CN1296914C - Optical disk device and control method thereof - Google Patents

Abstract

The invention provides an optical disk device and a control method thereof. Equipped with: a reading unit (15) that reads the reflected light irradiated on the light speed point (72) on the optical disc (D) and outputs a read signal; detects the address information of the current beam spot (72) based on the read signal unit (12); a holding unit (59) for holding address information detected by the detection unit (12); a moving unit (20, 38) for moving the beam spot (72) in the inner or outer peripheral direction of the optical disc (D) Detecting the address information after the movement of the beam spot (72) by the detection unit (12) detection of the moving unit (20,38), comparing with the address information before the movement kept by the holding unit (59), determining the beam spot (72 ) The determination unit (61) of the reliability of the movement.

Description

Optical disc device and control method thereof

technical field

The present invention relates to an optical disc device and its control method, in particular to a method for confirming an address when performing its track transition.

Background technique

As is well known, optical discs such as DVD (Digital Versatile Disc: high-density disc) are becoming popular recently as recording media for digital data. Furthermore, high reliability is desired in an optical disc device for reproducing these optical discs.

In such an optical disc, the recording area is provided as a spirally formed track, and the track number is included in the address information. And, when processing such as fast forward and fast rewind during playback, after the pickup is sent by the motor, the lens is properly tilted by the actuator to perform fine adjustment (track shift) for each track. Therefore, when judging whether or not the destination address has been correctly diverted at the time of track jumping, it is judged whether or not the track number is a desired number.

Japanese Unexamined Patent Publication No. 2002-109756 discloses an optical disc device that executes track transfer when commanded to transfer, and determines whether the transfer has succeeded based on address information. Here, if it is determined that it is not the target track, the jump is repeated again.

In the technology of the above-mentioned JP-A-2002-109756, it is determined whether the transfer is successful or not based on the transferred address. However, since this method detects the physical address after the one-track jump, it is not known whether the physical address of the adjacent track after the one-track jump has been detected, and it is considered possible to detect the physical address of another track. Therefore, if the physical address is not detected for the second time for comparison after one track jump, it is not known whether the physical address is correct or not, so it takes time to detect the physical address reliably.

Contents of the invention

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a system that can quickly confirm the reliability of the jump processing by comparing the address before the jump processing with the address after the jump processing when the beam spot is shifted from track to track. An optical disc device and a control method thereof.

According to one aspect of the present invention, there is provided an optical disc device, which is characterized in that it includes: a reading unit that reads the reflected light of a beam spot irradiated on the optical disc and outputs the read signal; Take a signal to generate a wobble signal corresponding to the wobble change of the above-mentioned optical disc, and detect the detection unit of the physical address information of the current beam spot based on the wobble signal; keep the physical address information detected by the detection unit; the holding unit; on the above-mentioned optical disc A moving unit that moves the above-mentioned beam spot by one track in the inner or outer circumferential direction; the determination unit uses the track number of the physical address information detected by the detection unit after the above-mentioned moving unit completes the movement of the above-mentioned beam spot When the Hamming distance is 1 compared with the track number of the physical address information held by the holding unit before the beam spot shift, it is determined that the beam spot has been moved correctly.

According to another aspect of the present invention, there is provided a control method of an optical disc device, the reading unit of the optical disc device reads the reflected light of the beam spot irradiated on the optical disc, and outputs the read signal thereof, the control method of the optical disc device The method is characterized in that it includes: a detection unit generates a wobble signal corresponding to the wobble change of the optical disc according to the read signal read by the read unit, and a first step of detecting the physical address information of the current beam spot based on the wobble signal; The second step of holding the detected physical address information by the holding unit; the third step of moving the beam spot by one track in the inner or outer direction of the optical disc by the moving unit; After the moving unit completes the movement of the beam spot, the physical address information detected by the detection unit is compared with the track number of the physical address information held by the holding unit before the beam spot moves, and when the Hamming distance is 1 , it is judged by the judging unit that the fourth step of moving the beam spot has been correctly performed.

Description of drawings

FIG. 1 shows an embodiment of the present invention, which is a block diagram for explaining an optical disc device.

Fig. 2 is a diagram showing a detailed configuration of a pickup of the optical disc device in the same embodiment.

FIG. 3 is a block diagram showing details of a wobble PLL unit/address detection unit of the optical disc apparatus in the same embodiment.

4 is a waveform diagram illustrating signal waveforms at the time of signal reading by a wobble PLL unit/address detection unit of the optical disc apparatus in the same embodiment.

