| 摘要 |
PURPOSE:To estimate the extent of 'warpage' of a transfer material and to accurately judge whether or not both-surface copying operation is available by detecting the total amount, distribution, amount per unit area of a developer with an image read signal. CONSTITUTION:An original reader 21 reads an original image formed on the 1st surface of the transfer material and supplies the image signal to an image density calculating means 22 and an image area calculating means 23. The image density signal is sent to a mean image density calculating means 24, whose image area signal is sent to both the means 24 and an image area occupation rate calculating means 25. The means 25 calculates the occupation rate alpha of the image area and the means 24 calculates mean image density gamma. The density gamma is supplied to a comparing and judging means 26 and the occupation rate alpha is supplied to a limit mean image density calculating means 27. Limit mean image density beta is calculated from data from a memory 28 and the occupation rate alpha and supplied to the means 26. The means 26 compares the density gamma and density beta with each other, judges that an image can be formed on the 2nd surface of the transfer material when gamma is smaller than beta, and supplies its output signal to a machine operation executing means 29 to start the both-surface copying operation. |
