201215236 六、發明說明： 【發明所屬之技術領域】 本發明係關於驅動發光部之驅動裝置及具備其之發光裝 置。 ' 【先前技術】 * 先前，已知有具備串聯連接之複數之LED(發光二極 體），與對LED供給恆定電流之升壓型驅動電路之發光裝置 (例如參照專利文獻1及專利文獻2)。 專利文獻1中揭示一種對每個LED反向並聯連接齊納二 極體之顯示裝置。該顯示裝置中，當LED發生開路故障之 情形時，藉由使與故障之LED反向並聯連接之齊納二極體 擊穿，而形成回回避故障之LED之旁通路徑，因此可使故 障之LED外之LED發光。 專利文獻2中揭示有以短路部對應每個LEI)之方式設置 之點亮裝置。當該短路部在對應之LED發生開路故障之情 形時，使對應之LED之兩端短路。藉此，該點亮裝置中， 即使複數之LED中之一部分發生開路故障之情形時亦可使 故障之LED外之LED點亮。 • [先前技術文獻] . [專利文獻] [專利文獻1]日本特開2009-59835號公報 [專利文獻2]日本特開2009-38247號公報 【發明内容】 [發明所欲解決之問題] 157384.doc 201215236 此處’在專利文獻2所揭示之先前之點亮裝置中，當 LED產生開路故障之情形時，由於點亮之lED數量減少， 使得LED中之順向電壓降之合計降低。並且，在對[ED供 給恆定電流之升壓型驅動電路中，無法輸出低於驅動電路 之電源電壓之電壓。 因此，由於LED開路故障，會有led中之順向電壓降之 合計小於驅動電路之電源電壓之虞，並且，在led中之順 向電壓降之合計小於驅動電路之電源電壓之情形中，會有 從驅動電路對led流動過大電流之問題β 本發明係為解決上述問題而完成者，其目的係提供一種 抑制起因於發光部中之一部分故障（開路故障）而使得所有 發光部無法發光之情形，且抑制於發光部中流動過大電流 之驅動裝置及具備其之發光裝置。 [解決問題之技術手段] 本發明之驅動裝置之特徵在於：其具備驅動串聯連接之 複數之發光部之驅動電路；與前述複數之發光部中之一部 分並聯設置之旁通電路；及控制前述旁通電路之控制電 路’前述旁通電路包含開關及電壓下降部，前述控制電路 控制前述開關之開閉。 根據該構成，當旁通電路並聯設置之發光部故障之情形 時’藉由控制電路將開關設為導通狀態，而可形成旁通路 徑’因此可使串聯連接之複數之發光部中與旁通電路串聯 連接之發光部發光。即’可抑制起因於串聯連接之複數之 發光部中之一部分故障而使得所有發光部無法發光。又， 157384.doc .4. 201215236 藉由於旁通電路設置電壓下降部，且開關成導通狀態，則 在形成旁通路徑之情形中，可抑制發光部中流動過大電 流’因此可防止發光部損傷。 根據本發明之驅動裝置，較佳為前述複數之發光部區分 成複數之發光部群，前述旁通電路與前述發光部群並聯設 置，别述控制電路在前述發光部之任一者故障之情形時， 將與故障之前述發光部所屬之發光部群並聯設置之旁通電 路之開關設為導通狀態。 根據該構成，當發光部之任一者故障之情形時，可形成 回避故障之發光部之旁通路徑，因此可使故障之發光部所 屬之發光部群以外之發光部群之發光部發光，，又，根據該 構成，旁通電路之數量可與發光部群之數量相同，亦可少 於發光部之數量。因此，與每個發光部設置旁通電路之情 形相比，可削減旁通電路之成本及安裝面積。 根據本發明之驅動裝置，較佳為前述複數之發光部群包 含第1發光部群與第2發光部群’前述旁通電路包含與前述 第1發光部群並聯設置之第1旁通電路部，及與前述第2發 光部群並聯設置之第2旁通電路部，於前述第丨旁通電路部 上設置第1開關及第1電壓下降部，於前述第2旁通電路部 上設置第2開關及第2電壓下降部。 根據該構成，於第1發光部群之發光部故障之情形時， 藉由形成回避第1發光部群之旁通路徑，而可使第2發光部 群之發光部發光。又，於第2發光部群產生故障之情形 時，藉由形成回避第2發光部群之旁通路徑，而可使第1發 157384.doc 201215236 光部群之發光部發光。 根據本發明之驅動裝置，較佳為前述控制電路在將前述 以開關及前述第2開關設為關斷狀態，而使前述驅動電路 動作之情料，當對前述發Μ未流動驅動電_，將前 述第1開關設為導通狀態而判斷驅動電流是否流動，若判 斷驅動電流流動之情形時’使前述驅動電路之動作繼續。 根據該構成，將第丨開關設為導通狀態之情形中/根據 驅動電流流動可判斷第1發光部群之發光部故障。而當判 斷第1發光部群之發光部故障之情形時，可使第2發光^群 之發光部發光。 根據本發明之驅動裝置，較佳為前述控制電路在將前述 第1開關及前述第2開關設為關斷狀態，而使前述驅動電路 動作之情形時，當對前述發光部未流動驅動電流時，將前 述第2開關設為導通狀態而判斷驅動電流是否流動，若判 斷驅動電流流動之情形時，使前述驅動電路之動作繼續。 根據該構成，將第2開關設為導通狀態之情形中，由於 驅動電流流動，而可判斷第2發光部群之發光部故障。而 當判斷第2發光部群之發光部產生故障之情形時，可使第工 發光部群之發光部發光。 根據本發明之驅動裝置，較佳為具備記憶部，其記憶前 述第1發光部群之發光部是否產生故障，且記憶前述第2發 光部群之發光部是否產生故障。 根據該構成，在記憶第1發光部群之發光部之故障後， 無需判斷第1發光部群之發光部是否故障，且在記憶第2發 157384.doc • 6 · 201215236 光部群之發光部之故障後，無需判斷第2發光部群之發光 部是否故障。 根據本發明之驅動裝置，前述第1電壓下降部及前述第2 電壓下降部亦可包含恆定電壓二極體。 根據該構成’可使自驅動電路供給之電壓容易下降。 根據本發明之驅動裝置，前述第1電壓下降部及前述第2 電壓下降部亦可包含電阻器。 根據該構成’可使自驅動電路供給之電壓容易下降。 根據本發明之驅動裝置，前述第丨電壓下降部及前述第2 電壓下降部亦可包含電晶體。 根據該構成，可使自驅動電路供給之電壓容易下降。 根據本發明之驅動裝置，較佳為前述複數之發光部收納 於封裝中，前述第1開關、前述第2開關、前述第丨電壓下 降部、前述第2電壓下降部、及前述控制電路與前述封裝 個別設置。 根據該構成，可抑制收納發光部之封裝之構成的複雜 化。 根據本發明之驅動裝置’前述驅動電路較佳為升壓型開 關整流器。 根據該構成，藉由將電源電壓升壓並供給於複數之發光 部，可驅動複數之發光部。 根據本發明之驅動褒置，以前述發光部及前述旁通電路 構成之電流路徑之電壓下降較佳為供給於前述驅動電路之 電源電壓以上》 157384.doc 201215236 根據該構成，由於以發光部及旁通電路構成之電流路徑 之電壓下降不低於電源電壓，因此可防止發光部中流動過 大電流。 本發明之發光裝置較佳為具備串聯連接之複數之發光 部’與驅動前述發光部之驅動裝置，前述驅動裝置為上述 任一項之驅動裝置。 根據該構成，可獲得可抑制所有發光部無法發光，且可 抑制發光部中流動過大電流之發光裝置。 [發明之效果] 利用本發明之驅動裝置及具備其之發光裝置，可抑制起 因於發光部中之一部分故障而使得所有發光部無法發光之 情形’且可抑制發光部中流動過大電流。 【實施方式】 以下’針對本發明之實施形態參照附圖進行說明。 〈實施形態1> 參照圖1，針對實施形態i之發光裝置100之構成進行說 明。 發光裝置100具備串聯連接之8個發光部1，與驅動發光 部1之驅動裝置2。 發光部1例如係LED(發光二極體）。串聯連接之發光部1 收納於封裝3中，一端與封裝3之端子3a連接，另一端與封 裝3之端子3b連接。 8個發光部1區分成2個發光部群（第1發光部群丨a及第2發 光部群lb)，4個發光部1分別屬於第1發光部群la及第2發 157384.doc 201215236 光部群lb。第1發光部群la與第2發光部群lb間之節點N1與 封裴3之端子3 c連接。 驅動裝置2包含：驅動發光部1之驅動電路10;用以使驅 動電路10動作之電源20 ;與複數之發光部1並聯設置之旁 通電路30 ;控制旁通電路30之控制電路40 ;記憶發光部1 是否發生開路故障（以下稱作「故障」）之記憶部50。 旁通電路30包含：與第1發光部群la並聯設置之第1旁通 電路31 ;與第2發光部群lb並聯設置之第2旁通電路部32 » 第1旁通電路部31由第1開關33及電壓下降部34構成，第 2旁通電路部32由第2開關35及電壓下降部34構成。第1開 關33之一端與封裝3之端子3a連接’另一端與節點N2連 接。第2開關35之一端與封裝3之端子3b連接，另一端與節 點N2連接。 電壓下降部34設於節點N1與節點N2之間，具有第1電壓 下降部34a及第2電壓下降部34b。第1電壓下降部3牦及第2 電壓下降部34b例如係恆定電壓二極體（齊納二極體）。第j 電壓下降部（恆定電壓二極體）34a之陽極與封裝3之端子孔 連接，陰極與第2電壓下降部（恆定電壓二極體）3仆之陰極 連接。第2電壓下降部（怪^電壓二極體）3扑之陽極與節點 N2連接。即第i電塵了降部（惶$電壓二極體）W與第^ 壓下降部（恆定電壓二極體）34b為反向串聯連接。 此處’作為第i電虔下降部（但定電壓二極體）3心，選定 擊穿電Mvzl為電源20之電源„Vee、與第2發光部料 之4個發光部（LED)1之順向電壓降Vf2及第2電壓下降部浪 157384.doc 201215236 定電壓二極體）34b之順向電壓降Vfz2之合計之差以上之元 件。 另’考慮到電源20之電源電壓Vcc之變動（例如在鉛蓄電 池之標準電源電壓Vce為12V之情形中為10 V〜14 V)，及由 於元件之偏差或溫度所引起之發光部（LED)l之順向電壓降 之變動（例如3.4 V~4 V)及第2電壓下降部（恆定電壓二極 體）34b之順向電壓降vfZ2之變動（例如0·6 V〜0.7 V)之情形 時，作為第1電壓下降部（恆定電壓二極體）34a，選定擊穿 電壓Vzl為電源20之電源電壓Vcc之最大值（例如14 V)、第 2發光部群lb之4個發光部（LED)l之順向電壓降Vf2之最小 值（例如3.4 V)及第2電壓下降部（恆定電壓二極體）34b之順 向電壓降Vfz2之最小值（例如〇.6 V)之合計之差以上的元 件。即，以第1電壓下降部34a及第2電壓下降部34b、第2 發光部群1 b之4個發光部1中之電壓下降之和不低於電源2〇 之電源電壓Vcc之方式構成。 同樣的，作為第2電壓下降部（恆定電壓二極體）34b，選 定擊穿電壓Vz2為電源20之電源電壓Vcc、第1發光部群ia 之4個發光部（LED)l之順向電壓降vfl及第1電壓下降部（恆 疋電壓一極體）34a之順向電麼降vfzi之合計之差以上的元 件。 另，考慮到電源20之電源電壓Vcc之變動（例如在鉛蓄電 池之標準電源電壓Vcc為12 V之情形中為1〇 v〜14 V)，及 由於元件之偏差或溫度所引起之發光部（Led) 1之順向電壓 降之變動（例如3.4 V〜4 V)及第1電壓下降部（恆定電壓二極 157384.doc -10- 201215236 體）34a之順向電壓降Vfzl之變動（例如〇·6 V〜0.7 V)之情形 時，作為第2電壓下降部（恆定電壓二極體）34b，選定擊穿 電壓Vz2為電源20之電源電壓Vcc之最大值（例如丨4 V)、第 1發光部群1 a之4個發光部（LED)l之順向電壓降vfl之最小 值（例如3·4 V)及第1電壓下降部（恆定電壓二極體）34&之順 向電壓降Vfz 1之最小值（例如〇.6 V)之合計之差以上的元 件。即’以第1電壓下降部34a及第2電壓下降部34b、第1 發光部群la之4個發光部1中之電壓下降之和不低於電源2〇 之電源電壓Vcc之方式構成。 又，第1發光部群la之元件數與第2發光部群ib之元件數 相同，因此第1發光部群1 a之順向電壓降vfl之合計值與第 2發光部lb之順向電壓降Vf2之合計值接近，因此有時第2 電壓下降部（恆定電壓二極體）3 4b之擊穿電壓Vz2亦可與第 1電壓下降部（怪定電壓二極體）34a之擊穿電壓Vzl相同。 又’以8個發光部（LED) 1之順向電壓降之合計不低於電 源20之電源電壓Vcc之方式構成。 第1開關3 3及第2開關3 5在通常時經控制成關斷狀態。並 且’第1旁通電路部3 1藉由第I開關33經控制成導通狀態， 而形成回避第1發光部群la之旁通路徑pS-NS-SAb-SAa-Sc-Nl) ’ 第 2旁通 電路部 32藉由第 2開關 35經控制成 關斷狀 態’而形成回避第2發光部群lb之旁通路徑（N1-3 c-3 4a-34b-N2-35) 〇 控制電路40控制第1開關33及第2開關35之開閉。具體言 之，控制電路40基於記憶於記憶部50之資訊，判斷發光部 157384.doc 201215236 1未故障之情形時’將第1開關33及第2開關35設為關斷狀 態’使驅動電路1 〇動作。控制電路4〇基於記憶於記憶部5〇 之資訊’判斷第1發光部群13之發光部1產生故障之情形 時’將第1開關3 3設為導通狀態’使驅動電路〗〇動作。控 制電路40基於記憶於記憶部5〇之資訊，判斷第2發光部群 lb之發光部1故障之情形時，將第2開關35設為導通狀態， 使驅動電路10動作。 參照圖2，針對發光裝置1〇〇之驅動電路1〇之構成進行說 明。 驅動電路10係對發光部1供給恆定電流之升壓型開關整 流器。驅動電路10具有：串聯連接之電感器n、二極體 12、及電流檢測電阻15 ;設於二極體12及電流檢測電阻15 間之接地點之間之電容器13 ;設於電感器丨丨及二極體12間 之接地點之間之FET(場效型電晶體）14 ;控制檢測電流檢 測電阻15之兩端之電壓之;ρΕΤ14之開/關比率之控制器16。 該驅動電路10中，控制器16控制FET14之開/關比率，以使 電流檢測電阻15之兩端電壓成為期望值，藉此控制輸出電 壓。 但’來自驅動電路丨0之輸出電壓必定高於電源2〇之電源 電壓Vcc。例如在FET14保持導通狀態下，會經由電感器 11及FET14使電源20與接地點持續短路，使得電感器 FET14燒毁或損壞。又，在FETU保持關斷狀態不，電感 器iWlFETM雖然不會燒毁或損壞，但電源2〇之電源電壓 Vcc會經由電感器11及二極體12而施加於電容器13及複數 157384.doc -12- 201215236 之發光邛1。即，驅動電路1〇可將高於電源2〇之電源電壓 Vcc之電壓施加於封裝3之端子化與端子外之間，但無法將 低於電源20之電源電壓Vcc之電壓施加於封裝3之端子域 端子3 b之間。 . 接著，參照圖3，針對檢測實施形態1之發光裝置100之 故障時之動作進行說明。 首先，發光裝置100中，於步驟S1中，利用控制電路 40(參照圖1)將第i開關33及第2開關35(參照圖〇設為關斷 狀態，使驅動電路1〇(參照圖1}動作。 接著，於步驟S2中，利用控制電路4〇，基於電流檢測電 阻15(參照圖2)之兩端電壓，判斷是否從驅動電路1〇輸出特 疋之恆定電流。即，判斷驅動電流是否正常流動。然後， 當判斷未從驅動電路1〇輸出特定之恆定電流之情形時，移 至步驟S3。另一方面，當判斷從驅動電路1〇輸出特定之恆 疋電"IL之情形時，故障之檢測動作結束。從驅動電路1 〇輸 出特定之恆定電流之情形中，所有發光部丨中皆流動特定 之恆定電流，因此所有發光部1發光。 接著，於步驟S3中，利用控制電路40停止驅動電路10之 動作。然後，於步驟S4中，利用控制電路4〇使第2開關3 5 . 保持關斷狀態下，將第1開關3 3設為導通狀態。藉此，形 成回避第1發光部群la之旁通路徑。其後，於步驟μ中， 利用控制電路40重新開始驅動電路1〇之動作。 接著，於步驟S6中，利用控制電路4〇，基於電流檢測電 阻1 5之兩端電壓’判斷是否從驅動電路丨〇輸出特定之恆定 157384.doc •13- 201215236 電流。而當判斷未從驅動電路10輸出特定之恆定電流之情 形時，移至步驟S7。 另一方面，當判斷從驅動電路1〇輸出特定之恆定電流之 情形時，移至步驟S1卜從驅動電路1〇輸出特定Μ定電 流之情形中，由於經由旁通路徑僅於第2發光部料之發 光部1流動特定之怪定電流，因此第2發光部群此發光部 1發光。然後，利用控制電路40判斷第!發光部群以之發光 部1故障。 接著’於步驟S7中，利用控制電路4〇停止驅動電路1〇之 動作。然後，於步⑽中’利用控制電路4〇將第斶㈣ 設為關斷狀態，且將第2開關35設為導通狀態。藉此形成 回避第2發光部_之旁通路徑。其後，於步驟％中，利 用控制電路40重新開始驅動電路10之動作。 接著，於步驟川中，利用控制電路40,基於電流檢測 :阻15之兩端電壓’判斷是否從驅動電路1〇輸出特定之恆 定電流。然後’判斷從驅動電路1〇輸出特定之值定電流之 情形中’移至步驟S11。從驅動電路1〇輸出特定之值定電 流之情形中，由於經由旁通路徑而僅於第·光部群“之 發光部1流動特^之怪^電流，因此第设光部群U之發光 部1發光。然後，利用控制電路40判斷第2發光部ib之發光 部1故障》 另一方面’判斷未從驅動電路1〇輸出特定之怪定電流之 It形中，於步驟S12中，停止驅動電路1〇之動作，移至步 驟SU。未從驅動電路1G輸出特定之惶定電流之情形中， 157384.doc 201215236 利用控制電路40判斷第1發光部群la及第2發光部群113之發 光部1故障》 然後’於步驟S11中，由於第1發光部群ia或第2發光部 群lb之發光部1發光’因此驅動電路10之動作繼續。其 後，於步驟S13中’利用記憶部50記憶發光部1之故障狀 態。 具體言之，將第1開關33及第2開關35設為關斷狀態，使 驅動電路10動作之情形中’當未從驅動電路1〇輸出特定之 恆定電流時’判斷發光部1之任一者故障。然後，藉由將 第1開關33設為導通狀態’而使驅動電流正常流動之情形 時，由於第1發光部群1 a之發光部1故障，因此使該情形古己 憶於記憶部50内。又，藉由將第2開關35設為導通狀態， 而使驅動電流正常流動之情形時，由於第2發光部群丨b之 發光部1故障’因此使該情形記憶於記憶部5 〇内。又，即 使將第1開關3 3及第2開關3 5之任一者設為導通狀態，驅動 電流亦未正常流動之情形時，由於第丨發光部群1&及第2發 光部群ib之發光部丨故障，因此使該情形記憶於記憶部5〇 内。另，此時亦可利用報知機構（省略圖示）報知發光部 故障。 檢測圖3所示之發光裝置100之故障之動作在發光裝置 100之電源投入時只要進行丨次即可，無需在每次使發光部 1發光時進行。即，在發光裝置100之電源投入後斷續進行 複數次發光部1之發光之情形中，在第丨次發光之前需要 測發光裝置1〇〇之故障之動作，但在第2次以後之發光之前 157384.doc •15- 201215236 則無需檢測發光裝置1 〇〇之故障之動作。其理由在於，於 發光部1之發光時，如前述在電源投入時（進行檢測發光裝 置100之故障之動作時），基於記憶於記憶部5 0(較佳為非揮 發性記憶體）之資訊，控制第1開關33及第2開關35之開閉 之故。 如上述，驅動裝置2具備：驅動串聯連接之複數之發光 部1之驅動電路10;與複數之發光部1中之一部分並聯設置 之旁通電路30 ;及控制旁通電路30之控制電路40，旁通電 路30包含第1開關33及第2開關35、電壓下降部34，控制電 路40控制第1開關33及第2開關35之開閉。 又，驅動裝置2中，複數之發光部1區分成複數之發光部 群（第1發光部群la及第2發光部群lb)，旁通電路30與第1發 光部群la及第2發光部群lb並聯設置，控制電路40在發光 部1之任一者故障之情形中，將與故障之發光部1所屬之第 1發光部群la或第2發光部群lb並聯設置之旁通電路30之第 1開關33或第2開關35設為導通狀態。 又，驅動裝置2中，複數之發光部群包含第1發光部群la 與第2發光部群lb，旁通電路30包含與第1發光部群la並聯 設置之第1旁通電路部31、及與第2發光部群lb並聯設置之 第2旁通電路部32，第1旁通電路部31中設有第1開關33及 第1電壓下降部34a，第2旁通電路32中設有第2開關35及第 2電壓下降部34b。 又，驅動裝置2中，控制電路40將第1開關33及第2開關 35設為關斷狀態而使驅動電路10動作之情形中，當對發光 157384.doc •16· 201215236 部1未流動驅動電流時，將第1開關33設為導通狀態而判斷 驅動電流是否流動’當判斷驅動電流流動之情形時，繼續 驅動電路之動作。 又’驅動裝置2中，控制電路4〇將第1開關33及第2開關 35設為關斷狀態而使驅動電路1〇動作之情形中，當對發光 部1未流動驅動電流時’將第2開關35設為導通狀態而判斷 驅動電流是否流動’當判斷驅動電流流動之情形時，繼續 驅動電路10之動作。 又’驅動裝置2中，具備記憶部5〇，其記憶第i發光部i 群1 a之發光部1是否故障（例如開路故障），且記憶第2發光 部群lb之發光部1是否故障。 又，驅動裝置2中，第1電壓下降部34a及第2電壓下降部 34b包含恆定電壓二極體。 又，驅動裝置2中’複數之發光部1收納於封裝3内，第1 開關33、第2開關3 5、第1電壓下降部34a、第2電壓下降部 34b、及控制電路40與封裝3個別設置。 又，驅動裝置2中，驅動電路1 〇係升壓型開關整流器。 又，驅動裝置2中，發光部1及旁通電路30構成之電流路 徑下之電壓下降為供給於驅動電路10之電源電壓以上。 如上述’發光裝置1〇〇中，藉由與第1發光部群1&並聯設 置第1旁通電路31，當第1發光部群la之發光部1故障之情 形時’藉由控制電路40將第1開關33設為導通狀態，可形 成旁通路徑，因此可使第2發光部群lb之發光部1發光。 又’藉由與第2發光部群lb並聯設置第2旁通電路部32， 157384.doc -17· 201215236 當第2發光部群lb之發光部1產生故障之情形時，藉由控制 電路40將第2開關35設為導通狀態，可形成旁通路徑，因 此可使第1發光部群1 a之發光部1發光。 藉此，可抑制起因於第1發光部群1&之發光部1或第2發 光部群lb之發光部1故障而使得所有發光部1無法發光。 又，發光裝置100中，於第1旁通電路31中設置第1電壓 下降部34a ’將第1電壓下降部（恆定電壓二極體）34a之擊穿 電壓Vzl設為大於電源20之電源電壓Vcc之最大值（例如電 源電壓Vcc在10 V〜14 V間變動之情形為14 V)、與第2發光 部群lb之4個發光部（LED)l之順向電壓降Vf2之最小值（例 如在3.4 V〜4 V間變動之情形中為34 v)及第2電壓下降部 (怪定電壓二極體）34b之順向電壓降Vfz2之最小值（例如在 0.6 V〜0.7 V間變動之情形中為〇 6 V)之合計之差。利用如 此之構成’將第1開關3 3設為導通狀態而形成旁通路徑之 情形中’第1電壓下降部34a及第2電壓下降部34b、與第2 發光部群lb之4個發光部1中之電壓下降之和不低於電源2〇 之電壓Vcc ’因此可防止第2發光部群ib之發光部1中流動 過大電流。藉此，可防止第2發光部群lb之發光部1損傷。 並且’驅動電路10可將電源20之電源電壓Vcc升壓，而對 第2發光部群lb之發光部1供給特定之恆定電流。 又，於第2旁通電路32中設置第2電壓下降部34b，將第2 電壓下降部（恆定電壓二極體）34b之擊穿電壓VZ2設為大於 電源20之電源電壓Vcc之最大值（例如電源電壓Vcc在1〇 V〜14 V間變動之情形中為14 V)、與第1發光部群la之4個 157384.doc • 18 · 201215236 發光部（LED)l之順向電壓降Vfl之最小值（例如在3.4 V~4 V間變動之情形中為3 4 v)及第1電壓下降部（恆定電壓二極 體）34a之順向電壓降vfzl之最小值（例如在0.6 V〜0.7 V間變 動之情形中為0.6 V)之合計之差。利用如此之構成，將第2 開關35設為導通狀態而形成旁通路徑之情形中，第1電壓 下降部34a及第2電壓下降部34b、與第1發光部群13之4個 發光部1中之電壓下降之和不低於電源2〇之電源電壓Vcc， 因此可防止第1發光部群la之發光部1中流動過大電流。藉 此’可防止第1發光部群la之發光部損傷。並且，驅動電 路10可將電源20之電源電壓Vcc升壓，而對第1發光部群ia 之發光部1供給特定之恆定電流。 另，於第1旁通電路31中形成旁通路徑之情形中，在第1 電壓下降部34a會產生電力損失’於第2旁通電路32中形成 旁通路徑之情形中’在第2電壓下降部34b會產生電力損 失。因此，若第1電壓下降部（恆定電壓二極體）34a之擊穿 電壓Vzl大於電源20之電源電壓Vcc之最大值、第2發光部 群lb之4個發光部（LED)l之順向電壓降Vfz2之最小值及第2 電壓下降部（恆定電壓二極體）34b之順向電壓降Vfz2之最小 值之合計之差，則該擊穿電壓Vzl較佳在滿足該條件之範 圍内儘可能小。又，若第2電壓下降部（恆定電壓二極 體）34b之擊穿電壓Vz2大於電源20之電源電壓Vcc之最大 值、與第1發光部群la之4個發光部（LED)l之順向電壓降 Vfl之最小值及第1電壓下降部（恆定電壓二極體）34a之順向 電壓降Vfz 1之最小值之合計之差，則該擊穿電壓Vz2較佳 157384.doc -19· 201215236 在滿足該條件之範圍内盡可能小。 又，發光裝置100中，藉由與4個發光部i所屬之第丨發光 部群1 a(第2發光部群1 b)並聯設置第丨旁通電路部3丨（第2旁 通電路部32) ’於第1旁通電路部31(第2旁通電路部32)設置 第1電壓下降部34a(第2電壓下降部34b)，與在每個發光部 1 (LED)設置具有電壓下降部之旁通電路之情形相比可削 減零件件數。再者，可減少封裝3之端子數（引出線數），因 此可謀求封裝3之製造成本（引出線之製造成本等）之降低及 封裝3之可靠性之提高（例如封裝3之氣密性之提高）。 又，發光裝置1〇〇中，藉由以8個發光部（LED)1中之順向 電壓降之合計不低於電源20之電源電壓Vcc之方式構成， 而將第1開關33及第2開關35設為關斷狀態之情形中，可防 止發光部1中流動過大電流。並且，驅動電路1〇可將電源 2〇之電源電壓Vcc升壓，而對所有發光部1供給特定之恆定 電流》 又，發光裝置1〇〇中，由於第！電壓下降部34a及第2電壓 下降郤34b為恆定電壓二極體，而與使用電阻器作為電壓 下降部之情形不同，第1旁通電路部31及第2旁通電路部32 中電壓下降量不受電流之影響，因此可容易設計電路。 又，發光裝置100中，藉由將電壓下降部34與封裝3個別 設置，而可將電壓下降部34配置於易散熱之場所◎再者’ 可抑制封裝3之構成複雜化。 又發光裝置1 〇〇中，藉由將第1開關33及第2開關3 5、 控制電路40與封裝3個別設置，而可抑制封裝3之構成複雜 157384.doc -20· 201215236 化。 又，發光裝置100中，藉由設置記憶發光部1是否故障之 記憶部5 0，於記憶第1發光部群1 a(第2發光部群1 b)之發光 部1之故障後’可基於所記憶之資訊而控制第丨開關33(第2 開關35)之狀態。藉此，在記憶第1發光部群ia(第2發光部 群lb)之發光部1之故障後，下次起動時無需進行檢測如上 述之故障時之動作，因此可抑制起動時花費時間。 又，發光裝置100中，由於驅動電路10係升壓型開關整 流器，藉由升壓電源20之電源電壓Vcc並供給於複數之發 光部1，而可驅動複數之發光部1。 接著’參照圖4，針對實施形態1之變形例1之發光裝置 11〇之構成進行說明。 發光裝置110中’與上述發光裝置100不同，取代具有第 1電壓下降部3 4a及第2電壓下降部3 4b之電壓下降部3 4(參 照圖1)，而設置具有電阻器111之電壓下降部112(參照圖 4) » 電阻器111以將第1開關3 3設為導通狀態而形成旁通路徑 之情形中之電壓下降量大於正常時（第1開關33及第2開關 35為關斷狀態，所有發光部1發光時）之第1發光部群1&之4 個發光部1之電壓下降量之方式構成。 根據如此之構成’將第1開關33設為導通狀態而形成旁 通路徑之情形中，由於電阻器11與第2發光部群lb之4個發 光部1中之電壓下降之和，大於第1發光部群1&及第2發光 部群lb之8個發光部1中之電壓下降，因此可防止第2發光 157384.doc -21 - 201215236 部群lb之發光部1中流動過大電流。 另，電阻器111亦可在將第1開關33設為導通狀態而形成 旁通路徑之情形中，以第2發光部群lb之4個發光部1之電 壓下降量與電阻器111中之電壓下降量之合計大於電源20 之電源電壓Vcc之方式構成。 若如此構成，則在將第1開關33設為導通狀態而形成旁 通路徑之情形中，由於電阻器111、第2發光部群lb之4個 發光部1中之電壓下降之和不低於電源20之電源電壓Vcc， 因此可防止第2發光部群lb之發光部1中流動過大電流。 同樣的’電阻器111以將第2開關35設為導通狀態而形成 旁通路徑之情形中之電壓下降量大於正常時（第1開關33及 第2開關35為關斷狀態，所有發光部1發光時）之第2發光部 群lb之4個發光部1之電壓下降量之方式構成。 若如此構成，則在將第2開關35設為導通狀態而形成旁 通路徑之情形中’由於電阻器1U、第丨發光部群1&之4個 發光部1中之電壓下降之和大於第丨發光部群1&及第2發光 部群lb之8個發光部1中之電壓下降，因此可防止第1發光 部群1 a之發光部1中流動過大電流。 另’電阻器111亦可在將第2開關35設為導通狀態而形成 旁通路徑之情形中，以第丨發光部群13之4個發光部1下之 電壓下降量與電阻器1U中之電壓下降量之合計大於電源 2〇之電源電壓Vcc之方式構成。 若如此構成’則在將第2開關35設為導通狀態而形成旁 通路徑之情形中，由於電阻器m、第丨發光部群1&之4個 157384.doc •22· 201215236 發光部1中之電壓下降之和不低於電源2〇之電源電壓Vcc， 因此可防止第1發光部群1&之發光部丨中流動過大電流。 另，發光裝置110之其他構成與上述發光裝置1〇〇相同。 • 發光裝置100中，由於電壓下降部112具有電阻器U1， 藉此與使用恆定電壓二極體作為電壓下降部之情形相比， 可謀求作為電壓下降部之可靠性之提高’且可降低製造成 本。 另，發光裝置110之其他效果與上述發光裝置1〇〇相同。 接著，參照圖5，針對實施形態丨之變形例2之發光裝置 120之構成進行說明。 發光裝置120中，與上述發光裝置1〇〇(參照圖”不同， 第1旁通電路部31之電壓下降部121設於第丨開關33與封裝3 之端子3a間，第2旁通電路部32之第2電壓下降部122設於 第2開關3 5與封裝3之端子3 b之間。 第1電壓下降部121具有恆定電壓二極體123。該恆定電 壓二極體123之陽極與第丨開關33連接，陰極與封裝3之端 子3a連接。作為恆定電壓二極體123，選定擊穿電壓Vzl為 大於電源2G之電源電壓Vee之最大值（例如電源電|〜在 V 14 V間變動之情形中為14 v)、與第2發光部群化之々 個發光部（LED)l之順向電壓降Vf2之最小值（例如在3.4 V〜4 V間變動之情形中為3 4 v)之合計之差的元件。 第2電壓下降部122具有怪定電壓二極體124。該惶定電 麗-極體124之陽極與封裝3之端子儿連接，陰極與第：開 關35連接。作為怪定電壓二極體⑶，選定擊穿電壓Vz2為 157384.doc •23· 201215236 大於電源20之電源電壓Vcc之最大值（例如電源電壓vcci〇 V〜14 V間變動之情形中為14 V)、與第1發光部群1&之4個 發光部（LED)l之順向電壓降Vfi之最小值（例如在3 4 v〜4 V間變動之情形中為3.4 V)之合計之差的元件。 另’發光裝置120之其他構成與上述發光裝置ι〇〇相同。 發光裝置120中，藉由將具有恆定電壓二極體123之第i 電壓下降部121配置於第1開關33與封裝3之端子3a之間， 將具有恆定電壓二極體124之第2電壓下降部122配置於第2 開關35與封裝3之端子3b之間，藉此即使第1開關33及第2 開關35同時成為導通狀態之情形時，在自驅動電路之輸 出電壓超過恆定電壓二極體123及恆定電壓二極體124之擊 .穿電壓之前不會短路。並且，由於在自驅動電路1〇之輸出 電壓超過擊穿電壓之前，會轉變成由驅動電路1〇對複數之 發光部1進行之恆定電流控制，因此可抑制對驅動電路 1 〇、第1開關33及第2開關35、電源20施加過大負荷。 另’發光裝置120之其他效果與上述發光裝置1〇〇相同。 接著’參照圖6，針對實施形態1之變形例3之發光裝置 130之構成進行說明。 發光裝置130中，與上述發光裝置120不同，取代具有恆 定電壓二極體123之第1電壓下降部121及具有恆定電壓二 極體124之第2電壓下降部122(參照圖5)，而設置具有電阻 器131之第1電壓下降部！ 32及具有電阻器133之第2電壓下 降部134。即，第1電壓下降部132及第2電壓下降部134分 別包含電阻器131及133。 157384.doc -24- 201215236 電阻器13 1以將第1開關3 3設為導通狀態而形成旁通路徑 之情形中之電壓下降量大於正常時（第i開關33及第2開關 35為關斷狀態，所有發光部！發光時）之第工發光部群1&之4 個發光部1之電壓下降量之方式構成。 另，電阻器131亦可在將第1開關33設為導通狀態而形成 旁通路徑之情形中，以第2發光部群11?之4個發光部（LED)1 之電壓下降量與電阻器131中之電壓下降量之合計大於電 源20之電源電壓Vcc之方式構成。 若如此構成，則在將第1開關33設為導通狀態而形成旁 通路徑之情形中，由於電阻器131 '第2發光部群113之4個 發光部1中之電壓下降之和不低於電源2〇之電源電壓vcc， 因此可防止第2發光部群1 b之發光部中流動過大電流。 電阻器13 3以將第2開關3 5設為導通狀態而形成旁通路徑 之情形中之電壓下降量大於正常時（第1開關33及第2開關 35為關斷狀態’所有發光部1發光時）之第2發光部群11?之4 個發光部1下之電壓下降量之方式構成。 另，電阻器133亦可在將第2開關35設為導通狀態而形成 旁通路徑之情形中’以第1發光部群13之4個發光部（LED) 1 之電壓下降量與電阻器133中之電壓下降量之合計大於電 源20之電源電壓Vcc之方式構成。 若如此構成’則在將第2開關35設為導通狀態而形成旁 通路徑之情形中’由於電阻器133、第1發光部群^之4個 發光部1中之電壓下降之和不低於電源2〇之電源電壓Vcc， 因此可防止第1發光部群1 a之發光部丨中流動過大電流β 157384.doc -25· 201215236 另’發光裝置130之其他構成與上述發光裝置12〇相同。 發光裝置130中’由於第1電壓下降部132具有電阻器 131，第2電壓下降部134具有電阻器133，藉此與使用恆定 電壓一極體作為電壓下降部之情形相比，可謀求作為電壓 下降部之可靠性之提高，且可降低製造成本。 另’發光裝置130之其他效果與上述發光裝置12〇相同。 接著，參照圖7〜圖1 〇 ’針對實施形態！之變形例4〜7之發 光裝置140、150、160、及170之構成進行說明。 發光裝置140(參照圖7)、15〇(參照圖8)、160(參照圖9)、 及1 70(參照圖1 〇)中’ 4個發光部1為串聯連接。另，發光裝 置140、150、160、及170之其他構成分別與發光裝置 100、110、120、及130相同。即，串聯連接之發光部i之 數量只要為複數則可為任意個。 接著’參照圖11 ’針對實施形態1之變形例8之發光裝置 180之構成進行說明。 發光裝置180中’於第1旁通電路部31上並聯連接2個發 光部1 ’於第2旁通電路部32上並聯連接有3個發光部1。 因此，作為恆定電壓二極體123，選定擊穿電壓Vzl為大 於電源20之電源電壓Vcc之最大值（例如電源電壓vcc在10 V〜14 V間變動之情形中為14 V)、與第2發光部群lb之3個 發光部（LED)l之順向電壓降Vf2之最小值（例如在3.4 V~4 V間變動之情形中為3.4 V)之合計之差的元件。作為恆定 電壓二極體124,選定擊穿電壓Vz2為大於電源2〇之電源電 壓Vcc之最大值（例如電源電壓Vcc在1〇 V〜14 V間變動之情 157384.doc -26- 201215236 形中為14 V)、與第1發光部群la之2個發光部1之順向電壓 降Vfl之最小值（例如在3.4 V〜4 V間變動之情形中為3.4 V) 之合計之差的元件。即，第1發光部群la之發光部1之數量 亦可與第2發光部群lb之發光部1之數量不同。 接著，參照圖12 ’針對實施形態1之變形例9之發光裝置 190之構成進行說明。 發光裝置190中，於第1旁通電路部31上並聯連接有2個 發光部1，於第2旁通電路部32上並聯連接有3個發光部1。 因此，電阻器13 1在將第1開關33設為導通狀態而形成旁 通路徑之情形中，以第2發光部群lb之3個發光部（LED)l之 電壓下降量與電阻器131中之電壓下降量之合計大於電源 20之電源電壓Vcc之方式構成。電阻器133在將第2開關35 設為導通狀態而形成旁通路徑之情形中，以第1發光部i a 之2個發光部（LED) 1之電壓下降量與電阻器133中之電壓下 降量之合計大於電源20之電源電壓Vcc之方式構成。 又’根據實施形態1，顯示於第1旁通電路部31及第2旁 通電路部3 2上設置恆定電壓二極體或電阻器之例，但不限 於此’亦可於第1旁通電阻部3 i上設置恆定電壓二極體， 於第2旁通電路部32上設置電阻器。 <實施形態2> 首先’參照圖13 ’針對實施形態2之發光裝置200之構成 進行說明。 發光裝置200中，與上述發光裝置100不同，係將8個發 光部1區分成4個發光部群20la〜發光部群20Id，2個發光部 157384.doc •27· 201215236 1分別屬於發光部群201a〜發光部群201d。即，由2個發光 部1分別構成發光部群201a〜發光部群201d。 旁通電路202包含：與發光部群201a並聯設置之旁通電 路部202a ;與發光部群20 lb並聯設置之旁通電路部202b ; 與發光部群201c並聯設置之旁通電路部202c ;與發光部群 201(!並聯設置之旁通電路部202(1。 旁通電路部202a〜旁通電路部202d分別具有開關203a〜開 關203d、電壓下降部204a〜電壓下降部204d。電壓下降部 204a〜電壓下降部204d分別具有恆定電壓二極體205a〜恆定 電壓二極體205d。 另’開關203a〜開關203d中之任一者對應於本發明之 「第1開關」’開關203a〜開關203d中除作為第1開關者外之 任一者對應於本發明之「第2開關」。又，電壓下降部 204a〜電壓下降部204d中之任一者對應於本發明之「第1電 壓下降部」，電壓下降部204a〜電壓下降部204d中除作為第 1電壓下降部者外之任一者對應於本發明之「第2電壓下降 部」。 作為恒定電壓二極體205 a〜怪定電壓二極體205d，分別 選定擊穿電壓為與包含故障之發光部1之發光部群 (20 la〜20 Id)並聯設置之恆定電壓二極體（2〇5a〜205d)之擊 穿電壓、與發光之發光部1之順向電壓降之合計大於電源 20之電源電壓Vcc之元件。 控制電路40控制開關203a〜開關203d之開閉。 另，發光裝置200之其他構成與上述發光裝置100相同。 157384.doc -28 - 201215236 接著，參照圖14及圖15，針對檢測實施形態2之發光裝 置200之故障時之動作進行說明。 首先，發光裝置200中，於圖14之步驟⑵卜利用控制 電路40(參照圖13)將開關2〇3a〜開關⑽參照圖⑼設為關 斷狀態，使驅動電路〗〇(參照圖13)動作。 接著’於步驟S22中，利用控制電路，基於電流檢測電 參照圖2)之兩端電屢，判斷是否從驅動電㈣輸出特 定之值定電流。即，判斷驅動電流是否正常流動。然後， 當判斷未從驅動電路10輸出特定之值定電流之情形時，移 至步驟S23。另-方面，當判斷從驅動電路ι〇輸出特定之 f疋電/机之凊形時，故障之檢測動作結束。從驅動電路1 〇 輸出特定之恆定電流之情形中，所有發光部丨中皆流動特 疋之恆定電流，因此所有發光部1發光。 接著，於步驟S23中，利用控制電路4〇停止驅動電路1〇 之動作。然後，於步驟S24中，利用控制電路4〇將開關 2〇3a〜開關203d依次僅1個設為導通狀態。例如開關2〇3&為 導通狀態之情形中，形成回避發光部群20la之旁通路徑， 開關203b為導通狀態之情形中，形成回避發光部群Μα之 旁通路徑。開關203c為導通狀態之情形中，形成回避發光 部群201c之旁通路徑，開關2〇3d為導通狀態之情形中，形 成回避發光部群201d之旁通路徑。然後，將開關2〇3&〜開 關203d之任一者僅設1個為導通狀態後，於步驟S25中，利 用控制電路40重新開始驅動電路1〇之動作。 接著’於步驟S26中，利用控制電路40，基於電流檢測 157384.doc •29· 201215236 電阻15之兩端電壓，判斷是否從驅動電路1〇輸出特定之恆 定電流。然後’當判斷未從驅動電路1〇輸出特定之恆定電 流之情形時，移至步驟S27e另一方面，當判斷從驅動電 路10輸出特定之恆定電流之情形時，移至步驟S38(參照圖 15) » 接著，於步驟S27中，利用控制電路40判斷是否已試過 所有開關203a〜開關203d。即，在僅將開關203&設為導通 狀態之狀態、僅將開關203b設為導通狀態之狀態、僅將開 關203c設為導通狀態之狀態、僅將開關2〇3d設為導通狀態 之狀態下’判斷是否已判斷特定之恆定電流是否流動。然 後’ ‘判斷開關203a~開關203d已一個個依次全部設為導 通之狀態之情形時，移至步驟S28。另一方面，當判斷開 關203a〜開關203d未一個個依次全部設為導通之狀態之情 形中，返回至步驟S23。 接著’於步驟S28中，利用控制電路40停止驅動電路1〇 之動作。然後，於步驟S29中’利用控制電路40將開關 203a〜開關203d中之2個設為導通狀態。例如開關2〇3a及開 關203b為導通狀態之情形中，形成回避發光部群201a及發 光部群201b之旁通路徑；開關203a及開關203c為導通狀態 之情形中’形成回避發光部群201a及發光部群201c之旁通 路徑；開關203 a及開關203d為導通狀態之情形中，形成回 避發光部群20la及發光部群20Id之旁通路徑。開關203b及 開關203c為導通狀態之情形中，形成回避發光部群20lb及 發光部群201c之旁通路徑；開關203b及開關203d為導通狀 157384.doc •30· 201215236 態之情形中，形成回避發光部群201b及發光部群201d之旁 通路徑；開關203c及開關203d為導通狀態之情形中，形成 回避發光部群201c及發光部群201d之旁通路徑。然後，開 關203a〜開關203d中任2個被設為導通狀態後，於步驟S30 中’利用控制電路40重新開始驅動電路1 〇之動作。 接著’於步驟S3 1中，利用控制電路40，基於電流檢測 電阻15之兩端電壓，判斷是否從驅動電路1〇輸出特定之恆 定電流。然後，當判斷未從驅動電路1〇輸出特定之恆定電 /”l之情形時，移至步驟s 3 2。另一方面，當判斷從驅動電 路1〇輸出特定之恆定電流之情形中，移至步驟S38(參照圖 15)。 接著’於步驟S32中，利用控制電路40判斷是否已試過 所有組合。即’在將開關203a及開關2〇3|3設為導通狀態之 狀態、將開關203a及開關203c設為導通狀態之狀態、將開 關203a及開關203d設為導通狀態之狀態、將開關2〇3b及開 關203c設為導通狀態之狀態、將開關2〇3b及開關2〇3d設為 導通狀態之狀態、將開關203c及開關2〇%設為導通狀態之 狀態下，判斷特定之恆定電流是否流動。然後，判斷已試 過所有組合之情形時’移至步驟S33(參照圖15)。另一方 面，判斷未試過所有組合之情形時，返回至步驟S28。 接著，於步驟S33中，利用控制電路4〇停止驅動電路1〇 之動作《然後，於步驟S34中，利用控制電路將開關 2〇3a〜開關2〇3d中之3個設為導通狀態。例如，開關2〇3a〜 開關2〇3c為導通狀態之情形中，形成回避發光部群201a〜 157384.doc •31 · 201215236 發光部群201c之旁通路徑；開關2〇3a、開關203b及開關 203 d為導通狀態之情形中，形成回避發光部群2〇ia、發光 部群201b、發光部群201d之旁通路徑。開關203a、開關 203c及開關203d為導通狀態之情形中，形成回避發光部群 201a、發光部群201c、發光部群2〇ld之旁通路徑；開關 203b〜開關203d為導通狀態之情形中，形成回避發光部群 201b〜發光部群201 d之旁通路徑 '然後，當開關2〇3a〜開關 203d中之任意3個被設為導通狀態後，於步驟S35中利用控 制電路40重新開始驅動電路1〇之動作。 接著’於步驟S36中’利用控制電路4〇，基於電流檢測 電阻15之兩端電壓’判斷是否從驅動電路1〇輸出特定之怪 定電流。然後’當判斷未從驅動電路丨〇輸出特定之恆定電 流之情形時，移至步驟S 3 7。另一方面’當判斷從驅動電 路1 〇輸出特定之恆定電流之情形時，移至步驟S38。 接著，於步驟S37中，利用控制電路40判斷是否已試過 所有組合。即’在將開關203a〜開關2〇3c設為導通狀態之 狀態、將開關203a、開關203b、開關203d設為導通狀態之 狀態、將開關203a、開關203c、及開關203d設為導通狀態 之狀態、及將開關203b〜開關203d設為導通狀態之狀態 下’判斷特定之恆定電流是否流動。然後，判斷已試過所 有組合之情形時，於步驟S39中，停止驅動電路1〇之動 作，移至步驟S40 ^另一方面，判斷未嘗試所有組合之情 形中，返回至步驟S33。 然後’於步驟S38中，由於任一 LED群（201a〜2〇ld)之發 157384.doc •32· 201215236 光部1發光’因此繼續驅動電路10之動作。其後，於步驟 S40中，利用記憶部5〇記憶發光部i之開路之故障狀態。 發光裝置200中，如上述，2個發光部1分別附屬於發光 部群201a~S光部群20 Id，藉此與4個LED附屬於LED群之 情形相比，可減少起因於1個發光部i之故障而無法發光之 發光部1之數量。 另’發光裝置200之其他效果與上述發光裝置100相同。 實施形態2中，雖例示電壓下降部2〇4a~電壓下降部204d 分別具有怪定電壓二極體205a〜悝定電壓二極體2〇5d之 例’但不限於此，例如如圖16所示之實施形態1之變形例 之發光裝置210，電壓下降部211a〜電壓下降部21 Id亦可分 別具有電阻器212a〜電阻器212d。另，電壓下降部211 a〜電 壓下降部211d中之任一者對應於本發明之「第1電壓下降 部」’電壓下降部211 a~電壓下降部211d中除作為第1電壓 下降部者外之任一者對應於本發明之「第2電壓下降部」。 實施形態2中，乃顯示於故障檢測時將開關2〇3a〜開關 203d設為一個個依次導通之狀態後’將開關2〇3a〜開關 203d中之2個設為導通狀態，其後將開關2〇3a〜開關203d中 之3個設為導通狀態之例’但不限於此，亦可在故障檢測 時’藉由將開關203a〜開關203d中之3個設為導通狀態，而 判斷與導通狀態之開關（203a〜203d)並聯設置之發光部群 (201 a〜201d)之發光部是否產生故障，且在對各發光部群 201a〜發光部群201d進行該判斷後，將與故障之發光部1所 屬之發光部群（201a〜201d)並聯設置之開關（2〇3a〜2〇3d)設 157384.doc •33- 201215236 為導通狀態。 實施形態1中，乃顯示將複數之發光部1區分成2個發光 部群（第1發光部群la及第2發光部群lb)之例，而在實施形 態2中，乃顯示將複數之發光部1區分成4個發光部群（發光 部群201a〜發光部群2〇ld)之例，但不限於此，區分複數之 發光部1之發光部群之數量可為任意。 實施形態1及實施形態2中，開關（33、35、203a〜203d)可 為中繼式開關，亦可為如圖1 7所示之開關電路5〇〇。該開 關電路500包含n通道型m〇S-FET501、p通道型MOS-FET502、電阻器503及電阻器504。該開關電阻500中，利 用控制電路40(參照圖1)控制經由電阻器5〇3施加於M〇s_ FET501之閘極之電壓。由mM〇s_FET5〇1根據閘極電壓切 換開/關狀態，使得流動於電阻器5〇4之電流產生變動，因 此MOS-FET502之閘極電壓有所變化。藉此，切換M〇s_ FET502之開/關狀態。若M〇S_FET5〇2成為導通狀態，則從 端子505a側向端子5〇5b側流動電流。因kM〇s_FET5〇2作 為開關發揮功能。 專利文獻2所記載之旁通路徑係使用如保險絲般之零件 且利用機械性動作（彈簧之動作等）者，因此需要導入特殊 之機構，認為不易實現。與此相對，若使用開關電路5〇〇 等之電氣動作之開關（33、35、203a〜203d)構成旁通路徑， 則無需導入特殊之機構而容易實現。 實施形態1及2中’雖例示使用恆定電壓二極體（123、 124 205a〜205d)或電阻器⑴i、13ι、133、212&〜212句作 157384.doc •34· 201215236 為電壓下降部（34 、 112 、 121 、 122 、 132 、 134 、 204a〜204d、21 la〜21 Id)之例，但不限於此，作為電壓下 降部，亦可使用如圖18所示之電壓下降電路6〇(^該電壓 下降電路600包含恆定電壓二極體6〇1、pnp型電晶體6〇2、 二極體603、電阻器604。電壓下降電路6〇〇中，當電晶體 602之集極-射極間之電壓變高，若連接於電晶體6〇2之基 極-集極間之恆定電壓二極體601擊穿時，則電晶體6〇2之 基極電流流動。藉此，電晶體602之集極·射極間之電壓大 致維持在恆定電壓二極體601之擊穿電壓Vz。二極體6〇3係 用以確保從電晶體602之集極側向發射級側之電流路徑而 設。如此，第1電壓下降部（112、121、132)及第2電壓下降 部（112、122、134)包含電晶體602。 又’作為電壓下降部’亦可使用如圖19所示之電壓下降 電路700。該電壓下降電路7〇〇包含恆定電壓二極體7〇1、 npn型電晶體702、二極體703、電阻器704。另，電壓下降 電路700中，取代pnp型電晶體6〇2(參照圖18)，而設有npn 型電晶體702。 【圖式簡單說明】 圖1係顯示本發明之實施形態丨之發光裝置之構成之電路 圖。 圖2係顯示圖1所示之發光裝置之驅動電路之構成之電路 圖0 圖3係用以說明檢測圖1所示之發光裝置之故障時之動作 之流程圖。 157384.doc •35- 201215236 圖4係顯示本發明之實施形態1之變形例1之發光裝置之 構成之電路圖。 圖5係顯示本發明之實施形態1之變形例2之發光裝置之 構成之電路圖。 圖6係顯示本發明之實施形態1之變形例3之發光裝置之 構成之電路圖。 圖7係顯示本發明之實施形態1之變形例4之發光裝置之 構成之電路圖。 圖8係顯示本發明之實施形態1之變形例5之發光裝置之 構成之電路圖》 圖9係顯示本發明之實施形態1之變形例6之發光裝置之 構成之電路圖。 圖10係顯示本發明之實施形態1之變形例7之發光裝置之 構成之電路圖。 圖11係顯示本發明之實施形態1之變形例8之發光裝置之 構成之電路圖。 圖12係顯示本發明之實施形態1之變形例9之發光裝置之 構成之電路圖。 圖13係顯示本發明之實施形態2之發光裝置之構成之電 路圖。 圖14係用以說明檢測圖13所示之發光裝置之故障時之動 作之流程圖。 圖15係用以說明檢測圖13所示之發光裝置之故障時之動 作之流程圖。 157384.doc -36- 201215236 圖16係顯示本發明之實施形態2之變形例之發光裝置之 構成之電路圖》 圖1 7係顯示開關電路之構成之電路圖。 圖18係顯示電壓下降電路之構成之電路圖。 圖19係顯示電壓下降電路之構成之電路圖。 【主要元件符號說明】 1 發光部 la 第1發光部群（發光部群） lb 第2發光部群（發光部群） 2 驅動裝置 3 封裝 10 驅動電路 30 旁通電路 31 第1旁通電路部（旁通電路 部） 32 第2旁通電路部（旁通電路 部） 33 第1開關（開關） 34 電壓下降部 34a 第1電壓下降部（恆定電壓 二極體） 34b 第2電壓下降部（恆定電壓 二極體） 35 第2開關（開關） 157384.doc •37· 201215236 40 控制電路 50 記憶部 100 、 110 、 120 、 130 、 140 、 150、160、170、180、190、 200 ' 210 發光裝置 111 電阻器 112 電壓下降部（第1電壓下降 部、第2電壓下降部） 121 第1電壓下降部（電壓下降 部） 122 第2電壓下降部（電壓下降 部） 123 、 124 恆定電壓二極體 131 、 133 電阻器 132 第1電壓下降部（電壓下降 部） 134 第2電壓下降部（電壓下降 部） 201a〜201d 發光部群 202 旁通電路 202a〜202d 旁通電路部 203a〜203d 開關（第1開關、第2開關） 204a〜204d 電壓下降部（第丨電壓下降 部、第2電壓下降部） 157384.doc • 38 · 201215236 205a~205d 恆定電壓二極體 211a~211d 電壓下降部（第1電壓下降 部、第2電壓下降部） 212a~212d 電阻器 500 開關電路（開關） 600 電壓下降電路（電壓下降 部） 602 電晶體 700 電壓下降電路（電壓下降 部） 702 電晶體 157384.doc -39-201215236 SUMMARY OF THE INVENTION [Technical Field] The present invention relates to a driving device for driving a light-emitting portion and a light-emitting device provided therewith. [Prior Art] In the prior art, a light-emitting device including a plurality of LEDs (light-emitting diodes) connected in series and a boost-type drive circuit that supplies a constant current to the LED is known (for example, refer to Patent Document 1 and Patent Document 2) ). Patent Document 1 discloses a display device in which a Zener diode is connected in reverse parallel to each LED. In the display device, when the LED has an open circuit failure, the Zener diode connected in reverse parallel connection with the faulty LED is broken down to form a bypass path for the LED to avoid the fault, thereby making the fault The LED outside the LED emits light. Patent Document 2 discloses a lighting device provided such that a short-circuit portion corresponds to each LEI). When the short-circuit portion is in an open circuit failure of the corresponding LED, the two ends of the corresponding LED are short-circuited. Thereby, in the lighting device, even if one of the plurality of LEDs has an open circuit failure, the LED outside the LED of the failure can be lit. • [Previous Technical Literature]. [Patent Document 1] JP-A-2009-59835 [Patent Document 2] JP-A-2009-38247 SUMMARY OF THE INVENTION [Problems to be Solved by the Invention] 157384. Doc 201215236 Here, in the prior lighting device disclosed in Patent Document 2, when the LED generates an open circuit failure, the total amount of forward voltage drops in the LED is lowered due to a decrease in the number of lit LEDs. Further, in the boost type drive circuit for supplying a constant current to the ED, it is impossible to output a voltage lower than the power supply voltage of the drive circuit. Therefore, due to the LED open circuit failure, the sum of the forward voltage drops in the LED is less than the power supply voltage of the driving circuit, and in the case where the sum of the forward voltage drops in the LED is smaller than the power supply voltage of the driving circuit, There is a problem that excessive current flows from the driving circuit to the LED. The present invention has been made to solve the above problems, and an object thereof is to provide a situation in which all of the light-emitting portions cannot be illuminated by suppressing a part of the failure (open circuit failure) caused by the light-emitting portion. And a driving device that suppresses excessive current flowing in the light-emitting portion and a light-emitting device including the same. [Technical means for solving the problem] The driving device of the present invention is characterized in that it comprises a driving circuit for driving a plurality of light-emitting portions connected in series; a bypass circuit provided in parallel with one of the plurality of light-emitting portions; and controlling the side The control circuit of the pass circuit 'the bypass circuit includes a switch and a voltage drop unit, and the control circuit controls opening and closing of the switch. According to this configuration, when the light-emitting portion provided in parallel with the bypass circuit fails, "the bypass path can be formed by the control circuit turning the switch into an on state", so that the plurality of light-emitting portions connected in series can be bypassed. The light-emitting portions in which the circuits are connected in series emit light. That is, it is possible to suppress failure of one of the plurality of light-emitting portions caused by the series connection so that all of the light-emitting portions cannot emit light. Again, 157384. Doc . 