| 摘要 |
PURPOSE:To reduce the influence of noise by reducing the light unevenness on a film by an optical fiber and a light diffusing plate and reducing the noise component by the output of a CCD one-dimensional line sensor and the correlative double sampling method and providing a signal correcting circuit part with a means which adds and averages white-and-black correcting data. CONSTITUTION:A light diffusing plate 6 is inserted between the exit end of an optical fiber 5 and an X-ray film 7 to reduce the spatial light variance of the quantity of projected light. The light transmitted through and diffused by the X-ray film 7 passes an optical mirror 9 to focus a film image on a CCD one-dimensional line sensor 12 by a focusing lens 10 and is converted to an electric signal proportional to the intensity of light. An optical output monitor signal detected by a photodetector 18 passes an amplifier 19 and an AD converter 20 to obtain a digital signal REF. A signal correcting circuit 21 performs various corrections and logarithmic conversion with AD-converted digital signal SIG and REF to obtain correct X-ray film density information, and this information is stored in a picture memory and is outputted to a CRT display device 23 or the like as required.
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