Color Image Forming Apparatus Single-Rotation Density Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing color image forming apparatuses using electrophotography face challenges in precise image density control due to variations in environmental conditions and consumable usage, leading to increased processing time and reduced precision when trying to eliminate toner patches within one rotation of the image bearing member.
Innovation Solution
A color image forming apparatus with an optical detecting unit, position detecting unit, and light-quantity adjusting unit that forms and detects images within one rotation of the image bearing member, allowing for quick and precise image density control by determining the light-emission quantity based on detection results from positional displacement and light-quantity adjustment images.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the light-emission quantity is increased to improve detection precision, then the toner adhesion amount can be detected more accurately, but the reflected light quantity becomes too large causing the photodetector output to be fixed at the upper limit
Solution Approach 1:
The patent applies preliminary action by forming a light-quantity adjustment image and determining the appropriate light-emission quantity before performing the actual density detection. This preliminary calibration ensures that the light emission is optimized for accurate detection without causing photodetector saturation, thus resolving the contradiction between detection precision and reliability.
2Measurement precision
If the image bearing member is rotated multiple times to eliminate solid patches before detection, then the toner amount calculation precision is improved, but the processing time is significantly increased
Solution Approach 1:
The patent performs preliminary action by forming the light-quantity adjustment image and determining optimal light emission parameters before the actual density measurement. This allows the system to achieve accurate toner amount calculation without requiring multiple rotations for patch elimination, thus reducing processing time while maintaining precision.
Solution Approach 2:
The patent changes the parameter of light-emission quantity based on detection results from the light-quantity adjustment image. By dynamically adjusting this parameter, the system achieves precise density control in a single rotation, eliminating the need for repeated rotations and patch elimination procedures.
3Stability of the object's composition
If the light-emission quantity is decreased to avoid photodetector saturation, then the system operates more stably, but the reflected light quantity becomes too small causing large errors in toner adhesion amount calculation
Solution Approach 1:
The patent uses preliminary action by forming a light-quantity adjustment image and determining the optimal light-emission quantity before actual density detection. This preliminary step ensures the light emission is calibrated to an appropriate level that maintains system stability while providing sufficient reflected light for accurate toner adhesion amount calculation.
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 enables efficient and precise image density control while reducing processing time by eliminating the need for additional cleaning operations and maintaining precision, as light-quantity adjustment patches are formed and detected within a single rotation of the image bearing member.
Implementation Method 1
a patch or an image bearing member is irradiated with light by a light-emitting element, and light reflected from the patch or the image bearing member is received by a photodetector
Data Source
AI summary
A color image forming apparatus in which a positional displacement detection image and a light quantity adjustment image are formed within a one-rotation length of an image bearing member (intermediate transfer belt). A light-emission quantity when detecting density is determined on the basis of a detection result of a light quantity adjustment image formed within the one-rotation length using light-emission quantity that is provided when light is emitted to the positional displacement detection image. This allows, for example, image density control to be performed quickly while precision of the image density control is maintained.