4. In the case where the bypass circuit is provided with the voltage drop portion and the switch is turned on, in the case where the bypass path is formed, excessive current flow in the light-emitting portion can be suppressed, so that the light-emitting portion can be prevented from being damaged. According to the driving device of the present invention, it is preferable that the plurality of light-emitting portions are divided into a plurality of light-emitting portion groups, and the bypass circuit is provided in parallel with the light-emitting portion group, and the control circuit is in a failure state of any of the light-emitting portions. At this time, the switch of the bypass circuit provided in parallel with the light-emitting portion group to which the light-emitting portion of the failure is located is placed in an on state. According to this configuration, when any one of the light-emitting portions fails, the bypass path of the light-emitting portion that avoids the failure can be formed. Therefore, the light-emitting portion of the light-emitting portion group other than the light-emitting portion group to which the defective light-emitting portion belongs can be caused to emit light. Further, according to this configuration, the number of bypass circuits may be the same as the number of the light-emitting portion groups, or may be smaller than the number of the light-emitting portions. Therefore, the cost and the mounting area of the bypass circuit can be reduced as compared with the case where the bypass circuit is provided for each of the light-emitting portions. According to the driving device of the present invention, it is preferable that the plurality of light-emitting unit groups include the first light-emitting unit group and the second light-emitting unit group. The bypass circuit includes a first bypass circuit unit that is provided in parallel with the first light-emitting unit group. And a second bypass circuit unit provided in parallel with the second light-emitting unit group, wherein the first switch and the first voltage drop unit are provided in the second bypass circuit unit, and the second bypass circuit unit is provided on the second bypass circuit unit. 2 switch and second voltage drop unit. According to this configuration, when the light-emitting portion of the first light-emitting portion group is in a state of failure, the light-emitting portion of the second light-emitting portion group can be caused to emit light by forming a bypass path for avoiding the first light-emitting portion group. Further, when the second light-emitting unit group is in a state of failure, the first transmission 157384 can be formed by forming a bypass path for avoiding the second light-emitting unit group. Doc 201215236 The light department of the light department group shines. According to the driving device of the present invention, it is preferable that the control circuit operates the driving circuit by setting the switch and the second switch to an off state, and when the driving circuit is not flowing, When the first switch is turned on, it is determined whether or not the drive current flows, and when it is determined that the drive current flows, the operation of the drive circuit is continued. According to this configuration, in the case where the second switch is turned on, it is possible to determine that the light-emitting portion of the first light-emitting portion group is malfunctioning based on the flow of the drive current. On the other hand, when it is determined that the light-emitting portion of the first light-emitting portion group is defective, the light-emitting portion of the second light-emitting group can be caused to emit light. According to the driving device of the present invention, it is preferable that the control circuit operates the driving circuit when the first switch and the second switch are turned off, and when the driving current is not applied to the light emitting portion. When the second switch is turned on, it is determined whether or not the drive current flows. When it is determined that the drive current flows, the operation of the drive circuit is continued. According to this configuration, in the case where the second switch is turned on, it is possible to determine that the light-emitting portion of the second light-emitting portion group has failed due to the flow of the drive current. On the other hand, when it is determined that the light-emitting portion of the second light-emitting portion group is defective, the light-emitting portion of the light-emitting portion of the first light-emitting portion can be made to emit light. According to the driving device of the present invention, it is preferable that the memory unit includes a memory unit that stores a failure of the light-emitting unit of the first light-emitting unit group and that the light-emitting unit of the second light-emitting unit group is in trouble. According to this configuration, after the failure of the light-emitting portion of the first light-emitting portion group is memorized, it is not necessary to determine whether or not the light-emitting portion of the first light-emitting portion group is defective, and the second transmission is 157384. Doc • 6 · 201215236 After the failure of the light-emitting unit of the light group, it is not necessary to determine whether the light-emitting unit of the second light-emitting unit group is defective. According to the driving device of the present invention, the first voltage drop portion and the second voltage drop portion may include a constant voltage diode. According to this configuration, the voltage supplied from the drive circuit can be easily lowered. According to the driving device of the present invention, the first voltage drop portion and the second voltage drop portion may include a resistor. According to this configuration, the voltage supplied from the drive circuit can be easily lowered. According to the driving device of the present invention, the second voltage drop portion and the second voltage drop portion may include a transistor. According to this configuration, the voltage supplied from the drive circuit can be easily lowered. According to the driving device of the present invention, preferably, the plurality of light emitting units are housed in the package, and the first switch, the second switch, the second voltage drop unit, the second voltage drop unit, and the control circuit are Package individual settings. According to this configuration, the complexity of the configuration of the package accommodating the light-emitting portion can be suppressed. The driving circuit according to the present invention is preferably a step-up switching rectifier. According to this configuration, the plurality of light-emitting portions can be driven by boosting the power supply voltage and supplying them to the plurality of light-emitting portions. According to the driving device of the present invention, the voltage drop of the current path formed by the light-emitting portion and the bypass circuit is preferably supplied to the power supply voltage of the driving circuit or more 157384. According to this configuration, since the voltage drop of the current path formed by the light-emitting portion and the bypass circuit is not lower than the power source voltage, excessive current can be prevented from flowing in the light-emitting portion. Preferably, the light-emitting device of the present invention includes a plurality of light-emitting portions ′ connected in series and a driving device for driving the light-emitting portion, and the driving device is any one of the above-described driving devices. According to this configuration, it is possible to obtain a light-emitting device capable of suppressing that all of the light-emitting portions cannot emit light and suppressing excessive current from flowing in the light-emitting portion. [Effects of the Invention] With the driving device of the present invention and the light-emitting device including the same, it is possible to suppress a situation in which all of the light-emitting portions cannot emit light due to a failure of one of the light-emitting portions, and it is possible to suppress an excessive current from flowing in the light-emitting portion. [Embodiment] Hereinafter, embodiments of the present invention will be described with reference to the drawings. <Embodiment 1> A configuration of a light-emitting device 100 according to Embodiment 1 will be described with reference to Fig. 1 . The light-emitting device 100 includes eight light-emitting portions 1 connected in series, and a driving device 2 that drives the light-emitting portion 1. The light-emitting portion 1 is, for example, an LED (Light Emitting Diode). The light-emitting unit 1 connected in series is housed in the package 3, and one end thereof is connected to the terminal 3a of the package 3, and the other end is connected to the terminal 3b of the package 3. The eight light-emitting units 1 are divided into two light-emitting unit groups (the first light-emitting unit group 丨a and the second light-emitting unit group lb), and the four light-emitting units 1 belong to the first light-emitting unit group la and the second light-emitting unit 157,384, respectively. Doc 201215236 Light department group lb. The node N1 between the first light-emitting portion group 1a and the second light-emitting portion group lb is connected to the terminal 3c of the package 3. The driving device 2 includes: a driving circuit 10 for driving the light-emitting portion 1; a power source 20 for operating the driving circuit 10; a bypass circuit 30 provided in parallel with the plurality of light-emitting portions 1; and a control circuit 40 for controlling the bypass circuit 30; The light-emitting unit 1 has a memory unit 50 in which an open circuit failure (hereinafter referred to as "fault") occurs. The bypass circuit 30 includes a first bypass circuit 31 that is provided in parallel with the first light-emitting portion group 1a, and a second bypass circuit portion 32 that is provided in parallel with the second light-emitting portion group lb. The first switch 33 and the voltage drop unit 34 are configured, and the second bypass circuit unit 32 includes a second switch 35 and a voltage drop unit 34. One end of the first switch 33 is connected to the terminal 3a of the package 3, and the other end is connected to the node N2. One end of the second switch 35 is connected to the terminal 3b of the package 3, and the other end is connected to the node N2. The voltage drop unit 34 is provided between the node N1 and the node N2, and has a first voltage drop unit 34a and a second voltage drop unit 34b. The first voltage drop unit 3A and the second voltage drop unit 34b are, for example, constant voltage diodes (Zener diodes). The anode of the jth voltage drop portion (constant voltage diode) 34a is connected to the terminal hole of the package 3, and the cathode is connected to the cathode of the second voltage drop portion (constant voltage diode). The anode of the second voltage drop unit (blank voltage diode) is connected to the node N2. That is, the i-th electric dust falling portion (惶$ voltage diode) W and the second voltage lowering portion (constant voltage diode) 34b are connected in reverse series. Here, as the i-th power drop portion (but constant voltage diode) 3, the breakdown power Mvzl is selected as the power source „Vee of the power source 20 and the four light-emitting portions (LEDs) of the second light-emitting unit material. Forward voltage drop Vf2 and second voltage drop part 157384. Doc 201215236 Constant voltage diode) 34b The difference between the sum of the forward voltage drops Vfz2 and more. In addition, 'the fluctuation of the power supply voltage Vcc of the power supply 20 (for example, 10 V to 14 V in the case where the standard power supply voltage Vce of the lead storage battery is 12 V), and the light-emitting portion (LED) due to the deviation or temperature of the components l The change in the forward voltage drop (for example, 3. 