RF Bill Discrimination Using Signal Voltage Analysis
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Solution Overview
Problem
Traditional bill discrimination apparatuses face limitations in accurately determining the thickness and state of bills, particularly old bills or those with attached tape, due to high manufacturing costs and low reliability, and struggle to detect foreign objects or security threads effectively.
Innovation Solution
A bill discrimination apparatus and method using a radio frequency (RF) signal to detect the thickness, state, and presence of foreign objects on bills by analyzing the voltage of the RF signal transmitted through the bill, allowing for accurate differentiation between normal and tampered bills, including those with security threads or multiple overlaid bills.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional ultrasonic or displacement methods are used to detect bill thickness, then manufacturing cost is reduced, but measurement precision and reliability deteriorate
Solution Approach 1:
The patent replaces traditional mechanical thickness detection methods (ultrasonic sensors, displacement sensors) with an electromagnetic field-based RF detection system. The RF signal transmission characteristics change when bills are stacked, allowing the control unit to detect bill count and thickness without mechanical contact, thereby maintaining low manufacturing cost while improving measurement precision and reliability.
Solution Approach 2:
The patent utilizes changes in RF signal transmission parameters (signal strength, phase, or frequency) as bills are inserted between the antennas. By monitoring these parameter variations, the system accurately determines bill thickness and count without requiring complex mechanical measurement devices, thus achieving high precision at low cost.
2Device complexity
If traditional light-based methods are used to detect bill state, then device complexity is reduced, but reliability deteriorates due to errors
Solution Approach 1:
The patent replaces optical detection systems with an RF electromagnetic field-based system. The RF signals penetrate the bills and their transmission characteristics reveal information about bill state (authenticity, damage, tape attachment). This substitution maintains simple device architecture while significantly improving detection reliability by avoiding the errors inherent in optical methods.
3Measurement precision
If RF signal transmission method is used to detect bill thickness and state, then measurement precision and reliability are improved, but device complexity increases
Solution Approach 1:
The RF detection system serves multiple functions simultaneously: it detects bill thickness, bill count, bill state (authenticity, damage), and foreign objects. By using a single RF transmission-reception system for all these detection tasks, the patent achieves high measurement precision across multiple parameters without proportionally increasing device complexity.
Solution Approach 2:
The system monitors multiple RF signal parameters (amplitude, phase, frequency shifts) to extract various bill characteristics from a single detection system. This multi-parameter analysis enables comprehensive bill assessment without requiring separate specialized sensors for each measurement type, thus improving precision while controlling complexity.
4Measurement precision
If RF signal analysis is used to detect foreign objects and security threads, then detection accuracy is improved, but use of energy increases
Solution Approach 1:
The patent employs periodic RF signal transmission with the control unit sending signals at intervals as bills pass through the detection zone. This periodic action allows sufficient time for signal transmission, reception, and analysis while minimizing energy consumption by keeping the system inactive between measurement cycles, thus achieving high detection accuracy without excessive energy use.
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 RF-based method enhances accuracy and reduces manufacturing costs by providing reliable discrimination of bill conditions and foreign objects, improving the detection of tampered or damaged bills, and reducing errors associated with traditional ultrasonic or light-based methods.
Implementation Method 1
a transmission antenna radiating a radio frequency (RF) signal; a reception antenna receiving the RF signal from the transmission antenna
Data Source
AI summary
A bill discrimination apparatus and method using a radio frequency (RF) signal that includes a transmission antenna radiating the radio frequency (RF) signal; a reception antenna receiving the RF signal from the transmission antenna; and a control unit providing the RF signal to the transmission antenna, and detecting a thickness of a bill, a state of the bill, or a presence of a foreign object on the bill based on a voltage of the RF signal transmitted through the bill and received by the reception antenna when the bill is between the transmission antenna and the reception antenna. The RF signal has a preset, specific frequency.