Ultrasonic Headset Button Control via Impedance Encoding
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Solution Overview
Problem
Conventional headset button arrangements for electronic devices, such as cellular telephones, offer limited functionality and can introduce undesirable clicking noises during normal use, especially when actuated during microphone operations.
Innovation Solution
The use of resistively encoded buttons and ultrasonic tone generation in headsets that convey button press data as ultrasonic signals over the microphone and ground lines, allowing for simultaneous button control and voice communication without interrupting audio signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional button arrangements are used in headsets, then button functionality is provided, but clicking noises are introduced during microphone operation
Solution Approach 1:
The patent replaces the mechanical button-actuation method (which generates clicking noises) with an ultrasonic tone-based communication system. The button press is detected by measuring changes in electrical impedance across the microphone line, and this information is encoded as ultrasonic tones transmitted to the electronic device. This substitution eliminates mechanical contact noise while preserving button functionality.
Solution Approach 2:
The patent introduces ultrasonic tones as an intermediary carrier to transmit button press information. Instead of directly shorting the microphone line to ground (which causes audible clicks), the system uses ultrasonic frequency signals as a mediator to convey control commands. The electronic device detects these ultrasonic tones and interprets them as button inputs, thereby eliminating harmful audible noises.
2Ease of operation
If button press detection short circuits the microphone line to ground, then button input is registered, but audio signals are interrupted
Solution Approach 1:
The patent changes the detection parameter from electrical short-circuiting (voltage change) to impedance measurement. By measuring impedance changes across the microphone line in response to button presses, the system can detect button inputs without creating complete short circuits. This allows the microphone line to remain electrically continuous for audio transmission while still enabling reliable button input detection through impedance variations.
3Adaptability or versatility
If additional contacts are added to the audio connector for microphone signals, then microphone functionality is enabled, but connector complexity increases
Solution Approach 1:
The patent makes the existing audio connector contacts serve multiple functions. The tip and ring contacts, originally designed for audio only, are also used to carry microphone signals and detect button presses through impedance measurements. By implementing multi-functionality in the existing connector architecture, the system enables microphone capabilities without adding physical contacts, thereby avoiding increased connector complexity.
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 seamless button control of electronic devices, like pausing media or answering calls, without audible interference or disruption of microphone signals, enhancing user interaction and reducing noise issues.
Implementation Method 1
The accessory may have an ultrasonic tone generator that conveys ultrasonic tones in response to user input activity
Data Source
AI summary
Electronic devices and accessories such as headsets for electronic devices are provided. A microphone may be included in an accessory to capture sound for an associated electronic device. Buttons and other user interfaces may be included in the accessories. An accessory may have an audio plug that connects to a mating audio jack in an electronic device, thereby establishing a wired communications link between the accessory and the electronic device. The electronic device may include power supply circuitry for applying bias voltages to the accessory. The bias voltages may bias a microphone and may adjust settings in the accessory such as settings related to operating modes. User input information may be conveyed between the accessory and the electronic device using ultrasonic tone transmission. The electronic device may also gather input from the accessory using a voltage detector coupled to lines in the communications path.