MEMS Fabry-Perot Array Sensor for Real-Time Color Stabilization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Marking engines face color inconsistency and instability due to environmental and mechanical factors, with existing feedback control systems failing to provide sufficient stability, especially in multi-separation IOI images, and on-paper spectrophotometer measurements being unable to correct colors frequently enough.
Innovation Solution
A Micro-Electro-Mechanical System (MEMS) based Fabry-Perot array sensor is used to non-invasively measure spectral information from toned patches on a photoreceptor unit or output substrate, allowing for dynamic reconfiguration to provide accurate spectral data at high frequencies, supporting real-time color stabilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If on-paper spectrophotometer measurements are used for color correction, then color accuracy can be measured, but the measurement frequency is insufficient to correct colors in real-time
Solution Approach 1:
The patent replaces the mechanical spectrophotometer measurement system with a photodiode array-based optical measurement system. This substitution enables non-contact, high-speed spectral measurement by using multiple photodiodes with different spectral sensitivities to simultaneously capture color information across the visible spectrum, eliminating the bottleneck of sequential mechanical scanning while maintaining measurement accuracy.
Solution Approach 2:
The patent transitions from single-point sequential measurement to multi-point parallel measurement by arranging photodiodes in an array configuration. This dimensional change from 1D sequential scanning to 2D/3D spatial parallel detection enables simultaneous measurement of multiple wavelengths and positions, dramatically increasing measurement frequency for real-time color correction.
2Reliability
If feedback control systems are implemented to correct color inconsistency, then color stability can be improved, but the systems fail to provide sufficient stability in multi-separation IOI images
Solution Approach 1:
The patent segments the color measurement function into multiple independent photodiode elements, each sensitive to different wavelength ranges. This segmentation allows independent measurement and correction of different color separations (cyan, magenta, yellow, black) in multi-separation IOI images, enabling precise control of each color layer while maintaining overall color stability.
Solution Approach 2:
The patent creates a universal measurement system that can handle both single-color and multi-separation IOI images using the same photodiode array infrastructure. The system universally applies spectral measurement principles across different image types and color configurations, providing adaptable color stabilization without requiring separate specialized systems.
3Productivity
If measurement frequency is increased to enable real-time color correction, then color stabilization improves, but environmental and mechanical factors cause ongoing instability
Solution Approach 1:
The patent implements a continuous feedback control loop where the photodiode array constantly monitors color patch reflectance values, compares them against target values, and generates correction signals that are applied back to the marking engine. This closed-loop feedback system dynamically compensates for environmental and mechanical variations, maintaining color consistency despite ongoing instability factors.
Solution Approach 2:
The patent establishes continuous measurement and correction action by constantly illuminating color patches with broadband light and continuously capturing spectral data with the photodiode array. This uninterrupted measurement stream ensures real-time detection and correction of color drift, maintaining consistent color output throughout operation despite varying environmental conditions.
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 Fabry-Perot array sensor enables frequent and accurate measurement of spectral information, enabling effective color stabilization and improved image quality by adjusting toner amounts in real-time, even at high processing rates, and supports multi-axis color control in marking engines.
Implementation Method 1
A Micro-Electro-Mechanical System (MEMS) based Fabry-Perot array sensor is used to non-invasively measure spectral information from toned patches on a photoreceptor unit or output substrate
Implementation Method 2
a photoreceptor unit, such as, for example, a belt or roller, whose electrostatic charge varies in response to being exposed to light, is placed between a toner supply and the substrate
Data Source
AI summary
A Micro-Electro-Mechanical System (MEMS) based Fabry-Perot array may be used as a spectral filter to light sensing array, such as a CCD or CMOS photodetector. Applying different voltages to the electrodes of individual Fabry-Perot cells within the array allows a gradient in the Fabry-Perot air gap across the Fabry-Perot array. In this manner the MEMS Fabry-Perot array serves as a spectral filter of light passing through the Fabry-Perot array to the photodetector array. Embodiments of the disclosed sensor, used with LEDs that emit light outside the photosensitivity range of a photoreceptor belt, may be used to measure spectral information from toned patches and/or images placed upon a photoreceptor belt within a marking system. Other embodiments of the disclosed senor, used with LEDs that emit light of any wavelength, may be used to measure spectral information from toned patches or images placed by a marking system upon a non-photosensitive output substrate, such as an intermediate belt or paper.