PROBLEM TO BE SOLVED: To provide an electronic endoscope system capable of obtaining sufficiently bright images without affecting observation with special light even when the system is in a distant view observation condition in which light quantity is short.SOLUTION: In a close view observation mode, image pickup is executed by irradiating a body cavity with a first blue narrow band light Bn1 and a first green narrow band light Gn1. An exposure quantity is detected from image pickup signals obtained by the image pickup. If the exposure quantity is less than a predetermined value, the close view observation mode is switched to a distant view observation mode. In the distant view observation mode, the image pickup is executed by irradiating the body cavity with a second blue narrow band light Bn2 obtained by increasing a half value width of the first blue narrow band light Bn1 and a second green narrow band light Gn2 obtained by increasing a half value width of a first green narrow band light Gn1. As described above, since the second blue narrow band light Bn2 and the second green narrow band light Gn2 have a half value width wider than that of the first blue narrow band light Bn1 and the first green narrow band light Gn1 respectively, light quantity shortage in the distant view observation can be solved.COPYRIGHT: (C)2012,JPO&INPIT【課題】光量が不足する遠景観察状態にある場合であっても、特殊光観察に影響を与えることなく、十分に明るい映像を取得することができる。【解決手段】近景観察モード時には、第1青色狭帯域光Bn1及び第1緑色狭帯域光Gn1を体腔内に照射して撮像する。この撮像により得られる撮像信号から露光量が検出される。露光量が一定値未満である場合には、近景観察モードから遠景観察モードに切り替えられる。遠景観察モードでは、第1青色狭帯域光Bn1の半値幅を拡げた第2青色狭帯域光Bn2及び第1緑色狭帯域光Gn1の半値幅を拡げた第2緑色狭帯域光Gn2を体腔内に照射して撮像する。第2青色狭帯域光Bn2及び第2緑色狭帯域光Gn2は第1青色狭帯域光Bn1及び第1緑色狭帯域光Gn1と比較して半値幅が拡がっているため、遠景観察時における光量不足が解消される。【選択図】図5
