| 摘要 |
PURPOSE:To represent a variable density pattern by utilizing the interference between a density amplitude waveform and a reference grating. CONSTITUTION:Sampling is carried out firstly by using scanning lines. Namely, a density amplitude is represented by a waveform. The maximum value of the density amplitude of this waveform is about a half the pitch of the scanning lines and its thickness is about a half the pitch of the scanning lines. Thus, the amplitude waveform representing the density distribution corresponds to each scanning line and is drawn at the same pitch with the scanning lines. When a pattern is drawn on transparent paper and superposed upon the waveform, and then only part of the density waveform is seen through the transparent part of the pattern. The waveform appearing at the transparent part has a more white part then the width of the transparent part where the original density pattern is seen brightly, but has a less white part and a more black part where the original density pattern is seen dark. Namely, it seems that the density is nearly proportional to the amount of the dark part. When this is viewed at slight distance, the pattern having variable density is recognized through human eyes.
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