Near-infrared cut filter and solid-state imaging device
View Patent ↗There are provided a near-infrared cut filter that effectively uses near-infrared absorbing glass and a near-infrared absorbing dye and is excellent in a near-infrared shielding property, and a high-sensitivity solid-state imaging device including the same. A near-infrared cut filter includes: a near-infrared absorbing glass substrate made of CuO-containing fluorophosphate glass or CuO-containing phosphate glass; and a near-infrared absorbing layer containing a near-infrared absorbing dye (A) and a transparent resin (B), on at least one principal surface of the near-infrared absorbing glass substrate, wherein an average value of a transmittance in a 400 nm to 550 nm wavelength range is 80% or more, and an average value of a transmittance in a 650 nm to 720 nm wavelength range is 15% or less.
1. A near-infrared cut filter comprising:
a near-infrared absorbing glass substrate made of CuO-containing fluorophosphate glass or CuO-containing phosphate glass; and
a near-infrared absorbing layer comprising a near-infrared absorbing dye and a transparent resin, and provided on at least one-principal surface of the near-infrared absorbing glass substrate, wherein the near-infrared absorbing film is a resin film in which the near-infrared absorbing dye is dispersed in the transparent resin, and an absorption spectrum of a 400 nm to 850 nm wavelength range of the resin film has a maximum absorption wavelength in a 650 nm to 750 nm wavelength range,
wherein in the near-infrared cut filter, an average value of a transmittance in a 400 nm to 550 nm wavelength range is 80% or more, and an average value of a transmittance in a 650 nm to 720 nm wavelength range is 15% or less.
2. The near-infrared cut filter according to claim 1 ,
wherein a refractive index of the transparent resin is 1.45 or more.
3. The near-infrared cut filter according to claim 1 ,
wherein the near-infrared absorbing dye is 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.
4. The near-infrared cut filter according to claim 3 ,
wherein the near-infrared absorbing dye is the squarylium-based compound which is at least one selected from squarylium-based compounds expressed by the following-formula (F1),
where R 4 s and R 6 s each independently represent a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group or an alkoxy group each having 1 to 6 carbon atoms, an acyloxy group having 1 to 10 carbon atoms, or —NR 7 R 8 , where R 7 and R 8 are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or —C(═O)—R 9 , where R 9 is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 11 carbon atoms which may each have a substituent, or an alaryl group having 7 to 18 carbon atoms which may have a substituent and may have an oxygen atom between carbon atoms,
where at least one pair of R 1 and R 2 , R 2 and R 5 , and R 1 and R 3 form a heterocycle A, a heterocycle B, and a heterocycle C, respectively, having 5 or 6 members including a nitrogen atom by coupling with each other, and when not forming the heterocycle, R 1 and R 2 each independently represent a hydrogen atom, an alkyl group or an allyl group each having 1 to 6 carbon atoms which may have a substituent, or an aryl group or an alaryl group each having 6 to 11 carbon atoms, and when not forming the heterocycle, R 3 and R 5 each independently represent a hydrogen atom, a halogen atom, or an alkyl group or an alkoxy group each having 1 to 6 carbon atoms.
5. The near-infrared cut filter according to claim 3 ,
wherein the near-infrared absorbing dye is the squarylium-based compound which is at least one selected from squarylium-based compounds expressed by the following formula (F11),
where R 1 s each independently represent a hydrogen atom, an alkyl group or an allyl group each having 1 to 6 carbon atoms which may have a substituent, or an aryl group or an alaryl group each having 6 to 11 carbon atoms,
R 3 s each independently represent a hydrogen atom, a halogen atom, or an alkyl group or an alkoxy group each having 1 to 6 carbon atoms,
R 6 s each independently represent a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group or an alkoxy group each having 1 to 6 carbon atoms, or an acyloxy group having 1 to 10 carbon atoms,
R 7 s and R 8 s each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or —C(═O)—R 9 , where R 9 is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 11 carbon atoms which each may have a substituent, or an alaryl group having 7 to 18 carbon atoms which may have a substituent and may have an oxygen atom between carbon atoms,
X 1 s are each independently a group expressed by the following formula (1x) or (2x), and
Y 1 s are each independently single bond or one of groups expressed by the following formulas (1y) to (5y),
where in the formula (1x), four Zs each independently represent a hydrogen atom, a hydroxyl group, an alkyl group or an alkoxy group each having 1 to 6 carbon atoms, or —NR 28 R 29 , where R 28 and R 29 each independently represent a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, R 21 to R 26 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 10 carbon atoms, and R 27 represents an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms.
