.201126219 六、發明說明： 【發明所屬之技術領域】 本發明係關於一種使用於光模組的塑膠光纖軟線，尤 其係關於適合於電視內配線等之影像關連之光通訊系統的 塑膠光纖軟線。 【先前技術】 光纖之中的塑膠光纖軟線，由於所有原料係以塑膠構 成，因此與石英系光纖比較，有傳遞損失稍大的缺點，但 是有輕量、加工性良好且可在低成本下製造之優點，在進 行光通訊的收發之各種光瘼組中，大多使用於傳遞損失並 不構成問題的近距離光傳輸路徑。 在專利文獻1中，記載有適合使用於光模組之光纖軟 線，將4條之光纖並列，利用合成樹脂之帶狀化材料而一 起被覆爲帶狀者。 先前技術文獻 專利文獻 專利文獻1 :日本特開2008 - 1 0 8 3 7號公報（尤其是其第 5圖） 【發明内容】 [發明欲解決之課題] 使用光纖軟線於電視內配線等之時，能輕易進行配線 作業是一大課題，又，亦必須消除受到發光元件之組裝誤 差的影響以致結合損失易變大之問題。 本發明之目的在於提供一種塑膠光纖軟線，能容易地 201126219 進行配線作業，即使發光元件之組裝誤差大至某個程度， 亦可將結合損失抑制在預定値以下，作爲目的。 [解決課題之手段] 依照本發明之塑膠光纖軟線，係將複數條塑膠光纖加 以一體化作成帶狀，其特徵在於各塑膠光纖係由芯部、圍 住芯部的包覆層、圍住包覆層的第1保護層、及包圍第1 保護層的第2保證層形成，塑膠光纖係藉由與第2保護層 形成一體的連接用橋接器彼此連接。 塑膠光纖（以下有稱爲「POF」之情形）係下列者所形 成：由以聚合物作爲基質的有機化合物所形成之芯部、折 射率與芯部不同（一般爲由低折射率之聚合物所形成）之包 覆層、及1層或複數層之樹脂製保護層。POF可爲被稱作 階變折射率（Step index)(SI)型，係由在芯部具有高折射率 的材料，且在包覆層具有低折射率的材料之2層構造所構 成；又，亦可爲被稱作梯度折射率（graded index)(Gl)型， 具備折射率之大小從中心朝向外側（半徑方向）具有分布之 芯部。藉作成GI型，使更高速的通訊成爲可能。通常’傳 輸頻帶係與光纖的距離成反比，但是考慮將傳輸頻帶作爲 —定之時，GI型比SI型更能使長距離的通訊變爲可能。 圍住包覆層的保護層係作成3層以上，此時’最外層 係相當於第2保護層，連接用橋接器係與此最外層之保護 層形成一體，第1保護層亦可由複數層形成。 先前技術的塑膠光纖軟線，係以保持爲橫一列的扁平 狀態之方式，作成POF以樹脂固定之構造，相對於此’在 •201126219 依本發明之塑膠光纖軟線中，POF係藉由厚度與第2 層大致相等的連接用橋接器彼此連接。如此，藉由使 用橋接器具有可撓性，不僅使塑膠光纖軟線可在扁平 進行處理，而且在通過圓形孔之時等可變形爲捲曲 態。又，連接用橋接器與先前技術者比較，撕裂之強 低，因此能使塑膠光纖軟線分離爲單芯的POF之作業 進行。因而，適合於電視內配線等之使用。 連接用橋接器可設置於複數條P OF在水平面上配 橫一列之情況的底面（最下點）或頂面（最上點），又，亦 置於上下之正中央（與各P OF之中心軸爲相同高度）， 設置於底面或頂面與上下之正中央之間的任意之位置 連接用橋接器雖然通常係設置於相同位置（使得所有 用橋接器位置同一面內），但是並不限定於此。連接用 器之長度係以能適當地變形爲捲曲之狀態的方式，由 連接用橋接器之位置而適宜地設定。 P OF之芯數雖然不限定，但是通常以處理容易之 量，係爲20芯以下。 當POF之芯徑爲ΙΟΟμιη以上且較佳爲150μπιΗ_ 即使發光元件之組裝誤差大至某個程度時，亦可將結 失抑制在預定値以下（例如3dB以下）。相對於120μιη 寸的受光元件，當芯徑超過300μπι時面積比爲144: 光之損失大且結合損失超過-8dB，因此POF之芯徑以 300μιη以下爲宜，更佳爲250μιη以下。如此，在與 之連接時的定位也只需粗略即可，此可減輕與連接 保護 連接 狀態 之狀 度降 容易 置爲 可設 亦可 。各 連接 橋接 設置 點考 t時， 合損 之尺 90 0， 作成 :接器 之連 201126219 接時的麻煩。 POF之線徑爲2mm以下，較佳爲1 .5mm以下。 7 5 0 μιη以下。在此’ POF之線徑係指包含芯部及包 保護其等之1層的樹脂製保護層（外覆層）的直徑。 之芯徑作成1〇〇μηι以上且P〇F之線徑作成2mm以 此而具有上述效果且處理上變成容易。 在各塑膠光纖軟線之500~850nm的至少任何一 中，以 ΝΑ = (ηι2-η22),/2 (公式中，光纖芯部中心部的折射率：η, |在光 層中折射率最低之部分的折射率：η2) 表示的開口數（ΝΑ)係爲0.25以上爲適合，0.3 較佳。如此，即使將POF以彎曲的狀態使用時，亦 損失，因此如電視內配線般，即使以將POF彎曲而 形態之光模組進行使用之情況時，亦可容易地確保 性能。開口數之上限並無特別限定。 作爲芯部及包覆層而使用的塑膠之種類，若透 且能使用於光傳輸，並無特別限定。例如，可舉出 丙基酸酯系單體之聚合物、苯乙烯系單體之聚合物。 丙基酸酯系單體可舉出：甲基丙基酸甲酯（ΜΜΑ)、 基酸乙酯、η-甲基丙基酸丙酯、η-甲基丙基酸丁酯 酸甲酯、丙基酸乙酯、η-丙基酸丙酯、η·丙基酸丁 乙烯系單體可舉出：苯乙烯（St)、α-甲基苯乙烯、氯 (CISt)、溴苯乙烯等，此等之共聚物亦無妨。其他之 更佳爲 覆層及 將POF 下，藉 個波長 纖包覆 以上爲 可抑制 使用的 必要的 明性高 (甲基） (甲基） 甲基丙 、丙基 酯；苯 苯乙烯 共聚合 201126219 物成分，可爲如：醋酸乙烯、苯甲酸乙烯酯、乙酸乙烯苯 酯、氯乙酸乙烯酯等之乙烯酯類；N-n-丁基馬來酸亞胺、 N-tert-丁基馬來酸亞胺、N-異丙基馬來酸亞胺、N-環己基 馬來酸亞胺等之馬來酸亞胺類等。其他亦可使用聚碳酸酯 系塑膠、環烯系塑膠、非晶氟系塑膠等。 至少1條塑膠光纖（POF)之芯部具有折射率分布爲較 佳。藉此，即使軟線長度爲長之情況時，亦能獲得良好的 傳輸性能。芯部形成折射率分布的POF，利用例如在一般 之SI型的芯部組成（例如氯苯乙烯/甲基丙烯酸甲酯）中加 入數％之磷酸三苯酯（TPP)，從中心部朝向半徑方向減少 TPP濃度而獲得。 POF藉由連接用橋接器彼此連接的構成，雖然並未特 別限定，但是可作成例如複數條P〇F配置爲橫一列’使相 鄰的POF彼此之間的間隙成爲0或微小的間隙，同時連接 用橋接器設置爲使POF之最下點〜由最下點之45°上部之點 彼此相連繫。在此，「最下點」係意爲複數條P0F在水平 面上配置爲橫一列之時的底面，並非指在使用時之「下」 的意思。利用連接用橋接器形成的面係爲平行於通過各 P OF之中心的面之面。如此，塑膠光纖軟線在沿著水平面、 垂直面等設置之情況，複數條P〇F係使相鄰P0F彼此接觸 或幾乎接觸的方式配置爲橫一列’使扁平狀態的使用爲可 能。在此狀態下，即使複數條P〇F來到連接用橋接器之內 側而變形爲捲曲之狀態時，相鄰的P0F彼此接觸或幾乎接 觸的複數條P0F會阻礙此而防止變形’使塑膠光纖軟線可 .201126219 作爲常時位於扁平狀態者而處理，故能使 另一方面，此塑膠光纖軟線之複數條POF 器之外側而變形爲捲曲之狀態係很容易 形，可使塑膠光纖軟線通過孔的作業容易 使複數條POF不易來到連接用橋接器之內 之狀態的範圍的話，相鄰POF之間的間隙 如相鄰POF之間的間隙亦可爲POF之最大 度。 最下點~由最下點算起45°上部之點的 光纖軟線作爲常時在扁平狀態者而處理， 複數條POF來到連接用橋接器之外側而變 的範圍。 複數條POF之相鄰的POF彼此之間的 〇或微小的間隙，亦可在放大到P〇F之第 3倍以下的範圍內。此時，相鄰的P〇F彼 體上係作成POF之徑的0·75倍到1·5倍之 對連接用橋接器之POF可變形的部分之 POF徑之1.25到2倍。又，相鄰的POF彼 各POF之徑「大致相等」，係意指複數條 橋接器之內側而變形爲捲曲之狀態之時相 間隙係爲〇或微小的間隙之意。依此’藉并 可使複數條POF來到連接用橋接器之內倜 狀態，因應使用之形態而設定間隙之大小 種之用途。 作業容易進彳了。 來到連接用橋接 ’利用如此的變 進行。只要爲能 側而變形爲捲曲 亦可不爲0，例 徑的1 5 %以下程 範圍是可使塑膠 而且係爲容易使 形爲捲曲之狀態 間隙並不限定於 2保護層之徑的 此之間的間隙具 間隔爲較佳。又， 長度 '宜作成爲 :此之間的間隙與 Ρ Ο F來到連接用 鄰的Ρ 0 F之間的 等間隙作成爲大， 丨而變形爲捲曲之 >，藉此可對應各 201126219 又，連接用橋接器亦可作成，將各塑膠光纖之中心部 設置爲彼此相連。此時，在不區別內側及外側（上側及下側） 下，可容易地將複數條POF變形爲捲曲之狀態。即，如上 述，當連接用橋接器設置爲使POF之最下點〜由最下點算 起45°上部之點彼此相連繫之情況，相對於有區別上下之需 要，藉由如此之作法，而有可消除區別上下之需要的優點。 反之，連接用橋接器設置爲使塑膠光纖之最下點〜由最下點 算起45°上部之點彼此相連繫之情況，清楚地進行上下之區 別，有在連接之時容易分別左右之連接方向的優點。使因 應用途的連接用橋接器之位置設定爲可能。 形成被覆POF的第1保護層、第2保護層及連接用橋 接器的合成樹脂，雖然並未限定，但是宜選擇能滿足POF 及塑膠光纖軟線所需要的強度、難燃性、柔軟性、耐藥品 性、耐熱性等者。例如，可舉出以：氯乙烯系樹脂、氯化 氯乙烯系樹脂、低密度聚乙烯、高密度聚乙烯、氯化聚乙 烯、乙烯-醋酸乙烯酯共聚物、氯乙烯-乙烯-醋酸乙烯酯共 聚物、丙烯酸系樹脂、氟系樹脂、醋酸乙烯酯-氯乙烯共聚 物、聚碳化物酯等作爲主成分者。 此外，各POF彼此之拘束力（連接用橋接器之強度）， 宜爲0.3〜5 kgf。連接用橋接器之厚度係設定爲使各p〇F彼 此之拘束力在上述範圍內。此拘束力係在100mm/分之速度 下，可藉測定將2芯拉裂時之強度而求出。爲了將拘束力 作成預定値以下使POF彼此容易分離，亦可作成在連接用 橋接器設置缺口。雖然缺口可設在所有的連接用橋接器， 201126219 但是亦可只設在一部分之連接用橋接器。缺口可在製造塑 膠光纖軟線時之擠出成型時形成，可不需要追加之製程而 設置。 雖然此塑膠光纖軟線可使用於各種之用途，但適合於 藉由光纖傳輸光信號的光傳輸裝置（光通訊系統）中影像信 號傳輸之用，尤其適於配線空間之極度受限制的電視內配 線等。在電視內配線使用之情況，POF之波長宜爲5 00~850 nm，亦可爲5 00~7 5 0nm(可見光線），亦可爲7 8 0〜8 5 0nm之 光源（紅外線）。 [發明之效果] 依照本發明之塑膠光纖軟線，各塑膠光纖係由芯部、 圍住芯部的包覆層、圍住包覆層的第1保護層、及包圍第 1保護層的第2保護層形成，塑膠光纖係藉由與第2保護 層形成一體的連接用橋接器彼此連接，因此能使電視內配 線等之影像關連光通訊系統中之配線作業容易進行。又， 藉將各塑膠光纖之芯徑作成ΙΟΟμιη以上且爲3 00μιη以下， 即使發光元件之組裝誤差大至某個程度時，亦可將結合損 失抑制在預定値以下，因而，在與連接器之連接時的定位 也只需粗略即可，此可減輕與連接器之連接時的麻煩。 【實施方式】 以下將參照圖面說明本發明之實施形態。在以下之說 明中，係將圖之上下稱爲上下，將圖之左右稱爲左右。 第1圖及第2圖係顯示依本發明之塑膠光纖軟線之第 1實施形態。 -10 - 201126219 塑膠光纖軟線（1)係由複數條（圖示爲4條）之POF(塑膠 光纖）（2)、及將POF(2)彼此連接的連接用橋接器（3)所形成。 複數條POF(2)係以扁平狀態配置爲橫一列，使得相鄰 的POF彼此之間的間隙成爲0或微小的間隙，連接用橋接 器（3)係設置成依此方式配置的各P0F(2)之最下點彼此相 連繫。 所有POF(2)係爲相同形狀，連接用橋接器（3)亦爲全部 作成相同形狀。 此塑膠光纖軟線（1)在沿著水平面、垂直面等設置之情 況，複數條POF (2)係以相鄰POF彼此接觸或幾乎接觸的方 式配置爲橫一列，使扁平狀態的使用爲可能。在此狀態下， 即使複數條P〇F(2)來到連接用橋接器（3)之內側而變形爲 捲曲之狀態時（在第1圖之狀態中將直線狀之連接用橋接器 (3)變形爲U字狀），相鄰的P0F彼此接觸的複數條POF(2) 會阻止此而防止變形，使塑膠光纖軟線（1)可作爲常時位於 扁平狀態者而處理，故能使作業容易進行。另一方面，此 塑膠光纖軟線（1)在連接用橋接器（3)未接觸於水平面等之 自由狀態下，複數條P〇F(2)來到連接用橋接器（3)之外側而 變形爲捲曲之狀態（在第1圖之狀態中將直線狀之連接用橋 接器（3)變形爲倒U字狀），而作成如第2圖般係很容易， 利用如此的變形可使塑膠光纖軟線（1)通過孔的作業容易 進行。 各P0F (2)係由下列者所形成：以聚合物作爲基質的有 機化合物所形成之芯部（11)、折射率與芯部不同（一般由低 -11- 201126219 折射率之聚合物所形成）之包覆層（12)、保護此等之外覆層 (第1保護層）（13)及護套（第2保護層）（14)。連接用橋接器 (3)與護套（14)形成一體。 此塑膠光纖軟線（1)係以可獲得高速之傳輸速度的方 式而作成由4條POF (2)所形成的4芯帶體構造。但是，先 前技術之4芯軟線係將4條保持爲橫一列之扁平狀態的方 式，以樹脂固定的構造，相對於此，當依本塑膠光纖軟線 (1)時，第1圖所示之4條P〇F(2)係可變形爲：並列爲橫一 列的扁平狀態、及第2圖所示之4條POF(2)係將連接用橋 接器（3)作於內側而並列爲二列二層的狀態（全體爲作成剖 面大致圓形或剖面大致方形之捲曲狀態）。 