Optical laminate
AssigneeNitto Denko Corporation
InventorsMasato KATSUDA, Yudai NUMATA, Shoichi MATSUDA
Life of this patent
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Abstract
This optical stack has a first main surface and a second main surface that is on the opposite side from the first main surface, wherein: the optical stack includes an optical filter layer that transmits infrared rays and reflects visible light, and a diffusion layer that diffuses visible light; the reflectivity with respect to infrared rays having a wavelength of 850 nm is 66%; and when the second main surface is disposed on a pattern that is readable using infrared rays, the pattern being formed on a foundation having a backscatter rate of 19%, the pattern can be read using infrared rays from the first-main-surface side.
Claims14
An optical stack having a first main surface and a second main surface on the opposite side to the first main surface, the optical stack comprising:
- an optical filter layer transmitting infrared light and reflecting visible light;
- and
- a diffusion layer diffusing the visible light,
- wherein when disposed on an infrared-readable pattern formed on an underlying layer having a reflectance of 66% and a backscattering ratio of 19% for infrared light having a wavelength of 850 nm such that the second main surface faces the pattern, the optical stack enables the pattern to be read by the infrared light from the side of the first main surface.
Dependencies are inferred from the claim text.