Optical filter

Patent metadata

Field	Value
Publication number	US-2024192413-A1
Application number	US-202418401808-A
Country	US
Kind code	A1
Filing date	Jan 2, 2024
Priority date	Jul 7, 2021
Publication date	Jun 13, 2024
Grant date	—

Abstract

An optical filter, includes: a substrate, a dielectric multilayer film 1 laid on or above one major surface of the substrate, and a dielectric multilayer film 2 laid on or above the other major surface of the substrate, in which the substrate includes a near infrared ray absorbing glass and a resin film, the resin film includes a resin and a pigment (NIR1), and the optical filter satisfies all of spectral characteristics (i-1) to (i-7).

First claim

What is claimed is:

1 . An optical filter, comprising:
a substrate, a dielectric multilayer film 1 laid on or above one major surface of the substrate, and a dielectric multilayer film 2 laid on or above the other major surface of the substrate, wherein the substrate comprises a near infrared ray absorbing glass and a resin film, the resin film comprises a resin and a pigment (NIR1), and the optical filter satisfies all of the following spectral characteristics (i-1) to (i-7): (i-1) in a spectral transmittance curve at an incident angle of 0 degrees, an average transmittance T 450-600(0deg)AVE at a wavelength of 450 nm to 600 nm is 85% or more, (i-2) in the spectral transmittance curve at an incident angle of 0 degrees, a maximum transmittance T 450-600(0deg)MAX at the wavelength of 450 nm to 600 nm is 90% or more, (i-3) in the spectral transmittance curve at an incident angle of 0 degrees, a wavelength IR50 (0deg) at which a transmittance is 50% is in a range of 610 nm to 650 nm, (i-4) in a spectral transmittance curve at an incident angle of 40 degrees, a wavelength IR50 (40deg) at which a transmittance is 50% is in the range of 610 nm to 650 nm, (i-5) an absolute value of a difference between the wavelength IR50 (0deg) and the wavelength IR50 (40deg) is 8 nm or less, (i-6) in the spectral transmittance curve at an incident angle of 0 degrees, a maximum transmittance T 750-1200(0deg)MAX at a wavelength of 750 nm to 1,200 nm is 2.5% or less, and (i-7) in a spectral transmittance curve at an incident angle of 60 degrees, a maximum transmittance T 750-1200(60deg)MAX at the wavelength of 750 nm to 1,200 nm is 2.5% or less.

2 . The optical filter according to claim 1 , further satisfying the following spectral characteristics (i-8) and (i-9):
(i-8) the maximum transmittance T 450-600(0deg)MAX /the maximum transmittance T 750-1200(0deg)MAX ≥50, and (i-9) the maximum transmittance T 450-600(0deg)MAX /the maximum transmittance T 750-1200(60deg)MAX ≥50.

3 . The optical filter according to claim 1 , wherein the substrate satisfies all of the following spectral characteristics (ii-1) to (ii-5):
(ii-1) an average internal transmittance T 450-600AVE at the wavelength of 450 nm to 600 nm is 85% or more, (ii-2) a maximum internal transmittance T 450-600MAX at the wavelength of 450 nm to 600 nm is 90% or more, (ii-3) a wavelength IR50 at which an internal transmittance is 50% is in a range of 610 nm to 650 nm, (ii-4) a maximum internal transmittance T 710-760MAX at a wavelength of 710 nm to 760 nm is 5% or less, and (ii-5) a maximum internal transmittance T 750-1200MAX at a wavelength of 750 nm to 1,200 nm is 10% or less.

4 . The optical filter according to claim 3 , wherein the substrate further satisfies the following spectral characteristic (ii-6):
(ii-6) the maximum internal transmittance T 450-600MAX /the maximum internal transmittance T 750-1200MAX ≥15.

5 . The optical filter according to claim 1 , wherein at least one of the dielectric multilayer film 1 and the dielectric multilayer film 2 satisfies all of the following spectral characteristics (v-1) to (v-3):
(v-1) in a spectral reflectance curve at an incident angle of 5 degrees, a maximum reflectance R 750-900(5deg)MAX at a wavelength of 750 nm to 900 nm is 99% or more, (v-2) in a spectral reflectance curve at an incident angle of 60 degrees, a maximum reflectance R 750-900(60deg)MAX at the wavelength of 750 nm to 900 nm is 98% or more, and (v-3) in the spectral reflectance curve at an incident angle of 60 degrees, a maximum reflectance R 1000-1200(60deg)MAX at a wavelength of 1,000 to 1,200 nm is 75% or more.