6. The near-infrared cut filter according to claim 1 ,
wherein an amount of the near-infrared absorbing dye is 0.1 to 20 parts by mass with respect to 100 parts by mass of the transparent resin.
7. The near-infrared cut filter according to claim 1 , further comprising:
one or more dielectric multilayered films provided on at least one of a surface of the near-infrared absorbing layer and a surface of the near-infrared absorbing glass substrate, wherein each of the one or more dielectric multilayered films comprises high-refractive-index dielectric films and low-refractive-index dielectric films which are alternately stacked.
8. The near-infrared cut filter according to claim 7 ,
wherein in at least one of the one or more dielectric multilayered films, a transmittance in a 420 nm to 650 nm wavelength range is 90% or more, a transmittance in a 750 nm to 1100 nm wavelength range is 10% or less, and a shortest wavelength, for which a transmittance is 50% in a wavelength range longer than 600 nm, exists in a wavelength range of over 650 nm and 730 nm or less.
9. A solid-state imaging device comprising:
the near-infrared cut filter according to claim 1 , and
a solid-state image sensor,
the near-infrared cut filter and the solid-state image sensor being disposed in order from a side where light of a light source enters.
10. The near-infrared cut filter according to claim 7 ,
wherein each of the high-refractive-index dielectric films has a refractive index of not less than 2.2 and not more than 2.5, and each of the low-refractive-index dielectric films has a refractive index of 1.45 or more and less than 1.55.
11. The near-infrared cut filter according to claim 10 ,
wherein the high-refractive-index dielectric film comprises TiO 2 and the low-refractive-index dielectric film comprises SiO 2 .
12. The near-infrared cut filter according to claim 8 ,
wherein a difference spectrum ratio represented by the following formula is 0.9 or less:
the
difference
spectrum
ratio
=
an
area
of
a
550
nm
to
780
nm
wavelength
range
in
a
first
difference
spectrum
an
area
of
a
550
nm
to
780
nm
wavelength
range
in
a
second
difference
spectrum
wherein the first difference spectrum is a subtraction of a transmittance of the near-infrared cut filter when an incident angle is 30° from a transmittance of the near-infrared cut filter when an incident angle is 0°, and the second difference spectrum is a subtraction of a transmittance of a hypothetical filter when an incident angle is 30° from a transmittance of the hypothetical filter when an incident angle is 0°, wherein the hypothetical filter is identical to the near-infrared cut filter except for not comprising the near-infrared absorbing layer.
13. The near-infrared cut filter according to claim 7 ,
wherein the one or more dielectric multilayered films comprise:
a first dielectric multilayered film provided on the near-infrared absorbing layer and
a second dielectric multilayered film provided on a principal surface of the near-infrared absorbing glass substrate, the principal surface being opposite to the principal surface on which the near-infrared absorbing layer is provided.
14. The near-infrared cut filter according to claim 13 ,
wherein the first dielectric multilayered film is an anti-reflection film.
15. The near-infrared cut filter according to claim 13 ,
wherein a transmittance of the second dielectric multilayered film is 1% or less for light in a wavelength range of 400 nm or less.
16. The near-infrared cut filter according to claim 1 ,
wherein a thickness of the near-infrared absorbing glass substrate is from 0.03 to 5 mm.
17. The near-infrared cut filter according to claim 1 ,
wherein a transmittance of the near-infrared absorbing glass substrate is 80% or more for light in a wavelength range of from 400 nm to 550 nm, and is 40% or less for light in a wavelength range of from 750 nm to 1000 nm.
