JPS63241779A - Disk reproducing device - Google Patents

Abstract

PURPOSE:To return a pickup to a program area and perform the fast retrieval operation of data, by controlling the movement of the pickup in position relation between the present position of the pickup and a main storage area, and updating address information. CONSTITUTION:When an optical pickup 15 is positioned in a readin area, and also at a position far from the program area than the position of an address TL in a program RAM24, the pickup 15 is moved to a program area side by the number of tracks in which the number of tracks interposed between the begining part of the program and a targeted position is added on the number of tracks interposed between the present position of the pickup 15 and the position of the address TL. Also, when the pickup 15 is positioned in the read-in area and also it is positioned to the program area nearer than the position of the address TL, the present position of the pickup 15 is stored instead of the address TL.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) This invention is applicable to optical compact discs (CDs), for example.
Related to disc playback devices such as players, especially CD-RO
The present invention relates to a device suitable for use in reproducing M (read only memory).

(Prior Art) As is well known, in the field of audio equipment, information signals such as audio signals are processed using PCM (Pulse Code Modulation) in order to record and reproduce information with as high density and high fidelity as possible.
2. Description of the Related Art Digital recording and reproducing systems that use technology to convert data into digitized data, record it on a recording medium such as a disk or magnetic tape, and reproduce the data have become widespread.

Of these, compact discs, which use discs as recording media, are now the mainstream, with pit rows corresponding to digitized data formed on a 12 cm diameter disc that can be read optically. There is.

On the other hand, a compact disc player that plays the above-mentioned compact disc moves an optical pickup containing a semiconductor laser, a photoelectric conversion element, etc. in a linear tracking manner from the inner circumference of the disc toward the outer circumference. Compact disc at constant linear velocity (CL
V) The data recorded on the compact disc is read by rotating the compact disc.

In the above-mentioned compact disc, a huge amount of information is recorded in the program area (radius 25 to 58+nm), which can provide about 1 hour of stereo playback on one side, and the index data etc. are stored in the lead-in area (radius 23 nm). ~251nffl), and is capable of high-density recording not seen in conventional analog recording and reproducing systems, as well as realizing advanced control functions and performance.

Here, in the compact disc as described above, subcode data is recorded together with digitized data of audio signal components in order to improve operability and realize more advanced functions. This subcode data is P
, Q, R, S, T, U.

It consists of 8 types called v and W, and each frame of digitized data contains 1 bit for a total of 8 bits, and one subcode frame is made up of 98 frames. ing.

Among these, subcode data P indicates a change in a plurality of data (hereinafter described as a song) recorded on the disc. The subcode data Q is called address data, and in the program area, the song number (TNO) of the many songs recorded, the clause number (index), the elapsed time for each of the nine songs (relative address), and the program It shows the total elapsed time (absolute address) etc. from the starting end of the area.

Note that other subcode data R-W are currently used to display graphics images on the screen of a television receiver in synchronization with the audio data being played.
It is used as graphics image display data and graphics display screen operation data.

On the other hand, in the disk loading area, TOC (Table of Content) data indicating the start position of multiple songs in the program area using the absolute address is recorded as main information. Furthermore, the elapsed time (address) within the lead-in area is recorded in the subcode data Q within the lead-in area. However, the address based on the subcode data Q in this lead-in area and the absolute address based on the subcode data Q in the program area are unrelated.

That is, the subcode data Q includes a relative address indicating the elapsed time for each song in the program area as shown in FIG. 3(a), and a relative address indicating the elapsed time for each song as shown in FIG. An absolute address indicating the total elapsed time is recorded.

Further, in the subcode data Q, an address indicating the elapsed time in the program area is recorded, as shown in FIG. 3(a).

Here, the compact disc player is provided with a data search function that uses address information based on subcode data Q to quickly select a desired song. That is, when the power switch is turned on, the compact disc player automatically reads TOC data from the lead-in area of the disc, stores it in memory, and then enters a standby state.

