| 摘要 |
PURPOSE:To compensate the lack of uniformity of lightness toward direction substantially orthogonal to irradiated direction, by picking up selectively one of plural kinds of compensation information stored in a memory. CONSTITUTION:A signal Vin reading a white original is divided at a shading compensating signal VC at a compensation circuit 1 and a compensated output signal Vout is outputted. Since the signal VC can be estimated in advance, a plurality of compensation signals VC1, VC2,... corresponding to the time change and types of fluorescent light are stored in an ROM4'. Which is to be selected out of plural kinds of compensation signals stored in the ROM4' is executed by presetting a selection switch 6. The selected compensation signal is converted into an analog compensation signal at a D/A converter 5, applied to the compensation circuit 1 and the Vout is obtained. |
