Patents by Inventor Rama N. Singh

Rama N. Singh 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: 5597222
    Abstract: A projection display which includes reflective light valves such as liquid crystal spatial light modulators, and a 1.times. optical relay lens system. The 1.times. optical relay lens system eliminates the requirement for a projection lens having a large retrofocus distance. Projection displays based upon reflective liquid crystal light valves (spatial light modulators) require dichroic beam splitters necessary for color separation and a polarizing beam splitter necessary for light valve operation positioned between the light valves and the projection lens. The 1.times. optical relay lens produces a relayed intermediate image of the light valves, and incorporates therein the dichroic beam splitters and the polarizing beam splitter. The 1.times. optical relay lens produces an intermediate image which is projected by the projection lens at a given magnification with minimal working distance, which results in relatively less residual lateral color and an inexpensive projection lens.
    Type: Grant
    Filed: January 17, 1995
    Date of Patent: January 28, 1997
    Assignee: IBM Corporation
    Inventors: Fuad E. Doany, Rama N. Singh
  • Patent number: 5401934
    Abstract: A lens system for a laser scanning apparatus which incorporates two transfer lenses in tandem. The transfer lenses include angular reflecting mirrors, correction lenses, and concave mirrors. The transfer lenses are located between the projection mask and the target of the scanning apparatus wherein the laser beam passed through the projection mask is reflected by an angularly disposed mirror through the first correction lens onto the first concave mirror where it is reflected back through the first correction lens and onto another angularly disposed mirror where the beam is sent to and back from the second concave mirror through the second correction lens and then onto the target.
    Type: Grant
    Filed: March 8, 1993
    Date of Patent: March 28, 1995
    Assignee: International Business Machines Corporation
    Inventors: Thomas Ainsworth, Jr., George Chiu, Rama N. Singh, Janusz S. Wilczynski
  • Patent number: 5315604
    Abstract: Structure is disclosed for the ablation of material by the use of a laser beam wherein the laser provides a beam which is directed through an illumination and projection optical system for imaging on the material which is to be ablated. In the present invention the peak power of the laser beam is adjustable. The laser beam peak power adjustment structure includes a laser that provides a pulsed beam. The laser beam is directed into a beam splitter wherein the laser beam is split into two beam components. The first beam component passes through beam splitter with negligible or no delay, then passes through a quarter waveplate and impinges on a first mirror which reflects it back to the beam splitter. The second beam component is directed at an angle of 90 degrees by the beam splitter and toward a second mirror. The second mirror is at a predetermined distance from the beam splitter which introduces a total predetermined delay for the reflected second beam component as it is directed back to the beam splitter.
    Type: Grant
    Filed: January 28, 1993
    Date of Patent: May 24, 1994
    Assignee: International Business Machines Corporation
    Inventors: George Chiu, Rama N. Singh, Janusz S. Wilczynski
  • Patent number: 5241423
    Abstract: An optical system of a NX reduction catadioptric relay lens having sub-half micron resolution over the ultraviolet band width is described. A spherical mirror with a stop at the mirror is used to work at substantially the desired reduction ratio and the desired high numerical aperture sufficient to provide the desired high resolution. A beam splitting cube with appropriate coatings is used to form an accessible image of an object on an image plane. Refracting correctors in the path of the slow beam incident on the mirror and in the path of the fast beam reflected on the mirror are designed to fix the aberrations of the image formed by the mirror.
    Type: Grant
    Filed: August 1, 1991
    Date of Patent: August 31, 1993
    Assignee: International Business Machines Corporation
    Inventors: George L. Chiu, Rama N. Singh, Janusz S. Wilczynski
  • Patent number: 5089913
    Abstract: An optical system of a NX reduction catadioptric relay lens having sub-half micron resolution over the utlraviolet band width is described. A spherical mirror with a stop at the mirror is used to work at substantially the desired reduction ratio and the desired high numerical aperture sufficient to provide the desired high resolution. A beam splitting cube with appropriate coatings is used to form an accessible image of an object on an image plane. Refracting correctors in the path of the slow beam incident on the mirror and in the path of the fast beam reflected on the mirror are designed to fix the aberrations of the image formed by the mirror.
    Type: Grant
    Filed: July 11, 1990
    Date of Patent: February 18, 1992
    Assignee: International Business Machines Corporation
    Inventors: Rama N. Singh, Janusz S. Wilczynski
  • Patent number: 5052763
    Abstract: An optical system having a substantially flat image field is disclosed. The optical system is formed from optical subsystems wherein an input optical subsystem forms an intermediate image has a curvature which compensates that from the remaining optical components of the system to result in a substantially flat image for the optical system. Preferably the optical elements preceding the intermediate image and the optical elements succeeding the intermediate image are separately corrected for odd aberrations. The optical elements preceding the intermediate image and the optical elements succeeding the intermediate image compensate for each other and result in a substantially aberration free flat image for the optical system. The optical system preferably contains an input optical subsystem and an output optical subsystem wherein the input optical subsystem is a catadioptric system and wherein the output optical system is a dioptric system.
    Type: Grant
    Filed: August 28, 1990
    Date of Patent: October 1, 1991
    Assignee: International Business Machines Corporation
    Inventors: Rama N. Singh, Janusz S. Wilczynski