×

Position information input apparatus and method

  • US 6,963,331 B1
  • Filed: 03/14/2000
  • Issued: 11/08/2005
  • Est. Priority Date: 03/17/1999
  • Status: Expired due to Fees
First Claim
Patent Images

1. An apparatus for outputting position information corresponding to light having a cyclically varying intensity, said apparatus comprising:

  • a detection device that receives the light, said detection device comprising a plurality of photoelectric conversion elements, arranged in a predetermined physical array;

    difference signal generating means for generating, for each photoelectric conversion element, a difference signal corresponding to a difference between an output of the photoelectric conversion element when the light cycle is at a first point and an output of the photoelectric conversion element when the light cycle is at a second point, the first point being at a higher intensity than the second point;

    threshold setting means for setting a threshold value on the basis of a level of said difference signal obtained from each photoelectric conversion element;

    selection means for selecting effective photoelectric conversion elements by comparing said threshold value with the difference signal generated by said difference signal generating means; and

    output means for outputting the difference signals corresponding to the selected effective photoelectric conversion elements.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×