Thermal Printer Feed Speed Control via ON Dot Prediction
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Solution Overview
Problem
Printers using thermal line heads face inefficiencies in changing the feed speed of the printing medium due to the time required to adjust the motor's revolution speed, leading to prolonged printing times when the number of ON dots changes abruptly.
Innovation Solution
A printer system that includes a processor to set and adjust the feed speed by specifying the number of lines with ON dots and controlling the printing medium's speed in the auxiliary scanning direction, allowing for sequential one-line printing and optimizing feed speed changes based on the number of ON dots.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the feed speed is changed rapidly to match sudden changes in the number of ON dots, then the printing efficiency is improved, but the motor cannot respond quickly enough due to its inherent inertia, causing delays in feed speed adjustment
Solution Approach 1:
The processor performs preliminary action by predicting future feed speed requirements based on the sequence of ON dot counts in the printing data. It anticipates when the feed speed needs to change and prepares the speed adjustment in advance, allowing the motor to reach the target speed without delay. This is implemented by examining the printing data ahead of time and pre-calculating the optimal feed speed changes.
Solution Approach 2:
The system dynamically adjusts the feed speed based on the actual printing requirements rather than using a fixed speed. The processor continuously monitors the number of ON dots and modifies the feed speed accordingly, creating a dynamic response that adapts to changing printing conditions. This dynamic adjustment allows the system to optimize printing efficiency for each specific pattern.
2Adaptability or versatility
If the motor revolution speed is changed frequently to match varying numbers of ON dots, then the printing adaptability is improved, but the time required for speed switching accumulates, prolonging the total printing time
Solution Approach 1:
The processor performs preliminary action by analyzing the printing data in advance and predicting when feed speed changes are needed. By preparing the speed adjustment sequence beforehand, the system minimizes the actual time spent switching speeds during printing. The processor creates an optimized speed profile that anticipates future requirements.
Solution Approach 2:
The system maintains continuous printing operation by overlapping the feed speed adjustment with the printing process. Instead of stopping or waiting for speed changes to complete before printing, the system continues printing while the motor gradually adjusts its speed. This continuous action reduces the cumulative time loss from speed switching.
3Productivity
If the feed speed is increased to compensate for the time required to change motor speed, then the overall printing time is reduced, but the printing precision may be compromised due to speed fluctuations during adjustment
Solution Approach 1:
The system uses dynamic speed adjustment that smoothly transitions between different feed speeds based on the printing requirements. Rather than abrupt changes, the processor implements gradual acceleration and deceleration profiles that maintain printing precision while optimizing overall speed. The dynamic response ensures stable printing during speed transitions.
Solution Approach 2:
The processor changes the feed speed parameter smoothly and controllably rather than making abrupt jumps. By using controlled parameter transitions with defined acceleration and deceleration rates, the system maintains printing precision during speed changes. The parameter adjustment is optimized to balance speed and precision requirements.
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 approach reduces the time required to complete printing by allowing for faster feed speed adjustments and maintaining optimal printing efficiency, even with sudden changes in the number of ON dots.
Implementation Method 1
The heating elements for a single line of an image that will be formed are arrayed in a main scanning direction on the thermal line head. The printer may operate the thermal line head by applying an electric current to the heating elements to generate heat.
Data Source
AI summary
A printer includes a feeding portion, a printing portion and a processor. The feeding portion is configured to feed a printing medium in an auxiliary scanning direction. The printing portion includes a plurality of heating elements arrayed in a main scanning direction and configured to perform printing of one line at a time on the printing medium. The processor is configured to set, based on a first speed, a number of lines for each of which a number of ON dots is specified, specify numbers of ON dots for the set number of lines, set a second speed based on a maximum value among the specified numbers of ON dots, control the feeding portion such that the feed speed is changed from the first speed to the second speed, and control the printing portion such that the printing is performed sequentially one line at a time.