Light reflecting film, and light controlling film, optical film, functional glass and head-up display including the light reflecting film

Patent metadata

Field	Value
Publication number	US-10241241-B2
Application number	US-201515502899-A
Country	US
Kind code	B2
Filing date	Oct 8, 2015
Priority date	Oct 10, 2014
Publication date	Mar 26, 2019
Grant date	Mar 26, 2019

Abstract

A light controlling film comprises a light reflecting film and a light controlling layer that are laminated. The light reflecting film comprises at least two laminated light reflecting layers including at least one of light reflecting layers PRL- 1 to PRL- 3 that a central reflection wavelength of 400 nm-500 nm, 500 nm-600 nm, and 600 nm-700 nm, respectively, and a reflectance to ordinary light at the central reflection wavelength of 5%-25%. The at least two light reflecting layers have central reflection wavelengths that are different from each other. All of the at least two laminated light reflecting layers have a property of reflecting polarized light having the same orientation. The light controlling layer comprises two quarter wave plates, and the light reflecting film is laminated so as to be interposed between the two quarter wave plates.

First claim

The invention claimed is:

1. A light controlling film comprising a light reflecting film and a light controlling layer that are laminated,
the light reflecting film including at least two light reflecting layers that are laminated, the at least two light reflecting layers including at least one of light reflecting layers among a light reflecting layer PRL- 1 , a light reflecting layer PRL- 2 and a light reflecting layer PRL- 3 ,
the light reflecting layer PRL- 1 having a central reflection wavelength of greater than or equal to 400 nm but less than 500 nm and a reflectance to ordinary light at the central reflection wavelength of greater than or equal to 5% but less than or equal to 25%,
the light reflecting layer PRL- 2 having a central reflection wavelength of greater than or equal to 500 nm but less than 600 nm and a reflectance to ordinary light at the central reflection wavelength of greater than or equal to 5% but less than or equal to 25%,
the light reflecting layer PRL- 3 having a central reflection wavelength of greater than or equal to 600 nm but less than 700 nm and a reflectance to ordinary light at the central reflection wavelength of greater than or equal to 5% but less than or equal to 25%,
the at least two light reflecting layers having central reflection wavelengths that are different from each other,
all of the at least two light reflecting layers that are laminated having a property of reflecting polarized light that has the same orientation,
the light controlling layer comprising two quarter wave plates,
the light reflecting film being laminated so as to be interposed between the two quarter wave plates,
wherein each of the light reflecting layers has a half width of greater than or equal to 100 nm but less than or equal to 500 nm, and the half width is a full width at half maximum which is a width of wavelength defined by a difference between a wavelength at a long wavelength side and a wavelength at a short wavelength side corresponding to 50% of a maximum reflectance of each of the light reflecting layers, and
wherein a wavelength corresponding to 50% of the maximum reflectance is calculated based on a reflectance derived from selective reflectance obtained by subtracting an average value of a reflectance other than the selective reflection region from a value of the maximum reflectance in the selective reflection region.

2. The light controlling film according to claim 1 , wherein the two quarter wave plates are laminated with such a positional relationship that slow axes are orthogonal to each other.

3. An optical film comprising the light controlling film according to claim 1 and at least one intermediate film that are laminated.

4. The optical film according to claim 3 , wherein the light controlling film is laminated such that the light controlling film is interposed between two intermediate films.

5. A functional glass comprising the optical film according to claim 3 .

6. The functional glass according to claim 5 , wherein the optical film is interposed between two glass sheets to constitute a laminated glass.

7. A head-up display comprising the optical film according to claim 3 .

8. The head-up display according to claim 7 , wherein the head-up display comprises a projector for displaying an image, the projector is provided with a P polarized light emitting units, and the optical film is disposed in a laminated manner such that a slow axis of the quarter wave plate is at 45 degrees to emitted P polarized light.

9. A functional glass comprising the light controlling film according to claim 1 .

10. The functional glass according to claim 9 , wherein the light controlling film is interposed between two glass sheets to constitute a laminated glass.

11. A head-up display comprising the functional glass according to claim 9 .

12. A head-up display comprising the light controlling film according to claim 1 .

13. The head-up display according to claim 12 , comprising a projector for displaying an image, the projector being provided with a circularly-polarized light emitting units to emit circularly polarized light in the same orientation as circularly polarized light selectively reflected by the light reflecting film.

14. The head-up display according to claim 12 , comprising a projector for displaying an image, the projector being provided with a P polarized light emitting units.

15. The head-up display according to claim 14 , wherein the light controlling film is disposed in a laminated manner such that a slow axis of the quarter wave plate is at 45 degrees to emitted P polarized light.

16. The head-up display according to claim 14 , wherein the functional glass is disposed in a laminated manner such that a slow axis of the quarter wave plate is at 45 degrees to emitted P polarized light.

17. The light controlling film according to claim 1 , wherein the at least two light reflecting layers further include a light reflecting layer PRL- 4 having a central reflection wavelength of greater than or equal to 700 nm but less than or equal to 950 nm and a reflectance to ordinary light at the central reflection wavelength of greater than or equal to 5% but less than or equal to 25%,
the light reflecting layer PRL- 4 having a property of reflecting polarized light that has the same orientation as the light reflecting layer PRL- 1 , the light reflecting layer PRL- 2 and the light reflecting layer PRL- 3 .

Assignees

• Nippon Kayaku Kk

Inventors

• Tanaka Kouichi
• Takahashi Chihiro
• Yokoyama Yui
• Hayasaki Tomoyuki

Classifications

• G02B5/26

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

• G02B5/0816 Primary

  Multilayer mirrors, i.e. having two or more reflecting layers (G02B5/0883, G02B5/0891 take precedence) · CPC title

• G02B2027/0194

  with combiner of laminated type, for optical or mechanical aspects · CPC title

• G02B5/30

  Polarising elements (light-modulating devices with active elements G02F1/00) · CPC title

• G02F1/1335

  Structural association of cells with optical devices, e.g. polarisers or reflectors · CPC title