Problem to be solved: to provide an electronic endoscope system capable of photographing an object image illuminated by any illumination light with proper exposure when observing an object using illumination light having different characteristics.An electronic endoscope system according to one embodiment of the present disclosure repeats alternating illumination and illumination of illumination light and non illumination, and illuminates the first illumination light, and at least one of light and spectral characteristics is different from the first illumination light A light source portion which switches alternately between illumination light and an image pickup device for imaging an object illuminated by illumination light, and a charge stored in the imaging element during the illumination period of illumination light are read from all pixels which are non illumination periods of the illumination light following the irradiation period PeriodAn image pickup device control means is provided. The light amount of the first illumination light is larger than the light amount of the second illumination light, and the irradiation period of the first illumination light is shorter than the irradiation period of the second illumination light. Further, the sum of the irradiation period of the first and second illumination light and the whole pixel reading period for one period is formed so as to be an integral multiple of the entire pixel readout period.Diagram【課題】特性の異なる照明光を使用して被写体を観察する場合に、何れの照明光で照明された被写体像も適正露出で撮影可能な電子内視鏡システムを提供する。【解決手段】本開示の一実施形態に係る電子内視鏡システムは、照明光の照射と非照射とを交互に繰り返し、且つ照射する照明光を、第1の照明光と、光量及び分光特性の少なくとも一方が該第1の照明光と異なる第2の照明光と、の間で交互に切り替える光源部と、照明光により照明された被写体を撮像する撮像素子と、照明光の照射期間中に撮像素子にて蓄積された電荷を、該照射期間に続く該照明光の非照射期間である全画素読み出し期間に読み出す撮像素子制御手段と、を備えている。そして、第1の照明光の光量は、第2の照明光の光量よりも大きく、第1の照明光の照射期間は、第2の照明光の照射期間よりも短い。また、一周期分の、第1および第2の照明光の照射期間と全画素読み出し期間との合計が、全画素読み出し期間の整数倍となるように構成されている。【選択図】図5
