Electronic leveling apparatus and method of controlling focusing operation of the electronic leveling apparatus

摘要

The present invention intends to provide an electronic leveling apparatus or the like in which a pattern image of a staff received on a photoelectric converting unit is converted into an electric signal, a peak of contrast is detected based on the obtained electric signal, and thus focusing control is carried out. According to the arrangement of the present invention, there is provided an electronic leveling apparatus for use with a staff as a target of collimation having a pattern arrayed in the longitudinal direction thereof for determining level difference, in which a telescope optical system including a focusing optical system forms an image of the pattern, a photoelectric converting unit receives a light beam from the telescope optical system and converts the light beam into a signal of the pattern, a focusing drive unit forms the pattern on the photoelectric converting unit, and a focusing control unit detects a focusing status and controls the focusing drive unit based on the output signal from the photoelectric converting unit.