Platen Surface Scanning for Multi-Directional Print Defect Detection
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Solution Overview
Problem
Existing printing devices are unable to effectively detect defects other than nozzle ejection defects, such as unevenness, off-center placement, and wrinkles, in the printing process.
Innovation Solution
A printing device with a platen, print head, reader, and controller that performs multiple reading and printing processes in different directions to obtain scan data and detect defects, including a platen moving member to adjust the position of the platen and reader to maintain contact with the printing target surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single reading process is performed in one direction, then the reading speed is maintained, but the ability to detect various defects (unevenness, off-center placement, wrinkles) is insufficient
Solution Approach 1:
The reading process is segmented into multiple independent reading operations: a first reading process in a first direction and a second reading process in a second direction. Each reading process captures different aspects of the printing target surface, enabling comprehensive defect detection including unevenness, off-center placement, and wrinkles that would be missed by a single reading direction
Solution Approach 2:
The patent introduces a directional dimension to the reading process by performing readings in multiple directions (first direction and second direction). This multi-directional approach adds a dimensional aspect to defect detection, allowing the system to identify surface defects that are orientation-dependent or only visible from specific viewing angles
2Measurement precision
If multiple reading processes in different directions are performed, then various defects can be detected, but the reading time and process complexity increase
Solution Approach 1:
The first reading process and second reading process are performed in continuous sequence without interruption to the overall printing workflow. The platen moves the printing target through the reading positions in a continuous manner, ensuring that the useful action of reading is maintained throughout the process while minimizing idle time
Solution Approach 2:
The reading processes are performed at predetermined positions along the platen path, allowing the system to prepare and capture scan data proactively as the printing target passes through the reading zone. This preliminary capture of data in multiple directions occurs naturally during the platen's movement, avoiding additional time-consuming operations
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
The device can detect a range of defects beyond nozzle ejection issues, such as unevenness, off-center placement, and wrinkles, by using scan data from multiple reading processes, enhancing the quality of printed images.
Implementation Method 1
reading, by controlling the reader, a surface of a printing target on the platen to obtain first scan data
Data Source
AI summary
In a printing device, a reader is positioned upstream of a print head in a first moving direction. The controller includes one or more processors. The controller performs a first reading process including moving, by controlling a platen moving member, the platen in the first moving direction, and reading, by controlling the reader, a surface of a printing target on the platen to obtain first scan data. The controller performs a printing process after starting the first reading process. The printing process includes printing, by controlling the print head, an image on the surface of the printing target on the platen. The controller performs a second reading process including moving, by controlling the platen moving member, the platen in a second moving direction opposite the first moving direction, and reading, by controlling the reader, the image on the surface of the printing target to obtain second scan data.