Portable Thermal Printer Sheet Type Detection by Reverse Conveyance
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Solution Overview
Problem
Existing thermal printers face inefficiencies in determining the type of sheet being used due to the potential misdetection of marks on sheets, leading to prolonged processing times as they often require conveying sheets in both forward and reverse directions to accurately identify the sheet type.
Innovation Solution
A portable terminal equipped with multiple sensor units that detect the presence of a sheet and specific marks on the sheet, allowing for rapid identification of sheet type by conveying the sheet in a reverse direction after initial detection, utilizing a drop-in method for sheet insertion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single sensor unit is used to detect marks on sheets, then the device complexity is reduced, but the measurement precision deteriorates due to potential misdetection of marks
Solution Approach 1:
The detection function is segmented into two independent sensor units: a first sensor unit for detecting sheet presence/absence and a second sensor unit for detecting mark information. This segmentation allows each sensor to be optimized for its specific detection task, improving overall measurement precision while maintaining manageable device complexity.
2Measurement precision
If the sheet is conveyed in both forward and reverse directions to detect marks, then the measurement precision is improved, but the loss of time increases due to prolonged processing
Solution Approach 1:
The first sensor unit performs preliminary detection of sheet presence/absence at the cutter unit position before the main mark detection process. This preliminary action allows the system to prepare for the subsequent reverse direction conveyance and mark detection by the second sensor unit, optimizing the overall detection sequence and reducing total processing time.
Solution Approach 2:
The sheet conveyance mechanism acts as an intermediary that positions the sheet between the two sensor units. By controlling the sheet to be conveyed in reverse direction after initial detection, the system enables the second sensor unit to detect marks at the optimal position without requiring complex multi-directional conveyance, thus reducing processing time while maintaining detection accuracy.
3Productivity
If the sheet is conveyed in reverse direction after initial detection, then the productivity is improved by reducing processing time, but the device complexity increases due to additional sensor units and control mechanisms
Solution Approach 1:
Each sensor unit is designed with multi-functionality: the first sensor unit detects both sheet presence and sheet position, while the second sensor unit detects both mark information and sheet characteristics. This universality allows the system to achieve high productivity through efficient detection without requiring excessive specialized components, thereby managing device complexity while improving sheet type determination speed.
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
Enables quick and accurate determination of sheet type, reducing processing time and minimizing waste by optimizing sheet handling and cutting operations based on mark detection.
Implementation Method 1
a first sensor unit configured to detect presence or absence of a sheet
Implementation Method 2
a second sensor unit configured to detect information related to a mark provided on the sheet
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A portable terminal (12) has a thermal head (312). The portable terminal (12) includes: a first sensor unit (151) configured to detect presence or absence of a sheet; a second sensor unit (152) configured to detect information related to a mark provided on the sheet; and a sheet determination unit (251) configured to determine a kind of the sheet. The sheet determination unit (251) is configured to determine a kind of the sheet based on a result of detecting information related to the mark with use of the second sensor unit (152) after the sheet is conveyed in a reverse direction with respect to a direction of discharging the sheet.