IMAGE READER

PURPOSE:To obtain a stable image signal output by providing a lamp which illuminates a film on which an image is recorded and a control means which controls the brightness of the lamp according to the read scanning line density of a CCD sensor, and holding the quantity of stored light of the CCD sensor nearly constant regardless of the read scanning line density. CONSTITUTION:When a figure (a) shows a 16 lines/mm. output signal, every other line is led out as shown in a figure (b) at the time of 8 lines/mm.. When, however, the density is 12 lines/mm., a sampling output is not simple like 8 lines/mm., so a storage time varies. This is shown by the dotted line in a figure (c). Namely, the storage time of 12 lines/mm. is (ts2+tr2)>(ts+tr) and longer than that of 16 lines/mm.. An image signal, therefore, increases. A lamp voltage control circuit 6 controls a lamp voltage corresponding to the scanning line density so as to suppress the increase in the image signal. Consequently, the image signal output of the CCD sensor 3 is held constant regardless of the scanning line density.