| 摘要 |
PURPOSE:To make a proper automatic density adjustment without any prescanning by varying the size of an effective detection area according to a specified trimming area. CONSTITUTION:A lamp 4, a carriage 7, an optical fiber 20, a photodetecting element 29, and a peak holding circuit 27 constitute a density detecting means, which detects density information on the effective detection area of an original O optically when the original O is lighted and scanned, and converts it into an electric signal. A control means CPU 28 processes the density information generated by this density detecting means and controls a developing bias, etc., to adjust and control the image density of a recording image. Then the size of the effective detection area is varied according to the specified trimming area. Thus, when the original is lighted and scanned, the density information in the trimming area is detected and the density of the recording image is adjusted according to the result, so the accuracy of the automatic density adjustment is improved without any prescanning. |
