JP2003203353A - Optical disk drive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical disk drive capable of playing and recording data without being affected by a defect. <P>SOLUTION: This optical disk driver is provided with a peak and bottom detecting means 5 which can set a time constant for RF detection in a plurality of stages and detects the peak level and the bottom level of an RF signal, an RF existence/nonexistence detecting means 6 for deciding the existence/ nonexistence of the RF signal on the basis of an output signal from the peak and bottom detecting means 5, a time constant switching means 7 that can switch the time constant of the peak and bottom detecting means 5, and a controller for giving to the time constant switching means 7 a command for setting one time constant in the peak and bottom detecting means 5 in accordance with the number of rotations of an optical disk 1. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc device capable of reproducing information on an optical disc by an optical pickup even if the optical disc has a defective inner peripheral portion.

[0002]

2. Description of the Related Art Optical disk devices include audio CDs, CD-ROMs, CD-R / RWs, and DVDs.
Have already been put to practical use, and application to various fields and high performance are being actively carried out. Especially in recent years, with the rapid market expansion of personal computers, the penetration rate of built-in optical disk devices into personal computers has increased, and the use of portable personal computers and optical disks for external connection via a personal computer interface connection has been increasing. Applications are expanding.

In this optical disc device, a CD-R / RW drive device which is a recordable / reproducible optical disc is taken as an example, and the structure of a conventional optical disc device, particularly, a recorded portion of the optical disc by processing an RF signal is described. FIG. 4 shows a configuration for determining an unrecorded portion (hereinafter, RF signal peak-bottom detection control unit).
It will be described based on. FIG. 4 is a block diagram of an RF signal peak-bottom detection controller in a conventional optical disc device. In FIG. 4, reference numeral 1 is an optical disk, 2 is a pickup module, 2a is an optical pickup for recording / reproducing data by converging a light spot on the optical disk 1 by using an objective lens, and 2b is an optical pickup 2a. And 3 are spindle motors for rotating the optical disc 1 and 4 are R for generating RF signals.
F amplifier, 5 is a peak bottom detection means, and 6 is an RF presence / absence detection means. Here, the RF signal is a data signal of the optical disc 1 extracted by the pickup module 2. The RF signal peak-bottom detection controller of the conventional optical disk device is composed of these components.

The operation of the conventional RF signal peak-bottom detection controller will be described. As shown in FIG. 4, the pickup module 2 is composed of a spindle motor 3 for rotating the optical disc 1, an optical pickup 2a, and a feed section 2b. The RF amplifier 4 generates an RF signal based on a signal output from a detector (not shown) provided in the optical pickup 2a inside the pickup module 2 and outputs it to the peak-bottom detection means 5. The peak / bottom detection means 5 detects the peak and bottom of the RF signal input from the RF amplifier 4.

The RF presence / absence detection means 6 reads the absolute value of the difference signal between the peak and bottom of the RF signal output from the peak / bottom detection means 5 and determines the presence / absence of the RF signal. The optical disc device judges the recorded portion and the unrecorded portion of the optical disc 1 based on the result of the RF presence / absence detecting means 6.

[0006]

As described above,
The conventional recordable / reproducible optical disk device is an optical disk 1
When the recorded portion and the unrecorded portion of the above data are determined, the difference between the peak level and the bottom level of the RF signal is calculated based on the RF signal detected by the peak / bottom detection means 5, and the absolute value thereof is obtained. The presence or absence of the RF signal is determined by seeking However, since the recording speed tends to increase year by year, the required band for peak bottom detection is increasing, and the time constant of the peak bottom detecting means 5 is decreasing. If the band of this peak bottom detection becomes high,
Even a small defect (scratch) on the optical disc 1 will exceed the threshold value (reference voltage) for peak-bottom detection, resulting in erroneous determination of a recorded portion and an unrecorded portion.

Among the recordable optical disks (CD-R, CD-RW) currently on the market, there are rare products which have defects (scratches) on the recording surface in the optical disk manufacturing process. Sometimes In particular, the defects of the optical disc are often located in the inner peripheral portion of the optical disc. In the inner peripheral portion, there are an OPC area and a PMA area in which the management information of the optical disc is recorded. If the peak bottom detection fails in this area, the position of the management information cannot be determined. As a result, the data on the optical disk could not be read, resulting in an error.

