JPH103755A - Method and device for evaluating playability of optical disk deriving device and encoder, disk and decoder used for evaluation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To objectively and quantitatively evaluate playability by using the evaluating disk recorded with a sine wave continuous signal and a tone burst signal which are always constant at their levels in their respective reproducing frequency bands. SOLUTION: A synthetic signal of the continuous signals S1 and S2, each having a single frequency in a reproducing frequency band respectively and the tone burst signal Stb having a fixed period is recorded on an optical disk recording medium having no record. Afterward, the evaluating optical disk recording medium Dtp is produced by adding a flaw, dirt, etc., by printing etc. to the surface of a recording and reproducing surface. Thisaevaluating optical disk Dtp is loaded into an evaluating optical disk drive device X, and individual frequency components are separated and extracted from a regenerated reproducing signal via various filters B1 to B3. Then, as to single frequency S1 and S2' components, reproducing output levels for the individual frequency components respectively are measured by audio levelmeter C1 and C2, and as to a tone burst signal Stb' component, a tone burst period is measured by a frequency counter C3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for evaluating a capability of correcting an error such as a tracking error in an optical disk drive, so-called pre-ability, an evaluation encoder, an evaluation disk and an evaluation decoder.

[0002]

2. Description of the Related Art Conventionally, an optical disk drive device evaluates the ability of an optical disk drive apparatus to autonomously correct and reproduce an error caused by such a scratch or dirt on an optical disk recording medium having a scratch or dirt attached thereto, that is, a so-called playability. There is a need.

A conventional method for evaluating playability of an optical disk drive, an evaluation apparatus and an evaluation disk will be described in detail with reference to the drawings. FIG. 6A is a recording / reproducing view of an optical disk recording medium for playability evaluation of an optical disk drive device of a conventional method example, and FIG. 6B is a schematic explanatory diagram of the playability evaluation method.

In the figure, α is a playability evaluation device,
Dm is an optical disk recording medium, Dmp is a conventional optical disk recording medium for evaluation, P is a print layer, and X is an optical disk drive to be evaluated.

The conventional playability evaluation apparatus α shown in FIG. 6B is composed of a conventional evaluation optical disk recording medium Dmp and an evaluation target optical disk drive device X.

[0006] Such a playability evaluation device α
A method for evaluating the playability of the optical disk drive device X to be evaluated using the method will be described in detail. First, predetermined scratches and stains are pseudo-printed on the recording / reproducing surface of a general optical disk recording medium Dm on which a music signal has been recorded as a printing layer P of ink or the like, as shown in FIG. Next, an evaluation optical disk recording medium Dmp is prepared.

Next, as shown in FIG. 6B, the evaluation optical disk recording medium Dmp is mounted on the evaluation target optical disk drive device X, and a speaker S is connected to a reproduction output terminal of the evaluation optical disk drive device X for reproduction. The playability of the optical disk drive device X to be evaluated was evaluated by the evaluator directly listening to the reproduced output signal and confirming the reproduced noise generation amount and the skipped sound generation amount.

[0008]

However, the playability evaluation method and the evaluation apparatus α of the conventional optical disk drive apparatus and the evaluation optical disk recording medium Dmp
Has the following disadvantages. In other words, the first point is that the evaluator directly listens to the playback signal and evaluates the playability based on whether or not playback is possible and whether or not sound skipping occurs. It is qualitative and has the disadvantage that it cannot be evaluated objectively and quantitatively.

Second, since an evaluation disc Dmp in which a music signal whose level in each reproduction frequency band dynamically fluctuates at all times is used, a recorded audio signal is reproduced when reproducing a signal in a compact disc format. Despite the degree of error correction and the nature of the signal output waveform when an error occurs in each playback frequency band, objectively determine the amount of error occurrence in which playback frequency band There was a disadvantage that it could not be quantitatively evaluated.

Third, when a dedicated evaluation device is used, the price of the device is extremely high, and there is a disadvantage that the evaluation cannot be performed easily at low cost.