4 V~4 V) and the variation of the forward voltage drop vfZ2 of the second voltage drop (constant voltage diode) 34b (for example, 0·6 V~0. In the case of 7 V), the breakdown voltage Vzl is selected as the maximum value (for example, 14 V) of the power supply voltage Vcc of the power supply 20, and the second light-emitting portion group lb is used as the first voltage drop portion (constant voltage diode) 34a. The minimum value of the forward voltage drop Vf2 of the four light-emitting portions (LEDs) l (for example, 3. 4 V) and the minimum value of the forward voltage drop Vfz2 of the second voltage drop (constant voltage diode) 34b (for example, 〇. 6 V) The difference between the total of the components. In other words, the sum of the voltage drops in the four light-emitting portions 1 of the first voltage drop portion 34a, the second voltage drop portion 34b, and the second light-emitting portion group 1b is not lower than the power source voltage Vcc of the power source 2A. Similarly, as the second voltage drop portion (constant voltage diode) 34b, the breakdown voltage Vz2 is selected as the power supply voltage Vcc of the power source 20, and the forward voltages of the four light-emitting portions (LED) 1 of the first light-emitting portion group ia. The element which is equal to or greater than the difference between the sum of the vfl and the first voltage drop portion (constant voltage one-pole body) 34a. In addition, considering the fluctuation of the power supply voltage Vcc of the power source 20 (for example, 1 〇 v to 14 V in the case where the standard power supply voltage Vcc of the lead storage battery is 12 V), and the light-emitting portion due to variations in components or temperature ( Led) The change in the forward voltage drop of 1 (for example, 3. 4 V to 4 V) and the first voltage drop (constant voltage dipole 157384. Doc -10- 201215236 body) 34a forward voltage drop Vfzl changes (for example 〇 · 6 V ~ 0. In the case of 7 V), the breakdown voltage Vz2 is selected as the maximum value of the power supply voltage Vcc of the power supply 20 (for example, 丨4 V) as the second voltage drop unit (constant voltage diode) 34b, and the first light-emitting unit group 1 The minimum value of the forward voltage drop vfl of the four light-emitting portions (LED) 1 (for example, 3·4 V) and the minimum voltage drop Vfz 1 of the first voltage drop portion (constant voltage diode) 34 & Value (for example, 〇. 6 V) The difference between the total of the components. In other words, the sum of the voltage drops in the four light-emitting portions 1 of the first voltage drop portion 34a and the second voltage drop portion 34b and the first light-emitting portion group 1a is not lower than the power source voltage Vcc of the power source 2A. Further, since the number of elements of the first light-emitting unit group la is the same as the number of elements of the second light-emitting unit group ib, the total value of the forward voltage drop vfl of the first light-emitting unit group 1 a and the forward voltage of the second light-emitting portion 1b Since the total value of the falling Vf2 is close, the breakdown voltage Vz2 of the second voltage drop portion (constant voltage diode) 34b may be different from the breakdown voltage of the first voltage drop portion (the strange voltage diode) 34a. Vzl is the same. Further, the sum of the forward voltage drops of the eight light-emitting portions (LEDs) 1 is not lower than the power supply voltage Vcc of the power source 20. The first switch 3 3 and the second switch 35 are normally controlled to be in an off state. Further, the first bypass circuit unit 31 is controlled to be in an on state by the first switch 33, and forms a bypass path pS-NS-SAb-SAa-Sc-Nl) of the first light-emitting unit group la. The bypass circuit unit 32 forms a bypass path (N1-3 c-3 4a-34b-N2-35) bypassing the second light-emitting unit group lb by the second switch 35 being controlled to the OFF state 〇. The control circuit 40 The opening and closing of the first switch 33 and the second switch 35 are controlled. Specifically, the control circuit 40 determines the light-emitting portion 157384 based on the information stored in the memory unit 50. Doc 201215236 1 In the case of no failure, the first switch 33 and the second switch 35 are turned off, and the drive circuit 1 is operated. When the control circuit 4 determines that the light-emitting unit 1 of the first light-emitting unit group 13 has a failure based on the information stored in the memory unit 5', the control circuit 4 operates the drive circuit 〇 by turning the first switch 3 3 into an on state. When the control unit 40 determines that the light-emitting unit 1 of the second light-emitting unit group lb has failed based on the information stored in the memory unit 5, the control circuit 40 turns on the second switch 35 to operate the drive circuit 10. Referring to Fig. 2, the configuration of the driving circuit 1A of the light-emitting device 1A will be described. The drive circuit 10 is a step-up type switching rectifier that supplies a constant current to the light-emitting unit 1. The driving circuit 10 has: an inductor n connected in series, a diode 12, and a current detecting resistor 15; a capacitor 13 disposed between the grounding point between the diode 12 and the current detecting resistor 15; and is disposed in the inductor 丨丨And an FET (Field Effect Transistor) 14 between the grounding points of the diodes 12; a controller 16 for controlling the voltage across the current detecting resistor 15; and an opening/closing ratio of ρΕΤ14. In the drive circuit 10, the controller 16 controls the on/off ratio of the FET 14 so that the voltage across the current detecting resistor 15 becomes a desired value, thereby controlling the output voltage. However, the output voltage from the drive circuit 丨0 must be higher than the power supply voltage Vcc of the power supply 2〇. For example, when the FET 14 is kept in an on state, the power source 20 and the ground point are continuously short-circuited via the inductor 11 and the FET 14, so that the inductor FET 14 is burnt or damaged. Moreover, although the FETU remains off, the inductor iWlFETM will not be burned or damaged, but the power supply voltage Vcc of the power supply 2 施加 will be applied to the capacitor 13 and the plurality 157384 via the inductor 11 and the diode 12. Doc -12- 201215236 The illuminating 邛1. That is, the driving circuit 1〇 can apply a voltage higher than the power supply voltage Vcc of the power supply 2〇 between the terminal of the package 3 and the outside of the terminal, but cannot apply a voltage lower than the power supply voltage Vcc of the power supply 20 to the package 3. Between terminal field terminals 3 b. . Next, an operation of detecting a failure of the light-emitting device 100 according to the first embodiment will be described with reference to Fig. 3 . First, in the light-emitting device 100, in step S1, the i-th switch 33 and the second switch 35 are turned on by the control circuit 40 (see FIG. 1) (refer to FIG. 1 as an off state, and the drive circuit 1 is turned on (see FIG. 1). Next, in step S2, based on the voltage across the current detecting resistor 15 (see FIG. 2), it is determined whether or not a constant current of the characteristic is output from the driving circuit 1A. That is, the driving current is judged. Then, when it is judged that the specific constant current is not output from the drive circuit 1〇, the process goes to step S3. On the other hand, when it is judged that the specific constant current "IL is output from the drive circuit 1? When the drive circuit 1 〇 outputs a specific constant current, a specific constant current flows in all of the light-emitting portions ,, so that all of the light-emitting portions 1 emit light. Next, in step S3, control is performed in step S3. The circuit 40 stops the operation of the drive circuit 10. Then, in step S4, the second switch 35 is activated by the control circuit 4. When the off state is maintained, the first switch 3 3 is turned on. Thereby, a bypass path that avoids the first light-emitting unit group la is formed. Thereafter, in step μ, the operation of the drive circuit 1 is restarted by the control circuit 40. Next, in step S6, using the control circuit 4'', based on the voltage across the current detecting resistor 15', it is judged whether or not a specific constant is output from the driving circuit 157. Doc •13- 201215236 Current. On the other hand, when it is judged that the specific constant current is not output from the drive circuit 10, the process proceeds to step S7. On the other hand, when it is judged that a specific constant current is output from the drive circuit 1A, the process proceeds to step S1, and in the case where a specific predetermined current is output from the drive circuit 1A, since only the second light-emitting portion is passed through the bypass path. Since the light-emitting portion 1 of the material flows a specific constant current, the light-emitting portion 1 emits light in the second light-emitting portion group. Then, the control circuit 40 determines that the light-emitting portion 1 is malfunctioning. Then, in step S7, the operation of the drive circuit 1 is stopped by the control circuit 4?. Then, in step (10), the second (th) is set to the off state by the control circuit 4, and the second switch 35 is set to the on state. Thereby, a bypass path that avoids the second light-emitting portion_ is formed. Thereafter, in step %, the operation of the drive circuit 10 is restarted by the control circuit 40. Next, in the step S1, the control circuit 40 determines whether or not to output a specific constant current from the drive circuit 1A based on the current detection: voltage across the resistor 15. Then, 'there is judged that the drive circuit 1 〇 outputs a specific value constant current' to the step S11. In the case where a specific value constant current is outputted from the drive circuit 1A, only the current of the light-emitting portion 1 of the "light-receiving portion group" flows through the bypass path, so that the light of the light-group portion U is set. Then, the control unit 40 determines that the light-emitting unit 1 of the second light-emitting unit ib is malfunctioning, and on the other hand, determines that the specific shape of the constant current is not output from the drive circuit 1〇, and stops in step S12. The operation of the driving circuit 1 moves to step SU. In the case where a specific predetermined current is not output from the driving circuit 1G, 157384. Doc 201215236 The control unit 40 determines that the light-emitting unit 1 of the first light-emitting unit group la and the second light-emitting unit group 113 is malfunctioning. Then, in step S11, the light-emitting unit of the first light-emitting unit group ia or the second light-emitting unit group lb 1 Illumination 'The action of the drive circuit 10 thus continues. Thereafter, in step S13, the failure state of the light-emitting unit 1 is memorized by the memory unit 50. Specifically, when the first switch 33 and the second switch 35 are turned off, and the drive circuit 10 is operated, "when a specific constant current is not output from the drive circuit 1", it is determined that either of the light-emitting portions 1 is determined. The fault. When the driving current is normally flown by turning the first switch 33 into the on state, the light emitting unit 1 of the first light emitting unit group 1 a is broken, so that the situation is recalled in the memory unit 50. . When the driving current is normally flown by the second switch 35 being turned on, the light-emitting unit 1 of the second light-emitting unit group 丨b is malfunctioning. Therefore, this situation