Lens holding device

Abstract

Abstract PURPOSE:To hold the capacity of a lens and to form a lens system having a high temperature resistance, by fitting deformation absorbing parts, which absorb thermal stress, to each other and fixing the lens into a lens housing so that the shape of the lens is not changed even by the variation of temperature when the lens is fitted to a lens fitting part of the lens housing. CONSTITUTION:When the variation of temperature is given to a selfdeformation absorbing lens 40 fixed into a lens housing 30, a plastic lens body 41 is expanded and contracted in accordance with the repetition of the variation of temperature; and at a high temperature, the thermal stress generated in the radial direction is absorbed by the elastic deformation of a lens housing deformation absorbing part 32, which is provided in the lens housing 30, and a lens deformation absorbing part 42, which is provided on the outside circumference of the lens body 41, to prevent the change of the radius of curvature of the plastic lens body 41. Therefore, since it is unnecessary to widen the clearance to a lens fitting part 33 specially and it is possible to set the lens as conventional, the capacity of the lens is held in the same level as conventional. Thus, the movement of the focus position and the degradation of aberrations due to the variation of temperature are prevented, and the use temperature range is extended in case of a plastic lens especially.

Inventors

• 👤 Hitoshi Minegishi
• 👤 峯岸　仁
• 👤 Noboru Yamada
• 👤 登 山田

Bibliographic Details