Image Forming Apparatus Shared Power Supply Toner Collection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In image forming apparatuses with shared high-voltage power supplies, there is a risk of incomplete toner collection from the intermediate transfer member due to mismatched voltage application timings for discharging and collecting toner, leading to residual toner remaining on the intermediate transfer member.
Innovation Solution
The apparatus employs a common power source to apply alternating voltages to both the primary transfer member and the toner charging member, ensuring that residual toner is charged with opposite polarity and transferred to the image bearing member, while also allowing for a toner charging member cleaning mode to prevent toner accumulation on the charging roller, thereby ensuring effective toner collection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a shared high-voltage power supply circuit is used for both discharging toner from the toner charging roller and collecting toner on the photosensitive member, then device complexity and cost are reduced, but toner collection reliability deteriorates due to mismatched voltage application timings
Solution Approach 1:
The patent applies dynamic voltage polarity switching to the shared power supply circuit, where the polarity is alternately switched between positive and negative states. This dynamic control allows the same power supply to provide appropriate voltage polarity at different timing - positive polarity for discharging toner from the toner charging roller and negative polarity for collecting toner on the photosensitive member, thereby resolving the timing mismatch problem while maintaining circuit sharing
Solution Approach 2:
The patent implements periodic voltage polarity switching synchronized with the rotation period of the toner charging roller. The voltage polarity is switched at specific intervals corresponding to the roller's rotation, ensuring that discharging and collecting operations receive appropriate voltage polarity at the correct moments in each cycle, thus maintaining reliable toner collection despite using a shared power supply
2Reliability
If voltage polarity is switched alternately to discharge toner from the toner charging roller, then cleaning performance is improved, but toner may not be collected exactly due to timing mismatch with the common power source
Solution Approach 1:
The patent employs feedback control where the voltage polarity switching is synchronized with the rotational position of the toner charging roller. By detecting the roller's rotation state and adjusting the voltage switching timing accordingly, the system ensures that voltage is applied at the optimal moment for both discharging and subsequent collection, eliminating timing mismatches
Solution Approach 2:
The patent applies voltage to the toner charging roller in advance during specific phases of the roller's rotation to discharge toner before it reaches the collection zone. This preliminary action ensures that toner is discharged at the correct position and timing, allowing the shared power supply to effectively both discharge and collect toner without synchronization issues
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 solution ensures satisfactory collection of discharged toner even when using a shared power source, maintaining cleaning performance and reducing the need for dedicated toner collection mechanisms, thus enhancing the efficiency and reliability of the image forming process.
Implementation Method 1
a toner charging member that is provided downstream of the secondary transfer part and upstream of the primary transfer part in a moving direction of the intermediate transfer member, and charges residual toner remaining on the intermediate transfer member
Implementation Method 2
the charged residual toner is transferred from the intermediate transfer member to the image bearing member by the primary transfer member
Data Source
AI summary
The image forming apparatus is capable of collecting discharged toner satisfactorily even when a power source for discharging toner from a voltage application member to a moving member and a power source for collecting the discharged toner from the moving member onto an image bearing member are provided in common.