminum garnet (YAG: Ce). In addition, there are many known phosphors in the art, each with its particular advantages with respect to efficiency and color rendering. A combination of two parts, 21〇 and 22〇, in the spectrum 200 of the white combination of lines perceived by the human eye. This blending of colors is referred to as additive color mixing. The absorption spectrum of the phosphor 23 〇 (part of) is also shown in FIG. Obviously, this absorption spectrum 230 extends from (near) UV to the visible portion of the electromagnetic spectrum, especially the blue portion of 125277.doc 11 200833165. This absorption characteristic of the phosphor causes the phosphor to appear pale yellow in the ambient light environment by preferentially filtering out the blue portion of the ambient spectrum. This pale yellow appearance of pc-LEDs under ί 照明 lighting conditions causes interference in many applications. It should be noted that 'the current state of the pc-LED does not apply to the illuminating body deposited on the LED wafer, obstructing or dispersing the flip-chip cover, or any other configuration known in the art. powder. The fact is that the ceramic sheet containing the phosphor (or color conversion agent) is placed in the vicinity of the tightness of the D曰a sheet in the light receiving relationship. For the purposes of the present invention, the term "led" is intended to include such newly described ceramic sheets. Figure 3 shows a mobile phone 300 including a digital camera 32A and an auxiliary lighting device 31. The mobile phone 3 includes one (color) A screen (which may have a backlight using the pc_LED described herein) and a keyboard, both of which are not shown. The auxiliary lighting device 310 acts as a flash to facilitate taking photos and/or video pictures in cloudy, dark or nighttime conditions. In order to provide sufficient illumination of the scene or object to be photographed, the modern mobile phone 300 is equipped with at least one high power pc-312 in the auxiliary lighting device 3 10. One example of this PC*"LED 3 12 is philips LumiLeds hxeon F/ Wh. These LEDs can sustain very high peak currents to enable the desired flash function. Normally the peak current is 1 mA for up to 3 〇〇 ^^ when the function is on (ie, when S produces a flash) Flash cycle. At a typical forward voltage of 3.6 V, with this function turned on, 'spoon 3.6 W power is supplied to the LED. Compared to the conventional 6 lux generated by the conventional A WΛ LED can therefore produce 125277.doc -12- 200833165 up to 79 lux at a distance of 1 m. It should be noted that these Zwxeon F/aA LEDs can also be driven in continuous mode with a current of approximately 35 mA or less. Low level illuminance of the scene or object. According to the present invention, the pc_LED 312 is supplied with a very small residual current to control its visual appearance to be neutral white in the functionally closed state of the auxiliary illuminating device 3 10. This residual current can be 9 μΑ. It is small, and only about 21 gW is supplied to pc_LED 3 12. This power consumption in the functionally closed state will have little effect on battery life. More specifically, a typical mobile phone battery has about 400 to 1 at 3·6 V.容量m Ah capacity. This is equal to 14 to 3. 6 Wh. Therefore, when the continuous use of 2 turns to control the visual appearance of pc_LED 312 to neutral white, the mobile phone battery has 7 to 18 thousand The capacity of the hour (khours). This capacity far exceeds the applicable economic life of the mobile phone itself. Figure 4 shows one of the purposes for indoor lighting. Downlights ^ Recording 1 ight) Knowledge 400. § Hai Lighting | 4〇〇 includes an optical cavity 41 〇 in which at least one LED 420 is mounted. The LED 420 is capable of emitting a "primary light" 4 21 relative to the short wavelength of the parent. In addition, the illuminator 4 The crucible includes a transparent window 430 covering the optical cavity 410, and the light generated by the LED 420 is transmissive through the transparent baffle 4300. In addition, the window 43 is provided with a color conversion coating or layer 440, for example, by screen printing, spin coating, or any other suitable coating technique known in the art. The color conversion layer 44 absorbs the primary light 421 and converts it into a relatively long wavelength "secondary light," In the case where a suitable color conversion material (mixture) is applied, the human eye perceives the primary light and the secondary light emitted from the lighting fixture 400 as white 125277.doc -13 - 200833165 light. This material may be a phosphor or a mixture of phosphors (eg, CAS) or it may be an organic color conversion agent (or mixture) such as coumarin or quinoline dye. This type of lighting fixture 400 is referred to as a remote ph〇sphorescent „ or a “rem〇te fluorescent” fixture. As with individual pc-LEDs, the far-end fluorescent lighting fixture 4 does not have a whitish view under ambient lighting conditions when turned off. The fact is that depending on the absorption characteristics of the material in the color conversion layer 440, it is perceived that the far-end fluorescent lighting fixture has a distinct milky white (primarily yellowish) color. Converting the luminaire 4〇〇2 milky white appearance to a neutral white appearance poses technical problems for itself. The present invention provides a solution by incorporating a control member 3 in a lighting fixture 400 for providing residual current to the at least one LED in a functionally closed state of the lighting fixture to implement a color conversion layer 44 Neutral white appearance when the function is off. Therefore, the mixing of the primary light 42 丨 and the secondary light 441 generated in the luminaire 4 is brighter than the reflected ambient light from the luminaire. The residual current I provided to the led 42 必需 necessary to render the luminaire 400 in neutral white will generally depend on the area a of the coated window 43 、, depending on the ambient illuminance E, and on the lighting fixture, depending on the relationship [The number of EDs N ·· 1 = (1) For a typical indoor illumination level up to several hundred lux, the coefficient _ is in the range 〇·〇3 mA/cm2<c<3 mA/cm2. 