Image forming apparatus

Claim 2

The image forming apparatus as defined in claim 1, further comprising: a developing particle antisticking grid having a developing particle passing holes in the opposite position to the gates of said control grid, said developing particle antisticking grid being positioned between said control grid and said developing particle holder; wherein a potential having same polarity as that of charged developing particles is given from said power source section to said developing particle antisticking grid.

Claim 3

The image forming apparatus as defined in claim 2, wherein the developing particle passing holes on said developing particle antisticking grid are formed so that their diameter is larger than that of the gates of said control grid.

Claim 4

The image forming apparatus as defined in claim 1, further comprising: a developing particle flying stabilization grid having developing particle passing holes, said developing particle flying stabilization grid being positioned between said control grid and said counter electrode, wherein a potential for generating an electric field which promotes the flying of toner from said control grid towards said counter electrode is given to said developing particle flying stabilization grid.

Claim 5

The image forming apparatus as defined in claim 4, further comprising flying direction deflecting means for deflecting a flying direction of the developing particles from said developing particle flying stabilization grid towards said counter electrode to a direction which is at right angles to the flying direction by at least one of the electric field and magnetic field, said flying direction deflecting means being positioned between said developing particle flying stabilization grid and the counter electrode.

Claim 6

The image forming apparatus as defined in claim 1, further comprising recording medium potential giving means for giving a potential, which generates an electric field having a same direction as that of the electric field between said control grid and said counter electrode when the developing particles fly through said control grid towards said counter electrode, to an opposite side of the recording medium to the developing particle holder side.

Claim 7

The image forming apparatus as defined in claim 1, wherein an electrode group including said counter electrode and said control grid between said counter electrode and said developing particle holder is integrated, and said electrode group can be installed to and removed from an image forming apparatus main body.

Claim 8

An image forming apparatus, comprising: a developing particle holder for holding developing particles by means of either of electric force and magnetic force; a counter electrode positioned opposite to said developing particle holder; a control grid including (1) a first electrode layer on a closer side to said developing particle holder, on which a plurality of control electrodes are arranged in one direction (2) a second electrode layer on a far side from said developing particle holder, on which a plurality of control electrodes are arranged parallel to the control electrodes of the first electrode layer and in a different direction from that of the first electrode layer (3) and a control grid having an opening for composing gates as passing sections of developing particles, which is formed in a position where the control electrode of said first electrode layer is overlapped on the control electrode of said second electrode layer; a power source section for (1) giving a potential which generates a prescribed potential difference between said developing particle holder and said counter electrode, and for (2) giving a potential to each electrode on said first and second electrode layers of said control grid; and grid potential control means for changing an electric field existing between said developing particle holder and said counter electrode by changing the potential given from said power source section to the each control electrode of said control grid according to image signals in order to form an image by controlling flying of developing particles from said developing particle holder through said gate towards said counter electrode and by adhering the developing particles to a recording medium in a direction where the developing particles fly.

Claim 9

The image forming apparatus as defined in claim 8, wherein said first electrode layer is formed by arranging a plurality of the control electrodes, which are composed of wire rods folded back at an angle of 180 degrees at their centers, said control electrodes are arranged parallel to one another in a prescribed direction, wherein said second electrode layer is formed by arranging a plurality of the control electrodes, which are composed of wire rods turned down at their centers and extended parallel from the turning point to the other direction, parallel to a direction where a prescribed angle is formed with the arrangement direction of the control electrodes of said first electrode layer.

Claim 10

The image forming apparatus as defined in claim 8, wherein said first electrode layer is formed by arranging a plurality of board-like control electrodes, which have circular openings for composing of the gates in a lengthwise direction, parallel to one another in a prescribed direction, wherein said second electrode layer is formed by arranging a plurality of the control electrodes, which have circular openings for composing of the gates in a lengthwise direction, parallel to one another in a direction where a prescribed angle is formed with the arrangement direction of the control electrodes of said first electrode layer.

Claim 11

The image forming apparatus as defined in claim 8, further comprising: a developing particle antisticking grid having a developing particle passing hole in the opposite position to the gates of said control grid, said developing particle antisticking grid being provided between said control grid and said developing particle holder, wherein a potential having same polarity as that of charged developing particles is given from said power source section to said developing particle antisticking grid.

