Information-processing system using free-space optical communication and free-space optical communication system

An information-processing system using free-space optical communication, including an information-collecting apparatus and one or more communication nodes, where the information-collecting apparatus collects predetermined items of information from each of the remote communication node or nodes through free-space optical communication, which is characterized in that:

• each of the communication node or nodes includes:
• a signal generator for producing a pilot signal having a predetermined frequency onto which an identification signal containing the aforementioned items of information is superimposed, the frequency of the identification signal being higher than that of the pilot signal;
• and
• a light transmitter for emitting light containing the signal produced by the signal generator as information,
• and the information-collecting apparatus includes:
• an image capturer having an imaging device with a two-dimensional array of a plurality of micro photo-receiving elements;
• a position recognizer for detecting the pilot signal from an optical signal coming from each communication node within a two-dimensional image captured by the image capturer and for recognizing a position of each communication node within the image;
• and
• an identification information acquirer for selectively reading detection signals produced by micro photo-receiving elements located at or close to images of corresponding communication nodes recognized by the position recognizer in the image capturer, where a speed of reading the detection signals is higher than that of capturing the two-dimensional image, and for acquiring the aforementioned items of information of each communication node located within the captured image on a basis of the signals read out, wherein
• the information-collecting apparatus is an information terminal to be operated by a user's hand;
• the identification signal superimposed by the signal generator of each communication node minimally contains, as one of the aforementioned items of information, identification information by which the communication node can be identified;
• and
• in a process of acquiring signals from one or more pixels from which the identification information of each communication node is obtained, the identification information acquirer specifies auxiliary pixels around a central pixel and reduces or corrects an effect of a hand movement by using the signals read out from the auxiliary pixels.