| 摘要 |
<p>A signal generating system for an electronic musical instrument utilizing an electronic beam tube with a radiation intercepting structure and means to derive a signal from beam current pulses produced by scanning the structure. The width of pulses is modulated according to the width of individual components of the structure and the pulse width modulated wave is transformed to analog form by a low pass filter. The structure includes several aligned sections and the widths of each section at corresponding points of alignment are representative of the pulse-sampled amplitudes of the tonal qualities of different musical instruments. The rate of repetitively scanning the mask determines the frequency of the musical note generated, and the signal that forms the note is produced by direct pick up of beam current from the radiation intercepting structure if the structure is a conductive target inside the tube or by secondary emission or by electro-optic transducing means in the case of an optical mask on a light-emitting tube.</p> |
