Color image forming device
AssigneeHitachi Koki Co., Ltd.
InventorMasayasu Anzai
Life of this patent
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Abstract
A light conductive photosensitive member belt is charged uniformly by use of a charger and an electric charge latent image having three values is formed by means of a laser beam light L.sub.1. After then, after the passage of time t.sub.1, a yellow developing device is used to develop yellow and, after the passage of time t.sub.2, a magenta developing device is used to develop magenta. Next, the photosensitive member belt is recharged by a recharger and another latent image having three values is formed by means of a laser beam light L.sub.2. After then, after the passage of time t.sub.1, a cyan developing device is used to develop cyan and, after the passage of time t.sub.2, a black developing device is used to develop black. Then, these four color toner images are transferred to recording paper.
Claims6
A color image forming device for forming a multicolor image, comprising:
- a light conductive photosensitive member;
- a charger for charging said light conductive photosensitive member;
- means for exposing said light conductive photosensitive member according to color information to be recorded to provide multi-level latent images thereon;
- first developing means for developing a first latent image by a first colored toner having a polarity opposite to said first latent image;
- a first bias power source for applying a first bias voltage to said first developing means, said first latent image having a charged voltage greater than said first bias voltage, said first developing means being positioned so that a time necessary for moving said light conductive photosensitive member from a position for first light image exposure to a position for first development is longer than a time necessary for attenuating a surface voltage of said light conductive photosensitive member after the light image exposure down to a value lower than said first bias voltage applied to said first developing means;
- second developing means for developing a second latent image by a second colored toner having a polarity identical with said second latent image;
- a second bias power source for applying a second bias voltage to said second developing means, said second latent image having a charged voltage smaller than said second bias voltage, said second developing means being positioned so that a time necessary for moving said light conductive photosensitive member from a position for the light image exposure to a position for second development is longer than a time necessary for attenuating a surface voltage of said light conductive photosensitive member after the light image exposure down to a value in the neighborhood of the saturation residual voltage of said light conductive photosensitive member.
Dependencies are inferred from the claim text.