JP2005322300A - Signal processor and optical disk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately detect a defect irrespective of writing power during recording, disk reflectance or a variance in amplifier gain, and to determine whether a defect in the surface of an optical disk causes the recording mistake of optical information in one RUB. <P>SOLUTION: The reflected light of a multipulse recording light reflected on the recording surface of an optical disk is converted into a multipulse signal by a photoelectric conversion means 104A, this multipulse signal is converted into the signal of a binary recording data waveform, the signal of the recording data waveform is compared with a reference potential to detect the level of the recording data waveform signal with respect to the reference voltage as a data error corresponding to the defect in the surface of the optical disk, and determination is made based on the number of data errors as to whether the defect of the optical disk surface causes the recording mistake of optical information in one RUB. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is attached to the surface of an optical disc using reflected light of the recording light reflected from the recording surface when recording optical information by irradiating the recording surface of the optical disc capable of recording / reproducing. The present invention relates to a signal processing apparatus for grasping and processing optical information recording errors on the recording surface due to defects such as fingerprints, scratches, and dust, and an optical disk apparatus using the signal processing apparatus.

  High-density optical disc recording / reproducing apparatuses that record or reproduce data by irradiating a recording medium such as a disc with laser light have appeared. For example, in a recording apparatus that supports optical discs such as CD-R / RW, DVD-R, DVD-R / RW, DVD + RW, and Blu-ray discs such as DVR-BULE, which are high-density discs using a short wavelength light source near 400 nm, The track on the optical disc is irradiated with a laser beam modulated with the recording data, whereby the optical data is recorded on the optical disc by, for example, a phase change recording method.

  Here, when data is recorded on the optical disc as described above, if the surface of the optical disc has a defect, the optical disc of 680 nm (such as DVD-R) has a thick disc cover layer, laser light. However, there was no room for fingerprints, scratches, dust, etc. on the surface of the optical disk due to the large beam diameter and the long recording wavelength.

  By the way, since the optical disks themselves such as CD-R / RW, DVD-R, DVD-R / RW, and DVR-BULE are handled in a bare state, the surface of the optical disk is likely to have fingerprints, scratches, dust, etc. Becomes a defect and causes a failure in recording or reading data on the optical disk. For example, the amount of laser light reaching the recording surface of the optical disc is reduced to prevent correct recording, and the amount of reflected light from the optical disc is changed to prevent accurate data reading.

  On the other hand, a 400 nm Blu-ray disc has a recording density about 5 times that of a 680 nm optical disc and the thickness of the disc cover layer is 1/7, so that it is easily affected by defects attached to the disc surface. . Therefore, in order to strengthen the defect determination processing in the ECC (Error Check and Correct) part, the 1 ECC part (1 RUB) is increased to 64 KBytes. However, if an unexpected large fingerprint or a large scratch is attached to the disk surface. These defects reach 1/3 of 1RUB, and data of 1RUB is broken. In this case, if there is a fingerprint or scratch in the address area of the RUB and the address data also becomes an error, the recording is stopped, so that no recording error occurs. However, since three RUB addresses are inserted in one RUB and the frequency is as low as 200 KHz, these disturbances are not easily received. However, if the address can be read during recording, it will be recorded even if there are fingerprints or scratches on the surface of the optical disc. In other words, there is a problem that the number of defects existing in one RUB is sequentially recorded regardless of whether or not the number of defects is an amount that causes the data of one RUB to fail.