Here, the present invention provides a playability evaluation method and an evaluation apparatus for an optical disk drive capable of objectively and quantitatively evaluating playability, an evaluation disk evaluation encoder, and an evaluation decoder.

[0012]

In order to solve the above problems, the present invention employs the following novel characteristic methods and means. That is, a feature of the method of the present invention is that a composite signal of a continuous signal of at least two or more types in a reproduction frequency band and a tone burst signal of a fixed period is recorded on an optical disk recording medium on which nothing is recorded. Thereafter, scratches and stains are added to the surface of the recording / reproducing surface by printing or the like to create an evaluation optical disk recording medium, and the evaluation optical disk recording medium is mounted on an evaluation target optical disk drive, and a reproduced signal reproduced at each frequency. An optical disc which separates and extracts each component, measures a reproduction output signal level for each frequency component for the two or more types of continuous signal components of a single frequency, and measures a tone burst cycle for the tone burst signal component This is a method for evaluating playability of a drive device.

A first feature of the apparatus of the present invention is that an evaluation encoder for generating and outputting a composite signal of a continuous signal of at least two or more types in a reproduction frequency band and a tone burst signal of a fixed period, After recording the synthesized signal of the evaluation encoder, an evaluation disk in which scratches and dirt are added to the surface of the recording / reproducing surface by printing or the like, and an evaluation in which a reproduction output signal of the evaluation disk is separated and output for each frequency component Playability evaluation device for an optical disk drive device comprising a decoder for use in an optical disc.

A second feature of the apparatus according to the present invention is that the playability of an optical disc drive apparatus for generating and outputting a composite signal of a continuous signal of at least two or more single frequencies in a reproduction frequency band and a tone burst signal of a fixed period. This is an evaluation encoder.

A third feature of the apparatus of the present invention is that a first sine wave oscillator oscillating and outputting a low frequency continuous sine wave signal in a reproduction frequency band of the optical disk drive to be evaluated;
A second sine wave oscillator that oscillates and outputs a high frequency continuous sine wave signal in the reproduction frequency band of the evaluation target optical disc drive device; and a constant burst tone burst signal in the reproduction frequency band of the evaluation target optical disk drive device. Playability of an optical disc drive device comprising: a tone burst oscillator that oscillates and outputs; and a mixer that mixes the outputs of the first sine wave oscillator, the second sine wave oscillator, and the tone burst oscillator and outputs the result as an evaluation signal. This is an evaluation encoder.

A fourth feature of the apparatus of the present invention is that, after recording a composite signal of at least two or more types of single-frequency continuous signals in a reproduction frequency band and a tone burst signal having a fixed period, scratches and dirt are removed. This is a playability evaluation disk of the optical disk drive device added to the surface of the recording / reproducing surface by printing or the like.

A fifth feature of the apparatus of the present invention is that a composite signal of a continuous signal of at least two or more types in a reproduction frequency band and a tone burst signal of a fixed period is separated and output for each frequency component. This is a decoder for evaluating playability of the optical disk drive.

A sixth feature of the present invention is that a low-pass filter for separating and outputting a first sine wave continuous signal from an evaluation signal reproduced and output from an evaluation target optical disk drive device, and a second sine wave from the evaluation signal A playability evaluation decoder for an optical disc drive device, comprising a high-pass filter that separates and outputs only a continuous signal and a band-pass filter that separates and outputs only a tone burst signal from the evaluation signal.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A playability evaluation method and an evaluation device, an evaluation encoder, an evaluation disk and an evaluation decoder of an optical disk drive according to an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of an evaluation encoder constituting a playability evaluation device of an optical disk drive device according to an example of the present invention, FIG. 2 is a block diagram of the same evaluation decoder, and FIG. FIG. 3B shows an output waveform diagram of the first sine wave oscillator.
3C is an output waveform diagram of the same tone burst oscillator, and FIG. 3D is a waveform diagram of the same evaluation signal Test.

