| 摘要 |
An array of acoustic transmit/receive transducers is placed near the body to be imaged. Acoustic energy is projected upon the body sequentially from different ones of the transducers, each projection covering the entire scene or field of view which it is desired to image. The electrical signals produced from reflected acoustic energy picked up by different transducers are phase shifted, or time delayed as appropriate, so that those from any particular point within the body will additively combine in amplitude, while signals from other points will not. In so doing, there is preserved not only the information about the amplitude of the combined signal from the transducers, but also any information about phase shifts (or time delays as the case may be) which does not result in complete alignment of the signals from the different transducers. The resulting complex signals are further processed, to vectorially add them. The signals produced by this further vectorial addition are then used for the visual display of the image. The resulting image is as if the energy projected upon the body had been formed into a scanning beam which is continuously focused in range at all points in the field of view.
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