在電視內配線中，係將4芯帶體構造的塑膠光纖軟線 (1)作成端部或適宜的中間部爲2芯或單芯，將各連接用橋 接器（3)撕裂，而能容易地將4芯帶體構造分離爲單心。 此外，藉將複數條P〇F(2)之相鄰POF之間的間隙作成 實質爲〇，即使連接用橋接器（3)將各P〇F(2)之最下點〜由 最下點起之90°上部（較佳爲最下點之45°上部）之點彼此相 連繫之時，亦可獲得上述作用效果。 第3圖顯示作爲本發明之塑膠光纖軟線（1)的使用之1 形態的光模組（21)。第3圖中，光模組（21)具備：底部基板 (22)、在底部基板（22)上以預定間隔配置之4個正方形板狀 發光元件（23)、用於固定4個發光元件（23)之透明的樹脂模 塑材（24)、驅動各發光元件（23)之驅動器IC(25)、及POF 連接器（26)，此POF連接器（26)形成有用於使塑膠光纖軟 -12- 201126219 線（1)之各P〇F(2)與各發光元件（23)位置對準且剖面爲圓形 之POF插入孔。 在發光元件（23)上，如第3(b)圖誇大地顯示般，有組 裝誤差，因此以往有光模組（2 1)中之結合損失變大的問 題，在塑膠光纖軟線（1)之各POF(2)與POF連接器（26)連接 之時，必須抑制位置之偏差，因而亦有連接時須要費周章 的問題。 因而，在本實施形態之塑膠光纖軟線（1)中，利用作成 如下之構成，來消除上述問題。 1. POF(2)之芯徑係爲ΙΟΟμηι以上且爲300μιη以下。 2. POF(2)之線徑係爲2mm以下。 3. POF(2)之開口數係爲0.25以上。 4. 塑膠光纖軟線（1)係以多芯構造作成帶型（緞帶型）， POF(2)彼此之拘束力（連接用橋接器（3)之強度）係爲 0.3 〜0·5 kgf° 5. 將塑膠光纖軟線（1)連接到光源的P〇F連接器（26)係平坦 型。 此外，上述之開口數係各塑膠光纖在5 00〜8 5 0nm之至 少任何一個波長中，以NA = (n/-1122) 1/2表示。 (公式中，光纖芯部中心部的折射率：n 1 ’在光纖包覆 層中折射率最低之部分的折射率：nz)。 利用上述1 ~5之構造所獲得的效果’係如下列" 由於POF(2)之芯徑爲ΙΟΟμηι以上且爲300^mW下’即 使ifii POF連接器（26)之連接精度爲粗略時’亦能將結合損 -13- 201126219 失抑制在預定値以下。例如，藉將 P〇F(2)之芯徑作成 ΙΟΟμιη »發光元件（2 3 )之尺寸爲1 0 μπι時，即使組裝誤差爲 ±50μιη時，亦可將結合損失抑制在3dB以下。 由於POF(2)之線徑係爲2mm以下，處理上變成容易。 由於POF(2)之開口數係爲0..25以上，如後述般，能抑 制對彎曲的損失，使配線之統一成爲可能》 由於塑膠光織軟線（1)係以多芯構造作成帶型（緞帶 型），POF(2)彼此之拘束力（連接用橋接器（3)之強度）係爲 0.3〜0.5kgf，彎曲容易且處理變容易，又與POF連接器（26) 之連接時的加工也變容易。 由於將塑膠光纖軟線（1)連接到光源的POF連接器（26) 係平坦型，故塑膠光纖軟線（1)之連接部分的薄型構造變成 可能。 在使用於電視內配線等之時，塑膠光纖軟線（1)並不限 定於第1圖及第2圖所示之實施形態者，各種之形態爲可 能。例如，複數條P〇F(2)之相鄰的POF彼此之間的間隙並 不限定於〇或微小的間隙，如以下所示，亦可在放大到 P〇F(2)之第2保護層（14)之徑的3倍以下的範圍內。 第4圖及第5圖顯示本發明之塑膠光纖軟線（1)之第2 實施形態》 塑膠光纖軟線（1)係由複數條（圖示爲4條）之POF(2)、 及將POF(2)彼此連接的連接用橋接器（4)所形成。 第2實施形態之塑膠光纖軟線（1)，連接用橋接器（4) 之大小係與第1實施形態者不同，因此複數條P〇F(2)之相 -14- 201126219 鄰P〇F彼此之間的間隙係大致等於POF(2)之最大徑的方式 以扁平狀態配置爲橫一列，連接用橋接器（4)係設置爲比第 1實施形態之連接用橋接器（3)更大P0F(2)之最大徑分量， 依此方式而將配置後的各P OF (2)之最下點彼此相連。 依此方式藉由將間隙放大，複數條P〇F(2)與第2圖所 示者爲相反方向之狀態，即來到連接用橋接器（4)之內側而 能變形爲捲曲之狀態（在第4圖之狀態中將直線狀之連接用 橋接器（4)變形爲U字狀）。 因而，當依本第2實施形態之塑膠光纖軟線（1)時，第 4圖所示之4條P〇F(2)可變形成並列爲橫一列的扁平狀 態、及第5圖所示之4條P0F(2)可變形成將連接用橋接器 (4) 作於外側而並列爲二列二層的狀態（全體爲作成剖面大 致圓形或剖面大致方形之捲曲狀態）。與第1實施形態同樣 地，可獲得使塑膠光纖軟線（1)通過孔的作業能容易地進行 之效果。因而，因應塑膠光纖軟線（1)之使用形態將間隙之 大小作成預定之値，將第1實施形態者與第2實施形態者 分開使用，藉此可對應更廣的範圍。 第6圖及第7圖顯示本發明之塑膠光纖軟線的第3實 施形態。 塑膠光纖軟線（1 )，係由複數條（圖示爲4條）之 P〇F(2)、及將P〇F(2)彼此連接的連接用橋接器（5)所形成。 本實施形態的塑膠光纖軟線（1)，在作成連接用橋接器 (5) 將各POF(2)之中央部彼此連接之點，與第1及第2實施 形態者不同。伴隨於此，相鄰POF(2)彼此之間的間隙係設 -15- 201126219 定爲比各P〇F(2)之徑更小一些。 當依此塑膠光纖軟線（1)時，可變形成第6圖所示之4 條POF(2)並列爲橫一列的扁平狀態、及第7圖所示之4條 POF(2)並列成二列二層的狀態（全體的剖面爲略圓形或剖 面略方形之捲曲狀態），與第1及第2實施形態同樣地，可 獲得使塑膠光纖軟線（1)通過孔的作業能容易地進行之效 果。 相對於在第1及第2實施形態中有區別上下之需要， 第3實施形態之塑膠光纖軟線（1)有不必要區別上下（不僅 可從第6圖所示之狀態變形爲第7圖所示的倒U字狀，雖 然圖示省略，但亦可變形爲U字狀）的優點，可適合於使用 在欲避開上下之區別的用途。在第1及第2實施形態者中， 清楚地進行上下之區別，有在連接之時容易分別左右之’連 接方向的優點。使此等對應用途而分開使用，藉此可適用 於各種用途。 當依照上述之第1到第3實施形態所示的塑膠光纖軟 線U)時，在不從外部對此施加力而爲自由狀態下沿著水平 面、垂直面等設置之時，複數條P OF (2)配置爲橫一列而在 扁平狀態之使用爲可能，以合成樹脂製造之連接用橋接器 (3 )(4)(5)在進行彈性變形時，能容易地使全體變形爲剖面 略圓形或剖面略方形之捲曲狀態，故藉由這種變形可使通 過配管內等之作業容易進行，因賦予前述1〜5之構成及藉 此等獲得的效果，能適合於藉由光纖傳輸光訊號的光傳輸 裝置（光通訊系統）之影像信號傳輸之用。上述塑膠光纖軟 -16 - 201126219 線（i)可與各種光模組組合使用，雖然其用途並未限定，但 特別適用於高度受限且配線空間極度受限制的電視內配線 等之影像關連光通訊系統。 此外，在電視內配線使用之情況，P〇F(2)之波長宜爲 5 00〜8 5 0nm，亦可爲 5 00~7 5 0nm(可視光線），亦可爲 7 80〜 8 5 0nm之光源（紅外線）。 實施例 製作表1所示使用塑膠光纖之塑膠光纖軟線，使用 C CD攝影機進行傳輸評價。塑膠光纖軟線（1)係作成第1圖 所示之第1實施形態者，將外覆層（第1保護層）（13)之直徑 作成75 Ομηι。芯部組成從實施例1至7均作成共同，氯苯 乙烯（CISt)爲70%，甲基丙基酸甲酯（ΜΜΑ)爲3 0%。實施例 8芯部中心部之組成係作成：氯苯乙烯（CISt)爲66%，甲基 丙基酸甲酯（MMA)爲28%，磷酸三苯酯（TPP)爲6%，使TPP 之濃度從中心部朝向半徑方向減少，藉以在芯部形成折射 率分布。包覆層之組成從實施例1至5均作成相同，苯乙 烯（St)爲40%，甲基丙基酸甲酯（MMA)爲60%。實施例6及 7與從實施例1至5及實施例8比較，苯乙烯增加而甲基 丙基酸甲酯則減少苯乙烯的分量。又，第1保護層及第2 保護層之原料分別爲聚碳化物酯及低密度聚乙烯》軟線長 度從實施例1至7均作成相同爲3 m，實施例8爲5 m »開 口數（NA)使用遠場圖形測定器而測定爲820nm。 -17- 201126219 [表1] 福 折射率 mm： 獅脈 雛 _ NA 分布 ⑽ CISt (**%) MMA mw/o) TPP eay〇) St (®S%) MMA 實施例1 200 0.33 SI 3 70 30 0 40 60 實施例2 150 0.33 SI 3 70 30 0 40 60 實施例3 80 0.33 SI 3 70 30 0 40 60 實施例4 250 0.33 SI 3 70 30 0 40 60 實施例5 320 0.33 SI 3 70 30 0 40 60 實施例6 200 0.28 SI 3 70 30 0 50 50 實施例7 200 0.22 SI 3 70 30 0 60 40 實施例8 200 0.35 SI 5 66 28 6 40 60 傳輸評價，係將從CCD攝影機輸出的類比信號轉換爲 數位信號，更加以序列化之後，以LVDS方式進行傳輸。 類比信號轉換、序列化、LVOS對應信號轉換係使用市販之 通訊用板。在各實施例中，作出8處或16處以半徑l〇mm 彎曲90度設置的配線，在受光元件之前設置及未設置透鏡 之情況分別進行評價。評價係以即時（real time)方式傳輸 C CD攝影機之影像，是否可顯示在顯示器上而進行。對1〇〇 個光模組進行發光側之連接而進行的結果顯示於表2。 -18- 201126219 [表2] 受光兀件有透鏡 受光元件李 蠛鏡 90度彎曲 8處 90度彎曲 16處 90度-曲 8處 90度彎曲 16處 實施例1 〇 〇 〇 〇 實施例2 〇 〇 〇 〇 實施例3 △3 △2 Δ4 Δ5 實施例4 〇 〇 〇 〇 實施例5 〇 〇 X X 實施例6 〇 〇 〇 △3 實施例7 〇 X X X 實施例8 〇 〇 〇 〇 表2中’〇、△及χ係分別表示下列意思。 〇：100個之連接均可顯示在顯示器。 △:所示之數字的個數之連接，無法顯示在顯示器。 X :無法顯示在顯示器。 由實施例3之傳輸評價結果了解，當芯徑爲8 0 μιη 時，有無法確保傳輸性能之可能性，故芯徑宜作成100 μιη 以上。又，由實施例5之傳輸評價結果了解，當芯徑爲320μιη 時，無法確保沒有受光透鏡之情況的傳輸性能之可能性爲 強，故芯徑宜作成300μιυ以下。又，由實施例6及7之傳 輸評價結果了解，當開口數爲0.22時，無法確保傳輸性能 之可能性爲強，當開口數放大到〇. 2 8時，雖然不是完全但 大致可確保，故開口數宜作成0.25以上，尤其是0.30以上。 又，由實施例8之傳輸評價結果了解，芯徑宜具有折射率 分布。 -19- 201126219 產業上利用之可能性 藉使用本發明之塑膠光纖軟線，可容易進行配線作 業，同時可將結合損失抑制在預定値以下，因此能有助於 電視內配線等之影像關連光通訊系統之性能提高。 【圖式簡單說明】 第1圖係顯示依本發明之塑膠光纖軟線之第1實施形 態的剖面圖。 第2圖係顯示將第1實施形態之塑膠光纖軟線變形後 之情況的形狀之剖面圖。 第3圖係以示意顯示連接依本發明之塑膠光纖軟線的 連接器及光源的圖，第3(a)圖係前視圖，第3(b)圖係俯視 圖。 第4圖係顯示依本發明之塑膠光纖軟線之第2實施形 態的剖面圖》 第5圖係顯示將第2實施形態之塑膠光纖軟線變形後 之情況的形狀之剖面圖。 第6圖係顯示依本發明之塑膠光纖軟線之第3實施形 態的剖面圖。 第7圖係顯示將第3實施形態之塑膠光纖軟線變形後 之情況的形狀之剖面圖。 【主要元件符號說明】 1 塑膠光纖軟線 2 POF(塑膠光纖） 3,4,5 連接用橋接器 -20- 201126219 6 缺口 11 芯部 12 包覆層 13 外覆層（第1保護層） 14 護套（第2保護層） -21 -BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic optical fiber cord for use in an optical module, and more particularly to a plastic optical fiber cord for an optical communication system suitable for image connection in a television. [Prior Art] Since the plastic optical fiber cord in the optical fiber is made of plastic, it has a disadvantage of slightly higher transmission loss than the quartz-based optical fiber, but it is lightweight, has good workability, and can be manufactured at low cost. The advantage is that in various optical groups in which optical communication is transmitted and received, it is often used for a short-distance optical transmission path in which transmission loss does not pose a problem. Patent Document 1 describes