| 摘要 |
PURPOSE:To reduce greatly the return distortion of a luminance and a color signal generated owing to the spatial sampling of a photosensitive part which is spatially discrete and to obtain a reproduced color image of high quality by changing directions of optical band limitation and obtaining square-law characteristics of the cosine of the return distortion. CONSTITUTION:A direction shown by dotted lines is an optical band limitation direction; and conventional optical band limitation crossing space frequency positions (0, + or -1/2Py) and (+ or -1/2Px, 0) is not performed and band limitation on diamond-shaped lines connecting (0, + or -1/2Px, + or -1/4Py) and (+ or -1/Px, 0) is carried out. Band limitation characteristics of a conventional filter are compared with those of this invention and then characteristics of respective band-limiting filters in directions of axes Wy, Ws, and Wx are as shown by dotted lines in figures (a), (b), and (c). Solid lines indicate characteristics of a conventional example. A return distortion component almost at a zero-beat point is suppressed greatly with cosine square-law characteristics. Zero beats generated at the position (1/2Px, 0) have almost no variation inside of the position, but have the peak reduced almost to half outside of it with the cosine square-law characteristics.
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