In a document copying machine, a means by which parts of the image of the original is obscured so that it is not produced onto the copy material.

文件复印机上使用的一种方法，将原件映象的某一部分掩盖起来，使其不复印到复印件上。

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In a document copying machine, a means by which parts of the image of the original is obscured so that it is not produced onto the copy material.

文件复印机上使用的一种方法，将原件映象的某一部分掩盖起来，使其不复印到复印件上。

youdao