Patent Document ID: 20020020313
Application ID: 09915501
Patent Status: 0

Claim One:
1. In a method of forming an image by using a plurality of image stations each comprising a single rotatable image carrier and two developing means each for developing a particular latent image formed on said single image carrier in a respective color to thereby produce a toner image, and by switching a developing function from one of said two developing means to the other developing means while said single image carrier is in rotation, sequentially transferring toner images produced by said two developing means to an intermediate image transfer body one above the other, and transferring a resulting color image from said intermediate image transfer body to a recording medium, a test patch image is formed on said single image carrier at each image station after image formation using an upstream one of said two developing means in a direction of rotation of said single image carrier or before image formation using a downstream one of said two developing means, whereby image quality compensation control is effected by sensing a density of said test patch image.