Charging Device Resistor Unit Ripple Reduction
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Solution Overview
Problem
Conventional image forming apparatuses using laser printing face issues with unstable charging potential due to ripple in the charging voltage, leading to defective image output, especially at high speeds or with high resolution printing, and require additional power devices complicating miniaturization.
Innovation Solution
A charging device with a resistor unit connected in parallel to the charging member to stabilize the charging potential, using a power unit that supplies electric power to the charging member and reduces ripple, allowing for stable power supply without additional power devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If corona discharge is used to charge the photoconductive medium surface, then the charging process can be performed, but ripple occurs due to inconstant charging voltage causing defective image output
Solution Approach 1:
A capacitor is introduced as an intermediary component between the power supply and the charging member. The capacitor stores electrical energy and releases it to compensate for voltage fluctuations, thereby smoothing the charging voltage and reducing ripple effects that cause image defects.
Solution Approach 2:
The invention changes the electrical parameters of the charging system by adding capacitance to the circuit. This parameter change transforms the inconstant charging voltage into a more stable voltage profile, reducing the amplitude of voltage ripple and improving charging potential stability.
2Reliability
If AC power is supplied to obviate charging potential ripple, then constant surface potential is applied to the photoconductive medium, but additional power devices are required making miniaturization difficult
Solution Approach 1:
The capacitor is integrated into the existing power supply circuit of the charging device, merging the ripple reduction function with the power supply system. This combination eliminates the need for separate additional power devices while maintaining constant surface potential on the photoconductive medium.
Solution Approach 2:
The capacitor serves dual functions: it acts as part of the power supply circuit while simultaneously providing ripple reduction and voltage stabilization. This self-service approach allows the system to maintain constant surface potential without requiring external additional power devices.
3Reliability
If corona discharge charging is used, then the charging process can be performed, but additional power devices are required which deteriorates design freedom
Solution Approach 1:
The capacitor is designed to perform multiple functions within the charging device: voltage stabilization, ripple reduction, and energy storage. This multi-functionality allows the system to achieve reliable charging voltage stability while maintaining design freedom, as the single component serves multiple purposes without requiring additional specialized devices.
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 provides a stable charging potential to the photoconductive medium, improving image quality and enabling high-speed, high-resolution printing without the need for additional power devices, thus enhancing the design freedom of the image forming apparatus.
Implementation Method 1
The charging process of the printing operation includes electrical-charging a photoconductive medium surface with a negative charge using corona discharge
Implementation Method 2
a resistor unit to reduce a ripple on the surface of the charging member
Data Source
AI summary
A charging apparatus includes a charging member to charge a surface of a photoconductive medium, a power unit to supply an electric power as a bias voltage to the charging member, and a resistor unit to reduce a ripple on the surface of the charging member. Accordingly, a stability of the charging apparatus is secured without using a separate power device.