Receiver Speaker Power Control for Stereo Audio
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Solution Overview
Problem
Current mobile communication devices are limited in their ability to produce high-quality stereo audio due to the power constraints of their speakers, often resulting in uneven playback when trying to reproduce both audio channels simultaneously, as they typically have a single high-power handsfree speaker and a lower-power receiver speaker.
Innovation Solution
A mobile communication device is designed to operate in two modes: call mode and multimedia mode, where the receiver speaker's power level is adjusted to accommodate either close proximity to the ear for voice communications or further distances for media playback, allowing for the simultaneous use of both the handsfree and receiver speakers to reproduce audio channels without the need for a third speaker.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the receiver speaker operates at high power levels for multimedia playback, then audio quality improves, but the speaker may be damaged due to excessive power
Solution Approach 1:
The system dynamically adjusts the power level of the receiver speaker based on the operational mode. In call mode, the receiver speaker operates at high power suitable for ear proximity, while in multimedia mode, it operates at reduced power levels appropriate for greater listening distances, preventing speaker damage while maintaining audio quality
Solution Approach 2:
The patent changes the power parameter of the receiver speaker according to the operational context. By detecting whether the device is in call mode or multimedia mode, the system adjusts the power delivery to the receiver speaker accordingly, optimizing both performance and reliability for each scenario
2Device complexity
If a single high-power handsfree speaker is used for both call and multimedia modes, then device complexity is reduced, but audio quality in call mode deteriorates due to the speaker being positioned away from the ear
Solution Approach 1:
The receiver speaker serves dual functions: in call mode, it operates as a high-power earpiece speaker positioned near the ear for voice communications, and in multimedia mode, it operates as a lower-power auxiliary speaker for stereo audio playback. This multi-functionality eliminates the need for separate speakers for different purposes
3Power
If the receiver speaker is positioned close to the ear for voice calls, then call audio quality improves, but the speaker cannot provide sufficient power for high-quality multimedia playback
Solution Approach 1:
The system dynamically adjusts the power output of the receiver speaker based on its operational role. When positioned close to the ear during calls, it delivers high power for clear voice transmission. During multimedia playback, it operates at lower power levels appropriate for the greater effective listening distance, enabling high-quality stereo reproduction without requiring the speaker to be physically closer to the ear
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 solution enables improved audio quality by allowing the device to produce higher power levels suitable for multimedia use without damaging the speakers, enhancing the user's listening experience by reproducing both audio channels simultaneously at appropriate power levels.
Implementation Method 1
a receiver speaker (676) comprised in an audio subsystem of the mobile communication device (4), the mobile communication device (4) being arranged to select between a first mode of operation, referred to herein as the 'call mode'... and a second mode of operation, referred to herein as the 'multimedia mode'
Data Source
Figure 1
Figure 2-1~2-2
Figure 3-1~3-2
AI summary
An audio subsystem in a mobile communication device (600) has a speaker (676). In one implementation, the audio subsystem (644,700) has a higher-gain power amplifier (708), a lower-gain power amplifier (736), and a switching system (722) configured to route signals produced by the lower-gain power amplifier to the speaker while the device is operative in a first mode and configured to route signals produced by the higher-gain power amplifier to the speaker while the device is operative in a second mode. In another implementation, the audio subsystem (644,750) has a power amplifier (708) coupled to the speaker and a power supply control (726) controlled to provide voltage at a first voltage level (724) to the power amplifier while the device is operative in a first mode and controlled to provide voltage at a second, higher, voltage level to the power amplifier while the device is operative in a second mode.