an optical fiber cord suitable for use in an optical module, in which four optical fibers are arranged in parallel, and a strip-shaped material of synthetic resin is used to cover a strip. PRIOR ART DOCUMENT PATENT DOCUMENT Patent Document 1: Japanese Laid-Open Patent Publication No. 2008-108 (No. 5, FIG. 5) [Summary of the Invention] [Problems to be Solved by the Invention] When an optical fiber cord is used for wiring in a television or the like It is a major issue to be able to perform wiring work easily, and it is also necessary to eliminate the problem that the coupling loss is easily increased due to the assembly error of the light-emitting elements. SUMMARY OF THE INVENTION An object of the present invention is to provide a plastic optical fiber cord which can be easily wired to 201126219. Even if the assembly error of the light-emitting element is large to some extent, the bonding loss can be suppressed to a predetermined value or less. [Means for Solving the Problem] According to the plastic optical fiber cord of the present invention, a plurality of plastic optical fibers are integrated into a strip shape, and each of the plastic optical fibers is composed of a core portion, a cladding layer surrounding the core portion, and a surrounding package. The first protective layer covering the first protective layer and the second protective layer surrounding the first protective layer are formed, and the plastic optical fibers are connected to each other by a bridge for connection integrally formed with the second protective layer. A plastic optical fiber (hereinafter referred to as "POF") is formed by a core formed of an organic compound having a polymer as a matrix, and having a refractive index different from that of the core (generally a polymer having a low refractive index) The coating layer formed) and the resin protective layer of one or more layers. The POF may be a step index (SI) type, which is composed of a material having a high refractive index at the core and a two-layer structure of a material having a low refractive index in the cladding layer; It may also be a graded index (Gl) type, and has a core having a distribution of refractive index from the center toward the outside (radial direction). Borrowing into a GI type makes high-speed communication possible. Generally, the transmission band is inversely proportional to the distance of the optical fiber. However, when the transmission band is considered to be fixed, the GI type enables communication over long distances more than the SI type. The protective layer surrounding the cladding layer is formed into three or more layers. In this case, the outermost layer corresponds to the second protective layer, and the bridge for connection is integrated with the protective layer of the outermost layer, and the first protective layer may be composed of a plurality of layers. form. The prior art plastic optical fiber cord has a structure in which the POF is fixed by a resin in such a manner as to maintain a flat state in a horizontal row. In contrast, in the plastic optical fiber cord according to the present invention, the POF is made of thickness and The two layers of approximately equal connections are connected to each other by a bridge. Thus, by using the bridge to have flexibility, not only the plastic optical fiber cord can be processed in a flat shape but also deformed into a curled state when passing through a circular hole. Further, the bridge for connection has a lower tear strength than the prior art, so that the separation of the plastic optical fiber cord into a single-core POF can be performed. Therefore, it is suitable for use in wiring and the like in a television. The connecting bridge can be disposed on the bottom surface (lowest point) or the top surface (upper point) of a plurality of P OFs in a horizontal plane, and is also placed in the center of the upper and lower sides (with the center of each P OF) The shaft is at the same height. The bridge for connection at any position between the bottom surface or the top surface and the center of the upper and lower sides is usually placed at the same position (so that all the bridge positions are in the same plane), but it is not limited. herein. The length of the connector is appropriately set by the position of the bridge for connection so as to be appropriately deformed into a state of being crimped. Although the number of cores of P OF is not limited, it is usually 20 cores or less in terms of ease of handling. When the core diameter of the POF is ΙΟΟμηη or more and preferably 150 μπιΗ_, even if the assembly error of the light-emitting element is large to some extent, the loss can be suppressed to be less than or equal to a predetermined value (for example, 3 dB or less). With respect to the light-receiving element of 120 μm, the area ratio is 144 when the core diameter exceeds 300 μm: the loss of light is large and the bonding loss exceeds -8 dB, so the core diameter of the POF is preferably 300 μm or less, more preferably 250 μm or less. In this way, the positioning when connecting with it is only required to be rough, which can reduce the degree of connection with the connection protection and can be easily set. When each connection bridge is set to the point t, the damage is 90 0, which makes it possible to connect the 201126219. The wire diameter of the POF is 2 mm or less, preferably 1.5 mm or less. 7 5 0 μηη or less. Here, the wire diameter of the POF refers to the diameter of the resin protective layer (overcoat layer) including the core portion and the protective layer. The core diameter is 1 〇〇μηι or more and the wire diameter of P 〇 F is 2 mm, which has the above effects and is easy to handle. In at least one of 500 to 