Banknote Detection Using Crisscross Photoelectric Sensors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional banknote detection systems in financial self-service equipment face a 'blind zone' issue due to insufficient photoelectric sensors, leading to inaccurate banknote location detection, which is costly to resolve by increasing sensor numbers, especially in long banknote conveying passages.
Innovation Solution
An apparatus using three photoelectric sensors arranged in a crisscross pattern within the banknote passage, including sensors at the entrance, exit, and inside, with strategically placed reflecting mirrors to ensure accurate banknote location detection without increasing sensor count, employing a sensor state recording and determining unit to decode sensor states for precise location calculation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the number of photoelectric sensors is increased to reduce blind zones, then the detection accuracy of banknote location is improved, but the cost and device complexity increase significantly
Solution Approach 1:
The patent applies dimensionality change by arranging photoelectric sensors in a crisscross pattern rather than parallel alignment. The first photoelectric sensor is positioned at the entrance with its light beam crossing the passage width, the second sensor is positioned at the exit with crossing light beam, and the third sensor is positioned inside the passage with crossing light beam. This crisscross arrangement creates multiple detection planes that eliminate blind zones without requiring additional sensors, thereby resolving the contradiction between detection accuracy and device complexity
Solution Approach 2:
The patent introduces a light beam as an intermediary element that traverses the banknote passage in a crisscross manner. The light beam from each photoelectric sensor crosses the passage width and interacts with the banknote at multiple potential locations. This intermediary light beam enables a single sensor to detect banknotes at multiple positions along the passage, effectively eliminating blind zones without increasing sensor count
2Device complexity
If photoelectric sensors are arranged in parallel at certain distances, then the structure is simple, but blind zones are created when the distance exceeds banknote width
Solution Approach 1:
The patent transitions from parallel sensor arrangement to crisscross arrangement, changing the spatial dimension of light beam propagation. Instead of light beams traveling parallel to the passage direction, the light beams now traverse across the passage width in a crisscross pattern. This dimensional change allows the light beam to cover the entire passage width at multiple points, eliminating blind zones while keeping the sensor count low
Solution Approach 2:
The patent inverts the conventional parallel arrangement approach by using crossing light beams instead. Rather than having sensors detect banknotes by direct line-of-sight in parallel, the light beams are oriented to cross the passage, creating detection zones that overlap and eliminate blind spots. This inverted approach achieves better coverage with fewer sensors
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
Accurately determines banknote locations in the passage with only three sensors, effectively eliminating the blind zone problem while maintaining a low cost, enhancing banknote control accuracy and reducing operational expenses.
Implementation Method 1
a banknote location is detected by a photoelectric sensor arranged in the equipment, and determined according to a state of the photoelectric sensor
Implementation Method 2
both of the first reflecting mirror and the second reflecting mirror are arranged in a face-to-face manner at an inclined angle of 45 degrees, to control a light beam emitted by the light-emitting end to be vertically directed to the first reflecting mirror, then reflected to the second reflecting mirror, and then vertically directed to the light-receiving end via reflection by the second reflecting mirror
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A banknote position detection device is provided in a banknote channel. The banknote position detection device comprises: a first photoelectric sensor disposed at a banknote channel inlet, a second photoelectric sensor disposed at a banknote channel outlet, a third photoelectric sensor disposed at a banknote channel middle portion. The first photoelectric sensor comprises a light emitting end, a light receiving end, a first reflector and a second reflector, wherein the light emitting end and the light receiving end are disposed symmetrically at two side ends at an upper inlet of a lower channel plate of the banknote channel, and are configured to detect whether a banknote reaches the banknote channel inlet. The second photoelectric sensor comprises a light emitting end, a light receiving end, a third reflector and a fourth reflector, wherein the light emitting end and the light receiving end are disposed symmetrically at two side ends at an upper outlet of the lower channel plate of the banknote channel, and are configured to detect whether the banknote reaches the banknote channel outlet.