Abstract: A multicolor image forming method in which a plurality of latent images are sequentially formed and developed on an image carrier on top of each other on the image carrier. The second and any successive color toners are developed in a non-contact manner. A developed image on a photoconductive element is prevented from being contaminated by subsequent developing stages and toner on the photoconductive element is prevented from contaminating the developer in the subsequent developing stages by reducing the amount of toner which improperly flies between the photoconductive element and the developing stages. Such a prevention of the flight of toner can be accomplished by keeping the potential of the toner on the photoconductive element within a predetermined threshold of the voltage of the toner in the subsequent developing stages. Also, properties of the various toners can reduce the improper flight of the toner such as by controlling the relative amounts of hydrophobic SiO.sub.

Abstract: A paper guide device for guiding a sheet of paper to an image transfer device includes an upper guide plate and a lower guide plate, and an elastic transfer guide plate which is attached to the upper paper guide plate. A free end of the elastic transfer guide plate faces the transfer device and is bent downward such that a bend or crease line is perpendicular to a paper feed direction. The free end of the elastic transfer guide plate is parallel to paper feed direction at a transfer position to better orient/direct the paper as it approaches a photosensitive member or image transfer location. The arrangement allows for a compact paper feed design, while avoiding adverse effects which can occur where paper (particularly thicker paper) springs as it exits a paper guide.

Abstract: A multicolor image forming method of the kind sequentially developing a plurality of latent images formed on an image carrier by toners of respective colors and transferring the resulting toner images to a recording medium at the same time. Development in the second color and successive colors is implemented as noncontact type development using a thin layer of nonmagnetic toner. This toner layer satisfies a condition of dt/.epsilon.t<590(.mu.m).sup.2 where dt and .epsilon.t are respectively the thickness and the average volume specific inductive capacity of the layer. The toner for the development in the second color and successive colors is produced by polymerization and has an average volume particle size of 10 .mu.m or less. Development in the first color is implemented by a toner having a relatively sharp particle size distribution, not including relatively large particles, having a sharp charge amount distribution, and not producing particles of low charges.

Abstract: In a developing device for an image forming apparatus, a developing roller has dielectric portions and conductive portions distributed regularly or irregularly over the surface thereof. The surfaces of the dielectric portions are smaller in height than the surfaces of the conductive portions. The difference in height is greater than one-half of the volumetric mean particle size of a toner. A charge opposite in polarity to a charge to be deposited on the toner is deposited on the dielectric portions. The dielectric portions, or recesses, each has a width more than three times as great as the volumetric mean particle size of the toner and a depth less than five times the volumetric particle size. The dielectric portions may be greater in height than the conductive portions and may be implemented as spiral grooves inclined more than 30 degrees relative to the axis of rotation of the developing roller. The developing roller may be moved at a higher linear velocity than a photoconductive drum.

Abstract: A dry-type developing device is capable of converting electrostatic latent image formed on the surface of latent image carrying member to visible image by use of developer powder, and the developing device comprises a latent image carrying member for carrying electrostatic latent image formed thereon at the respective different positions, a first developer carrying member for holding thereon two components type developer having non-magnetic toner and magnetic carrier, a second developer carrying member disposed so as to adjacently oppose the first developer carrying member and the latent image carrying member, a control device for regulating the amount of developer on the first developer carrying member, a first electric field forming device for forming a first direct-current electric field between the first and second developer carrying members, and a second electric field forming device for forming a second direct-current electric field between the latent image carrying member and the second developer carry