| 摘要 |
PURPOSE:To reduce cost by providing a shared eyepiece part for a graduated optical system and a centripetal optical system, reflecting a light path for a centripetal optical system at a prearranged position in the light path, thus providing a reflective member facing toward the eyepiece part. CONSTITUTION:A light (a) on a graduated optical system focuses an image on a focusing plate 6 through a horizontal graduated plate 3 and objective lens 4, 5. In the meantime, the light (a) is already past a perpendicular graduated plate which turns to meet the rotation of a telescope prior to the entry of the said light into a support 1 of the telescope that turns on a fixed part 2 and the image of the said light on the graduated plate is in a conjugated position with a horizontal graduated plate 3. A centripetal operation is carried out by inserting an insertable/detachable rectangular prism 7 provided at a cross point for the light (a) and a perpendicular shaft so that a cross line 30 on a focussing plate 10 within the visual field of the eyepiece part 8 may overlap a center of surveying 31. The prism 7 is removed from the light path and readings of an image (312) on a horizontal graduated disc 3 which appears in a window H and a value of a rotary position (92) H and a value of a rotary position (92) inside a vertical plane which appears in a window V are obtained. In this manner, it is possible to reduce the cost of a device. |
