Patent ID: 6624402
Filing Date: 2003-09-23
Classification: G01C,G02B

Abstract:
A surveying instrument having an AF apparatus, comprising:a focus detector that detects a focus state of a focusing lens through a collimation telescope, and that outputs an indication of the focus state; and a controller that moves the focusing lens of the collimation telescope to a focal position, based on the output from the focus detector, said controller moving the focusing lens of the collimation telescope a specific default distance to another focal position when the focus detector outputs an out-of focus state after the controller moves the focusing lens of the collimation telescope to the focal position; wherein said surveying instrument includes a single focus mode at which only one detection of the output of the focus detector and only one movement of the focusing lens by the controller, based on the detected output, are carried out, and a continuous focus mode at which a plurality of detections of the output of the focus detector and a plurality of movements of the focusing lens by the controller, based on the detected outputs, are sequentially carried out, said detection and said movement, of said single focus mode and said continuous mode, being selectively performed.