| 摘要 |
PURPOSE:To simplify the structure, by detecting at least 4 points of a circular part and at least 2 points of a linear part, in a projection pattern, and calculating the extent of deformation of a projection luminous flux in accordance with its detected data. CONSTITUTION:A light beam from a light source 1, which has been made to a collimated luminous flux is made incident to a lens 3 to be detected, which has been placed, shifting by a prescribed distance, and is refracted and polarized. Just behind the lens 3 to be detected is placed a mask 4 having a circular port 4a and a linear port 4b, and just before a linear sensor 5 is placed a mask 6 having two linear slits 6a, 6b. The linear sensor 5 detects each point of the luminous fluxes which has passed through the circular port 4a and the linear port 4b of the mask 4, at a position for conforming with the slits 6a, 6b in the course of its rotation, and provides 6 pieces of point information in all. A detection signal from the linear sensor 5 is provided to an operating circuit 9 through an amplifier 8, and a value indicating the refractive force of the lens 3 to be detected is displayed on a display device 10. |
