Inkjet Print Head Deviation Adjustment via Stepwise Pattern Selection
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Solution Overview
Problem
Conventional inkjet recording apparatuses face challenges in accurately adjusting the deviation of print positions between dots formed at different timings, particularly in bidirectional printing, leading to image quality degradation due to the difficulty in distinguishing small differences between adjacent recording patterns and determining the correct adjustment pattern when patterns are deviated in opposite directions.
Innovation Solution
A recording apparatus that includes a print head with a scanning unit, an adjustment-chart output unit for printing an adjustment chart with recording patterns having varying deviation amounts, and an ejection-position adjusting unit that calculates and applies an adjustment value based on selected patterns to correct print position deviations, ensuring accurate alignment of dots formed at different timings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional test patterns with small deviation amounts are used for adjustment, then measurement precision is improved, but difficulty of detecting and measuring increases due to inability to distinguish small differences visually
Solution Approach 1:
The patent transforms the one-dimensional visual distinction problem into a two-dimensional solution by grouping patterns into multiple sets with different base deviation amounts. Each set contains patterns with fine deviations, but the sets themselves are separated by larger deviation steps, allowing visual selection of the appropriate set first, then fine adjustment within that set.
Solution Approach 2:
The patent divides the adjustment patterns into multiple separate groups (first group, second group, third group, etc.), where each group contains patterns with small deviation increments. This segmentation allows the user to first identify which group to use based on overall deviation magnitude, then perform precise adjustment within that group, solving both the visual distinction and precision requirements.
2Productivity
If bidirectional printing is performed to improve productivity, then print speed is improved, but manufacturing precision deteriorates due to dot position deviation between forward and backward printing
Solution Approach 1:
The patent implements a feedback mechanism where the user visually inspects the printed test pattern to determine the deviation direction and magnitude, then inputs this observed information back into the system. The system uses this feedback to calculate the appropriate timing adjustment, creating a closed-loop system that compensates for the bidirectional printing deviation.
Solution Approach 2:
The patent changes the timing parameter of ink ejection based on the observed deviation. By adjusting the ejection timing offset for backward printing relative to forward printing, the system compensates for the mechanical deviation inherent in bidirectional movement, thereby maintaining dot position accuracy while preserving the speed benefits of bidirectional printing.
3Ease of operation
If multiple recording patterns with different deviation amounts are provided, then ease of operation is improved for adjustment, but device complexity increases
Solution Approach 1:
The patent enables the user to perform the adjustment function themselves by providing visually distinguishable test patterns with known deviation characteristics. The user inspects the printed pattern, determines the deviation, and inputs the correction value, eliminating the need for complex automated measurement and adjustment systems while maintaining ease of operation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enables precise adjustment of print position deviations, improving image quality by enhancing the ability to distinguish between recording patterns and accurately correct deviations, even in high-resolution printing scenarios, thereby reducing surface roughness and maintaining image quality.
Implementation Method 1
a piezoelectric element is used as the energy generating unit that generates energy for pressurizing ink in the ink passage and which ejects ink droplets by deforming a vibration plate, which forms a wall surface of the ink passage, by the piezoelectric element
Implementation Method 2
an electrostatic inkjet head is also known, in which a vibration plate, which forms a wall surface of the ink passage, and an electrode are arranged in parallel as the energy generating unit and which ejects ink droplets by changing the internal volume of the ink passage by deforming the vibration plate by electrostatic force generated between the vibration plate and the electrode
Data Source
AI summary
A recording apparatus includes: a recording unit; an adjustment-chart output unit that outputs an adjustment chart for adjusting deviation of a print position between a first dot and a second dot that are formed for images on a recording medium at different timings with a print head; and an ejection-position adjusting unit that records a plurality of combinations, each containing a reference pattern for reference of an image position and adjustment patterns that are deviated from the reference pattern in a stepwise manner such that the deviation amounts are shifted by M-times of a deviation amount corresponding to the recording resolution, receives selection of an adjustment pattern closest to the reference pattern from the outside, obtains an adjustment value based on the adjustment pattern of the selected combination, sets the adjustment value as a new adjustment value, and adjusts an ejection position of the print head.