IMAGE-FORMING DEVICE HAVING ON-LINE IMAGE QUALITY ASSESSMENTAND RELATED METHOD

摘要

An electrophotographic (EP) image-forming device and related method are provided for on-line quantitative assessment of the image information and development process. The EP image-forming device has a primary charger (118) , an exposure device (120), a toning station (125), a transfer charger (130), a fusion station (140), and a cleaner (150) operatively disposed about the photoconductor. A transmission densitometer (165, 170) is positioned adjacen t to the photoconductor. The densitometer determines the photoconductor densit y and the combination photoconductor and toner density for each step area on t he image frame. The density readings are stored in memory. The photoconductor densities are subtracted from the combined densities to provide measured ton er densities, which are then averaged for each step area. The average measured toner densities or voltage readings are compared to the aim toner densities or voltage readings for each step in the step tablet to quantitatively assess t he image quality of the image-forming process. Preferably, every image frame on the photoconductor is assessed successively.