	US 12,422,602 B2
	Optical filter
Kazuhiko Shiono, Fukushima (JP); Takuro Shimada, Fukushima (JP); Yuichiro Orita, Fukushima (JP); Nanako Nishimoto, Fukushima (JP); and Takashi Nagata, Shizuoka (JP)
Assigned to AGC Inc., Tokyo (JP)
Filed by AGC Inc., Tokyo (JP)
Filed on Apr. 20, 2023, as Appl. No. 18/303,668.
Application 18/303,668 is a continuation of application No. PCT/JP2021/038464, filed on Oct. 18, 2021.
Claims priority of application No. 2020-176883 (JP), filed on Oct. 21, 2020.
Prior Publication US 2023/0258853 A1, Aug. 17, 2023
Int. Cl. G02B 5/20 (2006.01); G02B 5/22 (2006.01)

CPC G02B 5/208 (2013.01) [G02B 5/223 (2013.01); G02B 5/226 (2013.01)]

13 Claims

1. An optical filter comprising:

a substrate; and

a dielectric multilayer film laid on or above at least one major surface of the substrate as an outermost layer, wherein

the substrate comprises a resin film comprising a dye (IR) and a resin,

the dye (IR) has a maximum absorption wavelength in a wavelength of 680 to 800 nm in the resin, and

the optical filter satisfies all of the following spectroscopic characteristics (i-1) to (i-23):

spectroscopic characteristics (i-1) to (i-9) in a spectral transmittance curve at an incident angle of 0°:

(i-1) an average transmittance T_{440-490(0deg)AVE}in a wavelength of 440 to 490 nm is 85% or higher;

(i-2) an average transmittance T_{490-560(0deg)AVE}in a wavelength of 490 to 560 nm is 90% or higher;

(i-3) an average transmittance T_{560-590(0deg)AVE}in a wavelength of 560 to 590 nm is 83% or higher;

(i-4) a wavelength IR50_(0deg)at which a transmittance is 50% is in a wavelength of 600 to 680 nm;

(i-5) a maximum transmittance T_{700-760(0deg)MAX}in a wavelength of 700 to 760 nm is 2% or lower;

(i-6) a transmittance T_750(0deg)at a wavelength of 750 nm is 0.5% or lower;

(i-7) a maximum transmittance T_{760-800(0deg)MAX}in a wavelength of 760 to 800 nm is 1% or lower;

(i-8) a maximum transmittance T_{800-900(0deg)MAX}in a wavelength of 800 to 900 nm is 1% or lower; and

(i-9) a maximum transmittance T_{900-1100(0deg)MAX}in a wavelength of 900 to 1,100 nm is 1% or lower;

spectroscopic characteristics (i-10) to (i-18) in a spectral transmittance curve at an incident angle of 30°:

(i-10) an average transmittance T_{440-490(30deg)AVE}in the wavelength of 440 to 490 nm is 84% or higher;

(i-11) an average transmittance T_{490-560(30deg)AVE}in the wavelength of 490 to 560 nm is 90% or higher;

(i-12) an average transmittance T_{560-590(30deg)AVE}in the wavelength of 560 to 590 nm is 83% or higher;

(i-13) a wavelength IR50_(30deg)at which a transmittance is 50% is in the wavelength of 600 to 680 nm;

(i-14) a maximum transmittance T_{700-760(30deg)MAX}in the wavelength of 700 to 760 nm is 2% or lower;

(i-15) a transmittance T_750(30deg)at the wavelength of 750 nm is 0.5% or lower;

(i-16) a maximum transmittance T_{760-800(30deg)MAX}in the wavelength of 760 to 800 nm is 1% or lower;

(i-17) a maximum transmittance T_{800-900(30deg)MAX}in the wavelength of 800 to 900 nm is 1% or lower; and

(i-18) a maximum transmittance T_{900-1100(30deg)MAX}in the wavelength of 900 to 1,100 nm is 5% or lower;

(i-19) an absolute value of a difference between the wavelength IR50_(0deg)and the wavelength IR50_(30deg)is 8 nm or smaller; and

spectroscopic characteristics (i-20) to (i-23) in a spectral transmittance curve at an incident angle of 70°:

(i-20) a maximum transmittance T_{700-760(70deg)MAX}in the wavelength of 700 to 760 nm is 1.5% or lower;

(i-21) a transmittance T_750(70deg)at the wavelength of 750 nm is 1.5% or lower;

(i-22) a maximum transmittance T_{760-800(70deg)MAX}in the wavelength of 760 to 800 nm is 1.5% or lower; and

(i-23) a maximum transmittance T_{800-900(70deg)MAX}in the wavelength of 800 to 900 nm is 1.5% or lower.