PROBLEM TO BE SOLVED: To maintain visibility of a structure of interest, such as a surface blood vessel, in narrow band light observation using a complementary color system image pickup device.SOLUTION: A V-LED 20a emits purple narrow band light Vn. A G-LED 20c emits green light G that is then converted into green narrow band light Gn through wavelength restriction by a green narrow band filter 22. The inside of a subject is alternately irradiated with the purple narrow band light Vn and the green narrow band light Gn through alternate lighting up of the V-LED 20a and the G-LED 20c. A complementary color system image pickup device 29 includes a Cy pixel and a Mg pixel that are sensitive to both of the purple narrow band light Vn and the green narrow band light Gn. The complementary color system image pickup device 29 outputs a first image signal by picking up an image of the subject under illumination with the purple narrow band light Vn and outputs a second image signal by picking up an image of the subject under illumination with the green narrow band light Gn. A special image, in which visual recognition is possible while separating a surface structure such as a surface blood vessel, and a medium-deep structure such as medium-deep blood vessel from each other, is displayed on a monitor 5 on the basis of the first and second image signals.COPYRIGHT: (C)2015,JPO&INPIT【課題】補色系撮像素子を用いる狭帯域光観察において、表層血管など注目する構造の視認性を維持する。【解決手段】V-LED20aは紫色狭帯域光Vnを発する。G-LED20cは緑色光Gを発し、この緑色光Gは緑色狭帯域フィルタ22で波長制限されて緑色狭帯域光Gnとなる。V-LED20aとG-LED20cを交互に点灯することにより、紫色狭帯域光Vnと緑色狭帯域光Gnとが交互に検体内に照射される。補色系撮像素子29は、紫色狭帯域光Vnと緑色狭帯域光Gnの両方に感応するCy画素及びMg画素を有する。補色系撮像素子29は、紫色狭帯域光Vnで照明中の検体を撮像して第1画像信号を出力するとともに、緑色狭帯域光Gnで照明中の検体を撮像して第2画像信号を出力する。これら第1及び第2画像信号に基づいて、表層血管などの表層の構造と、中深層血管など中深層の構造とを分離して視認することができる特殊画像がモニタ5に表示される。【選択図】図2
