Developing Device Magnetic Flux Density Distribution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional developing devices with a two-component developer experience fluctuations in developer coating amount due to deviations in the positional relationship between the magnetic flux density distribution of the magnet roller and the regulating member, particularly influenced by both normal and tangential magnetic flux densities.
Innovation Solution
A developing device design where the magnetic flux density of the regulating pole has two maximum values in the normal direction, with specific angular and positional arrangements to minimize fluctuations, including a rotatable developing member, a magnet with a regulating pole, and a regulating portion that opposes the outer peripheral surface between the maximum positions, ensuring stability in developer coating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the magnetic flux density distribution of the magnet roller is designed with two maximum values in the normal direction, then the developer coating amount can be stabilized against positional deviations, but the complexity of the magnet roller design increases
Solution Approach 1:
The magnet roller is designed with specific magnetic flux density parameters: two maximum values (Pe1 and Pe2) in the normal direction with an angle of 20° to 50° between them, and a minimum value between the maxima. The regulating member is positioned at an angle of 10° to 30° from the first maximum position. These parameter specifications create a magnetic field distribution that stabilizes developer coating amount against positional deviations while maintaining manageable design complexity through quantitative guidelines.
2Manufacturing precision
If the regulating member is positioned opposite to the first maximum position of magnetic flux density, then the developer coating can be controlled, but the system becomes sensitive to positional deviations
Solution Approach 1:
The system uses asymmetric positioning where the regulating member is placed at an angle of 10° to 30° from the first maximum position (Pe1) rather than directly opposite to it. This asymmetric arrangement, combined with the specific angular relationship (20° to 50°) between the two maximum positions, creates a magnetic field configuration that provides both control capability and robustness against positional deviations, resolving the contradiction between precision control and sensitivity.
3Adaptability or versatility
If the angle between the two maximum positions is made large, then the latitude in pole position increases, but the magnetic flux density distribution becomes less effective at regulating developer amount
Solution Approach 1:
The patent specifies that the angle between the two maximum positions (Pe1 and Pe2) should be 20° to 50°, and the regulating member should be positioned at 10° to 30° from the first maximum position. These parameter ranges optimize the balance between providing sufficient latitude in pole position arrangement and maintaining effective developer amount regulation. The magnetic flux density distribution within these angular parameters ensures both adaptability and precision 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
The solution effectively stabilizes the developer coating amount by moderating the magnetic flux density distribution, reducing fluctuations even when the positional relationship between the magnet roller and the regulating member is deviated, thus enhancing the latitude in pole position and maintaining consistent image formation.
Implementation Method 1
a magnet provided non-rotatably and stationarily inside the rotatable developing member and provided with a regulating pole... a minimum position where a magnetic flux density of the regulating pole in a normal direction relative to an outer peripheral surface of the rotatable developing member is a minimum value is downstream of a first maximum position where the magnetic flux density of the regulating pole in a normal direction relative to the outer peripheral surface of the rotatable developing member is a first maximum value
Implementation Method 2
a regulating portion configured to regulate an amount of the developer carried on the rotatable developing member by a magnetic force of the regulating pole
Data Source
AI summary
With respect to a rotational direction of a rotatable developing member of a developing device, an opposing position where a regulating portion of the developing device is opposed to an outer peripheral surface of the rotatable developing member is between a first maximum position and a position where a magnetic flux density of a regulating pole in a tangential direction relative to the outer peripheral surface of the rotatable developing member is zero. With respect to the rotational direction of the rotatable developing member, the position where the magnetic flux density of the regulating pole in the tangential direction relative to the outer peripheral surface of the rotatable developing member is zero is within a range of ±2° of a midpoint between the first maximum position and a second maximum position or is downstream of the range.