| 摘要 |
PURPOSE:To provide a focus correcting mechanism whose structure is simple, whose cost is low and which is miniaturized as the focus correcting mechanism of an optical equipment, especially, the correction mechanism correcting out-of- focus caused by temperature change. CONSTITUTION:This mechanism is provided with a cylindrical lens barrel 10 constituted by attaching a photoreceiving body at one end, a cylindrical body 30 being a cylinder constituted by attaching a condensing lens 2 in a hollow hole and inserted to move and slide in an optical axis direction in the lens barrel 10, a bar 40 like a bar consisting of a material having the coefficient of thermal expansion larger than that of the lens barrel 10 and constituted by pivotally coupling its one end with one end of the lens barrel 10, and an arm 45 constituted by pivotally supporting and coupling one end with the other end of the bar 40, pivotally supporting and coupling other end with the cylindrical body 30, and pivotally supporting its specified middle spot so as to freely rock in the lens barrel 10. The bar 40 is expanded or contracted by the change of ambient temperature and the clindrical body 30 is moved in a direction where it comes close to the photoreceiving body or a direction where it goes away from the photoreceiving body by the lever action of the arm 45. |
