Semi-Transparent Reflectors

• US 20120087009A1
• Filed: 10/12/2010
• Published: 04/12/2012
• Est. Priority Date: 10/12/2010
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Motor Engineering & Manufacturing North America Incorporated (Toyota Motor Corporation)
• Inventors: Grayson, Benjamin Alan, Banerjee, Debasish, Ishii, Masahiko
• Granted Patent: US 10,067,265 B2
• Time in Patent Office: Days
• US Class Current: 359/584
• CPC Class Codes: G02B 1/005 made of photonic crystals or photonic band gap materials photonic band-gap structures or photonic lattices in integrated optics G02B6/1225; photonic band-gap structures or photonic lattices in optical fibres G02B6/02295
• CPC Class Codes: G02B 1/10 Optical coatings produced by application to, or surface treatment of, optical elements G02B1/08 takes precedence
• CPC Class Codes: G02B 5/0825 the reflecting layers comprising dielectric materials only
• CPC Class Codes: G02B 5/0833 comprising inorganic materials only

Abstract

In one embodiment, a semi-transparent reflector may include a multilayered photonic structure. The multilayered photonic structure includes a plurality of coating layers of high index dielectric material and a plurality of coating layers of low index dielectric material. The plurality of coating layers of high index dielectric material and the plurality of coating layers of low index dielectric material of the multilayered photonic structure are arranged in an [LH . . . (LH)^N . . . L] structure. L is one of the plurality of coating layers of low index dielectric material. H is one of the plurality of coating layers of high index dielectric material. N is a positive integer. The multilayered photonic structure has substantially constant reflectance values for wavelengths of electromagnetic radiation in a visible spectrum over a range of angles of incidence of the electromagnetic radiation.

Claims

1. A semi-transparent reflector comprising a multilayered photonic structure, the multilayered photonic structure comprising a plurality of coating layers of high index dielectric material and a plurality of coating layers of low index dielectric material, wherein:

the plurality of coating layers of high index dielectric material and the plurality of coating layers of low index dielectric material of the multilayered photonic structure are arranged in an [LH . . . (LH)^N . . . L] structure, wherein;

L is one of the plurality of coating layers of low index dielectric material;

H is one of the plurality of coating layers of high index dielectric material;

N is a positive integer; and

the multilayered photonic structure has substantially constant reflectance values for wavelengths of electromagnetic radiation in a visible spectrum over a range of angles of incidence of the electromagnetic radiation.

2. The semi-transparent reflector of claim 1, wherein an average of the substantially constant reflectance values is greater than a target reflectance value minus two standard deviations of the substantially constant reflectance values and the average of the substantially constant reflectance values is greater than the target reflectance value minus the two standard deviations of the substantially constant reflectance values.

3. The semi-transparent reflector of claim 2, wherein the target reflectance value is from about 51% to about 95%.

4. The semi-transparent reflector of claim 3, wherein a standard deviation of the substantially constant reflectance values is less than about 7% reflectance.

5. The semi-transparent reflector of claim 4, wherein the visible spectrum is from about 400 nm to about 900 nm or from about 400 nm to about 800 nm.

6. The semi-transparent reflector of claim 4, wherein the range of angles of incidence is from about 0°

to about 45°

.

7. The semi-transparent reflector of claim 1, wherein the plurality of coating layers of low index dielectric material comprise a low refractive index from about 1.4 to about 1.6.

8. The semi-transparent reflector of claim 1, wherein the plurality of coating layers of high index dielectric material comprise a high refractive index from about 1.9 to about 2.3.

9. The semi-transparent reflector of claim 1, wherein:

the plurality of coating layers of high index dielectric material consists of 8 to 12 coating layers of high index dielectric material; and

the plurality of coating layers of low index dielectric material consists of 9 to 13 coating layers of low index dielectric material.

10. The semi-transparent reflector of claim 1, wherein each of the plurality of coating layers of high index dielectric material and each of the plurality of coating layers of low index dielectric material have a layer thickness from about 0.05 nm to about 500 nm.

11. The semi-transparent reflector of claim 1, wherein the multilayered photonic structure is coupled to a surface of an electronic display, a window or a vehicle.

12. A vehicle comprising:

a communication system that receives or transmits a transmission signal;

a non-metallic vehicle component comprising a multilayered photonic structure, the multilayered photonic structure comprising a plurality of coating layers of high index dielectric material and a plurality of coating layers of low index dielectric material, wherein;

the plurality of coating layers of high index dielectric material and the plurality of coating layers of low index dielectric material of the multilayered photonic structure are arranged in an [LH . . . (LH)^N . . . L] structure;

L is one of the plurality of coating layers of low index dielectric material;

H is one of the plurality of coating layers of high index dielectric material;

N is a positive integer;

the multilayered photonic structure has substantially constant reflectance values for wavelengths of electromagnetic radiation in a visible spectrum over a range of angles of incidence of the electromagnetic radiation from about 0°

to about 45°

; and

the multilayered photonic structure is substantially transparent to the transmission signal.

13. The vehicle of claim 12, wherein:

an average of the substantially constant reflectance values is greater than a target reflectance value minus two standard deviations of the substantially constant reflectance values;

the average of the substantially constant reflectance values is greater than the target reflectance value minus the two standard deviations of the substantially constant reflectance values; and

the target reflectance value is from about 51% to about 95%.

14. The vehicle of claim 12, wherein the non-metallic vehicle component is a trim piece, a vehicle emblem, a grille, a hood ornament, a wheel cover, a bumper, a bezel, a taillight, a reflector, a video monitor coating, or a mirror.

15. The vehicle of claim 12, wherein the transmission signal is a K-band transmission, a Ka-band transmission or a V-band transmission.

16. The vehicle of claim 12, wherein the non-metallic vehicle component is coupled to an exterior surface of the vehicle and disposed within a transmission path of the communication system.

17. The vehicle of claim 12, wherein:

the plurality of coating layers of high index dielectric material consists of 8 to 12 coating layers of high index dielectric material; and

the plurality of coating layers of low index dielectric material consists of 9 to 13 coating layers of low index dielectric material.

18. A non-metallic vehicle component comprising a multilayered photonic structure comprising a plurality of coating layers of high index dielectric material and a plurality of coating layers of low index dielectric material alternately arranged, wherein:

the multilayered photonic structure has substantially constant reflectance values for wavelengths of electromagnetic radiation in a visible spectrum from about 400 nm to about 800 nm over a range of angles of incidence of the electromagnetic radiation from about 0°

to about 45°

;

an average of the substantially constant reflectance values is greater than a target reflectance value minus two standard deviations of the substantially constant reflectance values;

the average of the substantially constant reflectance values is greater than the target reflectance value minus the two standard deviations of the substantially constant reflectance values;

a standard deviation of the substantially constant reflectance values is less than about 3% reflectance; and

the target reflectance value is from about 51% to about 95%.

19. The non-metallic vehicle component of claim 18, wherein:

the plurality of coating layers of high index dielectric material and the plurality of coating layers of low index dielectric material of the multilayered photonic structure are arranged in an [LH . . . (LH)^N . . . L] structure;

L is one of the plurality of coating layers of low index dielectric material;

H is one of the plurality of coating layers of high index dielectric material; and

N is a positive integer.

20. The non-metallic vehicle component of claim 18, wherein:

the plurality of coating layers of high index dielectric material and the plurality of coating layers of low index dielectric material of the multilayered photonic structure are arranged in an [HL . . . (HL)^N . . . H] structure;

L is one of the plurality of coating layers of low index dielectric material;

H is one of the plurality of coating layers of high index dielectric material; and

N is a positive integer.