Development Voltage and Primary Transfer Control for Drum Ghost Suppression
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Solution Overview
Problem
Image forming apparatuses with intermediate transfer systems suffer from drum ghost and agglomerated white spots due to inconsistencies in surface potential caused by primary transfer current and development frequency, making it difficult to suppress both issues simultaneously.
Innovation Solution
Implement a control unit that simultaneously adjusts the frequency of the alternating-current voltage of the development voltage and the primary transfer current to optimize image quality, using a first image quality improvement mode that includes specific settings based on absolute humidity and cumulative driving distance to balance the trade-off between drum ghost and agglomerated white spots.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the primary transfer current is increased to suppress drum ghost, then surface potential consistency is improved, but agglomerated white spots occur more frequently
Solution Approach 1:
The patent applies parameter changes by adjusting the frequency of the alternating-current voltage component of the development voltage. Specifically, when drum ghost is detected, the control unit changes the frequency to a value different from the normal printing frequency. This frequency modification alters the interaction between toner particles and the development field, suppressing drum ghost without causing agglomerated white spots, thus resolving the contradiction between surface potential consistency and harmful artifacts.
2Object-generated harmful factors
If the development frequency is adjusted to suppress agglomerated white spots, then toner distribution is improved, but drum ghost becomes more prominent
Solution Approach 1:
The patent uses parameter changes by modifying the frequency of the alternating-current voltage in the development voltage. By selecting specific frequency values different from the standard printing frequency, the system can suppress agglomerated white spots while maintaining adequate surface potential consistency, thereby resolving the trade-off between reducing harmful artifacts and maintaining image quality.
3Ease of operation
If fixed development frequency and primary transfer current settings are used, then device operation is simplified, but image quality deteriorates under environmental fluctuations
Solution Approach 1:
The patent implements feedback by detecting the occurrence of drum ghost and automatically adjusting the alternating-current voltage frequency in response. The control unit monitors image quality issues and dynamically modifies the development voltage parameters accordingly. This feedback mechanism maintains simple operation for users while automatically compensating for environmental fluctuations and durability changes to preserve image quality consistency.
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
Effectively suppresses both drum ghost and agglomerated white spots while maintaining image quality, with the ability to adapt to environmental fluctuations and enhance user convenience by allowing simultaneous adjustment of development frequency and primary transfer current.
Implementation Method 1
The charging device charges the surface of the image carrying member. The charging voltage power supply applies a charging voltage to the charging device.
Implementation Method 2
The exposure device exposes the surface of the image carrying member charged by the charging device to form an electrostatic latent image in which charging is attenuated.
Implementation Method 3
The development device includes a developer carrying member which carries a developer containing a toner, and supplies, to the image carrying member, the toner contained in the developer carried by the developer carrying member to develop the electrostatic latent image into a toner image.
Implementation Method 4
The primary transfer member is pressed against the image carrying member through the intermediate transfer member. The transfer voltage power supply applies, to the primary transfer member and the secondary transfer member, a transfer voltage of a polarity opposite to the toner image.
Implementation Method 5
The secondary transfer member secondarily transfers, on a recording medium, the toner image primarily transferred on the intermediate transfer member.
Data Source
AI summary
An image forming apparatus includes an image carrying member, a charging device, a charging voltage power supply, an exposure device, a development device, a development voltage power supply, an intermediate transfer member, a primary transfer member, a secondary transfer member, a transfer voltage power supply and a control unit. The development device includes a developer carrying member which carries a developer containing a toner. The development voltage power supply applies, to the developer carrying member, a development voltage in which an alternating-current voltage is superimposed on a direct-current voltage. The transfer voltage power supply applies a transfer voltage to the primary transfer member and the secondary transfer member. The control unit performs a first image quality improvement mode in which the frequency of the alternating-current voltage of the development voltage and a primary transfer current flowing between the image carrying member and the primary transfer member are simultaneously changed.