Therefore, conventionally, a defect detection signal corresponding to a signal having a relatively fast level change corresponding to a defect on the disk recording surface using a reflected light identification unit from a pull-in signal corresponding to the reflected light of the recording medium, and a disk A dust detection signal corresponding to a signal having a relatively slow level change corresponding to the dust on the surface is generated, and the defect detection signal and the dust detection signal are used to compensate the recording of the defective portion with the power of the laser beam ( For example, refer to Patent Document 1), or the data recorded from the recording medium is read by the second light beam after being divided into three, and an error of the read data is detected and the data is recorded from the reflected light. If the result of both the error detection and the defect detection is below a predetermined criterion, the recording is judged as good. , If at least one of the result of the error detection and defect detection exceeds the criterion is one that determines the recording as defective (for example, see Patent Document 2).
JP 2000-31375 A Japanese Patent Laid-Open No. 5-274817

In such a conventional method, defects on the disk recording surface and dust attached to the disk surface can be identified and detected.
However, defects on the surface of a Blu-ray disc include black belt-like defects such as large scratches and large dirt caused by black magic, spot-like defects that expose the recording surface through the disc cover layer, and There are scratch-like defects attached with small scratches and fingerprints, and single defects attached with dust and scratches. The disk reflectivity of these defects is shown in FIG.
In FIG. 4, the reflectance 20% represents the reflectance of the recording surface of the Blu-ray disc, and the reflectance 10% is the reflectance when the recording surface of the Blu-ray disc is made amorphous by the light beam. Then, the reflectance of the black belt-like defect 71 decreases to a maximum of zero, and the reflectance of the spot-like defect 72 reaches a maximum of nearly 100%. Further, the reflectance of the scratch-like defect 73 and the single defect 74 is as shown in FIG.

However, in the conventional method as described above, when various defects having different reflectivities exist on the disk surface as shown in FIG. 4, these defects are reliably detected, and the number of defects present in one RUB is 1 RUB. There is a problem that it is not possible to determine whether or not the amount of data is in an amount that causes the data to fail.
Further, conventionally, there is a problem that variations in write power during recording, variations in disc reflectivity and amplifier gain adversely affect disc defect detection, and accurate defect detection cannot be performed.

  The present invention has been made to solve such a conventional problem, and enables accurate defect detection without being affected by variations in write power, disc reflectivity and amplifier gain during recording. In addition, it is possible to grasp in advance the optical information recording error on the recording surface due to defects such as fingerprints, scratches, and dust attached to the surface of the optical disk, and the defect attached to the surface of the optical disk is within one RUB. It is an object of the present invention to provide a signal processing apparatus and an optical disc apparatus using the signal processing apparatus that can accurately determine whether or not the defect causes an optical information recording error.

  In order to achieve the above object, the present invention uses the reflected light of the multi-pulse recording light reflected by the recording surface when irradiating the recording surface of the optical disc with multi-pulse recording light to record optical information, A signal processing device that detects and processes the presence or absence of defects such as fingerprints, scratches, and dust attached to the surface of the optical disc, and receives multi-pulses upon receiving reflected light of multi-pulse recording light reflected on the recording surface. A photoelectric conversion means for converting the signal into a defect signal upon receiving the reflected light whose level changes due to a defect on the surface of the optical disc and converting the defect signal into a defect signal; The signal conversion means for converting the multi-pulse signal output from the photoelectric conversion means and the multi-pulse signal on which the defect signal is superimposed into a binary recording data waveform signal. A reference potential generating circuit for generating a reference potential corresponding to the type of the defect; and a recording data waveform signal for the reference potential by comparing a recording data waveform signal output from the signal converting means with the reference potential And a defect detection means for detecting a change in the level as a data error corresponding to a defect on the surface of the optical disk, and a defect attached to the surface of the optical disk based on the number of data errors detected by the defect detection means is 1 RUB (Recording Unit Block) ), Defect determination means for determining whether or not the defect causes an optical information recording error.

