Image Recording Apparatus Conveyance Control for Ink Density Uniformity
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Solution Overview
Problem
Ink-jet recording apparatuses face issues with ink short supply leading to uneven ink discharge, causing streak-like unevenness in density along the scanning direction due to varying carriage velocities during multiple recording passes.
Innovation Solution
An image recording apparatus that adjusts the conveyance length of overlapping recording areas based on determined carriage velocities to ensure consistent ink landing, using a controller to manage the conveyer and carriage movements, ensuring that areas with lower ink landing amounts overlap, thus preventing streak-like unevenness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the carriage moving velocity is increased to improve productivity, then the recording speed is improved, but the landing area of ink spreads excessively in the conveyance direction causing streak-like unevenness in density
Solution Approach 1:
The patent applies dynamics by making the conveyance amount adjustable based on the carriage velocity. When the carriage velocity varies between recording passes, the conveyance amount is dynamically adjusted to compensate, ensuring that the landing positions of ink align properly across passes even when speeds differ, thus preventing streak-like unevenness while maintaining high recording speeds
Solution Approach 2:
The patent changes the conveyance parameter (conveyance amount) based on the carriage velocity parameter. By adjusting the conveyance amount according to the actual carriage velocity in each recording pass, the system compensates for velocity variations and their effect on ink spread, maintaining consistent image quality across passes with different speeds
2Reliability
If different carriage velocities are used in different recording passes to prevent ink short supply, then ink supply reliability is improved, but streak-like unevenness in density occurs due to differences in ink landing positions
Solution Approach 1:
The patent implements feedback by measuring the actual carriage velocity in each recording pass and using this information to adjust the conveyance amount in subsequent passes. This feedback mechanism allows the system to compensate for velocity variations that cause ink landing position shifts, maintaining image quality while allowing velocity changes for ink supply reliability
Solution Approach 2:
The patent performs preliminary action by calculating and setting the conveyance amount before each recording pass based on the planned or actual carriage velocity. This advance adjustment ensures that even when different velocities are used to prevent ink short supply, the ink landing positions will align properly across passes
Data Source
AI summary
There is provided a liquid discharge apparatus including a conveyer, a carriage, a head and a controller. In a case of recording an image on a recording medium, the controller executes: obtaining information regarding a supply state of liquid from a liquid tank to the head in a case of executing each of recording passes; determining a moving velocity of the carriage with respect to each of the recording passes, based on the obtained information regarding the supply state; and adjusting a conveyance amount, by which the recording medium is conveyed in each of conveying operations, depending on moving velocities of the carriage determined with respect to two continuous recording passes, respectively, included in the recording passes, so as to adjust length in the conveyance direction of an overlap area in which recording areas by the two continuous recording passes overlap with each other.