| 摘要 |
PURPOSE:To detect the irradiation position of an optical beam with a high accuracy and to transmit information with a high grade, by a simple constitution as a whole by guiding a reflecting light beam to an observation optical system together with the optical beam folded and sent in parallel after an incident light beam is reflected with a half mirror. CONSTITUTION:An optical beam LA1 is reflected, made incident on an observation optical system 5 with a half mirror 31 arranged in the light flux of the optical beam LA1, and after an incident light beam LA5 is reflected by the half mirror 31, it is folded in parallel and made incident on the observation optical system 5. The incident light beam LA5 to come in the injection direction of the optical beam LA1 can be made incident on the observation optical system 5 in parallel to a reflecting light beam LA8 of the optical beam LA1. Thus, the same image as that when the return optical beam is suppressed and a light source 2 is arranged at the irradiated position by the optical beam can be obtained, the irradiated position by the optical beam can be detected with a high accuracy and the information can be transmitted with a high grade, by the easy constitution as a whole. |
