Printer Media Conveyance Control for Motor Overheating Prevention
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Solution Overview
Problem
Existing media conveyance control methods, such as PID control, continue to drive the motor after media conveyance has stopped, leading to motor overheating due to reactive torque adjustments for slight tension variations in continuous media, which affects the printer's efficiency and throughput.
Innovation Solution
A media conveyance control method that positions a movable member to apply specific torque to the paper roll in the opposite direction of tension when conveyance stops, using a lower power level than required for maintaining constant tension, and switches to PID control during conveyance to manage positional deviations and suppress tension variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If PID control is used to maintain constant tension on the medium after media conveyance stops, then the tension on the medium is maintained, but the motor continues to be driven and overheats
Solution Approach 1:
The patent applies periodic action by switching the control method based on the conveyance state. During conveyance, PID control maintains constant tension. When conveyance stops, the control switches to a different mode that applies constant torque to prevent medium sagging, avoiding continuous motor operation and overheating while still maintaining tension stability.
Solution Approach 2:
The patent changes the control parameters based on the conveyance state. During conveyance, PID control with specific gains is used. When conveyance stops, the control parameters are changed to apply constant torque instead of continuous PID adjustment, reducing motor activity while maintaining the necessary tension to prevent medium sagging.
2Loss of energy
If the motor is stopped completely after media conveyance stops, then power consumption is reduced, but the medium sags and tension is lost
Solution Approach 1:
The patent uses periodic action by implementing different control strategies based on the conveyance state. During conveyance, full PID control maintains tension. After conveyance stops, the system transitions to a low-power mode that applies minimal constant torque just enough to prevent medium sagging, significantly reducing power consumption while maintaining basic tension stability.
Solution Approach 2:
The patent applies partial action by providing just enough torque after conveyance stops to prevent medium sagging, rather than continuing full PID control. This partial torque application is sufficient to maintain the necessary tension stability without the excessive power consumption of continuous motor operation.
3Stability of the object's composition
If continuous PID control is applied after conveyance stops, then tension is maintained, but the motor runs unnecessarily and reduces throughput
Solution Approach 1:
The patent implements periodic action by switching control modes based on conveyance state. During conveyance, PID control maintains tension for quality printing. After conveyance stops, the system switches to a simpler constant torque mode that maintains basic tension with minimal motor activity, enabling faster start-up for the next printing job and improving overall throughput.
Solution Approach 2:
The patent applies dynamics by making the control system adaptive to different operational states. The control strategy dynamically changes from full PID control during conveyance to constant torque control after conveyance stops, optimizing both tension maintenance and motor efficiency for different phases of operation to improve productivity.
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
Prevents the media supply motor from overheating while maintaining tension on the medium after conveyance has stopped, improving printer efficiency by reducing power consumption and allowing quicker start-ups without the need for pre-tensioning or rewinding.
Implementation Method 1
supplying power to the media supply motor to apply constant torque to the paper roll
Implementation Method 2
because the friction of members that support the roll acts on the roll, and detent torque acts on the media supply motor
Implementation Method 3
a movable member that moves in response to a change in the tension on the medium between the roll and the conveyance mechanism
Data Source
AI summary
When conveyance of the recording paper 3 by the conveyance mechanism 12 stops, the printer 1 supplies power of a specific current level to the supply motor 25. This applies specific torque to the paper roll 2 in the opposite direction as the direction in which tension is applied to the recording paper 3 by a spring 30, and holds the movable member 27 at the same position as when conveyance of the recording paper 3 stopped. The torque applied to the paper roll 2 to hold the print position of the movable member 27 is torque sufficient to hold the paper roll 2 still without rolling, and is less than the torque required to turn the paper roll 2 to maintain constant tension on the recording paper 3. Little current is therefore supplied to the supply motor 25, and the supply motor 25 is prevented from overheating.