Therefore, when the user externally sets the song number (TNO) of a desired song, the absolute address of the starting position of the song with the set song number can be obtained based on the TOC data stored in the memory or in the one-doin area. It will be done. Then, based on this absolute address, the number of tracks interposed between the starting end of the program area and the target position is calculated.

On the other hand, a compact disc player puts the disc in playback mode, reads the data in the program area with an optical pickup, obtains the absolute address of the current position of the optical pickup, and, based on this absolute address, moves from the beginning of the program area to the current position. The number Np of tracks intervening up to the position is calculated by calculation.

After that, the compact disc player performs (Np −N
o) The following calculations are performed to determine the direction in which the optical pickup is to be moved and the number of tracks to be traversed by the optical pickup, and the optical pickup is moved based on the determined matters.

Thereafter, similar operations are repeated until the absolute address of the target position and the absolute address of the current position of the optical pickup match, and data retrieval is performed at this point.

The above-mentioned CD system was developed for the purpose of recording and reproducing audio data, but in recent years, attention has been paid to the enormous recording capacity of compact discs, and compact discs have been used in computers, etc. A so-called CD-ROM system has been developed to be used as a read-only data recording medium for an arithmetic processing control system.

This CD-ROM system is a system in which a new format is added to the CD-ROM system so that digital information can be recorded and played back without changing the recording/playback format of the CD system. In other words, in the CD system, a two-channel analog audio signal is sampled at 44°l kHz, converted to PCM data into 16-bit digitized data, and recorded, but in the CD-ROM system, as shown in Figure 4. As shown, these 16 bits are converted into 8 bits (1 byte).
The data is recorded by dividing the data into 2352-byte blocks.

Here, in FIG. 4, the synchronization pattern is for recognizing the start of each block, and is composed of 12 bytes. Further, the header is address information of a block corresponding to subcode data Q in the CD system, and is composed of 4 bytes. Further, the user data is an area used by the user and consists of 2048 bytes. Additionally, error correction data is provided for two purposes: to detect and correct errors in data (mode 1) and for use by users (mode 2). It consists of 288 bytes.

Among these, mode 1 is used when errors cannot be corrected by parity correction of the C1 and C2 series of audio CD formats, and the error rate was eventually improved to 10-12. Therefore, it can be fully used as a computer recording medium. Furthermore, by using mode 2, the amount of data available to the user can be increased to 2048+288-2338 bytes, but the data error rate is 10'9.

It should be noted that one block in the CD-ROM system corresponds to one subcode frame in the above-mentioned CD system, and one block is reproduced every 1/75 seconds. For example, in mode 1, 2 bytes of data are recorded per block, so the data transfer rate is 2k x 75-150 bytes/sec. Therefore, a CD-ROM disc with one hour's worth of data recorded on one side has a size of 150x 60x.
It becomes possible to record 60-540 megabytes of information.

This storage capacity is 500~
This is equivalent to 1,000 pages, or about 270,000 documents with 2,000 characters per page. That is, CD-
The ROM system has a low error rate and a large storage capacity.

Furthermore, in the CD-ROM system, the entire disk may not be used as a data recording medium for a computer, but a portion of the disk may be used for recording audio data.

That is, by rewriting the control bits of the subcode Q between the data area and the audio area, it is possible to mix data for the computer and audio data.

In the CD-ROM system, in order to obtain data from a disc, a computer keyboard is used to transfer predetermined commands to the CD-ROM playback device.

Then, the CD-ROM playback device searches for the desired absolute address specified by the command, transfers the data recorded at the position of that absolute address to the computer, and
The data is processed by the computer, and the data can then be transferred from the disk to the computer.

By the way, as mentioned above, the CD-ROM system is
Since it is used as a data recording medium for an arithmetic processing control system such as a computer, it is required that its data read speed, that is, data search operation, be executed at high speed. As described above, the data retrieval operation generally uses a method in which the optical pickup is moved while referring to the absolute address of the subcode data Q and counting the number of tracks. For this reason, if external vibration is applied or there is a large scratch on the disc while the optical pickup is moving due to a data search, the amount of movement of the optical pickup will become inaccurate, and the optical pickup will not be able to read the lead-in data. You may end up in the area.

