Medium Feeding Device Motor Sharing and Gear Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional medium feeding devices for image forming apparatuses require an exclusive motor to move the medium placing plate upward and downward, increasing complexity and cost.
Innovation Solution
A medium feeding device with a movable medium placing member, a feeding mechanism, a conveying mechanism, a lifting unit, a medium detecting unit, and a driving force transmission system that allows the medium placing member to move upward and downward without an exclusive motor, using a control unit to manage the driving force transmission based on detection and shifting of the feeding mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an exclusive motor is provided to move the medium placing plate upward and downward, then the medium can be fed reliably one by one, but the device complexity and cost increase
Solution Approach 1:
The patent combines the function of moving the medium placing plate with the feeding mechanism by using the same motor (71) that drives the pickup roller (602). The motor's rotation is transmitted through a gear mechanism (including one-way gear 612d, planet gears 612g, and lift-up gear 612k) to drive the swinging shaft (605) and medium placing plate (604) upward, eliminating the need for a separate exclusive motor.
Solution Approach 2:
The motor (71) serves multiple functions: it directly drives the pickup roller (602) for feeding media, and through the gear transmission system, it also drives the medium placing plate (604) upward. This multi-functional design reduces the total number of motors and components while maintaining reliable medium feeding.
2Measurement precision
If an exclusive motor and height sensor are provided to control the medium placing plate height, then the medium can be positioned accurately, but the number of components and cost increase
Solution Approach 1:
The patent uses a photo coupler (612n) to detect the position of the swinging shaft (605) and provides feedback to the control unit (62). The control unit monitors the output signal from the photo coupler and stops the motor (71) when the medium placing plate (604) reaches the predetermined position, achieving accurate positioning without requiring additional height sensors.
Solution Approach 2:
The photo coupler (612n) serves as a position detection device that works within the existing gear mechanism, eliminating the need for separate height sensors while maintaining positioning accuracy.
3Adaptability or versatility
If a gear mechanism is provided to transmit driving force to the lifting unit, then the motor can serve multiple functions, but the device complexity increases
Solution Approach 1:
The patent employs a dynamic gear mechanism where the one-way gear (612d) allows rotation in one direction (transmitting driving force from motor to lift-up gear) but prevents rotation in the opposite direction. This dynamic characteristic enables the system to automatically disengage the lifting function when the medium placing plate reaches the upper position, simplifying control without requiring complex switching mechanisms.
Solution Approach 2:
The gear mechanism with one-way gear (612d) automatically controls the transmission of driving force based on the rotation direction. When the medium placing plate reaches the upper position and pushes the pickup roller upward, the one-way gear automatically stops transmitting force, eliminating the need for external control of the transmission mechanism.
Data Source
AI summary
A medium feeding device includes a medium placing member, a feeding mechanism for feeding the medium, and a lifting unit for moving the medium placing member toward the feeding mechanism. A first switching unit connects a transmission of a driving force from a driving source to the lifting unit based on a shifting of the feeding mechanism. A second switching unit connects the transmission based on control by a control unit. The control unit causes the second switching unit to transmit the driving force to the lifting unit to move the medium placing member upward based on detection by a medium detecting unit. When the medium placing member moves upward to a predetermined position, the first switching unit disconnects the transmission, holding the medium placing member at the predetermined position. The control unit causes the second switching unit to disconnect the transmission so that the medium placing member moves downward.