US 6,714,748 B1 · Image forming apparatus, recording medium in which test-pattern image forming program is recorded, test-pattern image forming method, and skew angle calculation method · patentgrep

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Abstract

An image forming apparatus equipped with a first image forming unit, plural second image forming units, and a test-pattern image forming control unit for controlling the first and second image forming units which controls the first and second image forming units to form a test-pattern image, in such a manner that first and second marks of different densities are disposed adjacent to one another, based on test-pattern image data. This test-pattern image data includes first data serving to arrange a plurality of first color lines, which have each a predetermined line width, at a predetermined pitch by the first image forming unit, second data serving to form the first mark overlapping with the plural first color lines by the second image forming units, and third data serving to form the second mark displaced in a direction perpendicular to the plural first color lines. Before shipping the apparatus from a factory or when inspecting or repairing the apparatus at user's site, the customer engineer can easily grasps causes for possible positional errors using this simple test pattern and hence can cope with such trouble by exchanging or adjusting positions of parts comfortably and efficiently.

Claims16

Dependent claims

An image forming apparatus comprising:

a plurality of image forming units for forming different color images on recording paper, said plural image forming units including a first color image forming unit for forming a first color image, and at least one second color image forming unit for forming a second color image;
and
test-pattern image forming control means for controlling said first and second image forming units to form a test-pattern image composed of first and second marks different in density, which are arranged adjacent to one another without any gap therein between, based on test-pattern image data that includes
first data serving to arrange a plurality of first color lines, each having a predetermined line width, at a predetermined pitch by said first color image forming unit,
second data serving to form said first mark by arranging a plurality of second color lines, each having a line width equal to that of the individual first color line, at a pitch equal to that of said first color lines by said at least one second color image forming unit so as to overlap with said first color lines within a first region occupying part of an area where said plural first color lines are arranged, and
third data serving to form said second mark by displacing a plurality of second color lines in a direction perpendicular to said first color lines within a second region contiguous to said first region and by arranging said second color lines, each having a line width equal to that of the individual first color line, at a pitch equal to that of said first color lines by said at least one second color image forming unit;
and
each of said first and second color lines is a transverse line extending in a primary scanning direction perpendicular to a direction of conveyance of the recording paper;
and
said test-pattern image composed of said first and second marks contains a longitudinal succession of portions of said plural first color lines extending transversely and is formed on the recording paper at least at scanning-start- and scanning-end-side marginal regions in the secondary scanning direction.

7 more elements

An image forming apparatus comprising:

a plurality of image forming units for forming different color images on recording paper, said plural image forming units including a first color image forming unit for forming a first color image, and at least one second color image forming unit for forming a second color image;
and
test-pattern image forming control means for controlling said first and second image forming units to form a test-pattern image composed of first and second marks different in density, which are arranged adjacent to one another without any gap therein between, based on test-pattern image data that includes:
first data serving to arrange a plurality of first color lines, each having a predetermined line width, at a predetermined pitch by said first color image forming unit,
second data serving to form said first mark by arranging a plurality of second color lines, each having a line width equal to that of the individual first color line, at a pitch equal to that of said first color lines by said at least one second color image forming unit so as to overlap with said first color lines within a first region occupying part of an area where said plural first color lines are arranged, and
third data serving to form said second mark by displacing a plurality of second color lines in a direction perpendicular to said first color lines within a second region contiguous to said first region and by arranging said second color lines, each having a line width equal to that of the individual first color line, at a pitch equal to that of said first color lines by said at least one second color image forming unit;
and
each of said first and second color lines is a transverse line extending in a primary scanning direction perpendicular to a direction of conveyance of the recording paper;
and
said test-pattern image composed of said first and second marks contains a longitudinal succession of portions of said plural first color lines extending transversely and is formed on the recording paper at least at scanning-start- and scanning-end-side marginal regions in the secondary scanning direction, wherein:
each of said first and second color lines is a longitudinal line extending in a direction of conveyance of the recording paper;
and
said test-pattern image composed of said first and second marks contains a transverse succession of portions of said plural first color lines extending longitudinally and is formed on the recording paper at at least scanning-start- and scanning-end-side marginal regions in the primary scanning direction.

10 more elements

An image forming apparatus comprising:

a plurality of image forming units for forming different color images on recording paper, said plural image forming units including a first color image forming unit for forming a first color image, and at least one second color image forming unit for forming a second color image;
and
test-pattern image forming control means for controlling said first and second image forming units to form a test-pattern image composed of first and second marks different in density, which are arranged adjacent to one another without any gap therein between, based on test-pattern image data that includes:
first data serving to arrange a plurality of first color lines, each having a predetermined line width, at a predetermined pitch by said first color image forming unit,
second data serving to form said first mark by arranging a plurality of second color lines, each having a line width equal to that of the individual first color line, at a pitch equal to that of said first color lines by said at least one second color image forming unit so as to overlap with said first color lines within a first region occupying part of an area where said plural first color lines are arranged, and
third data serving to form said second mark by displacing a plurality of second color lines in a direction perpendicular to said first color lines within a second region contiguous to said first region and by arranging said second color lines, each having a line width equal to that of the individual first color line, at a pitch equal to that of said first color lines by said at least one second color image forming unit;
and
each of said first and second color lines is a transverse line extending in a primary scanning direction perpendicular to a direction of conveyance of the recording paper;
and
said test-pattern image composed of said first and second marks contains a longitudinal succession of portions of said plural first color lines extending transversely and is formed on the recording paper at least at scanning-start- and scanning-end-side marginal regions in the secondary scanning direction, wherein:
each of said first and second color lines is a longitudinal line extending in a direction of conveyance of the recording paper;
and
said test-pattern image composed of said first and second marks contains a transverse succession of portions of said plural first color lines extending longitudinally and is formed on the recording paper continuously from a scanning-start-side marginal region to a scanning-end-side marginal region in the secondary scanning direction.

