Method and apparatus for removing a portion of a developing material deposited on a non-image area of a surface of a latent image carrier

An electrophotographic method comprising the steps of:

• providing an electrostatic latent image carrier supported for movement in one direction and having a stationary magnet enclosed therein, a developer reservoir containing a mass of magnetic developing material therein, a developer collecting electrode roll spaced from the latent image carrier with a gap defined between the electrode roll and the latent image carrier, and a height regulating plate;
• forming an electrostatic latent image on a surface of the latent image carrier;
• positioning the surface of the latent image carrier within the developer reservoir;
• depositing the developing material on the surface of the latent image carrier so as to cause the developing material to be magnetically attracted onto the surface of the latent image carrier by said stationary magnet;
• moving the latent image carrier so as to pass beneath the height regulating plate to level the developing material on the image carrier, forming a developer layer of substantially uniform thickness smaller than the gap between the latent image carrier and the electrode roll;
• and
• causing the developer layer to confront the electrode roll to remove the developing material deposited on a non-image area of the surface of the latent image carrier while allowing the developing material to remain as deposited on the image area by applying an alternating current voltage to said electrode roll.

An electrophotographic method which comprises the steps of:

• providing an electrostatic latent image carrier supported for movement in one direction and having a stationary magnet enclosed therein, a developer reservoir containing a mass of magnetic developing material therein, a developer collecting electrode roll spaced from the latent image carrier with a gap defined between the electrode roll and the latent image carrier, and a height regulating plate;
• forming an electrostatic latent image on a surface of the latent image carrier;
• positioning the surface of the latent image carrier within the developer reservoir;
• depositing the developing material on a surface of the latent image carrier so as to cause the developing material to be magnetically attracted onto the surface of the latent image carrier by said stationary magnet;
• moving the latent image carrier so as to pass beneath the height regulating plate to level the developing material on the image carrier, forming a developer layer of substantially uniform thickness greater than the gap between the latent image carrier and the electrode roll;
• and
• causing the developer layer to confront the electrode roll to remove the developing material which has been deposited on a non-image area of the surface of the latent image carrier while allowing the developing material to remain as deposited on the image area by applying an alternating current voltage to said electrode roll.

An electrophotographic apparatus, which comprises:

• an electrostatic latent image carrier supported for movement in one direction and having a stationary magnet enclosed therein;
• a mass of magnetic one component developer adjacent said electrostatic latent image carrier;
• and
• means for removing developing material which has been deposited on a non-image area of the surface of said latent image carrier while allowing developing material to remain as deposited on an image area of the surface of said latent image carrier, said means comprising an electrode roll spaced from said latent image carrier with a gap defined between said electrode roll and said latent image carrier and a high voltage alternating electric current power source connected to said electrode roll.

An electrophotographic apparatus, which comprises:

• an electrostatic latent image carrier supported for movement in one direction and having a stationary magnet enclosed therein;
• means for forming an electrostatic latent image on said latent image carrier;
• a developer reservoir positioned adjacent said latent image carrier and containing a mass of magnetic developing material therein, said developer reservoir allowing the developing material to be magnetically deposited on a surface of said latent image carrier by said stationary magnet;
• a height regulating means for levelling developing material deposited on said image carrier while forming a developer layer of a substantially uniform thickness;
• and
• means for removing developing material which has been deposited on a non-image area of the surface of said latent image carrier while allowing developing material to remain as deposited on an image area of the surface of said latent image carrier, said means comprising a developer collecting electrode roll positioned downstream of said height regulating means with respect to the direction of movement of said latent image carrier, said electrode roll being spaced from said latent image carrier with a gap defined therebetween.

An electrophotographic apparatus, comprising:

• an electrostatic latent image carrier supported for movement in one direction and having a stationary magnet enclosed therein;
• means for forming an electrostatic latent image on said latent image carrier;
• a developer reservoir positioned adjacent said latent image carrier and containing a mass of magnetic developing material therein, said developer reservoir being operable to allow the developing material to be magnetically deposited on a surface of said latent image carrier by said stationary magnet;
• a height regulating means for levelling developing material deposited on said image carrier while forming a developer layer of a substantially uniform thickness;
• means for removing developing material which has been deposited on a non-image area of the surface of said latent image carrier while allowing developing material to remain as deposited on an image area of the surface of said latent image carrier, said means comprising a rotatably supported developer collecting electrode roll positioned downstream of said height regulating means with respect to the direction of movement of said latent image carrier, said electrode roll being spaced from said latent image carrier with a gap defined therebetween and said electrode roll including a stationary magnet enclosed therein, and a high voltage power source for applying an alternating current voltage to said electrode roll.