Tape Feed Control for Accurate Front Margin Printing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing tape printing apparatuses suffer from errors in the front margin due to backlash in the gear train mechanism when switching tape feeding directions, causing misalignment of the printing start position.
Innovation Solution
The apparatus includes a drive motor that rotates in two directions, a platen drive shaft, a gear train mechanism, a printing head, and a sensor, with a control section that adjusts tape feeding to align the printing start position by feeding the tape in specific directions based on the sensor's detection, compensating for backlash.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the tape feeding direction is switched from forward to backward using the gear train mechanism, then the tape can be repositioned for printing, but the backlash in the gear train causes the printing start position to shift from the detection position
Solution Approach 1:
The control section performs preliminary actions by first feeding the tape in the forward direction to a predetermined position, then switching to backward feeding. This preliminary forward movement compensates for the backlash that will occur during direction switching, ensuring that the printing start position aligns correctly with the detection position after the backward feed.
Solution Approach 2:
The system uses feedback from the sensor that detects the presence or absence of the tape at the detection position. The control section monitors the sensor output during tape feeding and uses this feedback information to determine when the leading end of the tape has reached the appropriate position, thereby compensating for backlash effects and achieving precise alignment.
2Productivity
If the tape is fed in backward direction until the printing start position reaches the printing position, then printing can begin, but the backlash causes error in the front margin distance
Solution Approach 1:
The control section performs a preliminary forward feed of the tape to a predetermined position before the actual backward feeding begins. This preliminary action sets up the tape in a position that accounts for the upcoming backlash, ensuring that when backward feeding occurs, the final position achieves the correct front margin distance despite the mechanical backlash in the gear train.
Solution Approach 2:
The sensor provides continuous feedback during the tape feeding process, allowing the control section to monitor the tape position in real-time. This feedback enables the system to compensate for backlash by adjusting the feeding distance based on the sensor's detection of the tape's leading end position, thereby maintaining accurate front margin measurements.
3Reliability
If the leading end of the tape is located upstream of the detection position, then the sensor cannot detect the tape, but feeding the tape forward and then backward increases the time before printing can start
Solution Approach 1:
The control section performs a preliminary forward feed of the tape to a predetermined position that is closer to the detection position, rather than waiting for the tape to be detected upstream. This preliminary positioning reduces the total distance the tape needs to travel during backward feeding, thereby reducing the time delay before printing can start while still ensuring reliable detection.
Solution Approach 2:
The sensor provides feedback that enables the control section to determine when the leading end of the tape has reached the predetermined position during forward feeding. This feedback mechanism allows the system to optimize the forward feeding distance, positioning the tape as close as possible to the detection position without overshooting, thus minimizing the subsequent backward feed distance and overall time delay.
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 ensures accurate alignment of the printing start position, reducing errors in the tape margin and minimizing the time from the printing start command to the start of printing, while maintaining reliable tape detection regardless of color or material.
Implementation Method 1
a sensor that has a detection position located downstream of a printing position by the printing head and detects the presence or absence of the tape
Data Source
AI summary
A tape printing apparatus acquires a printing start command, and when a margin distance, which is a distance from a leading end of a tape to a printing start position of the tape, is shorter than a sensor-head distance, which is a distance between a detection position and a printing position, and the leading end of the tape is located in a second feeding direction with respect to the detection position, the tape printing apparatus feeds the tape in a first feeding direction, locates the leading end of the tape in the first feeding direction with respect to the detection position by a predetermined distance, feeds the tape in the second feeding direction, determines that the leading end of the tape passed the detection position, and then feeds the tape in the second feeding direction until the printing start position of the tape comes to the printing position.