| 摘要 |
PURPOSE:To measure the MTF of a camera lens to be inspected on a film surface by directing image luminous flux of a chart for MTF measurement which is passed through the camera lens to be inspected to a photoelectric converting element for MTF measurement and a viewfinder focus detection part through switching operation. CONSTITUTION:Slits 32 and 32' in an image height and an image direction which are necessary for measurement are arranged on the object-side surface of the lens 35 to be inspected which crosses its optical axis at right angles, and the respective are lighted by light sources 31 and 31' respectively. The center slit 32 is replaced with a semicircle chart 33 on an object surface by a chart switching mechanism 34. Luminous flux from the semicircle chart 33 on the object surface passes through the lens 35 to strike a changeover mirror 37, and the luminous flux is guided firstly to the viewfinder focus detecting part 40 to form an image on the image pickup surface of a video camera 44. Then, the semicircle chart 33 is replaced with the slit 32 and the mirror 37 is moved back at the same time, so that the luminous flux incident from the lens 35 forms an image on a line sensor 38. Then, an MTF processor 39 removes noises of the line sensor and performs A/D conversion. |
