Color image recording method and apparatus

摘要

A color image recording apparatus according to the present invention comprises a light-sensitive drum, a first developing device for developing a first electrostatic latent image on the drum surface as a first toner image, a second developing device for developing a second electrostatic latent image as a second toner image on the drum surface along with the first toner image, and a developing bias voltage source for applying a developing bias voltage to the second developer device comprising a DC component and an AC component of a predetermined period, wherein the AC component has a waveform such that the time for the voltage to change from a value such that an electric field making toner move toward the electrostatic latent image is maximum to a value such that the electric field becomes minimum is set to be at least 1/2 of the predetermined period of the AC component. According to a method of the present invention a first toner is electrostatically attracted to an electrostatic latent image on the surface of a light-sensitive drum, and then a second toner is electrostatically attracted to the electrostatic latent image on the drum surface by applying a periodic AC electric field in which the time during which the electric field develops the electrostatic latent image with the second toner exceeds the time during which the electric field does not develop the electrostatic latent image with the second toner. The developed first and second toner images are then simultaneously transfered to a copy sheet.