| 摘要 |
PURPOSE:To detect accurately the number of revolutions of a rotary scanning part which is incorporated in a fore-end probe of an ultrasonic catheter diagnos tic device. CONSTITUTION:A light-projecting part 13 held by a holder 17 is disposed in a fore-end probe 3 of a small-diameter tube and a reflecting plate 20 for reflecting and diffusing a light flux emitted from this light-projecting part 13 is provided so as to oppose the holder 17. A light-sensing part 15 sensing the total quantity of light on the front of the reflecting plate 20 is held at a position being apart from the light-projecting part 13 of the holder 17. A rotary disk 19 having a radial light-intercepting pattern is fixed at a middle position in the axial direction between the holder 17 of a rotating shaft 9 of a rotary reflector 5 and the reflecting plate 20. A fixed disk 18 having light-intercepting patterns and interrupting an optical path from a light-emission space to the light-sensing part 15 by superposition of the light-intercepting patterns is fixed on the inner peripheral surface of a liner tube 6 coaxially with the rotary disk 19. The number of times of the interruption of the optical path which corresponds to the number of revolutions of the rotary reflector 5 is measured. |
