• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.863-864
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• 2010

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.6
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• pp.56-61
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• 2011

A class-D audio amplifier is widely used in coil speaker. This paper presented the technique for applying a class-D audio amplifier to the ceramic flat speaker. This technique can be achieved by employing a matching transmitter in order to replace class-G amplifier that is drven by voltage level to class-D amplifier employing power driving method. Consequently, the presented technique can improve the efficiency by making the voltage driving level a litter larger. We evaluate the sound-level efficiency using the various mediums such as wood, plastic, and paper. From the simulation results, the proposed technique employing a class-D audio amplifier rather than a class-G one showed a 10% improvement. The proposed system can be applicable for the mobile appliances as an external slim speaker.

• Journal of KSNVE
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• v.11 no.2
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• pp.323-328
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• 2001

The paper describes a theoretical study on the flexural vibration of an elastic rectangular plate with periodically nonuniform material properties. The approximate solution of the natural frequency and mode shape has been obtained using the perturbation technique for sinusoidal modulation of the flexural rigidity and mass density. It has been shown that distributed modes exist in the plate which Is a two-dimensional model of the flat panel speaker.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.131-136
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• 2004

스피커는 진동판의 크기와 형태 외에도 소재 또는 내부구조에 따라 구동 특성이 달라진다. 본 연구에서는 동일한 신호가 입력되는 두 진동판 사이에 공동을 형성시킨 경우, 다공성 흡음재를 삽입한 경우 스피커의 특성 변화를 관측하였다. 특히, 다공성 흡음재를 삽입한 경우, 다공성 물질의 체적을 동일하게 하고 진동판 표면 상태에 따른 영향과 진동판 상의 진동 전달 경로에 의한 영향을 제거하여 내부물질에 따른 특성의 변화를 측정하였다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.4
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• pp.333-336
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• 2017

A speaker diaphragm generates a divided vibration. The influence of the break-up mode is sufficient to cause a shape change in the diaphragm. In this paper, is widely used in ultra-thin multi-media devices, including smart phones is the advance guard of the IT sector, the micro-speakers and its target. Micro-speakers are different from general speakers. The plate has structural form and space constraints. In particular, they utilize a closed-type drive space. It is difficult to provide cooling for the auxiliary suspension structure because of the heat generated in the moving coil. The present study considered the relationship between the break-up mode and the heat transfer of the diaphragm. An experiment was conducted in two stages to compare the embodiment of the break-up mode and heat transfer in a certain frequency range. The changes in the heat were determined through measurements and thermal imaging of the break-up mode. The break-up mode tendency of the diaphragm could be rapidly predicted based on the imaging results using the thermal imaging camera. This will help in the optimal design of micro-speakers.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.545-546
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• 2008

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.711-712
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• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.603-604
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• 2010

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.10
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• pp.109-115
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• 2016

In this paper, In this paper, we use two methods to compare the slim speakers. That way, the diaphragm scan using laser and diaphragm photographed using a thermal imaging camera. Slim speaker has the structure of a flat plate type. Break-up mode by this characteristic is displayed in a larger size. Further, since the installation space is narrow, it has limited moving coil cooling. As a result, the break-up mode slim speakers, a significant impact on quality. In this study, try to connect the break-up mode of the diaphragm, the heat transfer mode of the diaphragm. Experiment for comparison, a two-step. The first step is to measure the divided vibration through the vibration plate scan. The second step measures the diaphragm photographed using a thermal imaging camera. Then, compare the results of both of the same frequency. Thus, comparing the heat transfer pattern and the pattern of break-up mode. Tend to be analysis of break-up mode from the pattern comparison, and document for the optimum design.

• The Journal of the Acoustical Society of Korea
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• v.18 no.3
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• pp.73-78
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• 1999

The paper describes a theoretical study on the flexural vibration of an elastic flat bar with periodically nonuniform material properties. The approximate solution of the natura1 frequency and mode shape has been obtained using the perturbation technique for sinusoidal modulation of the flexural rigidify and mass density. The numerical solution obtained by using the finite element method verifies the trend of the approximate solution. It appears that distributed vibrations exist in the low modes, and this approach can be extended to the vibration analysis of the p1ate in the flat panel speaker.