| 摘要 |
PROBLEM TO BE SOLVED: To provide a pair of binoculars where a convergence value is surely accurately corrected at the time of short-distance observation with simple structure and by which high optical accuracy is obtained. SOLUTION: In a pair of binoculars 1, the convergence value is corrected by turning objective optical systems 21L and 21R interlocked with the actuation of a focusing mechanism 5 so as to change a distance between their optical axes O<SB>1L</SB>and O<SB>1R</SB>. The centers of the optical systems 21L and 21R exist outside from lines 400L and 400R passing the centers of turning (guide shafts 11L and 11R) and parallel with the up-and-down direction of a pair of binoculars 1 in Figure in an infinity focusing state, and also exist inside from the lines 400L and 400R in the shortest distance focusing state. When the tilt angles of line segments 500L and 500R linking the centers of the optical systems 21L and 21R with the centers of turning thereof in the infinity focusing state to the up-and-down direction are defined asαand focusing is gradually performed from the infinity focusing state toward a short distance side,αis kept a fixed value until the focal distances of observation optical systems 2L and 2R become a prescribed value (convergence value correction starting distance). COPYRIGHT: (C)2005,JPO&NCIPI
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