Apparatus and method for increasing the coverage area of a control electrode during direct electrostatic printing

A control device in an image recording apparatus in which charged toner particles are deposited in an image configuration on an information carrier, comprising:

• a substrate having a plurality of control electrodes;
• one or more variable voltage sources connected to each control electrode to selectively produce an electrostatic field which permits or restricts particle transport from a particle source towards the information carrier;
• at least one set of deflection electrodes;
• and
• at least one deflection voltage source connectable to each set of deflection electrodes to influence a symmetry of the electrostatic fields, thereby increasing an area on the information carrier that each control electrode may transport the charged toner particles.

A control device in an image recording apparatus in which charged particles are deposited in an image configuration on an information carrier, comprising:

• a substrate having a plurality of control electrodes;
• one or more variable voltage sources connected to each control electrode to selectively produce an electrostatic field which permits or restricts particle transport from a particle source towards the information carrier;
• at least one set of deflection electrodes;
• at least one deflection voltage source connectable to each set of deflection electrodes to influence a symmetry of the electrostatic fields;
• and
• wherein the substrate has a top surface facing the particle source and an opposite surface facing the information carrier, and the control electrodes are etched on said top surface of the substrate.

A control device in an image recording apparatus in which charged particles are deposited in an image configuration on an information carrier, comprising:

• a substrate having a plurality of control electrodes;
• one or more variable voltage sources connected to each control electrode to selectively produce an electrostatic field which permits or restricts particle transport from a particle source towards the information carrier;
• at least one set of deflection electrodes;
• at least one deflection voltage source connectable to each set of deflection electrodes to influence a symmetry of the electrostatic fields;
• and
• wherein the substrate has a top surface facing the particle source and an opposed surface facing the information carrier, and the deflection electrodes are etched on said opposite surface of the substrate.

A control device in an image recording apparatus in which charged particles are deposited in an image configuration on an information carrier, comprising:

• a substrate having a plurality of control electrodes, said substrate having a plurality of apertures arranged therethrough, said control electrodes including at least one control electrode arranged symmetrically about a central axis of each aperture;
• one or more variable voltage sources connected to each control electrode to selectively produce respective electrostatic fields which are symmetric about each aperture and which permit or restrict particle transport from a particle source towards the information carrier;
• at least one set of deflection electrodes;
• at least one deflection voltage source connectable to each set of deflection electrodes to influence a symmetry of the electrostatic fields about said apertures, said deflection electrodes including at least one deflection electrode segment positioned adjacent to each aperture, said deflection voltage source including a deflection voltage source connectable to at least one deflection electrode segment of each aperture to produce a deflection force modifying the symmetry of the electrostatic field about a central axis of each aperture;
• wherein said at least one deflection electrode segment includes:
• a first deflection electrode segment at least partially extending on one side of a transverse axis of each aperture;
• and
• a second deflection electrode segment symmetrically opposed to said first segment about the central axis of each aperture.

A method for improving the print quality on an information carrier having a plurality of print areas of an image recording apparatus including a control array having a plurality of apertures, a control electrode surrounding each aperture, a first deflection electrode segment arranged adjacent to each aperture and a second deflection electrode segment arranged in a position symmetrically opposed to said first deflection electrode segment with respect to a central axis of its associated aperture, wherein for each print area on said information carrier said method comprises the steps of:

• a) performing a first print sequence by supplying a control voltage to each control electrode to produce a substantially symmetric electrostatic field about each aperture to permit or restrict particle transport therethrough, and creating an electric potential difference between said first deflection electrode segment and said second deflection electrode segment of each aperture to alter the symmetry of each electrostatic field in a first direction;
• b) performing a second print sequence by supplying a control voltage to each control electrode to produce a substantially symmetric electrostatic field about each aperture to permit or restrict particle transport therethrough, and supplying all deflection electrode segments with a same voltage to maintain the symmetry of each electrostatic field;
• and
• c) performing a third print sequence by supplying a control voltage to each control electrode to produce a substantially symmetrical electrostatic field about each aperture to permit or restrict particle transport therethrough, and reversing the electric potential different of step (a) to alter the symmetry of each electrostatic field in a direction opposed to said first direction with respect to a central axis of each aperture.

A method for improving the print quality of an image recording apparatus including a control array having a plurality of apertures, a control electrode surrounding each aperture, a first deflection electrode segment arranged adjacent to each aperture and a second deflection electrode segment arranged in a position symmetrically opposed to said first deflection electrode segment with respect to a central axis of its associated aperture, said method comprises the steps of:

• a) supplying a control voltage to each control electrode to produce a substantially symmetric electrostatic field about each aperture to permit or restrict particle transport therethrough, and creating an electric potential difference between said first deflection electrode segment and said second deflection electrode segment of each aperture to alter the symmetry of each electrostatic field in a first direction;
• b) supplying a control voltage to each control electrode to produce a substantially symmetric electrostatic field about each aperture to permit or restrict particle transport therethrough, and supplying all deflection electrode segments with a same voltage to maintain the symmetry of each electrostatic field;
• and
• c) supplying a control voltage to each control electrode to produce a substantially symmetrical electrostatic field about each aperture to permit or restrict particle transport therethrough and reversing the electric potential different of step (a) to alter the symmetry of each electrostatic field in a direction opposed to said first direction with respect to a central axis of each aperture, wherein the electric potential differences of steps (a) and (c) are maintained during a time period t.sub.d, so that 0<t.sub.d <T, where T is a total time of one step.

