Coin Acceptor Using Time-of-Flight Proximity Sensing

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Solution Overview

Problem

Conventional coin machines using optical sensors for coin detection are prone to contamination and wear, leading to reduced accuracy and reliability due to dust interference and quick degradation of optical components.

Innovation Solution

A coin machine incorporating proximity sensors, ambient-light sensors, and infrared light sources, utilizing time-of-flight range sensing technology to measure coin distance and quantity, combining these into a single package for enhanced accuracy and reliability, and featuring a control module for managing coin tubes and dispensing operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional optical sensors are used for coin detection, then the sensing device can detect coins in the coin tube, but the optical components wear quickly and are easily contaminated by dust, reducing accuracy and reliability

Engineering Contradiction:

Improvecoin detection reliabilityVSAvoidoptical component service life

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent replaces conventional optical sensors with a proximity sensor that uses electromagnetic fields instead of optical components. This substitution eliminates the problems of dust contamination and optical component wear, as the proximity sensor detects coins through electromagnetic induction without requiring direct optical contact. The proximity sensor measures changes in electromagnetic field caused by the presence of metallic coins, providing reliable detection without the durability issues of optical systems.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If optical sensors are used for coin detection, then coin quantity can be sensed, but dust interference and component wear lead to reduced measurement precision

Engineering Contradiction:

Improvecoin quantity sensing accuracyVSAvoiddust contamination and component wear

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The proximity sensor uses electromagnetic field-based detection instead of optical sensing, eliminating susceptibility to dust interference. The electromagnetic field penetrates through air and minor contaminants without degradation, maintaining measurement precision. Additionally, the solid-state proximity sensor has no moving parts or delicate optical surfaces that can wear, ensuring consistent detection accuracy over extended service periods.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If conventional optical sensing devices are used, then coin detection is possible, but the system requires frequent maintenance and calibration due to contamination and wear

Engineering Contradiction:

Improvecoin machine operational efficiencyVSAvoidsensing device maintenance frequency

Core Design Contradiction:

ProductivityVSEase of repair

Solution Approach 1:

The proximity sensor's electromagnetic field-based operation eliminates the need for optical alignment and cleaning procedures required by conventional optical sensors. The solid-state construction with no moving parts or exposed optical surfaces means the sensor requires minimal maintenance, simply needing power supply connections and basic calibration that remains stable over time. This significantly reduces downtime and maintenance costs while improving overall machine productivity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 provides high detection accuracy and reliability, with long-distance measurement capabilities, fast response, low power consumption, and low manufacturing costs, ensuring precise tracking of coin quantities and status in coin tubes.

Implementation Method 1

measuring the time taken for the reflected light to travel from the coins in the coin tube to the optical sensor module and then multiplying the time thus measured by the speed of light

Methodology Applied

Scientific EffectTime of flight: Time of Flight

Implementation Method 2

combines proximity sensor, ambient-light sensor and infrared light source technologies for detection of coins in coin tubes

Methodology Applied

Scientific EffectInfrared radiation: Infrared Radiation

Data Source

PatentEP3309757A1Coin machine using proximity and ambient light sensing technology

Publication Date: 2018.04.18 INT CURRENCY TECH

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AI summary

A coin acceptor includes main body having coin dispenser mounted therein, coin tubes mounted in the main body and disposed at the bottom side of the coin dispenser, and sensing device including multiple optical sensor modules respectively aimed at the coin tubes. The distance between each optical sensor module and the coins in the respective coin tube is calculated by: measuring the time taken for the reflected light to travel from the coins in the respective coin tube to the proximity sensor of the respective optical sensor module and then multiplying the time thus measured by the speed of light. The number of coins in each coin tube is calculated by: deducting the distance between the respective optical sensor module and the coins in the respective coin tube from the pre-measured depth of the empty coin tube, and then dividing the reminder thus obtained by the thickness of single coin.