| 摘要 |
PROBLEM TO BE SOLVED: To provide a lens device that can prevent dew formation from being generated in a lens irrespective of a temperature of a use environment.SOLUTION: A lens device 300 detachably connected to an imaging device imaging a subject and generating image data of the subject comprises: a lens frame 310 that houses and fixes a plurality of lenses with optical axes of the plurality of lenses aligned and arranged inside; a first lens 320 that is fixed at one end of the lens frame 310; a second lens 330 that is fixed at an intermediate part in an optical axis direction of the lens frame 310; and a third lens 340 that is fixed at other end of the lens frame 310. The lens frame 310 includes a connection hole 318 connecting first space K1 and second space K2, and a ratio of a surface area of an external face of the lens frame 310 to a volume of the lens frame 310 is more than 4. Further, the lens frame 310 has pressing rings and sealing members which are high in thermal conductivity interposed between the first lens and the third lens and between the third lens and the lens frame. |
