Optical Toner Adhesion Detection for Image Density Stabilization
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Solution Overview
Problem
Existing image forming apparatuses face issues with changes in image density due to variations in toner density and charging amounts, leading to inconsistent image quality.
Innovation Solution
The apparatus includes an exposure device for forming an electrostatic latent image with an increased exposure amount and a developing device to visualize the latent image as a black toner image with an increased developing bias, utilizing a rotatable image bearer and an optical sensor to detect reflection light and adjust toner adhesion, thereby stabilizing image density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional image forming apparatuses are used, then image formation is achieved, but image density changes due to variations in toner density and charging amounts
Solution Approach 1:
The patent implements a feedback mechanism where an optical sensor detects the actual toner adhesion amount on the image bearer, and this detection information is fed back to the controller. The controller then adjusts the developing bias voltage based on the detected toner adhesion amount, creating a closed-loop control system that maintains consistent image density despite variations in toner density and charging conditions.
Solution Approach 2:
The patent dynamically changes the developing bias voltage parameter based on real-time detection of toner adhesion amount. By adjusting this critical parameter according to actual toner deposition conditions, the system compensates for variations in toner density and charging amounts, thereby maintaining stable image density and quality consistency.
2Manufacturing precision
If an optical sensor is added to detect toner adhesion amount, then image density can be stabilized, but device complexity increases
Solution Approach 1:
The patent replaces complex mechanical or electrical measurement systems with an optical detection system. The optical sensor uses light reflection principles to non-contactly measure toner adhesion amount, eliminating the need for complex mechanical measurement mechanisms while achieving accurate and reliable toner deposition detection.
Solution Approach 2:
The patent introduces an optical sensor as an intermediary measurement device between the developing process and the control system. This intermediary component enables indirect but accurate measurement of toner adhesion amount through optical properties, simplifying the overall measurement system while providing the necessary feedback for precise control.
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 stabilizes image density by accurately detecting toner adhesion and adjusting the image forming conditions, resulting in high-quality toner images despite variations in toner density and charging amounts.
Implementation Method 1
a first optical sensor disposed opposite the image bearer to detect an amount of reflection light reflected by the black toner pattern on the image bearer
Implementation Method 2
The first optical sensor includes a light-emitting element to emit light toward the black toner pattern on the image bearer
Data Source
AI summary
An image forming apparatus includes an image bearer to bear a black toner pattern formed with a black toner image under an increased exposure amount and an increased developing bias. A first optical sensor detects an amount of reflection light reflected by the black toner pattern on the image bearer. The first optical sensor includes a light-emitting element to emit light toward the black toner pattern on the image bearer and a light-receiving element to receive the reflection light reflected by the black toner pattern on the image bearer. A toner adhesion amount converter converts the amount of the reflection light detected by the first optical sensor into a toner adhesion amount of toner adhered to the image bearer and adjusts an image density according to the toner adhesion amount.