Sheet Feed Lift Control Using Encoder Pulses for Accurate Sheet Count
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional sheet feeding devices inaccurately estimate the remaining quantity of sheets based on sensors detecting the lift plate's position, leading to potential errors in sheet feeding operations.
Innovation Solution
A sheet feeding device equipped with a lift plate, feeding portion, lifting member, motor, control portion, and encoder, which uses a rotary member and optical sensor to accurately count pulse signals and adjust motor operation to prevent erroneous sheet quantity sensing, ensuring precise control over sheet feeding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the remaining quantity of sheets is determined based on the ascending time of the lift plate, then the sheet feeding device can operate without additional sensors, but the measurement precision of sheet quantity becomes inaccurate
Solution Approach 1:
The patent replaces the mechanical time-based measurement system with an optical encoder system. The encoder detects the rotation angle of the lifting member through optical sensing, converting mechanical motion into precise angular position data. This substitution eliminates the need for multiple sensors while achieving accurate sheet quantity measurement through mathematical calculation based on the encoder's pulse signals.
Solution Approach 2:
The encoder acts as an intermediary between the lifting member's mechanical motion and the sheet quantity measurement. By detecting the rotation angle of the lifting member through optical means, the encoder provides precise positional information that can be mathematically converted to sheet quantity, serving as a mediator that enables accurate measurement without direct contact with the sheets.
2Device complexity
If the pulse signal counting continues without interruption during motor stoppage, then the counting process remains simple, but erroneous readings occur due to vibrations
Solution Approach 1:
The control portion applies preliminary anti-action by detecting motor stoppage conditions and actively preventing erroneous pulse signal counting before incorrect sheet quantity data can be generated. When the motor stops, the system identifies this state and suspends pulse signal processing, thereby counteracting the harmful effect of vibrations that would otherwise cause false readings.
Solution Approach 2:
The system implements feedback by continuously monitoring the motor's operational state and using this information to control the pulse signal counting process. The control portion receives feedback about motor stoppage conditions and adjusts the counting operation accordingly, creating a closed-loop system that prevents erroneous readings while maintaining simple overall control logic.
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 accurate estimation of remaining sheets, preventing errors in feeding operations and reducing the need for additional sensors, thus enhancing operational reliability and component efficiency.
Implementation Method 1
The optical sensor has a light emitter and a light receiver disposed so as to face each other across the movement path of the plurality of sensing targets and changes the level of the pulse signal between when the light from the light emitter reaches the light receiver and when it does not
Data Source
AI summary
A sheet feeding device includes a lift plate, a feeding portion, a lifting member lifting the lift plate, a motor coupled to a pivot shaft serving as the pivot fulcrum of the lifting member, a control portion, and an encoder outputting a pulse signal according to the rotation of the pivot shaft. The encoder includes a rotary member and an optical sensor. The control portion recognizes the remaining quantity of sheets on the lift plate based on the count value of the pulse signal. When the motor stops being driven, the control portion thereafter does not count the pulse signal until a predetermined period elapses.