  The present invention also provides an optical disk that is rotationally driven by a driving means, an optical pickup that is moved in the radial direction of the optical disk by a feeding means, and a recording and / or reproducing operation of the rotation of the optical disk and the movement of the optical pickup. And a signal processing means for performing signal processing of a recording operation on the optical disk by the optical pickup, and irradiates the recording surface of the optical disk with multi-pulse recording light. A signal that detects and processes the presence or absence of defects such as fingerprints, scratches, and dust attached to the surface of the optical disc using the reflected light of the multi-pulse recording light reflected on the recording surface when optical information is recorded. The signal processing device receives the reflected light of the multi-pulse recording light reflected by the recording surface, Photoelectric signal that receives the multi-pulse reflected light whose level changes due to a defect on the surface of the optical disk, converts it into a defect signal, and superimposes the defect signal on the multi-pulse signal for output. Conversion means; signal conversion means for converting the multi-pulse signal output from the photoelectric conversion means and the multi-pulse signal superimposed with the defect signal into a binary recording data waveform signal; and the defect A reference potential generation circuit for generating a reference potential corresponding to the type of the recording data, a signal of the recording data waveform output from the signal conversion means and the reference potential, and a change in the level of the recording data waveform signal with respect to the reference potential Detecting a data error corresponding to a defect on the surface of the optical disk, and the number of data errors detected by the defect detecting means Defects attached to et the optical disk surface, characterized in that it comprises a defect determining means for determining whether the defect causing recording errors of the optical information in the 1RUB (Recording Unit Block).

In the signal processing device and the optical disc apparatus of the present invention, the photoelectric conversion means receives the reflected light of the multi-pulse recording light reflected by the recording surface of the optical disc and converts it into a multi-pulse signal, and due to a defect on the surface of the optical disc. It receives reflected light whose level changes and converts it into a defect signal, and superimposes the defect signal on a multi-pulse signal and outputs it. The signal conversion means converts the multi-pulse signal output from the photoelectric conversion means and the multi-pulse signal on which the defect signal is superimposed into a binary recording data waveform signal. The defect detection means compares the recording data waveform signal output from the signal conversion means with the reference potential, and detects a change in the signal level of the recording data waveform relative to the reference potential as a data error corresponding to a defect on the surface of the optical disc. Further, the defect determination means determines whether or not the defect attached to the surface of the optical disc is a defect that causes an optical information recording error in one RUB from the number of data errors detected by the defect detection means.
Therefore, according to the present invention, it is possible to accurately detect a defect without being affected by variations in write power during recording, disc reflectivity and amplifier gain, and fingerprints attached to the surface of the optical disc. Whether or not the optical information recording error on the recording surface due to defects such as scratches and dust can be grasped in advance, and whether or not the defect attached to the surface of the optical disc is a defect that causes an optical information recording error in 1 RUB. Can be judged accurately.

  In the best mode of the present invention, it is possible to accurately detect defects without being affected by variations in write power during recording, disc reflectivity or amplifier gain, and fingerprints attached to the surface of the optical disc. Whether or not the optical information recording error on the recording surface due to defects such as scratches and dust is grasped in advance, and whether or not the defect attached to the surface of the optical disc is a defect that causes an optical information recording error in one RUB. In order to achieve the purpose of accurate determination, the photoelectric conversion means receives the reflected light of the multi-pulsed recording light reflected on the recording surface of the optical disk and converts it into a multi-pulse signal, and the level due to defects on the optical disk surface. When the reflected light is changed, it is converted into a defect signal, the defect signal is superimposed on a multi-pulse signal, and is output from the photoelectric conversion means by the signal conversion means. The multi-pulse signal on which the multi-pulse signal and the defect signal superimposed are converted into a binary recording data waveform signal, and the recording data waveform signal and reference output from the signal conversion means by the defect detection means The change in the level of the recording data waveform signal with respect to the reference potential is detected as a data error corresponding to a defect on the optical disk surface, and the defect determination means detects the change in the level of the recording data waveform signal relative to the reference potential. It is determined whether or not the attached defect is a defect that causes an optical information recording error in one RUB.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing the overall configuration of an optical disc apparatus provided with a signal processing apparatus according to the present invention.

A configuration of the optical disc apparatus 101 shown in FIG. 1 will be described.
This optical disk apparatus 101 includes a spindle motor 103 as a driving means for rotationally driving an optical disk 102 which is an optical recording medium such as a DVD ± R / RW, a CD-R / RW, or a Blu-ray disc, an optical pickup 104, A feed motor 105 is provided as drive means for moving the optical pickup 104 in the radial direction of the optical disk 102.
Here, the spindle motor 103 and the feed motor 105 are configured to be driven and controlled by a servo control unit 109 that is controlled based on a command from the system controller 107.