A method for improving the print quality of an image recording apparatus including a control array having a plurality of apertures a control electrode surrounding each aperture, a first deflection electrode segment arranged adjacent to each aperture and a second deflection electrode segment arranged in a position symmetrically opposed to said first deflection electrode segment with respect to a central axis of its associated aperture said method comprises the steps of:

• a) supplying a control voltage to each control electrode to produce a substantially symmetric electrostatic field about each aperture to permit or restrict particle transport therethrough, and creating an electric potential difference between said first deflection electrode segment and said second deflection electrode segment of each aperture to alter the symmetry of each electrostatic field in a first direction;
• b) supplying a control voltage to each control electrode to produce a substantially symmetric electrostatic field about each aperture to permit or restrict particle transport therethrough, and supplying all deflection electrode segments with a same voltage to maintain the symmetry of each electrostatic field;
• and
• c) supplying a control voltage to each control electrode to produce a substantially symmetrical electrostatic field about each aperture to permit or restrict particle transport therethrough, and reversing the electric potential different of step (a) to alter the symmetry of each electrostatic field in a direction opposed to said first direction with respect to a central axis of each aperture, wherein the electric potential differences of steps (a) and (c) are maintained during a time period t.sub.d, so that 0<t.sub.d <t.sub.b <T, where T is a total time of one step and where t.sub.b is a time period during which particle transport is permitted through an aperture.

A method for improving the print quality of an image recording apparatus including a control array having a plurality of apertures, a control electrode surrounding each aperture, a first deflection electrode segment arranged adjacent to each aperture and a second deflection electrode segment arranged in a position symmetrically opposed to said first deflection electrode segment with respect to a central axis of its associated aperture, said method comprises the steps of:

• a) supplying a control voltage to each control electrode to produce a substantially symmetric electrostatic field about each aperture to permit or restrict particle transport therethrough, and creating an electric potential difference between said first deflection electrode segment and said second deflection electrode segment of each aperture to alter the symmetry of each electrostatic field in a first direction;
• b) supplying a control voltage to each control electrode to produce a substantially symmetric electrostatic field about each aperture to permit or restrict particle transport therethrough, and supplying all deflection electrode segments with a same voltage to maintain the symmetry of each electrostatic field;
• and
• c) supplying a control voltage to each control electrode to produce a substantially symmetrical electrostatic field about each aperture to permit or restrict particle transport therethrough, and reversing the electric potential different of step (a) to alter the symmetry of each electrostatic field in a direction opposed to said first direction with respect to a central axis of each aperture, wherein the electric potential difference of steps (a) and (c) are maintained during a time period t.sub.d, so that 0<t.sub.b <t.sub.d <T, where T is a total time of one step and where t.sub.b is a time period during which particle transport is permitted through an aperture.

A method for improving the print quality of an image recording apparatus including a control array having a plurality of apertures, a control electrode surrounding each aperture, a first deflection electrode segment arranged adjacent to each aperture and a second deflection electrode segment arranged in a position symmetrically opposed to said first deflection electrode segment with respect to a central axis of its associated aperture, said method comprises the steps of:

• a) supplying a control voltage to each control electrode to produce a substantially symmetric electrostatic field about each aperture to permit or restrict particle transport therethrough, and creating an electric potential difference between said first deflection electrode segment and said second deflection electrode segment of each aperture to alter the symmetry of each electrostatic field in a first direction;
• b) supplying a control voltage to each control electrode to produce a substantially symmetric electrostatic field about each aperture to permit or restrict particle transport therethrough, and supplying all deflection electrode segments with a same voltage to maintain the symmetry of each electrostatic field;
• and
• c) supplying a control voltage to each control electrode to produce a substantially symmetrical electrostatic field about each aperture to permit or restrict particle transport therethrough, and reversing the electric potential different of step (a) to alter the symmetry of each electrostatic field in a direction opposed to said first direction with respect to a central axis of each aperture, wherein the electric potential difference of step (a) decreases during step (a) and the electric potential difference of step (c) increases during step (c).

A method for improving the print quality of an image recording apparatus including a control array having a plurality of apertures, a control electrode surrounding each aperture, a first deflection electrode segment arranged adjacent to each aperture and a second deflection electrode segment arranged in a position symmetrically opposed to said first deflection electrode segment with respect to a central axis of its associated aperture, said method comprises the steps of:

• a) supplying a control voltage to each control electrode to produce a substantially symmetric electrostatic field about each aperture to permit or restrict particle transport therethrough, and creating an electric potential difference between said first deflection electrode segment and said second deflection electrode segment of each aperture to alter the symmetry of each electrostatic field in a first direction;
• b) supplying a control voltage to each control electrode to produce a substantially symmetric electrostatic field about each aperture to permit or restrict particle transport therethrough, and supplying all deflection electrode segments with a same voltage to maintain the symmetry of each electrostatic field;
• and
• c) supplying a control voltage to each control electrode to produce a substantially symmetrical electrostatic field about each aperture to permit or restrict particle transport therethrough, and reversing the electric potential different of step (a) to alter the symmetry of each electrostatic field in a direction opposed to said first direction with respect to a central axis of each aperture, wherein the electric potential difference of step (a) alters the symmetry of the electrostatic fields to deflect the trajectory of attracted particles obliquely against motion of an information carrier.

A control device in an image recording apparatus in which charged particles are deposited in an image configuration on an information carrier, including a substrate positioned between a particle source and a moving information carrier, said substrate comprising:

• a plurality of apertures arranged in at least one transverse row having a transverse axis extending perpendicular to a motion of the information carrier;
• at least one control electrode arranged symmetrically about a central axis of each aperture;
• at least one deflection electrode segment arranged adjacent to each aperture;
• and
• at least one spacer extending parallel to the motion of the information carrier between two adjacent apertures to maintain a constant distance between the substrate and the particle source.