In such a case, there will be no data in the disk glued-in area.
Although an address indicating the passage of time is recorded, it has no relation to the absolute address in the program area, so it is impossible to move the optical pickup out of the locked-in area using normal data search operations. It becomes impossible.

Therefore, in the conventional CD-ROM playback device, all the song numbers of subcode data Q in the lead-in area are "0".
', it is detected that the optical pickup has entered the lead-in area, and a kick operation is performed for a predetermined number of tracks N to sequentially return the optical pickup to the program area. .

However, in order to prevent hunting when the optical pickup converges after the kick operation, it is not possible to increase the number of tracks that can be jumped over in one kick operation, so the optical pickup is deep in the lead-in area. If the user enters the lead-in area, it takes time to escape from the lead-in area, resulting in a problem that high-speed data retrieval cannot be performed.

(Problems to be Solved by the Invention) As described above, in conventional disc playback devices, once the pickup enters the disc loading area, it takes time to return to the program area, and high-speed data This has the problem that it becomes impossible to perform a search operation.

Therefore, this invention was made in consideration of the above circumstances, and even if the pickup enters the lead-in area of the disc during data retrieval, it can be quickly returned to the program area, allowing high-speed data processing. It is an object of the present invention to provide an extremely good disc playback device that can perform a search operation.

[Structure of the Invention] (Means for Solving the Problems) That is, the disc reproducing device according to the present invention has a main recording area in which a first information signal is recorded together with first address information, and a second recording area. The first and second information signals are read from a disk having a sub-recording area in which the information signals are recorded together with second address information that is not related to the first address information. is in the main recording area of the disk, the pickup is searched based on the first address information of the current position of the pickup and the first address information of the externally set target position based on a data search request given from the outside. The target is a device equipped with data retrieval means for calculating the number of intervening trucks between the current position of the pickup and the destination position and moving the pickup to the destination position.

The device is equipped with a storage means capable of storing second address information at an arbitrary position in the sub-recording area of the disc, and based on a data search request, the sub-recording unit determines whether the current position of the pickup is in the main recording area of the disc or not. determine whether it is in the area,
With the pickup determined to be in the sub recording area,
The second address information of the current position of the pickup is compared with the second address information stored in the storage means.

Here, if a comparison result is obtained in which the current position of the pickup is closer to the main recording area than the position indicated by the second address information stored in the storage means, the second address information stored in the storage means is Pick up the current position of the second
The address information is updated to the first address information, and the pickup is forcibly moved toward the main recording area until the first address information is obtained.

Further, if a comparison result is obtained in which the current position of the pickup is farther from the main recording area than the position indicated by the second address information stored in the storage means, the second address information of the current position of the pickup and the storage The second stored in the means
Based on the address information, the number of tracks intervening between the current position of the pickup and the position indicated by the second address information stored in the storage means is calculated, and the starting end of the main recording area is added to the calculated value. The pickup is moved toward the main recording area by the number of tracks added to the number of tracks interposed between the target position and the target position.

(Function) According to the above configuration, when the current position of the pickup is in the sub-recording area and the second position stored in the storage means is
If the main recording area is farther from the main recording area than the position indicated by the address information, the number of tracks intervening between the current position of the pickup and the position indicated by the second address information stored in the storage means is Since the pickup is moved toward the main recording area by the number of tracks that are intervening between the starting end of the area and the target position, the pickup moves toward the main recording area of the disk during data retrieval. If the pickup enters the main recording area (program area), it is possible to quickly return the pickup to the main recording area (program area) without repeating the kick operation as in the conventional case, allowing for high-speed data search operations. can.

Also, if the current position of the pickup is in the sub recording area,
If the position is closer to the main recording area than the position indicated by the second address information stored in the storage means, the second address information stored in the storage means is replaced with the second address information of the current position of the pickup. Since the second address information stored in the storage means approaches the main recording area each time it is updated, it effectively assists the above-mentioned return operation to the main recording area. It is something that can be done.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a CD-R to which this invention is applied.
This is an OM type disc playback device, and an overview thereof will first be described. That is, the control circuit 11 drives and controls the disc motor 13 and the pickup feed motor 14 via the disc reproduction system control circuit 12. When the data recorded on the disk 1B is reproduced by the optical pickup 15, the reproduced signal is guided to the RF detection circuit 17.

