To enable a surveying instrument to focus on an object surely even under an environment in which a subject becoming a range noise is present in between the surveying instrument and the object without Loss of convenience by an automatic focusing function by making the instrument to be of the constitution in which an automatic focusing function and a distange priority focusing function are selectively used.
A focus lens position control part 44 moves a focus lens 31 to a focal position by operating a focus lens driving device 27 based on the output of either a focus lens position calculating part 23 or a focusing state calculating part 42 and the lens position data of the focus lens 31 detected by a focus lens position detector 29. The movement control of the focus lens 31 is performed in an automatic focusing mode in a state in which the focusing state calculating part 42 is connected to the focus lens position control part 44 by a focusing mode selection switch 45 and also is performed in a distance priority mode in a state in which the focus lens position calculating part 23 is connected to the focus lens position control part 44.
KOJIMA YOICHI
TAKAYAMA MOCHIYUME
Next Patent: CONVERGING LENS