| 摘要 |
This invention is directed to provide an infrared camera lens that is simple in lens configuration and has lens pieces including only spherical surfaces but no aspheric surfaces. The invention is also directed to provide an infrared camera lens of a design that facilitates and implements an airtight environment within the lens barrel because the foremost or first lens closest to the object stays still during focusing, and the entire length of the lens system is unchanged for focusing. The infrared camera lens comprises the foremost or first single spherical lens piece of positive refractivity, the succeeding or second single spherical lens piece of negative refractivity, and the third single spherical lens piece of positive refractivity. At least the second single spherical lens piece of negative refractivity or the third single spherical lens piece of positive refractivity is to be moved for focusing.
|
