Charging Roller Cleaner Positioning for Gear Pressure Angle Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Related-art charging devices using non-contact type charging methods, such as charging rollers, are susceptible to displacement due to pressure angle forces generated by gear mechanisms, leading to uneven and insufficient charging of photoconductors, which affects image quality in image forming apparatuses.
Innovation Solution
A charging device comprising a charging roller, a drive transmission device, and a charging roller cleaner, where the drive transmission device includes a gear train that transmits torque from the image carrier to the charging roller, and the charging roller cleaner is positioned to contact the rear surface of the charging roller to prevent displacement caused by pressure angle forces, while also cleaning the charging roller.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a non-contact type charging roller is used to charge the photoconductor, then charging uniformity is improved, but the charging roller is susceptible to displacement due to pressure angle forces from the gear mechanism
Solution Approach 1:
The patent introduces a preliminary counteracting force through the spring member that opposes the pressure angle force from the gear mechanism before displacement occurs. The spring member is pre-loaded to apply a force in the opposite direction to the pressure angle force, thereby preventing the charging roller from moving away from the photoconductor during operation.
Solution Approach 2:
The spring member acts as a counterbalancing element that provides a counter-force to the pressure angle force generated by the gear meshing. This counter-force compensates for the destabilizing effect of the pressure angle, maintaining the charging roller's position stability while preserving the non-contact charging benefit.
2Measurement precision
If the charging roller is positioned closer to the photoconductor to maintain a constant charging gap, then charging precision is improved, but the charging roller becomes more susceptible to displacement from pressure angle forces
Solution Approach 1:
The spring member is pre-loaded to provide a counteracting force that balances the pressure angle force before any displacement occurs. This preliminary anti-action allows the charging roller to maintain a precise, constant charging gap while being protected from displacement by the gear mechanism's pressure angle forces.
Solution Approach 2:
The patent modifies the force balance parameters by introducing a spring member with specific stiffness and pre-load characteristics. By adjusting the spring constant and pre-load force, the system achieves an optimal balance between maintaining precise charging gap and preventing displacement from pressure angle forces.
3Speed
If a gear mechanism is used to drive the charging roller, then rotational speed control is improved, but pressure angle forces cause the charging roller to move away from the photoconductor
Solution Approach 1:
The spring member provides a counterbalancing force that offsets the pressure angle force generated by the gear mechanism. This allows the gear-driven charging roller to maintain precise rotational speed control while the spring counteracts the lateral displacement force, preventing the roller from moving away from the photoconductor.
Solution Approach 2:
The patent changes the force equilibrium parameters by introducing a spring element with specific mechanical properties. The spring constant and pre-load are selected to balance the pressure angle force at the operating speed, allowing the gear mechanism to control rotational speed effectively without causing charging roller displacement.
Data Source
AI summary
A charging device includes a charging roller, a drive transmission device, and a charging roller cleaner. The charging roller opposes an image carrier driven to rotate and rotates to charge the image carrier. The charging roller cleaner contacts the charging roller to clean the charging roller. The drive transmission device transmits torque from the image carrier to the charging roller, and includes an image carrier gear and a driven gear. The image carrier gear and the driven gear form a gear train to drive the charging roller in response to rotation of the image carrier. The charging roller cleaner is disposed facing a rear surface of the charging roller to prevent displacement of the charging roller due to a force generated by a pressure angle formed between the image carrier gear and the driven gear when the charging roller rotates in response to rotation of the image carrier.