Dot Recording Apparatus Asymmetric Pixel Group Staggering
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Solution Overview
Problem
Existing dot recording apparatuses suffer from banding issues along the main and sub-scan directions due to rectangular pixel group arrangements, leading to image quality deterioration, particularly at boundaries between adjacent pixel groups.
Innovation Solution
The dot recording apparatus adjusts the dot rate gradually and periodically in both the main and sub-scan directions by using non-linear boundaries and complementary relationships between passes, with zigzag-shaped boundaries intersecting the main and sub-scan directions to suppress banding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If rectangular pixel groups are arranged in a tiled pattern for efficient dot recording, then productivity is improved, but banding occurs along the boundaries causing image quality deterioration
Solution Approach 1:
The patent applies asymmetry by arranging pixel groups in a staggered pattern where odd-numbered and even-numbered pixel groups are shifted relative to each other in the main scan direction. This asymmetric arrangement breaks the regular tiled pattern that causes banding, while still maintaining efficient dot recording coverage through the complementary relationship between adjacent pixel groups.
Solution Approach 2:
The patent segments the recording area into multiple pixel groups with different arrangements. By dividing the pixel groups into odd-numbered and even-numbered sets with different positioning patterns, the patent creates segmented regions that prevent continuous banding while maintaining overall recording efficiency.
2Ease of manufacture
If pixel groups are arranged with boundaries parallel to scan directions, then ease of manufacture is improved, but banding along long boundaries stands out causing image quality deterioration
Solution Approach 1:
The patent introduces asymmetry in the boundary arrangement by staggering odd and even pixel groups. This creates non-parallel boundaries that are less visible and reduce banding effects, while still maintaining relatively simple manufacturing through systematic positioning patterns.
Solution Approach 2:
The patent addresses the boundary problem by introducing a staggered arrangement that effectively adds a dimensional offset between adjacent pixel groups. This shifts the boundaries out of alignment in the main scan direction, reducing their visibility and banding effects without significantly complicating the manufacturing process.
3Productivity
If pixel groups are tiled in the main scan direction, then productivity is improved, but rapid dot rate changes at boundaries cause banding to stand out
Solution Approach 1:
The patent uses asymmetric staggering of pixel groups to eliminate the sharp transitions at boundaries. By offsetting odd and even pixel groups, the dot rate changes become more gradual across boundaries, preventing the rapid changes that cause visible banding while maintaining high main scan efficiency.
Data Source
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AI summary
A main scan pass which relatively moves a recording head and a recording medium in a main scan direction and forms dots on the recording medium, and a sub-scan which relatively moves the recording medium and the recording head in a sub-scan direction that intersects with the main scan direction, are performed, and thereby multi-pass recording which completes forming of the dots on a main scan line by N (N is an integer equal to or greater than 2) times of the main scan passes is performed. A dot rate which represents a rate of pixels in which dot recording is performed in each main scan pass of the multi-pass recording is set so as to be changed gradually and periodically over a plurality of sections in the main scan direction. The number of values of the dot rates different from each other in the plurality of sections lined up in the main scan direction is set so as to be equal to or greater than 3.