A signal modulator / demodulator & ECC (Error Check and Correct) unit 108 shown in FIG. 1 performs signal modulation, demodulation, addition of ECC (Error Correction Code), and error correction processing based on ECC.
In accordance with a command from the system controller 107, the optical pickup 104 applies a light beam from the laser light source 104B to the recording surface of the rotating optical disk 102 through a not-shown optical system and one main spot for recording / reproduction and a tracking surface. It is configured to irradiate two side spots separately. Further, the optical pickup 104 has a photoelectric conversion means (photodiode) 104A, and various kinds of signals output from the photoelectric conversion means 104A according to reflected light fluxes corresponding to the main spot and side spot reflected from the recording surface of the optical disc 102. The signal is configured to be supplied to the reproduction amplifier 120.

  The amplifier 120 generates and amplifies signals such as a focus error signal, a tracking error signal, and an RF signal based on various signals output from the photoelectric conversion means 104A of the optical pickup 104. For example, a photodiode amplifier for 100 MHz RF (high frequency signal) reproduction is used, and the gain of the amplifier 120 is automatically set according to a set command signal from the system controller 107 according to recording and reproduction. The configuration is set. The photoelectric conversion means 104A is a constituent element of the signal processing apparatus 200. When optical information is recorded on the optical disk 102, the photoelectric conversion means 104A receives reflected light of the recording light reflected by the recording surface and converts it into an electrical signal. At the same time, it receives reflected light whose level changes due to a defect on the surface of the optical disk, converts it into a defect signal, and superimposes the defect signal on the electric signal for output.

The signal output from the amplifier 120 is configured to be input to the servo control unit 109 as a control signal for focusing and tracking according to the type of the optical disc 102 as a recording medium, and to the signal modulator / demodulator & ECC unit 108. In the signal modulator / demodulator & ECC unit 108, predetermined processing such as demodulation and error correction processing of the RF signal output from the amplifier 120 is performed.
Here, if the recording signal demodulated by the signal modulator / demodulator & ECC unit 108 is, for example, for computer data storage, it is sent to the external computer 130 or the like via the interface 111. As a result, the external computer 130 or the like can receive a signal recorded on the optical disc 102 as a reproduction signal. Contrary to the above case, the recording data from the external computer 130 is modulated by the signal modulator / demodulator & ECC unit 108 and output to the laser control unit 121. By driving the laser light source 104B, the data from the external computer 130 is converted. The optical disc 102 can be written.

  Also, if the recording signal demodulated by the signal modulator / demodulator & ECC unit 108 is for audio / visual use, it is converted into an analog signal by the D / A conversion unit of the D / A, A / D converter 112 and processed by audio / visual processing. Supplied to the unit 113. Audio / video signal processing is performed by the audio / visual processing unit 113 and transmitted to an external imaging / projection device via the audio / visual signal input / output unit 114. Contrary to the above case, the information taken into the audio / visual processing unit 113 from the external imaging / projection device through the audio / visual signal input / output unit 114 is converted into the A / D of the D / A and A / D converter 112. The signal is converted into a digital signal by the conversion unit, further modulated by the signal modulator / demodulator & ECC unit 108, and output to the laser control unit 121. By driving the laser light source 104B, the audio / visual information is received from the external imaging / projection device on the optical disc 102 can be written.

The optical pickup 104 is connected to a feed motor 105 for moving to a predetermined recording track on the optical disk 102, for example. The servo control unit 109 controls the spindle motor 103, the feed motor 105, and the focusing direction and tracking direction of a biaxial actuator (not shown) that holds the objective lens of the optical pickup 104.
The laser control unit 121 controls the laser light source 104B in the optical pickup 104, and is configured to control the output power of the laser light source 104B in the recording mode and the reproduction mode.

