JPH01162314U - - Google Patents

Description

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the structure of an infrared lens according to this invention, and FIG. 2 is an aberration diagram of the infrared lens according to this invention. 1 is a convex meniscus first lens, 2 is a concave meniscus second lens, 3 is a convex meniscus third lens, 4
is the aperture diaphragm.

Claims (1)

[Claims for Utility Model Registration] All are made of silicon, starting from the object side:
A convex meniscus first lens with its convex surface facing the object side,
A concave meniscus second lens with its concave surface facing the object side,
and a third convex meniscus lens with its convex surface facing the object side, and an aperture stop located near the object side of the first convex meniscus lens, and when the absolute value of the composite focal length is converted to 100, the following Infrared lens characterized by having the following parameters: Surface Radius of curvature Surface spacing 1 186.04 31.29 2 305.30 40.43 3 -77.18 31.24 4 -99.21 37.89 5 156 .46 32.00 (Aspherical diameter radius of curvature) 6 292.47 The shape of the aspherical surface 5 is expressed by the relational expression X=cy ² 1+√1−(1+k)c ² y ² +Dy
⁴ +Ey ⁶ +Fy ⁸ +Gy ¹⁰ , C=6.39140×10 ⁻³ , K=−4.39791×10 ⁻¹ , D=−2.223876×10 ⁻⁸ , E=1.324126×10 ⁻¹¹ , F=−4.894522×10 ⁻¹⁵ , G=5.252993×10 ⁻¹⁹ . Here, y is the distance from the optical axis, and x is the deviation of the aspherical surface from a reference plane that includes the intersection of the optical axis and the aspherical surface and is perpendicular to the optical axis.