Printer Mark Sensor Emittance Control for Media Detection
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Solution Overview
Problem
Existing printer technologies face challenges in accurately detecting marks on recording media due to varying light reflection based on the type of media, leading to inconsistent mark detection and indexing issues.
Innovation Solution
An inkjet printing device that adjusts light emittance levels based on the type of print medium, using a mark sensor to project light at different emittance levels and set thresholds for accurate mark detection, even when marks cannot be detected, and conveys the medium at a slower speed to ensure accurate indexing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If light is projected at a specific emittance level to detect marks, then mark detection can be performed, but accurately detecting marks may not be possible depending on the type of recording medium
Solution Approach 1:
The patent applies dynamics by making the light emittance level adjustable rather than fixed. The controller dynamically changes the emittance level of the light source based on the detected media type, allowing the system to adapt its detection parameters to match the reflective properties of different recording media surfaces.
Solution Approach 2:
The patent implements parameter changes by modifying the emittance level parameter of the light source according to the media type. The system detects the media type first, then adjusts the light emittance parameter to an appropriate level for accurate mark detection on that specific media type, thereby resolving the contradiction between detection accuracy and media versatility.
2Measurement precision
If the print medium is conveyed at normal speed, then productivity is maintained, but accurate detection of light reflection changes may not be achieved
Solution Approach 1:
The patent applies preliminary action by performing mark detection and media type identification at a reduced conveyance speed before the actual printing process. This preliminary detection phase allows accurate measurement of light reflection changes without compromising overall productivity, as the slower speed is only used for detection, not for the main printing operation.
Solution Approach 2:
The patent segments the printing process into distinct phases: a detection phase at reduced speed for accurate mark and media type detection, and a printing phase at normal speed for productivity. This segmentation allows the system to achieve both measurement precision during detection and high productivity during the main printing operation.
3Measurement precision
If a fixed threshold is used for mark detection, then the detection process is simple, but detecting other than marks cannot be prevented
Solution Approach 1:
The patent applies parameter changes by making the detection threshold dynamic rather than fixed. The controller adjusts the detection threshold based on the detected media type and the actual light reflection characteristics observed during detection, allowing the system to distinguish true marks from false detections while maintaining simple detection operations.
Solution Approach 2:
The patent implements feedback by using the detected light reflection values to dynamically adjust the detection threshold. The system monitors the actual reflection characteristics during detection and adjusts the threshold accordingly, creating a feedback mechanism that prevents false detections while maintaining operational simplicity.
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
The solution enables precise detection and indexing of marks on various types of media, preventing false detection and ensuring accurate positioning for printing, regardless of the media type, by setting appropriate emittance levels and thresholds based on the media's reflective properties.
Implementation Method 1
the position at which to start printing is determined based on an amount of light reflected from the printing surface of the print medium
Implementation Method 2
an emittance controller configured to set an emittance level of light that the mark sensor projects
Data Source
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AI summary
Technology enabling accurately detected marks on a print medium according to the type of print medium is provided. A printer 1 has a media type identifier 110 that determines the type of medium; a mark sensor 76 that projects light and detects a mark on the medium; and an emittance controller 111 that sets the emittance level of the light the mark sensor 76 projects. The printer 1 can change the operating mode according to the type of medium M identified by the media type identifier 110. In the white medium mode, the mark sensor 76 detects a mark MR with the emittance level set to a white medium emittance level. In the non-white medium mode, the mark sensor 76 detects a mark MR with the emittance level set to a non-white medium emittance level, which is higher than the white medium emittance level.