Image Reading Smear Correction via Reference Data
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional image reading apparatuses face challenges in correcting image degradation caused by smear, which occurs due to unwanted light entering the charge transfer portion, leading to increased reading time and varying correction effectiveness, especially when the smear occurrence position is unknown and the light exposure is not constant.
Innovation Solution
An image reading apparatus and method that utilize a first memory to store reference smear amount data for each color component, allowing an image processing unit to calculate and apply a correction amount based on the difference between brightness values of color components, effectively correcting brightness values and reducing smear influence without increasing costs or degrading performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an additional charge transfer operation is executed to correct smear, then smear correction is achieved, but image reading time increases
Solution Approach 1:
The patent stores reference smear amount data in advance during a measurement period before actual image reading. This preliminary action allows the correction process to use pre-prepared data, eliminating the need for additional charge transfer operations during reading and maintaining high reading speed while achieving effective smear correction.
2Object-affected harmful factors
If aluminum light shielding is enhanced to prevent smear, then light shielding ability improves, but manufacturing precision requirements increase and cost rises
Solution Approach 1:
The patent replaces the mechanical/light-physical approach of enhancing aluminum light shielding with an electronic/digital approach. By using software-based smear correction algorithms and reference data storage, the system achieves smear prevention without requiring higher manufacturing precision of physical light shielding components.
3Ease of manufacture
If the wafer area of the circuit board is decreased for cost reduction, then apparatus cost decreases, but light shielding ability degrades
Solution Approach 1:
The patent substitutes physical light shielding structures with digital correction methods. By storing reference smear data and applying correction algorithms, the system maintains effective smear prevention without requiring large wafer areas for extensive light shielding plates, thus reducing apparatus cost while preserving light shielding ability.
4Productivity
If charge transfer and exposure are performed simultaneously to maintain reading speed, then reading efficiency is maintained, but smear occurrence increases
Solution Approach 1:
The patent converts the harmful effect of simultaneous charge transfer and exposure (which causes smear) into a beneficial correction opportunity. By measuring and storing reference smear amounts during normal simultaneous operation, the system characterizes the smear pattern and uses it to correct images, thereby maintaining reading speed while eliminating smear effects.
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 solution enables effective smear correction without increasing apparatus cost or degrading reading performance, allowing simultaneous charge storage and transfer, thereby maintaining high reading speed and accuracy.
Implementation Method 1
An apparatus of this type sequentially switches and uses three LEDs for emitting light beams of R, G, and B color components to irradiate the original surface with light
Implementation Method 2
The LED irradiates an image original with light. When the light reflected by the image original enters the array of a photodiode 201, charges are stored to generate an image signal
Data Source
AI summary
Correction of brightness of image data outputted by an image sensor which includes a light emitting portion, a photoelectric conversion portion in which a plurality of photoelectric transducers are arrayed in line, and a charge transfer portion. For a smear occurred at the charge transfer portion, reference smear amount data is stored, corresponding to each of color components of light from the light emitting portion and a correction target pixel. A correction amount for brightness is based on a difference between brightness values of a first color component and a second color component and the reference smear amount data.