Position recognizing device and position recognizing method

A position recognizing method for receiving light from at least one light source and recognizing a position of the light source, comprising:

• a position detecting step of making light having light intensity change corresponding to a pseudorandom number sequence unique to the light source incident on a plane of incidence, generating a photocurrent corresponding to intensity of the light at an incident position, said photocurrent flowing into a resistance from said incident position, and thereby providing a plurality of output signals corresponding to said incident position;
• a correlation operation step of subjecting the plurality of output signals obtained at said position detecting step and said pseudorandom number sequence to a correlation operation, and separating and extracting signals corresponding to said plurality of output signals using a result of the correlation operation;
• and
• a decoding step of determining said incident position by subjecting the signals corresponding to said plurality of output signals obtained at said correlation operation step to an operation.

A position recognizing device for receiving light from a plurality of light sources and recognizing a position of each of the light sources, comprising:

• light sources including generating circuits for generating pseudorandom number sequences unique to the respective light sources and a plurality of light emitting units for emitting light having light intensity change corresponding to said pseudorandom number sequences, respectively;
• at least two light receiving devices for receiving the light from said plurality of light sources;
• and
• a processing device for calculating a two-dimensional position or a three-dimensional position of each of a plurality of said light sources from incident position information obtained by each of the two said light receiving devices;
• wherein each of the two said light receiving devices includes:
• a position detecting element for receiving incident light from the plurality of said light sources, generating photocurrents corresponding to intensity of the light at incident positions, said photocurrents flowing into a resistance from said incident positions, and thereby providing a plurality of output signals corresponding to said incident positions;
• a correlation operation unit for subjecting the plurality of output signals of said position detecting element and said pseudorandom number sequences to a correlation operation, and separating and extracting signals corresponding to said plurality of output signals using a result of the correlation operation;
• and
• a decoding unit for determining said incident positions by subjecting the signals corresponding to said plurality of output signals from said correlation operation unit to an operation.