In FIG. 1, the signal processing apparatus 200 uses the reflected light of the recording light reflected by the recording surface of the optical disc 102 when the optical information is recorded by irradiating the recording surface of the optical disc 102 with the recording light. For detecting and processing optical information recording errors on the recording surface due to defects such as fingerprints, scratches and dust attached to the surface (the surface of the cover layer). In addition to the photoelectric conversion means 104A, the signal conversion means 201, a reference potential generation circuit 202, a defect detection unit 203, and a defect determination unit 107B.
Here, the recording light emitted from the laser light source 104B includes a write (recording) level rL (6 mW) and an erase (erase) level eL (4.5 mW) as schematically shown in FIG. 2A, for example. And a ternary level multi-pulse with a cool (cooling) level cL (0.4 mW).
Therefore, when optical information is recorded on the optical disc 102, multipulse recording light such as 6T schematically shown in FIG. 2A is irradiated onto the recording surface of the optical disc 102, and the multipulse reflected by the recording surface is reflected. The reflected light of the recording light is received by the photoelectric conversion means 104A and converted into an electric signal. That is, the photoelectric conversion means 104A outputs a multipulse signal in which a multipulse signal corresponding to the multipulse recording light and a defect signal are superimposed.

  The signal converter 201 includes an equalizer circuit 201A for equalizing the frequency amplitude of the multipulse signal output from the photoelectric converter 104A through the amplifier 120 and the multipulse signal superimposed with the defect signal, and the equalizer circuit 201A. And a low-pass filter (LPF) 201B for attenuating the multi-pulse signal equalized in (1) and shaping it into a binary recording data waveform signal.

The reference potential generation circuit 202 integrates and converts the signal equalized by the equalizer circuit 201A of the signal conversion means 201 into a DC level signal and generates a reference potential of a predetermined level corresponding to the type of defect shown in FIG. Is configured to do.
The defect detection unit 203 compares the recording data waveform signal output from the low-pass filter 201B of the signal conversion unit 201 with the reference potential output from the reference potential generation circuit 202, and the recording data waveform signal is the reference. A comparison circuit 203A that outputs as a high level signal when exceeding the potential, and outputs as a low level signal when the recording data waveform signal does not exceed the reference potential, and a high level signal output from the comparison circuit 203A. It is composed of a retriggerable monostable multivibrator 203B that takes out a period during which a low level signal is output as a retrigger as a data error corresponding to a defect on the signal optical disk surface.

The defect determination means 107B is provided in the system controller 107. From the number of errors detected by the defect detection means 203, a defect attached to the surface of the optical disk 102 is recorded as an optical information recording error in one RUB (Recording Unit Block). It is determined whether or not this is a defect that causes a defect.
Further, the system controller 107 is provided with a replacement RUB control means 107A. This replacement RUB control means 107A does not correct an error even if data is recorded with ECC attached to one RUB, and the defective RUB cannot be correctly reproduced. This is for performing defect processing for recording data to be recorded on a well-known alternating RUB (not shown) provided on the recording surface of the optical disc 102, and the defect determination means 107B detects the optical information on the surface of the optical disc. When the defect is determined to cause a recording error, a defect processing interrupt command is output to the replacement RUB control unit 107A.

Next, FIG. 2 and FIG. 3 are operational waveform diagrams showing processing operations as to whether or not defects such as fingerprints, scratches, and dust attached to the surface of the optical disc 102 are defects that cause optical information recording errors in one RUB. Will be described with reference to FIG.
First, detection of defects such as fingerprints, scratches, and dust attached to the surface of the optical disk 102 is performed using the optical pickup 104. That is, the laser light source 104B is driven by supplying the signal modulated by the signal modulator / demodulator & ECC unit 108 according to the recording data to the laser light source 104B through the laser control unit 121, and the recording light emitted from the laser light source 104B is supplied. The recording surface of the optical disk 102 is irradiated through an optical system (not shown). At this time, the recording light emitted from the laser light source 104B has a multipulse waveform as schematically shown in FIG.

