PURPOSE: To prevent damage on an optical beam scanning mechanism in an automatic medical examination car by supporting the optical beam scanning mechanism using a lever member supported by a base through a hollow elastic member so as to absorb impact and vibration in transport.

CONSTITUTION: A supporting table 54 of an optical beam scanning mechanism is supported by a lever member 80a and an axis member 84a supported by a base 50 through a bolt 100, a coil spring 98 and a hollow elastic member 82a. When the base 50 is vibrated up and down by driving of a medical examination car, an amount of displacement of a locking member 86a is a rotation with the axis member 84a of the lever member 80a around a locking member 94a, and the hollow elastic member 82 is pressed in the form that the displacement amount is added and releases inside air to the outer air through a ventilation hole 92a so as to carry out a damping action. Thus, damage on the optical beam scanning mechanism is prevented and accurate reading can be ensured.