850 nm of each plastic optical fiber cord, ΝΑ = (ηι2-η22), /2 (in the formula, the refractive index of the central portion of the core of the optical fiber: η, | has the lowest refractive index in the optical layer The partial refractive index: η2) indicates that the number of openings (ΝΑ) is 0.25 or more, and 0.3 is preferable. As described above, even when the POF is used in a bent state, it is lost. Therefore, even when the optical module in which the POF is bent is used as in the case of wiring in the television, the performance can be easily ensured. The upper limit of the number of openings is not particularly limited. The type of the plastic used as the core portion and the coating layer is not particularly limited as long as it can be used for light transmission. For example, a polymer of a propyl ester monomer or a polymer of a styrene monomer can be given. Examples of the propyl ester-based monomer include methyl propyl methacrylate, ethyl amide, η-methyl propyl methacrylate, and methyl η-methyl propyl acrylate. Examples of the propyl acrylate, the η-propyl propyl ester, and the η-propyl butyl methacrylate monomer include styrene (St), α-methyl styrene, chlorine (CISt), and bromostyrene. These copolymers are also fine. Others are better coatings and POFs, which are coated with a wavelength fiber to suppress the necessary high (M) (methyl) methyl propyl and propyl esters; 201126219 The composition may be, for example, vinyl acetate, vinyl benzoate, vinyl acetate, vinyl acetate, etc.; Nn-butyl maleimide, N-tert-butyl maleic acid A maleimide such as an imine, N-isopropylmaleic acid imide or N-cyclohexylmaleic acid imide. Others can also use polycarbonate plastic, cycloolefin plastic, amorphous fluorine plastic. The core of at least one plastic optical fiber (POF) preferably has a refractive index distribution. Thereby, good transmission performance can be obtained even when the length of the cord is long. The core forms a POF of a refractive index distribution, for example, by adding a few percent of triphenyl phosphate (TPP) to a core composition of a general SI type (for example, chlorostyrene/methyl methacrylate), from the center toward the radius Obtained by reducing the TPP concentration in the direction. The configuration in which the POFs are connected to each other by the bridge for connection is not particularly limited. However, for example, a plurality of P〇Fs may be arranged in a horizontal row to make the gap between the adjacent POFs zero or a small gap. The connection bridge is set such that the lowest point of the POF is connected to the point of the upper 45° of the lowermost point. Here, the "lowest point" means a bottom surface when a plurality of P0Fs are arranged in a horizontal row on a horizontal plane, and does not mean "down" when used. The face formed by the bridge for connection is parallel to the face passing through the center of each P OF. Thus, in the case where the plastic optical fiber cord is disposed along a horizontal plane, a vertical plane, or the like, a plurality of P〇F systems are arranged such that adjacent P0Fs are in contact with each other or in close contact with each other to make the flat state possible. In this state, even if a plurality of P〇Fs are deformed into a state of being curled by the inside of the connecting bridge, a plurality of P0Fs in which adjacent P0Fs are in contact with each other or almost in contact with each other hinder the deformation and make the plastic optical fiber. The cord can be handled as a normal state in the case of a flat state, so that on the other hand, the outer side of the POF of the plastic optical fiber cord is deformed into a curled state, which is easy to shape, and the plastic optical fiber cord can pass through the hole. If the operation is likely to make it difficult for a plurality of POFs to reach the state of the connection bridge, the gap between adjacent POFs such as the gap between adjacent POFs may be the maximum degree of POF. The lowest point is the fiber optic cord that is at the 45° upper point from the lowest point, and is treated as a normal flat state, and a plurality of POFs come to the outside of the bridge for connection. The 〇 or minute gap between the adjacent POFs of the plurality of POFs may be enlarged to a range less than the third time of P 〇 F. At this time, the adjacent P〇F is 0.25 to 2 times the POF diameter of the POF deformable portion of the connection bridge which is 0.75 times to 1.5 times the diameter of the POF. Further, the diameters of the adjacent POFs and the POFs are "substantially equal", and mean the phase gap in which the inner side of the plurality of bridges is deformed into a curled state, or the gap is a small gap. According to this, a plurality of POFs can be brought to the inner state of the bridge for connection, and the size of the gap can be set according to the form of use. The work is easy to enter. Come to the connection bridge ‘use this change. As long as it is deformed to the energy side, the curl may not be 0, and the range of 15% of the diameter of the diameter is such that the plastic can be easily curled and the gap is not limited to the diameter of the 2 protective layer. The gap spacing is preferred. Further, the length 'supplements should be made such that the gap between the gaps and the Ρ F F is equal to the gap between the adjacent Ρ 0 F of the connection, and is deformed into a curled one, thereby corresponding to each of the 201126219 Further, the connection bridge may be formed such that the central portions of the respective plastic optical fibers are disposed to be connected to each other. At this time, a plurality of POFs can be easily deformed into a curled state without distinguishing