Below, the conventional RF detection mechanism is shown in FIG.
It will be described based on. FIG. 5 is a diagram showing a peak-bottom detection waveform of an RF signal in a conventional optical disc device.
In FIG. 5, the A'waveform represents an RF signal. B'waveform is R
The waveform of the peak of the F signal is detected, C'is the waveform of the bottom of the RF signal, and the E'waveform is the absolute value of the difference signal between the B'waveform and the C'waveform (| (peak)-(bottom) | ) Represents. When the voltage becomes equal to or higher than the reference voltage D ′ of the E ′ waveform, the RF detection presence / absence unit 6 determines that there is an RF signal. G'indicates the waveform of the portion where the RF signal is present. The F ′ portion represents a portion having a defect (scratch) in the manufacturing process of the optical disc 1.

When the optical pickup 2a reads the defective portion of F ', the RF detection signal in the portion of F'exceeds the reference voltage D'which is a threshold value, and the RF signal is present even though there is no RF signal. I will judge that there is. When this phenomenon occurs in the OPC area or the PMA area of the optical disk 1, the optical disk device cannot read the optical disk data because the exact position of the RF signal on the optical disk 1 is unknown, and the operation ends with an error.

Therefore, the present invention has been made to solve the above problems, and even if an optical disk having a defect on the inner peripheral side generated in the manufacturing process is used, data reproduction / recording is not affected by the defect. It is an object of the present invention to provide an optical disk device capable of performing the above.

[0011]

In order to achieve the above object, the optical disk device of the present invention can set the time constant for RF detection in a plurality of steps, and can detect the peak level and the bottom level of the RF signal. The bottom detection means, the RF signal presence / absence detection means for determining the presence / absence of the RF signal based on the output signal from the peak / bottom detection means, the time constant switching means for switching the time constant of the peak / bottom detection means, and the optical disc It is characterized in that the peak bottom detection means is provided with a controller for giving a command for setting one time constant to the time constant switching means in accordance with the number of revolutions.

As a result, even if an optical disk having a defect on the inner peripheral side generated during the manufacturing process is used, data reproduction / recording can be performed without being affected by the defect.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is an optical pickup for recording / reproducing data by converging a light spot on the optical disc by using an objective lens. An RF amplifier that generates an RF signal from the output signal of the photodetector, a time constant for RF detection can be set in multiple stages, and a peak-bottom detection unit that detects the peak level and bottom level of the RF signal; RF signal presence / absence detection means for determining the presence / absence of an RF signal based on the output signal from the detection means, time constant switching means for switching the time constant of the peak / bottom detection means, and peak / bottom according to the number of revolutions of the optical disk. An optical disk device comprising a controller for giving a command for setting one time constant to the detection means to the time constant switching means. Ri, by setting the time constant switching means optimal one time constant selected by the controller, even if the optical disc with a defect generated in the manufacturing process or the like is used, data reproduction-without being affected by the defect
Records can be made.

According to a second aspect of the present invention, when the controller determines that there is an RF signal based on the output signal from the peak bottom detection means, the optical disc is read and the optical disc is read. 2. When it is not possible, the time constant switching means resets the time constant of the peak-bottom detection means to another time constant, and the presence or absence of the RF signal is determined again. It is an optical disk device, and even if the first read fails, the controller sets another time constant in the time constant switching means, so even if a defective optical disk that has occurred during the manufacturing process is used, data can be reliably reproduced.・ Recording is possible.

According to a third aspect of the present invention, the controller causes the time constant switching means to reset the time constant of the peak-bottom detection means a predetermined number of times, so that the optical disc cannot be read. The optical disc device according to claim 2, wherein the number of times of resetting is set, and if the reading is performed only the number of times of resetting, the optical disk device according to claim 2 is not a defect. Can exit as an error.

The first embodiment of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a block diagram of an RF signal peak-bottom detection controller of an optical disk device according to Embodiment 1 of the present invention. In FIG. 1, 1 is an optical disc, 2 is a pickup module, 2a is an optical pickup, 2b is a feed unit, 3 is a spindle motor, 4
Is an RF amplifier, 5 is a peak-bottom detection means capable of setting a time constant for detection in a plurality of stages, 6 is an RF presence / absence detection means, 7 is a time constant switching means, and 8 is a controller. The peak-bottom detection control unit of the first embodiment is composed of these constituent elements, but the constituent elements having the same reference numerals are basically the same as those of the conventional optical disk device, and therefore will not be described in detail here.