On the other hand, when the reflected light of the multi-pulse recording light reflected by the recording surface of the optical disk 102 is incident on the photoelectric conversion means 104A through an optical system (not shown), the photoelectric conversion means 104A shows the state shown in FIG. A signal with a simple waveform is output. Thereafter, the signal is amplified by the amplifier 120 and output to the signal conversion unit 201. At this time, the signal waveform output from the amplifier 120 is the same as that shown in FIG.
When the output signal from the amplifier 120 is input to the equalizer circuit 201A of the signal conversion means 201, the frequency amplitude of the signal shown in FIG. 2B is equalized by the equalizer circuit 201A and has a waveform as shown in FIG. It becomes. When the signal output from the equalizer circuit 201A passes through the low-pass filter 201B, the multipulse signal is attenuated, and as shown in FIG. 2D, the peak level of the signal is high and the erase level is low. It is shaped into a binary recording data waveform signal close to recording NRZI (Non Return to Zero Inverted). The binary recording data waveform signal is input to the defect detection means 203.

Next, the operation of the signal processing apparatus 200 will be described in detail with reference to the operation waveform diagram of FIG.
3A shows the multi-pulse recording light 31 irradiated on the recording surface of the optical disc 102, and FIG. 3B shows a waveform corresponding to the black belt-like defect 71 shown in FIG. Is attached to the surface of the optical disc 102. In such a state, when the multi-pulse recording light 31 shown in FIG. 3A is irradiated onto the recording surface of the optical disc 102 and the reflected light of the multi-pulse recording light passes through the defect 71 portion, The reflection level of the reflected light of the multi-pulse recording light passing through the portion is lower than the reflection level of the other reflected light except the portion of the defect 71. As a result, when these reflected lights are incident on the photoelectric conversion means 104A, the photoelectric conversion means 104A gives a multi-pulse shape corresponding to the reflected light of the multi-pulse-like recording light 31, as shown in FIG. And a multi-pulse signal in which the defect signal 33 whose level changes due to the defect 71 is superimposed. When this multi-pulse signal is input to the equalizer circuit 201A of the signal conversion means 201, the multi-pulse signal is equalized by the equalizer circuit 201A, further attenuated by passing through the low-pass filter 201B, and recorded. It is shaped into a binary recording data waveform signal close to NRZI (Non Return to Zero Inverted). A recording data waveform signal 34 at this time is shown in FIG. This signal 34 is output to the comparison circuit 203A of the defect detection means 203.

On the other hand, the reference potential generating circuit 202 integrates and converts the signal equalized by the equalizer circuit 201A into a DC signal, and generates a reference potential Vref of a predetermined level corresponding to the defect 71 shown in FIG. Vref is output to the comparison circuit 203A of the defect detection means 203.
The comparison circuit 203A compares the recording data waveform signal 34 output from the low-pass filter 201B with the reference potential Vref from the reference potential generation circuit 202, and as shown in FIG. When 34 exceeds the reference potential Vref, it is output as a high level signal, and when the recording data waveform signal 34 does not exceed the reference potential Vref, it is output as a low level signal. Then, by inputting the high-level signal output from the comparison circuit 203A as a retrigger for the retriggerable monostable multivibrator 203B, the retriggerable monostable multivibrator 203B is configured as shown in FIG. A period during which a low level signal is output is taken out as a data error corresponding to the defect 71 on the surface of the signal optical disk.

  The data error signal detected by the defect detection unit 203 is taken into the defect determination unit 107B of the system controller 107, so that the defect attached to the surface of the optical disc 102 is recorded by 1RUB (Recording) from the number of errors detected by the defect detection unit 203. It is determined whether or not the defect causes an optical information recording error in the unit block. Here, when the ratio of the defect occupying in one RUB is 5% or more, it is determined that the defect on the surface of the optical disc 102 is a defect causing an optical information recording error, and the defect is recorded in one RUB determined to be a defect. An interrupt command for recording the recording data to be recorded on the replacement RUB of the optical disk 102 is output to the replacement RUB control unit 107A. When the ratio of the number of data errors in one RUB is 5% or less, it is determined that there is no defect causing an optical information recording error on the surface of the optical disc 102.

