| 摘要 |
PURPOSE:To accurately secure the accuracy of a stop position at a returning time even when the moving speed of an optical system unit is changed. CONSTITUTION:When the first moving frame 6 of the optical system by an arrow 31), reference movement quantity to a shown by an arrow 31), reference movement quantity to a return position 5 from the position of a timing switch 15 is actually measured by the number of pulses, for example. From the reference movement quantity, braking movement quantity which is required for setting the moving speed of the unit 3 on the returning path of the unit 3 to be prescribed at the position of the switch 15 and previously stored in a memory is subtracted. Besides, the traveling movement quantity of the unit 3 is calculated. Then, the braking of the unit 3 is started to be controlled from a position where the unit 3 is returned by the traveling movement quantity after it starts a return action from the position 5. In such a manner, the unit 3 is controlled so as to secure a distance required for braking based on the distance that the unit 3 is actually moved. |
