Near-infrared cut filter and solid-state imaging device

Patent metadata

Field	Value
Publication number	US-10310150-B2
Application number	US-201615279688-A
Country	US
Kind code	B2
Filing date	Sep 29, 2016
Priority date	Jan 14, 2015
Publication date	Jun 4, 2019
Grant date	Jun 4, 2019

Abstract

There are provided a near-infrared cut filter having a sufficient near-infrared blocking property and being capable of reducing or preventing, in a solid-state imaging device using the near-infrared cut filter, occurrence of a phenomenon that an object which did not exist on the original subject appears in a taken image, and also a highly sensitive solid-state imaging device having the near-infrared cut filter. A near-infrared cut filter includes a stack having a near-infrared absorbing glass substrate and a near-infrared absorbing layer containing a near-infrared absorbing dye and a transparent resin on at least one main surface of the near-infrared absorbing glass substrate, and a dielectric multilayer film formed on at least one main surface of the stack, wherein maximum transmittance at an incident angle of 31 to 60 degrees with respect to light with a wavelength of from 775 to 900 nm is 50% or less.

First claim

What is claimed is:

1. A near-infrared cut filter comprising:
a stack comprising:
a near-infrared absorbing glass substrate; and
a near-infrared absorbing layer provided on at least one main surface of the near-infrared absorbing glass substrate and comprising a near-infrared absorbing dye and a transparent resin; and

a dielectric multilayer film provided on at least one main surface of the stack, wherein
the near-infrared absorbing glass substrate has a maximum absorption wavelength λ Gmax in a wavelength of from 775 to 900 nm in an absorption spectrum of a wavelength of from 400 to 1100 nm at an incident angle of 0 degree,
the near-infrared absorbing dye has a maximum absorption wavelength λ max at a wavelength of from 650 to 750 nm,
the dielectric multilayer film has a near-infrared reflective property,
transmittance λ(λ max ) in λ max of the near-infrared absorbing layer is lower than transmittance T(λ Gmax ) in λ Gmax of the near-infrared absorbing glass,
transmittance T(λ max ) of the near-infrared absorbing layer is 5% or less,
transmittance T(λ Gmax ) of the near-infrared absorbing glass substrate is 50% or less,
the dielectric multilayer film has a near-infrared reflecting band in which average transmittance of light with a wavelength of from 430 to 660 nm is 90% or more, and in which transmittance is 20% or less in a wavelength of from 700 to 1200 nm,
an average value of the near-infrared cut filter of transmittance of light with a wavelength of 450 to 550 nm is 80% or more, and
maximum transmittance of the near-infrared cut filter at an incident angle of 31 to 60 degrees with respect to light with a wavelength of from 775 to 900 nm is 50% or less.

2. The near-infrared cut filter according to claim 1 , wherein the near-infrared absorbing glass substrate has absorptance at an incident angle of 0 degree with respect to light with a wavelength of from 775 to 900 nm of 75% or more.

3. The near-infrared cut filter according to claim 1 , wherein the dielectric multilayer film comprises a dielectric multilayer film with a near-infrared reflective property, the film having maximum transmittance of 1% or less at an incident angle of 0 degree with respect to light with a wavelength of from 800 to 900 nm, and maximum transmittance of 3% or more at an incident angle of 31 to 60 degrees with respect to light with a wavelength of from 775 to 900 nm.

4. The near-infrared cut filter according to claim 3 , wherein the near-infrared absorbing layer is provided on one main surface of the near-infrared absorbing glass substrate, and the dielectric multilayer film with a near-infrared reflective property is provided on another main surface of the near-infrared absorbing glass substrate.

5. The near-infrared cut filter according to claim 1 , wherein
λ Sh ( D _ T 20%)≤λ Sh ( R 30_ Ts 50%)≤λ Sh ( R 0_ T 50%)≤λ Lo ( D _ T 20%)   Formula (1)

is satisfied,
provided that a wavelength with which transmittance of light at an incident angle of 0 degree becomes 50% on a short wavelength side of the near-infrared reflecting band of the dielectric multilayer film is λSh(R0_T50%), a wavelength with which transmittance of s polarization component becomes 50% in light at an incident angle of 30 degrees is λSh(R30_Ts50%), a wavelength with which transmittance becomes 20% on a short wavelength side of the λ max of the near-infrared absorbing layer is λSh(D_T20%), and a wavelength with which transmittance becomes 20% on a long wavelength side of the λ max is λLo(D_T20%).

