Printing Apparatus Sensor Alignment for Variable Width Media
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Solution Overview
Problem
Conventional printing apparatuses fail to maintain high-quality printing when dealing with printing media of varying widths, as the positional relationship between upstream and downstream print heads remains misaligned, leading to suboptimal printing results.
Innovation Solution
A printing apparatus with a transport mechanism, a first print head that prints a lead line, a second print head downstream for alignment, a printing position sensor, and a moving mechanism to adjust the sensor's position based on the printing medium's width, ensuring accurate alignment and high-quality printing across different widths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the edge sensor position is adjusted according to printing paper width, then the edge detection accuracy is improved, but the positional alignment between upstream and downstream print heads deteriorates
Solution Approach 1:
The patent makes the printing position sensor movable in the width direction through a moving mechanism, allowing it to dynamically adjust its position according to the printing paper width. This dynamic adjustment capability enables the sensor to maintain accurate detection of the lead line position while preserving the positional relationship between upstream and downstream print heads, thereby resolving the contradiction between measurement precision and manufacturing precision.
Solution Approach 2:
The patent separates the functions of edge detection and printing position detection into different sensors: the edge sensor detects the edge position of the printing paper, while the printing position sensor detects the lead line position printed by the upstream print head. This functional segmentation allows each sensor to be optimized independently, with the printing position sensor being movable to maintain alignment accuracy regardless of paper width changes.
2Productivity
If multiple print heads are arranged at intervals, then printing coverage and efficiency are improved, but maintaining consistent printing quality across different print heads becomes more difficult
Solution Approach 1:
The patent implements a feedback mechanism where the printing position sensor detects the actual position of the lead line printed by the upstream print head, and this detection information is used to adjust the printing position of the downstream print head. This closed-loop feedback system ensures that printing position consistency is maintained across multiple print heads arranged at intervals, thereby preserving printing quality while maintaining high productivity.
Solution Approach 2:
The lead line printed by the upstream print head serves as an intermediary reference mark that mediates the positional relationship between upstream and downstream print heads. The printing position sensor detects this intermediary lead line to determine the correct printing position for the downstream print head, ensuring consistent printing quality across multiple print heads without requiring complex direct coordination mechanisms.
3Adaptability or versatility
If the printing apparatus is designed to handle various paper widths, then versatility is improved, but the complexity of maintaining accurate sensor positioning increases
Solution Approach 1:
The patent employs a movable printing position sensor with a moving mechanism that can dynamically reposition itself in the width direction according to the printing paper width. This dynamic design provides versatility for handling various paper widths while maintaining relatively simple system architecture, as the sensor automatically adapts its position based on the detected lead line position rather than requiring complex pre-positioning mechanisms for each paper width.
Solution Approach 2:
The printing position sensor system is self-adjusting: when the printing paper width changes, the sensor automatically moves to detect the lead line printed by the upstream print head, and the system automatically adjusts the downstream print head position based on the detected lead line position. This self-service capability provides versatility for various paper widths without requiring complex external positioning controls or manual adjustments.
Data Source
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AI summary
A printing apparatus for printing on a printing medium. The apparatus includes the following elements: a transport mechanism for transporting the printing medium in a transport direction; a first print head for printing an image on the printing medium, and printing a lead line used as a reference for determining a printing position in a width direction; a second print head for performing printing based on a position of the lead line; a printing position sensor for detecting the position of the lead line in the width direction; and a moving mechanism for moving the printing position sensor in the width direction of the printing medium according to a width dimension of the printing medium.