| 摘要 |
PURPOSE:To enable a measurement of the size of a body with high precision by photodetecting only luminous fluxes by arranging optical fiber having an optical system which photodetects only parallel luminous fluxes among luminous fluxes incident to the tip part. CONSTITUTION:The tip part of each optical fiber 4 has a small opening and is positioned at the focus position of each lens 5. Only luminous fluxes parallel to the optical axes of lenses 5 are led into optical fibers 4 and reach photoelectric detectors 6, where their light intensity is detected. Respective photoelectric detectors 6 are successively inspected by driving and signal detecting circuit 8 to detect the light intensity distribution of the incident luminous fluxes. When the size of body 1, for example, is measured by using such sensor 7, no measurement error occurs because only parallel luminous fluxes 9 and 9' are detected even if body 1 shifts in position to 1', so that the measurement will be taken with high precision. |
