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US 12,699,256 B2Granted
Infrared imaging lens and infrared camera
AssigneeNippon Electric Glass Co., Ltd.
InventorsYoshimasa Matsushita, Fumio Sato, Nobuo Hori
Life of this patent
Estimating the term…
Abstract
An infrared imaging lens (1) includes a plurality of lenses (L1 to L3) which are disposed in respective positions, the plurality of lenses each being made of glass having a refractive index of 2.8 to 4.0 measured at a wavelength of 10 μm, the infrared imaging lens having an image circle having a diameter which is 0.7 times to 1.3 times a focal length of the infrared imaging lens.
Claims20
An infrared imaging lens, comprising a plurality of lenses which are disposed in respective positions,
- the plurality of lenses each being made of glass having a refractive index of 2.8 to 4.0 measured at a wavelength of 10 μm, wherein
- a first lens,
- a second lens, and
- a third lens are disposed in this order from an object side to an image surface side, the third lens has positive power and a meniscus shape that is convex to the image surface side, and
- the infrared imaging lens has an image circle on an image surface, the image circle having a diameter which is 0.7 time to 1.3 times a focal length of the infrared imaging lens.
2 more elements
An infrared imaging lens, comprising a plurality of lenses which are disposed in respective positions,
- the plurality of lenses each being made of glass having a refractive index of 2.8 to 4.0 measured at a wavelength of 10 μm,
- the infrared imaging lens having, in the image circle, a modulation transfer function of not less than 0.17 in a wavelength range of 7 μm to 14 μm at a spatial frequency of 41.7 cycles/mm.
Dependencies are inferred from the claim text.