Patents by Inventor Asher Albert Friesem

Asher Albert Friesem 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: 6169613
    Abstract: A holographic optical device includes a light transmissive substrate carrying first and second laternally separated holographic optical elements. The first holographic optical element diffracts incident light into the substrate where it is trapped by internal reflection so that light impinges more than once at different angles at different locations on at least one of the first and second holographic optical elements with a significantly higher efficiency for one angle of incidence. The second holographic optical element diffracts light out of the substrate. The second holographic optical element may be a display hologram for displaying a three-dimensional image.
    Type: Grant
    Filed: June 3, 1997
    Date of Patent: January 2, 2001
    Assignee: Yeda Research & Devel Co., Ltd.
    Inventors: Yaakov Amitai, Asher Albert Friesem, Isaac Shariv
  • Patent number: 5966223
    Abstract: A holographic optical device having a light transmissive substrate with a first holographic optical element carried by the substrate, and a second holographic optical element also carried by the substrate but laterally offset from the first holographic optical element. The first holographic optical element diffracts waves from each data point in a display source into a collimated plane wave such that the plane wave is trapped inside the substrate by internal reflection, and the first holographic optical element also corrects field aberrations over the entire field of view by being recorded using at least one aspheric wavefront. The second holographic optical element diffracts the trapped plane waves out of the substrate.
    Type: Grant
    Filed: June 3, 1997
    Date of Patent: October 12, 1999
    Assignee: Yeda Research & Development Co., Ltd.
    Inventors: Asher Albert Friesem, Yaakov Amitai, Silviu Reinhorn, Isaac Shariv
  • Patent number: 5682255
    Abstract: A holographic optical device includes a light-transmissive substrate, a first holographic optical element, and a second holographic optical element that is laterally disposed on the substrate from the first holographic optical element. At least one of the holographic optical elements is a complex diffraction grating that can handle a multiplicity of plane and/or spherical waves arriving from a range of angles, and having a range of wavelengths. Applications for the device include a wavelength division multiplexer/demultiplexer, an image reconstructor, a beam expander/compressor, and a visor/head-up display.
    Type: Grant
    Filed: November 13, 1995
    Date of Patent: October 28, 1997
    Assignee: Yeda Research & Development Co. Ltd.
    Inventors: Asher Albert Friesem, Yaakov Amitai