Image Quality Defect Definitions - Xerox DocuPrint N2025 Service Manual

Introduction
This section contains image quality repair procedures to assist in correcting image quality
defects. These procedures provide defect samples, definitions and specifications to help iden-
tify the type of defect that exists, the test pattern to use, and actions required to correct the
defects.
Throughout these procedures, the term "vertical" refers to the process direction (the direction
paper travels through the printer); the term "horizontal" refers to the scanning direction (the
direction the laser beam scans across the page).
Be sure to check the paper tray to determine whether paper is being fed long edge or short
edge first. This determines "vertical" and "horizontal" for paper fed from that particular tray.
Cleaning procedures should always be performed before beginning any Print Quality Repair
procedure.
Be sure that the paper meets printer specifications. Changing the paper, or using paper from a
previously unopened ream, will resolve many print quality issues.
After resolving an image quality problem, return to Image Quality Checkout to verify that no
other image quality defects exist.
Sample reproductions of the various image quality patterns are included under Image Quality
Specifications.
Use the Image Quality RAPS to further diagnose machine problems.
In the Y/N (Yes/No) steps of the RAPs, a Yes response will lead you to the next step. A No
response will indicate a corrective action, or will direct you to another step. When the indicated
corrective action has been completed, go to Section 1 and restart the Initial Actions to verify
that the problem has been corrected.
Initial Issue
DocuPrint N2025/N2825

Image Quality Defect Definitions

The System Controller Test Print is used to evaluate each of the print quality parameters. Each
area of the test pattern is used for a print quality parameter. The areas and the print quality
parameters are listed in Image Quality Checkout.
Table 1 Image Quality Defect Definitions
Defect Definitions
LIGHT PRINTS: The overall image density is too light.
BLANK PRINTS: Prints with no visible image.
SPOTS: There are spots of toner on the page.
HORIZONTAL DELETIONS: There are areas of the image that are extremely
light or missing entirely. These areas run horizontally across the page in the
direction of scanning.
VERTICAL DELETIONS: There are areas of the image that are extremely
light or missing entirely. These areas run vertically along the page in the
direction of paper movement.
SPOT DELETIONS: Solid areas are marked with irregular white areas.
VERTICAL STREAKS: Extraneous dark lines/bands in the process direction. IQ RAP 7
HORIZONTAL STREAKS: Extraneous dark lines/bands in the direction of
scan.
RESIDUAL IMAGES: The image from a previous print, which was not
removed during the cleaning process, has been developed on the current
print.
BLACK PRINTS: The print is completely covered with toner and has no visi-
ble image.
BACKGROUND: Uniform toner contamination in non image areas. Refer to
the Background specification.
UNEVEN DENSITY: The text/line darkness and solid area density image var-
ies across the print.
SKEWED IMAGE: Angular displacement of the image from its intended posi-
tion on the print. Refer to the specification.
DAMAGED PRINTS: Creases, wrinkles, excessive curl, cuts, folds or
embossed marks.
REGISTRATION (lead edge to trail edge): Displacement of the image, in the
process direction, from its intended position on the print.(inboard to out-
board): Displacement of the image, in the direction of scan, from its intended
position on the print.
SKIPS / SMEARS: Skip-Loss or stretching of the image in bands across the
process direction. Smear-The distortion of the image in bands across the pro-
cess direction that cause it to appear to be blurred or compressed.
UNFUSED IMAGE: Part of or all of the image is unfused. Refer to the specifi-
cation.
RESOLUTION: At 600 DPI, the two pixel lines and halftone patches cannot
be reproduced clearly on the print.
02/2000
Introduction, Image Quality Defect Definitions
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Go To:
IQ RAP 1
IQ RAP 2
IQ RAP 3
IQ RAP 4
IQ RAP 5
IQ RAP 6
IQ RAP 8
IQ RAP 9
IQ RAP 10
IQ RAP 11
IQ RAP 12
IQ RAP 13
IQ RAP 14
IQ RAP 15
IQ RAP 16
IQ RAP 17
IQ RAP 18
Image Quality Repair Analysis Procedures