Hand Dryer Capacitive Detection for Universal User Accessibility
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Solution Overview
Problem
Conventional hand dryers are inaccessible to children and individuals in wheelchairs due to sensor placement, and they often project water droplets onto the floor during use, causing cleanliness issues in public places.
Innovation Solution
A hand dryer design featuring capacitive detectors made of continuous conductive elements around the perimeter of the opening, allowing detection from any side and minimizing water projection through strategically arranged air blowing holes and surfaces that create air curtains to deflect droplets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If proximity sensors are incorporated on the upper side of the facing surfaces, then the hand dryer can be activated by users of normal height, but children and persons in wheelchairs cannot easily activate it
Solution Approach 1:
The detection system is segmented into multiple zones: upper detection zone and lateral detection zones. The capacitive detector is divided into multiple capacitive zones that can independently detect hands at different positions, allowing activation from various heights and angles.
Solution Approach 2:
The detection capability is extended from a single upper zone to multiple dimensions by adding lateral detection zones. The capacitive detector covers not only the upper facing surface but also extends to lateral surfaces, creating a three-dimensional detection volume that accommodates users of different heights and positions.
2Ease of operation
If the cavity is opened superiorly and laterally for hand insertion, then users can easily insert their hands, but water droplets are projected onto the floor through the side openings
Solution Approach 1:
An air curtain is introduced as an intermediary barrier between the drying cavity and the external environment. This stream of air acts as a mediator that prevents water droplets from escaping through the lateral openings while allowing hand insertion to proceed normally.
Solution Approach 2:
The air stream that could potentially carry water droplets outward is redirected to form a protective air curtain. The same air flow mechanism is converted from a potential source of droplet projection into a protective barrier that prevents droplet escape, transforming a harmful effect into a beneficial one.
3Device complexity
If conventional sensors are used in hand dryers, then the detection system is simple, but the sensors must be placed on upper surfaces making them inaccessible to children and wheelchair users
Solution Approach 1:
The capacitive detector serves multiple functions: it detects hands from upper positions, lateral positions, and various heights simultaneously. This multi-functional detection system replaces the need for multiple separate sensors positioned at different locations, maintaining simplicity while achieving universal accessibility.
Solution Approach 2:
The capacitive detection principle is applied to multiple surfaces (upper and lateral) creating a distributed detection network. Rather than using different types of sensors for different positions, the same capacitive detection technology is replicated across multiple zones, simplifying the overall system architecture.
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
Enables easy activation for users of varying heights and abilities without modifying existing components and significantly reduces water droplet projection onto the floor, maintaining cleanliness.
Implementation Method 1
the detecting means comprise a capacitive detector made of at least a continuous conductive element
Implementation Method 2
the volume being delimited by two facing walls and provided with blow holes
Implementation Method 3
air blown is injected before its ejection by the holes
Data Source
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AI summary
Hand dryer (1) having volume (V) for receiving the hands delimited by two facing walls (2, 3) and provided with blow holes (4), an opening delimiting the volume (V) by its sides superior (L1) and lateral (L2, L3), the walls (2, 3) being provided in their part opposed to the volume (V) for receiving the hands with a fence (5) delimiting a volume (VS) wherein air is injected blown before its ejection by the holes (4), each one of the fences comprising an upper wall (51), two lateral walls (52, 53) and a lower wall (54), the hand dryer (1) being provided with means for detecting the introduction of hands in the volume (V), wherein the detecting means comprise a capacitive detector made of at least a continuous conductive element (C1) which runs in the vicinity of the upper (51) and lateral (52, 53) walls of one of the fences (5).