between the inner side and the outer side (upper side and lower side). That is, as described above, when the connection bridge is disposed such that the lowest point of the POF - the point at which the upper portion of the POF is 45 degrees from the lowermost point is connected to each other, with respect to the need for distinction between the upper and lower sides, by doing so, There are advantages to eliminating the need for distinction. On the other hand, the bridge for connection is set so that the lowest point of the plastic optical fiber is connected to the upper point of the 45° from the lowest point, and the difference between the upper and lower sides is clearly made, and the connection is easy to be left and right at the time of connection. The advantage of direction. It is possible to set the position of the bridge for connection due to the application. The synthetic resin forming the first protective layer, the second protective layer, and the bridge for connection of the POF is not limited, but it is preferably selected to satisfy the strength, flame retardancy, flexibility, and resistance required for POF and plastic optical fiber cords. Drug, heat resistance, etc. For example, vinyl chloride resin, chlorinated vinyl chloride resin, low density polyethylene, high density polyethylene, chlorinated polyethylene, ethylene-vinyl acetate copolymer, vinyl chloride-ethylene-vinyl acetate may be mentioned. A copolymer, an acrylic resin, a fluorine resin, a vinyl acetate-vinyl chloride copolymer, a polycarbide ester, or the like is a main component. Further, the binding force of each POF (the strength of the bridge for connection) is preferably 0.3 to 5 kgf. The thickness of the bridge for connection is set such that the respective restraining forces of the respective p〇F are within the above range. This restraining force is obtained at a speed of 100 mm/min, and can be determined by measuring the strength at which the two cores are pulled apart. In order to make the binding force into a predetermined crucible and to make the POFs easily separated from each other, it is also possible to provide a gap in the connection bridge. Although the gap can be set in all the bridges for connection, 201126219, but only a part of the bridge for connection. The notch can be formed during extrusion molding of a plastic optical fiber cord, and can be provided without an additional process. Although the plastic optical fiber cord can be used for various purposes, it is suitable for image signal transmission in an optical transmission device (optical communication system) for transmitting optical signals through an optical fiber, and is particularly suitable for extremely limited television wiring in a wiring space. Wait. In the case of wiring in a TV, the wavelength of the POF should be 500 to 850 nm, or 500 to 750 nm (visible light), or a light source (infrared) of 780 to 850 nm. [Effect of the Invention] According to the plastic optical fiber cord of the present invention, each of the plastic optical fibers is composed of a core portion, a cladding layer surrounding the core portion, a first protective layer surrounding the cladding layer, and a second protective layer surrounding the first protective layer. Since the protective layer is formed and the plastic optical fibers are connected to each other by the bridge for connection integrally formed with the second protective layer, it is possible to facilitate the wiring work in the image-related optical communication system such as the wiring inside the television. In addition, when the core diameter of each of the plastic optical fibers is ΙΟΟμηη or more and is 300 μm or less, even if the assembly error of the light-emitting element is large to some extent, the bonding loss can be suppressed to a predetermined value or less, and thus, the connector is The positioning at the time of connection can also be roughly rough, which can alleviate the trouble of connecting with the connector. [Embodiment] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the upper and lower sides of the figure are referred to as the upper and lower sides, and the left and right sides of the figure are referred to as the left and right. Fig. 1 and Fig. 2 show a first embodiment of a plastic optical fiber cord according to the present invention. -10 - 201126219 The plastic optical fiber cord (1) is formed by a plurality of (four-illustrated) POF (plastic optical fiber) (2) and a connecting bridge (3) that connects the POF (2) to each other. The plurality of POFs (2) are arranged in a horizontal state in a horizontal row so that the gap between adjacent POFs becomes 0 or a slight gap, and the bridge for connection (3) is set to each of the P0Fs configured in this manner ( 2) The lowest point is connected to each other. All of the POFs (2) have the same shape, and the connecting bridges (3) are also all formed in the same shape. When the plastic optical fiber cord (1) is disposed along a horizontal plane, a vertical plane, or the like, a plurality of POFs (2) are arranged in a horizontal row in such a manner that adjacent POFs are in contact with each other or are in close contact with each other, so that the use of a flat state is possible. In this state, even if a plurality of P〇F(2) are brought into the state of being crimped inside the connecting bridge (3) (in the state of Fig. 1, the linear connecting bridge (3) ) deformed into a U shape), a plurality of POFs (2) in which adjacent P0Fs are in contact with each other prevent this from being deformed, so that the plastic optical fiber cord (1) can be handled as a person who is always in a flat state, so that the work can be easily performed. get on. On the other hand, the plastic optical fiber