| 摘要 |
PURPOSE:To decide a desired picture signal range in response to a desired picture area by setting an area that can be regarded as a direct radiation part at a position distant from an actual direct radiation part in case a binary picture includes the only direct radiation part. CONSTITUTION:The faint exciting light 5 performs the main scan of a sheet 1, and the simulating light 9 is emitted from the sheet 1 irradiated by the light 5. The light 9 is received by a photomultiplier tube 1 and converted into the electric signals. The output signal S of the tube 11 is turned into a digital signal by an A/D converter 17 and a pre-read picture signal Sp is obtained. An arithmetic part 18 decides a desired picture signal range which sets an area that can be regarded as a direct radiation part at a position distant from an actual direct radiation part based on the signal Sp and then decides the main reading conditions. A sheet 1' which is through with the pre-read job is set at a main reading part 30' and scanned by a light beam 5' more intensive than the pre-reading light. An obtained picture signal SQ is sent to an arithmetic part 18' to undergo a proper picture process. |
