Optical filter comprising a variable transmittance layer

• US 10,401,654 B2
• Filed: 02/02/2018
• Issued: 09/03/2019
• 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:
  US15/887,668
• Publication Number:
  US 20180224677A1
• Time in Patent Office: 578 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 variable transmittance layer having a first spectrum in a dark state and a second spectrum in a faded state, wherein each of the first and second spectra comprise a visible portion;

an infrared (IR) blocking layer, wherein the variable transmittance layer and the infrared (IR) blocking layer comprise a stack; and

a color balancing layer having a third spectrum and comprising part of the stack, wherein the third spectrum comprises a visible portion, the first and third spectra combine to provide a dark state spectrum approximating a dark state target color, and the second and third spectra combine to provide a faded state spectrum approximating a faded state target color.

2. 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.

3. The optical filter of claim 2 wherein the voltage applied is from 0.1 V to 2.5 V.

4. The optical filter of claim 1 further comprising an ultraviolet (UV) blocking layer that comprises part of the stack, wherein the UV blocking layer has a cutoff wavelength of between 370 nm and 435 nm.

5. The optical filter of claim 4 wherein the UV blocking layer blocks about 50% of incident UV light at the cutoff wavelength.

6. The optical filter of claim 1 comprising:

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

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

a contrast ratio of at least 5.

7. 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 faded state.

8. 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 faded state.

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