Drive Unit Gear System for Compact Image Forming Apparatus
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing drive units for electrophotographic image forming apparatuses occupy more space due to multiple drive connections required for rotating image bearers and rotary members, leading to increased complexity and potential for rotation fluctuations affecting image quality.
Innovation Solution
A tandem image forming apparatus with a multistage gear system that decouples the drive force transmission to the photoreceptor and rotary members, using a photoreceptor drive unit and development drive unit with involute spline-shaped joints to reduce the number of gear meshing cycles and minimize space occupation, while ensuring accurate and efficient rotation of all components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate transmission routes are used to drive the image bearer and rotary members, then reliable independent rotation is achieved, but the number of drive connections increases and occupies more space
Solution Approach 1:
The patent merges the drive connections by making the rotary member's drive gear engage with the output gear of the motor that also drives the image bearer. This consolidation reduces the number of separate transmission routes while maintaining reliable independent rotation through coordinated gear engagement.
Solution Approach 2:
The motor's output gear serves multiple functions: it directly drives the image bearer and simultaneously engages with the rotary member's drive gear. This multi-functionality allows a single drive connection to control multiple components, reducing overall system complexity.
2Reliability
If multiple drive connections are made to rotary members, then independent rotation control is achieved, but space occupation increases inside the apparatus
Solution Approach 1:
The patent combines the drive mechanism for the rotary member with the existing motor output structure. The drive gear of the rotary member engages with the motor's output gear, merging two drive functions into one location and reducing the space required for separate transmission routes.
3Power
If gear meshing frequency is increased to transmit drive force to multiple components, then power transmission efficiency is improved, but banding and color unevenness occur
Solution Approach 1:
The patent extracts the rotary member's drive connection from the direct gear meshing path with the motor. Instead of continuous gear meshing, the rotary member's drive gear engages with the motor's output gear at a reduced frequency, taking out the harmful high-frequency meshing that causes banding while maintaining sufficient power transmission.
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A drive unit (51) for rotating a first rotary member (1) and a second rotary member (9a; 9c) disposed around the first rotary member (1) includes a drive source (52), an output gear (52a) driven by the drive source (52), a first gear (53) configured to engage the output gear (52a), a first joint member (55) projecting from the first gear (53) coaxially and coupled to the first rotary member (1), a second gear (54) smaller in diameter than the first gear (53) and connected between the first gear (53) and the first joint member (55), a driven gear (56) to engage the second gear (54) to be driven thereby, disposed within an area of the first gear (53) in a radial direction thereof, and a second joint member (57) projecting from the driven gear (56) coaxially and connected to the second rotary member (9a; 9c). The first gear is greater in diameter than the output gear, and the driven gear is smaller in diameter than the first gear.