The RF detection circuit 17 amplifies the input reproduction signal and generates a signal component to be supplied to the servo circuit 18 and a signal component to be supplied to the EFM demodulation circuit 19. Of these, the servo circuit 1B performs various functions for performing focus servo and tracking servo on the optical pickup 15, CLV servo on the disk motor 13, and linear tracking servo on the pickup feed motor 14. It performs the function of generating a signal.

In addition, the optical pickup 15. Various servos for the disk motor 13 and pickup feed motor 14 are performed based on various signals output from the servo circuit 18 and various control signals generated by the control circuit 11 via the disk reproduction system control circuit 12.

On the other hand, the EFM demodulation circuit 19 shapes the waveform of the reproduced signal output from the RF detection circuit 17, performs EFM demodulation (14-bit to 8-bit conversion), and separates a synchronization signal that becomes subcode data from the demodulated signal. , this synchronization signal is supplied to the subcode Q detection circuit 20, and the demodulated signal from which the synchronization signal has been separated is sent to the D/A (digital/analog) conversion circuit 21. The signal is supplied to the unscrambler 22 and the synchronization detection circuit 22.

Here, when the detected subcode data Q is TOC data of the lead-in area, the subcode Q detection circuit 20 transfers the TOC data to a program RAM (random access memory) 2 via a control circuit 11.
4 and is used for data retrieval.

Further, the D/A conversion circuit 21 converts the input demodulated signal into an analog signal, performs necessary error correction and error correction processing, and outputs it to the speaker drive circuit 25, where the speaker is played. It becomes sound-driven.

The above configuration is the same as that of a CD-type disc playback device, and by adding the configuration described below, it is possible to play CD-
A ROM type disk playback device has come to be realized. That is, the demodulated signal output from the EFM demodulation circuit 19 is converted to the C signal shown in FIG. 4 by the synchronization detection circuit 23.
After the block synchronization pattern of the D-ROM is detected and the scramble process is removed by the unscrambler 22, one block of data shown in FIG. 4 is stored in the decode RAM 2G.

Further, each output of the unscrambler 22 and the synchronization detection circuit 23 is supplied to a header detection circuit 27, where header data in one block is detected and taken into the control circuit 11. Here, when the control circuit 11 performs a data search, it uses the subcode data Q outputted from the subcode Q detection circuit 20 and the header data outputted from the header detection circuit 27. This is because the standard allows the address based on subcode data Q and the address based on header data to differ by up to 1 second, and the final data search is always performed using header data. It is.

Furthermore, the data written in the decode RAM 2B is subjected to a predetermined error detection process, and if an error has occurred, the control circuit 11 drives the RAM controller 28 and error correction circuit 29 to correct the error. is executed.

Then, the decode RAM 2B undergoes error correction processing.
The data is written to the buffer RAM 30. In this case, the buffer RAM 30 includes a decode RAM 2
Instead of writing all the data stored in B, the control circuit 11 controls the RAM controller 31 so that only the user data shown in FIG. 4 is written to the buffer RAM 30. ing.

In this way, when all data is written to the buffer RAM 30, the control circuit 11 controls the interface 32.
A data read request signal is generated to the computer 33 via the data read request signal. Then, after the computer 33 completes preparations for data reading, it generates a predetermined signal to the control circuit 11 via the interface 32. When the control circuit 11 receives this predetermined signal, it controls the address of the user data written in the buffer RAM 30 via the RAM controller 31, and
operates to transfer data to.

Note that the CD-ROM disc playback device shown in FIG. 1 normally sends a predetermined command to the control circuit 11 via the interface 32 by operating the keyboard 33a of the computer 33 to control the disc playback system. Although it operates by controlling it to a predetermined state, a key switch group 34 is provided so that simple operations can be performed even when the computer 33 is not connected.

