摘要 |
Methods and apparatus are provided for recording/reproduction of data in a probe-based data storage device (1) in which application of a write signal causes formation of an indentation in a storage surface (5) by a probe of the device (1). Instead of storing information in the presence or absence of indentations on the storage surface as is conventionally done in such devices, information is stored in the form of grooves of variable length separated by lands of variable length. More particularly, a sequence of n>1 successive bits of a first value (typically “1's”) in a recording signal is recorded by applying a series of write signals at respective probe-positions on the storage surface (5). These probe-positions are spaced at w≦̸M, where M is the indentation merging distance, so that the resulting indentations merge to form a groove in the storage surface (5) spanning n readback sample positions. The readback signal corresponding to the recording signal is sampled at timings corresponding to the readback sample positions to recover the original bit sequence. High density recording is provided because the readback sample position spacing s here satisfies s<D, where D is the indentation interference threshold.
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