PROBLEM TO BE SOLVED: To visually confirm a filled state of an adhesive poured into between a protective cover and a sleeve member.SOLUTION: An illumination optical system unit 26A comprises an optical fiber 37A, a phosphor 38, a ferrule 60 as a holding member for holding the phosphor 38 and the optical fiber 37A, a cylindrical sleeve member 61 for covering the outer periphery of the phosphor 38, and a protective cover 36 for sealing the distal end of the sleeve member 61. The ferrule 60 holds the phosphor 38 and is fitted in a fitting hole 71 of the sleeve member 61. Since an uneven pattern 75 which emits a structural color is formed at a receiving part 70 of the sleeve member 61, when the adhesive 72 is poured into from a gap between the outer peripheral surface 36a of the protective cover 36 and the inner peripheral surface 70a of the receiving part 70, the filling state of the adhesive 72 is viewed from the distal end side of the protective cover 36.COPYRIGHT: (C)2012,JPO&INPIT【課題】保護カバーとスリーブ部材との間に流し込んだ接着剤の充填状態を視認可能とする。【解決手段】照明光学系ユニット26Aは、光ファイバ37Aと、蛍光体38と、蛍光体38及び光ファイバ37Aを保持する保持部材としてのフェルール60と、蛍光体38の外周を覆う筒状のスリーブ部材61と、スリーブ部材61の先端を封止する保護カバー36とから構成される。フェルール60は、蛍光体38を保持し、スリーブ部材61の嵌合孔71に嵌合される。スリーブ部材61の受け部70に構造色を発する凹凸パターン75が形成されているので、保護カバー36の外周面36aと受け部70の内周面70aとの隙間から接着剤72を流し込んだとき、保護カバー36の先端側から接着剤72の充填状態を視ることができる。【選択図】図6