Similarly, in this disc playback device, the necessary display is normally performed on the CR7 screen 33b of the computer 33, but in consideration of the case where the computer 33 is not connected, a simple display is performed on the display output control circuit. 35 on the display section 3B.

In the figure, numeral 37 is a program ROM, which stores a program for operating the control circuit 11 together with the program RAM 24.

In the CD-ROM disc reproducing apparatus configured as described above, the data search operation will be described below with reference to the flowchart shown in FIG. First, when the program starts (step Sl), the lead-in area is automatically reproduced and the TOC data is written into the program RAM 24, as described above. Then,
The control circuit 11 stores the program RAM 2 in step S2.
The address TL of the lead-in area at the time when writing of TOC data to
Write and store it in M24.

Then, in step S3, the control circuit 11 determines whether a data search is requested by operating the keyboard 33a of the computer 33, and if it is requested (YES),
In step S4, the absolute address of the data of the target position input and set using the keyboard 31a is written to the program RA.
The number of tracks interposed between the start end of the program area and the target position is calculated by reading from M24.

After that, the control circuit engineer 1 determines whether or not the subcode data Q can be read stably in step S5, and if it can be read stably (YES), the control circuit engineer 1 determines whether or not the subcode data Q can be read stably. Then, the absolute address Tp of the current position of the optical pickup 15 is obtained, and the number Np of tracks interposed between the starting end of the program area and the current position is calculated.

Then, in step S7, the control circuit 11 determines whether the current position of the optical pickup 15 is within the lead-in area. In this determination, as mentioned above, all TNOs of subcode data Q in the lead-in area are "
0". If the lead-in area is not within the lead-in area (No), the control circuit 11
In step S8, the calculation (Np - No) is performed, and in step S9, it is determined in which direction the optical pickup 15 should be moved from the current position.

After that, the control circuit 11 actually moves the optical pickup (5) in step SlO, and in step Sll,
Determine whether the data search has ended.

This determination is made by reading the absolute address of the subcode data Q when the optical pickup 15 has finished moving, and determining whether or not the absolute address matches the absolute address of the target position.

If the data search has been completed (YES), the process ends (step 512); if the data search has not been completed (No), the process returns to step S5 and the above-described operations are repeated. .

On the other hand, if it is determined in step S7 that the optical pickup 15 is within the lead-in area (YE
S) In step S13, the control circuit 11 compares the address TL written in the program RAM 24 with the address Tp of the current position in the lead-in area.

Then, if TL<Tp, that is, if the current position of the optical pickup 15 is closer to the program area than the position indicated by the address TL (YES), the control circuit 11 sets the above address TL in step S14. Address T instead of
The stored contents are updated so that p is stored in the program RAM 24.

Thereafter, in step S15, the control circuit 11 sets a certain kick amount in order to return the optical pickup 15 to the program area by a kick operation, and also sets the kicking direction in step S1B. Then, in step SlO, the control circuit 11 repeats the kicking operation on the optical pickup 15, and returns the pickup 15 to the program area one by one.

Further, in step S13, if TL<Tp is not satisfied, that is, if the current position of the optical pickup 15 is farther from the program area than the position indicated by the address TL (NO), the control circuit 11:
In step S17, based on the address TL previously stored in the program RAM 24, the number of tracks NL interposed between the starting end of the lead-in area and the position indicated by the address TL is calculated.

Then, in step S18, the control circuit 11 determines the number of tracks No. and N obtained in steps S4, SO, and S17.
Based on p and NL, the calculation No + (NL - Np) is performed, and the calculation result is used as the number of tracks to be traversed by the optical pickup 15. That is, the above calculation adds the number of tracks interposed between the current position of the optical pickup 15 and the position indicated by the address TL, and the number of tracks interposed between the starting end of the program area and the target position. The number of tracks obtained is as follows.

Thereafter, in step S1B, the moving direction of the optical pickup 15 is set, and in step SIO, the optical pickup 15 is moved in the set moving direction so as to cross the tracks by the number of tracks calculated in step 818. be done.

