PURPOSE: To obtain the appropriate retracting amount of a light or a tray table without using an expensive potentiometer and a controller by providing a sensor for detecting the approach of the heat part of a patient only in the course of operation of a chair on the light, and retracting the light so as not to collide with the head part of the patient by a signal from the sensor.
CONSTITUTION: An ultrasonic distance sensor 17 for detecting the approach of the heat part of a patient to a light 13 only in the course of operation of a chair 5 is provided on the lower end part of the light 13, and in the case of operating the chair 5 in order to rinse out his mouth, approach of the heat part of the patient to the light 13 is detected by the ultrasonic distance sensor 17, and it is retracted to a position in which it does not collide with the heat part of the patient by an adjustment motor. Or an ultrasonic distance sensor 18 for detecting the approach of the upper body of the patient to a tray table 8 is provided on the patient side end of the lower face of the tray table 8, and when it is detected by the ultrasonic distance sensor 18 that the upper body of the patient approaches the tray table, the tray table 8 is retracted to a position in which the upper body of the patient does not collide therewith by an actuator.
KIMURA SHIYUUSUKE
NOGUCHI KUNITOSHI
