Method for suppressing phantom images

• US 6,380,961 B1
• Filed: 10/06/2000
• Issued: 04/30/2002
• Est. Priority Date: 10/12/1999
• Status: Expired due to Term

• Current Assignee: Océ-Technologies B.V. (Canon Inc.)
• Original Assignee: Océ-Technologies B.V. (Canon Inc.)
• Inventors: Ophelders, Cornelis A. W., Van Der Loop, Gerardus C. W.
• Primary Examiner(s): PENDEGRASS, JOAN H
• Application Number:
  US09/680,428
• Time in Patent Office: 571 Days
• Field of Search: 347/115, 347/116, 347/131, 358/1.9, 358/530, 358/448, 358/300
• US Class Current: 347/131
• CPC Class Codes: H04N 1/58 Edge or detail enhancement; Noise or error suppression, e.g. colour misregistration correction H04N1/62 takes precedence

Abstract

A method for suppressing phantom images in a digital copying or printing process wherein toner material in the form of pixels of image information (D (x,y), in which D is the image density for point x,y, is transferred through a sequence of process steps from a photoconductive surface to an image-recording medium, where at least one process step is influenced in a predetermined manner by at least one preceding process step for the same surface point x,y, which comprises connecting the image information for each pixel of image information to be printed on the basis of image information D(x,y-Δy1) for at least the pixel associated with the same surface point x,y, and said preceding process step, thereby compensating for the influence of said preceding process step.

Claims

1. A method for suppressing phantom images in a digital copying or printing process wherein toner material in the form of pixels of image information (D (x,y)), in which D is the image density for point x,y, is transferred through a sequence of process steps from an image registration medium to a final image receiving medium, where at least one process step is influenced in a predetermined manner by residual toner deposits resulting from at least one preceding process step for the same surface point x,y, which method comprises associating the image information for each pixel of image information to be printed on the basis of image information D(x,y-Δ

y1) for at least the pixel associated with the same surface point x,y, and said preceding process step, so as to compensate for the influence of the residual toner deposits of said preceding process step.

2. The method according to claim 1, wherein the toner material is disposed on a support medium which supplies toner to a transfer zone where a latent image is developed by the toner, the sequence of process steps to which each point on the surface of said support medium is subjected being the developing steps occurring in the subsequent developing cycles of said support medium.

3. The method of claim 2, wherein the support medium is a donor drum or an endless donor belt.

4. The method according to claim 1, wherein said image registration medium is a photoconductive endless belt or drum.

5. The method according to claim 4, wherein the sequence of process steps to which each point on the surface of said photoconductive belt or drum is subjected comprises the steps in which said surface point is brought into contact with an intermediate image carrier in successive cycles of said belt or drum.

6. The method according to claim 1, wherein said image registration medium is a drum containing a plurality of electrodes extending around the surface thereof, and the sequence of process steps to which each point on the surface of this drum is subjected comprise a first step in which toner is adhered to the surface of the drum by energizing one or more electrodes thereof, and a subsequent step in which the toner thus adhered to the drum is transferred onto the image-recording medium.

7. The method according to claim 1, wherein the correction of image information depends on parameters which represent the properties and conditions of the process steps involved, and the method further comprises adjusting said parameters in accordance with the current status of the copying or printing machine.

8. An image reproduction system comprising a digital image processing system and a printer utilizing the method of claim 1.

9. The image reproduction system according to claim 8, wherein said printer is a color printer.