Therefore, according to the configuration of the above embodiment, the optical pickup 15 is located within the lead-in area and further from the program area than the position indicated by the address TL stored in the program RAM 24. In this case, the number of tracks is equal to the number of tracks interposed between the current position of the optical pickup 15 and the position indicated by the address TL, plus the number of tracks interposed between the start end of the program area and the destination position. - Since the optical pickup 15 is moved to the program area side, the optical pickup 15 can be quickly moved to the program area side without repeating the kick operation as in the conventional case.
can be moved close to the target position, and high-speed data searches can be performed.

Furthermore, if the optical pickup 15 is within the lead-in area and closer to the program area than the position indicated by the address TL stored in the program RAM 24, the current position of the optical pickup 15 is The address Tp of the program RAM 24 is written first.
Since the address TL is stored in place of the address TL stored in the address TL, each time the stored contents of the address are updated, the position indicated by the address approaches the program area, so this is done in step S17, 318. The operation of returning to the program area can be effectively assisted.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and can be implemented with various modifications without departing from the gist thereof.

[Effects of the Invention] Therefore, as detailed above, according to the present invention, even if the pickup enters the disk drive-in area during data retrieval, it can be quickly returned to the program area, allowing high-speed processing. Accordingly, it is possible to provide an extremely good disc playback device that can perform accurate data searches.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of a disc playback device according to the present invention, Fig. 2 is a flowchart for explaining the operation of the main parts of the embodiment, and Fig. 3 shows the lead-in area of the disc. FIG. 4 is a diagram showing the relationship between the addresses recorded in the program area and the data format in the CD-ROM system. DESCRIPTION OF SYMBOLS 11... Control circuit, 12... Disk reproduction system control circuit, 13... Disc motor, 14... Pickup feed motor, 15... Optical pickup, I6...
... Disk, 17... RF detection circuit, 18... Servo circuit, 19... EFM demodulation circuit, 20... Subcode Q detection circuit, 21... D/A conversion circuit, 22.
...Unscrambler, 23...Synchronization detection circuit, 24
...Program RAM, 25...Speaker drive circuit, 26...Decode RAM, 27...Header detection circuit, 28...RAM controller, 29...Error correction circuit, 80...Buffer RAM , 31...RA
M controller, 32...interface, 33.
... Computer, 34 ... Key switch group, 35.
...Display output control circuit, 36...Display section, 37...
Program ROM.

Claims (1)

[Claims] A main recording area in which a first information signal is recorded with first address information, and a sub record in which a second information signal is recorded with second address information not related to the first address information. The first and second information signals are read from a disk having a recording area via a pickup, and the first and second information signals are read from a disk having a main recording area of the disk based on a data search request given from outside while the pickup is in the main recording area of the disk. The number of trucks intervening between the current position of the pickup and the destination position is calculated from the first address information of the current position of the pickup and the first address information of the externally set destination position, and the number of tracks interposed between the current position of the pickup and the destination position is calculated. The disk reproducing apparatus includes a data retrieval means for moving the pickup to a target position, a storage means for storing second address information of an arbitrary position in the sub-recording area of the disk, and a storage means for storing second address information of an arbitrary position of the sub-recording area of the disk; determining means for determining whether the current position is in the main recording area or the sub-recording area of the disc; a comparison means for comparing second address information of the position with second address information stored in the storage means, and a second address at which the current position of the pickup is stored in the storage means by the comparison means; If a comparison result is obtained that is closer to the main recording area than the position indicated by the information, updating the second address information stored in the storage means to second address information of the current position of the pickup; a first control means for forcibly moving the pickup toward the main recording area until first address information is obtained; and a second control means for storing the current position of the pickup in the storage means by the comparison means. If a comparison result is obtained that is farther from the main recording area than the position indicated by the address information,
From the second address information of the current position of the pickup and the second address information stored in the storage means, from the current position of the pickup to the position indicated by the second address information stored in the storage means The pickup is moved toward the main recording area by the number of tracks obtained by adding the number of tracks intervening between the starting end of the main recording area and the target position to the calculated value. 1. A disc playback device comprising: second control means for moving the disc.