Thermal Transfer Printer Spool Drive Field Oriented Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Thermal transfer printers using stepper motors suffer from limited positional resolution and tension spikes, leading to inaccuracies and potential tape damage, necessitating improved smooth tension control and high positional resolution.
Innovation Solution
Implementing field-oriented control for the spool drive motors, coupled with encoders for continuous torque control and sinusoidal current adjustments to prevent jerky movements and mechanical resonance, ensuring smooth tape movement and high positional accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If stepper motors are used to drive the supply spool and take-up spool, then the printer can achieve basic tape transport functionality, but positional resolution is limited by the step size of the motors and tension spikes occur each time the motors are energized
Solution Approach 1:
The patent replaces the mechanical stepper motor system with an electromagnetic motor system (such as a DC motor or servo motor) that provides continuous rotational control. This substitution eliminates the discrete step movements that cause tension spikes and limits positional resolution, enabling smooth and precise tape transport through electronic control of motor speed and torque.
Solution Approach 2:
The patent introduces feedback mechanisms including encoders on the spools and motors to continuously monitor tape position, spool rotation, and motor performance. This feedback enables closed-loop control that adjusts motor operation in real-time to maintain constant tape tension and achieve high positional resolution, preventing the tension spikes and positioning errors inherent in open-loop stepper motor systems.
2Device complexity
If stepper motors are energized in discrete steps, then the motors can be controlled with simple drive circuits, but the tape is subjected to tension spikes and jerky movements occur
Solution Approach 1:
The patent replaces the step-based mechanical control approach with continuous electromagnetic control. Motors such as DC motors or servos provide smooth rotational movement when driven by continuous voltage, eliminating the jerky tension spikes associated with discrete stepper motor actuation while maintaining controllable and predictable tape transport.
Solution Approach 2:
The patent implements continuous motor operation instead of discrete step activation. The motor runs continuously with smoothly varying speed and torque commands, ensuring uninterrupted and tension-free tape transport. This continuous action eliminates the periodic tension spikes that occur with each stepper motor activation cycle.
3Measurement precision
If high positional resolution is achieved through smaller step sizes, then positioning accuracy improves, but the frequency of motor energization increases causing more tension spikes
Solution Approach 1:
The patent replaces the stepper motor system with a continuously controllable motor system that achieves high positional accuracy through electronic speed and position control rather than mechanical step increments. This allows the tape to be transported at high speeds with precise positioning without the tension spikes that would result from high-frequency stepper motor energization.
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
This solution provides smooth tension control, high positional resolution, and reduced risk of tape breakage, resulting in improved print quality and extended tape lifespan by eliminating positional inaccuracies and mechanical resonance issues.
Implementation Method 1
Field oriented control driving the supply motor and the take-up motor so as to continuously and uninterruptedly control motor torque of said motors
Implementation Method 2
the supply spool is provided with a supply encoder and the take-up spool is provided with a take-up encoder, which encoders provide positional information
Implementation Method 3
Problems of mechanical resonance are also reduced with this technique as the periodic stimulation caused in the prior art by pulsed operation of the stepper motors, is absent
Implementation Method 4
thermal transfer printer for selectively transferring a meltable ink material carried on a tape to a substrate
Data Source
Figure 1
AI summary
Thermal transfer printer for selectively transferring a meltable ink material carried on a tape to a substrate intended to receive ink from said tape for printing an image on the substrate, the printer comprising a supply spool for the tape, a take-up spool for the tape, and a printhead between the supply spool and the take-up spool, wherein the supply spool is driven by a supply motor and the take-up spool is driven by a take-up motor, and that the printer comprises a spool drive controller which is configured to energize the supply motor and the take-up motor so as to arrange that the tape is un-wound from the supply spool and wound onto the take-up spool, wherein the spool drive controller is embodied with field oriented control driving the supply motor and the take-up motor so as to continuously and uninterruptedly control motor torque of said motor's.