| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a technology for forming a patch image suitable for control and obtaining adequate gradation correction characteristics based upon the result of the detection of its density, in an image forming apparatus and an image forming method which control the gradation correction characteristics based upon the result of the detection of the patch image density. <P>SOLUTION: As a patch image for the control of the gradation correction characteristics, the apparatus forms an image Ip having a gradation image Ig which continuously changes in gradation level and a header Ih which is formed prior to the formation of the gradation image Ig and has a length not shorter than the circumference Ldr of a development roller. Toner on the surface of the development roller is consumed for the formation of the header Ih, and the gradation image Ig is formed with toner freshly supplied to the development roller. This operation hinders density changes from being exhibited in the gradation image Ig. In addition, the result of the detected density of the header Ih can be used for the correction of the result of the detection of the gradation image Ig. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
