The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 21, 1999
Filed:
Dec. 11, 1996
Annette C Grot, Cupertino, CA (US);
John S Hoch, Santa Clara, CA (US);
Robert C Taber, Palo Alto, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
The hologram card generates a hologram image in response to an illumination light beam. The hologram card comprises a substrate of a first plastic material having a first refractive index. The substrate has a contoured surface. The contoured surface is formed to include localized topological features constituting a diffractive optical element. The diffractive optical element is structured to generate a hologram image when illuminated by the illumination light beam. The hologram card also comprises a protective layer of a second plastic material having a second refractive index that differs from the first refractive index by less than 0.2. The protective layer covers the contoured surface of the substrate. The protective layer is chemically bonded to, and directly contacts, at least the topological features constituting the diffractive optical element.