FIG. 4 is a recording / reproducing view of the optical disk recording medium for evaluation, FIG. 5 (a) is an output waveform diagram of the same low-pass filter, and FIG. 5 (b) is an output waveform diagram of the same high-pass filter. 5 (c) is an output waveform diagram of the same bandpass filter, and FIG. 5 (d) is a waveform diagram of the same evaluation signal Test '.

In the figure, β is a playability evaluation device,
A is an evaluation encoder, A1 is a first sine wave oscillator, A
2 is a second sinusoidal oscillator, A3 is a tone burst oscillator, A4 is a mixer, B is an evaluation decoder, B1 is a low-pass filter, B2 is a high-pass filter, B3 is a band-pass filter, C1 and C2 are audio level meters, C
3 is a frequency counter, Dt is an optical disk recording medium, Dt
p is an optical disk recording medium for evaluation, P is a print layer, R is an optical disk writing device, and X is an optical disk drive device to be evaluated.

The playability evaluation device β shown in FIGS. 1 and 2 is connected to an input terminal of the optical disk writing device R and generates an evaluation signal Test for evaluation and outputs an evaluation encoder A; And an evaluation decoder B for separating and extracting a reproduction output for each reproduction frequency band.

The encoder A for evaluation shown in FIG. 1 is a first sine wave continuous signal S1 (f1 = 200) which is a low frequency in the reproduction frequency band of the optical disk drive X to be evaluated.
Hz), and a second sine wave which is a high frequency within the reproduction frequency band of the optical disk drive X to be evaluated in synchronization with the first sine wave oscillator A1. A second sine-wave oscillator A2 that oscillates and outputs a continuous signal S2 (f2 = 20 kHz); and a second sine-wave oscillator A1 and a second sine-wave oscillator A2 that synchronize with the second sine-wave oscillator A2. A tone burst signal Stb (ft) having a fixed period within the reproduction frequency band
b = 1 kHz, tone burst period = 1 sec), and the tone burst oscillator A3, and the respective outputs of the first sine wave oscillator A1, the second sine wave oscillator A2, and the tone burst oscillator A3 are evaluated. Signal S
and a mixer A4 that outputs a test.

The evaluation decoder B shown in FIG. 2 comprises a low-pass filter B1 for separating and outputting only the first sine-wave continuous signal S1 'from an evaluation signal Test' reproduced and output from the optical disk drive X to be evaluated, Signal St
est ′, a high-pass filter B2 that separates and outputs only the second sine wave continuous signal S2 ′, and the evaluation signal Stes
and a band-pass filter B3 for separating and outputting only the tone burst signal Stb 'from t'.

Such a playability evaluation device β
A method for evaluating the playability of an optical disk drive using the method will be described in detail. First, as shown in FIG.
Optical disc writing device R is connected to the output terminal of evaluation encoder A.
Is connected, and an optical disk recording medium on which nothing is recorded is mounted on the optical disk writing device R.

Next, the evaluation encoder A and the optical disk writer R are operated, and the first sine wave signal of at least two or more types of sine wave signals in the reproduction frequency band is supplied to the optical disk recording medium on which nothing has been written. A wave continuous signal S1,
An evaluation signal Test created by mixing the second continuous sine wave signal S2 and the tone burst signal Stb is synthesized and recorded.

The evaluation signal Test shown in FIG.
The first sine wave continuous signal S1 (f1 = 2) shown in FIG.
00 Hz, signal level L1 = -6 dB) and FIG.
A second sine wave continuous signal S2 (f2 = 20 kHz,
The signal level L2 = -6 dB) and the tone burst signal Stb (ftb = 1 kHz, signal level Ltb = 0 dB, tone burst period Ttb = 1 se) shown in FIG.
and c).

Next, scratches and stains are artificially added to the recording / reproducing surface of the optical disk recording medium on which the evaluation signal Test is recorded by printing with ink or the like, thereby producing an evaluation optical disk recording medium Dtp.

Next, as shown in FIG. 2, an evaluation decoder B is connected to the reproduction output of the optical disk drive apparatus X to be evaluated, and the evaluation optical disk recording medium Dtp is mounted and reproduced. The servo circuit of the optical disk drive device X to be evaluated is disturbed by pseudo scratches, stains, and the like added as the print layer P to the disk, and the reproduction output of the optical disk drive device X to be evaluated is affected by these disturbances. The evaluation signal Test 'shown in FIG.