FIG. 5 is a diagram showing a peripheral layout of an optical disc recording track for explaining the processing of the optical disc device in the same embodiment.

6 is a diagram showing a next-generation DVD physical address format for explaining a wobble signal of an optical disc handled by the optical disc device in the same embodiment.

Fig. 7 is a diagram for explaining the track jump when the address is not read during the jump of the optical disc device in the same embodiment.

FIG. 8 is a diagram for explaining track jump when address reading is performed when the optical disc device in the same embodiment jumps.

FIG. 9 is a flowchart for explaining the operation of reading an address when the optical disc device is transferred in the same embodiment.

Detailed ways

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an optical disc device described in this embodiment, and FIG. 2 is a diagram showing a detailed configuration of a pickup of the optical disc device. FIG. 3 is a block diagram showing a wobble PLL unit/address detection unit of the optical disk device.

<Optical disc device according to the present embodiment>

(composition and action)

The optical disc drive described in this embodiment is configured as shown in FIGS. 1 and 2 . Here, the optical disc D is an optical disc capable of recording user data or a read-only optical disc, but it will be described as a recordable optical disc in this embodiment. Recordable optical discs include DVD-R, DVD-RAM, CD-R, CD-RW and the like.

On the surface of the optical disk D, lands and grooves are spirally formed. This disk D is driven to rotate by a spindle motor 13 . Recording and reproduction of information on the optical disk D are performed by the pickup 15 .

The pickup 15 is coupled to a spindle motor 30 via a gear. The spindle motor 30 is controlled by a spindle motor driver 31 connected to a data bus 39 . An unillustrated permanent magnet is provided on a fixed portion of the spindle motor 30 , and the pickup 15 moves in the radial direction of the optical disk D by excitation of an unillustrated drive coil.

An objective lens 22 is provided on the pickup 15 as shown in FIG. 2 . The objective lens 22 can be driven by the drive coil 21 to move in the focus direction (direction of the optical axis of the lens). In addition, the objective lens 22 is driven by the drive coil 20 so that it can move in the tracking direction (direction perpendicular to the lens optical axis), and by moving the beam spot of the laser light, it is possible to perform track shifting as will be described later.

The modulation circuit 19 performs 8-14 modulation (EFM) on user data supplied from the host device 44 via the interface circuit 43 at the time of information recording, and provides EFM data. The laser control circuit 18 supplies a writing signal to the semiconductor laser diode 28 based on the EFM data supplied from the modulation circuit 19 at the time of information recording (at the time of mark formation). In addition, the laser control circuit 18 supplies a read signal smaller than a write signal to the semiconductor laser diode 28 when information is read.

The semiconductor laser diode 28 generates laser light in response to a signal supplied from the laser control circuit 18 . Laser light generated from the semiconductor laser diode 28 is irradiated onto the optical disc D via the collimator lens 25 , the half prism 24 , the optical system 23 and the objective lens 22 . The reflected light from the optical disk D is introduced into the photodetector 26 via the objective lens 22 , the optical system 23 , the half prism 24 , and the condensing lens 27 .

The photodetector 26 is composed of photodetection units divided into four, and supplies detection signals A, B, C, and D to the RF amplifier 12 . The RF amplifier 12 supplies the tracking error signal TE as (A+D)-(B+C) to the tracking control unit 38, and supplies the focus error signal FE as (A+C)-(B+D) to the focus control Unit 37.

In addition, the RF amplifier 12 supplies the wobble signal W as (A+D)-(B+C) to the wobble PLL unit/address detection unit 36, and supplies the RF signal W as (A+D)+(B+C). to the data regeneration unit 35.

On the other hand, the output signal of the focus control unit 37 is supplied to the focus drive coil 21 . In this way, the laser light is always controlled to be accurately focused on the recording film of the optical disc D. As shown in FIG. In addition, the tracking control unit 38 generates a track driving signal corresponding to the tracking error signal TE, and supplies it to the driving coil 20 in the tracking direction.

By performing the focus control and tracking control described above, the sum signal RF of the output signals of the photodetectors of the photodetector 26 reflects changes in reflectivity from pits and the like formed on the tracks of the optical disc D corresponding to the recording information. This signal is supplied to the data regeneration unit 35 .

The data reproduction unit 35 reproduces recorded data based on the reproduction clock signal from the PLL circuit 16 . In addition, the data reproduction unit 35 has a function of measuring the amplitude of the signal RF, and the measured value is read by the CPU 40 .