6. The near-infrared cut filter according to claim 1 , wherein wavelength λ(T85%), wavelength λ(T45%), and wavelength λ(T5%) with which transmittance of light at an incident angle of 0 degree in a wavelength of from 550 to 720 nm becomes 85%, 45%, and 5%, respectively, satisfy
{λ(T45%)−λ(T85%)}≥{λ(T5%)−λ(T45%)}  Formula (2).

7. The near-infrared cut filter according to claim 1 , wherein on the at least one main surface of the near-infrared absorbing glass substrate, reflectance at an incident angle of 5 degree with respect to light with a wavelength of from 430 to 600 nm is 2% or less, which is measured excluding reflection on an interface and a surface opposite to the at least one main surface of the near-infrared absorbing glass substrate.

8. The near-infrared cut filter according to claim 1 , wherein the dielectric multilayer film is provided on the near-infrared absorbing layer, and has dielectric film in contact with the near-infrared absorbing layer, and a refractive index of the dielectric film is 1.4 or more and 1.7 or less.

9. The near-infrared cut filter according to claim 1 , having a wavelength λ 0 (NIR) with which transmittance at an incident angle of 0 degree becomes 50% and a wavelength λ 30 (NIR) with which transmittance at an incident angle of 30 degrees becomes 50% in a region of a wavelength longer than 600 nm, wherein an absolute value of a difference between the wavelengths |λ 0 (NIR)−λ 30 (NIR)| is 5 nm or less.

10. The near-infrared cut filter according to claim 1 , wherein an average of an absolute value of a difference between transmittance at an incident angle of 0 degree and transmittance at an incident angle of 30 degrees is 3% or less in light with a wavelength of from 600 to 750 nm.

11. The near-infrared cut filter according to claim 1 , wherein the near-infrared absorbing dye comprises at least one selected from the group consisting of a cyanine-based compound, a phthalocyanine-based compound, a naphthalocyanine-based compound, a dithiol metal complex-based compound, a diimonium-based compound, a polymethine-based compound, a phthalide compound, a naphthoquinone-based compound, an anthraquinone-based compound, an indophenol-based compound and a squarylium-based compound.

12. The near-infrared cut filter according to claim 1 , further comprising an ultraviolet absorbing layer comprising an ultraviolet absorber and a transparent resin, wherein an average value of transmittance of the near-infrared cut filter at an incident angle of 0 degree is 70% or more in a wavelength of from 430 to 450 nm, and an average value of transmittance of the near-infrared cut filter at an incident angle of 0 degree is 5% or less in a wavelength of from 350 to 390 nm.

13. A solid-state imaging device comprising the near-infrared cut filter according to claim 1 and an optical member comprising a solid-state image sensing device, wherein the near-infrared cut filter and the solid-state image sensing device are disposed in order from a side of object of shooting or a side through which light from a light source enters.

14. A near-infrared cut filter comprising:
a stack comprising:
a near-infrared absorbing glass substrate;
a near-infrared absorbing layer provided on at least one main surface of the near-infrared absorbing glass substrate and comprising a near-infrared absorbing dye and a transparent resin; and
a dielectric layer with a thickness of 5 nm or more provided between the near-infrared absorbing glass substrate and the near-infrared absorbing layer; and

a dielectric multilayer film provided on at least one main surface of the stack, wherein
the dielectric layer comprises an alkali barrier film comprising at least one material selected from SiO 2 , SiO x (where 0.8≤x<2) and Al 2 O 3 and
maximum transmittance of the near-infrared cut filter at an incident angle of 31 to 60 degrees with respect to light with a wavelength of from 775 to 900 nm is 50% or less.

15. A near-infrared cut filter comprising:
a stack comprising:
a near-infrared absorbing glass substrate;
a near-infrared absorbing layer provided on at least one main surfa

Assignees

• Agc Inc

Inventors

• Sugiyama Takashi
• Hosoi Katsumasa
• Komori Atsushi
• Ooi Yoshiharu
• Hasegawa Makoto

Classifications

• H01L27/14618

  Electricity · mapped topic

• H01L27/14625

  Electricity · mapped topic

• G02B5/226

  Glass filters · CPC title

• G02B5/281

  designed for the infrared light · CPC title

• G02B5/26

  Reflecting filters (G02B5/28 takes precedence) · CPC title