Developing device for image forming apparatus

An image forming apparatus, comprising:

• an image bearing device;
• a charger which charges said image bearing device;
• an exposing device which irradiates light to said charged image bearing device for forming an electrostatic latent image on said image bearing device;
• a developing device which has developer for developing said image bearing device by said developer;
• and
• a transfer charger to transfer said developed image to a medium, wherein a developing starting voltage of said developing device is higher than a residual voltage of said image bearing device,
• wherein said developer includes a two component developer comprising magnetic toner and magnetic carriers, and
• wherein said developing device comprises a developing sleeve which faces said image bearing device and bears said two component developer, a doctor blade which controls the quantity of said developer on said developing sleeve and a plurality of magnets which are provided in said developing sleeve, wherein said developing starting voltage is controlled in response to a gap between said image bearing device and said developing sleeve, a gap between said developing sleeve and said doctor blade, a ratio of the surface velocity of said developing sleeve to that of said image bearing device, and a magnetic force of said magnets.

An image forming apparatus, comprising:

• an image bearing means;
• charging means for charging said image bearing means;
• means for forming an electrostatic latent image on said image bearing means;
• a developing means for developing said electrostatic latent image on said image bearing means, wherein a developing starting voltage of said developing means is higher than a residual voltage of said image bearing means;
• and
• means for transferring said developed image to a recording medium,
• wherein said developing means includes a two component developer comprising magnetic toner and magnetic carriers, and
• wherein said developing means comprises means for bearing said two component developer, means for regulating the thickness of said two component developer on said bearing means and means for adhering said two component developer on said bearing means, wherein said developing starting voltage is controlled in response to a gap between said image bearing means and said bearing means, a gap between said bearing means and said regulating means, a ratio of the surface velocity of said bearing means to that of said image bearing means, and an adhering force of said adhering means.

An image forming apparatus for forming a toner image on a sheet of paper, comprising:

• image bearing means;
• charging means for charging said image bearing means;
• means for forming an electrostatic latent image on said image bearing means;
• developing means for developing said electrostatic latent image on said image bearing means;
• transferring means for transferring said developed image;
• and
• means for applying a bias voltage to said charging means, said developing means and said transferring means,
• wherein said means for applying includes a resistor between a high voltage power source and said developing means, and a variable resistor connected in series with a constant voltage device, said variable resistor and said constant voltage device being connected to a ground and to a point between said resistor and said developing means.

An image forming apparatus, comprising:

• an image bearing device;
• a charger which charges said image bearing device;
• an exposing device which irradiates light to said charged image bearing device for forming an electrostatic latent image on said image bearing device;
• a developing device which has developer for developing said image bearing device by said developer;
• and
• a transfer charger to transfer said developed image to a medium, wherein a developing starting voltage of said developing device is higher than a residual voltage of said image bearing device.