cord (1) is deformed in a free state in which the connecting bridge (3) is not in contact with the horizontal plane, etc., and the plurality of P〇F(2) are deformed to the outside of the connecting bridge (3). In the state of being curled (the linear bridge (3) is deformed into an inverted U shape in the state of Fig. 1), it is easy to make the image as shown in Fig. 2, and the plastic fiber can be made by such deformation. The operation of the flexible wire (1) through the hole is easy. Each of the P0F (2) is formed by a core portion (11) formed of an organic compound having a polymer as a matrix, and having a refractive index different from that of the core (generally formed of a polymer having a refractive index of from low-11 to 201126219) The coating layer (12) protects the outer coating (first protective layer) (13) and the sheath (second protective layer) (14). The connecting bridge (3) is integrated with the sheath (14). This plastic optical fiber cord (1) is constructed in a 4-core ribbon structure formed of four POFs (2) in such a manner that a high-speed transmission speed can be obtained. However, the prior art 4-core cording system maintains four strips in a flat state in a row, and is a resin-fixed structure. In contrast, when the plastic optical fiber cord (1) is used, the first one shown in FIG. The strip P〇F(2) can be deformed into: a flat state in which the columns are arranged side by side, and the four POFs (2) shown in Fig. 2 are connected to the inner side of the bridge (3) and are arranged in two columns. The state of the second layer (the whole is a curled state in which the cross section is substantially circular or the cross section is substantially square). In the wiring inside the TV, the plastic optical fiber cord (1) of the 4-core strip structure is made into an end portion or a suitable intermediate portion is a 2-core or a single core, and the connecting bridges (3) are torn, which can be easily The 4-core strip structure is separated into a single core. In addition, by making the gap between the adjacent POFs of the plurality of P〇F(2) substantially 〇, even if the connecting bridge (3) sets the lowest point of each P〇F(2) to the lowest point The above effects can also be obtained when the points of the upper 90° (preferably the upper 45° uppermost point) are connected to each other. Fig. 3 shows an optical module (21) in the form of a plastic optical fiber cord (1) of the present invention. In Fig. 3, the optical module (21) includes a bottom substrate (22), four square plate-shaped light-emitting elements (23) arranged at predetermined intervals on the base substrate (22), and four fixing light-emitting elements (for fixing) 23) a transparent resin molding material (24), a driver IC (25) for driving each of the light-emitting elements (23), and a POF connector (26) formed with a soft plastic optical fiber - 12-201126219 Each P〇F(2) of the line (1) is aligned with each of the light-emitting elements (23) and has a circular POF insertion hole. In the light-emitting element (23), as shown in Fig. 3(b), there is an assembly error. Therefore, in the prior art, the coupling loss in the optical module (2 1) becomes large, and the plastic optical fiber cord (1) When each POF (2) is connected to the POF connector (26), it is necessary to suppress the positional deviation, and thus there is a problem that it takes a lot of trouble to connect. Therefore, in the plastic optical fiber cord (1) of the present embodiment, the above configuration is eliminated to eliminate the above problem. 1. The core diameter of POF (2) is ΙΟΟμηι or more and 300 μm or less. 2. The wire diameter of POF (2) is 2 mm or less. 3. The number of openings of POF (2) is 0.25 or more. 4. The plastic optical fiber cord (1) is made into a belt type (sand ribbon type) with a multi-core structure, and the binding force of the POF (2) is (the strength of the connecting bridge (3)) is 0.3 to 0·5 kgf° 5. The P〇F connector (26) that connects the plastic optical fiber cord (1) to the light source is flat. In addition, the number of openings mentioned above is represented by NA = (n/-1122) 1/2 in any one of the wavelengths of 5 00 to 850 nm. (In the formula, the refractive index of the central portion of the core of the optical fiber: n 1 ' is the refractive index of the portion having the lowest refractive index in the optical fiber cladding layer: nz). The effect obtained by using the above structures 1 to 5 is as follows: Since the core diameter of the POF (2) is ΙΟΟμηι or more and 300 ^ mW, even if the connection accuracy of the ifii POF connector (26) is rough. It is also possible to suppress the combined damage -13 - 201126219 below the predetermined threshold. For example, when the core diameter of P〇F(2) is ΙΟΟμιη » When the size of the light-emitting element (2 3 ) is 10 μm, the bonding loss can be suppressed to 3 dB or less even when the assembly error is ±50 μm. Since the wire diameter of the POF (2) is 2 mm or less, handling becomes easy. Since the number of openings of the POF (2) is 0..25 or more, as described later, it is possible to suppress the loss of bending and make the wiring uniform." The plastic optical woven cord (1) is formed into a belt type by a multi-core structure. (Sand ribbon type), the binding force of the POF (2) (the strength of the bridge for connection (3)) is 0.3 to 0.5 kgf, the bending is easy and the handling becomes easy, and when it is connected to the POF connector (26) Processing is also easy. Since the POF connector (26) that connects the plastic optical fiber cord (1) to the light source is flat, the thin structure of the connection portion of the plastic optical fiber cord (1) becomes possible. When used in wiring in a television or the