JP2005032294A - Disk reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reproduce original audio data without adversely affecting the reproducing control of a disk even though track data kind is decided wrongly as ROM data and obtained from TOC information while reproducing a CD-DA and a multi-session disk. <P>SOLUTION: In a disk reproducing device which performs reproducing control based on TOC information being notified from a disk driving/reproducing means, the followings are conducted, i.e., when TOC information is obtained from a lead-in area (S1) and a leading address of a data area is retrieved (S2), the data kind of the leading track included in the TOC information is referred (S3). When the data kind indicates audio data (S4), all of the identification information of each track within a session are rewritten to correspond to audio data, the TOC information is changed (S5) and the changed TOC information is notified to a control means (S6). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a disc playback device such as a compact disc (CD), and more particularly, to an error in TOC information in a device that performs disc playback based on TOC (Table Of Contents) information written in a specific area of the disc. The present invention relates to a technique useful for eliminating operational inconveniences that occur at the time of determination.
[0002]
[Prior art]
Conventionally, compact disc digital audio (CD-DA) has been widely used as an audio recording medium such as music. On the other hand, CD-ROMs are widely used as recording media for program data and image data used in computers and game machines. This CD-ROM is standardized based on the CD-DA technology, and its physical format and basic data format are the same as those of the CD-DA.
[0003]
In the CD, data is recorded in the format of “lead-in” indicating “data recording position”, “data”, and “lead-out” indicating the end of data, and audio data is recorded in the “data” portion. CD-DA is recorded with only CD, and CD-ROM is recorded with ROM data such as program data and image data in the “data” portion. A series of information based on the above format is called a “session”, and a CD is a “single session” CD in which only one session is recorded on one CD, and a CD-R that has recently appeared. As described above, there are two types of “multi-session” CDs that allow a plurality of sessions to be recorded on one CD.
[0004]
In the case of a CD-ROM, a part (track) may be audio data in accordance with the standard, and in fact, such “audio track” and ROM data such as program data and image data are recorded. There are CD-ROMs in which “data tracks” are mixed. For such discs, CD-DA disc playback devices (so-called “CD players”) can play audio tracks and listen to music, and data track programs can be executed on a personal computer or the like. You can also view images of image data. However, when a data track of a CD-ROM is reproduced by a CD player, the CD player treats the data of the CD-ROM in the same manner as a PCM audio signal, and performs digital / analog (D / A) conversion and reproduction from a speaker or the like. The playback sound becomes random digital noise such as “gar” and “pea”. Therefore, on the CD player side, for example, the disc type is discriminated based on the identification code recorded on the disc, and when the disc is a CD-ROM, the disc cannot be played or is played back in operation. However, some devices have been devised such as muting so as not to produce sound.
[0005]
In the innermost circumference of the disc (CD-DA, CD-ROM), there is an area (lead-in area) in which so-called TOC information is written, in addition to information such as audio data. As will be described in detail later, the TOC information includes the number of songs (= tracks) recorded on the disc, the absolute start time of each track, the start address of each track, and the data type of each track (for each track). Identification information indicating whether the recorded data is audio data or ROM data is included.
[0006]
In a conventional disc (CD) playback device, the TOC information is acquired from the lead-in area of the disc on the CD drive side prior to playback of the disc. This is because the TOC information is necessary for the control of the music selection operation and the display of the number of songs and the recording time. On the CD drive side, the TOC information is acquired, and the head address (start address of the first track) of the data area of the disc is searched. Then, the TOC information is notified to the host computer that controls the disc playback apparatus centrally. And waits for instructions from the host computer. That is, on the host computer side, playback control is performed on the CD drive based on the notified TOC information.
[0007]
As a technique related to the above prior art, for example, when a CD-ROM disc including an audio track is played in a disc playback device such as a CD player, only the audio track other than the data track is automatically programmed. There is one that prevents the user from reproducing the data track by mistake (for example, see Patent Document 1).
[0008]
[Patent Document 1]
JP-A-10-124978
[0009]
[Problems to be solved by the invention]
As described above, in the conventional technique, before playing a disc, the TOC information is acquired from the lead-in area of the disc on the CD drive side, and the head address of the data area is searched. On the other hand, on the host computer side, playback control is performed based on the notified TOC information.
