Image forming method and apparatus having a ratio of a thickness or a weight per unit area between liquid developer on a developing device and image carrier being smaller than about 0.71

摘要

A testing method for a liquid developer which adjusts a narrow gap formed between circumferences of two moving elements, applies different electric potentials to surfaces of the two moving elements to generate an electric field at the narrow gap, and applies the liquid developer to at least one of the two moving elements at a position upstream from the narrow gap in a moving direction of the two moving elements. Further, the method measures one of 1) a thickness, 2) a weight per unit area, and 3) a volume per unit area of liquid developer adhered to the circumferences of the two moving elements at a position downstream from the narrow gap in the moving direction of the moving elements, and calculates a ratio of one of 1) the thicknesses, 2) the weights, and 3) the volumes of the liquid developer between the two moving elements according to a measuring result in the measuring step.