Image Reading Apparatus Blue Light Calibration
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Solution Overview
Problem
Existing image forming apparatuses face challenges in accurately calibrating color reproduction due to variations in the brightness and spectrum of blue light emitted by white LEDs, leading to inconsistencies in RGB tones detected from original documents.
Innovation Solution
The apparatus employs a light source unit with a blue LED and a yellow fluorescent body to emit white light, using a B reference value for calibration to adjust the blue light spectrum, and calculates a B correction value to account for variations in the blue light amount, ensuring accurate color reproduction by calibrating the light amount of the blue spectrum based on a calibration document.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a white LED is used as a light source, then energy efficiency and lifespan are improved, but variation in blue light spectrum causes color reproduction errors
Solution Approach 1:
The system performs preliminary calibration by detecting the actual blue light spectrum characteristics before normal operation. A correction value is calculated in advance based on the detected blue light amount and stored for later use, preventing color reproduction errors before they occur during actual image reading
Solution Approach 2:
The system changes the parameter of blue light correction by detecting variations in blue light spectrum and calculating a corresponding correction value. This dynamic parameter adjustment compensates for LED spectrum variation, allowing accurate color reproduction while maintaining LED energy efficiency
2Measurement precision
If separate calibration processes are performed for each light source spectrum, then calibration accuracy is improved, but calibration time and complexity increase
Solution Approach 1:
The system merges the calibration process for blue light spectrum into the existing calibration workflow. Instead of performing separate calibration for each light source, the blue light correction is integrated into the overall calibration process, reducing total calibration time while maintaining accuracy
Solution Approach 2:
The calibration document serves multiple functions: it calibrates both the standard light spectrum and provides reference for blue light spectrum correction. This multi-functional approach eliminates the need for separate calibration processes, reducing time and complexity
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
This solution effectively reduces reading errors in color reproduction by accurately accounting for variations in the blue light spectrum, ensuring consistent RGB tones without requiring new hardware, thereby improving the accuracy of color calibration.
Implementation Method 1
a blue LED 52a and a yellow fluorescent body 52b
Implementation Method 2
a blue LED 52a and a yellow fluorescent body 52b
Implementation Method 3
an image sensor 53 that generates, in accordance with the reflected light, image data ID
Data Source
AI summary
An image reading apparatus includes a light source unit and an image reading unit. The light source unit radiates white light containing a light having a first spectrum and a light having a second spectrum. The image reading unit generates image data in accordance with light reflected from the original document. The reflected light contains the light having the first spectrum and the light having the second spectrum. The image reading unit determines a correction value for calibrating a light amount of the light having the first spectrum as a ratio of a calibration reference value to a reflection light amount of the light having the first spectrum from a calibration document advance-prepared for calibration of the light having the second spectrum. The calibration reference value is set as a reference reflection light amount of the light having the first spectrum.