Optical disk reproducing method and reproducing device

A reproducing device, optical disc technology, applied in optical recording/reproducing, digital recording/reproducing, instruments, etc., can solve problems such as complex cost of optical pickups

Inactive Publication Date: 2002-09-18
PANASONIC CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, this method disadvantageously causes an increase in the complexity and cost of the optical pickup

Method used

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  • Optical disk reproducing method and reproducing device
  • Optical disk reproducing method and reproducing device
  • Optical disk reproducing method and reproducing device

Examples

Experimental program
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Embodiment 1

[0050] Next, an optical disc reproducing apparatus and a reproducing method used therein according to Embodiment 1 of the present invention will be described with reference to the accompanying drawings. In this embodiment, the half-width intensity of the beam spot of the reproduction laser is substantially the same as the width of the pits recorded on the optical disc. That is, in this embodiment, an optical disc having a relatively low recording density is reproduced using an apparatus including an optical pickup to be used for reproduction on a high recording density optical disc. Terminology, the "half-width intensity (w)" of the laser beam spot refers to the beam diameter corresponding to 1 / 2 of the maximum value of the laser beam intensity, such as image 3 As shown, the figure shows the intensity profile of the beam spot of the laser.

[0051] Figure 4 The entire structure of the optical disk reproducing apparatus according to this embodiment is shown. The optical dis...

Embodiment 2

[0079] Next, an optical disc reproducing apparatus and a reproducing method according to Embodiment 2 of the present invention will be described.

[0080] This embodiment relates to an optical disk reproducing apparatus for reproducing two types of optical disks, a regular optical disk having a high recording density and a conventional optical disk having a relatively low recording density, by using an apparatus including an optical pickup designed to reproduce an optical disk having a high recording density . In a high recording density optical disc, pits recorded on the disc have a width of about 0.15 microns to 0.22 microns, and a length of about 0.15 microns to 0.9 microns. In a low recording density optical disc, pits recorded on the disc have a width of about 0.25 microns to 0.35 microns, and a length of about 0.35 microns to 2 microns.

[0081] The difference between the optical disc reproducing device according to this embodiment and the optical disc reproducing devic...

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Abstract

A reproduction method, comprising the steps of: performing an addition operation on detection signals obtained by the first photodetection unit group and detection signals obtained by the second photodetection unit group to generate a sum signal, and outputting the sum signal to the signal processing section; performing a differential operation on the detection signal obtained by the first photodetection unit group and the detection signal obtained by the second photodetection unit group to generate a differential signal, and outputting the differential signal to the signal processing part; digitizing the sum signal to generate a binary signal, and generating a binary signal edge pulse; and outputting the binary signal edge pulse as a reproduced edge from the signal processing part when an amplitude equal to or greater than a predetermined value of the differential signal is detected pulse; and generate reproduced data.

Description

technical field [0001] The invention relates to an optical disc reproducing method and a reproducing device. Background technique [0002] DVD (Digital Versatile Disc) is known as an optical disc capable of storing large amounts of digital information. For DVD, a technique of recording / reproducing 4.7 GB (gigabit) of data on one surface of a disc having a diameter of 12 cm using a red laser light having a wavelength of about 650 nm has been realized. The pits formed on the recording surface of the optical disc each have a width of about 0.3 microns and a length of about 0.4 to 2.0 microns. Such pits have an intensity at half width of about 0.6 microns by using (see image 3 ) of the laser spot for reading. In a DVD-ROM (Read Only Memory) disc, pits are formed in an elliptical concave / convex shape. In the stepped portion of the pit, diffraction is caused by the emitted laser beam spot, and the amount of reflected light varies due to the diffraction. By utilizing this chan...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G11B7/005G11B20/10
CPCG11B7/005G11B20/10009
Inventor 古宫成二口龙太郎石桥广通
Owner PANASONIC CORP
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