Optical filter comprising a variable transmittance layer

• US 9,921,421 B2
• Filed: 01/18/2017
• Issued: 03/20/2018
• Est. Priority Date: 05/29/2012
• Status: Active Grant

• Current Assignee: Solutia Canada, Inc. (Eastman Chemical Company)
• Original Assignee: Switch Materials, Inc.
• Inventors: Branda, Neil Robin, Erno, Zachary Bryce, Finden, Jeremy Graham, Lam, Duhane, Loo, Charles Joseph Gongming, Sargent, Jonathan Ross, Smit, Matthew Paul, Von Hahn, Peter Alexander, Wiggin, Douglas Malcolm
• Primary Examiner(s): HASAN, MOHAMMED A
• Application Number:
  US15/409,196
• Publication Number:
  US 20170192257A1
• Time in Patent Office: 426 Days
• Field of Search: 359238, 359239, 359722, 359642, 359885, 359891
• CPC Class Codes: B29D 11/00634 Production of filters
• CPC Class Codes: B32B 17/10486 photochromic
• CPC Class Codes: B32B 17/10513 Electrochromic layer
• CPC Class Codes: B32B 17/10633 Infrared radiation absorbing or reflecting agents
• CPC Class Codes: B32B 17/10761 containing vinyl acetal
• CPC Class Codes: B32B 2307/402 Coloured
• CPC Class Codes: B32B 2307/42 Polarizing, birefringent, filtering
• CPC Class Codes: B32B 2315/08 Glass
• CPC Class Codes: B32B 2419/00 Buildings or parts thereof walls, panels B32B2607/00
• CPC Class Codes: B32B 2551/00 Optical elements
• CPC Class Codes: B32B 2605/006 Transparent parts other than made from inorganic glass, e.g. polycarbonate glazings
• CPC Class Codes: B32B 2605/08 Cars
• CPC Class Codes: B32B 37/12 characterised by using adhesives
• CPC Class Codes: B60J 3/04 adjustable in transparency
• CPC Class Codes: E06B 2009/2417 Light path control; means to control reflection
• CPC Class Codes: E06B 2009/2464 featuring transparency control by applying voltage, e.g. LCD, electrochromic panels
• CPC Class Codes: E06B 9/24 Screens or other constructions affording protection against light, especially against sunshine; Similar screens for privacy or appearance; Slat blindsoperating, guiding or securing devices or arrangements for roll-type closures E06B9/56; free-hanging flexible screens A47H23/00
• CPC Class Codes: G02B 5/208 for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation
• CPC Class Codes: G02B 5/23 Photochromic filters
• CPC Class Codes: G02C 7/10 Filters, e.g. for facilitating adaptation of the eyes to the dark; Sunglasses
• CPC Class Codes: G02C 7/101 : having an electro-optical light valve electro-optical elements per se G02F
• CPC Class Codes: G02C 7/102 : Photochromic filters
• CPC Class Codes: G02F 1/0102 : Constructional details, not otherwise provided for in this subclass
• CPC Class Codes: G02F 1/157 : Structural association of cells with optical devices, e.g. reflectors or illuminating devices
• CPC Class Codes: G02F 2203/05 : wavelength dependent
• CPC Class Codes: G02F 2203/48 : Variable attenuator
• CPC Class Codes: Y10T 29/49826 : Assembling or joining

Abstract

A optical filter comprising a variable transmittance layer having a first spectrum in a dark state, and a second spectrum in a faded state; and a color balancing layer having a third spectrum; each of the first, second and third spectra comprising a visible portion; the first and third spectra combining to provide a dark state spectrum approximating a dark state target color; and the second and third spectra combining to provide a fades state spectrum approximating a faded state target color. The optical filter may further comprise a light attenuating layer. The optical filter may further comprise part of a laminated glass.

Claims

1. An optical filter comprising:

(a) a variable transmittance layer having a first spectrum in a dark state, and a second spectrum in a faded state; and

(b) a polymer color balancing layer having a third spectrum, wherein the variable transmittance layer and the color balancing layer are laminated together and comprise part of a stack;

(c) each of the first, second and third spectra comprising a visible portion;

(d) the first and third spectra combining to provide a dark state spectrum approximating a dark state target color; and

(e) the second and third spectra combining to provide a faded state spectrum approximating a faded state target color.

2. The optical filter of claim 1 further comprising a first glass layer that comprises part of the stack, wherein the variable transmittance layer and the color balancing layer are laminated to the first glass layer.

3. The optical filter of claim 2 further comprising a second glass layer that comprises part of the stack, wherein the variable transmittance layer and the color balancing layer are laminated to the second glass layer.

4. The optical filter of claim 1 wherein the color balancing layer comprises polyvinyl butyral (PVB).

5. The optical filter of claim 1 further comprising an ultraviolet (UV) blocking layer.

6. The optical filter of claim 5 wherein the UV blocking layer has a cutoff wavelength of about 435 nm or less.

7. The optical filter of claim 1 further comprising a light-attenuating layer.

8. The optical filter of claim 1 wherein the variable transmittance layer comprises a switching material transitionable from a faded state to a dark state when exposed to electromagnetic radiation, and from a dark state to a faded state with application of a voltage.

9. The optical filter of claim 8 wherein the electromagnetic radiation is UV light.

10. The optical filter of claim 8 wherein the electromagnetic radiation has a component with a wavelength of 450 nm or less.

11. The optical filter of claim 8 wherein the voltage applied is from about 1.1 to about 2.5 V.

12. The optical filter of claim 1 further comprising an infrared (IR)-blocking layer.

13. The optical filter of claim 1 comprising any one or more of:

a. an LTA in a dark state of less than about 15%;

b. an LTA in a faded state of greater than about 5%; and

c. a contrast ratio of at least 5.

14. The optical filter of claim 1 comprising a light transmission value of 1% or less in the dark state and 6% or higher in the light state.

15. The optical filter of claim 1 comprising a light transmission value of 5% or less in the dark state and 15% or higher in the light state.

16. The optical filter of claim 1 wherein the target color of the dark state and color of the optical filter in the dark state provide a delta C value of from about 0 to about 20.

17. The optical filter of claim 1 wherein the target color of the dark state and color of the optical filter in the dark state provide a delta E value of from about 0 to about 20.

18. The optical filter of claim 1 wherein the target color of the faded state and color of the optical filter in the faded state provide a delta C value of from about 0 to about 20.

19. The optical filter of claim 1 wherein the target color of the faded state and color of the optical filter in the faded state provide a delta E value of from about 0 to about 20.

20. A device comprising the optical filter of claim 1, wherein the device is a laminated glass, an ophthalmic device, an automotive glazing product or an architectural glazing product.