Abstract:
A drive-condition setting device applied to an optical scanning apparatus having a fiber and an actuator that vibrates a distal end of the fiber, the drive-condition setting device detects a scan pattern of the illumination light output from the fiber, measures resonance frequencies in the x direction and the y direction of the fiber, sets a drive frequency and a drive voltage based on the resonance frequencies such that conditional expressions below are satisfied: when fx>fy, fd fx and Vx≤Vy (2), and when fx≤fy, fd fy and Vx≥Vy (4) where fd denotes the drive frequency, Vx denotes a maximum voltage of a X direction drive signal, and Vy denotes a maximum voltage of a y direction drive signal.
Abstract:
A scanning endoscope system includes an endoscope that includes an illumination fiber that is configured to guide illumination light for illuminating a subject and to emit the illumination light from an emitting end, and an actuator section that is configured to swing the emitting end of the illumination fiber according to a voltage or a current of an electrical signal that is applied to cause the illumination light to scan the subject, and a driver unit configured to apply, to the actuator section, the electrical signal that takes, as a drive frequency, a frequency at which an amount of change in amplitude at a time of swinging of the emitting end of the illumination fiber is at or below a predetermined value even when frequency characteristics of the amplitude are changed due to a change in a use condition of the endoscope.
Abstract:
A vibration generating unit includes an element unit, and the element unit includes a piezoelectric element generating an ultrasonic vibration by being supplied with electric power. A proximal-side fixing member abuts on the element unit from a proximal direction side and a distal-side fixing member abuts on the element unit from a distal direction side such that the element unit is sandwiched between the proximal-side fixing member and the distal-side fixing member in a longitudinal direction. The distal-side fixing member has a greater acoustic impedance than the proximal-side fixing member.