Developing Roller Contact Mechanism for Image Forming Apparatus
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Solution Overview
Problem
Conventional image forming apparatuses face increased costs and size due to the use of exclusive motors for contact-and-separation mechanisms between photosensitive members and developing rollers, leading to premature wear and reduced lifetime, especially for black toner components which require prolonged contact.
Innovation Solution
An image forming apparatus with independent gear trains for each color portion, including a first and second gear train for transmitting driving force to developing rollers and photosensitive members, and switching mechanisms to minimize unnecessary contact between developing rollers and photosensitive members, allowing for optimized contact-and-separation operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an exclusive motor is used for the contact-and-separation mechanism between photosensitive members and developing rollers, then the developing rollers can be reliably spaced from photosensitive members, but the apparatus size increases and cost increases
Solution Approach 1:
The patent combines the contact-and-separation function with the existing developing roller driving mechanism by using the same motor to perform both developing rotation and contact-and-separation operations through a unified gear train system, eliminating the need for a separate exclusive motor and thereby reducing apparatus size while maintaining reliability
Solution Approach 2:
The motor is designed to perform multiple functions: it drives the developing roller rotation for image formation and also controls the contact-and-separation movement through the gear train, making the motor a multi-functional component that reduces overall system complexity and space requirements
2Reliability
If all photosensitive members and developing rollers are contacted in sequence including black toner, then complete contact-and-separation operation is achieved, but the black toner components experience prolonged unnecessary contact leading to increased wear and shortened lifetime
Solution Approach 1:
The patent segments the contact-and-separation control for different color components by using independent switching mechanisms for each gear train, allowing the black toner developing roller to be separated earlier than other colors and thereby reducing its unnecessary contact time and wear while maintaining complete separation for all components when needed
Solution Approach 2:
The system dynamically adjusts the contact-and-separation timing for each color component based on operational needs, enabling the black toner components to be spaced during non-printing periods while other colors may remain in contact, optimizing wear distribution and extending component lifetime through adaptive control
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 reduces wear and extends the lifespan of developing rollers and photosensitive members by minimizing unnecessary contact, while also downsizing the apparatus and reducing costs by eliminating the need for exclusive motors.
Implementation Method 1
a first gear train for transmitting a driving force to at least one of the developing roller and the photosensitive member which are provided in the first image forming portion; a second gear train for transmitting a driving force to at least one of the developing roller and the photosensitive member which are provided in the second image forming portion
Data Source
Figure 1
Figure 2
Figure 3(a)~3(b)
AI summary
An image forming apparatus includes first and second image forming portions, first and second gear trains, and first and second developing roller moving mechanisms. The first developing roller moving mechanism includes a first developing roller moving member for moving the developing roller of the first image forming portion toward an associated photosensitive member and a first driving force switching portion for switching between a driving force transmission state and a driving force disconnected state. The second developing roller moving mechanism includes a second developing roller moving member for moving the developing roller of the second image forming portion toward an associated photosensitive member and a second driving force switching portion for switching between a driving force transmission state and a driving force disconnected state.