Overlapping Short Nozzle Rows Density Correction
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Solution Overview
Problem
Image recording apparatuses using line heads composed of short nozzle rows face issues with streak-shaped density unevenness and white spots due to the complexity of precisely aligning nozzle rows, leading to high costs, low reliability, and poor yield.
Innovation Solution
An image recording apparatus with a line head configured by arranging overlapping short nozzle rows, utilizing a conveyance information generating unit, a recording medium detecting unit, and a recording data controlling unit to detect the edge of the recording medium and perform density corrections based on conveyance information, thereby eliminating the need for precise alignment and preventing density unevenness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If short nozzle rows are arranged to form a line head, then cost is reduced and reliability is improved, but streak-shaped density unevenness and white spots occur due to alignment difficulties
Solution Approach 1:
The patent applies parameter changes by modifying the nozzle arrangement parameters - specifically arranging nozzles in a staggered pattern where odd-numbered nozzles are positioned at different locations than even-numbered nozzles. This parameter modification allows the system to achieve uniform ink deposition without requiring precise alignment between multiple short nozzle rows, thereby resolving the contradiction between improved reliability and manufacturing precision requirements
2Ease of manufacture
If short nozzle rows are used instead of full-line heads, then cost and yield are improved, but density unevenness occurs in overlapping portions
Solution Approach 1:
The patent applies local quality by implementing different nozzle arrangements for different regions - odd-numbered nozzles and even-numbered nozzles are arranged at different staggered positions. This localized differentiation ensures that overlapping portions receive uniform ink deposition from both odd and even nozzles, preventing density unevenness while maintaining the manufacturing advantages of short nozzle rows
3Area of stationary object
If multiple short nozzle rows are arranged to cover the recording medium width, then the recording width is increased, but the complexity of alignment increases
Solution Approach 1:
The patent applies segmentation by dividing the nozzle array into multiple independent short nozzle rows (odd-numbered and even-numbered nozzles arranged separately). Each segment can be manufactured and positioned independently, yet the staggered arrangement ensures that they work together to provide uniform coverage across the entire recording width without requiring complex alignment procedures
Data Source
AI summary
An image recording apparatus, in which a line head is configured by arranging a plurality of nozzles, some of which are made to overlap, of short nozzle rows each having a jetting nozzle row arranged in one direction relative to a conveyance direction of a recording medium being conveyed by a conveyance mechanism and which forms records an image by jetting ink from the jetting nozzles onto the recording medium, comprises a conveyance information generating unit which generates conveyance information indicating a conveyance distance of the recording medium, a recording medium detecting unit which detects an edge of the recording medium being conveyed, and a controlling unit which performs a density correction of an image recorded by an overlapping portion of the short nozzle rows on the basis of a detection result of the recording medium detecting unit and the conveyance information obtained from the conveyance information generating unit.