Multilayer infrared reflecting optical body

• US 6,451,414 B1
• Filed: 11/22/1999
• Issued: 09/17/2002
• Est. Priority Date: 01/13/1998
• Status: Expired due to Term

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Wheatley, John A., Ouderkirk, Andrew J.
• Primary Examiner(s): Kelly, Cynthia H.
• Assistant Examiner(s): SHEWAREGED, BETELHEM
• Application Number:
  US09/447,336
• Time in Patent Office: 1,030 Days
• Field of Search: 428/212, 428/910, 359/359, 359/584, 359/590
• US Class Current: 428/212
• CPC Class Codes: B32B 17/10018 comprising only one glass sheet
• CPC Class Codes: G02B 5/0841 comprising organic materials, e.g. polymers
• CPC Class Codes: G02B 5/305 including organic materials, e.g. polymeric layers
• CPC Class Codes: G02B 5/3083 Birefringent or phase retarding elements G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001
• CPC Class Codes: Y10S 428/91 Product with molecular orientation
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree

Abstract

An optical body comprising (a) a dielectric multilayer film having a reflecting band positioned to reflect infrared radiation of at least one polarization at an incident angle normal to the film, the reflecting band having a short wavelength bandedge λ_a0 and long wavelength bandedge λ_b0 at a normal incident angle, and a short wavelength bandedge λ_aθ and long wavelength bandedge λ_bθ at a maximum usage angle θ, wherein λ_aθ is less than λ_a0 and λ_a0 is selectively positioned at a wavelength greater than about 700 nm; and (b) at least one component which at least partially absorbs or reflects radiation in the wavelength region between λ_aθ and λ_a0 at a normal angle of incidence.

Claims

1. An optical body comprising:

(a) a multilayer film having a reflecting band positioned to reflect infrared radiation of at least one polarization at an incident angle normal to the film, said reflecting band having a short wavelength bandedge λ

_a0 and long wavelength bandedge λ

_b0 at a normal incident angle, and a short wavelength bandedge λ

_aθ

and long wavelength bandedge λ

_bθ

at a maximum usage angle θ

, wherein λ

_aθ

is less than λ

_a0 and λ

_a0 is selectively positioned at a wavelength greater than about 700 nm; and

(b) at least one component which at least partially absorbs or reflects radiation in the wavelength region between λ

_aθ

and λ

_a0 at a normal angle of incidence.

2. The optical body of claim 1 wherein said multilayer film is dielectric.

3. The optical body of claim 1 wherein at least one layer of said multilayer film comprises a metal or metal oxide.

4. The optical body of claim 1 wherein said at least one component also at least partially absorbs or reflects radiation in the wavelength region between λ

_bθ

and λ

_b0 at a maximum usage angle θ

.

5. The optical body of claim 1 further comprising another component which at least partially absorbs or reflects radiation in the wavelength region between λ

_bθ

and λ

_b0 at a maximum usage angle θ

.

6. The optical body of claim 1 wherein said at least one component partially absorbs or reflects at _λ

_aθ

or greater where λ

_aθ

is 700 nm or greater at the maximum usage angle θ

.

7. The optical body of claim 1 wherein said at least one component is separate from the film and comprises a dye or pigment.

8. The optical body of claim 1 wherein said at least one component is part of the film and comprises a dye or pigment.

9. The optical body of claim 1 wherein said at least one component is a pigment comprising copper phthalocyanine.

10. The optical body of claim 1, wherein each of the layers of the multilayer film is optically isotropic.

11. The optical body of claim 1, wherein at least some of the layers of the multilayer film are birefringent.

12. An optical body for absorbing or reflecting radiation over a range of wavelengths defined by a lower wavelength edge, the optical body comprising:

(a) a multilayer film having a normal incidence reflection band that is defined by reflection of radiation of at least one polarization at an incident angle normal to the multilayer film, wherein the normal incidence reflection band is within the range of wavelengths; and

(b) at least one additional component that at least partially absorbs normally incident radiation in a wavelength region between the normal incidence reflection band of the multilayer film and the lower wavelength edge of the range of wavelengths.

13. The optical body of claim 12, wherein the at least one additional component is separate from the multilayer film and comprises a dye or pigment.

14. The optical body of claim 12, wherein the at least one additional component is part of the multilayer film and comprises a dye or pigment.

15. The optical body of claim 12, wherein said multilayer film is dielectric.

16. The optical body of claim 12, wherein at least one layer of said multilayer film comprises a metal or metal oxide.

17. The optical body of claim 16, wherein the metal or metal oxide at least partially absorbs normally incident radiation in a wavelength region between the normal incidence reflection band of the multilayer film and the lower wavelength edge of the range of wavelengths.

18. The optical body of claim 12, wherein the at least one additional component also absorbs or reflects light at wavelengths higher than the normal incidence reflection band of the multilayer film.

19. The optical body of claim 12, wherein the lower wavelength edge is an infrared wavelength.

20. An optical body for absorbing or reflecting infrared light, the optical body comprising:

(a) a multilayer film having a normal incidence reflection band that is defined by reflection of infrared radiation of at least one polarization at an incident angle normal to the multilayer film; and

(b) at least one additional component that at least partially absorbs or reflects normally incident radiation in a wavelength region between the normal incidence reflection band of the multilayer film and 700 nm.

21. An optical body for absorbing or reflecting infrared light, the optical body comprising:

a multilayer film comprising

a) a first multilayer segment comprising a plurality of layers and having a reflecting band that reflects at least 90% of infrared light of one polarization over a first wavelength range; and

b) a trailing segment comprising a plurality of layers, the trailing segment having a reflecting band that reflects light in a second wavelength range that i) extends over at least 50 nm, ii) is adjacent to the first wavelength range, and iii) covers lower wavelengths than the first wavelength range;

wherein the multilayer film reflects at least 90% of infrared light of the one polarization at the edge of the second wavelength range adjacent to the first wavelength range and reflects no more than 25% of light of the one polarization at the opposite edge of the second wavelength range.

22. The optical body of claim 21, wherein within the second wavelength range, the multilayer film reflects at least 90% of infrared light at the edge of the second wavelength range adjacent to the first wavelength range and reflects no more than 25% of light at the opposite edge of the second wavelength range.

23. An optical body for absorbing or reflecting radiation over a range of wavelengths defined by a lower wavelength edge, the optical body comprising:

(a) a first multilayer structure comprising a plurality of birefringent layers, the first multilayer structure having a normal incidence reflection band that is defined by reflection of radiation of at least one polarization at an incident angle normal to the first multilayer structure, wherein the normal incidence reflection band is within the range of wavelengths; and

(b) a second multilayer structure consisting essentially of optically isotropic materials, wherein the second multilayer structure at least partially reflects normally incident radiation in a wavelength region between the normal incidence reflection band of the first multilayer structure and the lower wavelength edge of the range of wavelengths.

24. The optical body of claim 23, wherein the first multilayer structure further comprises a plurality of optically isotropic layers.