[0010]
In this case, the CD drive side can correctly determine various information included in the TOC information, in particular, identification information indicating the data type of the track (whether it is audio data or ROM data). For example, the host computer that has received the notification of the TOC information performs appropriate reproduction control according to the data type of each track (if it is audio data, it performs processing for reproducing the audio signal, and reads the ROM data. If this is the case, it is possible to perform processing necessary for reproduction of image data and execution of a program), there is no particular problem.
[0011]
However, inconvenience occurs when the data type of the track cannot be correctly determined on the CD drive side. For example, when a multi-session disc (a disc in which audio data is recorded on all the tracks in the first session) is reproduced, the CD drive is affected in some way and the first TOC information is recorded. If the data type of each track in one session is erroneously determined as ROM data and acquired, the data of the track is recorded even though the actual track data type recorded in the data area is audio data. The type is notified to the host computer as “ROM data”.
[0012]
In this case, since the data type of each track in the first session is recognized as ROM data (not audio data) on the host computer side, control relating to audio reproduction is not performed on the CD drive side. For this reason, there is a problem that the process for reproducing the audio signal is not performed even though the track is originally recorded with the audio data.
[0013]
Such an inconvenience can occur in the same way for a single session disc in which only one session including a plurality of tracks is recorded, and a disc (CD-DA) in which only audio data is recorded in each track.
[0014]
The present invention was created in view of such problems in the prior art, and when reproducing a CD-DA or multi-session disc, the data type of the track is erroneously determined as ROM data and acquired from the TOC information. It is an object of the present invention to provide a disc reproducing apparatus that can reproduce original audio data without affecting the disc reproduction control.
[0015]
[Means for Solving the Problems]
In order to solve the above-described problems of the prior art, a disc reproducing apparatus according to the present invention drives a disc and reads and reproduces information signals from a plurality of tracks included in at least one session recorded on the disc. Drive / reproducing means, and control means for performing reproduction control based on the TOC information notified from the driving / reproducing means, wherein the driving / reproducing means obtains TOC information from the lead-in area on the disc When the head address of the data area is retrieved, the identification information instructing the data type of the head track included in the TOC information is referred to, and if the data type indicates audio data, The TOC information is changed by rewriting the identification information of each track to be compatible with audio, and the changed TOC information And notifies the serial controller.
[0016]
According to the disk reproducing apparatus of the present invention, when the TOC information is acquired from the lead-in area on the disk by the drive / reproducing means (CD drive) and the head address of the data area is searched (conventional) First, referring to the identification information indicating the data type of the first track (first track in the session) included in the TOC information without notifying the TOC information to the control means (host computer). After confirming whether the data type is audio data, in the case of audio data, all the identification information of each track in the session is rewritten to be compatible with audio, the TOC information is changed, and the changed TOC information is changed. The control means is notified.
[0017]
For example, when playing back a multi-session disc (a disc in which audio data is recorded on all tracks in the first session), due to some influence in the drive / playback means, the first track of the first session of the first session is determined from the TOC information. Even if the data type is erroneously determined as ROM data and acquired, the TOC information is changed to correspond to the original “audio” based on the determination processing of the data type of the head track as described above. The control means can be notified of the data type of the track as “audio data”.
[0018]
As a result, the control means recognizes the data type of the track as the original audio data without being affected by the erroneous determination of the TOC information by the drive / playback means. (I.e., it can be reproduced as audio data).
[0019]
In addition, it is only necessary to determine the data type of the first track (that is, it is not necessary to determine the data type of the track by accessing all the tracks in the session), so the TOC information reading time is relatively shortened. can do.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 schematically shows a part of the configuration of a disk reproducing apparatus according to an embodiment of the present invention.