is stored in the memory unit 5A. Further, even when either of the first switch 3 3 and the second switch 35 is turned on and the drive current does not flow normally, the second light-emitting unit group 1 & and the second light-emitting unit group ib Since the light-emitting portion is defective, this situation is memorized in the memory portion 5A. In addition, at this time, the notification unit (not shown) may be used to notify the light-emitting unit of the failure. The operation of detecting the failure of the light-emitting device 100 shown in Fig. 3 is only required to be performed once when the power of the light-emitting device 100 is turned on, and it is not necessary to perform the light-emitting portion 1 every time. In other words, in the case where the light emission of the light-emitting unit 1 is intermittently performed after the power supply of the light-emitting device 100 is turned on, it is necessary to measure the malfunction of the light-emitting device 1 before the second light-emitting, but the light is emitted after the second time. Before 157384. Doc •15- 201215236 There is no need to detect the malfunction of the illuminator 1 。. The reason for this is that, when the light is emitted by the light-emitting unit 1, the information stored in the memory unit 50 (preferably a non-volatile memory) is used when the power is turned on (when the operation of detecting the failure of the light-emitting device 100 is performed). The opening and closing of the first switch 33 and the second switch 35 are controlled. As described above, the drive device 2 includes: a drive circuit 10 that drives the plurality of light-emitting units 1 connected in series; a bypass circuit 30 that is provided in parallel with one of the plurality of light-emitting units 1; and a control circuit 40 that controls the bypass circuit 30, The bypass circuit 30 includes a first switch 33, a second switch 35, and a voltage drop unit 34, and the control circuit 40 controls opening and closing of the first switch 33 and the second switch 35. Further, in the drive device 2, the plurality of light-emitting units 1 are divided into a plurality of light-emitting unit groups (the first light-emitting unit group la and the second light-emitting unit group lb), the bypass circuit 30, the first light-emitting unit group la, and the second light-emitting unit. The group lb is provided in parallel, and the control circuit 40 sets a bypass circuit in parallel with the first light-emitting unit group la or the second light-emitting unit group lb to which the malfunctioning light-emitting unit 1 belongs in the case where any of the light-emitting units 1 fails. The first switch 33 or the second switch 35 of 30 is placed in an on state. Further, in the drive device 2, the plurality of light-emitting unit groups include the first light-emitting unit group la and the second light-emitting unit group lb, and the bypass circuit 30 includes the first bypass circuit unit 31 provided in parallel with the first light-emitting unit group la, The second bypass circuit unit 32 provided in parallel with the second light-emitting unit group lb is provided with a first switch 33 and a first voltage drop unit 34a in the first bypass circuit unit 31, and the second bypass circuit 32 is provided in the second bypass circuit unit 32. The second switch 35 and the second voltage drop unit 34b. Further, in the drive device 2, when the control circuit 40 sets the first switch 33 and the second switch 35 to the off state to operate the drive circuit 10, the pair of lights 157384. Doc •16·201215236 When the first drive 33 is not in the drive current, the first switch 33 is turned on to determine whether or not the drive current flows. When the drive current is judged to flow, the operation of the drive circuit is continued. In the case of the drive device 2, when the control circuit 4 turns the first switch 33 and the second switch 35 to the off state and the drive circuit 1 is operated, when the drive current is not applied to the light-emitting unit 1, 'the first The switch 35 is set to the ON state to determine whether or not the drive current flows. When the drive current is judged to flow, the operation of the drive circuit 10 is continued. Further, the drive unit 2 includes a storage unit 5 that memorizes whether or not the light-emitting unit 1 of the i-th light-emitting unit i group 1a is malfunctioning (for example, an open-circuit failure), and whether the light-emitting unit 1 of the second light-emitting unit group lb is in trouble. Further, in the drive device 2, the first voltage drop portion 34a and the second voltage drop portion 34b include a constant voltage diode. Further, in the drive device 2, the plurality of light-emitting units 1 are housed in the package 3, and the first switch 33, the second switch 35, the first voltage drop unit 34a, the second voltage drop unit 34b, and the control circuit 40 and the package 3 are housed in the package 3. Individual settings. Further, in the drive device 2, the drive circuit 1 is a step-up type switching rectifier. Further, in the drive device 2, the voltage drop in the current path formed by the light-emitting portion 1 and the bypass circuit 30 is equal to or higher than the power supply voltage supplied to the drive circuit 10. In the above-described 'light-emitting device 1', when the first bypass circuit 31 is provided in parallel with the first light-emitting portion group 1 & and the light-emitting portion 1 of the first light-emitting portion group 1a fails, the control circuit 40 is used. Since the first switch 33 is turned on and a bypass path can be formed, the light-emitting portion 1 of the second light-emitting portion group lb can be made to emit light. Further, the second bypass circuit portion 32 is provided in parallel with the second light-emitting portion group lb, 157384. Doc -17· 201215236 When the light-emitting unit 1 of the second light-emitting unit group lb is in a failure state, the control circuit 40 turns on the second switch 35 to form a bypass path, so that the first light-emitting unit can be formed. The light-emitting portion 1 of the group 1 a emits light. As a result, it is possible to prevent the light-emitting portions 1 of the first light-emitting portion group 1& or the light-emitting portion 1 of the second light-emitting portion group lb from malfunctioning, so that all of the light-emitting portions 1 cannot emit light. Further, in the light-emitting device 100, the first voltage drop portion 34a is provided in the first bypass circuit 31. The breakdown voltage Vz1 of the first voltage drop portion (constant voltage diode) 34a is set to be larger than the power source voltage of the power source 20. The maximum value of Vcc (for example, 14 V when the power supply voltage Vcc varies between 10 V and 14 V) and the minimum voltage drop Vf2 of the four light-emitting portions (LED) 1 of the second light-emitting portion group lb ( For example, at 3. The minimum value of the forward voltage drop Vfz2 of 34 v) and the second voltage drop portion (odd voltage diode) 34b in the case of a variation between 4 V and 4 V (for example, at 0. 6 V~0. In the case of a change between 7 V, the difference is 〇 6 V). In the case where the first switch 3 3 is turned on to form a bypass path, the first voltage drop portion 34a and the second voltage drop portion 34b and the fourth light-emitting portion group lb are four light-emitting portions. The sum of the voltage drops in 1 is not lower than the voltage Vcc' of the power source 2〇. Therefore, excessive current can be prevented from flowing in the light-emitting portion 1 of the second light-emitting portion group ib. Thereby, it is possible to prevent the light-emitting portion 1 of the second light-emitting portion group lb from being damaged. Further, the drive circuit 10 can boost the power supply voltage Vcc of the power supply 20, and supply a specific constant current to the light-emitting portion 1 of the second light-emitting portion group lb. Further, the second voltage drop unit 34b is provided in the second bypass circuit 32, and the breakdown voltage VZ2 of the second voltage drop unit (constant voltage diode) 34b is set to be larger than the maximum value of the power source voltage Vcc of the power source 20 ( For example, in the case where the power supply voltage Vcc varies between 1 〇V and 14 V, it is 14 V), and the first light-emitting portion group la is four 157,384. Doc • 18 · 201215236 The minimum value of the forward voltage drop Vfl of the light-emitting part (LED) l (for example, at 3. In the case of a variation between 4 V and 4 V, the minimum value of the forward voltage drop vfzl of the 3 4 v) and the first voltage drop (constant voltage diode) 34a (for example, at 0. 6 V~0. In the case of a change between 7 V, it is 0. 6 V) The difference between the total. With such a configuration, in the case where the second switch 35 is turned on to form a bypass path, the first voltage drop portion 34a and the second voltage drop portion 34b and the four light-emitting portions 1 of the first light-emitting portion group 13 are formed. Since the sum of the voltage drops in the middle is not lower than the power supply voltage Vcc of the power source 2, it is possible to prevent an excessive current from flowing in the light-emitting portion 1 of the first light-emitting portion group 1a. By this, it is possible to prevent the light-emitting portion of the first light-emitting portion group la from being damaged. Further, the drive circuit 10 can boost the power supply voltage Vcc of the power supply 20, and supply a specific constant current to the light-emitting portion 1 of the first light-emitting portion group ia. In the case where the bypass path is formed in the first bypass circuit 31, a power loss is generated in the first voltage drop portion 34a. 'In the case where the bypass path is formed in the second bypass circuit 32, the second voltage is generated. The drop portion 34b generates a power loss. Therefore, the breakdown voltage Vzl of the first voltage drop portion (constant voltage diode) 34a is larger than the maximum value of the power source voltage Vcc of the power source 20, and the forward direction of the four light-emitting portions (LED) 1 of the second light-emitting portion group lb. The difference between the minimum value of the voltage drop Vfz2 and the minimum value of the forward voltage drop Vfz2 of the second voltage drop portion (constant voltage diode) 34b is preferably such that the breakdown voltage Vzl is within the range satisfying the condition. May be small. Further, the breakdown voltage Vz2 of the second voltage drop portion (constant voltage diode) 34b is larger than the maximum value of the power source voltage Vcc of the power source 20, and the four light-emitting portions (LEDs) of the first light-emitting portion group la The breakdown voltage Vz2 is preferably 157384. The difference between the minimum value of the voltage drop Vfl and the minimum value of the forward voltage drop Vfz 1 of the first voltage drop portion (constant voltage diode) 34a. Doc -19· 201215236 is as small as possible within the range that satisfies this condition. Further, in the light-emitting device 100, the second bypass circuit portion 3 is provided in parallel with the second light-emitting portion group 1a (second light-emitting portion group 1b) to which the four light-emitting portions i belong (second bypass circuit portion) 32) 'The first bypass voltage portion 31a (second voltage drop portion 34b) is provided in the first bypass circuit portion 31 (second bypass circuit portion 32), and a voltage drop is provided in each of the light-emitting portions 1 (LED) In the case of the bypass circuit of the part, the number of parts can be reduced. Furthermore, since the number of terminals (the number of lead wires) of the package 3 can be reduced, the manufacturing cost of the package 3 (the manufacturing cost of the lead wires, etc.) can be reduced and the reliability of the package 3 can be improved (for example, the airtightness of the package 3) Improve)). Further, in the light-emitting device 1A, the first switch 33 and the second switch are configured such that the total voltage drop in the eight light-emitting portions (LEDs) 1 is not lower than the power supply voltage Vcc of the power source 20. In the case where the switch 35 is set to the off state, excessive current can be prevented from flowing in the light-emitting portion 1. Further, the