# US 11,079,617 B2 · Optical filter comprising a variable transmittance layer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,079,617 B2 - Document ID: US11079617B2 - Status: Granted - Kind: B2 - Application number: 16/522,420 - Filed: 2019-07-25 - Published: 2019-11-14 - Granted: 2021-08-03 - Earliest claimed: 2012-05-29 - Assignees: Solatia Canada Inc. - Applicants: Solutia Canada Inc. - Inventors: Neil Robin Branda; Zachary Bryce Erno; Jeremy Graham Finden; Duhane Lam; Charles Joseph Gongming Loo; Jonathan Ross Sargent; Matthew Paul Smit; Peter Alexander Von Hahn; Douglas Malcolm Wiggin - Web page: https://patentgrep.com/patent/US11079617B2 ## CPC - G02F 1/0102: {Constructional details, not otherwise provided for in this subclass} - B29D 11/00634: {Production of filters} - B32B 17/10486: {photochromic} - B32B 17/10513: {Electrochromic layer} - B32B 17/10633: {Infrared radiation absorbing or reflecting agents} - B32B 17/10761: {containing vinyl acetal} - B32B 37/12: characterised by using adhesives - B60J 3/04: adjustable in transparency - E06B 9/24: Screens or other constructions affording protection against light, especially against sunshine; Similar screens for privacy or appearance; {Slat blinds}(operating, guiding or securing devices or arrangements for roll-type closures E06B9/56; free-hanging flexible screens A47H23/00) - G02B 5/208: {for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation} - G02B 5/23: Photochromic filters - G02C 7/101: {having an electro-optical light valve (electro-optical elements per se G02F)} - G02C 7/102: {Photochromic filters} - G02F 1/157: Structural association of cells with optical devices, e.g. reflectors or illuminating devices - B32B 2307/402: Coloured - B32B 2307/42: Polarizing, birefringent, filtering - B32B 2315/08: Glass - B32B 2419/00: Buildings or parts thereof - B32B 2551/00: Optical elements - B32B 2605/006: Transparent parts other than made from inorganic glass, e.g. polycarbonate glazings - B32B 2605/08: Cars - E06B 2009/2417: {Light path control; means to control reflection} - E06B 2009/2464: {featuring transparency control by applying voltage, e.g. LCD, electrochromic panels} - G02C 7/10: Filters, e.g. for facilitating adaptation of the eyes to the dark; Sunglasses - G02F 2203/05: wavelength dependent - G02F 2203/48: Variable attenuator - Y10T 29/49826: Assembling or joining - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS - B29D: PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE (making granules B29B9/00; making preforms B29B11/00) - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - B60J: WINDOWS, WINDSCREENS, NON-FIXED ROOFS, DOORS, OR SIMILAR DEVICES FOR VEHICLES; REMOVABLE EXTERNAL PROTECTIVE COVERINGS SPECIALLY ADAPTED FOR VEHICLES (fastening, suspending, closing, or opening of such devices E05) - E06B: FIXED OR MOVABLE CLOSURES FOR OPENINGS IN BUILDINGS, VEHICLES, FENCES OR LIKE ENCLOSURES IN GENERAL, e.g. DOORS, WINDOWS, BLINDS, GATES (shades or blinds for greenhouses A01G9/22; curtains A47H; lids for car boots or bonnets B62D25/10; skylights E04B7/18; sunshades, awnings E04F10/00) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G02C: SPECTACLES; SUNGLASSES OR GOGGLES INSOFAR AS THEY HAVE THE SAME FEATURES AS SPECTACLES; CONTACT LENSES (trial frames for testing the eyes A61B3/04; goggles or eyeshields not having the same features as spectacles A61F9/00) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract An 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 faded 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 ### Claim 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 a light transmission value of the variable transmittance layer in the dark state is lower than a light transmission value of the variable transmittance layer in the faded state, and wherein each of the first and second spectra comprise a visible portion; and an ultraviolet (UV) blocking layer that has a cutoff wavelength of between 370 nm and 435 nm, wherein the variable transmittance layer and the UV blocking layer comprise a stack, wherein the optical filter comprises: an LTA in the dark state of less than about 30%; and an LTA in the faded state of greater than about 5%, wherein the LTA in the dark state is less than the LTA in the faded state. ### Claim 2 (depends on 1) The optical filter of claim 1, further comprising 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. ### Claim 3 (depends on 2) The optical filter of claim 2, 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. ### Claim 4 (depends on 3) The optical filter of claim 3, 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. ### Claim 5 (depends on 2) The optical filter of claim 2, wherein the color balancing layer comprises polyvinyl butyral (PVB). ### Claim 6 (depends on 2) The optical filter of claim 2, wherein the dark state target color and color of the optical filter in the dark state provide a delta C value of from about 0 to about 20. ### Claim 7 (depends on 2) The optical filter of claim 2, wherein the dark state target color and color of the optical filter in the dark state provide a delta E value of from about 0 to about 20. ### Claim 8 (depends on 2) The optical filter of claim 2, wherein the faded state target color and color of the optical filter in the faded state provide a delta C value of from about 0 to about 20. ### Claim 9 (depends on 2) The optical filter of claim 2, wherein the faded state target color and color of the optical filter in the faded state provide a delta E value of from about 0 to about 20. ### Claim 10 (depends on 1) The optical filter of claim 1, wherein the variable transmittance layer comprises a switching material transitionable from the faded state to the dark state when exposed to electromagnetic radiation, and from the dark state to the faded state with application of a voltage. ### Claim 11 (depends on 10) The optical filter of claim 10, wherein the voltage applied is from 0.1 V to 2.5 V. ### Claim 12 (depends on 1) The optical filter of claim 1, further comprising an infrared (IR) blocking layer that comprises part of the stack. ### Claim 13 (depends on 1) The optical filter of claim 1, wherein the UV blocking layer blocks about 50% of incident UV light at the cutoff wavelength. ### Claim 14 (depends on 1) A device comprising the optical filter of claim 1, wherein the device comprises a laminated glass, an ophthalmic device, an automotive glazing product, or an architectural glazing product. ### Claim 15 (depends on 1) The optical filter of claim 1, further comprising a light-attenuating layer. ### Claim 16 (depends on 1) The optical filter of claim 1, comprising a contrast ratio of at least 5. ### Claim 17 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 a light transmission value of the variable transmittance layer in the dark state is lower than a light transmission value of the variable transmittance layer in the faded state, and wherein each of the first and second spectra comprise a visible portion; and an ultraviolet (UV) blocking layer that has a cutoff wavelength of between 370 nm and 435 nm, wherein the variable transmittance layer and the UV blocking layer comprise a stack, wherein the optical filter comprises a light transmission value of 1% or less in the dark state and 6% or higher in the faded state. ### Claim 18 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 a light transmission value of the variable transmittance layer in the dark state is lower than a light transmission value of the variable transmittance layer in the faded state, and wherein each of the first and second spectra comprise a visible portion; and an ultraviolet (UV) blocking layer that has a cutoff wavelength of between 370 nm and 435 nm, wherein the variable transmittance layer and the UV blocking layer comprise a stack, wherein the optical filter comprises a light transmission value of 5% or less in the dark state and 15% or higher in the faded state.