| 摘要 |
PURPOSE:To shorten the setting time of a lens by calculating the MTF of a lens to be measured and illuminance on an image-formation surface at a time from video signals from respective linear image sensors of an MTF measuring machine. CONSTITUTION:Light sources such as fluorescent lamps 11 and 12 light up a chart plate 14 having charts 13 (131-13m) consisting of slits and images of the charts 13 are formed on photodetection surfaces of linear image sensors 16 consisting of charge-coupled elements through the lens 15 to be measured. The charge-coupled elements 16 are so arranged that the direction of an array of numbers of photoelements phi1-N is perpendicular to the lengthwise direction of the images 13a of the slits 13, convert short-directional illuminance distributions of the slit images 13a into electric signals, and output a video signal in time series by self-scanning. This video signal is processed by Fourier transformation to calculate the MTF value of the measured lens 15 and illuminance on the image-formation surface. |
