Defect Inspection Device Using Nozzle Mapping for Printed Matter
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Solution Overview
Problem
Conventional defect inspection methods for printed matters struggle with accurately and efficiently inspecting defects when the pattern changes per sheet or when printing conditions are altered, leading to misregistration and decreased inspection performance.
Innovation Solution
A defect inspection device and method that utilize a single-pass type printing device with an inkjet head and a moving mechanism, which performs registration between reference data and imaging data using nozzle mapping information and print timing information, allowing for high-accuracy and high-speed defect inspection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional matching method is used for registration between reference data and imaging data, then registration accuracy can be achieved, but processing time increases significantly for large-sized images
Solution Approach 1:
The patent segments the registration process into two distinct stages: a rough registration phase using print timing information to align the overall image, and a fine registration phase using nozzle mapping information to correct local misalignments. This segmentation allows the system to achieve high registration accuracy without processing the entire registration task at full detail level, thus reducing overall processing time while maintaining precision where needed.
Solution Approach 2:
The patent performs preliminary rough registration using print timing information before conducting the final fine registration using nozzle mapping information. This preliminary action establishes a baseline alignment that reduces the computational burden of the subsequent detailed registration process, enabling faster processing while achieving high final accuracy.
2Productivity
If reference data is acquired from printed matter using glossy paper, then inspection can be performed, but large brightness differences occur when inspecting printed matter on wood-free paper, reducing inspection performance
Solution Approach 1:
The patent creates a virtual reference data model based on print timing information and nozzle mapping information rather than physically acquiring reference data from actual printed matter. This copying approach generates ideal reference data that accounts for the specific printing device characteristics, eliminating brightness differences caused by varying paper types while maintaining accurate inspection capability.
Solution Approach 2:
The patent changes the approach from acquiring reference data with fixed physical parameters (paper type, printing conditions) to generating reference data through parameter-based calculation using print timing and nozzle mapping. This allows the reference data to be adapted to different paper types and conditions without being constrained by the physical characteristics of the reference sample, thereby maintaining inspection performance across various media.
3Adaptability or versatility
If variable printing or changed printing conditions are used, then printing versatility is improved, but conventional defect inspection methods cannot perform inspection due to pattern changes
Solution Approach 1:
The patent implements a dynamic reference data generation system that adapts to variable printing conditions and pattern changes. Instead of using fixed reference data from a single printing condition, the system dynamically generates appropriate reference data based on the specific print timing information and nozzle mapping information for each printing job, enabling defect inspection to function effectively across diverse printing scenarios including variable data printing and different paper types.
Data Source
AI summary
Provided are a defect inspection device, a defect inspection method, and a program, and a printing device and a method of manufacturing a printed matter, in which a defect of a printed matter is inspected by performing registration between reference data and imaging data of the printed matter printed on the basis of the reference data with high accuracy at high speed. The reference data and the imaging data of the printed matter printed on the basis of the reference data by a single-pass type printing device that includes an inkjet head having a plurality of nozzles disposed in a nozzle direction are acquired, registration between the imaging data and the reference data in the nozzle direction is performed by using nozzle mapping information indicating a correspondence relationship between positions of the plurality of nozzles and pixel positions of the imaging data in the nozzle direction, and a defect of the printed matter is inspected in response to an input of the imaging data and the reference data that have been subjected to registration.