Hand Dryer Sensor Control for Fast and Reliable Hand Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing hand dryer devices face issues with false hand detection due to noise, leading to delayed detection and increased drying time, and require extended cycle times when no hand is detected, resulting in inefficient operation.
Innovation Solution
The hand dryer device employs a control unit that uses a majority decision among hand detection determination results from multiple cycles to improve accuracy and reduce power consumption, with intermittent driving cycles adjusted based on detection results to minimize false positives and speed up operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple hand detection determinations are made to reduce false detection due to noise, then hand detection accuracy is improved, but the hand detection determination time is delayed
Solution Approach 1:
The control unit performs preliminary hand detection determinations during the intermittent driving periods before the blower unit needs to start. By making multiple determinations in advance and storing the results, the system准备好 the detection outcome so that when a hand is actually detected, the blower can start immediately without waiting for additional determination cycles.
Solution Approach 2:
The system dynamically adjusts the number of determination cycles based on the detection results. When a hand is detected in one of the preliminary determinations, the system stops making further determinations and immediately activates the blower, rather than completing a fixed number of cycles regardless of outcome.
2Use of energy by moving object
If the cycle time of intermittent driving is increased in the absence of hand detection, then power consumption is reduced, but the time for next hand detection determination increases
Solution Approach 1:
During periods when no hand is detected, the control unit performs preliminary hand detection determinations in advance during the intermittent driving cycles. By preparing the detection results beforehand, the system ensures that when a hand appears, the detection outcome is already available, eliminating the need to wait for the next intermittent driving cycle to start the blower.
3Speed
If only one hand detection determination is made, then the operation response is fast, but false detection due to noise occurs
Solution Approach 1:
The control unit performs multiple hand detection determinations in advance during intermittent driving periods before the blower needs to start. By preparing multiple detection results beforehand, the system has ready-made reliable outcomes so that when a hand is detected, the blower can activate immediately without compromising detection reliability.
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 approach enhances hand detection accuracy, reduces power consumption, and decreases drying time by quickly activating the blower unit when a hand is detected, while preventing noise-induced malfunctions and ensuring efficient operation.
Implementation Method 1
a hand detection unit having a light-emitting element to detect presence or absence of the hand in the drying space
Implementation Method 2
a blower unit to generate the airflow to be blown out of the nozzle
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A hand dryer device (1) includes hand dryer nozzles (3a, 3b) to blow airflows into a hand drying portion (3) in which a hand is placeable, a blower unit (6) to generate the airflow to be blown out of the hand dryer nozzles (3a, 3b), a hand detection sensor (11) having a light-emitting element to detect the presence or absence of the hand in the hand drying portion (3), and a control unit (12) to make a hand detection determination of whether the hand is present or absent in the hand drying portion (3) on the basis of a detection result of the hand detection sensor (11), and control driving of the blower unit (6) on the basis of a determination result of the hand detection determination. The control unit (12) controls an intermittent driving of the light-emitting element of the hand detection sensor (11). In consecutive first and second driving cycles of the hand detection sensor (11), when a determination result in the first driving cycle and a first determination result in the second driving cycle differ from each other, the control unit extends a driving period of the hand detection sensor (11) in the second driving cycle.