| 摘要 |
PROBLEM TO BE SOLVED: To provide a field communication system that comprises optical communication means including a light source able to control its irradiation range in an appropriate state depending on the use of the optical communication means.SOLUTION: In a field communication system comprising a communication path for field communication and optical communication means, a light source part of the optical communication means is characterized by including irradiation range control means which controls the irradiation range of output light in an appropriate state depending on the use of the optical communication means. |
