Multi-Key Input Scanning With Variable Hold Time Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional input devices with multiple keys require a lengthy selection holding time to accurately determine operational states, leading to inefficiencies in high-speed output detection due to the need for uniform waiting times across all keys, including those in non-operational and operational states.
Innovation Solution
The input device employs a control unit that sets varying selection holding times based on output variations, using a common reference potential and a switching unit to sequentially connect input keys to a lower potential, allowing for shorter holding times for non-operational keys and longer times for operational keys, thereby optimizing detection speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a uniform selection holding time is applied to all input keys, then accurate detection of operational states is achieved, but detection time is extended due to waiting for voltage stabilization in non-operational keys
Solution Approach 1:
The patent applies different selection holding times to different input keys based on their operational states. Non-operational keys use a shorter selection holding time, while operational keys use a longer selection holding time to allow voltage stabilization. This localized differentiation resolves the contradiction by optimizing detection time for each key individually rather than using a uniform time for all keys.
Solution Approach 2:
The patent dynamically adjusts the selection holding time based on the operational state of each input key. The control unit determines whether each key is operational or non-operational and sets the holding time accordingly. This dynamic adaptation allows the system to minimize detection time while maintaining accurate detection of operational states.
2Measurement precision
If the selection holding time is extended to detect operational keys accurately, then detection precision is improved, but productivity decreases due to slower overall detection speed
Solution Approach 1:
The patent applies different selection holding times to different input keys based on their operational states. Non-operational keys use a shorter selection holding time, while operational keys use a longer selection holding time to allow voltage stabilization. This localized differentiation resolves the contradiction by optimizing detection time for each key individually rather than using a uniform time for all keys.
Solution Approach 2:
The patent segments the detection process into different time intervals for different keys. By dividing the input keys into operational and non-operational groups and applying different holding times to each group, the system achieves both high precision for operational keys and high overall detection speed through parallel processing of multiple keys with different timing requirements.
3Stability of the object's composition
If a longer selection holding time is used for all keys, then voltage stabilization is ensured for operational keys, but time loss increases due to unnecessary waiting for non-operational keys
Solution Approach 1:
The patent applies different selection holding times to different input keys based on their operational states. Non-operational keys use a shorter selection holding time, while operational keys use a longer selection holding time to allow voltage stabilization. This localized differentiation resolves the contradiction by optimizing detection time for each key individually rather than using a uniform time for all keys.
Solution Approach 2:
The control unit automatically determines the operational state of each input key and sets the appropriate selection holding time without external intervention. The system self-adjusts the detection parameters based on the actual state of each key, eliminating unnecessary waiting time for non-operational keys while ensuring proper stabilization time for operational keys.
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 significantly reduces the time required to detect outputs for all keys, enabling high-speed detection by differentiating between operational and non-operational states without the need for uniform waiting times, thus enhancing detection efficiency.
Implementation Method 1
Each input key whose output varies according to a variation in the pressing force applied thereto is composed of a resistor formed on a substrate and an elastically deformable contact disposed opposite to the resistor. When the input key is operated to cause the contact to be pressed against the resistor, the resistance value varies due to a variation in the contact area between the contact and the resistor
Data Source
AI summary
An input device is provided. An input device includes a plurality of input keys; a voltage setting unit; a switching unit; a detecting unit; and a control unit. When the switching unit selects one of the input keys, the control unit controls the detecting unit to detect voltages at least two times for a selection holding time where the selection of the input key is held. When the detected voltages do not vary or in a switching state where the variation is within a predetermined range, the control unit controls the switching unit to select the next input key after the selection holding time of the input key has elapsed. When the voltages detected at least two times vary or when the variation is beyond the predetermined range, the control unit sets the selection holding time of the input key to be longer than the switching state.