发明名称 |
Even-odd symmetric computation in a polyphonic tone synthesizer |
摘要 |
In a musical instrument having one or more tone generators in which a plurality of data words corresponding to the amplitudes of a corresponding number of evenly spaced reference points defining the waveform of one cycle of an audio signal are transferred sequentially from a note register to a digital-to-analog converter in repetitive cycles at a rate proportional to the pitch of the tone being generated, apparatus is provided for computing the set of data points in the note register from a set of points defining a quarter cycle of the waveform. The calculation of the quarter cycle of data points is divided into two sets. One set is calculated using the odd-numbered harmonics and the other set is caculated using the even-numbered harmonics. The complete waveform is reconstructed from the two sets during the transfer of data to the note registers. By reducing the number of calculated points to one-quarter of a waveform the calculation time is reduced thereby making the instrument capable of faster response to time varying tonal changes.
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申请公布号 |
US4249448(A) |
申请公布日期 |
1981.02.10 |
申请号 |
US19790028038 |
申请日期 |
1979.04.09 |
申请人 |
KAWAI MUSICAL INSTRUMENT MFG CO LTD |
发明人 |
DEUTSCH, LESLIE J;DEUTSCH, RALPH |
分类号 |
G10H7/08;G10H7/10;(IPC1-7):G10H1/08 |
主分类号 |
G10H7/08 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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