Patent ID: 8330726

Claim:
A position detection apparatus for detecting a pointing device being situated on a detection plane, said position detection apparatus comprising: a pair of imaging sections, each imaging section comprising an area image sensor in which light-sensitive elements are arrayed in a two-dimensional pattern to produce a two-dimensional image of pixels, and an image formation lens, and the pair of the imaging sections image an area over the detection plane in a given field of view from two lateral sides of the detection plane to output an image signal corresponding to all pixels of the given field of view, wherein the two-dimensional image includes a two-dimensional space that is both parallel to the detection plane and perpendicular to the detection plane; marker means disposed to at least four peripheral corners of the detection plane and each functioning as a reference for defining a particular field of view along a distortion of the detection plane within a range of the given field of view to be imaged by the imaging sections; a selection means utilizing the image signal as an input to select particular pixels as a portion of all of the pixels in the two dimensional space along the distortion of the detection plane, corresponding to the particular field of view within the range of the given field of view from the light-sensitive elements, only the particular pixels of the particular field of view configured for processing, the particular pixels comprising: a first row of a plurality of pixels parallel to the detection plane; and a second row of a plurality of pixels parallel to the detection plane, the second row being different from the first row, wherein the second row of the plurality of pixels comprises a number of pixels different from a number of pixels for the first row of the plurality of pixels; and an image processing means, which utilizes a particular image signal corresponding to the particular pixels having been selected by the selection means as an input to execute the image processing, thereby outputting a coordinate of an indicating position on the detection plane indicated by the pointing device.