Patents by Inventor Clara E. Nelson

Clara E. Nelson has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7557208
    Abstract: Described are naphthols useful in the manufacture of novel indeno-fused photochromic naphthopyran materials.
    Type: Grant
    Filed: November 11, 2008
    Date of Patent: July 7, 2009
    Assignee: Transitions Optical, Inc.
    Inventors: Robert W. Walters, Anil Kumar, Clara E. Nelson, Anu Chopra
  • Patent number: 7517982
    Abstract: Described are naphthols useful in the manufacture of novel indeno-fused photochromic naphthopyran materials.
    Type: Grant
    Filed: March 1, 2007
    Date of Patent: April 14, 2009
    Assignee: Transitions Optical, Inc.
    Inventors: Robert W. Walters, Anil Kumar, Clara E. Nelson, Anu Chopra
  • Publication number: 20090062533
    Abstract: Described are naphthols useful in the manufacture of novel indeno-fused photochromic naphthopyran materials.
    Type: Application
    Filed: November 11, 2008
    Publication date: March 5, 2009
    Applicant: TRANSITIONS OPTICAL, INC.
    Inventors: Robert W. Walters, Anil Kumar, Clara E. Nelson, Anu Chopra
  • Patent number: 7320826
    Abstract: Described are photochromic articles that include a substrate, a temperature dependent reducing amount of at least one organic photochromic material (b) that changes from more absorbing to less absorbing of radiation in its activating spectral absorbance as the temperature increases from 10° C. to 35° C. and at least one other photochromic material (c) that is different from photochromic material (b). In the article, photochromic material (b) is interposed between photochromic material (c) and a source of activating radiation. The photochromic article demonstrates a more consistent photochromic response, for example, an optical density response loss of 50 percent or less over a temperature range of from 10° C. to 35° C. as measured in the Photochromic Temperature Dependence Test. Methods for producing the aforedescribed articles are also disclosed.
    Type: Grant
    Filed: March 20, 2003
    Date of Patent: January 22, 2008
    Assignee: PPG Industries Ohio, Inc.
    Inventors: Anil Kumar, Barry Van Gemert, Forrest R. Blackburn, Clara E. Nelson
  • Patent number: 7262295
    Abstract: Described are photochromic materials of indeno [2?,3?:3,4]naphtho[1,2-b]pyran structure, characterized in that they have a nitrogen or sulfur containing substituent at the 11-position ring atom, are substantially free of spiro-substituents at the 13-position and have been adapted to provide an increase in the sensitivity, visible lambda max or a combination thereof as measured in the Indenonaphthopyran Photochromic Performance Test. Optional substituents can be present at the other positions of the indeno [2?,3?:3,4]naphtho [1,2-b]pyran structure. Also described are naphthols used to produce the photochromic materials and photochromic articles that contain or that have coatings containing at least one of the novel photochromic materials or combinations thereof with other photochromic materials.
    Type: Grant
    Filed: March 20, 2003
    Date of Patent: August 28, 2007
    Assignee: Transitions Optical, Inc.
    Inventors: Robert W. Walters, Anil Kumar, Clara E. Nelson, Anu Chopra
  • Patent number: 7166357
    Abstract: Described are photochromic articles that include a substrate and a photochromic amount of at least one organic photochromic material (b) represented by graphic formula XIII adapted to change from an unactivated state to an activated state by exposure to radiation substantially in a wavelength range from 380 to 410 nanometers (nm) when measured over a wavelength range of from 380 to 700 nm. The photochromic articles demonstrate a photochromic response when activated behind an ultraviolet blocking transparency such as an automotive windshield. For example, the photochromic articles retain at least 12 percent of the activation measured as change in optical density or delta OD under outdoor simulating conditions in the Outdoor Test when tested under conditions simulating an eyeglass wearer behind an automotive windshield in the Behind the Windshield Test. Methods for producing the aforedescribed photochromic articles are also described.
    Type: Grant
    Filed: March 20, 2003
    Date of Patent: January 23, 2007
    Assignee: Transitions Optical, Inc.
    Inventors: Anil Kumar, Michael S. Misura, Robert W. Walters, Barry Van Gemert, Anu Chopra, Clara E. Nelson
  • Publication number: 20040191520
    Abstract: Described are photochromic articles that include a substrate and at least one photochromic material adopted to change from an unactivated form to an activated form upon exposure to actinic radiation. The activated form of the photochromic material changes from more absorbing to less absorbing of radiation in the absorption region of its unactivated form as the temperature increases from 10° C. to 35° C. The photochromic article demonstrates a more consistent photochromic response, for example, an optical density response loss of 50 percent or less over a temperature range of from 10° C. to 35° C. as measured in the Photochromic Temperature Dependence Test. Methods for producing the aforedescribed articles are also disclosed.
    Type: Application
    Filed: March 20, 2003
    Publication date: September 30, 2004
    Inventors: Anil Kumar, Barry Van Gemert, Forrest R. Blackburn, Clara E. Nelson
  • Publication number: 20040185255
    Abstract: Described are photochromic materials of indeno [2′,3′:3,4]naphtho[1,2-b]pyran structure, characterized in that they have a nitrogen or sulfur containing substituent at the 11-position ring atom, are substantially free of spiro-substituents at the 13-position and have been adapted to provide an increase in the sensitivity, visible lambda max or a combination thereof as measured in the Indenonaphthopyran Photochromic Performance Test. Optional substituents can be present at the other positions of the indeno [2′,3′:3,4]naphtho [1,2-b]pyran structure. Also described are naphthols used to produce the photochromic materials and photochromic articles that contain or that have coatings containing at least one of the novel photochromic materials or combinations thereof with other photochromic materials.
    Type: Application
    Filed: March 20, 2003
    Publication date: September 23, 2004
    Inventors: Robert W. Walters, Anil Kumar, Clara E. Nelson, Anu Chopra
  • Publication number: 20040185268
    Abstract: Described are photochromic articles that include a substrate and at least one photochromic material adapted to change from an unactivated state to an activated state by exposure to radiation substantially in a wavelength range from 380 to 410 nanometers (nm) when measured over a wavelength range of from 380 to 700 nm. The photochromic articles demonstrate a photochromic response when activated behind an ultraviolet blocking transparency such as an automotive windshield. For example, the photochromic articles retain at least 12 percent of the activation measured as change in optical density or delta OD under outdoor simulating conditions in the Outdoor Test when tested under conditions simulating an eyeglass wearer behind an automotive windshield in the Behind the Windshield Test. Methods for producing the aforedescribed photochromic articles are also described.
    Type: Application
    Filed: March 20, 2003
    Publication date: September 23, 2004
    Inventors: Anil Kumar, Michael S. Misura, Robert W. Walters, Barry Van Germert, Anu Chopra, Clara E. Nelson