The operation of the peak / bottom detection control section in the first embodiment will be described. As shown in Figure 1,
The pickup module 2 includes a spindle motor 3 that rotates the optical disc 1, an optical pickup 2a, and a feed unit 2b. The RF amplifier 4 generates an RF signal based on a signal output from a photodetector (not shown) provided in the optical pickup 2 a inside the pickup module 2 and outputs it to the peak-bottom detection means 5. The peak / bottom detection means 5 detects the peak and bottom of the RF signal input from the RF amplifier 4.

The RF presence / absence detection means 6 reads the absolute value of the difference signal between the peak and bottom of the RF signal output from the peak / bottom detection means 5, and determines the presence / absence of the RF signal. The optical disc device judges the recorded portion and the unrecorded portion of the optical disc 1 based on the result of the RF presence / absence detecting means 6.

By the way, the time constant switching means 7 is for setting the time constant for detection with respect to the peak and the bottom waveform of the RF signal detected by the peak / bottom detection means 6 in a plurality of steps. The setting of the time constant for the time constant switching means 7 is performed by the controller 8 as follows. First, a predetermined one time constant, which is considered to be optimal in advance, is set corresponding to the set rotation speed of the optical disk device, and it is determined whether the contents of the optical disk 1 can be read by this. The time constants of the peak and bottom waveforms of the RF signal detected by the peak-bottom detection means 5 are reset to the time constants at different stages, and the steps are repeated until the reading is possible. As a result, the time constant finally selected by the controller 8 is
This is an optimum time constant for RF detection. If the reading cannot be repeated a predetermined number of times, an error occurs.

FIG. 2 is a flow chart showing the operation of the optical disc device according to the first embodiment of the present invention at the time of RF signal peak bottom detection. The operation of the peak-bottom detection controller of the optical disk device according to the first embodiment will be described below with reference to FIG.

First, when the power is turned on, the controller 8
Sets the number of rotations according to the type of optical disc (S
1). At this time, the controller 8 sets the time constant, which is considered to be optimum for the number of rotations set for each optical disk 1, to RF.
The peak bottom detection means 5 is set. Therefore, the time constant switching means 7 is instructed to set this optimum time constant (S2).

Next, the controller 8 confirms whether the rotational speed setting and the time constant setting are correct (S3). Next, in order to read the OPC area and PMA area recorded on the optical disc 1, the presence or absence of RF is detected (RF detection) by the peak bottom detection means 5 (S4).

Then, it is judged whether the result of the RF presence / absence detecting means 6 exceeds the reference voltage D which is the threshold value of RF presence / absence (S5).

If the voltage exceeds the reference voltage D, which is the threshold value for the presence or absence of RF, the data in the OPC area and PMA area actually recorded on the optical disc 1 is read to determine whether the contents of the optical disc 1 can be read (S6). ). If the contents of the optical disc 1 can be determined, it is determined that the optical disc 1 can be read,
This process is regarded as normal and is ended with OK.

If the contents of the optical disc 1 cannot be determined,
When it is determined that the reading could not be performed, the RF detection operation is performed again only n times of the number of retries corresponding to the number of predetermined time constants (S7). If it is determined that the number of times (the number of loops) has exceeded a predetermined n times, this process ends with NG.

When the RF detection operation does not exceed the predetermined number of retries n times, the controller 8 resets the time constant of another stage to the time constant switching means 7 (S8), and S4 is executed. Returning to this, the presence or absence of RF is detected by the peak-bottom detection means 5 in order to read the OPC area and PMA area recorded on the optical disk again, and the process is repeated up to n times of retries. When the reading is possible, this process is regarded as normal and is ended with OK. Eventually, if the number of retries exceeds n, an error occurs and NG ends.

