Waveshaping reshaping equipment

A waveform shaping and equipment technology, applied in line transmission parts, read/write signal modification, gearbox control/balance, etc., can solve problems such as lack, data smoothing error, unstable jitter, etc. Reduce, data smoothing error reduction, reduce the effect of unstable signals

Inactive Publication Date: 2003-11-05
PANASONIC CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0015] However, such a circuit excludes low-band fluctuation components in a steady state or even a state where no defects occur, and thus, due to the lack of information provided by low-frequency fluctuation components, data smoothing errors occur and the possibility of unstable jitter increases

Method used

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  • Waveshaping reshaping equipment
  • Waveshaping reshaping equipment
  • Waveshaping reshaping equipment

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0063] Shown in FIG. 1 is a block diagram of a reproduction signal processing apparatus 200, showing a reproduction signal processing apparatus 200 in the first embodiment of the present invention. As shown in FIG. 1 , the reproduced signal processing apparatus 200 includes a pulse waveform shaping apparatus 100 and a digital circuit 1300 .

[0064] A signal recorded on the optical disc 1 is reproduced by an optical pickup circuit 2 as a reproduced signal RS.

[0065] The pulse waveform shaping apparatus 100 includes a first detection circuit 3 for detecting a reproduced signal RS reproduced by the optical pickup circuit 2 at a predetermined time constant and detecting an upper envelope RSU, and a second detection circuit 4 for detecting a signal generated by the optical pickup circuit 2. The optical pickup circuit 2 reproduces the reproduced signal RS at a predetermined time constant, and detects a lower envelope RSD, an averaging circuit 5 for finding the average value AVE o...

Embodiment 2

[0080] FIG. 6 is a block diagram describing the structure of a reproduction signal processing apparatus 200A of the second embodiment of the present invention. The parts in the figure that are the same as those in FIG. 1 and have been described above will not be repeated here. The reproduction signal processing apparatus 200A includes a waveform shaping apparatus 100A and a digital circuit 1300 .

[0081] In addition to the part shown in FIG. 1, the waveform shaping device 100A includes an unbalance detection circuit 8, and the averaging circuit 5 weights the upper envelope RSU and the lower envelope RSD with a weighting coefficient of M:N, thereby calculating The average value AVE is obtained, where the weighting factor is substantially proportional to the unbalanced amount of the reproduced signal RS.

[0082] Unbalance generally occurs under certain disc groove conditions or recording conditions. If a recording pit to be written is larger than a specified standard pit, neg...

Embodiment 3

[0110] FIG. 11 is a block diagram illustrating the structure of a reproduced signal processing apparatus 200B of the third embodiment of the present invention. Parts that appear in the figure that are the same as those in Fig. 1 that have already been described will not be repeated here. The reproduced signal processing device 200B includes a waveform shaping device 100B and a digital circuit 1300 .

[0111] The waveform shaping apparatus 100B includes, in addition to the parts shown in FIG. 1, a drop detection circuit 13 for detecting a dropout indicating a drop in the amplitude of the reproduced signal R.

[0112] When the drop detection circuit 13 detects that there is a drop, at least one of the first detection time constant used by the first detection circuit 3 and the second detection time constant used by the second detection circuit 4 is greater than when no drop is detected. The time constant is shorter. When a dip is detected, the negative feedback digital smoothin...

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PUM

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Abstract

A waveform shaping device comprises a first detection circuit which detects a reproduced signal reproduced from an optical disc by an optical pickup circuit, and detects an upper envelope of the reproduced signal by using a first detection time constant; a second circuit for detecting the reproduced signal The detection circuit uses the second detection time constant to detect the lower envelope of the reproduced signal; the average circuit applies a weight represented by a weighting coefficient to each upper envelope and lower envelope, and calculates each upper envelope The average value of the line and the lower envelope; there is also a subtraction circuit for subtracting a signal corresponding to the average value from the reproduced signal to obtain an output shaped waveform signal.

Description

technical field [0001] The present invention relates to a waveform shaping device and a reproduced signal processing device including the same, in particular to a waveform shaping device for optimizing digitization or A / D (analog / digital) conversion of a reproduced signal obtained by an optical pickup circuit , and a reproduction signal processing device including the device. Background technique [0002] Recently, optical discs are widely used in various conditions and can be stored in various ways. In this case, the surface of the disc is often scratched or exposed to dust, and it is required to determine a highly accurate signal if information needs to be read from a scratched or dusty disc. [0003] In particular, an optical disc that stores information in high density, such as DVD (Digital Versatile Disc), has a low signal / noise ratio (SNR) at the shortest recessed portion, and if the signal is digital, it is of course required to generate minimal errors. [0004] Inf...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G11B20/10
CPCG11B20/10G11B20/10009
Inventor 堀邊隆介川上真一青木和弘兼上陽一
Owner PANASONIC CORP
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