Image Erasing Apparatus Using Periodic Heating to Reduce Memory Density
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Solution Overview
Problem
The 'memory phenomenon' occurs when images are printed on paper sheets that have undergone image erasing using erasable ink, leading to density changes in erased image portions, making it difficult to reuse paper effectively.
Innovation Solution
An image erasing apparatus that includes a heating unit, feedback mechanism, and control unit, which heats the paper sheet multiple times to efficiently erase images using a leuco dye-based ink, while controlling humidity and pass count to manage afterimage and memory density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a paper sheet is heated once to erase an image, then the image is removed, but afterimage and memory density remain visible
Solution Approach 1:
The patent applies periodic action by heating the paper sheet multiple times (first heating, second heating) rather than once. The control unit controls the heating unit to perform sequential heating operations, where each heating cycle further reduces afterimage and memory density, achieving complete erase only after repeated periodic heating actions.
Solution Approach 2:
The patent applies preliminary action by performing a first heating operation before a second heating operation. The first heating preliminarily reduces the image density, and then the second heating further reduces the remaining afterimage and memory density, ensuring complete erase. This sequential preliminary action prevents residual visibility.
2Productivity
If heating temperature is increased to erase image faster, then erase efficiency improves, but paper quality deteriorates
Solution Approach 1:
The patent uses periodic action with multiple heating cycles at moderate temperature rather than a single high-temperature heating. This approach maintains paper quality by avoiding excessive heat while still achieving efficient erase through repeated heating actions, each contributing to progressive image removal.
Solution Approach 2:
The first heating operation serves as a preliminary action that removes the majority of the image at moderate temperature, preserving paper quality. The second heating then completes the erase of remaining afterimage and memory density, avoiding the need for excessive high-temperature heating that would damage the paper.
3Manufacturing precision
If humidity is increased to reduce memory density, then erase quality improves, but processing time increases
Solution Approach 1:
The patent applies preliminary action by performing humidity treatment between the first and second heating operations. This preliminary humidity preparation facilitates more effective memory density reduction during the second heating, achieving better erase quality without requiring excessive processing time in a single step.
Solution Approach 2:
The patent uses periodic action with alternating heating and humidity treatment cycles. The control unit coordinates the heating unit and humidity generation unit to perform sequential operations, where each cycle progressively reduces afterimage and memory density, balancing erase quality with reasonable processing time through repeated moderate interventions.
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 apparatus effectively nonvisualizes afterimages and reduces memory density to a hard-to-recognize level, enabling efficient reuse of paper by optimizing heating processes and humidity control.
Implementation Method 1
a heating unit that heats the paper sheet
Implementation Method 2
a feedback mechanism that supplies the paper sheet heated by the heating unit to the heating unit again
Data Source
AI summary
According to one embodiment, an image erasing apparatus decolors an image printed on a paper sheet using an ink containing at least a leuco dye, a developer, water, a water-soluble organic solvent, and a surfactant. The image erasing apparatus includes a heating unit, a feedback mechanism, and a control unit. The heating unit heats the paper sheet. The feedback mechanism supplies the paper sheet heated by the heating unit to the heating unit again. The control unit causes the feedback mechanism to supply the paper sheet to the heating unit a plurality of times so as to heat the paper sheet a plurality of times.