Patent ID: 11971565
Assignee: PTOT (SUZHOU) INC.
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 17:
18. 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 the absolute difference between the wavelength with the transmittance at 80% of the absorption film and the wavelength with the transmittance at 50% of the absorption film is lower than 50 nm;
wherein in the ultraviolet band, the absolute difference between the wavelength with the transmittance at 80% of the absorption film and the wavelength with the transmittance at 50% of the absorption film is lower than 23 nm; the absolute difference between the wavelength with the transmittance at 50% of the absorption film and the wavelength with the transmittance at 20% of the absorption film is lower than 16 nm.