Image Scanning Device Control Method for Paper Bill Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image scanning devices for paper bills suffer from low scanning accuracy due to issues like output saturation and phosphorescence afterglow, leading to reduced contrast and inaccurate identification of genuine vs. counterfeit bills.
Innovation Solution
An image scanning device with a controller that controls the light source's emission time and acquires electric signals both during and after emission, employing an interweaved scanning method to avoid disturbances, and using a gray sample for compensation to enhance contrast.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If transmission scanning method is used, then scanning speed is improved, but output saturation occurs on photosensitive sensor due to direct irradiation of light source, generating incidental image and reducing scanning accuracy
Solution Approach 1:
The patent applies periodic action by using intermittent light source emission instead of continuous illumination. The controller controls the light source to emit light periodically, with specific timing sequences that allow the photosensitive sensor to capture images at appropriate moments when direct light irradiation is avoided, thereby preventing output saturation while maintaining scanning efficiency
Solution Approach 2:
The patent maintains continuity of useful action through coordinated operation of multiple light sources and the sensor. While one light source is emitting, another is preparing or the sensor is capturing data, ensuring that the scanning process continues without interruption. The controller coordinates the emission timing of red, green, and blue light sources with the sensor's data acquisition to maintain continuous scanning operation
2Loss of information
If ultraviolet light source is used for reflection scanning, then secondary light excitation is achieved, but phosphorescence afterglow disturbs other colors and reduces scanning accuracy
Solution Approach 1:
The patent uses periodic action by controlling the ultraviolet light source to emit in specific time intervals and sequences. The controller emits ultraviolet light to excite secondary light, then waits for the phosphorescence afterglow to subside before emitting other wavelengths or capturing images that would be disturbed by the afterglow, thereby eliminating the harmful effect while maintaining the useful secondary light detection
Solution Approach 2:
The patent applies preliminary action by pre-cooling the photosensitive sensor or pre-timing the emission sequence before ultraviolet irradiation. The controller is configured to emit ultraviolet light only after the sensor has been prepared and will capture the secondary light signal before the phosphorescence afterglow becomes significant, preventing the afterglow from interfering with the measurement
3Device complexity
If line-by-line sampling with white sample compensation is used, then scanning process is simplified, but contrast of scanned secondary light image is poor and image is not clear
Solution Approach 1:
The patent introduces an intermediary gray sample with specific optical density (OD≥0.1) between the light source and the sensor during the compensation process. This gray sample serves as a mediator that provides a reference signal with appropriate attenuation, allowing the controller to accurately calibrate the sensor's response and subsequently enhance the contrast of the scanned secondary light images without complicating the overall scanning process
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 significantly improves the accuracy of paper bill identification by mitigating the effects of output saturation and phosphorescence afterglow, resulting in clearer and more accurate scanned images with enhanced contrast.
Implementation Method 1
authenticity detection performed by means of scanning secondary light excited by an ultraviolet light source or an infrared light source etc. The secondary light refers to fluorescent light
Implementation Method 2
phosphorescent light and infrared light etc. excited and generated by irradiation of irradiation light on printing ink and paper
Implementation Method 3
a photosensitive sensor... convert light signals from the lens into electric signals
Data Source
Figure 1~2
Figure 3~5
Figure 6~8
AI summary
The invention discloses an image scanning device and a control method thereof, wherein the image scanning device includes: a bearing member, configured to receive a paper bill; a light source; a lens, wherein the incidence side of the lens and the bearing member are correspondingly arranged and the lens is configured to receive reflected light or transmission light of the paper bills under the irradiation of the light source and receive emitted light of the light source; a first converter, arranged on the emergent side of the lens and configured to convert light signals from the lens into electric signals; a controller, connected with the light source and the first converter, and configured to control the light emitting time of the light source, acquire the electric signals during the light emitting process of the light source, and acquire the electric signals again after the light source stops emitting light for a preset period of time. Through the invention, the problem of low accuracy of paper bill scanning in the prior technologies is solved, and the effect of increasing the accuracy of paper bill identification is achieved.