PROBLEM TO BE SOLVED: To provide a control device capable of acquiring suitable captured images of a treatment instrument and a subject even when the treatment instrument is included within an imaging range, and to provide an endoscope apparatus, a diaphragm control method, etc.SOLUTION: The control device 100 includes: an image acquisition unit 204 for acquiring the captured image from an imaging section 200 that images the subject 101 a treatment instrument presence/absence determination unit 212 for determining whether the treatment instrument for applying a treatment to the subject 101 is included within the imaging range of the imaging section 200 and a diaphragm control unit 209 for controlling a diaphragm of the imaging unit 20 based on the determination result on whether the treatment instrument is included within the imaging range.COPYRIGHT: (C)2012,JPO&INPIT【課題】処置具が撮像範囲に含まれている場合にも処置具や被検体の好適な撮像画像を取得可能にする制御装置、内視鏡装置及び絞り制御方法等の提供。【解決手段】制御装置100は、被検体101を撮像する撮像部200からの撮像画像を取得する画像取得部204と、撮像部200の撮像範囲内に、被検体101に対して処置を施すための処置具が含まれているか否かを判定する処置具有無判定部212と、撮像範囲内に処置具が含まれているか否かについての判定結果に基づいて、撮像部20の絞り制御を行う絞り制御部209を含む。【選択図】図3
