Novel long wave infrared prime camera lens

Abstract

The invention provides a novel long wave infrared prime camera lens. Three lenses are sequentially arranged along the optical axis from the object side to the image side. The first lens is a meniscus shaped lens with the convex face facing to the object side and with positive refractive power, the second lens is a lens with negative refractive power, and the third lens is a lens with the convex face facing to the image side and with positive refractive power. The lenses satisfy the formulas of 0< FNO*f12*f3* (n1-1) / (f*f*R1) < 1 and 1*10 <-5>< dn1 / dT< 5*10<-5>, wherein f is the focal distance of a whole optical system, n1 is the center wavelength refractive index of a material of the first lens, FNO is the F number of the optical system, f12 is the combined focal distance of the first lens and the second lens, f3 is the focal distance of the third lens, R1 is the approximate curvature radius of the convex face of the first lens, and dn1 / dT is the refractive index temperature coefficient of the material of the first lens. Three types of chalcogenide glass materials are adopted, the structure is simple, the performance is reliable, and the novel long wave infrared prime lens can be applied to the infrared vehicle-mounted assistance, security and protection monitoring field with poor heat dissipation within the wide temperature range.

Description

technical field [0001] The invention relates to a novel long-wave infrared fixed-focus lens, in particular to a long-wave infrared fixed-focus lens which has adiabatic performance in a wide temperature range and can be widely used in the field of vehicle-mounted night vision and security monitoring. Background technique [0002] With the maturity of uncooled detector technology, long-wave infrared uncooled optical systems have been widely used in both military and civilian fields. Due to the large temperature coefficient of refractive index of infrared optical materials, drastic changes in operating temperature will have a serious impact on the infrared optical system, causing problems such as system focal length changes, image plane drift, and image quality degradation. The infrared optical system for these special application fields must be designed with adiabatic design, and the influence of temperature changes on the imaging quality of the system must be considered in th...

AI Technical Summary

Problems solved by technology

However, the existing optical athermalization lens solution has the following problems. First, the athermalization difference is realized by utilizing the difference in thermal properties of various materials. This solution has problems such as many materials used, a large number of lenses, a relatively complex structure, and high cost; The adiabatic difference is realized by utilizing the characteristic of diffractive optical elements with negative heat dissipation. This solution has the problem that the transmittance of the optical system decreases significantly due to the diffraction efficiency of the diffractive surface.

Images