Optical device

#1. Field of the Invention

#The present invention relates to an optical device having an optical system mount plate, on which an optical system is mounted, and a casing, in which the optical system mount plate is housed, and more particularly to an optical device in which a bottom of the casing is provided with a screw-hole forming part which is threadingly fit on a screw provided on a tripod head.

#2. Description of the Related Art

#The objects and advantages of the present invention will be better understood from the following description, with reference to the accompanying drawings in which:

#FIG. 1 is a horizontal sectional view showing an embodiment of an optical device according to the present invention, in a state in which a movable casing section is set at a retracted position;

#FIG. 2 is a sectional view along line II-II of FIG. 1;

#The present invention will be described below with reference to the embodiments shown in the drawings.

#FIG. 1 shows an internal structure of an optical device, to which an embodiment of the present invention is applied, the optical device being a binocular telescope with a photographing function. FIG. 2 is a sectional view along line II-II of FIG. 1, and in FIG. 2, some elements are omitted so as to simplify the drawing. In the embodiment, the binocular telescope has a casing 10, which comprises a main casing section 10A and a movable casing section 10B.

#A pair of telescopic optical systems 12R and 12L are provided in the casing 10. The telescopic optical systems 12R and 12L have a symmetrical structure, and are used for a right telescopic optical system and a left telescopic optical system. The right telescopic optical system 12R is mounted in the main casing section 10A, and contains an objective lens system 13R, an erecting prism system 14R, and an ocular lens system 15R. An observation window 16R is formed in a front wall of the main casing section 10A, and is aligned with the objective lens system 13R. The left telescopic optical system 12L is mounted in the movable casing section 10B, and contains an objective lens system 13L, an erecting prism system 14L, and an ocular lens system 15L. An observation window 16L is formed in a front wall of the movable casing section 10B, and is aligned with the objective lens system 13L.