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US 6,305,781 B1Granted
Method and apparatus for improved bi-directional error for multicolor printers
AssigneeXerox Corporation
InventorVirgil Joseph Hull
Life of this patent
Estimating the term…
Abstract
An apparatus and method for forming an image with fluids having different firing velocities from a bi-directional print head results in a reduction in bi-directional misalignment error. The bi-directional misalignment error is reduced by delaying the firing of a drop of the higher velocity fluid on the return swath of the print head.
Claims17
A method of forming an image having a resolution on a medium, the method comprising:
- moving a print head in a first direction and a second direction opposite the first direction;
- firing a first drop of a first fluid at a first velocity while the print head is moving in the first direction to form a first dot on the medium;
- firing a first drop of a second fluid at a second velocity different from the first velocity while the print head is moving in the first direction to form a second dot on the medium;
- firing a second drop of the second fluid at the second velocity while the print head is moving in the second direction to form a third dot on the medium, the third dot substantially aligned with the second dot in a direction perpendicular to the first direction;
- firing a second drop of the first fluid at the first velocity while the print head is moving in the second direction to form a fourth dot on the medium;
- wherein the drops of the first and second fluids are fired from particular nozzles of a row of nozzles in the print head, the particular nozzles selectively sequentially fired in strokes, each stroke beginning at one end of the row and ending at the other end of the row;
- and
- relatively adjusting the firing between the first and second drops of the first fluid by at least one stroke such that a distance between the first dot and the fourth dot is less than or equal to a predetermined amount.
5 more elements
An image forming apparatus, comprising:
- a print head movable in a first direction and a second direction opposite the first direction, the print head being capable of firing drops of a first fluid at a first velocity and drops of a second fluid at a second velocity different from the first velocity;
- and
- a controller that controls the firing of the drops of the first fluid and the drops of the second fluid such that
- a first drop of the first fluid is fired at the first velocity while the print head is moving in the first direction to form a first dot on a medium,
- a first drop of the second fluid is fired at the second velocity while the print head is moving in the first direction to form a second dot on the medium,
- a second drop of the second fluid is fired at the second velocity while the print head is moving in the second direction to form a third dot on the medium, the third dot being substantially aligned with the second dot in a direction perpendicular to the first direction,
- a second drop of the first fluid is fired at the first velocity while the print head is moving in the second direction to form a fourth dot on the medium,
- wherein the print head has a row of nozzles and the controller controls the firing of the drops of the first fluid and the drops of the second fluid such that the drops of the first fluid and the drops of the second fluid are fired from particular nozzles of the row of nozzles, the particular nozzles selectively sequentially fired in strokes, each stroke beginning at one end of the row and ending at the other end of the row;
- and
- the firing of the first drop of the first fluid and the firing of the second drop of the first fluid are relatively adjusted by at least one stroke such that a distance between the first dot and the fourth dot is less than or equal to a predetermined amount.
7 more elements
An image forming apparatus, comprising:
- means for moving a print head in a first direction defining a stroke and a second direction defining a stroke opposite the first direction;
- first firing means for firing a first drop of a first fluid at a first velocity while the print head is moving in the first direction to form a first dot on a medium;
- and
- second firing means for firing a first drop of a second fluid at a second velocity different from the first velocity while the print head is moving in the first direction to form a second dot on the medium, wherein:
- the second firing means fires a second drop of the second fluid at the second velocity while the print head is moving in the second direction to form a third dot on the medium, the third dot substantially aligned with the second dot in a direction perpendicular to the first direction, and
- the first firing means fires a second drop of the first fluid at the first velocity while the print head is moving in the second direction to form a fourth dot on the medium;
- and
- means for relatively adjusting the firing between the first and second drops of the first fluid by at least one stroke such that a distance between the first dot and the fourth dot is less than or equal to a predetermined amount.
5 more elements
Dependencies are inferred from the claim text.