like, the plastic optical fiber cord (1) is not limited to the embodiment shown in Figs. 1 and 2, and various forms are possible. For example, the gap between adjacent POFs of a plurality of P〇F(2) is not limited to a helium or a minute gap, and may be enlarged to a second protection of P〇F(2) as shown below. The diameter of the layer (14) is within 3 times or less. Fig. 4 and Fig. 5 show a second embodiment of the plastic optical fiber cord (1) of the present invention. The plastic optical fiber cord (1) is composed of a plurality of (four illustrated) POFs (2) and a POF (Fig. 2) Connections connected to each other are formed by a bridge (4). The plastic optical fiber cord (1) of the second embodiment differs from the first embodiment in the size of the bridge (4) for connection. Therefore, the phase of the plurality of P〇F(2)-14-201126219 neighboring P〇F is different from each other. The mode in which the gap is substantially equal to the maximum diameter of the POF (2) is arranged in a horizontal row in a flat state, and the bridge for connection (4) is set to be larger than the bridge for the connection (3) of the first embodiment. (2) The maximum diameter component, in which the lowest point of each of the configured P OF (2) is connected to each other. In this way, by enlarging the gap, the plurality of P〇F(2) and the second figure are in the opposite direction, that is, when they come to the inside of the connecting bridge (4), they can be deformed into a curled state ( In the state of Fig. 4, the linear connecting bridge (4) is deformed into a U shape. Therefore, in the case of the plastic optical fiber cord (1) according to the second embodiment, the four P〇F(2) shown in Fig. 4 are variably formed in a flat state in a horizontal row and in the fifth embodiment. The four P0Fs (2) are variably formed in a state in which the connecting bridges (4) are arranged on the outer side and are arranged in two rows and two layers (all in a curled state in which the cross section is substantially circular or the cross section is substantially square). As in the first embodiment, the effect of allowing the plastic optical fiber cord (1) to pass through the hole can be easily performed. Therefore, the size of the gap is made predetermined in accordance with the use form of the plastic optical fiber cord (1), and the first embodiment can be used separately from the second embodiment, thereby making it possible to cope with a wider range. Fig. 6 and Fig. 7 show a third embodiment of the plastic optical fiber cord of the present invention. The plastic optical fiber cord (1) is formed by a plurality of (four shown) P〇F(2) and a connecting bridge (5) that connects P〇F(2) to each other. The plastic optical fiber cord (1) of the present embodiment is different from the first and second embodiments in that the connection bridge (5) is connected to the central portion of each POF (2). Along with this, the gap between the adjacent POFs (2) -15-201126219 is set to be smaller than the diameter of each P〇F(2). According to the plastic optical fiber cord (1), the four POFs (2) shown in Fig. 6 can be formed and arranged in a flat state of one horizontal column, and four POFs (2) shown in Fig. 7 are juxtaposed into two. In the same manner as in the first and second embodiments, the state in which the plastic optical fiber cord (1) passes through the hole can be easily performed in the state of the second layer (the entire cross section is a slightly circular shape or a slightly rounded cross section). The effect. The plastic optical fiber cord (1) according to the third embodiment is not necessarily different from the upper and lower sides in terms of the difference between the first and second embodiments (not only from the state shown in Fig. 6 but also to the seventh figure). The inverted U-shape shown in the figure is not limited, but may be deformed into a U-shape, and may be suitable for use in a case where the difference between the upper and lower sides is to be avoided. In the first and second embodiments, the difference between the upper and lower sides is clearly distinguished, and there is an advantage that it is easy to separate the left and right 'connection directions at the time of connection. These uses can be used separately for various purposes, thereby being applicable to various uses. According to the plastic optical fiber cord U) shown in the first to third embodiments described above, when a force is applied from the outside to the horizontal plane, the vertical plane, or the like in a free state, a plurality of P OF (P OF ( 2) It is possible to use it in a flat state in a horizontal row, and the connecting bridges (3) (4) and (5) made of synthetic resin can be easily deformed into a slightly circular shape when elastically deformed. Or a slightly square-shaped curled state, so that the work such as the inside of the pipe can be easily performed by the deformation, and the effect obtained by the configuration of the above 1 to 5 and the like can be adapted to transmit the optical signal by the optical fiber. Optical signal transmission device (optical communication system) for image signal transmission. The above-mentioned plastic optical fiber soft-16 - 201126219 line (i) can be used in combination with various optical modules. Although its use is not limited, it is particularly suitable for image-related light such as TV inner wiring with limited height and extremely limited wiring space. Communication system. In addition, in the case of wiring in the television, the wavelength of P〇F(2) is preferably 500 to 850 nm, and may be 500 to 750 nm (visible light) or 7 80 to 850 nm. Light source (infrared). EXAMPLES A plastic optical fiber cord using a plastic optical