Patents by Inventor MRIDULA MADHUSUDAN

MRIDULA MADHUSUDAN 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).

  • Method to design a security feature on the substrate of security documents using sub wavelength grating
    Patent number: 9221293
    Abstract: Method of designing a security thread in security documents with better color contrast at any viewing angle is claimed. The invention discloses designing of security thread in security documents like bank notes using subwavelength gratings with period and thickness less than the wavelength of light. The sub wavelength gratings preferably asymmetric are designed such that the Oth order reflections are of longer wavelength (red) and the higher order reflections (diffracted orders) are of shorter wavelengths (blue/green). The security thread so designed gives better color contrast unlike the rainbow colors of prior art thus allowing better and easier distinction of authentic documents.
    Type: Grant
    Filed: October 24, 2013
    Date of Patent: December 29, 2015
    Assignee: Council of Scientific & Industrial Research
    Inventors: Bala Pesala, Mridula Madhusudan
  • METHOD TO DESIGN A SECURITY FEATURE ON THE SUBSTRATE OF SECURITY DOCUMENTS USING SUB WAVELENGTH GRATING
    Publication number: 20150113793
    Abstract: Method of designing a security thread in security documents with better color contrast at any viewing angle is claimed. The invention discloses designing of security thread in security documents like bank notes using subwavelength gratings with period and thickness less than the wavelength of light. The sub wavelength gratings preferably asymmetric are designed such that the Oth order reflections are of longer wavelength (red) and the higher order reflections (diffracted orders) are of shorter wavelengths (blue/green). The security thread so designed gives better color contrast unlike the rainbow colors of prior art thus allowing better and easier distinction of authentic documents.
    Type: Application
    Filed: October 24, 2013
    Publication date: April 30, 2015
    Applicant: Council of Scientific & Industrial Research
    Inventors: BALA PESALA, MRIDULA MADHUSUDAN