Optical filter

Patent metadata

Field	Value
Publication number	US-12422602-B2
Application number	US-202318303668-A
Country	US
Kind code	B2
Filing date	Apr 20, 2023
Priority date	Oct 21, 2020
Publication date	Sep 23, 2025
Grant date	Sep 23, 2025

Abstract

An optical filter including: a substrate; and a dielectric multilayer film laid on or above at least one major surface of the substrate as an outermost layer, in which the substrate includes a resin film including 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 specific spectroscopic characteristics.

First claim

What is claimed is:

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.

2. The optical filter according to claim 1 , wherein the resin film further comprises a dye (U) having a maximum absorption wavelength in a wavelength of 370 to 430 nm in the resin, and
the optical filter further satisfies the following spectroscopic characteristic (i-24):
(i-24) an absolute value of a difference between UV50 (0deg) and UV50 (30deg) is 5 nm or smaller, where the UV50 (0deg) is a wavelength at which a transmittance in a spectral transmittance curve in a wavelength of 400 to 440 nm at the incident angle of 0° is 50% and the UV50 (30deg) is a wavelength at which a transmittance in a spectral transmittance curve in the wavelength of 400 to 440 nm at the incident angle of 30° is 50%.

3. The optical filter according to claim 2 , wherein the dye (U) comprises a merocyanine dye.

4. The optical filter according to claim 1 , wherein the resin film satisfies all of the following spectroscopic characteristics (ii-1) to (ii-4):
(ii-1) an average internal transmittance T 440-490 AVE in a spectral transmittance curve in the wavelength of 440 to 490 nm is 84% or higher;
(ii-2) an average internal transmittance T 490-560 AVE in the spectral transmittance curve in the wavelength of 490 to 560 nm is 94% or higher;
(ii-3) an average internal transmittance T 560-590 AVE in the spectral transmittance curve in the wavelength of 560 to 590 nm is 80% or higher; and
(ii-4) a maximum internal transmittance T 700-760 MAX in the spectral transmittance curve in the wavelength of 700 to 760 nm is 5% or lower.

5. The optical filter according to claim 1 , wherein the resin film further satisfies the following spectroscopic characteristic (ii-5):
(ii-5) a maximum internal transmittance T 760-800MAX in a spectral transmittance curve in the wavelength of 760 to 800 nm is 15% or lower.

6. The optical filter according to claim 1 , wherein in a spectral transmittance curve of a coating film formed by dissolving the dye (IR) in the resin so that a transmittance at a maximum absorption wavelength becomes 10% to obtain a solution and applying the solution to an alkali glass plate, the dye (IR) satisfies all of the following spectroscopic characteristics (iii-1) to (iii-3):
(iii-1) an average internal transmittance T 440-490AVE in the spectral transmittance curve in the wavelength of 440 to 490 nm is 94% or higher;
(iii-2) an average internal transmittance T 490-560AVE in the spectral transmittance curve in the wavelength of 490 to 560 nm is 94% or higher; and
(iii-3) an average internal transmittance T 560-590AVE in the spectral transmittance curve in the wavelength of 560 to 590 nm is 94% or higher.

7. The optical filter according to claim 1 , wherein the dye (IR) comprises three or more compounds each having a maximum absorption wavelength in a wavelength of 680 to 800 nm in the resin.

8. The optical filter according to claim 1 , wherein the dye (IR) comprises:
one or more compounds (A) each having a maximum absorption wavelength in a wavelength of 680 nm or longer and shorter than 720 nm in the resin;
one or more compounds (B) each having a maximum absorption wavelength in a wavelength of 720 nm or longer and shorter than 740 nm in the resin; and
one or more compounds (C) each having a maximum absorption wavelength in a wavelength of 740 nm or longer and 780 nm or shorter in the resin.

9. The optical filter according to claim 1 , wherein the dye (IR) is selected from a squarylium dye or a cyanine dye.

10. The optical filter according to claim 1 , wherein the dielectric multilayer film satisfies all of the following spectroscopic characteristics (iv-1) to (iv-12):
spectroscopic characteristics (iv-1) to (iv-6) in a spectral transmittance curve at the incident angle of 0°:
(iv-1) an average transmittance T 440-490(0deg)AVE in the wavelength of 440 to 490 nm is 90% or higher;
(iv-2) an average transmittance T 490-560(0deg)AVE in the wavelength of 490 to 560 nm is 90% or higher;
(iv-3) an average transmittance T 560-590(0deg)AVE in the wavelength of 560 to 590 nm is 90% or higher;
(iv-4) a shortest wavelength IR50 (0deg) at which a transmittance is 50% in a wavelength of 600 nm or longer is in a wavelength of 630 to 730 nm;
(iv-5) a maximum transmittance T 700-760(0deg)MAX in the wavelength of 700 to 760 nm is 25% or higher; and
(iv-6) a maximum transmittance T 760-900(0deg)MAX in the wavelength of 760 to 900 nm is 2% or lower; and

spectroscopic characteristics (iv-7) to (iv-12) in a spectral transmittance curve at the incident angle of 30°:
(iv-7) an average transmit

Assignees

• Agc Inc

Inventors

• Shiono Kazuhiko
• Shimada Takuro
• ORITA Yuichiro
• NISHIMOTO Nanako
• Nagata Takashi

Classifications

• G02B5/281

  designed for the infrared light · CPC title

• G02B5/226

  Glass filters · CPC title

• G02B5/223

  containing organic substances, e.g. dyes, inks or pigments · CPC title

• G02B5/20

  Filters (polarising elements G02B5/30) · CPC title

• G02B5/22

  Absorbing filters {(G02B5/201 - G02B5/208 take precedence)} · CPC title