drive circuit 1A can boost the power supply voltage Vcc of the power supply 2, and supply a specific constant current to all of the light-emitting units 1 again. The voltage drop unit 34a and the second voltage drop 34b are constant voltage diodes, and the voltage drop amount in the first bypass circuit unit 31 and the second bypass circuit unit 32 is different from the case where the resistor is used as the voltage drop unit. It is immune to current, so the circuit can be easily designed. Further, in the light-emitting device 100, the voltage drop portion 34 and the package 3 are separately provided, whereby the voltage drop portion 34 can be disposed in a place where heat is easily dissipated. Further, the configuration of the package 3 can be suppressed. Further, in the light-emitting device 1, the first switch 33, the second switch 35, the control circuit 40, and the package 3 are separately provided, thereby suppressing the complexity of the package 3 157384. Doc -20· 201215236. Further, in the light-emitting device 100, by providing the memory unit 50 in which the memory light-emitting unit 1 is malfunctioning, after the failure of the light-emitting unit 1 of the first light-emitting unit group 1a (second light-emitting unit group 1b) is restored, The state of the third switch 33 (the second switch 35) is controlled by the information that is memorized. As a result, after the failure of the light-emitting unit 1 of the first light-emitting unit group ia (second light-emitting unit group lb) is memorized, it is not necessary to perform an operation for detecting the above-described failure at the next startup, so that it takes time to start. Further, in the light-emitting device 100, since the drive circuit 10 is a step-up type switching rectifier, the plurality of light-emitting units 1 can be driven by the power supply voltage Vcc of the boost power supply 20 and supplied to the plurality of light-emitting units 1. Next, the configuration of the light-emitting device 11A according to the first modification of the first embodiment will be described with reference to Fig. 4 . In the light-emitting device 110, 'the voltage drop portion having the resistor 111 is provided instead of the voltage drop portion 34 (see FIG. 1) having the first voltage drop portion 34a and the second voltage drop portion 34b, unlike the above-described light-emitting device 100. Portion 112 (see FIG. 4) » When the voltage drop amount in the case where the resistor 111 is in the on state by the first switch 3 3 is turned on, the first switch 33 and the second switch 35 are turned off. In the state, all of the light-emitting units 1 and the light-emitting units 1 of the first light-emitting unit group 1 & In the case where the bypass path is formed by setting the first switch 33 to the ON state as described above, the sum of the voltage drops in the four light-emitting portions 1 of the resistor 11 and the second light-emitting portion group lb is larger than the first The voltage in the eight light-emitting units 1 of the light-emitting unit group 1& and the second light-emitting unit group lb is lowered, so that the second light-emitting 157384 can be prevented. Doc -21 - 201215236 Excessive current flows in the light-emitting unit 1 of the group lb. Further, in the case where the first switch 33 is turned on to form a bypass path, the resistor 111 may have a voltage drop amount of the four light-emitting portions 1 of the second light-emitting portion group lb and a voltage in the resistor 111. The total amount of the drops is larger than the power supply voltage Vcc of the power source 20. According to this configuration, when the first switch 33 is turned on to form a bypass path, the sum of voltage drops in the four light-emitting portions 1 of the resistor 111 and the second light-emitting portion group lb is not lower than Since the power source voltage Vcc of the power source 20 prevents excessive current from flowing in the light-emitting portion 1 of the second light-emitting portion group lb. Similarly, when the voltage drop amount in the case where the bypass path is formed by the second switch 35 being turned on is greater than normal (the first switch 33 and the second switch 35 are turned off, all the light-emitting portions 1 are turned off) The voltage drop amount of the four light-emitting portions 1 of the second light-emitting portion group lb at the time of light emission is configured. With this configuration, in the case where the second switch 35 is turned on to form a bypass path, the sum of the voltage drops in the four light-emitting portions 1 of the resistor 1U and the second light-emitting portion group 1 & Since the voltages in the eight light-emitting portions 1 of the light-emitting portion group 1& and the second light-emitting portion group lb are lowered, it is possible to prevent an excessive current from flowing in the light-emitting portion 1 of the first light-emitting portion group 1a. In the case where the resistor 111 is in the on state and the bypass path is formed, the voltage drop amount of the four light-emitting portions 1 of the second light-emitting portion group 13 and the resistor 1U may be used. The sum of the voltage drop amounts is larger than the power supply voltage Vcc of the power source 2〇. According to this configuration, in the case where the second switch 35 is turned on to form a bypass path, the resistor m and the second light-emitting portion group 1 & 4 157384. Doc •22· 201215236 The sum of voltage drops in the light-emitting unit 1 is not lower than the power supply voltage Vcc of the power supply unit 2, so that excessive current can be prevented from flowing in the light-emitting unit 第 of the first light-emitting unit group 1& The other configuration of the light-emitting device 110 is the same as that of the above-described light-emitting device 1A. In the light-emitting device 100, since the voltage drop portion 112 has the resistor U1, it is possible to improve the reliability of the voltage drop portion as compared with the case where the constant voltage diode is used as the voltage drop portion. cost. In addition, other effects of the light-emitting device 110 are the same as those of the above-described light-emitting device 1A. Next, a configuration of a light-emitting device 120 according to a second modification of the embodiment will be described with reference to Fig. 5 . In the light-emitting device 120, unlike the above-described light-emitting device 1 (see FIG.), the voltage drop portion 121 of the first bypass circuit portion 31 is provided between the third switch 33 and the terminal 3a of the package 3, and the second bypass circuit portion The second voltage drop unit 122 of 32 is provided between the second switch 35 and the terminal 3b of the package 3. The first voltage drop unit 121 has a constant voltage diode 123. The anode and the cathode of the constant voltage diode 123 The switch 33 is connected, and the cathode is connected to the terminal 3a of the package 3. As the constant voltage diode 123, the selected breakdown voltage Vzl is greater than the maximum value of the power supply voltage Vee of the power supply 2G (for example, the power supply |~ varies between V 14 V) In the case of 14 v), the minimum value of the forward voltage drop Vf2 of the one light-emitting portion (LED) 1 grouped with the second light-emitting portion (for example, at 3. An element having a total difference of 3 4 v) in the case of a variation between 4 V and 4 V. The second voltage drop unit 122 has a strange voltage diode 124. The anode of the cathode-electrode body 124 is connected to the terminal of the package 3, and the cathode is connected to the: switch 35. As the strange voltage diode (3), the selected breakdown voltage Vz2 is 157384. Doc •23· 201215236 The maximum value of the power supply voltage Vcc larger than the power supply 20 (for example, 14 V in the case where the power supply voltage is changed between vcci〇V and 14 V), and the four light-emitting units (LEDs) of the first light-emitting unit group 1& The minimum value of the forward voltage drop Vfi of l) (for example, in the case of a variation between 3 4 v and 4 V). 4 V) The difference between the components. The other configuration of the light-emitting device 120 is the same as that of the above-described light-emitting device. In the light-emitting device 120, the ith voltage drop portion 121 having the constant voltage diode 123 is disposed between the first switch 33 and the terminal 3a of the package 3, and the second voltage having the constant voltage diode 124 is lowered. The portion 122 is disposed between the second switch 35 and the terminal 3b of the package 3, whereby the output voltage of the self-driving circuit exceeds the constant voltage diode even when the first switch 33 and the second switch 35 are simultaneously turned on. 123 and constant voltage diode 124 strike. There is no short circuit before the voltage is applied. Further, since the output voltage of the self-driving circuit 1〇 exceeds the breakdown voltage, the constant current control by the driving circuit 1〇 for the plurality of light-emitting units 1 is suppressed, so that the driving circuit 1 and the first switch can be suppressed. 33, the second switch 35, and the power source 20 are subjected to an excessive load. The other effects of the light-emitting device 120 are the same as those of the above-described light-emitting device. Next, the configuration of the light-emitting device 130 according to the third modification of the first embodiment will be described with reference to Fig. 6 . Unlike the above-described light-emitting device 120, the light-emitting device 130 is provided instead of the first voltage drop portion 121 having the constant voltage diode 123 and the second voltage drop portion 122 (see FIG. 5) having the constant voltage diode 124. The first voltage drop portion of the resistor 131 is provided! 32 and a second voltage dropping portion 134 having a resistor 133. In other words, the first voltage drop unit 132 and the second voltage drop unit 134 include the resistors 131 and 133, respectively. 157384. Doc -24- 201215236 When the voltage drop amount in the case where the bypass path is formed by the first switch 33 being turned on is greater than normal (the i-th switch 33 and the second switch 35 are off), In the case where all of the light-emitting portions are illuminated, the four light-emitting portions 1 of the first light-emitting portion group 1 & Further, in the case where the first switch 33 is turned on to form a bypass path, the resistor 131 may be a voltage drop amount and a resistor of the four light-emitting portions (LEDs) 1 of the second light-emitting portion group 11 The sum of the voltage drop amounts in 131 is larger than the power supply voltage Vcc of the power source 20. According to this configuration, when the first switch 33 is turned on and the bypass path is formed, the sum of the voltage drops in the four light-emitting portions 1 of the second light-emitting portion group 113 of the resistor 131' is not lower than Since the power supply voltage vcc of the power supply 2〇 is prevented, excessive current flows in the light-emitting portion of the second light-emitting portion group 1b. When the voltage drop amount in the case where the bypass path is formed by the second switch 35 being turned on is larger than normal (the first switch 33 and the second switch 35 are turned off), all the light-emitting portions 1 emit light. The second light-emitting unit group 11 is configured to have a voltage drop amount under the four light-emitting units 1. Further, in the case where the second switch 35 is turned on to form a bypass path, the resistor 133 may also have a voltage drop amount of the four light-emitting portions (LEDs) 1 of the first light-emitting portion group 13 and the resistor 133. The sum of the voltage drop amounts in the middle is larger than the power supply voltage Vcc of the power source 20. In the case where the second switch 35 is turned on to form a bypass path, the sum of the voltage drops in the four light-emitting portions 1 of the resistor 133 and the first light-emitting portion group is not lower than The power supply voltage Vcc of the power supply 2〇 prevents the excessive current β 157384 from flowing in the light-emitting portion 第 of the first light-emitting unit group 1 a. Doc -25· 201215236 The other configuration of the light-emitting device 130 is the same as that of the