Printer Head Poke Adjustment for Trailing End Banding
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Solution Overview
Problem
Existing recording systems, such as inkjet printers, experience banding issues due to misalignment of the recording sheet relative to the recording head, particularly when the trailing end of the sheet passes through the rollers, leading to uneven printing and increased complexity in preventing jumping or skipping.
Innovation Solution
A recording system that includes a control device to adjust the 'head poke' amount, ensuring the trailing end of the recording medium is not nipped by the rollers, by alternately performing intermittent feeding and recording operations, and adjusting the head poke amount based on predicted trailing end positioning to prevent banding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the trailing end of the recording sheet passes through the pair of rollers, then the recording sheet is pushed out in the feed direction, but this causes misalignment between the recording head and the recording sheet, resulting in banding
Solution Approach 1:
The control device predicts the position where the trailing end will be nipped by the rollers and adjusts the head poke amount in advance to prevent the trailing end from being positioned within the predetermined range, thereby preventing banding before it occurs
Solution Approach 2:
The system calculates and sets the appropriate head poke amount before the recording operation begins, based on predicted trailing end position, ensuring proper alignment is maintained throughout the recording process
2Difficulty of detecting and measuring
If a sensor is provided in the feed path to monitor the trailing end position, then the trailing end position can be detected, but this increases the complexity and cost of the recording system
Solution Approach 1:
The control device uses existing system parameters (recording sheet length, feed amount, head poke amount) to self-calculate the predicted trailing end position without requiring external sensors or additional detection devices
Solution Approach 2:
The patent replaces the mechanical sensor-based detection system with a computational approach using the control device to calculate trailing end position based on known system parameters
3Manufacturing precision
If the nozzles of the recording head are restricted before and after the trailing end passes through the rollers, then uneven printing is prevented, but the speed of image recording becomes slower
Solution Approach 1:
The control device calculates the appropriate head poke amount in advance to ensure the trailing end is positioned outside the nip range, allowing continuous recording without speed reduction or nozzle restriction
4Reliability
If a mechanism is provided to vary the nipping pressure of the pair of rollers, then jumping or skipping is prevented, but the recording system becomes more complicated and larger in size
Solution Approach 1:
The control device calculates and sets the appropriate head poke amount in advance to prevent the trailing end from being nipped by the rollers, eliminating the need for variable nipping pressure mechanisms
Solution Approach 2:
The patent replaces the mechanical variable pressure mechanism with a control system that uses calculation and positioning (head poke adjustment) to achieve the same reliability in preventing feeding instability
Data Source
AI summary
A recording system includes: a feeding device including a pair of rollers that cooperate with each other to nip a recording medium; a recording device which is configured to record an image on the recording medium; and a control device which is configured to control operations of the feeding device. The control device includes an adjusting portion which is configured to adjust an amount of head poke such that a trailing end of the recording medium is not stopped inside the predetermined range relative to a nip position of the pair of rollers.