| 摘要 |
PURPOSE:To obtain the titled device with high vibration resistance by making information light incident to an half mirror, deviding the incident light into measuring light and reference light, reflecting the light transmitted through the half mirror by a plane mirror, and then transmitting the reflected light through the half mirror again. CONSTITUTION:When information light is made incident to a half mirror 8, a part of the incident light is transmitted through a semi-transmission surface of a half mirror 8 and the other part is reflected by the semi-transmission surface and divided into measuring light and reference light. The transmitted light through the half mirror which is shown by a broken line is reflected by a plane mirror 11, transmitted through the half mirror 8 again and made light parallel to the light reflected by the half mirror 8 which is shown by a full line and shifted in the horizontal direction to the advancing direction. Then, the measuring light and reference light reach an area sensor 9 through an image formation lens L4. Thus, the optical path shown by the broken line can be changed by displacing the plane mirror 11 by a piezo-electric element. |
