Patent ID: 11971565
Assignee: PLATINUM OPTICS TECHNOLOGY INC.
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. An absorption type near-infrared filter, comprising:
a first multilayer film;
a second multilayer film; and
an absorption film between the first multilayer film and the second multilayer film, the absorption film comprising an infrared absorbing dye with a weight percentage between 1% and 3% and an ultraviolet absorbing dye in a weight percentage between 4% and 10%;
wherein in the ultraviolet band, the difference of between the wavelength with the transmittance at 80% of the absorbing film and the wavelength with the reflectivity at 80% of the first multilayer film falls in the range between 25 nm and 37 nm, the difference of between the wavelength with the transmittance at 50% of the absorbing film and the wavelength with the reflectivity at 50% of the first multilayer film falls in the range between 6 nm and 14 nm, and the difference of between the wavelength with the transmittance at 20% of the absorbing film and the wavelength with the reflectivity at 20% of the first multilayer film falls in the range between −6 nm and 2.5 nm.