above-described light-emitting device 12A. In the light-emitting device 130, since the first voltage drop unit 132 has the resistor 131 and the second voltage drop unit 134 has the resistor 133, it is possible to use voltage as compared with the case where a constant voltage one-pole body is used as the voltage drop unit. The reliability of the lowering portion is improved, and the manufacturing cost can be reduced. The other effects of the light-emitting device 130 are the same as those of the above-described light-emitting device 12A. Next, referring to Fig. 7 to Fig. 1 针对 ' for the embodiment! The configurations of the light-emitting devices 140, 150, 160, and 170 of the modifications 4 to 7 will be described. The four light-emitting units 1 in the light-emitting device 140 (see Fig. 7), 15A (see Fig. 8), 160 (see Fig. 9), and 1 70 (see Fig. 1) are connected in series. Further, other configurations of the light-emitting devices 140, 150, 160, and 170 are the same as those of the light-emitting devices 100, 110, 120, and 130, respectively. In other words, the number of the light-emitting portions i connected in series may be any number as long as it is plural. Next, the configuration of the light-emitting device 180 according to the eighth modification of the first embodiment will be described with reference to Fig. 11'. In the light-emitting device 180, two light-emitting portions 1' are connected in parallel to the first bypass circuit portion 31. Three light-emitting portions 1 are connected in parallel to the second bypass circuit portion 32. Therefore, as the constant voltage diode 123, the selected breakdown voltage Vzl is greater than the maximum value of the power supply voltage Vcc of the power supply 20 (for example, 14 V in the case where the power supply voltage vcc varies between 10 V and 14 V), and the second The minimum value of the forward voltage drop Vf2 of the three light-emitting portions (LEDs) 1 of the light-emitting portion group lb (for example, at 3. In the case of a change between 4 V and 4 V, it is 3. 4 V) The difference between the components. As the constant voltage diode 124, the selected breakdown voltage Vz2 is greater than the maximum value of the power supply voltage Vcc of the power supply 2〇 (for example, the power supply voltage Vcc varies between 1 〇 V and 14 V 157384. Doc -26- 201215236 The minimum value of the forward voltage drop Vfl of the two light-emitting portions 1 of 14 V) and the first light-emitting portion group la (for example, at 3. In the case of a change between 4 V and 4 V, it is 3. 4 V) The difference between the components. In other words, the number of the light-emitting portions 1 of the first light-emitting portion group 1a may be different from the number of the light-emitting portions 1 of the second light-emitting portion group lb. Next, a configuration of a light-emitting device 190 according to a ninth modification of the first embodiment will be described with reference to Fig. 12'. In the light-emitting device 190, two light-emitting portions 1 are connected in parallel to the first bypass circuit portion 31, and three light-emitting portions 1 are connected in parallel to the second bypass circuit portion 32. Therefore, in the case where the resistor 13 1 is in the ON state to form the bypass path, the voltage drop amount of the three light-emitting portions (LED) 1 of the second light-emitting portion group lb and the resistor 131 are The sum of the voltage drop amounts is greater than the power supply voltage Vcc of the power source 20. When the second switch 35 is turned on to form a bypass path, the resistor 133 has a voltage drop amount of the two light-emitting portions (LED) 1 of the first light-emitting portion ia and a voltage drop amount in the resistor 133. The sum is larger than the power supply voltage Vcc of the power source 20. Further, according to the first embodiment, a constant voltage diode or a resistor is provided on the first bypass circuit unit 31 and the second bypass circuit unit 32, but the present invention is not limited thereto. A constant voltage diode is provided on the resistor portion 3 i, and a resistor is provided on the second bypass circuit portion 32. <Embodiment 2> First, the configuration of the light-emitting device 200 according to the second embodiment will be described with reference to Fig. 13'. In the light-emitting device 200, unlike the above-described light-emitting device 100, eight light-emitting units 1 are divided into four light-emitting unit groups 20la to 20Id, and two light-emitting units 157384.doc • 27·201215236 1 respectively belong to the light-emitting unit group. 201a to illuminating unit group 201d. In other words, the two light-emitting units 1 constitute the light-emitting unit group 201a to the light-emitting unit group 201d. The bypass circuit 202 includes a bypass circuit portion 202a provided in parallel with the light-emitting portion group 201a, a bypass circuit portion 202b provided in parallel with the light-emitting portion group 20bb, and a bypass circuit portion 202c provided in parallel with the light-emitting portion group 201c. The light-emitting unit group 201 (the bypass circuit unit 202 provided in parallel) (1. The bypass circuit unit 202a to the bypass circuit unit 202d have a switch 203a to a switch 203d, and a voltage drop unit 204a to a voltage drop unit 204d. The voltage drop unit 204a The voltage drop unit 204d has a constant voltage diode 205a to a constant voltage diode 205d. The other one of the 'switches 203a to 203d' corresponds to the "first switch" of the present invention, the switches 203a to 203d. The "second switch" of the present invention is the one of the voltage drop unit 204a to the voltage drop unit 204d, and the "first voltage drop unit" of the present invention corresponds to the "second switch" of the present invention. Any one of the voltage drop unit 204a to the voltage drop unit 204d other than the first voltage drop unit corresponds to the "second voltage drop unit" of the present invention. The constant voltage diode 205a is a strange voltage two. Polar body 205d, minute The breakdown voltage is selected to be a breakdown voltage of a constant voltage diode (2〇5a to 205d) provided in parallel with the light-emitting portion group (20 la to 20 Id) of the light-emitting portion 1 including the failure, and the light-emitting portion 1 of the light-emitting portion The sum of the forward voltage drops is greater than the component of the power supply voltage Vcc of the power source 20. The control circuit 40 controls the opening and closing of the switches 203a to 203d. The other configuration of the light-emitting device 200 is the same as that of the above-described light-emitting device 100. 157384.doc -28 - 201215236 Next, an operation for detecting a failure of the light-emitting device 200 according to the second embodiment will be described with reference to Figs. 14 and 15. First, in the light-emitting device 200, the control circuit 40 (see Fig. 13) will be used in the step (2) of Fig. 14 The switch 2〇3a to the switch (10) are turned off with reference to Fig. 9 (9), and the drive circuit 〇 (see Fig. 13) is operated. Next, in step S22, the control circuit is used to refer to both ends of Fig. 2 based on the current detection. The electric power is repeatedly determined to output a specific value constant current from the driving electric power (four), that is, it is judged whether or not the driving current flows normally. Then, when it is judged that the specific value constant current is not output from the driving circuit 10, the process moves to the step. S23. On the other hand, when it is judged that a specific shape of the electric motor is output from the driving circuit ι, the detection operation of the failure ends. In the case where the driving circuit 1 〇 outputs a specific constant current, all the light-emitting portions 丨Since all of the constant currents are flowing, all the light-emitting units 1 emit light. Next, in step S23, the operation of the drive circuit 1 is stopped by the control circuit 4A. Then, in step S24, the switch is controlled by the control circuit 4 Only one of the 2〇3a to the switch 203d is turned on in order. For example, in the case where the switch 2〇3& is in the on state, the bypass path of the avoiding light emitting unit group 20la is formed, and in the case where the switch 203b is in the on state, the bypass path for avoiding the light emitting unit group Μα is formed. When the switch 203c is in the ON state, the bypass path of the avoidance light-emitting unit group 201c is formed, and when the switch 2〇3d is in the ON state, the bypass path for avoiding the light-emitting unit group 201d is formed. Then, if only one of the switches 2〇3&~ switch 203d is turned on, the control circuit 40 restarts the operation of the drive circuit 1 in step S25. Then, in step S26, the control circuit 40 determines whether or not to output a specific constant current from the drive circuit 1A based on the voltage across the resistor 15 of the current detection 157384.doc •29·201215236. Then, when it is judged that the specific constant current is not output from the drive circuit 1A, the process goes to step S27e. On the other hand, when it is judged that the specific constant current is output from the drive circuit 10, the process goes to step S38 (refer to FIG. 15). Then, in step S27, it is judged by the control circuit 40 whether or not all the switches 203a to 203d have been tried. In other words, in a state where only the switch 203 & is in an on state, a state in which only the switch 203b is in an on state, a state in which only the switch 203c is in an on state, and only a switch 2〇3d is in an on state. 'Judge whether it has been judged whether a specific constant current flows. Then, when the determination switches 203a to 203d are all turned on in order, the process goes to step S28. On the other hand, when it is judged that none of the switches 203a to 203d are sequentially turned on, the process returns to step S23. Then, in step S28, the operation of the drive circuit 1 is stopped by the control circuit 40. Then, in step S29, two of the switches 203a to 203d are turned on by the control circuit 40. For example, in the case where the switch 2〇3a and the switch 203b are in an on state, a bypass path for avoiding the light-emitting unit group 201a and the light-emitting unit group 201b is formed. When the switch 203a and the switch 203c are in an on state, the avoidance light-emitting unit group 201a is formed. The bypass path of the light-emitting unit group 201c; in the case where the switch 203a and the switch 203d are in an on state, a bypass path for avoiding the light-emitting unit group 20la and the light-emitting unit group 20Id is formed. When the switch 203b and the switch 203c are in the on state, the bypass path of the avoiding light emitting unit group 20lb and the light emitting unit group 201c is formed, and the switch 203b and the switch 203d are in the ON state of 157384.doc • 30·201215236, forming avoidance. When the switch 203c and the switch 203d are in an ON state, the bypass path of the light-emitting unit group 201b and the light-emitting unit group 201d is a bypass path in which the light-emitting unit group 201c and the light-emitting unit group 201d are bypassed. Then, when either of the switches 203a to 203d is turned on, the operation of the drive circuit 1 is restarted by the control circuit 40 in step S30. Then, in step S31, the control circuit 40 determines whether or not to output a specific constant current from the drive circuit 1A based on the voltage across the current detecting resistor 15. Then, when it is judged that the specific constant electric/"1 is not output from the drive circuit 1", the process proceeds to step s3 2. On the other hand, when it is judged that the specific constant current is output from the drive circuit 1? Go to step S38 (refer to Fig. 15). Next, in step S32, it is judged by the control circuit 40 whether or not all combinations have been tried. That is, 'the switch 203a and the switch 2〇3|3 are turned on, and the switch is turned on. 203a and 203c are in an on state, a state in which the switch 203a and the switch 203d are in an on state, a state in which the switch 2〇3b and the switch 203c are in an on state, and the switch 2〇3b and the switch 2〇3d are set. When the state of the ON state is set and the switch 203c and the switch 2〇% are turned on, it is determined whether or not a specific constant current flows. Then, when it is judged that all the combinations have been tried, the process proceeds to step S33 (refer to FIG. 15). On the other hand, when it is judged that all the combinations have not been tried, the process returns to step S28. Next, in step S33, the operation of the drive circuit 1 is stopped by the control circuit 4". Then, in step S34, the control is utilized. Three of the switches 2〇3a to 2〇3d are turned on. For example, in the case where the switches 2〇3a to 2〇3c are in an on state, the avoidance light-emitting unit groups 201a to 157384.doc • 31 are formed. 