Optical Time-of-Flight Fill Level Sensor for Coin Tubes

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Solution Overview

Problem

Existing methods for determining the filling level of coin tubes, such as using light barriers and ultrasonic sensors, suffer from inaccuracies and dependencies on environmental conditions, limiting the precision and capacity of coin storage devices.

Innovation Solution

A device employing optical radiation transmitters and receivers to measure the transit time of light pulses reflected from the top of coin stacks, allowing for precise and reliable determination of the filling level independent of external influences, with high-precision sensors ensuring accurate measurement of every coin in the tube.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If light barriers are used to determine fill level, then the structure is simple, but measurement precision is insufficient because only discrete fill level values can be determined

Engineering Contradiction:
Improvefill level measurement precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical light barrier system with an optical time-of-flight measurement system. Instead of using discrete light barriers that detect presence/absence, the invention uses optical radiation transmitters and receivers to measure the time for light to travel to and from the coin stack, enabling continuous and precise fill level measurement while maintaining structural simplicity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the measurement parameter from discrete light barrier interruption detection to continuous time-of-flight measurement. By measuring the time period for optical radiation to travel to the coin stack and back, the system achieves continuous fill level determination rather than discrete values, significantly improving measurement precision.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If ultrasonic sensors are used to measure fill level, then measurement can be obtained, but reliability is reduced due to strong dependence on temperature and humidity

Engineering Contradiction:
Improvemeasurement reliabilityVSAvoidenvironmental dependence
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the ultrasonic acoustic measurement system with an optical measurement system. By using optical radiation instead of sound waves, the invention eliminates the strong dependence on temperature and humidity that affects sound speed, thereby significantly improving measurement reliability and reducing environmental sensitivity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If ultrasonic sensors are used, then fill level can be measured, but productivity is limited due to large blind area requiring minimum distance from top coin

Engineering Contradiction:
Improvecoin tube capacityVSAvoidblind area
Core Design Contradiction:
ProductivityVSArea of stationary object

Solution Approach 1:

The patent replaces ultrasonic sensors with optical radiation transmitters and receivers. Optical radiation has a much smaller blind area compared to ultrasonic sensors, allowing the measurement system to be positioned closer to the top coin. This eliminates the requirement for minimum distance (e.g., 2 cm) and maximizes the usable capacity of the coin tube.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Measurement precision

If discrete light barriers are used, then device complexity is low, but measurement precision is insufficient as coins between barriers are not detected

Engineering Contradiction:
Improvecoin detection accuracyVSAvoidundetected coins
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The invention changes from discrete light barrier detection to continuous time-of-flight measurement. By measuring the exact time for optical radiation to reach the top of the coin stack and return, the system continuously determines the fill level, ensuring that all coins are accounted for and eliminating the information loss that occurs with discrete barrier detection.

Inventive Principle:
Principle #35Parameter changes

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 solution provides accurate and reliable filling level measurements, maximizing the capacity of coin tubes by eliminating blind areas and environmental dependencies, ensuring every coin is accounted for.

Implementation Method 1

optical radiation emitted by the optical radiation transmitter hits coins filled into the at least one coin tube and is reflected by coins filled into the at least one coin tube

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

based on a time period between the emission of optical radiation and the receipt of the corresponding measurement signal by the at least one optical receiver to determine the fill level

Methodology Applied
Scientific EffectTime of flight: Time of Flight

Data Source

PatentEP3274969B1Device for determining the fill level of coin tubes
Publication Date: 2019.11.06 CRANE PAYMENT INNOVATIONS LTD
  • EP3274969B1 patent drawingFigure 1~2

AI summary

The invention relates to a device for determining the filling level of at least one coin tube that can be filled with coins, comprising at least one optical radiation transmitter that is arranged in a defined position relative to the at least one coin tube in such a way that optical radiation transmitted from the optical radiation transmitter impinges on coins filled into the at least one coin tube and is reflected by coins filled into the at least one coin tube, also comprising at least one optical radiation receiver that is arranged in a defined position relative to the at least one coin tube in such a way that optical radiation, which is transmitted by the at least one optical radiation transmitter and reflected by coins filled into the at least one coin tube, is received by the at least one optical radiation receiver as a measurement signal, and comprising a control and evaluation device which is connected to the at least one optical radiation transmitter and the at least one optical radiation receiver, and which is designed to control the at least one optical radiation transmitter for the transmission of optical radiation and to determine the filling level of the at least one coin tube having coins, based on a time period between the transmission of optical radiation and the receiving of the corresponding measurement signal via the at least one optical receiver.