[0021]
In the illustrated disk reproducing apparatus 30, 10 is a disk (CD-DA or CD-ROM) on which data such as music to be reproduced is recorded, and 11 is a turntable on which the disk 10 is placed. The disk 10 is loaded by a loading unit (not shown) and is chucked by being sandwiched between a turntable 11 and a pressing plate (not shown). Reference numeral 12 denotes a spindle motor that rotationally drives the turntable 31 on which the disk 10 is mounted at a constant linear velocity. Reference numeral 13 denotes a recording surface of the disk 10 that is irradiated with laser light and reflected by the reflected light. An optical pickup 14 that reads recorded data, and 14 indicates a feed motor (for example, a stepping motor, a DC motor, etc.) that moves a thread (not shown) to which the optical pickup 13 is attached in the radial direction of the disk 10.
[0022]
The optical pickup 13 outputs four current signals (A signal, B signal, C signal, D signal) obtained from the main spot of the laser beam and two current signals (E signal, F signal) obtained from the side spot. Is done. Although not specifically shown, the optical pickup 13 has an actuator (not shown) for shifting an objective lens (not shown) in the pickup in a direction parallel to the surface of the disk 13. When a tracking servo, which will be described later, is on, an appropriate bias voltage is applied to the actuator to shift the objective lens in a direction parallel to the surface of the disk 10. Reference numeral 15 denotes an RF (Radio Frequency) amplifier that variably amplifies the current signal output from the optical pickup 13 by converting it into a voltage, and generates a reproduction RF signal and an EFM (Eight to Fourteen Modulation) signal. A focus error signal is generated based on the B / C / D signal, and a tracking error signal is generated based on the E / F signal.
[0023]
Reference numeral 16 denotes a servo circuit controlled by a system controller 20 to be described later, and includes a focus servo control unit 16a, a tracking servo control unit 16b, a pickup feed servo control unit 16c, and a spindle servo control unit 16d as functional blocks. Yes. The servo circuit 16 generates a focus control signal, a tracking control signal, a pickup feed control signal, and a rotation control signal from each of the servo control units 16a to 16d based on the focus error signal and the tracking error signal supplied from the RF amplifier 15. Then, each part of the disk drive system is controlled based on the generated control signals. That is, based on the focus control signal, the focus actuator (not shown) of the optical pickup 13 is driven and controlled so that the laser beam from the optical pickup 13 is focused on the signal surface of the disk 10, and based on the tracking control signal. The tracking actuator (not shown) of the optical pickup 13 is driven and controlled so that the laser beam can track the track of the disk 10, the feed motor 14 is driven and controlled based on the pickup feed control signal, and the rotation control signal is used. The spindle motor 12 is driven and controlled. Further, the servo circuit 16 has a function of adjusting a gain related to a variable amplification operation performed by the RF amplifier 15.
[0024]
Reference numeral 17 denotes a digital signal processing circuit controlled by a system controller 20 to be described later, and is constituted by, for example, a DSP (digital signal processor). The digital signal processing circuit 17 basically has a timing for generating the control signals by the servo control units 16a to 16d of the servo circuit 16 based on the reproduction RF signal supplied from the RF amplifier 15. It has a function of generating a synchronization signal and demodulating an EFM signal supplied from the RF amplifier 15 and outputting it as compressed data. Further, the digital signal processing circuit 17 extracts the TOC information from the reproduction RF signal, performs a predetermined determination process based on the TOC information as will be described later, and changes the TOC information according to the result. If the TOC information after the change is not changed, the TOC information is also notified to the system controller 20 as it is.
[0025]
The digital signal processing circuit 17 has a TOC information storage unit 17a for temporarily storing the acquired TOC information. In the example shown in the figure, the TOC information storage unit 17 a is built in the digital signal processing circuit 17, but it is not necessarily built in, and may be provided separately from the digital signal processing circuit 17. In short, it is sufficient that the digital signal processing circuit 17 is connected so that the acquired TOC information can be accessed.
[0026]
In the example of FIG. 1, a data writing system is omitted for simplification of illustration, but in reality, a recording head that generates a magnetic field corresponding to the data at the time of data writing is near the surface of the disk 10. Further, a circuit such as a head driver for supplying data to the recording head is appropriately arranged. Accordingly, at the time of writing data to the disk 10, the digital signal processing circuit 17 performs EFM modulation on the compressed data supplied from the memory controller 19 described later and outputs the compressed data to the head driver.