The evaluation decoder B shown in FIG. 2 separates the evaluation signal Test 'by a low-pass filter B1, a high-pass filter B2, and a band-pass filter B3 for each frequency component.

The low-pass filter B1 (cut-off frequency 400 Hz) is obtained from the evaluation signal Test 'as shown in FIG.
The first sine wave continuous signal S1 ′ (frequency f
1 ′ = 200 Hz, signal level L1 ′) Only components are separated and extracted, and the output signal level L1 ′ is measured by an audio level meter C1 or an oscilloscope connected to the output terminal of the low-pass filter B1.

Here, since the signal level L1 'fluctuates with an increase in the reproduction noise generation amount at the low frequency f1' in the reproduction frequency band, the error generation amount at the low frequency f1 'is determined by the signal level L1' fluctuation amount. Can be measured.

The high-pass filter B2 (cut-off frequency 10 KHz) is obtained from the evaluation signal Test 'by using FIG.
The second sine wave continuous signal S2 ′ (frequency f
2 ′ = 20 kHz, signal level L2 ′) Only components are separated and extracted, and the output signal level L2 ′ is measured by an audio level meter C2 or an oscilloscope connected to the output terminal of the high-pass filter B2.

Here, since the signal level L2 'decreases with the fluctuation of the reproduction noise generation amount at the high frequency f2' in the reproduction frequency band, the error generation amount at the high frequency f2 'is determined by the fluctuation amount of the signal level L2'. Can be measured.

Bandpass filter B3 (center frequency =
1 KHz) from the evaluation signal Test ′ shown in FIG.
The tone burst signal Stb ′ (frequency ft) shown in FIG.
b ′ = 1 kHz, tone burst cycle Ttb ′) Only components are separated and extracted, and the tone burst cycle Ttb ′ is measured by a frequency counter C3 or an oscilloscope (not shown) connected to the output terminal of the bandpass filter B3.

Here, since the tone burst period Ttb 'fluctuates with an increase in the tracking error occurrence amount, the tracking error occurrence amount is changed to the tone burst period Ttb'.
It can be measured by the amount of fluctuation.

As described above, the playability evaluation method and the evaluation apparatus β of the optical disk drive of the present invention, the evaluation disk Dtp, the evaluation encoder A, and the evaluation decoder B are provided in a predetermined evaluation optical disk recording medium Dtp.
Is reproduced by the optical disk drive X to be evaluated, and the playability of the optical disk drive X to be evaluated is evaluated by separating and measuring the reproduced signal into each component.

[0039]

By employing the method and means of the present invention, the following effects can be obtained. In other words, the first point is that the evaluator directly listens to the playback signal and evaluates the playability based on whether or not playback is possible and whether or not sound skipping occurs. Therefore, the amount of playback noise and the amount of skipping are objective and quantitative. There are advantages that can be evaluated.

Secondly, since an evaluation disc on which a sine wave continuous signal and a tone burst signal having a constant level in each reproduction frequency band are always used is used, when the signal of the compact disc format is reproduced, the recording is performed. Regarding the degree of error correction and the nature of the signal output waveform at the time of error occurrence for each playback frequency band of the reproduced audio signal, how much error occurrence amount exists in which playback frequency band, It has the advantage that it can be evaluated objectively and quantitatively.

As a third point, there is an advantage that a dedicated evaluation device is not required and an inexpensive and easy evaluation can be performed using a general measuring device such as an audio level meter and a frequency counter.

[Brief description of the drawings]

FIG. 1 is a block diagram of an evaluation encoder constituting a playability evaluation device of an optical disk drive device as an example of the device of the present invention.

FIG. 2 is a block diagram of the same evaluation decoder.

FIG. 3A is an output waveform diagram of the first and second sine wave oscillators, FIG. 3B is an output waveform diagram of the same and second sine wave oscillators,
(C) is an output waveform diagram of the tone burst oscillator.
(D) is a waveform diagram of the evaluation signal Test.

