Developing Device Asymmetric Conveying Screw Toner Agitation
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Solution Overview
Problem
Existing developing devices fail to efficiently agitate toner uniformly, leading to development errors due to uniform toner flow rate and excessive charging, which results in improper toner attachment on the photosensitive drum and reduced fluidity.
Innovation Solution
A developing device with conveying screws featuring blades of varying diameters along the rotary shaft, creating differential toner pressing forces and flow rates, ensuring efficient agitation and preventing toner deterioration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If uniform diameter blades are used in conveying screws, then the device structure is simple, but the toner cannot be sufficiently agitated and flow rate is constant
Solution Approach 1:
The patent applies asymmetry by making the blade diameter vary along the axial direction of the rotary shaft. Specifically, the blade has a first diameter at one end and a second diameter at the other end, with the diameters being different. This asymmetric blade design creates variable pressing forces on the toner throughout rotation, generating different flow rates that improve agitation efficiency while maintaining reasonable structural complexity.
Solution Approach 2:
The patent applies local quality by creating different blade sections with different diameters along the axial direction. The blade is divided into a first blade section and a second blade section, where each section has different dimensional characteristics. This allows different parts of the blade to perform different functions - creating varied toner pressing forces and flow rates in different regions, thereby improving overall agitation effectiveness.
2Productivity
If toner is pressed more by conveying screws to improve agitation, then agitation efficiency improves, but externally added agents are buried or come off causing toner conveyance error and reduced fluidity
Solution Approach 1:
The patent applies periodic action through the variable diameter blade design that creates alternating pressing and releasing cycles. As the blade rotates, different sections with different diameters sequentially press the toner, creating a periodic pressing-releasing pattern. This periodic action provides sufficient agitation over time without continuously applying excessive force that would bury or remove externally added agents, thus maintaining toner fluidity and preventing conveyance errors.
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 device effectively agitates toner with varying flow rates along the axial direction, preventing excessive charging and toner deterioration, thereby improving toner attachment accuracy and fluidity.
Implementation Method 1
a conveying screw arranged in the housing (102), and including a rotary shaft (107) and a blade (106) provided on the rotary shaft (107) for conveying the toner from one end of the rotary shaft toward the other end thereof by the rotation of the rotary shaft
Implementation Method 2
A toner pressing force of the blade (106) differ depending on the angle of rotation of the rotary shaft (107)
Implementation Method 3
a developing roller (103) provided in the housing (102) in a state where a part of the developing roller (103) is exposed from the housing (102), and rotatable to obtain the toner conveyed by the conveying screw (104, 105)
Implementation Method 4
The toner conveyed to the outside by the developing roller (103) is supplied to the photosensitive drum (101) while having specified electric charges given thereto by this charger (110) and having an amount thereof restricted to a specified amount
Implementation Method 5
A charged state at a position where the latent image was formed in this way is such that the charged toner supplied from the developing roller (103) is attached thereto
Data Source
AI summary
A developing device (100) according to the present invention is provided with a housing (102) for holding toner, conveying screws (104, 105) arranged in the housing (2) and each including a rotary shaft (107) and a blade (106) arranged on the rotary shaft (107) for conveying the toner from one end of the rotary shaft (107) toward the other end thereof by the rotation of the rotary shaft (107), and a developing roller (103) provided in the housing with a part of the developing roller (103) being exposed from the housing, and rotatable to obtain the toner conveyed by the conveying screws (104, 105). The conveying screws (104, 105) are constructed, for the efficient agitation of the toner, such that toner pressing forces of the blades (106) differ depending the angle of rotation of the rotary shaft (107).