[0027]
Reference numeral 18 denotes a memory such as a DRAM used for storing compressed data for a predetermined time, 19 denotes a memory controller controlled by a system controller 20 to be described later, and has a data compression / decompression unit 19a as its functional block. ing. While performing predetermined communication with the system controller 20, the memory controller 19 writes the compressed data output from the digital signal processing circuit 17 to the memory 18 intermittently and at high speed during reproduction, while continuously from the memory 18. The compressed data is read out at a normal and normal speed, the read compressed data is decompressed by the data compression / decompression unit 19a and converted into audio data, etc., and then output to the outside. On the contrary to the above, the memory controller 19 compresses the externally input audio data and the like by the data compression / decompression unit 19a into the compressed data, and then continuously and normally stores the compressed data in the memory 18. While writing at a speed, the compressed data is read intermittently and at high speed from the memory 18, and the read compressed data is output to the digital signal processing circuit 17.
[0028]
Reference numeral 20 denotes a system controller constituted by a microcomputer, which controls the servo circuit 16, the digital signal processing circuit 17, and the memory controller 19 in accordance with a predetermined program. Specifically, based on the TOC information supplied from the digital signal processing circuit 17, it has a function of controlling the disc playback process when the TOC information is erroneously determined, as will be described later.
[0029]
The system controller 20 is connected to a memory 21 such as a DRAM, a memory 22 such as an EEPROM, an operation unit 23 and a display unit 24. The memory 21 is for temporarily storing an address (data) on the disk 10 at the center position of the optical pickup 13 immediately after pickup feeding by the feeding motor 14. This address (data) is detected by the optical pickup 13 immediately after the pickup is sent, and further acquired by the system controller 20 via the RF amplifier 15 and the digital signal processing circuit 17. The memory 22 is for storing circuit offset data and the like measured in advance at the time of product shipment.
[0030]
The operation unit 23 is used to perform operations such as power on / off, playback, recording, editing, and ejection. As operation keys for the operation, a PLAY key for performing a playback operation and a recording operation are provided. Various operation keys such as a REC key for performing, a next song seek key for searching for the next song, a previous song seek key for searching for the previous song, and a STOP key for stopping the recording / playback operation are provided. The display unit 24 is composed of, for example, an LCD or the like, and is for displaying a track number, elapsed performance time, and the like.
[0031]
In the above configuration (disc player 30), each of the functional blocks indicated by 12 to 19 corresponds to “drive / reproducer” as a whole, and the system controller 20 serves as the “controller” and the TOC information storage unit 17a. Corresponds to “memory means”.
[0032]
FIG. 2 shows a format configuration of data recorded on the disc (CD) 10, in which (a) is a frame configuration of data supplied from the digital signal processing circuit 17 to the system controller 20, (b) ) Shows the configuration of the subcode in the frame, (c) shows the configuration of the Q data in the subcode, and (d) shows the configuration of the data portion in the Q data.
[0033]
As shown in FIG. 2A, one frame includes a synchronization pattern portion (24 channel bits), a sub-coding portion (1 symbol, that is, 14 channel bits), a first data portion (12 symbols), and a first parity. Part (4 symbols), a second data part (12 symbols), and a second parity part (4 symbols). Although illustration is omitted here, 3 bits of combined bits are included in the frame in order to combine each symbol (the synchronization pattern is also regarded as one symbol). The total number of combined bits is 34 × 3 = 102 channel bits. Therefore, one frame consists of 588 channel bits in total.
[0034]
As shown in FIG. 2B, 98 frames form a series of information (subcode frames) including frame synchronization information, subcode information, data, and parity information. Subcode data in 98 frames represents subcode information as one block. These sub-code information includes (i) information on program functions such as cuing of a music piece (or movement) and reproduction according to a preset order, and (ii) additional information such as text information. . The subcode P channel and Q channel are used as information (i), and the subcode R, S, T, U, V. Each channel of W is used. The P channel indicates a pause between music and is information used for rough cueing. The Q channel is information for more detailed control.
