The light scanning endoscope apparatus includes an illution optical fiber that emits light from a distal end portion supported swingably, a driving section that drives a distal end portion of the illution optical fiber, and a driving section that illutes the driving section And a signal generation unit for generating a drive signal D for spirally scanning the tip portion of the optical fiber. The signal generating unit includes an amplitude enlargement period P1 for enlarging the amplitude of the fiber drive signal D substantially from 0 to a maximum value, an amplitude reduction period P2 for reducing the amplitude of the drive signal from the maximum value to 0 practically, , And the envelope E of the drive signal D is smoothly connected with the inclination of substantially 0 at the boundary between the amplitude expansion period P1 and the amplitude reduction period P2, and the amplitude expansion period P1 and the amplitude The longer period of the reduction period P 2 is set as the effective scanning period.光走査型内視鏡装置は、揺動可能に支持された先端部から光を射出する照明用光ファイバと、照明用光ファイバの先端部を駆動させる駆動部と、駆動部に対して照明用光ファイバの先端部をスパイラル走査させる駆動信号Dを生成する信号生成部とを備える。信号生成部は、前記ファイバの駆動信号Dの振幅を実質的に0から最大値まで拡大する振幅拡大期間P1と、駆動信号の振幅を最大値から実施的に0まで縮小させる振幅縮小期間P2とを含む駆動信号Dを生成し、振幅拡大期間P1と振幅縮小期P2との境界において、駆動信号Dの包絡線Eは傾きが実質的に0で滑らかに繋がっており、振幅拡大期間P1と振幅縮小期間P2のうち長い方の期間を有効走査期間とする。