When the objective lens 22 is controlled by the above-mentioned tracking control unit 38, the pickup 15 is controlled by controlling the spindle motor 30 so that the objective lens 22 is at an optimal position on the optical disc.

In addition, the motor control circuit 14, the laser control circuit 18, the PLL circuit 16, the data reproduction unit 35, the focus control unit 37, the tracking control unit 38, etc. can be configured as a servo control circuit in one LSI chip. These circuits are controlled by the CPU 40 via the bus 39 .

The CPU 40 performs overall control of the optical disc device in accordance with operation commands supplied from the host device 44 via the interface circuit 43 . Moreover, CPU40 uses RAM41 as a work area, and performs predetermined operation|movement according to the program recorded in ROM42.

In addition, as shown in Figure 3, the wobble PPL unit/address detection unit 36 has: wobble PLL circuit 51; Synchronization signal detection unit 56; Address area initial detection unit 57; Address hold unit 58; 59 ; an address comparison unit 60 ; a reliability determination unit 61 .

Here, the wobble PLL circuit 51 has: an A/D circuit 52 that supplies a wobble signal; an integrating circuit 53 that integrates its output; a D/A circuit 55 that converts and D/A its output; The vibration signal is supplied to the VCO circuit 54 of the A/D circuit 52. The wobble PLL unit/address detection unit 36 judges the reliability at the time of track jump based on the wobble signal W and outputs the reliability flag F to the data bus 39 together with the track address output AD, as will be described in detail later.

(track transfer)

The optical disc device having the above-mentioned structure, which performs playback processing and recording processing, performs track jump as described below, and the reliability of the track jump was also confirmed.

FIG. 4 is a diagram showing signal waveforms at the time of signal reading by the wobble PLL unit/address detection unit 36 of the optical disk device of this embodiment, and FIG. 5 is a diagram showing an example of the layout around recording tracks of an optical disk handled by the same optical disk device. . 6 is a diagram showing an example of a next-generation DVD physical address format of an optical disc wobble signal processed by the same optical disc device. FIG. 7 is a diagram for explaining track jump when an address is not read when the same optical disc device is switched. FIG. 8 is a diagram for explaining track transition when address reading is performed in the same optical disc device. FIG. 9 is a flow chart illustrating an address reading operation when the same optical disc device is transferred.

FIG. 4 is a signal waveform diagram at the time of signal reading, showing the relationship of each signal when wobble modulation is used to correspond to the recording track as an addressing method of the optical disc recording medium. Digital data is reproduced (or recorded) from the snaking recording track, and the data recorded at this time is recorded at a designated position.

Then, the physical address information is obtained by reading and demodulating the wobble signal W corresponding to the wobble 71 of the recording track by the wobble PLL unit/address detection unit 36 . FIG. 4 shows the reading beam 72 on the track, the detected wobble signal W, and the modulation rule when information is embedded in the wobble modulation. Address information is recorded using the sine wave (NPW) of the wobble signal W as pit information "0" and the cosine wave (IPW) as "1".

In addition, FIG. 5 is a diagram showing a layout of physical address information in a structure in which both lands and grooves are used for recording tracks of an optical disc recording medium. Since addressing using wobble modulation is performed in the groove, it is necessary to configure accurate addressing even when recording and reproducing on the land.

Therefore, the structure of the partition method is adopted, and the optical disc recording medium is divided into a plurality of areas in the radial direction, and the recording capacity in each area constitutes a certain segment information packet, and the wobble modulation of the channel is embedded in it as the physical address information. area number", "track number" and "segment number". When the area is changed, the recording capacity is optimized by changing the division angles constituting the segments in units of substantially equal recording densities.

If the structure shown in FIG. 5 is set, in the land/groove system, the address information using the groove wobble is used except that the track number is the same value between adjacent tracks, and the physical address can be read even in the land track. information. The track number is arranged for the land and the groove, and since the information can be obtained regardless of the land or the groove, there is no problem.

(Physical address information)

In addition, FIG. 6 is a diagram showing the data structure of the physical address in an overall relational diagram. Physical address information is embedded in aggregates 84 to 86 called WAP (Wobble Address Periodic Position) composed of 17 groups (81 to 83) of WDU (Wobble Data Unit). Because this WAP connection can complete the track wobble, the period determined by the WAP becomes the embedding period of the physical address data.

The physical address data 85 is composed of 39 bits. As shown in each information 87, there are "segment information (Segment information)", "segment address (Segment address)", "zone address (Zone address)", "parity address (Parity address) )", "Groove address", "Land address". The physical address data 85 is divided into groups of 3 bits and embedded in the modulation process assigned to each WDU. That is, here, the memory area number is 89, the track number is 90, and the segment number is 91.