[0035]
As shown in FIG. 2C, the Q data includes a control unit, an address unit, a data unit, and a CRC (Cyclic Redundancy Code) unit. The control unit is composed of 4 bits Q1 to Q4, and records a table for identifying the number of audio channels, emphasis, digital data, and the like. Of the 4 bits of Q1 to Q4 constituting the control unit, 1 bit (second bit from the top = Q2) indicates whether or not the data recorded in the track is audio data. That is, this control bit (Q2) is identification information that indicates the data type of the track. When the control bit (Q2) is “0”, it indicates that audio data is recorded on the track (that is, an audio track). In this case, “1” indicates that ROM data other than audio data is recorded on the track (that is, a data track other than the audio track).
[0036]
The address portion is composed of 4 bits Q5 to Q8, and a control signal indicating the format and type of data in the data portion described later is recorded. The CRC part is composed of 16 bits Q81 to Q96, and data for performing error detection of the cyclic code is recorded. The data portion consists of 72-bit data Q9 to Q80. When the 4-bit data of the address parts Q5 to Q8 is “0001”, the data part (TOC) in the lead-in area of the disc has the format shown in FIG.
[0037]
That is, as shown in FIG. 2D, the data part includes an MNR part indicating a music (or movement) number, a POINT part indicating the type of information, a “minute” component of elapsed time in the music, “second” MIN, SEC, FRAME, ZERO, and POINT of the contents of the MIN, SEC, and FRAME components respectively indicating the component and frame number, and the PMIN and PSEC portions indicating the seconds component and frame number, respectively. And PFRAME sections, each of which consists of 8-bit data. Among these, the MNR part, the MIN part, the SEC part, the FRAME part, and the ZERO part are all fixed to “00” in hexadecimal notation, and “0” is assigned to all 8 bits.
[0038]
The PMIN section indicates the first music (or movement) number when the POINT section is "A0" in hexadecimal display, and the last music when the POINT section is "A1" in hexadecimal display. (Or movement) Indicates the number. When the POINT part is displayed in hexadecimal and “A2”, the PMIN part, the PSEC part, and the PFRAME part indicate the absolute time when the lead-out area starts. Furthermore, when the POINT part is expressed by a 2-digit BCD, the PMIN part, the PSEC part, and the PFRAME part respectively represent the addresses at which the songs (or movements) indicated by the numerical values start in absolute time. It becomes.
[0039]
Next, the disc playback process at the time of erroneous determination of TOC information performed by the disc playback apparatus 30 according to the present embodiment will be described with reference to FIG. 3 showing an example of the processing flow. In this processing flow, it is assumed that only one session (the number of tracks is N) is recorded on one CD for simplicity of explanation.
[0040]
In the first step S1, TOC information is acquired from the lead-in area on the disk 10. As described with reference to FIG. 2, the TOC information includes the start addresses (PMIN, PSEC, and PFRAME) of the first to Nth tracks recorded on the disc, the track data type ( Identification information (control bit) indicating whether the data is audio data or ROM data is included. This TOC information is acquired based on the cooperative action of each functional block indicated by 12 to 17 in FIG. The acquired TOC information is temporarily stored in the TOC information storage unit 17 a by the digital signal processing circuit 17.
[0041]
In the next step S2, the digital signal processing circuit 17 searches the TOC information stored in the TOC information storage unit 17a for the head address (first track start address) of the data area.
[0042]
In the next step S3, in the digital signal processing circuit 17, the data type of the first track is determined from the Q channel (FIG. 2) of the subcode of the first track included in the TOC information stored in the TOC information storage unit 17a. With reference to the identification information (control bit) to instruct, the data type of the track is confirmed.
[0043]
In the next step S4, the digital signal processing circuit 17 determines whether the confirmed data type indicates audio data (YES) or not (NO). If the determination result is YES, the process proceeds to step S5, and if the determination result is NO, the process proceeds to step S6.
[0044]
In step S5 (when the data type of the first track is audio data), the digital signal processing circuit 17 compares the TOC information stored in the TOC information storage unit 17a with the first to Nth items in the session. All the identification information of each track is rewritten to correspond to “audio”, and the TOC information is changed.
[0045]
At this time, if the disc 10 is a CD-DA type multi-session disc, all the identification information of each track of all sessions recorded on the disc is rewritten to correspond to “audio”.
[0046]
This is based on the multi-session rule that when the first track is “audio data”, all the tracks in the session are “audio data”. However, when the first track is “ROM data”, the subsequent tracks in the session are not necessarily “ROM data”.
