Slider Phone Key Debounce for Accidental Press Filtering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Users often inadvertently activate keys on electronic devices with slider form factors when opening or closing them, leading to accidental key presses and user frustration due to the movement of housings relative to each other.
Innovation Solution
Implementing modules in electronic devices to modify key press processing by setting different debounce limits based on housing movement, canceling registered key presses if movement occurs shortly after, and increasing debounce time for error-prone keys when housing movement is detected, thereby reducing accidental key activations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a key press is registered with a standard debounce limit, then key response speed is improved, but accidental key presses during housing movement are not filtered out
Solution Approach 1:
The patent applies dynamics by making the debounce limit adjustable based on housing movement state. The system dynamically switches between a first debounce limit (when housing is stationary) and a second debounce limit (when housing is moving), allowing the key press registration criteria to adapt to the current operational context. This resolves the contradiction by using a longer debounce limit during housing movement to filter accidental presses while maintaining a shorter limit during stable operation for faster response.
Solution Approach 2:
The patent changes the debounce limit parameter based on the housing movement state. When the housing is detected to be in motion, the system switches to a second debounce limit value that is longer than the first debounce limit value used when the housing is stationary. This parameter change allows the system to filter out accidental key presses during movement while maintaining normal response speed during stable operation.
2Reliability
If a longer debounce limit is used for all key presses, then accidental key presses are filtered out, but legitimate key presses are delayed
Solution Approach 1:
The system dynamically adjusts the debounce limit based on housing movement detection. When the housing is stationary, a shorter first debounce limit is applied to ensure quick response to legitimate key presses. When housing movement is detected, the system switches to a longer second debounce limit to filter accidental presses. This dynamic adjustment eliminates the need for a universally long debounce limit, thus avoiding unnecessary delays for legitimate key presses.
Solution Approach 2:
The patent implements parameter changes by switching between two debounce limit values based on the housing movement state. The first debounce limit (shorter) is applied when the housing is stationary, and the second debounce limit (longer) is applied when the housing is moving. This conditional parameter change ensures that longer debounce times are only applied when necessary for filtering accidental presses, minimizing time loss for legitimate key presses.
3Reliability
If housing movement detection is added, then accidental key presses can be identified, but device complexity increases
Solution Approach 1:
The patent applies self-service by utilizing the existing housing movement detection capability that is already present in slider form factor devices for their primary function. The same movement detection mechanism is repurposed to identify accidental key presses, eliminating the need for separate detection hardware. This approach identifies accidental presses without significantly increasing device complexity.
Data Source
AI summary
A method for key press registration in an electronic device uses a first key press debounce limit (233) if a first housing of the electronic device has not moved relative to a second housing of the electronic device and a second key press debounce limit (236) if the first housing has moved relative to the second housing. In one implementation, the second debounce limit is at least twice the first debounce limit. By using different debounce limits based on whether housing movement has recently been detected, the electronic device reduces the effect of an inadvertent key press made while opening or closing the electronic device.