公开(公告)号：US20040252905A1

公开(公告)日：2004-12-16

申请号：US10458427

申请日：2003-06-11

Applicant: XEROX CORPORATION

Inventor： Howard A. Mizes ,  R. Victor Klassen

IPC: G06K009/40

CPC classification number: H04N1/00002 ,  H04N1/00005 ,  H04N1/00042 ,  H04N1/0005 ,  H04N1/00082 ,  H04N1/00092 ,  H04N1/405 ,  H04N1/6033

Abstract: Diminished intensity defects occur in electrostatic printing between image regions having grey levels, i.e., different electrostatic potential and toner densities. Such defects occur when higher density regions nullstealnull toner from lower density regions. The system and methods according to this invention compensate for these defects by modifying the input image data. The input image data in lighter regions that precede or occur near a light-to-dark transition to a dark region are raised above the input image values. Thus, when printed, the printed image intensity values in such regions are higher than the corresponding image intensity values. As a result, when the higher density regions steal the extra toner provided due to the raised values, the gray level of the printed image corresponds to the desired gray level. The magnitude of these defects is periodically measured with a calibration pattern to generate and/or update compensation factors used in the compensation process.

Abstract translation: 在具有灰度级的图像区域（即，不同的静电电位和调色剂密度）之间的静电印刷中出现缺陷强度缺陷。 当较高密度区域从较低密度区域“偷”“调色剂时，会发生这种缺陷。 根据本发明的系统和方法通过修改输入图像数据来补偿这些缺陷。 在暗区域的暗到暗过渡之前或之后的较亮区域中的输入图像数据升高到输入图像值之上。 因此，当打印时，这些区域中的打印图像强度值高于相应的图像强度值。 结果，当较高密度区域由于升高的值而窃取提供的多余的调色剂时，印刷图像的灰度等于期望的灰度级。 这些缺陷的大小通过校准模式周期性地测量，以产生和/或更新补偿过程中使用的补偿因子。

公开(公告)号：US20040135878A1

公开(公告)日：2004-07-15

申请号：US10342543

申请日：2003-01-15

Applicant: XEROX CORPORATION

Inventor： Howard A. Mizes ,  Daniel E. Viassolo

IPC: B41J002/47

CPC classification number: G06K15/1247 ,  G06K15/027 ,  H04N1/4015

Abstract: A method of adjusting print uniformity in a xerographic device is provided. The method includes: a) printing a test pattern, b) transferring the printed test pattern to a scanner, c) scanning the printed test pattern and detecting line information, d) communicating the detected information to a computer, e) determining measurements from the detected line information, f) calculating the difference between the measurements and target values, and g) depending on the difference, adjusting a current supplied to an individual LED of an LED printbar associated with the measurement to reduce the difference. In one aspect, a test pattern line is associated with an individual LED. In another aspect, test pattern lines are associated with two adjacent LEDs and three adjacent LEDs. In yet another aspect, the test pattern includes dotted lines. In still another aspect, the invention includes a xerographic device with an LED printbar, a computer, and a scanner device.