| 摘要 |
PURPOSE:To make the area of the photodetecting device smaller than the conventional area and to make the attitude detecting device in the excavator compact, economical and advantageous by being equipped with the recessed surface reflection mirror to reflect the laser beam and equipped with the photodetecting element along the locus line of the focus of the recessed surface reflection mirror. CONSTITUTION:The first and second half mirrors 10 and 11 to a projecting laser beam L are provided in parallel on a reference axial line P of the excavator, reflecting laser beams L1 and L2 are respectively photodetected, and the first and second photodetecting devices 12 and 13 to detect the photodetecting position respectively concerning in one axial direction are provided. The third two-axial direction photodetecting position detecting type photodetecting device 16, in which the photodetecting position detecting direction to a transmitting laser beam L3 comes to be X axial and Y axial directions, is provided in the condition orthogonal to the reference axial line P. For the first and second half mirrors 10 and 11, the reflecting surface is formed at the curved surface equivalent the locus to shift in parallel the curved line approximate to the parabola. The first and second photodetecting devices 12 and 13 are equipped with a photodetecting element 15 along the locus line of the focus to the parabola to form the curved surface. |