18. The near-infrared cut filter according to claim 1 ,
wherein a thickness of the near-infrared absorbing layer is from 0.1 to 100 μm.
19. The near-infrared cut filter according to claim 1 ,
wherein the near-infrared absorbing layer further comprises an ultraviolet absorbent.
20. The near-infrared cut filter according to claim 19 ,
wherein the ultraviolet absorbent is at least one selected from the group consisting of a benzotriazole-based ultraviolet absorbent, a benzophenone-based ultraviolet absorbent, a salicylate-based ultraviolet absorbent, a cyanoacrylate-based ultraviolet absorbent, a triazine-based ultraviolet absorbent, an okizanirido-based ultraviolet absorbent, a nickel complex salt-based ultraviolet absorbent, and an inorganic ultraviolet absorbent.
21. The near-infrared cut filter according to claim 1 , further comprising a light shielding member in a black frame shape disposed on an end portion of a principal surface of the near-infrared cut filter.
22. A near-infrared cut filter comprising:
a near-infrared absorbing glass substrate made of CuO-containing fluorophosphate glass or CuO-containing phosphate glass;
a near-infrared absorbing layer comprising a near-infrared absorbing dye and a transparent resin, on at least one principal surface of the near-infrared absorbing glass substrate; and
one or more dielectric multilayered films provided on at least one of a surface of the near-infrared absorbing layer and a surface of the near-infrared absorbing glass substrate, each of the one or more dielectric multilayered films comprising high-refractive-index dielectric films and low-refractive-index dielectric films which are alternately stacked,
wherein in the near-infrared cut filter, an average value of a transmittance in a 400 nm to 550 nm wavelength range is 80% or more, and an average value of a transmittance in a 650 nm to 720 nm wavelength range is 15% or less.
23. The near-infrared cut filter according to claim 22 ,
wherein each of the high-refractive-index dielectric films has a refractive index of not less than 2.2 and not more than 2.5, and each of the low-refractive-index dielectric films has a refractive index of 1.45 or more and less than 1.55.
24. The near-infrared cut filter according to claim 23 ,
wherein the high-refractive-index dielectric film comprises TiO 2 and the low-refractive-index dielectric film comprises SiO 2 .
25. The near-infrared cut filter according to claim 22 ,
wherein a refractive index of the transparent resin is 1.45 or more.
26. The near-infrared cut filter according to claim 22 ,
wherein an amount of the near-infrared absorbing dye is 0.1 to 20 parts by mass with respect to 100 parts by mass of the transparent resin.
27. The near-infrared cut filter according to claim 22 ,
wherein in at least one of the one or more dielectric multilayered films, a transmittance in a 420 nm to 650 nm wavelength range is 90% or more, a transmittance in a 750 nm to 1100 nm wavelength range is 10% or less, and a shortest wavelength, for which a transmittance is 50% in a wavelength range longer than 600 nm, exists in a wavelength range of over 650 nm and 730 nm or less.
28. The near-infrared cut filter according to claim 27 ,
wherein a difference spectrum ratio represented by the following formula is 0.9 or less:
the
difference
spectrum
ratio
=
an
area
of
a
550
nm
to
780
nm
wavelength
range
in
a
first
difference
spectrum
an
area
of
a
550
nm
to
780
nm
wavelength
range
in
a
second
difference
spectrum
wherein the first difference spectrum is a subtraction of a transmittance of the near-infrared cut filter when an incident angle is 30° from a transmittance of the near-infrared cut filter when an incident angle is 0°, and the second difference spectrum is a subtraction of a transmittance of a hypothetical filter when an incident angle is 30° from a transmittance of the hypothetical filter when an incident angle is 0°, wherein the hypothetical filter is identical to the near-infrared cut filter except for not comprising the near-infrared absorbing layer.
29. The near-infrared cut filter according to claim 22 ,
wherein a thickness of the near-infrared absorbing layer is from 0.1 to 100 μm.
30. A solid-state imaging device comprising:
the near-infrared cut filter according to claim 22 , and
a solid-state image sensor,
the near-infrared cut filter and the solid-state image sensor being disposed in order from a side where light of a light source enters.