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Technical Information

Spherical Fresnel Lens Design
Appropriate models

EX-35T/35R, RX-40QZ/40PT, SX-360Z/360ZV,FX-360, FX-40/40D, CX-502/502AM, CX-702/702RS, DX-40/60/40PLUS/60PLUS, MX-40QZ/50QZ/40PT

Spherical lens provides a precise focal length to each of the multiple lens segments (uniform distance between each lens segment and the pyroelectric elements). This enable each lens segment to face precisely towards its detection area, and creates detection zones without distortion, achieving a new levelin lens design precision.

Conventional Flat Lens

Optex Spherical Lens



Conventional flat lenses inevitably create sensitivity distortion problems when they are bent to fit a curved housing. Optex's spherically designed lens will obtain sharp detection because no bending is required.

The spherical fresnel lens differs from the conventional flat fresnel lens in that the distance between the lens and the pyro-electric elements is the same across the entire lens (the focal length is always the same). It therefore collects infrared rays more efficiently.





Each focused image (detection zone) has poorly defined borders (=inaccurate sensitivity) and does not produce sufficient contrast against the background (=low detection performance). Because the IR energy is poorly focused, objects entering these low contrast border areas produce weak, poorly defined electrical signals within the detector.

Each focused image (detection zone) has sharply defined edges (=accurate sensitivity) and it produces the maximum signal contrast against the background area (=high detection performance). This sharp focus provides the maximum signal power to the detector, compared to a weak, sluggish signal created by a poorly focused zone.