The WDU 82 embedded with address information has 3 bits, and 1 bit corresponds to 4 wobbles. Therefore, the first four wobbles of the WDU are constituted as an IPW, which facilitates identification of the beginning of the WDU. As a result, 68 wobbles after address information embedding of WDU 82 are defined as NPW.

Therefore, since the entire address data is 39 bits, the required WDU82 is 13 units, the initial WDU is configured with the synchronization signal 84 of the WAP, and the three units of the rear WDU83 are composed of a non-modulation unit (Unity field) 86.

With such a track wobble modulation embedded in the recording track of the physical address, information data is recorded, but the recording data 92 in this case records 71 bytes of VFO (playback operation) at the beginning for data of 77376 bytes. , used to easily generate a certain frequency signal of the channel clock for data demodulation), and record the "PA field (PA field)", "Reserved field (Reserved field)" and "buffer area" used for data block connection processing in the rear The total of (Bufferfield) is 22 bytes.

In total 77469 bytes are recorded over 7 physical segments (9996 wobbles). By such restriction to record information data at a designated place using "physical segment" address data, readout of address data of the physical segment becomes important.

A physical address is recorded on the wobble of the optical disc with the above configuration. When reading the physical address from the wobble of the optical disc, a synchronization signal is detected from the wobble signal W, a timing signal corresponding to the synchronization signal is generated, address information is extracted from the wobble signal corresponding to the timing signal, demodulated, and obtain.

(how to obtain address information)

Hereinafter, a case where the method of this embodiment is not used and a case where the method of this embodiment is used will be respectively described for the timing of acquiring address information based on the above-mentioned wobble signal.

First, a case where the address information acquisition method of this embodiment is not used will be described using FIG. 7 . In FIG. 7, when a one-track jump is performed from the current track point P1 to the adjacent track point P2, the detection of the physical address starts from the track point P2.

Here, when the track point P2 is outside the physical address area, the physical address detection is performed from the track point P3. Then, the reliability of the physical address should be confirmed, and the physical address of the track point P4 in the figure should be further detected, and compared with the track point P3, the correctness of the track point arrival point can be confirmed.

However, in such a method, in order to ensure the reliability of the physical address detection, it takes time to detect the physical address of the track point P3 or the track point P4.

On the other hand, the method of acquiring address information in this embodiment will be described. The next-generation DVD physical address format of the wobble signal of the optical disc is shown in FIG. 6. The physical address is composed of "area number", "track number" and "segment number". One physical address is constituted by one WAP. Among them, by using the property that the Hamming distance of adjacent track numbers in the same segment is 1, the reliability of the physical address at the time of 1-track transition can be confirmed.

That is, in the method of acquiring address information in this embodiment, the address detection unit 36 in FIG. 3 is used as shown in FIG. 8, and these procedures are also explained using the flowchart in FIG.

First, registers and the like for each physical address of the current recording track point PA are always held in the address holding unit 58 (S11). Hereinafter, as an example, after the pickup 15 is moved by the spindle motor 30 and the like according to the user's operations such as fast forward and fast rewind, when a track jump is required, one track is transferred from the CPU 40 and the like to the address detection unit 36. The pre-jump address holding unit 59 supplies a command of the 1-track jump command J to hold the pre-jump address held in the address holding unit 58 in the 1-track pre-jump address holding unit 59 (S11).

At the same time, the tracking control unit 38 supplies a tracking control signal to the driving coil 20 by instructing the tracking control unit 38 to position track jump command J from the CPU 40 or the like. Accordingly, the objective lens 22 is displaced, and the beam spot is track-shifted from the track point PA to the track point PB (S12).

Then, the physical address of the point PB after the one-track jump is acquired and stored in the address holding unit 58 (S13). Thereafter, the address comparison unit 60 compares the track number by comparing the address before the one-track jump from the address holding unit 59 before the one-track jump, and the address after the one-track jump from the address holding unit 58 (S14).

At this time, when the beam spot shifts to the outer peripheral side of the optical disc, it is judged whether the track number included in the address information is only increased by the amount of movement, and when the beam spot is moved to the inner peripheral side of the optical disc, it is judged whether the track number is only increased by the amount of movement. Reduce moving parts.

Then, the judgment result of the address comparing unit 60 is provided to the reliability judging unit 61, and if the reliability judging unit 61 confirms that the track number changes by 1 track, then the reliability flag F is set to “1”, for example, and provided to the CPU 40 or Track control unit 38 . Thus, when the migration is successful, the migration process is terminated, and when the migration is not successful, the process returns to step S11, and the track migration process is performed again (S15).

