Patent ID: 9307156
Filing Date: 2016-04-05
CPC Classification: G01J,H04N

Claim Text:
1. An imaging method comprising: providing an imager operable in the longwave infrared spectral region of electromagnetic radiation; providing a neutral density filter characterized by transmission of longwave infrared radiation and by resistance to heat; positioning said neutral density filter between said imager and an entity emanating electromagnetic radiation and heat; imaging said entity, said imaging including using said imager and said neutral density filter, wherein said neutral density filter attenuates longwave infrared radiation emanating from said entity, said neutral density filter resists heat emanating from said entity, and said imager receives longwave infrared radiation attenuated by said neutral density filter; wherein said neutral density filter is made of a material having a thermal conductivity of greater than zero W/m-K and less than or equal to 0.13 W/m-K.