PROBLEM TO BE SOLVED: To easily and surely detect a light transmission loss occurring at an intermediate part of an optical path from a light source to an illumination window at the distal end of an endoscope.SOLUTION: The endoscope apparatus 100 includes: a plurality of illumination windows 43A, 43B arranged at the distal end of an endoscope insertion part 25 inserted into a subject, to emit illumination light. The endoscope apparatus includes the light source LD light guide members for transmitting output light from the light source LD to the plurality of illumination windows 43A, 43B respectively through the endoscope insertion part 25 wavelength changing members 57A, 57B arranged between the light emission ends of the light guide members and the illumination windows 43A, 43B respectively to change the wavelength of light transmitted by the light guide members a single temperature sensor 63 for detecting heat generation from the wavelength changing members and a light transmission loss detecting means for detecting the occurrence of light transmission loss of the light guide members based on the change of a temperature detection value output from the temperature sensor 63 when the light source LD is lighted.COPYRIGHT: (C)2012,JPO&INPIT【課題】光源から内視鏡先端部の照明窓までの光路途中に発生する光伝送損失を、簡単かつ確実に検出する。【解決手段】内視鏡装置100は、被検体内に挿入される内視鏡挿入部25の先端に、照明光を出射する複数の照明窓43A,43Bが配置されている。この内視鏡装置は、光源LDと、光源LDからの出力光を内視鏡挿入部25を通じて複数の照明窓43A,43Bのそれぞれに伝送する導光部材と、導光部材の光出射端と照明窓43A,43Bとの間にそれぞれ配置され、導光部材により伝送される光を波長変換する波長変換部材57A,57Bと、波長変換部材からの発熱を検出する単一の温度センサ63と、光源LDの点灯時に温度センサ63から出力される温度検出値の変化に基づいて、導光部材の光伝送損失の発生を検出する光伝送損失検出手段と、を備えた。【選択図】図1