6 . The optical filter according to claim 1 , wherein the near infrared ray absorbing glass satisfies all of the following spectral characteristics (iii-1) to (iii-6):
(iii-1) an average internal transmittance T 450-600AVE at the wavelength of 450 nm to 600 nm is 90% or more, (iii-2) an internal transmittance T 450 at a wavelength of 450 nm is 92% or more, (iii-3) a wavelength IR50 at which an internal transmittance is 50% is in a range of 625 nm to 650 nm, (iii-4) an average internal transmittance T 750-1000AVE at a wavelength of 750 nm to 1,000 nm is 2.5% or less, (iii-5) a maximum internal transmittance T 1000-1200MAX at a wavelength of 1,000 nm to 1,200 nm is 5% or less, and (iii-6) the internal transmittance T 450 /the maximum internal transmittance T 1000-1200MAX ≥10.

7 . The optical filter according to claim 1 , wherein the resin film satisfies all of the following spectral characteristics (iv-1) to (iv-4):
(iv-1) an average internal transmittance T 450-600AVE at the wavelength of 450 nm to 600 nm is 92% or more, (iv-2) an internal transmittance T 450 at a wavelength of 450 nm is 85% or more, (iv-3) IR50 (L) −IR50 (S) ≥90 nm where IR50 (S) is a shortest wavelength and IR50 (L) is a longest wavelength at which an internal transmittance is 50% in a spectral transmittance curve at a wavelength of 650 nm to 900 nm, and (iv-4) a minimum internal transmittance T 700-800MIN at a wavelength of 700 nm to 800 nm is 10% or less.

8 . The optical filter according to claim 1 , wherein the resin film further comprises a pigment (NIR2), and
the pigment (NIR2) has a maximum absorption wavelength in the resin longer than a maximum absorption wavelength of the pigment (NIR1) in the resin by 30 nm to 100 nm.

9 . The optical filter according to claim 1 , wherein the resin film further comprises a pigment (UV) having a maximum absorption wavelength in 360 nm to 440 nm in the resin, and
the optical filter further satisfies the following spectral characteristics (i-10) to (i-14): (i-10) in the spectral transmittance curve at an incident angle of 0 degrees, an average transmittance T 360-400(0deg)AVE at a wavelength of 360 nm to 400 nm is 1% or less, (i-11) in the spectral transmittance curve at an incident angle of 40 degrees, an average transmittance T 360-400(40deg)AVE at the wavelength of 360 nm to 400 nm is 1% or less, (i-12) in the spectral transmittance curve at an incident angle of 0 degrees, a wavelength UV50 (0deg) at which a transmittance is 50% is in a range of 400 nm to 440 nm, (i-13) in the spectral transmittance curve at an incident angle of 40 degrees, a wavelength UV50 (40deg) at which a transmittance is 50% is in the range of 400 nm to 440 nm, and (i-14) an absolute value of a difference between the wavelength UV50 (0deg) and the wavelength UV50 (40deg) is 3 nm or less.

10 . The optical filter according to claim 1 , wherein the resin film comprises a squarylium compound as the pigment (NIR1), and
the resin film further comprises at least one of a squarylium compound and a cyanine compound as a pigment (NIR2) having a maximum absorption wavelength in the resin longer than the maximum absorption wavelength of the pigment (NIR1) in the resin by 30 nm to 100 nm.

11 . An imaging device comprising the optical filter according to claim 1 .

Assignees

• Agc Inc

Inventors

• Shiono Kazuhiko
• Shimada Takuro
• ORITA Yuichiro
• Endo Kiyokazu
• Nagata Takashi

Classifications

• G02B5/282

  reflecting for infrared and transparent for visible light, e.g. heat reflectors, laser protection · CPC title

• G02B5/281

  designed for the infrared light · CPC title

• G02B5/285

  comprising deposited thin solid films (G02B5/281 - G02B5/289 take precedence; multilayered film filters for fibre optic multiplexing G02B6/29361) · CPC title

• G02B5/226

  Glass filters · CPC title

• G02B5/223

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