Image Forming Apparatus Transfer Voltage for Blade Blocking-Layer Formation
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Solution Overview
Problem
During the initial operation of a brand-new process cartridge in an image forming apparatus, the formation of a blocking layer on the cleaning blade is hindered by electrical discharge and adhesion issues, leading to cleaning defects and vertical streaks in the output image.
Innovation Solution
Applying a constant voltage of the same polarity as the toner's normal charge to the transfer roller during specific periods of the initial operation, such as the warming up rotating and blocking layer forming periods, to prevent electrical discharge and ensure proper formation of the blocking layer on the cleaning blade.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a voltage is applied to the transfer member during the initial operation, then electrical discharge occurs between the image bearing member and the transfer member, but this electrical discharge hinders the formation of a blocking layer on the cleaning blade
Solution Approach 1:
The patent applies a preliminary action by controlling the voltage applied to the transfer member during specific periods before and during the toner supply operation. A first voltage is applied during a second period immediately before the toner supply, and a second voltage (different from the first voltage) is applied during a first period when toner is supplied. This preliminary voltage control prevents electrical discharge that would otherwise hinder blocking layer formation on the cleaning blade, thereby preventing cleaning defects and vertical streaks in the output image.
2Productivity
If the cleaning blade is used to clean remaining toner from the image bearing member, then toner is removed, but cleaning defects and vertical streaks occur due to improper blocking layer formation
Solution Approach 1:
The patent changes the voltage parameter applied to the transfer member during different periods of the initial operation. By applying a first voltage during the second period and a second voltage during the first period, the electrical conditions are optimized to enable proper blocking layer formation on the cleaning blade. This ensures that the cleaning blade can effectively remove remaining toner without causing cleaning defects or vertical streaks in the output image, thus maintaining both cleaning productivity and image quality.
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
Prevents cleaning defects and vertical streaks in the output image by maintaining frictional force and pressure at the cleaning blade, ensuring smooth toner transfer and stable image quality.
Implementation Method 1
electrical discharge between the image bearing member and the transfer member
Implementation Method 2
maintaining frictional force and pressure at the cleaning blade
Data Source
AI summary
An image forming apparatus incudes an image bearing member, a developing member, a transferring member, an applying portion, a cleaning blade, and a controller. The controller executes an initial operation in which the image bearing member in a brand-new state is shifted to a printable state and an image forming operation. The controller controls the applying portion so as to apply a constant voltage to the transfer member in the initial operation different from that in the image forming operation, during a second period immediately before a first period for supplying the toner from the developing member to the image bearing member in the developing region, and controls so that the constant voltage in the second period has a normal charge polarity of the toner and becomes a voltage value which does not generate electrical discharge between the image bearing member and the transfer member.