Variable-Length Distributed Mode Actuator for Wider DML Frequency Range
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Solution Overview
Problem
Distributed mode loudspeakers (DMLs) face limitations in generating a wide range of frequencies, which affects their ability to accurately reproduce sounds, particularly in varying output modes and volumes.
Innovation Solution
The DML adjusts the length of its cantilevered portion by changing the length of the supported portion of the distributed mode actuator, allowing for dynamic selection of fundamental frequencies based on output mode, content type, and volume, using a frequency selection module to send signals to the support element to alter the actuator's resonance mode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the DML uses a fixed-length actuator, then the structure is simple, but the frequency range is limited
Solution Approach 1:
The patent applies the dynamics principle by making the actuator length adjustable rather than fixed. The support element can change its length dynamically based on control signals, allowing the cantilevered portion length to vary. This enables the DML to adapt its fundamental frequency to different operating conditions (handheld vs. hands-free mode, different volume levels) while maintaining a relatively simple overall structure without requiring multiple separate actuators.
2Adaptability or versatility
If the DML increases the cantilevered portion length for lower frequencies, then low frequency reproduction improves, but the device size increases
Solution Approach 1:
The patent uses the dynamics principle to allow the actuator length to change based on operating mode. In handheld mode, the support element extends to provide a longer cantilevered portion for better low-frequency reproduction. In hands-free mode, the support element retracts to shorten the cantilevered portion. This dynamic adjustment enables the device to achieve good low-frequency performance when needed without permanently increasing the device size.
3Adaptability or versatility
If the DML adjusts the supported portion length to change frequency, then frequency adaptability improves, but the control complexity increases
Solution Approach 1:
The patent applies the parameter changes principle by adjusting the physical parameter of actuator length to change the fundamental frequency. The frequency selection module determines the appropriate length based on operating mode (handheld/hands-free) and volume level, then controls the support element to achieve the desired cantilevered portion length. This approach changes a key physical parameter (length) to achieve frequency adaptability while keeping the control logic relatively straightforward based on mode and volume detection.
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 enables DMLs to generate sounds in a wider range of frequencies and higher volumes, leading to more accurate sound reproduction and improved performance across different usage scenarios.
Implementation Method 1
A DML may use a distributed mode actuator ('DMA'), e.g., a piezoelectric transducer, to cause the panel to vibrate and generate sound
Implementation Method 2
The support element may include an electroactive element. When the electroactive element receives the signal, a shape of the support element changes
Data Source
AI summary
Methods, systems, and apparatus, including computer programs encoded on computer storage media, for changing a distributed mode loudspeaker's fundamental frequency. One of the systems includes a distributed mode loudspeaker comprising an actuator that includes: a supported portion, and a cantilevered portion having a length, a first fundamental frequency, and adapted to create a force to cause vibration of a load to generate sound waves using the first fundamental frequency; a support element connected to the supported portion of the actuator and adapted to adjust, based on a change to a shape of the support element, a size of the length of the cantilevered portion to change the first fundamental frequency to a second fundamental frequency with which the load will generate sound waves; and a frequency selection module that provides a signal to the support element to cause the support element to change shape.