Multi-exponent run-length data conversion method and apparatus and red light multi-exponent optical device

Abstract

The present invention provides a multi-level run-length data conversion method for a red-light multi-level optical storage device, wherein the track pitch of the red-light multi-level optical storage device is greater than or equal to 0.52 microns, and the method includes the following steps: a modulation step and Or the demodulation step, wherein, the run-length limited coding that adopts is the 4-yuan (d, k) code of code rate R=5 / 8 bits / symbol, is used for the 5-bit source word that the decimal system user data is formed Transform into a codeword composed of 8 multi-level symbols or convert a codeword composed of 8 multi-level symbols into a 5-bit source word composed of decimal user data, where the code elements include '0' and '1' , '2', and '3', d+1=3 means that the minimum number of consecutive identical symbols is 3, and k+1 is equal to 10, indicating that the maximum number of consecutive identical symbols is 10. The present invention also provides a multi-level run length data conversion device, and a red light multi-level optical storage device using the above method or device.

Description

technical field [0001] The present invention relates to high-density digital storage technology, more specifically, to a multi-level run length data conversion method and device for red light multi-level optical storage devices, and to a multi-level run length data conversion method and device using the above-mentioned multi-level run length data conversion method and device A red-ray multi-level optical storage device (such as a red-light multi-level read-only optical disc). Background technique [0002] Conventional optical discs all use a run-length (referred to as run length) limited encoding scheme, that is, RLL (Run Length Limited, run length limited) encoding. RLL means that the channel sequence stored on the optical disc satisfies the following conditions: there are at least d '0's and at most k '0's between two '1's in the sequence. The two parameters d and k specify the minimum and maximum run lengths that may appear in the sequence, respectively. The parameter d...

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Problems solved by technology

Such a surface structure connected between different pits makes the duplication and production of this type of read-only optical disc very difficult, mainly because the physical shape of the joint can not be accurately controlled, so that the bit error rate increases when the optical disc is read.

In addition, the multi-order RLL code scheme in the above patent documents does not solve the problem of controlling the DC component of the modulated channel sequence. Therefore, in the actual optical disc reading process, it is easy for the optical disc to fail to servo correctly, resulting in a high error rate or even failure to read the disc. disk reading

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