  According to this embodiment, the reflected light of the multi-pulse recording light reflected by the recording surface when the optical information is recorded by irradiating the recording surface of the optical disc 102 with the multi-pulse recording light is reflected in the multi-pulse form. In addition to receiving the reflected light whose level changes due to a defect on the optical disk surface, it converts it into a defect signal and superimposes the defect signal on a multipulse signal, and the multipulse signal and the defect signal are superimposed. The multi-pulse signal is converted into a binary recording data waveform signal, and the recording data waveform signal is compared with the reference potential, and changes in the level of the recording data waveform signal relative to the reference potential are dealt with on the surface of the optical disc. From the number of data errors, a defect on the surface of the optical disk is a defect that causes an optical information recording error in one RUB. It is possible to absorb variations in write power, disc reflectivity, and amplifier gain during recording, enabling accurate defect detection regardless of these variations. In addition, it is possible to grasp in advance the optical information recording error on the recording surface due to defects such as fingerprints, scratches, and dust attached to the surface of the optical disk, and the defect attached to the surface of the optical disk It is possible to accurately determine whether the defect causes a recording error.

It is a block diagram which shows the structure of the whole optical disk apparatus provided with the signal processing apparatus concerning this invention. It is a wave form diagram which shows operation | movement of the signal processing apparatus shown in FIG. It is a wave form diagram which shows operation | movement of the signal processing apparatus shown in FIG. It is explanatory drawing showing the relationship between defects, such as a fingerprint attached to the surface of an optical disk, a crack, and dust, and the disk reflectivity of these defects.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 101 ... Optical disk apparatus, 102 ... Optical disk, 103 ... Spindle motor, 104 ... Optical pick-up, 104A ... Photoelectric conversion means, 104B ... Laser light source, 105 ... Feed motor, 107 ... System controller, 107A ... ... Replacement RUB control unit 107B ... Defect determination means 108 ... Signal modulator / demodulator & ECC unit 109 ... Servo control unit 112 ... D / A, A / D converter, 120 ... Amplifier, 200 ... Signal processing device, 201... Signal conversion means, 202... Reference potential generation circuit, 203... Defect detection means, 201 A... Equalizer circuit, 201 B ... low-pass filter, 203 A ... comparison circuit, 203 B. Monostable multivibrator.

Claims (10)