That is, if the track point PB to which the track jump is applied is a physical address area, by detecting the address information in the track point PB, it can be judged that the track jump is performed correctly. In addition, if the track point PB used for the track jump is outside the physical address, it can be judged that the track jump is performed correctly by detecting the address information in the track point PC.

That is, if the address information acquisition method of this embodiment is adopted, the reliability of the track transition can be confirmed more quickly than the case of not using the method of this embodiment shown in FIG. The location is correct.

In addition, the present invention is not limited to the above-mentioned embodiments themselves, and the constituent elements can be modified and embodied in various ways within a range not departing from the gist. In addition, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments. For example, some constituent elements may be deleted from all the constituent elements shown in the embodiments. Furthermore, components related to different embodiments may be combined as appropriate.

Claims (8)

1. An optical disc device, characterized in that it comprises: A reading unit (15) that reads the reflected light of the beam spot (72) irradiated on the optical disc and outputs the read signal; A detection unit (12) that generates a wobble signal corresponding to the wobble change of the above-mentioned optical disc based on the reading sequence signal read by the above-mentioned reading unit (15), and detects the physical address information of the current beam spot (72) based on the wobble signal ; a holding unit (59) for holding physical address information detected by the detection unit (12); A moving unit (20, 38) for moving the beam spot (72) by one track in the inner or outer peripheral direction of the optical disc (D); The determining unit (61) combines the track number of the physical address information detected by the detecting unit (12) after the moving unit (20, 38) has completed the movement of the beam spot (72) and the holding unit ( 59) When the Hamming distance is 1 compared with the track number of the physical address information stored before the beam spot (72) is moved, it is determined that the beam spot (72) has been moved correctly. 2. The optical disc device according to claim 1, characterized in that: The holding unit (59) always holds current physical address information no matter whether the beam spot (72) moves or not. 3. The optical disc device according to claim 1, characterized in that: The moving means (20, 38) re-moves the beam spot (72) when the judging means (61) determines that the beam spot (72) has failed to move. 4. The optical disc device according to claim 1, characterized in that: The determination unit (61) determines whether the track number included in the address information increases in proportion to the amount of movement when the beam spot (72) moves toward the outer peripheral side of the optical disc. When the inner peripheral side of the optical disk is moved, it is judged whether or not the above-mentioned track number has been decreased in proportion to the amount of movement. 5. A control method for an optical disc device, wherein a reading unit (15) of the optical disc device reads reflected light from a beam spot (72) irradiated on the optical disc, and outputs a read signal thereof, and the control method for the optical disc device Features include: The detection unit (12) generates a wobble signal corresponding to the wobble change of the above-mentioned optical disc according to the read signal read by the above-mentioned read unit (15), and detects the physical address information of the current beam spot (72) based on the wobble signal. 1st step (S11); The second step (S11) of holding the detected physical address information by the holding unit (59); A third step (S12) of moving the beam spot (72) by one track in the direction of the inner or outer circumference of the optical disc (D) by the moving unit (20, 28); The physical address information detected by the detecting unit (12) after the moving unit (20, 28) has completed the movement of the beam spot (72) and the holding unit (59) are held by the address comparing unit (60). Compared with the track number of the above-mentioned physical address information before the beam spot (72) moves, when the Hamming distance is 1, it is judged by the judging unit (61) that the above-mentioned beam spot (72) has been moved correctly Fourth step (S13-S15). 6. The control method of an optical disc device according to claim 5, characterized in that: In the second step (S11), the holding unit (59) always holds the current physical address information regardless of whether the beam spot (72) moves or not. 7. The control method of an optical disc device according to claim 5, characterized in that: When it is judged by the determination unit (61) that the movement of the above-mentioned beam spot (72) has failed in the above-mentioned 4th step, the above-mentioned beam spot (72) is performed by the moving unit (20, 38) again in the above-mentioned 3rd step (S12). ) movement. 8. The control method of an optical disc device according to claim 5, characterized in that: In the fourth step (S13-S15), the judging unit (61) judges whether the track number included in the address information is divided by the amount of movement when the beam spot (72) moves toward the outer peripheral side of the optical disc. Correspondingly increase, when the above-mentioned light beam spot (72) moves to the inner peripheral side of the above-mentioned optical disk, it is judged whether the above-mentioned magnetic track number decreases correspondingly according to the moving amount.

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