125277.doc -14- 200833165 As an example, consider a down illuminator 400 having a phosphor coated (eg, YAG/CAS) window 430 having a diameter of 6 cm (area A = 28 cm2), Includes N = 20 1W InGaN LEDs 420 with an efficiency of 50 lm/W. This down illuminator 400 typically produces 1000 lm overnight. At c = 0.3 mA/cm2, the residual current to each individual LED 420 is 1 = 0.42 mA. Alternatively, it is possible to provide residual current only to a portion of the LED 420 present in the lighting fixture 400. For example, in a down illuminator example where residual current is only provided to one half of the LED 420 present, it is meant that the current level will have to be set to 1 = 0.84 mA for each "active" LED. Non-uniform distribution of residual current is another alternative. For example, in the case of a down illuminator that provides 1 LED 420 with Iaver, 5 LEDs with 0.5xlaver, and 5 LEDs with 2xlaver, the average residual The current Iaver = 0.42 mA produces a similar appearance to the luminaire 400. Another example is a luminaire 400 comprising a phosphor coated window 430 having a lateral dimension of 113 x 3 cm2 (area A = 3 40 cm2), the The phosphor coated window 430 is mounted at a distance from the 1W LED 420 (N=40). This lighting fixture is suitable for replacing typical TL lighting fixtures. Also, the typical indoor ambient illumination (c=0.3 mA/cm2) is about Each LED requires an average residual current of I = 2-7 mA to cause the luminaire 400 to appear whitish. In one embodiment of the invention, the luminaire 400 includes a light sensor 450 for detecting ambient illuminance E. The control member 3 based on the sensor signal according to the photo Degree E adjusts the residual current of the LED 420. This situation is advantageous because higher ambient illumination requires a larger residual current to be brighter than ambient light reflected by 125277.doc • 15· 200833165. At lower ambient illumination, the residual current can be reduced, thereby making the luminaire 400 more energy efficient. In fact, the residual current can be set to zero below a predetermined ambient illuminance because the human eye distinguishes colors. The ability to sharply decrease in the dim ambient illumination due to the visual system's self-clearing vision to dark vision. The dependence of the residual current 每一 for each LED 420 on the ambient illumination E can be further clarified and expressed as: Depending on the characteristics of the color conversion layer, c# is typically in the range i mA / lm < c # < 100 mA / lmU = 1 〇 mA / lm for yag / cas fillant mixture and 50 lm / W overall lighting 400 efficiency is typical In one embodiment, the lighting fixture 400 includes a presence sensor, or is capable of receiving a signal from an external "presence sensor"., a presence sensor, in the presence of a person The lighting fixture 400 is indicated. In the absence of a person (ie, having a zero presence signal ''), the residual current supplied to the LED 420 in the lighting fixture 4 (9) is turned off to conserve power. The embodiments exemplify the invention, but it is obvious that other embodiments may alternatively be used to achieve the same object. Therefore, the invention is not limited to the embodiments described above, but may also be applied to a light-emitting device including a pc_LED. Any other application device that has a neutral white appearance when the function of the device is off, such as a downlight, a car headlight, a daytime running light, a digital video camera, a blower, and the like. In addition, the present invention can be applied to LED backlight-based backlight modules for use in atmosphere panels for navigation, navigation, marking, poster backlighting, and for LCD panels. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 schematically shows a light-emitting device of the kind stated. Figure 2 shows a graph of the spectral power distribution of light emitted by a pc_LED using a particular phosphor and the absorption spectrum of the phosphor. Figure 3 shows a mobile phone including a digital camera and an auxiliary lighting device. Figure 4 shows a lighting fixture in accordance with the present invention. [Main component symbol description] 1 illuminating device 2 pc-LED 3 controller 4 power circuit 5 power supply 6 user operable command 200 spectral power distribution 210 first part 220 second part 230 absorption spectrum 300 mobile phone 310 auxiliary illuminating device 312 Pc -LED 320 Digital Camera 400 Lighting 410 Optical Cavity 125277.doc -17- 200833165 420 LED 421 Primary Light 430 Transparent Window 440 Color Conversion Layer 441 Secondary Light 450 Sensor ί 125277.doc - 18-