| 摘要 |
PROBLEM TO BE SOLVED: To provide an audiovisual device for correcting aberrations such as the color aberration of an acoustic lens or the like and obtaining acoustic images correctly focused to an object. SOLUTION: A two-stage transducing system is adapted and the acoustic images to be formed by a main lens 1 are electroacoustically transduced by a receiver array on a surface different from the focus surface and received as a reception signal group. The reception signal group is introduced through an A/D converter array 5 to a digital signal processor 6, many partial video images are image-formed by image formation transformation such as Fourier transformation for the respective sub apertures of the receiver array 4 there and final video images are obtained by editing the partial video images. The contents of the image formation transformation are corrected for each position of the sub aperture, that is the degree of eccentricity from an optical axis, and each observation frequency. As the result of correction, the focus of the entire system is precisely matched with the object and the video images for which one or more kinds of the aberrations including the color aberration intrinsic to the main lens 1 are corrected are obtained. |
