| 摘要 |
PURPOSE:To improve a compensation effect and accuracy, by subtracting a light- out output value from light-on output value of a solid-state image pickup element by flickering light source in order to perform a temperature compensation. CONSTITUTION:When a dark current component corresponding to each photoelement of a CCD11 is stored in a correction value RAM25, a computer 19 for controlling lights on a lamp 13. An analog signal corresponding to a light strength distribution of a slit image is transmitted out of the CCD11 and stored in a data RAM30. If all slit image data and dark current component data of the CCD11 are written in the RAM30 and compensation value RAM25, the contents are successively read out to be inputted in an arithmetic processing circuit 31 where the contents of the RAM25 is subtracted from the contents of the RAM30, and the result of it is again stored in the RAM30. As a result, the contents of the RAM30 become compensated slit image data which are performed by the Fourier transformation by the computer 19 to find an MTF. |
