Image forming apparatus which establishes image formation values using environmentally sensitive references

摘要

Disclosed is an image forming apparatus which reproduces halftone by using variable area toning method. The image forming apparatus stores a reference pattern data for adjusting bias voltage of developing device. The image forming apparatus also stores density toning data used for printout. An image of the reference pattern data has a dot pattern of which the optical density is more sensitive to environmental fluctuation than that of density toning data.