fiber shown in Table 1 was produced, and a C CD camera was used for transmission evaluation. The plastic optical fiber cord (1) is the first embodiment shown in Fig. 1. The diameter of the outer cover (first protective layer) (13) is 75 Ομηι. The core composition was made common from Examples 1 to 7, with chlorostyrene (CISt) of 70% and methyl propyl methacrylate (30%). The composition of the central portion of the core of Example 8 was prepared as follows: chlorostyrene (CISt) was 66%, methyl methacrylate (MMA) was 28%, and triphenyl phosphate (TPP) was 6%, making TPP The concentration decreases from the center portion toward the radial direction, thereby forming a refractive index distribution in the core. The composition of the coating layer was the same from Examples 1 to 5, with styrene (St) of 40% and methyl propyl methacrylate (MMA) of 60%. In Examples 6 and 7, as compared with Examples 1 to 5 and Example 8, styrene was increased and methyl propyl methacrylate was used to reduce the amount of styrene. Further, the raw materials of the first protective layer and the second protective layer are respectively a polycarbide ester and a low-density polyethylene. The cord lengths are the same as 3 m from Examples 1 to 7, and Example 8 is 5 m » the number of openings ( NA) 820 nm was measured using a far field pattern measuring device. -17- 201126219 [Table 1] F refractive index mm: Lions _ NA distribution (10) CISt (**%) MMA mw/o) TPP eay〇) St (®S%) MMA Example 1 200 0.33 SI 3 70 30 0 40 60 Example 2 150 0.33 SI 3 70 30 0 40 60 Example 3 80 0.33 SI 3 70 30 0 40 60 Example 4 250 0.33 SI 3 70 30 0 40 60 Example 5 320 0.33 SI 3 70 30 0 40 60 Example 6 200 0.28 SI 3 70 30 0 50 50 Example 7 200 0.22 SI 3 70 30 0 60 40 Example 8 200 0.35 SI 5 66 28 6 40 60 Transmission evaluation, analog signal output from CCD camera Converted to a digital signal, more serialized, then transmitted in LVDS mode. Analog signal conversion, serialization, and LVOS-compatible signal conversion use a commercially available communication board. In each of the examples, wirings which were set at 8 or 16 and bent at 90 degrees in a radius of 10 mm were evaluated, respectively, before and after the light receiving elements were provided. The evaluation is performed by real-time transmission of the image of the C CD camera, whether it can be displayed on the display. The results of the connection of the light-emitting sides of one optical module are shown in Table 2. -18- 201126219 [Table 2] The light-receiving element has a lens light-receiving element. The mirror is bent at 90 degrees. The eight-part 90-degree bend is 16 at 90 degrees. The curved portion is at 90 degrees. The first embodiment is the first embodiment. Example 3 Δ3 Δ2 Δ4 Δ5 Example 4 〇〇〇〇 Example 5 〇〇 XX Example 6 〇〇〇 △ 3 Example 7 〇 XXX Example 8 〇〇〇〇 Table 2 in '〇, △ And the following indicate the following meanings. 〇: 100 connections can be displayed on the display. △: The number of connections shown is not displayed on the display. X : Cannot be displayed on the monitor. From the results of the transmission evaluation of Example 3, it is understood that when the core diameter is 80 μm, there is a possibility that transmission performance cannot be ensured, so the core diameter should be made 100 μm or more. Further, from the results of the transmission evaluation of Example 5, it is understood that when the core diameter is 320 μm, the possibility of ensuring the transmission performance without the light receiving lens is strong, and therefore the core diameter is preferably made 300 μm or less. Further, from the results of the transmission evaluation of Examples 6 and 7, it is understood that when the number of openings is 0.22, the possibility of ensuring the transmission performance is strong, and when the number of openings is enlarged to 〇. 2 8 , although it is not complete, it is substantially ensured. Therefore, the number of openings should be 0.25 or more, especially 0.30 or more. Further, from the results of the transmission evaluation of Example 8, it is understood that the core diameter preferably has a refractive index distribution. -19- 201126219 The possibility of industrial use By using the plastic optical fiber cord of the present invention, wiring work can be easily performed, and the coupling loss can be suppressed below a predetermined threshold, thereby facilitating image-related optical communication such as wiring in a television. The performance of the system is improved. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross-sectional view showing a first embodiment of a plastic optical fiber cord according to the present invention. Fig. 2 is a cross-sectional view showing the shape of the plastic optical fiber cord of the first embodiment after being deformed. Fig. 3 is a view schematically showing a connector and a light source for connecting a plastic optical fiber cord according to the present invention, Fig. 3(a) is a front view, and Fig. 3(b) is a plan view. Fig. 4 is a cross-sectional view showing a second embodiment of the plastic optical fiber cord according to the present invention. Fig. 5 is a cross-sectional view showing the shape of the plastic optical fiber cord of the second embodiment. Fig. 6 is a cross-sectional view showing a third embodiment of the plastic optical fiber cord according to the present invention. Fig. 7 is a cross-sectional view showing the shape of the plastic optical fiber cord of the third embodiment after being deformed. [Main component symbol description] 1 Plastic optical fiber cord 2 POF (plastic optical fiber) 3, 4, 5 Connection bridge -20- 201126219 6 Notch 11 Core 12 Cover layer 13 Cover layer (1st protective layer) 14 Set (2nd protective layer) -21 -