FIG. 3 is a diagram showing an RF detection waveform when the time constant switching means is used in the optical disk device according to the first embodiment of the present invention. The operation of the RF signal peak-bottom detection controller according to the first embodiment of the present invention will be described with reference to FIG. In FIG. 2, the A waveform represents an RF signal. The B waveform represents a waveform in which the peak of the RF signal is detected, the C waveform represents a waveform in which the bottom of the RF signal is detected, and the E waveform is the absolute value (| (peak)-(bottom) |) of the difference signal between the B waveform and the C waveform. Is an RF detection signal that is a waveform representing E waveform reference voltage D
When the above is reached, the RF detection means determines that there is an RF signal. G shows the waveform of the part where the RF signal is present. The F portion represents a portion having a defect (scratch) in the manufacturing process of the optical disc 1 or the like.

When the optical pickup 2a reads the F portion, the RF detection signal exceeds the threshold reference voltage D in the defective portion of the optical disc 1 as shown by the H waveform (broken line) before the time constant is switched. Therefore, it is determined that there is an RF signal even though there is no RF signal. When this phenomenon occurs in the OPC area or PMA area of the optical disc, the exact position of the RF signal on the optical disc 1 cannot be known,
The optical disc device causes an error because the optical disc data cannot be read.

However, in the optical disk device of the first embodiment, the controller 8 uses the peak-bottom detection means 5
In response to the rotation speed, a command is issued to set another preset time constant in multiple stages. When the switching to the time constant is repeated up to n times and the proper time constant can be set, the OPC area of the optical disc 1, the PMA
When the data is read from the area, the RF detection signal does not exceed the reference voltage D, which is the threshold value, even in the defective portion of the optical disc 1 like the waveform after switching the time constant of the I waveform (solid line). It is possible to determine that there is no RF signal in the portion where there is no. If this determination cannot be made even with the retry setting for n times, the error can be terminated as an error of another cause other than the error due to the defect.

[0031]

As described above, the optical disk device of the present invention is provided with the peak-bottom detection means and the time constant switching means which can set the time constant in a plurality of stages, and by setting the optimum time constant with the controller, Even if an optical disc having a defect in the inner peripheral portion generated during the manufacturing process is used, data reproduction / recording can be performed without being affected by the defective portion.

[Brief description of drawings]

FIG. 1 is a block diagram of an RF signal peak-bottom detection controller of an optical disc device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the optical disk device according to Embodiment 1 of the present invention at the time of RF signal peak-bottom detection.

FIG. 3 is a diagram showing an RF detection waveform when a time constant switching unit is used in the optical disc device according to the first embodiment of the present invention.

FIG. 4 is a block diagram of an RF signal peak-bottom detection controller in a conventional optical disc device.

FIG. 5 is a diagram showing a peak-bottom detection waveform of an RF signal in a conventional optical disc device.

[Explanation of symbols]

1 optical disc 2 pickup module 2a Optical pickup 2b Feed section 3 spindle motor 4 RF amplifier 5 Peak-bottom detection means 6 RF presence / absence detection means 7 Time constant switching means 8 controller

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G11B 20/18 572 G11B 20/18 572C 572F 576 576C (72) Inventor Shingo Sakata Kadoma City, Osaka Prefecture Address 1006 Matsushita Electric Industrial Co., Ltd. F term (reference) 5D044 BC04 CC04 FG16 GK19 5D090 AA01 BB04 CC04 CC18 DD03 DD05 EE17 HH02

Claims (3)

[Claims] 1. An optical pickup for recording / reproducing data by condensing a light spot on the optical disc using an objective lens, and an RF signal is generated from an output signal of a photodetector of the optical pickup. The RF amplifier and the time constant for RF detection can be set in multiple stages.
Peak-bottom detection means for detecting the peak level and bottom level of the F signal; RF signal presence / absence detection means for determining the presence / absence of an RF signal based on the output signal from the peak-bottom detection means; A time constant switching means capable of switching a constant, and a controller for giving a command for setting one time constant to the peak bottom detection means to the time constant switching means in accordance with the number of revolutions of the optical disc. Characteristic optical disk device. 2. The optical disc is read when the controller determines that there is an RF signal based on the output signal from the peak-bottom detection means, and when the optical disc cannot be read, 2. The optical disk device according to claim 1, wherein the time constant switching means resets the time constant of the peak-bottom detection means to another time constant, and the presence or absence of the RF signal is determined again. 3. The controller causes the time constant switching means to reset the time constant of the peak-bottom detection means a predetermined number of times, and judges that an error has occurred when reading from the optical disk is not possible. The optical disk device according to claim 2, wherein: