| 摘要 |
PURPOSE:To defog optical lens surfaces by flowing internal gas by using a defogging device for an optical lens, specially, a lens moving group. CONSTITUTION:The zoom moving group 2 is moved in a movement direction 5a, and then the gas in the lens barrel 1 flows along a flow passage 6. The gas is blown to the surface of the optical lens 7, which is defogged. When the moving group 2 is moved in a movement direction 5b, the internal gas flows in the opposite direction in the flow passage 6, and the gas is blown similarly to the surface of the optical lens 7 to remove fog. The surfaces of the optical lens are defogged by such a simple structure that the gas in the optical lens flows simultaneously with the zooming of the optical lens. |