FIG. 4 is a recording / reproducing surface diagram of the optical disc recording medium for evaluation.

FIG. 5A is an output waveform diagram of the low-pass filter;
(B) is an output waveform diagram of the same high-pass filter, (c) is an output waveform diagram of the same band-pass filter, and (d) is a waveform diagram of the same evaluation signal Test '.

FIG. 6 (a) is a recording / reproducing view of a playability evaluation optical disk recording medium of an optical disk drive device according to a conventional method example, and FIG. 6 (b) is a schematic explanatory diagram of the playability evaluation method.

[Explanation of symbols]

 α, β Playability evaluation device A Evaluation encoder A1 First sine wave oscillator A2 Second sine wave oscillator A3 Tone burst oscillator A4 Mixer B Evaluation decoder B1 Low-pass filter B2 High-pass filter B3 Band-pass filter C1, C2 Audio level Meter C3 Frequency counter Dmp, Dtp Evaluation optical disk recording medium P Print layer R Optical disk writer S Speaker X Evaluation target optical disk drive

Claims (7)

[Claims] After recording a composite signal of a continuous signal of at least two or more single frequencies in a reproduction frequency band and a tone burst signal of a fixed period on an optical disk recording medium on which nothing is recorded, a scratch or the like is generated. An evaluation optical disk recording medium is created by adding dirt or the like to the surface of the recording / reproducing surface by printing or the like, and the reproduction signal reproduced by mounting the evaluation optical disk recording medium on the evaluation target optical disk drive device is separated for each frequency component. Extracting, for the two or more types of single-frequency continuous signal components, measuring a reproduction output signal level for each frequency component, and for the tone burst signal component, measuring a tone burst period. A playability evaluation method for an optical disk drive. 2. An evaluation encoder for generating and outputting a composite signal of a continuous signal of at least two or more types of single frequencies in a reproduction frequency band and a tone burst signal having a constant period, and recording a composite signal of the evaluation encoder. After that, an evaluation disk in which scratches and dirt are added to the surface of the recording / reproducing surface by printing or the like, and an evaluation decoder for separating and outputting a reproduction output signal of the evaluation disk for each frequency component are provided. Characteristic playability evaluation device for optical disk drive. 3. A playability evaluation encoder for an optical disk drive device, which generates and outputs a composite signal of a continuous signal of at least two types of single frequencies in a reproduction frequency band and a tone burst signal of a constant period. . 4. A first sine wave oscillator for oscillating and outputting a low frequency sine wave continuous signal within a reproduction frequency band of an evaluation target optical disk drive, and a high frequency within a reproduction frequency band of the evaluation target optical disk drive. A second sine wave oscillator that oscillates and outputs a sine wave continuous signal of the following, a tone burst oscillator that oscillates and outputs a tone burst signal having a constant cycle within a reproduction frequency band of the evaluation target optical disc drive device, and the first sine wave A playability evaluation encoder for an optical disk drive, comprising: an oscillator, a mixer for mixing respective outputs of the second sine wave oscillator and the tone burst oscillator and outputting the mixed signal as an evaluation signal. 5. After recording a composite signal of a continuous signal of at least two types of single frequencies in a reproduction frequency band and a tone burst signal of a constant period, the surface of the recording / reproduction surface is printed with a flaw or dirt by printing or the like. A playability evaluation disk for an optical disk drive device, characterized by being added to the above. 6. An optical disc drive device for separating and outputting a composite signal of a continuous signal of at least two or more single frequencies in a reproduction frequency band and a tone burst signal of a fixed period for each frequency component. Decoder for playability evaluation. 7. A low-pass filter that separates and outputs a first sine wave continuous signal from an evaluation signal reproduced and output from an evaluation target optical disk drive device, and a high-pass filter that separates and outputs only a second sine wave continuous signal from the evaluation signal. A playability evaluation decoder for an optical disk drive, comprising: a filter; and a bandpass filter that separates and outputs only a tone burst signal from the evaluation signal.