Claim 12

The image forming apparatus as defined in claim 11, wherein the developing particle passing hole on said developing particle antisticking grid is formed so that it has a larger diameter than that of the gates of said control grid.

Claim 13

The image forming apparatus as defined in claim 8, further comprising: a developing particle flying stabilization grid having a developing particle passing hole, said developing particle flying stabilization grid being provided between said control grid and said counter electrode, wherein a potential, which generates an electric field for promoting the flying of toner from said control grid towards said counter electrode, is given to said developing particle flying stabilization grid.

Claim 14

The image forming apparatus as defined in claim 13, further comprising flying direction deflecting means for deflecting a flying direction of the developing particles from said developing particle flying stabilization grid towards said counter electrode to a direction which is at right angles to the flying direction by at least one of the electric field and magnetic field, said flying direction deflecting means being positioned between said developing particle flying stabilization grid and the counter electrode.

Claim 15

The image forming apparatus as defined in claim 8, further comprising recording medium potential giving means for giving a potential, which generates an electric field having a same direction as that of the electric field between said control grid and said counter electrode when the developing particles fly through said control grid towards said counter electrode, to an opposite side of the recording medium to the developing particle holder side.

Claim 16

The image forming apparatus as defined in claim 8, wherein an electrode group including said counter electrode and said control grid between said counter electrode and said developing particle holder is integrated, and said electrode group can be installed to and removed from an image forming apparatus main body as one unit.

Claim 17

An image forming apparatus, comprising: a developing particle holder for holding developing particles by means of either of electric force and magnetic force; a counter electrode positioned opposite to said developing particle holder, said counter electrode having a developing particle passing hole for allowing developing particles which flew from said developing particle holder to pass; a control grid having a plurality of gates as a passing section of the developing particles, said control grid being provided between said developing particle holder and said counter electrode; a power source section for giving a potential which generates a prescribed potential difference between said developing particle holder and said counter electrode and for giving a potential to said control grid; and grid potential control means for changing an electric field existing between said developing particle holder and said counter electrode by changing the potential given from said power source section to said control grid according image signals in order to form an image by controlling flying of developing particles from said developing particle holder through said gate towards said counter electrode and by adhering the developing particles to a recording medium in an opposite side to the developing particle holder side of the counter electrode.

Claim 18

The image forming apparatus as defined in claim 17, further comprising: a developing particle flying stabilization electrode positioned on an opposite side to the counter electrode side with respect to the recording medium, wherein a potential, which generates an electric field having a same direction as that of an electric field existing between said control grid and said counter electrode when the developing particles fly towards the counter electrode through said control grid, is given from said power source section to said developing particle flying stabilization electrode.

Claim 19

The image forming apparatus as defined in claim 17, further comprising recording medium potential giving means for giving a potential, which generates an electric field having a same direction as that of the electric field between said control grid and said counter electrode when the developing particles fly through said control grid towards said counter electrode, to an opposite side of the recording medium to the developing particle holder side.

Claim 20

The image forming apparatus as defined in claim 19, wherein said recording medium potential giving means is a roller which is pressed against the counter electrode side on the recording medium in a pair of rollers for charging the recording medium while transferring it in a carrying direction.

Claim 21

The image forming apparatus as defined in claim 17, wherein an electrode group including said counter electrode and said control grid between said counter electrode and said developing particle holder is integrated, and said electrode group can be installed to and removed from an image forming apparatus main body as one unit.

Claim 22

An image forming apparatus, comprising: a plurality of gates being selectively opened and closed for allowing developing particles, which forms an image on a recording medium, to pass, said plurality of gates being arranged in a matrix-fashion; storing means being divided plurally; image data writing means for successively writing image data inputted from an outer apparatus per line into a plurality of storing means; image data reading means for reading out image data from said storing means other than said storing means where image data are written by said image data writing means; and signal converting means for creating switching data of the gates from the image data read out by said image data reading means.

Claim 23

The image forming apparatus as defined in claim 22, wherein said storing means includes: an odd memory for storing the image data on odd lines; and an even memory for storing the image data on even lines.

Claim 24

The image forming apparatus as defined in claim 23, wherein said gates include a matrix where an interval for an odd picture element is provided uniformly between lines.