Image Forming Apparatus Unidirectional Pulse Motor Mode Switching
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Solution Overview
Problem
Conventional image forming apparatuses face challenges in efficiently switching between modes, leading to prolonged downtime, user stress, and reduced apparatus lifetime due to errors in mode switching and initialization processes.
Innovation Solution
An image forming apparatus equipped with a pulse motor and a moving mechanism that allows bidirectional rotation, enabling precise control of primary-transfer rollers and secondary-transfer rollers to switch between three positions using a single sensor and motor, optimizing mode switching time and reducing downtime.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If bidirectional rotation of pulse motor is used for mode switching, then mode switching time is reduced, but positional accuracy deteriorates due to error accumulation
Solution Approach 1:
The patent inverts the conventional approach by using unidirectional rotation instead of bidirectional rotation. The pulse motor rotates in a fixed direction (e.g., clockwise) regardless of the switching direction needed, and the movable frame is repositioned by controlling the number of rotations and using the detection means to identify the target position. This inversion eliminates error accumulation from bidirectional rotation while maintaining fast switching capability.
Solution Approach 2:
The patent employs feedback through the detection means (sensor) that detects the position of the movable frame. The control means uses this feedback signal to determine when the movable frame has reached the target position, allowing precise positioning without relying on bidirectional rotation. The feedback mechanism compensates for any variations in rotation speed or mechanical play.
2Measurement precision
If multiple sensors are used for position detection, then position detection accuracy is improved, but device complexity increases
Solution Approach 1:
The patent makes the single detection means serve multiple functions: it detects both the position of the movable frame during mode switching and the operational state (contact/separation) of the transfer rollers. By positioning the detection means to detect a detection object that moves with the movable frame, one sensor replaces what would traditionally require multiple sensors, thereby reducing device complexity while maintaining detection accuracy.
3Adaptability or versatility
If movable frame is swung for mode switching, then adaptability between modes is improved, but reliability deteriorates due to switching errors
Solution Approach 1:
The patent inverts the conventional switching approach by using unidirectional rotation with feedback-based position detection instead of bidirectional swinging. The movable frame is repositioned reliably by controlling the pulse motor to rotate a predetermined number of times in one direction, with the detection means confirming when the target position is reached. This eliminates the error accumulation and reliability issues associated with bidirectional swinging while maintaining full adaptability between modes.
Solution Approach 2:
The detection means provides feedback signals that allow the control means to verify when the movable frame has reached the correct position for each mode. This feedback mechanism ensures reliable switching operations by confirming position accuracy, preventing the switching errors that would otherwise occur with conventional bidirectional swinging methods.
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 enables reliable and efficient mode switching, reducing downtime and extending the apparatus' lifetime by minimizing errors and shortening the time required for switching between operational modes.
Implementation Method 1
a pulse motor rotatable bi-directionally on the basis of a pulse number of a driving signal
Data Source
AI summary
An image forming apparatus includes: an image carrying unit; a unit-to-be-moved; a pulse motor; a moving mechanism including a rotatable member provided with a member-to-be-detected; a detecting portion; an executing portion; and a controller for causing the executing portion to execute a first stop mode on the basis of detection of the detecting portion when the unit-to-be-moved is changed in position from the second or third position to the first position and to execute a second stop mode on the basis of a pulse number of a driving signal when the unit-to-be-moved is changed in position from the first or third position to the second position and when the unit-to-be-moved is changed in position from the first or second position to the third position, and for making the change at least between the second and third positions by only unidirectional rotation of the pulse motor.