10 more elements

An image forming apparatus comprising:

a plurality of image forming units for forming different color images on recording paper, said plural image forming units including a first color image forming unit for forming a first color image, and at least one second color image forming unit for forming a second color image;
and
test-pattern image forming control means for controlling said first and second image forming units to form a test-pattern image composed of first and second marks different in density, which are arranged adjacent to one another without any gap therein between, based on test-pattern image data that includes:
first data serving to arrange a plurality of first color lines, each having a predetermined line width, at a predetermined pitch by said first color image forming unit,
second data serving to form said first mark by arranging a plurality of second color lines, each having a line width equal to that of the individual first color line, at a pitch equal to that of said first color lines by said at least one second color image forming unit so as to overlap with said first color lines within a first region occupying part of an area where said plural first color lines are arranged, and
third data serving to form said second mark by displacing a plurality of second color lines in a direction perpendicular to said first color lines within a second region contiguous to said first region and by arranging said second color lines, each having a line width equal to that of the individual first color line, at a pitch equal to that of said first color lines by said at least one second color image forming unit;
and
each of said first and second color lines is a transverse line extending in a primary scanning direction perpendicular to a direction of conveyance of the recording paper;
and
said test-pattern image composed of said first and second marks contains a longitudinal succession of portions of said plural first color lines extending transversely and is formed on the recording paper at least at scanning-start- and scanning-end-side marginal regions in the secondary scanning direction, wherein:
each of said first and second color lines is a transverse line extending in a primary scanning direction perpendicular to a direction of conveyance of the recording paper;
and
said test-pattern image composed of said first and second marks contains a longitudinal succession of portions of said plural first color lines extending transversely and is formed on the recording paper at at least a scanning-start-side marginal region and a scanning-end-side marginal region in said primary scanning direction.

10 more elements

An image forming apparatus comprising:

a plurality of image forming units for forming different color images on recording paper, said plural image forming units including a first color image forming unit for forming a first color image, and at least one second color image forming unit for forming a second color image;
and
test-pattern image forming control means for controlling said first and second image forming units to form a test-pattern image composed of first and second marks different in density, which are arranged adjacent to one another without any gap therein between, based on test-pattern image data that includes:
first data serving to arrange a plurality of first color lines, each having a predetermined line width, at a predetermined pitch by said first color image forming unit,
second data serving to form said first mark by arranging a plurality of second color lines, each having a line width equal to that of the individual first color line, at a pitch equal to that of said first color lines by said at least one second color image forming unit so as to overlap with said first color lines within a first region occupying part of an area where said plural first color lines are arranged, and
third data serving to form said second mark by displacing a plurality of second color lines in a direction perpendicular to said first color lines within a second region contiguous to said first region and by arranging said second color lines, each having a line width equal to that of the individual first color line, at a pitch equal to that of said first color lines by said at least one second color image forming unit;
and
each of said first and second color lines is a transverse line extending in a primary scanning direction perpendicular to a direction of conveyance of the recording paper;
and
said test-pattern image composed of said first and second marks contains a longitudinal succession of portions of said plural first color lines extending transversely and is formed on the recording paper at least at scanning-start- and scanning-end-side marginal regions in the secondary scanning direction,
wherein said test-pattern image is a composite form of a plurality of pattern images to be formed on a single sheet of the recording paper, said plural pattern images including:
a first pattern image in which each of said first and second color lines is a transverse line extending in a primary scanning direction perpendicular to the direction of conveyance of the recording paper, said first pattern image being composed of said first and second marks, containing a longitudinal succession of portions of said plural first color lines and being formed on the recording paper at at least a scanning-start-side marginal region and a scanning-end-side marginal region in a secondary scanning direction perpendicular to the primary scanning direction;
a second pattern image in which each of the first and second color lines is a longitudinal line extending in the direction of conveyance of the recording paper, said second pattern image being composed of said first and second marks, containing a transverse succession of portions of said plural first color lines and being formed on the recording paper at at least a scanning-start-side marginal region and a scanning-end-side marginal region in the primary scanning direction;
and
a third pattern image in which each of the first and second color lines is a longitudinal line extending in the direction of conveyance of the recording paper, said third pattern image being composed of said first and second marks, containing a transverse succession of portions of said plural first color lines and being formed on the recording paper continuously from a scanning-start-side marginal region to a scanning-end-side marginal region in the secondary scanning direction.

12 more elements

Dependencies are inferred from the claim text.