When optical information is recorded by irradiating the recording surface of the optical disc with multi-pulse recording light, the reflected light of the multi-pulse recording light reflected on the recording surface is used to print fingerprints or scratches on the surface of the optical disc. A signal processing device that detects and processes the presence of defects such as dust,
Receiving the reflected light of the multi-pulse recording light reflected by the recording surface to convert it into a multi-pulse signal, and receiving the multi-pulse reflected light whose level changes due to a defect on the optical disk surface, Photoelectric conversion means for converting and outputting the defect signal superimposed on the multi-pulse signal; and
Signal conversion means for converting the multi-pulse signal output from the photoelectric conversion means and the multi-pulse signal superimposed with the defect signal into a binary recording data waveform signal;
A reference potential generation circuit that generates a reference potential according to the type of the defect;
Defect detection for comparing a recording data waveform signal output from the signal converting means with the reference potential and detecting a change in the level of the recording data waveform signal with respect to the reference potential as a data error corresponding to a defect on the surface of the optical disc. Means,
Defect determination means for determining whether or not the defect attached to the surface of the optical disc is a defect that causes an optical information recording error in one RUB (Recording Unit Block) from the number of data errors detected by the defect detection means. When,
A signal processing apparatus comprising:   2. The signal processing apparatus according to claim 1, wherein the multi-pulse recording light is composed of a multi-level multi-pulse of a write level, an erase level and a cool level.   The signal conversion means equalizes the frequency amplitude of the signal output from the photoelectric conversion means, and attenuates the multi-pulse signal equalized by the equalizer circuit to form a binary recording data waveform signal The signal processing apparatus according to claim 1, further comprising: a low-pass filter that performs processing.   The reference potential generating circuit is configured to integrate a signal equalized by an equalizer circuit that constitutes the signal converting means and convert the signal into a DC signal and generate a reference potential of a predetermined level according to the type of defect. The signal processing apparatus according to claim 1, wherein:   The defect detection means compares the recording data waveform signal output from the signal conversion means with the reference potential output from the reference potential generation circuit, and outputs a high level when the recording data waveform signal exceeds the reference potential. A comparison circuit that outputs a signal as a low level signal when the recording data waveform signal does not exceed a reference potential, and inputs a high level signal output from the comparison circuit as a re-trigger. 2. The signal processing apparatus according to claim 1, further comprising a retriggerable monostable multivibrator that extracts a period during which a level signal is output as a data error corresponding to a defect on the surface of the signal optical disc. An optical disc that is rotationally driven by a drive means;
An optical pickup moved in the radial direction of the optical disk by a feeding means;
Control means for controlling the rotation of the optical disc and the movement of the optical pickup in accordance with the recording and / or reproducing operation;
An optical disk device comprising signal processing means for performing signal processing of a recording operation on the optical disk by the optical pickup,
When the optical information is recorded by irradiating the recording surface of the optical disc with multi-pulse recording light, the reflected light of the multi-pulse recording light reflected on the recording surface is used, and the fingerprint attached to the surface of the optical disc It has a signal processing device that detects and processes the presence of defects such as scratches and dust,
The signal processing device includes:
Receiving the reflected light of the multi-pulse recording light reflected by the recording surface to convert it into a multi-pulse signal, and receiving the multi-pulse reflected light whose level changes due to a defect on the optical disk surface, Photoelectric conversion means for converting and outputting the defect signal superimposed on the multi-pulse signal; and
Signal conversion means for converting the multi-pulse signal output from the photoelectric conversion means and the multi-pulse signal superimposed with the defect signal into a binary recording data waveform signal;
A reference potential generation circuit that generates a reference potential according to the type of the defect;
Defect detection for comparing a recording data waveform signal output from the signal converting means with the reference potential and detecting a change in the level of the recording data waveform signal with respect to the reference potential as a data error corresponding to a defect on the surface of the optical disc. Means,
Defect determination means for determining whether or not the defect attached to the surface of the optical disc is a defect that causes an optical information recording error in one RUB (Recording Unit Block) from the number of data errors detected by the defect detection means. When,
An optical disc apparatus comprising:   7. The optical disc apparatus according to claim 6, wherein the multi-pulse recording light is composed of a multi-level multi-pulse of a write level, an erase level and a cool level.   The signal conversion means equalizes the frequency amplitude of the signal output from the photoelectric conversion means, and attenuates the multi-pulse signal equalized by the equalizer circuit to form a binary recording data waveform signal The optical disk apparatus according to claim 6, further comprising a low-pass filter.   The reference potential generating circuit is configured to integrate a signal equalized by an equalizer circuit that constitutes the signal converting means and convert the signal into a DC signal and generate a reference potential of a predetermined level according to the type of defect. The optical disk apparatus according to claim 6, wherein the optical disk apparatus is an optical disk apparatus.   The defect detection means compares the recording data waveform signal output from the signal conversion means with the reference potential output from the reference potential generation circuit, and outputs a high level when the recording data waveform signal exceeds the reference potential. A comparison circuit that outputs a signal as a low level signal when the recording data waveform signal does not exceed a reference potential, and inputs a high level signal output from the comparison circuit as a re-trigger. 7. The optical disc apparatus according to claim 6, further comprising a retriggerable monostable multivibrator that extracts a period during which a level signal is output as a data error corresponding to a defect on the surface of the signal optical disc.

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