Recording Device Transport Calibration for Roller Eccentricity Streaks

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Solution Overview

Problem

Existing recording devices face issues with transport accuracy errors, leading to streaky density unevenness due to transport roller eccentricity, which complicates the adjustment of transport amounts and affects the quality of recorded images.

Innovation Solution

A recording device and method that includes a control section to record test patterns with different liquid ejection amounts for boundary areas between patches, adjusting transport distances based on nozzle array length and transport roller circumference, to minimize the impact of transport roller errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the transport roller is used to transport the medium, then the medium can be transported efficiently, but transport roller errors (non-perfect circle or eccentricity) cause fluctuation in transport amount during a single revolution

Engineering Contradiction:
Improvetransport efficiencyVSAvoidtransport accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent changes the transport distance parameter to be based on the circumference length of the transport roller rather than the nozzle array length. Specifically, the transport distance is set to an integer multiple of the circumference length minus a fixed offset, which ensures that the transport roller completes an integer number of revolutions, thereby eliminating the effect of transport roller errors on the test pattern recording

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent records test patterns at multiple positions along the transport direction, creating copies of the same test pattern structure at different locations. This allows for evaluating transport accuracy at multiple points and obtaining a correct adjustment value that is not affected by local transport roller errors

Inventive Principle:
Principle #26Copying

2Manufacturing precision

If the transport amount is adjusted based on test pattern recording, then uneven density can be suppressed, but transport roller error affects the test pattern recording results making it difficult to obtain correct adjustment values

Engineering Contradiction:
Improvedensity uniformityVSAvoidadjustment value accuracy
Core Design Contradiction:
Manufacturing precisionVSMeasurement precision

Solution Approach 1:

The patent changes the fundamental parameter for transport distance calculation from nozzle array length to circumference length of the transport roller. This parameter change ensures that the transport roller completes exact integer revolutions during test pattern recording, eliminating the cumulative effect of transport roller errors and enabling accurate measurement of transport accuracy

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements a feedback mechanism where test patterns are recorded, evaluated for density uniformity, and used to calculate transport accuracy adjustment values. These adjustment values are then applied to correct the transport amount in subsequent recording operations, creating a closed-loop system that continuously improves density uniformity

Inventive Principle:
Principle #23Feedback

3Area of stationary object

If the nozzle array length is used as the transport distance, then the test pattern can cover the entire nozzle array, but the test pattern recording is affected by transport roller error when the nozzle array length differs from the circumference length

Engineering Contradiction:
Improvetest pattern coverageVSAvoidtransport accuracy
Core Design Contradiction:
Area of stationary objectVSManufacturing precision

Solution Approach 1:

The patent fundamentally changes the transport distance parameter from nozzle array length to a value based on the circumference length of the transport roller. This ensures that the transport roller completes an integer number of revolutions, eliminating the effect of transport roller errors while still allowing comprehensive test pattern coverage through multiple recording positions

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4344884B1Recording device and recording method
Publication Date: 2025.09.03 SEIKO EPSON CORP
  • EP4344884B1 patent drawingFigure 1
  • EP4344884B1 patent drawingFigure 2
  • EP4344884B1 patent drawingFigure 3A~3B

AI summary

A recording device (10) includes a transport roller whose circumference length is different from nozzle array length in a transport direction, performs TP recording control to record a group of test patterns, in which a plurality of test patterns including a first patch and a second patch with different positions in the transport direction are arranged in a main scanning direction, and in which an amount of liquid ejected for a boundary area between the first patch and the second patch is different for each test pattern, wherein, in the TP recording control, records a first TP group and a second TP group at different positions in the transport direction onto a medium, transports the medium by a first distance based on the nozzle array length as a transport between the recording of the first patch and the second patch of the TP, and, as a transport between the recording of the second patch of the first TP group and the recording of the first patch of the second TP group, transports the medium by a second distance, which is a difference between an integer multiple of the circumference length and two times the first distance.