Printer Media-End Detection Near the Print Position
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Solution Overview
Problem
Conventional printers face inaccuracies in print start position detection due to factors like platen roller diameter changes and slippage, especially with short print media lengths, leading to noticeable displacement of the print start position.
Innovation Solution
A printer design incorporating a first detection unit with a light-emitting and light-receiving element arranged close to the print position, utilizing a light-emitting element and a light-receiving element to detect the end of each print medium via the ink ribbon and continuous body, improving accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the sensor is mounted at a position upstream of and relatively distant from the thermal head, then the sensor can detect the print medium earlier, but the accuracy of the print start position detection deteriorates due to platen roller diameter changes and slippage
Solution Approach 1:
The patent transitions from mechanical detection (sensor upstream of thermal head) to optical detection (light-emitting and light-receiving elements at the print position). By using light transmission through the ink ribbon and continuous body, the system achieves accurate detection at the print position without relying on mechanical feeding distance, thus resolving the contradiction between early detection and accurate positioning.
2Device complexity
If the platen roller diameter changes due to temperature expansion or wear, then the feeding mechanism remains simple, but the print start position accuracy deteriorates due to rotational amount calculation errors
Solution Approach 1:
The patent replaces the mechanical feeding detection method (based on platen roller rotation) with an optical detection method. The light-emitting and light-receiving elements directly detect the print medium at the print position, eliminating the need to calculate feeding distance based on roller rotation. This substitution resolves the issue of accuracy deterioration caused by roller diameter changes while maintaining simple device structure.
3Ease of operation
If the print medium slips at the location between the thermal head and platen roller during feeding, then the feeding process remains simple, but the print start position accuracy deteriorates due to uncontrolled slippage
Solution Approach 1:
The patent introduces light as an intermediary to detect the print medium position. The light-emitting element and light-receiving element transmit light through the ink ribbon and continuous body to detect the print medium at the print position. This intermediary detection method allows accurate positioning without controlling or preventing mechanical slippage, thus maintaining feeding simplicity while improving accuracy.
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
Enhances the accuracy of the print start position by detecting the end of each print medium accurately, reducing displacement and improving overall printing precision.
Implementation Method 1
a first detection unit that is provided upstream of the print position in a feed direction of the continuous body, the first detection unit comprising a light-emitting element and a light-receiving element receiving, via the ink ribbon and the continuous body, light emitted from the light-emitting element
Implementation Method 2
a light-receiving element receiving, via the ink ribbon and the continuous body, light emitted from the light-emitting element, to detect an end of each of the print media
Data Source
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AI summary
One aspect of the present invention is a printer including: a feed roller that feeds a continuous body and an ink ribbon; a print head that prints information on each of the print media of the continuous body, the print head and the feed roller pinching the ink ribbon and the continuous body at a print position; and a first detection unit that is provided upstream of the print position in a feed direction of the continuous body, the first detection unit detecting an end of each of the print media in the feed direction of the continuous body. The first detection unit has a light-emitting element and a light-receiving element receiving, via the ink ribbon and the continuous body, light emitted from the light-emitting element.