[in Japanese]

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[in Japanese]

View full abstract

[in Japanese]

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[in Japanese]

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[in Japanese]

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The behavior of human vision at various locations on the retina is investigated by presenting the alphabetic letters and simple geometric patterns with short exposure durations. The subject is asked to draw the figure perceived or to give a detailed explanation of what has been observed.
As a result, It is clarified that the area of retina in which the concept in the stimulus is “recognized” is limited within a narrow area around fovea and that in the periphery, figures are “perceived”, features are detected or only the existance of stimulus is perceived. In the far periphery, only lightness or darkness is sensed.
The functional difference observed is to be ascribed not only to the characteristic of visual acuity, but to the genetical difference of the areas of retina. And, the difference reflects the hierachal nature of visual information processing system which consists of the steps of simple sensing, intermediate perception and complex recognition.

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The mechanism of television by video signal processing is analyzed, and a ghost reduction circuit is proposed.
The transfer function of television ghost is given by a linear combination of inphase components and quadrature components when a synchronous detection is used. By realizing a circuit with this transfer function, one can reduce not only in-phase components but also quadrature components.
The new method is shown to be efficient by computer simulation and circuit experiment.

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[in Japanese]

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