201215236 Bypass path of the light-emitting unit group 201c; when the switch 2〇3a, the switch 203b, and the switch 203d are in an on state, the bypass light-emitting unit group 2〇ia, the light-emitting unit group 201b, and the light-emitting unit group 201d are bypassed. In the case where the switch 203a, the switch 203c, and the switch 203d are in an ON state, a bypass path of the avoidance light-emitting unit group 201a, the light-emitting unit group 201c, and the light-emitting unit group 2〇ld is formed, and the switches 203b to 203d are turned on. In the middle, the bypass path of the light-emitting unit group 201b to the light-emitting unit group 201d is formed. Then, when any three of the switches 2〇3a to 203d are turned on, the control circuit 40 is used again in step S35. The operation of the driving circuit 1 is started. Next, 'in step S36, 'the voltage between the two ends of the current detecting resistor 15' is used to determine whether or not to output a specific strange current from the driving circuit 1 。. Then, when the judgment is not When the drive circuit 丨〇 outputs a specific constant current, the process goes to step S 37. On the other hand, when it is judged that a specific constant current is output from the drive circuit 1 ,, the process goes to step S38. Next, at step S37 In the control circuit 40, it is determined whether or not all combinations have been tried. That is, 'the switch 203a to the switch 2〇3c are in an on state, and the switch 203a, the switch 203b, and the switch 203d are turned on, and the switch is turned on. 203a, the switch 203c, and the switch 203d are in a state of being in an on state, and in a state in which the switches 203b to 203d are in an on state, it is determined whether or not a specific constant current flows. Then, when it is judged that all the combinations have been tried, in step S39, the operation of the drive circuit 1 is stopped, and the process proceeds to step S40. On the other hand, if it is determined that all combinations have not been tried, the process returns to step S33. Then, in step S38, since any of the LED groups (201a to 2〇ld) 157384.doc •32·201215236 the light portion 1 emits light, the operation of the drive circuit 10 is continued. Thereafter, in step S40, the memory unit 5 〇 memorizes the fault state of the open circuit of the light-emitting unit i. In the light-emitting device 200, as described above, the two light-emitting units 1 are respectively attached to the light-emitting unit groups 201a to S1, and the light-emitting unit group 20 Id is reduced in comparison with the case where four LEDs are attached to the LED group. The number of the light-emitting portions 1 that are defective in the portion i and cannot emit light. The other effects of the light-emitting device 200 are the same as those of the above-described light-emitting device 100. In the second embodiment, the voltage drop unit 2〇4a to the voltage drop unit 204d are exemplified as the example of the voltage-limiting diode 205a to the voltage-limiting diode 2〇5d, respectively, but are not limited thereto, and for example, as shown in FIG. In the light-emitting device 210 according to the modification of the first embodiment, the voltage drop unit 211a to the voltage drop unit 21d may have resistors 212a to 212d, respectively. In addition, any one of the voltage drop unit 211a to the voltage drop unit 211d corresponds to the "first voltage drop unit" of the present invention, and the voltage drop unit 211a to the voltage drop unit 211d are the first voltage drop unit. Any of them corresponds to the "second voltage drop portion" of the present invention. In the second embodiment, the switches 2〇3a to 203d are sequentially turned on in the case of the failure detection, and then two of the switches 2〇3a to 203d are turned on, and then the switches are turned on. An example in which three of the two switches 3a to 203d are in an on state, but is not limited thereto, and may be judged and turned on by setting three of the switches 203a to 203d to be in an on state during failure detection. Whether or not the light-emitting portions of the light-emitting unit groups (201 a to 201d) arranged in parallel in the state switches (203a to 203d) are in a state of failure, and the light-emitting unit group 201a to the light-emitting unit group 201d are subjected to the determination, and the malfunctioning light is emitted. The switches (2〇3a to 2〇3d) in which the light-emitting unit groups (201a to 201d) to which the unit 1 belongs are arranged in parallel are set to 157384.doc •33-201215236. In the first embodiment, the light-emitting unit 1 is divided into two light-emitting unit groups (the first light-emitting unit group la and the second light-emitting unit group lb), and in the second embodiment, the plural is displayed. The light-emitting unit 1 is divided into four light-emitting unit groups (light-emitting unit group 201a to light-emitting unit group 2〇1d). However, the present invention is not limited thereto, and the number of light-emitting unit groups that distinguish the plurality of light-emitting units 1 may be arbitrary. In the first embodiment and the second embodiment, the switches (33, 35, 203a to 203d) may be relay switches or may be switch circuits 5A as shown in Fig. 17. The switching circuit 500 includes an n-channel type m〇S-FET 501, a p-channel type MOS-FET 502, a resistor 503, and a resistor 504. In the switch resistor 500, the voltage applied to the gate of the M?s_FET 501 via the resistor 5?3 is controlled by the control circuit 40 (refer to Fig. 1). The on/off state is switched by the mM 〇s_FET 5 〇 1 according to the gate voltage, so that the current flowing through the resistor 5 〇 4 fluctuates, and thus the gate voltage of the MOS-FET 502 changes. Thereby, the on/off state of the M〇s_FET 502 is switched. When M〇S_FET5〇2 is turned on, a current flows from the terminal 505a side to the terminal 5〇5b side. It functions as a switch by kM〇s_FET5〇2. The bypass path described in Patent Document 2 uses a fuse-like component and uses mechanical action (such as the action of a spring). Therefore, it is necessary to introduce a special mechanism and it is considered that it is difficult to realize. On the other hand, when the bypass path is formed by using the switches (33, 35, 203a to 203d) for electrical operation such as the switch circuit 5, it is easy to realize without introducing a special mechanism. In the first and second embodiments, 'the constant voltage dipoles (123, 124 205a to 205d) or the resistors (1) i, 13 ι, 133, 212, and 212 are used as 157384.doc • 34·201215236 as the voltage drop unit (34). Examples of 112, 121, 122, 132, 134, 204a to 204d, and 21 la to 21 Id) are not limited thereto, and as the voltage drop portion, a voltage drop circuit 6 as shown in FIG. 18 may be used (^ The voltage drop circuit 600 includes a constant voltage diode 6〇1, a pnp type transistor 6〇2, a diode 603, and a resistor 604. The voltage drop circuit 6〇〇, when the collector-emitter of the transistor 602 The voltage between the electrodes becomes high, and if the constant voltage diode 601 connected between the base and the collector of the transistor 6〇2 breaks down, the base current of the transistor 6〇2 flows. Thereby, the transistor 602 The voltage between the collector and the emitter is substantially maintained at the breakdown voltage Vz of the constant voltage diode 601. The diode 6〇3 is used to ensure the current path from the collector side of the transistor 602 to the emission stage side. In this manner, the first voltage drop unit (112, 121, 132) and the second voltage drop unit (112, 122, 134) include electricity. The body 602. Also, as the voltage drop portion, a voltage drop circuit 700 as shown in Fig. 19 can be used. The voltage drop circuit 7A includes a constant voltage diode 〇1, an npn type transistor 702, and a diode. 703, resistor 704. In the voltage drop circuit 700, instead of the pnp type transistor 6〇2 (see Fig. 18), an npn type transistor 702 is provided. [Fig. 1] Fig. 1 shows the present invention. FIG. 2 is a circuit diagram showing a configuration of a driving circuit of the light-emitting device shown in FIG. 1. FIG. 3 is a view for explaining an operation of detecting a failure of the light-emitting device shown in FIG. Fig. 4 is a circuit diagram showing a configuration of a light-emitting device according to a first modification of the first embodiment of the present invention. Fig. 5 is a view showing a light-emitting device according to a second modification of the first embodiment of the present invention. Fig. 6 is a circuit diagram showing a configuration of a light-emitting device according to a third modification of the first embodiment of the present invention. Fig. 7 is a circuit diagram showing a configuration of a light-emitting device according to a fourth modification of the first embodiment of the present invention. Display FIG. 9 is a circuit diagram showing a configuration of a light-emitting device according to a sixth modification of the first embodiment of the present invention. FIG. 10 is a circuit diagram showing a configuration of a light-emitting device according to a sixth modification of the first embodiment of the present invention. Fig. 11 is a circuit diagram showing a configuration of a light-emitting device according to a modification 8 of the first embodiment of the present invention. Fig. 12 is a view showing a light-emitting device according to a ninth modification of the first embodiment of the present invention. The circuit diagram of the composition. Fig. 13 is a circuit diagram showing the configuration of a light-emitting device according to a second embodiment of the present invention. Fig. 14 is a flow chart for explaining the operation when detecting the malfunction of the light-emitting device shown in Fig. 13. Fig. 15 is a flow chart for explaining the operation when detecting the failure of the light-emitting device shown in Fig. 13. 157384.doc-36-201215236 Fig. 16 is a circuit diagram showing a configuration of a light-emitting device according to a modification of the second embodiment of the present invention. Fig. 17 is a circuit diagram showing a configuration of a switch circuit. Fig. 18 is a circuit diagram showing the configuration of a voltage drop circuit. Fig. 19 is a circuit diagram showing the configuration of a voltage drop circuit. [Description of main component symbols] 1 Light-emitting unit la First light-emitting unit group (light-emitting unit group) lb Second light-emitting unit group (light-emitting unit group) 2 Drive device 3 Package 10 Drive circuit 30 Bypass circuit 31 First bypass circuit unit (Bypass circuit unit) 32 Second bypass circuit unit (bypass circuit unit) 33 First switch (switch) 34 Voltage drop unit 34a First voltage drop unit (constant voltage diode) 34b Second voltage drop unit ( Constant voltage diode) 35 second switch (switch) 157384.doc •37· 201215236 40 control circuit 50 memory unit 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200 '210 Device 111 Resistor 112 voltage drop unit (first voltage drop unit, second voltage drop unit) 121 First voltage drop unit (voltage drop unit) 122 Second voltage drop unit (voltage drop unit) 123, 124 Constant voltage dipole Body 131, 133 Resistor 132 First voltage drop unit (voltage drop unit) 134 Second voltage drop unit (voltage drop unit) 201a to 201d Light-emitting unit group 202 bypass circuits 202a to 202 d bypass circuit units 203a to 203d switches (first switch, second switch) 204a to 204d voltage drop unit (then voltage drop unit, second voltage drop unit) 157384.doc • 38 · 201215236 205a~205d constant voltage two Polar body 211a to 211d Voltage drop unit (first voltage drop unit, second voltage drop unit) 212a to 212d Resistor 500 Switch circuit (switch) 600 Voltage drop circuit (voltage drop unit) 602 Transistor 700 Voltage drop circuit (voltage Drop section) 702 transistor 157384.doc -39-