Color Tone Density Control in Image Forming Apparatus
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Solution Overview
Problem
Current multi-path type color laser image forming apparatuses require excessive time to measure color-tone density (CTD) due to unnecessary operations when developing test patches in the order of Y, M, C, and K developers, which increases the time needed for CTD measurement.
Innovation Solution
Developing test patches sequentially from a developer that is preferentially developable, such as starting with the black (K) developer, and measuring CTDs using a CTD sensor to control development variables, allowing all developers to develop test patches during one OPC cycle, thereby minimizing the distance between test patches and reducing measurement time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If test patches are developed in the order of Y, M, C, and K developers as in related art, then the development operation follows the color printing job sequence, but the measurement time for CTD becomes excessively long due to unnecessary operations
Solution Approach 1:
The patent inverts the conventional test patch development sequence from Y-M-C-K to K-Y-M-C, starting with the black developer. This reversal eliminates unnecessary waiting time and operations, allowing the test patch development to be completed more efficiently within one OPC rotation cycle, thereby reducing CTD measurement time while maintaining operational simplicity
Solution Approach 2:
The patent performs preliminary positioning of the OPC at the home position where the black developer is located before starting test patch development. This preliminary action ensures that the development process begins immediately with the black developer without requiring the OPC to rotate through other positions first, eliminating unnecessary operations and reducing overall measurement time
2Productivity
If the OPC rotates to position each developer sequentially during test patch development, then all developers can develop test patches, but the rotation distance and time increase the measurement duration
Solution Approach 1:
The patent merges all four test patch developments (K, Y, M, C) into a single continuous OPC rotation cycle. By starting at the home position with the black developer and rotating through all developers in sequence without returning to home or performing intermediate positioning operations, the system completes all developments in one unified operation, maximizing productivity while minimizing time
Solution Approach 2:
The patent maintains continuous useful action by keeping the OPC rotating in one direction through all developers without stopping, reversing direction, or performing idle positioning movements. The development process continues uninterrupted from the black developer through yellow, magenta, and cyan developers, ensuring that every moment of OPC rotation performs useful development work rather than wasted motion
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 significantly reduces the time required to measure CTD by optimizing the sequence of test patch development and measurement, enhancing the efficiency of the image forming process.
Implementation Method 1
measuring CTDs of the developed test patches
Implementation Method 2
coats a toner to an organic photo conductor (OPC) using laser light ray modulated into a picture signal
Implementation Method 3
coats a toner to an organic photo conductor (OPC) using laser light ray modulated into a picture signal
Implementation Method 4
fixes the toner on the printing paper with high heat and pressure
Data Source
AI summary
A method of controlling a color-tone density (CTD) of an image forming apparatus including a plurality of developers configured to circularly perform a developing operation. The method includes developing test patches on an OPC sequentially from a developer to be developable preferentially, measuring CTDs of the developed test patches, and controlling a development variable using the measure CTDs.