Label Printer Sensor Light Interference Reduction
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Solution Overview
Problem
Conventional label printers face challenges in improving detection precision due to light interference between transmission and reflection type sensors, which hampers accurate detection of printing positions and paper ends.
Innovation Solution
A label printer design that alternates between single and dual light emission periods for transmission and reflection type sensors, allowing both sensors to operate simultaneously during paper conveyance to enhance detection precision by minimizing light interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If both transmission type sensor and reflection type sensor are arranged close to the top of substrate to enable simultaneous operation, then detection capability for paper end is improved, but light from one sensor migrates to the other sensor causing detection precision degradation
Solution Approach 1:
The patent implements periodic action by alternately switching between single light emission periods (where only one sensor emits light) and both light emission periods (where both sensors emit light simultaneously). This periodic switching enables both sensors to operate for paper end detection while minimizing light interference through controlled timing
Solution Approach 2:
The patent applies dynamics by making the light emission state changeable over time, transitioning between different emission modes (single vs. both sensors) based on operational requirements. This dynamic control allows optimization of both detection capability and precision at different time points
2Measurement precision
If light emission of unused sensor is stopped to reduce light interference, then detection precision of printing position is improved, but detection capability for paper end deteriorates
Solution Approach 1:
The patent uses periodic action by implementing alternating light emission periods where the unused sensor is activated during both light emission periods for paper end detection, while remaining inactive during single light emission periods for position detection. This periodic activation maintains both detection capabilities without continuous interference
Solution Approach 2:
The patent applies preliminary action by pre-arranging both light emission periods at specific intervals during paper conveyance, enabling both sensors to be activated in advance for paper end detection before the actual detection moment, thus preparing the system to handle both detection tasks effectively
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 effectively improves the detection precision of both printing positions and paper ends, reducing light interference and enhancing alignment accuracy.
Implementation Method 1
a transmission type sensor (21) configured to enable a first light emitting element (21a) to emit light to irradiate a printing medium with the light and to detect light transmitted through the printing medium
Implementation Method 2
a reflection type sensor (22) configured to enable a second light emitting element (22a) to emit light to irradiate a printing medium with the light and to detect light reflected by the printing medium
Data Source
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AI summary
In accordance with an embodiment, a label printer comprises a transmission type sensor configured to enable a first light emitting element to emit light to irradiate a printing medium with the light and to detect light transmitted through the printing medium; a reflection type sensor configured to enable a second light emitting element to emit light to irradiate a printing medium with the light and to detect light reflected by the printing medium; and a light emission control module configured to alternately switch a single light emission period in which either the first light emitting element or the second light emitting element emits light and a both light emission period in which both the first light emitting element and the second light emitting element emit light.