| 摘要 |
An endoscope apparatus includes an ultrasonic transducer disposed at the distal end portion of an endoscope. The ultrasonic wave transmission/reception time of the ultrasonic transducer is measured by a time counter. The measured time from the time counter and the velocity of propagation of ultrasonic wave are operated on by a calculator to calculate the distance between the distal end portion and a subject. The distance and the view angle of an observation optical system are operated on by a calculator, the ratio between the size of an image in the field of view of the observation optical system and the size of the subject is calculated, and the scale of a scale display panel disposed inside the field of view of the optical system is indicated in accordance with such ratio. The graduations of the scale are variable as a function of said calculated ratio. |
