Minolta Company, Ltd.

Other

Toshio Yamaki

Hiroshi Hiraguchi

Koji Uno

Hirokatsu Shimada

Yoshifumi Shibata

A recording apparatus of the present invention includes a bearing member for bearing a recording medium having toner and carrier and a backing electrode opposing to the bearing member for electrically attracting the toner on the bearing member. The toner and carrier are charged to opposite polarities. A substrate having a plurality of apertures is provided between the bearing member and the backing electrode. This allows the toner to propel from the bearing member toward the backing electrode. Further, both the toner and carrier have respective volume mean diameters smaller than a diameter of the apertures, and the volume mean diameter of the toner is larger than that of the toner. With the arrangement, the toner will propel through each aperture to form a corresponding image portion, i.e., dot, thereby forming a high quality image without any dot-defect.

Apparatus for propelling toner through apertures to form images on a recording medium

A tandem type direct printing apparatus,comprising a plurality of printing stations,and,for depositing printing particles,on a print medium,. The plurality of printing stations,and,are positioned in a moving direction of the print medium,. Each printing station,comprises a bearing member,for bearing charged printing particles,thereon, a backing electrode,opposed to the bearing member,, a printing head,disposed between the bearing member,and the backing electrode,, the printing head,having a plurality of apertures,through which the printing particles,can propel and a plurality of electrodes,disposed around the plurality of apertures,. Each of the plurality of apertures,of the printing head,in any one of the printing stations,corresponds to the aperture,of the printing head,in another printing station,so that the latter is closest to a line along the moving direction of the printing medium which passes through the center of the former.

Tandem type of direct printing apparatus using gating apertures for supplying toner

A printing device includes a bearing member for bearing printing particles each having an electric charge, a backing electrode for forming an electric field between the bearing member and the backing electrode, and a substrate located between the bearing member and the backing electrode. The substrate includes a plurality of apertures. For each aperture, the substrate includes an attracting electrode and a plurality of converging electrodes. When, a first voltage is applied to the attracting electrode, the printing particles are attracted and then separated from the bearing member. Then, a second voltage is applied to the converging electrodes, the printing particles propelling in the aperture are converged. The converged printing particles are then deposited onto a recording sheet being transported to form a dot having a clear contour.

Printing device for propelling printing material onto a recording medium to form images

A tandem type direct printing apparatus,comprising a plurality of printing stations,and,for depositing printing particles 38 on a print medium,to form a layer of printing particles. The plurality of printing stations,and,are positioned in a moving direction of the print medium,. The printing station positioned downstream with respect to the moving direction of the print medium forms a layer of printing particles on the layer of printing particles formed by the printing station positioned upstream. At least any one of the printing stations,and,is different in intention of the electric field from another by changing the voltage applied to the backing electrode,or the distance between the backing electrode,and the printing head,in accordance with a charge quantity of printing particles or the number of the layer of printing particles in the one of the printing stations.

The tandem type direct printing apparatus,comprises a plurality of printing stations,and,for propelling printing particles,born on a bearing member,through a plurality of apertures,formed on a printing head,and for depositing the printing particles,on a print medium,to form an image. The plurality of printing stations,and,are positioned in the moving direction of the print medium,to form the composite image on the print medium,. The method of the present invention comprises providing a control electrode for deflecting printing particles,in adjacent to each aperture,in at least one of the plurality of printing stations,and,, the control electrode,being positioned at least one side of a direction different from the moving direction of the print medium,; and applying a voltage to the control electrode,so that the printing particles,passing through the aperture,are deflected to adjust the position of the image formed on the print medium in the perpendicular direction to the moving direction of the print medium

Tandem type of direct printing apparatus and method for making a registration of composite image therein

A direct printing apparatus,for depositing printing particles,on a print medium,comprises a sleeve,for bearing charged printing particles,thereon, a drive roller,provided in the sleeve,, the drive roller,having a smaller outside diameter than an inside diameter of the sleeve,, a backing electrode,opposed to the sleeve,, a printing head,disposed between the sleeve,and the backing electrode,, the printing head,having a plurality of apertures 56 through which the printing particles,can propel and a plurality of electrodes,disposed around the plurality of apertures,. A spacer,is provided between the sleeve,and the printing head,. The sleeve,has a slack,through which the sleeve,comes into contact with the spacer

Direct printing apparatus

The printing head,includes an insulative member,in which pluralities of apertures,are formed. Doughnut-like first and second electrodes,and,are disposed around the aperture,. Pulse voltages V,(P) and V,(P) both having a certain polarity opposite to that of the toner particles are applied to the first and second electrodes,and,, energizing the toner particles,to afford propelling thereof. Subsequently, a voltage V,(B) having the same polarity as the charged toner particles,is applied to the second electrode,, forcing radially inwardly to converge the propelling toner particles,in the aperture,. This ensures that a dot and an image both having clear contour can be formed on the sheet

Apparatus and method for direct printing using first and second electrodes to deposit charged particles

A print head,comprises an insulative sheet member,that includes a plurality of apertures,arranged in rows. Arranged adjacent to each aperture,are first and second electrodes,and,. The first electrode,is communicated with a driver,while the second electrode,is communicated with a driver,or,. By applying first and second pulsating signals with the first and second electrodes, respectively, printing particles on a portion of bearing member,that opposes to the electrodes are energized to propel into corresponding aperture. A voltage and/or duration of the pulsating signal is determined according to the distance between the portion of the bearing member and the opposing aperture. Thereby, almost the same amount of printing particles are propelled into each aperture to form the same size dots on the sheet substrate

Depositing charged particles onto a sheet based on distances relative to a print head

The present invention provides a direct printing apparatus which prevents noise at a time of operation, downsizes the apparatus, prevents decrease of strength, and enables to certainly clean remaining printing particles. An endless belt member,disposed between a backing electrode,and a printing head,of printing station,, the endless belt member,receiving the printing particles,which are propelled from the printing head and cleaning means for cleaning the printing particles adhering to the surface of the endless belt member are provided, whereby the printing particles adhering to the apertures of the printing head are collected on the endless belt member so that the printing particles are recovered by the cleaning means. Concretely, the backing electrode is applied with a voltage of opposite polarity to the printing particles adhering to the printing head whereby the printing particles adhering to the apertures of the printing head is cleaned.

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Takatsuki, Japan

Toshio Yamaki