[0047]
In the next step S6, the digital signal processing circuit 17 notifies the system controller 20 of the TOC information. At this time, if the TOC information has been rewritten through the process of step S5, the changed TOC information is notified, and the data type of the first track is not audio data in step S4 (that is, ROM data). Is determined, the TOC information acquired initially is notified as it is.
[0048]
In the final step S7, the system controller 20 performs control related to disk reproduction in cooperation with the digital signal processing circuit 17 and the memory controller 19 based on the TOC information notified from the digital signal processing circuit 17. Then, this processing flow is “end”.
[0049]
As described above, according to the disk reproducing device 30 according to the present embodiment, the TOC information is acquired from the lead-in area on the disk 10 and the head address of the data area is searched by the function blocks indicated by 12 to 17. In this case, the TOC information is not notified to the system controller 20 at this time, but first, the identification information (control bit) of the first track included in the TOC information is referred to, and the data type of the track is the audio data. After confirming whether the data is ROM data or not, in the case of audio data, all the identification information of each track in the session is rewritten to correspond to “audio” to change the TOC information, and the changed TOC information is sent to the system controller 20. I'm trying to notify you.
[0050]
Therefore, for example, when playing a multi-session disc, the data type of the first track of the first session is erroneously determined as ROM data from the TOC information due to some influence in each of the functional blocks (drive / playback system) indicated by 12 to 17 Since the TOC information is changed to the original “audio” correspondence based on the determination processing of the data type of the first track as described above, the system controller 20 The track data type can be notified as “audio data”.
[0051]
As a result, the system controller 20 performs control related to disk reproduction in order to recognize the data type of the track as original audio data without being affected by the erroneous determination of the TOC information by the drive / reproduction system. be able to. That is, it can be reproduced as audio data.
[0052]
【The invention's effect】
As described above, according to the present invention, when a CD-DA or a multi-session disc is reproduced, even if the data type of the track is erroneously determined as ROM data from the TOC information, the disc is recorded. It is possible to provide a disc reproducing apparatus that can reproduce the original audio data without affecting the reproduction control. Further, it is only necessary to confirm (discriminate) the data type of the first track, and it is not necessary to access all the tracks in the session to determine the data type of the track. Time can be shortened.
[Brief description of the drawings]
FIG. 1 is a block diagram schematically showing a part of the configuration of a disc playback apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram showing a format configuration of data recorded on a disc (CD) in FIG. 1;
FIG. 3 is a flowchart showing an example of a disc playback process at the time of erroneous determination of TOC information performed by the disc playback apparatus of FIG. 1;
[Explanation of symbols]
10: Disc (CD-DA or CD-ROM),
12 ... Spindle motor (driving / reproducing means),
14 ... Feed motor (drive / reproducing means),
15 ... RF amplifier (driving / reproducing means),
16 ... Servo circuit (driving / reproducing means),
17: Digital signal processing circuit (driving / reproducing means),
17a ... TOC information storage unit (memory means),
19: Memory controller (driving / reproducing means),
20 ... System controller (control means).

Claims (3)

Driving / reproducing means for driving the disc and reading and reproducing information signals from a plurality of tracks included in at least one session recorded on the disc;
Control means for performing playback control based on the TOC information notified from the drive / playback means,
When the drive / playback means obtains TOC information from the lead-in area on the disc and searches for the start address of the data area, the drive / playback means refers to the identification information indicating the data type of the start track included in the TOC information. When the data type indicates audio data, the identification information of each track in the session is rewritten to be compatible with audio, the TOC information is changed, and the changed TOC information is notified to the control means. And a disc reproducing apparatus. The driving / reproducing means refers to identification information indicating the data type of the head track included in the TOC information, and when the data type indicates ROM data other than audio data, the TOC information is used as it is. 2. The disk reproducing apparatus according to claim 1, wherein the control means is notified. Further comprising memory means for storing the TOC information acquired by the driving / reproducing means,
3. The disk reproducing apparatus according to claim 1, wherein the driving / reproducing unit determines whether or not to change the TOC information with reference to the TOC information stored in the memory unit.

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