Touchpad Reaction Force Design for Clear Touch and Push Input
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Solution Overview
Problem
Existing touchpad input devices cannot distinguish between touch and push operations, leading to accidental push inputs during touch operations due to finger contact with the surface.
Innovation Solution
An input device with an electrostatic sensor, a push switch, a transmission member, and an actuator that generates vibration, providing distinct reaction forces in different stroke regions to differentiate between touch and push operations through tactile feedback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a touchpad allows both touch operation and push operation with finger contact, then the input device supports multiple input methods, but the operator cannot recognize which operation they are performing leading to accidental push operations
Solution Approach 1:
The actuator generates vibration that is transmitted to the operation panel via the transmission member. When lateral movement of the finger is detected during a touch operation, the actuator vibrates, providing tactile feedback to distinguish touch operations from push operations and prevent accidental pushes.
Solution Approach 2:
The electrostatic sensor detects lateral movement of the finger during touch operations and triggers the actuator to generate vibration. This feedback mechanism provides tactile distinction between touch and push operations, allowing operators to recognize their actions accurately and prevent accidental push operations.
2Reliability
If the operation panel is pushed deeply to activate a push switch, then the push operation is reliably detected, but the reaction force changes abruptly making it difficult to distinguish from heavy touch operations
Solution Approach 1:
The stroke region is divided into a first stroke region and a second stroke region. In the first stroke region, only the first elastic portion is engaged providing a first reaction force. In the second stroke region, both the first elastic portion and the push switch are engaged providing a second reaction force that is a resultant force of both components. This segmentation creates distinct reaction force characteristics for different operation depths.
Solution Approach 2:
The reaction force characteristics change based on the stroke region. In the vicinity of the boundary between the first stroke region and the second stroke region, the amount of change in the first reaction force with respect to stroke length is less than the amount of change in the second reaction force. This parameter change provides tactile feedback to distinguish push operations from touch operations.
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
Prevents accidental push operations during touch operations by providing clear tactile differentiation between touch and push strokes, allowing operators to recognize their actions accurately.
Implementation Method 1
an electrostatic sensor, where the operation panel allows a touch operation and a push operation to be performed thereon
Implementation Method 2
an actuator configured to generate vibration. The touch operation is an operation performed by the operator to touch a surface of the operation panel with the operator's finger and move the operator's finger. If lateral movement of the finger is detected by the electrostatic sensor in the touch operation, the actuator vibrates, and the vibration is transmitted to the operation panel via the transmission member.
Implementation Method 3
In a first stroke region in which the operation panel is pushed in the touch operation, a first reaction force exerted by pushing the operation panel is generated by the first elastic portion.
Implementation Method 4
In a second stroke region subsequent to the first stroke region in the push operation, a second reaction force exerted by pushing the operation panel is a resultant force of the reaction force generated by the first elastic portion and the operation feeling generated by the push switch.
Data Source
AI summary
An input device is characterized in that in a first stroke region in which an operation panel is pushed during a touch operation, a first reaction force that occurs by pushing the operation panel is generated by the first elastic portion. In a second stroke region including a stroke longer than in the first stroke region and a stroke for performing a push operation, a second reaction force that occurs by pushing the operation panel is a resultant force generated by a first elastic portion and the push switch. In the vicinity of a boundary between the first stroke region and the second stroke region, the amount of change in the first reaction force with respect to a stroke length is less than the amount of change in the second reaction force with respect to a stroke length.