Printing Device Illumination Control for Transparent Media
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Solution Overview
Problem
Existing printing systems face challenges in obtaining high-quality read images, especially when using transparent base materials, as reflective reading systems produce blackish backgrounds due to low light amounts, and transmissive systems may detect unwanted changes during density unevenness inspections, leading to inadequate corrections.
Innovation Solution
A printing apparatus with a control system that selectively uses transmissive or reflective illumination based on inspection type, allowing for optimal illumination settings for each inspection, including controlling emission intensities and using reference correction data for calibration, to stabilize read image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a reflective reading system is used to read transparent base materials, then the reading device can be positioned on the transport path, but the background of the base material becomes visible through the transparent material causing blackish background and unstable read images
Solution Approach 1:
The illumination system is segmented into two independent parts: a reflected light source for opaque materials and a transmitted light source for transparent materials. This segmentation allows each light source to be optimized for its specific material type, resolving the contradiction by enabling the reading device to be positioned on the transport path while preventing blackish backgrounds through appropriate light source selection.
Solution Approach 2:
The system dynamically switches between reflected light source and transmitted light source based on the material type being read. This dynamic adaptation allows the system to maintain high read image quality across different material types (opaque and transparent) while keeping the reading device in a fixed position on the transport path.
2Measurement precision
If a transmissive reading system is used to read transparent base materials, then stable read images can be obtained, but the system becomes more complex requiring light sources on both sides of the base material
Solution Approach 1:
The reading device is designed with multi-functionality to handle both opaque and transparent materials using a single device. By incorporating both reflected light source and transmitted light source, the system achieves universality, eliminating the need for separate reading devices for different material types while maintaining high read image quality.
Solution Approach 2:
The system changes the illumination parameters (light source position and type) based on the material being read. For transparent materials, the transmitted light source is activated with specific intensity parameters, while for opaque materials, the reflected light source is used. This parameter adaptation resolves the complexity issue by allowing a single device to optimize performance across different material types.
3Measurement precision
If transmissive illumination is used for density unevenness inspection, then accurate detection is possible, but unwanted changes in the read image may be detected leading to inadequate corrections
Solution Approach 1:
The system dynamically selects the illumination mode (reflected or transmitted) based on the inspection type. For density unevenness inspection of transparent materials, the transmitted light source is used to achieve accurate defect detection. For other inspection types, the reflected light source is used to avoid detecting unwanted changes. This dynamic selection resolves the contradiction between detection accuracy and correction accuracy.
Solution Approach 2:
The system uses feedback from the inspection type to determine the appropriate illumination mode. The control unit receives information about the inspection being performed and adjusts the light source configuration accordingly, ensuring that the correct illumination method is applied to avoid false detections that would lead to inadequate printing corrections.
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 system achieves stable acquisition of high-quality read images by tailoring illumination settings to inspection types, ensuring accurate detection and correction of printing defects, such as nozzle abnormalities and density unevenness.
Implementation Method 1
a transmitted light source that radiates light from a back surface side of the printed matter
Implementation Method 2
a reflected light source that radiates light from a front surface side of the printed matter
Data Source
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AI summary
Provided are a printing apparatus, a reading method, and a program capable of stably acquiring a high-quality read image. Provided are a printing section (102) that performs printing on a transparent base material to generate a printed matter; a reading section (40) that is disposed on one surface side of the base material and reads reflected light or transmitted light; an illumination section (122) including a reflective illumination part (122) that is disposed on the one surface side of the base material and irradiates the base material with illumination light and a transmissive illumination part (124) that is disposed on the other surface side of the base material and irradiates the base material with illumination light; an inspection information acquisition section (120) that acquires inspection information on an inspection performed on the printed matter; and an illumination control section (120) that selectively controls at least one of the reflective illumination part or the transmissive illumination part on the basis of the inspection information.