Image Forming Apparatus Mark Position Detection
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Solution Overview
Problem
Existing image forming apparatuses face inaccuracies in determining mark positions due to variations in reflectance and light reception signals caused by scratches, waste, and other factors, as they evaluate reflection conditions based on a single time point without considering reflectance variations, leading to inconsistent sensor sensitivity adjustments.
Innovation Solution
An image forming apparatus that includes a carrier, a forming device, a sensor with adjustable light emission and reception sensitivity, an evaluator that assesses the consistency of light reception signals over multiple measurements, and a controller that adjusts sensor sensitivity based on the evaluation to maintain accurate mark position determination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the apparatus evaluates the reflection condition of the belt surface based on a single time point light reception signal, then the sensor sensitivity can be adjusted, but the accuracy in determining the mark position varies depending on the light reception signal level due to reflectance variations
Solution Approach 1:
The apparatus performs preliminary multiple measurements of the light reception signal at different time points before determining mark position. By obtaining the average level from multiple measurements in advance, the system establishes a stable baseline that compensates for reflectance variations, ensuring consistent and accurate mark position determination.
Solution Approach 2:
The apparatus uses the average light reception signal level from multiple measurements as feedback to adjust the mark position determination. The evaluator compares the average level with the target level, and the controller makes corrections based on this feedback, creating a closed-loop system that maintains high measurement precision despite variations in belt surface reflectance.
2Adaptability or versatility
If the apparatus adjusts the sensor sensitivity based on single time point evaluation, then the sensitivity can be optimized for that moment, but the determination accuracy becomes inconsistent when light reception signal levels vary
Solution Approach 1:
The system performs preliminary multiple measurements and calculates the average light reception signal level before adjusting sensor sensitivity. This preliminary averaging action ensures that the sensitivity adjustment is based on a stable, representative value rather than a potentially anomalous single measurement, leading to more reliable and consistent mark position determination.
Solution Approach 2:
The evaluator provides feedback by comparing the average light reception signal level with the target level, and the controller uses this feedback to adjust sensor sensitivity. This feedback mechanism ensures that sensitivity adjustments are made based on comprehensive data from multiple measurements, maintaining measurement precision across varying light reception conditions.
3Measurement precision
If the apparatus uses multiple measurements to evaluate light reception signal consistency, then the accuracy in determining mark position improves, but the measurement time increases
Solution Approach 1:
The apparatus performs a limited number of multiple measurements (not exhaustive sampling) to obtain sufficient statistical information about the light reception signal. By using a practical, manageable number of measurements rather than complete sampling, the system achieves improved measurement precision while controlling measurement time to acceptable levels.
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 apparatus achieves improved accuracy in determining mark positions by reducing variations in light reception signals and maintaining consistent sensor sensitivity, thereby enhancing the reliability of color-deviation correction processes.
Implementation Method 1
the light receiving device being configured to receive light reflected from at least one of the carrier and the mark and output a light reception signal corresponding to a quantity of the received light
Data Source
AI summary
An image forming apparatus includes a carrier, a forming device forming a mark on the carrier, a sensor, a determiner, a changer, an evaluator and a controller. The sensor includes a light emitting device that emits light toward the carrier and the light receiving device that receives light reflected from the carrier or the mark and outputs a light reception signal corresponding to the received light quantity. The determiner determines a position of the mark based on the light reception signal. The changer changes sensor sensitivity by changing a quantity of light from the light emitting device or sensitivity of the light receiving device. The evaluator obtains the light reception signals multiple times and evaluates a degree of closeness between an average level of the light reception signals and a target level. The controller controls the changer to change the sensor sensitivity of the sensor according to an evaluation result.