Light Guide Preheating for Shading Correction in Image Scanners
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Solution Overview
Problem
Existing image reading technologies face challenges in accurately correcting shading errors due to temperature-induced thermal deformation of light guides and rod lens arrays, leading to inconsistencies between correction data acquisition and actual scanning, which affects image quality and productivity.
Innovation Solution
The image reading apparatus heats the light guide and rod lens array with irradiation light before outputting readout signals, ensuring that the deformation state matches the correction data acquisition state, thereby reducing shading correction errors and improving productivity by minimizing the need for frequent correction data retrieval.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If correction data is acquired at room temperature, then the correction process is simple and quick, but thermal deformation during scanning causes shading correction errors
Solution Approach 1:
The system performs preliminary heating of the light guide and rod lens array before acquiring correction data. This ensures that the optical components are already at their operating temperature when correction data is acquired, eliminating thermal deformation errors during actual scanning without requiring frequent re-acquisition of correction data
Solution Approach 2:
The system changes the temperature parameter of the light guide and rod lens array from room temperature to a stabilized operating temperature before acquiring correction data. This parameter change ensures that the deformation state during correction data acquisition matches the deformation state during scanning, resolving the accuracy issue
2Measurement precision
If correction data is frequently re-acquired to account for temperature changes, then shading correction accuracy is maintained, but productivity decreases due to repeated correction data retrieval
Solution Approach 1:
The system performs preliminary heating and stabilization of the optical components before the scanning process begins. This preliminary action ensures that subsequent scanning operations can proceed without frequent interruptions for correction data re-acquisition, maintaining both accuracy and productivity
3Measurement precision
If the light guide is heated before scanning, then the deformation state matches correction data acquisition, but additional heating time is required
Solution Approach 1:
The system merges the heating process with the initialization sequence by heating the light guide and rod lens array during the startup phase before correction data acquisition. This integration ensures that the heating time is part of the initial setup rather than an additional step, achieving both accuracy improvement and time efficiency
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 approach effectively reduces shading correction errors caused by temperature changes, enhancing image quality and increasing scanning productivity by maintaining consistent deformation states between correction data acquisition and scanning.
Implementation Method 1
heat the first light guide with the light emitted from the light emitter before the output device outputs the readout signal of each of the document and the base
Data Source
AI summary
An image reading apparatus includes a light emitter to irradiate a document with light, a first light guide to guide the light reflected by the document, an output device to output a readout signal obtained from the light reflected and guided by the first light guide, a base to correct shading in the readout signal, and circuitry to output a scanned image in which the shading of the document in the readout signal is corrected, based on correction data obtained from the readout signal of the base output from the output device, control a timing at which the light emitter emits the light and a timing at which the output device outputs a signal, and heat the first light guide with the light emitted from the light emitter before the output device outputs the readout signal of each of the document and the base.